US2682299A - Barometric draft regulator and burner control - Google Patents

Description

June 29, 1954 E. A. FIELD 2,682,299

BAROMETRIC DRAFT REGULATOR AND BURNER CONTROL Filed July 21, 1951 INVENTOIg. fawa/d /9, 56/0 @m ewe Patented June 29, 1954 UNITED STATEfi i ATENT OFFICE BAROMETRIC DRAFT REGULATOR AND BURNER CONTROL Claims. 1

This invention relates to improvements in barometric draft regulators and burner controls.

The main objects of this invention are:

First, to provide a barometric draft regulator for gas fired boilers and furnaces which is effective in controlling the updraft and also constitutes a venting-means in the case of downdrafts or backdrafts.

' Second, to provide a structure of this character which acts in the event of downdraft, internal pressure, or excessive pressure in the fine to 'close the. valve in the gas supply to the burner gate acting to direct the flow of gases against 1 the thermal switch element.

Fourth, to provide a structure having these advantages which is adapted for use both on horizontal and vertical flues.

Objects relating to details and economies of the invention will appear from the description to follow.

"The invention is pointed out in the claims.

A. preferred embodiment of the invention is illustrated in the accompanying drawings, in which:

Fig. 1 is a fragmentary view of a draft regulator embodying my invention partially in section on a line corresponding to the broken line l-| of Fig. 2. A wiring diagram is shown of the main control parts, the relationship of the control and the gas valve, which is shown conventionally as a solenoid valve, being illustrated.

Fig. 2 is a front elevational View illustrating the regulator as installed on a horizontal line.

1 Fig. 3 is a fragmentary perspective View partiall3 in section on a line corresponding to line 3- 3 of Fig. 2 illustrating details of the housing structure and the gate mounting.

Fig. 4 is a fragmentary view on a line corresponding to line ill-4 of Fig. 1.

The present invention relates to an automatic draft regulator and burner control which is suitable for use in connection with commercial and industrial gas fired boilers and furnaces. Since a gas burner can be extinguished easily by a downdraft it is important, unless the burner has a forced draft, that means he provided for bypassing the downdraft flow from the burner and thereby prevent or minimize the likelihood of the flame being extinguished or resulting in such combustion conditions that the dangerous creation and escape of monoxide or other dangerous gas is prevented.

In the embodiment of the invention illustrated, i represents a horizontal smoke flue and 2 a gate housing whichis secured to and opens into the flue, the details of-mounting not being illustrated. The housing includes an annular gate support member 3 which is positioned at the front of the housing and is provided with vertical rearwardly projecting wing-like side plates 5 having outturned flanges 6 at their forward ends. The gate 7 is shaped to swing between these side plates and has a forwardly inclined segmentalfiange-like top portion 6.

The pivot members is' fixedly secured to the front sideof the gate below the vertical center thereof. This pivotmernber 9 has pivot portions It at its ends'provided with knife-like pivot edges I I. The side plates 5'have elongated horizontal openings l2 therein through which these pivot portions project.

V shaped. plate-likebearing members l3 are disposed facing'upwardly and resting upon the bottom edges [4 of the slots of the plates 5. The bearing members have slots or notches It in their ends, the notches in the front ends of the bearing'members receiving the front edges It of the slots 12 and the notches in their rear edges being engaged by bearing retaining plates ll. The edges 16 are notched at 18 while the bearing retaining plates I! have notches M in their bearing member engaging edges. The slots or notches in the bearing members are of such transverse dimensions as to permit tilting of the bearing members on their support and thus permitting'them toalign-With the pivot edges H of the-pivots 1B.

The gate is provided with an adjustable platelike weight 20 which ismounted on the screw 2i for swinging adjustment in a plane parallel to the plane of the gate. The weight 23 is 'clampedtuponathe front sideof. the gate below the pivot thereof' while the weight 24 is adjustably supported on ;the rear side of the gate by having threaded engagement'with the bolt 25, the forward end ofwhich' clamps the weight 23 to the gate.

Toa-djust the gate to the desired draft it is provided withcav forwardly projecting arm 26 which is securedthereto above the pivot and adjacent one side edge to project a substantial distance. This arm has a downturned portion Ell with spaced holes 28 and 29 therein. A plurality of washer-like auxiliary weights are provided to permit adjustment of the gate to provide the desired closing torque or to adjust the gate to the desired draft. These weights are in the embodiment illustrated threaded upon a holder 3! having an eye 32 at its upper end connected by the chain 33 to the link 34 which is selectively engageable with the holes 28 and 29.

