US2693775A

US2693775A - Ash handling apparatus

Info

Publication number: US2693775A
Application number: US143653A
Authority: US
Inventors: Bernard C Berry
Original assignee: Allen Sherman Hoff Co
Current assignee: Allen Sherman Hoff Co
Priority date: 1950-02-11
Filing date: 1950-02-11
Publication date: 1954-11-09
Anticipated expiration: 1971-11-09

Description

Nov. 9, 1954 Filed Feb. 11. 1950 B. c. BERRY 2,693,775

ASH HANDLING APPARATUS 3 Sheets-Sheet l 5 m gig 7 330 3? l LF /&

I x- I I I O l i I |I I 1- nsaf' IA 'ENTOR. BERNARD C- BERRY ATTORNEYS Nov. 9, 1954 B. c. BERRY ASH HANDLING APPARATUS s Sheets- -Sheet' 2 Filed Feb. 11. 1950 .MH I w 2. Hm llllllllll I- O a J 4.. i E H. a u 9 IH M /M .T 0 7 m 1 5 INVENTOR. BERNARD 05am) ETTOENEYS Nov. 9, 1954 B. c. BERRY ASH HANDLING APPARATUS 3 Sheets-Sheet 3 Filed Feb. 11, 1950 INVENTOR.

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United States ASH HANDLING APPARATUS Bernard C. Berry, Philadelphia, Pa., assignor to The Allen-Sherman-Hotf Company, Philadelphia, Pa., a corporation of Pennsylvania Application February 11, 1950, Serial No. 143,653

6 Claims. (Cl. 110-165) This invention relates generally to the art of handling solid materials, and more particularly to novel apparatus for handling ashes initially in the form of slag from powdered fuel burning furnaces in which a positive or a negative gas pressure exists in the combustion chamber.

Considerable difficulty has been experienced heretofore in the handling of highly heated, non-gaseous products of combustion from the large furnaces of steam generating plants. This problem became important when these furnaces were so constructed that the ash hoppers were exposed to radiant heat of the combustion chambers of the furnace. When attempts were made to protect the refractory linings of the hoppers from the radiant heat of the combustion chambers by means of water in the hopper, an important difliculty was encountered. Since the water in the hoppers was discharged when the ashes were removed, the hopper linings were alternately heated by the high heat of the combustion chamber and quenched by cool water, and this repeated and extensive change in temperature was often more destructive to the hopper linings than the heat alone.

The foregoing difliculty has been greatly increased in the modern powdered fuel burning furnaces in which a gas pressure greater than or less than atmospheric pressure is maintained in the combustion chambers. The non-gaseous products of combustion in such furnaces are largely in the form of molten slag which either drops directly into the hoppers or collects on the walls of the combustion chambers at the outlets from the chambers and from time to time breaks offand falls into the hoppers in the form of large chunks of highly heated solid or semi-solid ash. Since the combustion chambers are open directly above the hoppers, the linings of the hopper walls are subjected to the extremely high heat of the combustion chambers, and must be protected therefrom if the linings are to have a reasonable length of service life. Furthermore, since in some furnaces the gas pressures in the combustion chambers are at greater than atmospheric pressure, means must be provided for preventing the escape of gas from the hoppers when the ashes are being removed. Otherwise, hot gases from the combustion chambers may flow through the hoppers and injure workmen in the vicinity of the discharge outlets of the hoppers. Similarly, in furnaces in which the gas pressures in the combustion chambers are less than atmospheric pressure, means must be provided for preventing infiltration of air into the combustion chambers through the hoppers when the ashes are being removed from said hoppers.

So far as I know, the problem of satisfactorily handling the non-gaseous products of combustion of modern solid fuel burning furnaces, particularly conventional positive or negative pressure-type furnaces in which powdered fuel is use, has not been solved prior to the present invention.

