US3616767A - Apparatus for the destruction of refuse - Google Patents

Abstract

IN A NOVEL APPARATUS USEFUL FOR THE INCINERATION OF REFUSE MATERIAL EMPLOYING ELECTRICAL HEATING MEANS, THE IMPROVEMENT WHICH COMPRISES LEVEL SENSING MEANS COUPLED WITH MEANS FOR EXHAUSTING A PORTION OF THE INCINERATOR TO LIMIT THE LEVEL OF RESIDUE CONTAINED WITHIN THE INCINERATOR. ESSENTIALLY, A PLURALITY OF SPOUTS ARE EMPLOYED ALONG THE VERTICAL AXIS OF THE INCINERATOR WHICH

SPOUTS ARE OPENED OR CLOSED DEPENDING UPON THE LEVEL OF RESIDUE DESIRED AS INDICATED BY THE SENSING MEANS.

Description

1971 K. J. SOUTHWICK APPARATUS FOR THE DESTRUCTION OF REFUSE 2 Sheets-Sheet 1 Filed Juno 9, 1970 FIG.

INVENTOR KENNETH J. SOUTHWICK ATTORNEY Nov. 2, 1971 K. J. SOUTHWICK APPARATUS FOR THE DESTRUCTION 0F REFUSE 2 Sheets-Sheet 2 Filed June 9. 1970 FIGZ FIG?) INVENTOR KENNETH J. SOUTHWICK f/,'. Ju

ATTORNEY United States Patent O 3,616,767 APPARATUS FOR THE DESTRUCTION OF REFUSE Kenneth J. Southwick, Quincy, Mass., assignor to Pyro- Magnetics Corporation, Needham, Mass. Continuation-impart of application Ser. No. 786,685, Dec. 24, 1968, now Patent No. 3,527,178. This application June 9, 1970, Ser. No. 44,788

Int. Cl. F23g 5/10 U.S. Cl. 110-8 E 14 Claims ABSTRACT OF THE DISCLOSURE CROSS REFERENCE TO' RELATED APPLICATION This application is a continuation-in-part of Ser. No. 786,685 filed Dec. 24, 1968, now Pat. No. 3,527,178 by Kenneth J. Southwick.

BACKGROUND OF THE INVENTION Part 1.Fie1d of the invention This invention relates to the incineration of refuse ma terial. More precisely, the invention disclosed herein relates to a novel incinerator which can efliciently incinerate material such as garbage, paper, cans, bottles and the like.

Part. 2.Description of the prior art The elimination or destruction of refuse is an outstanding problem of critical proportions. Incinerators are known and routinely employed in the destruction of such refuse. However, known incinerators leave much to be desired in both their operation and overall efficiency. For example, small scale incinerators such as those employed in the home can dispose of such refuse as paper or the like but cannot conveniently dispose of such refuse material as bottles and cans or the like. Moreover, large scale incinerators such as those employed to destroy refuse collected from municipalities leave much to be desired. For example, incinerators employed in such applications require supplemental fuels which limit the heat available for incineration of the refuse material and also contribute to the increased pollution of the air. Moreover, many present incinerators are not truly capable of continuous operation over extended times. Instead, their operation time is somewhat limited by the accumulation of the incinerated residue which must periodically be discharged therefrom by way of grates or the like thereby interrupting continuous operation. It is to these and related problems outstanding in the art of incineration in general to which the present invention is addressed to provide a novel solution therefor.

