CA1331573C - Dry thermal processor - Google Patents

Abstract

"IMPROVED DRY THERMAL PROCESSOR"

ABSTRACT OF THE DISCLOSURE
The processor is of the type incorporating horizontal, concentric, co-extensive inner and outer tubular members which rotate together. The processor is modified in the following respects:
- The front end of the inner tubular member is circumferentially corrugated and may be provided in the form of a plurality of parallel tubes arranged in a ring array, to thereby increase the shell area to promote heat transfer through the tube walls;
- Means are provided for interconnecting the tubular members, which means can accommodate differing rates of thermal expansion; and - A rock recycle tube assembly is provided to recover oversize material leaving the corrugated portion of the inner tubular member and reject it from the processor.

Description

BACKGROUND OF THE INVENTION 13 31~ 73

2 (i) Field_of the Invention

3 The present invention pertains in one aspect to an

4 improved version of a dry thermal processor for extracting volatile substances from a particulate host material. The 6 processor is of the type incorporating horizontal, concentric, 7 substantially co-extensive, inner and outer tubular members which 8 are interconnected and which rotate together about a horizontal 9 axis. The feedstock enters at one end of the inner tubular member, advances through it, and is heated by hot solids 11 returning through the annular space between the tubes.12 In another aspect, the invention pertains to an 13 improved version of the process wherein the feedstock is 14 initially advanced through the inner tubular member and is heated in two stages, firstly to vaporize water contained in the 16 feed6tock and secondly to pyrolyse hydrocarbons and produce coked 17 solids. The coked solids are transferred into the annular space, 18 wherein the coke is burned to produce hot 601ids. Part of the 19 hot solids is recycled into the hydrocarbon vaporization or reaction zone to provide needed heat for that zone. The balance 21 of the hot solids is returned through the annular space and is 22 used to transfer heat into the water vaporization or pre-heat 23 zone by contact with the wall of the inner tubular member.

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1 (ii) Prior Art 2 The present invention relates to improved versions of 3 the processor and the process disclosed in U.S. Patents 4,280,879 4 and 4,285,773.
A pilot plant-scale processor in accordance with the 6 patents was built and operated on an experimental basis for a 7 number of years. In the course of the work, certain problems 8 were ascertained and solutions to the problems were developed.
9 The processor and its method of operation were signifioantly modified. The modified versions of apparatus and process provide 11 the basis for the present invention.
12 The patented processor was originally designed with 13 the primary objective of extracting hydrocarbons from the oil 14 sands of the Athabasca region in Northern Alberta. Such oil sands typically comprise grains of sand individually sheathed in 16 a thin membrane of connate water. The water contains minute clay 17 particles. Bitumen is trapped in the interstices between the 18 water-shèathed sand grains. Stated otherwise, oil sand is a 19 mixture of particulate solids, water and hydrocarbons. The prior processor was designed to recover some of the hydrocarbons, 21 separate from the water and solids.
22 In the course of the piloting work, the patented 23 processor and its method of operation were shown to be applicable 24 to feedstock other than oil sand. Such ~feedstock also involved a mixture of particulate solids, water and volatile substances 26 (including hydrocarbons). More specifically, the processor was 27 operated to treat crushed oil shale and contaminated soil 28 mixtures from waste dumps, with beneficial results.

~3~ 3 1 In its original form, the patented processor 2 broadly involved the following:
3 - A pair of concentric, substantially co~
4 extensive, horizontal, radially spaced apart inner and outer tubes (sometimes referred to 6 as "tubular members") were provided. The 7 tubes were rigidly interconnected and adapted 8 to be rotated together about their g longitudinal axis;
lo ~ There was thus formed an enclosed, elongate, 11 cylindrical inner space and an enclosed outer 12 annular space. These spaces or passageways 13 were "open", in the sense that they were 14 substantially unobstructed except as described below;
16 The cylindrical inner passageway was divided 17 at a point along its length by a transverse 18 baffle into an upstream water vaporization 19 sone (or "pre-heat'l zoneJ and a downstream hydrocarbon vaporization zone (or "reaction"
21 zone). The baffle was supplied to assist in 22 segregating the gaseous atmospheres of the 23 pre-heat and reaction zones. Spiral open-24 ended chutes were associated with the baffle and formed passages extending through the 26 baffle at its periphery. These passages 27 enabled solids to move from the pre-heat zone 28 into the reaction zone. The presence of the 29 solids in the chutes combined with the ~3315~3 1 presence of the baffle itself to substantially 2 prevent the movement of gases from one zone to the 3 other;
4 - A conveyor extended through a first end frame for feeding feedstock into the first end of the pre-6 heat zone;
7 - Screwing elements, such as upstanding plates 8 angled relative to the longitudinal axis of the 9 inner tube, were secured to the inner surfaces of the inner and outer tubes, to add fine control for 11 advancing or retarding the movement of solids 12 through the inner space and the annular space;
13 - A first fan system, having a conduit extending 14 into the pre-heat zone, provided suction and means for withdrawing water vapour and light hydrocarbon 16 vapours from said zone;
17 - A second fan system, having a conduit extending 18 into the reaction zone, provided suction and means 19 for withdrawing hydrocarbon vapours therefrom;
- A baffle and seal assembly was provided at ths 21 second end of the inner tube. This baffle and 22 seal assembly was also of the previously described 23 spiral chute type and was adapted to prevent gas 2.4 movement between the reaction zone and the annular space, while still enabling coked solids to move 26 from the reaction zone into the second end of the 27 annular space;

~31~3 1 - The annular space provided a combustion zone 2 at its second end and a heat transfer zone at 3 its first end;
4 - An air injection system was provided to supply pre-heated air through the second end frame 6 into the combustion zone, for supporting 7 combustion of the coked solids;
- A gas burner fire tube also projected through g the second end frame into the combustion sone;
0 - A recycle assembly, connecting the annular 11 space with the first or upstream end of the 12 reaction zone, was provided at the first or 13 downstream end of the combustion zone, for 14 transferring some of the hot solids, leaving the combustion zone, back into the reaction 16 zone. The recycle assembly invol~ed a spiral 17 chute coiled around the inner tube and 18 extending through the tube wall. The chute 19 was adapted to scoop hot solids from the annular space and, as a result of rotation 21 with the inner tube, to deliver the solids to 22 the combustion zone. The chute and its load 23 combined to substantially prevent gas movement 2q between the annular space and the reaction zone;
26 - - There were lifter elements attached to the 27 inner surface of the outer tube in both the 28 combustion and heat transfer zones. In the 29 cor~oustion zone, these lifter~2 ~ould drop the 1~33~3 : ~
1 coked solids particles in dispersed, curtain-2 like fashion through the injected air, to 3 encourage combustion. In the heat transfer 4 zone, the hot solids were lifted and cascaded onto the pre-heat portion of the inner tube, 6 to supply heat to the tube wall by solid-to~
7 solid heat transfer;
8 - A third fan system, having a conduit extending g into the annular space, provided suction and means for withdrawing the flue gases 11 therefrom; and 12 - Means, such as a conveyor, extended through 13 the first end frame for removing cooled solids 14 from the downstream end of the annular space.
In the operation of the prior art processor, the 16 following occurred-17 - T~e feedstock was heated in the pre-heat zone 18 by heat transfer through the tube wall. In 19 the case of oil sand, large cohesive chunks were ablated by the heating and mild cascading 21 action within the rotating inner tube.
22 Contained water and the lightest, low boiling 23 point hydrocarbons were vaporized and removed 24 by the first fan system. And the contained rocks were freed from the rest of the oil 26 sands so that they could be separated by 27 screening at the downstream end of the zone 28 and removed from the main feed stream;

l - In the reaction zone, the pre-heated feed was 2 mixed with hot solids recycled from the 3 annulus, to thereby raise the temperature of 4 the feed. Hydrocarbons were vaporized and cracked. Residue coke formed on the solids 6 particles. And the hydrocarbon gases were 7 separately recovered by the second fan system;
8 - In the combustion sone, the coked solids were g lifted and dropped through the injected air and burned to yield hot solids. The solids 11 were also heated in part by the auxil.ary 12 heater. Part of the hot solids was recycled 13 into the reaction zone, to supply the heat 14 needed to raise the temperature of the feed to the desired hydrocarbon vaporising/cracking 16 temperature. And the balance of the hot 17 solids was advanced into the heat transfer 18 sone of the annulus;
19 - In the heat transfer zone, the hot solids were lifted and dropped onto the pre-heat portion 21 of the inner tube, to heat the inner tube wall 22 as required;
23 _ And the suction systems plus the seal devices 24 were used to substantially isolate the pre-heat, reaction and annular zone gaseous 26 atmospheres, one from another.
27 In a broad context, the processor can be 28 characterized as a self-powered heat transfer machine. Among :~t ~

