US1987905A - Control of temperature and fluid distribution in contact masses - Google Patents

Description

E. J. HOUDRY I Jan. 1 5, 1935.

CONTROL OF TEMPERATURE AND FLUID DISTRIBUTION IN CONTACT MASSES Filed March 31 INVENTOR J yoaaf y 54K. Mp

. ATTORNEY Patented Jan. 15,1935

UNITED STATES PATENT OFFICE DISTRIBUTION IN CONTACT MASSES Eugene J. Houdry, Woodbury, N. 1., assignor to Houdry Process CorporatlomDover, Del., a corporation of Delaware Application March 31, 1933, Serial No. 663,712

16 Claims.

This invention relates to apparatus utilizing contact masses for effecting chemical reactions, whether exothermic or endothermic. v More particularly, it has to do with fluid distribution within and throughout such masses as by the use of perforated conduits embedded in the masses 'and with the control of temperature by the rapid diffusion or removal of heat by suitable conducting means, such as fins, for example, projecting from the conduits into the contact masses. In certain respects the present invention may be considered as an improvement upon or further development of the invention disclosed in the copending application of Thomas B. Prickett, Serial No. 649,531, filed December 30, 1932, entitled Temperature regulation of contact masses. I r

Among the objects of the invention are to secure an even and uniform distribution of fluid within and throughout a contact mass, to eflect a uniform movement of heat into or out of a contact mass especially when the latter is a poor conductor of heat, to prevent an undue. or harmful rise in temperature in the whole or in any localized portion of a contact mass such as may occur during a regeneration of the mass by oxidation, and in general to improve prior forms of apparatus in the interest of more efiicient and satisfactory service.

In one aspect the invention involves the use of heat conducting means of irregular projection on a fiuid conduit and extending therefrom into the contact mass. Such means may take the form of fins, as in the aforesaid copending application, but the fins are preferably alternately long and short in radial extension. In the form illustrated, the short fins are diametrically opposite and in line with the long fins. In the assembly of a catalytic case or converter having both distributing and outlet conduits in uniform symmetrical arrangement with heat conducting means or fins only on the distributing conduits, the short fins of adjacent conduits are disposed in line but out of contact with one another, and the long fins are directed toward the adjacent outlet conduits. When the conduits are disposed in hexagonal arrangement, the preferred form of finned conduit has three short and three long fins. In another aspect, the invention involves the disposition of similarly finned conduits in the same or similar positions relative to each other within the converter, i. e. with their fins in substantial alignment in a number of planes extending across the converter, the planes corresponding to those defined by the fins on one conduit. This arrangement of finned members of the present invention as well as of the aforesaid application has the effect of dividing the entire contact mass into a multiplicity of smaller masses of the same size and shape with no part of any such mass beyond a predetermined distance from one of the enclosing fins or conduit walls.

In order to illustrate the invention, one concrete embodiment thereof is shown in the acl0 companying drawing, in which:

Fig. 1 is a vertical sectional view through a reaction case having both distributing and outlet conduits embedded in the contact mass, the view being taken substantially on the line 11 of 15 Fig. 2.

Fig. 2 is a fragmentary horizontal sectional view of a portion of the interior of the reaction chamber shown in Fig. 1.

Fig. 3 is an enlarged horizontal sectional view 20 through one of the finned conduits shown in Figs. 1 and 2.

Fig. 1 discloses a converter or reaction case 4, preferably of metal and cylindrical in form, surrounded by a thick layer of heat insulating 25 material 5, and having. therewithin, in spaced relation to its bottom, a partition or false bottom 6 defining a chamber 7 therebelow and supporting the contact mass M. Depending .upon the purpose of the reaction chamber, and the 3 products to be produced therein, contact mass M may be of inert absorbent material, or may possess catalytic activity, so as to be capable of effecting the desired modification, conversion,

' or transformation of the starting material. Em- 35 bedded in the mass are fluid conducting units serving to heat or to cool the mass, and, in either case, the heat exchange fluid may or may not be brought into direct contact with the mass. In-the present instance, the fluid, such as the 40 starting material, .is uniformly distributed throughout the contact mass M by a series of apertured conduits 8 embedded in the mass and having connections 9 which extend out through the top of converter 4 to connect with an inlet header or manifold 10. The products of the reaction are withdrawn by a series of apertured outlet conduits 11 mounted in partition 6 and extending into mass M in juxtaposed parallelism with distributing conduits 8 so as to discharge the products of the reaction into outlet chamber 7, which has a discharge connection 12.

