US2895887A - Differential ash scraper drive for a retort - Google Patents

Description

July 21, 1959 R. F. DEERING ET AL 2,895,887

DIFFERENTIAL ASH SCRAPER DRIVE FOR A RETORT Filed April 24, 1958 s Sheets-Sheet 2 FIG. 2

July 21, 1959 R. F. DEERING ET AL 2,395,887

DIFFERENTIAL ASH SCRAPER DRIVE FOR A RETORT Filed April 24, 1958 3 Sheets-Sheet 3 Ava ma X04440 A 04-47mm #:zaazrEh a 40/1 1044 8,/ fm/ y DIFFERE ASH SCRAPER DRIVE F OR A REPORT 12 Claims. (Cl. 202-222) This invention relates to improvements in solids-fluid contacting, and in particular concerns an improved apparatus for the production of hydrocarbon gases and oils from hydrocarbonaceous solids by thermal eduction.

:Among the various processes which have been proposed for educting hydrocarbons from oiland gas-containing solids such as oil shale, oil and tar sands, bituminous and sub-bituminous coals, and the like, one of the more successful is that described in the Berg US. Patent No. 2,501,153. It comprises passing the solids upwardly through a retort apparatus countercurrent to a-downwardly flowing hot gas at a suitable eduction temperature. As applied to the treatment of oil shale, the shale solids 'are fed upwardly in sequence through a disengaging section and akiln section of a retort having the general shape of a vertical inverted cone. Air or other oxygen-containing gas is introduced into the top of the retort and is passed downwardly therethrough. At the top of the kiln section, the air is preheated by contact with hot shale ash and passes to a lower level where it supports the combustion of carbonaceous deposits on the educted shale. The flue gas produced by such burning passes downwardly to lower levels within the kiln section where it heats the shale and educts hydrocarbon oils and gases therefrom. Themixture of educted hydrocar- "bons and flue gas passes downwardly in direct contact with the upwardly moving bed ofraw cool shale, whereby the hydrocarbon oils are at least partially condensed and the raw shale is preheated near the bottom of the kiln section. The hydrocarbons and flue gas then pass downwardly into the disengaging section where the liquid and gaseous products are drawn off and separated from the upwardly moving shale. A solids-feeding mechanism located below the disengaging section is provided to force the shale upwardly through the retort, and means are provided at the top of the retort for moving the shale ash over the periphery of the retort into a circumferential ash collection trough from which the ash is conveyed to disposal.

It has been found that in the interests of increasing the capacity of the retort without substantially increasing its height, and also in attaining improved operations by enlarging the area of the preheating and burning zones at the top of the retort 'it is desirable that the diameter of the retort at its upper periphery be as large as possible. However, increasing "the diameter of the retort-leadsto certain difficulties associated with handling the shale ash-at the top'of 'the'retort. One of such difiiculties'lies in the provision of suitable means for supporting the fairly massive rotary ash scrapers, and at "the same time providing for rotation of the scrapers at optimum'power and speeds. Moreover, asthe length of 'the'upper peripheryof the retort is increased, it becomes more and more difficult to attain distribution of ash in the ash collection trough. Also, it is desirable to provide a substantially air-tight hood or other structure tes Patent around and over the top of the retort for controlling the flow of air into the retort.

It is accordingly a primary object of the invention to provide improved ash handling means at the top of a retort of the type described.

It is 'a further object to provide improved means for distributing ash solids circumferentially around the top of a retort of the present type.

Another object is to provide, in a retort of the solids upfiow type, ash scraping and ash distributing means which can be rotated at difierent speeds with respect to one another, with the scraper preferably operable at a much slower speed, and which means can conveniently be located within a substantially air-tight structure surrounding the top of the retort.

Other and related objects will be apparent from the following detailed description 'of the invention, and v-arious advantages not specifically referred to herein will be apparent to those skilled in the art upon employment of the invention in practice.

The foregoing objects and attendant advantages are realized in accordance with the invention by the provision of an upper retort assembly comprising a substantially air-tight hood, rotating ash scraping means, and difierenti-ally rotating ash distribution means. The hood section has the general configuration of a vertical cone extending around the top of the retort, and coaxial with the vertical axis of the retort, and serves in part to support the ash scraping means. The hood section also supports the ash distributing means which operate within an ash collection trough extending around the periphery of the retort adjacent to the upper edge thereof. Sealing means are provided to maintain the ash removal means and ash distributing means in an air sealed movable relationship with respect to one another. Means are also provided for rotating the ash scraping and ash distributing means at diiierent speeds with respect to one another, "and preferably in opposite directions.

