US3043245A - Incinerators - Google Patents

Description

July 10, 1962 .1. w. HEBERT ETAL INCINERATORS Filed Feb. 17, 1955 IN V EN TORS f W 6 H w Ms 5 5 W 1 N mw m 0; WW Jm A w 3,043,245 I INClNERATGRS John W. Hebert and Paul R. Schubert, Bay City, and Henry L. Coies, Houghton, Mich assignors to Calcinator Corporation, Bay City, Mich.

Filed Feb. 17, 1955, Ser. No. 488,883 2 Claims. (Cl. 110-8) This invention relates to domestic incinerators and more particularly to a method of and means for removing smoke and odors from the off gases thereof.

As is Well known, in the normal operation of an incinerator which is employed to burn papers, trash, and garbage within a building, smoke and odoriferous fumes are given off as the products of combustion and proceed through a flue system to a chimney or the like whence they are discharged to atmosphere. Since the discharge or odor bearing fumes is obviously undesirable, particularly in areas of large population concentration some means of solving this problem has been sought ever since incinerators were first employed to burn refuse and garbage. The solution of the problem has been complicated by various widely variable factors such as the temperature within the incinerator at various stages during the combustion of refuse and garbage which in many cases must be dried prior to ignition. Dependent on the proportion of various materials charged to the incinerator, temperatures in the incinerator such as caused by the rapid burning of papers and other highly combustible materials will reach 1800 F. to 2000 F.; however, the normal or average temperature in the incinerator during combustion will be usually in the neighborhood of 500 F. to 575 F.

Adsorption agents have been introduced into incinerators without appreciable success since at higher temperatures within the range reached in the incinerator, the materials employed lose their adsorption properties and actually give off odors previously adsorbed, andin some cases will ignite and burn. Masking agents have been employed as counter-odorants; however, it has been determined that the odor supplants known masking agents as the temperature rises slightly above the average temperature in the incinerator and most masking agents are organic in nature and will not stand the temperatures developed in incineration. Further; since the fumes or gases bearing the odors are of a complex nature and vary with the material charged to the unit, filtration has been found impractical since it has not been possible to filter out the odor-bearing fumes.

It has been determined that odors in the olf gases are heavy in the drying stage of incineration prior to ignition and following the ignition period during a smouldering period. During the ignition period, however, when the temperatures developed within the incinerator and its outlet flue are in excess of 800 F., it has been discovered "that the odor is much diminished and when the temperatures reach 1000 F. the odor has disappeared from the OE gases of incineration. It is therefore believed that the odor bearing substances or fumes have been consumed at the high temperatures developed along with almost all of the smoke and the trash. a

One of the prime objects of the instant invention is to provide means for and a method of combusting odorbearing fumes and smoke during all stages of the incineration and thus reducing to a minimum or eliminating entirely odor and smoke in the off gases.

A further object of the invention is to design an incinerator with catalyst means designed, shaped, and looated with respect to other elements to provide an incinerator of the type mentioned in which catalyst means is an integral part of the incinerator unit.

3,hi3,245 Patented July 10, 1962 A further object of the invention is to design means incorporating a catalyst which permits the oxidation combustion of odor-bearing gases, smoke and the like at reduced temperatures which may be practically maintained for combusting or oxidizing undesirable elements in'the' ofi gases of an incinerator including a catalyst unit which may be readily reactivated and cleaned of tars and the like at a slightly elevated temperature by simply burning highly combustible materials such as paper in the incinerator unit and which can be readily removed and replaced where necessary.

Another object of the invention is to provide means for oxidizing or combusting odor-bearing gases and the like without flame by means of a catalyst which is maintained at an activation temperature by burner means.

A further object of the invention is to provide means of the type described which will operate satisfactorily in space which is ordinarily provided in conventional in cinerators.

A stil1 further object of the invention .is to design an incinerator of the type described which can be economically manufactured and maintained.

With the above and other objects in view, the present invention consists in the combination and arrangement of parts hereinafter more fully described, illustrated in the accompanying drawing, and more particularly pointed out in the appended claims, it being understood that equivalent changes may be made in the various elements which comprises the invention without departing from the spirit thereof or the scope of the appended claims.

