US3581683A

US3581683A - Refuse disposal apparatus and process

Info

Publication number: US3581683A
Application number: US19835A
Authority: US
Inventors: Martin Collier Jr
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-03-16
Filing date: 1970-03-16
Publication date: 1971-06-01
Anticipated expiration: 1988-06-01

Abstract

A refuse disposal apparatus includes a shell having a hopper assembly suspended therein. The hopper assembly comprises an inner wall defining a collection chamber and a jacket surrounding the inner wall. An airstream with refuse entrained in it discharges into the collection chamber where the refuse is dropped and allowed to collect. The air is exhausted from the chamber and enters an air channel between the jacket and inner wall. The air leaving the channel forms an air curtain within the shell, and beyond the air curtain the air passes downwardly along side a sleeve which encircles a combustion chamber. Below the combustion chamber the air at the outside of the sleeve impinges against a diverting surface which directs it inwardly and then upwardly into the center of the combustion chamber. A feed device at the base of the refuse collecting chamber feeds refuse into the upwardly directed draft at a controlled rate, thereby mixing the refuse and air and enabling the refuse to be burned in the combustion chamber. The gaseous products of combustion are diverted through the air curtain to remove particulates therefrom, while the solid residue is collected in a chute opening out of the diverting surface.

Description

United States Patent [72) Inventor Martin Collier, Jr.

1117 Alexander Drive, Festus, Mo. 63028 [22] Filed Mar. 16, 1970 [45] Patented June 1,1971

[54] REFUSE DISPOSAL APPARATUS AND PROCESS Primary Examiner-Kenneth W. Sprague AttorneyGravely, Lieder and Woodruff ABSTRACT: A refuse disposal apparatus includes a shell having a hopper assembly suspended therein. The hopper assembly comprises an inner wall defining a collection chamber and a jacket surrounding the inner wall. An airstream with refuse entrained in it discharges into the collection chamber where the refuse is dropped and allowed to collect. The air is exhausted from the chamber and enters an air channel between the jacket and inner wall. The air leaving the channel forms an air curtain within the shell, and beyond the air curtain the air passes downwardly along side a sleevewhich encircles a combustion chamber. Below the combustion chamber the air at the outside of the sleeve impinges against a diverting surface which directs it inwardly and then upwardly into the center of the combustion chamber. A feed device at the base of the refuse collecting chamber feeds refuse into the upwardly directed draft at a controlled rate, thereby mixing the refuse and air and enabling the refuse to be burned in the combustion chamber. The gaseous products of combustion are diverted through the air curtain to remove particulates therefrom, while the solid residue is collected in a chute opening out of the diverting surface.

PATENTED JUN nan $5 1 5 3 sum 1 BF 2 PATENTEIJV JUN 1 I971

sum

2 or 2 REFUSE DISPOSAL APPARATUS AND PROCESS BACKGROUND OF THE INVENTION This invention relates in general to the disposal of refuse and more particularly to an apparatus and process for disposing of refuse by means of incineration.

The disposal of municipal and industrial refuse has in recent years become a problem of major concern. From an economic standpoint incineration is one of the more desirable methods of refuse disposal since it reduces the refuse to an extremely small volume of solid residue which may easily be accommodated in land fill operations. Moreover, it has been the practice to construct incinerators close to the source of the refuse, that is, in the heart of population centers, and this avoids the expense of hauling large volumes of refuse to remote land fills.

lncinerators of current manufacture, however, discharge a considerable amount of smoke and flyash and emit obnoxious odors. Furthermore, they consume an enormous amount of fuel which is usually natural gas, and they do not accept liquid wastes.

SUMMARY OF THE INVENTION One of the principal objects of the present invention is to provide a refuse disposal apparatus which incinerates municipal refuse and thereby reduces it to an extremely small volume. Another object is to provide a disposal apparatus of the type stated which does not discharge significant amounts of smoke or flyash or emit odors and, therefore, avoids polluting the atmosphere. A further object is to provide a disposal apparatus which accepts liquid and sewage wastes. An additional object is to provide an incinerator which operates on an exothermic basis. and does not require conventional fuels after the start-up period. Still another object is to provide a disposal apparatus which converts the heat of combustion into useful energy. Yet another object is to provide a refuse disposal apparatus which is simple in construction and inexpensive to build. Another object is to provide a refuse disposal apparatus which is ideally suited for small municipalities. These and other objects 1 and advantages will become apparent hereinafter.

