ES3028371A1 - CHIMNEY DRAFT CLOSING DEVICE - Google Patents

Abstract

Device for closing the draft of a chimney. Device for closing the draft (12) of a chimney (1) comprising a support (2) configured to be fixed to the wall (11) of the chimney (1), a plurality of sets (3) of fan-shaped blades (4), where each set (3) of blades (4) is configured to rotate on at least one drive shaft (5), where the drive shaft (5) is coupled to a motor element (6) by means of a transmission element (7), such that the sets (3) of blades (4) are deployed rotationally in a synchronized manner from an initial retracted position to a final extended position for closing the draft (12) of the chimney (1), in order to find a device design that achieves effective closure of the passage of a fluid through the chimney draft with a very low pressure loss and with a low weight. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

CHIMNEY DRAFT CLOSING DEVICE

OBJECT OF THE INVENTION

The present patent application relates to a device for closing the draught of a chimney comprising a support configured to be fixed to the wall of the chimney, with a plurality of sets of fan-shaped deployable blades, where each set of blades is configured to rotate on at least one drive shaft, where the drive shaft is coupled to a motor element by means of a transmission element, such that the sets of blades are deployed in a rotational manner in a synchronized manner from an initial retracted position to a final extended position for closing the draught of the chimney, additionally incorporating notable innovations and advantages.

BACKGROUND OF THE INVENTION

It is a necessary design requirement to facilitate natural draft in the boiler-chimney assembly in domestic and industrial installations to achieve good combustion and flue gas evacuation. Industrial boilers are occasionally subject to frequent cycles of stopping and starting in short periods of time. Even when a "boiler bottling" operation is performed, this natural draft affects the convection banks, cooling them very rapidly and causing significant thermal stress on the boiler materials.

On the other hand, this natural draft represents a significant energy inefficiency, as both the metallurgy and the fluid stored inside the boilers must be reheated at each start-up. Another factor to consider is the loss of equipment availability, since minimizing thermal fatigue of the metallurgy during start-ups requires adhering to the heating curve established by the boiler manufacturer.

Additionally, when a boiler, whether industrial or domestic, is left cold for a period of time, an open chimney becomes a free passage from the outside through which various species of birds can enter, causing breakdowns or blockages, as well as suspended dust that can damage the burners.

To address these issues, large, heavy, metallic damper valves have been used, often restricting the flow of combustion gases. These valves generally utilize existing industrial designs, such as butterfly, guillotine, or gate configurations, adapting them to this specific function.

An illustrative document of what is known in the prior art would be CN218718897, relating to a conical shut-off valve at the top of a chimney. Said conical shut-off valve at the top of the chimney comprises a valve body. The inner side of the valve body is provided with a channel used for the penetration of a transmission chain. The end of the transmission chain is connected to a valve element via a pin. The inner side of the valve body is provided with an annular support plate that projects inward. The lower edge of the valve element has a ring-shaped structure. The section of the support plate is U-shaped, and the lower edge of the valve element is held in the support plate. According to the conical shut-off valve at the top of the chimney, the purpose of mechanically opening and closing the chimney is achieved through a mechanical transmission-type structure. The obstruction is achieved by the valve element moving up and down, thereby producing a sealing effect on the chimney.

Another document illustrating what is known in the state of the art would be GB190222242, which describes a four-way gas reversing valve provided with a plug, shutter or deflector, the faces being proportioned so that the gas is closed before the chimney outlet is opened.

Thus, and in view of all the above, there is still a need to design a chimney draught-stop device that effectively blocks the flow of fluids such as smoke, with a very low pressure drop and, if possible, with a low weight.

DESCRIPTION OF THE INVENTION

The present invention relates to a chimney draught-stop device, which is presented as a robust and versatile solution, as it can be implemented in most existing chimneys through easy assembly. Additionally, it is resistant to high gas temperatures with a low coefficient of expansion and presents no restrictions on the flow of combustion gases through the chimney.

More specifically, the chimney draught-closing device comprises a support configured to be fixed to the chimney wall, a plurality of fan-shaped deployable blade assemblies, each blade assembly configured to rotate about at least one drive shaft, the drive shaft being coupled to a drive element by means of a transmission element such that the blade assemblies rotate synchronously from an initial retracted position to a final extended position to close the chimney draught. This effectively closes the passage of a fluid, in this case combustion smoke, with very low pressure loss. Furthermore, since it has various removable and interchangeable parts, it is easily repairable on-site once installed.

