US3607128A

US3607128A - Axial flow reaction tower

Info

Publication number: US3607128A
Application number: US25027A
Authority: US
Inventors: Paul Mevenkamp; Hans-Dieter Marsch; Herbert Biskup
Original assignee: Uhde GmbH
Current assignee: ThyssenKrupp Industrial Solutions AG
Priority date: 1970-04-02
Filing date: 1970-04-02
Publication date: 1971-09-21
Anticipated expiration: 1988-09-21
Also published as: GB1287709A

Abstract

An axial flow delayed combustion furnace or reaction tower for synthesis gas production for pressures greater than 10 atm., and temperatures greater than 700* C., is provided with an inner thermal lining, an arch for supporting the catalyst, the arch being of ring shape and such that a stack is disposed at the center thereof through which the gas-conducting pipe extends. The lower end of the gas pipe is mounted in a reinforced collar on the floor of the reaction tower, and is connected to the tower floor through a sleeve-shaped expansion part.

Description

United States Patent [72] inventors Appl. No.

Filed Patented Assignee Priority Paul Mevenkamp Lichtendorf;

11ans-Dieter Marsch, Dortmund; Herbert Biskup, Dortmund-Aplerbeck, all of, Germany Apr. 2, 1970 Sept. 21, 1971 Friedrich Uhde GmbH Dortmund, Germany Oct. 25, 1966 Germany V 132151Va/12g Continuation-impart of application Ser. No.

677, 67, 061. 24, 19 7, now abandoned.

AXIAL FLOW REACTION TOWER 2 Claims, 2 Drawing Figs.

US. Cl 23/288, 23/277, 23/283, 23/288 L, 23/289, 122/510 Int. Cl B01j 9/04 Field of Search 23/288,

288.91, 288.92, 289, 277 US, 283 US, 284 US; 48/102 US, 107 US, 196 US, 197 US; 196/133, 110; 122/510 US, 511 US 7% R1 ib 'n [56] References Cited UNITED STATES PATENTS 1,833,188 11/1931 Larson 23/289X 1,839,738 l/l932 Casale.... 23/289 2,280,089 4/1942 1-1oudry.. 23/288 L 2,472,254 6/1949 Johnson 23/288 L X 2,614,033 10/1952 Cornell et al.. 23/288 2,634,194 4/1953 Nebeck 23/288 FOREIGN PATENTS 330,872 6/1930 Great Britain 23/288.92

Primary Examiner-Joseph Scovronek Attorney-Malcolm W, Fraser ABSTRACT: An axial flow delayed combustion furnace or reaction tower for synthesis gas production for pressures greater than 10 atm., and temperatures greater than 700C, is provided with an inner thermal lining, an arch for supporting the catalyst, the arch being of ring shape and such that a stack is disposed at the center thereof through which the gas-conducting pipe extends. The lower end of the gas pipe is mounted in a reinforced collar on the floor of the reaction tower, and is connected to the tower floor through a sleeveshaped expansion part,

AXIAL FLOW REACTION TOWER CROSS-REFERENCE TO RELATED APPLICATION This application constitutes a continuation-in-part of application, Ser. No. 677,667, filed Oct. 24, 1967, and entitled Axial Flow Reaction Tower (now abandoned).

BACKGROUND OF THE INVENTION The present invention concerns an axial flow reaction tower or delayed combustion furnace for the chemical conversion of highly heated and/or compresses reaction components in synthesis gas installations. Since the reaction tower is flowed through in an axial direction, with known constructions one of the feeding or discharge pipes leads over the entire outer length to the head of the reaction tower. The removal of a transfer pipe of this kind involves considerable technical expense. The high-temperature load makes it necessary to make the pipe out of high-alloy steel or to provide sufficient inner insulation, and increased system pressure requires a correspondingly strong construction of the pipe wall. Moreover, the control of a different heat expansion occurring between the outer pipe and reaction tower often causes great difficulties.

It is recognized that has may be conducted above the reactor floor by means of a central pipe, which is open at the top. Where the reactor is an almost pressureless vessel and no high temperature differences are present, the solution does not offer any difficulties. When the reactor, however, must be constructed for higher pressures, as for example atm., the operating temperature of the reaction lies above 700C. and the temperature differences between gas inlet and gas outlet pipes and between the latter and the sleeve temperature of the vessel are considerable, great difficulties occur in the construction of the passages of bricklining or masonry, in order to attain perviousness and in the control of the heat expansion present with the necessary great wall strengths. These difficulties were greater than the disadvantages and difficulties of the previous construction of the conduit disposed on the outside to the head of the delayed combustion furnace. For this reason, this last-mentioned construction was maintained in spite of everything.

SUMMARY OF THE INVENTION It is an object of the invention to provide an internally insulated reactor in which the catalyst rests upon a perforated supporting arch of high strength, said supporting arch being shaped to prevent any adverse effect upon its function by the passage of the central gas-conducting pipe.

It is a further object of the invention to provide an internally insulated reactor in which an internally insulated gas feed nozzle and an internal gas-conducting pipe are connected to the bottom of the reactor, the internal gas-conducting pipe being mobile in a radial direction and attached to the reactor bottom to form a gastight seal while extending to the head of the reactor and being open at the top.

Accordingly an axial flow delayed combustion furnace for synthesis gas production is provided for pressures greater than 10 atm., temperatures greater than 700C. with inner brick lining, catalyst supporting arch and lower gas feed through the floor of the delayed combustion furnace. Such furnace is characterized by forming the catalyst-supporting arch of ring or annular shape, and in such manner, that a stack or chute results in the center. This stack or chute extends upwardly into the head of the delayed combustion furnace by means of ceramic material within which is a gastight conduit pipe, which is attached to the gas feed conduit. In order to hold the gas conduit pipe in a central position within the furnace, additionally on the upper end is a known guide piece which permits axial shifting.