The present invention is embodied in a refuse disposal apparatus including a shell which contains a combustion chamber. Means introduce refuse and combustion air into the combustion chamber where the refuse is burned. An air curtain is also established in the shell, and the products of combustion are diverted through the air curtain before entering the atmosphere. The invention is also embodied in an apparatus including means for introducing refuse into a combustion chamber and a deflective surface for diverting a high velocity airstream upwardly into the combustion chamber. The process employed in the apparatus also forms part of the invention. The invention also consists in the parts and in the arrangements and combinations of parts hereinafter described and claimed.

DESCRIPTION OF THE DRAWINGS In the accompanying drawings which form part of the specification and wherein like numerals and letters refer to like parts wherever they occur:

FIG. 1 is a sectional view of a refuse disposal plant constructed in accordance with and embodying the present inven tron;

FIG. 2 is a top plan view of an incinerator forming part of the present invention;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 1; and

FIG. 4 is a sectional view taken along line 4-4 of FIG. 1.

DETAILED DESCRIPTION Referring now in detail to the drawings, 2 designates a refuse disposal plant which, broadly speaking, includes a feed conveyor 4, a crusher 6, a blower 8, a pneumatic conveyor tube 10, and an incinerator 12.

The conveyor 4 has an endless belt 14 which leads up to an inlet hopper 16 located above the crusher 6. Refuse of the type ordinarily collected from the households of a community is deposited on the belt I4 which conveys it to the inlet hopper 16.

The crusher 6 is of the conventional variety and includes the usual housing 18, the inlet of which opens into the hopper 16 at the end of the conveyor 4. The crusher 6 also has a rotor 20 journaled in the housing 118, and that, of course, engages the refuse and draws it across grates or other stationary members in the housing 18 so as to reduce the refuse to a relatively small size. That size should be smaller than the internal diameter of the pneumatic conveyor tube 10. The housing 18 is provided with a lateral chamber 22 for collecting heavy pieces of metal which are not reduced to a size small enough to pass through the grates in the housing 18. That metal is carried around the interior of the housing by the rotor 20 and thrown by centrifugal force into the chamber 22. The chamber 22 opens onto an endless conveyor belt 23 which runs through a magnetic separator.

The crusher 6 is supportedon a concrete pad 24 having a collecting hopper 26 formed in it directly beneath the housing 18. The hopper 26 collects the reduced material which passes through the grates in the crusher housing 18, and its sides converge to a mouth 28 which opens into a transfer trough 30 of generally circular cross section. The trough 30 is also disposed within the pad 24 and one of its ends is connected with a supply pipe 32 which leads to the discharge port of the blower 8. The other end of the transfer trough 30 is connected with the pneumatic conveyor tube 10 which in turn leads to and discharges into the incinerator 12. When the blower 8 is energized, a high velocity airstream is created in the pipe 32, trough 30, and tube 10, and the reduced refuse from the collecting hopper 26 becomes entrained in this airstream as it passes through the hopper mouth 28 and into the transfer trough 30. Since the airstream passes from the trough 30 to the tube 10, the reduced refuse is likewise carried into the conveyor tube and discharged into the incinerator 12 at the opposite end of that tube.

The incinerator 12 includes a cylindrical shell 40 which is preferably cast from concrete and is mounted on a concrete supporting pad 42. The shell 40 is provided with a pair of vertically spaced

cross walls

44 and 46, each having an annular configuration. At their peripheries the

walls

44 and 46 adjoin the cylindrical sidewalls of the shell 40, and from their undersides they are further supported by a series of gusset members 48 which are attached to the sidewall of the shell 40. The upper end of the shell 46 is closed by a concrete cover 50 which is bolted thereto and has a central vent stack 52 extending through it for venting the interior of the shell 40.

Suspended from the cover 50 by means of support rods 58 is a refuse hopper assembly 60 including an inner wall 62 which closes upon itself to form a cyclone-type collection hopper or chamber 64. At its lower end the inner wall 62 is provided with an inwardly tapered or conical portion 66 which connects with a downwardly extending feed tube 68. The tube 68 extends away from the chamber 64 and projects through the center hole in the annular cross wall 44 of the shell 40. The upper end of the wall 62 also turns inwardly and at its center is fitted with a discharge port 70 which extends into and terminates within the collection chamber 64.

