US2663593A - Apparatus for handling granular material - Google Patents

Description

Dec. 22, 1953 R. T. SAVAGE 2,663,593

APPARATUS FOR HANDLING GRANULAR MATERIAL Filed Dec. 15, 1951 2 Sheets-Sheet l INVNTOR K 6 256 12 [Jar age LJM VGA-MAL ATTORNEY Dec. 22, 1953 R. T. SAVAGE APPARATUS FOR HANDLING GRANULAR MATERIAL Filed Dec. 15, 1951 2 Sheets-Sheet 2 P/VfUMAT/C 4 INVENTOR v Kev/fie!) Zl/Zwage BY LA'mM MW ATTORNEY Patented Dec. 22, 1953 APPARATUS FOR HAN piano GRANULAR 4 MATER AL Reuben T. Savage, Ridley Houdry Process Corporation;

Park, Pa, assigimr to W m Del-l a corporation of Delaware Application December 15, 1951-, "Serial No. 261,840

6 Olaims. (Cl. 302-47) Thisinvention relates to the handling of granular material, such as contact material in the form of beads or pellets, having a particle size in the range of about 1-l5, and preferably about 2-8, millimeters in diameter, employed in the catalytic conversion of hydrocarbona The invention is particularly directed to a method and apparatus for transporting the granular material as a continuously moving stream over both an extended lateral or substantially horizontal distance and an extended ve'rtical distance.v

The invention finds particular application in the transfer of granular catalyst from point of delivery, such as a railroad siding, directly to the fresh catalyst make-up hopper of acatalytic hydrocarbon conversion unit, such as the type referred to in the article entitled Houdriflow': New design in catalytic cracking appearing at page 78 of the January 1-3, 1949; issue or the "Oil and Gas Journal.

I-Ieretofore it has been a practice when charging the storage hopper o'f'a hydrocarbon conversion unit with fresh make-up catalyst, to T1111- load the catalyst, which is commercially packed in moisture-proof bags, from a railroad car sitli ated at the nearest point of rail delivery, and to transport the bags of catalyst by a separate vehicle to the loading point of an elevator which is especially provided to elevate the catalyst substantially vertically to. the catalyst make-up hopper located at a convenient elevation in the conversion system. In 'many cases, the fresh oatalyst must be transported laterally for a distance of several hundred feet between the railroad sid= ing and the engage! of the pneumatic lift. The additional handling required, and the extra wane porting equipment needed, are obvious disadvantages of such method.

In accordance with the invention, the fresh catalyst is pneumatically conveyed substantially horizontally as a smoothly flowing stream through a tubular conveyor extending laterally from a loading vessel, catalyst delivery, to the engager of a pneumatic lift located adjacent to the catalyst nlake iip hopper, is then carried upwardly through the lift pipe by the same gas which effected its horizontal transportation, with or without the as'sistance of auxiliary lift gas introduced directly "into he lift ene g r, is disengaged from the gaseous material in known manner at the top of the lift,and is passed by gravity now into -the catalyst make-up hopper. 1

In a preferred embodiment crime invent n;

located at the point or the loaning 'vesssl at the inlet end or the hon zontal fun is located as or other delivery vehicle a minimum or non a ias close to the 69 as is bra-capable, so that be required trans-e ferrin'g the catalyst from the car to the inlet hopper. The catalyst discharges from the bot tom of the loading vessel into the inlet end or the horizontal conduit, or tubular conveyor, where it is engaged by a stream or gaseous material lit troduc'eol in anamount su-iiielent to convey the catalyst through the lioizontal conveyor to the lift engagei' without slinging or intermittent new. It has been observed that do as such horizontal movement the catalyst stream has a vertical con-- centratlon gradient reasiilg downwardly, and a vertical velocity gradient, teasing upw' a-Iy. The pneumatic lift my be of the general type illustrated in the aforementioned article in the Oil and Journal-f with one im ortant are ference; Whereas, in a U as part of a circulatory system, it was found dosirable to araihtaina compact moving bed or colulna of catalyst in the lower region or the en- -aseivessel surrounding a bottom portion or the lift pi e, the pneumatic lift or the present invention the catalyst introduced into the em eager from the horizontal transporting conduit prenatally falls freely to the bottom or the on gag'er vessel. 'The oataly t i then conveyed is ward-1y throug theiijft pipe by lift as compri in'g essentially the same gas which enact d its horizontal transportation, In other words, lift gas be introduced at the inlet end o'f the horizontal conveyor in sufficlent quantity not my to transport the catalyst the full horizontal distance, but also to elevate the catalyst at the endb'f its horizontal *r'un upwardl through the vertical lift path. In order to avoid any peel;- pressure difiiculties "in the horizontal conveyor when, roireason, the catalyst accum lat s within the ens-"seer and tends to tor-m a compact moving bed, a spaced concentric sleeve is. provided about the lower end or the lift The sleev extends vertically from a point in the upper region or the eheaser above he level of the can alyst inlet to a point adjacent to the lower end of the lift pipe The sleeve functions prime as a safe-goers against flooding or th'ee'ngag If the catalyst level within the enga er ises a substantial distance above the lower en, of the sleeve, the lift ga's discharging firom the h tal cons lt with the catalyst stream will entially disengage itself from renewing the path of least i" downwardly to afar a alyst and;

