US1637028A - Fuel-feeding mechanism - Google Patents

Description

July 26, 1927.

- 1,637,028 H. QUINN FUEL FEEDING MECHANI SM Filed Oct. 9, 1924 3 Sheets-Sheet 1 3 Sheets-Sheet 2 Filed 001;.

. 1,637,028 July 26, 1927. c H. QUINN FUEL FEEDING MECHANISM Filed Oct. a. 1924 s Sheets-Sheet 5 yuala/z'a Fiyj I Patented July 26, 1927.

UNITED STATES I 1,637,028 PATENT OFFICE.

CHARLES H. QUINN, OF SAN FRANCISCO, CALIFORNIA.

i FUEL-FEEIDING MECHANISM.

Application filed October 9, 1924. Serial No. 742,727.

An important object of the invention is to provide successively operable feed devices responsive to the energization of control circuits, or closing thereof by any means whatsoever, automatic or otherwise, for not only effecting fuel feeding but also for controlling the admission of secondary air and-correspondingly regulating the draft in the stack, the various control devices acting or functioning in sequence or rotation in the desired order, that is, when the ten'iperature of the lire box is to be raised, the stack draft is first increased, additional secondary air is next adn'iitted and finally the amount of fuel is increased; :and when the temperature is lowered the action is reversed, to

thereby insure maximum elliciency in the operation.

A further object of the invention is to provide fuel feeding mechanism and secondary air admission mechanism actuated by fluid pressure and controlled by electrical means responsive to the action of a suitable circuit closer. manual or automatic.

Still another object of the invention is the provision of draft control means within the furnace stack electrically controlled by movement of the means provided for controlling the fuel feeding means and secondary air admission means.

Another feature of the invention is the arrangement of the above mentioned control device in such manner and in such relation that failure, due to short circuits in the control circuit, will result in shutting down of the entire fuel feeding apparatus, closing of the secondary air inlets, and opening of the stack damper mechanism until the circuit is restored, in order that there will be, at all times, a stack draft which will remove gases of combustion and prevent flarebacks due to excessive pressure in the combustion chambers of the furnace.

\Vith these and other objects in view, the invention consists in the combination and arrangement of parts to be hereinafter more fully described and claimed, it being understood, however, that such changes may be made as will not depart from the spirit of the invention or the scope of the appended claims.

In the drawings chosen to illustrate a single embodiment of the invention and wherein like reference characters designa-te corresponding parts throughout the several views:

Figure l is a somewhat diagrammatic front elevation of a furnace equipped with my control mechanism, parts being shown in section, one unit being idle and the others in action.

EFigureQ is a view partly in elevation and partly in vertical longitudinal section,:showmg the furnace equipped with feeding mechanism and the draft control apparatua' one damper member being closed and the others open, the feed'and secondary air admission means being in operation.

Figure 3 IS a wiring diagram of the electrical apparatus.

Figure L is a detail view illustrating one of the valve mechanisms.

deferring more particularly to the drawings, the numeral 1 designates a furnace of any ordinary or preferred type having asso ciated therewith a boiler 2 for the generation of steam to be used in-a power or other plant. The furnace is equipped with the usual stack 3 provided for the purpose of giving the necessary draft'and carrying off gaseous products of combustion.

In carrying out theinvention I provide a battery or series offuel feeding units '4. of similar construction. While these :may vary in their details, depending upon the type of fuel utilized, I have shown, for convenience, a pulverized fuel feeding mechanism .in which each unit comprises a feed device 5 of the screw, blower or other type taking in fuel from a hopper, chute or the like 6, and discharging into a nozzle or con duit 7 leading into the furnace. The air blown =or fed in with the fuel furnishes a primary air supply. Exact details as to the feed device 5 arenot disclosed since such details form no part of my invention except as part of the general combination. The

feed mechanism 5 of each unit may be oper- IOU mon source of power, in which event the said mechanism 5 is adapted to be operated by rotation of a gear 8 in the manner hereinbefore described.

Figure 1 shows a series of such units arranged in spaced relation with their gears 8 adapted to be driven by means of gears 9 on a shaft 10. The gears 9 are normally rotatable or loose with respect to the shaft 10 and are formed with or carry clutch elements 11 of a cone or other type adapted to be engaged by other clutch elements 12, formed on or carried by shifting collar 13, splined on the shaft 10 so as to be capable of longitudinal movement thereon while rotating therewith.

