US2752869A

US2752869A - Incinerator

Info

Publication number: US2752869A
Application number: US267430A
Authority: US
Inventors: Jr Thomas J Keenan
Original assignee: OAKLAND SCAVENGER Co
Current assignee: OAKLAND SCAVENGER Co
Priority date: 1952-01-21
Filing date: 1952-01-21
Publication date: 1956-07-03
Anticipated expiration: 1973-07-03

Description

July 3, 1956 T. J. KEENAN, JR

INCINERATOR 5 Sheets-Sheet 2 Filed Jan. 21, 1952 IN VEN TOR.

THOMAS J. KEE/VA/V JR.

A T TORNE Y5 y 3, W56 T. J. KEENAN, JR 2,752,869

INCINERATOR Filed Jan. 21, 1952 5 Sheets-Sheet 3 INVENTOR. T'NOfl MS J- NEE/VA/VMW.

Jufly 3, 19% "r. J. KEENAN, JR

INCINERATOR 5 Sheets-Sheet 4 Filed Jan. 21, 1952 July 3, 1956 T. J. KEENAN, JR"

INCINERATOR Filed Jan. 21, 1952 5 Sheets-Sheet. 5

INVENTOR. THOMAS J. NEE/VAN JR humaami /MMM ATTORNEYS llNClNERATOR Thomas J. Keenan, Jr., Oakland, Calif., assignor to Oakland Scavenger Company, Oakland, Calif., a corporation of California Application January 21, 1952, Serial N0. 267,430

7 Claims. (Cl. 110-7) This invention relates to new and useful improvements in refuse incinerator and constitutes an improvement over Patent No. 2,481,504, issued September 13, 1949, to Ferro et al.

The instant invention employs a plurality of traveling grates arranged so that refuse is dumped onto the uppermost grate at the rear of the combustion chamber, is moved forwardly on said grate and is discharged therefrom onto the next grate in order, each succeeding grate being at a lower elevation than the preceding one. A fuel such as gas or oil is injected adjacent the lowermost grate, and the heat of the burning refuse, together with the heat of the fuel injected is used to evaporate moisture and burn the refuse on the grates at higher elevations.

One feature of this invention is the fact that the roof of the chamber in which the grates are installed is stepped, and at the rearward end of each step a drop wall is provided downwardly disposed at an angle of approximately 45 to the juncture of the riser of the next step in order. This construction hereinafter described in detail, promotes turbulence of the gases within the incinerator and thereby avoids stratification of the air and gases within the chamber and improves combustion by insuring thorough exposure of the refuse to oxygen.

Turbulence is also increased by the provision of hot air inlet nozzles in the side walls of the chamber adjacent the grate surfaces, said nozzles being staggered in angu lar relation so that all areas of the grate surface are subjected to blasts of air, and the zones of the grates intermediate the side walls are subjected to an equal amount of air with the zones adjacent the side walls. The combination of drop walls and air nozzles which has been described insures better combustion than is present in incinerators of the general type of the present inven tion which have heretofore been employed.

Another feature of the present invention is the employment of louvers forming the floor of the combustion chamber immediately beneath the grates. Said louvers are arranged to be tilted periodically, so that the fines and non-combustible material may be discharged from the floor beneath the grates.

Beneath the louvers and extending below the combustion chamber for approximately the full length thereof is a continuous conveyor which receives the sinter discharged from the lowermost grate and also receives the fines which drop when the louvers are opened. A water spray system is provided to quench the hot material on said conveyor so that on the discharge of the said conveyor said material may be safely handled. Said conveyor is preferably made of sectional steel pans so constructed that intermediate the ends of said conveyor a substantially uninterrupted imperforate surface is provided.

Another feature of the instant invention is the fact that each grate of the series of grates is individually t driven, with adjustable speed. This feature is of im- 2,7523% Patented .lluly 3, 1956 portance in that it has been found that various types of refuse vary in consistency from day to day and hence it is important that the grates be adjustable so that their velocity may be suited to the condition of the refuse being handled at any particular time.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings in which similar characters of reference represent corresponding parts in each of the several views.

In the drawings:

Fig. l is vertical longitudinal midsection through the interior of the combustion chamber.

Fig. 2 is a transverse vertical section taken substantially along the line 2-2 of Fig. 1.

Fig. 3 is a side elevation of the exterior of the combustion chamber.

Fig. 4 is a fragmentary vertical section of the side wall of the combustion chamber showing an enlarged detail of one of the over fire air ports, taken substantially along the line 44 of Fig. 1.

Fig. 5 is a section similar to Fig. 4 showing another of such over fire ports, taken substantially along the line 5-5 of Fig. 1.

Fig. 6 is similar to Fig. 4 showing another such over fire air port, taken substantially along the line 6-6 of Fig. 1.

