US2157993A - Incineration - Google Patents

Description

y 9, 1939- J. c. WOODMAN 2,157,993

INCINERATION Filed June 14, 1935 2 Sheets-Sheet 2 005000000 G U U 07 INVENTOR I JZ7'Jc;0/9 k/aadwa z I I 790M451; 'MQW MMM '0- a/WL IATTORIJVEYS Patented May 9, 1939 UNITED STATES PATENT OFFICE INCINERATION poration of Delaware Application June 14, 1935, Serial No. 26,661

Claims.

The present invention relates to incineration and more particularly to methods of and means for burning or incinerating materials, such, for example, as garbage and other waste material.

The principal objects of the invention are to provide novel and advantageous methods of and means for incineration. One of the more specific objects of the invention is to provide suitable draft in an incinerator of the vertical type with much lower forced draft air pressure than that required heretofore, thus effecting substantial economies. Another object is to provide for a freer feed of material down through the furnace chamber to grates at the bottom thereof. A further object is to provide grate structure whereby the burning material on the grates is thoroughly mixed and burned and fed to a discharge outlet.

According to a preferred embodiment of means for carrying out the invention, there is provided a furnace chamber that is relatively high to provide the necessary storage capacity and in which the material to be burned. is introduced at the top and gradually works down to the bottom where the burning is completed and the ashes and other residue, if any, are discharged in dry condition into a hopper so that they may be inspected before quenching. An important feature of the incinerator relates to the holding of material to be burned away from the side walls of the furnace chamber in such a manner that the horizontal cross sectional area of the storage space increases from the topof the furnace chamber to the bottom thereof. Preferably this effect is attained by the use of a plurality of sets of I vertically arranged tubes connected with a waterjacket to enable them to withstand the high temperatures in the furnace chamber. This arrangement aids the draft and also the burning and drying by permitting air and gases to pass upwardly at the sides of the furnace chamber, and facilitates the settling of the material to be burned as the material at the bottom of the furnace chamber is consumed on grates at the bottom of the furnace chamber.

Another feature relates to the grates located below the furnace chamber and on which the material to be burned is finally consumed. Pref erably the grates are made up of a plurality of grates or grate sections in the form of concentric circular or annular parts of which the upper surfaces slope to a central discharge opening, and these annular parts are rotated relatively to each other, as by rotating them in opposite directions. In this way the material at the bottom of the furnace will be thoroughly stirred up thus facilitating complete burning and discharge from the grates.

Other objects, features and advantages will appear upon consideration of the following description and of the drawings, in which Fig. 1 is a central vertical section of an incinerator embodying a preferred form of the invention;

Fig. 2 is a fragmentary section corresponding to a part of Fig. 1 but on a larger scale;

Fig. 3 is a section taken along the line 3-3 of Fig. 1; and

Fig. 4 is a section taken along the line 4-4 of Fig. 1.

Referring to the drawings, reference character Ill designates a furnace chamber of an incinerator of a vertical type. Preferably, as illustrated, the furnace chamber is circular insection and is relatively high to provide the necessary storage capacity for the materials to be burned. The section may take other shapes, for examplea rectangular shape. The walls of the furnace chamber are shown as formed by outer and inner plates II and I2, respectively, preferably of steel enclosing a water-jacket I3 surrounding the chamber and extending the full height thereof. It should be understood, however, that the water-jacket I3 may not extend the full distance between the top and the bottom of the furnace chamber, the remaining portions of the walls being of refractory material.

A suitable bottom for the water-jacket may be formed by a continuous welded steel plate I4 of U-section extending around the edges of the side plates I I and I2 and welded thereto at their outer sides. The top of the furnace chamber may comprise a lower steel plate I5 attached at its outer edge, as by welding, to the upper edge of the plate I2 and an upper steel plate I6 attached to the upper edge of the plate II, and both of the plates I5 and I6 may be annular in shape with their inner edges attached to the edges. of a vertically arranged tubular member I! providing an opening I3 through which the furnace chamber may be charged with the material to be burned. The plates I5 and I6 are separated sufficiently to provide steam space and this part of the waterjacket may serve as a steam and Water drum. Above the charging opening I8, there may be provided a feed hopper I9 having any suitable closing means such as a sliding door 20 operated by a power cylinder 2|.