13~ ~73 1 the factors that require attention in its design are the 2 following:
3 - Heat must be transferred from the hot solids, 4 moving through the annular space, to the cool solids moving through the pre-heat zone. The 6 transfer of heat must be sufficient so that the 7 exit temperature of the bed of feed in the pre~
8 heat zone is raised from ambient to a temperature 9 at which vaporization of watér contained in the feed will be essentially complete, without 11 significant vaporization of hydrocarbons. In the 12 case of oil sand, this exit temperature should 13 typically be about 550F;
14 - Such transfer of heat is affected by the extent of contact between the hot solids and the pre-16 heat zone tube wall, the temperature and volume 17 of the hot sand cascaded, the conductance of heat 18 through the tube wall, the transfer of heat from 19 the tube wall into the feed bed, and the movement of heat through the bed itself;
21 - Combustion of the coked solids and auxiliary fuels 22 must be sufficient to raise the temperature of the 23 solids to the desired value (in the case of oil 2~4 sand~ typically about 1300F), needed to satisfy the heat demands of the pre-heat and reaction 26 zones;
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1331~73 1 - The quantum of heat transferred into the reaction 2 zone by recycle of hot solids must be sufficient 3 to achieve the increase of temperature of the feed 4 in the reaction zone which is needed to crack the hydrocarbons and produce lighter molecular weight 6 hydrocarbons and coked solids;
7 - The foregoing factors must be obtained while 8 maintaining segregation of the gaseous products, 9 80 that contamination and hydrocarbon losses are minimal; and 11 - The machine is cubject to elongation, expansion ;;
12 and contraction due to variations in temperature 13 to which it is subjected. The outer tube is 14 internally insulated and thus is not heated to a high temperature. The lnner tube is, however, 16 heated to high temperature. Therefore, there is 17 a significant difference in the axial and radial 18 expansions of the two metal tubes. Therefore, the 19 processor needs to be designed to aocommodate the relatlvely different physlcal changes whlch occur 21 wlth heatlng.
22 It wlll be understood that there are a number of 23 operating parameters whlch become generally fixed. For example, 24 the rate of feed addition, the rate of reaycle of hot sand to the reaction zone, and the rate of hot sand movement through the 26 annular space all become relatively steady. -~

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'' ' ~ ~ 10 ~ ' ' 133~ ~73 1 It also will be understood that, for the majority of 2 operations, addition o~ supplemental heat is to be minimized, as 3 auxiliary or off-site fuel would be a significant cost factor in 4 the operation of the processor.
And it will further be understood that the machine 6 should be kept as short as possible.
7 With the foregoing background in mind, it is now 8 appropriate to summarize the invention.

In accordance with one aspect of the invention, a 11 processor of the type described is provided with at least one 12 circumferentially corrugated pre-heat tube. In larger forms of 13 the processor, processing a high throughput of feedstock, a 14 plurality of pre-heat tubes are used.
The plurality of pre-heat tubes are preferably 16 interconnected, to form a rigid beam-like structure. The pre-17 heat tubes also preferably are each formed with a 18 circumferentially corrugated configuration. The corrugated 19 configuration refers to a folding of the shell surface to obtain a larger surface area within an equivalent length. As previously 21 stated, in the case of very low throughput processors there may 22 not physiaally be enough room for more than one tube. In this 23 circumstance, a single pre-heat tube is provided having a 24 corrugated wall.
As a result of using a pre-heat tube having a 26 corrugated wall, and preferably using a plurality of such 27 corrugated pre-heat tubes, a pre-heat section of relatively 28 high surface area is provided in the shortest processor î~

~ 133:15~3 1 length. sy providing increased tube sur~ace area, the heat 2 transfer capacity of the pre-heat tube section is greatly 3 increased.
4 In test work carried out with the pilot processor, it was discovered that it was relatively easy to bring the required 6 heat to the inside surface of the pre-heat tube. But it was 7 found that the heat did not conduct well through the bed of 8 angular sand particles, which commonly are in point-to-point 9 contact and which do not roll to any significant extent within the bed. Because of the relatively low heat conductivity of the 11 bed, either the pre-heat zone surface area had to be increased 12 by lengthening the zone or the material throughput had to be 13 reduced in order to reach the desired end temperature. Another 14 affect of unresolved low heat transmission was the poor cooling of the exiting annular solids. This resulted in excessive solids 16 discharge temperatures.
17 The utilization of a plurality of pre-heat tubes, 18 particularly circumferentially corrugated tubes, significantly 19 alleviates these problems by greatly increasing the quantum of heat transferred from a quantum of annulus solids into a quantum 21 of feed in a specific time period.
22 The problem is preferably further alleviated by 23 controlling the bed width in a pre-heat tube so that the minimum ~-r~
24 angle, formed by imaginary lines exten~ing radially from the edges of the bed to the axis of the tube, is in the order of 26 about 110 degrees. By using a bed of these dimensions, there is 27 ensured a broad contact area between the hot steel of the pre-28 heat tube and the bed of feed.

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1 In summary then, by dint of experimentation we have 2 ascertained that a single tube, plain cylindrical shell pre-3 heat assembly requires an undesirably low feed rate or an 4 inordinately long pre-heating tube in order to achieve the desired oil sand bed end temperature. Having ascertained the 6 problem, we have developed a novel processor which is better 7 able to cope with this difficulty.
8 In another preferred aspect of the invention, the 9 plurality of pre-heat tubes are arranged in a ring-like pattern and a rock recycle tube is provided to extend along 11 the center line of the ring. Means, such as a screen and 12 chute assembly, recovers oversize rocks and lumps from the 13 feed at the downstream end of the pre-heat zone and transfers them into the rock recycle tube, for return to the feed end of the processor for removal. This change removes the rocks 16 from the processor in a way such that they will not damage 17 the lifters in the annular space. It was found in the 13 piloting program that the lifters are relatively fragile and 19 become damaged when impacted by the rocks. In the smaller 20 implementation of the processor, using a single pre-heat 21 tube, this rock recycle tube is also provided, centrally 22 located internal to the inner tube.
23In the course of processing oil sand with the pilot 2g processor, it was also discovered that a tarry deposit would build up on the inner surface of the pre-heat tube, 26 particularly at its downstream end (which is the hottest 27 end). This deposit was found to have an inhibiting effect on 28 heat transfer from the tube steel wall into the feed bed.
29 Two solutions to this problem suggest themselves. One could ~ 1~3~73 1 overdesign the processor to ensure that production targets 2 could be met in spite of the build-up of such a deposit. The 3 deposit could then be cleaned out during periodic shut-downs 4 of the line. Or one could devise a means for removing the deposit on an on-going basis or a means for preventing its 6 formation. We chose to explore the latter solutions.
7 As a first attempt to eliminate the deposit, chains 8 were hung within the tube to slap against the deposit to -~
9 dislodge it. These chains were unsuccessful. Then a stainless steel liner was applied to the inner surface of the 11 pre-heat tube at its downstream or second end. It was 12 anticipated that the slick surface of the liner, in combination with a slightly lower shell surface temperature, 14 perhaps lower than the cracking temperature for oil sand, would eliminate the build-up. However, the liner was also 16 not successul in sufficiently relieving the problem. It was 17 eventually noted that rocks present in the feed were 18 collecting at the pre-heat zone end and were impacting 19 against the tarry layer and shearing it away in chunks.
However, the quantities of rocks associated with the oil sand 21 .eeds treated by the processor were insufficient to 22 satisfactorily control the fouling of the pre-heat tube.
23 It is therefore a preferred aspect of the invention 24 to recycle some of the rocks, returning through the rock recycle tube, back into the first ends of the pre-heat tubes, 26 to thereby maintain an increased concentration of rocks in 27 the feed, for purposes of removing the tarry deposit.
28 In another preferred aspect of the invention, 29 modifications are made to alleviate the problems arising from 1 the differential thermal expansions and contractions which 2 characterise the inner and outer tubular members. As 3 previously stated, the outer tubular member is internally 4 insulated with refractory. The outer steel tube thus remains

5 relatively cool and its expansion or contraction due to

6 thermal effects is relatively minor. However, the inner

7 tubular member is within the insulation and expands and

8 contracts significantly when the processor changes between g the operative hot and inoperative cold modes.
lo In the case of the pilot processor, the problem of 11 differential thermal expansion was recognised but not 12 successfully dealt with. The first end of the inner tubular 13 member was supported by spring washer-loaded support posts.
14 These eventually failed and solid posts were welded in place.
15 This approach was subject to eventual cracking of the weld 16 sites. The support of the second end of the inner tubular 17 membèr was originally a group of similar spring washer-18 loaded, inclined, multiple post supports. This latter 19 assembly eventually failed as well and was replaced by 20 multiple vertical post supports welded to the two tubular 21 members.
22 The original connection of the inner and outer 23 tubular members at the junction of the pre-heat and reaction 24 zones was a spring connected structure wherein radial motion 25 flexed the springs in one plane, while inner member support 26 was provided by the stiff section of the spring in the other 27 plane. After significant operation, inspection of this area 28 revealed cracked welds. Modifications were made to this 29 area. More particularly, a plurality of internal pins, which ~:.

