US2577791A - Catalytic contacting unit with gas separator - Google Patents

Description

Dec. 11, 1951 D. MCKINNEY 2,577,791

CATALYTIC CONTACTING UNIT WITH GAS SEPARATOR Filed Dec. 31, 1947 INVENTOR ATTORN Y Patented Dec. 11, 1951 CATALYTIC CONTACTING UNIT WITH GAS SEPARATOR Dwight D. McKinney, Drexel Hill, Pa., assignor to Houdry Process Corporation, Wilmington, DeL, a corporation of Delaware Application December 31, 1947, Serial-No. 795,052

4 Claims. (01. 23-288) My invention relates to methods of an apparatus for either disengaging or engaging vapors or gases from or with contact material during movement thereof through a reaction housing.

My invention relates generally to a system wherein hydrocarbon vapors undergo conversion or reaction in the presence of heated contact material which moves or gravitates through a reaction housing. With a system of this character, it becomes necessary for vapors to be either disengaged from or engaged with the contact material in a lower zone of the reaction housing. This, in accordance with my invention, is accomplished in a novel and highly satisfactory manner.

To this end, in accordance with a broad concept of the invention, the contact material, during movement thereof through the aforesaid zone, is deflected in response to converging movement thereof along facing, downwardly inclined surfaces arranged, respectively, in diverging-converging relation as regards the vertical axis of the reaction housing.

From a somewhat broader aspect of the invention, the contact material, during movement thereof through the specified zone, may be deflected in response to movement thereof along a circumferentially complete surface inclined downwardly from the interior surface of the reaction housing and forming a circumferentially complete chamber therewith. More particularly, this downwardly inclined surface cooperates with the surface defined by a chamberforming conical member having its vertical axis coinciding with that of said reaction housing in order to effect converging movement of the contact material as referred to above.

Various other objects and advantages of my invention will become apparent from the following detailed description.

My invention resides in the disclosed methods and apparatus for either disengaging or engaging vapors or gases from or with moving contact material, the method steps, features and arrangements ofthe character described and claimed.

For anunderstanding of my invention and for an illustration of one form of apparatus with which the invention may be practiced, reference is to be had to the accompanying drawings in which:

Fig. 1 is a vertical sectional view, partly in elevation, showing apparatus as constructed in accordance with one form of the invention; and

Figs. 2 and 3 are horizontal sectional views, partly in plan, taken on the respective lines 2-2 and 3-3 of Fig. 1.

In an application filed of even date herewith Serial No. 795,051, filed December 31, 1947, I

' have disclosed an arrangement, which is generally similar to the arrangement herein disclosed, for controlling movement of gravitating contact material first through an engaging or disengaging zone and then through a purging zone, the present application being generic as regards said engaging or disengaging zone.

Referring to Fig. 1, I have shown a vertical housing I which, in horizontal cross section, may be circular or of any other suitable configuration. The housing 'I defines a reaction zone wherein hydrocarbon material is cracked or otherwise converted in the presence of contact material C which moves therethrough under the influence of gravity, the contact material C, usually after regeneration thereof in a suitable regenerating zone, not shown, being introduced into said housing I in suitable manner, as by an inlet pipe 2 extending through the top housing wall at the center thereof. As herein shown, the contact material C which gravitates through the pipe 2 may be discharged into a hopper 3 suitably supported at the top of the housing I. Depending from and communicating with the hopper 3 are a plurality of angularly related pipes 4 arranged substantially as a circular row around a center coinciding approximately with the vertical housing axis. The contact material, under the infiuence of gravity, gravitates through the hopper 3 and the pipes 4 below which it forms a downwardly moving solid bed B of contact material, the upper surface of which has conical configuration beneath each of the pipes 4. The lower end of the housing I, which may be conical, communicates with a discharge pipe 5 through which the spent" contact material passes toward the aforesaid regenerating zone. In known manner, the pipe 5 has associated therewith a valve 5a which restricts or impedes the flow of contact material therethrough so that, in the housing I, the contact material moves downwardly in solid bed fashion as noted above.

