US2389399A

US2389399A - Method and apparatus for contacting finely divided solid particles with fluids

Info

Publication number: US2389399A
Application number: US488681A
Authority: US
Inventors: Joseph G Alther
Original assignee: Universal Oil Products Co
Current assignee: Universal Oil Products Co
Priority date: 1943-05-27
Filing date: 1943-05-27
Publication date: 1945-11-20
Anticipated expiration: 1962-11-20

Description

New. 20, 1945. J. G. ALTHER 2,389,399

METHOD AND APPARATUS FOR CONTACTING FINELY DIVIDED SOLID PARTICLES WITH FLUIDS FiledMay 27, 1943 I 3 Sheets-Sheet l q ff ply e7? for" Nov. 20, 1945. ALTHER METHOD AND APPARATUS FOR CONTACTING FINELY DIVIDED SOLID PARTICLES WITH FLUIDS Flled May 27, 1945 3 Sheets-Sheet 2 J. G. ALTHER METHOD AND APPARATUS FOR CONTACTING F INELY DIVIDED SOLID PARTICLES WITH FLUIDS Filed May 2'7, 1945 3 Sheets-Sheet 3 e m a m 7 e a M f a w 0 W a 1 e W 3 i /M f 0 Q n z J UV 9 m 6 4 5 m 3 6 :1 6 k "w a i 1M, m ,4 6 6 w 2 6 m Cu 66 4 ad a3 a 5 fi fi 2 Q n j 7 x/ y d r K 2 d r n w 5 Q4. a a mu m ra r r Z f, 5 2 m5 5 e c l f a n 0 55 km? 5 g 2% 5/ unw lmuuunnn b fil lHHHl l l l -HHWI IHHH S l r. y 9 am 2/ m Patented Nov. 20, 1945 UNITED STATES PATENT OFFICE:

METHOD AND ArPAnA'rUs son CONTACT- ING FINELY mvman soup PARTICLES WITH FLUIDS Joseph G. Althcr, Ohicfll'o, 111., assignor to Universal Oil Products Company, Chicago, 111., a corporation oi Delaware Application May 27, 1943, Serial No. 488,881

14 Claim.

This invention relates to an improved method and apparatus for contacting flnely divided solid particles with fluids and more particularly to a method and apparatus which may be advantageously applied to the catalytic treatment of hydrocarbon oils and gases.

The method and apparatus herein disclosed are especially well adapted to processes for the con version of hydrocarbon oils such as catalytic cracking, dehydrogenation, aromatization, reforming, and the like, although the method may be readily applied to any process in which it isdesired to contact solid particles with streams of fluid. a

' As yet no entirely satisfactory method has been devised for the .continuous countercurrent contacting of finely divided solid particles with fluids, most of the heretofore proposed methods resulting in more or less channeling of the fluids passing through the moving bed of solid particles thereby effecting a relatively ineflicient process. Other difficulties present in conventional methods are high pressure drop, non-uniform contacting and excessive recycling of particles and fluids within the contacting zone.

The present invention ofiers a method by which the aforesaid difliculties can be eliminated in a simple and efiective manner by passing the solid particles downwardly at a steady uniform rate with substantially uniform particle dispersal throughout the contacting zone while at the same time maintainin a flow of the fluid to be contacted in a generally upward direction but substantially transverse to the motion of the dropping solid particles. v

One of the objects of this invention is the provision of a method for the countercurrent contacting of solid particles and fluids with substantially no back circulation of either solid parhydrocarbon oils, the catalyst first passes through a cracking step which is endothermic, therem accumulating a deposit of carbonaceous material which is removed by combustion, which is exothermic, in a succeeding stage of the process. The apparatus as provided in the present invention offers means for utilizing the exothermic heat of combustion as a source of heat for the endothermic portion of the process. 9

Another object of this invention is the provision for a substantially uniform rate of fall of solid particles throughout the contacting zone. This is accomplished by breaking up the fall of particles into a series of relatively short drops by spaced distribution means thereby substantiallybvercoming the accelerating eliect of gravity which in cases where free falling solid particles areemployed results in non-uniform contacting because of the increasing speed of the falling particles as they reach the lower extremity of their travel.

Broadly, this invention concerns a method of contacting a fluid with finely divided solid particles which comprises passing the finely divided solid particles in a downward direction with a 5 substantially uniform cross-sectional particle distribution through a zone through which said fluid is directed helically in an upward'directicn.