Fig. 7 is a fragmentary sectional view of a portion of the drop wall of the roof construction showing a drop wall nozzle detail.

Fig. 8 is an enlarged side elevation of the linkage system for tilting the louvers.

Fig. 9 is a fragmentary vertical longitudinal mid-section through the interior of a modified combustion chamber.

Fig. 10 is a side elevation of a portion of a conveyor employed in connection with this invention.

Fig. 11 is a transverse vertical section taken substantially along the line 11-11 of Fig. 10.

The instant incinerator is designed primarily for a relatively large scale operation wherein garbage, trash, and other industrial and household refuse is collected by scavengers in trucks; useful materials are salvaged; and the remainder is incinerated. Complete combustion of the refuse is essential for the avoidance of objectionable odors and smoke and further to eliminate the problem of disposal of matter which is not completely burned. Accordingly, there is provided a long narrow combustion chamber 2% having exterior side walls 21, a front wall 22, and a rear wall 23, and a roof 24 of novel construction. In the region of the combustion chamber all said walls are formed of refractory material. Said roof 24 is stepped upwardly from front to rear at different elevations which are hereinafter disclosed. A riser 27 is provided at the front of each step 28, said riser extending down substantially below the level of the horizontal portion of the roof step in front of said riser. An angularly disposed drop wall 29 joins the bottom of said riser with the horizontal stretch of the stepped roof portion in front of said riser, said walls 29 making about a 45 angle with the horizontal. The roof configuration is best shown in Fig. 1, it being apparent that the top of combustion chamber 20 is broken up by the steps 28 and angularly disposed drop walls 29. The function of this arrangement of the roof of the combustion chamber is to break up the path of the hot gases passing from the front of the chamber to the rear and promote turbulence, thereby preventing stratification of the gases within the combustion chamber and to effect the impingement of the hot gases upon the material on the grates. The roof and sides of the combustion chamber may be supported from external vertical and

horizontal beams

31 and 32, respectively.

Refuse is deposited in hopper 33 at the rear of the combustion chamber above the roof thereof and is carried by a horizontal movable belt 3 to chute 36 which extends downwardly at the rear of the uppermost grate 37 of the series of grates 2d. A wall is provided to impede gases tending to discharge upwardly through chute 36.

Each traveling grate 2'6 is supported horizontal at its upper and lower stretches by a plurality of transverse, horizontal, idler rollers which rollers prevent sag of the grates. Rollers 4!. pass through side walls 21 and are journalled on the exterior by pillow blocks 42. Sprocket 43 at the forward end of grate 2-6 is driven by shaft 44 which extends out through side wall 21 and is driven by motor as. Said motor is adjustable in speed so that the rate of travel on the grate 26 may be controlied. Each grate 2s proceeding from rear to front of the incinerator chambers 28 is stepped downwardly at a lower elevation, its rearward end extending under the forward end of the preceding grate to receive all the material discharged therefrom. It may be understood, as has heretofore been stated, each grate of the series of grates is individually driven and controlled.

interior side walls 21 and walls 47 close olf on an air duct 28 which extends longitudinally along each side of the exterior of combustion chamber 2'9, the air in said duets being preheated by means of conventional heat exchanger or pre-heater (not shown). A plurality of ports 51 is formed in interior side wall 21 communicating from said duct 48 to combustion chamber 25) as shown particularly in Figs. 2, 4, and 6, there being a set of nozzles 52 for each grate disposed in each side wall 21 opposite each grate 26 and above the level of the upper stretch. The angle which respect to the vertical of each nozzle 52; of each set of nozzles, as shown particularly in Figs. 4-6 varies. Therefore, the distance out from the side wall and toward the center of the grate at which air is directed varies for each nozzle and the resultant of the plurality of nozzles 52, 52a, 52b, and 52c, is to subject the entire upper stretch surface of grate 26 to air blast. Combustion is thus uniform throughout grate Z5 regardless of the distance from the side walls. It will be understood that air is supplied through ports 51 under draft from blower not shown) and controlled by suitable valves (not shown).

As has been stated, grates 26 are staggered in elevation, the highest grate 37 being at the back and the lowermost 53 being at the front of the combustion chamber 20. Vertical bulkheads 54 are disposed at the rear end of each grate 26, said bulkheads and normally closed louvers 56 forming a stepped floor d7 beneath grates 26.

Over fire nozzles 61 are disposed in front wall 22, and directed toward lower most grate 53, said nozzles being oil or gas fired as desired. The flame of said nozzles 61 ignites the refuse on said lowermost grate 53 and the heat of the burning refuse evaporates the moisture in the refuse and initiates combustion. The heat rising from lowermost grate 53 is carried upwardly to the grates 26 disposed rearwardly and evaporates the moisture of as well as burning the refuse thereupon. The spent hot gases may be discharged from the combustion chamber through opening 62 in side wall 21 over uppermost grate 37, and after subsequent treatments which are optional and form no part of this invention escape up the stack (not shown) to atmosphere. It will be understood that the heat of combustion within combustion chamber is such that the stack gases are free of odor and smoke, and hence, do not constitute a nuisance to the neighboring community. To insure against the escape of objectionable odors and smoke, standard precipitators and scrubbers and the like may be employed as required.

