Method for treating a gas current which is obtained by coal gasification
United States Patent 1 1 Hiitgens et a1.  
  METHOD FOR TREATING A GAS CURRENT WHICH IS OBTAINED BY COAL GASIFICATION [75] lnventors: Jochen Hiitgenst Duisburg-Hamborn; Giinter Adomat, Essen. both of German [73] Assignee: Gutehoflnungshutte Sterkrade 1 Aktiengesellschaft. Oberhausen. Germany [22] Filed: Dec. 18. 1972 [21] Appl. No.: 315.982  
 [30] Foreign Application Priority Data Dec. 18. 1971 Germany 2163096 152] US. Cl. 55/83; 55/264; 55/269; 415/112 [51] Int. Cl B0ld 45/00 [58] Field of Search 55/267. 268.269. 83. 264; 415/111. 114. 116. 175. 176.112.177.178.  
 39. 40. 41; 48/205. DIG. 8; 201/3. 4. 30;  
 156] References Cited UNITED STATES PATENTS 1.310.672 7/1919 Sherhondy ..4l5/179 UX 1.943.116 1/1934 Forrest ct a1. 62/90 2.399.865 5/1946 Halford 415/179 2.692.849 10/1954 Hyde 201/4 SEPARATOR 1 Apr. 22, 1975 2.793.506 5/1957 Mood 415/178 UX 2.957.318 10/1960 Morrison 62/9 UX 3.303.997 2/1967 Welch et a1 415/111 3.349.571 10/1967 Ncbgcn 62/39 X 3.372.555 3/1968 Becker 62/13 3.430.451 3/1969 Mehta ct a1 Ill/2.5 3.463.088 8/1969 Umbricht 415/111 UX 3.556.749 1/1971 Spacil 48/202 X 3.579.308 5/1971 Gowcr 48/D1G. 8 3.643.675 2/1972 Wcttcrstad 137/13 3.702.063 11/1972 Etzhach ct a1. 62/40 X 3.740.163 6/1973 Schinncrcr et a1 3(J8/D1G. l  
 Prinmr) Examiner-Bernard Nozick Alwrney. Agent, or Firm-McG1ew and Tuttle 1 1 ABSTRACT A method of treating a gas current which is obtained from coal by gasification comprises compressing the gas in several stages and prior to the entrance into a subsequent stage. cooling and separating the liquid from at least a portion of the gas and then heating the cooled and separated gas. The apparatus includes a plurality of compression stages with at least one of the stages having connections to a cooler and a water separator through which the gases pass and including a heater for treating at least the portion of the gas which passed through the cooler and separator and which is then delivered into a conduit for transferring all of the removed gas from the previous stage into a subsequent stage.  
 1 Claim, 2 Drawing Figures PATENTEUAFRZZIBYS 3. 879. 1 8O SEPARATOR ,6 [0a V cooLenMm filoc lU wo FIGZ  METHOD FOR TREATING A GAS CURRENT WHICH IS OBTAINED BY COAL GASIFICATION BACKGROUND OF THE&#39; INVENTION 1. Field of the Invention This invention relates. in general. to a method for treating a gas current which is obtained from coal by gasification and. in particularato a new and useful method and apparatus for compressing a gas obtained from coal by gasification in several stages wherein at least a portion of the gas is cooled and the liquid separated therefrom and thereafter heated before it is returned into a subsequent stage.  
 2. Description of the Prior Art The present invention is particularly applicable to a method for heating up a gas current which is&#39;obtained by the gasification of coal or coal dust and which contains no liquid constituents and is compressed in one or several stages. It is known. when the compression is effected in several stages. that the gas current is heated up after cooling and before its entrance into each of the compression stages by using a separate steam or electrical heating and to such a degree that the gas current passing into the subsequent compression stage has a temperature slightly above the point of condensation. This temperature is necessary in order to obtain a gas current which is free from liquid component parts which are capable of dripping. because otherwise&#39;the gas would cause erosion and corrosion of the interior of the compressor.  
  The disadvantages of the known equipment of this type is that it requires a very complicated design of reheating equipment which is expensive to manufacture.  
 SUMMARY OF THE INVENTION In accordance with the present invention. there is provided an improved method and corresponding device for heating up a gas current which has been removed from a stage and prior to its admission into a subsequent stage. With the inventive arrangement. the gas current is heated up between stages to a temperature slightly above the point of condensation. and it is divided into two partial currents. the first partial current which contains the bulk of the gas is conducted through a cooler and a drip separator and is thereafter reunited with the uncooled second partial current which is conducted through a by-pass. A particular advantage of the invention is that the leakage gas which escapes at the compensating piston or at the gland of a succeeding compression stage may be used as a heating gas. The particular advantage of the inventive device comprises an arrangement in which a heating zone is provided at the downstream side of the gas conduit which is connected between adjacent pressure stages and which is arranged after one or several intercoolers or after the gas passes through one or more drip separators. The heating zones comprise one or several conduits leading into the gas conduit for conducting the hot gas. or the heating gas conduit is connected to the gas conduit coming from the intermediate cooler, as a by-pass.  
