US2627827A - Fly-ash handling apparatus - Google Patents

Description

Feb. 10, 1953 'L, E -r]- 2,627,827

FLY*ASH HANDLING APPARATUS Filed Dec. 10, 1948 /Z 25 F|G.| /7 26 27 37 INVENTOR LACE'STER ELLIOTT ATTORNEY Patented Feb. 10, 1953 UNITED STATES PATENT OFFICE FLY-ASH HANDLING APPARATUS Lacester Elliott, Springfield, Ill.

Application December 10, 1948, Serial No. 64,490

12 Claims.

This invention relates generally to fly-ash handling apparatus for commercial furnaces in which solid fuels are burned, and it is a general object hereof to provide improved apparatus adapted to facilitate the continuous removal of fly-ash deposits.

It is well known that solid fuel burning furnaces require some provision for enabling the removal of fly-ash which is deposited therein. The more advanced furnace installations are generally or more usually equipped with mechanical or hydraulic fly-ash removing apparatus which is expensive to install and operate. The heretofore prevailing mechanical apparatus, because of its initial cost and complicated nature is most often used only in the larger furnaces.

The hydraulic apparatus is sometimes found objectionable due to the lack of proper space acin connection with existing furnace installations to improve operation thereof without requiring costly or extensive installation modifications.

Another object of the present invention is attained in a hopper assembly having structural and other useful features especially adapting the same for the rapid, effective and continuous withdrawal of fiy-ash and like incombustibles from a furnace.

Still another object of the invention is to combine a hopper structure and means operating in cooperation with the hopper to direct and constantly feed fly-ash deposits into the hopper, such means being exemplified by an agitating and crushing member rotatively disposed within the inlet portion of the hopper and having a close working fit with the hopper walls, whereby loose fly-ash particles are relatively easily passed into the hopper and agglomerated or sintered ash formations are first crushed or broken up sufliciently to render them admissible to the hopper.

A further object of the invention is attained. in the combination with the above mentioned hopper structure and assembly, of a fiy-ash dis posal blower system associated with the hopper 2 outlet and leading to a discharge in the region of the furnace fire box, whereby the fly-ash passing to the hopper is sucked into the blower system and returned to the fire box for recovery of residual heat values in the fly-ash and more complete combustion.

Other objects hereof will appear more particularly from the following description of a presently preferred structure and assembly, particular attention being directed to the drawing forming a part of this specification, and wherein:

Fig. 1 is a generally schematic view, in sectional elevation, of a furnace in which the improved hopper assembly has been incorporated in conjunction with a blower system;

Fig. 2 is an enlarged and fragmentary plan view, in section, of portions of the disclosure of Fig. 1 as seen at line 22 thereof;

Fig. 3 is a perspective view of the hopper assembly, with a portion of one wall broken away to disclose interior details;

Fig. 4 is a fragmentary sectional view, as seen at line 44 of Fig. 2, of the inlet zone of the hopper to show the relation of the agitator bar thereto;

Fig. 5 is a fragmentary end View of the hopper assembly showing a removable bearing block for the agitator member;

Fig. 6 is an exploded view in perspective of the agitator member, and portions of the drive shaft and shaft housing;

Fig. 7 is an elevational view of the power operated drive mechanism for the agitator member, as may be seen at line 1-1 of Fig. 2;

Fig. 8 is a perspective view of a modified form of agitator member having helical flights thereon. and

Fig. 9 is a vertical, fragmentary sectional view along line 99 of Fig. 2, showing an ashejector nozzle.

Referring to the drawing by suitable reference numerals it may be noted that the view of Fig. l discloses schematically and generally a commercial furnace structure It having a front wall I i, a bridge wall-l2 spaced rearwardly of the front wall and a rear wall l3 beyond the bridge wall. Side walls ls complete this portion of the furnace and therebyv define a firebox region above the fuel supporting grate members l5 and in front of the bridge wall 52, and a combustion zone or region extending over and beyond the bridge wall. The furnace may be provided with banks of water tubes which extend between the front and rear walls, and for present purposes 3 only a portion [6 of the lowermost tube bank has been included.

In a furnace of this general character, the ignition of the fuel occurs in the firebox region above the grates l5, while the combustion thereof extends into the zone over the bridge wall 12 and above a fly-ash collecting pit defined by the furnace region between the bridge wall I2 and side and rear walls I4 and 13, respectively. The fly-ash pit is generally, indicated at II. It is, of course, understood that the fiy-ash deposited in this pit H is for the most part, comprised of incompletely burned fuel particles which settle by gravity effects. As a consequence, isuch flyash may fuse and form larger agglomerate masses upon continued and prolonged exposure to the intense heat radiating thereto from above.

