CA2159096A1 - Regenerative device - Google Patents
Regenerative deviceInfo
- Publication number
- CA2159096A1 CA2159096A1 CA 2159096 CA2159096A CA2159096A1 CA 2159096 A1 CA2159096 A1 CA 2159096A1 CA 2159096 CA2159096 CA 2159096 CA 2159096 A CA2159096 A CA 2159096A CA 2159096 A1 CA2159096 A1 CA 2159096A1
- Authority
- CA
- Canada
- Prior art keywords
- blocks
- regenerative device
- housing
- central interior
- regenerative
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G7/00—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
- F23G7/06—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases
- F23G7/061—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases with supplementary heating
- F23G7/065—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases with supplementary heating using gaseous or liquid fuel
- F23G7/066—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases with supplementary heating using gaseous or liquid fuel preheating the waste gas by the heat of the combustion, e.g. recuperation type incinerator
- F23G7/068—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases with supplementary heating using gaseous or liquid fuel preheating the waste gas by the heat of the combustion, e.g. recuperation type incinerator using regenerative heat recovery means
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D19/00—Regenerative heat-exchange apparatus in which the intermediate heat-transfer medium or body is moved successively into contact with each heat-exchange medium
- F28D19/04—Regenerative heat-exchange apparatus in which the intermediate heat-transfer medium or body is moved successively into contact with each heat-exchange medium using rigid bodies, e.g. mounted on a movable carrier
- F28D19/045—Regenerative heat-exchange apparatus in which the intermediate heat-transfer medium or body is moved successively into contact with each heat-exchange medium using rigid bodies, e.g. mounted on a movable carrier with radial flow through the intermediate heat-transfer medium
Abstract
A regenerative device can thermally treat gases. This device has a housing (42) with a gas inlet (44) and a gas outlet (46). A cage (16) having a central interior is rotatably mounted in the housing between the inlet and the outlet. A plurality of gas permeable blocks (24) are mounted peripherally in the cage around its central interior to provide therethrough: (a) an incoming flow path from the inlet to the central interior, and (b) an outgoing flow path from the central interior to the gas outlet. This incoming flow path within the blocks is non-converging. A drive motor (38) can rotate the cage to move blocks successively past the inlet and the outlet.
Description
~VO 94/23246 ~ !3 G S ~ PCT/US93/05453 REGENERATIVE GAS TREATMENT
BACKGROUND OF THE INVENTION
10 1. Field of the Invention The present invention relates to regenerative apparatus and regenerative methods for thermally treating gases, and in particular, to systems for circulating blocks in order to transfer heat.
15 2. Description of Related Art Increasingly stringent environmental laws have required manufacturers and various businesses to reduce the amount of polluting or toxic emissions from various processes, especially emissions of volatile organic compounds (nV.O.C.n).
For example, waste solvent vapors, and various hydrocarbon fumes can be 20 produced from printing processes, or from baking, or cooking. Some industrial processes produce such toxic emissions as benzene, formaldehyde, etc.
Such po!lutants can be eliminated by heating them to the point where they decompose into non-toxic components such as water vapor or carbon dioxide.
25 A disadvantage with such thermal decomposition is the relatively high cost ofheating the pollutants. Thus a significant effort has been made to reduce the energy required for this thermal decomposition.
One known method for conserving energy is to use a heat exchanger to 30 return the heat from the exhaust of a furnace to preheat air entering the furnace.
Such preheaters have used heat exchangers of various types.
WO 94123246 '~` PCT/US93/05453 215~)0~6 In U.S. Patent 3,404,965 a drum is peripherally fitted with a number of porous ceramic blocks. The drum rotates around a horizontal axis between a gas inlet and outlet on opposite sides of the drum. A burner heats the inside of thedrum to thermally decompose pollutants delivered to the inside of the drum. The 5 thermally cleansed gas exits through the porous ceramic blocks and heats them.The heated blocks circulate to an upstream position so that the incoming gas stream is preheated by passing through the heated ceramic blocks.
One disadvantage with U.S. Patent 3,404,965 is that the porous ceramic 10 blocks present to the incoming gas stream a converging cross section. Thus incoming gas would accelerate if kept within the blocks. This undesirably reduces the residence time in the porous blocks. Moreover, the sides of the block are open so that incoming gas will either be driven to accelerate or tak~ the path of least resistance and leak through the sides of the converging block.
Also, the structure of U.S. Patent 3,404,965 is arran~ed to inject and withdraw ~as only over about half the circumference of the drum. This inability to use a greater number of the porous blocks decreases efficiency.
Also, this drum is completely enclosed in the hot interior of a casing lacking effective seals. For this reason, the casing enclosing the drum and the movin~
parts is double walled and insulated. Consequently, the moving parts inside the casing tend to be overheated. Also, incoming gas can escape to the casing surrounding the drum to eventually bypass the porous ceramic blocks.
In U.S. Patent 3,718,440 a ceramic disc having a number of triangular passages rotates past the inlet and outlet of a combustion chamber to return exhaust heat to the incoming gas stream. Various moving parts and bearings associated with the rotating disc are mounted for exposure to the cooler incoming 2 1 ~
1 gas flow to avoid overheating. The seals around the rotating disc, however, are necessarily exposed to relatively hot gas and special precautions are made to avoid overheating. Since this system uses a flat disc, little mass is available for transferring heat from outlet to inlet.
Accordingly, there is a need for an enhanced regener-ative gas treatment system that has enhanced efficiency, utilizes its gas permeable blocks more effectively; and keeps the heated areas confined so that moving parts are not unnecessarily exposed to high temperatures.
SUMMARY OF THE INVENTION
In accordance with the illustrative embodiments de-monstrating features and advantages of the present invention, there is provided a regenerative device for thermally treating gases. The device has a housing with a gas inlet and a gas outlet. A cage having a central interior ls rotatably mounted in the housing between the inlet and the outlet. A plurality of gas permeable blocks are mounted peripherally in the cage around the central interior to provide therethrough: (a) an incoming flow path from the inlet to the central interior, and (b) an outgoing flow path from the central interior to the gas outlet. This incoming flow path within the blocks is non-converging. The device also has a drive means for rotating the cage to move the blocks successively past the inlet and the outlet.
Alternate regenerative devices according to the principles of the same invention can also thermally treat gases. As before, a cage with a central interior is rotatably mounted in a housing between an inlet and outlet.
BACKGROUND OF THE INVENTION
10 1. Field of the Invention The present invention relates to regenerative apparatus and regenerative methods for thermally treating gases, and in particular, to systems for circulating blocks in order to transfer heat.
15 2. Description of Related Art Increasingly stringent environmental laws have required manufacturers and various businesses to reduce the amount of polluting or toxic emissions from various processes, especially emissions of volatile organic compounds (nV.O.C.n).
For example, waste solvent vapors, and various hydrocarbon fumes can be 20 produced from printing processes, or from baking, or cooking. Some industrial processes produce such toxic emissions as benzene, formaldehyde, etc.
Such po!lutants can be eliminated by heating them to the point where they decompose into non-toxic components such as water vapor or carbon dioxide.
25 A disadvantage with such thermal decomposition is the relatively high cost ofheating the pollutants. Thus a significant effort has been made to reduce the energy required for this thermal decomposition.
One known method for conserving energy is to use a heat exchanger to 30 return the heat from the exhaust of a furnace to preheat air entering the furnace.
Such preheaters have used heat exchangers of various types.
WO 94123246 '~` PCT/US93/05453 215~)0~6 In U.S. Patent 3,404,965 a drum is peripherally fitted with a number of porous ceramic blocks. The drum rotates around a horizontal axis between a gas inlet and outlet on opposite sides of the drum. A burner heats the inside of thedrum to thermally decompose pollutants delivered to the inside of the drum. The 5 thermally cleansed gas exits through the porous ceramic blocks and heats them.The heated blocks circulate to an upstream position so that the incoming gas stream is preheated by passing through the heated ceramic blocks.
One disadvantage with U.S. Patent 3,404,965 is that the porous ceramic 10 blocks present to the incoming gas stream a converging cross section. Thus incoming gas would accelerate if kept within the blocks. This undesirably reduces the residence time in the porous blocks. Moreover, the sides of the block are open so that incoming gas will either be driven to accelerate or tak~ the path of least resistance and leak through the sides of the converging block.
Also, the structure of U.S. Patent 3,404,965 is arran~ed to inject and withdraw ~as only over about half the circumference of the drum. This inability to use a greater number of the porous blocks decreases efficiency.
Also, this drum is completely enclosed in the hot interior of a casing lacking effective seals. For this reason, the casing enclosing the drum and the movin~
parts is double walled and insulated. Consequently, the moving parts inside the casing tend to be overheated. Also, incoming gas can escape to the casing surrounding the drum to eventually bypass the porous ceramic blocks.
In U.S. Patent 3,718,440 a ceramic disc having a number of triangular passages rotates past the inlet and outlet of a combustion chamber to return exhaust heat to the incoming gas stream. Various moving parts and bearings associated with the rotating disc are mounted for exposure to the cooler incoming 2 1 ~
1 gas flow to avoid overheating. The seals around the rotating disc, however, are necessarily exposed to relatively hot gas and special precautions are made to avoid overheating. Since this system uses a flat disc, little mass is available for transferring heat from outlet to inlet.
Accordingly, there is a need for an enhanced regener-ative gas treatment system that has enhanced efficiency, utilizes its gas permeable blocks more effectively; and keeps the heated areas confined so that moving parts are not unnecessarily exposed to high temperatures.
SUMMARY OF THE INVENTION
In accordance with the illustrative embodiments de-monstrating features and advantages of the present invention, there is provided a regenerative device for thermally treating gases. The device has a housing with a gas inlet and a gas outlet. A cage having a central interior ls rotatably mounted in the housing between the inlet and the outlet. A plurality of gas permeable blocks are mounted peripherally in the cage around the central interior to provide therethrough: (a) an incoming flow path from the inlet to the central interior, and (b) an outgoing flow path from the central interior to the gas outlet. This incoming flow path within the blocks is non-converging. The device also has a drive means for rotating the cage to move the blocks successively past the inlet and the outlet.
Alternate regenerative devices according to the principles of the same invention can also thermally treat gases. As before, a cage with a central interior is rotatably mounted in a housing between an inlet and outlet.