At the inside of the furnace chamber provisions are made to hold the materials to be burned away from the inside surfaces of the walls of chamber than the next set immediately below the same so that the horizontal cross sectional area of the storage space between the pipes or tubes increases from the top to "the bottom, thereby facilitating the settling of the materials to be burned as they are consumed on grates referred to hereinafter. As' disclosed in the drawings, there is an upper set of tubes 22, an intermediate set of tubes 23 and a lower set of tubes 24, all of which are connected to the water jacket so that water will circulate therethrough and render the pipes or tubes capable of withstanding the temperatureswithin the furnace chamber. The lower set of tubes 24 is spaced above the'grates so that the material'may spread out on the grates.

The tubes 22, 23 and 24 may be connected with the water jacket E3 in any suitable manner as by providing at each end of each of these tubes an extension 25 passing through the waterjacket inside of steel tubes 27 expanded into the water-jacket walls and attached with union Ts 28 and elbows 29, and nipples 30to the outside plate I l of the water-jacket 53, thereby providing a flexible connection with a wall of the Water-jacket and ready means of cleaning the tubes due to the provision of washout plugs 31 in the 'Ts, In order to avoid gaps. in the protective arrangement of tubes, the sets of tubes are arranged to overlap slightly, such arrangement being made possible by arranging the tubes of successive sets alternately around the furnace chamber. As seen at the upper ends of tubes 22 and lower ends of tubes 24, in Fig.1, and as indicated in Fig.3, the nipple 30 connected from each union T 28 extends upwardly if the union T is connected with the upper end of one of said vertical pipes in the furnace, and downwardly if the lowerend of the corresponding union T is connected with the lower end of one of said vertical pipes, thus assuring good circulation. The unused openings of the union Ts 28 are closed as indicated in Fig. 3.

Near the top of the furnace chamber is located an opening 32. in the side wall through which the gases of combustion pass into a duct 33 which may leadthem to a proper sized gas combustion chamber" and/or a waste heat steam boiler. The

gases of combustion may then pass through an air preheater or regenerator for heating the forced draft air supply and on to the chimney. Certain of thetubes 22 and 23 enclosing the material to be burned provide a guard for the opening 32 and prevent obstruction thereof no matter how full the furnace chamber may be.

In the side walls of the furnace chamber are provided door openings 34 equipped with. door frames35, doors 36 and door liners 37. As illustrated, these openings 34 are located near the bottom of the furnaeechamber to provide, if necessary, access with firing tools to the burning materials on the. hereinafter described grates. Preferably all, openings in the water-jacketwalls are formed by fianging the inside and outside plates of the water-jacket and butt-welding their flangedportionsf g V V i g The furnace chamber I!) may be supported by means of brackets 3s attached thereto and resting on I-beams 39 supported by columns 40 form- I-bearn rings carried by the structural frame.

The upper and outer section 4| is formed of perforated sectional plates resting on radial supports 46 and held in position by suitable means which may include flanges 41 at the outer edges of the sectional plates. For reasons to be brought out hereinafter certain of these sectional plates are provided'with perforated ribs or raised portions 48 projecting above the-general surface of the grate.

The lower and inner, grate section 42 is also formed of perforated sectional plates resting on radial supports 49 and certain of these perforated plates are also provided with perforated ribs or raised portions 48. The sectional plates of the grate section 42 are held in position by suitable means including, for example, flanges 50 at the outer edges of these sectional plates. At their inside edges the sectional plates of the lower grate section 42 are provided with downwardly extending perforated portions forming 'a cylindrical portion 5| extending downwardly into the upper end of the ash hopper 43. r

