US1502760A - Jet agitator for fuel-feeding devices - Google Patents

Description

July 29, 1924. 1,502 760 J. A. BARNARD JET AGITATOR FOR FUEL FEEDING DEVICES Filed Sent. 15 1920 2 Sheets-Sheet 1 July 29 1924. 1,502,760

J. A. BARNARD JET AGITATOR FOR FUEL FEEDING DEVICES Filed Sent. 13. 192o 2 Sheets-Sheet 2 to form which in use has Patented July 27 9, 1924.

JOHN BARNARD, or P mAnEnrHIA, PEN'NsYLVAnIAQ JET AeI TA'ron FOR FUEL-FEEDI G DEVICES.

Application filed September 13, 1920., serial No. 410,079.

T all whom. it may concem:

Be it known that I, JOHN A. BARNARD,

a citizen of the United States, residing at 2433 S. 21st St, Philadelphia, in the county of Philadelphia and State of Pennsylvania,

have invented certain new and useful Jet I Agitators for Fuel-Feeding -Devices, of

g which the following is a specification.

My invention relates particularly to se- .10 curing continuity of coal delivery through a chute, illustrated in connection Withun-- derfed grates.

where soft coal is fed through a hopper and wedges or arches within the hopper or .5 adjacent. thereto. J I

The purpose of my invention is to weaken the arch by a fluid iet orblast, preferably of air which may be directed from above or.

below as may be most convenient.

I A further purpose is to provide a protected nozzle within the coal chute or hop per and in position to deliver the jet against an arch or jam of fuel, to break down the arch and renew the feeding of the fuel.

A further purpose is to provide intermittent operation of the blast preferably 'corresponding to movements of a fuel feeding mechanism to maintain uniform supply of the fueL- A further purpose is to use a plurality of nozzles directed toward different positions where arches or jams are likely to occurso as to control the movement throughout a considerable I range.

A further purpose is, where two or more jets are .used, fed from a common source, to make that nozzle which is least protected from fuel ingress of smaller cross section than the section of one or o-thenbetter protected nozzles, that fuel accidentally entering through the first nozzle will be cleared through one of these other nozzles. Further "purposes will appear in the specification and in the claims. I

' My invention relates tothe processes involved as well as to mechanism by. which the processes'may be carried out. v I have preferred to illustratefmy invention by but one form thereof, selecting a proved to be simple, practical, efiicient and inexpensive, and. which at the same time well illustrates the principles of my invention;

Figure. 1 is a vertical section through the plunger casingzshowinga part of an under- It is applicable generally the great variation in the sizes; but when feed stoke'r to which my invention is applied, the driving mechanism being shown diagrammatically. i

Figure 2 is a section upon line 2-2 of Figure 1. i

Figure 3 is a fragmentary vertical section through the nozzles shown in, Figure 1.

Figure 4 is a rear elevation of the structure seen in Figure 3.

Figure 5 is valve 37.

Because my invention finds the greatest utility known to me in the maintenance of a supply of fuel for the feeding mechanism ofan underfed stoker and particularly because it has beentried out successfully by me in this connection, I have described the invention with reference to a common type of underfed stoker, intending to use this as typical of all automatic stokers as Well as use in various other arts where reliance is placed upon the substantial continuity of the fuel supply.

'Applying to the stokers: It is well known that banks of boilers having automatic supply of fuel for their grates do not yield the same return of water evaporated per pound .of fuel in each boiler, owing, among other causes, to the arching of the fuel in the constricting walls of the chute, pocket or boot within the bottom of -which the feeding mechanism moves. The (7 coal ordinarily used for this purpose is soft coalin which the larger lumps have been J broken but which is otherwise the run of mine? and contains ungraded sizesfrom the maximum selected to culm.

' When dry this fuel feeds by gravity with reasonable uniformity, nothwithstanding it is damp it is disposed to arch where there is a constriction in the passage. As a result of this, the fuel supply of some stokers is seriously interrupted before the appearance of the .fire or the poor vaporization from the boiler calls the attention of the boiler room force to the fact so that the trouble may be corrected.

