US1098935A - Method for controlling combustion. - Google Patents

Description

P. 3. BROWN. METHOD FOR CONTROLLING COMBUSTION.

APPLICATION FILED NOV. 28, 1911.

Patented June 2, 1914 4 SHEETSSHEET 1.

1H. BROWN. METHOD FOR CONTROLLING COMBUSTION. APPLICATION FILED HOV 28,1911.

1,098,935, Patented June 2,1914.

4 SHEETS-SHEET 2.

. I A 9 monmzvs F. H." BROWN. METHOD FOR CONTROLLING COMBUSTION.

APPLICATION I'JLED NOV. 28, 19H

Pe mtented June 2, 1914.

4 SHEETS-SHEET 3.

WITNE$SES ATWRNEYS F. H. BROWN.

METHOD FOR CONTROLLING COMBUSTION.

APPLICATION FILED NOV. 28,1911,

LUQQflSfi Patented June'2,1914.

4 SHEETS-SHEBT 4.v

monnsvs nate the manual control or interference with FRANCIS H. BROWN, RIDLEY PARK, PENNSYLVANIA;

METHOD FOR CONTROLLING COMBUSTION.

Specification of Lettei's Patent.

Patented J une 2, 1914 Application filed November 28, 1911. Serial No. 662,814.

To all whom it may concern:

Be it known that I, FRANCIS H. BROWN, a citizen of the United States, residing at Ridley Park, Delaware county, State of Pennsylvania, have invented a new and useful Method for Controlling Combustion, of which the following-is a specification.

The object of my present invention is to provide a new method of controlling combusti on wherein the rate of combustion in one or more furnaces will be automatically maintained uniform in all furnaces regardless of the thickness of the bed of fuel, that is to say, the rate of combustion will be maintained the same on a thick fire as on a thin fire and the rate of combustion on all the fires will simultaneously and automatically vary in accordance with the variations in the demands on the furnaces or the demands for steam and the entire operation of controlling combustion is rendered automatic, thereby enabling me to entirely elimithe draft for combustion, its introduction to the ash pit of each furnace, the exit of the products of combustion from the furnace,- and the supply of fuel to the furnace in" gardless of the thickness of the fire so that the conditions of control could not be maintained uniform and therefore satisfactory results were only obtained when the thickness of the bed ,of fuel, the load requirements and the draft conditions were coincidently in a certain relation.

In my present invention the attendant or fireman does not in anyway interfere with the admission of the draft-supply to the ash pit for combustion, or the supply of fuel to the furnace, or the discharge of the products of combustionfrom the furnace.-

In my present invention, I maintain a predetermined condition-pf pressure (above the bed of fuel under all rates of combustion and a varying draft pressure in the ash pit, said ash pit pressure varyin in accordance with the stack draft, the thickness of the bed of fuel and the load requirements, so that the'rate of combustion will be the same on a'thick as on a thin fire, all of said control. varying simultaneously and automatically according to the demands for steam and in such a manner as to maintain a uniform steam pressure in the boilers and obtain a very high furnace and boiler efficiency.

My invention further consists of a novel system of controlling combustion wherein thedraft producing mechanism is operated at a constant speed, producing a fixed draft pressure in a main draft discharge conduit, and the chimney draft is varied according to variations in the steam pressure, while the admission of air to the main draft conduit, the operation of the stoker and the means for controlling the exit of the products of combustion from the furnace are all automatically controlled by variations in the steam pressure, while the admission of draft for combustion beneath the bed of fuel in ea'chfurnace is individuallyand automatically controlled by variations of pressure Within the furnace- In the'accompanying drawings I have shown a sectional elevation of one type of furnace in conjunction with which my novel method may be employed with very advan tageous results, although it is to be understood that the same is adapted to be employed with any desired type of furnace and is not limited, to use with the type herein shown for the purpose of illustration.

