Patent Publication Number: US-2022221148-A9

Title: Thermogenic vortex combustor

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Certain features disclosed in this application are disclosed and claimed in U.S. Pat. No. 3,577,940 issued on May 11, 1971 to Robert J. Hasselbring and Robert L. Shields, and U.S. Pat. No. 3,727,563 issued on Apr. 17, 1973 to Robert J. Hasselbring and Robert L. Shields, and U.S. Pat. No. 3,568,017 issued on Apr. 25, 1972 to Norman R. Dibelius and William L. Zabriskie. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to combustors and has particular relation to industrial and municipal-type combustors for burning waste material, mobile combustors for first response disaster cleanup, and combustors using agricultural waste, coal, and tires as alternative fuels. 
     2. Description of the Prior Art 
     Conventional industrial and municipal type combustors ordinarily include one or more combustion chambers having drying grates with a flue for discharging to atmosphere the gaseous products of combustion of waste material in the chambers. Depending upon the efficiency of a particular combustor design varying amounts of noxious gases and ash are discharged through the flue to atmosphere. Prior combustor designs in general have been incapable of effecting good combustion of waste material such that the products of the resulting incomplete combustion consist of a large quantity of noxious gases and ash which are discharged to the surrounding atmosphere in the form of dense acrid smoke. 
     In an effort to comply with regulatory air pollution codes, more recent combustor designs have provided for cleaning the gaseous products of combustion prior to their discharge to atmosphere. Such flue gas cleaning apparatus is usually of costly and bulky construction and in some cases has not operated to clean the flue gases sufficiently to comply with the regulatory codes. One known flue gas cleaning apparatus includes means for conducting the gaseous products of combustion through water sprays so that the suspended ashes and other particulate matter are entrained in the water which is then collected and conveyed to a suitable clarification system. This type of flue gas cleaning apparatus is expensive and complex and contributes not only to the high cost and massive structure of prior art combustors, but also to water pollution. Further, the very high temperatures within the chambers necessary to effect good combustion result in very hot flue gases which may result in inefficient operation of the flue gas cleaning apparatus and resulting undesirable pollution of the surrounding atmosphere. The provision of flue gas cleaning apparatus thus imposes a limitation upon the temperature within the combustion chambers which contributes to the poor combustion realized by certain prior art designs. 
     It is necessary of course that provision be made for collecting and disposing of any non-combustible material. One known apparatus for accomplishing this function comprises a conveyor disposed beneath the combustion chambers for receiving such material and for conveying the same from the combustion chambers to a suitable disposition area. Such conveying apparatus is also very costly and in addition, occupies considerable space which further contributes to the high cost and massive structure of prior art combustors. 
     OBJECTS OF THE INVENTION 
     It is therefore a primary object of the invention to provide a novel and improved combustor capable of effecting substantially complete combustion of waste material and wherein essentially solid-free flue gases are discharged to the atmosphere to minimize air and water pollution. 
     It is another object of the invention to provide a novel and improved combustor of such character which avoids the use of costly and complex flue gas cleaning apparatus. 
     It is a further object of the invention to provide a novel and improved vortex combustor of the foregoing character wherein non-combustible material is discharged from the combustion chamber during the burning process by action of the vortex without the use of costly and bulky material handling and conveying apparatus. 
     It is a still further object of the invention to provide a novel and improved vortex combustor of the foregoing character wherein the burning process is more efficiently carried on and the removal of fly ash, as well as the discharge of non-combustible material are facilitated. 
     SUMMARY OF THE INVENTION 
     In carrying out the invention in one preferred form, a combustor is provided which includes a combustion chamber having spaced end walls and a side wall with its central longitudinal axis extending between the end walls. The chamber is preferably disposed in operative position with its central longitudinal axis extending horizontally or substantially horizontally. Means are provided for introducing a mixture of waste material and primary air into the chamber tangentially to the sidewall for establishing a vortical movement of the waste material toward one of the end walls and provision is made for igniting the waste material during its vortical movement. 
     Secondary air is introduced into the chamber substantially tangentially to the side wall at a plurality of regions which are spaced substantially throughout the entire length of the chamber and which are aligned along a horizontal axis. These regions are located adjacent the bottom of the chamber at one side thereof such that secondary air is introduced in directions to maintain the vortical movement of waste material. The secondary air entering the chamber at each of the mentioned spaced regions is controlled by an independently controllable damper which can be adjusted automatically and manually to control the amount of air entering the chamber and contributing to the vortex energy at each region. The secondary air is supplied through a blower-feed manifold and automatically controllable dampers control generally the secondary air distributed through the manifold. The automatic dampers are controlled adjustably and operate automatically in response to temperature variations in the chamber. 