Preferably, at least one blade of each set is connected to its respective drive shaft, each set of blades having a drive shaft, so that said blade can have a rotational movement about an independent rotation point, and different from that of other blades.

According to a preferred embodiment of the invention, at least a first blade comprises a protuberance, and at least a second blade adjacent to the first blade comprises a curved slot with an end of stroke, where the protuberance is configured to be inserted into the curved slot and pull the second blade upon reaching the end of stroke.

It is worth mentioning that the curved slot follows a circular path centered on its respective drive shaft, so that the rotation of the first blade and the adjacent second blade, with the protuberance inserted in the curved slot, occurs smoothly, in synchrony and without friction that leads to noise and premature fatigue of the materials and components that reduce their durability.

In more detail, the drive shaft is rotatably inserted into the support, so that it can rotate on it, in response to the rotation of the corresponding blades.

In a preferred embodiment of the invention, the device for closing the chimney draft comprises a plurality of drive shafts, where each set of blades is configured to rotate on its respective drive shaft, such that each can be deployed from its position in order to close the passage of smoke through the chimney draft.

Preferably, the chimney flue closing device comprises at least five sets of blades, for adequate coverage of the substantially circular surface of the chimney flue section.

Additionally, each assembly comprises at least three blades, for complete coverage of the substantially circular surface of the chimney flue section, minimizing the possibility of gaps and slots through which smoke can pass.

Optionally, the support is a circular crown, so that it adapts to the usual and general shape of the draft of existing chimneys.

Additionally, the support is configured to rest on a silencing element of the chimney, ensuring a solid fit, preventing vibrations and unwanted detachment.

According to another aspect of the invention, at least one blade is made of Teflon or polyester, thus providing high corrosion resistance while remaining very light. Additionally, these materials offer low thermal transmissibility and low expansion, even at high temperatures, which is suitable for dimensional stability that enables a good fit between the blades in the closed position.

In a preferred embodiment of the invention, the transmission element is a planetary gear system, enabling synchronized fan-shaped unfolding to achieve a precisely adjusted final position. Additionally, this transmission solution minimizes maintenance without compromising the robustness of the design.

Specifically, the planetary gear system solution enables a small advance of what would otherwise be the opening of the closing device, like a valve, resulting in synchronized and equal-percentage smoothness.

More specifically, the planetary gear system includes a plurality of ceramic needle bearings or gear wheels, which offer high compactness and minimized space, excellent performance under radial loads, and excellent performance in aggressive environments with low maintenance.

In a preferred embodiment of the invention, the transmission element comprises a first gearwheel coupled to the motor element, which meshes with a ring gear, which in turn meshes with a second gearwheel coupled to the drive shaft. In this way, the rotation of the motor element is transmitted precisely, without any jumps or rattles, to the blades.

More specifically, the ring gear comprises a first toothed surface on its outer radial surface, and a second toothed surface on its inner radial surface, such that the same piece collects the rotary impulse from the motor element and transfers it to the blades, maximizing the efficiency of motion transmission.

It should be noted that the first gear, coupled to the drive element, meshes with the first toothed surface, and/or the second gear, coupled to the drive shaft, meshes with the second toothed surface. In this way, each toothed surface acts as a gear, avoiding interference and allowing for a better physical arrangement of the components.

The accompanying drawings show, by way of non-limiting example, a chimney draught-closing device constructed in accordance with the invention. Other features and advantages of said chimney draught-closing device, object of the present invention, will become apparent from the description of a preferred, but not exclusive, embodiment, illustrated by way of non-limiting example in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 - Perspective view of the chimney flue, according to the present invention;

Figure 2 - Plan view of the device for closing the draft of a chimney, according to the present invention;

Figure 3A - Perspective view of the closing device in a first open position on the flue of a chimney, according to the present invention;

Figure 3B - Perspective view of the closing device in a second half-closed position on the flue of a chimney, according to the present invention;

Figure 3C - Perspective view of the closing device in a third closed position on the flue of a chimney, according to the present invention;

Figure 4 - Plan view of the chimney draught closing device and the transmitting element, according to the present invention;

Figure 5 - Plan view of a section of the support of the closing device, according to the present invention;

Figure 6 - Plan view of a blade of the closing device, according to the present invention;

DESCRIPTION OF A PREFERRED EMBODIMENT

In view of the aforementioned figures and, in accordance with the numbering adopted, one can observe in them a preferred embodiment of the invention, comprising the parts and elements indicated and described in detail below.

Figure 1 shows a perspective view of the flue (12) of a chimney (1), showing the inclusion of a silencer (13) inside its wall (11).

