US1956608A - Furnace control system - Google Patents

Description

May l, 1934a G. w. BAILEY FURNACE CONTROLSYSTEM Filed April 1,1, 1932 4 Sheets-Sheet' l O O 0 00060 b GEORGE WBH/LEY ATTORNEY M; i, 1934- G. w. BMM-:IYI 1,956,608 i FURNACE CONTROL SYSTEM Filed April 11, 1932 4 Sheets-Sheet 2 INVENToR ATTORNEY May 1, 1934.

G. W. BAILEY FURNACE CONTROL SYSTEM f vl E MR w Wv Em w., fw

Fi1edApri1 11. 1952 @fw my ATTORNEY May1,1934. G. w. BAILEY 1,956,608

FURNACE CONTROL SYSTEM Filed April 11. 1932 4 sheets-sheet 4 .-EIS' 1 FIG.4

FIG .6

Genres W Bfy/LEY INVENTOR 'BYMA'A A ATTORNEY 'Patented May 41, 1934l um'rla'o` STATES PATE-Nr OFFICE FUBNACE coN'raoL SYSTEM George W. Bailey, Cortland, N. Y. Application April 11, 1932, Serial .No..604,4'58

'14 claims. (01.' 23a-11) My inventionbroadly relates to novel air-flow controls and more specifically pertains to coordinated temperature responsive devices for furnaces capable of eecting completely autoy matic temperature regulation and which devices include a thermostatic switch serving to intermit tently start a motor or other power driven alrblast means for the purpose of forcing the rate of vheat delivery. As applied to a coal fired hot-air furnace, the run'ning fan motor induces circulation throughout the hot-air flues and simultaneously augments theash pit draft to stimulate combustion'of the fuel lying above the furnace grate. After the furnace temperature has been sufficiently raised-the blast fan is temporarily shut if, whereupon the hot air continues to circulate normally through` the distribution ducts by Vgravity in the conventional manner. e

My improved air distributing system includes an exteriorly disposed, auxiliary conduit which discharges i'nto the ash pit and whose intake end is commanded by an automatically controlled induction tube that is periodically `subjected to fan blast. Certain of my controls are preferably 3 housed within this air tube and among such, is

a thermostatically operated damper/valve located contiguous to the re box so as to come under the influence of its radiant heat and whereby the air,

conduit thatfunctions automatically in conforme;l

J ity with room heating needs.

As a further refinement, a pivotally mounted compensating valve is associated with the furnace stack, serving to automatically check the rate of combustion in the event the chimney draft L3 should become excessive under erratic weather conditions. The present system further contemplates the modification of existing house heating furnaces by the use of simple, standardized attachments adapted to be readily applied without 5 requiring extensive alterations in many prevailing types of hot-air furnaces. A time clock may be employed to set my air fan into operation between any desired day-time hours. All control appurtenances comprised in my system may be .35 centralizedin the furnace room to the end that all'distantly controlled draft adjusting chains. extended electric wiring and like extraneous adjuncts may be eliminated.

The object of my invention is to devise reliable and sensitive furnace appurtenances of the character indicated that shall promptly respond .to relatively small room temperature changes without requiring frequent manipulative superintendence.v In addition, the cited self-contained conduit together with its control features is made detachable as a unit to facilitate economical installation and otherwise promote a wide distribution onpart of myv improvements, all of which aspects will hereinafter be more explicitly pointed out. l

Reference -is had to the accompanying four sheets of drawings which are illustrative of a preferred structural embodiment of my invention, and in which drawings:

Fig. `1 schematically represents an elevational side-view taken in partialsection of a furnace assembly equipt with my improved controls, while Fig. 2 shows a horizontal cross-sectional view thereof as taken along the broken line 2`2 of Fig. 1.

Fig. 3 is a cross-sectional View of my furnace arrangement as taken through the vertical planev 3-3 of Fig. 2; Fig. 4 shows a similar fragmental view as taken along line 4-4 of Fig. 2, while Fig.