3~ Again, a plurality WO 94/23246 21 5 ~ ~ g ~ PCT/US93tO5453 of gas permeable blocks are mounted peripherally in the cage around the central interior to provide therethrough: (a) an incoming flow path from the inlet to the central interior, and (b) an outgoing flow path from the central interior to the gas outlet. A pair of air seals is mounted on opposite sides of the housing, each 5 between the gas inlet and the yas outlet. The air seals peripherally adjoin the cage and deliver air at a pressure higher than that inside the housing. This device also includes a drive means for rotating the cage to move the blocks successively past the inlet and the outlet.
A regenerative method according to the principles of the same invention can thermally treat gases with a plurality of gas permeable blocks arranged to encircle a central interior. The method includes the step of circulating the blocks around an upstream position and a downstream position. Another step is admitting the gases through the blocks at a spatially fixed, upstream location into 15 the central interior without converging the gases flowing through tha blocks. The method also includes the step of discharging gas from the central interior through the blocks at a spatially fixed, downstream location.
Another regenerative method, according to the principles of the same 20 invention can thermally treat gases, again with a plurality of gas permeable blocks arranged to encircle a central interior. The method includes as before, circulating the blocks around an upstream position and a downstream position. Another step is admittin~ the gases through the blocks at a spatially fixed, upstream location into the central interior. The method further includes the step of discharging ~as 25 from the central interior through the blocks at a spatially fixed, downstreamlocation. The method also includes the step of diverting external air to opposite sides of the housing between the upstream position and the downstream position to peripherally impinge on the blocks at a pressure hi~her than that around the blocks.
~O 94/23246 215 9 ~ 9 ~ PCT/US93/05453 Apparatus and methods of the foregoing type achieve a highly effective regenerative thermal treatment of gases. The present invention may take the form of a regenerative thermal oxidation device, a major purpose of which is conservation of fuel. The present invention further addresses the control of 5 volatile or~anic compounds, odor control and fume control.
Accordingly, the preferred embodiment of the present invention is an apparatus which is lightweight, compact and valveless for both commercial and industrial treatment of gases, including for example, gases from fast food grill10 exhausts (with volumes of about 2000 SCFM); wide ran~es of V.O.C.'s from printing and laminating may be disposed of with a high percentage of thermal energy recovery; emissions from painting and spray booths may be effectively disposed of at high rates of ener~y recovery; hydrocarbons from air strippers may be disposed of at high rates of thermal energy recovery, ~ases from solid waste 15 destruction may be disposed of; gases from municipal waste treatment may be disposed of; and emissions from various chemical manufacturing processes may be disposed of, again at high rates of thermal energy recovery. Automotive exhaust emissions as well as many other prospects of treatment are contemplated in accordance with the present invention.
The apparatus herein disclosed can be fabricated, constructed and shipped in an efficient and compact mechanism. This mechanism can be substantially lighter in weight than other regenerative units. The preferred apparatus eliminates the use of flow control valves, and their associated leakage and operational 25 problems.
c In a preferred embodiment a cage is mounted in a housing to rotate atop a number of rollers. The cage is driven by a ring gear on a lower edge of the cage. Preferably, a burner is mounted over the cage to heat the cage interior.
S,3 ~;
Z1S9096''-' This preferred embodiment has a plurality of rectan~ular blocks with a multiplicity of narrow passa~es. These ceramic blocks circulate past a ~as inletand yas outlet to exchange heat from the ~as outlet to the ~as inlet. The preferred blocks do not conver~e to restrict the ~as flowin~ from the ~as inlet.5 Thus incoming gas does not accelerate to decrease the residence time within the ceramic blocks. The preferred gas inlets and ~as outlets to~ether cover almost all the periphery of the ceramic blocks in the ca~e. Thus almost all of the ceramic blocks are in the process of either absorbin~ or delivering heat, thereby enhancing efficiency.
In the preferred embodiment a housing encircles the ca~e but does not enclose the moving parts and the parts supportin~ the cage. Thus these parts arenot subjected to the high temperatures within the cage.
The preferr~d embodiment also has an air seal that divides the periphery of the ca~e into an inlet and an outlet side. If the inlet and outlet are considered to be at the twelve o'clock and six o'clock positions, the preferred air seals are at the three o'clock and nine o'clock positions. The air seals provide a positive air flow that divides into an upstream and downstream branch to isolate the inlet and 20 outlet sides. Because of this positive pressure, ~as on the inlet side has noopportunity to pass to the outlet side and vice versa. By avoiding leaka~e bypassing the ca~e, efficiency is ~reatly enhanced.
In addition, the preferred embodiment has a separate heater located 25 adjacent to one of the air seals to bake off contaminants that have deposited on the ceramic blocks. The deposits are decomposed into water vapor and carbon dioxide thereby cleanin~ the passa~es in the ceramic blocks so they can operate efficiently.
21~909~
BRIEF C)ESCRIPTION OF THE DRAWINGS
The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred, but nonetheless 5 illustrative embodiments, in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein:
Figure 1 is an axonometric view of a regenerative device, in accordance with principles of the present invention, with portions cut away and portions partially exploded for illustrative purposes, wherein a continuous flow is 10 maintained without the use of flow control valves;
Figure 2 is a top view of the device of Figure 1;
Figure 3 is a side view of the device of Figure 1 shown connected to a downstream blower;
Figure 4 is a detailed sectional view of the air seal, taken along line 4-4 of 15 Figure 2;
Figure 5 is a cross-sectional view taken along line 5-5 of Figure 4;
Figure 6 is an detailed, exploded, axonometric view of the air seal of Figure l;
Figure 7 is a detailed, exploded, axonometric view of the optional thermal 20 means of Figure 1 for eliminating organic particulate and condensable buildup on the heat exchange media;
Figure 8 is a schematic diagram showing a method of circulating ~ases around the device of Figure 1; and Figure 9 is a sectional view of a fragment of the cage, which is an alternate 25 to that illustrated in Figure 2;
Figure 10 is a side view of another regenerativs device, also within the principles of the present invention, which is an alternate to that illustrated in Figure 3 and in which the flow gases are routed to operate solely as a heat exchanger.
;
215~96 DETAILED ~ESCRIPTION OF THE PREFERRED EMBODIMENTS
R~ferring to Figures 1 - 3 a regenerative device is mounted on four upright support beams 10, which support upper cross beams 12 and lower cross beams 14. The supporting frame apparatus 10, 12, 14 can be in a variety of forms and 5 modes, formats or arrangements. The entire beam arrangement 10, 12, 14 is then supported on a floor, ground, frame or the like.
A cage 16 is rotatably mounted on beams 14. Cage 16 is shown as having a plurality both of upstanding rectangular ceramic or metallic heat exchange media 10 passages 24 and intermediate polygonal insulation sections 26, which form thewalls of cage 16. It will be understood that there can be any number of heat exchange passages. The heat exchange media 24 forming a heat exchange passage provides suitable gas permeable channels or any suitable rneans such as will allow for gas flow communication into and out of cornbustion chamber 30.
Cage 16 is supported by a trio of equiangularly spaced rollers 18 mounted on cross beams 14. Rollers 18 underlie the periphery of support plate 20 whose edge is formed into a ring ~ear. Mounted atop support plate 20 is an insulating layer 22 forming a floor that may be lined with a heat resistant liner, such as 20 ceramic board and preferably constructed of refractory or ceramic material or the like, similar to the polygonal insulation sections 26. While ceramic board is disclosed, various other refractory materials can be used instead. Plate 20 and layer 22 have a circular border. Support plate 20 can be journaled on a central axle 21 that is mounted to the cross beams 14. Axle 21 keeps support plate 20 25 and the cage 16 centered on the rollers 18.
Mounted atop insulated base 22 are twenty four groups of equiangularly spaced, gas permeable blocks 24. In this embodiment, blocks 24 are stacked in a 4x4 arrangement, seven blocks high, although a different number of variously 21~ 9 ~ ~ ~ PCT/US931054~3 shaped blocks (including a solid monolith) arranged in different patterns are possible instead.
In this embodiment, each of the blocks 24 were rectangular ceramic solids 5 9" (22.8 cm) long with a 6" (15.2 cm) square end. This ceramic can be formed into a honeycombed structure having a multiplicity of square passages or cells running the full length of the block. The cells can have density of 25 to 400 cells per inch2 and one constructed embodiment employed 300 cells per inch2. This structure can be relatively open with 40% to 70% of the surface area exposed 10 to passages. In various alternate embodiments, the cell density and the shapeand mass of the block can be varied depending upon the amount of heat energy to be stored in the block, the heat transfer rate, the mass flow rate, as well as the passage size needed in view of the expected particle size. The ceramic material can be alumina, but various other kinds of ceramics and other materials are 15 possible. Gas permeable ceramics of this type can be purchased form Corning as Celcore type honeycomb supports.
In some embodiments, gas permeable blocks 24 may be made of a ceramic foam. Such ceramic foam can be obtained from Consolidated Aluminum, of 20 Hendersonville, North Carolina, as Selee brand open porous ceramic foam. In still other embodiments, a steel honeycomb can be made from corrugated sheet metal sandwiched between metal plates to provide a heat absorbing metallic body with high surface area.
Insulating blocks 26 are interleaved with the gas permeable blocks 24.
Insulating blocks 26 may be wedged-shaped monoliths sawed from a ceramic blanket. It will be appreciated that non-monolithic and other types of insulators can be used instead. Preferably, insulating blocks 26 are impervious to the gases handled by the system. The cylindrical space within the blocks 24 and insulators 2ls~a~
26 is referred to herein as a combustion chamber or central interior 30.
Mounted atop blocks 24 and insulators 26 is an annular insulating ceiling 28. The internal construction of the ceiling 28 has a heat resistant liner, 5 preferably constructed of refractory or ceramic material or the like, similar the polygonal insulation sections 26. The ceiling 28 is preferably sawed from ceramic board and clad on top by steel plate. The steel top of ceiling 28 can also have a ring gear around its periphery to facilitate a gear drive. The center of the ceiling 28 contains an opening to facilitate the installation of a burner or other heating 10 element described hereinafter.