In the drawings:

IFIG. l is a sectional side elevational view of an incinerator in accordance with the invention, the broken lines indicating the position of a cover or door in the catalyst unit when the charging door is opened.

FIG. 2 is a rear elevational View partly in section to show the various elements which comprise the invention.

FIG. 3 is a sectional elevational view taken on the line 3-3 of FIG. 4 illustrating the configuration of one of the catalyst saddles.

FIG. 4 is a top plan view of such a saddle member.

FIG. 5 is a top plan view of the secondary heating unit which is employed.

Referring now more particularly to the drawings and particularly to FIGS. 1 and 2 thereof in which we have shown a household incinerator similarto that shown in co-pending application, Serial No. 253,419, filed October 26, 1951, now Patent No. 2,715,880, for Refuse incinerators, a letter I generally designates our incinerator which includes an outer housing 8 provided with insulation 9.

Mounted within the housing 8 and spaced from the walls thereof is an inner casing 10 which defines the the charging door in Patent No. 2,696,178, to swing outwardly when the handle 18a is lifted. Openings 19 provided in the lower portion of the door frame admit suflicient air from the perimetral passage 11 to the combustion. chamber 14 to support combustion and a burner assembly B is shown in the front of the chamber 14 for dryingand igniting the materials charged. 7 V

The burner assembly B includes a regulating dial 20, a valve 20a into which a source of gas supply leads, and

' a burner head 22 which is disposed within a perforated able catalyst members comprising platinumv and or platilighter tube is obtained by removing the panel 26 in the front wall of the outer casing 8. Guides 27 support a reciprocable grate 28 which is actuated by a shaper'rod I 29 having a crank arm 30 in the usual manner. Underneath the grate is the conventional ash drawer 31 and a perforated'rear wall 32 is provided to partition the interior of the inner casinglt). Clearly the refuse will be charged'to the chamber 14 and the space 14a behind the wall or grate 32 will be open. The wall 32 is hingedly supported on a hook 33 on a unit C for eliminating the odor bearinggases, smoke, and' other unburned combustibles from the off gases which prior to the instant invention passed directly out of the flue F.

The unit C comprises an elongated housing ofgenerally rectangular section which includes a front wall 34, a rear wall 35, side walls-36, and a cover or topwall 37. The

unit C is mounted above the space 14a adjacent the rear Wall of the inner casing 10 as shown, the rear wall of the unit C having-a flue projection 38 which issupportedby a fitting 39 leading into the flue F which extends from outside the incinerator into the space 11 between the inner and outer walls 8 and 10 thereof. The lower portion of the front wall 34 is inclined rearwardly as shown andan opening 40 is provided therein to admit the produc ts'of. combustion to the unit C. Supported in the unit is a rectangular frame comprised of angle members 41 which support a screen 42. The screenftz supports a bed 43 of suitable catalyst members through which the off gases of combustion must pass and prevents flyash and other unburned particles from reaching and being deposited on the catalyst members.

When the oil. gases are admitted from the combustion chamber 14 directly'to the flue F as in all present day incinerators, they will contain varying amounts of odorbearing fumes and smoke dependent on the material charged to the incinerator. As noted, during the time when refuse and garbage are drying prior to ignition and after combustion when the ashes are smoldering, the fumes given off will be particularly heavy. During these stages of incineration, the temperature within the incinerator will be relatively low and insufiicient to burn or consume these fumes which will flow out of the incinerator to the chimney of the building in which the incinerator is located and thence to atmosphere to foul the air 7 in the; surrounding area. During the intermediate stage them off in the form of carbon dioxide, which is, of

Course, odorless; While it would not be economically feasible to provide a heating unit which would continuously heat theoif gases tothe extreme temperatures in this. range, we have discovered that by erhploying'asuit- 'able, catalyst in the pathof the gases, the temperature required to oxidize these gases will be materially lowered num oxide coated on a suitable catalyst carrier such as aluminum oxide or magnesium silicate are known, however, to our knowledge no one has ever before satisfactorily adapted catalyzing means to a household incinerator. H