In a more specific embodiment, the present invention comprises a continuous process for the conversion of hydrocarbon oils which comprises, passing finely divided solid cracking catalyst particles in a downward direction and with substantially uniform cross-sectional particle distribution through a zone maintained at a cracking temperature, simultaneously passing hydrocarbon vapors helically through said zone in an upward direction in contact with said catalyst particles whereby said hydrocarbon vapors are converted and a carbonaceous material is deposited upon said catalyst particles, withdrawing said catalyst particles having said carbonaceous deposit and passing them commingled with oxygen-containing gas in anupward direction and in heat exchange relation with but out of contact with said hydrocarbon vapors and said downward passing catalyst particles whereby said carbonaceous deposit is removed from said upward catalyst particles by combustion, separating the thus reactivated catalyst particles from the products of combustion and returning said reactivated cata--' iystparticles to said zone to again pass downwardly therethrough.

In order to more clearly illustrate the features and advantages or the present invention, rei'erence is made to the accompanying din drawings and following description thereof in connection with a catalytic cracking process.

Figure 1 of the drawings is an elevational view partly in section of one form of apparatus in which the process of the present invention may be conducted.

Figure 2 is an enlarged detail of a portion of the apparatus illustrated in Figure 1.

Figure 3 is an elevational view of a modified form of apparatus in which the present invention ma be conducted.

Figure 4 is another alternate form of appara tus for use in accomplishing the rocess herein disclosed.

Figures 5 and 6 illustrate two of the many possible arrangements of helical flights and heat exchange conduits which may 'be utilized.

Referring now to Figures 1 and 2, the main body of the contactor comprises an elongated substantially cylindrical shell i, closed at its lower end by a conical head 2 and at its upper end by the conically shaped head 3. Centrally dispors controlled by valve 1 may be introduced to the contactor. The reaction products are withdrawn through conduit 8 controlled by valve 3 from the upper portion or the contactor. Conduit 4 extends through head 3 and terminates in a cyclone separator ill, the eiiluent gases from which pass through conduit i I controlled by valve i2. Solid particles separated out in separator Ill pass through conduit l3 controlled by valve l4 to enter the upper portion of the contactor.

The finely divided solid particles introduced to the contactor through conduit 13 pass downwardly through the perforations in the helical flights and are removed from the lower end by means of conduit [5 controlled by valve i6.

When operating the contactor in a catalytic cracking process, finely divided cracking catalyst particles either informed shapes or as granules or powdered are introduced through conduit i3 controlled by valve I4. The size and density of the finely divided solid particles should be such that with the fluid velocities employed in the contacting zone, relatively little carrying efiect will be exerted by the fluid on the solid particles. The relative directions of travel of the solid particles and the fluid stream will, of course, have an effect upon the particle size and density which may be successively employed. For example, with true I countercurrent flow larger and/or denser partiline 8 controlled by valve 1 and pass spirally up the contactor, thereby contacting the falling catalyst particles and the reaction products will be withdrawn through line 8 controlled. by valve 3. The contaminated or spent catalyst particles will be withdrawn through conduit l5 controlled by valve i6 and will be commingled with oxygencontainlng regenerating gas passing through conduit 4 controlled by valve 1. The regenerating gas will act as a carrying medium for the catalyst particles conducting them upwardly through conunit 4. At the same time, the oxygen will cause combustion of the carbonaceous deposit on the catalyst, thereby supplying heat to the contactor. Additional oxygen may be introduced to conduit 4 through lines I 8 and I3 controlled by valves 20 and El respectively. This additional oxygen will supplement the original oxygen in the regenerat-. ing gas and spread out the burning in conduit 4 to more uniformly distribute the heat to the contactor. The length of condudt 4 within the contactor and the amounts of oxygen supplied at the various points should be regulated to obtain substantially complete burning of the carbonaceous deposit within the contactor.

The reactivated catalyst will be separated from the combustion products in separator i0 and be returned to the contactor through conduit I3 controlled by valve M. The spent regenerating gas will leave separator ill by means of conduit ll controlled by valve i2. Makeup catalyst may be introduced through line 22 controlled by valve 23 and suitable inert stripping medium may be introduced to conduit I3 through line as controlled by valve 25. The spent catalyst in conduit i5 may be stripped by suitable inert medium supplied through line 26 controlled by valve 21.

In some cases" where insufficient heat is supplied by the reactivation of the contaminated catalyst,

to conduct the endothermic cracking reaction it may be desirable to house the entire contactor in a furnace.