Figure" 1 is a sectional elevation of a furnace showing "a device embodying my invention in operative relation with respect thereto. Fig. 2 is an end elevation of a portion of Fig. 1. Fig. 3 is a sectional eleva tion of another embodiment of. my inven tion, showing more particularly the electrical control of the fuel feeding means. Fig. 4 represents a sectional elevation of the steam pressure actuated regulator seen in a portion of Fig. 1. Fig. 8 represents aside elevation of a portion of Fig. 1. Figs. 9 10 and 11 represent, respectively, sectional views of portions of Fig. 4:. Fig. 12 represents a side elevation showing one manner of connecting the engine to the Stoker grate. Fig. 13 represents a side elevation showing one manner of connecting the electric motor, seen in Fig. 3, to the stoker grate. Fig. let represents a sectional elevation of the furnace pressure. actuated regulator seen in Fig. 1. Fig. 15 represents a section on line m-w Fig. 14. Fig. 16 represents a plan View having certain parts removed for clearness of illustration.

Similar numerals of reference indicate corresponding parts in the figures.

Referringv to the drawings, 1 designates a furnace of any desired type, which in the present instance'is provided with an endless grate 2 beneath which. is located the'ash pit 3. The ash pit is provided with a wall t at one end so that the air in the ash pit will not escape "through the ash receiving chamber 5.

6 designates the furnace and combustion chamber above which is located a boiler. 7.

8 designates a connecting flue through which the waste products of combustion pass from the furnace to a main fine 45.

9 designates a steam conduit which leads to an automatic boilerpressure actuated regulating mechanism 10 the construction of which will hereinafter be fully set forth. The regulating mechanism 10 is provided with a diaph ngm which is actuated by the variations ofsceam pressure to control a valve mechanism 11 which in turn controls" the admission of motive fluid to actuate a motor 12 which latter controls the rocking movement of lever'13. The lever 13 controls a valve mechanism 1ewhich latter controls the passage of steam through a conduit 15 which is provided with a suitable valve it the steam passing from the valve mechanism 14 to a steam conduit 17 provided with a valve 18 and leading to a motor 19 which controls the operation of a stoker grate 2 of any desired or conventional'type with which the hopper 20 com municates, and since any desired type of Stoker mechanism may be employed, .1 have deemed it unnecessary in the present instance toillustrate and describe in detail the construction and operation of such a construction.

20 designates a hopper which'discharges on to the stoker grate 2. This steam 'con duit 15 has a branch conduit 21 leading therefrom which is provided with a valve 22 said branch conduit 21 leading to an engine driving a draft producing mechanism-2 i5 such as for example, a fan, which is adapted to operate at a constant speed.

intense The draft producing mechanism '24. is provided with a draft discharge conduit 25 which leads to a main draft conduit 26 extending in front of a battery of boilers and having branch conduits 27, each of which leads to one of the ash pits 3, as will be apparent to those skilled in this art.

28 designates dampers in the fines 8 leading to the main line 45, and operatively connected with a cable 29, and provided with counterbalances 30. The cable 29 passes over sheaths 32 which are connected with each other by cables 33 so that the cable 29 will move the dampers 28 in one direction, and the counterbalances .30 will move the same in the opposite direction. The cable 29 passes over pulleys 31 and is connected with the pivoted lever 13- whereby the regulating mechanism 10 will automatically control the movement of the dampers 28 in accordance with the variation of steam pressure. p

36 designates a furnace pressure actuated regulator of any desired or conventional.

type, the construction of which will be hereinafter fully set forth, itbeing understood that it is only necessary that a pressure regulator be employed which communicates with the interior of the furnace so that a variation of pressure within the furnace will operate a cable 37 which latter passes over rollers 38 and is operatively connected with a damper'39 located in a branch 27 and provided with a counterbalance 40. v

The damper 4-1 in the connecting flue 8 .is provided with a cable 42 passing over pulleys 1-3 tothe front of the boiler, thus providing manual means to start or stop' the boiler when desired by opening or closing the damper. Each damper 41 is provided with a counterweight 4A. Particular attention is directed to the fact that the damper 41 is never employed to regulate the combustion but is only used when it is desired to place one boiler in operation or out of operation, it being apparent that when the damper a1 is closed the damper 39 will also be closed.

