Title:
Apparatus for treating contaminated soil
Kind Code:
A1


Abstract:
An apparatus for destroying the contaminants found in contaminated soil prior to soil reclamation. The apparatus preferably includes three major sections or components and they are: a soil infeed section, a heating section, and a soil extraction section. The preferred infeed section includes a hopper placed in conjunction with an incline conveyor and a distally positioned dump chute. The heating section has a material receptacle in the form of a material receiving chute, a heater disposed adjacent to the interior of a longitudinal spirally internally veined rotating drum which communicates with the third section, which is a material extraction or expulsion section also in the form of an incline conveyor and a chute. The heater section includes a heater station which enables a supply of propane or LP gas to be connected thereto and ignited to fire heat the internal chamber of the rotating drum. The heating enables the contaminants such as hydrocarbons to be burned from contaminated soil.



Inventors:
Bouldin, Floyd E. (McMinnville, TN, US)
Application Number:
10/177168
Publication Date:
12/18/2003
Filing Date:
06/18/2002
Assignee:
BOULDIN FLOYD E.
Primary Class:
Other Classes:
110/236
International Classes:
F23G5/20; F23G5/44; F23G7/14; (IPC1-7): F23G7/00; F23G5/00
View Patent Images:



Primary Examiner:
RINEHART, KENNETH
Attorney, Agent or Firm:
STITES & HARBISON, PLLC (LOUISVILLE, KY, US)
Claims:

What is claimed is:



1. An apparatus for burning contaminants such as hydrocarbons from soil, comprising: at least one hopper for holding the soil to be processed, conveyor means for transporting the soil from the hopper to a heating chamber assembly for processing; and the heating chamber assembly further comprises a burner station, a soil infeed portion and a soil removal portion.

2. The apparatus of claim 1, further comprising: a trailer for supporting the at least one hopper, conveyor means and heating chamber.

3. The apparatus of claim 1, wherein the conveyor means further includes: at least one inclined conveyor having a proximal and distal end.

4. The apparatus of claim 1, wherein the heating chamber assembly further comprises: a heating cylinder.

5. The apparatus of claim 4, further comprising: means for rotating the heating cylinder during use.

6. The apparatus of claim 4, further comprising: means for supporting the heating cylinder in a declined orientation with respect to the soil removal portion such that the soil infeed portion of the heating cylinder vertically higher than the soil removal portion.

7. The apparatus of claim 1, further comprising means for preventing soil from escaping the heating chamber assembly at the soil removal section thereof.

8. The apparatus of claim 4, further comprising: means for preventing the soil from escaping the heating chamber assembly at the soil removal section which further comprises a cooperating circumferential plate and annular collar assembly interpositioned between the heating cylinder and the soil removal section.

9. The heating cylinder of claim 4, wherein the heating cylinder further comprises: an interior surface having spiral flutes protruding therefrom and provided to help move the soil from a proximal end to a distal end within the cylinder during use.

10. The apparatus of claim 4, further comprising: roller means for maintaining the proper operational alignment of the heating cylinder.

11. An apparatus for destroying the contaminants such as hydrocarbons found in contaminated soil, comprising: a heating chamber assembly for processing contaminated soil; and the heating chamber assembly further comprises a burner station, a rotatable heating cylinder, a soil infeed portion and a soil removal portion.

12. The apparatus of claim 11, further comprising: a trailer for supporting the heating chamber.

13. The apparatus of claim 11, wherein the conveyor means further includes: at least one inclined conveyor having a proximal and distal end placed adjacent to the soil infeed portion.

14. The apparatus of claim 11, wherein the heating chamber assembly further comprises: at least one inclined conveyor having a proximal and distal end placed adjacent to the soil removal portion.

15. The apparatus of claim 14, further comprising: means for rotating the heating cylinder during use.

16. The apparatus of claim 15, further comprising: means for supporting the heating cylinder in a declined orientation with respect to the soil removal portion such that the soil infeed portion of the heating cylinder vertically higher than the soil removal portion.