:`133~ ~73 were capable of radial growth, were installed but were 2 restrained from axial and torsional raovements by thrust 3 blocks. This system lasted only a short time before the 4 welds failed. Another modification was made. This second system involved a solidly welded structure offering some 6 radial flexibility due to outer member solid blocks being 7 welded in the middle of a wide flange which was subsequently 8 welded at either edge to the inner member. Post operation g inspection has not yet revealed cracking at the connection lo sites.
11 Investigation of alternate design aspects for this 12 area resulted in the conception of several solutions 13 involving uncoupling the inner and outer tubular members and 14 enabling free and independent movement of the tubular members in a radial direction with respect to each other, while 16 preventing movement in the axial and rotational directions.
17 These concepts produced mechanically complex arrangements, 18 with components prone to wear and a requirement for periodic 19 replacement.
Recognizing the inherent simplicity and security of 21 the rigid connection, it was determined that the key was not 22 to accept differential radial expansion and work around it 23 but to work with it and manipulate the intensity of 24 differential movement.
25To accommodate the relative dimensional changes of 26the tubular members, there is now provided one or more 27preferred features, namely:
28- Neans are provided for supporting the pre-heat 29tubes of the inner tubular member at their 16 :

~ 13~5~3 1 feed ends in a vertical direction, against 2 sagging, said means being operative to permit3 limited axial elongation or contraction of the 4 tubes. Preferably such means comprises an inwardly extending thin steel membrane or wall 6 which provides vertical support for the tubes but 7 can bend to accommodate their axial elongation or 8 contraction;

9 - Means are provided, at about the junction of the pre-heat and reaction zones, for locking the inner 11 and outer tubular members together for rotation 12 as a unit, for pinning them together to prevent 13 relative axial displacement, and to æupport and 14 centralize the inner tubular member in the outer tubular member. These means are adapted to 16 accommodate differential radial expansion and17 contraction of the two tubular members.

18 In one form, such means may involve providing19 radial spokes extending between the two tubular members and being solidly secured to 21 each of them. The materials, from which the 22 spokes and the outer tubular member shell (in23 the vicinity of the spokes) are made, are 24 preferably complementary, to minimize the difference in expansion and contraction. For 26 example, the outer tubular member shell may be 27 formed of material having a relatively high ~,;3 1 thermal coefficient of expansion (e.g. an 2 austenitic stainless steel). The spokes, and 3 perhaps the inner tubular member in the vicinity 4 of the spokes, may be formed of material having a relatively low thermal coefficient of expansion 6 (e.g. a Ni-Cr alloy steel). In a preferred 7 embodiment, the spoke may be hollow and air-8 cooled through an aperture formed in the outer 9 tubular member.

In another form, the means may comprise a peg-11 and-socket system wherein one tubular member 12 carries spoke6 and the other carrles sockets which 13 lock onto the spokes but permit of limited radial 14 expansion; and - Means are provided for supporting the vaporization 16 tube against sagging, while permitting of axial 17 elongation and contraction. Such means may 18 comprise a loosely fitting collar supporting the 19 tube and tangential struts, pivotally secured to the collar, extending out and affixed to the outer 21 tubular member.
22 In summary then, the spokes and the wall of the outer 23 tubular member at the spokes are adapted to expand and contract 24 substantially the same amount even though the tubular members are at differing temperatures along most of their length.
26 In another preferred aspect of the invention, a 27 novel riding ring assembly is provided. In applications such 28 as oil sand processing, the processor necessarily has to be 29 very large to process the large tonnages of feedstock that are needed for economic viability. A typical outer tube 31 diameter might be 30 feet. To rotate and support an outer `` 1~31~73 ::
1 tube, it would be conventional in the kiln art to use a 2 riding ring having circumferential gear teeth, to be acted on 3 by a driven roller gear. Conventionally, a riding ring would 4 be a cast one-piece steel element or a bolted-together sectional ring. However toothed ring assemblies having a 6 large diameter tend to oval and are subject to alignment 7 problems.
8 In accordance with a preferred feature of the g invention, a sectional riding ring assembly comprising inner and outer ring members is provided. The ring members are 11 radially spaced apart and interconnected by circumferentially 12 spaced apart struts that function as heat-dissipating fins.
Rubber tires are used to support and drive the ring assembly.
This riding ring arrangement is characterized by the following advantages:
16 the use of tires accommodates alignment 17 changes and reduces the observance of tight 18 tolerances in machining the assembly;
19 - the struts protect the tires from being damaged by the full extent of the heat 21 associated with the inner ring member of the 22 assembly; and 23 - the tires better spread the load.
24 In accordance with another preferred feature, the solids transfer chutes associated with the reaction zone are 26 modified by providing internal transverse weirs at spaced 27 points along their passageways. The weirs cause the sand 28 charge moving through the chute passageway to create a 29 plurality of sand seals or plugs along the length of the ~

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1~31573 1 passageway. These multiple plugs reduce the leakage of gas 2 through the passageway. Gas trapped between the plugs has an 3 opportunity to escape back to its original zone through the slots 4 between the weirs and the chute wall. As a result of incorporating the weirs, the product yield from the reaction zone 6 is enhanced and its contamination is reduced.

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8 - Figure 1 is a schematic side view of a single pre-heat 9 tube version of the processor, with arrows of different types indicating the various streams that would be present in 11 connection with oil sand processing;
12 Figure 2 is a sectional side view showing both the 13 inner and outer tubular members for a multiple pre-heat tube 14 processor;
Figures 3 - 6 are sectional end views taken along the 16 lines 3--3, 4--4, 5--5, and 6--6 respective of Figure 2;
17 Figure 7 is a sectional side view showing both the 18 inner and outer tubular members for a single pre-heat tube 19 processor;
Figure 7a is a side view of a slightly modified version 21 of the single tube processor of Figure 7, showing an alternative 22 form of support for the pre-heat tube;
23 Figures 8 - 10 are sectional end views taken along the 24 lines 8--8, 9--9, and 10--10 respectively of Figure 7;
Figure 11 is a perspective view from the first end of 26 the internals of the inner tubular member at the feed inlet of 27 the pre-heat zone, showing the junction means or transition tube, 28 the inlet ends of the pre-heat tubes, multiple corrugated pre-~ '.
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1331~73 1 heat tubes, and the pre-heat discharge transition tube - only one 2 of the pre-heat tubes is shown fully corrugated; ~. .
3 Figure 12 is a perspective, partly-broken-away view of4 part of one corrugated pre-heat tube in the inner tubular member, showing the details of the interrupted corrugations, and internal 6 elements;
7 Figure 13 is a perspective partly-broken-away view from 8 the first end of the internals of the inner tubular member at the 9 junction of the pre-heat and reaction zones, showing the transition tube, the seal chute and the spokes;
11 Figure 14 is a perspective partly-broken-away view 12 showing the major gas seal and solids transfer chutes for the 13 processor, including the pre-heat zone to reaction zone seal, 14 the recycle sand chutes, and the reaction zone discharge seal;
lS Figure 15 is a sectional view of the pre-heat zone to 16 reaction zone spiral seal chute of Figure 14, showing the sealing 17 action of the particulate bed;
18 Figure 16 is a sectional end view of the helical seal 19 chute used at each of the reaction zone discharge and recycle areas of the processor shown in Figure 14, illustrating the ;:
21 sealing arrangement involving the weirs and particulate beds;
22 Figure 17 is a side view of the chute of Figure 16;
23 Figure 18 is a perspective, partly-broken-away view of24 part of the chute of Figure 16; : -~
Figure 19 is a sectional side view of an alternative 26 peg-and-hole type spoked support assembly;

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1 Figure 20 is a sectional end view of the of the 2 assembly of Figure 19;
3 Figures 21 and 22 are simplified side views showing 4 the peg-and-hole assembly of Figure 19 when the processor is cold and hot respectively, 6 Figure 23 is a perspective view of part of the peg-7 and-hole assembly of Figure 19;
8 Figure 24 is a perspective partly-broken-away view g of the major inner tubular member supports including the pre-heat feed end support, the central spoked support, and the 11 reaction zone end support;
12 Figure 25 is a sectional side view of the first end 13 Qf the multiple tube processor showing the end frame, the 14 seals and the rock recycle means;
Figure 26 is a sectional side view of the first end ., -16 of the single tube processor showing the end frame, the seals 17 and the rock recycle means;
18 Figure 27 is an expanded view of the seal shown in ;
19 Figure 25; and Figure 28 is a sectional side view of the second 21 end of the processor showing the end frame, the seal, the :~
22 auxiliary burner means, and the combustion air inlet means.

23 DESCRIPTION OF THE PREFERRED EMBODIMENT ~:
24 The processor 1 comprises inner and outer tubular25 members 2, 3. The tubular members 2, 3 are substantially 26 concentric, co-extensive and horizontal. The outer tubular - -27 member 3 carries external riding rings 4 which are driven, 28 for rotation. The tubular members 2, 3 are interconnected, 3~ ~73 1 so that rotation of the outer tubular member 3 induces 2 corresponding rotation of the inner tubular member 2. Stationary 3 end frames 5, 6 seal and enclose the open ends of the outer 4 tubular member 3.
From its left hand (in the drawing) or first end, the 6 inner tubular member 2 forms an internal longitudinal passageway 7 which sequentially provides a pre-heat zone A followed by a 8 reaction zone B. An annular space 7 is formed between the 9 radially spaced apart tubular members 2, 3. This annular space 7 sequentially provides from its second end a combustion zone C
11 followed by a heat transfer zone D.
12 The processor will now be described in greater detail.
13 It will be noted that some of the drawings illustrate a single 14 pre-heat tube version of the processor, which would be used in a low throughput application such as cleaning waste dump solids.
16 In others of the drawings, there is illustrated a high throughput 17 processor having multiple pre-heat tubes. This latter version 18 would be used for oil sand processing.