     A discharge flue port has an open end opening in the chamber near the one end wall and substantially concentric with the central longitudinal axis of the chamber. Means are provided external to the chamber and this discharge flue, in which a recuperator is attached in such a way as to return air flow heated with the superheated exhaust gases for use in the secondary air manifold and for the intake means that provides the mixture of waste material and primary air. This recuperator provides necessary heated air flows to those portions of the process that benefit from the heated air, such as drying the shredded waste material prior to entering the chamber and creating a more efficient primary air flow. Additionally, the heated air is added to the secondary air manifold for injection into the chamber, again increasing the efficiency of the burning process. 
     A second discharge port includes an open end opening in the chamber adjacent to the inner surface of the side wall for discharging from the chamber during the burning process non-combustible material entrained in the outer region of the vortex. The open end of the second discharge port is located adjacent the bottom of the chamber at the side thereof substantially opposite one of the regions of introduction of the secondary air. The material discharged by the second port is conveyed through a conduit to a separator which separates the gases and the solid material and means are provide to introduce the separated gases and any solid particles suspended therein back into the combustion chamber. 
     The burning waste material moves in the vortical path from the entry point substantially near the front end wall, towards the back end wall, in a free vortex with means provided by use of an adjustable baffle that increase the residence time and allow for the waste material to be entrained back into the outer region of the vortex for continuous burning until complete combustion has been achieved. This baffle enhances the deflection of these residual combustible materials, with adjustments allowed for various fuel sources and conditions. 
     Means are further provided to integrate the various components of the invention, to ensure proper and efficient control and management of the entire operational process. These means include a combination of a computer and programmable controls, with applicable software and preset conditions, and with the capability of being connected to popular network interface protocols. This network interfacing will allow for real-time data transmission, as well as remote access of the various operational controls. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a schematic diagram of a combustor embodying the invention showing in particular the path of vortical movement of the waste material within the combustion chamber, the method of controlling non-combustibles, the distribution paths of secondary air, the inclusion of automation controls, and the location of the recuperator; 
         FIG. 2  is a view in end elevation of the combustion chamber; 
         FIG. 3  is a view in section taken along the line  3 - 3  of  FIG. 2  and including a schematic illustration of the automatic secondary air control means; 
         FIG. 4  is a view in section taken along the line  4 - 4  of FIG. showing baffle mechanism and bottom gutter; 
         FIG. 5  is a view in side elevation of the combustion chamber and the secondary air manifold and recuperator associated therewith; 
         FIG. 6  is a view in section taken along the line  6 - 6  of  FIG. 5 ; 
         FIG. 7  is a view in side elevation of a damper mechanism associated with the manifold; 
         FIG. 8  is a view in side elevation of the recuperator attached to the external flue pipe as seen in  FIG. 5 ; 
         FIG. 9  is a view in section taken along the line  9 - 9  of  FIG. 8 . 
     
    
    
     DESCRIPTION OF A PREFERRED EMBODIMENT 
     Referring now to the drawings, there is illustrated in  FIGS. 1-9  a combustor embodying the invention and comprising in general a size reduction unit for chopping up the waste material, means for introducing the waste material and primary air into a combustion chamber for establishing a vortical movement of the waste material, means for igniting the waste material during its vortical movement, means for introducing secondary air into the chamber, discharge means for discharging gaseous products of combustion, and non-combustible material from the combustion chamber, a separator for separating the gaseous and solid material discharged by the discharge means, and a recuperator to recycle exhaust waste back to various systems or components. The combustor of the present invention is particularly suited for disposing of solid industrial and municipal waste materials, including but not limited to standard waste, such as for example, paper, peanut hulls, cardboard cartons, wood scrap, garbage, foliage, woody biomass, plastic items and more. However, the combustor is also capable of disposing of liquid waste material such as oils, paint sludges and plating tank residue. 