Lowermost grate 53 discharges through opening 63 .4 adjacent the front of combustion chamber 20 and the spent refuse drops upon the top stretch of upwardly and rearwardly moving conveyor 66, which preferably extends below combustion chamber 29 for the full length thereof. Said conveyor 66, which may be of the type known as the No Leak apron conveyor manufactured by Link-Belt Company, is made up of a plurality of connected steel pans 67 linked together and passing over sheaves 63 at each end through which the conveyor is driven. Said conveyor on is so constructed that the refuse and moisture deposited thereon does not pass through, but is held in the individual pans 67 which make up the conveyor. Each said pan 67 comprises a substantially rectangular bottom 82 and upwardly, outwardly diverging sides 83. The sides 33, as best shown in Fig. 30, have their front and rear edges 84 upwardly diverging. The adjacent pans 67 are interleaved, as best shown in Fig. 11, so that a tight joint is obtained. The forward and rearward edges of the bottom 32 are formed with a roll $6 which likewise facilitates forming of a tight joint and also facilitates locking and unlocking of the pans 67 as the conveyor passes around the end sprockets 68. Each of the pans 67 is mounted on a continuous conveyor chain of the link type 87 which has an adapter link 88 connected thereto. The chains 37 are connected at alternate links to wheels 89 supported by tracks 91. Accordingly, the chain 87 is advanced by its driving sprocket and supported by wheels 89 running on tracks $31. In its straight stretches, the rolled edges 36 of the adjacent pans are in tight contact, which prevents air or water passing through the conveyor, and the side edges 33 are likewise interlocked. However, at the turns around the sprockets, the pans are capable of unfolding to permit the turning movement. Disposed above the conveyor 66 are water pipes as provided with spray heads 71 arranged to spray water upon the pans e"; and thus quench the hot spent material thereon so that w ten the material is discharged at the end of the conveyor 66 into discharge hopper 72 it is relativ-my cool and may be conveyed away without fire hazard.

Below grates 2.6 and closing off said grates from conveyor 66 is horizontal stepped flooring 57 made up of vertical bulkheads 54 and a plurality of normally approximately horizontal disposed, transverse louvers 56. When in closed position said louvers overlap and provide a continuous flooring beneath grates 26 upon which fines dropping from grates 26 are collected. Said louvers are supported by tiltable transverse, horizontally disposed square shafts 76 extending out through side walls 21, each said shaft 76 being attached to round shaft 77 the outer end of which bears crank '73 which is in turn fastened to horizontally slidable link 79. It will be seen particularly with reference to Fig. 1 that louvers 56 are arranged in horizontal stretches corresponding to the horizontal grates 26. All of the louvers 56 in a given stretch are connected to a single link '79. Thus, by sliding link 79 all of the louvers of a stretch are tilted simultaneously and accordingly the fines drop onto pan conveyor 66, and are ultimately carried out to discharge hopper 72. The tilting of the louvers 56 thus enables cleaning of the floor 57 of combustion chamber 20 when required without interference with operation of the incinerator. In closed position said louvers 56 overlap slightly and are approximately horizontal and prevent air or gases within the incinerator chamber 20 from escaping. It will be noted particularly with reference to Fig. 2 that beneath louvers 56 slanting side skirts 81- direct the fines dropping through louvers 56 toward the center of the structure and onto pan conveyor 66.

Operation Refuse is deposited in hopper 33 and continuously carried by conveyor 34 to chute 36 Where it drops down to the rear of the uppermost moving grate 37. The refuse subjected to hot gases liberated in lower steps of incinerating chamber 2! which vaporize moisture and initiate combustion of the combustible material in the refuse. The speed of the grate 37, as well as the subsequent grates upon which refuse is disposed, is regulated so as to accomplish most complete combustion being regulated to suit and accommodate the type and composition of refuse handled at any particular time. As required, external heat may be applied in the form of gas or oil fuel through nozzles 61. Heated air is forced across the upper stretch of the grate 26 to support combustion of the combustible material through ports 51, nozzles 52 thereof disposed in such fashion as to subject the entire surface of grate 26 to air. Air to support combustion and promote turbulence is also forced through roof nozzles 61. Refuse is discharged from the forwardrnost end of each grate onto the rearmost end of the next lower grate in order, and thence from step to step to lowermost grate 53 which in turn discharges through opening 63 onto rearwardly moving pan conveyor 66 which moves the sinter up to discharge hopper 72, the sinter meanwhile being subjected to quenching action of water spray 71. As fines collect on top of louvers 56 from time to time the attendant tilts louvers 56 by longitudinal movement of links '79 whereupon the fines drop onto conveyor 66.