The invention will be more clearly understood from the :followingdescription and drawings in which:

Figure l is an elevation view in partial cross-section of a retort apparatus incorporating the particular improvements of the present invention;

Figure 2 is an enlarged view in partial cross-section of :the upper end of the retort illustrated in Figure 1, and shows in detail the construction and operation of the improved ash handling and distribution means; and

mechanism comprising-feeder piston 22 for forcing shale solids upwardly through the retort.

Upper-assembly -10 comprises a'rotatable ash scraper 11 'for scraping thetop surface of thebed of solids which extends above the top edge of the kiln section. Assembly 10 also'comprises rotatable circumferential ash distributing means 13 which-distribute the shale ash within circular ash trough 14 to oneor moreiash discharge hoppers 29'inthe bottom thereof. The outer layer ofsolids bed 12*comprises a'preheating'zone 15 wherein the incoming air ispreheated by heat exchange against the hot shale ash, andimmediately below preheating zone 15 there is 'situated burning zone 116 wherein the preheated air burns carbonaceous material from the ieducted shale. It

may be noted that bed 12 is maintained essentially in the shape of a cone by means of rotating ash scraper 11.

Kiln section 17 is in theshape of an inverted frustum of.a cone, and contains an eduction zone 18 wherein the hydrocarbons are educted from the shale by the downwardly moving stream of hot flue gas produced in burning zone 16, and also contains a part of shale preheating or fluid cooling zone 19 wherein the hot mixture of educted hydrocarbons and flue gas is cooled and partially condensed by heat exchange against the raw shale.

Disengaging section 20, likewise of inverted frustoshape, is located immediately beneath kiln section 17 and contains a part of cooling zone 19 and separation zone 21 wherein thefluid products and flue gas are separated from the shale solids.

'Ihe solids-feeding mechanism comprises a reciprocating feeder piston 22 enclosed within feeder housing 23.

Feeder piston 22 is contained within feeder cylinder 24 mounted on trunnion 25. Hydraulic actuating cylinder 26 disposed within cylinder 24 vertically reciprocates piston 22 in feeder cylinder 24. A second actuating hydraulic cylinder 27 positioned within feeder housing 23 permits feeder cylinder 24 to be placed in communication either with the lower opening in disengaging section 20 or with the outlet of shale feed hopper 28. Piston 22 is shown as having just completed forcing a charge of shale upwardly into the retort proper. In the succeeding cycle of operation, actuating cylinder 27 is retracted to draw feeder cylinder 24 into communication with hopper 28. Actuating cylinder 26 is then retracted to draw piston 22 into its lowermost position, thereby allowing feeder cylinder 24 to fill with shale from hopper 28. Actuating cylinder 27 is then extended to return feeder cylinder 24 to the vertical position shown, and actuating cylinder 26 is then extended to raise piston 22 and force the shale charge upwardly into the retort. This cycle of operations is repeated continuously, thereby feeding raw shale into the bottom of the retort and displacing hot spent shale ash from the top thereof.

As the raw shale passes upwardly through disengaging section.20 it is preheated by the hot hydrocarbons and flue gas passing downwardly therethrough. The preheated shale then moves upwardly through zones 18 and 16 wherein eduction and burning occur, respectively, as previously explained. The hot shale ash is cooled in zone 15 and discharged over the upper edge of the retort into ash collection trough 14. Ash scraping means 11 and ash distribution means 13 facilitate handling of the ash as hereinafter explained.

As a result of gas blower 36 taking suction at the bottom of the retort through line 35, air enters the re tort through ash chute 29 and passes downwardly into zone 15 and throughzone 16 as a flue gas as previously explained. The educted liquids fill the feeding section and the disengaging section to the level of apertures 32, and liquid and gaseous educted hydrocarbons and flue gaspass through apertures 32 into separator-settler 33 which takes the form of a closed vessel extended around disengaging section 2 0. From separator-settler 33 the liquid products are withdrawn and passed to storage through line 34. The gases are withdrawn from the upper part of separator-settler 33 by blower 36 and are passed to one or more mist separators 37. The latter may comprise a cyclone. separator, an oil absorber, an

electrostatic precipitator, etc. The mist recovered in separator 37 is passed through line 38 to be combined with the liquid products in line 34, and the remaining gases are forced by gas blower 36 through gas product line to disposal means, not shown.

