US2119322A - Air inlet means for incinerators and furnaces - Google Patents

Description

AIR INLET MEANS FOR INGINERATORS AND FURNACES May 31,1938. HwEwlN 2 2,119,322

Filed Sept. 29, 1933 5 Sheets-Sheet 1 Ig 3 I M y v H. w. EWING 2,119,322

AIR INLET MEANS FOR INCINERATORS AND FURNACES Filed Sept. 29, 1933 5 Sheets$heet 2 l5 i 1a 0 E v HUU'S 'S'UH' i H. W. EWING May 31, 1938.

Y AIR INLET MEANS FOR INCINERATORS AND FURNACES s Sheets-Shet 5 0 1 m Mn; A m 2 a E: ZV fl/ 2 1 A A l 4 2?? 0 4 v 7 Z? 8 4. 9 -1 h 4 Z2? 2%? 6/? 4 2% m 2 E Z? Patented May 31, 1938 UNITED STATES PATENT OFFIQE AIR INLET MEANS FOR, INCINERATORS AND FURNACES 8 Claims.

The present invention relates to air inlet means for incinerators and furnaces and particularly to an inlet structure which is applicable as a unit to a combustion chamber wall for supplying air to the chamber to facilitate combustion.

The structure of the present invention is more particularly useful in connection with garbage burners or incinerators, so-called.

It has been found from experience, in regard to the operation of garbage burners, that air supplied through the ash and fire doors is .insufficient to promote proper combustion. thermore, where there is too much air supplied to garbage burners, oftentimes unburned trash is drawn up the stack and strewn over the landscape. I I

It has also been found that oftentimes the stack or chimney draft varies due to weather, climatic and other conditions, thus affecting the combustion of the garbage in the incinerators. The stack draft must be considered in connection with the successful operation of an incinerator and therefore the air supplied to the in-- cinerator should be varied in accordance with the stack draft.

Provision must be made to regulate to some extent the admitted air in accordance with the stack draft. Preferably such provision should be automatic, to thus eliminate the presence of an attendant or operator for a garbage burner or incinerator.

An object of the present invention is to provide an air inlet structure for air supply to an in-- cinerator which may, as a unit, be installed in garbage burner or incinerator of any commercial size, and which is self-contained, and which is automatic in operation.

Another object of the invention is to provide an air inlet structure with a throat opening to- 40 ward the combustion chamber, which throat is provided with. a downwardly directed air passageway for delivering air into the chamber above the grate andfor downdraft, together with means for admitting outside air to such passageway, and also with means for automatically cutting off or reducing the flow of air whenever the stack draft increases.

A further object of the invention is to provide an air inlet structure applicable to any size of commercial or household incinerator, which structure is provided with means for supplying air to the combustion chamber above the grate, and which structure has air inlet capacity for maximum size incinerators, together with means for reducing the air admission capacity when Fur:

the structureis applied to an incinerator of a size smaller than maximum.

A yet further object of the invention is to provide air inlet structure having air inlet means which structure may be applied as a unit to an incinerator or like combustion chamber, and which is installed in a wall of the incinerator.

A further object of the invention is to provide an air inlet structure, made as a unit and applied as a unit, which structure has an air capacity of such maximum amount as to enable application to the largest size of commercial or household incinerators and which may be as readily applied to smaller incinerators.

A still further object of the invention is to provide an air admission structure for incinerators and the like so constructed and arranged that it may be readily installed without requiring expert supervision.

The structure is provided with means for compensating air admission through the inlet which means may be adjusted to admit only the proper amount of air required for the particular size and conditions of use of the incinerator to which such structure may be applied. In other words, the structure is made with maximum air inlet capacity and means for adjusting such capacity to fit the particular installation, and when so adjusted, the air inlet capacity remains constant for that particular installation.

The above, other and further objects of the invention will be apparent from the following description, and accompanying drawings.

Embodiments of the present invention are illustrated in the accompanying drawings, and the views thereof are as follows:

Figure 1 is a front elevational View of an incinerator equipped with an air inlet structure embodying the principles of the present invention.