When .the desired reaction, whether exothermic or endothermic, requires the use of a contact massM. which has low thermal conductivity, and especially when the contact mass must be periodically regenerated or reactivated with a large production of heat, as when contaminants deposited therein are removed by oxidation, it is essential that the heat be diffused through the mass or withdrawn from the mass uniformly within certain prescribed limits. Instead of increasing the number of inlet and outlet conduits, adequate temperature control has been found to be possible by the use of heat conducting members, such as fins, extending from the conduits, as disclosed in the aforesaid copending application Serial No. 649,531. While an important measure of heat control is attained when the fins extend in a haphazard manner, "it has been found that improved results are secured by carefully mounting the conduits so that the fins are in substantial alignment throughout the reaction chamber, the number of planes so defined conforming to the number of fins on one of the conduits. The fins then appear in banks of parallel planes which intersect one another. This arrangement has the effect of dividing the contact mass into a plurality of smaller masses of substantially the same size and shape, and in which identical operating conditions occur.

While the heat conducting means may be applied to all of the conduits, both distributing and outlet, the preferred arrangement, as herein disclosed, is to provide fins on the distributing conduits 8 only. The fins so provided extend axially of the conduit through some or all of the length thereof, as may be found preferable or desirable, but are of different ra-, dial projection. Long fins 13. alternate with short fins 14, both of which are symmetrically spaced about each distributing conduit 8, as is apparent from Figs. 2 and 3 of the drawing. With distributing conduits arranged in hexagonal formation about each outlet conduit 11, as indicated in Fig. 2, each inlet conduit is provided with three long fins 13, 120 apart, and with three interposed short fins 14, also 120 apart, adjacent long and short fins being accordingly 60 apart. The distributing conduits are mounted in converter 4, so that the long fins 13 extend toward the axes of adjacent outlet conduits 11, while short fins 14 extend toward the axes of adjacent distributing conduits to line; up with corresponding short fins thereon. This arrangement, as clearly indicated in Fig. 2, serves to divide the contact mass M into a plurality of small masses m of identical size and shape; being substantially triangular in horizontal section and being confined between portions of the walls of one outlet conduit and two inlet conduits, and certain long and short fins radiating from the latter. Suitable clearance is provided between the free edges of the long fins 13 and the adjacent walls of outlet conduits 11, and between the free aligned edges of short fins 14 to assure even packing and distribution of the contact mass.

By the herein-shown preferred arrangement of distributing conduits having fins of unequal projection, it is possible to dispense with the use of any fins on the outlet conduits. However, if fins of the same projection only were provided, there would not be sufiiciently complete division of the large contact mass into small masses of equal size and shape to attain at least one very important and desirable result, namely that no portion of the mass is more than a certain predetermined distance (not over two inches) from a heatv conducting element, be it one of the conduits or one of the fins.

While the present invention is capable of general application to all chemical reactions involving the use of contact masses, details of apparatus for one specific operation are given below, this operation being the conversion of heavy hydrocarbon starting material into light hydrocarbon products. By preference, the contact mass for this reaction consists of molded fragments composed largely or wholly of activated silicate of alumina having very poor thermal conductivity, but arranged for regeneration in situ. During transformation, the entire mass is maintained at any desired operating temperature between 775 and 925 F., and, during regeneration of the mass by oxidation through the use of fresh air diluted, as required, with inert material such as flue gas or steam, the reaction temperature is preferably held throughout the mass in a 50 range, with a. top tem perature not exceeding 1100* F. The apparatus conforms to that illustrated in the drawing, the outlet conduits being 3-inch standard steel tubes and the distributing conduits 2 -inch standard steel pipes. The conduits are disposed in the hexagonal arrangement illustrated in Fig. 2, with a -inch distance between all conduit centers. The projection for the long fins is 1 13/16 inches, and for the short fins 1 1/16 inches. With the fins disposed in alignment, no part of the contact mass is more than 1 inches away from a heat conducting wall, which distance has been found to be quite adequate and satisfactory from an economical as well as from an operating standpoint. With such apparatus, a very high degree of uniformity of control of all operating conditions is attained. This permits conversion at the optimum temperature for any starting material as well as the complete freeing of all portions of the contact mass of contaminating deposits during regeneration, so that a maximum yield of product may be attained.

I claim as my invention:

1. The combination with a contact mass for effecting an exothermic or an endothermic reaction of a series of fiuid conduits embedded in said mass in uniform distribution and in parallel arrangement, certain of said conduits having heat conducting means radiating therefrom into said mass, said means being of differing projection and arranged to cooperate with each other and with said conduits so as to divide the entire contact mass into a plurality of smaller masses of uniform size and shape.

2. The combination with a contact mass for effecting chemical transformations of fiuid conduits embedded therein in uniform distribution and in parallel arrangement, certain of said conduits having fins extending therefrom into said mass, said fins being uniformly disposed and arranged in cooperation with each other and with the conduits to divide the contact mass into substantially equal parts, thereby to facilitate uniform temperature control of the entire mass.

