US2175301A - Method of destroying refuse matter - Google Patents

Description

Oct. 10, 1939'. H MORETON 2,175,301

METHOD OF DESTROYING REE USE MATTER Filed Au 19, 1935 1 I ,7W7Ld 47 Z] .90

Patented Oct. 10, 1939 PATENT OFFICE METHOD OF DESTROYING REFUSE MATTER Henry H. Moreton,

Santa Monica, Calif.

Application August 19, 1935. Serial No. 36,934

8 Claims.

This invention is a method for destroying waste material such as garbage, sewage, and the like.

Heretofore it has been proposed to incinerate garbage, sewage, etc., but owing to the high moisture content of such materials, the speed of combustion thereof is retarded, with the result that smoke, gases and objectionable odors are discharged into the surrounding atmosphere during the incinerating process.

One of the objects of the invention is to provide for complete and economical physical destruction of garbage by incineration, whereby practically no residue is left, so that the possibility of either soil or water pollution is reduced to the absolute minimum. A further object is to provide for complete incineration of garbage in such manner that the discharge of objectionable and offensive odors, smokes and gases into the surrounding atmosphere is prevented. A further object is to provide a system of low installation cost and highly economic operation, capable of providing for initial dehydration of the garbage and subsequent complete incineration in a continuous process. A further object is to employ the caloric values inherent to the garbage being treated, to assist in the incineration of the material being treated, after its dehydration.

The invention will be hereinafter fully set forth and particularly pointed out in the claims.

In the accompanying drawing:

Figure 1 is a vertical elevation more or less diagrammatic in character, illustrating an apparatus constructed in accordance with the invention, certain parts being shown in section. Figure 2 is a detail sectional View of a portion of one of the rotatable furnaces. Figure 3 is a side elevation diagrammatically illustrating a modification. Figure 4 is another modification.

Referring to the drawing, I designates a combined dehydrator and incinerator, which consists of a relatively long cylindrical chamber In, rotatively supported in a longitudinally inclined position, in a well known manner, by suitable bearings l l. Rotation of the cylindrical chamber may be effected by any suitable means, such as a gear l2 engaging a gear-ring [3, which encircles the cylinder Ill. The higher end of said cylinder 10 projects into a receiving chamber it, through the top of which extends an inlet chute [6.

The open lower end of the cylindrical chamber In extends into a burner box 20, into which is projected one or more burners 2| for gas, oil, or the like, the delivery ends of the burners being directed axially toward the incinerator I, in such manner as to project the flame into the open low r end of the latter. The burner casing rests upon a suitable platform 22, onto which the chamber I0 deposits the material which is discharged from the lower end thereof, said platform having a 5 chute 23 which communicates with the interior of a mixing apparatus 24, operated by a suitable motor 25. The mixing apparatus 24 may be of any suitable or desired construction, such as the common type of apparatus usually employed for mixing concrete. It is preferred however, to provide the mixer with a depending baflle 26, so as to trap the gases within the mixing chamber, said gases being withdrawn by a suitable blower 21, which discharges the gases into the burner cham- 15 ber l4. The outer end of the receiving chamber l4 discharges into a stack S. The mixer is provided with a discharge spout 28, leading from the upper portion of the mixing chamber, and which discharges onto a suitable conveyor 29, by which the material discharged from the mixer may be elevated to such a position that the material will be discharged into the chute I6.

The garbage is placed in a suitable hopper G, which communicates through a suitable conduit 30 with the discharge chute 23, so that at a position below the platform 22, the garbage will be intermingled with the heated granular material, as the latter travels from said platform to the mixer 24. By this means a preliminary mixing of the garbage and granular material is effected before they are delivered to the mixer 24 through said chute 23.

In operation, assuming that the burners 2| are lighted and functioning, an initial charge of sand, or other similar non-absorbent inorganic granular material, capable of withstanding high temperature without fusing, is fed to the conveyor 29 from a suitable source through a conduit 3!, said sand being elevated by the conveyor 29 and delivered to the interior of the chamber I0 through the chute l6. As the chamber I0 is rotated, the granular material is tumbled by a rotary motion and caused to travel downwardly toward the lower end of the chamber so as to be discharged through the chute 23 into the mixer 24. When the sand reaches the mixer 24, the apparatus has been primed. In this connection, it is to be understood that it is preferred to use good sharp silica sand, and a sufficient quantity must be initially introduced to insure continuing cycles of operation in a manner about to be described. As the sand travels through the chamber II), it will receive a high temperature due to the heat generated by the burners, which are directed toward the downwardly flowing material in such manner as to impart the desired temperature to the sand, but the heat must be regulated so as to avoid fusing temperatures, because fusing of the sand particles would greatly impair the operation. Obviously, as the granular material moves out of the sphere of maximum heating influence of the burners 2 I, the temperature thereof will begin to drop, and this drop of temperature naturally progresses during travel of said material through the chute 23 and the mixer 24.