SUMMARY OF THE INVENTION In accordance with the present invention, an improvement in novel apparatus for incineration is presented. Essentially, the basic apparatus may be described as an integration of structural elements combined in a fashion to provide two adjacent zones. In the first zone which functions as a heat generating zone, a mass of material is heated by electrical means to provide heat for the incineration of refuse material charged to the second ice zone. The mass of material heated in the first zone can be, for example, a pure metal, metal alloy, metal refuse or other electrically conducting material, if desired. The electrical heating means heats the mass to its melting temperature and maintains the mass in a semi-molten or preferably molten state. The level of the melted mass approximately defines the boundary between the zones. The heat generating zone provides a high temperature environment in the second zone wherein the major portion of incineration occurs. The second zone is provided with means to charge refuse material thereto and means to introduce a fluid thereto. The fluid which can be air or like fluids provides support for and/or promotes incineration of the material charged into the zone. The products of incineration are continually removed from the incinerator during the operation. The manner by which the product is removed depends primarily on the nature of the material incinerated and the nature of the product resulting from Substantially complete incineration thereof. For example, easily combustible material such as paper or the like can be rapidly incinerated and converted to relatively light products upon incineration. These products are easily discharged from the incinerator by entrainment with gaseous products emerging therefrom. The products of less readily combustible materials such as glass or metal which are produced in the present apparatus are collected at the boundary between the first and second zones which is approximately defined by the level of the melted material in the first zone. At this boundary, the products are heated to a molten state or semi-molten state and means are provided to remove the products.

For example, in the improvement of the present invention removal spouts or the like are located in a plurality of positions along the vertical axis of the incinerator to remove excess melted material to a desired level. Sensing means are provided to register the level of molten material and activating means to open or close the spouts are employed to draw off a sufficient amount of material to maintain the desired level.

Many advantages can be derived from the use of the present incinerator. Chief among these is the reduced pollution of the atmosphere. Unlike present incinerators, the apparatus of the present invention does not require the use of secondary fuels such as coal, coke, gas or the like. Instead, the refuse material is employed as the primary fuel and thus the amount of pollution is limited to that created by the incineration of the refuse material alone. Also in present incinerators employing secondary fuels, the heat available is primarily limited by the fuel employed. Accordingly, the operating temperatures cannot be conveniently varied. In contrast thereto, the present apparatus permits variations in temperatures. For example, if the only refuse material involved should be easily combustible such as paper or the like, a low melting metal or alloy can be employed in the first zone and can be heated by electrical induction heating means of a preselected frequency. Accordingly, the incineration temperature can be varied by selecting the appropriate combination of metal and power input in the first zone thereby permitting close adjustment and control between the energy and/or heat required to incinerate the particular refuse material involved. Another advantage in the present incinerator is that incineration can be conducted in a substantially continuous fashion over extended periods of time since the incineration products are continuously removed therefrom during operation.

The present improvement described herein provides additional control over the amount of molten or residue material which remains in the incinerator. For example, if a large amount of non-conductive material has reduced the electrical conducting capability of the basic mass, the material may be drained out completely by activating a lower spout and the incinerator recharged with conductive material. Further, any crust which might form and block the overflow system as was described in the basic invention may be removed by opening a lower spout draining the support from the crust in an operation and causing it to collapse and fragment. Additionally, in some operations a large mass is needed, i.e., in an operation in which a large amount of refuse is deposited, for example an automobile. In others, only a small mass is needed. By adjusting the size of the mass, to the minimum needed for a particular operation, input energy to heat the mass is conserved accordingly.

Other advantages and benefits involved in the practice of the present invention will be set forth in detail hereinafter or will be apparent to those skilled in the art from the following detailed description.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a cut-away view in elevation of an incinerator employing the invention;

FIG. 2 is a cross-sectional view along line A'A of FIG. 1; and

FIG. 3 is a cross-sectional view along line BB of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, there is shown an incinerator solidly supported on supports 7. The incinerator has two adjacent zones; zones 1 and 2. Zone 1 is defined by a periphery wall 4 which is preferably fabricated of an electrically non-conductive refractory material but can be fabricated of an electrically conductive material depending on the type of electrical heating means involved. In turn, Wall 4 is oftentimes bounded by another reinforcing wall 8 also preferably fabricated of suitable refractory material. The lower boundary of zone 1 is defined by a layer 6 of a non-conductive heat resistant material preferably in particulate form such as foundry sand. The upper level of zone 1 is defined by dashed line 5. In the operation of the incinerator, a material such as a relatively pure metal and/or metal alloy is charged to zone 1. The charged material is then heated preferably to above its melting point by electrical heating means 10 which as shown is a water cooled, high frequency induction heating coil wrapped about a substantial portion of zone 1. The level of the heated mass of material is determined by the open or closed condition of the various exhaust spouts as will be described below. Electrical insulation means 12 are employed to isolate electrical heating means 10 from any metal components of the incinerator which may be located near induction heating means 10. Grounding means (not shown) can also be employed in manners known to the art.

