Dec- 5, 1933- ' s. c. G. EKELUND 1,938,139 METHOD OF PRODUCING COMBUSTIBLE GAS Filed Sept. 15, 192.7

Jnventor.

Llgnesses:' Patented Dec. 5, 1933 1,938,139

UNITED sures, PATENT,‘ OFFICE 1,938,139 . METHOD OF. PRODUCING COMBUSTIBLE GAS Sven Carl Gunnar Ekelund, Stockholm, Sweden _ ‘Application September 15, 1927, . Serial No, 219,778, and in Sweden June 27, 1927 4 Claims. (Cl. 48—203)

My invention relates to a new method ‘of throughthey are the‘allowed hot zoneto leave of the’the producer,same. For before the producing gas in gas-producers as well as cer tain improvements in gas-producers-required for gasifying medium oxygen from the air may be a‘ successful utilization of the method. . This used. The way, in which the ‘principle is to be 5 case is continuation in part of my prior applica practised, .is preferably the following. ,, ,e tion No. 141,830 ?led October 15, 1925 new A certain portion of the hot gas, coming 7 from the partial combustion. zone of the pro Patent No. 1,758,786. 3 > The invention has for its principal objects, ducer and gcing upwards, is caused to pass by ?rst, to produce a reducing gas, which is com thev main gas outlet and is withdrawn through a preheating chamber, in which the fuel is ?rst 65 7 10 posed of merely a few single components, such as carbon monoxide, hydrogen and nitrogen; charged. The ' hot gas will here deliver its‘ 7 ~_ second, to produce such a gas also from an un sensible heat to the fuel, preheating it and coked fuel; third, to produce a gas with such causing it to give oif its volatile matters. a high temperature, that is may be used for These are thus mixed with the producer gas 15 certain metallurgical purposes without being and thegas-mixture is. then made to enter into 70 previously preheated; fourth, to provide a gas the‘ hot fuel zone of the producer. Therein H producing system, capableof delivering a gas the’gas will be decomposed ,intocarbon monoxide ‘an’d'hydrogen, which gasestogether with nitro with these qualities. I ' . . As- an ingress some circumstances connected gen constitute the major part of the gas obtained l'rcm the producer directly 'fromthe producer 75 20 with the producing of gas in an ordinary way are ?rst to be mentioned. If an uncol'zed fuel, gas outlet, and the sulphur ofvthe distillation as coal or ‘peat, or a partially cokedi one, is gases will be combined with the slag as well as gasi?ed, so are all or the‘ greatest part of the the sulphur of the coke. In this way the gas volatile matters of the fuel to be found in the is to a certain extent made to circulate in the 80 25 producer gas without being decomposed. The producer. ' > . ' volatiles consist 'of steam, carbon‘ dioxide, As mentioned previously and later on, the pur hydrocarbons and sulphuretted hydrogen. When pose of the invention cannot be obtained, with using the producer gas for such a purpose as out adopting the gas'circulation principle to a reduction of ores the enumerated constituents slagging gas producer; The reasons for’ this .fact are not difficult to understand. In a gas 85 30 are detrimental for the process, ?rst, because the reducing power of the gas is lowered; sec producer .not working with fusion of- the ash ,, ond, because of a very undesirable deposition or slag the rate of gasification is, much lower of solid carbon, caused by the hydrocarbons,” and'therefore the temperature everywhere in ,that may badly clog the furnace; and third, the producer will be relatively low. The quantity of‘ “surplus heat” in the partial combustion zone 90 35 because the sulphur in the gas will be absorbed by the reduced metal- ‘and spoil its good is also small, and the process will be imperative ‘ . when a considerable amount of cold circulation qualities. ‘ ' ‘ " ' A decomposition of the volatiles and absorp gas is still lowering the temperature. This of tion of the sulphur already-in the producer ‘course especially when the gas is allowed to contain steam in excess. The steam will then 95 V4O'must therefore be realized to ?ll the conditions interfere with the process in suchv a way, that given above. 7 » As it has been stated, that‘slagging gas pro the carbon monoxide partly is transformed to ducers, i.e. producers of the type, in which the carbon dioxide, whereby, consequently, the calo ric value of the gas will be lowered and the gas ash contents of the fuel is caused to melt and is 10o 45 removed in a liquid'form, are able to produce cannot be used for reduction of ores. A balance of heat made up for a gas producing - ‘ a gas suitablefor reduction purposes, in a more rational manner than in ordinary‘ producers process withgas circulation adapted to the sys while the principle of gasifying the fuel, by tem will show, that by using the gas circulation meltingthe ash simultaneously is utilized also ' principle it is, undercertain conditions and es pecially in a slagging gas producer, possible to 105 50 in'my method. However, in combination with this’ principle there is another that must be obtain a very‘ hot gas and this without overheat- - employed,~if it shall be possible to solve the ing the partial combustion zone of the’ same. The reason forthis remarkable fact is, that by problem wholly. ~ ~ " - The principle referred to is briefly, that the the‘ circulation the heat is spread-upwards in 55 ‘volatiles must be caused to enter and pass the producer; the upper layers of fuel are get- 110 2 1,938,139‘ ting warmer and the lower colder than is the An advantage of the slagging gas producer is‘, case, when no circulation is employed. This that the coal may be charged in a fairly small makes it possible to use preheated. air or air with size, 1/4” as a minimum. In the circulating gas an addition of oxygen, whereby the temperature main pipe a dust‘ collector is