  In one embodiment of the invention. the gas is removed from a high pressure stage and a portion thereof is passed through a cooler and a water separator and joined to a portion which is by-passed a location downstream from the cooler and separator and before it enters back into the next compression stage.  
  In another embodiment. the gas is passed successively through a cooler and a separator and then into a heating zone which is generated by a connecting line from the sealing gland of the next pressure stage.  
  Accordingly. it is an object of the invention to provide a method of treating a gas current which is obtained from coal by gasification and which comprises compressing the gas in several stages. and prior to the entrance into a subsequent stage. cooling and separating the liquid from at least a portion of the gas and subsequently heating the cooled and separated gas before it is returned into the next stage either by using a portion of the removed but uncooledand unseparated gas or by using a return heating line from a packing gland of the next successive stage. j  
  A further object of the invention is to provide a device for treating a gas currentbetweencompressing stages which includes first and second compressing stages having a conduit with a cooler and a water separator therein through which the gases pass and with a second conduit for a portion of the gas to permit by passing of the cooler and the water separator and which leads to a connection conduit to the second stage along with the cooled and separated gas to provide a heating thereof. i  
 A further object is to provide an arrangement in which substantially all or all of-the gasespass through v a cooler and a separator and then the cooled and separated gas, is joined with gas which is supplied from -a packing gland of the next pressure stage before the combined gas is delivered to the next pressure stage.  
  A further object of the invention is to provide an ap-- paratus for treating gas which is obtained by coal gasification which is simple in design. rugged in construction and economical to manufacture.  
  The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention. its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.  
 BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:  
  FIG. 1 is a schematic diagram-ofa compressor having a heating gas conduit for cooled and separated liquid which comprises a gas by-pass; and  
  FIG. 2 is a diagram similar to FIG. 1 of another embodiment of the invention and in which leakage gas is used as a heating gas.  
 GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings. in particular. the invention embodied therein in FIG. 1 comprises a device for treating a gas current obtained from coal by gasification and which comprises a first or high compression stage 1 which is connected to a gas treatment conduit 10 which is divided into two branches 10a and 10b. The total gas current which leaves the high compression stage 1 is directed as a total gas mG through the conduit 10 and a portion thereof. the bulk of the gas flows through the branch conduit 10a as the gas mGl which is conducted through a cooler l4 and a separator 16 through a combined conduit 10c which leads into the second stage 2.  
 In accordance with the invention. a smaller portion 5 of the gas &#34;162 flows through the by-pass conduit b having a regulating valve and it heats the gas flowing through the conduit 10a before it passes through the combined conduit IOC to the second stage 2. Thus. with the method of the invention. a second gas current or partial current &#34;102 which is separated from the main current mG before its entrance into the cooler and separator is regulated in respect to current flow quantity so that it acts on the partial gas current mGl to lead it above the point of condensation. Due to the heating of 1 the undercooled partial current mGl, the last liquid constituents of this gas current are evaporated and the re-united gas current passes through the conduit 10 into the compression stage 2 free from liquid compo nent parts which are capable of dripping.  
  In the embodiments shown in FIG. 2. a high pressure stage 1 is connected to a conduit l0 having a cooler 14 and a drip separator 16&#39; through which the gas current is directed. In this example. the gas current H16 in its entirety flows through the cooler and the separator and the heat necessary to heat the gas to remove any further condensation is effected by a connecting line 20 which connects to a gland 22 providing a seal at the discharge end of the next stage 2 a heating gas mGl which is a leakage gas flows through the conduit 20 and into a combined conduit 10c so that the leakage gas mGl mixes with the gas mG&#39; in a sufficient quantity to heat the combined gas to a temperature above the condensation point.  
  In each of the embodiments described. a heating zone is effected to treat the gases which are removed and pass through the cooler and the separator in each case. This heating zone may consist of a foreign gas heating zone or ofa heat exchanger which forms a part of the conduit shown at 10:- or 10c in FIGS. 1 and 2, respectively. In the case of a foreign gas heating. one or more connecting conduits are provided for supply ing the hot gas. In the case of a heat exchanger, this may take the form of a jacket surrounding the conduit or 100 or of a separate pipe arranged within the same.  
  While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles. it will be understood that the invention may be embodied otherwise without departing from such principles.  
 What is claimed is:  
  l. A method of treating gas current attained from coal by gasification. comprising compressing the gas in several stages, removing the gas from one of said stages and. prior to its entrance into a subsequent stage, cooling at least a portion of the gas and separating the liquid therefrom. and collecting leakage gas from a subsequent compression stage and subsequently heating the cooled and separated gas before it is delivered to the next stage by contacting it with the leakage gas.