The hopper assembly 60 further includes a jacket 72 which is located in spaced relation from, but covers that portion of the inner wall 62 located generally above the tapered portion 66. Thus, the spaced sides of the inner wall 62 and the jacket 72 create an annular air channel 73 which is supplied with air from the discharge port 70.

The lower tapered portion 66 of the wall 62 is covered by a tapered skirt 74 which also forms part of the hopper assembly 60. The tapered skirt 74 is spaced outwardly from the lower tapered portion 66, but nevertheless conforms with the taper of that section. At its upper end the skirt 74 is provided with an annular lip 76 which projects upwardly for a short distance into the space between the jacket 72 and the wall 62.v On the other hand, the lower end of the skirt 74 is provided with a downwardly extending collar 78 which surrounds the feed tube 68 and like that tube projects through the hole in the cross wall 44. The collar 78 and tube 68 are, however, spaced from one another, and disposed in the annular space between them is a gas manifold 80 having gas nozzles 82 projecting downwardly from it. The manifold 80 is fastened to and supported by the collar 78, and its nozzles 82 project below the lower ends of both the collar 78 and the feed tube 68.

The upper end of the jacket 72 supports a variable speed gear motor 84 connected with a hollow drive shaft 86 which extends downwardly through the discharge port 70 as well as completely through the collection chamber 64. At its lower end the hollow drive shaft 86 is provided with a feed screw 88 which is contained within the feed tube 68.

The pneumatic conveyor tube enters the incinerator 12 through the shell 40 and immediately inwardly from the sidewall of that shell it is fitted with a bellows-type expansion joint 89. Beyond the expansion joint 89 the tube 10 passes through the jacket 72 and opens into the collection chamber 64 generally tangential to the side of the inner wall 62 thereof. Thus, the airstream from the tube 10 and the refuse entrained in that airstream discharge into the chamber 64 and in so doing tend to follow the cylindrical side of the wall 62. This causes the air and refuse to initially swirl around the chamber 64. Since the airstream from the conveyor tube 10 experiences an expansion when it enters the collection chamber 64, it loses its velocity and drops the formerly entrained refuse to the bottom of the chamber 64. The air, on the other hand, flow inwardly and is exhausted through the discharge port 70. As previously noted, the air upon leaving the port 70 flows across the top of the inner wall 62 and into the annular air channel 73 between the sides of the jacket 72 and the inner wall 62. Most of this air is discharged downwardly to the outside of the skirt 74, although some of it is deflected inwardly by the lip 76, and that deflected air eventually flows across the nozzles 82, supplying combustion air for the combustible gas discharged from those nozzles. The chamber 64, therefore, tends to fill with the refuse fonnerly entrained in the airstream, and this refuse can only be removed by energizing the gear motor 84 and thereby rotating the feed screw 88.

ln order to maintain the level of the refuse in the collection chamber 64 fairly constant, the support rods 58 have load cells 90 interposed in them. These load cells 90 are connected to the circuitry through which the motor for the endless belt 14 is powered. Accordingly, the speed at which the conveyor 4 introduces refuse into the crusher 6 is dependent on the weight of the hopper assembly 60 as sensed by the load cells 90.

Directly beneath the refuse hopper assembly 60, a large cylindrical dispersion sleeve 92 is positioned within the shell 40, and it extends between the pair of

cross walls

44 and 46 to which it is connected by means of suitable brackets. The upper end of the sleeve 92 projects completely through the center hole in the annular cross wall 44, but the side of the sleeve 92 is spaced slightly inwardly from the surface defining that hole so that a narrow annular passageway 94 exists between the wall 44 and the outer surface of the sleeve 92. Furthermore, the upper end of the sleeve surrounds the collar 78 on the tapered skirt 74 of the hopper assembly 60, but is located a substantial distance below the lower end of the jacket 72 which is at the discharge end of the annular air channel 73. The diameter of the dispersion sleeve 92 is slightly less than the diameter of the jacket 72 and more closely approaches the diameter of the lip 76 at the upper end of the tapered skirt 74. Consequently, most of the air discharged from the space between the jacket 72 and inner wall 62 flows to the outside of the dispersion sleeve 92 and passes through the narrow annular passageway 94, although a relatively small quantity is deflected inwardly into the interior of the sleeve 92. To prevent the airstream from impinging on the flat upper surface of the cross wall 44 and thereby dispersing laterally, a short outwardly flared lip 96 is fastened to the cross wall 44 at the annular inner margin thereof. Thus, the airstream issuing from the annular air channel 73 is for the most part channeled into the passageway 94, and between the jacket 72 and the passageway 94 the airstream forms an annular air curtain 0 within the shell 40.

