US2664450A

US2664450A - Process for the production of acetylene by incomplete combustion of hydrocarbons

Info

Publication number: US2664450A
Application number: US162685A
Authority: US
Inventors: Sachsse Hans; Kosbahn Thomas; Lehrer Erwin
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 1950-05-18
Filing date: 1950-05-18
Publication date: 1953-12-29
Anticipated expiration: 1970-12-29

Description

Dec. 59, 1953 H. SACHSSE ETAL PROCESS FOR THE PRODUCTION OF ACETYLENE BY INCOMPLETE COMBUSTION 0F HYDROCARBONS Filed May 18, 1950 INVENTORS: HANS SACHSSE THOMAS KOSBAHN ERW IN LEHRER ATT'YS ing in larger scale.

Patented Dec. 29, 1953 PROCESS FOR THE PRODUCTION OF AGE"- LENE BY INCOMPLETE COMBUSTION OF HYDROCARBONS Hans Saehsse, Kelheim (Danube), Thomas Kosbahn, Heidelberg-Rohrbach, and Erwin Lehrer, Bad Durkheim, Germany, assignors to Badische Anilin- & Soda-Fabrik Aktiengesellschaft,

Ludwigshafen (Rhine), Germany Application May 18, 1950, Serial No. 162,685

4 Claims.

The present invention relates to the production of acetylene by incomplete combustion of hydrocarbons and the object of this invention is an improved process suitable for carrying out the said acetylene producing method.

The preferred technique in producing acetylene by incomplete combustion of hydrocarbons with oxygen is to preheat the hydrocarbons and the oxygen separately and to subject them, after mixing, to reaction with the formation of a flame, care being taken that the flame reaction does not encroach into the mixing chamber for the gases, because by the striking back of the very hot flame, the apparatus would be injured or destrayed. Since the gases, by reason of the preheating, are in a reactive condition, it is furthermore necessary to effect the intimate mixing of the gases in the shortest possible time so that the possibility of a premature reaction in the mixing chamber is minimized. Whereas quite a number of techniques are known to satisfy these demands in small-scale operations, substantial difliculties are encountered when operat- In this case it has been proposed to split up the amount of oxygen to be mixed with the hydrocarbons into several partial streams and to do the mixing by means of nozzles arranged parallel to each other, or to cause the two gases to flow together through slits, series of holes or channels or to allow them to impinge on each other at high speeds, and to keep the chamber adjoining the place at which mixing takes place and through which the gas mixture has to flow to the point where the flame reaction takes place as small as possible in order to avoid too long and injurious a sojourn of the preheated, very reactive mixture therein. Furthermore, it has been found convenient to adopt the space between the mixing means and the flame chamber to the size and shape of the flame chamber, to improve operation.

It has been found, however, that such apparatus, while providing a substantial improvement, do not satisfy the requirements when large amounts of hydrocarbons are to be handled in a continuous process for example, when throughputs of 1000 cubic meters of hydrocarbons or more per hour are contemplated. The gas mixture will then, even in these apparatus, be liable to premature reactions and back-flashing of the flame which even accurate supervision can scarcely avoid, so that frequent interruption oi the operation and destruction of the burners result.

The object of this invention is a combustion process for the production of acetylene by incomplete combustion of hydrocarbons which substantially comprises using a supply means for the gases to be reacted, this means being arranged in as symmetrical as possible a position about the axis of the direction of flow oi the gas mixture, an elongated mixing chamber of, preferably, circular cross-section following the supply means and a gas distributor preceding the flame chamber. The symmetrical shape of the supply means and the elongated shape of the mixing chamber make the two gases entering in a preheated state meet each other with practically the same direction of flow, and slow down by degrees the speed of the gas mixture in the long narrow space, serving to complete the mixing, so that no eddies are formed such as would give rise to detrimental retardation of the outlet from the mixing chamber. The length of the mixing chamber should be at least three times its width. A preferred form of construction provides enlarging the mixing chamber conically towards the gas distributor and giving it a very slight opening angle.

The speed of flow of the two gases at their junction point is chosen high enough so that a flame cannot live therein. For this purpose the sum of the mean speeds of the hydrocarbon gas and the oxygen gas should be greater than about meters per second, measured at 0 C. and 760 millimeters (mercury gauge).

Various embodiments of apparatus used according to the invention are shown in the accompanying drawings but the invention is not limited to the particular embodiments shown.

Referring to the drawings, Figs. 1, 2, 3a and 3b represent elevations, at least partly in section, of various forms of apparatus suitable for use according to the invention.

Referring to Figure l, the gas supply tube a. and the smaller-sized tube b for the supply of the other gas are concentrically fitted into one another so as to form the nozzle I. This merges into a mixing tube 2 and then into a conical mixing chamber 3 which is separated from the reaction or flame chamber 5 proper by a gas distributor 4 consisting of numerous parallel tubes or of a block provided with numerous channels. For a rapid mixing of the gases it is useful to impart to one of the gas streams a spiral movement, for example, by providing whirling means 5 in tube b.

Referring to Figure 2. this shows a modificatlon of the apparatus shown in Figure 1 in which the tube b terminates in a bundle of narrow tubes 1.

According to the modification shown in Figures 3a and 3b, a sort of annular nozzle 8a or 8!: is provided by which the gas stream entering through the tube a is split up into two parts, so that one of the partial streams meets the gas stream-introduced through the tube b in its axis part while the other meets it at its periphery.

