US2459344A - Gas producer - Google Patents

Description

`Ian. 18, 1949. F, sEPULcHRE 2,459,344

l GAS PRODUCER Filed March 17, 1945 2 Sheets-Sheet l zNveN'roR. Femm sew/M6 by HW/tmwc Jan. 18, 1949. F. sEPULcl-:RE

GAS PRODUCER Filed March 17, 1945 2 Sheets-Sheet 2 PULLHRB Mm. A110'.

Patented Jan. 18, 1949 GAS PRODUCER Fernand Sepulchre, Paris, France Application March 17, 1945, Serial No. 583,340 In France January 28, 1943 2 Claims.

My invention has for its object improvements in gas-producers comprising a single vat, chiefly with a view to ensuring the maximum possible dissociation of the steam and the total gasication through cracking of all the volatile, liquid or gaseous products carried by the gas producer gases, and obtained through distillation of the fuel, injection into the furnace of similar products or through any other cause.

It is known that in most gas producers of known type, comprising a single vat, the elimination of the tar and of the like objectionable products carried along by the gases in the case of certain fuels, leads to the greatest diculties.

In fact the unvarying distance separating the outlet of the air injecting means from the inlet into the gas collecting means is always comparatively important in such apparatuses; for this reason the collecting means is for certain rates in a cooler zone in which the tar and like objectionable volatile products may be distilled for instance, instead of being destroyed so that they are to be found again in the gases which is Very detrimental to the purifying and utilization apparatuses.

In order to remove the drawbacks, it has already been proposed to provide gas producers with a gas-collecting pipe adjacent to the nozzle, arranged for instance concentrically with reference to the latter, whereby the air blown in through said nozzle returns back to enter the collecting means after following a path the length of which depends on the rate of combustion. Such an arrangement leads in practice to the same result as if, in the usual arrangement of independent nozzle and collecting means, the relative position of the nozzle with reference to the collecting means were modified in accordance with the rate of combustion in order to maintain constantly at the entrance into said collecting means an invariable and sufficiently high temperature preventing any distillation at this point, while allowing a regular gasification of the fuel.'

However in the known devices of this type, the entrance of the gas collecting pipe is arranged behind the nose or opening of the injection nozzle. Consequently the gases generated in the combustion chamber in front of the nozzle opening return to the rear thereof into a less hot zone or reduction zone. In this less hot zone the temperature of which is always underneath o()o C., the gases and the products from the upper strata of the gas-producer where the fuel is being distilled before it is burnt, are not entirely dissociated,

certain of said products such as methane CHl being decomposed entirely only above 1400 C.

To prevent any of these distillation products from being carried away in too large amounts with the gas producer gas which would lead to a diminution in the eiciency of the operation, it

is indispensable for the inlet into the collecting pipe to be exactly located in the hottest zone (1600 to 1800 C.) of the fire boX, i. e. at the very level at which the injection pipe opens.

Through this arrangement, all the gases, whether distillation or gas producer gases, are compulsorily removed from inside the furnace zone itself where the temperature is the highest, whereby all the gaseous products admixed with the gas producer gas and carried along with it through the gas outlet, are dissociated or crackedl and eliminated thereby from the gas collected which is thus produced in a very pure state.

It is this arrangement which forms the chief feature of my invention. As a counterpart, this arrangement has the drawback of providing a very compact furnace which is therefore liable to be considerably fouled by the waste .of the combustion formed and deposited in front of the collecting pipe and nozzle arrangement especially if the fuel used has high ash-contents. To re move the serious disturbances in the working which are the consequence of the presence of slag and ashes preventing the extensionof the furnace in front of the collecting pipe, there is provided in certain cases underneath the main furnace a secondary furnace the chief object of which is to constrain the slags formed by the .ashcontaining fuel to move downwards. It is then possible to feed the pipe and nozzle arrangement with constantly fresh fuel and to ensure thus the constancy of the gasification and thereby of the dissociation and cracking phenomena which forms the object of my invention.

This association of the collecting pipe and nozzle arrangement with the complementary furnace forms a secondary feature of my invention. This association differs from the similar known systems inasmuch as the gases produced by this second combustion are alsoremoved through the collecting pipe and nozzle arrangement which forms the only gas outlet located in the hottest part of the gas-producer where the complete dissociation and cracking of the products formed by n the'heat-decomposition of the fuel or other in` jected material is performed.