the hit inlet through the annular pneumatic an employed eslstanoe, will flow passage formed between the sleeve and the lift pipe.

While, in most cases, satisfactory operation of the transportation system as a whole may be obtained by introducing all the required lift gas at the inlet end of the horizontal conduit, in some cases it may be desirable to employ a minimum quantity of gas consistent with uniform catalyst flow within the horizontal conduit, which minimum amount of gas may be insufficient to effect the elevation of the catalyst upwardly through the lift pipe. For example, when'it is desired to transfer the catalyst from the siding to the catalyst make-up hopper in the shortest possible time, the rate of gas introduction must be increased. At the higher gas input the rate of catalyst flow through the horizontal conveyor may be such as to cause impingement of the discharging stream of catalyst particles against the opposite side wall of the engager. Because of the friable or frangible nature of the catalyst, such impingement may cause an undesirable amount of catalyst attrition. In such case, it is contemplated that an additional, but minor, amount of gaseous material may be introduced directly into the engager vessel at any suitable location, preferably at its upper end. This does not, however, preclude the introduction of additional minor amounts of lift gas at other locations within the engager, such as axially below the lift, or laterally of the lower end portion of the lift in the peripheral region of the engager vessel.

- Since the present transportation system is not part of the circulatory system of the hydrocarbon conversion unit, there is little reason for providing adjustable control of the catalyst flow rate. The lower end of the lift pipe and the lower end of the sleeve may therefore be set initially at themost suitable level within the engager, which setting should be adequate forall normal operation of the lift.

. It is apparent from the foregoing that the lift engager functions as a combination disengager and engager, in that the catalyst may be disengaged from its transporting gas upon introduction into the lift engager, and may subsequently be re-engaged by the same gas, which has been conveyed out of contact with the catalyst to the region immediately surrounding the lift inlet.

For a fuller understanding of the invention reference may be had to the following description and claims taken in connection with the accompanying drawings forming a part of this application, in which:

7 Fig. 1 is a diagrammatic elevational view of the entire transporting system;

Fig. 2 is a fragmentary elevational view, in partial section, showing the details of the inlet end of the horizontal conveyor;

.Fig. 3 is a plan view of thereceiving hopper and fragmentary portion of the loading vessel shown in Fig. 2;

Fig. 4 is a sectional view, in elevation, of the lift engager; and

Fig. 5 is a plan view of the lift engager shown in Fig. 4.

Referring to the drawings, the transporting system as a whole is diagrammatically shown in Fig. l. A loading vessel I I is located adjacent to a, railroad siding some distance from the conversion unit, at which a car l2 containing the catalyst may be parked. A loading platform [3 is provided between the railroad car and the loading vessel to facilitate the manual transfer of bags of catalyst into the receiving hopper IQ of the loading vessel. The bags may be broken over the edge of the receiving hopper and the contents dumped therein for subsequent discharge into the loading vessel.

The communicating passage between the receiving hopper and the loading vessel is provided with a plug-type closure mechanism, to be fully described hereinafter in connection with Figs. 2 and 3, which controls the admission of catalyst into the loading vessel and provides a pressure seal after loading is completed.

When the loading vessel has been sufficiently charged with catalyst, the p1ug-type closure member is seated in the discharge opening of the receiving hopper, to provide a pressure seal, and the catalyst is then passed by gravity flow from the lower end of the loading vessel into a horizontal tubular conveyor (6 through a conduit I5, connected to the top of the conveyor tube near its inlet end.

Gaseous material, such as air, is introduced by conduit l'i into the end of conveyor tube It. As the gas flows past the juncture with conduit l5, it engages the incoming catalyst particles and conveys them through the conveyor tube to a pneumatic lift, generally indicated by the numeral IS. A conduit l9 conveys a portion of the gas from conduit 11 to the upper region of loading vessel ll, so as to equalize the pressure while catalyst is being transferred between the vessel and the horizontal conveyor.