The radial supports 46 of the upper grate section are mounted on the upper circular races of non-frictional bearings 52, such as ba'll bearings, of which the lower races are mounted on the radial members 49 supporting the lower grate section 42. Preferably the upper races have sides extending downwardly over the sides of the lower races to keep ashes from entering the space between the two races. Similarly the radial members are supported by non-friction bearings 53 of which the lower races are supportedbn I- beam rings 54 carried by the structural frame support of the furnace. At the outer end sof the radial supports 46 and 49, are twocircdlar racks 55 and 5 6, one rack 55 being attached tothe under sides of the radial supports 46 and the other rack 56 being attached to the upper sides of the radial supports 49. Between. the two racks is mounted a driving pinion 5'lmounted on a drive shaft 58 that is turned from outside of the furnace by any suitable means such as an electric motor through some speed reducing and/or controlling medium. In this waylthe two sections of the grates are rotated in oppo site directionsand, as the materials are burned to an ash or clinker, work them into, the discharge opening 42a at the center of the grates. It will be evident that the perforated ribs 48 assist in breaking up the material and working it toward the central discharge opening. The

' ribs 4&instead of being radial as illustrated, may

take other forms such as spirals or curved ribs adapted to workthe, material toward the center. However, one great advantage of the .radial are rangementis that the ribs will work equally well irrespectiveof the direction of rotation. ItJnay be desirable to varythe speed of rotation of the grate sections and to reverse the direction ofro}; tation periodically or as desired.

From the discharge'opening'fla in the center of the grates, the ash or clinker will fall into and accumulate in the ash hopper or chamber 43 which is equipped at its bottom with a substantially air tight gate or door 50 preferably operated by a cylinder 6! actuated by pressure fluid, such as air, oil, water or steam. In order to facilitate the clean burning of any material lodged in the ash hopper, the sides of the hopper are provided with air holes 62. When the ash hopper becomes filled with ash or clinker and it is desired to empty the same, it is necessary to hold back the material at the upper part of the hopper. For this purpose, use may be made of a plurality of plungers 63 movable horizontally through openings 65 in the sides of the hopper, by suitable means such as a cylinder 55 operated by fluid under pressure, such as air, oil, water or steam. The plungers 63 are to be moved into and across the ash hopper or chamber to restrict the opening and hold the materials up until burned, either when first starting the furnace or when at any time it is desired to restrict the downward move ment of the material.

During operation of the incinerator, the plungers 63 are normally partially or wholly withdrawn from the ash hopper t3, but, when the ash hopper becomes filled with ash or clinker, the plungers are forced into and against the burned material to hold up the material above them and the gate or door Bil at the bottom is opened to discharge the ash or clinker. Preferably the discharged material passes directly into an ash storage hopper 66 equipped With quenching nozzles or sprays 6? to throw water on and cool the ash and clinker, and this storage hopper is provided at its bottom with a gate or door 68 of a water collecting type and provided with a drain 69 for the waste water. The door 68 may be operated by means including a cylinder 10.

The whole grate mechanism, except for the driving unit and the drive shaft bearing, and all or a portion of the ash hopper or chamber immediately beneath the grates is encased by plates or walls lea forming a substantially air tight chamber H, receiving forced draft air through one or more ducts l2. To prevent the passage of the forced draft air into the furnace chamber ID between the top of the grates and the bottom of the walls of the furnace chamber, there is provided a water seal 7264 between the top of the grates and the bottom of the walls of the furnace chamber. This water seal may comprise a plate 13 extending around the top of the circular grates and downwardly into water in a trough 14 at the upper edge of the walls a of the air tight chamber H.

Inasmuch as some fine ash sifts through the grates into the forced draft air chamber ll beneath the grates, several air tight gates 15 may be provided between the forced draft air chamber and the ash storage hopper 56 whereby this fine ash may be discharged periodically into the ash storage hopper for ultimate removal with the main portion of the resulting ash and clinker resulting from the burning of the materials charged into the furnace chamber.

