US3563188A - Smokeless trash incinerator system - Google Patents

Abstract

An incinerator unit for disposal of a variety of waste materials having an initial burning chamber of avoid section providing a lower trash-burning zone and an upper heat-reflecting zone having a narrowed portion of parabolic section, an air supply system for presenting air under the fire and over the fire, and an afterburner system arranged along a stack for the incinerator. The afterburner system provides a supplemental air supply and a preassembled fuel-supported burner unit disposed thereabove. Vertically spaced along the flue, or stack, is a final selfcontaining fire zone supported by supplemental preheated air passing into the fire zone from a heat exchanger which is mounted on and surrounds the flue. After retention and burning in the final fire zone, the effluent is passed to the atmosphere at an acceptable level of smoke and fly ash.

Description

United States Patent [111 3,563,188

[72] Inventors i g- 3%" 3,199,475 8/1965 Siagel 1. 110/18 x to, Lzberws Bakker south Euclid, Qhio Primary Examiner-Kenneth W. Sprague [211 Appl 812,518 At1orneys-Woodrow W. Portz and lrvin L. Groh [22] Filed Feb. 25, 1969 22:32: Corporation ABSTRACT: An incinerator unit for disposal of a variety of Cleveland Ohio waste materials having an initial burning chamber qf ovoid section providing a 'lowe'rt'rash h urning zone and an upper heat-reflecting zone having a narrowed portion of parabolic [54] SMOKELESS TRASH INCINERATOR SYSTEM section, an air supply system for presenting air under the fire 8 Claims, 8 Drawing Figs. and over the fire, and an afterburner system arranged along a stack for the mcmerator.

[52] US. Cl 110/8 The afterbumer System provides a supplemental i supply [51 F233 5/12 and a preassembled fuel-supported burner unit disposed [50] Field ofsearch 110/7, 8, thereabove vertically spaced akmg the fl or Stack i a 18156 final self-containing fire zone supported by supplemental pre- References Cited heated air passing into the fire zone from a heat exchanger which is mounted on and surrounds the flue. UNITED STATES PATENTS After retention and burning in the final fire zone, the ef- 0,244 6/1965 l-loskinson 110/ 18 fluent is passed to the atmosphere at an acceptable level of 3, 2 6 9 ,340 8/l9 66 Crawford e t al. I 110/8 smoke and my ash.

MWHH m I R WI 3,563,188

Ll BERTUS BAKKER PATENTEU FEB] 6 Ian SHEET 2 OF 3 70 INVENTORS JOHN P. PROSSER BY Ll BERTUS BAKK ER PATENTED FEB 1 s |97| SHEET 3 OF 3 OOOOOOOOOOOO OOOOOOOOOOOOO OOOOOOOOOOOO INVENTORS JOHN P. PROSSER LIBERTUS BAKKER most rigid air pollution control agency.

BACKGROUND OF THE INVENTION 1 The demand by the public and agencies representing them for control of air pollution by; heavy industry and air-contaminating practices by commercial organizations, such as burning of waste materials and discharging organic-containing fumes into the atmosphere has'produced a great number of devices which claim toburn smoke more or less completely.

Many devices and units have beenpresented tothe market v discharged from the ov od chamber to complete combustion place which use the application of the afterburner principle of burning smokeand they appear in many forms, such as a second fire zone or chamber connected by a passageway from the initial burning zone. These fire zones are usually a duplicate of the initial burner chamber. Flue gases may have an obnoxious odor,-may contain skin and eye irritating components, and depending on the waste matter being disposed of may be quite toxic. Thermal breakdown of such components to compounds' less objectionable'is generallypossible. i j v Control of delivery of waste materials to an incinerator is impractical,therefore it is necessary to provide within a single unit a combination of features which'will effectively balance air fuel mixture, temperature and retention time for the thorough incinerationof'a variety of waste materials, and at the same time present to the atmosphere a clean effluent having only a fly ash content'well within the requirementsof the Themajor problem in incinerating solid and liquid materials is to efficiently incinerate the gases and gas-suspended materials liberated from the initially incinerated solids and liquids to stack effluent having. satisfactorily low pollution levels; The engineering aspects of theproblem are to inject sufficient heat and air into the incinerating system without excessive use of fuel and unduly large and complicated equipment.