The lower end of the dispersion sleeve 92 projects into the hole in the center of the lower cross wall 46, but again the sides of the sleeve 92 are spaced inwardly from the surfaces on the wall 46 which define the hole therein. Consequently, a narrow annular passageway 98 exists between the sleeve 92 and the lower cross wall 46. The foregoing disposition of the sleeve 92 within the shell 40 creates a cylindrical combustion chamber 100 and an annular air chamber 102 within the incinerator 12. The combustion chamber 100 is located within the dispersion sleeve 92 and its function and operation will subsequently be described. The air chamber 102, on the other hand, is vertically defined by the

cross walls

44 and 46 and laterally defined by the dispersion sleeve 92 and cylindrical sidewall of the shell 40. While the air chamber 102 is supplied with air primarily through the annular passageway 94, it may receive additional air from an auxiliary air pipe 104 which extends through the cylindrical sidewall of the shell 40. The air pipe 104 is also connected to the blower 8. Finally, the dispersion sleeve 92 has a plurality of small apertures 106 which do not extend radially, but on the contrary, are canted so that the air passing through them induces a swirl or vortex-type of air flow in the combustion chamber 100.

While some air enters the combustion chamber 100 through the apertures 106, a much larger quantity of air flows through the annular passageway 98. Beyond the passageway 98 that airstream is turned inwardly and diverted upwardly into the center of the combustion chamber 100 by a shaped combustion crucible 108 which is attached to and supported by the lower cross wall 46. More specifically, the crucible 108 possesses an annular configuration and at its center is pro vided with an integrally formed ash collecting chute 110. That portion of the crucible surface which is presented upwardly toward the combustion chamber 100 possesses a concave profile between the chute 110 and the inner margin of the annular cross wall 46 and forms a curved deflecting or diverting surface 112 for directing the air which flows through the annular passageway 98 inwardly and then upwardly into the center of the combustion chamber 100.

At its lower end the collecting chute 110 on the combustion crucible 108 opens into a horizontally disposed screw conveyor 114 which conveys the ashes resulting from combustion of the refuse horizontally and deposits them in an ash hopper 116.

The hollow drive shaft 86, which extends through the collection chamber 64 and rotates the feed screw 88, at its lower end opens into the combustion chamber 100. At its upper end the hollow interior of the shaft 86 is connected to a liquid waste line 118, thus enabling liquid waste to be introduced into the combustion chamber through the hollow drive shaft 86. The waste line 118 extends through the shell 40 and connects to a source of liquid wastes such as sewage plant, petroleum refinery, or pumping station. The interior of the drive shaft 86 contains a small sparge line 120 which extends axially through the shaft and terminates at the upper end of the combustion chamber 100 also. The upper end of the sparge line 120 also extends through the shell 40 and connects to a source of combustible gas. This gas may be the methane derived from sewage treatment operations.

Above the upper cross wall 44, a ring of boiler tubes 122 surrounds the refuse hopper assembly 60, and these tubes 122 are connected to manifolds 124 and 126. Positioned above the tubes 122 are a plurality of removable grates 128.

The gas manifold 80 at the bottom of the hopper assembly 60 is supplied with a combustible gas such as natural gas through a gas line 130. In addition to the nozzles 82, the manifold 80 also supports an electric igniter 132 which is positioned adjacent to one of the nozzles 82. The igniter 132 is supplied with electrical current through an electric line 134.

The liquid waste line 118, the sparge line 120, the gas line 130 and the electric line 134 each have flexible segments therein to accommodate slight movement between the shell 40 and the hopper assembly 60.

OPERATION Solid refuse such as the trash which is collected from the households of a community is deposited on the endless belt 14 of the conveyor 4 and transferred to the crusher 6 where it is shredded or otherwise reduced to a small size. Heavy pieces of tramp metal which do not reduce enter the lateral chamber 22 of the crusher 6, are removed by the conveyor 23, and are separated magnetically, the separated portion being sold as scrap. The reduced refuse drops downwardly into the collection hopper 26 and eventually passes through the mouth 28 thereof and into the transfer trough 30. Upon entering the transfer trough 30 the reduced refuse becomes entrained in the airstream maintained by the blower 8, and since that airstream enters the pneumatic conveyor tube 10, the refuse is conveyed into and through the tube with the airstream.