probably necessary in the partial combustion zone is again raised to let the gas pass before it is entering the blow 80 to its normal value, but the temperature of the er. If using ejector blowers the dust may not upper zones of the producer at the main gas be so troublesome. The dust may be briquetted outlet and of the gas withdrawn is raised fur and so charged once again or itlmay be recom thermore. The calculation will show‘ that when bined with the gas on the high pressure side or" 10 gasifying rather good coals by means of air pre the blower or immediately put in the gas or air 85 heated to 400° C. it is possible to obtain the gas stream in the tuyeres. with a temperature of 1000° C. This means, as The hearth of the producer is to be provided is already stated, that the gas directly from pro with a refractory lining preferably of magne ducer can be used for important metallurgical site bricks, bauxite bricks or carbon bricks or 15 purposes as reduction of ores and also for melt other materials capable of resisting a liquid 90 ing metals, as f. i. iron in the openhearth process, slag of basic character. The slag being basic without employing regenerators. it will readily absorb the sulphur from the coke The gas obtained from the gas producer may and the circulation gas. If, however, the ?n have the following composition of approximately ished producer gas still contains a small portion 20 30% CO, 10% E2 and 60% N2. The composition of the sulphur, this can be removed by passing 95 may, however, vary and particularly the ratio the gas. through a layer of lime, which atthe of hydrogen to carbon monoxide. high temperature of the gas absorbs the sulphur Also when gasifyingcoke or charcoal a gas forming calcium sulphide. In order'tofuse an circulation is preferably to be used, particularly acid ash of the fuel basic additions, such as lime, _~ 25 when the fuel is moist. It will then be dried limestone or slag, are charged on the producer. ioo and preheated when coming down under the Granulated blast furnace slag may be used. main gas outlets of the producer. Certain ad~ Slag. and limestone will hardly form any-dust, vantages can be reached by introducing steam which is an advantage. The limestone prevents into the fuel bed of the producer, coke oven gas, the coal from sticking in the distillation zone, other similar gases containing hydrogen, as nat and therefore no more stoking is wanted in the 105 ural gas, blast furnace gas, ?ue gas from ‘an case of gasii'ying coal than for gasifying coke. electrical blast furnace, or raw oil, all these If coal with a great caking ability is used "it additions preferably together with hot air and may be suitable to mix the coal, with, some coke, introduced into the hot zone of the producer. peat or the like. If using an iron-containing. 35 The simplest arrangement of the distillation slag or if, charging iron ores in the ‘producer, 110 zone is to let it occupy a chamber placed di~ pig iron is obtained as a byproduct in addition rectly over the gas generating chamber and to the slag. The latter may also be of a certain over the level in which the inner openings of the value as. a raw material for making cement, if main gas outlets are openingtowards that cham it is holding proper amounts of silicic acid, lime,“ 40 ber. The shaft diameter may be the same or aluminium oxide etc. The usefulness of the slag smaller above the gas generating chamber than ‘for this-purpose may be improved by adding also» under the ‘same. a material containing titanic acid to the'charge. The circulation gas is preferably being drawn The accompanying drawing illustrates a pro through a pipe by means of an exhauster, en ducer as proposed for theprocess. Fig. ,l, is an 45 closed rotary blowers or ejectors. In order to elevation of the producer seen from the outside. I20 diminish as far as possible the quantity of pro On Fig. 1 hot air is supplied to the annular ducer gas used for the preheating this amount tube 1 and is introduced into the fuel bed of the of'gas may be withdrawn from thehot zone of producer through the tuyere openings 2.‘ The the producer and in a special pipe by its own recirculated-gas is passing into the, annular tube , 50 ‘pressure passed over to the distillation zone. v3 and is,,.as shown in the drawing, introduced 125 Usually such a method will, however, mean a partly through the tuyere openings 4 and partly complication of the process. The circulation through the pipes 5, connected to the air tuyeres. gas can be introduced at any suitable height The gas can also wholly be passed one ‘way above the bottom of the producer: above, below ‘ either at 4 or at 5. Burning the gas with the.__v 55 ' or in the combustion zone of theproducer. When air is possible only, when entering ‘the air 130 introduced in the same level as the air,, the gas tuyere openings or slightly above. The gas ris is advantageously burnt whollyor partly with ing upwards in the producer divides near__the the air, because of the fact that the temperature conduits 7, through which the major portion of combustion is then getting lower than when of ‘the gas is withdrawn to the annular pipe 8. 