     More specifically, the combustor as schematically shown in  FIG. 1  includes a size reduction unit  10  designed to shred and chop the waste material into pieces small enough to be efficiently conveyed to and burned in the combustion chamber. If the waste material to be disposed of is already of an acceptable size, such as sawdust, then the size reduction unit  10  is not required. The size reduction unit  10  may be of any suitable construction and includes a hopper  12  having an open end  14  into which the waste material is fed for size reduction by a shredding and chopping mechanism (not shown) operated by a motor (not shown). After being reduced in size, the waste material is drawn into a pneumatic conveying system including a commercially available blower  16  operated by a motor (not shown) which entrains the size reduced material in a primary air stream and transports it through a pipe  20  which opens into a combustion chamber  22 . The size reduction unit  10  and blower  16  are connected to a programmable control panel  101 , the purpose being to control the operation of said size reduction unit  10  and primary air blower  16 , described hereinafter. The combustion chamber  22  may be of any suitable configuration and is preferably cylindrical including a pair of spaced end walls  24  and  26  connected by an annular side wall  28 . The chamber  22  is preferably disposed when in operative position so that its central longitudinal axis which extends between the end walls  24  and  26  is horizontal or substantially horizontal as shown in  FIGS. 3 and 5 . Saddles are used for overall chamber stability, with a front full saddle  106 , two mid positioned half saddles,  107  and  108 , and a rear full saddle  109 . The front saddle  106  is positioned at the intersection of the front end wall  26  with the annular side wall  28 , and the rear saddle  109  is positioned at the intersection of the rear end wall  26  with the annular side wall  28 . If desired, the end wall  24  of the chamber  22  may include an access door  30  to permit access to the interior of the chamber  22 . A specially tempered site glass  31  offers visual access through the door  30 , allowing the operator to look into the chamber without the need to open the access door  30 . If also desired, end walls  24  and  26  can be adjustably releasable to facilitate easier maintenance of the chamber  22 . In the specific embodiment of the invention illustrated, the side wall  28  of the chamber  22  comprises an outer casing  32  ( FIG. 3 ) formed of any suitable material such as low carbon steel and the casing  32  is lined with one or more inner layers  34 / 35 / 36  of any suitable refractory material such as fire brick. The innermost layer  34  of any suitable material such as high density refractory material is designed to exhibit good resistance to abrasion and impact and capable of extremely high temperatures, whereas the layer  35  may be designed to have good heat insulating qualities or to transfer the heat to a remote location, such as insulating firebrick, capable of withstanding temperatures above 2,300° F. A thin layer of refractory material  36  that offers very good insulating properties (often referred to as “paper”) is layered between the insulating firebrick  35  and the outer casing  32 . The desired thicknesses of these refractory layers depends on the amount of reduction in temperature so that the outer casing temperature meets current OSHA standards, namely to remain at or below 150° F. while the combustor is in operation. In the embodiment illustrated, the pipe  20  enters the chamber  22  tangentially of the side wall  28  near the top of the chamber  22  adjacent the end wall  26  and at the left side of the chamber as viewed in  FIG. 2 . In certain installations it may be desirable to have the pipe  20  enter the chamber  22  at a region which is substantially midway between the end walls  24  and  26 . 
     Continuous injection of a mixture of size-reduced waste material and air into the chamber  22  from the pipe  20  tangentially to the side wall  28  establishes a vortical flow of the waste material which travels from adjacent the end wall  26  toward the end wall  24  in a clockwise direction as viewed from the end wall  26  in  FIG. 1  or in the direction of the arrow  37  in  FIG. 6 . It is understood of course that the pipe  20  may be disposed to enter the chamber  22  at the upper right hand side thereof instead of the upper left hand side in which event the direction of the vortex would be reversed from the clockwise direction illustrated to a counterclockwise direction. 
     The total pressure of the air exiting from the pipe  20  can be as high as 20 inches H 2 O and is preferably about 12 inches H 2 O. However, such pressure can be as low as 4 inches H 2 O when burning finely divided, highly combustible material at a lower heat release rate. Therefore, pressures of air exiting from the pipe  20  are generally within the range of 4 inches H 2 O to 20 inches H 2 O. 
     In order to ignite the waste material entering the chamber  22 , a suitable commercially available burner  38  is disposed near the end wall  26  of the chamber  22  to fire tangentially into the chamber adjacent the top and at the right side thereof as viewed in  FIG. 2 . The burner  38  can be fueled with natural gas or propane gas for remote applications. Under conditions wherein a mixture of waste material and air is continuously fed into the chamber  22 , it has been observed that the burner  38  may ordinarily be turned off after ignition of the waste material is accomplished. 