Referring now more particularly to Figures 2-and 3,

1 upper assembly comprises a frusto-conical hood extending around the top of kiln section 17 coaxially therewith. The hood comprises independent sections, a lower stationary mantle 102, an upper rotating mantle 106, and

I a central scraper carrier 118. Circular ash trough 14,

having an essentially U-shaped cross-section, is secured at its outer rim to the lower periphery of stationary mantle 102, and extends therefrom to the upper periphery of kiln section 17, being secured thereto by a flange 100. Supporting braces 101 extend downwardly at an angle from the outer edge of trough 14 to the walls of the kiln section. A circular horizontal platform 103 is supported above the upper surface of stationary mantle 102 by legs 103a, and continuous circular track 104 and a continuous circular sand-filled sealing trough 105 are positioned on its upper surface as shown.

Upper rotating mantle 106 is ring-shaped, having a horizontal upper surface 106a and a lower surface 106b which flares outwardly at substantially the same angle as the angle of lower stationary mantle 102. Rotating mantle 106 is supported on stationary mantle 102 by means of a series of flanged wheels 110 mounted on axles 109 and riding on circular track 104. Circular sealing element 111 extends downwardly from the outer edge of upper mantle 106 into the body of sand contained in sealing trough 105, and serves to prevent gases from escaping upwardly through the annulus between the upper and lower mantles. The ash distributing means comprises a plurality of U-shaped members 13 extending downwardly into trough 14 from supporting arms 107. The latter are attached to and extend radially outward from lower surface 106b of rotating mantle 106. As

will be seen, rotation of the upper mantle 106 causes dis- I tributors 13 to travel around trough 14 and uniformly distribute the shale ash therein and carry it to ash chute 29.

' 117 on its inner and outer peripheries, respectively, is

mounted on gear mount 114. Circular ash scraper carrier 118, which may also be referred to as a second rotatable mantle section, is disposed within the central opening of first rotating mantle 106a and extends downwardly therethrough towards the top of kiln section 17. Ash scrapers 11 are secured to the bottom end of carrier 118 and extend radially therefrom at a negative angle so that when rotated they trim the upper surface of ash bed 12 in the shape of a broad cone having a central vertex 120. The scrapers 11, for example, may operate about one foot above the kiln top on a broad twenty-two foot diameter bed. Scraper carrier 118 is supported on upper mantle 106 by a series of flanged wheels 122 disposed on axle 121. Circular sealing elements 123 extends downwardly from scraper carrier 118 into the bed of sand in circular sealing trough 113, and serves to restrict the passage of oxygen-containing gases upwardly over the hot ash discharged through chute 29, and then through the annulus between carrier 118 and upper mantle 106 has the preheated oxygen-containing gas is supplied to the retort. If desired, the retort may be pressurized above atmospheric pressure at its top.

Rotation of upper mantle 106 is produced by stationary motive means 124, which conveniently takes the form of an electric motor supplied with electric power through cable 137, mounted on support 126 erected on stationary mantle 102. Motive means 124 operates through a suitable speed reducer 125 connected to stationary gear 127 in mesh with the outer teeth 117 of ring gear 115. A second motive means 128, which may conveniently take the form of an electric motor supplied with electric power through cables 132 and slip ring assembly 133 mounted on post 134 extending from the top of scraper carrier 118, is likewise supported on platform mounted on top of scraper carrier 118 and operates through a suitable speed reducer 129 to drive planetary gear 131 in mesh with inner teeth 116 of ring gear 115.

As stated, motive means 124 drives stationary gear 127 which in turn drives ring gear 115 affixed to upper mantle assess? 1%, whereby the latter and the ash distributing means attached thereto are caused to rotate at any desired speed. Ring gear 115 is likewise in mesh with planetary gear 131 which is rigidly attached to scraper carrier 118, and it will be seen that if planetary gear 131 is restrained from rotating, scraper carrier 118 and scrapers 11 will rotate at the same speed as that of distributors 13. On the other hand, if planetary gear 131 is rotated by motive means 128 in a direction opposite to that of stationary gear 127, scraper carrier 118 and scrapers 11 will rotate in the same or opposite direction as that of rotating mantle 106 and distributors 13, depending upon whether planetary gear 131 is turned faster or slower than gear 127. Accordingly, the direction of rotation and the speeds of scrapers 11 and distributors 13 can be varied at will, both with respect to each other and with respect to kiln 17, by suitably controlling motive means 126 and 128. At suitable speeds for an oil shale retort, for example, if speed reducer 120 drives the mantle section 106 of distributors 13 at 120 r.p.h., and speed reducer 129 drives scraper carrier 118 at 115 r.p.h. in opposite direction relative thereto, then the scrapers 11 are operated to run forward at a net 5 r.p.h. in relation to the ash bed.

