US1598842A - Apparatus for handling powdered fuel - Google Patents

Description

Sept. 7 1926. 1,598,842

M. W. ARROWOOD APPARATUS FOR HANDLING POWDERED FUEL Original Fild MaI-Cb 1.4-, .1923 2 sheets` sheet l u Il sept. 7 1926.

* -1,598,842 M. w. ARRowooD APPARATUS FOR HANDLING POWDERED FUEL originl Film Maren 14, 1923 2 Sheets-Sheet 2 `als vPatented Sept. 7,1926.

UNITED STATES.

PATENT OFFICE.

i MILTON W. .ARROWOD, 0F WORCESTER, MASSACHUSETTS. l

`L rrfinana'rus non` HANDLING rownnnnn FUEL.

original apsnaation sled March 14, i923, serial Na". 624,927. Divided and this application sled Januari le, 1924. serial No. 686,506.

i This invention relates to the handling of powdered coal and similar material, thepresent application pending application,

-March 14, 1923.

In feedinggpowdered coal from hoppers and similar containers, there is a tendency ifor the coal to pack and form 'an arch, which interferes with the continuous feeding being a division of my Serial No. 624,927, filed 10 operation. One of the purposes of my present invention is to prevent this arching and facilitate the uniform feeding of the coal. The coal in extremely linely powdered conf dition has a tendency to work into the bearings of the movable parts4 of the apparatus with the result that they customarily wear rapidly. Another object of this invention, is to dispose the bearings for the movable parts of the apparatus outside the housings in which the powdered coal is confined, s0 that the coal is practically excluded from the bearings, and their life isy thereby much prolonged. l

Another purpose of the invention is to provide novel gates. for regulating the delivery of powdered coal from the hopper to the mixing apparatus, which gates will prevent escape and leakage of the coal around them, and also to provide means -for agitating the fuel to maintain a uniform consistency and uniform weight per cubic unit thereof.

Other objects and advantages of this in- 'vention should be. readily appreciated as thez same Abecomes better understood by reference to the following description, when considered in" connection with the accom- I panying drawings.

Referring to the drawings: l

Fig. 1 is a vertical sectional view through an apparatus embodying my invention;

Fig. 2' is a plan view partially in section of one end of the coal feeding and preliminary mixing apparatus.. this ligure being 'taken on the line 2 2 of Fig. 3;

Fig. 3 lis r a sectional view on ther line 3-3 of Fig. 2;`and

Fig. lis a fragmentary view of the mechanism for operating the control gates shown in Figs. 2 and 3.

`Referring now to the drawings more in detail, reference character 5 indicates generally the lower portion of a hopper in which the powdered coal isstored and from which it is fed, this hopper being connected by a closed joint with a tapered trough or recep- 55 tacle 6 into which the powdered material falls by gravity from the hopper when the control gates are open. The gates 7 and 8, which may be lof any preferred form, either curved or flat as shown', vare mounted on shafts 9 and 11, respectively, extendin through the walls of the hopper base an journaled in outboard bearings. Each shaftv is provided outside the hopper with an arm 12 which armsare connected by an operat- `ingl link 13.1,. It will be manifest that by moving the link 13y longitudinally, rotative lmovements will be imparted to the shafts 9 and 1,1, to open and close the gates. It will be observed from Fig. 3 that a stop ledge 14 is disposed beneath the outer edge of gate 8 and a similar ledge 15 is disposed over the outer edge of gate 7, whereby the movements of these gates in lolle direction are limited. The inner edges of the gates overlap when in closed position so that when the gates are positionedas shown in full lines in Fig..2, the flow of material from the hopper is completely shut olf. By rotating the gates in a Iclockwise direction, viewing Fig. -3, they may be opened orpartially opened to Aany desired degree, as indicated in dotted lines, to permit the requisite iow of material from the hopper. VTo insure a leak-tight fit, the margin of each gate is preferably provided with a feltsealingstrip 16, held in place by ai retaining strip 17, which'holds the felt strip snugly against the end walls of the passage.

y The tapered shape of the hopper induces a tendency of the coalv in the hopper to form an arch over the gate or gates so thatit will not feed uniformly.` This objectionable arch, however, may be obviated by suspending within the hopper one or more heavy chains 18 which hang down to a point in proximity to the gate. The constant vibration of such a chain or chains resulting from the operation of the machinery, prevents the objectionable arching of the material in the hopper. 1

Beneath the gate -within the trough 6 and abovevthe bottom thereof, there is mounted a. rotatable shaft 19,7provided with radially extending spokes or fingers 21, preferably inclined with respect to the longitudinal axis --of said shaft and adapted upon rotation of the shaft to agitatel the material passing through the trough, thereby breaking any.

