US 3144312 A
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Description (OCR text may contain errors)
Aug. 11, 1964 c. MERTENS 3,144,312
CATALYTIC CONVERSION PLANT FOR THE CONTINUOUS GENERATION OF GASES OF ANY KIND ou'r or HYDROCARBONS Filed June 6. 1961 I NVENTOR W M E A w m M L J m .w J B m H Elihu i LFILLV\\\ \1 United States Patent CATALYTIC CUNVERSION PLANT FOR THE CQN- TINUOUS GENERATION 9F GASES OF ANY KIND OUT OF hYDRQCAREONS Carl Mertens, Am Holzwege 15, Bochum- Linden, Germany Filed June 6, 1961, Ser. No. 150,605 1 Claim. (Cl. 48-95) This invention relates to a catalytic conversion plant for the continuous generation of industrial gases of any kind for further chemical treatment, town gas, synthetic gases or gases rich in olefine from hydrocarbons with reactants such as air, oxygen and water vapour, which have been added singly or in a definite ratio. Orthodox plants of this type sufler from the disadvantage of requiring great amounts of heat for pre-heating the charging mixture and for executing the reaction, as well as necessitating long contact pipes.
This invention is based on the idea of creating a catalytic conversion plant which combines a compact construction and a minimum supply of heat with a high efficiency in operation.
In terms of the invention this problem is solved by the arrangement of a conversion element, a heat exchanger, an operative air preheater, and a burner in one unit, which is detachably connected with a steam generator by means of a flange connection. A further advantage of this arrangement lies in the fact that the conversion element can be easily exchanged and any repair work or renewal of parts can be effected without any trouble to adjoining plants.
In compliance with this invention, the pipes of the conversion element may have a ribbed or corrugated finish in order to increase the heating surface.
Further features and details of the invention are shown in the following description with reference to the drawing in which a form of construction is demonstrated.
FIG. 1 shows the plant in elevation;
FIG. 2 shows a cross-section on the line AA' of FIG. 1;
FIG. 3 shows a cross-section on the line B-B of FIG. 1.
The catalytic conversion plant of this invention consists of the conversion element 1, the heat exchanger 2, the air preheater 3, the burner 4, and the steam generator 5. The conversion element 1, the heat exchanger 2, the air preheater 3 and the burner 4 forms one unit which is detachably connected with the steam generator 5 by means of a flange connection 6. The conversion element 1 consists of three concentrically arranged pipes 7, 8, and 9 which form two annular spaces 10 and 11. The annular spaces 10 and 11 are connected at their bottom and are filled with a catalytic agent. On top of the annular spaces 10 and 11 there is the heat exchanger 2 annexed to them. The heat exchanger 2 consists of two concentric pipes 12 and 13 forming the annulus 14 which is closed at its top and connected with the annulus 10 in its lower part; it is provided with a connecting piece 15. In the annulus 14 there are pipes 16 in circular arrangement. They are in their lower part connected with the annulus 11 and on top they are connected with a chamber 17 having a circular section. The heat exchanger 2 is surrounded by the air preheater 3. In its interior there is the burner 4 in which a suitable fuel is burnt with air, producing flue gas. The air preheater 3 consists of three concentrically arranged pipes 18, 19, and 20, being closed in their upper and lower parts. They form two annular spaces 21 and 22 which are in connection with each other and provided with inlet and outlet pipe connections 23 and 24. The steam generator 5 consists of four concentrically arranged pipes 25, 26, 27, and 28 which are 3,144,312 Patented Aug. 11, 1964 closed at their top and bottom. They form three annular spaces 29, 30 and 31. The conversion element 1 projects into the inner pipe 28. The external annulus 29 is provided with a connecting piece 32 for the outlet of the flue gases. The annulus 30 in the middle has a connecting piece for the intake of the feed water. At the bottom of the pipes 26 and 27 there are connections 35 between the internal annulus 31 and the external annulus 29. A connecting piece 36 in the bottom of the pipe 26 serves for the elutriation of the steam generator 5.