19 The Pre-Heat Tubes The inner tubular member 2 shown in Figure 2 21 comprises multiple, substantially parallel, spaced apart, 22 horizontal pre-heat tubes 8 joined at their first and second 23 ends to vertical baffles 10 and 11 respectively. Figures 2, 24 3 and 4 show five tubes, however this number is based upon the required throughput of the processor and the minimum 26 tubular dimensions required for maintenance access. The 27 baffle 10 is secured around its periphery to a short first 1 3 ~ 3 1 transition tube 9. The baffle 11 is secured around its periphery 2 to a short second transition tube 12. The second end of the 3 second transition tube 12 is joined by a flange 13 to the first 4 end of a vaporization tube 14 of reduced diameter. The internal passageways 15 of the pre-heat tubes 8 communicate through 6 apertures 16 formed in the baffle 11 with the chamber 17 of the 7 second transition tube 12. The baffle 11, transition tube 12 and 8 flange 13 together form part of a junction means joining the pre-9 heat tubes 8 and vaporization tube 14.
The pre-heat tubes 8 are arranged in an annular 11 pattern. Their internal passageways 15 collectively form the 12 pre-heat zone A.
13 ~s shown, the side wall of each pre-heat tube 8 is 14 formed in a corrugated configuration. The corrugations 18 are circumferential in nature. That is, the corrugations lie in 16 vertical radial planes relative to the tube axis. The 17 corrugations increase the area of the heat-conducting steel wall 18 for a given length, compared to a straight-walled tube, and 19 thereby significantly increase the thermal transmissibility of the tubes. As the corrugations 18 are circumferential in nature, 21 many of the hot particles dropped thereon will momentarily and 22 individually contact the tube wall, so that there is particle-23 to-steel wall heat transfer. However, due to the roundness of 24 the circumferentially corrugated wall, the initial particles are quickly shed, so that newly dropped hot particles may repeat the 26 process. Each corrugation is preferably interrupted on its 27 circumference for insertion of an advancing or reversing plate 2~ 19. The plates 19 provide means for controlling, by advancing 1331~73 1 or retarding, the movement of the feedstock axially through the 2 pre-heat passageways 15.
3 Advancing plates 20 are secured to the inner surface 4 of the first transition tube 9, to feed the feedstock to be processed into the inlet ends of the pre-heat passageways 15.
6 Conveyors 21 extend through the first end frame 5 to .
7 deliver fresh feedstock to the transition tube 9. The conveyors 8 21 and end frame 5 are more specifically described below.

~: 24a - 1~31~73 1 At their inlet ends, the pre-heat tubes 8 are 2 supported by a thin vertical steel wall or membrane 22, 3 secured around its periphery to the outer tubular member 3.
4 This membrane 22 is adapted to provide sufficient vertical support to constrain the pre-heat tubes ~ from bending or 6 sagging significantly. However, the membrane 22 is 7 sufficiently flexible in a transverse direction so as to flex 8 with the pre-heat tubes 8 when they elongate, expand or 9 contract due to thermal effects. The membrane 22 surface is lo sufficiently perforated or discontinuous to allow the spent solids from the heat transfer zone D to pass through it and 12 exit the processor 1.
13 As shown in Figure 3, the pre-heat tu~es 8 are 14 preferably tied together in a plurality of vertical planes by links 23, for mutual support.
16 In the single pre-heat tube version shown in Figure 17 7a, the pre-heat tube 8 is supported by pivotally mounted 8 braces 22a extending from the outer tubular member 3. Four 19 braces 22a are provided in a vertical plane in spaced relation around the pre-heat tube 8.
21 It will be noted that the membrane 22, or, 22 alternatively, the braces 22a provide means for supporting 23 the pre-heat tubes in a generally vertical direction to 24 prevent sagging thereof, said means being operative to so support the pre-heat tube(s) while enabling them to expand 26 and contract axially and radially.

:~ ~ 3 1 ~ 7 3 1 Oversize Screen/Rock Return Tube 2 In the case where oil sand is the feedstock, it 3 contains oversize solids, such as rocks and oil sand lumps. The 4 pre-heat step is designed to mechanically ablate the lumps and heat the feed from an inlet ambient temperature to an outlet 6 temperature (e.g. 550F) at which the contained connate water has 7 been vaporized and the oversize solids may reasonably be 8 separated form the rest of the tacky feed by screening. The 9 oversize solids should not be allowed to proceed into the downstream zones, as they can damage the lifters and plug the 11 chute seals which are described below and which are located in 12 the downstream zones. So at the outlet of the pre-heat tubes 8 13 there is provided means for screening and separating oversize 14 solids from the feed stream. There is also provided means for conveying the screened oversize solids to the first end of the 16 processor for removal and means for transferring the oversize 17 solids between the screening means and the conveying means.
18 More particularly, in the case of the multiple pre-19 heat tube processor, there is provided a rock recycle or return tube 24 which extends centrally through the ring of 21 pre-heat tubes 8. The rock return tube 24 has upstanding 22 angled plates 25 mounted on its inner surface for advancing 23 the oversize solids from its second end to its first end. At 24 its first end, the rock return tube 24 is joined to the baffle 10 and at its second end to the baffle 11. At its second 26 end, the rock return tube 24 communicates through an aperture 27 16a with the chamber 17 of the transition tube 12. A tubular 28 cage 26, formed by the spaced-apart coils 27 of a continuous, ~J~
:..~.~' 31~73 1 circularly formed bar, is positioned in the chamber 17 2 immediately downstream of the pre-heat tubes discharge 3 apertures 16. A rock chute 28 of spaced bars leads from the 4 cage 26 to the inlet aperture 16a of the rock return tube 24.
Thus, the pre-heated feed exiting the pre-heat 6 tubes 8 drops onto the coils 27 of the cage 26. The oily 7 sand particles drop through the openings in the screen or 8 cage 26 while the oversize solids are transferred by chute 28 g into the inlet end of the rock return tube 24, for conveyance lo to the first end of the processor 1. Here the greatest part 11 of the oversize solids drops into a chute 29 for removal from 12 the processor 1.

13 Rock RecYcle 14 As previously mentioned, it has been found in the case of oil sand feed that a tacky layer of tarry sand 16 gradually builds up on the inner surface of the wall of each 17 pre-heat tube 8 at its second end. This layer impedes 18 transfer of heat from the tube wall to the oil sand bed. As 19 mentioned, it has been found that impacting the layer with rocks will cause chunks of the deposit to shear off. This 21 finding has led to our concept of using rocks to scour the 22 layer from the second ends of the pre-heat tubes 8.
23 To this end, we recycle some of the rocks, 24 returning through the rock return tube 24, back into the inlet ends of the pre-heat tubes 8. We thereby maintain a 26 greater concentration of rocks in the pre-heat zone A than 27 would normally be contributed by the feed. This concentrated 28 stream of rocks is used to scour the inner surface of the ~3~
1 pre-heat tubes 8. The quantity of rocks recycled would be 2 determined during operation.
3 To achieve such recycling, the pre-heat inlet end of the rock return tube 24 is provided with slots 30 which function to allow some of the returning smaller rocks to drop 6 back into the pre-heat feed stream, while the tube 24 7 functions to eject the remainder out of the processors 8 through a center line chute 29.
9 The profile of the rock recycle tube corrugations lo 18 would be appropriately matched to the feedstock. A
11 feedstock less prone to depositing the tarry sand would not 12 need large rocks recycled and the profile could be more 13 pointed, like a sawtooth. In situations where it is expected 14 to process very tacky feedstock, a corrugation profile more like that of a square thread, with a wide flatter profile, 16 could be used to provide access to all surfaces by the 17 recycling rock charge.