. 5 further illustrates an enlarged detail olf-.the

sectioned portion of Fig. 1. "Y

Fig.` 6 represents aface view of a'balanced chimney draft regulator that may be used in association with my other devices and Fig. '111s a wiring diagram pertaining to my thermostatic motor controls.

Referring more specifically to the drawings, the structural embodiment of my controls as applied toa hot-air -furnace will first be described.

The more essential conventional elementsthereof comprise a cylindrical shell or furnace Jacket- 10 containing the combustion space or fire box 11 equipt with a series of transversely disposed grate bars 13 and a fuel feed door 12 disposed at the front of the furnace. Underneath said grate lies the ash pit 14 forming a closed space that is confined -between spaced side-walls 15 and the circular rear pit wall 16, which latter sets radially inward from the surrounding foot portion of the furnace shell 10. The free forward end of said side walls are preferably carried into engagement with the front'of the shell and the pit given access through the customary ash door 11. When closed, the ash pit'is intended to be kept 'substantially air sealed except for egress upwardly through the grate .bar passages.

The topmost portion of the iire box may be provided with a crownplate or superimposedl header 18 having a flue outlet 19 that leads to the chimney 20. Said flue may be equipt with the usual manually operated throttle valve 21v and a draft check22, although these supplemenmay each be provided with a oor register 27 which preferably feed into the common downcomer or the like means 28 to return the enervated room air inthe flow direction indicated by arrows to the bottom housing section 29 or other similar collector duct means. The forward end of said housing may be adjoined to a. rear shell opening that communicates freely with the reheating chamber 23 to constitute an extension thereof (see Fig. 2).

The ,present invention is more largely concerned with controls that are preferably centered in the vicinity of said collector duct. The illustrated box-like housing or elbow member comprises flat complementary side walls such as 30 together with a top wall 31 provided with a circular opening 32 into.which the down-comer may be connected. The bottom wall 33 of said housing is shown apertured in alignment with the down-comer axis and a removable end cover 35 provides for access to the housing interior. A plurality of pivotally mounted fan blades 36 rotate about a common upright axistocommand the wall opening 32 and these radially spaced blades are preferably given a considerable screw pitch so as not to unduly impede the rate of gravity air ilow therethrough when this arises solely from small temperature differences. An electric motor 37 of the Vertical type drives the fan and blows the air current axially downward and radially: outward from the fan tips; the motor maybe supported upon the stanchion 38 having a foot flange that rests directly upon the solid furnace foundation 39. Said stanchion is loosely entered through the bottom wall aperture out of direct contact therewith and closed with a suitable cushioning plate 40 arranged to afford a Psubstantially noiseless fan motor mounting with the minimum of sound transmission to the adjacent metallic furnace ducts.

An adjustable thermostatic motor switch 41 may be-placed in the down-comer near the discharge end thereof beneath the fioor register 27 and made responsive to temperature changes occurring in the returnv air current. This thermostat may be of any suitable type but is preferably constructed with a spiral temperature responsive element adapted to adjustably oscillate a switch actuating spindle. Asindicated in Fig. l, this coiled element 41 may be disposed interiorly of the 'down-comer duct.

spindle and protectively housed within the casing Y 41A. The operative tilt position of this bulb may Said switch may be of' the mercurial bulb type tiltably carried .by the that the'bulb tilt may be altered from the outside of the casing without cover removal.

