NL2037658B1 - Premix gas burner and method for manufacturing a premix gas burner - Google Patents

Abstract

A B S T R A C T The invention pertains to a premix gas burner for combusting a premix burner gas containing a fuel gas, wherein at least a part of the port wall of the tubular gas supply chamber is arranged in the flange opening of the metal plate of the planar mounting flange, wherein at least a part of the outer port wall surface of the tubular gas supply chamber faces at least a part of the inner flange wall of the metal plate of the planar mounting flange. Fig. 1

Description

P36627NL01/NBL

Premix gas burner and method for manufacturing a premix gas burner

The invention pertains to a premix gas burner, a method for manufacturing a premix gas burner, a premix gas burner system and a heating appliance.

Tubular premix gas burners, e.g. cylindrical premix gas burners, are known. In a type of premix gas burners, the premix gas burner comprises a gas supply chamber which receives the premix gas through an inlet port. A burner deck extends around at least a part of the gas supply chamber. The premix burner further comprises a mounting flange for mounting the burner in a heating appliance, for example a building utility heating appliance. Often, an end cap closes the gas supply chamber on the side of the gas supply chamber opposite to the gas inlet port.

In order to ensure safe operation of a heating appliance comprising the burner, a sensor can be arranged in the vicinity of the burner deck of the premix gas burner, for example in order to detect whether combustion takes place or not. Often, the distance between the sensor and the burner deck plays an important role in the reliability of the sensor input.

The manufacturing of known tubular burners often requires expensive tooling. In particular when the burner comprises a large mounting flange, the costs of tooling can be high. Also, when relatively small series of a specific burner type are to be manufactured, the tooling costs can be a problem. Often tooling has to be provided that is specific for a certain burner design, and for relatively small series of a certain burner design the tooling costs can amount to a relatively large portion of the total manufacturing costs.

The invention aims to provide an improved premix gas burner and a method for manufacturing such a burner. In embodiments, the invention aims to provide a premix gas burner that is suitable for use in a heating appliance comprising a sensor in the vicinity of the burner deck, and a method for manufacturing such a burner. In embodiments, the invention aims to provide a premix gas burner which can be manufactured without design-specific tooling, and a method for manufacturing such a burner.

In a first aspect of the invention, this object is obtained by a premix gas burner for combusting a premix burner gas containing a fuel gas, comprising:

- a tubular gas supply chamber which is adapted to receive the premix burner gas, which gas supply chamber has a gas inlet port, wherein the tubular gas supply chamber comprises a port wall which extends around the gas inlet port, the port wall having an inner port wall surface facing the gas inlet port and an outer port wall surface on a side opposite to the inner port wall surface, - a burner deck which extends around at least a part of the tubular gas supply chamber, which burner deck comprises a tubular metal burner deck plate, which metal burner deck plate has a chamber facing surface on one side and a flame facing surface on the opposite side, and a plurality of gas outflow apertures that extend through the tubular metal burner deck plate from the chamber facing surface to the flame facing surface, the gas outflow apertures allowing the premix burner gas to flow from the gas supply chamber to a combustion zone adjacent to the flame facing surface of the tubular metal burner deck plate, - a planar mounting flange which extends in a flange plane, which planar mounting flange comprises a metal plate, the metal plate having a plate thickness and a flange opening, the plate thickness of the metal plate extending in a direction perpendicular to the flange plane, and the flange opening extending through the metal plate over the entire plate thickness of the metal plate, which flange opening is delimited by an inner flange wall, wherein at least a part of the port wall of the tubular gas supply chamber is arranged in the flange opening of the metal plate of the planar mounting flange, wherein at least a part of the outer port wall surface of the tubular gas supply chamber faces at least a part of the inner flange wall of the metal plate of the planar mounting flange.

Preferably, the inner flange wall has a wall height that corresponds to the plate thickness of the metal plate. This allows the planar mounting flange to be manufactured easily, quickly and cheaply, for example by cutting it from a metal plate by e.g. laser cutting or water jet cutting, or by die cutting (i.e. stamping with a cutting die).

The premix gas burner according to the invention is suitable for combusting a premix burner gas containing a fuel gas. In the premix burner gas, the fuel gas is mixed with an oxidiser. The oxidiser for example is or comprises oxygen, for example the oxidiser is air.

Optionally, the premix gas burner according to the invention is adapted for use in an oxy-fuel combustion process, wherein oxy-fuel combustion is the process of burning a fuel using pure oxygen, or a mixture of oxygen and recirculated flue gas, instead of air. The fuel gas for example is or comprises methane, propane and/or hydrogen. For example, the fuel gas is a gas mixture comprising both methane and hydrogen. For example, the fuel gas comprises at least 20% by volume of hydrogen, optionally at least 80% by volume of hydrogen, for example at least 98% by volume of hydrogen. The fuel gas and the oxidiser are mixed with each other before entering the premix gas burner.

For example, the premix gas burner according to the invention is a building utility premix gas burner, which is suitable for use in building utility appliances, e.g. appliances for heating or providing hot water. Optionally, the premix gas burner is a building utility premix gas burner which is adapted to modulate between a minimum load and a full load. For example, the ratio of the full load over the minimum load is at least 3, preferably at least 4. Optionally, the ratio of the full load over the minimum load is at least 5, for example at least 7. For example, the premix gas burner according to the invention is a residential building utility premix gas burner which is suitable for use in a residential building utility appliance (i.e. an appliance for use in a residential building), for example in a residential building appliance having an output power of 10 up to and including 100kW. For example, the premix gas burner according to the invention is a commercial building utility premix gas burner which is suitable for use in a commercial building utility appliance (i.e. an appliance for use in a commercial building), for example in commercial building utility appliances having an output power of 100kW up to and including 1MW or for example in commercial building utility appliances having an output power of more than 1MW, e.g. 5 MW.

The premix gas burner according to the invention comprises a tubular gas supply chamber which is adapted to receive the premix burner gas. For example, the tubular gas supply chamber is a cylindrical gas supply chamber, e.g. a cylindrical gas supply chamber with a circular, oval or elliptical cross-sectional shape.

The gas supply chamber has a gas inlet port. The gas inlet port is for example a circular gas inlet port, an oval gas inlet port or an elliptical gas inlet port. In an embodiment, the tubular gas supply chamber is a cylindrical gas supply chamber with a circular cross-sectional shape and the gas inlet port is a circular gas inlet port. In an embodiment, the tubular gas supply chamber is a cylindrical gas supply chamber with an oval cross-sectional shape and the gas inlet port is an oval gas inlet port. In an embodiment, the tubular gas supply chamber is a cylindrical gas supply chamber with an elliptical cross-sectional shape and the gas inlet port is an elliptical gas inlet port.

The tubular gas supply chamber comprises a port wall which extends around the gas inlet port. The port wall has an inner port wall surface facing the gas inlet port and an outer port wall surface on a side opposite to the inner port wall surface. The port wall is for example a circular port wall, an oval port wall or an elliptical port wall, depending on the shape op the gas inlet port.

The premix gas burner according to the invention comprises a burner deck which extends around at least a part of the tubular gas supply chamber. The burner deck comprises a tubular metal burner deck plate. For example, the tubular metal burner deck plate is a cylindrical metal burner deck plate, e.g. a cylindrical metal burner deck plate with a circular, oval or elliptical cross-sectional shape.

Optionally, the tubular, e.g. cylindrical, metal burner deck plate is manufactured from a flat metal plate of which two opposite edges are connected to each other, e.g. by a butt joint (e.g. a butt weld) or by an overlap joint. In case the joint causes the cross-sectional shape to have a deviation from a prefect circle, oval or ellipse, the cross-sectional shape is still considered to be circular, oval or elliptical, respectively.

The metal burner deck plate has a chamber facing surface on one side and a flame facing surface on the opposite side, and a plurality of gas outflow apertures that extend through the tubular metal burner deck plate from the chamber facing surface to the flame facing surface, the gas outflow apertures allowing the premix burner gas to flow from the gas supply chamber to a combustion zone adjacent to the flame facing surface of the tubular metal burner deck plate.

Optionally, the flame facing surface is a free flame facing surface. Alternatively, a layer, e.g. a metal fibrous layer, for example a metal knitted layer, or a metal woven layer or a metal non-woven layer, is arranged on the flame facing surface.

Optionally, a blind portion, without any gas outflow apertures that extend from the gas supply chamber towards the combustion zone, is present between the burner deck and the gas inlet port. Optionally, the blind portion is formed by an extended part of the tubular metal burner deck plate. Optionally, the blind portion extends around the circumference of the tubular gas supply chamber over a blind portion length.

The premix gas burner according to the invention comprises a planar mounting flange which extends in a flange plane. The mounting flange allows the premix gas burner to be mounted in a heating appliance, for example a building utility device for providing heat or hot tap water.

The flange plane is the general plane in which the planar mounting flange extends. For example, the planar mounting flange comprises a mounting surface which is adapted to engage a burner mounting surface of a heating appliance when the premix gas burner according to the invention is arranged in a heating appliance. In that case, the flange plane is the plane in which the mounting surface extends when the premix gas burner according to the invention is arranged with its mounting surface on a flat refence surface. The mounting surface of the planar mounting flange can for example be the surface of the planar mounting flange facing of the burner deck or the surface of the planar mounting flange facing away from the burner deck.

The planar mounting flange comprises a metal plate. Optionally, the planar mounting flange is a metal plate. The metal plate has a plate thickness and a flange opening. The plate thickness of the metal plate extends in a direction perpendicular to the flange plane, and the flange opening extends through the metal plate over the entire plate thickness of the metal plate. The flange opening is delimited by an inner flange wall.

Optionally, the metal plate is an annular metal plate.

Atleast a part of the port wall of the tubular gas supply chamber is arranged in the flange opening of the metal plate of the planar mounting flange, wherein at least a part of the outer port wall surface of the tubular gas supply chamber faces at least a part of the inner flange wall of the metal plate of the planar mounting flange.

Optionally, the metal plate for example comprises a single flange opening. The flange opening is for example a circular, elliptical or oval flange opening. The flange opening is for example a central flange opening. The single flange opening accommodates the part of the port wall as well as providing a gas passage to allow premix gas to flow into the tubular gas supply chamber via the gas inlet port.

Optionally, the metal plate comprises a flange opening for receiving a part of the port wall of the tubular gas supply chamber and in addition thereto one or more gas passages for allowing the premix gas to enter the tubular gas supply chamber.

Optionally, the metal plate comprises multiple flange openings, each for receiving a part of the port wall of the tubular gas supply chamber, and in addition thereto one or more gas passages for allowing the premix gas to enter the tubular gas supply chamber.

Preferably, the inner flange wall has a wall height that corresponds to the plate thickness of the metal plate. This allows the planar mounting flange to be manufactured easily, quickly and cheaply, for example by cutting it from a metal plate by e.g. laser cutting or water jet cutting or by die cutting (i.e. stamping with a cutting die).