.In operations of-this character as hereaccordance with any change in the pressure within the furnace and the thickness of each fire, so that a thick fire oflering more resistance to the draft will get a greater draft pressure and volume in the ash'pit while the draft on the thin-fire would be corre-' spondingly cut down. p I

The construction and operation of the regulator 10 will now be described, special attention being directed to Figs. 1 to .13 inclusive. The steam passing from the boiler 7 through the conduit 9, passes into *the chamber 50, above a diaphragm which is constructed and operates in the manner now to be fully set forth,

51 designates an upper diaphragm, and 52 designates a lower diaphragm, between which is located a central spacing block 53.

54: designates spacing rings,any desired -number of which may be employed and which form a flexible joint near the outer periphery of the diaphragms 51 and 52.

55 designates a spacing annulus between the diaphragms 51 and 52, the parts being secured in assembled condition by means of fastening device .56, which pass through the diaphragms 51 and 52, the annulus 55, and the two parts of the casing of the regulator 10. The central spacing block 53 is apertured as indicated at 57, in order that a bar 58 maybe pivoted therein on the pivot pins 59 and 60, as will be best understood by reference to Fig. 16L This bar 58 has secured thereto an arm 61, mounted in an aperture 62 which extends through the central spacing block 53, the rings 54 and the spacing annulus 55, and is pivotally supported on the pins 63 and 64.

65 designates an aperture extending through the spacing block 53, the rings 54 and the annulus 55, as best seen in Fig. 12, in order that an arm 66 secured to the bar 58 may freely move therein, so that the movement of the diaphragm may be communicated to mechanism exterior of the diaphragm casing in such a manner as to entirely eliminate the friction-which ordinarily takes place in devices of this general characterl The diaphragm construction herein described, forms thechamber 50 on one side of the diaphragm and a chamber 67 on the opposite side'thereor", and the standard of pressure which is desired in'the chamber 67 is provided by the proper actuation of the valve controlled. conduit 68 which communicates with both of said chambers, it being seen that the liquid in the chamber 67 seals the lower open end of an inverted container 69, thereby forming an air cushion 70 within such container, the air cushion being varied as desired by controlling the fluid passing through the valve controlled conduit 68 until the desired standard of pressure is provided on one side of the diaphragm. The arm 66 has connected therewith an arm 71,

upward movement of the piston ,which latter, by means of an adjustable cona ,lever- 82 fulcrumed at 83 to a bracket 84,

carried by a piston rod 85. The bracket 84: is prevented from rotating by means of the rod Sid-passing through an aperture87, in

the casing 12. The lever 82 is connected with a valve stem 88, provided with a plurality of heads 89 and 90 and a reduced neck 91. with ports in avalve bushing 92 which is secured in the piston 93 having the enlarged heads 94 and 95 and a reduced neck 96; The

casing 12 is provided with a port 97, see

FigA, whereby motive fluid passes into the chamber of the casing 12 between the heads 94 and 95, and the flow ofthe motive fluid to actuate the piston 93 is-asiollows:-The motive fluid passes from the internal chamber of the casing through a port 98, and through the port 99 in the valve bushing 92 into the chamber 100. Assuming that the valve stem '88 is moved downwardly the motive fluid will pass from the ports 99, around the reduced neck 91 of the valve, and since the valve head 90 has uncovered the ports 101 the motive fluid will pass through the passages 102, beneath the piston 93, and cause the same to move upwardly, it being understood that assuming that the diaphragm does not move the movement of the piston 93 will cause the valve head 90 to register with the port 101 on a predetermiigd n such upward movement of the piston 93, and when the valve heads 89 and 90 have changed their position .to reverse the move ment of the piston 93 the motive fluid in the The valve heads 89 and 90 coiiperate chamber 103 will exhaust through the passages 102 the ports 1.0 1, and the port 105 in vthe lower end of the valve bushing 92, and

thence through the hollow piston stem-106,

the passage 107 in the brackets 108, and

thence through the conduit 109 to a desired point of utilization or discharge. :li' the valve heads 89 and 90 move upwardly, the valve head 90 will close the ports 101, and

the valve head 89 will open the ports 110;

connected therewith the pin 118, which engages the slot 119 of the lever 13, will cause.