The pneumatic conveyor tube 10 discharges the airstream and entrained refuse into the collection chamber 64 generally tangentially to the inner side of the inner wall 62, and as a result, a swirl or vortex-type flow is established in the chamber 64. This type of flow coupled with the expansion of the airstream and consequent loss of velocity causes the refuse to drop to the bottom of the chamber 64 where it collects. The air on the other hand flows out of the upper end of the chamber 64 through the discharge port 70 and enters the annular air channel 73 located between the inner wall 62 and the jacket 72.

At the base of the jacket 72 a small amount of the air is diverted inwardly by the lip 76, and that air flows between the tapered skirt 74 and conical portion 66 of the inner wall 62. It is eventually discharged into the upper end of the combustion chamber 100 past the nozzles 82 located at the lower end of the skirt 74. Thus, the small quantity of air diverted inwardly at the lip 76 serves as combustion air for the gas discharged at the nozzles .82, and when the igniter 132 is energized, a selfsustaining flame will be established at the nozzles 82. This flame will burn as long as the combustible gas flows through the gas line 130 to-the manifold 80.

By far the largest quantity of air flows to the outer side of the lip 76 and is discharged from the annular air channel 73 as an annular air curtain a possessing an extremely high velocity This air curtain a occupies the space between the lower end of the jacket 72 and the annular passageway 94 located at the inner edge of the cross wall 44. Most of the air at the lower end of the curtain a is channeled into the annular passageway 94 by the outwardly flared lip 96 on the cross wall 44 and the upper end of the dispersion sleeve 92 located inwardly from that lip, although the upper end of the sleeve 92 does divert a small amount of air into the combustion chamber 100.

The air discharging from the passageway 94 enters the air chamber 102 where it experiences an expansion and corresponding increase in pressure due in part to the absorption of heat radiating from the dispersion sleeve 92. Additional air may be supplied to the chamber 102 through the auxiliary air pipe 104 so as to increase the pressure of the air in the chamber 102 still further. A small amount of air from the annular chamber 102 enters the combustion chamber 100 through the apertures 106, and since these apertures 106 are all canted in the same direction relative to the respective radii along which they lie, a swirl or vortex is induced within the combustion chamber 100.

While a small amount of air is diverted through the apertures 106, most of the air in the annular chamber 102 discharges through the annular passageway 98 located at the inner edge of the lower cross wall 46. That air flows at a relatively high velocity through the passageway 98 and upon leav ing the passageway 98 impinges against the concave diverting surface 112 of the combustion crucible 108. The surface 112,

due to its contour, diverts the airstream inwardly and then turns it upwardly into the center of the combustion chamber 100. The air leaving the inner margin of the surface 112 converges a short distance above the open upper end of the chute 110, and thus a strong upwarddraft d is directed into the combustion chamber 100. That draft is rotated by the swirling air which enters the combustion chamber through the small apertures 106. Moreover, the converging air or draft d tends to form a sphere of turbulent air in the center of the combustion chamber 100, that sphere being in turn rotated by the air issuing from the apertures 106.

When the gear motor 84 is energized, the feed screw 88 rotates and discharges the refuse from the collecting chamber 64 at a controlled rate. This refuse falls downwardly, but upon encountering the upwardly directed draft d in the combustion chamber 100, remains more or less suspended in that draft. The flame at the nozzles 82 initially ignites the refuse, forming a ball of flame which is buoyed upwardly by the upwardly directed draft d and therefore remains concentrated in the approximate center of the combustion chamber 100. In other words, the upwardly directed draft d created by the diverting surface 112 supplies a large amount of oxygen to oxidize the refuse and in effect causes the combustion to occur as a ball of fire which locates in the approximate center of the combustion chamber 100. The heavier pieces of refuse fall through the draft d and into the open upper end of the chute where they rest on the ashes collected therein and are likewise oxidized. Thus, the heavier pieces burn as a bed of ashes and add to the ashes in the chute 110. The screw conveyor 114 withdraws a sufficient amount of ashes from the chute 110 to prevent the ashes from overflowing onto the concave diverting surface 112, yet allows enough ashes to remain in the chute 110 to seal the bottom of the chamber 100.