Cutting the planar mounting flange from a metal plate in particular by e.g. laser cutting or water jet cutting allows a lot of freedom of design, with respect to e.g. the shape of the flange opening or flange openings, and/or the provision of other features such as an opening for accommodating an ignition pen and/or for a sensor, ad/or the outer contour of the planar mounting flange.

Cutting the planar mounting flange from a metal plate in particular by e.g. laser cutting or water jet cutting also allows for cost efficient production of small series of premix gas burners. On the other hand, die cutting allows for higher production speeds and is cost effective for larger series.

In an embodiment, the tubular metal burner deck plate is or is part of a tubular element.

On one end of the tubular element, and end cap is provided. The gas outflow apertures are provided in the wall of this tubular element, and a pattern of gas outflow apertures extends over at least a part of the length of the tubular element. The gas supply chamber is present within the tubular element, and is optionally delimited by the tubular metal burner deck plate and the end cap. The end of the tubular element opposite to the end where the end cap is arranged forms the inlet port of the gas supply chamber. Optionally, the port wall is part of the tubular metal burner deck plate.

The structure of premix gas burner according to the invention allows to obtain a high manufacturing accuracy, for example in relation to the perpendicularity of the flame facing surface of the burner deck relative to the mounting flange. This helps to obtain a reliable and reproducible position of the flame facing surface of the burner deck inside a heating appliance in which it is to be mounted, which in turn helps to achieve a reliable sensor input to a sensor that is arranged in the vicinity of the burner deck.

The structure of premix gas burner according to the invention allows to obtain a higher manufacturing accuracy for example in relation to the perpendicularity of the flame facing surface of the burner deck relative to the mounting flange, than known structures of premix gas burners, in which the port wall of the tubular gas supply chamber is clampingly arranged over a circular ridge which is provided on the mounting flange. So, in the known structure of premix gas burners, the ridge on the mounting flange clampingly engages the inner port wall surface of the gas supply chamber. In the premix burner according to the invention, it is not necessary that the outer port wall clampingly engages the inner flange wall of the metal plate of the planar mounting flange.

The premix gas burner according to the invention can for example be manufactured by a method for manufacturing a premix gas burner in accordance with the invention (including the described embodiments of these methods).

In an embodiment of the premix gas burner according to the invention, the flame facing surface of the tubular metal burner deck plate extends at a burner deck angle relative to the flange plane, which burner deck angle is between 88° and 92°, optionally between 89° and 91°, for example between 89.5° and 90.5° (limits of ranges included).

For example, this can be achieved by providing a corresponding angle of the inner flange wall relative to the flange plane and/or by providing a slightly oversized flange opening that allows to align the tubular metal burner deck plate relative to the planar mounting flange or vice versa and fix the relative position of the tubular metal burner deck plate and the planar mounting flange, e.g. by welding.

These values of the burner deck angle allow to define the position of the flame facing surface of the tubular metal burner deck plate accurately and reproducibly, so the distance between the flame facing surface of the tubular metal burner deck plate and a sensor that is located close to the burner deck, e.g. a sensor that is used to determine whether combustion takes place or not, is accurately and well defined. This increases the reliability of the sensor signal. For example, when a sensor is used to measure a temperature as an indication of whether or not combustion takes place, the distance between the flame facing surface of the tubular metal burner deck plate and the sensor may influence the value of the measured temperature at the location of the sensor. For a reliable interpretation of such a measured temperature, the distance between the sensor and the flame facing surface of the tubular metal burner deck plate has to be known accurately.

In an embodiment of the premix gas burner according to the invention, at least a longitudinal section of the flame facing surface of the tubular metal burner deck plate has a perpendicularity tolerance of 0.5 millimeters or less relative to the flange plane, for example a perpendicularity tolerance of between 0.4 millimeters and 0.2 millimeters, e.g. a perpendicularity tolerance of 0.3 millimeters.

For example, this can be achieved by providing a suitable perpendicularity of the inner flange wall and/or by providing a slightly oversized flange opening that allows to align the tubular metal burner deck plate relative to the planar mounting flange or vice versa and fix the relative position of the tubular metal burner deck plate and the planar mounting flange, e.g. by welding.

These values of the perpendicularity tolerance allow to define the position of the flame facing surface of the tubular metal burner deck plate accurately and reproducibly, so the distance between the flame facing surface of the tubular metal burner deck plate and a sensor that is located close to the burner deck, e.g. a sensor that is used to determine whether combustion takes place or not, is accurately and well defined. This increases the reliability of the sensor signal. For example, when a sensor is used to measure a temperature as an indication of whether or not combustion takes place, the distance between the flame facing surface of the tubular metal burner deck plate and the sensor may influence the value of the measured temperature at the location of the sensor. For a reliable interpretation of such a measured temperature, the distance between the sensor and the flame facing surface of the tubular metal burner deck plate has to be known accurately.

In accordance with the generally applied definition in the art, a perpendicularity tolerance of x millimeters means that a certain line or plane has to extend between two parallel reference lines or two parallel reference planes, respectively, that are at a distance of x millimeters for each other and that are perpendicular to a base line or base plane. So, in this embodiment, at least a longitudinal section of the flame facing surface of the tubular metal burner deck plate extends between two reference planes that are perpendicular to the flange plane, have the same shape as the longitudinal section of the tubular metal burner deck plate and are at a distance from each other that corresponds with the distance defined by the perpendicularity tolerance. So, if for example the perpendicularity tolerance is 0.3 millimeters, these two reference planes are 0.3 millimeters apart from each other.

In a variant of this embodiment, the longitudinal section of the flame facing surface of the tubular metal burner deck plate that is subject to this perpendicularity tolerance is arranged such that it is located adjacent to a sensor position when the premix gas burner is arranged in a heating appliance.

In a variant of this embodiment, the flame facing surface of the tubular metal burner deck plate has a perpendicularity tolerance of 0.5 millimeters or less relative to the flange plane, for example a perpendicularity tolerance of between 0.4 millimeters and 0.2 millimeters, e.g. a perpendicularity tolerance of 0.3 millimeters.

In an embodiment of the premix gas burner according to the invention, the tubular metal burner deck plate is a cylindrical metal burner deck plate with a circular cross section, and at least an angular section of the flame facing surface of the tubular metal burner deck plate has a roundness tolerance of 3 millimeters or less, for example a roundness tolerance of between 0.2 millimeters and 1.0 millimeters, e.g. a roundness tolerance of 0.7 millimeters.

In accordance with the generally applied definition in the art, a roundness tolerance of x millimeters means that the radius of the angular section has to lie between two concentric reference circles, which reference circles have a difference in radius of x millimeters. So, in this embodiment, at least an angular section of the flame facing surface of the tubular metal burner deck plate lies between two concentric reference circles that have a difference in radius with respect to one another that that corresponds with the distance defined by the roundness tolerance. So, if for example the roundness tolerance is 0.2 millimeters, these two reference circles have a radius difference of 0.2 millimeters.

In a variant of this embodiment, the angular section of the flame facing surface of the tubular metal burner deck plate that is subject to this roundness tolerance is arranged such that it is located adjacent to a sensor position when the premix gas burner is arranged in a heating appliance.

In a variant of this embodiment, the flame facing surface of the tubular metal burner deck plate has a roundness tolerance of 3 millimeters or less relative to the flange plane, for example a roundness tolerance of between 0.2 millimeters and 1.0 millimeters, e.g. a roundness tolerance of 0.7 millimeters.

In an embodiment, the tubular metal burner deck plate is a cylindrical metal burner deck plate with a circular cross section, and at least an angular section of the flame facing surface of the tubular metal burner deck plate has a roundness tolerance of 3 millimeters or less, for example a roundness tolerance of between 0.2 millimeters and 1.0 millimeters, e.g. a roundness tolerance of 0.7 millimeters and at least a longitudinal section of the flame facing surface of the tubular metal burner deck plate has a perpendicularity tolerance of 0.5 millimeters or less relative to the flange plane, for example a perpendicularity tolerance of between 0.4 millimeters and 0.2 millimeters, e.g. a perpendicularity tolerance of 0.3 millimeters.

This further improves the accuracy of the flame facing surface of the tubular metal burner deck plate.

Optionally, the flame facing surface of the tubular metal burner deck plate has a perpendicularity tolerance of 0.5 millimeters or less relative to the flange plane, for example a perpendicularity tolerance of between 0.4 millimeters and 0.2 millimeters, e.g. a perpendicularity tolerance of 0.3 millimeters.

Optionally, the flame facing surface of the tubular metal burner deck plate has a roundness tolerance of 3 millimeters or less relative to the flange plane, for example a roundness tolerance of between 0.2 millimeters and 1.0 millimeters, e.g. a roundness tolerance of 0.7 millimeters.

Optionally, the flame facing surface of the tubular metal burner deck plate has a perpendicularity tolerance of 0.5 millimeters or less relative to the flange plane, for example a perpendicularity tolerance of between 0.4 millimeters and 0.2 millimeters, e.g. a perpendicularity tolerance of 0.3 millimeters and the flame facing surface of the tubular metal burner deck plate has a roundness tolerance of 3 millimeters or less relative to the flange plane, for example a roundness tolerance of between 0.2 millimeters and 1.0 millimeters, e.g. a roundness tolerance of 0.7 millimeters.

In an embodiment, the tubular metal burner deck plate is a cylindrical metal burner deck plate with a circular cross section, and at least an angular section of the flame facing surface of the tubular metal burner deck plate has a roundness tolerance of 3 millimeters or less, for example a roundness tolerance of between 0.2 millimeters and 1.0 millimeters, e.g. a roundness tolerance of 0.3 millimeters and the flame facing surface of the tubular metal burner deck plate extends at a burner deck angle relative to the flange plane, which burner deck angle is between 88° and 92°, optionally between 89° and 91°, for example between 89.5° and 90.5° (limits of ranges included).

This further improves the accuracy of the flame facing surface of the tubular metal burner deck plate.

Optionally, the flame facing surface of the tubular metal burner deck plate has a roundness tolerance of 3 millimeters or less relative to the flange plane, for example a roundness tolerance of between 0.2 millimeters and 1.0 millimeters, e.g. a roundness tolerance of 0.7 millimeters.

In an embodiment of the premix gas burner according to the invention, at least a part of the outer port wall surface of the tubular gas supply chamber engages, for example clampingly engages, at least a part of the inner flange wall of the metal plate of the planar mounting flange.

In an embodiment of the premix gas burner according to the invention, the flange opening of the metal plate of the planar mounting flange is a cut opening, e.g. a laser cut opening or a water jet cut opening. In this embodiment, the flange opening is made by cutting, e.g. by laser cutting or by water jet cutting or by die cutting (i.e. stamping with a cutting die).

In an embodiment of the premix gas burner according to the invention, the port wall and the planar mounting flange are connected to each other by at least one weld.

Optionally, the port wall and the planar mounting flange are connected to each other by a plurality of spot welds. Optionally, the spot welds are equally distributed over the circumference of the port wall.

Optionally, the port wall and the planar mounting flange are connected to each other by a spot weld pair, which spot weld pair comprises two spot welds which are arranged diametrically opposite to each other.