17. The apparatus of claim 11, further comprising means for preventing soil from escaping the heating chamber assembly at the soil removal section thereof.

18. The apparatus of claim 11, further comprising: means for preventing the soil from escaping the heating chamber assembly at the soil removal section which further comprises a cooperating circumferential plate and annular collar assembly interpositioned between the heating cylinder and the soil removal section.

19. The heating cylinder of claim 11, wherein the heating cylinder further comprises: an interior surface having spiral flutes protruding therefrom and provided to help move the soil from a proximal end to a distal end within the cylinder during use.

20. The apparatus of claim 11, further comprising: roller means for maintaining the proper operational alignment of the heating cylinder

Description:

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to apparatuses and methods for the removal of contaminates, such as hydrocarbons, from soil, and more particularly those apparatuses used to raise the temperature of soil containing the contaminate (e.g., hazardous, volatile hydrocarbons) to facilitate the removal thereof. The present apparatus and method is also believed to be particularly well suited for the removal of hydrocarbon contaminants from soil, clay, silt, or sand, etc.

[0003] 2. Description of the Related Art.

[0004] Growing environmental awareness has caused recognition of the potential environmental and health hazards associated with soil that has become contaminated with hydrocarbons. Tanks for storing hydrocarbons such as crude oil or products such as gasoline or diesel sometimes develop leaks resulting in discharge of a portion of their contents into the surrounding soil. Over time the hydrocarbons can accumulate in the soil eventually causing contamination of nearby water supplies.

[0005] Solids can also accumulate within the tanks themselves. Over time, these solids can form an emulsion of solids and hydrocarbons often referred to as sludge. This sludge generally forms a layer at the bottom of a tank that must eventually be removed. An inexpensive way for decontaminating such sludge or contaminated soil is desirable.

[0006] Many techniques have been developed to remediate soil and groundwater which becomes contaminated with, for example, hydrocarbons. Some techniques are limited to the remediation of soil only and others remediate both the soil and the underlying groundwater.

[0007] “Vapor extraction” is a common method of environmental remediation. This method draws vapors containing volatile hydrocarbons from the soil. As these vapors are withdrawn from the soil, the quantity of hydrocarbons remaining in the soil and the underlying groundwater is gradually reduced. When vapor extraction is conducted long enough, the quantity of hydrocarbons remaining in the soil and groundwater are reduced to a point which is considered non-threatening to the public health. When the vapors are drawn from the soil and exhausted into the atmosphere, with or without treatment, the method is called “open-loop”. When the vapors are drawn from the soil, treated, and pumped back down into the soil, the method is called “closed-loop”.

[0008] Because the vapors drawn from the soil often contain hazardous hydrocarbons, local, state, or federal environmental regulations may require that the vapors be treated to prevent air pollution. When the treatment equipment generates heat, and this heat is used to heat the treated vapors prior to injecting them back into ground, the process is called “closed-loop, thermally-enhanced vapor extraction”. The heated vapors slowly raise the temperature of the contaminated soil, thereby enhancing the vaporization of the remaining hydrocarbons in the soil.

[0009] “Pump and treat” is a common method of remediating contaminated groundwater. It uses a pump to extract contaminated groundwater from the ground. The extracted groundwater is treated to remove the dissolved and floating hydrocarbons before being discharged to a local sewer or surface water.

[0010] The prior art can be conveniently divided into four groups: closed-loop technologies, both thermally-enhanced (thermal) and non-thermally-enhanced (non-thermal); and open-loop technologies, both thermal and non-thermal. Techniques in these categories have been developed to simultaneously treat both soil and groundwater, groundwater only, soil only, and free (hydrocarbon) product only. The present invention is concerned primarily with the treatment of soil only or in combination with only trace amounts of ground water.

