US2088037A - Fuel regulating system - Google Patents

Description

` July 27, 1937. L sHELFHQUT 2,088,037

FUEL REGULATING SYSTEM Filed Jan. 13, 1936 2 Sheets-Sheet l July,2,7, 1937. L,m scHELFHou-r FUEL REGULATING SYSTEM Filed Jan. 13, 1936 2 Sheets-Sheet 2 egresado-1y `21, "1937,

, M t ff 12.088.037y` y l i g FUEL nriGuLATINGvsYsTEM 'i VSchelfliout, Chicago, y

Application Jsiiirsry 13. 193s, srislfNp. 58,823 u v slcisi'msrpxkol. 236:40) f i,'

My invention relates to a fuel :regulating systeni for` boilers,'furnaces, or thelike, and it has,

to do more particularly with mechanism for regulating the opening and closing of4 damper struc ture'. 'of

One of the objects of my invention'is'to provide an improved Vsystemjof the foregoing char- `Another object is to' provide an improved arrangement for controlling the operation of stack damper structures.

Still another objec t isnto provide a controlI system of the foregoing character wherein xnearfisjy are provided for retaining the boiler heat d ur- L ing non-'fuel-feedperiods byminim'izing heat lossV through the boiler stack; increasing the'length" of l non-fuel-feed periods; decreasing the fre` iquency oi fuel feed periods; andy reducing fuel consumption of the furnace;

A furtherobject is to providein a system off `the foregoing characterincluding fuel feeding .means vand a forced draft means,l anf'improved` stack` damper control wherein the ,damper is` opened and closed invtii'n'ed relationto the cutting in and out,`res`pectively, ofthe 'fuel feed.

and the forced draft means."

Otherobjectsar'e toyprovide a furnace, boiler,

' or the like, regulating system that is quite simplew in construction, is easy" tol install and maintain; is automatic in operation requiring a n1inimum` of attention, reduces "fuel' waste to the minimuxn`, and which insures greater efficiencyin the operi' ation of the furnace at'ainuch reduced Acost.'v v Y `is .heated by theboilerto desired extent for Other" objects and advantages willfbeco'me'ap parent as this' description progresses and by refj-V y particularly adapted 'for ahouseheating system. r

erence tov the drawings'wherein,

Figure 1 is aside-elevation of a furnace 'havv describe'd,' it is desirablefthattlie vfuel feed and the forc'eddrai'tA be cut out` when the water, or

ing one forni of regulating mechanism embodyi ing myinvention applied thereto;

Fig. 2 is a front 'elevational view ofthe struc- 1 Fig.' s is s diagrsmfiilustranng the electrical y circuit and its relationtto "theoperating partsof l the structure shownin Figs. 1y and 2;

Fig. `5`fis a view partly in section of a modified form of damperactuating devicewhich is elec- Itrically operat In the drawings, 1 have` illustrated my invenj'- tion as applied toa hot water heatingfboiler I0 having-a flre-box`(not shown) to which 'fueliin 5 this instancecoal) is fed by an underfeed type of invent/i011'.

byan electricmotor I3. It Iwill be understood, 5

however. that any other'type of boiler or furnace may be used, and any other type of feeding means having utility in'connection lwith my invention l may v'be employed without departing from myv j f In the use of fuel feedingl structuresfof Vthe foregoing character, it is customary .to'ernploy forced'draft means and,.toftl1at` end, I employ la fan-typeblower I4 dri'ven by an ,electricmo-.f l" u tor is (Figrs) and connected tothe boiier'nreffiis y boxV-by aronduit isjial 1). friiejbmwer jig-4 is preferablyzlocatedat the rear of v'the boiler v structure independently ofthe. stoker Il but'j it will be appreciated thatfit may also be Vdif.v f 1 rectly associated witl'ilthe'stoker at the'frontof 20 x `uns boiler; or litymay beH connectedwith the' boiler vaiany other suitable point. The boiler structure is further provided -with a flue or stacki'l in which there' is' located a damper I8 pivotally yst ipp'orted bya shaft I 91fin25 thswau of themes-(Fig: 1). "The shaftwls j projects through the wall ofthe stack for recepf tionI Lof'an` actuating ann 20 whichLas will be n described more particularly" lhereinafter, is

yadapted'jto beactuatedto swingv the damper f8 l30 toopen andclosed positions. l

'riiefboiier mjfuruier inciuqes schsmber 2 1,l or the like. adapted tocon'tainzwater 22 which l anyfdesired purpose. The structureillustrated is `35 I n the use ofstructuresof the character just other mediumto be heated,V reaches adesired40 temperature and I accomplish this 'in the following manner: 'Ihe 'stoker motor i3 and .blower motor I5 are connected in 'series in an electrical circuit indicated by the numerals za z4, 25, 2s and 21. This circuit is controlled by a switch A28 45 which may take anyisuitable form andmay be manually or y'automatically controlled or both.