     In order to enhance combustion of the waste material and to maintain the energy of its vortical flow in a predetermined and controlled manner through the entire length of the combustion chamber, provision is made for introducing controlled quantities of high velocity secondary air into the chamber  22  during the burning process and at spaced regions throughout the length of the chamber. To this end, a commercially available, motor-driven fan or blower  40  is disposed to introduce secondary air into an elongated manifold  42  suitably supported externally of the chamber and extending along an axis substantially parallel to the longitudinal axis of the chamber. Also the manifold  42  is located preferably near the bottom and at the right side of the chamber as viewed in  FIG. 2 . The secondary air is injected substantially tangentially into the chamber through a plurality of substantially equally spaced openings  44  in the side wall  28  and at regions located downstream of the region of introduction of the mixture of primary air and waste material. In a preferred embodiment, the openings are provided along the entire length of the chamber and are four in number. Additionally, and as illustrated in  FIG. 6 , the tangential injection of the secondary air into the chamber is provided by means of conduits  46  extending between the manifold  42  and the bottom portion of the chamber. If desired, means (not shown) may be provided for preheating the secondary air which is introduced into the chamber  22  through the openings  44  by means of the fan  40 , manifold  42 , and conduits  46 . With the described arrangement the combustible waste material is substantially completely burned in suspension in a free vortex with the heavier solid waste fragments and non-combustible material traveling in a vortical path along the inner surface of the layer  34  and migrating toward the end wall  24 . The solid material is forced toward the inner surface of the layer  34  by the tangential component of velocity of the vortex whereas the radially inward component of velocity creates high relative velocity between the air and burning material which greatly accelerates the combustion rate. 
     Additionally, in the described arrangement, the tangential injection of the secondary air through the openings  44  and at spaced points along the length of the chamber has the beneficial effect of periodically contributing to the vortex energy in the chamber. Thus, compensation is provided for losses in vortex energy or for effectively sustaining the vortex as the waste material progresses vertically along the length of the chamber. 
     The periodic or spaced tangential injection of secondary air and the resultant sustenance of the vortex along the entire length of the chamber enhance the efficiency of the waste burning process. Also, it reduces any tendency of combustion material particles, such as fly ash, to drop out of the vortex and settle on the bottom of the chamber which, if permitted to occur, can present substantial difficulties in effecting removal of such particles from the chamber and can require longer shut down times for chamber cleaning purposes. Also, it can adversely affect exhaust emissions. 
     For the purpose of predeterminedly controlling the secondary air generally and individually at each of the particular regions of injection into the chamber, adjustable control means are provided between the blower  40  and the manifold  42  and in each of the conduits  46  extending between the manifold and the chamber. More specifically, a damper comprising, for example a butterfly valve  48  is provided in the manifold  42  between the fan and the main portion of the manifold to which the several conduits  46  are connected. The operation of the butterfly valve  48  is determined by the operation of a suitable proportional motor  50  adapted for positioning the valve between open and closed positions in accordance with the degree of energization of the motor. The motor energization is, in turn, determined by a suitable control means generally indicated and designated  52  in  FIG. 3 . The control means  52  is operatively connected to a thermocouple or other suitable thermally responsive device  54  which extends into the chamber  22  to sense the temperature therein and provide an appropriate control signal. Specifically the control means  52  is adapted for automatically operating the damper or valve  48  in response to temperature variations within the chamber and such that the valve is moved toward its most open position in response to increases in temperature thereby to increase the flow of secondary air into the system, and toward its closed position in response to decreases in temperature thereby to decrease the flow of air into the system. The control means  52  is adjustably presettable so that the temperature range over which the valve automatically opens and closes is predeterminable by the operator, and is operatively connected to programmable controller panel  101  for additional operational controls. 
     The secondary air entering the chamber  22  through the openings  44  is further and individually controllable by means of separate and independently adjustable dampers  56  interposed one in each of the conduits  46 . Each damper  56  is adapted for further controlling the secondary air as it enters the chamber at its respective region along the vortical path of the waste material. Thus, the dampers  56  are effective for enabling the operator to control separately and individually the energy added to the vortex at each of the regions, permitting more or less energy to be introduced as required to maintain a desired vortical profile and in accordance with experience as to regions where more or less energy is needed to compensate for energy losses in the vortex. 