Optionally, the port wall and the planar mounting flange are connected to each other by a plurality of spot weld pairs, each spot weld pair comprising two spot welds which are arranged diametrically opposite to each other. For example, four or eight spot weld pairs are provided.

Optionally, the port wall and the planar mounting flange are connected to each other by at least one TIG-weld (i.e. a weld that is been made by a tungsten inert gas welding process).

Optionally, no additional welding material is used in the TIG-weld.

In an embodiment of the premix gas burner according to the invention, the port wall and the planar mounting flange are made of different materials, e.g. different types of steel.

In known premix gas burners, the flange is often made of a different type of steel than the port wall. The reason for this is that a known design in which the flange has to be provided with a ridge requires a ductility of the flange material that is not found in the heat resistant type of steel which is used for the tubular metal burner deck plate. The tubular metal burner deck plate and the port wall are often made from the same material as they are usually integrated with each other and formed out of the same metal plate. In this embodiment, the materials that are traditionally used for the flange and the gas inlet port can be applied. So, if for example a small series of a particular burner design has to be manufactured, the materials that are already in stock for known burners can be used.

In an embodiment of the premix gas burner according to the invention, the port wall and the planar mounting flange are made of the same materials, e.g. the same type of steel.

Optionally, the port wall of the gas inlet port is formed from the tubular metal burner deck plate.

The invention makes it possible to use the same type of material for the planar mounting flange as for the port wall, as the planar mounting flange does not have to be ductile.

An advantage of this is that this may allow welding without adding welding material.

Welding without addition of welding material is advantageous because it generally results in a cleaner appearance of the welding area, and it reduces costs as no additional welding material is required.

A further advantage is that no additional thermal stresses are introduced due to different thermal expansion coefficients of the metal of the planar mounting flange and of the port wall of the gas inlet port. This reduces the risk of failure due to thermal fatigue and extend the lifetime of the premix gas burner.

In an embodiment of the premix gas burner according to the invention, a gastight connection is provided between the port wall and the planar mounting flange, for example a hydrogen-gastight connection.

Optionally, the gastight connection is provided by a weld that connects the port wall and the planar mounting flange with each other, e.g. a weld that extends around the entire circumference of the joint between the port wall and the planar mounting flange, optionally a

TIG-weld (i.e. a weld that is been made by a tungsten inert gas welding process), optionally a

TIG-weld without additional welding material.

In an embodiment of the premix gas burner according to the invention, the inner flange wall of the metal plate of the planar mounting flange comprises a protrusion that extends into the flange opening, and the port wall of the tubular gas supply chamber comprises a notch that accommodates the protrusion of the inner flange wall. For example, the protrusion extends in radial direction of the flange opening.

Optionally, the inner flange wall of the metal plate has multiple protrusions and the port wall of the tubular gas supply chamber comprises multiple notches. Each protrusion of the inner flange wall is accommodated in a notch of the port wall.

Optionally, the inner flange wall of the annular metal has three protrusions and the port wall of the tubular gas supply chamber comprises at least three notches. Each protrusion of the inner flange wall is accommodated in a notch of the port wall.

Optionally, in case the inner flange wall of the metal plate has multiple protrusions (e.g. three protrusions), the protrusions are not equally distributed over the inner flange wall of the metal plate. So, the pitch between two neighboring protrusions is not the same for all pairs of neighboring protrusions. Preferably, in this case the notches in the port wall are arranged to match the positions of the protrusions in such a way that there is only one relative position of the planar mounting flange and port wall in which the protrusions can be arranged into the notches. This facilitates a proper position of the tubular metal burner deck plate relative to the planar mounting flange (“poka yoke").

Optionally, at least one protrusion has a protrusion reference surface on the side facing the burner deck, and at least one notch has a notch reference surface facing in the direction away from the burner deck. The protrusion reference surface and the notch reference surface are adapted to engage each other. This way, a reference for the relative position of the planar mounting flange and the gas supply chamber and/or reference for the relative position of the planar mounting flange and the burner deck in axial direction of the premix gas burner can be provided.

In an embodiment of the premix gas burner according to the invention, the port wall of the tubular gas supply chamber comprises a protrusion that extends into the flange opening, and the inner flange wall of the metal plate of the planar mounting flange comprises a notch that accommodates the protrusion of the port wall. For example, the protrusion extends in axial direction of the flange opening.

Optionally, the port wall of the tubular gas supply chamber has multiple protrusions and the inner flange wall of the metal plate comprises multiple notches. Each protrusion of the port wall of the tubular gas supply chamber is accommodated in a notch of the inner flange wall.

Optionally, the port wall of the tubular gas supply chamber has three protrusions and the inner flange wall of the metal plate comprises at least three notches. Each protrusion of the port wall of the tubular gas supply chamber is accommodated in a notch of the inner flange wall.

Optionally, the port wall of the tubular gas supply chamber has multiple protrusions and the metal plate of the planar mounting flange comprises multiple notches. Each protrusion of the port wall of the tubular gas supply chamber is accommodated in a notch of the metal plate of the planar mounting flange.

Optionally, the port wall of the tubular gas supply chamber has three protrusions and the metal plate of the planar mounting flange comprises at least three notches. Each protrusion of the port wall of the tubular gas supply chamber is accommodated in a notch of the metal plate of the planar mounting flange.

Optionally, in case the port wall has multiple protrusions (e.g. three protrusions), the protrusions are not equally distributed over the port wall. So, the pitch between two neighboring protrusions is not the same for all pairs of neighboring protrusions. Preferably, in this case the notches in the metal plate of the planar mounting flange (e.g. in the inner flange wall of the metal plate) are arranged to match the positions of the protrusions in such a way that there is only one relative position of the planar mounting flange and port wall in which the protrusions can be arranged into the notches. This facilitates a proper position of the tubular metal burner deck plate relative to the planar mounting flange (“poka yoke”).

In an embodiment of the premix gas burner according to the invention, the planar mounting flange comprises at least one opening, protrusion and/or notch that makes that the premix gas burner can be mounted in the heating appliance only in a single position and orientation relative to the part of the heating appliance that it is mounted upon (“poka yoke”).

In a variant of this embodiment, this is achieved by providing mounting holes (e.g. bolt holes) in the planar mounting flange in such a way that the premix gas burner can be mounted in the heating appliance only in a single position and orientation relative to the part of the heating appliance that it is mounted upon (“poka yoke”).

In an embodiment of the premix gas burner according to the invention, the planar mounting flange has a mounting surface which extends parallel to the flange plane at a side facing away from the burner deck, and the port wall of the tubular gas supply chamber has a free axial end surface facing away from the burner deck, and the free axial end surface of the port wall is - in a direction perpendicular to the flange plane - arranged closer to the burner deck than the mounting surface of the planar mounting flange.

This arrangement allows to weld the port wall to the mounting flange using additional welding material, without compromising the flatness of the mounting surface.

In an embodiment of the premix gas burner according to the invention, the planar mounting flange has a mounting surface which extends parallel to the flange plane at a side facing towards the burner deck and a counter surface on the side of the planar mounting flange opposite to the mounting surface. In this embodiment, the port wall of the tubular gas supply chamber has a free axial end surface facing away from the burner deck, and the free axial end surface of the port wall is - in a direction perpendicular to the flange plane - arranged closer to the burner deck than the counter surface of the planar mounting flange.

This arrangement allows to weld the port wall to the mounting flange using additional welding material, without compromising the flatness of the counter surface.

In an embodiment of the premix gas burner according to the invention, the planar mounting flange has a mounting surface which extends parallel to the flange plane at a side facing away from the burner deck, and the port wall of the tubular gas supply chamber has a free axial end surface facing away from the burner deck, and the free axial end surface of the port wall is - in a direction perpendicular to the flange plane - arranged further away from the burner deck than the mounting surface of the planar mounting flange.

In this arrangement, the port wall protrudes from the mounting surface of the planar mounting flange. Therewith, the outer port wall optionally provides an inner support surface for a gasket.

In an embodiment of the premix gas burner according to the invention, the planar mounting flange has a mounting surface which extends parallel to the flange plane at a side facing towards the burner deck and a counter surface on the side of the planar mounting flange opposite to the mounting surface. In this embodiment, the port wall of the tubular gas supply chamber has a free axial end surface facing away from the burner deck, and the free axial end surface of the port wall is - in a direction perpendicular to the flange plane - arranged further away from the burner deck than the counter surface of the planar mounting flange.

In this arrangement, the port wall protrudes from the counter surface of the planar mounting flange. Therewith, the outer port wall optionally provides an inner support surface for a gasket.

In an embodiment of the premix gas burner according to the invention, the planar mounting flange has a mounting surface which extends parallel to the flange plane at a side facing away from the burner deck, and the port wall of the tubular gas supply chamber has a free axial end surface facing away from the burner deck, and the free axial end surface of the port wall is flush with the mounting surface of the planar mounting flange.

This arrangement allows to accurately position the planar mounting flange and the burner deck in height relative to each other prior to connecting the planar mounting flange and the port wall to each other (e.g. by welding). In addition, this arrangement allows easy access to the welding location in an automated welding process if an automated welding process is used for connecting the planar mounting flange and the port wall.

In an embodiment of the premix gas burner according to the invention, the planar mounting flange has a mounting surface which extends parallel to the flange plane at a side facing away from the burner deck and a counter surface on the side of the planar mounting flange opposite to the mounting surface. In this embodiment, the port wall of the tubular gas supply chamber has a free axial end surface facing away from the burner deck, and the free axial end surface of the port wall is flush with the mounting surface of the planar mounting flange.

This arrangement allows to accurately position the planar mounting flange and the burner deck in height relative to each other prior to connecting the planar mounting flange and the port wall to each other (e.g. by welding). In addition, this arrangement allows easy access to the welding location in an automated welding process if an automated welding process is used for connecting the planar mounting flange and the port wall.

In an embodiment of the premix gas burner according to the invention, the plate thickness of the planar mounting flange is at least 1.25 millimeter, optionally at least 1.5 millimeter, for example at least 2 millimeter, optionally at least 3 millimeter.

In an embodiment of the premix gas burner according to the invention, the premix gas burner is a building utility premix gas burner, which preferably is adapted to modulate between a minimum load and a full load. For example, the ratio of the full load over the minimum load is at least 3, preferably at least 4. Optionally, the ratio of the full load over the minimum load is at least 5, for example at least 7.

In an embodiment of the premix gas burner according to the invention, at least some of the gas outflow apertures of the metal burner deck plate of the burner deck are arranged in clusters.

In an embodiment of the premix gas burner according to the invention, all of the gas outflow apertures of the metal burner deck plate of the burner deck are arranged in clusters.

The smallest heart-to-heart distance between adjacent gas outflow apertures in the same cluster is smaller than the smallest heart-to-heart distance between a first gas outflow aperture in a first cluster and a second gas outflow aperture in a second cluster, the second cluster being adjacent to the first cluster.