As the heated sand is discharged into the chute 23, the garbage is fed to said chute from the tank G. The garbage may be fed in any desired form, but it is preferred to comminute it before placing it in the tank G. As the garbage leaves the conduit 30, it mingles with the traveling sand so that a preliminary mixture of sand and garbage is discharged into the mixer 24, where the constituents are more thoroughly mixed by agitation. The pressure created by the agitation within the mixer forces the finely mixed materials upwardly between the baffle plate 26 and the adjacent end of the mixer casing and out through the discharge spout 28 to the conveyor 29. During travel of the granular material from the platform 22 to the conveyor 29, the temperature of said material has fallen to a considerable degree, but remains sufiiciently high to elevate the temperature of the garbage material to such a degree that the lighter, more volatile constituents of the latter are vaporized, and the vapors are withdrawn by the pump 21. However, the temperature of the granular material is not sufiiciently high to drive off all of the moisture, and as a consequence the particles of granular material, as they are discharged into the conveyor have become surface-coated with} unvaporized moisture of the garbage. This moisture inherently carries inorganic matter in solution.

The conveyor 29 elevates the final heated mixture of garbage and granular material to such position that it may be discharged through chute l6 into the chamber l0. As the mixture travels downwardly through the incinerator, it is subjected to a temperature which is sufficiently high to completely dehydrate the surface coating of the granular material while the mixture is travelling through the upper part of said chamber l0. However, as the mixture travels downwardly through the chamber, the temperature maintained in the latter, i. e. an incinerating temperature, is such that as dehydration is completed, the organic constituents of the surface coatings, as well as the solid organic garbage constituents which are intermixed with the granular material are successively ignited and completely incinerated. Due to the interruption of an annular bafile 32 placed within the cylinder II], a constantly moving bed of fire back of the baffle is provided, with the result that complete combustion takes place in this zone. It is to be understood, however, that the temperature within the heating zone is never sufficiently high to fuse the sand or other granular material. The combustion is so complete that there is practically no residual organic matter left by the arbage, and the material which will be discharged from the lower end of the chamber will be practically dried heated sand, which is immediately again deposited upon the platform 22 for transfer into the mixer 24. From this point, the cycles become continuous and automatic, the sand and garbage being passed through the mixing and dehydrating, stages, new garbage being mixed with the sand as it flows through the chute 23. As dehydration and incineration take place during the travel of the mixture through the chamber, steam is produced which tends to reduce the odors, but if additional steam is required, it may be supplied to the receiving chamber [4 through a pipe 33, leading from a source not shown. As the dehydration continues, combustible gases are given off, which are ignited by the heat within the cylinder, and the same is true of the fumes delivered by the blower 21. These gases aid in the combustion of dehydrated residual material. The products of combustion pass to the stack through box [4. Should it be necessary to add fresh sand from time to time, it may be supplied through the pipe 3|.

If desired, sewage may be mixed with the garbage as it is introduced into the chute 23, leading to the mixer 24, as shown in Figure 4, wherein a tank 35 is connected by means of a pipe 36 with the conduit 30, so that the sewage may be commingled with the garbage as the latter is entrained with the sand passing from the incinerator to the mixer. In this manner, sewage and garbage may be simultaneously destroyed.

In lieu of feeding the garbage and sand through a mixer, the garbage may be directly fed to the chute l6, as illustrated in Figure 3, in which the garbage is supplied by means of a conveyor 36 leading to the chute l6 and joining with the delivery end of the conveyor 29. With this arrangement, the garbage and sand are intermingled as they are introduced into the chute l6, and a preliminary sand heating step is omitted.

The advantages of the invention will be readily apparent to those skilled in the art to which it belongs. An important advantage is that the non-absorbent granular material becomes surface-coated by such moisture content as remains with the garbage as it is introduced into the incinerator, thereby creating a condition which makes it easy to so control the passage of the mixture through the chamber that even dehydration is effected. Therefore, after the apparatus is once put into operation and the first cycle has been completed, less heat is required at the burner end than would otherwise be required, thereby reducing the chances of fusing the sand and yet insuring that the sand when it leaves the incinerator will be in a condition for immediate mixing with more garbage, so that a continuous hot sand cycle is provided. Another advantage is that as the garbage and sand mixture enters the chamber In, it will first give off its moisture near the upper end of said chamber and later will be completely incinerated as it approaches the lower end of the chamber, the combustible gases given off during this stage being capable of developing sufiicient B. t. u. to very materially aid in the destruction of garbage introduced during subsequent cycles. Another advantage is that the mixture of sand and garbage travels in a general longitudinal path, and that the burners project their flames in lines parallel with said path and at the terminal end thereof, so that the hottest zone in the incinerator is adjacent to its annular internal bafile.