In a large plant, a variation of so much as a tenth of a'pou'nd of coal perhorse power or kilowat developed is serious, so that the loss from this cause. mounts up rapidly. My invention is intended to protect against stoppages of fuelflow by means ofa fluid jet or blast, directed intermita longitudinal section of the 65 tently '(if for a plunger conveyor) against the point or points of usual stoppage and automatic in its. action. I-prefer to use air for my blast because it is the least expen: sive and does not add any injurious constituents to the coal. The moisture in steam is relatively low per volume of steam, but nevertheless the added, moisture makes steam of lessadvantage in proportion to the quantity of its moisture, which must be evaporated by the fire.

In Figure 1, I have shown an automaticunderfeed stoker having front furnace wall 7 tuiyfare box 8, and fuel way9, within' which the el is placed and advanced by a plurality of plungers of which two only are shown, at 10 and 11. The upper plunger is operated by the connecting rod 12 pivoted to it'at 13 and the lower plunger is operated by rod 14 from a lower ram operating bar 15 connected to the connecting rod at 16 and to the bar 14 through pin 17 and a sliding collar 18..

- Whatever the character of the hopper, chute or other fuel-feeding passage, my invention contemplates the use of jets to break up arches of fuel which maybe set up there and the number, placing and direction of the jets will depend upon the character, position and extent of the arches, whether determined by the design of the fuel passage or by experience in operation.

Between the sleeve 18 the'collar 19 upon the bar 14, a number of U-shaped adjusting pieces 20 are placed, the number dependin upon the extent of travel to the right w ich is to be given to the ram 11. This ram is an agitator rather than a feeder for the fuel.

Movement of the operating lever 15 to the left causes the sleeve 18 to engage a collar 21 upon the end of the rod 14, providing for the withdrawal of the plunger 11 to a fixed initial position in this type of stoker. The operatlnglever 15 is pivoted at a point below the structure shown, and any other agitatv ing lunger or plungers hich are used may be similarly connectedt ii it.

The connectlng rod 12 is operated by a pina r 22 in'a crank 23 operating about a shaft24 which, in this form, is driven by skew gear 25 meshing with a worm wheel 26, driven by a worm 27. In the illustration, the-worm is driven by a chain 28- and sprocket wheel 29. This construction is all old and forms one means of many by which a plunger 10, op-v erating'in the ram box 30 or some other conveyor removes fuel from the bottom of a hopper here illustrated by the extension hopper 31.

The exact po1nt or points at which arches are most apt to occur will differ with different shapes ofthe boot, with different pres-.

sures of coal and with various other diflterences which need not be considered and the iocatien of my blast in the present showing operate an intermittent jet, because the inihas been selected with a view to taking care -monly form in one or both of two locations,

above or below the position of my nozzle holder 32 and I have therefore here illus- 7- trated two nozzles 33, 34:, one directed upwardly to attack-the under side of the upper arch andthe other directed downwardly to attack the upper side of the lower arch.

The two nozzles take their fluid supply from a common point 35, fed through pipe. 36 and connections valved at 37 and connected to a compressed air pipe system 38 which is available as part of the stoker equipment. Couplings 39 are shown for convenience in attachment. Any fluid, liquid, gaseous or vapor, which-can be driven as a jet. will break up the arch, and the particular fluid must be chosen for its cheapness and ease of handling and to avoid injurious addition .to the fuel. 1

In the illustration, Figure 2, the extension hopper 31 is provided with a number of boots 40, 40, 40 40 and parts 41 of the ram boxes for separate rams 10, each of which'parts and the stoker fed from it may be separately put out of service by a jam above the ram.