Each unit further includes a piston rod 14 extending through a cylinder 15 and car-- rying a piston 16 within the cylinder. The rod of each unit is pivotally connected with a pair of toggle links 17 and 18, the former of which is pivoted at one end upon some suitable support such as a bearing 17 and the latter of which is pivotally connected with the collar 13. Obviously. upward movement of the piston rod will tend to straighten the links 17 and 18 and force the movable clutch element 12 into engagementwith the associated clutch element 11 for locking the gear 9 upon the shaft 10 for rotation therewith and consequent driving of the gear 8 of the feed device 5. The numeral 19 designates a compressed air pipe having branches 20 connected with the cylinders 15 of all the units. Tnterposed between these branch pipes and the cylinders are electromagnetically operated control valves indi cated at 21.. These valves, being themselves old and well knownand consequently not illustrated in detail, are so arranged that when they are opened they will permit compressed air to flow into the cylinders beneath the pistons 16 therein for moving the rods 14 upwardly to actuate the toggle links. Suitable springs 22 are provided for normally urging the pistons downwardly. It should be understood that any desired or necessary bleed or other ports 23 may be provided to avoid compression of air above the pistons and suitable ports may be provided in the valves '21, which ports open on the closing of said valves to permit exhaust of the compressed air beneath the pistons so that they may return to lowered position, under the influence of the springs when the electro-magnetic control valves are closed.

The furnace 1 is provided in one wall, preferably its front, with groups of openings 25 arranged in vertically spaced. relation and normally covered by movably mounted doors 26. The doors for each group of openings may be and preferably are connected by a rod 27 or the like so that they may be operated simultaneously and each piston rod 14 is preferably pivotally connected with a link 14, in its turn pivotally connected at 28 with the uppermost door of the associated group so that upon upward movement of any piston the doors 26 of the corresponding unit will be opened at the same time that the clutch mechanism for the feeding means is thrown into operation, thereby admitting additional or secondary air to the furnace in accordance with the rate of feed of the fuel.

In order that the stack draft may be automatically regulated by the means for controlling the feeding of the fuel and the admission of the secondary air, I provide a series of damper plates 29 pivotally mounted at 80 within the stack 3 and having crank arms 31 with which are connected links 32 in turn pivotally connected with rods 3 which extend downwardly and into the cylinders The rods carry pistons 35 operating within the cylinders and normally urged downwardly by coil springs 36. The muneral 37 designates a compressed air conducting p ipe having branches for supplying compressed air to the cylinders 34-, and interposed between the branches and the cylinders are elect:'o-magnetically operated valves similar to the above described valves 21 and likewise not shown in detail. These valves are so arranged as to permit compressed air to enter the cylinders beneath the pistons 35 therein for forcing them upwardly against the resistance of the springs 36. Any necessary bleed or other ports it) may be provided for preventing comp rcssing of the air above the pistons and any other ports may be provided for permitting escape of the air from beneath the pistons when the valves 39 are closed after having been opened. Under normal conditions the pistons 35 are at theirv lowermost positions and all the dampers 29 are in fully openv position. Y

in. order that the electro-magnets 39 in the valves 89 may be controlled by the fuel feed controlling mechanism, I provide the piston rods 14; with contacts 4-2 adapted to engage and bridge contacts tdand 4A the former of which are all connected with a common conductor connected with one term nal of a suitable source of current 46 and the latter of which are connected with the respective electro-magaiets 39 of the valves 89. The remaining terminals of these magnets are connected by a common conductor 47 with the other terminal of the source of current. lVhile any preferred on: cuit control mechanism may be provided for energizing the eleotro-magnets 21 of the valves 21, I have in the present instance illustrated a rotary drum 48 of insulating material carrying segments 49 of different lengths adapted to engage with contacts connected with the respective electro-m nets 21. The other terminals of these elec- Riff Ill)

tro-magnets are connected by a common conductor 51 with one terminal of the source of current 46, while the segments 49 are all connected with the other terminal of the source of current. If preferred, separate sources of current may be used for energizing the two sets of el'ectro-magnets as this is an immaterial detail.