The direct high frequency induction heating means illustrated in FIG. 1 is preferred in heating the mass of material disposed in zone 1. However, it is to be understood that other electrical induction heating means such as indirect and semi-direct electrical induction heating means as well as dielectric heating means can be employed.

For example, interior wall 4 may be comprised of a graphite clay mixture. In indirect heating of the mass, that is Where the mass may attain insufficient electrical conductivity to support direct induction heating through the addition of non-conducting materials, i.e., glass in actual operation, the graphite wall is heated by induction and the mass is heated indirectly by conduction.

Semi-direct heating may be employed when a normally non-conducting wall, i.e., a clay graphite wall becomes conductive at temperatures higher than ambient. In this case, the mass itself is sufficiently conductive to gain temperature by direct induction heating. Conduction heating of the wall follows allowing a rise in temperature providing conductivity sufiicient to allow additional wall heating by the indirect method. The frequencies employed will depend upon such factors as the nature of the material to be incinerated, the size of the incinerator and the particular metal heated in zone 1. The frequencies normally employed are those between about 60-960 c.p.s. which can be obtained by rotating generators or converters or the like. If higher frequencies are employed, e.g., from about 9'60l0 ,000 c.p.s. or even higher, motor generator sets and converters can be employed as suitable sources of power. Oftentimes, two separate frequencies with separate induction coils can be employed to obtain maximum efliciency at minimum cost.

Oftentimes, means to completely purge or discharge the heated material from zone 1 are desirable in incinerators of the type described. One arrangement of such means is shown in FIG. 1 in which bottom plate 17 having plug 14 in the central regions thereof is supported by supports 19. Plug 14 can be removed from plate 17 by actuating lever 16. Layer 6 which is normally a heat resistant and electrically non-conducting particulate material such as foundry sand can be drained from zone 1 together with the heated material. Alternately, supports 19 can be withdrawn thereby permitting the removal of plate 17 and discharge of the mass in zone 1.

Zone 2 defines the incinerator chamber and comprises a periphery of preferably electrically non-conducting refractory material 20 which is normally bounded by an insulating or reinforcing wall 22 also preferably fabricated of non-conducting refractory. At the lower portion of zone 2, a series of tuyeres 26 are provided to introduce a fluid to zone 2 to promote and/or maintain the incineration of refuse material. The fluid is introduced to zone 2 such as from wind box 24 by way of tuyeres 26. As illustrated in FIG. 1, three series of tuyeres 26 are arranged concentrically one above the other about zone 2. The number of series and the concentric arrangement and the shape of the individual tuyeres can vary and is dependent primarily upon such factors as the nature of the material incinerated and the particular fluid employed. Accordingly, modifications of these features can be employed to introduce sufiicient fluid to promote and/or maintain incineration of the refuse material delivered to zone 2. For example, as further illustrated in FIG. 2, tuyeres 26 are positioned approximately equidistant about zone 2 and arranged to direct fluid angularly downwardly to the center of zone 2 and tangentially to the periphery of zone 2.

The fluid, which can be preheated, is introduced to zone 2 to promote and/or maintain the incineration of refuse material delivered thereto. Normally air or oxygen-enriched air is the fluid employed. However, other fluids can be employed sometimes alone or in combination with others. These can be combustible in nature such as the various lower boiling hydrocarbons or diverse other hydrocarbons normally employed as fuels. Also normally non-combustible fluids such as water vapor can be employed especially when high temperatures are generated Within the incinerator chamber. Under such conditions the water vapor or like fluid can be broken down into its elemental components providing additional heat for incineration. Inert gases such as nitrogen and argon or the like which can ionize under conditions of high temperatures to generate heat can oftentimes be advantageously employed. Normally, the fluid is introduced to zone 2 under somewhat higher than atmospheric pressure to promote agitation of the refuse material delivered to zone 2 thereby promoting rapid and eflicient incineration. Also by employing high pressures which can be alternately or selectively regulated, removal of the products of incineration is enhanced. One arrangement of providing high agitation and efiicient incineration involves a series of tuyeres arranged one above the other concentrically about the periphery of zone 2 with each series of tuyeres being connected to fluid sources under different pressures,