Mounted atop cross beams 12 is a heater means, shown harein as a burner 32 for injecting a flame down into the center of central interior 30. Burner 32 cooperates with a forced air blower 34. Natural gas is supplied as a fuel, 15 although the burner may consume other fuels such as propane, waste solvents, No. 2 heating fuel, etc. In some embodiments the gas being treated inside cage 16 may be so exothermic that additional heat need not be added through burner 32. Burner 32 has a nozzle that is concentrically mounted through a fixed annular insulating plug 31.
In the preferred embodiment, burner 32 is thermostatically regulated by a thermocouple 33 to keep the temperaturc within the central interior 30 in the vicinity of 1500à to 2000àF, although other temperatures are contemplated for decomposing various types of contaminants. Accordingly, interior 30 functions 25 as a combustion chamber for heating incomin~ gases up to temperatures of 2000àF or more, by rneans of one or more burners 32 of the oil or gas operated type therein, or with an electrical heating elernent.
Cage 16 is rotated about axle 21 by a drive means 38, shown herein as a 2 1 5 ~ ~ 9 6 variable speed, electric motor with a gear reducer for driving pinion 40, which engayes ring gear 22. Motor 38 is arranged to turn cage 16 at a preferred speed of 6 revolutions per minute or less. The speed of motor 38 will vary the period of the regenerative cycle and thereby establish the effective thermal efficiency of the 5 unit.
A housing 42 encircles cage 16. Housing 42 has an eight-sided ceiling and floor with a circular opening occupied by cage 16. Housing 42 has two opposite, parallel walls that span between diverging walls 42A and converging walls 42B.
10 Walls 42A connect to a pyramidically shaped duct 44, herein referred to as a gas inlet. Similarly, walls 42B connect to a pyramidically shaped duct 46, herein referred to as a gas outlet. Ducts 44 and 46 will evenly distribute gases around the cage 16 to radially pass through their heat exchange passages. Gas outlet 46connect to a blower 48 driven by electric motor 50 to induce a draft through cage 15 16.
The housing 42 is shown mounted on the upper side of cross beams 14.
Preferably, but not necessarily, all of the housing 42 is constructed of steel with internal or external insulation as required.
The device of Figures 1 -3 is about 8 feet (2.44 meters) tall and is designed to operate in the range of 5,000-7,000 SCFM, although clearly the device can be sized differently to operate at different capacities. The various steel plates forming housing 42, cage 16 and ducts 44 and 46 are typically made of 3/16"
25 (0.47 cm) steel plate, although other materials and dimensions are possible.
Leakage between the inlet 44 and outlet 46 is prevented by a pair of air seals 52. Air seals 52 effectively provide air nozzles around the internal periphery of the housing 42 next to cage 16. One of the air seals 52 is shown for mounting in an opening 54 (Figure 1 ) in the side of housing 42. Air seal 52 forms a duct with two parallel duct walls 56 covered by a faceplate 58 having several inlet holes 60.
Clean air from outlet 46 or the like is supplied back to the air seal 52 to pressurize the slot opening 54 adjacent the rotating cage 16, thus preventing any cross contamination between the dirty process gases in the inlet 44 and the clean exhaust in the outlet 46. Similarly, air can be exhausted from the air seal 52 and reintroduced to the inlet 44 or directly into the combustion chamber 30, thus 10 preventing any cross contamination between the dirty process ~ases in the inlet 44 and the clean exhaust in the outlet 46.
Because blower 48 can induc~ a draft or ne0ativa pressure within ca~e 16, in soms embodi.ne,)ts ambient air will flow by itself into inlets 60 of air seal 52.
15 The air will enter opening 54 and divide into an upstream and downstream branch. This dividing air flow prevents leakage of gas around the outside of cage 16 from inlet 44 to the outlet 46 or vice versa.
A thermal means 62 is shown herein as an auxiliary high temperature 20 burner tube 64 fed by a regulator valve 66 and designed to be rnounted inside the opening 68 in housing 42. Once tube 64 is in place, opening 68 is covered by a faceplate 70. Burner tube 64 can be supplied with the same fuel as burner 32, although other energy sources can be used as well. Burner tube 64 can raise the temperature of ceramic blocks 24 to bake off residual or~anic particulate, 25 aerosols, or condensables that condense in blocks 24. Burner tube 64 is designed to provide heat sufficient to decompose these deposits into such harmless constituents as water vapor or carbon dioxide.
The thermal means 62 can be placed at different angular positions for 215~0~
baking and decomposing deposits on the gas permeable blocks 24. In some embodiments this thermal device can extend over a larger angular interval or maybe segregated into a number of spaced burners that operating at different hei~hts.
Referring to Figures 4 - 6, duct walls 56 of air seal 52 are shown mounted on vertical braces 72. The inner ends of duct walls 56 have vertically oriented wipers 74 in the form of a stainless steel brushes bolted to the inside edges ofduct walls 56. Brushes 46 provide an imperfect seal between the duct walls 56 and the periphery of cage 16. Air from opening 60 can thus branch in an 10 upstream and downstream direction, that is, clockwise and counterclockwise around cage 16.
A flange 76 is mounted to project radially outward from the steel cap of upper insulating layer 28 of cage 16. Annular seal 78 is toroidal with an inwardly 15 directed flange bolted to the underside of flange 76. Seal 78 presses against the top of housing 42. Similarly, an outwardly projecting, radial flange 80 is secured to the steel skin of lower insulating layer 22. A toroidal seal 82, similar to seal 78, is bolted atop flange 80 in a similar fashion. Seal 82 bears on the underside of housing 42. Seals 78 and 82 prevents gas leaks from housing 42.
Referring to Figure 7, previously mentioned burner 64 is shown as a tube with a heat deflecting shield 64A. Regulating valve 66 is shown as a thermo-statically operated valve to control the heat produced by the burner. Shut off valve 84 is serially connected upstream of valve 66.
The schematic diagram of Figure 8 shows the flow paths throu~h cage 16.
In this embodiment, a forced air blower 86 delivers contaminated gases to the upstream side of cage 16 to force the gases through the gas permeable blocks 24. Once inside central interior 30, the gases flow through the downstream side WO 94/2324ti PCT/US93/0~453 2159~96 of the cage 16 through blocks 24. An induced draft is provided by previously mentioned blower 48. In this eMbodiment, the cleansed ~as from blower 48 directly applies positive air pressure to air seals 52 on opposite sides of cage 16.
In this embodiment, pressure above ambient must be applied to the air seals 52 5 to overcome the positive pressure forced by blower 86. It will be appreciated that some embodiments will not employ forced draft blower 86 so air seals 52 can r~lyon the negative pressure from induced draft blower 48.
The incoming flow of gases is schematically shown in the arrangement 10 illustrated, to be through the heat exchange passages 24 as shown by the arrows. Because cage 16 rotates, these arrows represents flow at a given moment in time. Furthermore, as cage 16 rotates, the heat exchange media 24 no longer have sufficient heat to adequately prehaat incoming ~ases.
Accordingly, cage 16 rotates past air seals 52 to support the heat exchange.
The seals not only act as an air seal between the inlet and outlet, but also flush any dirty residual gases through the heat exchange media 24 into the combustion chamber 30. Alternatively, air seal 52 can exhaust clean air out of the combustion chamber 30. Regardless, gas flow through the heat exchange 20 media 24 is reversed after the cage 16 passes the nozzle of air seal 52, such that the heat exchange media 24 will now absorb heat, from the passage of clean gaseous products of combustion radially outwardly through to the outlet. By appropriate speed control of the rotation of cage 16, the preheat and recovery cycle of the heat exchange media 24 will be maintained.
Appropriate rotational speed control of cage 16 may be programmably controlled by means of a suitable control circuit, which may function in the form of a set speed or exhaust temperature control.
~WO 94123246 2 I 5 9 ~ ~ ~ PCT/US93/054~3 It is desirable to have air movement means, such as blowers 86 and 48 at both locations, in that the system can operate either with forced air at the inlet side, in which a blower or other suitable air moving means 86 can be provided, or the system can operate by means of an induced partial vacuum, in which case 5 an air movement means, such as a blower 48 or other air movement can be used.
However, in some instances it may be desirable to have air movement means, both at the inlet and outlet locations. Furthermore, the air movement means are described and illustrated as blowers only by way of example; such means may also include, for example, fans or induction devices, and indeed, even in the 10 absence of such mechanical device, natural convection can be provided by the combustion process itself.
Figure 9 is a sectional view of a portion of the device illustrated in Figure 2. Similar components here bear the same reference numeral as before. In tha 15 embodiment of Figure 9 gas permeable blocks 90 offer a diverging passageway to incoming gas. Blocks 90 in the upstream position have a narrower upstream cross-section than the downstream cross-section. In this embodiment, the blocks 90 are in the shape of a trapezoidal prism, although other diverging shapes can be employed instead. Since the passageway through blocks 90 diver~e, incoming 20 gas entering the block will not accelerate and will in fact decelerate to increase the residence time through the block.
As an alternate to the system shown and described herein, combustion chamber 30 and burner 32 (or an alternate electrical heating element) can be 25 eliminated to facilitate use as a heat exchanger apparatus only, such that the inlet 44 acts as an inlet chamber for a high temperature process exhaust, and the outlet 46 acts as the outlet chamber for a preheated fresh air supply to a process.
Additional chambers can replace the central combustion chamber 30 with a process outlet chamber and a clean air inlet chamber. These chambers assist in directing the process air and clea~ air through the heat exchange cage.
Figure 10 illustrates such a device. This device is similar to that shown in Figure 3, wherein components similar to that previously illustrated have the same 5 reference numerals. In the embodiment of Figure 10, the central interior is divided by partition 30E into two semi-cylindrical compartments 30A and 30B. Interior half 30A is shown with an interior outlet 30C while interior 30B is shown with an interior inlet 30D. The incomins flow path shown through inlet 44 and blocks 24 and into interior 30A exits from interior outlet 30C. An outgoing flow path is 10 shown passing through interior inlet 30D to pass through interior 30D and blocks 24 to exit through outlet 46 for discharge by blower 48.
To facilitate an understanding of the principles associated with the foregoing apparatus, its operation will be briefly described. Contaminated gases15 may be delivered to gas inlet 44 by either a forced or induced draft. These ~ases can contain such volatile or~anic compounds that may be found in the exhaust hood of a cooking or baking process, a paint drying process, or other industrialprocess producing pollutants that can be thermally decomposed to reduce environmental hazards.
