EP0011586B1 - Method and apparatus for heating using liquid fuel, the apparatus being also usable for burning solid fuel - Google Patents

Abstract

1. Apparatus for heating using liquid fuel such as oil or liquefied fatty material, the apparatus being also usable for burning a solid fuel, comprising a body or casin (1) comprising a central cavity constituting the combustion chamber (2) of the said apparatus and an inlet (12) for liquid fuel suitable for coupling to a feeding means and opening into the upper part of the said cavity, characterized in that a plurality of superposed grids (8, 8a, 8b, 8c, 8d, 8e) is installed in the lower part of the said combustion chamber (2), below the said inlet (12) for liqud fuel, in such a manner that the combustion of said fuel takes place on the same assembly of grids (8, 8a, 8b, 8c, 8d, 8e).

Description

The present invention relates to an apparatus and method for liquid heating the apparatus which can also burn solid fuel.

There is already known a stove arranged to operate either by means of a liquid fuel, or with a solid fuel (US Patent No. 1,485,668). For this, this stove comprises, on the one hand, in a conventional manner, a grate on which the solid fuel can burn and, on the other hand, a Bunsen burner arranged at its upper part. When it is desired to produce sufficient heat using exclusively liquid fuel, the grid must be filled with refractory materials which must then be removed when one wants to burn a solid fuel. On the other hand, the Bunsen burner can only function satisfactorily with liquid fuels rich in hydrocarbons, while its operation can be disturbed as a result of fouling resulting from the combustion of solid fuels which must also be products relatively rich in hydrocarbons.

The invention proposes to remedy the drawbacks and inadequacies of known heating devices capable of burning both liquid and solid fuels.

The heating appliance according to the present invention is notably remarkable in that it comprises a body or envelope comprising a central cavity constituting the hearth of said appliance and an inlet for liquid fuel capable of being connected to a supply installation and opening into the upper part of said cavity; a plurality of superimposed grates being installed in the lower part of said hearth, below said liquid fuel inlet.

The method of heating by the combustion of a liquid fuel according to the invention is remarkable in that said fuel is burned on a set of superimposed grids on which it is made to flow, preferably by gravity.

The heat generator according to the invention offers the advantage of operating as well by the combustion of various solid fuels such as coal, coke, wood, sawdust, household waste, etc., as by the combustion of liquid fuels such as 'oils or liquefied fatty substances of various origin, without the need to make any modification of said heat generator to switch from one combustion mode to another.

Another advantage of this heating appliance is that it can be supplied both with traditional solid or liquid fuels, rich in hydrocarbons, prepared and sold for heating, as with household or industrial waste, or oils. used lubrication such as drain oil; said heating device can then fulfill the function of a domestic or industrial incinerator.

• La figure 1 est une vue en coupe verticale et à caractère schématique d'une installation de chauffage comportant une chaudière réalisée selon l'invention.
• La figure 2 est une vue en plan de l'ensemble de grilles, avec arrachement partiel des grilles superposées.
• La figure 3 est une vue en plan analogue à la figure 2, illustrant un autre mode d'exécution de l'ensemble de grilles.
• La figure 4 est une vue en coupe verticale et à caractère schématique d'une variante d'exécution de l'appareil de chauffage revendiqué.

These aims, characteristics and advantages, and others still, will emerge more clearly from the description which follows and from the appended drawings in which:

• Figure 1 is a vertical sectional view in schematic of a heating installation comprising a boiler produced according to the invention.
• Figure 2 is a plan view of the set of grids, with partial cutaway of the superimposed grids.
• Figure 3 is a plan view similar to Figure 2, illustrating another embodiment of the set of grids.
• Figure 4 is a schematic vertical sectional view of an alternative embodiment of the claimed heater.

Reference is made to said drawings to describe advantageous examples, although in no way limitative, of embodiment of the heating apparatus according to the invention.

The latter comprises a body or casing 1 having a circular or other section and executed in sheet steel, cast iron or any suitable refractory material.

This envelope delimits the hearth 2 of the heating device which can be a stove emitting heat by radiation, or, as shown in the drawings, a central heating boiler. In the latter case, at least one exchanger 3 is installed at the top of the fireplace.