Having thus explained the nature of the invention and described an operative manner of constructing and using the same, although without attempting to set forth all of the forms in which it may be made, or all of the forms of its use, what is claimed is:

1. A method of destroying garbage comprising heating a refractory non-absorbent granular material to a high temperature by causing it to travel through a heated zone maintained at a temperature below the fusing point of said material, recycling all of the non-absorbent material through said heated zone while the material is still in its heated state, mixing garbage with the hot non-absorbent material before the latter starts its recycling stage, and completely destroying the garbage by causing the temperature within said heating zone to incinerate the garbage constituents while the mixture of sand and garbage is traveling through said zone during said recycling stage, and discharging the recycled garbage-free refractory material from said heated zone in an unchanged granular state.

2. A method of destroying garbage comprising heating a refractory non-absorbent granular material to a high temperature by causing it to travel through a heated zone maintained at a temperature below the fusing point of said material, recycling all of the non-absorbent material through said heated zone while the material is still in its heated state, mixing garbage with the hot non-absorbent material before the latter starts its recycling stage, causing the mixture to move through said heating zone in such manner as to increase the temperature as the mass approaches the end of the recycling stage, causing the temperature within said heating zone to incinerate the garbage constituents of the mixture while said mixture is traveling through said zone and discharging the recycled garbage-free refractory material from said heated zone in an unchanged granular state.

3. A method of destroying garbage comprising heating a refractory non-absorbent granular material to a high temperature by causing it to travel through a heated zone maintained at a temperature below the fusing point of said material, recycling all of the non-absorbent material through said heated zone while the material is still in its heated state, mixing garbage with the hot non-absorbent material before the latter starts its recycling stage, imparting a rotary tumbling movement to the mixture during its travel through said heated zone, causing the temperature within said heating zone to incinerate the garbage constituents of the mixture while said mixture is travelling through said zone and discharging the recycled garbage-free refractory material from said heated zone in an unchanged granular state.

4. A method of destroying garbage consisting of mixing heated inorganic granular material with garbage in such manner as to provide the particles of granular material with surface coatings of unvaporized garbage moisture and to distribute garbage solids throughout the granular material, dehydrating said coatings and subsequently incinerating the organic constituents of said coatings and of the distributed garbage solids by subjecting the mixture to an incinerating temperature while passing through a heated zone.

5. A method of destroying garbage consisting of mixing heated inorganic granular material with garbage in such manner as to provide the particles of granular material with surface coatings of unvaporized garbage moisture and to distribute garbage solids throughout the granular material, conducting ofi any vapors which may be produced during the mixing stage, dehydrating said coatings and subsequently incinerating the organic constituents of said coatings and of the distributed garbage solids by subjecting the mixture to an incinerating temperature while passing through a heated zone.

6. A method of destroying garbage consisting of mixing comminuted garbage with a travelling mass of heated refractory granular material in such manner as to provide the particles of granular material with surface coatings of unvaporized garbage moisture and to distribute garbage solids throughout the granular material, causing the moving refractory material and garbage mixed therewith to travel through a heated zone, and dehydrating said coatings and subsequently incinerating the organic constituents of the coatings and the distributed garbage solids by maintaining said zone at an incinerating temperature while the sand is conveying the garbage therethrough.

7. A method of destroying garbage comprising heating a refractory non-absorbent granular material to a high temperature by causing it to travel through a heated zone maintained at a temperature below the fusing point of said material, recycling all of the non-absorbent material through said heated zone while the material is still in its heated state, mixing garbage with the hot non-absorbent material before the latter starts its recycling stage, dehydrating the garbage constituents and then incinerating the residual constituents by subjecting the mixture to an incinerating temperature while the mixture is travelling through the heated zone during the recycling stage of the refractory material, and discharging the recycled garbage-free refractory material from said heated zone in an approximately unchanged granular state.

8. A method of destroying garbage comprising heating a refractory non-absorbent granular material to a high temperature by causing it to travel through a heated zone maintained at a temperature below the fusing point of said material, recycling all of the non-absorbent material through said heated zone while the material is still in its heated state, mixing garbage with the hot non-absorbent material before the latter starts its recycling stage and in such manner as to provide the particles of granular material with surface coatings of unvaporized garbage moisture, and to distribute garbage solids throughout said granular material, dehydrating said coatings and subsequently incinerating the organic constituents of said coatings and of the distributed garbage solids by subjecting the mixture to an incinerating temperature while passing through said' heated zone during the recycling stage of said refractory material, and discharging the recycled garbage-free refractory material from the heated zone in an unchanged granular state.

HENRY H. MORETON.

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