US2152411A - Gas producer - Google Patents

Description

March 28, 1939. H. ISENDAHL GAS PRODUCER Filed Aug. 22, 1938 JNBNT lunlF Patented Mar. 28, 1939 UNITED STATES PATENT ()F FI'CE Application August 22, 1938, Serial No. 226,205 In Germany January 15,1937

4 Claims.

This invention relates to a gas producer for vehicles, and has for its object to increase the throughput of a producer and, simultaneously, the heating value of the gas formed.

An increase in throughput involves also an increase in the supply of steam that has to be superheated and decomposed as much as possible in the producer, which is quite diflicult. Furthermore, if the steam is produced in a jacket surrounding the body of the producer according to a known method, it is necessary to adapt the amount of steam produced to requirements and thereby to prevent the production of excesssteam which must either be passed off to the outside or condensed.

The invention attains its object and. overcomes the difficulties mentioned in the following manner:

Beginning at the level of the grate, i. e., approximately at the part where the hottest zone is located, the lower portion of the producer is insulated, for instance by a brick lining, against the loss of heat by radiation. Above this lower portion, in a zone of lower temperatures, the water jacket or that portion thereof which holds the water required for evaporation is positioned, and on top of this portion a superheating space is provided in which the steam and air mixture to be supplied to the producer is superheated.

The combination according to the invention produces the following technical advance:

The quantity of steam produced is always adapted to the prevailing demand. The steam produced is highly superheated together with the air and introduced in this condition into the producer wherein simultaneously a high temperature is maintained so that the heating power of the gas is increased on account of the higher hydrogen content. The throughput may be much higher than usual without retarding the steam pro duction and the superheating of the steam and air mixture.

The superheating space is preferably so dimensioned that its height is considerable compared with its basal surface, whereby a large surface is provided for the passage of heat from the producer to the superheating space. This heat transfer is always greater than that between the surface of the water and the superposed steam and air mixture. Extensive superheating is therefore possible only by causing'the heat from the producer to pass to the steam and air mixture through the iron wall and not byway of the water. It is advisable, moreover, to fix the level of the water in the water space so as to be enabled to vary the extent of steam production by altering the level and thereby influencing the hydrogen content of the gas. The heating value of the producer gas can thus be adjusted by controlling the water level in the water space.

The insulation of the lower portion of the shaft by brickwork may have a detrimental effect in certain circumstances, for instance when the temperatures are too high. It may happen that the brickwork will not be able to withstand these high temperatures or that incrustations form when fuels are used that produce deleterious ashes. According to the invention, this can be avoided by inserting in the zone of gasification of the shaft an inwardly conical or funnel-like cylinder which reduces the cross section of the shaft indownward direction and forms a hollow space with the cylindrical shaft. The lower edge of this funnel-like member terminates above the zone of the highest temperatures, and the fuel slopes from this lower edge towards the cylindrical Wall of the producer.

Owing to its elevated position the funnel is not exposed to the great stresses due to the temperatures prevailing in the zone of incandescence. The funnel is, furthermore, made from cast iron on which slag does not settle as .it does on stoneware. In this way, a space free from ashes and fuel is formed between the inner wall of the shalt, the funnel and the ashes sloping below whereby the iron inner wall of the shaft is pro tected against high temperatures, though it still receives enough heat to insure sufficient superheating of the steam and air mixture in the su perheating chamber. funnel member .or slag ring slopes away from the wall of the producer, a certain amount of heat will accumulate within the space formed between said ring and said wall, which heat will act to carry over, when the load increases, until the operation of the producer can be stepped up.

The insertable funnel-like sleeve is preferably so formed as to be exchangeable and insertable in different producers. If the producer shaft has a rectangular cross section that of the funnel is ellipse-shaped to round off the corners of the rectangle.

The invention is illustrated by way of example in the accompanying drawing, in which Figure 1 shows an embodiment the lower part of'which' is provided with brickwork and Fig. 2 is a view of a producer according to the invention in whose lower body portion a cast-iron funnel is inserted.

The producer 4 is constructed in the form of a i shaft furnace of rectangular cross section, though other cross-sectional forms are possible also of course. The gasifying shaft 2 is shut off below by a flat grate comprising the three bars '3 which are movable to permit variation of the cross sections of passage and also shaking of the fuel bed. The portion of the producer I disposed above the bars 3 has a brickwork lining 4 adapted in height to the position of the zone of incandescence. At the outside of the wall of the shaft Due to the fact that the.