This invention solves these problems in a new and quite satisfactory manner. According to the present invention, I provide an ash handling system which is gastight and which is maintained substantially full of water not only during the collection of ashes, but also during the removal of ashes from the system. More specifically, this system preferably comprises a hopper having a gastight connection to the furnace surrounding the ash discharge passage from the combustion chamber and having a discharge opening in its lower portion, a vessel in gas-tight connection to the hopper and having an ashreceiving opening in register with said discharge opening means including a conduit communicating with the hopper for delivering water into the hopper so that the level of water in the hopper may be regulated and maintained as desired by automatic or manual means, and means for delivering water into the vessel to maintain a predetermined water level in said vessel. a closure means or gate is provided for the discharge opening of the hopper to control the flow of solids from the hopper, and ash-crushing means is provided in the vessel in the path of flow of solids from the hopper. If desired, the closure means may be omitted in certain instances, especially when the ash-crushing means is present. Near its lower end, the vessel is connected to means, such as a centrifugal pump, by which ashes and water may be removed from the vessel. Alternatively, the ashes and water may be discharged from the vessel by means of gravity a suitable opening being provided at or near the bottom of the vessel, closure means being provided to regulate the flow of ashes and water through the discharge opening. In any event, however, flow of Water into the vessel is provided for automatically so that when the pump is drawing the vessel contents off or the vessel discharge door is open, water is flowing into the vessel as fast as necessary to avoid starving the pump or drawing oversize solid bodies through the throat of the hopper discharge opening. To this end a conduit is provided having its inlet end in the hopper substantially below the normal water level of the hopper and communicating with the vessel.

The present invention will be better understood by those skilled in the art from the drawings which accompany and form a part of this specification and in which:

Fig. 1 is a vertical, sectional view taken through a powdered-fuel burning, positive-pressure type furnace equipped with an ash handling system embodying the present invention in a preferred form;

Fig. 2 is a fragmentary, sectional view taken on line 22 of Fig. 1;

Fig. 3 is a vertical, sectional view taken on line 33 through the overflow assembly of the Fig. 2 system;

Fig. 4 is a view like Fig. 3 but is taken on line 44 thrjough the make-up and equalizer assembly of Fig. 2; an

Fig. 5 is a view taken on line 5-5 of Fig. 2, showing the float chamber arrangement.

In Figs. 1 and 2, 1 designates the discharge passage leading down from the combustion chamber of a powdered fuel burning, positive gas pressure-type furnace. Water tubes 2 constitute the usual water wall of such a furnace and are supplied with water from headers 3 and 4.

-Positioned below the furnace to receive non-gaseous products of combustion such as solids, semi-solid, or fluid ash or slag from the combustion chamber is a hopper 5. This hopper may be of conventional form and is preferably connected at its upper end to the furnace about discharge opening 1 thereof by a gas seal indicated generally at 6. This seal may be quite like that shown and described in U. S. Patent No. 2,275,652 to Pursel. As shown, this seal consists of a wall 7 depending from the furnace into a trough defined by the outer side wall 8 of the hopper, a bottom wall 9 extending outwardly from wall 8, and a wall 10 extending upwardly from wall 9. A body of water 11 is maintained in this trough to a depth sufficient to submerge part of the vertical length of depending wall 7.

Pipes

12 and 13 serve as overflow pipes to prevent the rise of water in the trough above the desired level while pipe 14 (Fig. 3), preferably controlled by a float valve (not shown), serves to supply water to the trough as required for the maintenance of the predetermined level.

In its lower portion access openings and doors 19 are provided in the hopper walls and at its lower end hopper 5 is provided with a discharge opening 15 with a gate or closure 16 which serves to control the flow of solids through opening 15. Closure 16 may be operated in any convenient manner, but as shown is connected to a piston rod 17 of a piston (not shown) in a conventional hydraulic cylinder 18, the inlet and exhaust valves of this cylinder and the fluid pressure source and connecting lines not being shown. A jet nozzle 3a is disposed in the Preferably,

lower portion of hopper and connected to pipe 4a equipped with a valve to control the flow of water to the nozzle to flush down the hopper walls and clear ash out of the ash discharge opening.