I have illustrated in accompanying drawing several diagrammatical examples of execution of my invention in order to make said invention appear more clearly.

Figs. 1 and 2 recall to mind several known types of nozzles and gas collecting pipes.

Fig. 3 illustrates the principle of my invention.

Figs. 4 to 11 show a number of forms of execuftion of a nozzle and collecting pipe arrangement in accordance with my invention.

Fig. l2 illustrates a gas producer provided with a double furnace in accordance with my invention.

Fig. 13 shows lastly an example of application to a gas producer of a plurality of nozzle and collecting pipe arrangements in accordance with my invention.

It is apparent from Fig. l that in a gas producer l of known type, the gases flow inside the latter through a minimum unvarying path h corresponding to the distance between the outlet of the nozzle 4 and the inlet into the gas-collecting 5 to remain for certain rates of operation in a less warm part whereby the gases have a tendency to 'become cooler in the vicinity of said pipes. The temperature is then too low to ensure gasification of the volatile material admixed with the gas producer gas and reducing the elciency of the operation, while the temperature remains yet suilicientv to ensure its distillation. On the other hand, this volatile'material is always accompanied more or less according to the fuel used by tarry or acid material of which the detrimental action in the utilization apparatuses is well known.

In the device, also well known, shown in Fig. `2, it has already been proposed, as is the case of my invention, to use a collecting pipe 5 in one with the nozzle d; for instance, it may surround same in a manner such that the gases return towards their starting point after they have followed a loop-shaped path which is automatically variable inaccordance with the rate of combustion whereby the collecting pipe is held whatever the rate of combustion may be, at a substantially constant temperature. But, in the device illustrated, the collecting pipe is arranged to the rear of the end of the nozzle and ata distance h thereof which places it as in the case of Fig. 1, inside a zone which is at a lower temperature estimated at say 300 C. and this leads also, but here for all rates of running to a distillation of the 'volatile material in the f uel and its carrying away with the gas-producer gases.

In the arrangement of the nozzle and collectingpipe as proposed by my invention (Fig. 3), the injector element l and the collector element 5 are on the contrary located at the same point of the gas-producer whereby the distance 71, separating the end of the air nozzle and the inlet into the collecting pipe is reduced practically to zero. The two elements are preferably arranged coaxially, in this case, the injector element 4 may be placed inside the collector element 5 or reversely without the principle of my invention beingmodied thereby. As in the known device of Fig. 2, the gas returns towards its starting point in a manner such that the length of the penetration loop h', h", h" along which the gases progress inside the fuel varies automatically in accordance with the ow of injected air. It may thus be very small or even equal to zero for small loads, therefore whatever the path h', h, or h" followed by the gases may be, the relative position of the nozzle with reference to the collecting pipe, in accordance with the invention, has for its result in contradistinction with the known devices, to place the gas outlet 4 directly in the hottest zone of the furnace, estimated at between say 1600 and 1800 C.

The unavoidable passage through this high temperature zone of all the combustible products, whether solid, liquid or gaseous carried into the collecting pipe, whether said products are introduced into or generated insidethe gas producer, ensures in all cases their complete transformation, through dissociation or cracking, into a very pure gas which is thus produced with a very high eiiiciency. This absence of any more or less objectionable volatile matter adapted to condense inside the gas at its outlet from the generating gas producer solves in an elegant manner what-V ever the vegetal or mineral fuel used may be, the difficult problem of the necessary purification, which allows the use of one and same purifier whatever may be the fuel used either raw or carbonized.

It is thus apparent that my invention allows the tota-l gasification of Vthe fuel under the best conditions inside an apparatus adapted to burn really any fuel whatever, in particular in the nozzle and collecting pipev form a unitary part.

It comprises an injection duct Il surrounded by a casing 5 integral therewith and adapted to receive the gases, a collecting space 6 provided between said two elements being in open communication with the exhaust pipe 7. A grateshaped part 9 affords means for separating th fuel from the collected gas. i

Figs. 5, 6 and '7 are end views corresponding to Fig. 4 and show different forms of execution. In Figs. l and 5 the two pipes considered are circular and concentric. In the modication. shown in Fig. 6, the nozzle is flattened and the annular space 6 between the pipes comprises two separate compartments arranged respectively above and below the duct 4or nozzle ll. In the modication shown in Fig. 7, the injection duct is starshaped while the gas outlet means are formed by four elements inserted between the'arms of 'th element 4.