said lever to be rocked on its fulcrum 120 and through the medium of the slot 121 and the pin 122, imparting a travel to the valve rod 123. The valve rod 123 has connected therewith a cup shaped valve 124, having ports 125 at its closed end, in order to balance' the same. The valve mechanism 14 is provided with an inlet port 126, with which the steam conduit 15 communicates, and with a'discharge port 127, with .which the The inlet 126 conduit 17 communicates. communicates with an annular chamber 128, having ports 129 in its side with which latter are adapted to register ports 130, in the valve 124.

causing a partial rotation of the valve during such longitudinal movement. The valve rod 123 has adjustably connected therewith a shoe 131 whichengages a guide 132, carried by a bracket 133, which is pivoted at 134 to the arm 135 of a split sleeve 136 provided with a screw 137, whereby the same may be fastened to the casing of the valve mechanism 14. Thebracket 136 has mounted thereon a worm 138 which meshes with a rack139 on the bracket 133 whereby the in clination of the guide 132 may be varied as desired, thereby varying the amount of partial rotation of the valve 124, and thus the amount of steam passing from the conduit 15 to the conduit 17 so that the motor 19 controlling the stoker, illustrated as comprising the traveling grate 2 is automatically controlled in accordance with variations of speed pressure.

The construction and operation of the pressure regulator 36 will be clearly apparent from Figs. 1, 14 and 15. The casing'140 has an apertured extension 141 communicating with the combustion chamber 6 of the furnace whereby the pressure in the fur-' nace is exerted against a diaphragm 142 having its outer periphery fixed as at 143, provided with a plate 144 to which is adjustably connected one end of the lever 145, by means of a set screw 146 which is in swiveled connection with the plate 144. The lever 145 is fulcrumed at 147 and provided with an arm 148, to which is pivoted an inverted. container 149 having a removable plug 150. The open end of the container cable 37, whereby the valves or dampers 39,

of each individual furnace are automatically controlled with variations of pressure within its respective furnace. The exhaust in the valve mechanism 154 passes through a discharge conduit 162 into the container 163, in order to maintain a constant level therein, said container being provided with a discharge conduit 164.

165 designates a valve controlled conduit adapted. to communicate with a source of fluid supply, whereby the volume and pres sure of the cushion 151 may be varied as desired.

The operation and purpose of my novel method will now be readily apparent to those skilled in the art to which this invention appertains and is as follows :As the steam pressure begins to lower, the regulating-mechanism 10, which is controlled by variations of steam pressure, will cause the lever 13 to be rocked on its fulcrum thereby causing the cable 29 to open the dampers 28. As the pressure within the furnace varies the pressure regulator 36 will be actuated thereby causing the cable 37 to actuate the damper 39 and thus permit the air for combustion to pass into the ash pit 3 beneath the bed of fuel on the endless grate 2.

Particular attention is directed to the fact that in my present invention 1 eliminate entirely the manual control of the draft for combustion and maintain the same rate of.

combustion on all firesalike regardless of the differing thickness of the various fires and the entire operation is automatic. The stack damper 28 and the stoker (where mechanical stoking is employed) are automatically controlled by variations in steam pressure and the admission of air to each ash pit is automatically controlled by the variations of pressure within the furnace above the bed of fuel. As the bed of fuel increases in thickness it is necessary to increase the draft pressure to maintainthe same rate of combustion and in order to maintain a uniform condition of pressure above the bed of fuel as the pressure in the combustion chamber decreases ,the regulator 36 will be actuated in adirection to increase the draft pressure below the' bed of fuel and thereby increase the combustion. it is also sary to vary the draft pressure below the bed of fuel as the damper in the main flue is moved in the direction of either opens.