In accordance with the foregoing descriptions of the apparatus, contaminated fumes, odors, and V.O.C.'s that are to be burnt, enter the apparatus through inlet 44 to pass through the heat exchange passages in blocks 24 and to be preheated to temperatures very close to the incineration 25 temperature. Gases to be treated are drawn through the gas permeable blocks 24 into central interior 30. Within interior 30, burner 32 injects a flame (although supplemental heat may be unnecessary for highly exothermic decompositions).
Accordingly, volatile organic compounds such as waste solvent vapors, or fumes containing toxic substances such as benzene or formaldehyde will be -W094/~K PCT~S93/05453 21S~96 .. . .
decomposed. Regardless, oxidation is then completed in the combustion chamber 30 by means of autoignition of V.O.C. or by means of the gas or oil burner 32 or by an alternate electrical heating element that maintains a preset oxidation temperature.
Gases delivered into such apparatus containing V.O.C.'s may self-ignite while still in the heat exchange passages, in which event, such will facilitate and expedite the combustion in the combustion chamber. In some situations, the incoming gases may contain sufficient V.O.C.'s such that the ener~qy released can 10 provide all of the heat required for the apparatus and the burner 32 or otherelectrical heating element will shut off. After the burnin~ is effected in the combustion chamber 30, purified gases will be discharged through the opposit~
heat exchange passages 24.
The temperature produced by burner 32iS regulated by a thermocouple to keep the temperature hiqh enough to decompose the expected contaminants.
The hot, cleansed gas reaches gas outlet 46 by passing through gas permeable blocks 24, thereby heatin~ them. The blocks 24 revolve as ca~e 16 is turned by motor 38 whose gear 40 en~qa~qes ring gear 20. Accordin~q. ly, heated blocks 24 20 eventually circulate to an upstream position so that incoming gas flowing through inlet 44 p~sses through recently heated blocks 24 to preheat the incomin~ ~as.
This preheating reduces the amount of ener~qy required by burner 32, thereby reducing the energy demand.
In environments where the decomposition is exothermic, burner 32 may be eliminated altogether and the decomposition may proceed on its own. In either case, the exchange of heat between the outlet and inlet enhances efficiency and ensures adequate heat for decomposition.
WO 94123246 PCT/US93/05453 ~
~lS90~6 It will be noted that the bearings/axles 21 and rollars 18 rotatably supporting cage 16 are external and are not subjected to the high temperatures within cage 16.
Furthermore, air drawn through apertures 60 in air seals 52 pass within duct walls 56 and into opening 54 (Figur~ 1) of housinçl 42. Upon entering housing 42, the air of air seal 52 divides into an upstream and downstream branch. These two flows avoid leakage from gas inlet 44 to ~as outlet 46 past cage 16.
As blocks 24 circulate, they are continually exposed to volatile organic compounds that solidify and precipitate within the narrow channels in blocks 24.Eventually, these channels in blocks 24 can clog or occlude, thereby adversely affecting system operation. To prcvent such occlusion, thermal means 62 bakes 15 blocks 24 to decomposes the deposits therein. The BTU rating of burner 64 is designed with reference to the type of deposits, the size of the blocks, and thenecessary degree of cleansing.
The operation with respect to the apparatus of Fi~ure 8 is the same except 20 that the forced draft caused by blower 86 produces a positive pressure insidecage 16 so that air seals 52 must work with a greater positive pressure. Blower 88 connected downstream of blower 48 supplies this positive pressure.
Also, operation with respect to the embodiment of Figure 9 is similar 25 except that the incoming gas traverses a diverging passage in blocks 90.
Accordingly, the ~as decelerates within the block 90 so that the residence time within the block is increased.
Referring to Figure 10, the illustrated structure is arranged as a general ~ 094/~K PCT~S93/054~3 2i5~0~6 purpose heat exchanger. The interior partition 30E prevents gas flow from inlet 44 to outlet 46. Thus, there are two isolated flow paths. Gas flowing into chamber 30B may be relatively hot and may flow through and heat gas permeable blocks 24 before exiting through outlet 46 and blower 48. As before, motor 38 5 rotates cage 16so that heated blocks 24 adjacent outlet 46 are brought to an upstream position adjacent inlet 44. Consequently, the isolated gas flow throughinlet 44iS heated by blocks 24 and thereby exchanges heat with the gas flow through chamber 30B. The gas from inlet 44 passing through blocks 24 flows through chamber 30A to exit through interior outlet 30C.
It is to be appreciated that various modifications may be implemented with respect to the above described preferred embodiments. The illustrated cage can be rotatably supported in various fashions with ball bearings, supporting tracks, etc. Also, the cage can be rotated by chains, ratchets, hydraulic motors, etc. In 15 addition, the power source for rotating the cage can be from an internal combustion engine, turbine, hydraulic motor, etc. Moreover, the number, shape and size of the gas permeable blocks can be altered, depending upon the desired capacity, heat transfer, efficiency, etc. While only a pair of air seals are shown, in other embodiments a different number of seals can be used depending upon the 20 desired integrity of the seal. While the burner that heats the interior of the ca~e is mounted above, in some embodiments the burner can be mounted below or in various other positions. Also, the apparatus can be constructed in any of various sizes, with the height and diameter of the cage such as will effect the desired - capacity of the apparatus. Thus, the apparatus herein described, while being 25 preferably intended to provide small, lightweight, valveless units can also provide compact and portable larger units. Also, the materials employed herein can be varied depending upon the desired strength, heat capacity, corrosion resistance,immunity to wear, thermal stability, etc. Thus, the material of construction of the various components as set forth by way of example herein, are merely examples WO 94/23246 PCT/US93/05453 ~
215909~
of those that are preferred, and the same are not intended to be limitin~.
Additionally, while in the system shown and described herein, the combustion chamber 30 is in the center of the heat exchan~er passa~es, it will 5 be understood that the combustion chamber 30 could, if desired, be located on the outside of the cage 16 in plac~ of the inlet 44 and outlet 46. Then the new inlet and outlet would be located in the middle of the heat exchanQe media with entry and exit through the top, bottom or center of the ca~e.
Obviously, many modifications and variations of the present invention are possible in light of the above teachin~s. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
A regenerative method according to the principles of the same invention can thermally treat gases with a plurality of gas permeable blocks arranged to encircle a central interior. The method includes the step of circulating the blocks around an upstream position and a downstream position. Another step is admitting the gases through the blocks at a spatially fixed, upstream location into 15 the central interior without converging the gases flowing through tha blocks. The method also includes the step of discharging gas from the central interior through the blocks at a spatially fixed, downstream location.
Another regenerative method, according to the principles of the same 20 invention can thermally treat gases, again with a plurality of gas permeable blocks arranged to encircle a central interior. The method includes as before, circulating the blocks around an upstream position and a downstream position. Another step is admittin~ the gases through the blocks at a spatially fixed, upstream location into the central interior. The method further includes the step of discharging ~as 25 from the central interior through the blocks at a spatially fixed, downstreamlocation. The method also includes the step of diverting external air to opposite sides of the housing between the upstream position and the downstream position to peripherally impinge on the blocks at a pressure hi~her than that around the blocks.
~O 94/23246 215 9 ~ 9 ~ PCT/US93/05453 Apparatus and methods of the foregoing type achieve a highly effective regenerative thermal treatment of gases. The present invention may take the form of a regenerative thermal oxidation device, a major purpose of which is conservation of fuel. The present invention further addresses the control of 5 volatile or~anic compounds, odor control and fume control.
Accordingly, the preferred embodiment of the present invention is an apparatus which is lightweight, compact and valveless for both commercial and industrial treatment of gases, including for example, gases from fast food grill10 exhausts (with volumes of about 2000 SCFM); wide ran~es of V.O.C.'s from printing and laminating may be disposed of with a high percentage of thermal energy recovery; emissions from painting and spray booths may be effectively disposed of at high rates of ener~y recovery; hydrocarbons from air strippers may be disposed of at high rates of thermal energy recovery, ~ases from solid waste 15 destruction may be disposed of; gases from municipal waste treatment may be disposed of; and emissions from various chemical manufacturing processes may be disposed of, again at high rates of thermal energy recovery. Automotive exhaust emissions as well as many other prospects of treatment are contemplated in accordance with the present invention.
The apparatus herein disclosed can be fabricated, constructed and shipped in an efficient and compact mechanism. This mechanism can be substantially lighter in weight than other regenerative units. The preferred apparatus eliminates the use of flow control valves, and their associated leakage and operational 25 problems.
c In a preferred embodiment a cage is mounted in a housing to rotate atop a number of rollers. The cage is driven by a ring gear on a lower edge of the cage. Preferably, a burner is mounted over the cage to heat the cage interior.
S,3 ~;
Z1S9096''-' This preferred embodiment has a plurality of rectan~ular blocks with a multiplicity of narrow passa~es. These ceramic blocks circulate past a ~as inletand yas outlet to exchange heat from the ~as outlet to the ~as inlet. The preferred blocks do not conver~e to restrict the ~as flowin~ from the ~as inlet.5 Thus incoming gas does not accelerate to decrease the residence time within the ceramic blocks. The preferred gas inlets and ~as outlets to~ether cover almost all the periphery of the ceramic blocks in the ca~e. Thus almost all of the ceramic blocks are in the process of either absorbin~ or delivering heat, thereby enhancing efficiency.
In the preferred embodiment a housing encircles the ca~e but does not enclose the moving parts and the parts supportin~ the cage. Thus these parts arenot subjected to the high temperatures within the cage.
The preferr~d embodiment also has an air seal that divides the periphery of the ca~e into an inlet and an outlet side. If the inlet and outlet are considered to be at the twelve o'clock and six o'clock positions, the preferred air seals are at the three o'clock and nine o'clock positions. The air seals provide a positive air flow that divides into an upstream and downstream branch to isolate the inlet and 20 outlet sides. Because of this positive pressure, ~as on the inlet side has noopportunity to pass to the outlet side and vice versa. By avoiding leaka~e bypassing the ca~e, efficiency is ~reatly enhanced.
In addition, the preferred embodiment has a separate heater located 25 adjacent to one of the air seals to bake off contaminants that have deposited on the ceramic blocks. The deposits are decomposed into water vapor and carbon dioxide thereby cleanin~ the passa~es in the ceramic blocks so they can operate efficiently.
