GB2056638A - Husk burner - Google Patents

Abstract

A grain husk burner comprises a shaft (1) having an upper supply opening (10) and a lower discharge opening (11). The shaft (1) is partitioned by means of a shelf (4) which restricts the passageway for grain husks (M) between the supply and discharge openings such that the husks (M) flow downwardly from said shelf (4) to form below the shelf (4) a heap having an exposed surface. The exposed surface of said heap bounds, together with the shelf (4) and the walls of the tank (1), a combustion chamber (a). The combustion chamber (a) has an inlet (5) for combustion air, the combustion air being exhausted from the chamber (a) via a secondary combustion chamber (7) and an exhaust outlet (60) continuing an extractor fan (6). <IMAGE>

Description

SPECIFICATION Husk burner This invention relates to an improvement of burner for the dry distillation or carbonization of grain husks and for the combustion of evaporation gas thereof.

An object of this invention is to provede a grain husk burner which comprises: a husk tank having at its upper part a supply opening and at its lower part a discharge opening for husks; shelf means provided in the tank slantedly with an angle of downward inclination larger than an angle of repose of husks, the lower free edge of said shelf means being to have the husks which are flowing down from said edge heap underneath the shelf means with a surface of the angle of repose of husks; a carbonation and combustion chamberwhich is free from the husk being formed by the lower surface of shelf means, the surface of husks heaped underneath the shelf means and inner walls of the tank; an air inlet opening communicating with the exterior of the tank and opening to the combustion chamber above the surface of husks heaped underneath the shelf means; and a blower with a suction opening which communicates with the combustion chamber through a passage.

Other objects shall be clarified in course of the following description of this invention.

A preferred embodiment of the husk burner made in accordance with this invention is explained hereinunder more in a concrete way, with reference to the accompanying drawing.

In the drawing; Figure lisa vertical cross sectional view of the husk burner made in accordance with this invention, Figure 2 is a perspective view of disassembled parts of passage means of a secondary combustion chamber, Figure 3 is a vertical cross sectional view of shutter means in its parts, Figure 4 is a disassembled perspective view of damper means of an outer tube provided to the secondary combustion chamber, Figure 5 is a front view of the husk burner with its parts broken, and Figure 6 is a plan view of the burner.

In Figures 1 and 2, a husk tank lisa square column having at its upper part a supply opening which communicates with a hopper 2 and having at its lower part a exhaust opening 11 which is provided with shutter means 3. The part of the column 1 which is under said exhaust opening 11, constitutes a storage 13 for cinders which has at its rear side, viz., at the right side in Figure 1, ain outlet opening 12.

And, within said tank and from its upper part to its middle part, there is provided a shelf 4 which projects suspendedly towards a rear side wall 15 from aforward sidewall l4ofthetankwith an angle of inclination which is largerthan an angle of repose of husks M. The rear and lower free edge 40 of said inclined shelf 4 is apart from the rear side wall with a predetermined distance /. With these constructions, when grain husks M is supplied into the column 1, they flow down from the lower edge 40 of inclined shelf 4 to the part under said shelf, forming a heap with a slant corresponding to the aforementioned angle of repose. Thus, a space a which is free from the flow or heap of husks, is formed between the lower surface of the inclined shelf 4 and the flowing slant m of the husks with the angle of repose.This space a is shut out from the outside spaces by means of the inclined shelf 4, the slant of husks m which extends between the forward side wall 14 and the lower edge 40, said forward side wall 14, and side walls 16, 17, and it forms a combustion chamber in which husks Mare burnt along their slant of repose m.

Numeral 5 indicates an air supply inlet for supplying combustion air into the aforementioned carbonation, dry distillation and combustion space or chamber a. Said air supply inlet 5 is provided to a rear end of a cylinder 50 which extends transversely through the forward wall 14so as to make the air supply inlet open in the space a. As described in the latter part of this specification, air in the combustion space a is sucked by a blower 6 through a tubular passage 7, viz., secondary combustion chamber, into a suction outlet 60, whereby air surrounding the cylinder 50 is sucked from an outside opening 51 of said cylinder so as to enter into the combustion space a through the air supply inlet 5.The said outside opening 51 is provided with a control valve 52, and a cylinder 53 which is provided with said control valve 52 and fitted to the cylinder 50, is removable from it so as to allow a firer to be inserted into the combustion space a through the cylinder 50, when the space is firstly ignited.

The aforementioned shutter means 3'which lies over the exhaust opening 11, is consisted of a pair of gridirons 30, 30, one of which is stationarily fitted to a lever 31 so as to be slideable over the other into a position where they overlap each other to completely close the exhaust opening or into another position where they make gaps therebetween to have cinders discharged therethrough. As illustrated in Figure 3, each gridirons has pores 32, through which air is also sucked into the combustion space a through the husk layer from the exhaust opening 11, when the blower 6 is operated and suction pressure works in the combustion space a as described in the above.

The aforementioned tubular passage 7 which constitutes a secondary combustion space or chamber, is formed within a tubular body 70 which is transversely fitted to the husk tank 1 at its forward wall 14, and at a location where its rear end faces to an upper part of the combustion space a. The tubular body 70 which constitutes the tubular passage 7 is illustrated in detail in Figure 2. This tubular body is consisted of a plurality of partitions 72 with throughpipes 71 and a plurality of tubes 73 of a short length which are sandwiched by the partions, so that the partitions 71 and the tubes 73 are aligned cooxially, but the through-pipes 71 are not in alignment, forming the zigzag passage 7.The through-pipes 73 of the rear-most partition open to the combustion space a, while to the forward-most partition, there is provided a funnel form tube 74 which reduces its diameter gradually towards its free end 75. This free end of a reduced diameter constitutes an ejection opening of combustion gas.