3. In combination, a case containing a con tact mass, a series of fluid distributing conduits embedded in said mass, a series of outlet conduits also embedded in said mass, and heat conducting members of differing projection extending from the conduits of one of said series and dividing the entire mass into interconnected masses of substantially uniform size and shape enclosed by said members and said conduits of both said series.

4. In combination, a case containing a contact mass, a series of fluid distributing conduits embedded in said mass, a series of outlet conduits also embedded in said mass, and heat conducting members of differing projection extending radi-' ally from the conduits of the distributing series to divide the entire mass into interconnecting masses of substantially uniform size and shape enclosed by said members and said conduits of both series.

5. In combination, a case containing a contact mass, a series of fluid distributing conduits embedded in said mass, a series of outlet conduits also embedded in said mass, and long and short heat conducting members extending radially from the conduits of the distributing series, all 01' said long members extending toward immediately adjacent conduits of said outlet series.

6. In combination, a case containing a contact mass, a series of fluid distributing conduits embedded in said mass, a series of outlet conduits also embedded in said mass, and long and short heat conducting members extending radially from the conduits of the distributing series, all of said short members extending toward immediately adjacent conduits of said distributing series.

7. In combination, a case containing a contact mass, a series of fluid distributing conduits embedded in said mass, a series of outlet conduits also embedded in said mass, and long and short heat conducting members extending radially from the conduits of the distributing series, said short members extending toward adjacent conduits of said distributing series and being disposed in spaced alignment with similar short members on the latter.

8. In combination, a case containing a contact mass, 9. series of fluid distributing conduits embedded in said mass, a series of outlet conduits also embedded in said mass, and long and short heat conducting members extending radially from the conduits of the distributing series, said long members extending toward adjacent conduits of said outlet series, and said short members extending toward and aligned with similar short members on adjacent conduits of said distributing series.

9. In combination, a container for a contact mass, series of fluid conduits extending into said mass in symmetrical arrangement, and heat conducting means on certain of said conduits extending therefrom into said mass and so arranged in cooperation with their own and adja cent conduits to divide the mass into a plurality of smaller masses of substantially the same size and shape.

10. In combination, a container for a contact mass, a series of distributing conduits embedded in said mass, a series of outlet conduits embedded in said mass in symmetrical arrangement with each other and with said distributing conduits, heat conducting means on the conduits of one of said series extending therefrom into said mass and symmetrically disposed and arranged to divide the mass into a plurality of smaller masses of equal size and shape and generally triangular in cross section, each of said smaller masses being confined between portions of a conduit of one series and two conduits of the other series.

11. In combination, a container for a contact mass, series of fluid conduits extending into said mass in symmetrical arrangement, and heat conducting means in the form of fins radiating symmetrically from certain of said conduits, said finned conduits being so arranged that the fins thereon are disposed in parallel intersecting planes thereby to divide the contact mass into a plurality of masses of the same size and shape.

12. In combination, a container for a contact mass, a series of distributing conduits embedded in said mass, a series of outlet conduits embedded in said mass in symmetrical arrangement with each other and with said distributing conduits, heat conducting means in the form of fins radiating from said distributing conduits and extending longitudinally of the latter, said distributing conduits being arranged to dispose said flns in line with each other in parallel intersecting planes extending across said container thereby to divide the contact mass into a plurality of smaller masses of the same size and shape, each of said smaller masses being generally triangular in cross section and confined between portions of one outlet conduit and of two distributing conduits and the fins thereof.

13. In a reaction chamber containing a contact mass of poor thermal conductivity, heat conducting means embedded in said mass and adapted for distributing fluid therethrough and for withdrawing fluid therefrom, said means comprising perforated conduits and projecting members or fins extending from certain of said conduits, said means being so distributed through said mass that no part of the latter is more than two inches away from said means.

14. In combination, a container for a contact mass, apertured conduits extending into said container and embedded in said contact mass, saidconduits having heat conducting members radiating therefrom, said conduits and said members thereon being symmetrically disposed relative to each other so as to divide said contact mass into a plurality of masses of substantially the same size and shape with no part of any of said last named masses more than two inches from said conduits and/or said members thereon.

15. In combination, a container for a contact' mass, apertured conduits extending into said container and embedded in said contact mass, said conduits having heat conducting fins radiating therefrom, said conduits and said flns being so disposed in said mass that every part of the latter is within at least one and a half inches of a heat conducting surface of said conduits or fins.

16. A conduit adapted to be embedded in a contact mass for the purpose of distributing fluid therein or for removing fluid therefrom, said conduit having apertures at intervals along its length, two series of longitudinally extending heat conducting flns uniformly spaced about said conduit and extending radially therefrom, the fins of one series being of greater projection than the fins of the other series, the fins of both series being arranged to alternate with a short fin diametrically opposite and coplanar with a long fin.

EUGENE J. HOUDRY.

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