When hydrocarbon material is to be cracked in the housing I, the contact material C hereinbefore referred to should be catalytic in character and the temperature thereof, upon admission to the housing I, should range between 800 F; and 1000 F. or higher, for example, about 300 F. Any suitable kind of catalytic contact material may thus be utilized such, for example, as activated clay pellets, or synthetic silica-alumina pellets or beads, etc. having suitable major dimensions such as between "1 5 and of an inch. Other suitable catalysts for cracking include synthetic plural oxide composites, silicious or nonsilicious in character and containing, for example, zirconia, alumina or beryllia. In lieu of a cracking operation, other types of conversion operations such, for example, as one wherein hydrocarbon material of the character referred to below is desulphurized under known conditions with catalytic contact material of the general character referred to above, or equivalent. Or, reforming or dehydrogenation of naphthas or other normally liquid hydrocarbons may be effected in the presence of the above or other desired types of catalyst, certain of which are well known in the art. In lieu of the conversion operations described above, heavy hydrocarbon material may be vaporized and viscosity-broken in the presence of inert contact material of known character.

Hereinafter, in a detailed manner, the invention is described with respect to an operation involving disengagement of converted vapors from suitable cracking contact material which may be of the character described above. During such an operation, hydrocarbon vapors such, for example, as vaporized gas oil, naphtha or lighter hydrocarbons having suitable elevated temperature, as in a range from 750 F. to 1000 F., are admitted continuously through a pipe 6 to the space above the bed B. As hereinafter described,

these vapors pass through the housing I concurrently as regards the gravitating contact material C and, in the presence thereof, are subjected to a cracking operation, the resulting cracked vapors, in accordance with the invention, being disengaged from the contact material in a novel manner as hereinafter described. As this operation proceeds, a suitable gaseous medium such as steam is admitted, in accordance with the invention to the lower portion of the housing I to prevent passage of cracked products through the pipe 5.

Relerring particularly to Figs. 1 and 3, I have shown a chamber-defining, conical deflecting member I which may comprise a cylindrical lower portion la, Fig. l. concentrically disposed with respect to the conical member 1 is a chamber-defining annular member 8. As shown, the annular member 8 may be defined by sloping inner and outer sides which converge upwardly to an apex having annular configuration, said inner and outer sides terminating, if desired, in the respective lower portions 8a and 8b, the lower portion 8a being annular and concentrically disposed with respect to the aforesaid lower portion Ia of the conical member 1 whereas the lower portion 82), throughout its circular length, is spaced equidistantly from and at the same angle as the adjacent interior surface of the lower conical end of the housing I. As shown, all of the lower portions of the members I and 8 may terminate at a common horizontal plane. The members 1 and 8 may be supported in any suitable manner for example, as disclosed in my aforesaid pending application.

A pipe 9 extends from the exterior of the housing I into and through the chambers defined by the respective members 'I and 8, this pipe being provided with ports or passages 9a which communicate with said chambers, respectively. For the purpose hereinafter described, this pipe 9 is traversed by a gaseous medium which is engaged with the contact material at the lower surfaces of the members I and 8.

Resting upon the annular apex of the member 8 and secured thereto in suitable manner, as by a welded joint, is an upstanding tubular member It]. A second tubular member II having height substantially less than that of the tubular member I0 is disposed exteriorly thereof in concentric spaced relation with respect thereto. As shown, the upper surface of the member II is disposed to substantial extent below the corresponding surface of the member I0. A third tubular member I2 is disposed below and outwardly of the tubular member II, the upper sur-'- face of said tubular member I2 being disposed at the same level as the lower surface of the tubular member II. Extending upwardly from the upper surface of the tubular member II is a circumferentially complete, frusto-conical member I3 .which engages and is secured to the interior surface of the housing I. The member I3, with the adjacent interior surface of said housing I, defines a chamber A having disposed therein a plurality of frusto-conical members I4 arranged in spaced, inter-leaved relation. As shown, the respective upper surfaces of the outer members I4 are spaced from the adjacent surface of the member I3 whereas the upper surface of the inner member I4 is secured to said member I3. Accordingly, the members I4 define a circuitous path within the chamber A which is utilizable as hereinafter described.