As disclosed in Fig. 2, I further provide for an auxiliary conduit 42 of which a medial region is preferably shaped to lie snugly around. an ex` terior portion of the shell or jacketlO and which conduit establishes communication between the interior of the housing 29 and the ash pit 14. Said arcuate conduit is so designed that it may readily be applied to certain existing furnaces and to this end, the pit terminal region of the conduit may be provided With a branch conduit 43 of which the innermost end is enteredV into the pit side wall l5, the jacket shell l0 for this purpose being apertured by a suitable cutter to closely pass said branch therethrough. The outermost free end of this branch may be anged and provided With a cap 44 that is rotatably mounted for manipulation by a conveniently located handle 45. A cylindrical cock-like plug 46 of the truncated type may be attached to the cap and rotatably entered into the flanged mouth of the conduit. The conduit 42 discharges laterally into said branch conduit contiguous to its flange, the

disposition being such that when the truncated plug is kept in its full-line position, the air-blast is allowed to freely enter the ash pit but when said plug is rotated through a full half-turn into or intake end of the conduit 42. This is extended to constitute the controlled induction tube 47 that may terminate in a detachable elbow having a horizontally disposed funnel 48 or other blast diverting means, which latter is cooperative-v ly held in 'perimetrically embraced or radial rc- L lation with the tips of the rotating fan blades 36; while the motor is operating, a substantial volume of circulated air may thereby be bypassed and blown through the opened arcuate conduit.

As will be obvious, the major portion of the fanl blast will at the same time be directed into the heating chamber 23, which in turn accelerates the hot-air flow through the flues 24.

The tube 47'and adjoining end of said conduit may be interconnected by an elongated flange as at 49, the disposition of the described uid conducting. members being such that-said tube assembly may as a unit be removably entered and sustained in place through a relatively small oblong hole cut into the side-wall 30 without dismantling the housing 29 or'the upheld downcomer 28. Figs. 2 and 4 show the use of twin cooperative valves disposed in series within the confines of the control tube 47.- Of these, the butterily draft valve 50 is provided with a depending spindle 51 which carries a vane 52 adapt,- ed to be automatically opened when the fan blast blows thereagainst and thus throws the exteriorly disposed iioating vane into its tilted position 52A. One movabletip of said valve is made to open counter to the air flow prevailing in the conduit 42 and the actuating Vane is purposely placed in the path of the remaining major air flow portion so as to augment the opening effort exerted upon such substantially balanced draft valve.

A baille plate 58 (see Fig. 5) may beresorted to for contracting and directing the air flow against the relatively small actuated vane. The spring 53 coiled around the spindle'yieldably closes the last named valve while the fan blast is discontinued, thus automaticallycutting off the air draftA through the conduit leading into the'ash pit and thereby bringing about a correspondingreduction inthe rate of fuel combustion. When the fan is inoperative, the reduced air-flow impact becomes relatively small and fails to open the draft valve.

The companion control valve 54 may be similarly fulcrumed but in this instance, the depending trunm'on 55 is shown equipt with a supplementary thermostat 56 of the exteriorly disposed, spiral bimetal strip type of which the innermost end is operatively attached to said actuating trunnion while its outermost spiral end maybe shiftably positioned through the medium of the adjusting screw 57. The spiral disposition is such that any augmented temperature acts to shut' the valve 54'. A stop pin 59 may be interposed between these closely spaced valves to prevent interference. This supplementary thermostat is also made responsive to the temperature of the collective room" air returningk to the furnace heating chamber through the down-comer 28. By manipulating the adjusting screw ,57, the `initial temperature at which the control valve 54 is intended -to open,` may readily be altered to meet the room heating requirements.

It is further emphasized that the thermostat 56 isv purposely placed reasonably close to the exterior of thetrebox 1l and subjected to the influence of radiant heat .emanating therefrom. My auxiliary thermostat may be located within the furnace jacket confines or the interconnect-v ing chamber end of. the housing 29, thus exposing and subjecting this temperature `responsive element to direct radiant heat, its contiguous disposition being such that an intervening `body of air serves as a continuous, unobstructed heat conductive medium between the fire box and said element. Should the rate of fuel combustion at any time attain inordinate proportions, the thermostat 56 acts in the capacity of a safety device to dominate and automatically cut off the auxiliary ash pit draft, notwithstanding that the returning room air may not as yet have attained a temperature suicient of itself to actuate either 4the thermostat 41 or the thermostat 56. It will be observed that the twin valve controls that command the conduit 42, serve to doubly protect the auxiliary draft that is allowed to enter the ash pit.