60 the incandescent coke is directlyburned by the and the outlet 9, and a certain amount flows air. Burning the circulation gas immediately further upwards through the preheating and ' decomposes the volatiles, and the oxidized prod coal distillation chamber 10, driving off, the ucts are thereafter reduced by carbon. The moisture and some of thevolatiles, and the gas tuyeres are preferably to be made as burners, ,mixture is relatively cold when leaving the, 65 letting them also act as ejectors, so that the air chamber through the piping 11, passing thence AG ' is drawing the gas with it, the gas in this way to the dust collector 12 and eventually some sweeping around the central pipe keeping it sufli other well known cleaning means and condensor, ciently cold. The amount of circulation gas is not shown in the drawing, and is assembling the then to be moderated either by altering the blower 13, from which it ispassed through a velocity of air in the pipe openings or by means conduit entering the annular pipe 3 into the 145 of valves in the gas piping. The number of fuel bed of the producer. In the incandescent tuyéres depends on the size of producer. Tar fuel bed the distillation products are decomposed may be extracted from the circulation gas by into single gases. ,The ?xedproducer. gas is condensing. When treatinghighly bituminous drawn off through the outlets 7,, 8, and 9; The ' 75 coal this is of economic importance. gas outlet ?ues 7 are given an inclined position, 150 1,938,139 3 to prevent coarse dust from following the gas. preheating and distillation zone and ‘preheating At the top 14 means should be provided for and coking the fuel therein, withdrawing the continuously feeding fuel such as coal or coke, mixed producer gas and distillation vapors and and ?uxes such as chalk and slag into the cham gases, then mixing and burning the vapors and ber. This may be done by a screw conveyor. gases with the air, passing the mixture into the 80 The chamber should always be ?lled with fuel incandescent coke zone and decomposing and up to a constant level, in the drawing denoted ?xing the vapors into gas, withdrawing the hot by a dot and dash line. At the flues 7 either a producer gas from the upper part, of the in gas collecting cylindrical iron ring is suspended candescent zone and from below the superposed 10 or arranged in the inside wall of the producer, preheating, and distillation zone, and withdraw 85 or the shaft diameter is being enlarged below ing molten slag from the lower portion of the the ?ues, so that the gas assembles in a free incandescent zone. , ' space above an annular, oblique surface of the 3. A process of continuously generating pro fuel. The molten slag is tapped at the bottom ducer gas from solid fuel, said gas having a 15 at 15, and when pig iron is produced, the slag temperature over 1000° C. and composed es 90 may be tapped through a certain taphole a little sentially of carbon monoxide, hydrogen and ni higher up on the hearth. Regulating, means for trogen in the ratio of more nitrogen than carbon the air and the circulation‘ gas and safety-means monoxide; which comprises injecting hot air into preventing explosions, as f. i. a safety valve in a lower vcoke zonein a gas producer and thereby 20 the air pipings, belong also to the equipment generating producer gas and forming molten 95 of the producer although not shown. slag, passing a portion of the hot producer gas Having now fully disclosed my invention, I into a superposed fuel preheating and distilla claim and desire to secure by Letters Patent of tion zone and preheating and coking the fuel the United States: 7 therein, withdrawing the mixed producer gas 25 l. A process of continuously generating pro and distillation vapors and gases, condensing tar 100 ducer gas vfrom solid fuel, said gas having a from the mixture of gases and then passing the temperature over 1000° C. and composed essen resulting stripped gases into the incandescent tially of carbon monoxide; hydrogen and nitro-} coke zone’ and decomposing and ?xing ‘the vaporsv gen in the ratio of more nitrogen than carbon into gas, withdrawing the hot producer gas from monoxide; which comprises injecting hot air the upper part of the incandescent zone and v105 into a lower coke zone in a gas producer and from below the superposed preheating and dis thereby generating producer gas and forming tillation zone, and withdrawing molten slag molten slag passing a portion of the hot pro from the lower portion of the incandescent zone; ducer gas into a superposed fuel preheating and ' 4. A process of continuously generating pro 35 distillation zone and preheating and coking the ducer gas from solid fuel, said gas having a tem 110 fuel therein, withdrawing the mixed producer gas perature over 1000° C. and composed essentially and distillation vapors and gases, then passing of carbon monoxide, hydrogen and nitrogen, the mixture together with the air into the in which comprises injectinghot air into a lower candescent coke zone and decomposing and ?x coke zone in a gas producer and thereby gen 40 ing the vapors into, gas, withdrawing the hot erating producer gas and forming molten slag, 115 producer gas from the upper part of the in passing a portion of the hot producer gas into candescent zone and from below the superposed a superposed fuel preheating and distillation zone preheating and distillation zone, and withdraw and preheating and coking the fuel therein, ing molten slag from the lower portion of the withdrawing the mixed producer gas and distilla 45 incandescent zone. _ tion vapors and gases, then passing the mixture 120 2. A process of continuously generating pro into the incandescent coke zone and decompos ducer gas from solid fuel, said gas having a ing and ?xing the vapors into ‘gas, withdrawing temperature over 1000° C; and composed es the hot producer gas from the upper part of the sentially of carbon monoxide; which comprises incandescent zone and from below the super 50 injecting hot air into a lower coke zone in a posed preheating and distillation zone, and with 125 gas producer and thereby generating producer drawing molten slag from the lower portion of gas and forming molten slag passing a portion the'incandescent zone. of the hot producer gas into a superposed fuel SVEN CARL GUNNAR EKELUND. 5.5. 130

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