We have found that a bed 43 of ceramic saddle members called berl saddles which are coated with platinum or platinum oxide will operate very satisfactorily. Such a member is shown in FIG. 3, the ceramic (porous Alundurn) core being indicated at 44 and the coating of catalytic material at 45. The saddles will oifer a minimum resistance to flow, have high catalytic activit and will withstand flash temperatures in the incinerator which my reach 1200 F; The instant saddles (see FIG. 3) were prepared by coating the'Alundum core with a solution containing .02 to .025 mg. of platinum per ml., the platinum being in the form of a neutral solution of platinum chloride. The saddles were thence heated to a temperature sulficient to reduce the platinum chloride to particles of platinum and platinum oxide which fused to the porous ceramic material. It has been determined that such a catalyst produced a good cleanup of dense fumes from burning garbage at a temperature as low as 375 F. when the fumes were proceeding through the catalyst I path for the gases proceeding through thebed. When andja; relatively complete combustion can be obtained without a flamerso long as: temperatures of from 575 F. 10: 100- are maintainedto, activate the catalyst. Suitsaddles of of an inch in length were used in the bed the pressure drop across adepth of five inches of the saddles was only .05 to .07 of an inch of water at a gas velocity of forty to eighty feet per minute so it will be seen that the gas flow-will not be severely restricted.

Mounted in the chamber 48 below the screen 42 is a burner 49 which is served by a gas supply line 50. I The fuel gas supplied is the same as that supplied to the com bustion burner head 22. The burner '49 is provided with longitudinally extending reduced heads 51a which have a plurality of. small longitudinal flame ports 51 the upper ends thereof, so thatthe flow of flue gases which is mixed with air coming through enlarged openings 52, 53, and 54 in the walls 8, 10, and 38 respectively will not tend to lift or smother the flame. Gases given off in the combustion chamber are deficient in air'tosupport com bustion at the burner 49, however, air from these. openings is mixed therewith to maintain good flames at the burner 49 suflicient to keep the catalyst at temperatures within therprescribed range (575-700 'F.). A valve (not shown) similar to the valve 20a and having a control such as at 20, is providedin the line 50 to permit the regulation of the heat provided by the burner 49 andv for most purposes the catalyst bed 43 will be maintained at a temperature of about 600 The member 55 is a pilot tube which maintainsv a pilot flame for lighting the burner 49 when a valve is operated to admit fuel gas through the line 50. The element 56 is a thermocouple which is electrically connected to such a valve to turn oif the gas supply in the event the pilot flame goes out for some reason.

. Provided in the front .wall 34 of the unit Cabove the bed 43 of catalytic members is an inlet 57 normally closed by a cover 58 which has an annular flange 58a overlying the edges of the inlet 57. The flange 58a has an eye 59 i which pivotally supports the cover on a trunnion 60 fixed on the front wall 34 of the unit C above the inlet 57. 'An'angular rod 61 having laterally turned ends 61a adapted to be accommodated in eyes 62 and 63 on the cover 58 and door =18 respectively isv employed to pivot the. cover 58 to open position (as shown in broken lines in FIG. 1) whenever the charging door 18 is opened.

This provides a free path for smoke and flue gases to reach the flue F when the charging door 18 is opened during operation of the incinerator and eliminates the possibility of smoke and the like backing up out of the door opening into the room in which the incinerator is located. The rush of air from the opening 15 to the inlet 57 and flue tends to prevent the smoke from rising out of the opening 15 when the door 18 is opened.