Numeral 8 indicutes an outer cylinder which provides a wind passage b around the tubes 70,74 which constitute the aforementioned secondary combustion chamber or passage 7. This wind passage b does communicate with the suction outlet 60 of blower 6, but it is independent from the combustion space a. Its rear end communicates with an outer jacket 80 which embraces the husk tank at its part where the combustion chamber a is located and which has an air inlets 81, as best shown in Figure 6.

Its forward end is insertedly fitted to the casing 61 of the blower 6. When the blower6 operates, the air which is sucked from the air inlets 81, cools down the outer surfaces of the tubes 70, while it dilutes combustion gas which comes out from the top tube 75 and increases the amount of gas so that air heated to a preditermined temperature can be exhausted from the outlet opening 62. The air which is taken from the air inlets81 and heated by the jacket 80 may be introduced of its part to the passage 7 as a secondary air, through bores or opening 76 provided to the tubes 70.

Numeral 9 indicates a control valve for adjusting a temperature of heated air which is obtainable from the opening 62. This valve 9 changes the degree of opening of said top opening 62 in reponseto a heat sensor 90 which is provided to the opening 62 of blower 6. The sensor 90 could be any of convention alone including a thermostat which utilizes expansion of liquid or gas by heat. A piston 90a is actuated by the sensor, whereby an arm 9a of the control valve 9 is operated so as to close the valve completely or partly in accordance with the elevation of temperature.

Temperature of heated air which is taken out from the opening 62 can be also controlled by the following means. A rotatable ring plate 92 with window holes and a corresponding stationary ring plate 94 with window holes 93 are provided in the passage b. The overlapping relation between the window holes 91 and 94 can be changed by the manual operation of a lever 96 which is fitted to the rotatable ring plate 92 and projects of its free end outwardly from the jacket 8, so that air to be taken from outside through air inlet 81 can be controlled to a desired amount.

Operation, functions and effects ofthe husk burner of this invention are as follows.

When husks M start to burn along the surface m of their heap with the angle of repose which constitutes a lower bottom surface of the combustion space a and exposes to said space, lower layers of husks are gradually taken out from the exhaust opening 11 with the operation of the lever 31 which moves reciprocately and intermittently by a driving means such as an electric motor, not shown. This invites the lowering ofthe burning upperslantm of husk, and also invites the supply of new husks M onto said slant. Thus, the husk is continuously carbonated along the slant m and gasified, and burnt in the combustion space a. This combustion in the combustion space depends upon an amount of air to be supplied to said space by the blower 6 through the air supply inlet 5.And, since said amount of air or the flow of air which is sucked by the blower 6 through the tubular passage 7, is adjustable by means of the control valve 52 of the air supply inlet 5, the temperature within the combustion chamber a can readily be kept constant, viz., about 900 c so that husks can be stably gasified, being carbonized, and be burnt in the combustion chamber.

The combustion gas thus primarily burnt in the combustion chamber is blown into the tubular passage 7 by the suction of blower 6, whereby it is further and completely burnt in the passage 7 under a constant blow resistance and under a constant high temperature, since said passage forms zigzag air ways and communicates with the suction opening 60 of blower 6.

The wind passage b which is formed by the outer cylinder 8 surrounding the aforementioned passage 7 and which communicates with the jacket 80 surrounding the combustion chamber a, can cool down the tank 1 at its outer wall and can prevent the over-heat of the tank on account of atmospheric air which is sucked from the openings 81, past through said jacket 80, and jointed to the burnt blow of gas at the passage 7 or outside said passage.

Temperature of burnt gas and air heated thereby which are taken out from the outlet opening 62 of the blower 6 is kept substantially constant on account of the fact that since the sensor 90 which is actuated by a temperature at the outlet 62 of blower 6, operates the control valve 9 of the outlet opening 75 of passage 7 to automatically adjust an opening degree of said outlet opening 75, an exhaust amount and combustion conditions are simultaneously and automatically controlled.

Claims (8)

1. A grain husk burnerwhich comprises: a husk tank having at its upper part a supply opening and at its lower part a discharge opening for husks; shelf means provided in the tank slantedly with an angle of downward inclination largerthan an angle of repose of husks, the lower free edge of said shelf means being to have the husks which are flowing down from said edge heap underneath the shelf means with a surface of the angle of repose of husks; a carbonation and combustion chamber which is free from the husk being formed by the lower surface of shelf means, the surface of husks heaped underneath the shelf means and inner walls of the tank; an air inlet opening communicating with the exterior of the tank and opening to the combustion chamber above the surface of husks heaped underneath the shelf means; and a blower with a suction opening which communicates with the combustion chamber through a passage.

2. A grain husk burner as claimed in claim 1, which the passage is tubular and zigzag, forming a secondary combustion chamber, and is surrounded with an outer tube which communicates at its one of ends with the suction opening of blower through damper means therebetween and at another end communicates directly with the exterior of the tank and not through the carbonation and combustion chamber.

3. A grain husk burner as claimed in claim 1, in which the outer tube communicates at said another end with the exterior of the tank through a jacket surrounding the tank and having air inlet openings.

4. A grain husk burner as claimed in Claim 1, in which the passage has at its outlet opening valve means which controls a degree of said opening in response to temperature sensing means provided to the suction opening of blower.

5. A grain husk burner as claimed in Claim 1, in which the shelf means heats the husks stored above it, preliminary to the carbonation and combustion thereof in the combustion chamber.

6. A grain husk burner as claimed in claim 2, in which the outer tube communicates selectively with the passage.

7. A grain husk burner substantially as described herein with reference to the accompanying drawings.

8. The features as herein described, or their equivalents, in any novel selection.