DESCRIPTIONIOF THE INVENTION The. present invention is concerned with a multipurpose trash burner of the type in which the initial combustion utilizes a fluidized bed or hearth and an afterburner system to dispose of smoke and odor produced by the burning of certain waste materials. A fluidized bed or hearth consists of a section for presenting fluidizing' gas to thehearth. Vigorous agitation of the bed particles gives rise to severaldesirable characteristics insofar as combustion of a multiplicity of waste products to be consumed in an incinerator is concerned. The particles act as a large heat reservoir and their movement within the bed tends to disseminate heat and combustion within the bed.. No hot zone will develop in the bed. The fluidizing gas is air. Because of vigorous motion of both the air and the solid, contact between the burning particles and theoxygen in the air is excellent. To a substantial extent, distillation products are at least partially consumed in a fluidized bed before they leave the bed thereby reducing theamount of unburned hydrocarbons leaving the unit..

The recovery of combustion heat from. waste incineratiom: 1 according to the present invention, enables the use of this heat to further heat, or superheat, the suspended or gaseous matter liberated by the initial combustion of the waste matter. This recovery of heat isaccomplishedby the inclusion as a part of v the initial burner chamber-a parabolic arch construction redirecting radiant heat in substantially a vortex pattern. returning it toward the bed of burning waste. The smoke and gases absorb this reflected heat prior to entry into the plenum chamber.

Therefore, the principal objectof the invention is to com blue elements into a simple and effective incinerating unit for smoke and odor disposal caused by burning waste matter, especially a general purpose incinerator capable of handling wastes high in carbon including those of high as well as low molecular weight. The incinerator is to be of rugged simplified design with a minimum of parts, trouble-free, and susceptible of being manufactured at a comparable orless cost than other designs commercially available.

the waste material.

lt'is also an object to utilize, in a substantial manner, heat from stack gases "to preheat air to be mixed with gases thereof.

For" achieving such objects, special features,-in addition to the oviod chamben'are an afterburner system containing an air-supplying device and a fuel-supported ring burner which will produce fuel-supported flames emitting into the direction of the flue gases, as well as substantially at right angles thereto; a fire resistant annulus. shaped to produce turbulence in'the gases passing through the burner; an independent air-fed heat exchanger surrounding thestack and supplying preheated air to a self-supportingtire zone within the stack in downstream relation to the fuel-supplied burner. As just suggested, the afterburner system furtherprovides a final fire zone within the stack which is located above the inlet of preheated air from the heat exchanger to achieve effective recircling of heat within the stack structure considered alone, and an apertured fire resistant body or block provided with a plurality of vertical and elongated holes providing controlled passage for stack gases to the final fire zone. g

It is to be understood that the incinerator may be fitted and equipped, e.g., at the plenum chamber, with a thermocouple arrangement which controls the gas burner to maintain a temperature range, such as of approximatelyl,l00 to L350" within the final fire zone. Most gases will burn at a lower temperature than l,350 F. However, carbon monoxide requires a constant temperature range of 1,200to l,350 and, since the plicating, and confusing to the presentation of the invention.

FIGURES OF THE'DRAWING FIG. 1 is a side elevation of the incinerator unit, showing the vertical spacings of several elements of the afterburner system as disposed along the flue downstream, i.e., upwardly, from the plenum chamber. Wall sections are broken away from the fire box and the plenum chamber to expose the interiors thereof.

FIG. Us a cross section of the ovoid tire box taken along line 2-2 of FIG. 1. FIG. 3 is a line depiction-of a cross section of an air feeder of the afterburner structure taken on line 3-3 of F IG. 1.

FIG. 4 is a section of a burner of the afterburner structure taken on line 4-4 of FIG. 1.

FIG. 5 is a cross section taken on line 5-5 of FIG. 4.

FIG. 6 is a cross section taken on line 6-6 of FIG. 4.

FIG. 7 is a sectional view of v ,a stack-mounted heat exchanger showing in section an apertured refractory body, stack,and heat exchanger construction.

vFIG. 8 is a section taken on line 8-8 of FIG. 7.

INITIAL COMBUSTION CHAMBER Referring now to the drawings, particularly FIG. 2, the initial combustion chamber I1 is of ovoid cross section forming a lower zone 12 and an upper zone 13. The outer shell 14 em braces a hearth 15 and a heat-reflecting wall 16. Embedded in 22, also embedded in the hearth lining, which direct air through slots 23 and 24.

The initial combustion chamber 11 is held in operative position by end pieces 25 and 26 which have base pieces 27 and 28 secured to the end pieces as by weld metal. Conveniently positioned on chamber 11 is an electrical control panel 29. ln one end of chamber 11 is an aperture 35 forming a passageway to a cylindrical plenum chamber 36.