As will be seen from the foregoing, the apparatus of the invention provides ash scraping and ash distribution means contained within an air-tight hood surrounding the top of the retort and especially adapted for use in conjunction with large diameter retorts. Furthermore, said scraping and distribution means are readily capable of being rotated in either direction and at any desired speed with respect to each other as well as to the retort proper. It will be understood, of course, that any of the particular elements referred to above in connection with the drawings may be replaced by equivalent elements or means. Thus, the sand-filled sealing troughs and sealing elements associated therewith may be replaced by other conventional rotating sealing assemblies or sealing legs and the flanged wheel and track arrangements may be replaced by skids, hearings, or other suitable friction-reducing devices. Other variations and substitutions within the scope of the invention will be apparent to those skilled in the mechanical arts. In essence, the apparatus of the invention comprises, in combination with an open-top retort of the class described, a differential planetary drive assembly of at least two rotatable supporting mantle sections above the open top retort, each of which mantle sections supports respective rotatable working apparatus thereunder, motive means for driving a first supporting mantle section at a selected speed of rotation, and a second motive means mounted on the second supporting mantle section, said second motive means being mechanically engaged with the first driven mantle section, whereby the second mantle section and supported working apparatus are driven by the second motive means at a speed which is relative to the first moving mantle section and supported working apparatus.

A particular embodiment of the present invention has been described above by way of illustration, although it should be understood that the invention is to be limited only in accordance with the following claims since persons skilled in the art may devise various embodiments and modifications still within the limitations of said claims.

We claim:

1. In an apparatus for feeding solids upwardly through a kiln and removing ash from above the kiln top, the improvement in combination therewith of a differential planetary drive assembly located above said kiln top comprising: a first rotatable mantle section; a second rotatable mantle section, respective working apparatus for said first and second sections, each of which sections is adapted to support respectively, one of said working apparatus rotatable therewith; a first motive means for driving said first rotatable mantle section at a selected speed of rotation; and a second motive means mounted on said second rotatable mantle section, which second motive means is mechanically engaged with said driven first rotatable mantle section, whereby said second rotatable mantle section and its supported working apparatus are driven with a rotation which is relative to rotation of said first rotatable mantle section and its supported workmg apparatus.

2. Apparatus according to claim 1 in which saidworking apparatus supported by said first mantle comprises rotatable ash distributing means movable circumferentially exterior to said kiln and concentric with respect to its said imaginary center line and said working apparatus supported by said second mantle comprises rotatable ash scraper means movable in contact with said upward moving solids mass above said kiln, said movement of. said ash scraper being substantially concentric with respect to said imaginary center-line of said kiln.

3. Apparatus according to claim 1 in which said first rotatable mantle section is provided with sealing means and said stationary mantle section is provided with cooperating sealing means engaging said sealing means of said first rotatable mantle section, and in which said second rotatable mantle section is provided with a second sealing means and said first rotatable mantle section is provided with a cooperating second sealing means engaging said second sealing means of said second rotatable mantle section, whereby said first rotatable mantle section is rotatably movable in substantially an air sealed relationship with said stationary mantle section and said second rotatable mantle section is rotatably movable in substantially an air sealed relationship with said first rotatable mantle section.

4. Apparatus according to claim 1 in which said first rotatable mantle section is supported by said stationary mantle section and in which said second rotatable mantle section is supported by said first rotatable mantle section.

5. Apparatus according to claim 4 in which said first rotatable mantle section is provided with wheel means rotatably supported by said stationary mantle section which is provided with a cooperating and supporting first circular track engaging said wheel means, and in which said second rotatable mantle section is provided with wheel means rotatably supported by said first rotatable mantle section which is provided with a second cooperating and supporting circular track engaging said wheel means of said second rotatable mantle section.

6. Apparatus according to claim 1 in which said first rotatable mantle section is provided with gear means for mechanically engaging said motive means for driving said first rotatable mantle section, and in which said gear means is also provided for mechanically engaging said second motive means mounted on said second rotatable mantle section.

7. Apparatus according to claim 6 in which said gear means comprises: an external ring gear for mechanically engaging said motive means for driving said first rotatable mantle section, and; an internal ring gear for mechanically engaging said second motive means mounted on said second rotatable mantle section.

8. Apparatus according to claim 6 in which said first motive means and second motive means each comprise a driving gear, a speed reducer and an electric motor power means.

9. Apparatus according to claim 8 in which said second motive means is provided with a slip ring assembly for receiving electric power external to said second rotatable mantle section.

10. Apparatus according to claim 1 in which said solids contacted by fluids in said contacting vessel comprises oil shale.

11. Apparatus according to claim 1 in which said first rotatable mantle section is in a frusto-conical form which extends upward and inward from said stationary mantle section toward said imaginary center line of said kiln to a position concentrically around said second rotatable mantle section.