     The total pressure of the air entering the chamber  22  through the openings  44  can be as high as 20 inches H 2 O and is preferably about 12 inches H 2 O. However, such pressure can be as low as 4 inches H 2 O when burning finely divided, highly combustible material at a lower heat release rate. Therefore, pressures of air entering the chamber  22  through the openings  44  are generally within the range of 4 inches H 2 O to 20 inches H 2 O. 
     The construction of the dampers  56  is best seen in  FIGS. 6 and 7 , and each such damper comprises a housing  58  of generally rectangular cross section and having suitable flanges for mounting in the respective conduits  46 . Also, each damper includes an appropriate flapper element  60  which is pivotally movable about one end thereof between fully open horizontal and fully closed vertical positions illustrated in dash lines in  FIG. 7 . The pivoting of the element  60  is specifically accomplished by mounting it on a rod  62  suitably rotatably mounted between the side walls of the housing  58 . A set screw  70  is threadedly mounted in the collar and carrying a lock nut  72 . This arrangement permits the operator of the system to presettably position and lock each of the flapper elements  60  in a desired adjusted position in its respective damper housing for thereby controlling the air entering the chamber at its respective region and for the purpose discussed above. This arrangement is particularly adapted for manual individual adjustment of the dampers  56 . However, it will be seen from the foregoing that, if desired, each of the dampers  56  could be controlled automatically in a manner similar to the butterfly valve and also that the dampers  56  could be automatically controlled individually or in a cooperating coordinated manner in response to various predetermined parameters such as, for example, secondary air temperature or temperature at different regions in the chamber, and networked with the programmable controller panel  101 . 
     In order to discharge gaseous products of combustion from the chamber  22  to atmosphere first discharge means is provided including a first discharge port or flue  74  having an open end opening in the chamber in the region of the end wall  24  and substantially concentric with the central longitudinal axis of the chamber  22 . As best shown in  FIG. 3  the flue  74  includes a hollow cylinder or flue pipe  76  of any suitable material to resist extremely high temperatures and impact, extending through and suitably mounted in an opening in the end wall  24 . In the particular embodiment of the invention shown, the end wall  24  includes adjacent layers  78  and  79  of high density refractory material and insulating firebrick, and a layer  80  with very good insulating properties, and an outer annular plate  82  secured together by suitable fasteners (not shown). The end wall  26  of the chamber  22  may be similarly formed. The cylinder  76  is releasably attached to a flue section (not shown) which terminates in an open end opening to atmosphere. 
     Second discharge means is provided for discharging from the chamber  22  during the burning process of non-combustible material. For this purpose, the preferred embodiment provides a second discharge port  84  having an open end  85  opening in the chamber  22  at a region downstream from the point of introduction of the waste material in the region adjacent the inner surface of the end wall  24  and adjacent the inner surface of the layer  34  for receiving and discharging from the chamber non-combustible material which is entrained in the outer region of the vortex. In the illustrated embodiment the port  84  comprises a conduit  86  extending through the side wall  28  substantially tangentially thereto and substantially horizontally at the bottom of the chamber as viewed in  FIGS. 2 and 3  with its open end  85  opening at the inner surface of the layer  34 . The conduit  86  leads to suitable separator and disposal means described hereinafter. With the described arrangement, the opening  85  is in the path of the non-combustible material which during operation of the combustor is at the outer region of the vortex and which has migrated to adjacent the end wall  24 , and the action of the vortex causes such material to enter the opening  85  for discharge from the chamber  22 . As shown in  FIGS. 2 and 3  the conduit  86  extends horizontally adjacent the bottom of the chamber. Also, and as seen from  FIG. 1 , the discharge opening  85  provided by the conduit  86  is located substantially opposite and in substantially the same horizontal plane as one of the secondary air openings  44 . This relative positioning of the second discharge port  85  and one of the secondary air openings  44  results in the injected secondary air from that opening being effective in assisting in the direction of fly ash and other waste materials through the second discharge port  85 . To further facilitate the path of the non-combustible materials, a gutter  110  is cut into the bottom of the chamber along the previously described horizontal plane from the discharge opening  85  and the secondary air opening  44 . ( FIG. 4 ) This gutter  110  is located substantially adjacent the end wall  24 , and extended from a position in front of one of the air openings  44  and the secondary discharge opening  85 . Also it serves effectively to prevent waste material from accumulating in front of, and obstructing passage through, the discharge port  85 . It is to be understood that although a single conduit  86  is illustrated, a plurality of such conduits can be provided if desired. Moreover, the conduit  86  can be replaced by a scoop positioned to receive material in the outer region of the vortex and connected to a conduit extending through the chamber wall. Also, each such conduit or scoop can be arranged to cooperate with an oppositely disposed secondary air inlet to obtain the resultant benefits described above. 