It is important, therefore, to remove the flyash as quickly as possible to prevent its undue exposure to the heat of combustion, and to reduce any later difficulties in effecting its removal. The present invention is principally directed to improved means for removing this flyash, and the following description will'serve to point out the features and improvement therein.

In the example shown in Fig. 1, the furnace fly-ash pit i1 is-formedwith a thick bottom wall l8 of usual masonry construction, this wall having an upper funnel shaped surface which slopes or converges in each of the four principal planes to a bottom opening l9 ofelongate or rectilinear form. The convergent faces of the wall 18 are lined with glazed orother form of fire brick 20 to provide protection for wall [8 against heat destruction and fly-asherosion.

The improved fly-ash receiving-hopper assembly 22, shown in more detail in Fig. 3, is disposed within the bottom opening IQ of the pit I1, and the space about the hopper is closed off by skewed bricks -23 cemented in place: and partly supported on ledge elements Zlcarried by the, hopper. Thus, the fly-ash particles falling into the pit I! are directed by the converging walls toward the bottom opening I9, and through the provision of agitating and crushing means associated with thehopper 22 such fly-ashis easily caused to pass into thehopper '22 at a rate which will eliminate the tendency of the. fly-ash to fuse or bridge over the opening l9.

As may be seen in Figs. '1 :and 2,-the fiy-ash passing into the hopper 22 is positively removed therefrom by a pneumatic disposal system. This system includes a motor driven blower 2 5, and an air conduit 26 connecting the blower outlet with a suitable conduitl-I located below the furnace and below the hopper 22. .The conduit 27 emerges from below the furnace at the outer portion 28, and this portion 28 may extend to a discharge end (not shown) located in the front wall II of the furnace so as to deliver the fly-ash into the firebox for recovery of the heat values contained in the unburned portions thereof. Where the conduit 2'? passesbelow hopper 22 (Figs; 1 and 2), there is-provided an injector nozzle '29 and a suitable lateral inlet opening for fly-ash admission to'the conduit'ZTand entrainment thereof with the air flowing through the conduit past the nozzle 29. This-nozzle 29 develops a negative pressure orsuction'aeffect. inthe hopper 22 and assists the movement of flyeash through the hopper and into the conduit 21.

Turning now to Figs. 3, 4 and 5, the hopper 22 is seen to be formed of a pair of casting parts 31 abutment when assembled. Since the castings are substantially identical, the same reference numerals will serve to indicate like parts of each. Thus, each casting 3! includes a flat side wall 32, and opposite end wall portions 33 which are oppositely angularly directed from an elongate upper margin 34 to a lower margin 35. The upper margin 34 and the opposite, lower margin 35 are each free of any wall parts so as to provide inlet and outlet openings for the hopper. The upper marginal portions of the castings 3| are each laterally extended, as at 36, to form spaced side wall elements defining spaced seat zones in conjunction with extended lip portions 3'! of the marginal end walls 33. In assembly, the castings 3| are disposed in facing relation with the marginal end walls 33 in abutment (Fig. 3), thereby placing the flat side walls 32 in closely spaced relation to form an elongate and rectilinear inlet opening 3% at the top of the hopper 22 and a reduced bottom outlet port between the lower margins 35. This bottom port is further defined by the securement of an adapter ring or short tube 39 welded or otherwise secured to the margins 35 and end .walls 33. The two castings .3! are held in assembly by a plurality of screws 45 slidably disposed in suitable bosses M in one casting part and threadedly engaged in matching ring 39. This passage 43 is further divided into a plurality of convergent channels by theaddition of coacting internal projections, deflecting flanges or vane elements 14,45, 46; and 47. Each casting part 3i carries a set of these vane elements so that the vanes of one part abutthose of the opposite part to :bridge the side walls "32. Fig. 3 illustrates the disposition of such vanes-on one casting part, and it is to be noted that the several vanes coact to form convergent channels. Thus, vane M coacts with theadjacent-e'nd walls 33 to form a convergent channel 44C, vanes ld and '65 form channel 450, vanes 45 and 6! form channel 45C, and vane 41 and the adjacent end walls 33 form channel 570. The area between vane elements-d5 and 45 is closed at the top by the abutment thereof and, hence, does not constitute an effective channel. Since the adapter ring 39 is connected into the air conduit 2! at the zone of the injector nozzle 29', the suction effect thereof is communicated'to the hopper passage iS, and the present disposition of vane elemerits has the effect of distributing this suction flow in a uniform manner throughoutv the hopper passage with the result that fly-ash is more readily drawn through the hopper 22.