Chute 28 provides means to introduce the refuse material into the incineration zone 2. As illustrated in FIG. 1, chute 28 is arranged to direct the refuse material to that portion of zone 2 opposite slag spouts 30, e.g., to that portion of wall 4 bounded by MM of FIG. 3. This arrangement of chute 28 is preferable but as will be apparent from the further description, other arrangements of chute 28 can be employed. The refuse material delivered into zone 2 can include easily combustible material such as paper, leaves and garbage or the like as well as materials which are not normally readily combustible such as materials of metal (cans) or of glass (bottles). Accordingly, the nature of the refuse material will normally determine the area in zone 2 where the major incineration of the material occurs. For example, when temperatures above 2000 F. are generated in zone 2 of FIG. 1, easily combustible material will undergo substantially complete incineration oftentimes almost immediately after being introduced to zone 2, e.g., well above the junction of zones 1 and 2 as indicated by line AA of FIG. 1. Moreover, the major portion of the products of the incineration of such materials are readily removed from zone 2 by the fluid flow therethrough.

Having described the basic structure, reference is now made to the improvement which comprises the present invention. As mentioned above, at least one removal spout 30 has closure means 56 for preventing outflow. Sensing means 41, conducting electrodes for example, are included for detecting the level of the molton mass. As is obvious, a variety of means may be used. For instance, a window may be inserted in the side of the incinerator and simple observation used to determine the level of the molten mass. Other means such as optical or radiation pyrometers may be used as well as thermocouples. Suitable units of the above are available from Lewis Engineering Company, Naugatuck, Conn.

As shown in the drawing, electrode 41A imbedded in the incinerator wall provides a common ground for electrodes 41B and 41C. Relay 42 is connected between electrodes 41A and 41B and relay 44 between electrodes 41A and 41C. Both relays are sufficiently sensitive to activate upon application of a current of the magnitude that will be found in the conductive mass as induced by coil 10. A signal switched by relay 462 is channeled to the reverse or closed terminal of hydraulic pump 46 through relay 48 and a signal switched by relay 44 is channeled to the forward or open terminal of the same motor. Additionally, a signal switched by relay 44 serves to deactivate relay 48. Power sources for the pump and the signals are not shown and may take any convenient form known in the art.

In operation, the level of the mass rises contacting electrode 41B. The pump is in reverse or closed condition and remains so while the level continues to rise. Relay 48 is normally closed.

When the level rises to the position of electrode 41C, relay 44 is switched to deactivate or open relay 48 and to simultaneously engage the hydraulic pump. The pump operates hydraulic motor or lever 50 through lines 52 and 54 opening door 56 allowing a portion of the mass to escape through exhaust spout 30A. As the level falls, biasing current is removed from relay 44 halting the opening of door 56A and closing relay 48. The door will now begin to close since relay 42 will switch pump 46 to the reverse position through closed relay 48. As the door closes, some of the mass will continue to exhaust until the door is firmly closed. The pump is chosen to operate the door at a rate which will allow a sufficient amount of mass to escape to accomplish the purpose of the invention. 'In particular, it will be seen that it will be advantageous to operate the pump at a higher speed in the forward or opening mode than in the reverse or closing mode.

Exhaust spouts 30B and 30C are also shown which may be arranged to operate in the same way as the system described above. These are illustrated without the control apparatus for clarity. Optionally, means for heating the spouts in the form of coils 58 may be used to insure even exhaust flow and to prevent clogging.

Referring briefly to FIG. 3, the use of additional spouts placed in the same plane about the periphery of the incinerator is shown. It will be understood that any combination of spouts may be employed in arrangements which are most convenient to the user.

Additionally, it will be appreciated that it is not necessary in the practice of the invention to provide an automatic response by gate 56 to level sensor 41. It is sufirciently advantageous to monitor the level and to have means provided for the reduction of the level at the option of the user. For example, the output of the electrode sensing system shown in FIG. 1 may be registered on a meter, the meter observed, and the gate opened normall by the observer.