In the operation. let it be assumed that the drum 48 is in such position that all of the segments thereon are out of engagement with the'contacts 50. All the electro-magnets 2 s are then deenergized and the springs 22 act to hold the pistons 16 in their lowermost positions. At such a time all the doors 26 are closed and all the clutch members 12 are out of engagement with the clutch members 11 so that the entire feeding mechanism is idle. The shaft 10' maybe. and preferably is, rotated at a constant speed by a suitable source of power. It will be noted that the contacts 42 are in engagement with and bridge the respective contacts 43 and 44, thus closing the circuits through all the electro-magnets 39" and maintaining the valves 39 in open position so that the pistons 35 will be held in elevated position with the dampers 29 closed. VVhenthe drum 48 is rotated by any means, such for instance as manually or by that disclosed in the hereinafter mentioned copending applications, it is obvious that the segments 49 will be brought successively into engagement with the associated contacts 50. lVhenever a segment 49 engages a contact '50, it is apparent that the circuit will be closed through the electro-magnet 21 connected with the latter and this will result in open ing of the valve and admission of compressed air into the associated cylinder 15 whereupon the piston 16 therein will be moved upwardly, forcing the piston rod 14 upwardly and straightening the toggle links 17 and 18 of the unit. This will cause engagement of the clutch element 12 with the adjacent clutch element 11 for locking the gear 9 for rotation with the shaft 10. Naturally, this will result in driving the gear 8 and operating the unit which feeds fuel through the conduit 7 into the furnace. The upward movement of the piston rod 14 causes all the doors 26 of the associated group to move upwardly and uncover the openings 25 for admitting additional or secondary air required for insuring thorough combustion. The upward movement of the piston rod also causes the contact 42 to move out of engagement with the cont acts 43 and 44, thus breaking the circuit through the associated electro-inagnet 39 and closing the valve 39 to cut off the flow of compressed air into the associated cylinder. hen this occurs, the piston within the cylinder is moved downwardly by the spring 36 and this results in opening one damper 29. When the drum 48 is turned still further, the successive segments 49 thereon will engage-the successive contacts 50 and energize the electro-magnets of the successive units for throwing additional units into service, the groups of doors being successively opened and the dampers being likewise correspondingly opened. In this way it is evident that the fuel feeding means, secondary air admission means and draft control means all operate in unison so that all requirements under different loaclcon- (lit-ions will be met.

A distinct feature of importance is that inthe event of failureof the current supply,

all the electro-magnets 21 will be deenergized, which will result in shutting down of the entire feeding mechanism and opening of all the dampers, until the: circuit is restored. This is necessary to insure, at all times, stack draft to remove gases of combustion and prevent back-fire in thecombustion chamloer of the furnace. I

A fuel feeding and draft controlling mechanism constructed in agcord ance with the present invention will operate automatically in accordance with the requirements of a power or heating plant or the like when. some suitable variable current or speed fluctuation responsive device is used for controlling the closing of the circuits through the successive electromagnetic air control means for the cylinders ofthe fuel feeding units. Logically, the mechanism will insure economy in fuel'consump-tion as the feeding units and draft devices may be rendered operative or inoperative in accordance with the work required of the furnace. At the sametime, the arrangement of the damper mechanism and secondary air admission means and their relation to the fuel feeding units will prevent either excessive or insuflicient draft or air supply and in this way it is apparent that the greatest efficiency will be insured.

I have not illustrated or described herein the means or mechanism for operating the drum 48 as hereinbefore described for the reason that one manner of operating the drum has been described in detail in m co-pending application, Serial No. 753,306, filed December 1, 1924, and in my other co-pending application, Serial No. 682,664, filed December 26, 1923, I have illustrated an alternative method for the operation of the said drum and it is to be understood that either mechanism may be utilized to actuate the device in the manner hereinbefore described.

Having now described my invention, what I claim is:

1. In furnace feeding mechanism, a series of fuel and air feeding units and means for successively throwing said units into operation and actuating them conjointly, each unit comprising a fuel feeding device, ,a

vice, an operative connection between said air supplying'device and said means for.

throwing the unit into operation, and an operative connection between the former connection and thestack draft control device.

3. In furnace feeding mechanism, a plurality of fuel. and air feeding units and means for throwing a variable number of said units into operation for simultaneous actuation, eaclr nnit con'iprising a fuel feeding device, a secondary air supplying device, a stack, draft control device, an operative connection between said air supplying device and said means for throwing the unit into operation, and an operative connection between the former connection and the stack draft control. device.

4-. In furnace feeding meclnmism, a series of fuel and air feeding units and means for successively throwing said. units into operation and actuating them conjointly, each unit comprising a fuel feeding device, a secondary air supplying device, a stack draft control device, a mechanical connection between said. air supplying device and said of fuel and air feeding units and means for successivelythrowing said units into operation and actuating them conjointly, each unit comprising a fuel. feeding device, a secondary. air supplying device, a stack draft control device, a mechanical connection between said air supplying device and said means for throwing the unit into operation, electropneumatically operated means for actuating the stack draft control device, and means operated by movement of said mechanical connection for controlling said electro-pneumatic means.

6. In furnace feeding mechanism, a series of fuel and air feeding units and means for successively throwing said units into operation and actuating them conjointly, each unit comprising a fuel feeding device, a secondary air supplying device, a stack draft control device. a mechanical connection tei'nveen said air supplying device and said means for throwing the unit into operation, electro-pneumatic means for operating the means for throwing the unit into operation, E-ltHil TOIDHQUGtlC means for throwing the stack draft control device into operation, and means operated by said mechanical connectiot-i. for controlling said last named electromagnetic means.

in testimony whereof I affix my signature.

; CHARLES H. QUINN.

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