     The present invention further provides a separator  96  which is effective for separating the non-combustible materials discharged through the conduit  86  and for dropping this solid material into a suitable container  98 . Gases and some combustible material in the form of ash will be introduced into the separator  96  as byproducts of the separation process. The separator  96  is preferably a commercially available cyclone or vortex type separator wherein material discharged through the conduit  86  is introduced tangentially into the separator  96  with the result that the solid material drops out the open end of the separator into the container  98 . Such solid material constitutes ashes and other particulate matter formed in the combustion process and also non-combustible material which can be disposed of in any suitable manner. 
     In accord with the invention, the hot gases separated out by the separator  96  are introduced back into the chamber  22 . This is very advantageous in that it maintains the vortex within the chamber  22 , further cleans such gases by removing residual fly ash, and dries out wet waste material within the chamber  22 . For this purpose a conduit  99  extends coaxially into the separator  96  at the top thereof so that the hot gases separated by the action of the separator  96  are drawn into the conduit  99  through the central low-pressure area and are conveyed through the conduit  99  to a fan  95  to withdraw the separated hot gases from the conduit  99  and to introduce such into the chamber  22 . These gases are preferably introduced into the chamber  22  at an area downstream from the area of introduction of the secondary air. However, under certain conditions the secondary air fan  40  and the manifold  42  may be employed instead of the fan  95  to introduce the separated gases back into the chamber  22 . 
     The total pressure available from the primary and secondary air entering the chamber is utilized to introduce energy into the vortex for obtaining high combustion rates and also to accelerate material out through the conduit  86  and the flue pipe  76 . It has been observed that if the area of the orifice  71 , which constitutes the open end of the discharge fluc port, is too small relative to an optimum area, then the combustion rates will be lower than optimum because too much of the available pressure will be used to accelerate the flow of material out of the combustion chamber. On the other hand, if the area of the open end of the discharge flue port is too large relative to the optimum area, it is impossible to establish the vortex flow field required for effecting centrifugal separation of the fly ash and for obtaining substantially complete combustion of larger particles. Tests have demonstrated that the optimum area of the open end of the discharge flue port bears a specific relationship to the area of the cross-section of the combustion chamber  22  taken perpendicular to its longitudinal axis. 
     Most if not all of any non-combustible material will enter the conduit  86  as it initially reaches the end wall  24 . However, in the event that such material does not enter the conduit  86  when it initially reaches the end wall  24 , this material becomes entrained in the stream of hot gases which normally flows in the direction of the arrows  88  along the inner surface of the end wall  24  toward the open end  90  of the flue pipe  76  where a low pressure area exists. If the open end of the flue pipe  76  were flush with the end wall, a considerable portion of this material would enter the flue pipe  76  thus necessitating provision of flue gas cleaning apparatus to avoid pollution of the surrounding atmosphere. In order to reduce the amount of such solid material which exits from the chamber  22  through the flue pipe  76 , the flue pipe  76  is extended into the chamber  22  so that the inner open end of the flue pipe  76  is spaced axially inwardly from the end wall  24  as shown in  FIG. 3 . With this arrangement, the solid material which does not enter the conduit  86  tends to move from adjacent the end wall  24  along the diameter of the flue pipe  76  toward its open inner end. Such movement increases the time of residence of the material in the chamber  22  thus resulting in more complete combustion and a reduction in the amount of this material which enters the flue pipe if its open end were flush with the end wall  24 . 