Figure 2 shows a plan view of the draft closing device (12) of a chimney (1), including a support (2), and on it is mounted a set (3) of blades (4), configured for rotation on a drive shaft (5).

Figure 3A shows a perspective view of the closing device in a first open position on the flue (12) of a chimney (1), with the blades (4) folded, in an initial rotation position of the drive shaft (5).

Figure 3B shows a perspective view of the closing device in a second half-closed position on the draft (12) of a chimney (1), with the blades (4) semi-deployed, in an intermediate rotation position of the drive shaft (5).

Figure 3C shows a perspective view of the closing device in a third closed position on the draft (12) of a chimney (1), with the blades (4) fully deployed, in a final rotation position of the drive shaft (5).

Figure 4 shows a plan view of the draught-closing device (12) of a chimney (1) and the transmitting element (7). It shows the support (2) and the blades (4) deployed as a result of the rotation of the drive shaft (5) driven by the motor element (6), through the transmitting element (7). Said transmitting element (7) integrates a first toothed wheel (71), a second toothed wheel (72) and a toothed crown (73) between both. The latter has an outer radial surface (73a) comprising a first toothed surface (73c), and an inner radial surface (73b) comprising a second toothed surface (73d).

Figure 5 shows a plan view of a section of the support (2) of the closing device, which includes a housing for the insertion with rotation capacity of the drive shaft (5).

Figure 6 shows a plan view of a blade (4) of the closing device, which includes at least one protuberance (41) and a slot (42) with a limit switch (42a). The position of the drive shaft (5) for the rotation of the blade (4) can also be seen.

More particularly, as seen in Figures 3A, 3B and 3C, the device for closing the draft (12) of a chimney (1) comprises a support (2) configured to be fixed to the wall (11) of the chimney (1), and comprises a plurality of sets (3) of fan-shaped blades (4), where each set (3) of blades (4) is configured to rotate on at least one drive shaft (5), where the drive shaft (5) is coupled to a motor element (6) by means of a transmission element (7), such that the sets (3) of blades (4) are deployed rotatably in a synchronized manner from an initial retracted position, to a final extended position for closing the draft (12) of the chimney (1).

It should be noted that the driving element (6) is preferably an electric motor, although alternatives for a hydraulic or pneumatic drive could be used. Optionally, the mechanism may include a reduction element, the connection being actuated by a relay signal. Speed and torque can be regulated by means of a frequency converter. Alternatively, a digital pneumatic drive can be included, regulating speed and torque through a manual reduction control.

On the other hand, as seen in figures 2 and 3B, at least one blade (4) of each set (3) is connected to its respective drive shaft (5).

According to a preferred embodiment of the invention, as seen in Figure 6, at least a first blade (4) comprises a protuberance (41), and at least a second blade (4), adjacent to the first blade (4), comprises a curved slot (42) with an end of stroke (42a), where the protuberance (41) is configured to be inserted into the curved slot (42) and pull the second blade (4) when reaching the end of stroke (42a).

It is worth mentioning that, as seen in figure 6, the curved slot (42) follows a circular path centered on its respective drive shaft (5).

Additionally, as seen in figures 2 and 3B, the drive shaft (5) is rotatably inserted into the support (2), which preferably includes a plurality of through holes for this purpose.

Preferably, as seen in figures 2 and 3B, the device for closing the draft (12) of a chimney (1) comprises a plurality of drive shafts (5), where each set (3) of blades (4) is configured to rotate on its respective drive shaft (5).

In a preferred embodiment of the invention, as seen in Figures 2 and 4, the device for closing the draft (12) of a chimney (1) comprises at least five sets (3) of blades (4).

Additionally, as seen in figures 2 and 4, each set (3) comprises at least three blades (4).

It is worth mentioning that, as can be seen in figures 2 and 5, the support (2) is a circular crown, composed of removable sectors, which are assembled together by means of dovetail insertion. Said support (2) can be supported on brackets that are fixed to the walls (11) of the chimney (1) around its entire circumference by means of mechanical joining and/or welding points.

On the other hand, as can be seen in figures 1 and 3A, the support (2) is configured to rest on a silencing element (13) of the chimney (1).

According to another aspect of the invention, as seen in Figures 2 and 3C, at least one blade (4) is made of Teflon or polyester material.

On the other hand, as seen in figure 4, the transmission element (7) is a planetary gear system.