[0011] Soil Only

[0012] Technologies which treat soil only include: a closed-loop, thermal process disclosed in U.S. Pat. No. 4,982,788, titled “Apparatus and Method for Removing Volatile Contaminants from the Ground” issued on Jan. 8, 1991 to Donnely; two closed-loop, non-thermal processes disclosed in U.S. Pat. No. 4,890,673, titled “Method for Removing Volatile Contaminants from Contaminated Earth Strata” issued on Jan. 2, 1990 to Payne, and that disclosed in U.S. Pat. No. 4,730,672, titled “Method of Removing and Controlling Volatile Contaminants from the Vadose Layer of Contaminated Earth” issued on Mar. 15, 1988 to Payne; and an open-loop, non-thermal process disclosed in U.S. Pat. No. 4,886,119, titled “Method of and Arrangement for Driving Volatile Impurities from the Ground” on Dec. 12, 1989 to Bernhardt et al; in U.S. Pat. No. 4,842,448, titled “Method of Removing Contaminants from Contaminated Soil In Situ” on Jun. 27, 1989 to Koerner et al., and in U.S. Pat. No. 4,660,639, titled “Removal of Volatile Contaminants from the Vadose Zone of Contaminated Ground” on Apr. 28, 1987 to Visser et al.; and in U.S. Pat. No. 4,593,760, titled “Removal of Volatile Contaminants from the Vadose Zone of Contaminated Ground” on Jun. 10, 1986 to Visser et al.

[0013] Soil and Groundwater

[0014] Technologies which simultaneously treat both soil and groundwater include: a closed-loop, non-thermal process disclosed in U.S. Pat. No. 4,966,564 and entitled “Soil and Groundwater Remediation System” which issued Oct. 30, 1990 to Carberry; an open-loop, thermal process disclosed in U.S. Pat. No. 5,018,576 entitled “Process for In Situ Decontamination of Subsurface Soil and Groundwater” issued on May 28, 1991 to Udell et al.; and an open-loop, non-thermal process disclosed in U.S. Pat. No. 5,050,676 entitled “Process for Two Phase Vacuum Extraction of Soil Contaminants” issued on Sep. 24, 1991 to by Hess et al., in U.S. Pat. No. 4,945,988 entitled “Apparatus and Process for Removing Volatile Contaminants From Below Ground Level” issued on Sep. 24, 1991 to Payne et al., and in U.S. Pat. No. 4,832,122 entitled “In-Situ Remediation System and Method for Contaminated Groundwater” issued on May 23, 1989 to Corey et al.

[0015] Some of the above technologies use concepts found in processes developed to remove crude oil and other fuel hydrocarbons from the ground. These processes are summarized as follows:

[0016] Hydrocarbon Removal

[0017] Technologies which remove hydrocarbons from the ground include: closed-loop, thermal processes disclosed in U.S. Pat. No. 3,881,551, titled “Method of Extracting Immobile Hydrocarbons” issued on May 6, 1975 to Terry et al. and disclosed in U.S. Pat. No. 4,303,127, titled “Multistage Clean-Up of Product Gas from Underground Coal Gasification” issued on Dec. 1, 1981 to Freel et al.; and an open-loop, thermal process disclosed in U.S. Pat. No. 4,474,237, titled “Method for Initiating an Oxygen Driven In-Situ Combustion Process” issued on Oct. 2, 1984 to Shu; and an open-loop, non-thermal process disclosed in U.S. Pat. No. 4,369,839, titled “Casing Vacuum System” issued on Jan. 25, 1983 to Freeman et al. and disclosed in U.S. Pat. No. 4,345,647, titled “Apparatus to Increase Oil Well Flow” issued on Aug. 24, 1982 to Carmichael.