The gaseous material for conveying the granular material is introduced into the conveyor tube in such quantity as to produce the desired characteristics of flow and the desired velocity of discharge into the lift engager. Such gas may or may not, as desired, be sufiicient in amount to continue the transportation of the granular material upwardly through the vertical lift. In any event, however, the lift gas comprises all the gas discharged from the horizontal conveyor.

At the discharge end of the horizontal con-' veyor It the catalyst is introduced into the engager vessel 2i of the lift 18 through inlet nozzle 22. Where it enters the engager, the opening of nozzle 22 is vertically elongated, the upper side of the nozzle being horizontal, and the lower side being sloped sharply downward. The incoming stream of catalyst slides down the inclined bottom of nozzle 22 into the engager vessel 2|, and falls freely to the bottom. The gas entering the vessel with the catalyst, that is, the same gas which effected its horizontal transportation, carries the falling catalyst, in a reversal of flow, into and upwardly through the vertical lift pipe 23. The flow of catalyst is such that, under normal operation, there is no accumulation of catalyst in the form of a compact moving bed in the bottom of the engager. While it is contemplated that the transporting gas from conveyor 16 may be adequate to elevate the catalyst through the lift pipe, provision is made for the introduction also of additional lift gas into the lift engager 2!, to act as auxiliary or supplementary lift gas. Such additional lift gas may be introduced into the upper region of engager 2| through inlet conduit 24.

The stream of lift gas and catalyst discharges from the upper end of the lift pipe 23 into a conventional disengager 25 wherein, in known manner, the catalyst is disengaged from the lift gas. The separated lift gas may be discharged overhead from the disengager 25 to the atmos phere, or it may be passed, as through conduit 26, into the upper end of the catalyst make-up ammo hopper 21. The: disengaged. catalyst is collected in the lower region of disengager 25, and is passed by ravity flow through conduit :2 8 intowthe' upper end of catalyst make-up hopper 21..

Referring to Figs. 2 and :3-of the drawings, the

catalyst receiving hopper I14 of the loading Wessel mediate flange 32 secured to the portion 23 near its upper end rests upon the upper end of Y cylindrical member 3]. A fiat horizontal ring 33 encircles the lower end of portion 29, and is rigidly attached to the lower-end of cylindrical member 3|. An annular closure seat-. 4, formed of rubber or other suitable resilient material, is removably secured to the underface of ring .33 by bolts 35.

A closure member comprising a lower conical portion 36 and an upper stem 3"! is movably suspended to hang within the cylindrical portion 29 of the hopper M. The closure member is adapted, when raised to its uppermost position, to seat concentrically within the portion 29, with the upper surface of the conical portion 36 in sealing engagement with the resilient member 34.

A horizontal shaft 38' is provided at the upper rear end of the inlet hopper l4, the ends of the shaft being journaled at 39 and 40 in the side walls of the hopper. One end of shaft 38 extends outwardly from the side of the hopper to receive a handle 4| having a hand grip 42 at its forward end and a counter-weight 43 at its rear end. The handle 4| is rigidly secured to the shaft 38. Parallel link members 44 are rigidly secured at one end centrally along the shaft 38, the link members being spaced sufiiciently to receive between their free ends the upper end of stem 31. The stem 31 is pivotally attached to the free ends of link members 44 by a pivot pin 45. The linkage is so arranged that in the closed and the open positions of the closure member the mechanism will be positioned as indicated by the full and the dotted lines, respectively, in Fig. 2.

Referring to Figs. 4 and 5, the lift pipe 23 terminates at a low point within the engager vessel 2|, and is surrounded by a spaced concentric sleeve 48 supported at its upper end from the sides of the lift pipe by radial web members 49. The lower end of the sleeve 48 is maintained in concentric position by means of internal spacers 50 attached to the outer surface of the lift pipe. The ends of sleeve 48 are open, thereby forming an annular passage between the lift pipe and the sleeve extending from the upper region of the engager vessel to a point adjaoent the lower end of the lift pipe.