ing or closin due to the rise or fall of the steam pressure, and this is very accurately and reliably done by the employment of my novel controlling devices. Under these con ditions just the amount of air necessary to Support combustion to meet the demands for steam will be supplied and no more, and each fire will be made to perform its share of the work, the result of which is that a constantly high furnace efficiency is obtained which will not. be interfered with by the fireman or engineer attempting to manually control the draft.

The steam pressure actuated regulator 10 is described and broadly claimed in a copending application Serial No. 583,176, filed Sept. 22, sure actuated regulator is described and broadly claimed in a co-pending application.- Serial #604,613, filed Dec. 8, 1911.

In the broad and generic scope of my invention it immaterial whether the speed of the draft producing mechanism is .automatically controlled by the variations of steam pressure or driven at a constant speed by an electric or other motor, as indicated at 46 in Fig. 3, it being understood that the damper 39 would operate in' the manner above described in the operation, and it is also immaterial whether the stoker is con trolled by variation of steam pressure controlling the engine driving the stoker as described in the operation or controlled by Variations of steam pressure through the lever 1.3, as seen in Fig. 3 wherein the lever 13 is adjustably connected with a lever 47 of a rheostat 18 controlling the speed of the electric motor 4-5) which drives the stoker illustrated herein as a traveling grate 2. Both manners of operating the fuel feeding means and the draft producing mechanism have given very advantageous results in practice, and it is to be understood that both are within the spirit and scope of my i11- vcntion.

It will be apparent thatin accordance with my present'invention, I control the d aft pressure anterior to the burning fuel by first automatically varying the pressure posterior to the burning point of the fuel, in accordance with variations of load on the furnace, and I then utilize the variations of pressure thus produced to automatically vary the introduction of air anterior to the burning point of the burning fuel, the result of which is that one is enabled to maintain a substantially constant difference of pressure between the pressure anterior to and the pressure posterior to such burning point, and the standard of such difference of pressure may bevaried by adgustmg the furnace pressure actuated regulator 36.

Having thus describedmy invention, what 1910, while the furnace pres- I claim as new and desire to secure by Let ters Patent, is 2-- l. The method of controlling combustion in furnaces, which consists in varying the pressure above the fires to vary the rate of combustion on all the fires, simultaneously and proportionately to variations of load on the furnaces, and varying the draft for combustion to maintain an equal rate of combustion on all the fires which is substan tially constant for varying thicknesses of the beds of fuel.

2. The method of controlling combustion in furnaces, which consists in varying the pressure above the fires to vary the rate of combustion on all the fires, simultaneously and proportionately to variations of load on the furnaces, and. automatically varying the draft for combustion for each individual fire in accordance with the thickness of its bed offuel to maintain an equal rate of combustion on all the fires.

3. The method of controlling combustion in furnaces, which consists in varying the rate of combustion on all the fires 'simultaneously and proportionately to variations of steam pressure to thereby vary the pressnrein each individual furnace, and utilizing the variations in pressure in each individual furnace to vary the draft for combustion in accordance with the thickness of its bed of fuel and thus maintain an equal rate of combustion on all the fires.

4:. The method of controlling combustion in furnaces, which consists first in varying the rate of combustion on all the fires, simultaneously and proportionately to variations of load on the furnaces to vary the condition of pressure within each furnace, and then automatically varying by means of such variations in pressure, the draft for combustion for each individual fire in accordance with the thickness of its bed of fuel to maintain an equal rate of combustion on all the fires.

5. The method of controlling combustion in furnaces which consists in varying the pressure above the fires to vary the rate of combustion on all the fires simultaneously and proportionately to variations of load on the furnaces. varying the draft for combustion for each individual fire in accordance with the thickness of its bed of fuel to maintain an equal rate of combustion on all the fires, and automatically varying the fuel feed in accordance with the variation of load on the furnace.