In conjunction with a hopper assembly of the above described character, there is provided an agitator member or rotating bar 50,-shown in Figs. 2, 4 and 6. The member 50 is substantially square in section, and extends from a fixed type bearing block 5| to adjacent a removable bearing block 52 at its opposite end. The bearing 5! is mounted in one'hopper seat (Fig.3)

and is provided with a suitable bearing aperture 51. Thus, the member 50 is operatively and removably mounted across the hopper inlet opening 38 and within the side walls 32 thereof. It is preferred that the member 59 have a'close working fit within the hopper inlet 38 (Fig. 4) so that when it is disposed with its greatest width spanning such opening, fused or massed fly-ash particles may be crushed by it against the side walls 32. At other times, the loose fly-ash particles may freely pass into the hopper.

The drive shaft 55 for the member 50 extends through the adjacent furnace side wall It and is enclosed by a tubular housing 58, the latter housing also extends outwardly of the wall It and is seated in a close fitting wall sleeve element 59 to reduce the wall opening as far as possible. The outer end of the drive shaft projects beyond the housing, 58, as at 69 (Figs. 2 and '7), and carries a ratchet gear 6! which is keyed or otherwise removably fixed thereto. A pawl arm 62 is freely pivotally mounted on the shaft end portion 60 adjacent the gear 6!, and this arm 62 carries a pawl or finger element 53 which is operatively arranged to engage the ratchet teeth when the arm 62 is pivoted in a counter-clockwise direction, as viewed in Fig. 7. The clockwise direction of movement of the arm 52 merely causes the element 63 to ride over the ratchet teeth without driving engagement. obtained through an elongate driving tape 64 arranged for reciprocating movement within a. tubular or other suitable housing 65. This tape 64 and its housing 85 extend to a drive means (not shown), but which, as is indicated on the drawing, might be the drive arm of a Stoker mechanism used to supply fuel into the furnace. However, any suitable source of power could be employed for this purpose as, for example, a motor driven crank mechanism to which the tape 54 would be connected to produce the proper rate of reciprocating movement at pawl arm 52. In this way, the agitating and crushing member 50 is rotated in a step-by-step manner, and is caused to effect the desired agitation and crushing action on the fly-ash whereby the same may be easily passed into the hopper 22.

In Fig. 8, there is shown a modified agitator member 68 of the screw type. This member has a cylindrical body about which is secured a spirally formed element 59. The element may be of one piece or several pieces arranged to provide a continuous screw flight. When member 58' is employed in place of member 50, the flight 69 is made to have a close working clearance within the inlet 38 of the hopper 22 and between the i spaced side walls 32. The manner of operatively mounting member 68 is identical with that described for member 50.

The foregoing description is specifically directed to a presently preferred form of the invention, but it should be understood that certain variations of construction of the several parts and changes in the manner of assembly thereof can be effected without departing from the intended scope of the appended claims.

I claim:

1. In an ash receiving assembly for feeding ash to a pneumatic conveying system in a commercial furnace, the combination of a hopper body having an inlet and an outlet provided with a pneumatic connection, and enclosing walls defining a plurality of passages converging toward said outlet from said inlet, bearings positioned at said body inlet in spaced relation, an agitator member extending across said inlet and operatively sup- Actuation of the arm 62 isv '6 ported by said spaced bearings, said member having a close fit in the body inlet sufficient to permit loose ash particles to pass into the body and to permit agglomerate ash masses to pass when crushed between said member and the adjacent body walls, and an operating shaft rotatively supported by one of said spaced bearings and connected to said agitator member for operatively rotating the same.

2. An ash receiving hopper assembly comprising closely spaced side walls and opposite end walls cooperating with said side walls to form a hopper body characterized by an inlet of elongate rectilinear aspect, a restricted outlet, and a body passage convergently directed toward said outlet, and an ash agitator and clinker crushing member operatively disposed across said body inlet between and just below the upper margins of said side walls, said member being adapted for rotation about its longitudinal axis and having a close working clearance between said side walls, whereby loose ash particles are free to pass into the body passage and agglomerate ash formations are substantially crushed prior to entrance into said body passage.

3. An ash receiving hopper assembly as defined by claim 2 and in which said rotating member consists of an elongate bar substantially square in cross section and having a diagonal dimension less than the spacing of the side walls as determined by the close working clearance.

.1.. In a fiy-ash collecting hopper assembly for use in and with a pneumatic ash transporting system in a commercial furnace, a hopper body formed with closely spaced and parallel side walls and opposite end walls extending between the side walls to define a body passage open at its upper and lower margins said body having bearing seats formed between said side walls, with one seat at the upper end portion of each end wall, a bearing block carried in each seat, an ash agitating and crushing member operatively mounted in said bearing blocks and having a close working clearance between said body side walls within the margins thereof, and drive means operatively connected with said member.