In Figure 3 is illustrated a modified form of the apparatus in which the present process may through conduit 36 controlled by valve 3'! after stripping with suitable medium introduced through line 38 controlled by valve 39. The spent catalyst will commingle with oxygen-containing regenerating gas in conduit 40 and pass upwardly through the contactor and into regenerator 3i. In its upward passage through the contactor, the carbonaceous deposit on the catalyst will be at least partially removed by combustion and the remaining deposit will be burned oil in regenerator 3!. Additional oxygen may be introduced to conduit 40 to finish the burning by means of line 4! controlled by valve 42. The upward velocity of the regenerating gas in vessel 3| is insuflicient to maintain the catalyst particles moving in an upward direction, and settling therefore will take place thereby forming two phases of catalyst and gas. one relatively dense and the other light, the line of demarcation therebetween being indicated by the broken line 43. The eflluent gas from regenerator 3| will pass through conduit 44 into separator 45 and suspended catalyst particles will be removed and returned through conduit 4 to the dense phase in vessel 3 I. Reactivating cataLvst will be withdrawn from regenerator 3| by means of conduit" controlled by valve 48 passing into the upper end of contactor ".1 Suitable stripping gases may be introduced to conduit 41 by means of line 49 controlled by valve 50. The spent regenerating gases leaving separator 45 are recycled through conduit SI. and by means of blower 52 are returned through conduit 40 to act as carrying medium for the spent catalyst particles. Controlled quantities of oxygen-containing gases may be introduced through line 53 regulated by valve 54. Makeup catalyst may be introduced to the system through line 55 controlled by valve 58. Heat may be removed from the regenerating gases by means of a suitable waste heat boiler or heat exchanger ii. The pressure. on the system is maintained by means of pressure regulating valve I58, in conduit 59.

Aslin the apparatus shown in Figure 1, contactor 80 may be enclosed in a suitable heater or may be covered with suitable insulation not shown in order to conserve the desired heat for the processing reaction.

Figure 4 illustrates another modified form of the apparatus shown in Figure 1 which can be advantageously used in cases where more burning time is required to regenerate the spent catalyst. In this apparatus, the contactor is designated by numeral 60 which may besupplied with hydrocarbon vapors by means of conduit Bl controlled by valve 32, and the reaction products maybe withdrawn through conduit 63 controlled by valve 64. Reactivated catalyst will be introduced to the contactor by means of conduit 65 controlled by-valve 66. This catalyst may be stripped by suitable inert gases introduced through line 8'! controlled by valve 68. Makeup catalyst may be introduced to the system through line 39 controlled by valve 10. The catalyst particles will pass downwardly through contactor 60 effecting the desired conversion and the contaminated particles will be withdrawn through conduit ll controlled by valve 12. A suitable inert stripping medium may be introduced to conduit Ii, by means of line 13 controlled by valve 14. The spent catalyst particles after passing through valve 12 will be commingled with an oxygen-con- 'taining regenerating gas in conduit I5 bymeans of which they will be transported upwardly through the contactor and into regenerator 16.

as and utilized in any desired portion 01' the plant. v

Figure 5 shows across-sectional view through one of the contactors having 4 helical flights and one centrally disposed heat exchange conduit. It

is well within the scope of the invention; h'owever, to employ any convenient number of helical flights or heat exchange conduits; for example, a contractor having 6 perforate helical flights and 7 heat exchange conduits as'illustrated in Figure 6 may be employed.

Suitable conversion conditions and catalysts for the various processes coming within the scope of the present invention are well known in the art and need not be dealt with in detail in this specification.

I claim as my invention:

1. A continuous process for'the conversion of hydrocarbon oils which comprises passing finely divided solid cracking catalyst particles in a downward direction and with substantially uniform cross-sectional particle distribution through a, zone maintained atva cracking temperature, simultaneously passing hydrocarbon vapors helically through said zone in an upward direction in contact with said catalyst particles whereby said hydrocarbon vapors are converted and a carbonaceous material is deposited upon said catalyst particles, withdrawing said catalyst particles having said carbonaceous deposit and pass-' ing them commingled with oxygen-containing gas in an upward direction in heat exchange rela-.

' tion with but out. of contact with said hydrocar- Additionalair may be introduced to complete the regeneration of the catalyst by means of line 86 controlled by valve 81. In regenerator 16, the catalyst particles suspended in the regenerating gases will tend to settle because of the decreased velocity of the gases and will therefore have more time for completing reactivation. The emuent gases-from regenerator 16 containing suspended reactivated catalyst particles will be removed by means of conduit Ti and directed to separator It; The catalyst particles will be removed therein and returned to the contactor by means of conduit 65. The spent regenerating gases will be withdrawn from separator 18 by means of conduit I9 and will be recycled by blower 80 to conduit l5. Oiwgen-containing gases may be introduced to the regenerating gas stream through conduit 8! controlled by valve 82, and excessive pressure in the system is relieved by pressure regulating valve 93 in conduit 84. Heat may be removed irom the recycling regeneratinggases in a suitable heat exchanger or waste heat boiler bon vapors and said downward passing catalyst.