The jet supply ismost desirably intermittent, because less fluid is required to tial impacts of the jets yield a greater economy in theuse of the fluid supply, and because operation of the jet while the plunger is out would, serve no useful purpose and would tend to pack above the plunger. lVith a continuously operating conveyor the jet-:shoul d be continuous. I recognize that the intermittent jet -actuation could .be so arranged in a variety of way s,(fromdif 11o ferent moving parts, for example) and show ram operation as the most convenient form only. I provide for engagement by the end 42 of the ram with a springretracted plunger 43 of the valve 37 with each return of the ram, yielding a jet dur-' ing the time that a ramis in itsextreme position, and during this time only, while there is a place for the fuel to fall. The so-called whistle valve,-a well known arti- 12o cle of manufacture, has proved an effective valve* for this purpose and has been used by me successfully. Though the nozzles 33 and 34, where two are used can be. formed separately, of any material and shape desired, my wish to have the nozzles contracted at intermediate points such as .44: and of larger cross'secvtional area both to the front of that point casein mounting and cheapness of manuv facture have led me to form the nozzles within cast blocks 48 secured to a suitable wall of the chute or hopper as by a bolt 49. In this casting I core the portionsto the rear of the contractions 44 and drill and ream the flared portions 50 into them.

i I core the opening 51 which is threaded for attachment of the connecting pipe 36.

As will be recognized, the formation of the interior of the channels has to do with.

the efiiciency in the jet in the delivery of as compact a stream as possible against the arch of fuel and does not directly aifect the broader aspects of my invention.

With the construction shown, it proves difficult to drill and ream exactly into the end of the cored portions and for this reason, I have shown shoulders at 52 though .these shoulders have no special value in the construction shown. l

I find it.quite desirable that my nozzles a .shall project an. appreciable distance into the column of fuel flowing and'therefore have them terminate'at points 46 and 47,, I some distance from the sides of the casing, so as to strike the arches at effective points,

a distance-from the sides of the hopper to increase the benefit of the jets.

The opening 47 is protected from fuel inlet by its position below the protecting -wall 53, but upwardly directed jets are in danger of being clogged by fuel crowding into them. In order to rotect against this,

I provide a ledge 54 a ove' the outlet46. The wall 55 between this ledge and the out-' let may to advantage be made substantially parallel to the line of travel of .the jet. The upper edge 56 of the casting is made sharp enough to avoid clogging of fuel against it. I prefer to inake the cross sectional area of the upper nozzle, and particularly of its point of smallest cross section, smaller than that of smallest cross section of the lower nozzle, in order'that any fuel which may be .forced in throu h .the upper nozzle will drop into, the lower nozzle between the times of operating the jets and be driven out freely through the lower nozzle.

In operation, 'every return movement of the ram 10 presses the valve stem and causes fluid jets'to engage any arches which may be present breaking them down and renewing fuel flow. I This occurs at the time when the conveyor'(ram) is in position to receive and handle more fuel.

I. recognize that any number of nozzles may be used Within a single hopper and that characters of nozzle may be greatly varied to carry out my invention; also that with-knowledge of my. invention different designers will'prefer to construct the device in various ways as their preference or speclal needs may direct. I purpose including herein all of t ese various forms which come within the reasbnable spirit and scope of the claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. In a feeding device for fuel, walls forming a passage down which the fuel passes by gravity, a nozzle adapted to discharge a fluid jet within the passage in position to break down any arches of fuel formed, a cover. for the nozzle orifice pro tecting it from flow of fuel, connections for furnishing fluid supply under pressure. to said nozzle, a .valve and mechanically actuated means for intermittently operating it to control the supply.

2. In a fuel feeding device, walls forming a restricted passage Within which the fuel is likely to arch, a nozzle extending out into the passage and discharging upwardly in a direction diagonal to the passage, a supplemental cover protecting the outlet of the is likely to arch, in combination with a plurality of nozzles adapted to discharge into the passage directed one generally upwardly and'the other at an angle thereto and connecting with a common inlet passage,th upwardly directed nozzle being of smaller cross section than the one at an angle thereto and the outlets'of'both nozzles out of direct line of fluid flow, and con-' nections for supplying fluid under pressure to said nozzles.

5. In a fuel feeding device, walls forming a, restricted passage within which the fuel is likely to arch, a nozzle discharging into' said passage diagonally upward and of smaller cross section at an intermediate point near the orifice than at the orifice or back of that point, means for protecting the nozzle outlet from the direct line of fuelfiow and connections for providing fluid prwsure supply to said nozzle.