Normally, it is expected that immediately after its free fall to the lower region of the engager vessel 2| the catalyst will be conveyed into and upwardly through the lift pipe, without first forming a compact moving bed in the lower region of the engager. The gas entering the engager through nozzle 22 flows in part with the catalyst to the bottom of the engager and in part free from the catalyst downwardly through the annular passage 5|. If, at any time, the lift does not elevate the material as fast as it is received, the catalyst may accumulate as a compact bed at the bottom of the engager. In such case, there will be a preferential fiow of the maiorrportionorethe Mteasnomwardlv tlnrcugh the annular passage :5 1: iby reason of: the differ ence inpressure drop-through the annular passage and the compaictmoving bed. The liftpipe 223 zis eccen'tnically positioned the engager 22k, showman Fig. 5, so that it will not be in in way of. theustreamof catalyst. entering through nozzle 22. Thus, the catalyst may, :by reason .of: its'momentum, be proiected horizontally across the .engager vessel and be distributed uniformly over'the bottom; In order to preyenlt severe impingement of :the catalyst particles against the wall' of engager 2! cpposite to the inlet 22 when the system is operat ing at a high rate of how, the gas flow in conyeyor t6 be diminished and auxiliary lift gas may he into the upper end of the engag er '24 through inlet/line "24. With the use of auxiliary lifltgas. introduced through line 26, them-ate of gas at the inlet end of the horizontals conveyor may be su-ificient only to provide a uniform how of catalyst through the horizontal conveyor.

In order to remove catalyst from the lift when the latter has been. shutdown, a drain outlet 52 is provided at the bottom of engager vessel 2|.

In a commercial application of the invention, a 4-inch diameter horizontal conveyor tube was employed in conjunction with a 5-inch diameter vertical lift pipe in anarrangement similar to that illustrated in Fig. 19A supply of new bead catalyst was transported from a railroad siding 298 feet horizontally and then 173 feet vertically to the fresh catalyst make-up hopper of a catalytic hydrocarbon conversion unit. The average operating conditions are summarized below:

Air mass rate (horizontal 3.61 lb./sq. ft./sec. Catalyst mass rate (horizontal) 42 .1 lb./sq. ft./sec. Pressure drop:

Total 12.0 p. s. 1. Horizontal 8.0 p. s. i.

Under the above conditions, satisfactory operation of the transporting system as a whole was obtained. Precaution must be taken, however, to avoid flooding of the horizontal conveyor with catalyst. Despite the fact that at the air rates employed it was probable that stratified flow of catalyst occurred in the horizontal tube, there was no serious attrition problem. If stratification is considered undesirable in a particular case, however, it may be overcome by increasing the air rate until the stratification ceases and the catalyst flows smoothly in dispersed phase.

Such commercial application has indicated that, in transporting catalyst beads horizontally in accordance with the present invention, only negligible additional catalyst attrition can be attributed to the horizontal conveyor over that obtained by other transporting means.

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.

What is claimed is:

1. Apparatus for pneumatically conveying solid granular material from a supply point to a laterally and vertically remote receiving point comprising: a loading vessel at said supply point adapted to contain a mass of said granular material, a substantially horizontal tubular conveyor extending from a point adjacent to said loading vessel to a point substantially vertically below said receiving point, means for introducing as into the inlet end of said horizontal conveyor, means for withdrawing said granular material from said loading vessel and for introducing the same into said horizontal conveyor beyond the point of gas introduction, a lift enager vessel in open communication with the outlet end of said horizontal conveyor, a lift pipe extending from a level within said lift engager substantially below said outlet end of the horizontal conveyor upwardly to said receiving point,

a spaced sleeve surrounding the lower end portion of said lift pipe, said sleeve having its lower end adjacent to the lower end of said lift pipe and its upper end in open communication with the region of said lift engager above said outlet end of said horizontal conveyor, a lift disengager vessel at the upper end of said lift pipe, and means for conveying said granular material by gravity flow from said lift disengager to said receiving point. t

2. Apparatus as defined in claim 1 including means for introducing additional gas into said lift engager vessel to supplement the gas discharging from said horizontal conveyor in transporting said granular material into and through said lift pipe.

3. Apparatus as defined in claim 2 in which said means for introducing additional gas into said lift engager is located in the upper region thereof above said outlet end of said horizontal conveyor.

4. Apparatus as defined in claim 1 including means for pressnrizing said loading vessel.

5. Apparatus as defined in claim 1 in which said horizontal conveyor discharges radially into. said lift engager vessel, and in which said lift pipe and its surrounding sleeve is eccentric with respect to the axis of said lift engager vessel, and is substantially removed from the discharging stream of granular material.

6. Apparatus as defined in claim 5 in which the discharge end portion of said horizontal conveyor is of gradually increasing fiow area, the increase in said flow area being solely in a downward direction.

REUBEN T. SAVAGE.

References Cited in the file of this patent UNITED STATES PA'IEN'I'S Number Name Date 528,417 Duckham a Oct. 30, 1894 1,309,671 Weaver July 15, 1919 1,669,084 Grindle May 8, 1928 2,463,623 Huff Mar. 8, 1949 2,561,771 Ardern July 24, 1951 FOREIGN PATENTS Number Country Date 7,075 Netherlands Mar. 18, 1922

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