And more specifically, as can be seen in figure 4, the transmission element (7) comprises a first toothed wheel (71), coupled to the motor element (6), which meshes with a toothed crown (73), which in turn meshes with a second toothed wheel (72) coupled to the drive shaft (5).

Additionally, as can be seen in Figure 4, the toothed crown (73) comprises a first toothed surface (73c) on its outer radial surface (73a), and a second toothed surface (73d) on its inner radial surface (73b), which is usually referred to as a rack with teeth on the inside and outside.

In more detail, as can be seen in Figure 4, the first toothed wheel (71), coupled to the motor element (6), meshes with the first toothed surface (73c), and/or the second toothed wheel (72) coupled to the drive shaft (5) meshes with the second toothed surface (73d).

The details, shapes, dimensions and other accessory elements, as well as the components used in the implementation of the device for closing the chimney draught, may be conveniently replaced by others that are technically equivalent, and do not deviate from the essence of the invention or from the scope defined by the claims included after the list of numerical references below.

List numerical references:

1 fireplace

11 wall

12 shot

13 silencer

2 support

3 set

4 blades

41 protuberance

42 slot

42nd end of degree

5th drive axle

6 motor element

7 transmitting element

71 first gear

72 second gear

73 gear ring

73rd outer radial surface

73b inner radial surface

73c first toothed surface

73d second toothed surface

Claims (1)

1- Device for closing the draft (12) of a chimney (1) comprising a support (2) configured to be fixed to the wall (11) of the chimney (1), characterized in that it comprises a plurality of sets (3) of fan-shaped blades (4), where each set (3) of blades (4) is configured to rotate on at least one drive shaft (5), where the drive shaft (5) is coupled to a motor element (6) by means of a transmission element (7), such that the sets (3) of blades (4) are deployed rotatably in a synchronized manner from an initial retracted position to a final extended position for closing the draft (12) of the chimney (1). 2- Device for closing the draft (12) of a chimney (1), according to claim 1, characterized in that at least one blade (4) of each assembly (3) is connected to its respective drive shaft (5). 3- Device for closing the draft (12) of a chimney (1), according to any of the preceding claims, characterized in that at least a first blade (4) comprises a protuberance (41), and at least a second blade (4), adjacent to the first blade (4), comprises a curved slot (42) with an end of stroke (42a), where the protuberance (41) is configured to be inserted into the curved slot (42) and pull the second blade (4) when reaching the end of stroke (42a). 4- Device for closing the draft (12) of a chimney (1), according to claim 3, characterized in that the curved slot (42) follows a circular path with its center on its respective drive axis (5). 5- Device for closing the draft (12) of a chimney (1), according to any of the preceding claims, characterized in that the drive shaft (5) is rotatably inserted into the support (2). 6- Device for closing the draft (12) of a chimney (1), according to any of the preceding claims, characterized in that it comprises a plurality of drive shafts (5), where each set (3) of blades (4) is configured to rotate on its respective drive shaft (5). 7- Device for closing the draft (12) of a chimney (1), according to any of the preceding claims, characterized in that it comprises at least five sets (3) of blades (4). 8- Device for closing the draft (12) of a chimney (1), according to claim 7, characterized in that each assembly (3) comprises at least three blades (4). 9- Device for closing the draft (12) of a chimney (1), according to any of the preceding claims, characterized in that the support (2) is a circular crown. 10- Device for closing the draft (12) of a chimney (1), according to any of the preceding claims, characterized in that the support (2) is configured to rest on a silencing element (13) of the chimney (1). 11- Device for closing the draft (12) of a chimney (1), according to any of the preceding claims, characterized in that at least one blade (4) is made of Teflon or polyester material. 12- Device for closing the draft (12) of a chimney (1), according to any of the preceding claims, characterized in that the transmission element (7) is a planetary gear system. 13- Device for closing the draft (12) of a chimney (1), according to claim 12, characterized in that the transmission element (7) comprises a first toothed wheel (71), coupled to the motor element (6), which meshes with a toothed crown (73), which in turn meshes with a second toothed wheel (72) coupled to the drive shaft (5). 14- Device for closing the draft (12) of a chimney (1), according to claim 13, characterized in that the toothed crown (73) comprises a first toothed surface (73c) on its outer radial surface (73a), and a second toothed surface (73d) on its inner radial surface (73b). 15- Device for closing the draft (12) of a chimney (1), according to claim 14, characterized in that the first toothed wheel (71), coupled to the motor element (6), meshes with the first toothed surface (73c), and/or the second toothed wheel (72) coupled to the drive shaft (5) meshes with the second toothed surface (73d).