This configuration allows a design of a premix gas burner that is suitable for combustion of a hydrogen-containing premix burner gas containing a fuel gas, which fuel gas contains at least 20 vol% of hydrogen, optionally at least 40 vol% of hydrogen, for example at least 80 vol% of hydrogen, for example at least 98 vol% of hydrogen. It can however also be used for hydrocarbon fuels. In addition, tests appear to indicate that this embodiment results in relatively low burner deck temperatures at relatively low input loads, e.g input loads up to about 20% to 25% of the maximum load, at an air excess ratio of 1.3 -1.8, for example 1.5.

Optionally, in this embodiment, the premix gas burner is a building utility premix gas burner, which preferably is adapted to modulate between a minimum load and a full load. For example, the ratio of the full load over the minimum load is at least 3, preferably at least 4.

Optionally, the ratio of the full load over the minimum load is at least 5, for example at least 7.

In an embodiment of the premix gas burner according to the invention, at least some of the gas outflow apertures of the metal burner deck plate of the burner deck are arranged in clusters. Optionally, all of the gas outflow apertures of the metal burner deck plate of the burner deck are arranged in clusters. The smallest heart-to-heart distance between adjacent gas outflow apertures in the same cluster is smaller than the smallest heart-to-heart distance between a first gas outflow aperture in a first cluster and a second gas outflow aperture in a second cluster, the second cluster being adjacent to the first cluster.

In this embodiment, the clusters are arranged in a cluster pattern.

Optionally, the cluster pattern comprises an array of clusters that extends in longitudinal direction of the burner deck, with the clusters of the array being aligned with each other in the longitudinal direction of the burner deck. The clusters in the array are for example aligned center-to-center (i.e. with the centers of the clusters being aligned with each other, i.e. being positioned on a straight line extending through the centers of the clusters of the array), and/or edge-to-edge (i.e. with the edges of the clusters being aligned with each other, i.e. all left side edges or all right side edges being positioned on a straight line extending through the respective side edges of the clusters of the array). Optionally, the line extending through the aligned centers and/or aligned side edges of the clusters of the array extends at an array angle relative to the flange plane, and array angle is between 88° and 92°, optionally between 89° and 91°, for example between 89.5% and 90.5° (limits of ranges included). Optionally, the line extending through the aligned centers and/or aligned side edges of the clusters of the array extends perpendicular to the flange plane and has a perpendicularity tolerance of 0.5 millimeters or less relative to the flange plane, for example a perpendicularity tolerance of between 0.4 millimeters and 0.2 millimeters, e.g. a perpendicularity tolerance of 0.3 millimeters.

Optionally, the cluster pattern comprises an array of clusters that extends in circumferential direction of the burner deck, with the clusters of the array being aligned with each other in the circumferential direction of the burner deck.

In an embodiment of the premix gas burner according to the invention, the gas outflow apertures of the metal burner deck plate of the burner deck are uniformly distributed over the surface of the burner deck.

Optionally, in this embodiment, the premix gas burner is a building utility premix gas burner, which preferably is adapted to modulate between a minimum load and a full load. For example, the ratio of the full load over the minimum load is at least 3, preferably at least 4.

Optionally, the ratio of the full load over the minimum load is at least 5, for example at least 7.

In an embodiment of the premix gas burner according to the invention, a first group of gas outflow apertures of the metal burner deck plate of the burner deck is arranged in a first pattern, and a second group of gas outflow apertures of the metal burner deck plate of the burner deck is arranged in a second pattern, wherein the first pattern is different from the second pattern.

Optionally, the patterns are designed to control the distribution of the premix gas over the burner deck. Optionally, the patterns are designed such that no inner distributor within the as supply chamber is necessary.

Optionally, in this embodiment, the premix gas burner is a building utility premix gas burner, which preferably is adapted to modulate between a minimum load and a full load. For example, the ratio of the full load over the minimum load is at least 3, preferably at least 4.

Optionally, the ratio of the full load over the minimum load is at least 5, for example at least 7.

In an embodiment of the premix gas burner according to the invention, the premix gas burner further comprises an anti-noise device, e.g. an anti-noise tube. For example, the anti- noise device is connected to the planar mounting flange.

In an embodiment of the premix gas burner according to the invention, the premix gas burner further comprises a gas distributor, e.g. a gas distributor plate or a tubular gas distributor. For example, the gas distributor is connected to the planar mounting flange.

Alternatively, the gas distributor is connected to a wall of the gas supply chamber, e.g. to the port wall of the gas inlet port of the gas supply chamber.

Optionally, the gas distributor is a gas distributor plate having multiple gas passages, e.g. multiple circular gas passages. Optionally, in this embodiment, the metal plate of the planar mounting flange comprises an annular metal plate, and the gas distributor plate is arranged in the flange opening of the planar mounting flange. Optionally, the annular metal plate and the gas distributor plate are integral with each other.

In an embodiment of the premix gas burner according to the invention, the premix gas burner further comprises a thermo-acoustic interface, e.g. a thermo-acoustic interface plate.

For example, the thermo-acoustic interface is connected to the planar mounting flange.

Alternatively, the thermo-acoustic interface is connected to a wall of the gas supply chamber, e.g. to the port wall of the gas inlet port of the gas supply chamber.

Optionally, the thermo-acoustic interface is a thermo-acoustic interface plate having multiple gas passages, e.g. multiple circular gas passages. Optionally, in this embodiment, the metal plate of the planar mounting flange comprises an annular metal plate, and the thermo-acoustic interface plate is arranged in the flange opening of the planar mounting flange. Optionally, the annular metal plate and the thermo-acoustic interface plate are integral with each other.

In an embodiment of the premix gas burner according to the invention, the premix gas burner comprises: - a cylindrical gas supply chamber which is adapted to receive the premix burner gas, which gas supply chamber has a circular gas inlet port, wherein the cylindrical gas supply chamber comprises a cylindrical port wall which extends around the circular gas inlet port, the cylindrical port wall having an inner port wall surface facing the circular gas inlet port and an outer port wall surface on a side opposite to the inner port wall surface, - a burner deck which extends around at least a part of the cylindrical gas supply chamber, which burner deck comprises a cylindrical metal burner deck plate having a circular cross-sectional shape, which metal burner deck plate has a chamber facing surface on one side and a flame facing free surface on the opposite side, and a plurality of gas outflow apertures that extend through the cylindrical metal burner deck plate from the chamber facing surface to the flame facing free surface, the gas outflow apertures allowing the premix burner gas to flow from the gas supply chamber to a combustion zone adjacent to the flame facing free surface of the cylindrical metal burner deck plate, - a planar mounting flange which extends in a flange plane, which planar mounting flange comprises an annular metal plate,

the annular metal plate having a plate thickness and a flange opening, the plate thickness of the annular metal plate extending in a direction perpendicular to the flange plane, and the flange opening extending through the annular metal plate over the entire plate thickness of the annular metal plate, which flange opening is delimited by an inner flange wall, the inner flange wall preferably having a wall height that corresponds to the plate thickness of the annular metal plate, wherein at least a part of the cylindrical port wall of the cylindrical gas supply chamber is arranged in the flange opening of the annular metal plate of the planar mounting flange, wherein at least a part of the outer port wall surface of the cylindrical gas supply chamber faces at least a part of the inner flange wall of the annular metal plate of the planar mounting flange.

This embodiment provides an advantageous combination of features that makes the premix gas burner compatible with many heating appliances.

The invention further pertains to a method for manufacturing a premix gas burner, which method comprises the following steps: - receiving a planar mounting flange, which planar mounting flange extends in a flange plane and comprises a metal plate, the metal plate having a plate thickness and a flange opening, the plate thickness of the metal plate extending in a direction perpendicular to the flange plane, and the flange opening extending through the metal plate over the entire plate thickness of the metal plate, which flange opening is delimited by an inner flange wall, the inner flange wall preferably having a wall height that corresponds to the plate thickness of the metal plate, - receiving a tubular element, which tubular element is or comprises a tubular metal burner deck plate, wherein the tubular element accommodates a tubular gas supply chamber which is adapted to receive premix burner gas, which gas supply chamber has a gas inlet port, wherein the tubular gas supply chamber comprises a port wall which extends around the gas inlet port, the port wall having an inner port wall surface facing the gas inlet port and an outer port wall surface on a side opposite to the inner port wall surface, - arranging at least a part of the port wall of the tubular gas supply chamber in the flange opening of the metal plate of the planar mounting flange, thereby making that at least a part of an outer port wall surface of the tubular gas supply chamber faces at least a part of the inner flange wall of the metal plate of the planar mounting flange, - optionally, connecting the planar mounting flange and the port wall of the tubular gas supply chamber to each other,

- optionally, connecting an end cap to the tubular element on an end opposite to the gas inlet port.

The method according to the invention and its embodiments can for example be used to manufacture a premix gas burner according to the invention, including a premix gas burner according to the invention according to any of the described embodiments.

The method according to the invention allows to obtain a high manufacturing accuracy, in particular with respect to the position and/or orientation of the planar mounting flange relative to the tubular element. This makes the resulting premix gas burner suitable for use is a system in which a sensor is placed near the tubular burner deck plate, in particular is the distance between the tubular burner deck plate and the sensor is of importance. In addition, the method according to the invention provides a simplification of the manufacturing process and allows a cost-effective production of small series.

In an embodiment of the method according to the invention, prior to receiving the planar mounting flange, the planar mounting plate is cut out of a metal sheet, e.g. by laser cutting, water jet cutting or die cutting.

This embodiment provides a high level of design flexibility and allows a cost-effective production of small series.

In an embodiment of the method according to the invention, an angle of the inner flange wall relative to the flange plane is between 88° and 92°, optionally between 89° and 91°, for example between 89.5° and 90.5° (limits of ranges included).

This embodiment allows to obtain a high manufacturing accuracy.

In an embodiment of the method according to the invention, the tubular metal burner deck plate comprises a flame facing surface, and the flange opening is larger than the outer circumference of the outer port wall. Furthermore, in this embodiment, prior to connecting the planar mounting flange and the port wall of the tubular gas supply chamber to each other, the tubular element and the planar mounting flange are positioned relative to each other such that the flame facing surface of the tubular metal burner deck plate extends at a burner deck angle relative to the flange plane, which burner deck angle is between 88° and 92°, optionally between 89° and 91°, for example between 89.5° and 90.5° (limits of ranges included).

This embodiment allows to obtain a high manufacturing accuracy.

In an embodiment of the method according to the invention, the method further comprises the step of heating the planar mounting flange prior to the step of arranging at least a part of the port wall of the tubular gas supply chamber in the flange opening of the metal plate of the planar mounting flange. In addition, in this embodiment, the method further comprises the step of cooling the planar mounting flange or allowing the planar mounting flange to cool after the step of arranging at least a part of the port wall of the tubular gas supply chamber in the flange opening of the metal plate of the planar mounting flange.

This embodiment is an example of how gas tightness, e.g. for hydrogen-containing fuel gases, at the connection between mounting flange and port wall can be improved.

In an embodiment of the method according to the invention, the tubular metal burner deck plate has a chamber facing surface on one side and a flame facing surface on the opposite side. In this embodiment, prior to receiving the tubular element, the tubular metal burner deck plate has been provided with a plurality of gas outflow apertures that extend through the tubular metal burner deck plate from the chamber facing surface to the flame facing surface.