symmetrically disposed interiorly of the circumferentially complete member I3 is a conical member I5, which defines a chamber AI, the vertical axis of which, preferably, coincides substantially with that of the housing I. Depending from the conical member I5 is a tubular member I6, the lower surface of which may be disposed at approximately the same level as the upper surface of a tubular member I! which is disposed symmetrically around the aforesaid conical member I.

In accordance with a detailed feature of the invention, a plurality of inverted frusto-conical members I8 may be disposed within the chamber AI of the conical member I5. In suitable manner, the members I8 may be disposed generally in spaced nested relation so as to form a circuitous path utilizable as hereinafter described.

Further in accordance With another detailed feature of the invention, the lower surface of a frusto-conical screen I9, or equivalent, extends from the upper surface of the aforesaid tubular member I2 and engages the tubular member II. Similarly, the lower surface of another frustoconical screen 20, or equivalent, extends from the upper surface of the aforesaid tubular member I1 and engages the tubular member IS. The screens I9 and 20 should be welded or otherwise suitably secured to surfaces engaged thereby and the mesh thereof should be such that, as regards the contact material, only fines of such material are capable of passing therethrough.

Referring particularly to Fig. 1, a chamberdefining annular member 2I, the use of which is optional, is shown as disposed in the zone defined by the members I3 and I5, said annular member 2| being concentrically disposed with respect to the conical member I5. As shown, the annular member 2I may be defined by sloping inner and outer sides which converge upwardly to an apex having annular configuration, said inner and outer sides preferably terminating in the respective inclined portions 2 la.

Disposed within the annular member 2I, preferably in alinement with the apex thereof, is a tubular member 22 with which sets of frustoconical members 23, 23 and 24, 24 are cooperative in a passage-defining manner.

As shown. the members 28, 23 interiorly engage the respective inner and outer sides of the annular member 2| at a common level, and terminatein spaced relation with respect to the tubular member 22. The members 24, 24 are spaced interiorly from the respective inner and outer sides of said annular member 2| at a common level and, preferably, the members 24, 24 project below the lower surfaces of the inclined portions 2|a to substantial extent.

It will be understood that the various tubular, frusto-conical, conical and annular members hereinbefore described are supported in their respective positions in any suitable manner, for example, in the general manner described with re- *spect to the corresponding members disclosed in In the form of the invention herein shown, the

housing I is a cylindrical vessel which is circular in horizontal section. The vertical axis of the member I, the member 8, the conical members I3 and I5, and the member 2| are shown as coinciding with the vertical axis of the housing I. The same holds true as regards all of the parts previously described which are eircumferentially complete and extend either vertically or in inclined relation interiorly. of the lower portion of the housing The conical member I5 is inclined downwardly in symmetrical diverging relation with respect to the vertical axis of the housing and, likewise, the conical member I3 is inclined downwardly in symmetrical converging relation with respect to said housing axis. Hence, these two members define a path through which the contact material converges as it gravitates between them. The relation described immediately above is a preferred arrangement although, in some of its broader aspects, the invention is not to be thus restricted.

All of the parts hereinbefore described with the exception of the vertical tubular members and the pipes 25, 28 deflect the downwardly moving contact material and, therefore, these parts should be positioned with respect to a horizontal plane at an angle greater than the angle of repose of the moving contact material so as to at least minimize or even avoid retarded or hindered flow of the contact material on surfaces contacted thereby.