It now remains to describe my chimney draft adjunct shown in Figs. 2, 3 and 6. Locatd beneath the outlet flue 19 is a flanged framework 60 that is preferably inset into the chimney 20 as a substitute for the usual soot cleaning door. The rectangular opening of this frame is here controlled by a draft compensating or bypass valve 6l suspended upon the fulcrumshaft 62, which latter is vshown disposed above the horizontal v'center line of the valve plate in such fashion that the valve normally tends to close of its own weightinto its full-lined vertical position. The depending lower valve portion is additionally counter-weighted by a frictionally retained manipulative; lever 63 adapted to be shifted away from the .fulcrum axis and thereby adjustably alter. the counterbalancing effect to suit draft' frame flange as shown .by dotted outline in Fig. 6, the bypass valve becomes locked and inoperative. In its freed position, the valve plate 61 automatically opens inwardlyto check any uni foreseen excessive chimney draft resulting from.

windy Weatheror the like, the proper degree of valve tilt being governed by the lever position and thus preventingdisturbances in the nicely balanced action of my induction tube.

'The wiring diagram Fig. l7 shows a battery B. or other source of electric current successively commanded by a switch S and a time clock C located near the thermostat switch 4l and the lmotor 37 wired in series therewith through the lead wires such as W1 and W2. it being preferred to utilize an electric clock that needs no periodic to be in'mauy nra in' lool static switch 41 will complete the wiring circuit of Fig. 7` and start up the fan motor 37. 'Ihe resulting air blast will cause the vane 52 lto be rotated about the spindle 51 in a counter-clockwise direction as seen in Fig. 2 and thereby open the draftyalve 50 ,in the control tube 47. Provided the re box radiation has not yet reached prel scribed limits, the supplementary thermostat 56 will gradually shift and regulate the control valve 54 into a position that is proportionate to the temperature prevailing in the down-comer and thus allow the desired quota of air-blast to-fiow through the conduit 42 into the ash pit. Assuming the ash pit door 17 to be kept closed, substantially the whole of such measured forced draft willthenpass upwardly through the grate 13.

to accelerate the rate of fuel combustion.

The resulting increase in furnace' heat augments the temperature of the air circulating around the exterior of theA fire-box wall lland gradually raises the hot air discharge through thell flue 24 and the register 25, which in turn correspondingly augments the room temperature. The surplus of such warmed air may be repeatedly drawn into the down-comer 28 until the desired room temperature is attained. As a consequence, the thermostatic switch 41 is finally influenced to open the wiring circuit and shut down the motor 37 until such time that' the down-comer temperature drops suiliciently to again restart the motor. When the motor ceases to operate, the floating varie will be turned clockwise bythe spring 53 to shut off the butterfly valve 50 and thus prevent any of the circulated hot air from entering into the closed ash pit.

In the event that the fuel bed should become unduly forced bythe fan blast and burn at' an excessive rate, then the radiant fire-box heat will actuate the thermostat 56 and close the valve 54. The last named thermostat is made to supplement the action of the down-comer thermostatic switch 41 in case the latter should fail promptly to shut off the fan motor; that is to say, when the air blast temperature delivered through the conduit 42 exceeds predetermined limits, the thermostat 56 mayv close itsv valve 54 irrespective of Whether themotor remains in operation or not. The adjusting screw 57 serves` mightotherwise unfavorably affect the delicate balance of my various furnace controls. Under inclement weather conditions, this compensating valve may be set to bypass at any predetermined degree of chimney draft. ventional flue throttle valve 21 and the draft check 22, these need not be resorted to while my controls are kept in proper working order. As will be understood, the time clock C opens the Wiring, circuit between certain periods, especially during night hours, whereupon` the furnace con- /tinues to operate normally without air vblast at a relatively light firing rate. When however the -clock reestablishes the circuit, thefan motor will again be placed in service and thus promptly bring the respective rooms up to the desired raised temperature for `which the controls may have been set.