particles whereby said carbonaceous deposit is removed from said upward passing catalyst particles by combustion, separating the thus reactivated catalyst particles from the products of combustion and returning said reactivated catalyst particles to said zone to again pass downwardl therethrough;

2. A continuous process for the conversion of hydrocarbon oils which comprises passing finely divided solid cracking catalyst particles in a downward direction and with substantially uniform cross-sectional particle distribution through a.

zone maintained at a cracking temperature, simultaneously passing hydrocarbon vapors hell'- cally through said zone in an upward direction in contact with said catalyst particles whereby said hydrocarbon vapors are converted and d carbonaceous material is deposited upon said catalyst particles, withdrawing said catalyst particles having said carbonaceous deposit and passing them commingled with oxygen-containing gas in an upward direction in heat exchange relation with butout of contact with said hydrocarbon vapors and said downward passing catalyst parbonaceous deposit on said catalyst particle's supplies at least a portion of the endothermic heat of the cracking reaction.

4. The process as defined in claim 2 .iurther characterized in that the combustion of said carbonaceous deposit on said catalyst particles supplies at least a portion or the endothermic heat during its separate passage in heat exchange relation with but out of contact with said hydrocarbon vapors and said downward passing catalyst particles.

"I. An apparatus for contacting finely divided solid particles with a fluid which comprises in combination a vertically elongated closed vessel, at least one perforate helical flight having perforations of sumcient size to pass said finely divided solid particles and extending within said vessel from adjacent its lower end to adjacent its upper end, at least one vertically disposed conduit extending through said vessel from one end to the other, means for introducing finely divided solid particles to the upper end of said vessel, means for withdrawing said solid particles from the lower end of said vessel and directing them into and through the aforesaid at least one vertically disposed conduit, meansfor introducing flui to the lower end of said vessel and means for withdrawing fluid from the upper end of said vessel.

'8; An apparatus for contacting finely divided solid particles with a fluid which comprises in combination a vertically elongated closed vessel, a plurality of perforate helical flights having periorations of sufficient size to pass said finely dividedsolid particles and extending within said vessel from adjacent its lower end to adjacent its upper end. a plurality of vertically disposed conduits extending through said vessel from one end to.the other, means for introducing finely divided solid particles to the upper end of said vessel, means for withdrawing said solid particles from 'the lower end of said vessel and directing them into and through said vertically disposed conduit, means for introducing fluid to the lower end of said vessel and means for withdrawing fluid from the upper end of said vessel.

- 9. An apparatus for contacting finely divided solid particles with a fluid which comprises in combination a vertically elongated closed vessel,

at least one conduit extending through said vessel from one end to the other thereof, at least one perforate helical flight extending within said vessel fromadjacent its lower end, to adjacent its upper end, said conduit and helical flight being so arranged that they in combination occupy sub-- stantially the entire cross-sectional area of said 10. A conversion process which comprises pass- 1 ing a subdivided solid catalyst downwardly with substantially uniform cross-sectional particle distribution through a reaction zone, simultaneously passing hydrocarbon vapors upwardly in a hellcal path a through said zone, endothermically reacting the vapors while in countercurrent contact with the catalyst in said zone, removing carbonized catalyst from the reaction zone and passing the same with oxygen-containing gas in an upward direction in indirect heat exchange rela, tion withthe vapors and catalyst in the reaction zone, burning carbonaceous matter from the catathrough said chamber, a perforated helical baiile disposed within the reaction chamber around said conduit, a separator communicating with the upper end of said conduit, means for assing solid particles from the lower portion of said chamber upwardly through said conduit into-the separator, and means for returning solid particles from the separator to the chamber,

12. A method of catalyzing a conversion reac, tion with finely divided solid catalyst particles which comprises passing a fluid to be converted upwardly through a reaction zone in a helical path around a helical bailie, maintaining said zone under conversion conditions, simultaneously passing the solid particles in a downward direction through said zone in contact with the fluid, and dropping said particles from flight to flight of the helical baflie to provide substantially uniform cross-sectional particle distribution through said zone.

13. A method of converting hydrocarbons in the presence of subdivided solid catalyst particles, which comprises passing a hydrocarbon vapor upwardly through a reaction zone in ahelipassing the solid particles in a downward direction through said zone in contact with the vapor, and dropping said particles from flight to flight of the helical baiiie to provide substantially uniform cross-sectional particle distribution through said zone.

14. A catalytic cracking process which comprises passing hydrocarbon vapors at cracking temperature upwardly through a reaction zone in a helical path around a helical baiile, simultaneously passing subdivided particles of a solid cracking catalyst in a downward direction through said zone in contact with the vapors,- and dropping said particles from flight to flight oi. the

helical baflle to provide substantially uniform cross-sectional particle distribution through said zone.

JOSEPH G. ALTHER.