5. A hopper for use in connection with the collection and disposal of furnace fly-ash material, the hopper including matching metal parts, each having a side wall and opposite marginal end wall portions which are oppositely convergently directed from an elongate upper wall margin to an opposite and reduced lower wall margin, means securing said matching parts in assembly with said marginal end wall portions in registering abutment to constitute convergent end walls of the hopper for a hopper passage having an elongate top opening defined by said upper wall margins and an opposite, reduced bottom opening between the side walls, an agitator operatively disposed in, and substantially closing the top opening, and a plurality of vane elements carried by each matching part and positioned for abutting registration in bridging relation between said side walls.

6. A fiy-ash disposal hopper for use in a furnace installation, the hopper including a pair of matching metal parts, each part having an outer side wall and a pair of opposite marginal end wall portions extending at one side of the outer side wall and convergently directed from an elongate and free margin thereof, means securing said matching parts in assembly with the marginal end wall portions in abutment to form enclosing end walls of the hopper and to maintain said tion to extend into abutment and bridge the hopper passage between said side walls, the vane elements on each matching part being located between said marginal end wall portions, and furthat being alternately angularly directed so that the hopper passage is eifectively sub-divided thereby into a plurality of elongate channels extending between said opposite openings.

7., A fiy-ash hopperas defined in claim 6, and further characterized in that said side walls of said matching metal parts are maintained, when ,in assembly, ,in substantially parallel relation, and each of said elongate channels in the hopper passage is convergently formed and directed toward said bottom opening of the hopper passage. 8. ,In an ash-handling installation for use in a furnace having a fly-ash collecting pit, an air ,blower and connecting conduit leading from said .blower beneath the fly-ash collecting pit, said conduit having a suction port opening toward the collecting pit, a device between said suction port and the collecting pit for directing fly-ash deposited in the pit into said suction port, said device comprising a hopper body formed with an elongate ash-receiving inlet in the pit and an out- 7 let opening to said suction port, and a power driven ash-displacement member operatively mounted within said hopper inlet for agitating fly-ash deposits to facilitate passage thereof into -;said hopper body under the influence of gravity,

suction and displacement effect of said power ."driven member.

9. An ash handling installation as defined in claim 8, further characterized in that said hopper body is downwardly convergent and is provided with internal vane elements extending between said body inlet and outlet, said vanes forming a plurality of separate passages downwardly convergent and so acting to equalize the suction eifect produced at said suction port over substantially the full area of the body inlet.

10. A device for removing and reducing the contents of a furnace ash pit, including a hopper having an elongate rectangular inlet below the pit-and an outlet together with a suction connection in its lower portion, a crushing member said-system including a nozzle positioned in said conduit below said hopper outlet suction connection.

11. An ash crushing and feeding devicefor use with a fluid ash-transport system in a furnace provided with a fiy-ash collecting pit having a convergent bottom, the device comprising a hopper body formed by side and end walls and defining an elongate, slotted inlet opening adapted for registration with the bottom outlet of the fly-ash collecting pit, the bodyside and end walls of the hopper also forming an outlet port and a fluid connection, a fly-ash agitating and crushing member operatively positioned within and extending across said body inlet opening over the length thereof, and a power driven operating element connected to said member and projecting externally of the furnace.

12. Fly-ash handling apparatus for use with pneumatic conveying apparatus in commercial furnaces, comprising afly-ash, receivinghopper formed by closely spaced and substantially parallel side walls and opposite end walls convergently directed, a plurality of internal projections carried by the side walls, and defining therewith hopper passages convergently extending from an elongate, rectilinear inlet mouth to an outlet port, a connection at the outlet port, for attachment to a pneumatic conveyor conduit, bearing elements located at opposite ends of the hopper inlet mouth between said side walls, and an elongate fiy-ash agitating and crushing member rotatively supported at its opposite ends in said bearing elements, said member extending substantially from end to end of the inlet mouth and having a close working clearance with said side walls.

LACESTER ELLIIOTT.

REFERENCES CITED The following references are of record .in'the file of this patent:

UNITED STATES PATENTS Number Name Date 588,518 Weber Aug. 17, 1897 617,521 Day Jan. 10, 1899 1,086,880 Woolson Feb. 10, ,1914 1,278,405 vWatson Sept. 10,1918 1,408,972 Bell Mar. 7,1922

. 1,523,860 Coghlan et al Jan. 20, 19.25

1,666,768 Beaumont, Apr. 17,1928

1,756,320 Wiebe Apr. 29, 1930 1,943,780 .Allen Jan. 16, 1934 2,003,559 Scott June 4,1935

2,400,797 Webb May 21,1946

2,420,217 Allen May 6,1947

FOREIGN PATENTS Number I Country Date 427,745 Germany Apr. 13, 1926 387,877 Great Britain Dec. 15, 1932

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