[0018] Of the technologies cited above, six are closed-loop processes, of which three are thermal. Two of the three thermal technologies are used exclusively to recover hydrocarbon fuels; only one is known to be used for environmental remediations. In the thermal process cited above by Terry et al., it is not used for the environmental remediation of either soil or groundwater. Rather, it is used to extract a hydrocarbon fuel from deep beneath the earth. The process recirculates a heated fluid through a formation containing a solid hydrocarbon fuel. As the heated fluid passes through the formation, the solid fuel melts and flows through the formation to a well where it is pumped to the surface. The heat transfer medium is a liquid.

[0019] In addition, there are fourteen open-loop processes, of which only two are thermal. Of the two thermal processes, one is used to recover hydrocarbon fuels, and one is used for environmental remediations.

[0020] Only two of the above processes, whether open or closed loop, are used for environmental remediation and employ heat. Donnelly employs a combination of heat from a heat pump and an independent electric coil to heat air drawn from contaminated soil before it is reinjected into the ground. Udell et al. simply injects live steam into the ground.

[0021] The technologies cited above which are used to recover hydrocarbon fuels employ heat by either circulating a heated fluid through the geological formation containing the fuel or by igniting the formation itself. Terry et al. circulates a heated fluid; Freel et. al. and Shu ignite the formation. Both are inefficient and are not effective for soil remediation.

[0022] In general, the above references fall short of the goals of performing adequate soil remediation for several reasons. For example, the non-thermal processes for remediating contaminated soil developed by Carberry, Morrow, Hess et al., Payne et al., Corey et al., Payne, Bernhardt et al., Koerner et al., and Visser et al. are generally limited to more volatile hydrocarbons such as those found in gasoline.

[0023] Although the processes developed by Udell et al. and Donnelly do heat the soil, they are substantially complex and quite expensive to operate. In the case of Udell et al., steam is injected into the ground where it condenses. The condensing steam heats the soil and volatilizes high-boiling hydrocarbons, but as the condensed steam migrates vertically through the soil, it leeches hydrocarbons out of the soil. When the condensed steam reaches the underlaying water table it contaminates the groundwater. Special ground-water extraction wells are needed to extract and treat the contaminated groundwater from the ground. The cost of operating the steam boilers and extracting and treating the contaminated groundwater is very substantial. Further, none of the energy contained in the hydrocarbons removed from the soil is used to operate the process.

[0024] The process developed by Donnelly is also expensive to operate, and, again, none of the energy contained in the hydrocarbons removed from the soil is used to operate the process. The Donnelly process has the additional limitation of using a refrigerated coil to remove hydrocarbons from vapors drawn from the soil before these vapors are heated and reinjected back into the soil. Unless the refrigerated coil is operated in the cryogenic temperature range which would capture all of the hydrocarbons, which is unlikely due to the prohibitive cost, the vapors reinjected into the ground will contain significant amounts of hydrocarbons. Consequently, the Donnelly process actually recirculates hydrocarbons through the soil. This scheme limits the extent of remediation which can be achieved.

[0025] In a typical soil remediation, the soil is often a mixture of sand, silts, and clays which may be present in discrete layers, called lenses. When this soil is remediated using non-thermal vapor extraction, as demonstrated by the patents cited above, the hydrocarbons held by the silts and clays are very difficult to remove. Due to their high surface areas, clays and silts have a strong affinity for hydrocarbons and retard their volatilization.

[0026] It is preferred that the equipment for decontaminating such sludge or soil be somewhat portable so that it can be taken to the site of contamination, avoiding the relatively expensive process of moving large quantities of solids to a central processing facility.

SUMMARY OF THE INVENTION

[0027] The present invention can be summarized as heating apparatus capable of receiving soil for decontamination treatment. The invention can be stationary or mobile. The mobile embodiment includes a towable frame structure in the nature of a wheel mounted trailer with trailer hitch configuration suitable for engagement with a motorized vehicle enabling it to be towed from place to place.

[0028] The preferred embodiment of the present invention generally includes several distinct sections operably interconnected to carry out the soil decontamination process. One of the sections includes a hopper and an inclined conveyor. The conveyor preferably further includes a series of spaced apart transverse flights positioned across the surface of the conveyor belt which enables the soil to be carried upward and dumped into the next section. The next section is the heating section and includes a heating chamber or burner.