" Anoth'er and thermostatically-controlled switch 29 is also located in the electrical circuit in'series '.with the motors I3 'and I5.v The switch 29 may 50 ltake any suitable form controlled by a 'thermo` static element 30fdisposed inthechamber 2i in contact with the water therein. The thermostatic element ispreferably of standard formlconnected to the switch 29 in such away that, when 55 the temperature of the water reaches a certain point, it will open the switch 29 and the electrical circuit thereby cutting out the motors I3 and I and stopping the fuel feed and forced draft. Also, when the temperature of the water is lowered below a certain peint, the thermostatic element 30 functions to permit closing of the switch 29 thereby closing the electrical circuit and cutting in the motors I3 and I5 and starting fuel feed and the forced draft. The thermostat and switch control 29, 38 may take any suitable and well known form which is adjustable to cut in and out at variable water temperatures. The switch 23 may be termed a line or main power switch, and is usually cut in constantly, unless some over-load condition takes place, so long as it is desired to keep the boilerl in operation.

It will be seen that the foregoing, in initially I duced to a predetermined point, as above stated,

at which time the fuel feed and draft are again cut in, and this operation is continued over and over again.

When the fuel feed is cut in and the fan blower isvin operation, proper draft conditions require that the stack damper I8 be open. When the fuel ,feed is stopped, it is desired to conserve the boiler heat as far as possible and for thatpurpose it is desirable that the damper I8 be closed at this time to. minimize heat loss through the stack I'I. If the opening ,andl closing of the damper I8 is accomplished manually, the constant attention of an operator is required, due to the cutting in and out of the feed as described; otherwise aconsiderable waste of fuel will take place and the stoker mechanism will be worked at its maximum due to the frequency of feed cutin periods and the shortness of the feed cut-out periods.

My invention contemplates the provision of means for automatically opening and closing the damper I8 in direct timed relation to the cutting` in and out of the fuel feed and the forced draft. This is accomplished in accordance with my invention by inserting damper control means in the electrical circuit in series with the motors I3 and I5 vand the Iswitches 28 and 29.V In the operation of structuresv of this character, it is found that best results are obtained by having the damper open simultaneously with the beginning of fuel feed'and the beginning of forced Ydraft application and to haveit completely closed by the time that the fuel feed is stopped and the forced draft is no longer applied. In the use of i the fan blower above described, there is a continued but 'gradually reducing rotation of the fan I4 due to its own momentum after the circuit4 to its motor I5 is opened so that the forced draft is applied for a short time after the fuel feed is stopped, and to take care of this condition, I provide a damper control arrangement whereby the closing movement of the damper I8 is accomplished with a somewhat delayed action to compensate for the delayed draft cut-off.

In carrying out the foregoing features of my Y motors I3 and I5, so that when the circuit is opened by the switch 29 the motor I3 and air compressor will be stopped simultaneously with the cutting out of the fan blower and the fuel feed.

The air compressor 3I supplies air through a pipe 32 to a bellows-type diaphragm 33 having its lower edge secured to the bottom 34 of a casing 35 in sealed condition with respect Ythereto. The top of the casing 35 is provided with an upstanding lug 36 pivotallysupporting, as at 3'I, a lever arm 3B. The top of the diaphragm 33 is also provided with a lug 39 projecting upwardly through the top of the casing 35 and pivotally connected to the lever arm 38 as at 40 to one side of the pivot support 31. The right-hand end of the lever `arm 38 (as viewed in Figs. 1 and 4) is connected to a chain 4I passing over a 'pulley 42 and connected to one end of the damper arm 20. The other end of the lever arm 38 supports weight members 43 which may be adjusted along the lever arm toward and from the pivot 3'I to vary somewhat the rapidity of the collapsing action of the diaphragm 33 under conditions which will now be described.

When the air compressor motor isk cut in along with the feed and blower motors I3 and I5, air is immediately supplied to the then-collapsed diaphragm 33 raising the weighted end of the lever arm 38 and lowering its other end to swing the damper arm 20 and damper I8 to an open position. The air compressor 3| maintains the desired pressure within the diaphragm 33 to hold the`damper full open so long as the fuel feed means .is cut in, and anysuitable means (not shown) may be employed for intermittently cutting in andlout the air compressor independently of opening of the main electrical'circuit sol that substantially a predetermined pressure is maintained in the diaphragm by the compressor. However, when the main circuit 23-21 is opened by the switch 29 (or switch 28) and the fuel feed is stopped, the compressor 3I isrsimultaneously stopped and air is exhausted from the diaphragm 33 and through the compressorstructure by vrtue of the natural looseness of the operating parts ofA the latter. If found desirable, though, special provision may be made for bleeding air from the diaphragm when the compressor is stopped. When the compressor. is stopped, the weights 43 on the lever arm 38 cooperatively with the weight 44 on the damper arm I9 (opposite its chain connection) lower the weighted end of the lever arm 38, raising its other end and closing the damper I8. This action is a delayed one because of thetime required for exhausting of air from the diaphragm 33 through the compressor structure and this delayed action, togetherwith the rate of admission of air to the diaphragm 33, is

Vcontrolled by a needle valve 45 in the compressor casing cooperating with a, restricted opening 46 between the compressor chamber 41 and the pipe 32. In this way, the damper will move gradually toward its closed position and this action is delayed to such an extent that the damper is not fully closed until the fan blower I4 has completely stopped and a forced draft is no longer applied to the boiler. On the other hand, the cutting in of the Aair compressor 3I immediately builds up -a suicient pressure Within the diaphragm 33 to cause opening movement of the dampers abover explained practically simultaneously `with the starting of the fan blower I4 and the fuel feed.