Many advantages of the apparatus discussed above Will be apparent to those skilled in the art. For example, the temperatures obtained in the incineration zone can be varied over a wide range by controlling the power imput. Although high temperatures are preferred, e.g. temperatures above about 2000 F., low temperatures can be realized by employing low melting metals in the heat generating zone (zone 1). Accordingly, incinerators of the present invention present features which permit close adjustment and control over such operating parameters as energy imput and heat produced. These features permit design of large scale incinerators as well as small scale units which can be employed efiiciently in remote areas for incineration of specific refuse. Still another advantage of the present apparatus is the reduced volume of the products of incineration. Even the less readily combustible refuse material undergoes substantially complete incineration and is removed or extruded from the apparatus in a substantially molten state. The molten material can be molded into convenient shapes and disposed of in this form. Alternatively, the molten material can be quenched, pelletized or ground up and employed as an inert filler useful in the construction of roads and like structures. Perhaps the most outstanding advantage of the apparatus is the continuous manner in which it can operate. This is in marked contrast to present incinerators which must be periodically shut down at frequent intervals to remove products of incineration therefrom.

Many modifications of features of the apparatus described for the purpose of illustrating the invention can be employed without departing from the spirit and scope of the invention defined in the appended claims. For example, direct induction heating means, indirect induction and semidirect induction heating means or dielectric heating means can be employed for heating slag spout(s) 30. Also, various equipment normally employed with present incinerators can be associated with the apparatus of the present invention. Such equipment includes precipitators and filters or like equipment normally employed to reduce pollution. Afterburners can also be employed as well as energy recovery and energy conversion means such as to generate electricity which can be utilized in the operations involved. The manners and methods of integrating such elements with the present invention need not be discussed in detail since such manners and methods are well known to those skilled in the art to which the present invention pertains.

Having described my invention as well as manners of practicing same and preferred embodiments thereof, what I claim as new and desire to secure by US. Letters Patent is as follows:

1. In an incinerator comprising adjacent first and second zones,

said first zone defining a heat generating zone and comprising a periphery wall of refractory material, elec trical heating means operationally communicating with said zone and means to retain a mass of material in said zone to be heated by said electric heating means whereupon the upper level of said heated mass approximately defines the boundary between said first and second zone; said second zone defining primarily an incineration zone and comprising a periphery wall of refractory material, means to introduce an incineratable material to saidzone, means to introduce a fluid to said zone which in combination with heat generated in said first zone can cause incineration of material delivered to said second zone and removal means to remove molten products produced in said incinerator, the improvement which comprises:

means for determining the level of said heated mass in combination with activating means to engage said removal means to limit the level of said heated mass. 2. The apparatus of claim 1 wherein said means for determining the level of said heated mass comprises sensing means positioned within said incinerator said sensing means arranged to deliver a signal external to said incinerator.

3. The apparatus of claim 2 wherein said signal is applied to said activating means to operate said activating means.

4. The apparatus of claim 3 wherein said signal com- 5. The apparatus of claim 3 wherein said electrical heating means is a direct electrical induction heating means.

6. The apparatus of claim 3 wherein said electrical heating means is an indirect electrical induction heating means.

7. The apparatus of claim 3 wherein said electrical heating means is a semi-direct electrical induction heating means.

8. The apparatus of claim 3 wherein said electrical heating means is a dielectric heating means.

9. The apparatus of claim 3 wherein said means to introduce said fluid comprises a plurality of parts arranged about the periphery of said second zone near said boundary with said ports being operationally connected to a fluid source.

10. The apparatus of claim 4 including electrical heating means for heating said spout.

11. The apparatus of claim 4 wherein said sensing means is an electrical conducting sensing means.

12. The apparatus of claim 4 wherein said sensing means comprises an optical pyrometer.

13. The apparatus of claim 4 wherein said sensing means comprises a radiation pyrometer.

14. The apparatus of claim 12 including a plurality of removal means.

References Cited UNITED STATES PATENTS 3,344,758 10/1967 Wotschke l8 3,417,717 12/1968 Jacobovici 110-18 R 3,527,178 9/1970 Southwick ll0-8 E KENNETH W. SPRAGUE, Primary Examiner U.S. Cl. X.R. 110--l8 E

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