18 Advancin~ Means 19 Material moves in a rotating kiln by natural and induced means. Hydraulic action is a powerful impetus to 21 solids movement. As the processor rotates, the bed of solids 22 rises to its dynamic angle of repose and then begins a 23 slumping and rolling action. The material will readily roll 24 to an area of no solids, much like fluids flow downslope.
This results in a natural progression of solids away from the 26 source of feed. In the situation where this action is more 27 than required and the solids are moving too quickly, then 28 artificial retarding mechanisms are used. Where the solid 1 material is moving too slowly and the material is 2 accumulating in the zones, then advancing means may be 3 utilized.
4 In the corrugated pre-heat tubes 8, the corrugations 18 may be interrupted on their circumference 6 with upstanding, angled plates 19, installed to advance the 7 material to the next corrugation.
8 If the rate of advance through the pre-heat zone A
9 is excessive, then oppositely directed back-up plates 19 may lo be provided to spill some of the feed backwards and retard 11 its advance.
12 Angled plates are similarly provided on the inside 13 surfaces of the remainder of the inner and outer tubular 14 members, as required, to advance the feed stream 15 therethrough.
16 Such plates are provided to advance the feed at a 17 controlled rate through the various zones.
18 In the case of oil sand feed, we seek to heat the 19 incoming feed from ambient temperature (32 - 70F) to about 550F. As previously stated, this is done to vaporize 21 contained water, to ablate lumps, and to render the oil sand 22 amenable to screening. The temperature change is achieved 23 through the mechanism of cascading hot sand, issuing from the 24 combustion zone C at about 1300F, onto the outer surfaces of 25 the pre-heat tubes 8. As a result of heat transfer to the 26 tubes 8, the now-cooled sand issuing from the first end of 27 the heat transfer zone D is at a temperature of about 600F.
28 It has been determined that the coefficient of heat 29 transfer U through the steel wall of a pre-heat tube ~9 7 ~ ~
typically is about lOO ~tu/hour/sqft/F, while that through 2 the sand bed in the pre-heat tube is only about 10 such 3 units.
4 So the difficulty is not in getting heat to the inner surface of the tube wall - it is in getting heat 6 distributed through the sand bed.
7 In order to improve heating of the sand bed, we 8 have centered on increasing two factors, namely:
9 - the surface area of the steel wall forming a pre-heat zone A of given length; and 11 - the extent of the sand bed width within each 12 pre-heat tube.
13 Nore particularly, we use one or more corrugated lg pre-heat tubes and we prefer to maintain the width of the 15 sand bed as wide as is practical, whereby the extent of the 16 steel wall in direct contact with the sand bed is maximized.
17 Preferably, we utilize a bed angle of about 110 degrees (the 18 ~Ibed angle~ is the imaginary angle established by drawing 19 lines from the edges of the bed to the central axis of the 20 tubeJ. The bed depth and width can be controlled by 21 utilization of the advance and back-up plates l9.

22 The spokes 23 A plurality of spokes 61 are joined to the 24 transition tube 12 and extend outwardly and radially from it.
25 These spokes 61 rigidly connect the inner tubular member 2 to 26 the outer tubular member 3 to prevent rotational shifting of 27 the latter relative to the former and to transfer load 28 between the members 2, 3. The spokes 61 and outer tubular ~:

3 1~ ~! 3 1 member 3, in the area of the spokes, are formed of complementary 2 materials so that their thermal expansion rate is about equal.
3 In a broader statement of this feature, the rates of 4 expansion of the materials are complementary so that the amount of radial expansion is about the same, notwithstanding the 6 different temperatures of the inner and outer tubular members.
7 Thus the inner and outer tubular members 2, 3 are 8 pinned together at this central point along the length of the ~ ~-9 processor, so that one may not shift axially relative to the other. The inner tubular member 2 is suspended concentrically 11 within the outer tubular member 3. And a drive connection is 12 supplled between the outer and inner tubular members 3, 2 so that 13 they rotate as one. Yet these ends are achieved while permitting 14 of limited radial movement of the spokes 61 due to thermal expansion or contraction of the inner tubular member 2.
16 The spokes 61 elongate or contract as the outer tubular 17 member 3 also expands and contracts radially at a complementary 18 rate, due to an appropriate selection and use of material of 19 construction.
In summary then, the spokes/materials of construction 21 arrangement supplies drive connection and centralization while 22 accommodating the differing thermal expansion and contraction 23 rates of the inner and outer tubular members. ;~
24 Figure 19 illustrates an alternative spoked support scheme. Instead of a rigid connection between the spoke and 26 the outer tubular member support, a spoke 65 and matching hole 27 66 system iB used. Inwardly projecting spokes 6S, attached 28 to the outer tubular member 3, fit in to matching holes 29 66 formed in a flange 67 attached to the inner tubular member 2. The dimensions of holes 66 are sufficiently ~

31 ~ --- 1331~7~

1 precise to prevent axial or torsional movements of the inner 2 tubular member 2, yet will permit of radial expansion.
3 In either of these embodiments, the differential 4 radial expansions for inner and outer tubular members are enabled without deformation or forced displacement of said 6 members.

7 Inlet End Frame -~
8 The stationary end frame 5 se2~es the purpose of 9 sealing the annular space 7 and the pre-heat passageways 15 against the oxygenated atmosphere while allowing the 11 processor 1 to rotate.
12 The stationary end frame 5 comprises a first 13 housing 50 having a ring seal 51 which seals against the 14 outer surface of the rotating first end of the outer tubular mem~er 3. The first housing has a second ring seal 52 which 16 seals the annular space 7 against the outer surface of the 17 rotating inner member 2. Together, ring seals 51 and 52 13 close the open first end of the outer tubu7ar member 3.
19 A conduit 53 connects the first housing 50 to a suction fan 54, thereby providing means for drawing flue 21 gases from the annular space 7.
22 A chute 55 connects the first housing 50 to a 23 conveyor 56, thereby providing means for removing ~rocessed 24 solids from the annular space 7.
A second housing 57 provides a stationary mounting 26 frame to which the feed conveying means 21 may be fastened.
27 The second housing 57 has a ring seal 58 which seals against 28 the outer surface of the rotating inner tubular member 2, '~ `' ;F`

1~31 ~73 1 thus enclosing its open first end. The feed conveying means 2 21 is connected with the second housing 57, whereby it may 3 introduce feed into the pre-heat tubes 8.
4 A conduit 59 connects the second housing 57 to a suction fan 60, thereby providing means for drawing released 6 vapors from the pre-heat zone passageways 15.

7 Seal at Second End of Pre-~eat Zone 8 A baffle 70 extends vertically across the second 9 end of the transition tube 12 and is an extension of the lo flange 13.
11 Helical tubular chutes 71 extend through openings 12 formed in the peripheral portion of the baffle 70, as shown 13 in Figure 13. The inlet 72 of each chute 71 communicates 14 with the chamber 17 of the transition tube 12. The outlet 73 of each chute 71 communicates with the reaction sone B. In 16 operation, rotation of the chute 71 along a vertical plane 17 will cause a unit of sand to enter the chute inlet 72 when it 13 passes through the sand bed in the transition tube chamber 19 17. This unit of sand will pass through the baffle 70 via the chute 71 and will drain out the outlet 73 into the 21 reaction zone B later in the rotational movement.
22 The opening 74 between the transition tube chamber 23 17 and the reaction zone B, central to the helical seal 24 chutes 71, is an access port only and must be fitted with a cover baffle plate 75 for operation.
26 The baffle 70 and chutes 71 thus function to enable 27 solids to move between the transition tube chamber 17 and the 28 reaction zone B. But as explained below, they also function ;~ 33 ~31~73 1 to prevent the gases from moving therebetween in significant 2 amount. More particularly, if the chute 71 spirals through 360 3 degrees, there is always a sealing plug 76 of sand present in the 4 chute along part of its length. This plug 76 and the solid baffle 70 combine to minimize gas movement, although there is 6 always some small amount of gas that gets pumped through by the 7 sand plug.
8 The atmosphere in the pre-heat zone A is almost 9 entirely steam to the exclusion of most oxygen. There is no æerious harm done if some of the steam reaches the reaction zone 11 B. So the seal system between the two zones A and B can permit 12 of some gas leakage.
13 The baffles 70 and 11 combine with the transition tube 14 12 to provide junction means between the pre-heat and vaporization tubes.

16 Sealing the Vaporization Tube 17 It is desirable to provide as effective a seal against 18 gas movement between the reaction zone B and the annular space 19 7 as one aan manage. If hydrocarbons move from the reaction zone B into the combustion zone C, they of course burn and the product 21 yield from the processor 1 is reduced. If flue gases move from 22 the annular space 7 into the reaction zone B, they contaminate 23 the product stream and one must provide downstream means for 24 cleaning the product.
In this connect~on, it is necessary to provide, at the 26 interface between the second end of the reaction zone B and the 27 combustion zone C and at the point at which hot solids are 28 recycled from the annulus 7 into the first end of the reaction --- 133~73 1 zone C, means for conveying particulate solids through a solid 2 wall (~uch as a baffle or tube wall) while still maintaining a 3 seal against gas migration. We use helical chutes 82, 81 for 4 this purpose.
The combination of a solid wall and a helical chute 6 extending therethrough is however subject to the disadvantage 7 that a slug of gas will be pumped through the chute ahead of each 8 discrete chute-filling charge of sand moving through it.
9 This problem has been significantly ameliorated by providing transverse weirs 80 at spaced intervals along the 11 length of the internal passageways 131, 134 of each of the 12 recycle chutes 81 and the end chutes 82 respectively. The sand 13 forms plugs 83 at the weirs 80, which plugs substantially prevent 14 gas passage. The small amounts of remaining entrapped gases 84 can in part work their way back through the slot 80a left between 16 the lip of each weir 80 and the chute wall as the plug drains to 17 the following section between subsequent weirs. -~-18 Thus, at the second end of the vaporization tube 14 19 there is provided a transverse baffle 85 having twin helical end chutes 82 equipped with internal weire 80. Each chute 82 extends 21 through a minimum of 360 degrees of rotation, typically 540 22 degrees or one and one half revolutions. The helical end chutes 23 82 communicate with apertures 133 in the baffle 85 and are ;~
24 operative to transfer coked solids from the reaction zone B
through the baffle 85, while cooperating with contained sand 26 plugs 83 to substantially prevent movement of gas therethrough.
27 Each of the helical end chutes 82 progresses through 540 degrees 28 of rotation, while occupying the minimum space by following twin, -1 parallel, helical paths, finally discharging into the combustion 2 zone C through apertures 135.
3 A tube 86 is joined to the downstream side of the 4 baffle 85. The tube 86 is open at its downstream end and contains a helical screw 87. This tube 86 is provided simply as 6 a spacer, to extend the delivery of the coked solids to the 7 second end of the combustion zone C. The coked solids exiting 8 the end chutes 82 are discharged into this tube 86 and are fed 9 by the screw 87 through the tube outlet 88 into the second end of the combustion zone C.
11 Twin recycle chutes 81 are mounted around the first 12 end of the vaporization tube 14. These rotating helical recycle 13 chutes 81 extend through apertures 130 in the wall of the 14 vaporization tube 14 and function to transfer hot solids, issuing from the combustion zone C, into the first end of the reaction 16 zone B. The recycle chutes 81 also have internal weirs 80 to 17 improve sealing against flue gas migration with sand plugs. The 18 discharge aperture 132 of each recycle chute 81 is fitted with 19 a variable orifice member 89 adjustable external to the outer tubular member 3.
21 Comparative runs were carried out in the pilot 22 processor wherein, on the one hand, the chutes 81, 82 were 23 not equipped with weirs 80, and on the other hand, they were.
:.r~
24 These runs indicated that the oil product from the reaction zone B was improved by about 2 degrees API in quality when 26 the weirs were used. Also, it was found that the hydrocarbon ~- 133~L573 1 content in the gas stream drawn from the reaction zone B
2 increased from about 35% by volume to about 55% when the 3 weirs were in place.