[0029] The heating section generates a high heat within the interior of a cylindrical chamber. The selected temperature is sufficient to ignite the contaminants such as and destroy them. The high heat is preferably produced by a propane or LP gas flame blower configuration directed into the interior of a rotating steel cylinder. The flame raises the internal temperature of the steel cylinder and the exterior of the steel cylinder is shielded to maintain the efficiency of the system.

[0030] When contaminants are introduced into the cylinder of the heating section via an access chute having an inlet and a exit, the high heat causes the temperature of the soil to climb above its burning point, but remain below the melting point. The access chute allows the axial centerline of the cylinder to be offset from the end of the infeed conveyor and thus serves to shield the interior of the cylinder during use.

[0031] The cylinder further includes a series of internally projecting fins attached to its interior surface. The fins help move the soil from the proximal end to the distal end of the rotating declined cylinder during use. The cylinder also includes end plates which form flanges at the proximal and distal ends of the cylinder in order to reduce the size of the interior opening to the cylinder and assist with the efficient heating and processing of the soils.

[0032] An annular ring like flange is also provided adjacent the distal end of the cylinder and protrudes into it to enable the soil exiting the cylinder to be carefully removed without spilling from the cylinder. The annular flange(s) also enable the cylinder to maintain its proper operational alignment atop the declined frame on which it rotates during use.

[0033] Yet another section follows the heating section and preferably includes a hopper which collects the soil which is processed within the heating chamber and carries them from the burner chamber via an exit chute. The exit chute is placed adjacent to an inclined take-away conveyor which is used to carry the processed soil upwardly and out of the confines of the machine for cooling.

[0034] Of course, some considerations must take advantage of the relative height relationship between the first incline conveyor in the preferred embodiment and the dump height of the conveyor with reference to the proximal input flanged and of the rotating cylinder. It is preferred that a variance in height is presented in the event the soils emit flames within the cylinder during processing.

[0035] In addition, a metal, preferably stainless steel heat resistant cover overlies the combination of the steel cylinder and a heat absorbing blanket both of which turn underneath the cover. The cover is provided as a means to insulate the cylinder and reduce the temperature to the touch. The underside of the cover is preferably lined with a heat resistant insulating blanket which further has a tendency to resist heat transfer, enhance the efficiency of the rotating steel cylinder by trapping the heat inside of the burner chamber and therefore surrounding the blanket from which the high heat has a tendency to attempt to escape.

[0036] The preferred embodiment of the mobile version of the present invention positions all three of the primary components on an axled trailer as mentioned above. The axled trailer enables the apparatus to be taken to and removed from the contamination site thereby making the processing of the soil and its reclamation more efficient.

[0037] The present invention may be summarized in a variety of ways, one of which is the following: an apparatus for destroying contaminants in soil, comprising, at least one hopper, conveyor means for transporting the soil to be processed, and a heating chamber assembly further comprising a burner station, a soil infeed portion and a soil removal portion.

[0038] The preferred embodiment preferably further comprises a trailer portion supporting the at least one hopper, the conveyor means and the heating chamber. The conveyor means further includes at least one inclined conveyor having a proximal and distal end, and the heating chamber assembly further includes a heating cylinder and means for rotating the heating cylinder during use.

[0039] The preferred embodiment also includes means for supporting the heating cylinder in a declined position such that the infeed portion of the heating cylinder is higher than the soil removal portion, and preferably includes roller means for maintaining the proper alignment of the cylinder in the proper heating cylinder.

[0040] The preferred embodiment also includes means for preventing the soil from escaping the heating chamber assembly at the soil removal section thereof, and preferably includes a cooperating circumferential plate and annular collar assembly.

[0041] The interior of the heating chamber has spiral flutes to help move the soil from a proximal end to a distal end within the cylinder during use.