Figure 2 is an enlarged vertical sectional View through a portion of an incinerator wall, showing in side elevation an air inlet structure constructed in accordancewith the principles of the present invention.

Figure 3 is a vertical sectional View taken substantially in the plane indicated on the line III III of Figure 5.

Figure 4 is a sectional view taken substantially I in the plane indicated by the line IVIV of Figwe 6- V Figure 5 is an enlarged vertical sectional view taken through the illustrated structure, showing certain details of construction.

Figure 6 is an enlarged front elevational view of one form of unitary structure of the present invention.

Figure 7 is a rear elevational View of the form of structure illustrated in Figures 1-6 inclusive, made in accordance with the principles of the present invention.

Figure 8 is a fragmental vertical sectional view through an incinerator wall equipped with another form of air inlet which is made in accordance With the principles of the present invention.

Figure 9 is a fragmental horizontal sectional view through an incinerator wall taken substantially in the plane indicated by the line XX of Figure 8.

Figure 10 is a fragmental horizontal sectional view through an incinerator wall showing another form of air inlet structure of the present invention.

Figure 11 is an enlarged fragmental vertical sectional view through an air inlet structure of the form illustrated in Figure 10, and

Figure 12 is a vertical sectional view taken substantially in the plane indicated by line XIIXII of Figure 8.

The drawings will now be explained.

Figure 1 illustrates an incinerator, designated as A, which is representative of a well-known type of incinerator, from which extends the usual stack or chimney B. The term household type of incinerator is herein used as applicable to such incinerators as are applied to homes, apartments, hotels, clubs and like structures, while of course air inlet structure of the present invention is as readily applicable to large commercial type incinerators as it is to household incinerators.

One form of inlet structure of the present invention is constructed as a unit and, as herein illustrated in Figures 1-7 inclusive, comprises a frame I providing a door opening 2 which is closed by a door 3 hinged at 4 tothe frame. The structure herein illustrated shows the door opening 2 as being rectangular and the door 3 as being also rectangular. However, it is to be understood that the door opening and the door might of course be or" other shape, such as circular, as occasion may require.

Integrally formed with the frame I is what is herein termed a throat which is designated generally at C. The throat, in the present instance, is illustrated as rectangular in elevation, being formed with two side walls, a top wall, and a bottom wall. The top and bottom walls are inclined downwardly and rearwardly from the frame I so as to project admitted air downwardly toward the grate D of the incinerator A.

The throat is provided with a downwardly directed air passageway, attained, in the present instance, by making the throat C as a double walled structure, with the outer wall being designated at 5 and the inner wall at 6. These walls are spaced one from the other to provide passageway I. The side walls 5 and 6 are, in the form herein illustrated, connected by partitions 8 and 9 interposed between the walls 5 and 6 about medially of the height of the wall and which partitions slope downwardly and rearwardly. Such partitions therefore form, in the present instance, two air passageways. The walls forming the throat C are integral with the frame I with no provision for air admission except as hereinafter described.

The top of the outer wall 5 is provided with an elongated aperture II, and a duct structure I2 is suitably applied to the top III to overlie such aperture. The duct structure I2 is shown as rectangular in side elevation and with a horizontal upper surface. The duct structure I2 is placed against the upper margin of the frame I and is open at the front, as may be observed from Figure 4. Within the duct structure I2 there is provided an upstanding wall I3 which in length coincides with the length of the duct structure I2 and in height is less than the height of the duct structure.

A flap valve I4 is hinged on a pin I5 near the front margin of the duct structure I 2 and depends below the top margin of the upstanding wall or ridge I3. The lower margin of the flap valve I4 stops short of the upper surface of the top In of the outer wall C. A counterweight I6 is slidably mounted on a rod I'I secured to the flap valve I4. The counterweight I6 is secured in adjusted position on the rod I! by means of a set screw I8. The counterweight may be adjusted inwardly or outwardly with respect to the flap valve for normally maintaining such flap valve in open position with respect to the ridge or short wall I 3.

