US2678616A - Purification of incinerator gases - Google Patents

Description

May 18, 1954 ?D. KAY 2,678,616

PURIFICATION OF INCINERATOR GASES Filed Feb. 14, 1952 K V I 1 2 Y T 1 8 Y I? l "a? I0 i Zr Ps g ifigi Q1 Wm M fffia m Patented May 18, 1954 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to an apparatus and method for eliminating air contamination as a result of combustion. Where smoke abatement has been previously practiced, the apparatus employed has consisted of fly ash control units, electrical precipitators or Ozonorators, and other auxiliary machines which serve to extract from the products of combustion those foreign materials which constitute smoke. However, where such devices have been used they have been located adjacent the fire box, or source of smoke,

as a result of which they have been operated in the presence of high temperatures. The loca tion of these devices adjacent a source of high heat has preventedthem from operating at their maximum efficiency and created other problems which have strongly limited their satisfactory performance.

Accordingly, it is an object of the present invention to provide a smoke abatement means whereby the various units employed may be dis posed so as to provide a maximum operational emciency.

Another object of the present invention is to provide a smokeabatement means wherein the velocity of draught and the temperature of the gases passing through the various scavenging units may be held within optimum limits.

A further object of the present invention is to provide a smoke abatement means which may the use of a heater unit whereby the temperature of the smoke passing through the scavenging units may be controlled.

The invention consists of the construction, combination and arrangement of parts, as herein illustrated, described and claimed.

The accompanying drawing is a somewhat diagrammatic showing of a complete embodiment of the present invention, as applied to an apartment house incinerator system.

Referring to the drawing, N) indicates a furnace which may be the combustion chamber for either an incinerator, boiler, gas generating furnace, or the like, located in the basement or lowermost floor of a building. A stack ll leads from the furnace l0 upwardly through the building, and eventually above and beyond the roof l3 thereof. The various floors of the building have been diagrammatically indicated at I2, al though it is understood that the proportions shown have been arbitrarily chosen for the sake of clarity of the description.

At a level substantially above the fire box l6, and which is shown in the drawing as that of the roof is, there is provided an opening [4 in the stack l I. The gases of combustion, together with the smoke are led out of the stack l I through the opening M by a suitable duct 25. The duct 725 communicates with a suitable mechanical separator l5 which may be in the nature of a fly ash control unit or the like. Emerging from the separator l5, the smoke is led through a blower it which serves to maintain the draught in the stack H at a constant velocity, despite variations brought about, for example by the opening and closing of incinerator chute doors 2!. The constant velocity of the gases passing through the various scavenging units also makes it possible to operate said units at their maximum efficiency. Additionally, the location of the various units above and away from the fire box will insure a freedom from high temperatures prevalent in the furnace room, which tem peratures are detrimental to the operating eificiency of the scavenging units. 7

The blower l6 forces the smoke through the duct 26 into a heater unit ll. This unit I! may consist of either a series of coils 25 through which steam is passed, or electrical resistance units (not shown) capable of heating the air passed therebetween. The heater unit ll serves to maintain the smoke that passes therethrough at a constant temperature, despite variations in the actual temperature of the smoke which reaches the heater unit by way of the stack H and opening M.

As a result, the smoke which emerges from the heater unit ll is under complete control insofar as temperature is concerned, so as to achieve the maximum efiiciency from the electrical precipitator l8, Ozonorator or some heat medium, capable of burning the remaining particles therein, through which said smoke is passed after it leaves the heater H. The remaining gases are then allowed to return to the stack ll by way of the duct 21 and thereafter escape to the atmosphere in the usual manner.

In the event that it becomes necessary for any reason to by-pass the above described apparatus, there is provided a damper 23 in the stack ll between the openings 14 and 20, through which the smoke is normally passed in and out of said scavenging device. a In the normal operation and smoke abatement cycle, the damper 23 is in the closed position, shown in the drawing. As a protection against sudden excessively vhigh drafts within the stack l I, which draughts might interfere with the operation of the various units employed, there is provided a barometric damper 22 in the duct 26 immediatelybefore. the mechanical separator l5.

A second barometric damper 24 is located between the blower I6 and the heater unit 11. The operation of the barometric dampers is such that any sudden increase in draft, passingthrough the duct 26, will cause the dampers to swing open, admitting outside air and substantially checking the surge within the duct.

As an alternate form to the above, described smoke abatement mechanism and method, it has I been found that the smoke leaving the mechanical separator i has been purged of approximately 70% of the foreign matter therein. I-he remaining 30% may be dissipated to a degree which is well within the satisfactory operational limits, by means of introducing a streamofauxiliary air in the ratio of, for example, five to one. The auxiliary air may be introduced into the scavenging system at a point immediately beyond the blower it. air maybe-accomplished by means of louvres The introduction of the indicated at 28 by the dashed lines. Alternately, the barometric damper 24 may be employed for a this purpose.

'The remaining particles are thus dissipated within the mixture to such an extent that the smoke isinvisible as it leaves the stack. By

use of the stream of auxiliary-air it will he'possible to ;e1iminate the need for theheating unit 25 andthe costly electrical 'precipitator i8, or similar unit.

From the foregoing, it will be seen that there has been provided a smoke abatement device and furnace and vertically through floors ofabuilding in which ;the furnace is locatedand protrudingupwardly from the roof of ,the building,

, said stack having side inlets for said refuse material tobe treated located in-the building in cooperating relation to floors of the building, a

first duct connected with the stack and extending substantially horizontally from the upper portion of the stack above the roof of the building and constituting a bypass for products of combustion, smoke scavenging means within said duct, a blower associated with said smoke scavenging means adapted to create a regulated how of products of combustion outwardly from .said stack through said duct, an electric I precipitator communicating with the discharge end of said duct, a second duct connected at one end to the discharge end of the electric precipitator and at its other end being connected with a side of the stack above the first duct, and an ...impervious bafiie mounted in the stack between the first and second ducts and movable to opened 1 and closed positions.

.2. Ingan incinerator smoke abatement structure, a furnace, a refuse receiving and smoke conducting stack extending upwardly from said furnace and vertically through floors of aibuilding inwhich the furnace'is located and-protruding upwardly from the-roofof the building,

said stack having side inlets for said refuse material to be treated located in the building-in cooperating relation to floors of the building, a first duct connectedwiththe stackand'ex tending substantially horizontally from the upper; portion of the stack above the fioorofthe buildin with which the uppermost one of; said side inlets communicates; and constituting-a bypass for products of combustion, smoke-scavenging means within said first duct, a" blower in. said first duct associated with said. smoke scavenging means andadaptedtoicreate a regulated flow of productsoi combustion outwardly from said stack through said'first duct, a second duct connected at one end toithe. discharge end of said first ductand at its otheryend1 being connected with a side of the stack, above'said firstduct, and an impervious baffle mounted in the stack between the'first'and second ductsand .movable toopened and closed positions.

References Cited in thefile of'this patent UNITED STATES PATENTS Number Name Date 1,050,269 Walden j, 'Jan.;14,' 1913 1,508,331 Huberv -1 ..Sept.,9,;1924 1,651,636 Shaughnessy Dec. 6, 1927 2,161,412 Gregg etal. Junerfi, 1939 2,525,206 Clark Oct.. 1 0, .1950

FOREIGN PATENTS Number Country Date 109,105 Great Britain Sept. 5,1917

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