MEANS IN FURNACE INSTALLATIONS

Abstract: Means in furnace installations for the discharge of combustion residues from a fire grate (1). By means of the invention it is made possible that the combustion residues fed out from the grate (1) will be substantially completely burnt. The means comprises a discharging means (4) exhibiting at least one air supply duct (12) designed to supply air to the residues of burnt materials, which arrive in contact with the discharging means (4).

Description: Means in furnace installations The present invention relates to a means in furnace installations for the discharge of combustion resi¬ dues from a fire grate. It is a principal object of the invention to provide a means, which makes possible that the combustion residues, which are fed out from the grate, will be sub¬ stantially completely burnt. This object is obtained by a means according • to the present invention, which is substantially characte¬ 10 rized by a discharging means exhibiting at least one air supply duct designed to supply air to the residues of burnt materials, which arrive in contact with the discharging means. The invention is described in the following, - * - * - 1 reference being made to the accompanying drawing, in which Fig. 1 illustrates a means in the form of an oscillating conveyor designed according to the invention. A furnace grate, which in the drawing is indicated with the reference digit 1, and which can be of 20 any suitable design, in the illustrated example exhibits slit-shaped air flow ducts 2. Fuel, comprising solid mate¬ rial such as for example wood chips, sawdust, peat and coal cinder, is displaced along said furnace grate 1 according to its combustion, and the air supply for the combustion 5 takes place through said slit-shaped air flow ducts 2 from the underside of said grate 1. The forward feed of the fuel can by way of example be made by means of rakes, not shown in the drawing, or in any other suitable manner. This trans¬ portation of fuel is intended to take place at a speed chose 0 to the effect that the fuel shall be substantially completel burnt, when it arrives at the edge 3 of the grate 1. However this condition is not always fulfilled, as combustible mate¬ rial can remain, when passing said edge 3. This combustible material and of course also already completely burnt cinders arrive at a discharging conveyor 4, which in the illust¬ rated example comprises an. oscillating conveyor 4, but can of course comprise any kind of suitable conveyors. By way of example a worm conveyor can be used. The oscillation conveyor 4 illustrated in the drawing is formed by a grate plate 4 extending along the leading edge 3 of the furnace grate 1 in the direction of feed of the fuel, said grate plate 4 on its top side exhibiting air flow openings 5 similar to the air flow openings 2 arranged at the furnace grate 1. The plate 4 is at one end pivoted on a substantially horizontal pivot¬ ing shaft 6. The other end of the plate 4 is supported by an arm 7 of an articulation mechanism, which at its other end is pivoted on a pivot 8 projecting sidewise from the plate 4. The arm 7 is at its other end pivoted on a pivot 11 in eccentric arrangement projecting from a disc 10 rotat- ably driven by a driving motor 9. Said off-center arrange¬ ment produces an oscillating movement of the plate 4 round the pivoting shaft 6, when the motor 9 is started, and ma- terial fed forwards to the plate 4 will be fed out in the longitudinal direction of the plate in the direction of dis¬ charge indicated with an arrow in the drawing on account of the vibratory movement of the plate 4. Inside the plate 4 substantially along its whole length at least one air supply duct 12 is provided, which is closed at one end, and from which smaller cross¬ wise extending ducts 13 communicate with said air flow open¬ ings 5 located on the top side of the plate. The air supply duct 12 is at its open rear end via a flexible connecting pipe 14 connected with an air supply means 15, which by way of example can comprise a fan 15. The function of the means described above is the one that air from the fan 15 via the connecting pipe 14 is conducted to the air supply duct 12, from where it flows through the crosswise extending ducts 13 and out through the air flow openings 5 to the material deposited on the plate 4. This air supply makes possible that a combustion of non-burnt material can .take place while this material is fed forward in the longitudinal direction of the plate, and the thermal efficiency of the furnace is thereby in- creased, as substantially .all the fuel is -completely burnt thanks to the present means. As mentioned above, the discharging con¬ veyor can be designed in a great many ways. If this con¬ veyor comprises a worm, an air supply duct can preferably be arranged at its centric shaft in such a manner that combustion of the fuel is also made possible during the discharge of the fuel by means of the worm. The invention is not limited to the example of embodiment illustrated in the drawing and described above, but can be varied within the scope of the following claims. OMPI

Claims: C l a i m s 1. Means in furnace installations for the dis¬ charge of combustion residues from a fire grate (1) , c h a r a c t e r i z e d, b y a discharging means (4) exhibiting at least one air supply duct (12) designed to supply air to the residues of burnt materials, which arrive in contact with the discharging means (4) . 2. Means according to claim 1, c h a r a c t e ¬ r i z e d b y the discharging means (4) comprising an oscillating conveyor (4) , at one end of which said duct (12) is connected to an air supply means (15) . 3. Means according to claim 2, c h a r a c t e ¬ r i z e d b the oscillating conveyor (4) being formed by a grate plate (4) , which at one end is pivoted on a pivot shaft (6) . 4,. Means according to claim 3, c h a r a c t e ¬ r i z e d b the grate plate (4) at its other end being supported by a means (7-11) producing oscillations, whereby an oscillation of the plate (4) preferably can take place between an upper position, where the plate substantially is in the same plane as the fire grate (1) , and a lowered down position. 5. Means according to claim 4, c h a r a c t e ¬ r i z e d b said means (7-11) comprising a pivoting arm (7) connected with the grate plate (4) and rotatably driven by a motor (9) . 6. Means according to anyone of the claims 3-5, c h a r a c t e r i z e d b y the grate plate (4) at least on its top side exhibiting air flow openings (5) , which are in communication with said air supply duct (12) . 7. Means according to claim 6, c h a r a c t e ¬ r i z e d b the air supply duct (12) occupying a positio inside the grate plate (4) extending in the longitudinal direction of the same and via transversal ducts (13) being in communication with said openings (5) . 8. Means according to claim 1, c h a r a c t e r i z e d b y the discharging means comprising a worm con veyor, at the central axis of which said air supply duct is preferably located. OMPI Λ . r»I -PrOc_ι

Inventors: JOHANSSON S
Applicants: JOHANSSON S
Application year: 1981
Main classification: F23J1
IPC codes: F23H1, F23H13, F23J1