21~909~
BRIEF C)ESCRIPTION OF THE DRAWINGS
The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred, but nonetheless 5 illustrative embodiments, in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein:
Figure 1 is an axonometric view of a regenerative device, in accordance with principles of the present invention, with portions cut away and portions partially exploded for illustrative purposes, wherein a continuous flow is 10 maintained without the use of flow control valves;
Figure 2 is a top view of the device of Figure 1;
Figure 3 is a side view of the device of Figure 1 shown connected to a downstream blower;
Figure 4 is a detailed sectional view of the air seal, taken along line 4-4 of 15 Figure 2;
Figure 5 is a cross-sectional view taken along line 5-5 of Figure 4;
Figure 6 is an detailed, exploded, axonometric view of the air seal of Figure l;
Figure 7 is a detailed, exploded, axonometric view of the optional thermal 20 means of Figure 1 for eliminating organic particulate and condensable buildup on the heat exchange media;
Figure 8 is a schematic diagram showing a method of circulating ~ases around the device of Figure 1; and Figure 9 is a sectional view of a fragment of the cage, which is an alternate 25 to that illustrated in Figure 2;
Figure 10 is a side view of another regenerativs device, also within the principles of the present invention, which is an alternate to that illustrated in Figure 3 and in which the flow gases are routed to operate solely as a heat exchanger.
;
215~96 DETAILED ~ESCRIPTION OF THE PREFERRED EMBODIMENTS
R~ferring to Figures 1 - 3 a regenerative device is mounted on four upright support beams 10, which support upper cross beams 12 and lower cross beams 14. The supporting frame apparatus 10, 12, 14 can be in a variety of forms and 5 modes, formats or arrangements. The entire beam arrangement 10, 12, 14 is then supported on a floor, ground, frame or the like.
A cage 16 is rotatably mounted on beams 14. Cage 16 is shown as having a plurality both of upstanding rectangular ceramic or metallic heat exchange media 10 passages 24 and intermediate polygonal insulation sections 26, which form thewalls of cage 16. It will be understood that there can be any number of heat exchange passages. The heat exchange media 24 forming a heat exchange passage provides suitable gas permeable channels or any suitable rneans such as will allow for gas flow communication into and out of cornbustion chamber 30.
Cage 16 is supported by a trio of equiangularly spaced rollers 18 mounted on cross beams 14. Rollers 18 underlie the periphery of support plate 20 whose edge is formed into a ring ~ear. Mounted atop support plate 20 is an insulating layer 22 forming a floor that may be lined with a heat resistant liner, such as 20 ceramic board and preferably constructed of refractory or ceramic material or the like, similar to the polygonal insulation sections 26. While ceramic board is disclosed, various other refractory materials can be used instead. Plate 20 and layer 22 have a circular border. Support plate 20 can be journaled on a central axle 21 that is mounted to the cross beams 14. Axle 21 keeps support plate 20 25 and the cage 16 centered on the rollers 18.
Mounted atop insulated base 22 are twenty four groups of equiangularly spaced, gas permeable blocks 24. In this embodiment, blocks 24 are stacked in a 4x4 arrangement, seven blocks high, although a different number of variously 21~ 9 ~ ~ ~ PCT/US931054~3 shaped blocks (including a solid monolith) arranged in different patterns are possible instead.
In this embodiment, each of the blocks 24 were rectangular ceramic solids 5 9" (22.8 cm) long with a 6" (15.2 cm) square end. This ceramic can be formed into a honeycombed structure having a multiplicity of square passages or cells running the full length of the block. The cells can have density of 25 to 400 cells per inch2 and one constructed embodiment employed 300 cells per inch2. This structure can be relatively open with 40% to 70% of the surface area exposed 10 to passages. In various alternate embodiments, the cell density and the shapeand mass of the block can be varied depending upon the amount of heat energy to be stored in the block, the heat transfer rate, the mass flow rate, as well as the passage size needed in view of the expected particle size. The ceramic material can be alumina, but various other kinds of ceramics and other materials are 15 possible. Gas permeable ceramics of this type can be purchased form Corning as Celcore type honeycomb supports.
In some embodiments, gas permeable blocks 24 may be made of a ceramic foam. Such ceramic foam can be obtained from Consolidated Aluminum, of 20 Hendersonville, North Carolina, as Selee brand open porous ceramic foam. In still other embodiments, a steel honeycomb can be made from corrugated sheet metal sandwiched between metal plates to provide a heat absorbing metallic body with high surface area.
Insulating blocks 26 are interleaved with the gas permeable blocks 24.
Insulating blocks 26 may be wedged-shaped monoliths sawed from a ceramic blanket. It will be appreciated that non-monolithic and other types of insulators can be used instead. Preferably, insulating blocks 26 are impervious to the gases handled by the system. The cylindrical space within the blocks 24 and insulators 2ls~a~
26 is referred to herein as a combustion chamber or central interior 30.
Mounted atop blocks 24 and insulators 26 is an annular insulating ceiling 28. The internal construction of the ceiling 28 has a heat resistant liner, 5 preferably constructed of refractory or ceramic material or the like, similar the polygonal insulation sections 26. The ceiling 28 is preferably sawed from ceramic board and clad on top by steel plate. The steel top of ceiling 28 can also have a ring gear around its periphery to facilitate a gear drive. The center of the ceiling 28 contains an opening to facilitate the installation of a burner or other heating 10 element described hereinafter.
Mounted atop cross beams 12 is a heater means, shown harein as a burner 32 for injecting a flame down into the center of central interior 30. Burner 32 cooperates with a forced air blower 34. Natural gas is supplied as a fuel, 15 although the burner may consume other fuels such as propane, waste solvents, No. 2 heating fuel, etc. In some embodiments the gas being treated inside cage 16 may be so exothermic that additional heat need not be added through burner 32. Burner 32 has a nozzle that is concentrically mounted through a fixed annular insulating plug 31.
In the preferred embodiment, burner 32 is thermostatically regulated by a thermocouple 33 to keep the temperaturc within the central interior 30 in the vicinity of 1500à to 2000àF, although other temperatures are contemplated for decomposing various types of contaminants. Accordingly, interior 30 functions 25 as a combustion chamber for heating incomin~ gases up to temperatures of 2000àF or more, by rneans of one or more burners 32 of the oil or gas operated type therein, or with an electrical heating elernent.
Cage 16 is rotated about axle 21 by a drive means 38, shown herein as a 2 1 5 ~ ~ 9 6 variable speed, electric motor with a gear reducer for driving pinion 40, which engayes ring gear 22. Motor 38 is arranged to turn cage 16 at a preferred speed of 6 revolutions per minute or less. The speed of motor 38 will vary the period of the regenerative cycle and thereby establish the effective thermal efficiency of the 5 unit.
A housing 42 encircles cage 16. Housing 42 has an eight-sided ceiling and floor with a circular opening occupied by cage 16. Housing 42 has two opposite, parallel walls that span between diverging walls 42A and converging walls 42B.
10 Walls 42A connect to a pyramidically shaped duct 44, herein referred to as a gas inlet. Similarly, walls 42B connect to a pyramidically shaped duct 46, herein referred to as a gas outlet. Ducts 44 and 46 will evenly distribute gases around the cage 16 to radially pass through their heat exchange passages. Gas outlet 46connect to a blower 48 driven by electric motor 50 to induce a draft through cage 15 16.
The housing 42 is shown mounted on the upper side of cross beams 14.
Preferably, but not necessarily, all of the housing 42 is constructed of steel with internal or external insulation as required.
The device of Figures 1 -3 is about 8 feet (2.44 meters) tall and is designed to operate in the range of 5,000-7,000 SCFM, although clearly the device can be sized differently to operate at different capacities. The various steel plates forming housing 42, cage 16 and ducts 44 and 46 are typically made of 3/16"
25 (0.47 cm) steel plate, although other materials and dimensions are possible.
Leakage between the inlet 44 and outlet 46 is prevented by a pair of air seals 52. Air seals 52 effectively provide air nozzles around the internal periphery of the housing 42 next to cage 16. One of the air seals 52 is shown for mounting in an opening 54 (Figure 1 ) in the side of housing 42. Air seal 52 forms a duct with two parallel duct walls 56 covered by a faceplate 58 having several inlet holes 60.
Clean air from outlet 46 or the like is supplied back to the air seal 52 to pressurize the slot opening 54 adjacent the rotating cage 16, thus preventing any cross contamination between the dirty process gases in the inlet 44 and the clean exhaust in the outlet 46. Similarly, air can be exhausted from the air seal 52 and reintroduced to the inlet 44 or directly into the combustion chamber 30, thus 10 preventing any cross contamination between the dirty process ~ases in the inlet 44 and the clean exhaust in the outlet 46.
Because blower 48 can induc~ a draft or ne0ativa pressure within ca~e 16, in soms embodi.ne,)ts ambient air will flow by itself into inlets 60 of air seal 52.
15 The air will enter opening 54 and divide into an upstream and downstream branch. This dividing air flow prevents leakage of gas around the outside of cage 16 from inlet 44 to the outlet 46 or vice versa.
A thermal means 62 is shown herein as an auxiliary high temperature 20 burner tube 64 fed by a regulator valve 66 and designed to be rnounted inside the opening 68 in housing 42. Once tube 64 is in place, opening 68 is covered by a faceplate 70. Burner tube 64 can be supplied with the same fuel as burner 32, although other energy sources can be used as well. Burner tube 64 can raise the temperature of ceramic blocks 24 to bake off residual or~anic particulate, 25 aerosols, or condensables that condense in blocks 24. Burner tube 64 is designed to provide heat sufficient to decompose these deposits into such harmless constituents as water vapor or carbon dioxide.
The thermal means 62 can be placed at different angular positions for 215~0~
baking and decomposing deposits on the gas permeable blocks 24. In some embodiments this thermal device can extend over a larger angular interval or maybe segregated into a number of spaced burners that operating at different hei~hts.
Referring to Figures 4 - 6, duct walls 56 of air seal 52 are shown mounted on vertical braces 72. The inner ends of duct walls 56 have vertically oriented wipers 74 in the form of a stainless steel brushes bolted to the inside edges ofduct walls 56. Brushes 46 provide an imperfect seal between the duct walls 56 and the periphery of cage 16. Air from opening 60 can thus branch in an 10 upstream and downstream direction, that is, clockwise and counterclockwise around cage 16.