4 Sg~port For The VaPorization Tube In the case of the single pre-heat tube processor, 6 a plurality of rigid radially attached rod assemblies 90 7 interconnect the conduit 95 around its periphery with the 8 outer tubular member 3. Dependent upon the process 9 requirements, tube 86 may be too short or non-existent, thus lo requiring rods assemblies 90 to be attached to the conduit 95. These rod assemblies 90 function to support the second end of the inner tubular member 2, while permitting of 13 differing radial and axial expansion and contraction of the tubular members 2, 3.
In the case of the multiple pre-heat tube 16 processor, the rod assemblies 90 are shown connected 17 tangentially and pivotally to a collar 91, which is mounted 18 on the vaporisation tube 14/86, whereby elongation of the rod 19 as~emblies 90 would result in rotation of the collar while preserving its central location. Elongation of the second 21 end of the inner member 2 and the rotation of the collar 91 22 are allowed for by an adequate clearance gap between the 23 collar 91 and the tube 86.

24 The Reaction Zone In the reaction zone B, pre-heated solids having a 26 temperature of about 550F are mixed with recycled hot solids 27 having a temperature of about 1300F. The recycle rate of ~33~ ~7~
hot solids is controlled to ensure a mixture temperature of 2 about 975F. At this temperature, the lighter hydrocarbons 3 are vaporized and are withdrawn through the conduit 95. Coke 4 is formed on the sand, typically being about 3% by weight of the composite particle.
6 The rate of recycle may be controlled by the 7 adjustment of the recycle chute discharge orifice member 89.
8 This adjustment is made by a mechanism mounted external to 9 the outer tubular member 3. It would suffice in most lo instances to make a single adjustment for a particular 11 feedstock and the resulting process requirements. Recycle 12 rates of l to 3 times the feed rate are typical. This means 13 that material is being transported through the reaction zone 14 B at 2 to 4 times the processor feed rate.

The Combustion Zone 16 The outer tubular member 3 has a layer 100 of 17 refractory on its inner surface. Some of the working 18 components positioned in the annular space 7 are secured to 19 the wall of the outer tubular member 3, but they project and function internal to the refractory layer lO0.
21 A conventional burner lOl extends into the second 22 end of the combustion zone C, for the supply of supplemental 23 heat.
24 Combustion air is supplied to the con~ustion zone C, in about the stoichiometric amount or a slight excess 26 oxygen condition, via a tube 102 extending into the second 27 end of the combustion zone, for combustion of the coke.

~331573 1 Llfters 104 and 104a are attached to the wall of the 2 outer tubular member 3 and the vaporization tube 14 at spaced 3 intervals throughout the length of the combustion zone C.
4 The coke particles only burn satisfactorily when they are repeatedly lifted and dropped in the form of a curtain 6 through the pre-heated air flow. So the lifting capacity of the 7 lifters 104 has to be sufficient to ensure that the process 8 objectives for heat supply are achieved.
9 The heat supplied by the burner 101 is utilized to supplement the heat derived from combustion, as required to bring 11 the solids to the desired 1300F in the case of oil sand.
12 The solids are advanced through the annular space 7 by 13 a combination of the gas carrying capabilities of the exhaust 14 stream and angled plates (not shown) affixed to the inside surface of the outer tubular member 3.
16 As has previously been mentioned, part of the burned 17 hot solids are picked up by the recycle chute 81 and returned to 18 reaction zone B. To ensure that thi capability is maintained 19 during start-up and operation of the processor 1, we have provided a structure associated with the spokes 61 which prevents 21 the hot solids from moving downstream of the recycle chute 81 22 until it is being well supplied with solids to be recycled.
23 More particularly, the spokes 61 are attached to an 24 air plenum 107 which is secured to the transition tube 12.
Between the spokes 61, web segments 109 are also attached 26 to the air plenum 107, the outer edges of the web segments 109 27 are spaced from the inside surface of the outer tubular c-.~

133~73 member 3, to thus form an annular gap lO9a. Some of the web 2 segments 109 have an aperture 110 close to the air plenum 3 107. The web segments lO9 are adapted to reverse the sand 4 advancing through the annular space 7, yet the gaps lO9a enable free passage of the exhaust gases flowing through the 6 annular space 7. Thus the sand builds up when it first 7 begins to move through the annular space 7. The sand begins 8 to spill through the apertures 110 when it reaches them - but 9 by that time the recycle chutes 81 are able to scoop deeply lo into the built-up bank of sand. The apertures 110 lead the 11 overspill solids to the heat transfer sone B.

12 The Combustion Zone End Frame 13 The combustion zone stationary end frame 6 at the 14 second end of the outer tubular member serves the purpose of sealing the annular space 7 and the combustion zone C from 16 the external oxygenated atmosphere, while allowing the 17 processor 1 to rotate. The end frame 6 has a ring seal 116 18 which seals against the outer surface of the rotating second 19 end of the outer tubular member 3. The auxiliary burner 101 is installed in the end frame 6 and projects into the 21 combustion zone annulus C. The tube 102 projects through the 22 end frame 6, for supplyihg combustion air from a blower fan 23 1 03.

24 The Heat Transfer Zone The outer tubular member 3 has lifters 120 attached 26 to it in the heat transfer zone D, for lifting the hot solids 27 and dropping them onto the pre-heat tubes 8.

1~31573 1 Since it is desirable that the hot solids be repeatedly 2 brought into contact with the pre-heat tubes, the lifter capacity 3 may be as much as the space available allows, yet maintaining 4 adequate access for maintenance. Similar rules apply here as for the determination of combustion zone lifter size and number. The 6 free cross section area of the zone preferably should not be less 7 than that of the combustion zone cross sectional area as this 8 affects the gas velocities. The zone length and volume is 9 dependent upon the pre-heat zone length which has been previously determined.

11 The Ridina Ring Assemblies 12 A plurality of riding ring assemblies 150 are provided 13 at spaced points along the length of the outer tubular member 3.
14 The assemblies 150 function to support and rotate the processor.
More particularly, each riding ring assembly 150 comprises an 16 inner ring 151, affixed to the outer tubular member 3, and an 17 outwardly spaced outer ring 152 attached to the inner ring by a 18 plurality of webs 153. The webs 153 function as heat dissipating 19 fins so that the outer ring 152 is considerably cooler than the inner ring 151. Each ring assembly 150 is rotatably supported 21 by rubber tires 154 mounted on support standards 155. The ring 22 assemblies 150 are rotated by driven tires 156.
23 This arrangement has the following advantages:
24 - the double ring structure with intermediate heat exchange webs 153 is designed to ensure that the 26 outer rings 152 are sufficiently cool so as not 27 to damage the rubber tires 154; and . ., -~ 1331~73 - the use of the r~bber tires 154, preferably 2 inflated, permits of reasonable variation in 3 the manufacturing tolerances for the rings.