While the previous description has been primarily directed toa hot air furnace burning solid fuel, it will be apparent that similar underlying regulating features nd application to oil and'g'as fired furnaces. My simple control appurtenances are further applicable to both new or old furnace equipment and can be installed upon the latter at low first cost by the average householder without need of special tools or exceptional skill. In addition, itis not essential that all the described devices be introduced in v one and the same furnace; as an instance, the

valve controls associated with the conduit 42 may be separately utilized without fan cooperation. This disposition is particularly appropriate where the down-comer is connected to take cold air supply' from the outside atmosphere rather than vfrom any one of the rooms. On the other hand, where no blast motor is employed, the remaining thermostatically controlled valve 54 may` still be utilized to regulate the ash pit draft. The use of my double thermostats however insures a more accurate averaged control for all the fiue interconnected rooms which can thereby be held to within a few degrees of a common predetermined temperature. Anyof the individual room registers may be shut off without interfer- V ing with the proper operation of my furnace devices. If desired, the hub of the vane '5 2 may be loosely fitted to its spindle and adjustably fastened together bythe set screw 51A (see Fig. 4)

` to allow of shifting the angularity between the throttle valve 50 and its actuating vane; by this means, the degree of valve opening for any given blast pressure may be altered=within reasonable limits.

All the described controls may be'compactly located within the confines'of the furnace room,`

As disclosedin Fig. 1, this result is attained by making the thermostatic actiondependent upon the return temperatures prevailing in the downcomer 28 without need ofindividual room ther-l mostats. The described thermostat adjustments are intended to be so set that the blast fan is As regards the con-l 1,956,608 to ener the point at which the thermostat 5 6' shut down when'the Irespective heated rooms assume the desired l comfortable temperature,

after whch the normal gravity circulation of the heated furnace air is resumed. It is .believed that the foregoing description when read in connection with lthe accompanying drawings makes apparent theintended construction, operation, and advantages of my improvements' it being understood: that their more outstanding features are subject to considerable latitude in practical application, and'that various modifications may be' resorted to, all without departing from the 'spirit and scope of my invention as vdefined in the appended claims.

I claim:

1. In -a heating system, the `combination of ber, the combination of down-comer means con-` veying air tol the heating chamber, duct Ameans interposed between the down-comer and said chamber, an auxiliary conduit having one of its ends entered into said duct and of which conduit a medial portion extends `exteriorly of the jacket to bypass air from .the duct for delivery into said pit, and a thermostatically actuated valve commanding the air flow through said conduit, the thermostatic element of said valve being subjected to radiation emanating from said box.

3. A hot air furnace system comprising an apertured jacket enclosing a heating 'chamber and an ash pit including a pit side-wall having a hole therethrough in substantial alignment with the jacket aperture, tubiform housing means serving to convey air to the heating chamber, a branch conduit entered through the jacket aperture and said side-wall hole, an induction tube extending within the housing means and arranged to divert a portion of said air therethrough, an auxiliary conduit disposed exteriorly of the jacket and interconnecting said tube with the `branch conduit, and thermostatically actuated valve means controlling the air iiow through said auxiliary conduit.

4. A hot air furnace system comprising an ash pit, a heating chamber, duct means conveying air to the heating chamber, a power driven blast fan arranged to accelerate air circulation through said duct, means for intermittently starting said fan, an induction tube cooperating with said fan to divert a minor portion of said air circulation through the tube, conduit means interconnecting the tube with the ash pit, a draft vvalve of the butterfly type disposed interiorly of the conduit, and a floating vane disposed exteriorly` of -the conduit and operatively connected to the draft valve, said vane being actuated by a remaining portion of the fan blast.