EXTERIOR AlR SUPPLY SYSTEM Asingle blower 45, shown mounted exteriorly of the burner chamber, the plenum chamber, and'the afterburner system, supplies the auxiliary air where needed for proper combustion at each station. The air is directed by various ducts which may be sized, e.g., according to Bernoulli's Law" of mechanics of gas flow. The air ducts are supported substantially as portions of a blower unit construction. Proportionate diameter piping may be generally utilized to convey the air to intended regions of use and in the approximate amounts and velocities necessary for proper combustion at the station to which the air is directed. Valves 38, 39, 40, and 41 are provided in respective air ducts for further controlling rate of flow and timing of operation as desired.

Ducts or pipes 46 carry air to the initial combustion chamber 11 from the larger section of vertical pipe 47. An air duct 49 carries air to a region of zone 13 normally disposed above the trash charge supported by the hearth. Pipe 52 branches outwardly from the vertical duct 50 and carries air to an annular air inlet member 71 for tangentially injecting air into the adjacent flue 70. A pipe 54 branches from a portion of duct 50 of reduced diameter and forms a juncture with a heat exchanger to be later described.

An end wall 60 of the initial combustion chamber, which may be in the form of a door, is provided with hinges 61 and suitable latching device whereby the entire end may be opened for cleaning out purposes, to place large debris to be burned, or for ease of repair. Normally trash is placed in the chamber 11 through a smaller door 62 provided with suitable hinges and a latching device 63.

Vertical flue 70, i.e., a part of the stack structure, is connnected to plenum chamber 36 and supports the annular air supply member 71 slightly below a ring burner 80, i.e., in upstream relation thereto. The member 71 includes a series of directional vanes 72 circuitly spaced with respect to the longitudinal axis, in general, along the periphery, of the flue 50 to provide multiple openings through which air is injected nearly tangentially into flue 70 at many points to cause it to mix with stack gases in a somewhat spiral turbulent pattern as the mixture passes upwardly into and through a burner unit 80.

RING BURNER CONSTRUCTION For supporting the burner unit 80, the incinerator stack further includes a preferably annular angle support 81 surrounding the flue 70 and fixed thereto by means, such as weld metal. An H-ring 83 is attached to the support 81 by BOLTS 82. This ring embraces and supports a flre resistant annulus 84 of ceramic or other refractory material in outward-spaced generally-concentric relation with a ring burner 85.

The burner 85 is of ring shape, in generally-concentric relation with the axis of an adjacent flue, and provided with a series of apertures 86 for directing flame upwardly and another series of apertures 87 oriented at angle with aperture 86 for directing flame in a more radial inward direction. Flame emitting from these apertures may be discharged at approximately 90 apart. The object is to enable flames to discharge from the burner substantially upwardly as well as laterally to give a depth to the flame upwardly, i.e., downstream. from the burner. The annulus 84 has an inner surface of concave radial cross section in radially spaced relation with the burner to assist in mixing the smoke or stack gas and the flames.

As shown, the H-ring protrudes inwardly with respect to the inner periphery of the flue 70 as at 88 to cause turbulencein recycling of stack gas heat in consideration of capital and and resistance to rising gases thereby promoting the contact and oxidation of unburned compounds. The ring burner receives fluid fuel through a pipe 89 having a mixing valve 90. A pilot flame system is provided with a mixing valve 96 which is controlled by a thermocouple (not shown) which also controls the fuel supply to the ring burner 85.

The stack structure extends upwardly from the burner unit 80 as a flue 100 reinforced along its lower edge by an annular angle 101. Angle 101 rests on a leg ofthe H-ring 80 and is conveniently held in place by nuts and bolts 102. A shown in FIG. 5, the burner 85 is supported in the H-ring by brackets 105 which in turn are held in place by means such as the bracket stud 106 and nut 107.

HEAT EXCHANGER The heat exchanger generally shown as 110 in F 16$. 7 and 8 is supported along the flue 100 by a' band 111 affixed thereto as by weld metal 112. The heat exchanger 110 comprises an outer wall or housing 113 surrounding theflue 100 of greater diameter than flue 100 whereby a region or passageway 114 is formed for confining air. entering the heat exchanger at a juncture 115 in heat-exchanging relation .with the wall of the flue 100. A section of the fluel00 along a lower portion of the region 114 has a plurality of apertures 116 through which heated air may pass from'the region 114 to the interior of the flue. The apertures116 are restricted in size and number to establish a desired retention time for airpassing through the heat exchanger. Radially-extending and angularly-spaced heafitransferring vanes 120 affixed to said flue 100 may be provided for more effective transfer of heat from the stack gases to the air entering the stack through the heat exchanger.