A flange 76 is mounted to project radially outward from the steel cap of upper insulating layer 28 of cage 16. Annular seal 78 is toroidal with an inwardly 15 directed flange bolted to the underside of flange 76. Seal 78 presses against the top of housing 42. Similarly, an outwardly projecting, radial flange 80 is secured to the steel skin of lower insulating layer 22. A toroidal seal 82, similar to seal 78, is bolted atop flange 80 in a similar fashion. Seal 82 bears on the underside of housing 42. Seals 78 and 82 prevents gas leaks from housing 42.
Referring to Figure 7, previously mentioned burner 64 is shown as a tube with a heat deflecting shield 64A. Regulating valve 66 is shown as a thermo-statically operated valve to control the heat produced by the burner. Shut off valve 84 is serially connected upstream of valve 66.
The schematic diagram of Figure 8 shows the flow paths throu~h cage 16.
In this embodiment, a forced air blower 86 delivers contaminated gases to the upstream side of cage 16 to force the gases through the gas permeable blocks 24. Once inside central interior 30, the gases flow through the downstream side WO 94/2324ti PCT/US93/0~453 2159~96 of the cage 16 through blocks 24. An induced draft is provided by previously mentioned blower 48. In this eMbodiment, the cleansed ~as from blower 48 directly applies positive air pressure to air seals 52 on opposite sides of cage 16.
In this embodiment, pressure above ambient must be applied to the air seals 52 5 to overcome the positive pressure forced by blower 86. It will be appreciated that some embodiments will not employ forced draft blower 86 so air seals 52 can r~lyon the negative pressure from induced draft blower 48.
The incoming flow of gases is schematically shown in the arrangement 10 illustrated, to be through the heat exchange passages 24 as shown by the arrows. Because cage 16 rotates, these arrows represents flow at a given moment in time. Furthermore, as cage 16 rotates, the heat exchange media 24 no longer have sufficient heat to adequately prehaat incoming ~ases.
Accordingly, cage 16 rotates past air seals 52 to support the heat exchange.
The seals not only act as an air seal between the inlet and outlet, but also flush any dirty residual gases through the heat exchange media 24 into the combustion chamber 30. Alternatively, air seal 52 can exhaust clean air out of the combustion chamber 30. Regardless, gas flow through the heat exchange 20 media 24 is reversed after the cage 16 passes the nozzle of air seal 52, such that the heat exchange media 24 will now absorb heat, from the passage of clean gaseous products of combustion radially outwardly through to the outlet. By appropriate speed control of the rotation of cage 16, the preheat and recovery cycle of the heat exchange media 24 will be maintained.
Appropriate rotational speed control of cage 16 may be programmably controlled by means of a suitable control circuit, which may function in the form of a set speed or exhaust temperature control.
~WO 94123246 2 I 5 9 ~ ~ ~ PCT/US93/054~3 It is desirable to have air movement means, such as blowers 86 and 48 at both locations, in that the system can operate either with forced air at the inlet side, in which a blower or other suitable air moving means 86 can be provided, or the system can operate by means of an induced partial vacuum, in which case 5 an air movement means, such as a blower 48 or other air movement can be used.
However, in some instances it may be desirable to have air movement means, both at the inlet and outlet locations. Furthermore, the air movement means are described and illustrated as blowers only by way of example; such means may also include, for example, fans or induction devices, and indeed, even in the 10 absence of such mechanical device, natural convection can be provided by the combustion process itself.
Figure 9 is a sectional view of a portion of the device illustrated in Figure 2. Similar components here bear the same reference numeral as before. In tha 15 embodiment of Figure 9 gas permeable blocks 90 offer a diverging passageway to incoming gas. Blocks 90 in the upstream position have a narrower upstream cross-section than the downstream cross-section. In this embodiment, the blocks 90 are in the shape of a trapezoidal prism, although other diverging shapes can be employed instead. Since the passageway through blocks 90 diver~e, incoming 20 gas entering the block will not accelerate and will in fact decelerate to increase the residence time through the block.
As an alternate to the system shown and described herein, combustion chamber 30 and burner 32 (or an alternate electrical heating element) can be 25 eliminated to facilitate use as a heat exchanger apparatus only, such that the inlet 44 acts as an inlet chamber for a high temperature process exhaust, and the outlet 46 acts as the outlet chamber for a preheated fresh air supply to a process.
Additional chambers can replace the central combustion chamber 30 with a process outlet chamber and a clean air inlet chamber. These chambers assist in directing the process air and clea~ air through the heat exchange cage.
Figure 10 illustrates such a device. This device is similar to that shown in Figure 3, wherein components similar to that previously illustrated have the same 5 reference numerals. In the embodiment of Figure 10, the central interior is divided by partition 30E into two semi-cylindrical compartments 30A and 30B. Interior half 30A is shown with an interior outlet 30C while interior 30B is shown with an interior inlet 30D. The incomins flow path shown through inlet 44 and blocks 24 and into interior 30A exits from interior outlet 30C. An outgoing flow path is 10 shown passing through interior inlet 30D to pass through interior 30D and blocks 24 to exit through outlet 46 for discharge by blower 48.
To facilitate an understanding of the principles associated with the foregoing apparatus, its operation will be briefly described. Contaminated gases15 may be delivered to gas inlet 44 by either a forced or induced draft. These ~ases can contain such volatile or~anic compounds that may be found in the exhaust hood of a cooking or baking process, a paint drying process, or other industrialprocess producing pollutants that can be thermally decomposed to reduce environmental hazards.
In accordance with the foregoing descriptions of the apparatus, contaminated fumes, odors, and V.O.C.'s that are to be burnt, enter the apparatus through inlet 44 to pass through the heat exchange passages in blocks 24 and to be preheated to temperatures very close to the incineration 25 temperature. Gases to be treated are drawn through the gas permeable blocks 24 into central interior 30. Within interior 30, burner 32 injects a flame (although supplemental heat may be unnecessary for highly exothermic decompositions).
Accordingly, volatile organic compounds such as waste solvent vapors, or fumes containing toxic substances such as benzene or formaldehyde will be -W094/~K PCT~S93/05453 21S~96 .. . .
decomposed. Regardless, oxidation is then completed in the combustion chamber 30 by means of autoignition of V.O.C. or by means of the gas or oil burner 32 or by an alternate electrical heating element that maintains a preset oxidation temperature.
Gases delivered into such apparatus containing V.O.C.'s may self-ignite while still in the heat exchange passages, in which event, such will facilitate and expedite the combustion in the combustion chamber. In some situations, the incoming gases may contain sufficient V.O.C.'s such that the ener~qy released can 10 provide all of the heat required for the apparatus and the burner 32 or otherelectrical heating element will shut off. After the burnin~ is effected in the combustion chamber 30, purified gases will be discharged through the opposit~
heat exchange passages 24.
The temperature produced by burner 32iS regulated by a thermocouple to keep the temperature hiqh enough to decompose the expected contaminants.
The hot, cleansed gas reaches gas outlet 46 by passing through gas permeable blocks 24, thereby heatin~ them. The blocks 24 revolve as ca~e 16 is turned by motor 38 whose gear 40 en~qa~qes ring gear 20. Accordin~q. ly, heated blocks 24 20 eventually circulate to an upstream position so that incoming gas flowing through inlet 44 p~sses through recently heated blocks 24 to preheat the incomin~ ~as.
This preheating reduces the amount of ener~qy required by burner 32, thereby reducing the energy demand.
In environments where the decomposition is exothermic, burner 32 may be eliminated altogether and the decomposition may proceed on its own. In either case, the exchange of heat between the outlet and inlet enhances efficiency and ensures adequate heat for decomposition.
WO 94123246 PCT/US93/05453 ~
~lS90~6 It will be noted that the bearings/axles 21 and rollars 18 rotatably supporting cage 16 are external and are not subjected to the high temperatures within cage 16.
Furthermore, air drawn through apertures 60 in air seals 52 pass within duct walls 56 and into opening 54 (Figur~ 1) of housinçl 42. Upon entering housing 42, the air of air seal 52 divides into an upstream and downstream branch. These two flows avoid leakage from gas inlet 44 to ~as outlet 46 past cage 16.
As blocks 24 circulate, they are continually exposed to volatile organic compounds that solidify and precipitate within the narrow channels in blocks 24.Eventually, these channels in blocks 24 can clog or occlude, thereby adversely affecting system operation. To prcvent such occlusion, thermal means 62 bakes 15 blocks 24 to decomposes the deposits therein. The BTU rating of burner 64 is designed with reference to the type of deposits, the size of the blocks, and thenecessary degree of cleansing.
The operation with respect to the apparatus of Fi~ure 8 is the same except 20 that the forced draft caused by blower 86 produces a positive pressure insidecage 16 so that air seals 52 must work with a greater positive pressure. Blower 88 connected downstream of blower 48 supplies this positive pressure.
Also, operation with respect to the embodiment of Figure 9 is similar 25 except that the incoming gas traverses a diverging passage in blocks 90.
Accordingly, the ~as decelerates within the block 90 so that the residence time within the block is increased.
Referring to Figure 10, the illustrated structure is arranged as a general ~ 094/~K PCT~S93/054~3 2i5~0~6 purpose heat exchanger. The interior partition 30E prevents gas flow from inlet 44 to outlet 46. Thus, there are two isolated flow paths. Gas flowing into chamber 30B may be relatively hot and may flow through and heat gas permeable blocks 24 before exiting through outlet 46 and blower 48. As before, motor 38 5 rotates cage 16so that heated blocks 24 adjacent outlet 46 are brought to an upstream position adjacent inlet 44. Consequently, the isolated gas flow throughinlet 44iS heated by blocks 24 and thereby exchanges heat with the gas flow through chamber 30B. The gas from inlet 44 passing through blocks 24 flows through chamber 30A to exit through interior outlet 30C.