caked lumps or chunks therein and mixing the same so as to insure an uniformity 1n the consistency and specific gravity ofthe fuel, as Well as facilitating'the feeding of` the-coal to the feed screw 22 disposed in the bottom of the trough. This feed screw is mounted upona shaft 23 driven from any suitable source of power, and equipped with a gear 24 which meshes with and drives a companion gear 25 on the shaft 19. In order ,to prevent leakage of the coal around the shafts and to preclude its entrance as much as possible into the bearings, theshaft 17 isl mounted in outboard bearings 26 and 27,-

The other end of shaft 23 extends vthrough a shell 33 and is journaled in an outboard bearing 34, leakage at this end of the shaft being prevented by a stuffing box 35. Within the shell 33 there is disposed around the shaft a perforated cylinder 36, into which the coal is delivered by the feed screw 22. Air under suitable pressure is delivered to the interior of the cylinder 36 through a supply pipe 37, and this air is mixed with the coal in the cylinder, the mixture being fur ther facilitated by the passage of the coal and air together outwardly through the perforations 1n the cylinder walls. From shell 33 the mixture of coal and air isischarged througha neck 39 einto the mixer proper, or as it is commonly termed,-the burner,

This burner may be of Iany preferred construction but preferably comprises, as shown for illustrative purposes, an outer cylindrical shell 41 in which are disposed a plurality or concentrically arranged shells of progressively decreasing diameter, forming a series of fuel passages alternating with air passages from which air delivered at the intake end 42 of the burner is delivered radially v into the mixing passagesthrough apertures 43. The structural details of the burner will not be further elaborated upon as they are fully described and claimed in the parent application previously mentioned.

In the operation of'my invention, the hopper gates 7 and 8 having been opened the desired amount, the fuel inthe hopper which is prevented from arching by the-chain 18, falls by gravity into the trough 6 where it is broken up, Vagitated and mixed to a uniform conf Y perforated cylinder 36. Here it is partiallyy mixed with air, delivered into the cylinder 3b 'under pressure and upon being discharged outwardly through the perforations in this cylinder itbecomes further mixed as itis delivered into the surrounding cylinder 33. From this cylinder`33 it is delivered through the neck 39 into the burner and from thenc into the. combustion chamber.

The prevention of arching accomplished by the chain or chains 18, the control of the fuel delivery by the gates 7 and 8, and .construction and operation of these gates and .their capability of effectually preventing leakage around the same, thel protection of the bearings in which therotating -shafts o erate, the breaking up ofthe fuel in t e troughand `the deliver of the saine into the preliminary mixing cy inder, and the advantages of these various features should be appreciated without further description. 0bviousl descri ed may be varied within considerable limits without departing fromthe essence of the invention as defined in the following claims.

I claim: 1. In an apparatus of the character described, the combination of a hopper, a pair of vrotatable vertically swinging intermediately supported control gates mounted beneath said hopper so that adjacent margins of said gates overlapwhen thel gates are in closed position, and abutments at the sides of the hopper. against which the outer margins of said gates close.

2.A In an apparatus for feeding powdered fuel, the combination ofahopper, a trough the structural details illustrated and beneath said hopper, asealedcontrol gate l for controlling the delivery of fuel from said hopper to said trough, a removable carrying section for said gate means in the hopper for preventing arching of `the fuel therein, means in the trough foragitating and breaking up the fuel delivered thereto from the hopper, and a feed screw for delivering said fuel from the trough.

3. In an apparatusof vthe character de scribed, the combination of a hopper, a trough beneath said hopper, a control gate for controlling the delivery of material from said hopper to said trough, and means extending along the` margins of said gate for. sealing the same against leakage, said gate including a plurality of similarly movable sections mounted in the hopper and overlapping one another. i r

4. In anapparatusl ofthe character described, the'combinationof a` hopper, aoontrol gate for controllingithe delivery of material therefrom, felt sealing .strips for preventing leakage around the margins of said gate, said gate com risingya pair of similarly rotatable over appmg se'ctlons mount# noA f ed in the hopper, and oppositely acting stop ed beneath said hopper so that Ladjacentl margins of said gatesoverlap when the gates are in closedl position, abutments against which the outer margins of said gates close, and sealing strips .for preventing leakage around the gates.

6. In an apparatus of Ythe character de scribed, Ithe combination of .a hopper, a rotatable control gate mounted in outboard bearings beneath said hopper, abutment means for limiting the closing movement of said gate, and sealing strips for preventing leakage around the gate.

7, In an apparatus of scribed, the combination of a hopper, a pair of rotatable ,gates mounted in outboard bearings beneath said hopper, said gates b eing adapted to overlap when in vclosed position, abutments for limitting vthe closing movements of said gates, and` means for preventing leakage around the gates.

8, In an apparatus of the character described, the combination of aA hopper, and means for controlling the discharge from' said hopper, said means comprising a plurality of gates rotatably mounted on horizontal axes and adapted to overlap when in closed position.

MILTON W. 'ARROWOOD the character dec

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