A modified form of incinerator chamber is shown in Fig. 9. it will be observed that instead of the grates 26 being disposed horizontally, said grates are inclined at an angle of approximately with respect to the horizontal. It will be understood that the angle selected may vary depending upon the class of material being handled. Refuse travels down the sloping grates and is subjected to a more complete combustion by reason of the greater area of burning surface and the angle with respect thereto at which the gases impinge upon the grate surface.

I claim:

1. An incinerator for refuse comprising means forming an elongated incinerator chamber, a roof for said chamber having a series of steps stepping downwardly from rear to front, formed by substantially horizontal portions, substantially vertical riser portions, and angularly disposed connecting portions downwardly inclined from the rearward end of each horizontal portion to the bottom of the adjacent riser, a series of stepped traveling grates within said chamber corresponding to said steps of said roof, the forward end of one grate being arranged to discharge upon the rearward end of the next lowermost grate, said vertical risers terminating a substantial distance above the grate underlying said risers to permit flow of combustion gases from the lower to the upper grates, means for supplying air to support combustion to said grates, means for feeding refuse to the rearmost grate, and means for removing sinter.

2. An incinerator according to claim 1 which further includes a series of air ports in each side wall of said chamber elevated above each of said grates, each air port of each series being disposed at a different vertical angle directed at a difierent zone of said grate so that the sum of the transverse areas of the grate toward which said air is directed by each of said ports comprises the entire grate, and means for supplying heated air to said ports.

3. An incinerator comprising a plurality of traveling grates, each grate from rear to front being at a lower elevation and arranged to receive the discharge from the next upper grate, means for depositing refuse on the uppermost grate, means for conveying away sinter from the lowermost grate, walls forming a chamber about said grates, a roof for said chamber, said roof being stepped correspondingly to said grates, the rearmost part of the longitudinal stretch of each step of said roof being inclined downwardly and rearwardly at about a 45 angle to break up stratification of gases within said chamber and promote turbulence within said chamber, the lowermost portion of each step being elevated a substantial distance above the underlying grate to permit turbulent flow of gases over the top of each grate from the bottom to the top of said chamber.

4. An incinerator according to claim 3 which further includes air nozzles in said roof at certain of said downwardly inclined parts communicating with the interior of said chamber and directed downwardly toward said grates and means for supplying air to said nozzles.

5. An incinerator according to claim 3 which further includes a series of air ports in side walls of said chamber above the level of each of said grates, each air port or" each series being disposed at a different vertical angle directed at a different zone of said grate and means for supplying air through each of said ports, said ports being directed to discharge air to sweep the entire area of the top stretch of each grate.

6. An incinerator according to claim 3 which further includes air ports in side walls of said chamber above the level of each said grates, means for supplying air through each of said ports to sweep the entire area of the top stretch of each grate, and air nozzles in said roof at certain of said downwardly inclined parts, said nozzles communicating with the interior of said chamber and directed downwardly toward said grates, and means for supplying air to said nozzles.

7. In a refuse incinerator, means forming an elongated incinerator chamber, a stepped series of traveling grates in said chamber arranged so that each grate discharges upon the next lower grate, a plurality of transverse louvers below at least one of said grates arranged so that in closed position said louvers form a continuous, air-tight floor beneath said grate closing the bottom of said grate against the entrance of excess air from the underside of said grate, means operable to tilt said louvers from closed position to permit discharge of fines through said louvers, a movable water-tight conveyor beneath said louvers positioned to receive the discharge of fines through said louvers, the upper longitudinal run of said watertight conveyor being substantially impervious to water passing downwardly thereon from above, said conveyor extending beneath the discharge end of the lowermost of said grates to receive the sinter discharge theretrom, and a Water spray disposed above said conveyor and directed toward said watcrtight conveyor to quench materials thereon.

References Cited in the file of this patent UNITED STATES PATENTS 105,317 Dee July 12, 1870 231,208 Bresnahan Aug. 17, 1880 344,631 Craney June 29, 1886 468,482 Loughran Feb. 9, 1892 676,930 Woes June 25, 1901 837,887 Rock Dec. 4, 1906 839,754 Hall Dec. 25, 1906 1,240,737 Lamb Sept. 18, 1917 1,376,843 Underwood May 3, 1921 1,388,714 Hofmann Aug. 23, 1921 1,447,681 Michie Mar. 6, 1923 2,060,067 Greenwalt Nov. 10, 1936 2,389,077 Peterson .d Nov. 3, 1945 2,481,504 Ferro Sept. 13, 1949 FOREIGN PATENTS 568,160 Great Britain Mar. 21, 1945