a water jacket 5 is provided so as to be flush with the top edge of the brickwork 4 and extends upwardly approximately somewhat above the gas outlet 6. The water level in the jacket 5 is kept constant at 8 by a float 1 which regulates the amount of water flowing in from the receptacle 9. The steam space I above the water level 8 is supplied with air through a duct 1 I. At the upper end of the water jacket a funnel-shaped wall I5 is inserted in the producer I to provide at the circumference an annular space I! which is free from fuel and in which the gas formed may collect, so that the steam and air mixture in the space I0 is chiefly superheated by the sensible heat of the gas accumulating on this level. Below the jacket 5 another annular chamber I2 is provided on a level with the brickwork 4, which receives the steam and air mixture, superheated in the space 10, through the channel 13 for continued superheating if the brickwork 4 emits sufficient heat in outward direction. Should the brickwork 4 have too low a temperature, the annular space l2 may be dispensed with and the steam and air mixture superheated in the space It guided directly under the grate 3 and thus into the fuel bed. The grate 3 is so dimensioned that the sum of the free cross sections of passage is small relative to the cross section of the shaft '2. In the construction shown the cross section of passage of the grate totals for instance 125 cm. while the cross section of the shaft amounts to 770 cm.

In case of operation by suction the gas is drawn off in known manner and the fresh air drawn in as described. For heating up a blower E4 is preferably provided by means of which the heating air is forced into the producer. The heating up gas which is not yet suited for motor operation is discharged through a piping i5 branching off from the gas pipe and leading to the outside. The piping I5 is provided with suitable shut-off members. The producer gas that is up to standard is then passed in usual manner through a cleaning device into the mixer and finally into the engine.

In constructing the gas producer according to the invention adaptation of steam production to load variations is insured also. During a decrease in load the zone of incandescence in the shaft 2 becomes smaller and steam production is reduced while simultaneously the rate of flow of the steam and air mixture in the space H? is diminished and greater superheating of the mixture becomes possible. In other words, the reduced steam production at decreasing load is compensated for by increased overheating of the mixture so that the composition of the gas or its heat value remains practically constant at a change in output. V

The lower water level the jacket 5 affords the advantage thatgas up to standard is produced within a very short time owing to the rapid evaporation of the water.

In the construction shown in Fig. 2 the conical shell i8 is inserted on the level of the heating space 12 of the shaft, and between the shell I8 and the inner Wall of the space 2 a hollow space is is formed. Ihe conical shell or funnel i8 is made of cast iron, and its lower edge is located at such a level that it lies outside the zone of incandescence provided just above the grate and cannot be reached by the high temperatures.

From the lower edge of the funnel E8 the fuel and the ashes slope outwardly up to the inner wall of the producer. In the course of time, a layer of ashes is formed in this region, which prevents the passage of the gasification agent and serves also as heat accumulator. Furthermore, the inner wall of the air heating space. I9 is thus protected against the deposit of slag.

I claim:

1. A gas producer of the updraft type comprising a body member, a grate in said body member, a brick work wall within the lower portion of said body member above said grate to prevent the loss of heat, a reservoir arranged about said body member and above said insulated portion, whereby to provide steam generation, a super-heating chamber arranged above and in communication with said reservoir, and means for supplying air to said super-heating chamber to form an air and steam mixture, said super-heating chamber having a greater heat transfer area than said reservan.

2. A gas producer of the updraft type comprising a body member, a grate in said body member, heat insulating means surrounding the lower portion of said body member above said grate, a conical cast iron annulus extending inwardly from the body member whereby to form a free air space therebetween, said annulus being positioned so that the lower edge thereof lies above the hottest zone within said body member, a reservoir arranged about said body member and above said insulated portion whereby to provide steam generation, a super-heating chamber arranged above and in communication with said reservoir, and means for supplying air to said super-heating chamber to form an air and steam mixture, said super-heating chamber having a greater heat transfer area than said reservoir. I

3. A gas producer of the updraft type comprising a body member, a grate in said body member, heat insulating means surrounding the body member above said grate, a removably located conical cast iron annulus extending inwardly from the body member whereby to form a free air space therebetween, a reservoir arranged about said body member and above said insulated portion whereby to provide steam generation, a super-heating chamber arranged above and in communication with said reservoir, and means for supplying air to said super-heating chamber to form an air and steam mixture, said superheating chamber having a greater heat transfer area than said reservoir.

4. A gas producer of the updraft type comprising a body member, a grate in said body member,

heat insulating means surrounding said body r member above said grate, a removably located cast iron member which is arranged to taper in-' wardly from said body member whereby to form a free air space therebetween, said tapered member being shaped so as to permit insertion within producers having body members which differ in cross section, said tapered member being positioned so that the lower edge thereof lies above the hottest Zone within said body member, a reservoir arranged about said body member and above said insulated portion, whereby to provide steam generation, a super-heating chamber arranged above and in communication with said reservoir, and means for supplying air to said super-heating chamber to form an air and steam mixture, said super-heating chamber having a greater heat transfer area than said reservoir.

HERBERT ISENDAHL.

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