6. A nozzle for use in breaking down arches of fuelfin'lines of fuel flow, said nozzle having a passage way of decreasing cross section from the point of supply toward the outlet, a constriction nearthe outlet and an upwardly flared passage from the point of' constriction to the outlet, in coml bination with an overhang above the outlet protecting it from fuel flow, and walls forming a fuel feeding passa e within which the nozzle projects to disc arge against fuel arches therein.

7. In a nozzle for use in breaking down arches of fuel in lines of fuel flow, a cast body providing a cored passage extending from-the point of supply connection toward the outlet and outwardly flaring cut passages. from the termination of the cored passage to the point of discharge, one of the passages extending upwardly and another downwardly, in combination with walls forming agravity fuel passage within which the upwardly and downwardly directed passages are located. 4

8. In a device for 'use in breaking down arches of fuel in lines of fuel flow, walls forming a common inlet and nozzles therefrom, one of which points upwardly and another downwardly the upwardly directed nozzle having its smallest cross section of less area than the smallest cross section of the other. i

9. In a device for use in breaking down arches of. fuel lines of fuel flow, Walls forming a common inlet, nozzles therefrom, one of which points upwardly and the other downwardly, the upper nozzle having its smallest cross section of less area than the smallest cross section of the other, in combination with a protecting cover above the first nozzle and walls forming a gravity fuel feeding passage within WhlOll the nozzles project.

10. In a nozzle for use in breaking down arches of fuel in lines of fuel flow, a block having two connecting cored passages therein, one upwardly and the other downwardly directed and having upwardly and downwardly cut outwardly flaring passages leading therefrom, respectively, the smallest cross section of the upwardly directed passage being of less area than that of the downwardly directed passage, in combination with walls forming a gravity fuel feeding passage within which the block is. located.

11L Ina nozzle for use in breakingdown arches of fuel in lines offuel flow, an upwardly directed nozzle'located in the line of flow of the fuel and a protecting cover for the said nozzle extending diagonally upwardly and outwardly further into the line.

of flow from the'orifice of saidnozzle, in combination withwalls forming ,a'gravity fuel passage for the fuel flow.

12.-In a fuel feeding device for stokers, walls forming a passage way for gravity feeding of the fuel, an intermittently actuated conveyor feeding the fuel at intervals from-the-bottom of the vpassage, a nozzle directed into the passage toward the'posidirected within the passage and adapted to play upon an arch of-fuel therein, a source of fluid pressure supply for said nozzle, a valve controlling the supply to the nozzle and. an automatlc'means for actuating the valve operated by one of the movable conveyor parts and timed to actuate the valve at intervals between successive fuel removing operations of thejconveyor.

14. Ina fuel feeding device for stokers, walls forming a passage down which the fuel isfed by gravity, an intermittently actuated conveyor removing the fuel from the bottom of the' passage at intervals, a

.nozzle directed within the passage and adapted to play upon an arch of fuel there-- in, a source of fluid pressure supply for said nozzle, a valve controlling the supply to the nozzle, and an operating connection between'the valve and conveyor opened the conveyor, during retracting movement.

15. In a fuel feeding device for stokers, walls forming a passage down which the fuel is fed by gravity, 'a'plunger conveyor removing the fuel from the bottom of the passage at intervals, a. nozzle directed within the passage and adapted to play upon 'an arch of fuel therein, a source of. fluid' pressure supply for said nozzle, and an automatically closed valve controlling the suptions engaged'by the conveyor parts When thevconveyor plunger is in retracted position. b

. 16. The. method of breaking up arches plunger conveyor which consists in directing a fluidjet upon the arch at intervals and timing the intervals to correspond with retracted. positions of the plunger.

17 The method of breaking up arches of fuel in agravity feeding system for a plunger conveyor which consists in directing afluid jet upon the arch from within the path of fuel flow, startin and stopping the jetby valve control oft e fluid supply and in synchronizing the valve operation .to the movement of the conveyor mechanism, so that flow of the jet corresponds with retracted positions of the plunger.

JOHN A. BARNARD.

"ply to the nozzle, having opening connecof fuel'in a-gravity feeding system for a J

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