     In order to still further reduce the amount of solid material entering the flue pipe  76 , a baffle  92  is positioned adjacent the open inner end of the flue pipe  76  to divert outwardly toward the inner layer  34  of the chamber  22  any residual solid combustible particulates and non-combustible material which moves from adjacent the end wall  24  toward the open end of the flue pipe  76 . The arrangement is such that solid material moving in the direction of the arrows  88  engages the baffle  92  and is thereby deflected in the direction of the arrow  94  so that the material so diverted once again becomes entrained in the vortex for further burning and movement toward the end wall  24  for discharge through the conduit  86 . As shown in  FIGS. 3 and 4 , the baffle  92  preferably comprises a plate of any suitable material in the form of a ring suitably releasably attached as by bolts  69  to another ring-shaped plate (not shown) which is welded or otherwise secured to the pipe  76  adjacent its open end. Additionally, there is a ring  93  mounted on the periphery of the main plate of the baffle, that is suitably releasably attached as by bolts (not shown), and creates an angle or beveled edge tilted in the direction of the front end wall, towards the oncoming vortex and waste materials. The width of the beveled ring  93  and the angle thereto are established by the material being consumed in the combustion process. The ring  93  serves to increase the residence time of the burning waste material, and enhances the deflection of residual combustible material towards the outer region of the vortex. The baffle  92  preferably overlies the open end of the flue pipe  76  and includes a central circular orifice  71  having a diameter d ( FIG. 3 ) which is less than the inner diameter of the flue pipe  76 . The orifice  71  of the baffle  92  thus constitutes the open end of the discharge flue port. The outside diameter of the baffle  92  and the diameter d of its orifice  71  are selected to provide the optimum performance for the conditions involved. Under certain conditions the baffle  92  may surround the pipe  76  adjacent its open end in which event the open end of the pipe  76  constitutes the open end of the discharge flue port. 
     The detachable mounting of the flue  74  to the end wall  26  as previously described permits detachment of the flue pipe  76  and the baffle  92  from the chamber  22  so as to permit replacement or repair of pipe  76  and baffle  92  as desired. Additionally, this arrangement disposes the inner end of the flue pipe  76  and the baffle  92  adjacent the region of the vortex which can be influenced by the secondary air injected through the opening disposed for cooperation with the discharge port  85 . This arrangement together with the adjustability of the secondary air provided by the respective damper  56  affords the operator the opportunity to adjust the secondary air injected at this region in a manner to predeterminedly influence the energy condition of the vortex in the region of the flue pipe opening. Thus, one can adjust to a degree the pressure conditions in the region of the baffle  92  for thereby influencing the flow paths indicated by the arrows  88  and  94 . 
     In accord with the present invention, the ratio of the area of the open end of the discharge flue port to the area of a cross-section of the combustion chamber taken perpendicular to its longitudinal axis is selected to be within the range of 1/16 to 4/25 and is preferably about 1/9. In the illustrated embodiment of the invention these area ratios can be translated to corresponding diameter ratios with the result that the ratio of the diameter d of the open end of the circular discharge flue port to the diameter D of the cylindrical chamber  22  is selected to be within the range of ¼ to ⅖. This range of diameter ratios has been found to be effective over a range of diameters of the chamber from 1½ feet to 15 feet. 
     In the preferred embodiment of the invention the ratio of the diameter d and the diameter D is selected to be approximately ⅓ or in other words, the inner diameter D of the chamber  22  is selected to be about three times as great as the diameter d of the open end of the discharge flue port. It is understood of course that the invention is not limited to the particular cylindrical chamber configuration and circular discharge flue configuration illustrated and is applicable in its broader aspects to other configurations of the chamber and discharge flue which are non-cylindrical and non-circular. 
     The nature of the free vortex flow field is influenced strongly by the ratio of the diameter d to the diameter D. With proper dimensions of these diameters selected in accord with the invention, the strong free vortex flow field provides an increasing tangential velocity with decreasing radius. Thus the tendency of the particles to be drawn to the center of the chamber  22  by the drag forces imparted from the radially inward flow is counterbalanced by a stronger centrifugal force field. Therefore, the particles are maintained in suspension until complete combustion has occurred or until they are withdrawn from the chamber  22  through the conduit  86 . 
     The present invention further provides a means of recycling the heat produced by the combustion process inside of the chamber  22 , by use of a recuperator  105  ( FIG. 8 ) installed in the exterior section of the exhaust flue  76 . Air from the blower unit  40  is injected into the inlet plenum of the recuperator  105 . As seen in  FIG. 9 , a series of tubes extend from the inlet plenum to the outlet plenum, where two portals (not shown) transfer the heated or recuperated air to the secondary air manifold  42  just prior to the first in line secondary air opening  44 , and to the primary air and waste feed intake section pipe  20 . 