The gas outflow apertures make that at least a part of the tubular metal burner deck plate can be used as a burner deck. The gas outflow apertures can be made in the tubular burner deck plate either before or after connection of the tubular element to the planar mounting flange, but generally it will be easier to make these apertures (with the desired accuracy) in the tubular metal burner deck plate before connecting the tubular element to the planar mounting flange. Optionally, the tubular metal burner deck plate is made from a flat metal plate which is then rolled or otherwise brought into a tubular shape, and the gas outflow apertures are made in the flat metal plate before rolling or otherwise bringing the flat metal plate into a tubular shape.

In an embodiment of the method according to the invention, the end cap is connected to the tubular element on the end opposite to the gas inlet port prior to arranging at least a part of the port wall of the tubular gas supply chamber in the flange opening of the metal plate of the planar mounting flange.

Alternatively, the end cap is connected to the tubular element on the end opposite to the gas inlet port after arranging at least a part of the port wall of the tubular gas supply chamber in the flange opening of the metal plate of the planar mounting flange.

In an embodiment of the method according to the invention, the planar mounting flange and the port wall of the tubular gas supply chamber are connected to each other by a plurality of spot welds.

This provides a quick and cheap connection.

Optionally, the spot welds are equally distributed over the circumference of the port wall.

Optionally, the port wall and the planar mounting flange are connected to each other by a spot weld pair, which spot weld pair comprises two spot welds which are arranged diametrically opposite to each other.

Optionally, the port wall and the planar mounting flange are connected to each other by a plurality of spot weld pairs, each spot weld pair comprising two spot welds which are arranged diametrically opposite to each other. For example, four or eight spot weld pairs are provided.

In an embodiment of the method according to the invention, the port wall has an axial end surface, and the inner flange wall has a first rim. In this embodiment, the planar mounting flange and the port wall of the tubular gas supply chamber are connected to each other with the axial end surface of the port wall positioned flush with the first rim of the inner flange wall.

Optionally, the planar mounting flange and the port wall of the tubular gas supply chamber are connected to each other by a weld that extends over the axial end surface of the port wall.

Optionally, the port wall and the planar mounting flange are connected to each other by at least one TIG-weld (i.e. a weld that is been made by a tungsten inert gas welding process).

Optionally, no additional welding material is used in the TIG-weld.

In an embodiment of the method according to the invention, the port wall has an axial end surface, and wherein the inner flange wall has a first rim and a second rim, the second rim being located opposite to the first rim. In this embodiment, the planar mounting flange and the port wall of the tubular gas supply chamber are connected to each other with the axial end surface of the port wall positioned between the first rim and the second rim of the inner flange wall.

Optionally, the planar mounting flange and the port wall of the tubular gas supply chamber are connected to each other by a weld that extends over the axial end surface of the port wall.

Optionally, the port wall and the planar mounting flange are connected to each other by at least one TIG-weld (i.e. a weld that is been made by a tungsten inert gas welding process).

Optionally, no additional welding material is used in the TIG-weld.

In an embodiment of the method according to the invention, the inner flange wall has a first rim and a second rim, and the second rim is located opposite to the first rim. In this embodiment, the planar mounting flange and the port wall of the tubular gas supply chamber are connected to each other with the tubular element protruding from the flange opening on both sides of the flange.

Optionally, the planar mounting flange and the port wall of the tubular gas supply chamber are connected to each other by a weld that extends around the outer port wall surface of the port wall.

Optionally, the port wall and the planar mounting flange are connected to each other by at least one TIG-weld (i.e. a weld that is been made by a tungsten inert gas welding process).

Optionally, no additional welding material is used in the TIG-weld.

The invention further pertains to a method for manufacturing a premix gas burner, which method comprises the following step: - arranging an at least a part of a port wall of a tubular gas supply chamber in a flange opening of a metal plate of a planar mounting flange, thereby making that at least a part of an outer port wall surface of the tubular gas supply chamber faces at least a part of an inner flange wall of the metal plate of the planar mounting flange, wherein the tubular gas supply chamber is adapted to receive the premix burner gas, which tubular gas supply chamber has a gas inlet port, wherein the tubular gas supply chamber comprises a port wall which extends around the gas inlet port, the port wall having an inner port wall surface facing the gas inlet port and an outer port wall surface on a side opposite to the inner port wall surface, and wherein a burner deck extends around at least a part of the tubular gas supply chamber, which burner deck comprises a tubular metal burner deck plate, which metal burner deck plate has a chamber facing surface on one side and a flame facing surface on the opposite side, and a plurality of gas outflow apertures that extend through the tubular metal burner deck plate from the chamber facing surface to the flame facing surface, the gas outflow apertures allowing the premix burner gas to flow from the gas supply chamber to a combustion zone adjacent to the flame facing surface of the cylindrical metal burner deck plate, and wherein the planar mounting flange which extends in a flange plane, which planar mounting flange comprising the metal plate, the metal plate having a plate thickness and the flange opening, the plate thickness of the metal plate extending in a direction perpendicular to the flange plane, and the flange opening extending through the metal plate over the entire plate thickness of the metal plate, which flange opening is delimited by the inner flange wall, preferably the inner flange wall having a wall height that corresponds to the plate thickness of the metal plate.

This method can for example be used to manufacture a premix gas burner according to the invention, including a premix gas burner according to the invention according to any of the described embodiments.

In an embodiment of the method according to the invention, the flange opening in the metal plate of the planar mounting flange is made by cutting, e.g. by laser cutting or by water jet cutting or by die cutting (i.e. stamping with a cutting die).

In an embodiment of the method according to the invention, the port wall and the planar mounting flange are connected to each other by welding.

The invention further pertains to a premix gas burner system, which comprises: - a premix gas burner according to the invention, - a burner system controller, - a sensor system adapted to detect combustion, which sensor system is connected to the burner system controller, which sensor system comprises a sensor which is arranged adjacent to the flame facing surface of the tubular metal burner deck plate.

The invention further pertains to a heating appliance, for example a building utility heating appliance, which comprises the premix gas burner system according to the invention.

In a second aspect, the invention further pertains to a premix gas burner for combusting a premix burner gas containing a fuel gas, comprising: - a tubular gas supply chamber which is adapted to receive the premix burner gas, which gas supply chamber has a gas inlet port, wherein the tubular gas supply chamber comprises a port wall which extends around the gas inlet port, the port wall having an inner port wall surface facing the gas inlet port and an outer port wall surface on a side opposite to the inner port wall surface, - a burner deck comprising a metal fibrous layer, for example a metal knitted layer, or a metal woven layer or a metal non-woven layer, - a tubular gas distributor which extends around at least a part of the tubular gas supply chamber, the metal fibrous layer being arranged on an outer surface of the tubular gas distributor, which tubular gas distributor comprises a tubular metal distributor plate,

which tubular metal distributor plate has a chamber facing surface on one side and a burner deck facing surface on the opposite side, and a plurality of gas outflow apertures that extend through the tubular metal distributor plate from the chamber facing surface to the burner deck facing surface, the gas outflow apertures allowing the premix burner gas to flow from the gas supply chamber to a combustion zone adjacent to the burner deck, - a planar mounting flange which extends in a flange plane, which planar mounting flange comprises a metal plate, the metal plate having a plate thickness and a flange opening, the plate thickness of the metal plate extending in a direction perpendicular to the flange plane, and the flange opening extending through the metal plate over the entire plate thickness of the metal plate, which flange opening is delimited by an inner flange wall, the inner flange wall preferably having a wall height that corresponds to the plate thickness of the metal plate, wherein at least a part of the port wall of the tubular gas supply chamber is arranged in the flange opening of the metal plate of the planar mounting flange, wherein at least a part of the outer port wall surface of the tubular gas supply chamber faces at least a part of the inner flange wall of the metal plate of the planar mounting flange.

In this second aspect, the premix gas burner is of the type in which the burner deck comprises a metal fibrous layer, for example a metal knitted layer, or a metal woven layer or a metal non-woven layer, and this metal fibrous layer is arranged on an outer surface of a tubular gas distributor. The tubular gas distributor may differ from the burner deck of the premix gas burner according to the first aspect of the invention mainly in the size and pattern of the gas outflow apertures.

Features as described in relation to the burner deck of the premix gas burner according to the first aspect of the invention and embodiments thereof can be applied in a similar way to the gas distributor of the second aspect of the invention.

The invention will be described in more detail below under reference to the drawing, in which in a non-limiting manner exemplary embodiments of the invention will be shown. The drawing shows in:

Fig. 1: schematically, an embodiment of a premix gas burner according to the invention,

Fig. 2: schematically, the embodiment of figure 1 in cross-section,

Fig. 3: schematically, an example of a planar mounting flange which could be used in the embodiment of figure 1,

Fig. 3A: schematically, a variant of the planar mounting flange according to fig. 3,

Fig. 4: schematically, a first detail of the flange and the gas inlet port of the embodiment of figure 1,

Fig. 5: schematically, a second detail of the flange and the gas inlet port of the embodiment of figure 1.

Fig. 6: schematically, a perpendicularity tolerance,

Fig, 7, schematically, a roundness tolerance,

Fig. 8: schematically, a further detail of embodiment of the premix gas burner according to the invention,

Fig. 9: schematically, illustrates a variant of the detail of fig. 8,

Fig. 10: schematically, illustrates a variant of the detail of fig. 8 and fig. 9,

Fig. 11: schematically, illustrates a variant of the detail of fig. 8 and fig. 9 and fig. 10,

Fig. 12: schematically, illustrates a variant of the detail of fig. 8 and fig. 9 and fig. 10 and fig. 11,

Fig. 13: schematically, illustrates a variant of the detail of fig. 8 and fig. 9 and fig. 10 and fig. 11 and fig. 12,

Fig. 14: schematically, an embodiment of the planar mounting flange 3 in which a gas distributor is incorporated,

Fig. 14A: schematically, an annular metal plate of a planar mounting flange,

Fig. 14B: schematically, a planar gas distributor,

Fig. 15: schematically, a variant of the embodiment of fig.1 and fig. 2,

Fig. 16: schematically, a second variant of the embodiment of fig. 1 and fig. 2,

Fig. 17: schematically, a third variant of the embodiment of fig. 1 and fig. 2,

Fig. 18: schematically, a fourth variant of the embodiment of fig. 1 and fig. 2,

Fig. 19: schematically, an embodiment of a tubular gas distributor and planar mounting flange of a premix gas burned according to the second aspect of the invention.

Fig. 1 shows, schematically, an embodiment of a premix gas burner 1 according to the invention. Fig. 2 shows, schematically, the embodiment of figure 1 in cross-section.

The premix gas burner 1 of fig. 1 and fig. 2 comprises a cylindrical gas supply chamber 10 which is adapted to receive the premix burner gas. The gas supply chamber has a circular gas inlet port 11.

The cylindrical gas supply chamber 10 comprises a cylindrical port wall 12 which extends around the circular gas inlet port 11. The cylindrical port wall 12 has an inner port wall surface 12a facing the circular gas inlet port 11 and an outer port wall surface 12b on a side opposite to the inner port wall surface 12a.