The frame I is, adjacent the front opening of the duct structure I2, provided with an opening I9 into which is let a grill structure 20, which structure is provided With a plurality of spaced ribs ZI forming gaps or air passages 22. Against the outer face of the grill structure 20 is applied a slide plate 23 which is provided with a plurality of ribs to coincide with the spaced ribs 2I,

and, when the plate is moved, to regulate the openings through the gaps 22. Such plate 23 is slidable along the grill structure 20 and is secured in adjusted position by means of a screw 24 passing through a slot 25 in the slide and threaded into the grill structure 20. A handle 26 may be provided on the slide to manipulate it. The grill structure 20 is secured in position in the frame by means of bolts 21.

The duct structure I2 is herein illustrated as made separately from the throat C and is provided with apertured wings 28 for receiving bolts 29 to attach the duct structure to the throat. Of course, the duct structure might be cast integrally with the throat if so desired.

The duct structure I2, therefore, admits outside air to the upper portion of the passageway formed between the walls 5 and 6 of the throat C.

Similarly, another duct structure 3!! is applied to the bottom of the outer wall 5 where it communicates with an opening 3| in such bottom. In like manner, the duct structure 30 is provided with an upstanding short wall or ridge 32, and a flap valve 33 pivoted on a horizontal pivot pin 34 provided with a counterweight 35 slidable on a rod 36. The frame I is, adjacent the duct structure 30, provided with a cutout part 31 in which is inserted a grill member 38 carrying a slide 39, both grill and slide being constructed as described with reference to the grill 2H and plate 23 of the duct structure I2 and operating in the same manner.

There are provided, along the under surface of the lower duct structure 30 and the upper surface of duct structure I2, flanges or ribs 40 to serve as anchors when the structure is applied to a masonry wall, as illustrated in Figure 2.

In manufacturing these structures it is contemplated that the grill 2E and slide 23 will be so proportioned as to afford maximum air capacity to the largest size incinerator to which the structure might be applied.

When such a structure, manufactured with maximum air inlet capacity, is applied to a smaller sized incinerator, garbage burner, or other furnace, the plate 23 is then adjusted to reduce the size of air passageway 22 to accommodate the structure to the particular installation. When such adjustment has been ascertained, by trial, the plate 23 may be fastened in adjusted position by tightening the screws 24 whereupon the maximum air inlet capacity for the particular installation is readily and easily fixed.

When the structure of the present invention is applied to an incinerator, garbage burner, or other furnace, the counterweights l6 and 35 are adjusted so as to maintain the flap valves I4 and 53, respectively, in open position with respect to the ridges l3 and 32.

In operation, when a mass of garbage is placed on the grate l), the same may be ignited by applying a match to some combustible refuse within the incinerator or garbage burner, whereupon the refuse matter ignites and combustion of the garbage follows. The draft through the chimney or stack B thus draws in air from the outside through the grills and the duct structures l2 and 55 which incoming air passes under the free margins of the flap valves and over the tops of the ridges l3 and 32, thence through the openings l2 and 3! and into the air passageway I between the inner and outer walls 6 and 5. Because of the downward direction of the tops and bottoms of the throat, the incoming air is directed downwardly against the piled up mass of garbage on the grate and thus tends to dry the moist garbage and facilitate combustion. The downward direction of the air passage creates downdraft within the combustion chamber which facilitates combustion and reduces smoke, and the stack draft therefore functions to draw in the outside air for combustion purposes. Should the stack draft increase to a point where it overcomes the eifect of the counterbalances I6 and 35, then such suction will close the flap valves against the ridges l3 and 32 and thus cut off air admission to the combustion chamber. Such cutting off of the air admission prevents too rapid combustion and cuts down the rate of combustion of the fire so as to eliminate fly ash.

The downward direction of the air prevents the escape of such air up the stack without first entering into combustion, and furthermore supplies sufficient oxygen to prevent smoke and to materially aid combustion.