5. A hot air furnace system comprising an ash j pit, a heating chamber, duct means conveying air of variable temperature to the heating chamber, induction tube means arranged to divert a portion of the air flowing into the duct and def.

6. A hot air furnace system comprising an'ash' pit, a heating chamber, duct means conveying air of variable temperature to-the heating chamber,

' said duct including a wall aperture, a power driven blast fan disposed within the duct and serving to accelerate air circulation therethrough, induction tube means including a control valve provided with an actuating trunnion, said tube being detachablymounted through .the wall aperture and placed into cooperative relation with the fan to divert a portionv of the circulated air through said tube for deliveryxinto the ash pit, an elongated thermostat' of which one end portion is operatively attached to said trunnion and the opposite end of which thermostat is shiftably disposed, and adjusting screw means serving to alterthe position of said shiftable thermostat end. I

'7. A hot air furnace system comprising an ash pit, a heating chamber, a room registendowncomer means returning enervated air of variable temperature from the register' to .the heating chamber, duct means interposed between the down-comer and the heating chamber, an electric motor Vdriven fan means serving to acceleratek the flow of returned air, an automatically controlled induction tube means cooperating with said fan to divert a part of the returning air into said tube for delivery into the ash pit, a thermostatically actuated switch of which the thermostatic element is made responsive to temperature Avariations in the aforesaid returning air, a source of motor current, and lead wires operatively in- V veying a supply of 'air of variable temperature tothe heating chamber, tubiform housing means interposed between -the down-comer and said chamber, a motor driven blast fan serving to stimulate air circulation through said housing,

, switch means for intermittently starting said fan,

said switch being thermostatically controlled and made responsive to temperature changes in the\ conveyed air, and induction tube means arranged to divert for delivery. into the ash pit a portion of the air flowing into said housing, said tube being provided with a pair of automatic valves of which one is thermostatically controlled and the `other actuated by the fan blast.

10. A hot air furnace comprising re box means encased within a jacket to provide for a heating chamber therebetween andl which chamber' is supplied with air by duct means arranged to constitutea'continuation of said chamber, an outlet flue for said chamber, conduit means diverting a portion of such air supply to the re box, and control means commanding the air flow through said conduit, said means including a thermostat located within the aforesaid chamber in a directly responsive relation to the radiant heat emanating from the fire box and serving to' arrest air flow when the fire box reaches' chamber, an ash pit, tubular housing means conveying air to the heating chamber,- a fan of the rotating spiral bladed typemounted within the housing to turn about an upright axis and serving to accelerate the flow of said air, and an open ended conduit communicating with said housing to divert a portion of said conveyed air tothe ash pit, the receiving end of said conduit being cooperatively disposed in a-closely contiguous perimetric relation to the blade tip region of said fan and arranged to conduct air from said regionin a direction radially outward from the aforesaid vertical fan axis.

12. A hot air furnace comprising an ash pit, l

a jacketed heating chamber, duct means conveying air to the heating chamber and lwhich duct includes a wall aperture, a power driven blast fan disposed within the duct to accelerate the air circulation therethrough, valve controlled inductionv tube means removably insertedthrough the wall aperture and placed in a cooperative relation with the fan to divert a portion of the circulated air through said tube, anda conduit disposed exteriorly of the heating chamber jacket and of which conduit one end is detachably se-l cured to the delivery end of said tube and the other conduit end placed in communication with the ash pit, said tube being kept accessible and demountable without removal of the duct means. -13; In a heating system, a furnace including a Warm air duct, means for producing a forced draft for said warm air duct, a thermostat responslve tothe heat produced by said furnace, and means controlled by said thermostat for diverting a portion of the forced draft to the furnace l of combustion.

to increase the rate vGEORGE W. BAILEY.

Images