It is to be appreciated that various modifications may be implemented with respect to the above described preferred embodiments. The illustrated cage can be rotatably supported in various fashions with ball bearings, supporting tracks, etc. Also, the cage can be rotated by chains, ratchets, hydraulic motors, etc. In 15 addition, the power source for rotating the cage can be from an internal combustion engine, turbine, hydraulic motor, etc. Moreover, the number, shape and size of the gas permeable blocks can be altered, depending upon the desired capacity, heat transfer, efficiency, etc. While only a pair of air seals are shown, in other embodiments a different number of seals can be used depending upon the 20 desired integrity of the seal. While the burner that heats the interior of the ca~e is mounted above, in some embodiments the burner can be mounted below or in various other positions. Also, the apparatus can be constructed in any of various sizes, with the height and diameter of the cage such as will effect the desired - capacity of the apparatus. Thus, the apparatus herein described, while being 25 preferably intended to provide small, lightweight, valveless units can also provide compact and portable larger units. Also, the materials employed herein can be varied depending upon the desired strength, heat capacity, corrosion resistance,immunity to wear, thermal stability, etc. Thus, the material of construction of the various components as set forth by way of example herein, are merely examples WO 94/23246 PCT/US93/05453 ~
215909~
of those that are preferred, and the same are not intended to be limitin~.
Additionally, while in the system shown and described herein, the combustion chamber 30 is in the center of the heat exchan~er passa~es, it will 5 be understood that the combustion chamber 30 could, if desired, be located on the outside of the cage 16 in plac~ of the inlet 44 and outlet 46. Then the new inlet and outlet would be located in the middle of the heat exchanQe media with entry and exit through the top, bottom or center of the ca~e.
Obviously, many modifications and variations of the present invention are possible in light of the above teachin~s. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
Claims (50)
1. A regenerative device for thermally treating gases, comprising:
a housing (42) having a gas inlet (44) and a gas outlet (46);
a holding cage means (16) having a central interior (30) defining a space for rotating in said housing (42) between said inlet (44) and said outlet (46);
a plurality of gas permeable, refractory blocks (24) mounted peripherally in said holding cage means (16) around said central interior (30) to provide therethrough (a) an incoming flow path from said inlet (44) to said central interior (30), and (b) an outgo-ing flow path from said central interior (30) to said gas outlet (46); and drive means (38) for rotating said holding cage means (16) to move said blocks (24) successively past said inlet (44) and said outlet (46); characterized by:
a pair of air seal means (52) each mounted on opposite sides of said housing (42), each between said gas inlet (44) and said gas outlet (46) for periphe-rally adjoining said holding cage means (16), said seal means (52) conducting air and establishing a separate flow of said air into a clockwise stream and a counterclockwise stream around and in contact with said blocks (24).
a housing (42) having a gas inlet (44) and a gas outlet (46);
a holding cage means (16) having a central interior (30) defining a space for rotating in said housing (42) between said inlet (44) and said outlet (46);
a plurality of gas permeable, refractory blocks (24) mounted peripherally in said holding cage means (16) around said central interior (30) to provide therethrough (a) an incoming flow path from said inlet (44) to said central interior (30), and (b) an outgo-ing flow path from said central interior (30) to said gas outlet (46); and drive means (38) for rotating said holding cage means (16) to move said blocks (24) successively past said inlet (44) and said outlet (46); characterized by:
a pair of air seal means (52) each mounted on opposite sides of said housing (42), each between said gas inlet (44) and said gas outlet (46) for periphe-rally adjoining said holding cage means (16), said seal means (52) conducting air and establishing a separate flow of said air into a clockwise stream and a counterclockwise stream around and in contact with said blocks (24).
2. A regenerative device according to claim 1 wherein said blocks (24) have a honeycomb structure.
3. A regenerative device according to claim 1 wherein said blocks (24) are made of ceramic.
4. A regenerative device according to claim 3 wherein said blocks (24) have a honeycomb structure.
5. A regenerative device according to claim 1 comprising:
thermal means (62) peripherally mounted on said housing (42) to extend axially and to heat passing ones of said blocks (24) and bake off residual depositions on said blocks (24).
thermal means (62) peripherally mounted on said housing (42) to extend axially and to heat passing ones of said blocks (24) and bake off residual depositions on said blocks (24).
6. A regenerative device according to claim 5 wherein said thermal means (52) has a predetermined angular displacement relative to said gas inlet (44), said thermal means (62) being axially sized to heat all of said blocks (24) having said predetermined angular displacement from said gas inlet (44), so that all of said blocks (24) are heated upon one revolution of said holding cage means (16).
7. A regenerative device according to claim 6 wherein said thermal means (62) is located (a) nearer said gas inlet (44) than said gas outlet (46), and (b) to heat blocks (24) moving from said gas inlet (44) to said gas outlet (46).
8. A regenerative device according to claim 7 wherein said blocks (24) have a honeycomb structure.
9. A regenerative device according to claim 8 wherein said blocks (24) are made of ceramic.
10. A regenerative device according to claim 1 comprising:
heater means (32) for heating said central interior (30) to enhance thermal oxidation therein of said gases.
heater means (32) for heating said central interior (30) to enhance thermal oxidation therein of said gases.
11. A regenerative device according to claim 10 wherein said heater means (32) is mounted on said housing (42) coaxially with said holding cage means (16).
12. A regenerative device according to claim 11 wherein said heater means comprises a burner (32) mounted over said holding cage means (16) to inject a flame down into said central interior (30).
13. A regenerative device according to claim 12 wherein said blocks (24) have a honeycomb structure.
14. A regenerative device according to claim 1 comprising:
a plurality of insulation sections (26) interleaved with said blocks (24).
a plurality of insulation sections (26) interleaved with said blocks (24).
15. A regenerative device according to claim 12 comprising:
thermal means (52) peripherally mounted on said housing (42) to extend axially and to heat passing ones of said blocks (24) and bake off residual depositions on said blocks (24).
thermal means (52) peripherally mounted on said housing (42) to extend axially and to heat passing ones of said blocks (24) and bake off residual depositions on said blocks (24).
16. A regenerative device according to claim 15 comprising:
an annular seal means (78) mounted between said housing (42) and holding cage means (16) for preventing leakage.
an annular seal means (78) mounted between said housing (42) and holding cage means (16) for preventing leakage.
17. A regenerative device according to claim 16 wherein said holding cage means (16) comprises:
a ring gear (20) arranged to be driven by said drive means (38).
a ring gear (20) arranged to be driven by said drive means (38).
18. A regenerative device according to claim 17 wherein said housing (42) comprises:
a plurality of rollers (18) located to subja-cently support said holding cage means (16), said ring gear (20) being located on a lower edge of said holding cage means (16) to rotate azimuthally.
a plurality of rollers (18) located to subja-cently support said holding cage means (16), said ring gear (20) being located on a lower edge of said holding cage means (16) to rotate azimuthally.
19. A regenerative device according to claim 1 wherein said incoming flow path within said blocks (24) are diverging.
20. A regenerative device according to claim 1 wherein said housing (42) has an interior outlet (30C) and an interior inlet (30D), said incoming flow path communicating from said gas inlet (44) through said central interior (30) to said interior outlet (30C), said outgoing flow path communicating from said interi-or inlet (30D) through said central interior (30) to said gas outlet (46), said incoming flow path being isolated from said outgoing flow path.
21. A regenerative device according to claim 12 wherein said air seal means (52) comprises:
means (52) peripherally mounted on opposite sides of said housing (42) between said gas inlet (30D) and said gas outlet (46) to extend axially and to peripherally adjoin said holding cage means (16) and deliver air at a pressure higher than that inside said holding cage means (16).
means (52) peripherally mounted on opposite sides of said housing (42) between said gas inlet (30D) and said gas outlet (46) to extend axially and to peripherally adjoin said holding cage means (16) and deliver air at a pressure higher than that inside said holding cage means (16).
22. A regenerative device according to claim 21 comprising:
a blower (48) coupled to said gas outlet (46) for inducing a draft through said gas outlet (46) and said air seal means (52).
a blower (48) coupled to said gas outlet (46) for inducing a draft through said gas outlet (46) and said air seal means (52).
23. A regenerative device for thermally treating gases, comprising:
a housing (42) having a gas inlet (44D) and a gas outlet (46);
a holding cage means (16) having a central interior (30) for rotating in said housing (42) between said inlet (44) and said outlet (46);
a plurality of gas permeable, refractory blocks (24) mounted peripherally in said holding cage means (16) around said central interior (30) to provide therethrough (a) an incoming flow path from said inlet (44) to said central interior (30), and (b) an outgoing flow path from said central interior (30) to said gas outlet (46); and drive means (38) for rotating said holding cage means (16) to move said blocks (24) successively past said inlet (44) and said outlet (46); characterized by:
a pair of air seal means (52) each mounted on opposite sides of said housing (42), each between said gas inlet (44) and said gas outlet (46) for peripheral-ly adjoining said holding cage means (16) and conduct-ing air between a common zone and the opposite sides of said housing (42) at a pressure sized to avoid airflow from said gas inlet to said gas outlet bypassing said central interior (30).
a housing (42) having a gas inlet (44D) and a gas outlet (46);
a holding cage means (16) having a central interior (30) for rotating in said housing (42) between said inlet (44) and said outlet (46);
a plurality of gas permeable, refractory blocks (24) mounted peripherally in said holding cage means (16) around said central interior (30) to provide therethrough (a) an incoming flow path from said inlet (44) to said central interior (30), and (b) an outgoing flow path from said central interior (30) to said gas outlet (46); and drive means (38) for rotating said holding cage means (16) to move said blocks (24) successively past said inlet (44) and said outlet (46); characterized by:
a pair of air seal means (52) each mounted on opposite sides of said housing (42), each between said gas inlet (44) and said gas outlet (46) for peripheral-ly adjoining said holding cage means (16) and conduct-ing air between a common zone and the opposite sides of said housing (42) at a pressure sized to avoid airflow from said gas inlet to said gas outlet bypassing said central interior (30).
24. A regenerative device according to claim 23 wherein said air seal means (52) comprises:
a wiper (74) mounted on said housing (42) to extend axially and to peripherally engage said holding cage means (16).
a wiper (74) mounted on said housing (42) to extend axially and to peripherally engage said holding cage means (16).
25. A regenerative device according to claim 24 wherein said air seal means (52) comprises:
a duct (56) providing a passage through said housing (42), said wiper (74) being mounted on said duct (56) between said holding cage means (16) and said duct (56).
a duct (56) providing a passage through said housing (42), said wiper (74) being mounted on said duct (56) between said holding cage means (16) and said duct (56).