Instead of applying the air inlet structure to the door frame structure, as heretofore described, such air inlets may be made as unitary structures and applied at different parts in the walls of the incinerator, garbage burner or like furnace.

Figures 8 to 12 inclusive show another embodiment of the present invention, and contemplate separate air inlet structure manufactured as units and applied in the masonry structure of the incinerator.

The form of the invention illustrated in Figures 8 and 9 discloses a fragm-ental portion of a wall 55 in which is installed a fire door 42 of typical form. Above and below the fire door 42 are installed air inlet structures including air duct structures 43 and 49 of box form which extend horizontally against the face of the wall 4| above and below the door 42, each of which is provided with a plurality of ducts extending rearwardly through the wall and opening into the combustion chamber of the incinerator. The ducts of the upper duct structure 43 are illustrated as consisting of pipes let into such structure 43 and which are embedded in the masonry walls. There are three such pipes shown, the middle pipe 44 extending rearwardly from the duct 43 perpendicularly to it, while the other pipes or ducts t5 and 45 are inclined relative to the duct 43 and are divergently arranged with respect to each other. For directing the incoming air downwardly, the inner ends of these pipes are bent downwardly slightly, as indicated at 41 in Figure 8 preferably at 45 angles.

The lower duct structure 49 is likewise of box form and is provided with a plurality of pipes or ducts 50 which extend through the masonry wall and open into the combustion chamber of the incinerator. Preferably, these ducts 50 are parallel. The discharge ends of such ducts are preferably flush with the inner surface of the incinerator wall.

Figure 12 is a vertical, fragmental sectional view through one of the duct structures 43 or 45. These duct structures, so far as the construction of the same is concerned, are similar, so that a description of one will apply to both.

One end of a duct structure is closed by an end wall 5!, while the other end is open at 52 to the atmosphere. Inwardly of the open end is an upstanding ridge or cross wall 53, while above this wall at 54 is pivoted a flap valve 55. This fiap valve 55, like the others heretofore described, is provided with a rod 55 on which is slidably mounted a counterweight 5'! for adjusting the operation of the flap valve 55 to the stack draft through the air duct structure. A stop 58 may be provided to limit the maximum outward swing of such flap valve.

Additional air inlet structures may be placed in other positions of the masonry wall of the incinerator, such, for instance, as the structures 59 and 6!! which are arranged vertically alongside of and spaced from the door 42. The struc tures 59 and till, one of which is illustrated in section in Figure 11, includes a box like portion 6i having its upper end closed at 62 and its lower end also closed by a wall 63. Adjacent the lower wall 53 is an air inlet opening 65. the air inlet opening 64 is a ridge or short upstanding wall 55. The upper portion of the air opening 3 may, if desired, be provided with an inturned ledge 55 which extends to the pivot 61 of a flap valve 68. others, is provided with a rod 69 on which is slidable a counterweight T0.

Extending rearwardly from the duct structure 5! is vertically disposed throat 7! having in it a vertical air space 72 of narrow width.

The duct structures 43, 49, 55, 5B and SI all operate and function in the same manner as described with reference to the duct structures l2 and 30.

It will be observed that the air inlet structures to means for supplying additional air to incinerators, and like structures, for aiding combustion reducing smoke and increasing the efficiency of such incinerator.

The downward direction of the incoming air prevents the escape of air in the stack without- Inwardly of r This flap valve, like the.

first entering into combustion, and as before explained, provides additional oxygen for the prevention of smoke.

The flap valves may be adjusted to different draft action, such, for instance, as the valves in the duct structures l2 and 43 may be adjusted to close by influence of a lower stack draft than the flap valves in the duct structures 30 and 49.

If any of the flap valves does not shut, then the fire will become intense and possibly crack the brick. Another disadvantage results from the excessive stack draft carrying unburned trash up the stack. This occurs, however, only when there is too much air within the combustion chamber.