[0042] An advantage of the present invention is the ability to destroy the hazardous nature of contaminants such as hydrocarbons associated contaminated soil. An object of the present invention is to provide an apparatus for efficiently destroying and rendering inert the contaminants which become commingled and mixed within prior to soil reclamation and thereby making it possible.

[0043] A feature of the present invention is a heating chamber which preferably comprises a rotating, internally heated, steel cylinder.

[0044] An advantage of the present invention is to provide a rotating steel cylinder the internal confines for which the contaminated soil travels during the heating process and therefore during the step by which the contaminants are heated to destruction.

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] FIG. 1A is an elevated perspective view of the preferred embodiment of the present invention;

[0046] FIG. 1B is an elevated perspective view of the frame portion of the preferred embodiment of the present invention as shown in FIG. 1;

[0047] FIG. 2A is an elevated perspective view of the left side of the conveyor infeed portion of the preferred embodiment shown in FIG. 1;

[0048] FIG. 2B is an elevated perspective view of the right side of the conveyor infeed portion of the preferred embodiment shown in FIG. 1 and opposite the left side as shown in FIG. 2A;

[0049] FIG. 3A is a rear plan view of the burner section of the preferred embodiment taken in the direction opposite the arrow shown in the right hand margin of FIG. 2B;

[0050] FIG. 3B is an elevated perspective view of the burner section of the preferred embodiment taken in the direction of the arrow shown in the right hand margin of FIG. 2B;

[0051] FIG. 4 is an elevated perspective side view of the components shown opposite or behind those shown in FIG. 3B and taken in the direction of the arrow in that figure;

[0052] FIG. 5 is an elevated perspective end view of the heating cylinder of the preferred embodiment of the present invention;

[0053] FIG. 6A is an elevated perspective view of the soil removal chute of the present invention shown with an exit port substantially the same size as the cylinder diameter shown in FIG. 5;

[0054] FIG. 6B is an elevated perspective view of the soil removal chute of the present invention shown with an exit port opening having an optional trap door and having an exit port substantially the same size as the cylinder diameter shown in FIG. 5;

[0055] FIG. 7 is a side elevated perspective view of the heat blanket surrounding the heating cylinder;

[0056] FIG. 8 is a side plan view of a portion of the means for preventing soils from escaping the heating cylinder and including cooperating circumferential plate and annular collar assembly;

[0057] FIG. 9 is an elevated perspective end view of the cover shown in FIG. 1A complete with hanger brackets which facilitates the removal of the cover from the machine; and

[0058] FIG. 10 is an elevated perspective view of the underside surface of the cover shown in FIG. 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0059] With reference to FIG. 1A, a preferred embodiment of the present invention is designated generally by the reference numeral 10 and includes several sections or subassemblies which can be distinguished from one another by the function or operation of the components shown as designated therein and hereinbelow.

[0060] A trailer portion, designated generally by the reference numeral 12 incorporates a trailer tang 14 with hitch connection 15, attached to a trailer bed portion 16 having wheeled axles 18 for mobility. The trailer portion 12 also includes a heating chamber frame assembly designated generally by the reference numeral 13 of FIG. 1B.

[0061] Frame assembly 13 has spaced apart ends 17 and 19, a plurality of upright vertical supports 21, horizontal frame members 23, bearing supports 25, and a frame cover 27. The bearing supports 25 differ in vertical height in order to provide an imaginary declined plane from end 17 toward end 19 for optimum operable support of the heating chamber section 48 more thoroughly described below.

[0062] A soil input section, designated generally by the reference numeral 20 in FIG. 1A, includes a material hopper 22 having beveled side walls 24, an interior well 26, a beveled front wall 28, which presents an upper hopper opening 29 to allow the contaminated soil (not shown) to be easily dumped within the hopper well 26 for processing.