It will be evident that an incinerator constructed in accordance with the present invention has many advantageous features. The arrangement of tubes 22, 23 and 24 at the interior of the furnace chamber not only keeps the material away from the side walls of the chamber and prevents any possible closing of the gas outlet, but enables a good draft to be maintained at much less expense than would be involved in forcing the air through a mass of material extending completely across the furnace chamber all of the way up to the top of the mass. Also the arrangement of the groups of tubes so that the cross sectional area of the storage space in the furnace chamber increases from the top of the chamber to the bottom thereof tends to avoid any jamming of the material such as otherwise would be likely to occur, thereby assuring a free flow of the material down to the grates. Also a suitable stirring up of the material at the bottom of the furnace chamber to obtain complete burning of the material and discharge of the ash and clinker from the furnace chamber is effectively provided for by the arrangement of the grates in concentric sections sloping downwardly toward a central discharge and the relative movement between adjacent concentric sections. Although only two concentric sections are disclosed it is obvious that a larger number might be used.

Although the furnace chamber walls have bee described as formed of two steel plates properly stayed to form a water-jacket on all sides and extending the full height of the chamber or for a portion thereof, it should be understood that this part of the incinerator may be varied. For example, the walls of the furnace chamber may be lined at the inside of the water-jacketwith refractory materials, or they may be built of refractory materials surrounded on the outside with masonry and/or a steel plate casing. The top of the furnace chamber may also be varied, as by having the top become just a steam and Water drum with steel plate sides and top and bottom steel plate heads or by constructing the top of refractory materials surrounded on the outside with masonry and/or a steel plate casing, in which case there would be a separate steam or water drum connected with the water tubes.

It should be understood that various changes may be made and that certain features may be used without others without departing from the true scope and spirit of the invention.

Having thus described my invention, I claim:

1. In aparatus of the class described, the combination with a furnace chamber, an outlet for combustion gases at the upper part of said chamber and a grate at the bottom of said chamber supporting the material therein, of a plurality of sets of substantially vertical water-circulation pipes arranged at different heights in said chamber, the pipes in each set being arranged at intervals around the chamber and the cross sectional area of the storage space enclosed by the pipes increasing downwardly from set to set to facilitate the downward feed of the material, the lower set of pipes being spaced above the grate to allow the material to spread out there- 2.. In apparatus of the class described, the combination with a Water-jacketed furnace chamber, an outlet for combustion gases at the upper part of said chamber and a grate at the bottom thereof and supporting the material therein, of a plurality of sets of generally vertical pipes at different levels in said chamber and connected with such water-jacket at their upper and lower ends the pipes in each set being arranged at intervals around the chamber and the cross sectional area of the storage space enclosed by the pipes increasing downwardly from set to set to facilitate the downward movement of material.

3. An incinerator which comprises upright water-jacketed side-Walls, a chamber within the walls, a plurality of sets of upright tubes spaced inside of and connected to the water-jacket, whereby water may circulate through the tubes and water-jacket, said sets of tubes being arranged one above the other and forming a space in the central portion of the chamber for the burning of material which has a greater crosssectional area between the lower set of tubes than the set immediately above, means for introducing the material into the upper portion of the said space, a grate directly below the said space upon which the charge of material in the space rests, means for burning the material on the grate, and means for discharging ashes through the'central portion of the grate.

4. An incinerator which comprises upright water-jacketed side-walls, a chamber within the walls, a plurality of sets of upright tubes spaced inside of and connected to the water-jacket,

,- whereby water may circulate through the tubes and water-jacket, said sets of'tubes being arranged one above the other and forming a space in the central portion of the chamber for the burning of material which has a greater crosssectional area between the lower set of tubes than the set immediately above, means for introducing the material into the upper portion of the said space, a grate directly below the said space upon which the charge of material in the space rests, means for burning the material on the grate, an outlet for combustion gases in the comprises, charging means in the top of the furnac e chamber, a gas outlet from' the chamber near its top, grate mechanism providing the bottom of said chamber, a fluid-cooled openwork structure spaced inwardly from the side Walls and upwardly from said grate mechanism so arranged that the cross-sectional area of the space enclosed by the openwork structure increases downwardly from its top, said space being large enough to receive all material introduced through said charging means, the

spacing of the openwork structure above the grate mechanism enabling the material to spread out over thegrate mechanism and the interior shape of the openwork structure and its spacingfrom the side walls aiding the'upward draft through the furnace and the downward feed of material, and means for operating the grate mechanism to discharge ashes'and residual materialthrough a large opening in the grate.

JOSEPH C. WOODMAN.

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