End cap 50 closes the gas supply chamber 10 at the end opposite to the circular gas inlet port 11.

The premix gas burner 1 of fig. 1 and fig. 2 further comprises a burner deck 20 which extends around at least a part of the cylindrical gas supply chamber 10. The burner deck 20 comprises a cylindrical metal burner deck plate 21 having a circular cross-sectional shape.

The metal burner deck plate 21 has a chamber facing surface 21a on one side and a flame facing free surface 21b on the opposite side, and a plurality of gas outflow apertures 22 that extend through the cylindrical metal burner deck plate 21 from the chamber facing surface 21a to the flame facing free surface 21b. The gas outflow apertures 22 allow the premix burner gas to flow from the gas supply chamber 10 to a combustion zone 15 adjacent to the flame facing free surface 21b of the cylindrical metal burner deck plate 20. In the embodiment of fig. 1 and fig. 2, the gas outflow apertures are arranged in clusters.

The premix gas burner 1 of fig. 1 and fig. 2 further comprises a planar mounting flange 30 which extends in a flange plane. An example of a planar mounting flange is shown in fig. 3.

The planar mounting flange 30 comprises an annular metal plate 31. The annular metal plate 31 has a plate thickness 32 and a flange opening 33. The plate thickness of the annular metal plate 31 extends in a direction perpendicular to the flange plane, and the flange opening 33 extends through the annular metal plate 31 over the entire plate thickness of the annular metal plate 30. The flange opening 33 is delimited by an inner flange wall 34.

At least a part of the cylindrical port wall 12 of the cylindrical gas supply chamber 10 is arranged in the flange opening 33 of the annular metal plate 31 of the planar mounting flange 30. At least a part of the outer port wall surface 12b of the cylindrical gas supply chamber 10 faces at least a part of the inner flange wall 34 of the annular metal plate 31 of the planar mounting flange 30.

In the embodiment shown in the figures, the inner flange wall 34 has a wall height that corresponds to the plate thickness 32 of the annular metal plate 31.

The planar mounting flange 30 of fig. 3 comprises at least one, optionally three or four, mounting holes 39 that allow the planar mounting flange of the premix gas burner 1 to be fixed onto a burner mounting surface in a heating appliance.

In the embodiment of the planar mounting flange of fig. 3, the inner flange wall 34 of the annular metal plate 31 of the planar mounting flange 30 comprises a protrusion 35 that extends into the flange opening 33. In the embodiment shown in fig. 3, the inner flange wall 34 of the annular metal plate 31 has multiple, e.g. three, protrusions 35.

Fig. 3A shows, schematically, a variant of the planar mounting flange according to fig. 3.

The flange of fig. 3A can for example be used in the embodiment of fig. 1 and fig. 2.

In the variant of fig. 3A, the inner flange wall 34 of the metal plate has multiple protrusions 35 (e.g. three protrusions), and the protrusions 35 are not equally distributed over the inner flange wall 34 of the metal plate. So, the pitch between two neighbouring protrusions is not the same for all pairs of neighbouring protrusions.

The planar mounting flange 30 of fig. 3A comprises multiple, optionally three or four, mounting holes 39 that allow the planar mounting flange of the premix gas burner 1 to be fixed onto a burner mounting surface in a heating appliance. In the variant of fig. 3A, the mounting holes 39 are not equally distributed over the planar mounting flange 30. So, the pitch between two neighbouring mounting holes 39 is not the same for all pairs of neighbouring mounting holes 39. This facilitates a proper position of the premix gas burner 1 relative to the burner mounting surface in the heating appliance (“poka yoke”).

Optionally, in the variants of fig. 3 and fig. 3A. one or more further notches 48, which are for example peripheral notches as shown in fig. 3 and fig. 3A, are provided. These further notches 48 can be arranged such as to help position the burner in the heating appliance.

Optionally, they are arranged such that the burner can only be mounted in the correct way (“poka yoke”). Optionally, a combination of one further notch 48 and one mounting hole 39 is sufficient to ensure the burner can only be mounted in the correct way. In that case, the planar mounting flange 30 as shown in fig. 3 or in fig. 3A may be modified such that only a single mounting hole 39 and a single further notch 48 is present.

Fig. 4 schematically shows a first detail of the flange and the gas inlet port of the embodiment of figure 1, and fig. 5 schematically shows a second detail of the flange and the gas inlet port of the embodiment of figure 1.

Optionally, in the embodiment of the premix gas burner as shown in fig.1 and fig. 2, the flame facing free surface 21b of the cylindrical metal burner deck plate 21 extends at a burner deck angle relative to the flange plane, and burner deck angle is between 88° and 92°, optionally between 89° and 91°, for example between 89.5° and 90.5° (limits of ranges included).

Optionally, in the embodiment of the premix gas burner as shown in fig.1 and fig. 2, at least a part of the outer port wall surface 12b of the cylindrical gas supply chamber engages, for example clampingly engages, at least a part of the inner flange wall 34 of the annular metal plate 31 of the planar mounting flange 30.

Optionally, in the embodiment of the premix gas burner as shown in fig.1 and fig. 2, the flange opening 33 of the annular metal plate 31 of the planar mounting flange 30 is a cut opening, e.g. a laser cut opening or a water jet cut opening or a die-cut opening. In this embodiment, the flange opening is made by cutting, e.g. by laser cutting or by water jet cutting or by cutting by stamping with a cutting die.

Optionally, in the embodiment of the premix gas burner as shown in fig.1 and fig. 2, the cylindrical port wall 12 and the planar mounting flange 30 are connected to each other by at least one weld.

Optionally, in the embodiment of the premix gas burner as shown in fig.1 and fig. 2, a gastight connection is provided between the cylindrical port wall 12 and the planar mounting flange 30, for example a hydrogen-gastight connection.

In the embodiment of the premix gas burner as shown in fig.1 and fig. 2, the inner flange wall 34 of the annular metal plate 31 of the planar mounting flange 30 comprises a protrusion 35 that extends into the flange opening 33. In the embodiment shown in fig. 1, fig. 2 and fig. 3 and fig. 3A, the inner flange wall 34 of the annular metal plate 31 has multiple, e.g. three, protrusions 35. The cylindrical port wall 12 of the cylindrical gas supply chamber 10 comprises a notch 14 that accommodates the protrusion 35 of the inner flange wall 34. In the embodiment shown in fig. 1, fig. 2 and fig. 3, the cylindrical port wall 12 of the cylindrical gas supply chamber 10 comprises multiple, e.g. three, notches 14 that each accommodate a protrusion 35 of the inner flange wall 34.

In the embodiment of the premix gas burner as shown in fig.1 and fig. 2, the planar mounting flange 30 has a mounting surface 36 which extends parallel to the flange plane at a side facing away from the burner deck 20, and the cylindrical port wall 12 of the cylindrical gas supply chamber 10 has a free axial end 16 surface facing away from the burner deck 10, and the free axial end surface 16 of the cylindrical port wall 12 is - in a direction perpendicular to the flange plane - arranged closer to the burner deck 10 than the mounting surface 36 of the planar mounting flange 30.

Optionally, in the embodiment of the premix gas burner as shown in fig.1 and fig. 2, the plate thickness 32 of the planar mounting flange 31 is at least 1.25 millimeter, optionally at least 1.5 millimeter, for example at least 2 millimeter.

Optionally, in the embodiment of the premix gas burner as shown in fig.1 and fig. 2, the premix gas burner further comprises an anti-noise device, e.g. an anti-noise tube. For example, the anti-noise device is connected to the planar mounting flange.

Optionally, in the embodiment of the premix gas burner as shown in fig.1 and fig. 2, the premix gas burner further comprises a gas distributor, e.g. a gas distributor plate or a tubular gas distributor. For example, the gas distributor is connected to the planar mounting flange.

When the premix gas burner 1 is part of a premix burner system, and/or is mounted in a heating appliance, a sensor 40 may be provided, for example a sensor for detecting whether or not combustion takes place.

Optionally, in embodiments of the premix gas burner according to the invention, e.g. in the embodiment of fig. 1 and fig. 2 or of fig. 15, fig. 18, fig. 17 or fig. 18, at least a longitudinal section of the flame facing surface of the tubular metal burner deck plate has a perpendicularity tolerance of 0.5 millimeters or less relative to the flange plane, for example a perpendicularity tolerance of between 0.4 millimeters and 0.2 millimeters, e.g. a perpendicularity tolerance of 0.3 millimeters. For example, the longitudinal section of the flame facing surface of the tubular metal burner deck plate that is subject to this perpendicularity tolerance is arranged such that it is located adjacent to a sensor position when the premix gas burner is arranged in a heating appliance. Optionally, the flame facing surface of the tubular metal burner deck plate has a perpendicularity tolerance of 0.5 millimeters or less relative to the flange plane, for example a perpendicularity tolerance of between 0.4 millimeters and 0.2 millimeters, e.g. a perpendicularity tolerance of 0.3 millimeters.

In accordance with the generally applied definition in the art, a perpendicularity tolerance of x millimeters means that a certain line or plane has to extend between two parallel reference lines or two parallel reference planes, respectively, that are at a distance of x millimeters for each other and that are perpendicular to a base line or base plane. This is illustrated in fig. 8.

The flange plane 37 is the general plane in which the planar mounting flange 30 extends. For example, as shown in fig. 6, the planar mounting flange 30 comprises a mounting surface 36 which is adapted to engage a burner mounting surface of a heating appliance when the premix gas burner according to the invention is arranged in a heating appliance. In that case, the flange plane 37 is the plane in which the mounting surface 36 extends when the premix gas burner according to the invention is arranged on a flat refence surface.

Reference lines 23a and 23b extend perpendicular to the flange plane 37. The distance between the reference lines 23a and 23b is x, which x being equal to the value of the perpendicularity tolerance. In order to meet the tolerance requirement, the relevant part of the flame facing surface (i.e. the part of the flame facing surface to which the tolerance requirement applies), e.g. the free flame facing surface 21b of the cylindrical metal burner deck plate 21, has to be between the reference lines 23a and 23b.

Optionally, in embodiments of the premix gas burner according to the invention, e.g. in the embodiment of fig. 1 and fig. 2, or of fig. 15, fig. 17 or fig. 18, the tubular metal burner deck plate is a cylindrical metal burner deck plate with a circular cross section, and at least an angular section 24 of the flame facing surface of the tubular metal burner deck plate has a roundness tolerance of 3 millimeters or less, for example a roundness tolerance of between 0.2 millimeters and 1.0 millimeters, e.g. a roundness tolerance of 0.7 millimeters.

As is illustrated in fig. 7, the angular section 24 extends over an angle a1 of the circumference of the cylindrical metal burner deck plate 21, and over at least a part of the length of the cylindrical metal burner deck plate 21 in axial direction of the cylindrical metal burner deck plate 21, optionally over the full length of the cylindrical metal burner deck plate 21 in axial direction of the cylindrical metal burner deck plate 21.