[0063] In use, the hopper 22 is positioned adjacent to and/or supported by an inclined conveyor designated generally be the reference numeral 30, the proximal end 41P of which is in operable relationship with a hopper opening (not shown) in the bottom of the hopper 22. Inclined conveyor 30 is supported by upright supports 32 attached to the sides 36 of the conveyor and the trailer bed 16 referred to above. Exit chute 34 is directed downwardly and away from the distal end 41D opposite end 41P such that soils entering the hopper 22 are carried upward on a conveyor belt (not shown) interpositioned between the sides 36 of the inclined conveyor 30.

[0064] The conveyor belt is powered by a motor assembly 38 further preferably comprising an electric motor 40 positioned about a conventional roller shaft (not shown) to drive the conveyor belt upwardly from the proximal end 41P to the distal end 41D and in alignment with the exit chute 34 which directs the soils from the conveyor 30 into the heating chamber portion designated generally by the reference numeral 44. A drive axle cover 42 is positioned adjacent one of the sides 36 of the incline conveyor 30 to help minimize the possibility of inadvertent user contact with the components which rotate and turn therebelow.

[0065] The heating chamber portion 44 is further comprised of a burner station 46, a heating cylinder station 48, and a soil exit station 86 associated with the soil removal portion of the invention designated generally by the reference numeral 72.

[0066] The soil removal portion 72 includes an inclined conveyor similar to the one described as conveyor 30 and is designated generally by the reference numeral 74. The inclined conveyor 74 has a proximal and distal end 75P and 75D respectively. Proximal end 75P is positioned adjacent to the soil exit station 86 of the heating section 44.

[0067] After the contaminated soils are heated (i.e., processed) within the heating section 44 they are expelled therefrom by rotational migration from the entrance of the heating cylinder station 48 to the exit station 86 and are received by the removal portion 72 near the proximal end 75P of the inclined conveyor 74.

[0068] Upright frame supports 76 enable the incline conveyor 74 to be angled upwardly and away from the exit end 45 of the heating chamber section 44. In addition, cage 78 provides additional means but not total isolation from the exit end 45 because of the high temperatures associated with the processed soils.

[0069] Inclined conveyor 74 further includes spaced-apart sides 80 only one of which is shown in the figure, an ejection port 82 positioned at the distal end 75D. Processed soil is moved along a conveyor belt (not shown) upwardly and away from the heating exit section 45 and is expelled through the chute 82 onto the ground or into some other user provided receptacle.

[0070] Motor 84 is preferably electric and similar to that designated as motor 40 with respect to the infeed portion 20. It provides the rotational force to the roller bearing (not shown) sufficient to move the conveyor belt (not shown) and carry the soils. Deflecting baffle 86 may include an optional hinged door (see FIGS. 6A and 6B) enabling the heated soils that exit the heating section 44 to be carried away by the conveyor 74 as described.

[0071] With reference to FIGS. 2A and 2B, burner station 46 includes a vertical cabinet type housing 99 covering a variety of heating components including a heater assembly designated generally by the reference numeral 100. Heater assembly 100 further includes gas supply line 102 connected to an external supply of flammable gas (e.g., natural gas or propane) but not shown. Supply lines 102 and 106 further includes gas regulator(s) 108 to throttle the flow and pressure of the flammable gas into the burner 100. The exhaust of the burner is heat which is moved by blower 104 which is positioned opposite the vent assembly 110. The preferred embodiment of the vent assembly 110 is covered by an insulating blanket 111 enabling the heated exhaust from the burner to be blown into the interior of the heating chamber 124 (FIG. 5) during use.

[0072] With reference to FIGS. 2B, 3A, 3B, 4 and 5, the chute 34 is shown having an exit port 112, a circumferential plate 114, and an annular collar 115 which surrounds the exit port 112. The combination of the plate 114 and collar 115 and are sized to correspond to the relative dimensions of the end plate 126 and interior 124 of the heating cylinder 122 of FIG. 5.