The upper and lower downdraft air passageways direct the incoming air against the combustible mass at different heights in the combustion chamber and thus supply air in different quantities at different points in the mass. It may 50 happen that the incoming air through the upper passageway is drawn in at a greater rate than the air through the lower passageway, in which event the flap valve l4 might close against its ridge l3 without causing closing of the flap valve 33 against its ridge 32. In this event, part of the incoming air would be cut off, while another part would still be supplied to the combustion chamber for combustion purposes.

The counterweights l6 and 35 may be readily adjusted by removing the grills in front of such weights, whereupon the flap valves may be swung upwardly and outwardly as viewed in Figure 5, and the counterweights properly adjusted.

It will be observed that ,the inlet structure of the present invention may be readily applied to any incinerators or garbage burners, either of the bricked in or so called portable type, already in use, as all that is necessary to be done is to apply such structures to the wall of the burner and brick it in place as illustrated in Figure 2, whereupon the structure will be anchored in such wall.

The structure is self-contained in that it is provided with the proper air passageway and means for regulating incoming air by action of the stack draft. Furthermore, such structure may be manufactured to be applied to the maximum size garbage burner, and when applied to a smaller size is readily adjusted by means of the grill to such smaller size incinerator for successful combustion purposes.

When the air inlet structure shown in Figure 8 is used, the top and bottom ones 43 and 49 will be used without the side or vertical structures. When the vertical structures 59 and 68 are used, the top and bottom structures 43 and 49 will be omitted.

It will be observed that the air inlet structures of the present invention may be incorporated in the doorframe structure as a unit, or may be made as separate units, as illustrated in Figures 8 to 12 inclusive. In any event it will be observed that the air inlet structures are made as unitary structures and applied as such to the incinerator or furnace walls.

By making these air inlet structures as units, the need for expert supervision is eliminated, as any bricklayer may install such inlet structures in the walls of incinerators, or other furnaces, by following blueprints showing the position of such structures in such walls.

It is preferable that the upper flap valve be adjusted to be closed during the peak of burning.

The lower air inlet structures direct air against the mass of garbage which usually accumulates below the bottom margin of the door opening, and which mass is ordinarily soggy and, in many types of incinerators, remains unburned.

The throat Walls become heated during burning, and thus preheat, to some extent, the incoming air drawn in through such throats by the stack draft.

It will be observed that the present invention enables the direction of flow of the incoming air, automatically controls such inflow of air, and preheats such air.

Furthermore, the upper air passageways direct the incoming air against the top of the fire and thus cut down the creation of smoke.

The maintenance of a flap valve in normally open position allows admission of air into the incinerator during the time the garbage is not burning, to thereby absorb moisture from the garbage between burnings and dry the garbage for the next burning.

The invention has been described herein more or less precisely as to details, yet it is to be understood that the invention is not to be limited thereby, as changes may be made in the arrangement and proportion of parts, and equivalents may be substituted without departing from the spirit and scope of the invention.

The invention is claimed as follows:

1. A door structure for incinerators and the like, comprising a unit consisting of a door frame having a door opening therein, a door for said opening hinged to said frame, a throat extending inwardly from said frame about said opening, said throat having the top and bottom thereof inclined downwardly, said throat consisting of an outer part and an inner part, said parts being spaced one from the other to provide air passageway through said throat from front to back, downwardly inclined partitions between said parts at the sides of said throat to form upper and lower passageways, the top of the outer part having an air duct opening through it for air supply to the upper passageway, the bottom of said outer part having an air duct opening through it for air supply to the lower passageway, flap valves in said ducts, and counterweights on said flap valves to maintain the same normally open, said counterweights being adjustable to vary the responsiveness of said flap valves to draft conditions, said flap valves adapted to close by action of stack draft through the incinerator, the adjustment of said counterweights controlling the closing of said flap valves by the stack draft.