In accordance with the generally applied definition in the art, a roundness tolerance of x millimeters means that the radius of the angular section 24 has to lie between two concentric reference circles 25a, 25b, which reference circles 25a, 25b have a difference in radius of x millimeters. Optionally, the reference circles 25a, 25b extend into cylindrical planes or angular sections thereof along at least a part of the length of the cylindrical metal burner deck plate 21 in axial direction of the cylindrical metal burner deck plate 21.

In order to meet the tolerance requirement, the flame facing surface (i.e. the part of the flame facing surface to which the tolerance requirement applies), e.g. angular section 24 of the free flame facing surface 21b of the cylindrical metal burner deck plate 21, has to be between the reference lines 25a and 25b.

Optionally, for an elliptical or oval burner, e.g of the embodiment shown in fig. 16, a similar shape tolerance applies. In that case, at lest an angular section of the flame facing surface of the burner deck lies between two reference ellipses or reference ovals, respectively. The difference in local radius between the two reference ellipses or two reference ovals equals the shape tolerance value.

Fig. 8 schematically illustrates a further detail of embodiment of the premix gas burner according to the invention. This detail can be present in any of the embodiments of fig. 1 and fig. 2, fig. 15, fig. 16, fig. 17 and/or fig. 18.

In accordance with this detail, the planar mounting flange 30 has a mounting surface 36 which extends parallel to the flange plane at a side facing away from the burner deck, and the port wall 12 of the tubular gas supply chamber 10 has a free axial end surface 12 a facing away from the burner deck 20. The free axial end surface 12a of the port wall 12 is - in a direction perpendicular to the flange plane - arranged closer to the burner deck 20 than the mounting surface 36 of the planar mounting flange 30.

Fig. 9 schematically illustrates a variant of the detail of fig. 8. The variant of fig. 9 can for example be present in any of the embodiments of fig. 1 and fig. 2, fig. 15, fig. 16, fig. 17 and/or fig. 18.

In accordance with fig. 9, the planar mounting flange 30 has a mounting surface 36 which extends parallel to (and optionally even coincides with) the flange plane 37 at a side facing towards the burner deck and a counter surface 38 on the side of the planar mounting flange opposite to the mounting surface. In this variant, the port wall 12 of the tubular gas supply chamber 10 has a free axial end surface 12a facing away from the burner deck, and the free axial end surface 12a of the port wall 12 is - in a direction perpendicular to the flange plane - arranged closer to the burner deck than the counter surface 38 of the planar mounting flange 30.

Fig. 10 illustrates a further variant of the details of fig. 8 and fig. 9. The variant of fig. 10 can for example be present in any of the embodiments of fig. 1 and fig. 2, fig. 15, fig. 18, fig. 17 and/or fig. 18.

In accordance with fig. 10, the planar mounting flange 30 has a mounting surface 36 which extends parallel to the flange plane 37 at a side facing away from the burner deck. The port wall 12 of the tubular gas supply chamber 12 has a free axial end surface 12a facing away from the burner deck and the free axial end surface 12a of the port wall 12 is -ina direction perpendicular to the flange plane - arranged further away from the burner deck than the mounting surface 36 of the planar mounting flange 30.

Fig. 11 illustrates a further variant of the details of fig. 8 and fig. 9 and fig. 10. The variant of fig. 11 can for example be present in any of the embodiments of fig. 1 and fig. 2, fig. 15, fig. 16, fig. 17 and/or fig. 18.

In accordance with fig. 11, the planar mounting flange 30 has a mounting surface 36 which extends parallel to (and optionally even coincides with) the flange plane 37 at a side facing towards the burner deck and a counter surface 38 on the side of the planar mounting flange 30 opposite to the mounting surface 36. In this variant, the port wall 12 of the tubular gas supply chamber 10 has a free axial end surface 12a facing away from the burner deck,

and the free axial end surface 12a of the port wall 12 is - in a direction perpendicular to the flange plane - arranged further away from the burner deck than the counter surface 38 of the planar mounting flange 30.

Fig. 12 illustrates a further variant of the details of fig. 8 and fig. 9 and fig. 10 and fig. 11.

The variant of fig. 12 can for example be present in any of the embodiments of fig. 1 and fig. 2, fig. 15, fig. 16, fig. 17 and/or fig. 18.

In accordance with fig. 12, the planar mounting flange 30 has a mounting surface 36 which extends parallel to the flange plane 37 at a side facing away from the burner deck. The port wall 12 of the tubular gas supply chamber 10 has a free axial end surface 12a facing away from the burner deck, and the free axial end surface 12a of the port wall 12 is flush with the mounting surface 36 of the planar mounting flange 30.

Fig. 13 illustrates a further variant of the details of fig. 8 and fig. 9 and fig. 10 and fig. 11 and fig. 12. The variant of fig. 13 can for example be present in any of the embodiments of fig. 1 and fig. 2, fig. 15, fig. 16, fig. 17 or fig. 18.

In accordance with fig. 13, the planar mounting flange 30 has a mounting surface 36 which extends parallel to (or even coincides with) the flange plane 37 at a side facing away from the burner deck and a counter surface 38 on the side of the planar mounting flange 30 opposite to the mounting surface 36. In this variant, the port wall 12 of the tubular gas supply chamber 10 has a free axial end surface 12a facing away from the burner deck, and the free axial end surface 12a of the port wall 12 is flush with the mounting surface 36 of the planar mounting flange 30.

Fig. 14 schematically shows an embodiment of the planar mounting flange 30 in which a thermo-acoustic interface and/or a gas distributor 45 is incorporated.

In the embodiment of fig. 14, the thermo-acoustic interface and/or gas distributor 45 is or comprises a gas distributor plate with multiple gas passages 46, e.g. multiple circular gas passages.

In the embodiment of fig. 14, the planar mounting flange 30 and the thermo-acoustic interface and/or gas distributor 45 are integrated into a single component, which component can for example be manufactured by cutting it from a metal plate, e.g. steel plate, e.g. by laser cutting, waterjet cutting or by die cutting. In the example that is illustrated in fig. 14, the mounting flange 30 comprises three flange openings 33, each having their own inner flange wall 34. In this example, the inner port wall comprises for example multiple, e.g. three, protrusions, and the protrusions are to be arranged in the flange openings 33.

Alternatively, the planar mounting flange 30 and the thermo-acoustic interface and/or gas distributor 45 are manufactured separately and connected to each other. In that case, the planar mounting flange 30 is for example formed by an annular metal plate 31 which a single flange opening 33, e.g. a single central flange opening, as is shown schematically in fig. 14A.

A thermo-acoustic interface and/or gas distributor 45 is manufactured as a separate part. The gas distributor for example comprises multiple gas passages 48, e.g. multiple circular gas passages and at least one, e.g. three, notches 47. The thermo-acoustic interface and/or gas distributor 45 is then placed into the central flange opening 33 of the annular metal plate 31.

The notches 47 then form openings to receive parts of the port wall. The thermo-acoustic interface and/or gas distributor 45 is connected to the annular metal plate 31 for example by clamping, crimping or welding.

Fig. 15 schematically shows a variant of the embodiment of fig.1 and fig. 2.

In the embodiment of fig. 15, a blind portion 26, without any gas outflow apertures that extend from the gas supply chamber towards the combustion zone, is present between the burner deck 20 and the gas inlet port. Optionally, the blind portion 26 is formed by an extended part of the tubular metal burner deck plate 21. Optionally, the blind portion 26 extends around the circumference of the tubular gas supply chamber over a blind portion length 26a.

Fig. 16 schematically shows a second variant of the embodiment of fig.1 and fig. 2.

In the embodiment of fig. 18, the premix gas burner 1 comprises a cylindrical gas supply chamber 10 which is adapted to receive the premix burner gas. In the embodiment of fig. 16, the cylindrical gas supply chamber 10 has an oval or elliptical cross section. The gas supply chamber has an oval or elliptical gas inlet port.

The oval or elliptical cylindrical gas supply chamber 10 comprises an oval or elliptical cylindrical port wall which extends around the oval or elliptical gas inlet port, respectively.

The premix gas burner 1 of fig. 16 further comprises a burner deck 20 which extends around at least a part of the oval or elliptical cylindrical gas supply chamber 10. Optionally, multiple gas outflow apertures are arranged over the entire circumference of the burner deck, and optionally also over the entire length of the burner deck. The burner deck 20 comprises a cylindrical metal burner deck plate 21 having an oval or elliptical cross-sectional shape.

In the embodiment of fig. 16, the plane mounting flange 30 is for example provided with a single oval or elliptical flange opening.

Fig. 17 schematically shows a third variant of the embodiment of fig.1 and fig. 2.

In the embodiment of fig. 17, a first group 22a of gas outflow apertures 22 of the metal burner deck plate of the burner deck is arranged in a first pattern, and a second group 22b of gas outflow apertures 22 of the metal burner deck plate of the burner deck is arranged in a second pattern. The first pattern is different from the second pattern. Optionally, more than two groups of gas outflow apertures are present, all with different patterns or in which at least one of the at least two different patterns is repeated.

For example, the patterns are designed to control the distribution of the premix gas over the burner deck. Optionally, the patterns are designed such that no inner distributor within the as supply chamber is necessary.

Optionally, a blind portion 26, without any gas outflow apertures that extend from the gas supply chamber towards the combustion zone, is present between the burner deck 20 and the gas inlet port.

Optionally, in this embodiment, the premix gas burner is a building utility premix gas burner, which preferably is adapted to modulate between a minimum load and a full load. For example, the ratio of the full load over the minimum load is at least 3, preferably at least 4.

Optionally, the ratio of the full load over the minimum load is at least 5, for example at least 7.

In a variant of the embodiment of fig. 17, the gas outflow apertures 22 are arranged as shown in fig. 17, but are provided in a burner having a tubular gas supply chamber which has an oval or elliptical cross-sectional shape, e.g. a burner of the type as shown in fig. 16.

Fig. 18 shows, schematically, a fourth variant of the embodiment of fig. 1 and fig. 2.

In the embodiment of fig. 18, the premix gas burner 1 further comprises an anti-noise device 41, e.g. an anti-noise tube. In this example, the anti-noise device 41 is connected to the planar mounting flange 30.

Although fig. 18 shows the anti-noise device in combination with a cluster pattern of gas outflow apertures, the use of the anti-noise device 41 is not limited to such a cluster pattern.

Although fig. 18 shows the anti-noise device in combination with a burner having a tubular gas supply chamber which has a circular cross-sectional shape, the anti-noise device can also be applied in a burner having a tubular gas supply chamber which has an oval or elliptical cross-sectional shape, e.g. a burner of the type as shown in fig. 16.

The anti-noise device can be used in combination with any of the embodiments of the premix gas burner according to the invention.

Fig. 19 shows, schematically, an embodiment of a tubular gas distributor and planar mounting flange of a premix gas burned according to the second aspect of the invention.

In the embodiment of fig. 19, the premix gas burner 201 comprises a tubular gas supply chamber which is adapted to receive the premix burner gas. The gas supply chamber has a gas inlet port.