As illustrated in FIG. 1, this exchanger can advantageously be constituted by a helical coil arranged against the internal surface of the upper part of the side wall of the envelope 1. This coil has an inlet 4 and an outlet 5 accessible from the outside of the casing 1, for its connection to the flow and return pipes, respectively, of the distribution network of a central heating installation.

According to FIG. 4, the boiler has two superimposed exchangers 3'-3 ". The upper exchanger 3 'is, for example, assigned to the production of hot water intended for domestic uses, while the lower exchanger 3" is connected to the distribution network of a central heating installation.

In a conventional manner, an orifice 6 communicating with a pipe 7 for connection to a smoke duct, is formed at the upper part of the side wall of the body 1.

In the lower part of body 1, are mounted superimposed and so spaced, grids 8-8a-8b-8c-8d-8e, which can be formed by perforated plates (Figures 1 and 2) or by spaced bars (Figure 3).

The openings of these grids have decreasing dimensions from top to bottom.

Thus, as shown in FIG. 2, the upper grid 8 is provided with the largest perforations, while the dimensions of the perforations of the underlying grids decrease progressively, up to the lower grid 8e which has the smallest perforations. Similarly, when the superimposed grids are made up of spaced apart bars, as illustrated in FIG. 3, the spacing between the bars forming each of said grids decreases, from the upper grid 8 whose bars are most widely spaced, to the grid lower 8th whose bars are the least. In addition, the grids consisting of bars are arranged so that the bars of which each is made up, have a different orientation with respect to the bars forming the other grids. A space 9 is reserved in the lower part of the body 1, below the set of superimposed grids, for the reception of the ashes. In said lower part, the device comprises, in a manner known per se, one or more air intake orifices (not shown).

The upper part of the body 1 has an opening closed by a cover 10 comprising an axial orifice 11 traversed by the vertical portion of a tube 12, the lower end of which opens into the hearth 2 above the set of grids, and whose upper end is arranged to be able to be connected to a flexible pipe 13 connected to supply means.

This piping is, for example, connected, by its opposite end, to the base of a supply tank 14. The outlet orifice 15 of this tank is disposed above the level where the orifice is placed. inlet of the tubing 12, so that the liquid fuel contained in said tank can flow by gravity, until the outlet of said tubing.

A shutter such as a tap 16 is preferably installed on the pipe 12 or on the piping 13, to allow the flow of fuel, its interruption or the adjustment of the flow rate. A flexible or rigid pipe 17, on which an electric pump 18 is mounted, opens at the upper part of the reservoir 14, the lower end of this piping plunging into a storage tank 19.

The filling of the supply tank 14 is automatically controlled by a float 20 housed in said tank and acting on a contactor 21 controlling the starting or stopping of the pump 18. It is understood that the drop in the level of the liquid fuel contained in the supply tank causes the float to descend, which, when the predetermined low level is reached, acts, by means of the lever 22 of which it is integral, on the contactor 21 which controls the starting of the pump 18.

Similarly, when the desired filling level is reached, said float acts on the switch 21 which stops the pump.

The supply tank 14 can be fixed in an elevated position, in any convenient manner. As illustrated in FIG. 1, said tank is, for example, integral with two uprights 23 (only one of which is shown) intended to be housed by sliding, each in a sleeve 24 and in an underlying socket 25 integral with the periphery of the body of the heater, said uprights supported, by their lower end, in the bottom of said sockets.

It is understood that the heating device which has just been described is capable of operating as well by the combustion of a solid fuel as by the combustion of a liquid fuel.

In the first case, solid fuel such as coal, wood, sawdust, household or industrial waste, etc., is introduced into the hearth 2 through the upper opening of the body 1, after lifting or removing the cover 10 holding loading buffer location.

When it is desired to use a liquid fuel, such as oil or other liquefied fatty substance, the supply installation is put into operation. The liquid fuel flows through the intake manifold 12 and falls successively on the grids 8-8a-8b-8c-8d-8e which are coated or impregnated with said fuel. It then suffices to present a flame below the grates, for example by means of an ignited paper, to initiate combustion which then continues nominally, the supply installation ensuring the constant flow of oil over the grids.

The claimed heating appliance can also simultaneously burn a solid fuel, for example consisting of household, industrial, hospital waste, etc., and a liquid fuel, said appliance thus being able to fulfill the function of an incinerator.