6. The method of controlling combustion in furnaces, which consists in varying the pressure above the fires, to vary the rate of combustion on all the fires proportionately to variations of steam pressure in the .fur-

the fuel feed in accordance with variations of steam pressure, and automatically controlling the introduction of draft beneath the bed of fuel of each individual furnace in accordance with the variations of pressure within each individual furnace.

7. The method of controlling combustion in furnaces, which consists in automatically varying the pressure above the fires to vary the rate of combustion on all the fires in accordance with variations of steam pressure, feeding air to the ash pit of each furnace, automatically controlling the introduction of air into each ash pit in accordance with the variations of pressure within its respective furnace, and in accordance with the thickness of the bed of fuel of each individual furnace to maintain an equal rate of combustion on all the fires, feeding fuel to the fires, and automatically controlling the fuel feeding means simultaneously and proportionately to variations of load on the furnaces.

8. The method of controlling combustion in a furnace, which consists in first varying the pressure within the furnace in accordance-with the variations in steam pressure, and then utilizing the variations in pressure thus formed within the furnace to antomatically control the admission of draft trolling the exit of the products of combustion from the furnace by variations of steam pressure to first vary the pressure within the furnace, second automatically varying the draft beneath the bed of fuel in accordance with the thickness of the bed of fuel and the condition of pressure within the furnace above the bed of fuel, automatically controlling the fuel feed by variation of the steam pressure, and actuating the draft producing means at a constant speed.

11. Themethod of controlling draft pressure in the ash-pit of a furnace, which consists in first automatically varying the pressure above the bed of fuel in accordance with variations of load on the furnace, and in utilizing the varitions of pressure thus produced, to automatically vary the introduction of air into the ash-pit, and thereby maintain a substantially constant difference of pressure between the pressure above the bed of fuel and the pressure in said ash-pit.

in furnaces, which consists in first changing.

the stack or induced draft on a plurality of furnaces'to vary the rate of combustion on all the fires simultaneously and proportionately to variations of load on the furnaces, thereby changing the condition of pressure above the beds of fuel, then utilizing such change of furnace pressure to vary the introduction of draft for combustion on each individual furnace according to the resistance offered such draft by the thickness of its bed of fuel to thereby maintain an equal rate of combustion of all the fires.

14. The method of controlling coinbus tion, which consists first, in automatically varying the conditions within the furnace in accordanpe with the variations of load on such furnace, and then utilizing the variations of conditions within the furnace to vary the draft for combustion in accordance with the resistance offered such draft.

15. The method of controlling combustion in furnaces, which consists, first, in varying the conditions within each individual furnace in accordance with the variations of load on each furnace, and then utilizin the variations in condition in each indivldual furnace to automatically control the introduction of draft for combustion for such furnace in accordance with the variations in the thickness of its bed offuel.

16. The method of controlling combustion which consists first, in automatically vary' ing the conditions in the furnacein accord ance with variations in load on the furnace,

and then varying the draft for combustion in accordance with such variations and the varying resistance offered the draft for combustion introduced beneath the bed of fuel.

17. The method of controlling the draft pressure anterior to the burning point of the burning fuel in accordance with variations in load on the furnace, -which consists in first automatically varying the pressure posterior to the burning point of the fuel, and then utilizing the variations of re'ssure thus produced to automatically an correspondingly vary the introduction of air anterior to the burning point of the fuel and thereby maintain a substantially constant difference of pressurebetween the pressure anterior to and the pressure posterior to said burning point of the fuel.

18. The method of controlling combus- 5 tion, which consists in automatically varying the conditions within the furnace in accordance with Variations in load on the furnace, and utilizing the varying conditions Within the furnace to control introduction of draft the bed of fuel.

FRANCIS H. BROWN. lVitnesses H. S. FA RBANKS, C. D. MCVAY.

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