12. In an apparatus for the contacting of fluids and solids which comprises an open-top contacting vessel having an imaginary center line, a perforate fluid disengaging vessel, and a solids feeder case disposed at successively lower levels in a column, a solids inlet hopper opening downwardly into the top of said feeder case, an oscillating vertically acting piston solids feeder disposed in said feeder case, means for oscillating and reciprocating said piston solids feeder so as to receive a mass of solids from said hopper and force it upwardly and successively through said disengaging and contacting sections, a closed separator vessel surrounding said disengaging vessel, means for removing fluids therefrom to maintain flow of fluid downwardly through said rising mass of solids and a stationary mantle means above said contacting vessel, the improvement in combination therewith of a differential drive assembly located above said open-top contacting vessel comprising: a first rotatable mantle section, said first rotatable mantle section extending upward and inward in frusto-conical form toward said imaginary center line of said contacting vessel, said first rotatable mantle section being in inner concentric relationship with said stationary mantle means and in concentric relationship about said center line; rotatable ash distributing means movable circumferentially exterior to said contacting vessel and supported by said first rotatable mantle section; sealing means for said first rotatable mantle section; cooperating sealing means on said stationary mantle section for engaging said sealing means of said first rotatable mantle section; wheel means for said first rotatable mantle section; a cooperating circular track on said stationary mantle section engaging said wheel means of said first rotatable mantle section thereby supporting said first mantle section in rotatable relationship therewith; motive means for driving said first rotatable mantle section at a selected speed of rotation; external ring gear means on said first rotatable mantle section, for mechanically engaging said assess? motive means for driving said first rotatable mantle section; a second rotatable mantle section, said second rotatable mantle sectionextending inward to a position above said imaginary center line of said contacting vessel and in an inner concentric relationship with said first rotatable mantle section; rotatable ash scraper means movable in contact with siad upward moving solids mass and supported by said second rotatable mantle section above said open-top contacting vessel, said rotatable movement of said ash scraper means being substantially concentric with respect to said imaginary center line of said contacting vessel; sealing means for said second rotatable mantle section; a cooperating second sealing means on said first rotatable mantle section for engaging said sealing means of said second rotatable mantle section; wheel means for said second rotatable mantle section; a cooperating circular track on said first rotatable mantle section engaging said wheel means of said second rotatable mantle section thereby supporting said second mantle section in rotatable relationship therewith; a second motive means mounted on said second rotatable mantle section for driving said second rotatable mantle section; and an internal ring gear means on said first rotatable mantle section for mechanically engaging said second motive means for driving said second rotatable mantle section; whereby said stationary mantle section, said first rotatable mantle section and said second rotatable mantle section together provide a self supporting substantially air sealed complete mantle assembly above said contacting vessel which is sectionally rotatable thereby rotating supported ash distributing means and supported ash scraper means thereunder at different rotational speeds with respect to said contacting vessel.

Berg Mar. 21, 1950 Berg May 26, 1953

Claims (1)

1. IN AN APPARTUS FOR FEEDING SOLIDS UPWARDLY THROUGH A KILN AND REMOVING ASH FROM ABOVE THE AILN TOP, THE IMPROVEMENT IN COMBINATION THEREWITH OF A DIFFERENTIAL PLANETARY DRIVE ASSEMBLY LOCATED ABOVE SAID KILN TOP COMPRISING: A FIRST RATABLE MANTLE SECTION; A SECOND ROTATABLE MANTLE SECTION, RESPECTIVE WORKING APPARATUS FOR SAID FIRST AND SECOND SECTIONS, EACH OF WHICH SECTIONS IS ADAPTED TO SUPPORT RESPECTIVELY, ONE OF SAID WORKING APPARATUS ROTATABLE THEREWITH; A FIRST MATIVE MEANS FOR DRIVING SAID FIRST ROTATABLE MANTLE SECTION AT A SELECTED SPEED OF ROTATION; AND A SECOND MOTIVE MEANS MOUNTED ON SAID SECOND ROTABLE MANTLE SECTION, WHICH SECOND MOTIVE MEANS IS MECHANICALLY ENGAGED WITH SAID DRIVEN FIRST ROTATABLE MANTLE SECTION, WHEREBY SAID SECOND ROTATABLE MANTLE SECTION AND ITS SUPPORTED WORKING APPARATUS ARE DRIVEN WITH A ROTATION WHICH IS RELATIVE TO ROTATION OF SAID FIRST ROTATABLE MANTLE SECTION AND ITS SUPPORTED WORKING APPARATUS.

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