Mounted within a lower portion of the flue'l00 and above apertures 116 is a multiapertured block which may be of monolithic construction and constituted of a refractory material such as baked flrebrick clay. The block is supported in the flue 100 by retaining ring 126. The block 125 occupies a full cross section of the flue 100 and forms a base for a self containing flre zone and is provided with a plurality of openings 127 which are elongated in the lengthwise direction of the flue to permit controlled passage of substantially, but usually incompletely, oxidized gas and fly ash to enter the tire. zone 128 for final consumptionof smoke (suspended solids) and odors whereby a substantially clear odorless effluent may be discharged from the flue 100. The block 125 acts on the flue gases passing therethrough to interrupt any channeling of fresh air from the heat exchanger and stack gas from the ovoid chamber to effect good mixing. As the block becomes heated, especially if incandescent, the heated radiating surfaces of the block promote the further reaction of air oxygen with-oxidizable compounds issuing from the plenum 36.

lt will be appreciated that preheated air is fed into the tire zone 128 in order to maintain effective combustion temperatures for all oxidizable compounds ordinarily occurring in incinerator operation. The length of the heat exchanger 110 may be extended to any length deemed practical in the maintenance costs, since there is some gain-in the reclamation of heat possible at almost any length. The heat exchanger 110.

contributes to maintenance of combustion in the stack region 128, Le, the final combustion region of the incinerator. This completes the multistageheating and air-charging process for incinerating the gases or gas-suspended material'sliberated from the incinerator load and first subjected to concentrated radiant and reflected radiant heat within theparabolicallybounded upper zone of the ovoid chamber 11. Theburner 85 provides intermediate heating of the stack gases which may be controlled by apparatus well known to the art to*maintain a desired temperature range within the final combustion region 128 consistent with safe and economical operation of the incinerator.

We claim:

1. a trash incinerator comprising;

a trash-receiving chamber of ovoid cross section and end walls having a lower trash-burning zone defined by a lower broader portion of the chamber, and an upper heatreflecting zone defined by an upper narrower portion;

a stack connected with the upper, zone through one of said end walls and comprising a flue;

wall means in exterior spaced relation with said flue and combining with said flue to define a heat exchanger for air having a heat exchange' region, outlet apertures through the flueadjacent the upstream or downward end of the heat exchanger for feeding air from said region into the flue and an inlet for said region disposed substantially downstream or upwardly from said apertures; and

air-dispensing means disposed along the bottom of said chamber arranged for discharging airupwardly into and through a trash charge. I 2. The trash incinerator of claim 1 comprising a fluid-fuelburning burner disposed in said stack between said upper zone and said heat exchanger.

3. The trash incinerator of claim 1 comprising:

an air supply means with multiple openings for injecting air into the stack disposed along said stack between said upper zone and said heat exchanger; and

a fluid-fuel-buming burner disposed in said stack between and in spaced relation with said air supply means and said heat exchanger.

4. The incinerator of claim 3 comprising a multiapertured block occupyingsubstantially the entire cross section of said flue received in a lower portion of said heat exchanger immediately above said outlet apertures thereof, the apertures of said block being elongated in the lengthwise direction of the flue.

5. The incinerator of claim 3 wherein theair supply means includes a plurality of vanes circuitly spaced about the axis of a flueextending through the air supply means.

6. The incinerator of claim 3 comprising a burner unit wherein: p

said burner is ring-shaped and is generally-concentric relation with the axis of the enclosing flue and adjacent flue and has apertures for discharging flame both upwardly in a burner within the stack in spaced relation with the air-supplying means; a

a counterflow heat exchanger peripherally enclosing a flue of said stack as its inner wall and vplacing air entering said heat exchanger in heat exchange relation with gases passing through the flue; and

said flue having air outlet apertures at the lower end of the heat exchanger, the interior of the flue within the heat 7 exchanger being a final combustion zone for gases passing therethrough 8. A trash incinerator comprising;

a trash-receiving chamber having a lower trash-burning zone defined by a lower portion of the chamber, and an upper heat-reflecting zone defined; by an upper portion;

a stack connected with the upper zone through one of said end walls and comprising a flue;

wall means in exterior spaced relation with said flue and combining with said flue to define a heat exchanger for air having a heat-exchange region, outlet apertures through the flue adjacent the upstream end of the heat exchanger for feeding air from said region into the flue, and an inlet for said region disposed substantially downstream or upwardly from said] apertures; air-dispensing means disposed along the bottom of said chamber arranged for discharging air upwardly into and through a trash charge; an air supply means with multiple openings for injecting air into the stack disposed along said stack between said upper zone and said heat exchanger; and a fluid-fuel-burning burner disposed in said stack between and in spaced relation with said air supply means and said heat exchanger. I