2. A door structure for incinerators and the like comprising a unit consisting of a door frame having a door opening, a door for said opening hinged to said frame, a throat extending rearwardly from said frame and having an air passageway therethrough inclined downwardly and reaiwvardly from said frame, an air inlet duct communicating with said passageway, a flap valve pivoted to swing about a horizontal axis within said duct, a ridge engageable by said flap valve to cooperate therewith to prevent air passage through said duct when said flap valve is against said ridge, and a. weight attached to said flap valve to maintain said flap valve normally away from said ridge, said flap valve being movable against said ridge in opposition to said weight by increase of stack draft through the incinerator, said weight being adjustable to vary the movement of said flap valve by the stack draft.

3. A fire door structure for an incinerator including a door frame and a throat extending rearwardly from said frame and about the door opening in the frame, said throat having an air passageway therethrough for discharging air above the incinerator grate, means for controllably admitting outside air to said passageway, and means for automatically stopping air travel through said passageway whenever the stack draft through the incinerator increases to a predetermined point.

4. In a device for supplying over-grate air to the combustion chamber of an incinerator; in combination, a door frame casing having as a part thereof an inwardly and downwardly extending box-like throat having top, bottom and side walls; said throat walls having air passages therethrough; said frame having a duct in its upper part communicating with an upper air passage and another duct in its lower part communicating with a lower air passage; a loaded flap valve in each duct adapted to swing inwardly by influence of stack draft; a bridge wall across each duct towards which said valve is moved by stack draft for reducing air admission as the draft increases and against which said valve abuts to stop air admission when the stack draft reaches a predetermined amount, and means for controlling the amount of air admitted to said ducts.

5. In an incinerator or garbage burner, an air inlet structure for supplying air to the combustion chamber of said incinerator or garbage burner, said structure including means providing an air duct opening into the combustion chamber above the bottom thereof, a depending freely swingable flap valve pivoted to swing on a horizontal axis for controlling air travel through said duct, means providing a ridge engageable by said flap valve to cooperate therewith to prevent air travel through said duct when said flap valve is against said ridge, a weight attached to said flap valve to maintain said flap valve normally away from said ridge under the action of gravity and normally opening said duct for passage of air, said flap valve being movable against said ridge in. opposition to said weight by increase of stack draft through the incinerator, and said weight being adjustable to vary the responsiveness of movement of said flap valve to the stack draft.

6. In an incinerator or garbage burner having a combustion chamber and a door opening intosaid chamber, means for supplying air to said combustion chamber, said means including air ducts opening into said combustion chamber above the bottom thereof, one of said ducts being open to outside air above said door and the other of said ducts being open to outside air below said door, a depending freely swingable loaded flap valve for each duct adapted to swing inwardly by influence of stack draft through said chamber, and means providing a bridge wall across each duct and adjacent the bottom of the duct toward which its valve is moved by stack draft for reducing air admission as the draft increases and against which its valve abuts to stop air admission to its duct when the stack draft reaches a predetermined amount.

'7. In a garbage burner, means forming a combustion chamber for the garbage, a fire door structure providing entrance to said chamber, a door frame structure provided with air admission means to said chamber opening to the outside air above said fire door and adapted to deliver air to said chamber at a point adjacent the upper part of the door, said frame structure being also provided with air admission means to said chamber opening to the outside air below said fire door and adapted to deliver air to said charm ber at a point adjacent the bottom of the door, flap valves hinged to said air admission means and positioned to close said air admission means to air entrance when the velocity of air entering the chamber exceeds a predetermined maximum, and means on said flap valves to normally maintain the same swung away from closing position.

8. A door structure for incinerators and the like comprising a door frame having a door open ing, closure means for said opening, means formed integrally with said door frame and extending rearwardly therefrom, air inlet means formed integrally with said last-named means, said inlet means being adapted to communicate at one end with the exterior of the incinerator and at the other end with the interior of the incinerator, and means within said air inlet means for controlling the passage of air therethrough, said controlling means being so designed as to cause variationsin the air passing through the air inlet means in inverse proportion to variations in the draft of the incinerator.

HUGH W. EWING.

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