4 Example I ;
The performance of the processor is illustrated by 6 results achieved using the pilot plant unit. This unit 7 processed a variety of feedstocks, including oil sand 8 obtained from the Athabasca region of Alberta, Canada. The ~r~f~
g average continuous feed rate achieved was about 4.5 tons per o hour at a ro~ational speed of 4.5 to 5 rpm. -The unit was nearly 27 feet in length, with an 12 outer member diameter of just over 9 feet. Due to its small 13 size, experimental nature, and a desire for economical 14 modifications, a single pre-heat tube version was 15 implemented. The inner tubular member formed a corrugated, 16 11.5 foot long, 5.5 foot outer diameter pre-heat sone and a 17 7.9 foot long, 3.9 foot inner diameter reaction zone. The 18 second end of the pre-heat tube was connected to a 2 foot long transition tube which contained the pre-heat-to-reaction 20 zone seal. The pre-heat zone had a surface area of 340 21 square feet, which is a 45% increase over a plain non-22 corrugated shell. The depth of the bed in the pre-heat zone 23 was about 6 inches, resulting in a bed angle of about 110 24 degrees. The reaction zone depth was operated to achieve a 25 zone fill of about 20% of the total volume. With a recycling 26 sand ratio of about 1 to 1.5, this resulted in reaction zone 27 material retention times of about 4 minutes. The combustion ~-28 zone comprised a volume defined by a length of 9.8 feet and a - ~--:
42 `~

~ 333L~73 inner process diameter within the insulation of 7.8 feet.
2 Sixteen equally spaced combustion zone lifters were provided, 3 mounted internally to the outer tubular member. The lifters 4 were of an "L" shape, projecting ~0 inches radially inward with a 6 inch right angle tip. rhe heat transfer zone was 6 13.5 feet long with an inner process diameter of 7.8 feet.
7 This zone contained 16 lifter sets with a 4 inch by 4 inch 8 ~L" shape configuration. Feed was delivered to the pre-9 heating zone via a sealed belt conveyor projecting through lo the end frame at the first end. Flue gases were extracted 11 through a hood and spent hot solids were discharged through a 12 chute in this end frame. Pre-heat zone vapors were drawn 13 from the pre-heat zone through a conduit projecting through 14 the end frame. Twin fuel oil auxiliary burners and twin combustion air conduits projected through the end frame at 16 the second end. ~he processor rotated on two steel riding 17 rings, powered by a variable speed, hydraulic chain drive.
18 Illustration of the pilot plant performance may be 19 characterized by a selected group of runs totalling nearly 175 hours of operation at an average 4.4 tons/hour. This 21 group of runs was specifically performed on Athabasca oil 22 sand run-of-the-mine material, where no selection of the 23 feedstock quality was made. These runs were selected from a 24 much larger body of information with many different feed 25 stock and operating objectives. The hydrocarbon products 26 were processed only once, that is, no recycling of the 27 heavier products to the reaction zone were performed.
28 This material had a average bitumen content of 10.0 29 weight %, 5.4% water, the remaining 84.6% being quartz sand. ;

1331~73 The bitumen was converted to a number of products 2 when processed through the pilot unit. The bitumen products 3 were converted to 77.0% butane (C4H10) and heavier 4 hydrocarbons, 8.1% propane (C3H8) and lighter hydrocarbons (including hydrogen), 4.4% coke and 10.5% carbon present in 6 the gas streams as carbon monoxide (COJ and carbon dioxide 7 (CO2J. This was achieved with an average reaction zone 8 temperature of 976 degrees F and a combustion zone g temperature of 1216F.
The product oil, which is considered to be the 11 butane and heavier hydrocarbons, had an overall product 12 gravity of 23 degrees API, which is equivalent to a specific 13 gravity of 0.916. The average viscosity was 8.5 centipoise 14 at 30 degrees C. Athabasca bitumen gravity averages about 8.8 degrees API or a specific gravity of 1.009, being heavier 16 than water.
17 The processor consumed 3.4 million 8tu/hour of 18 which 1.4 million or over 40% was supplied by the combustion 19 of coke, the rest being supplied by auxiliary fuel. An 20 average 70% of the available coke was consumed. Over 0.7 21 million Btu/hour were lost through the outer tubular member.
'' :', 22 ExamPle II
23 A typical application of the single pre-heat tube 2~ processors is dump site clean-up or waste processing, in 25 which a hydrocarbon contaminated soil must be processed to 6 recover the hydrocarbons and discharge an environmentally 27 inert soil. These sites are often of a low overall tonnage 28 and are widely placed geographically. This suggests using a 133~L573 : ~
1 processor of a low capacity and one small enough to be 2 transported from site to site.
3 One example of a contaminated soil application is that ~ .
4 of a soil impregnated with polychlorinated biphenyl or PCB's as ~ :
known in the current terminology of the media.
6 The pilot unit was tested on about 23 on artificially 7 prepared soils, contaminated by mixing with nearly 600 pounds of 8 PCB's.
9 Of 100% of the PCB oil fed to the processor, only 0.04%
was detected as discharges to the environment, 93% was recovered 11 as liquid oils, and the remaining 7% was in large part converted 12 to coke or combustion byproducts CO or CO~.

~ .

Claims (26)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWED:

1. A dry thermal processor for recovering vaporizable substances from particulate host solids, comprising:
inner and outer, radially spaced apart, generally horizontal, interconnected, tubular members which rotate together about their longitudinal axes in response to drive applied to the outer tubular member;
said inner tubular member comprising a plurality of substantially parallel, spaced apart pre-heat tubes, a vaporization tube, and tubular junction means for connecting the pre-heat tubes and the vaporization tube;
said pre-heat tubes each having an open internal passageway, which passageways collectively form a pre-heat zone, said vaporization tube having an open internal passageway that forms a reaction zone, whereby in sequence a pre-heat zone and a reaction zone are provided by the inner tubular member;
said tubular members, the pre-heat tubes, the vaporization tube, the junction means, the pre-heat zone and the reaction zone each having first and second ends corresponding with the ends of the pre-heat and reaction zones remote from the junction means;
means, associated with the junction means, for passing solids from the pre-heat zone to the reaction zone and restricting gas movement therebetween;

said tubular members forming an annular space between them to provide, in sequence, an open combustion zone and an open heat transfer zone at the second and first ends thereof respectively, said combustion zone and said heat transfer zone each terminating at about the junction means, said annular space, combustion and heat transfer zones each having first and second ends corresponding with the ends of the pre-heat and reaction zones remote from the junction means;
means for closing the second end of the vaporization tube;
means for passing coked solids from the second end of the reaction zone, through said vaporization tube closing means, into the combustion zone and restricting gas movement between said zones;
means, located at the second end of the junction means, for recycling hot solids from the second end of the combustion zone into the first end of the reaction zone and restricting gas movement therebetween;
means for drawing gases separately from the pre-heat zone, the reaction zone, and the annular space;
said inner and outer tubular members having means for advancing solids at a controlled rate through the pre-heat and reaction zones and back through the combustion and heat transfer zones;
means extending into the combustion zone for injecting oxidizing gas thereinto for supporting combustion;
means extending into the combustion zone for supplying supplemental heat thereinto;

said outer tubular member carrying internal lifters in the combustion zone for lifting and dropping coked solids passing therethrough to assist combustion;
said outer tubular member carrying internal lifters in the heat transfer zone for lifting and dropping hot solids onto the pre-heat tubes;
stationary first and second end frames associated with the tubular members and closing the first and second ends of the annular space;
first means for closing the first end of the inner tubular member;
means for feeding feedstock into the first ends of the pre-heat tubes through the first means;
means for removing cooled solids from the first end of the annular space through the first end frame; and means for rotating the outer tubular member.

2. The processor as set forth in claim 1 wherein:
the pre-heat tubes are interconnected for mutual support.

3. The processor as set forth in claim 1 wherein:
the wall of each pre-heat tube is circumferentially corrugated along at least the major portion of its length.

4. The processor as set forth in claim 2 comprising:
a rock recycle tube having first and second ends, said rock recycle tube forming an internal passageway and extending through the space formed between the pre-heat tubes, said recycle tube having its second end communicating with the junction means, said recycle tube being arranged at its first end so as to reject oversize solids from the processor through the first means;
means, positioned in the junction means, for screening and separating oversize solids from the feedstock leaving the second ends of the pre-heat tubes; and means, interconnecting the oversize screening and separating means with the second end of the rock recycle tube passageway, for conveying the oversize solids from the former to the latter.

5. The processor as set forth in claim 4 comprising:
means at the first end of the rock recycle tube for feeding part of the oversize solids passing therethrough into the first ends of the pre-heat tubes.

6. The processor as set forth in claim 3 comprising:
a rock recycle tube having first and second ends, said rock recycle tube forming an internal passageway and extending through the space formed between the pre-heat tubes, said recycle tube having its second end communicating with the junction means, said recycle tube being arranged at its first end so as to reject oversize solids from the processor through the first means;

means, positioned in the junction means, for screening and separating oversize solids from the feedstock leaving the second ends of the pre-heat tubes; and means, interconnecting the oversize screening and separating means with the second end of the rock recycle tube passageway, for conveying the oversize solids from the former to the latter.

7. The processor as set forth in claim 6 comprising:
means at the first end of the rock recycle tube for feeding part of the oversize solids passing therethrough into the first ends of the pre-heat tubes.

8. The processor as set forth in claim 3 wherein:
the inner and outer tubular members are formed of metal, each member in use being subjected to a different temperature relative to the other member; and a plurality of radially extending spokes interconnect the inner and outer tubular members at the junction means, the spokes and the wall section of the outer tubular member connecting with the spokes being adapted to expand and contract substantially the same amount when the members are heated to different temperatures;
said spokes being operative to lock the inner and outer tubular members together whereby they rotate as a unit, to pin them together to prevent relative axial displacement, and to support and centralize the inner tubular member in the outer tubular member.