A vessel designated generally at 20 is disposed below hopper 5 to receive ashes discharged through opening and is connected to hopper 5 around opening 15 by means of a gas-tight connection 21 which encloses gate 16. Ash-crushing means is disposed in vessel in the path of ashes flowing through opening 15. As illustrated,

this crushing means consists of rolls 22 having a plurality of rows of lugs projecting radially outwardly therefrom. These rolls are geared together by gears 23 and are driven by motor 24 through pulley and belt arrangement 24a. Ledges 25 extend inwardly from opposite walls of closed vessel 20 to intercept solids discharged from hopper 5 and direct them between rolls 22. Thus, when rolls 22 are not rotating they, together with ledges 25, may effectively retain solids in hopper 5 in the absence of door 16. it is, however, generally preferable to include this door in the assembly so that vessel 20 may be emptied of water and ashes while the furnace is being fired and the hopper is full of water.

A conduit opens into the upper end of hopper 5 at approximately the average desired water level in the hopper. Another conduit 31 communicates with conduit 3d and with a source of water under pressure and is provided with a valve 32 to regulate the flow of water through conduit 31. Valve 32 is actuated automatically to maintain the water in the hopper at a predetermined level by means of control mechanism including a float 35 in a float chamber 36 communicating with the hopper through a conduit 37 which opens into the upper portion of the hopper. A lever 38 carried by float 35 and counterweighed is pivoted between its ends to the float chamber shell and cooperates with means such as electric switch indicated diagrammatically at 40 to close the valve so long as the float is in a certain predetermined level range and to open the valve to allow water to flow into the hopper when the float is in a certain lower level range. Suitable conventional electrical connections (not shown) are made to operatively tie switch 40 to the valve to accomplish this result.

In the event of an overflow condition in the hopper, the excess water is withdrawn by means of apparatus including an overflow chamber 42 which communicates with the upper portion of the hopper below the predetermined water level therein through a conduit 43. Chamber 42 is provided with a downwardly disposed conduit 45, the lower end of which is received in a second chamber 46 serving as a trap for water flowing through the latter conduit. The lower chamber in turn is provided with a drain pipe 48 equipped with a valve 47 which controls the flow of water into a pipe 49 which leads into a main drainage line (not shown).

Vessel 2!) is provided with a water nozzle 50 and water is delivered through a pipe 51 communicating with the aforesaid water source. Nozzle 50 is located near the bottom of the vessel so that water issuing therefrom will stir up the ashes in the vessel and assist in the evacuation of these ashes from the vessel. Opposite the nozzle an exhaust system opening is provided in the vessel wall through which an outlet pipe 53 communicates with the vessel. pump 55 whereby the mixture of ashes and Water is drawn through the pipe and pumped to a place of disposal.

Water is delivered into vessel 20 by means primarily of a conduit 56 having inlet opening 57 in hopper 5 below the desired average water level in the hopper, and having a discharge end 58 communicating with vessel 20. Valves 59 are provided in branches of conduit 56 to enable manual cut-ofl of the hopper and vessel through said conduit, but in normal operation these valves are maintained open.

Having thus described the present invention so that those skilled in the art may be able to understand and practice the same, I state that what I desire to secure bv Letters Patent is defined in what is claimed.

What is claimed is:

1. Ash handling apparatus comprising a hopper positioned to receive ashes from a furnace combustion chamber and having an ash-discharge opening in its lower portion, ,gas-sealing means operatively associated with said chamber and hopper to prevent escape of gas there- Pipe 53 leads to the intake side of a centrifugalof said hopper, a float control for regulating the flow of water through said conduit, another conduit connecting the interior of said vessel with the interior of the hopper below the opening of the first said conduit into the hopper and a centrifugal pump communicating with the lower part of said vessel for removing therefrom water and ashes which have passed said crushing means. A Q

2. Ash handling apparatus comprising a hopper positioned to receive ashes from a furance combustion chamber, and having an ash-discharge opening in its lower portion, gas-sealing, water trough means operatively associated with said chamber and hopper to prevent escape of gas therebetween, a vessel disposed to receive ashes passing through said opening, closure means for controlling flow of ash from the hopper to the vessel,-

gas-sealing means connecting said vessel to said hopper about said opening and enclosing said closure means, ashcrushing means in said vessel in the path of ash flowing from said hopper, a conduit for water opening into the upper part of said hopper, another conduit connecting the interior of the vessel with the interior of the hopper below the opening of the first said conduit into the hopper, and means including a discharge opening in the lower part of said vessel for removing from said vessel ashes which have passed said crushing means.