Since the feed screw 88 supplies a continuous flow of refuse to the fire at a constant rate and likewise since the airstream continues to supply fresh oxygen from the lower end, the flame continues and remains in the same location. The swirl created by the air entering through the apertures 106 causes the refuse to mix thoroughly with the air and makes the combustion extremely efficient. In time the flame becomes hot enough to become self-sustaining and the flow of combustible gas to the nozzles 82 may be shut off. Thus, the reaction in the combustion chamber 100 is exothennic. The flame in the combustion chamber 100 should be maintained between 1800 F. and 2000 F. to assure complete combustion and to destroy all bacteria.

The level of the refuse in the collection chamber 64 remains more or less constant due to the fact that the motor for operating the feed conveyor 4 is controlled by the load cells 90 through which the entire hopper assembly 60 is suspended. When the chamber 64 becomes overfilled, the cells 90 sense the increase in weight and cause the speed of the endless belt 14 on the feed conveyor 4 to decrease. On the other hand, when the hopper assembly 60 becomes too light, indicating too little refuse, the cells speed up the belt 14.

The solid products of combustion are minimal due to the extremely high temperature of the flame, and for the most part, collect in the ash collecting chute 110. In this connection, it should be noted that combustion of relatively light particles occurs at the center of the combustion chamber 100, whereas the heavier particles fall into the chute 110 and burn as a bed on the ashes therein. Since the diverting surface 112 turns the air upwardly prior to the center of the combustion chamber 100, the airstream passes over the bed of burning heavier particles, and they are consumed quite rapidly.

The gaseous products of combustion flow upwardly along the tapered skirt 74 at the bottom of the hopper assembly 60 and pass through the air curtain maintained between the lower end of the jacket 72 and the annular passageway 94. Since the distance between the lower end of the jacket 72 and the upper end of the dispersion sleeve 92 is quite large, the velocity of the gaseous products of combustion remains low and does not divert the air curtain a any appreciable amount. As a typical example the velocity of the air curtain a may be 12,000 ft./min., while the velocity of the spent gases which pass through the air curtain may be 500 ft./min. Flyash and smoke which may become entrained in the gaseous products of combustion do not pass easily through the air curtain and the air curtain a, in effect, functions as a filter for removing most of the smoke and flyash. Moreover, the small amount of air from the air curtain a which is diverted inwardly by the upper end of the sleeve 92, tends to direct or blast the flyash downwardly, and assists in preventing the escape of that flyash. The flyash which is removed from the gaseous products of combustion by the air curtain a becomes entrained in the air forming the air curtain a and is carried back into the combustion chamber 100 where it is subjected to further oxidation. Hence, repeated recycling of the flyash consumes the particles. Some of the flyash particles may settle out with the ashes which drop into the chute 110, and those particles will be withdrawn by the conveyor 114 and deposited in the hopper 116. By and large, the greater portion of refuse introduced goes to complete combustion.

After escaping from the air curtain a, the gaseous products of combustion flow along the outer surface of the jacket 72 and heat the jacket 72 which in turn heats the incoming air within the air channel 73, thereby enhancing the efficiency of the combustion process. The gaseous products of combustion also flow along the boiler tubes 122 and convert the water therein into steam which, after appropriate conversion, may be used to power the feed conveyor 4, crusher 6, and blower 8.

The grates 128 serve to remove still more flyash from the gaseous products of combustion so that the gases discharged from the stack are free of particulates and smoke.

Liquid sewage may also be introduced into the flame through the liquid waste line 118 and the hollow drive shaft 86, and it too will be oxidized. Bacteria within this sewage will be destroyed due to the high temperature of the flame. The intense heat of the flame, moreover, eliminates the emission of odors. In lieu of sewage, other liquid wastes such as heavy residues from petroleum refining operations and chemical byproducts may also be introduced into the flame through the line 118 and hollow drive shaft 86. Generally speaking, additional air should be supplied to the air chamber 102 from the auxiliary air pipe 104 when sewage is burned.

Any combustible gaseous wastes may be consumed by the flame also, and wastes of that nature are introduced through the sparge line 120. For example, methane which is usually emitted from sewage treatment plants may be burned.