In certain cases, I may employ the electrical 20 casing 51 lfor variably controlling the exhaust of stem 53 pivotally connected to the arm 50 as at control means illustrated in Fig. 5 for opening and closing the damper. This structure includes `a lever arm 50 similar to the lever arm 38 and connected to the stack damper as by the chain 4l of Fig. 1. The lever arm 50 is reciprocated about its pivot 5| by a solenoid 52 having its core 54. The solenoid is supported by a suitably llocated bracket 52. The solenoid stem is provided with apiston member 55 operable in the chamber'y 56 formed in the casing 51 which serves to guide the arm 50.

the solenoid stem is cushioned by a floating spring the movement of the solenoid stem in actuating Upward or opening movement of 58 freely surrounding the stem 53, and free movement of the piston 55 in both directions is permitted by bleed openings 59 and 60 in the casing 51. If desired, the upward or opening movement of the solenoid stem 53 may be further cushioned by a needle valve 6| 'adjustably mounted in the air from in front of the piston 55 to and through the casing opening 60. A similar arrangement (not shown) may be used, if desired, in connection with the opening 60. The solenoid is located in the main electrical circuit in series with the feed and fan motors similarly to the air compressor motor of the first-described form. When the circuit is closed, as previously described, the solenoid is energized raising its stem 53 to open the damper and vice vers'a when the main cir.

cuit is opened and the solenoid is de-energized.

I believe that the operation and advantages of my invention will be obvious from the foregoing. The arrangement that I employ is quite simple, but effective in operation. The stack damper is closed only under no draft conditions, and it is quickly opened to accommodate draft conditions when the fuel feed is started. This feature of my invention conserves boiler heat and increases the length of the feed cut-out periods and,

consequently,decreases the frequency of the feed cut-in periods. Such an arrangement tends to eliminate the human element in the operation of the boiler, and it cuts down the cost of operation not only from that standpoint'but also by reducing fuel waste to the very minimum.

It is to be understood that, although I have shown and described only two forms of my invention, other changes in `details and arrangements of parts may be resorted to without departing from the spirit and scope of my invenl tion as defined by the claims that follow.

I claim:

1. In a system of the class described for a furnace, boiler, or the like, `having a water heatn ing chamber-and a stack with a damper therein,

Y draft device and to close said damper when the f i a fuel feeder, a forced draft device, a damper actuator, motor means for operating said fuel feeder, draft device and damper actuator, connected in series in an electrical circuit, a thermostat device in said `water chamber, and a switch in said electrical circuit in series with said motor means and actuated by said thermostatdevice to open said circuit to cut out said feeder and water in said chamber reaches a certain temperature and vice versa when the temperature of said water is lowered below a certain point, said damper actuating device being constructed to `delay the closing action of said damper to approximately accommodate the gradual reduc.- ing draft applied by said draft device under its own momentum when its motor means is'cut out of operation.

v2. In a system of the class decribed for a furnace, boiler or the like, having a heating chamber and a stack with a'damper therein, a

fuel feeder, a forced draft device, a damper vactuating means including a member connected to said damper and fluid pressure supply means adapted by the direct application of fluid pressure to said member to move the latter to open said damper, which said member is moved by the release of iiuid pressure therefrom to close said damper with a delayed movement, motor means for operating said fuel feeder, draft device, fluid `pressure supply means, connected in series in an electrical circuit, a thermostat device associated with said chamber, and a switch in said electrical circuit in series with said motor means and actuated by said thermostat to open said circuit to cut out saidfeeder and draft device and also to cut out said fluid supply means to close said damper when acertain predetermined temperature conditionis reachedin said chamber and vice versa when the temperature condition in vsaid chamber,

actuator comprising a reciprocabler member, a

connection between said member and said damperV and an electrical device for actuating said member when said electrical device is energized so as to move said damper to and hold it in an open position; motor means for operating said rfuel feeder and draft device, said motor means and said electrical device being connected in series in an electrical circuit; a thermostat device in said water chamber; and a switch in saidelectrical circuit in series with `said motor means l and said electricalv device and actuated by said thermostat device to open said circuit to `cut out lsaid feeder and draft device and to deenergize said electrical device to closesaid damper when the water reaches a certain temperature and vice versa when the temperature of said water is lowered belovva certain point, said damper actuating device k,operating to delay the closing action'of vsaid damper to approximately accommodate ythe gradual reducing draft applied by said draft device under its own momentum when its motor meansy is cut out of operation.

LOUIS SCHELFHOUT.

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