Employing the combustion process of the invention, it is possible to worl; unsafely and With:- out trouble, considerably larger amounts of by; drocarbons into gas mixtures containing acetylene than hitherto.

The following example iur th er ill c trate this invention but the invention is'not l tgo to this example.

Example 1000 cubic meters of methane and e99 meters of oxygen per hour are introduced into one of the apparatus shown in the drawings. ":Ehe methane enters through 'the tube a and the oxyaen through the 4311.116 b. Both cases are-mated to from 500 to 500 C. before entry. $1113 8% mixture leaving the name chamber contains, in ddition to as percent of ace ylene. 1 .4 per cent of methane, 0.2 percent of ethylene. 24.6 per cent of carbon monoxide. 3A per cen of carbon dioxide, 56.2 per cent of hydrogen .and llAper cent of oxygen.

What we claim is:

1. A proce s ;or the production ofacety en by incomplete combustion of preheated hydrocarhon as with oxygen comprises supp y the hydrocarbon gas through a tube concentrically located within another tube through which the oxygen is sunplied, mixing the two gases in an elongated chamber .of circular cross- 'sectioniadjacentto said supply itubosland adapted to receive said gases, and distributing the gas mixture prior to its entry into the combustion chamber by means of a mock having a plurality of vparallel channels therein-mush, the cross-sectional area of said mixing chamber increasin from the end of said supply tubes to :the end oi said distributor block and the length of said mixing chamber being at least three times its width.

"2. Aprocess for the production of acetylene by incomplete combustion of preheated hydrocarhon gas with oxygen which comprises supplying the hydrocarbon gas through a tube concentrically located within another tube through which the oxygen is supplied, while maintaining such a speed of flow of the two gases at their juncvtion-point that -.the sum of their mean speeds Vexceeak meters per second.'measured .at 51 C. and 760 millimetres (mercury gauge) mixing the .two gases in an elongated chamber 01 circular cross-section adjacent to said supply tubes and adapted to receive said gases, andilistributing the gas mixture prior to its entry into the combustion chamber by means of a block having a plurality of parallel channels therethrough, the cross-sectional area of said mixing chamber increasing from the end ar a-15a 'gtubes to the end of said distributor block and the length of said mixing chamber being at least three times its width.

A process for the production of acetylene y ii lfiqmlllete cornbustion of preheated methane as with oxygen which comprises supplying the methane gas through a tube concentrically 1ocated"within another tube through which the oxygen is supplied, mixing the two gases in an el ogg gated "chamber of circular cross-section adjacent to said" supply tubes and adapted to receive said gases, and distributing the gas mixture -prior'to its entry into the combustion chamber by U ps of a block having a plurality of parallel channels therethrough, the cross-sectional area of said mixing chamber increasing jro rn ,the n 9 said su pl tube t t and .01 said ,clis: t bute block n th leng of an hamb r he e-s lea t on amass in n- A cess k p th u fqd s i ii 9 a sii slit y inqlmrlflts q usti n o pre eate metha ga w th payee; ybi t m erises ap ear h me hane as fib us. a be conce i ally 19 categi W t in anot e are thrburb uh sl the wee is tained a a ls mansions su h a s e 9 .i ew'q t e two asse s; th i election m t t a its s m 912 x 3 c ar. e d 3 9 m t e P r se ond n gasgure ia 1032; and m l e e Kine-"Fu y r so. o iiine us We a e in an detec ed n g c circu r (on) wer e c iiqsaids 1 tubes an more in r ce e $24 eases-e d is ibutin t e is m x u e pri to its ent y into the .cmbrst ee amb by was a bla k ha ing a nlii w o P al l nels tbere h oueh th times: ctionalaree of said mixing lcbambe 'inere sins m t e nd 9! aid s p ly ub s t the iid el a d i bl 9 meek as the can of sci? gge Q embn bein at least one i i s its w He ls $493 rHoMas Kosnann LEHREB- refer n es Gi e! i the il 9 th s aten LI E'PED @EA-Tfisi ra es-firs Number Name Date 230,852 Ehurch Mar. 15, 1881 246,321 Iitchfiled etial Aug. 30, 1881 32 ,77 6 Robertson get al Nov. 3, 1885 889,591 Luckenbach June 2, 1908 2,552.27"? Hasche May 8, 1951

Claims

1. A PROCESS FOR THE PRODUCTION OF ACETYLENE BY INCOMPLETE COMBUSTION OF PREHEATED HYDROCARBON GAS WITH OXYGEN WHICH COMPRISES SUPPLYING THE HYDROCARBON GAS THROUGH A TUBE CONCENTRICALLY LOCATED WITHIN ANOTHER TUBE THROUGH WHICH THE OXYGEN IS SUPPLIED, MIXING THE TWO GASES IN AN ELONGATED CHAMBER OF CIRCULAR CROSSSECTION ADJACENT TO SAID SUPPLY TUBES AND ADAPTED TO RECEIVE SAID GASES, AND DISTRIBUTING THE GAS MIXTURE PRIOR TO ITS ENTRY INTO THE COMBUSTION CHAMBER BY MEANS OF A BLOCK HAVING A PLURALITY OF PARALLEL CHANNELS THERETHROUGH, THE CROSS-SECTIONAL AREA OF SAID MIXING CHAMBER INCREASING FROM THE END OF SAID SUPPLY TUBES TO THE END OF SAID DISTRIBUTOR BLOCK AND THE LENGTH OF SAID MIXING CHAMBER BEING AT LEAST THREE TIMES ITS WIDTH.