9. The processor as set forth in claim 6 wherein:
the inner and outer tubular members are formed of metal, each member in use being subjected to a different temperature relative to the other member; and a plurality of radially extending spokes interconnect the inner and outer tubular members at the junction means, the spokes and the wall section of the outer tubular member connecting with the spokes being adapted to expand and contract substantially the same amount when the members are heated to different temperatures;
said spokes being operative to lock the inner and outer tubular members together whereby they rotate as a unit, to pin them together to prevent relative axial displacement, and to support and centralize the inner tubular member in the outer tubular member.

10. The processor as set forth in claim 9 comprising:
means extending inwardly from the outer tubular member for supporting the pre-heat tubes in a generally vertical direction to prevent sagging thereof, said means being arranged so as to support the pre-heat tubes while enabling them to expand and contract axially and radially.

11. The processor as set forth in claim 10 wherein:
the support means is an upstanding steel membrane connecting the pre-heat tubes with the outer tubular member.

12. The processor as set forth in claim 8 comprising:
means extending inwardly from the outer tubular member for supporting the second end of the vaporization tube in a generally vertical plane, said means being arranged so as to support the vaporization tube while enabling it to expand and contract axially and radially.

13. The processor as set forth in claim 12 wherein:
the support means for the first ends of the pre-heat tubes is an upstanding steel membrane connecting the pre-heat tubes with the outer tubular member; and the means interconnecting the second end of the vaporization tube with the outer tubular member is a collar rotatably mounted around the vaporization tube and a plurality of rods tangentially and pivotally connected with the collar and the outer tubular member.

14. The processor as set forth in claim 1 wherein:
the means for recycling hot solids from the combustion zone to the vaporization zone comprises an open-ended chute, of helical configuration, carried by the inner tubular member and extending through the wall of said member, said chute having a scoop inlet in the combustion zone, for picking up a charge of hot solids, and an outlet communicating with the vaporization zone; and the means for passing coked solids from the reaction zone through the means closing the second end of the vaporization tube into the combustion zone comprises an open-ended chute of helical configuration extending through said closing means.

15. The processor as set forth in claim 14 wherein:
the wall of each pre-heat tube is corrugated along at least the major portion of its length.

16. The processor as set forth in claim 15 comprising:
a rock recycle tube having first and second ends, said rock recycle tube forming an internal passageway and extending through the space formed between the pre-heat tubes, said recycle tube having its second end communicating with the junction means, said recycle tube being arranged at its first end so as to reject oversize solids from the processor through the first means;
means, positioned in the junction means, for screening and separating oversize solids from the feedstock leaving the second ends of the pre-heat tubes; and means, interconnecting the oversize screening and separating means with the second end of the rock recycle tube passageway, for conveying the oversize solids from the former to the latter.

17. The processor as set forth in claim 16 wherein:
the inner and outer tubular members are formed of metal, each member in use being subjected to a different temperature relative to the other member; and a plurality of radially extending spokes interconnect the inner and outer tubular members at the junction means, the spokes and the wall section of the outer tubular member connecting with the spokes being adapted to expand and contract substantially the same amount when the members are heated to different temperatures;
said spokes being operative to lock the inner and outer tubular members together whereby they rotate as a unit, to pin them together to prevent relative axial displacement, and to support and centralize the inner tubular member in the outer tubular member.

18. The processor as set forth in claim 17 comprising:
means extending inwardly from the outer tubular member for supporting the pre-heat tubes in a generally vertical direction to prevent sagging thereof, said means being arranged so as to support the pre-heat tubes while enabling them to expand and contract axially and radially.

19. The processor as set forth in claim 18 comprising:
means extending inwardly from the outer tubular member for supporting the second end of the vaporization tube in a generally vertical plane, said means being arranged so as to support the vaporization tube while enabling it to expand and contract axially and radially.

20. A dry thermal processor for recovering vaporizable substances from particulate host solids, comprising:
inner and outer, radially spaced apart, generally horizontal, interconnected tubular members which rotate together about their longitudinal axes in response to drive applied to the outer tubular member, said members being formed of metal, each member in use being subjected to a differenct temperature relative to the other;
said inner tubular member comprising a pre-heat tube, a vaporization tube, and tubular junction means for connecting the pre-heat tube and the vaporization tube;
said pre-heat tube having an open internal passageway which forms a pre-heat zone, said vaporization tube having an open internal passageway that forms a reaction zone, whereby in sequence a pre-heat zone and a reaction zone are provided by the inner tubular member;
said tubular members, the pre-heat tube, the vaporization tube, the junction means, the pre-heat zone and the reaction zone each having first and second ends corresponding with the ends of the pre-heat and reaction zones remote from the junction means;

the wall of the pre-heat tube being circumferentially corrugated along at least the major part of its length;
means, associated with the junction means, for passing solids from the pre-heat zone to the reaction zone and restricting gas movement therebetween;
a plurality of radially extending spokes interconnecting the inner and outer tubular members at the junction means, the spokes and the wall section of the outer tubular member at the spokes being adapted to expand and contract substantially the same amount when the members are heated to different temperatures, the spokes being arranged so as to lock the inner and outer tubular members together so that they rotate as a unit, to pin them together to prevent relative axial displacement, and to support and centralize the inner tubular member in the outer tubular member;
said tubular members forming an annular space between them to provide, in sequence, an open combustion zone and an open heat transfer zone at the second and first ends thereof respectively, said combustion zone and said heat transfer zone each terminating at about the junction means, said annular space, combustion and heat transfer zones each having first and second ends corresponding with the ends of the pre-heat and reaction zones remote from the junction means;
means for closing the second end of the vaporization tube;
means for passing coked solids from the second end of the reaction zone, through said vaporization tube closing means, into the combustion zone and restricting gas movement between said zones;

means, located at the second end of the junction means, for recycling hot solids from the second end of the combustion zone into the first end of the reaction zone and restricting gas movement therebetween;
means for drawing gases separately from the pre-heat zone, the reaction zone, and the annular space;
said inner and outer tubular members having means for advancing solids at a controlled rate through the pre-heat and reaction zones and back through the combustion and heat transfer zones;
means extending into the combustion zone for injecting oxidizing gas thereinto for supporting combustion;
means extending into the combustion zone for supplying supplemental heat thereinto;
said outer tubular member carrying internal lifters in the combustion zone for lifting and dropping coked solids passing therethrough to assist combustion;
said outer tubular member carrying internal lifters in the heat transfer zone for lifting and dropping hot solids onto the pre-heat tube;
stationary first and second end frames associated with the tubular members and closing the first and second ends of the annular space;
first means for closing the first end of the inner tubular member;
means for feeding feedstock into the first end of the pre-heat tube through the first means;

means for removing cooled solids from the first end of the annular space through the first end frame; and means for rotating the outer tubular member.

21. The processor as set forth in claim 20 comprising:
means extending inwardly from the outer tubular member for supporting the second end of the vaporization tube in a generally vertical plane, said means being operative to support the vaporization tube while enabling it to expand and contract axially and radially.

22. The processor as set forth in claim 20 wherein:
the means for recycling hot solids from the combustion zone to the vaporization zone comprises an open-ended chute, of helical configuration, carried by the inner tubular member and extending through the wall of said member, said chute having a scoop inlet in the combustion zone, for picking up a charge of hot solids, and an outlet communicating with the vaporization zone; and the means for passing coked solids from the reaction zone through the means closing the second end of the vaporization tube into the combustion zone comprises an open-ended chute of helical configuration extending through said closing means.

23. The processor as set forth in claim 21 wherein:
the means for recycling hot solids from the combustion zone to the vaporization zone comprises an open-ended chute, of helical configuration, carried by the inner tubular member and extending through the wall of said member, said chute having a scoop inlet in the combustion zone, for picking up a charge of hot solids, and an outlet communicating with the vaporization zone; and the means for passing coked solids from the reaction zone through the means closing the second end of the vaporization tube into the combustion zone comprises an open-ended chute of helical configuration extending through said closing means.

24. The processor as set forth in claim 20 comprising:
a rock recycle tube having first and second ends, said rock recycle tube forming an open internal passageway and extending centrally through the pre-heat tube, said recycle tube having its second end communicating with the junction means, said recycle tube being arranged at its first end so as to reject oversize solids from the processor through the first means;
means, positioned in the junction means, for screening and separating oversize solids from the feedstock leaving the second end of the pre-heat tube; and means, interconnecting the oversize screening and separating means with the second end of the rock recycle tube, for conveying the oversize solids from the former to the passageway of the latter.

25. The processor as set forth in claim 24 comprising:
an upstanding steel membrane, extending inwardly from the outer tubular member, for supporting the pre-heat tube at its first end while enabling it to expand and contract axially and radially.

26. The processor as set forth in claim 25 comprising:
a collar rotatably mounted around the vaporization tube and a plurality of rods tangentially and pivotally connected with the collar and the outer tubular member, for supporting the vaporization tube while enabling it to expand and contract axially and radially.