Since the ball of fire within the combustion chamber is maintained at between 1800" F. and 2000" F. and contains excess oxygen, no carbon monoxide is produced. Similarly, the intense heat within the combustion chamber eliminates odors in the gaseous as well as the solid products of combustion. Moreover, the air curtain a between the jacket 72 and the annular passageway 94 filters flyash and smoke out of the escaping gaseous products of combustion and reduces the emission of flyash to a minimum. Thus, the refuse disposal plant 2 may be located in populated areas and is ideally suited for small as well as large communities.

This invention is intended to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure which do not constitute departures from the spirit and scope of the invention.

What I claim is:

1. An apparatus for disposing of refuse, said apparatus comprising a supporting shell, a combustion chamber in the shell, feed means for introducing refuse into the combustion chamber, air directing means for directing air into the com bustion chamber to supply sufficient oxygen for combustion of the refuse whereby gaseous products of combustion are produced, the air directing means including a curved surface which is located at the bottom of the combustion chamber and curves upwardly about a central portion, the air directing means directing high velocity air onto the curved surface outwardly from where the surface curves upwardly whereby the curved surface directs the air upwardly so as to induce an upwardly directed draft in the combustion chamber, the feed means discharging the refuse so that it falls downwardly into the upwardly directed draft of air, a collecting chute in the central portion for collecting ashes resulting from the combustion, and air curtain means for establishing an air curtain in the shell, the gaseous products of combustion being diverted through the air curtain whereby particulates and smoke are removed from the gaseous products of combustion.

2. An apparatus according to claim 1 wherein a sleeve is mounted in the shell and the combustion chamber is within the sleeve; and wherein the curves surface is located at the base of the sleeve.

3. An apparatus according to claim 2 wherein the curved surface is on a crucible located beneath the sleeve and diverts the air from a downwardly directed flow along the outside of the sleeve to an upwardly directed flow within the sleeve.

4. An apparatus according to claim 3 wherein the feed means comprises a wall supported in the shell and defining a refuse collection hopper, and means for dispersing refuse from the hopper at a controlled rate.

5. An apparatus for disposing of refuse, said apparatus comprising a supporting shell, a combustion chamber in the shell, feed means for introducing refuse into the combustion chamber, air directing means for directing air into the combustion chamber to supply sufficient oxygen for combustion of the refuse whereby gaseous products of combustion are produced, the air directing means creating an upwardly directed draft of air in the combustion chamber and the feed means allowing refuse to fall downwardly into the draft of air, a jacket disposed within the shell, an inner wall disposed within and spaced inwardly from the jacket so as to form an air channel between the jacket and inner wall, the bottom of the air channel being open within the shell, means for supplying air to the air channel between the jacket and the inner wall, and an annular passageway for receiving air discharged from the air channel whereby an air curtain is established between the open bottom of the air channel and the annular passageway, the gaseous products of combustion being diverted through the air curtain whereby particulates and smoke are removed from the gaseous products of combustion.

6. An apparatus according to claim 5 wherein the inner wall defines a refuse collection hopper and wherein the feed means is at the base of the collection hopper.

7. An apparatus according to claim 6 wherein the inner wall has a port which provides communication between the refuse collecting chamber and the air channel; wherein the means for supplying air to the air channel comprises a blower, a conduit connecting the blower with the refuse collection hopper, and means for entraining the refuse in the airstream established by the blower whereby the refuse is conveyed to the collection hopper in the airstream.

8. An apparatus according to claim 5 wherein a sleeve is mounted in the shell and the combustion chamber is within the sleeve; wherein the annular passageway at the bottom of the air curtain is at the top of the sleeve; and wherein the air directing means comprises a diverting surface at the bottom of the sleeve, the diverting surface possessing a concave profile about a raised center portion so that air along the outer side of the sleeve is diverted inwardly and then upwardly into the combustion chamber.

9. An apparatus for disposing of refuse, said apparatus comprising means defining a combustion chamber, means for creating a high velocity airstream, a deflecting surface curving upwardly at the bottom of the combustion chamber about a center portion for diverting the airstream upwardly into the combustion chamber, feed means for introducing refuse into the top of the combustion chamber, the feed means being positioned such that the refuse will drop downwardly into the upwardly directed airstream, and a chute in the center portion for collecting the ashes resulting from incineration of refuse.

10. An apparatus according to claim 9 wherein the means defining the combustion chamber is a vertical sleeve; wherein the deflecting surface is concave about the center portion; wherein theairstream passes along the outer surface of the sleeve before impinging against the deflecting surface; and wherein the deflecting surface turns the airstream inwardly and then upwardly.