In operation after the burners 22 and 49 are lit and the chamber 14 is loaded with garbage, refuse, and the like the heaviest =fumes will be given off initially while the material is being dried prior to ignition. These fumes, which will have a very strong garbage odor, pass through the screen or grate 32 into the chamber 14a and thence through the opening 40 where they are mixed with air proceeding in through the opening 54. The screen 42 relieves them of flyash and any particular non-combustible matter prior to the time they reach the saddle bed 43. The saddle members may be superimposed one upon the other and will otter a large surface area for catalytic oxidation while offering relatively little resistance to the flow of the gases to the flue F. Flue gasses and fumes passing through the bed 43 which normally would require temperatures of 1000 to 1200 F. for combustion will be combusted at 575-700 F. Moreover, the heat provided .by their combustion will obviously tend to maintain the catalyst at the required temperature so once the catalytic combustion is started the burner 49 need supply very little heat to. the catalyst bed 43. Since the catalyst unit C is mounted entirely within the combustion chamber obviously it will be as well insulated as possible by the perimetral air space 11 and insulative material 9.

It should be apparent that we have perfected an incinerator which can be employed in large cities and will meet their rigid requirements relative to air pollution since, obviously the gas finally delivered to atmosphere will be substantially carbon dioxide.

The foregoing descriptive matter and drawings is in all cases to be interpreted as illustrative of the invention rather than as limiting the scope thereof. It is to be understood that various changes may be made in various elements of the invention wihout departing from the spirit thereof or the scope of the appended claims.

We claim:

1. In a garbage and refuse incinerator, a housing defining a combustion chamber, burner means in said chamber, a flue leading into said chamber, a casing mounted to cover the entrance to said flue from said chamber and depending therebelow, said casing having an opening therein opposite said flue, catalyst means in said casing below said latter opening, a burner in said casing below said catalyst means to maintain the same at a predetermined temperature, the casing having an opening in the lower end thereof admitting the ofi gases of combustion to said casing, a bypass opening door for the opening opposite said flue swingably mounted to swing out away from said casing, a charging door for said housing mounted to swing outwardly away from said housing, and means connecting said first mentioned door and charging door so that when the latter is opened the former will also be opened.

2. In an incinerator, an outer housing and an inner casing each provided with front, rear, and side walls and spaced one from the other to define a perimetral air passage around said inner casing, said outer housing and inner casing having aligned charging openings, a charging door hingedly mounted in the charging opening in the outer housing and swingable outwardly away therefrom, a burner within said inner casing in the lower front portion thereof, a fine leading out of the upper rear end of said casing, a depending casing including front and side walls mounted on the rear wall of said inner casing and having an opening so as to communicate with said flue,

said latter casing having also an inlet fitting in the front wall thereof opposite said first mentioned opening, a cover for said fitting hingedly mounted on said latter casing to swing outwardly away from said latter casing, a perforate member depending from said latter casing and dividing the interior of the inner casing below said latter easing into a combustion chamber and an off-gas collecting chamber, a screen spanning said latter casing intermediate its ends, a bed of generally superposed saddle members coated with a catalyst supported on said 1 screen, the lower end of said latter casing having an opening to pass gases from the collection chamber thereinto, a burner between said latter opening and screen mainatining said bed at a predetermined temperature, means for admitting fresh air to said latter burner, and an angular rod having laterally turned ends pivotally received on said charging door and inlet fitting cover to connect the same whereby said cover is opened to by-pass said 0135 gases to the flue directly from the combustion chamber when the charging door is opened.

References Cited in the file of this patent- UNITED STATES PATENTS Re. 18,622 Jones Oct. 18, 1932 1,137,424 Ricketts Apr. 27, 1915 1,509,674 Koehler Sept. 23, 1924 1,528,816 Cummings Mar. 10, 1925 1,796,501 erl Mar. 17, 1931 1,992,136 Wakefield Feb. 17, 1935 1,995,723 Van 'Denbu-rg Mar. 26, 1935 2,010,460 McKinley Aug. 6, 1935 2,121,733 Cottrell June 21, 1938 2,488,563 Sills Nov. 22, 1949 2,522,475 Walker Sept. 12, 1950 2,545,625 McKinley a Mar. 20, 1951 2,564,713 Miles Aug. 21, 1951 2,658,742 Suter Nov. 10, 1953 2,696,178 Hebert Dec. 7, 1954 2,711,139 Martin June 21, 1955 2,752,870 Short et a1. July 3, 1956

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