3. An ash hopper comprising a hopper having an opening in its upper portion to receive ash from a furnace combustion chamber and an ash discharge opening in its lower portion, a gas-tight, water seal connection between said hopper and chamber about said ash-receiving opening, a water-retaining vessel having an opening in its upper portion to receive ash from said discharge opening, a gas-tight seal connecting said vessel to said hopper about said opening, closure means for controlling the flow of ash from the hopper through said discharge opening into said vessel, a water inlet conduit extending through said water seal and into the upper part of said hopper a water outlet conduit communicating with the interior of said hopper its outlet being at a desired water level above the discharge opening of the inlet water conduit means into the hopper, another conduit connecting the interior of said vessel with the interior of said hopper below the opening of the said water inlet conduit into the upper part of said hopper, and means including a discharge opening in the lower part of said vessel for removing ash and water from said vessel.

4. An ash hopper comprising a hopper having an opening in its upper portion to receive ash from a furnace combustion chamber and an ash discharge opening in its lower portion, a gas-tight, water seal connection between said hopper and chamber about said ash-receiving opening, a water-retaining vessel having an opening in its upper portion to receive ash from said discharge openmg, a gas-tight seal connecting said vessel to said hopper about said opening, closure means for controlling the flowof ash from the hopper through said discharge openmg into said vessel, a water inlet conduit opening into the upper part of said hopper a water outlet conduit communicating with the interior of said hopper its outlet being at a desired water level above the discharge open mg of the inlet water conduit means into the hopper and extending out through said water seal, another conduit connecting the interior of said vessel with the interior of said hopper below said outlet, and means including an outlet in the lower part of said vessel and means for removing ash and water from said vessel.

3,. An ash hopper comprising a hopper having an opening in its upper portion to receive ash from a furnace combustion chamber and an ash discharge opening in its lower position, a gas-tight, water seal connection between said hopper and chamber about said ash-receiving opening, a water-retaining vessel having an opening in its upper portion to receive ash from said discharge opening, a gas-tight seal connecting said vessel to said hopper about said discharge opening, closure means for controlling the flow of ash from the hopper through said discharge opening into said vessel, a water inlet conduitopening into the upper part of the hopper, a float controlled conduit extending from the upper part of the hopper out through said water seal to maintain the water in the hopper at a predetermined level, a water outlet conduit communicating with the interior of said hopper its outlet being at a desired water level above the discharge opening of the inlet water conduit means into the hopper, another conduit connecting the interior of the vessel with the interior of the hopper below the inlet opening of said outlet conduit means including an outlet in the lower part of said vessel for removing ash and water from said vessel.

6. An ash hopper comprising a hopper having an opening in its upper portion to receive ash from a furnace combustion chamber and an ash discharge opening in its lower portion, a gas-tight water seal connection between said hopper and chamber about said ash-receiving opening, a water-retaining vessel having an opening in its upper portion to receive ash from said discharge opening, a gas-tight seal connecting said vessel to said hopper about said discharge opening, closure means for 20 controlling the fiow of ash from the hopper through said discharge opening into said vessel, a water inlet conduit References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,843,274 Foresman Feb. 2, 1932 1,914,991 Coughlan June 20, 1933 1,957,583 Foresman May 8, 1934 2,163,148 Linder June 20, 1939 2,275,652 Pursel Mar. 10, 1942 2,280,944 Foresman Apr. 28, 1942 2,344,347 Foresman Mar. 14, 1944