When the plant is in operation, air for the reaction passes through the tangentially placed connecting piece 23 and enters the air preheater 3 at a temperature of 20 to 35 C. It leaves it, preheated to a temperature of approximately 200 C. through the connecting piece 24 and is mixed with the steam for the reactions that is discharged through the connecting piece 33. The amount of hydrocarbon is fed to this mixture in measured quantities. The reactive mixture air-water vapour-hydrocarbon passes through the connecting piece 15 and enters the annulus 14 of the heat exchanger 2 in order to be preheated to a temperature of 450 to 500 C. by the conversion gases which flow as countercurrents through the pipes 16. At this temperature the conversion mixture enters the external annulus 10 of the conversion element 1 and transforms, first of all, especially With the reactive air and some water vapour conversion partly into conversion gases. The heating is effected by means of flue gases which rise as a countercurrent in the annulus 37, formed by the pipes 7 and 28. The flue gases interchange heat there, having a temperature of about 900 C. at the bottom and up to 750 C. at the top. Practically all of the heat of the flue gases is eliminated in the annulus 10 by means of the external pipe 7 of the conversion element 1, in order to facilitate the conversion. The conversion gases and the undecomposed hydrocarbons mixed with water vapour pass for the final decomposition of the still undecomposed hydrocarbons with water vapour from the annulus 10 into the annulus 11, which is also filled with a catalytic agent. This reaction consumes a great amount of heat which is for the greater part compensated by the direct heating of the internal pipe 9 with radiation heat of the flue gases that leave the burner 4. The finished conversion gas leaves the annulus 11 and enters the concentrically arranged pipes of the heat exchanger 2. There the greater part of the heat is indirectly dissipated to the heat exchanger 2 for raising the temperature of the charging mixture. The cooled conversion gas is tangentially discharged at 38.
The flue gases generated by the burner 4 radiate the heat required for the conversion, especially for that required in the water vapour reaction, to the annulus 11 which is filled with the catalytic agent. This is done in a countercurrent. The gases reverse their direction in the lower part in order to radiate in the annulus 37 the required heat in countercurrent to the charging mixture indirectly to the charge in the annulus 10. After covering the whole amount of conversion heat and the appropriate part of the reactive air preheating, the flue gases enter the annulus 31 to dissipate part of their heat to the steam generator 5. At two sides of this steam generator flue gas flows around it to eflect the vaporization of the water in annulus 30. Through the connections 35 the flue gases pass from the annulus 31 into the annulus 29, heating the annulus 30, and discharge through the connecting piece into the atmosphere. The steam leaves the steam generator 5 through the connecting piece 33. The reactive air enters the air preheater through the connecting piece 23, flows through the annulus 21 and in countercurrent also through the annulus 22 and leaves the preheater 3 through the connecting piece 24.
In spite of the high temperatures a refractory lining is not necessary because the upper parts in the air preheater 3 are kept cool.
Catalytic conversion plant for the continuous genera tion of gases, comprising a container, a plurality of coaxial vertical pipes one within the other Within the container and including an outer pipe, an intermediate pipe and an inner pipe forming outer and inner annular catalyst spaces, means extending between the outer and inner pipes closing oil such spaces from their outside, such spaces communicating adjacent their lower ends, a catalytic material in said spaces, means closing off a first of said catalyst spaces at the top, inner and outer pipe sections coaxial with said pipes extending upwardly from the top ends of the pipes and providing an annular heat-exchange space therebetween, said heat exchange space communicating with the other of said catalyst spaces, said heat exchange space having an inlet opening from outside the container, a plurality of tubes extending upwardly through said heat exchange space having their lower ends open to said first catalyst space, a collector connected to the upper ends of said tubes and having an outlet to the outside of the container therefrom, a burner in the space within the inner pipe section, means in the container to direct upwardly on the outside of the outer pipe gases flowing downwardly through the inner pipe and out of the open bottom thereof, an air preheater around the outer pipe section, said air preheater comprising three pipe elements coaxial with the pipe sections to form two air heating spaces, an inlet into one of said air heating spaces and an outlet from the other near one end thereof, said air heating spaces communicating near the other end only, a doublewalled steam generator in said container on the outside of said directing means, and means to guide gases from said burner from the outside of the outer pipe to flow in heat exchange relation with said steam generator.
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