The invention also relates to the process for producing heat by the combustion of oils or liquefied fatty substances, comprising burning an oil or a liquefied fatty substance, which is made to flow, preferably by gravity, over a set of superimposed grids.

According to the embodiment illustrated in Figure 4, the grids 8-8a-8b-8c-8d-8e, ... are carried by a cylinder 26 resting on a support plate 27 in the form of a crown or portion crown. This support plate is rigidly secured to the top of a cylinder 28 comprising a lateral opening 29 corresponding to the access opening to the space 9 formed in the body 1 and fitted with a sliding door 30, the interior volume of said cylinder corresponding to said space 9 reserved for receiving the ashes. The cylinder 28 has a bottom 31 disposed at a distance from the bottom 1a from the body 1. The bottom (31) is, for example, integral with feet 32 resting on the bottom 1a and making it possible to provide a recovery tank 33 between said bottoms 31 and 1a.

The lower edge of the opening 29 is disposed at a certain distance from the bottom 31, so that the lower part of the cylinder 28-31 constitutes a tray. This tank automatically pours into the recovery tank 33 by means of an elbow-shaped pipe 34 connected to an outlet orifice 35 formed in the side wall of the cylinder 28, at a level situated between the lower edge of the opening 29 and the bottom 31, a short distance from the latter.

The recovery tank 33 is provided, in its lower part, with a drainage orifice fitted with a plug 36. On the other hand, ventilation orifices 37 are provided at the upper part of the side wall of the reservoir recovery.

This arrangement of the lower part of the heating appliance makes it possible to recover the liquid fuel, in the event that the fire goes out and the admission of said fuel continues.

Claims (11)

1. Apparatus for heating using liquid fuel such as oil or liquefied fatty material, the apparatus being also usable for burning a solid fuel, comprising a body or casing (1) comprising a central cavity constituting the combustion chamber (2) of the said apparatus, and an inlet (12) for liquid fuel suitable for coupling to a feeding means and opening into the upper part of the said cavity, characterised in that a plurality of superposed grids (8, 8a, 8b, 8c, 8d, 8e) is installed in the lower part of the said combustion chamber (2), below the said inlet (12) for liquid fuel, in such a manner that the combustion of said fuel takes place on the same assembly of grids (8, 8a, 8b, 8c, 8d, 8e).

2. Apparatus for heating, according to claim 1, characterised in that the liquid fuel inlet is constituted by a simple tube (12).

3. Apparatus for heating, according to one of claims 1 and 2, characterised in that the openings of the superposed grids (8,...8e) have decreasing dimensions from the upper grid (8) to the lower grid (8e).

4. Apparatus for heating, according to claim 3, characterised in that the grids (8,...8e) are constituted by perforated plates, the perforations of the said plates having dimensions decreasing from the upper grid (8) to the lower grid (8e).

5. Apparatus for heating, according to claim 3, characterised in that the grids (8,...8e) are constituted by spaced bars, the spacing between the bars constituting each of the said grids decreasing from the upper grid (8) to the lower grid (8e).

6. Apparatus for heating, according to one of claims 1 or 5, in which the grids (8,...8e) are constituted by spaced bars, characterised in that the bars of which each of the said grids (8,...8e) is composed have a different orientation with respect to the bars constituting the other grids.

7. Apparatus for heating, according to claim 2, comprising a feeding means, characterised in that this latter is arranged to introduce the liquid fuel into the combustion chamber by gravity.

8. Apparatus for heating, according to claim 7, characterised in that the said feeding means comprises: a reservoir (14) the outlet opening (15) of which, connected to the inlet tube (12) by a flexible pipe (13), is placed at a level higher than that at which the entry opening of the said tube is placed; a storage tank (19) coupled to the upper part of the said reservoir by a pipe (17) on which is mounted a pump (18); means (20-21-22) for controlling the starting up of the said pump when the liquid fuel content in the reservoir reaches a predetermined low level and the stopping of it when the desired level of filling is reached.

9. Apparatus for heating, according to any one of claims 1, 2, 7 and 8, characterised in that it comprises, in its lower part, means (33) for the recuperation of liquid fuel.

10. Method for heating using liquid fuel such as oil or liquefied fatty material, characterised in that the said fuel is burned on an assembly of superposed grids (8,..., 8e) onto which it is caused to run, preferably by gravity.

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