[0073] The heating cylinder 122 is operably supported wheels 116 fitted to shafts 118 and held in proper alignment by bearing supports 25. The bearing supports 25 and the guide rollers 135 of FIGS. 6A and 6B maintain the heating cylinder in proper elevation above the frame 13 and axial position with respect to the exit end ring 130 (FIG. 6B).

[0074] With specific reference to FIGS. 3A and 3B, roller drive motor 127 has a motor shaft 129 fitted with drive sprocket 123. Chain 121 is laced onto the drive sprocket 123 and interlaced between tension sprockets 125 and cylinder drive sprockets 120. In use with the heating cylinder 122 having roller bearing surface 131 resting on the cylinder rollers 116 and against the guide rollers 135 (FIG. 8), the motor 127 imparts a rotational torque to the shaft 129 which then rotates the drive sprocket affixed thereto. Chain 121 turns the roller sprockets 120 in the same direction as the chain 121 is interlaced around them. Tensioners 125 take up the slack in the chain and are adjustable to compensate for the stretching of the chain over prolonged use.

[0075] The heating cylinder 122 is made of steel and has an internal chamber 124 and has spiral flutes 128, an external flanged end plate 126 having optional cutouts 133 or optional proximity peg 135 either of which allows the user to monitor the rotation of the cylinder 122 as properly rotating beneath the cover 146 which is provided to mate in close conjunction with plate 114 of FIG. 3B, 4 and 8. Blanket 142 is fastened around the exterior surface of the cylinder by band type fasteners 144 which resist high temperatures (e.g., wire, flexible hose clamps, metal banding, etc.). The blanket 142 is made from a high temperature resistant fabric or asbestos material, and is provided to insulate the cylinder from heat loss and improve efficiency.

[0076] In use, when flame is introduced into the interior of the steel cylinder 122 via the burner blower 104 through the vent assembly 110, the expansion of the steel cylinder 122 takes up the separation distance and space between plates 126 and 114 (FIG. 8) and guide rollers 135 help maintain the proper separation distance despite thermal expansion. The rotation of the cylinder is believed necessary to cause the soils to migrate from one end of the cylinder 122 to the exit end 45 (FIG. 1).

[0077] During operation the interior of the cylinder is approximately one thousand six hundred degrees (1600°) and the temperature of the soil exiting therefrom is approximately nine hundred degrees (900°). These temperature are believed to be adequate to cause the hydrocarbon contaminants associated with contaminated soils to burn and thus render the soil inert. The spiral flutes 128 assist with the migration of the soils.

[0078] With reference to FIGS. 6A and 6B, exit opening 132 further includes angled walls 134 and chute 136. The optional trap door 138 is operably configured to enable the weight of the heated soil to push it open against its biasing force enabling the soil to fall freely therethrough and be expelled from the cylinder 126. Chute 136 directs the soils from the cylinder to the exit 132.

[0079] With reference to FIGS. 9 and 10, a cover or shield component is designated generally by the reference numeral 146. Cover 146 includes an arcuate body 147 and interior reinforcing ribs 148 to maintain its curved shape and secure the insulation 152 to the interior surface 153 of the cover 146. The insulating material 152 allows the material to reflect heat inwardly back toward the cylinder blanket therefore helping to maintain the overall efficiency of the operating temperatures established within the cylinder.

[0080] The cover 146 also includes end flanges 151 and side flanges 156 enabling the cover to also serve as a shroud or cowling to further minimize inadvertent contact with the heated surface. Optional hangers 154 are provided as a lifting mechanisms of the cover such that what is potentially cumbersome is now easily managed by a sling arrangement fitted to the hangers 154 positioned at each end (only one of which is shown), to facilitate easy removal thereof.

[0081] These and other embodiments of the present invention shall become apparent after consideration of the scope of the specification, drawings, and claims set forth herein. All such embodiments and equivalents thereof are contemplated to be covered by and within the scope of the claims appended hereto, even though not specifically set forth herein due to the limitation of space.