11. An apparatus for disposing of refuse; said apparatus comprising a combustion chamber having an open upper end, a source of flowing air, means for channelling the flowing air into an air curtain which completely surrounds the upper end of the compression chamber, means at the bottom of the combustion chamber for diverting the flowing air upwardly into and through the combustion chamber downstream from the air curtain whereby an upwardly directed draft of air is created in the combustion chamber; feed means at the upper end of the combustion chamber for introducing refuse into the upwardly directed draft of air in the combustion chamber so as to incinerate the refuse and thereby create gaseous products of combustion, and means for diverting substantially all of the gaseous products of combustion through the air curtain at the upper end of the combustion chamber whereby particulates and smoke are removed from the gaseous products of combustion.

12. An apparatus according to claim 11 wherein the feed means comprises a hopper for holding the refuse, a feed tube projecting downwardly from the bottom of the hopper, a feed screw disposed within feed tube, and means for rotating the feed screw, whereby when the feed screw rotates refuse is dispensed into the combustion chamber at a metered rate.

13. An apparatus according to claim 12 wherein the flowing air passes into the hopper upstream from the air curtain; wherein the refuse is entrained in the flowing air and delivered to the hopper in the flowing air; and wherein the refuse is removed from the flowing air at the hopper so that the flowing air is substantially free of refuse where it forms the air curtain.

14. An apparatus according to claim 12 wherein the means for rotating the feed screw comprises a shaft extending through the interior of the hopper, and a motor connected to the shaft for rotating it; and wherein the shaft is free of any journals within the hopper.

15. An apparatus according to claim 11 wherein means are provided intermediate the air curtain and the lower end of the combustion chamber for diverting a small portion of the flowing air into the combustion chamber at its sides, the small portion of air diverted being directed to induce a swirl in the flowing air which is diverted upwardly into the combustion chamber from the bottom thereof.

16. An apparatus according to claim 11 wherein the feed means includes a hopper located above the combustion chamber; wherein the flowing air passes into the hopper upstream from the air curtain; wherein the refuse is entrained in the flowing air and is delivered to the hopper in the flowing air, but is removed from the flowing air in the hopper; wherein a jacket surrounds the hopper and is spaced outwardly therefrom so as to create an air channel between the hopper and the jacket; wherein the interior of the hopper opens into the air channel so that the flowing air passes into the air channel; and wherein the lower end of the air channel is disposed above the upper end of the combustion chamber and the air curtain originates at the lower end of the air channel.

17. A process for disposing of refuse; said process comprising creating an air flow, channelling the air flow into a generally annular air curtain disposed completely around the top of a combustion chamber of circular shape, diverting the air flow up into and through the combustion chamber downstream from the air curtain so as to create an upwardly directed draft of air in the combustion chamber, feeding refuse into the upwardly directed draft within the combustion chamber, incinerating the refuse in the combustion chamber so as to create gaseous products of combustion, and passing substantially all of the gaseous products of combustion through the air curtain whereby particulates and smoke are removed from the gaseous products of combustion.

18. A process according to claim 17 and further characterized by entraining the refuse in the air flow, and extracting the refuse from the air flow upstream from the air curtain.

Claims

1. An apparatus for disposing of refuse, said apparatus comprising a supporting shell, a combustion chamber in the shell, feed means for introducing refuse into the combustion chamber, air directing means for directing air into the combustion chamber to supply sufficient oxygen for combustion of the refuse whereby gaseous products of combustion are produced, the air directing means including a curved surface which is located at the bottom of the combustion chamber and curves upwardly about a central portion, the air directing means directing high velocity air onto the curved surface outwardly from where the surface curves upwardly whereby the curved surface directs the air upwardly so as to induce an upwardly directed draft in the combustion chamber, the feed means discharging the refuse so that it falls downwardly into the upwardly directed draft of air, a collecting chute in the central portion for collecting ashes resulting from the combustion, and air curtain means for establishing an air curtain in the shell, the gaseous products of combustion being diverted through the air curtain whereby particulates and smoke are removed from the gaseous products of combustion.

10. An apparatus according to claim 9 wherein the means defining the combustion chamber is a vertical sleeve; wherein the deflecting surface is concave about the center portion; wherein the airstream passes along the outer surface of the sleeve before impinging against the deflecting surface; and wherein the deflecting surface turns the airstream inwardly and then upwardly.