As hereinbefore stated, the contact material C, during operation of the disclosed apparatus, gravitates through the housing in solid bed fashion. Simultaneously, hydrocarbon vapors to be cracked are admitted continuously by way of the pipe 6 to said housing I and conditions are maintained such that the interior housing pressure is determined by that existing in the hereinbefore described outlet pipe 26. In known manner, a suitablesealing medium, such as a stream of flue gases, is admitted to the top of the housing by way of a pipe Ia, Fig. 1, this sealing medium being maintained under pressure slightly greater than the interior housing pressure in order to prevent passage of hydrocarbon vapors upwardly through the pipe 2. Accordingly, the admitted hydrocarbon vapors pass downwardly concurrently as regards the gravitating contact material and are disengaged therefrom in the manner hereinafter described. As the foregoing operation proceeds, steam, flue gases or other suitable purging gaseous medium is admitted to the chamber-forming members 1 and 8 by way of the pipe 9. The purging medium which is thus admitted is under pressure greater than that existing at the level of the aforesaid pipe 26 and. at the lower surfaces of the respective members I and 8, the purging medium is engaged with the contact material for passage upwardly and downwardly therethrough. In known manner. the operation last described prevents passage of cracked hydrocarbon vapors through the pipe 5.

The contact material, during passage thereof through the lower portion of the housing I, passes in converging manner between the conical members I3 and I5. In addition, the annular member 2|, when utilized imparts an-additional converging component to said contact material. The contact material thus converges until it arrives at the upper surfaces of the tubular members II and I6 through which it passes as a tubular stream.

By far the larger portion of the gravitating contact material moves through the lower portion of the housing I in the manner described above. However, contact material fines enter the chambers A and A I. These fines, as the operation continues, pass from said chambers through the respective lower outlets thereof and join the main column of gravitating contact material.

As stated above, hydrocarbon vapors to be converted are admitted continuously to the housing I by way of the conduit 6. As the operation proceeds, these vapors pass downwardly through said housing I, concurrently as regards the gravitating contact material, and are converted to cracked vapors which are disengaged from said contact material principally at the lower surfaces of the respective portions 2Ia of the annular member 2|, and at the lower surfaces of the respective tubular members II and I6.

The vapors which are disengaged in the zone of the annular member 2| pass along a circuitous path as imposed thereon by the members 23, 23 and 24, 24 with resultant separation from said vapors of contact material fines which thereafter gravitate downwardly, these vapors, substantially free from fines, passing into the chamber AI by way of the pipes 25. The vapors which are disengaged from the contact material C at the lower surface of the tubular member I6 pass through the screen 20 and enter said chamber AI where, as imposed by the members I8, they pass along a circuitous path with resultant separation therefrom of fines which thereafter gravitate downwardly. All of the substantially fines-free vapors thus entering the chamber AI pass therefrom by way of the pipe 26.

The vapors which are disengaged from the contact material at the lower surface of the tubular member II pass through the screen I9 and enter the chamber A. These vapors, under the control of the members I4, pass along a circuitous path with resultant separation therefrom of fines which thereafter gravitate downwardly, the substantially fines-free vapors leaving the chamber A by way of the pipe 21.

An important feature of the invention disclosed herein and also in my aforesaid pending applicatlon relates to the controlled movement of the contact material through the disengaging zone. In each instance, above the disengaging zone, the contact material gravitates in solid bed fashion. Thereafter, upon admission into and during passage through said disengaging zone, the contact material gravitates along facing, downwardly inclined surfaces arranged, respectively, in diverging-converging relation as regards the vertical axis of the reaction housing, these surfaces being exemplified by the conical members I3, I herein disclosed and by the conical screens disclosed in said pending application. Thus, as regards both applications, the contact material, while moving through the disengaging zone, flows as an annuular converging stream, the outer surface of this streamprogressively receding from the wall surface of the housing I during continued downward movement of the contact material.