26. A regenerative device according to claim 23 wherein said blocks (24) have a honeycomb structure.
27. A regenerative device according to claim 23 wherein said blocks (24) are made of ceramic.
28. A regenerative device according to claim 27 wherein said blocks (24) have a honeycomb structure.
29. A regenerative device according to claim 23 comprising:
thermal means (62) peripherally mounted on said housing (42) to extend axially and to heat passing ones of said blocks (24) and bake off residual depositions on said blocks (24).
thermal means (62) peripherally mounted on said housing (42) to extend axially and to heat passing ones of said blocks (24) and bake off residual depositions on said blocks (24).
30. A regenerative device according to claim 29 wherein said thermal means (62) has a predetermined angular displacement relative to said gas inlet (44), said thermal means (62) being axially sized to heat all of said blocks (24) having said predetermined angular displacement from said gas inlet (44), so that all of said blocks (24) are heated upon one revolution of said holding cage means (16).
31. A regenerative device according to claim 30 wherein said thermal means (62) is located (a) nearer said gas inlet (44) than said gas outlet (46), and (b) to heat blocks (24) moving from said gas inlet (44) to said gas outlet (46).
32. A regenerative device according to claim 23 comprising:
heater means (32) for heating said central interior (30) to enhance thermal oxidation therein of said gases.
heater means (32) for heating said central interior (30) to enhance thermal oxidation therein of said gases.
33. A regenerative device according to claim 32 wherein said heater means (32) is mounted on said housing (42) coaxially with said holding cage means (16).
34. A regenerative device according to claim 33 wherein said heater means (32) comprises a burner (32) mounted over said holding cage means (16) to inject a flame down into said central interior (30).
35. A regenerative device according to claim 32 comprising:
thermal means (62) peripherally mounted on said housing (42) to extend axially and to heat passing ones of said blocks (24) and bake off residual depositions on said blocks (24).
thermal means (62) peripherally mounted on said housing (42) to extend axially and to heat passing ones of said blocks (24) and bake off residual depositions on said blocks (24).
36. A regenerative device according to claim 35 comprising:
an annular sealing means (78) mounted between said housing (42) and said holding cage means (16) for preventing leakage.
an annular sealing means (78) mounted between said housing (42) and said holding cage means (16) for preventing leakage.
37. A regenerative device according to claim 36 wherein said holding cage means (16) comprises:
a ring gear (20) arranged to be driven by said drive means (38).
a ring gear (20) arranged to be driven by said drive means (38).
38. A regenerative device according to claim 37 wherein said housing (42) comprises:
a plurality of rollers (18) located to subja-cently support said holding cage means (16), said ring gear (20) being located on a lower edge of said holding cage means (16) to rotate azimuthally.
a plurality of rollers (18) located to subja-cently support said holding cage means (16), said ring gear (20) being located on a lower edge of said holding cage means (16) to rotate azimuthally.
39. A regenerative device according to claim 23 wherein said incoming flow path within said blocks (24) are diverging.
40. A regenerative device according to claim 23 wherein said housing (42) has an interior outlet (30C) and an interior inlet (30D), said incoming flow path communicating from said gas inlet (44) through said central interior (30) to said interior outlet (30C), said outgoing flow path communicating from said interi-or inlet (30D) through said central interior (30) to said gas outlet (46), said incoming flow path being isolated from said outgoing flow path.
41. A regenerative method for thermally treat-ing gases with a plurality of gas permeable blocks (24) arranged to encircle a central interior (30), compris-ing the steps of:
circulating said blocks (24) around an upstream position and a downstream position;
admitting said gases through the blocks (24) at a spatially fixed, upstream location into said central interior (30); and discharging gas from said central interior (30) through the blocks (24) at a spatially fixed, downstream location; characterized by:
sealing on the exterior of said blocks (24) at opposing peripheral positions between said upstream and said downstream locations by conducting air and esta-blishing a separate flow of said air into a clockwise stream and a counterclockwise stream around and in contact with said blocks (24).
circulating said blocks (24) around an upstream position and a downstream position;
admitting said gases through the blocks (24) at a spatially fixed, upstream location into said central interior (30); and discharging gas from said central interior (30) through the blocks (24) at a spatially fixed, downstream location; characterized by:
sealing on the exterior of said blocks (24) at opposing peripheral positions between said upstream and said downstream locations by conducting air and esta-blishing a separate flow of said air into a clockwise stream and a counterclockwise stream around and in contact with said blocks (24).
42. A regenerative method according to claim 41 comprising the step of:
heating passing ones of said blocks (24) to bake off residual depositions on said blocks (24).
heating passing ones of said blocks (24) to bake off residual depositions on said blocks (24).
43. A regenerative method according to claim 42 wherein the step of heating passing ones of said blocks (24) is performed by heating all of said blocks (24) having a predetermined angular displacement from said upstream position, so that all of said blocks (24) are heated at least once in every cycle.
44. A regenerative method according to claim 43 wherein the step of heating passing ones of said blocks (24) is performed (a) nearer said upstream position than said downstream position, and (b) on blocks (24) moving from said upstream position to said downstream position.
45. A regenerative method according to claim 41 comprising the step of:
elevating the temperature of said central interior (30) to enhance thermal oxidation therein of said gases.
elevating the temperature of said central interior (30) to enhance thermal oxidation therein of said gases.
46. A regenerative method according to claim 45 comprising the step of:
injecting a flame down into said central interior (30).
injecting a flame down into said central interior (30).
47. A regenerative method according to claim 41 wherein the step of admitting said gases through an upstream portion of said blocks (24) is performed with the gases flowing through said blocks (24) diverging.
48. A regenerative method according to claim 41 wherein the step of admitting said gases through an up-stream portion of said blocks (24) is performed by subsequently venting said gases from said central interior (30), the step of discharging gas from said central interior (30) is performed by first introducing gas and then keeping it isolated from the gases originating from said upstream portion of said blocks (24).
49. A regenerative method for thermally treat-ing gases with a plurality of gas permeable blocks (24) arranged to encircle a central interior (30), compris-ing the steps of:
circulating said blocks (24) around an upstream position and a downstream position;
admitting said gases through the blocks (24) at a spatially fixed, upstream location into said central interior (30); and discharging gas from said central interior (30) through the blocks (24) at a spatially fixed, down-stream location; characterized by:
sealing on the exterior of said blocks (24) at opposing peripheral positions between said upstream and said downstream locations by conducting air between a common zone and the opposite sides of said housing (42) at a pressure sized to avoid airflow from said upstream location to said downstream location bypassing said central interior (30).
circulating said blocks (24) around an upstream position and a downstream position;
admitting said gases through the blocks (24) at a spatially fixed, upstream location into said central interior (30); and discharging gas from said central interior (30) through the blocks (24) at a spatially fixed, down-stream location; characterized by:
sealing on the exterior of said blocks (24) at opposing peripheral positions between said upstream and said downstream locations by conducting air between a common zone and the opposite sides of said housing (42) at a pressure sized to avoid airflow from said upstream location to said downstream location bypassing said central interior (30).
50. A regenerative method according to claim 49 comprising the step of:
keeping pressure within said blocks (24) below ambient.
keeping pressure within said blocks (24) below ambient.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US3816093A | 1993-03-26 | 1993-03-26 | |
| US08/038,160 | 1993-03-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2159096A1 true CA2159096A1 (en) | 1994-10-13 |
Family
ID=21898389
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2159096 Abandoned CA2159096A1 (en) | 1993-03-26 | 1993-06-09 | Regenerative device |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0689655A1 (en) |
| CA (1) | CA2159096A1 (en) |
| WO (1) | WO1994023246A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109404939A (en) * | 2019-01-22 | 2019-03-01 | 常州大恒环保科技有限公司 | A kind of heat accumulating type heating power incinerator of built-in booster fan |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2720488B1 (en) * | 1994-05-24 | 1996-07-12 | Inst Francais Du Petrole | Rotary device for heat transfer and thermal purification applied to gaseous effluents. |
| FR2728483B1 (en) * | 1994-12-26 | 1997-01-24 | Inst Francais Du Petrole | IMPROVED ROTARY DEVICE FOR CATALYTIC PURIFICATION OF POLLUTED EFFLUENTS |
| US6193504B1 (en) | 1997-04-01 | 2001-02-27 | Engelhard Corporation | Portable rotary catalytic oxidizer systems |
| US5967771A (en) * | 1997-04-01 | 1999-10-19 | Engelhard Corporation | Rotary regenerative oxidizer |
| US5871347A (en) * | 1997-04-01 | 1999-02-16 | Engelhard Corporation | Rotary regenerative oxidizer |
| US6235249B1 (en) | 1997-04-01 | 2001-05-22 | Engelhard Corporation | Rotary oxidizer systems for control of restaurant emissions |
| JP5437734B2 (en) * | 2009-08-07 | 2014-03-12 | 株式会社荏原製作所 | Combustion exhaust gas treatment equipment |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3404965A (en) * | 1964-11-13 | 1968-10-08 | Benjamin P. Shiller | Fume combustion apparatus |
| GB1166209A (en) * | 1968-06-26 | 1969-10-08 | Kazakhsk Nii Energetiki | Apparatus for Carrying out Chemical Reactions in a Current of Gas Reagents and especially suitable for Burning out Combustible Components from a Gas Mixture of Low Calorific Value |
| US3870474B1 (en) * | 1972-11-13 | 1991-04-02 | Regenerative incinerator systems for waste gases | |
| FR2373769A1 (en) * | 1976-12-07 | 1978-07-07 | Air Ind | IMPROVEMENTS TO DYNAMIC HEAT EXCHANGERS |
| DE2951279A1 (en) * | 1979-12-20 | 1981-07-16 | L. & C. Steinmüller GmbH, 5270 Gummersbach | REGENERATIVE HEAT EXCHANGER |
| US5016547A (en) * | 1990-05-04 | 1991-05-21 | Salem Industries, Inc. | Regenerative incinerator |
-
1993
- 1993-06-09 CA CA 2159096 patent/CA2159096A1/en not_active Abandoned
- 1993-06-09 WO PCT/US1993/005453 patent/WO1994023246A1/en not_active Application Discontinuation
- 1993-06-09 EP EP93916452A patent/EP0689655A1/en not_active Ceased
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109404939A (en) * | 2019-01-22 | 2019-03-01 | 常州大恒环保科技有限公司 | A kind of heat accumulating type heating power incinerator of built-in booster fan |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0689655A1 (en) | 1996-01-03 |
| WO1994023246A1 (en) | 1994-10-13 |
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