As explained hereinabove, these relative positions of the nozzle and collecting pipe may be reversed without modifying the'principle of the invention. n v

In the case of Figs. 8 to 10, the nozzle element is independent of the gas collecting element. The gas-collecting element (or reversely the nozzle d) is constituted by one or more elements which are clearly distinct from the nozzle 4 (or reversely the gas-collecting element 5).

These Figures 5, `6 and '7 also show that the number of elements forming the collecting pipe or the nozzle, asthe case may be, may be reduced to few, in number, arranged preferably concentrically with reference to the nozzle-or to the co1- lecting pipe. As a limit, I may use by way of simplication a single element of any desired shape capable of receiving among the diiferent possible positions round the nozzle or the pipe'aJ position which experience alone may determine as the most favourable for the obtention of the cracking and dissociation phenomena which form the object of the invention.

Fig. 11 shows a system which proceeds from the above described forms of execution wherein the ducts fiand 5 forming the nozzle and the gas-collecting means are no longer parallel, but form with one another, an angle which may be as large as 90.

It has been disclosed hereinabove that the combination of a nozzle with a gas-collecting tube in accordance with my invention has for its object the total gasication of all the combustible material, whether solid, liquid or volatile which is introduced into the gas-producers. Now this system shows a serious drawback due to the fact that the furnace thus formed is, everything else remaining unchanged, more compact and consequently more liable than another, to be fouled, in particular a lump of solidified slag may prevent the general development of the gasification, which would have as a consequence to hinder the operation of the apparatus and thereby to disturb the proper progress of the dissociation and cracking phenomena.

-In order to remove this drawback in accordance with my invention, there have been provided the following modifications.

On one hand the waste products of the combustion should not pass through nor remain in the gas-collecting tube or near said tube. It is therefore necessary to keep the nozzle and gas collecting tube removed at a distance from the bottom of the generator i where the ashes and slag accumulate.

On the other hand, it is necessary to remove constantly from the collectingr pipe and nozzle arrangement, the slag which forms next to it. To this end, said arrangement as described hereinabove is associated with the known method consisting in the creation inside the generator i, underneath the main furnace M operating at high temperature, of a se-condary furnace N of reduced activity operating at low temperature. Or reversely, there is associated a collecting tube and nozzle arrangement with the grate of a gas producer of known type which it is desired to transform in accordance with my invention.

The second furnace is executed in the case of Fig. l2, by using two pivoting shaking gratos 8 and ii adapted to rock respectively by means of control levers not shown round aXes l5 and I5.

The air or the like combustion providing fluid admitted into the ash-box l0 through the duct I I under control of an adjusting valve l2 is diffused underneath the grates where it finishes the gasification of the fuel mixed with slag and ashes remaining in the zone N. This combustion provides for the slow sinking towards the grates 8 and 8 of the slag remaining in the zone M and consequently it allows an easier and more regular feed of the main furnace, with fresh fuel; generating gas of an excellent grade.

The grates 3 and 3 are periodically shaken or rocked in alternating directions so as to remove the ashes from the secondary furnace N and to drive the slag and waste products which have fallen on to said grates into the ash-box i, said slag and waste products are then exhausted through the blow-off door E3. The grates 8 and 8 may of course be replaced by any known device, controlled automatically or not, capable of eliminating the waste products from the combustion without stopping,r the progress of the gasification.

This application of the double furnace gas pro- Kil ducer is novel inasmuch as the gas formed in the secondary furnace N and the quality of which is poor by reason of the poor composition of the fuel highly loaded with ashes contained therein, is constrained before reaching the gas-collecting pipe, to pass through the main furnace M operating at high temperature where it is entirely reduced. The injection under the grates of a mixture of air or the like combustive fluid with a predetermined amount of steam or exhaust gases, dissociated or reduced under the above dened conditions, allows moreover if desired an advantageous adjustment of the rate of gasification in the lower ,furnace N at the speed which is the most suitable for producing the` regular sinking of the slag formed in the zone M.

This injection corresponds moreover to the purpose of the invention which has for its object the total gasification of the fuel inasmuch as the gas formed in the lower furnace N is for the same reason as that disclosed hereinabove, perfectly purified through dissociation and cracke ing inside ythe upper furnace M of all substances which are foreign to the gas producer gas. These substances may be produced through the distillation accompanied by decomposition by heat of the solid fuel rich in volatile matter forming the load of the generator, or of the valueless liquid fuel introduced purposely inside the apparatus.