As regards the disengaging operation, the described converging movement of the contact material is advantageous principally by reason of the fact that the amount of contact material which may be passed through the disengaging zone per unit of time, while obtaining efllcient disengagement of vapors, is substantially greater than the amount of contact material which may be passed through prior art reactors during the same unit of time assuming, in each instance, that the vapor flow is maintained substantially the same and that the height of the prior art disengaging zone remains unchanged. It should be noted that, as regards the present application, the efficiency of the disclosed disengaging system is improved as the annular space between the members II and I6 approaches the minimum space relation consistent with the passage therethrough of suiiicient contact material to maintain the desired rate of movement of contact material through the reaction zone proper.

Aside from the disengaging characteristic of the invention referred to above, the described arrangement for causing the contact material to move as an annular converging stream is desirable as regards the transition which necessarily occurs during the period that elapses while the contact material is being directed to the pipe 5 after movement thereof in solid bed fashion has ceased.

As stated above, disengagement of vapors occurs at the lower surfaces of the tubular members I I and I6. Some excess steam or other purging medium admitted to the housing by way of the pipe 9 mingles with these vapors and passes upwardly therewith into the respective chambers A and AI. The screens I9 and 20 are provided to prevent upward movement of the contact material in case the velocity and volume of all the vapor material last noted should be such as would otherwise cause this action to occur.

The tubular members I0, I2 and I1 assist in decreasing surging of the gravitating contact material and this aids in obtaining maximum removal of vapors from the contact material with minimum introduction of the purging medium by way of the pipe 9. In addition, the tubular members I2 and II are so located that they do not substantially retard gravitational movement of contact material fines.

After the contact material passes below the zone of the disengager arrangement described above, it engages and is deflected, during convergence thereof under the influence of the conical lower end of the housing I, by the chamberdeflning members 1, 8. Thereafter all of the 8 contact material passes through the pipe 5. As this operation proceeds, the purging medium is admitted continuously to the interior of the chamber-defining members I and 8 for engagement with the contact material at the respective lower surfaces thereof.

As stated in my aforesaid pending application, the chamber-forming members 1 and 8 have a dual function. That is, these members define chambers through ,whioh the purging medium passes prior to engagement thereof with the contact material and, in addition, said members maintain the gravitating contact material in separate streams as it passes through a major portion of the lower conical end of the housing I. Resulting from the function last stated, undesired channelling of the contact material is minimized or substantially prevented and this is accomplished in the absence of the horizontal prior art tube sheets which, ordinarily, are utilized for this purpose.

In its broader aspects, the invention is not to be limited to the detailed form thereof hereinbefore described. Thus, within the broad scope of the invention, there may be wide departure from the disclosed mechanical form of the disengager arrangement, the engager for the purging medium and the supporting mechanism therefor. It will be understood that the conical members, tubular members and other mechanical parts are formed from steel which is suitably resistant to the action of high temperature.

Although the preceding description relates specifically to apparatus which is utilized for disengaging purposes, it shall be understood as hereinbefore stated, that such apparatus may be utilized for engaging vapors with contact material. If so, it may be desirable for apparatus such as the members I4, I8, 23 and 24 to be omitted.

The claims of the present application are directed generally to a disengaging or engaging zone through which the contact material moves in a converging manner as hereinbefore described. A zone of this character may be defined by the conical members-I3, I5 herein disclosed, by the conical screens disclosed in my aforesaid pending application or otherwise as may be desirable.

With respect to my invention as hereinbefore described, vapors may pass in either direction along a path extending from the interior of the housing I to the exterior thereof, this path, interiorly of said housing I, communicating with the gravitating contact material in any suitable manner after convergence thereof has been initiated. In the appended claims, then, it shall be understood that expressions specifying that vapors are passed along a path as described are intended to be descriptive either of a disengaging operation or an engaging operation.

Obviously many modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof and, therefore, only such limitations should be imposed as are indicated in the appended claims.