The tubular gas supply chamber comprises a port wall which extends around the gas inlet port. The port wall has an inner port wall surface facing the gas inlet port and an outer port wall surface on a side opposite to the inner port wall surface.

In the embodiment of fig. 19, the premix gas burner further comprises a burner deck comprising a metal fibrous layer (not shown in fig. 19), for example a metal knitted layer, or a metal woven layer or a metal non-woven layer.

In the embodiment of fig. 19, the premix gas burner further comprises a tubular gas distributor 220 which extends around at least a part of the tubular gas supply chamber. The the metal fibrous layer is arranged on an outer surface of the tubular gas distributor 220, optionally over the entire outer surface of the tubular gas distributor 220. The tubular gas distributor 220 comprises a tubular metal distributor plate 221.

The tubular metal distributor plate 221 has a chamber facing surface on one side and a burner deck facing surface on the opposite side, and a plurality of gas outflow apertures 222 that extend through the tubular metal distributor plate 221 from the chamber facing surface to the burner deck facing surface. The gas outflow apertures 222 allow the premix burner gas to flow from the gas supply chamber to a combustion zone adjacent to the burner deck.

In the embodiment of fig. 19, the premix gas burner further comprises a planar mounting flange 230 which extends in a flange plane. The planar mounting flange 230 comprises a metal plate that has a plate thickness and a flange opening. The plate thickness of the metal plate extends in a direction perpendicular to the flange plane, and the flange opening extends through the metal plate over the entire plate thickness of the metal plate.

The flange opening is delimited by an inner flange wall, and the inner flange wall preferably has a wall height that corresponds to the plate thickness of the metal plate.

In the embodiment of fig. 19, at least a part of the port wall of the tubular gas supply chamber is arranged in the flange opening of the metal plate of the planar mounting flange, wherein at least a part of the outer port wall surface of the tubular gas supply chamber faces atleast a part of the inner flange wall of the metal plate of the planar mounting flange.

Optionally, a blind portion 228, without any gas outflow apertures 222 that extend from the gas supply chamber towards the combustion zone, is present between the zone with the gas outflow apertures 222 of the tubular gas distributor 220 and the gas inlet port.

In this second aspect, the premix gas burner 201 is of the type in which the burner deck comprises a metal fibrous layer, for example a metal knitted layer, or a metal woven layer or a metal non-woven layer, and this metal fibrous layer is arranged on an outer surface of a tubular gas distributor 220. The tubular gas distributor 220 may differ from the burner deck 20 of the premix gas burner 1 according to the first aspect of the invention mainly in the size and pattern of the gas outflow apertures 22, 222.

Claims (21)

CONCLUSIONS 1. A premix gas burner for combusting a premixed burner gas containing a fuel gas, comprising: - a tubular gas supply chamber adapted to receive the premixed burner gas, the gas supply chamber having a gas inlet port, the tubular gas supply chamber comprising a port wall extending about the gas inlet port, the port wall having an inner port wall surface facing the gas inlet port and an outer port wall surface on a side opposite the inner port wall surface, - a burner deck extending about at least a portion of the tubular gas supply chamber, the burner deck comprising a tubular metal burner cover plate, the tubular metal burner cover plate having a chamber-facing surface on one side and a flame-facing surface on the opposite side, and a plurality of gas outlet openings extending through the tubular metal burner cover plate from the chamber-facing surface, the gas outlet openings permitting the premixed burner gas from the gas supply chamber to a combustion zone; near the flame-facing surface of the tubular metal burner cover plate, - a flat mounting flange extending in a flange plane, which flat mounting flange comprises a metal plate, the metal plate having a plate thickness and a flange opening, the plate thickness of the metal plate extending in a direction perpendicular to the flange plane and the flange opening extending through the metal plate over the entire plate thickness of the metal plate, which flange opening is bounded by an inner flange wall, the inner flange wall preferably having a wall height corresponding to the plate thickness of the metal plate, at least a part of the port wall of the tubular gas supply chamber being arranged in the flange opening of the metal plate of the flat mounting flange, at least a part of the outer port wall surface of the tubular gas supply chamber facing at least a part of the inner flange wall of the metal plate of the flat mounting flange. 2. Premix gas burner according to claim 1, wherein the flame-facing surface of the tubular metal burner cover plate extends at a burner deck angle relative to the flange plane, which burner deck angle is between 88° and 92°, optionally between 89° and 91°, for example between 89.5° and 90.5°. 3. A premix gas burner according to any preceding claim, wherein at least a portion of the outer port wall surface of the tubular gas supply chamber engages at least a portion of the inner flange wall of the metal plate of the flat mounting flange. 4. Premix gas burner according to any one of the preceding claims, wherein the flange opening of the metal plate of the flat mounting flange is a cut opening, for example a laser-cut opening or a water jet-cut opening or a punch-cut opening. 5. Premix gas burner according to any of the preceding claims, wherein the port wall and the flat mounting flange are connected to each other by at least one weld. 6. Premix gas burner according to any one of the preceding claims, wherein a gas-tight connection is provided between the port wall and the flat mounting flange, for example a hydrogen gas-tight connection. 7. A premix gas burner according to any preceding claim, wherein the inner flange wall of the metal plate of the flat mounting flange comprises a projection extending into the flange opening, and the port wall of the tubular gas supply chamber comprises a recess receiving the projection of the inner flange wall. 8. A premix gas burner according to any preceding claim, wherein the port wall of the tubular gas supply chamber comprises a protrusion extending into the flange opening, and the inner flange wall of the metal plate of the flat mounting flange comprises a recess receiving the protrusion of the port wall. 9. A premix gas burner according to any preceding claim, wherein the flat mounting flange has a mounting surface extending parallel to the flange face on a side facing away from the burner deck, and wherein the port wall of the tubular gas supply chamber has a free axial end surface facing away from the burner deck, whereby the free axial end of the port wall — in a direction perpendicular to the flange plane — is closer to the burner deck than the mounting plane of the flat mounting flange. 10. Premix gas burner system, comprising: - a premix gas burner according to any of claims 1 to 9, - a burner system controller, - a sensor system adapted to detect combustion, the sensor system being connected to the burner system controller, the sensor system comprising a sensor disposed near the flame-facing surface of the tubular metal burner cover plate. 11. Heating appliance, for example a building utility heating appliance, comprising the premix gas burner system according to claim 10. 12. A method for manufacturing a premix gas burner, the method comprising the steps of: - receiving a flat mounting flange extending in a flange plane, the flat mounting flange comprising a metal plate, the metal plate having a plate thickness and a flange opening, the plate thickness of the metal plate extending in a direction perpendicular to the flange plane and the flange opening extending through the metal plate over the entire plate thickness of the metal plate, the flange opening being bounded by an inner flange wall, the inner flange wall preferably having a wall height corresponding to the plate thickness of the metal plate, - receiving a tubular element, the tubular element being or comprising a metal burner cover plate, the tubular element including a tubular gas supply chamber adapted to receive the premixed burner gas, the gas supply chamber having a gas inlet port, the tubular gas supply chamber comprising a port wall extending about the gas inlet port, the port wall having an inner port wall surface facing the gas inlet port and an outer port wall surface on a side opposite the inner port wall surface, - mounting at least a portion of the port wall of the tubular gas supply chamber into the flange opening of the metal plate of the flat mounting flange, ensuring that at least a portion of the outer port wall surface of the tubular gas supply chamber faces at least a portion of the inner flange wall of the metal plate of the flat mounting flange, - optionally, connecting the flat mounting flange and the port wall of the tubular gas supply chamber together, - optionally, connecting an end cap to the tubular member at an end opposite the gas inlet port. 13. A method according to claim 12, wherein, prior to receiving the flat mounting flange, the flat mounting flange is cut from a metal sheet, for example by laser cutting, water jet cutting or punching. Method according to any of claims 12 to 13, wherein the angle of the inner flange wall relative to the flange plane is between 88° and 92°, optionally between 89° and 91°, for example between 89.5° and 90.5°. A method according to any one of claims 12 to 14, wherein the tubular metal burner cover plate comprises a flame-facing surface, and the flange opening is larger than the outer circumference of the outer port wall, and wherein, prior to connecting the flat mounting flange and the port wall of the tubular gas supply chamber together, the tubular member and the flat mounting flange are positioned relative to each other such that the flame-facing surface of the metal burner cover plate extends at a burner deck angle relative to the flange plane, which burner deck angle is between 88° and 92°, optionally between 89° and 91°, for example between 89.5° and 90.5°. A method according to any one of claims 12 to 15, wherein the port wall has an axial end surface, and wherein the inner flange wall has a first edge, and wherein the planar mounting flange and the port wall of the tubular gas supply chamber are connected together with the axial end surface flush with the first edge of the inner flange wall. 17. A method according to any one of claims 12 to 15, wherein the port wall has an axial end surface, and wherein the inner flange wall has a first edge and a second edge, the second edge being opposite the first edge, and wherein the flat mounting flange and the port wall of the tubular gas supply chamber are connected to each other with the axial end surface lying between the first edge and the second edge of the inner flange wall. 18. A method as claimed in any one of claims 16 or 17, wherein the flat mounting flange and the port wall of the tubular gas supply chamber are connected by a weld extending across the axial end surface of the port wall. 19. A method as claimed in any one of claims 12 to 15, wherein the inner flange wall has a first edge and a second edge, the second edge being opposite the first edge, and wherein the flat mounting flange and the port wall of the tubular gas supply chamber are connected together with the tubular member extending from the flange openings on either side of the flange. 20. The method of claim 19, wherein the flat mounting flange and the port wall of the tubular gas supply chamber are connected by a weld extending around the outer port wall surface of the port wall 21. A method for manufacturing a premix gas burner, the method comprising the step of: - fitting at least a portion of a port wall of the tubular gas supply chamber into the flange opening of a metal plate of a flat mounting flange, thereby causing at least a portion of an outer port wall surface of the tubular gas supply chamber to face at least a portion of an inner flange wall of the metal plate of the flat mounting flange, the tubular gas supply chamber being adapted to receive the premixed burner gas, the gas supply chamber having a gas inlet port, the tubular gas supply chamber comprising a port wall extending about the gas inlet port, the port wall having an inner port wall surface facing the gas inlet port and an outer port wall surface on a side opposite the inner port wall surface, a burner deck extending about at least a portion of the tubular gas supply chamber, the burner deck comprising a tubular metal burner deck plate, the tubular metal burner cover plate having a chamber-facing surface on one side and a flame-facing surface on the opposite side, and a plurality of gas orifices extending through the tubular metal burner cover plate from the chamber-facing surface, the gas orifices permitting premixed burner gas to flow from the gas supply chamber to a combustion zone adjacent the flame-facing surface of the tubular metal burner cover plate, the flat mounting flange extending in a flange face, the flat mounting flange comprising a metal plate, wherein the metal plate has a plate thickness and a flange opening, wherein the plate thickness of the metal plate extends in a direction perpendicular to the flange plane and the flange opening extends through the metal plate over the entire plate thickness of the metal plate, which flange opening is bounded by an inner flange wall, wherein the inner flange wall preferably has a wall height corresponding to the plate thickness of the metal plate.