     The present invention further provides for a control means to integrate the various components for purposes of operational control, such as the size-reduction unit  10  and primary air blower  16 , the burner  38 , secondary air control  52  and motor  50 , a number of chamber atmospheric sensors  100 , and flue emissions sensors  102 . The control means  101  consists of any combination of commercially available devices, such as a computer, programmable automation controller, programmable logic controller, or similar industrial control system, along with the necessary wired and/or wireless interface materials and equipment. Readings from one or any combination of the atmospheric sensors can be used to cause adjustments with the burner and/or secondary air, using predetermined values. The recuperator  105  is similarly integrated into the control panel  101  to allow control and management of the air flow back to the secondary air manifold  42  and the feed and primary air intake  20 . 
     The chamber atmospheric sensors  100  measure, record, and transmit data related to conditions such as chamber temperature, vortex air speed, moisture content, BTU heat value of material being consumed, pressure, and capacity. The sensors  100  are connected to a control panel  101  that operates in combination with other network equipment as indicated previously, or separately to transmit data and signals to the various components to adjust the operation or functionality of each. For example, the size reduction unit  10  and primary air blower  16  can be connected to control panel  101  to automatically control each, in accordance with the overall system operation, including automatic safety shut-off capability. 
     The burner  38  is additionally controlled by the control panel  101  by use of a chamber atmospheric temperature sensor  100  transmitting temperature readings within the chamber, and allowing the burner  38  to be turned off following proper ignition of the shredded waste material, or to be turned on to increase the temperature of the mixture of the waste material and primary air, by energizing the burner  38  as with the initial ignition of waste entering the chamber  22 . 
     Control means are further provided for the secondary air process, with the use of an atmospheric sensor  100 , through the interfacing of the control panel  101  and the secondary air control  52  and motor  50 . Using predetermined criteria, the control panel  101  is capable of adjusting the flow of secondary air into the chamber  22 , by operationally controlling the secondary air blower  40 , manifold  42 , butterfly valves  48 , and dampers  56 . It has been observed that the control of the burner  38  together with the secondary air blower  40 , manifold  42 , butterfly valves  48 , and dampers  56 , can be adjusted in combination to more efficiently control the chamber temperature, moisture content, and vortex speed. 
     The flue emissions sensor  102  provides for monitoring and data retrieval of all flue emissions and conditions. Although not related to the operations of the combustion system and process, the flue emissions sensor  102  is connected to the control panel  101 , and to a computer system with commercially available software for collection, reporting, and transmitting of environmental data in accordance with current United States Environmental Protection Agency&#39;s air quality and emissions standards, as well as those for state and local agencies. The control panel  101  and/or any interconnected computer equipment is/are capable of being connected directly or indirectly and can communicate over popular network interface protocols such as TCP/IP, OLE for process control (OPC), and SMTP. This network interfacing will allow for real-time data transmission, as well as remote access of the various operational controls. 
     By means of the invention a very efficient combustor is provided characterized by the exhaust of gases to the atmosphere which are substantially free of particulate matter so as to minimize air and water pollution. In addition, non-combustible material is discharged from the combustion chamber during the burning process by action of the vortex so as to avoid the provision of costly and complex material handling apparatus for conveying such material away from the combustion chamber. Further, the provision of costly and complex flue gas cleaning apparatus is avoided by the invention which allows operation of the combustor at temperatures which are higher than that which would be allowable in the event flue gas cleaning apparatus were utilized. Moreover, the combustor effects substantially complete combustion of combustible waste material resulting in an extremely high percentage reduction in the original volume of waste material. 
     A typical design of the combustor of the present invention includes a combustion chamber having an internal length of 5.5 feet and an inner diameter D of 4 feet. The flue pipe  76  has an inner diameter of 18 inches and extends into the chamber a distance of about 18 inches from the inner surface of the end wall  24 . The baffle plate  92  has a diameter of approximately 24 inches and its orifice  71  has a diameter d of about 16 inches. Also, the conduit  86  has an inner diameter of between 4 and 6 inches. 
     A combustor of such design presently appears capable of disposing of solid waste having up to 49% moisture content and normally 40% ash content and a sufficient BTU rating based on the waste material introduced, to effect more than 99 percent destruction of combustible material. It presently appears that such a combustor design emits particulate matter to the atmosphere of not more than 0.2 grains per standard dry cubic foot of flue gas. The forgoing results seem to be obtainable with chamber temperatures between 1,800° F. and 2,200° F. 
     Although the invention has been described with reference to certain specific embodiments thereof, numerous modifications are possible, and it is desired to cover all modifications falling within the spirit and scope of the invention.