This admission into the secondary furnace N of the combustive fluid admixed or not with steam or gas may be reduced and eventually done away with through a suitable adjustment of the valve I2 which depends on the rate of gasication. It is thus possible to prevent this admission from becoming predominant for low gas outputs where by it is possible to keep the principal furnace M active as much as possible. When the producer is stopped, on the contrary, the valve i2 is advantageously held open so as to produce through the pipe il and the nozzle 4 the flap valve hl controlling which is held open, a draught allowing the incandescence of the two furnaces to be maintained whereby the gas producer may be easily started again without any reignition.

Conversely, the abovedes-cribed combination may also be of use with the lower furnace acting as a principal furnace while the upper furnace M operating at high temperature has for its sole object the purification of the totality of the gas through dissociation and cracking. This novel association differs from the similar processes which have also for their object the cracking of tar. In fact, the gas collecting pipe according to the invention, which forms the auxiliary cracking furnace instead of being located inside the zone where the fuel admixed with ashes and with slag has already become poorer through its passage inside the principal furnace (which leads to a deterioration of the gas formed part of which burns of necessity in contact with this second injection of combustive uid) is located in the zone fed directly with fresh fuel, capable therefore of being oXidised through the totality of the combustive fluid injected in both furnaces in order to produce a gas as pure as possible.

In addition to these two extreme cases, it is possible to consider an entire range of intermediary operations depending on relative adjustment of the admission of combustive fuel on one hand into the nozzle and on the other into the pipe Il. In the case of half the admission into the upper furnace M and of half the admission into the lower furnace N, the generator operates 50% at high temperature and 50% at low temperature, which allows the combination in one and same apparatus of the two forms of gasication while avoiding their drawbacks.

The double gasifying process described allows in fact the continuous and complete gasication of the totality of the solid, liquid and volatile fuel, enclosed in the generator under the conditions which are the most suitable for obtaining a pure gas having a high caloriiic power. The device for total gasification which forms the object of my invention avoids thus not only all depositing of distillation tar and of the like objectionable products formed in the known gasication systems at low temperature for solid fuel, but also the losses through unburnt fractions which are inherent to the known methods of gasification at high temperature for the same fuel Whichfmoreover require generally the periodical emptying of the furnace.

Lastly it should be remarked that the different forms of execution of the invention which have been described hereinabove may include for a given generator a plurality of nozzle and collecting pipe arrangements disposed for instance radially in a common inclined or horizontal plane. Thus the radial arrangement shown in Fig. 13 (in which for greater clearness only two operating nozzles have been shown) allows the injection of combustion fluid to be concentrated for the entire cross-section of the gas producer, whereby it is possible to reach gasification temperatures which are much higher than With a single nozzle and colecting pipe arrangement. This forms an improvement in my above disclosed invention, on one hand because it furthers the phenomena of dissociation and cracking of the solid fuel, however moist or rich in volatile material it may be, the utilization of which would be otherwise difficult and on the other hand because it allows an easier melting and flowing towards the bottom of the generator l, out of which lit is easily removed,` of the slag formed by the combustion of the fuel with the highest contents of ashes.

' What I claim is: K

l.. In combustion with an air gas producer, the provision of a furnace, a nozzle adapted to inject combustive material continuously into said furnace and a gas-collecting pipe mounted coaxially with said nozzle and adapted to remove the gases formed out of said nozzle, the openings of said nozzle and gas-collecting tube lying substantially in the same plane perpendicular to the axis of the nozzle.

` 2. In combination with an' air gas producer, the provision of 'a furnace, a nozzle adapted to inject combustive material continuously into said furnace and a gas collecting pipe perpendicular to and opening in close proximity with said nozzle and adapted to remove the gases formed out of said nozzle, the openings of said nozzle and gascollecting tube lying substantially in the same plane perpendicular to the axis of the nozzle FERNAND SEPULCHRE.

4REFERENCEs CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name v Date 2, 376,149 Kalle May 15, 1945 FREIGN'PA'I'ENTS Number Country Date 166,867 Germany Jan. 13, 1906 OTHER REFERENCES Haslam et al.: Fuels and Their Combustion, Dp. 336-337, 543-544.

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