A further feature of the invention consists in producing at the passage point of the gas-conducting pipe through the sleeve of the delayed combustion furnace, a gastight elastic connection permitting of low heat discharge between hot inner gas-conduction pipe and the only moderately hot sleeve of the delayed combustion furnace, so that the gas conduction pipe rests by means of a collar on a support bracket and is connected gastight through a flexible expansion pipe with the sleeve of the furnace.

The arrangement of the arch according to the invention insures a uniform flow across the catalyst bed because the gas path through the catalyst bed, and the perforated arch and consequently the gas pressure drop from the catalyst bed inlet to the catalyst bed outlet on the perforated arch is of the same level. If no provision were made for a catalyst-supporting arch, the lower part of the axial flow reaction tower would have to be filled with catalyst or with a filling material that leaves much free volume. Owing to gas paths of different length from the catalyst bed inlet through the catalyst and filling material to the gas outlet nozzle, the flow distribution and, consequently the catalyst load would be nonuniform. As compared to a dome-type supporting arch, an annular catalystsupporting arch has the advantage that, for any given diameter of the axial flow reaction tower, it provides better stability to carry the considerable weight of the catalyst.

Through this arrangement according to the invention, the pipe leading to the head of the reaction tower is exposed only to relatively slight stresses. The pressure load corresponds to the pressure loss found with the flow inside the pipe and the reaction tower, while the temperature drop results from the temperature difference between the highly heated reaction mixture in the inside of the pipe and the likewise hot content of the reaction tower.

An inner pipe of this kind consequently, in comparison with a transfer pipe led outside of the furnace, needs to exhibit only a low wall strength and needs no, or only slight, insulation. Occuring heat expansions are allowed for in simple ways through the unilateral reinforcement of the inner pipe at the floor of the reaction tower. Advantageously, moreover the pipe is set over a reinforced collar on a support arranged on the floor of the reaction tower and is tightly joined independently with the tower floor by such a support construction through a sleeveshaped expansion part. Through this kind of connection of the pipe with the tower, heat expansions can also be compensated in a radial direction. At the head of the tower the pipe is guided axially in a suitable manner.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a vertical sectional view of an axial flow reaction tower embodying the invention; and

FIG. 2 is an enlarged fragmentary sectional view of the lower end portion of the reaction tower.

DESCRIPTION OF PREFERRED EMBODIMENT The reaction tower 1 serves for the further conversion of the gas mixture coming out of a tube-cracking furnace (not shown) which is heated to about 800C. This gas is lead through through the pipe 2 to the head 3 of the reaction tower and there reaches, with the addition of heated oxygen or air, a temperature of about 1200 C. With the passage of the gas mixture through the catalyst 4, an endothermic reactiontakes place which causes a temperature drop near the outlet connection 5 to about 970 C. The reaction tower is lined inside, for the protection of a steel shell 6, as well as for the prevention of greater heat loss, with a thick coat of insulation material 7. The pipe 2 is only provided with an outer insulation stack 8, which is to prevent the heat from being drawn from the reaction chamber 9 and which in addition protects the pipe 2 against direct contact with hot burning gas.

In the lower portion of the reaction tower or furnace is an annular arch 4a on which the catalyst 4 is supported. The arch is of heat resistant masonry and extends around the inside of the furnace as indicated on FIG, 1. The central portion 4b of the arch has an axial passage through which the gas pipe 2 extends and has a shelf or ledge 40 on which the pipe-insulating stack 8 is supported. The arch 4a provides a free space over the entire cross-sectional area of the reaction tower.

In the bottom or floor part 10 of the reaction tower l the pipe 2 extends through and is tightly connected to plate 11, which rests on a supporting bracket 12. A radially flexible expansion part 13 connects the plate 11 rigidly to the floor part 10. The bracket 12 is provided in the upper part with recesses 12a in order to reduce the contact face and thereby to decrease the heat outflow from the gas-conducting pipe 2 into the vessel sleeve. At the upper end 14 the pipe 2 has a guide piece 15 which extends into the head 3 of the reaction tower, so that it can expand unhindered in an axial direction.

From the above, it will be apparent that within the reaction tower l is a pipe 2 through which the highly heated or compressed reaction products pass. Through apertures at the top of the pipe the reaction products enter the inside of the tower and after passage through the catalyst 4, and through the perforated arch 4a pass from the tower through the outlet 5.

What We claim is:

1. An axial flow reaction for synthesis gas production for pressures greater than 10 atm. and temperatures higher than 700 C. comprising in combination an upright tower body having internal thermal insulation, a central lower gas feed nozzle with internal thermal insulation, a lateral gas discharge nozzle in the lower part of said body also provided with internal thermal insulation, a central gas-conducting pipe commencing in said gas feed nozzle and extending vertically upward into the upper part of the tower body and having an open end in the upper part of said body, a radially flexible expansion part providing a gastight connection between said gas feed nozzle and said gas-conducting pipe, said expansion part being surrounded by insulation, the space between lower tower wall insulation and lower part of said gas-conducting pipe being filled with a catalyst support structure in the form of a ring-shaped arch which reaches to the tower body insulation and surrounds said gas-conducting pipe, said arch being perforated and the hollow space having a direct connection to the gas discharge nozzle, said gas-conducting pipe having an outer insulation above said ring-shape arch, the major portion of the space above said ring-shape arch being filled with catalyst, and said gas-conducting pipe terminating in the free space.

2. An axial flow reaction tower as claimed in claim 1, characterized in that said expansion part consists of a plate attached to said gas-conducting pipe by means of a gastight weld, said plate terminating in a thin flexible part which is attached to the bottom of said tower body by a gastight weld.