I claim as my invention:

1. In gas-solid contacting apparatus, the combination of a housing adapted to be traversed by gravitating contact material and gas, a circumferentially complete member inclined downwardly from the lower interior surface of said housing and forming a circumferentially complete chamber therewith, a conical member disposed substantially concentrically with respect to the vertical axis of said reaction housing within the chamber defined by said circumferentially complete member and defining therewith the boundaries of a passageway into which the contact material converges during gravitational movement thereof, and means for the passage of gas, which means communicates with the exterior of the housing, with the contact material and includes saidchamber.

2. In gas-solid contacting apparatus, the combination of a reaction housing adapted to be traversed by gravitating contact material and gas, a circumferentially complete member inclined downwardly from the lower interior surface of said housing and forming a circumferene tially complete chamber therewith, a conical member and an annular chamber defining member, both disposed concentrically with respect to the vertical axis of said reaction housing within the space bounded by said circumferentially complete member with said annular member disposed between said circumferentially complete member and said conical member, all of said members defining boundaries of passageways into which the contact material converges during gravitational movement thereof, and means for the passage of gas, which means communicates with the exterior of the housing, with the contact material and includes said circumferentially complete chamber.

3. In gas-solid contacting apparatus, the combination of a housing adapted to be traversed by gravitating contact material and gas, a circum ferentially complete member inclined downwardly from the lower interior surface of said housing and forming a circumferentially complete chamber therewith, a conical member disposed substantially concentrically with respect to the vertical axis of said reaction housing within the chamber defined by said circumferentially" complete member and defining therewith the boundaries of a passageway into which the contact material converges during gravitational movement thereof, means for the passage of gas, which means communicates with the exterior of the housing, with the contact material and includes said'chamber, a plurality of annular chamber defining members spaced below said circumferentially complete member and said conical member and a second means for the passage of gas, which second means for the passage of gas extends between the exterior of said housing and said annular chamber defining members.

4. In apparatus for the contact of gas with a bed of solid particles in, a contacting chamber, said apparatus comprising a closed housing containing said contacting chamber, means for introducing said particles to said housing and to said chamber, means for removing said particles from said housing, and means for introducing gas to said housing for iiow'through said bed of particles, the combination'thereof with gas disengaging means comprising a hollow conical member positioned within said contacting chamber, a plurality of inverted frusto-conical bafiie members concentrically positioned within the hollow particle-free space under said conical member and radially spaced from the latter and from each other so as to form a plurality of upwardly extending annular passages therebetween, alternate baflle members being attached along their upper circumference to the underside of said conical member, thereby providing a tortuous path to the upper region of said hollow space for gas disengaged from the exposed surface portion of said bed beneath said hollow conical member, and means for removing disengaged gas from said upper region.

DWIGHT D. MCKINNEY.

REFERENCES or'rnn The following references are of record in the file or this patent:

UNITED STATES PATENTS

Claims (1)

1. IN GAS-SOLID CONTACTING APPARATUS, THE COMBINATION OF A HOUSING ADAPTED TO BE TRAVERSED BY GRAVITATING CONTACT MATERIAL AND GAS, A CIRCUMFERENTIALLY COMPLETE MEMBER INCLINED DOWNWARDLY FROM THE LOWER INTERIOR SURFACE OF SAID HOUSING AND FORMING A CIRCUMFERENTIALLY COMPLETE CHAMBER THEREWITH, A CONICAL MEMBER DISPOSED SUBSTANTIALLY CONCENTRICALLY WITH RESPECT TO THE VERTICAL AXIS OF SAID REACTION HOUSING WITHIN THE CHAMBER DEFINED BY SAID CIRCUMFERENTIALLY COMPLETE MEMBER AND DEFINING THEREWITH THE BOUNDARIES OF A PASAGEWAY INTO WHICH THE CONTACT MATERIAL CONVERGES DRUING GRAVITATIONAL MOVEMENT THEREOF, AND MEANS FOR PASSAGE OF GAS, WHICH MEANS COMMUNICATES WITH THE EXTERIOR OF THE HOUSING, WITH THE CONTACT MATERIAL AND INCLUDES SAID CHAMBER.

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