Claims (8)

1. A TRASH INCINERATOR COMPRISING; A TRASH-RECEIVING CHAMBER OF OVOID CROSS SECTION AND END WALLS HAVING A LOWER TRASH-BURNING ZONE DEFINED BY A LOWER BROADER PORTION OF THE CHAMBER, AND AN UPPER HEAT-REFLECTING ZONE DEFINED BY AN UPPER NARROWER PORTION; A STACK CONNECTED WITH THE UPPER ZONE THROUGH ONE OF SAID END WALLS AND COMPRISING A FLUE; WALL MEANS IN EXTERIOR SPACED RELATION WITH SAID FLUE AND COMBINING WITH SAID FLUE TO DEFINE A HEAT EXCHANGER FOR AIR HAVING A HEAT EXCHANGE REGION, OUTLET APERTURES THROUGH THE FLUE ADJACENT THE UPSTREAM OR DOWNWARD END OF THE HEAT EXCHANGER FOR FEEDING AIR FROM SAID REGION INTO THE FLUE AND AN INLET FOR SAID REGION DISPOSED SUBSTANTIALLY DOWNSTREAM OR UPWARDLY FROM SAID APERTURES; AND AIR-DISPENSING MEANS DISPOSED ALONG THE BOTTOM OF SAID CHAMBER ARRANGED FOR DISCHARGING AIR UPWARDLY INTO AND THROUGH A TRASH CHARGE.

2. The trash incinerator of claim 1 comprising a fluid-fuel-burning burner disposed in said stack between said upper zone and said heat exchanger.

3. The trash incinerator of claim 1 comprising: an air supply means with multiple openings for injecting air into the stack disposed along said stack between said upper zone and said heat exchanger; and a fluid-fuel-burning burner disposed in said stack between and in spaced relation with said air supply means and said heat exchanger.

4. The incinerator of claim 3 comprising a multiapertured block occupying substantially the entire cross section of said flue received in a lower portion of said heat exchanger immediately above said outlet apertures thereof, the apertures of said block being elongated in the lengthwise direction of the flue.

5. The incinerator of claim 3 wherein the air supply means includes a plurality of vanes circuitly spaced about the axis of a flue extending through the air supply means.

6. The incinerator of claim 3 comprising a burner unit wherein: said burner is ring-shaped and is generally-concentric relation with the axis of the enclosing flue and adjacent flue and has apertures for discharging flame both upwardly in the direction of stack gas travel and radially inward; and an annulus having an inner surface of concave radial cross section in radially outward spaced relation with the burner.

7. The incinerator of claim 1 wherein the stack comprises in the order named and proceeding in the downstream or upward direction of the stack: an air supply means for injecting air into a lower portion of the stack; a burner within the stack in spaced relation with the air-supplying means; a counterflow heat exchanger peripherally enclosing a flue of said stack as its inner wall and placing air entering said heat exchanger in heat exchange relation with gases passing through the flue; and said flue having air outlet apertures at the lower end of the heat exchanger, the interior of the flue within the heat exchanger being a final combustion zone for gases passing therethrough.

8. A trash incinerator comprising: a trash-receiving chamber having a lower trash-burning zone defined by a lower portion of the chamber, and an upper heat-reflecting zone defined by an upper portion; a stack connected with the upper zone through one of said end walls and comprising a flue; wall means in exterior spaced relation with said flue and combining with said flue to define a heat exchanger for air having a heat-exchange region, outlet apertures through the flue adjacent the upstream end of the heat exchanger for feeding air from said region into the flue, and an inlet for said region disposed substantially downstream or upwardly from said apertures; air-dispensing means disposed along the bottom of said chamber arranged for discharging air upwardly into and through a trash charge; an air supply means with multiple openings for injecting air into the stack disposed along said stack between said upper zone and said heat exchanger; and a fluid-fuel-burning burner disposed in said stack between and in spaced relation with said air supply means and said heat exchanger.

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