When the regulator is installed on a horizontal flue, as illustrated, the link 34 should be engaged with the hole 29. These holes have been spaced to generally compensate for the difference in draft conditions commonly found in horizontal and vertical flues. When the gate swings outwardly as the result of a downdraft as indicated by the dotted lines in Fig. l, the auxiliary weight is supported by the chain 35 which is connected to the eye 32 of the holder 3| and to the bracket 36 projecting from the housing. The weights 20, 23 and 24 constitute weighting means for the gate and are so disposed relative to the gate, when the gate is in a closed position, that the center of gravity of the gate and said weighting means thereon is disposed vertically below the pivotal axis of the gate, so that when the gate is opened inwardly due to an updraft or indraft the gate automatically returns to a closed position after such updraft, and so that when the gate is opened outwardly due to a downdraft or outdraft the gate automatically returns to a I" closed position after such downdraft. The weight 30 supported by the chain 33 and the arm 26 on the gate, as heretofore described, produces additional closing on the gate when the gate moves inwardly due to an indraft, but when the gate moves outwardly due to an outdraft the weight 30 is supported by the chain 35 and bracket 36 on the housing as heretofore described. Also when there is neither an indraft nor an outdraft the weight 30 is supported by the chain 35 and bracket 30 on the gate housing; otherwise the weight 30 would open the gate outwardly from a closed position when there was neither an indraft nor an outdraft. The arrangement is such that the closing torque on 1? the gate is greater when the gate is moved inwardly due to indraft than when moved outwardly due to an outdraft, and the gate is in a closed position when there is neither an indraft nor an outdraft.

In the diagrammatic portion of Fig. 1, 3! represents a burner control valve of the solenoid type. The thermal switch 38 is connected to a suitable current source indicated at 39. The switch is connected by the line 40 to the burner control valve 4! which is shown conventionally, this being a solenoid type valve, details of which are not illustrated. The connection 42 indicates the second connection for the switch to the valve. A signal 43 may be connected in series in the line 40 if desired. The switch 38 is, in the embodiment illustrated, mounted on the outlet box 45 which is supported on the bracket 44 on top of the housing member 3 so that the switch 38 is supported in a plane adjacent and above the path of the upper edge of the gate and is supported between the outer end of the housing and the general plane extended of the upper draft control portion of the gate when said portion is opened outwardly due to an outdraft, as shown in Fig. 1. When the gate swings outwardly as the result of an outdraft, the escaping gases are, when the switch 38 is mounted as illustrated, directed by the gate against the thermal switch.

4 If the gases are heated the switch will be actuated.

The time of the actuation of the switch depends, of course, upon the temperature of the gases but ordinarily there is sufficient heat in the gases to actuate the switch in a matter of seconds. Usually downdrafts or backdrafts are of short duration and as the gate swings to closed position the thermal switch quickly cools, again opening the valve if it is the automatic type as indicated. However, it will be understood that a switch may be used that requires manual resetting. If the automatic opening type thermal switch is employed the opening and closing of the valve is controlled by the thermal switch and no manual resetting of the apparatus is required. A slight outdraft will not actuate the thermal switch as the hot gases must impinge or act on the switch for at least a number of seconds before the switch will be actuated. Therefore the switch constitutes a time delay element in the system. In the event there is an outdraft when the burner is not in operation, the switch will not be actuated since the outdraft gases will be relatively cool.

I have illustrated and described my invention in an embodiment thereof which has proven to be very satisfactory and to accomplish the purpose for which it is desired. I have not attempted to illustrate or describe other modifications in the signal connections, the use of valves requiring manual resetting and the like, as it is believed that this disclosure will enable those skilled in the art to adapt my invention as may be desired.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a barometric draft regulator and burner control, an open ended gate housing, a control gate disposed in said housing adjacent to the open end thereof and pivotally mounted to swing about an approximately horizontal axis, and having an upper draft control portion above said axis opening inwardly during an indraft and outwardly beyond the outer end of the housing during an outdraft, said gate being disposed approximately vertical when closed, weighting means on said gate, the center of gravity of the gate and weighting means thereon being disposed vertically below the pivotal axis of the gate to effect a closing torque on the gate, an arm mounted on said gate above its pivotal axis and projecting outwardly therefrom, said arm having a downwardly projecting outer portion with vertically spaced holes therein, a bracket projecting forwardly from said housing, an auxiliary weight for producing additional closing torque on the gate when the gate opens inwardly due to an indraft, a first weight supporting element connecting said auxiliary weight to said arm and selectively engageable with said holes therein, a flexible second supporting element connected to said auxiliary weight and to said bracket and of such length as to support the auxiliary weight when the gate opens outwardly during an outdraft, and burner valve control means comprising a thermal switch, an electrically controllable fuel supply valve and an electric circuit having therein said thermal switch and said electrically controllable fuel supply valve, said thermal switch being disposed adjacent to the outer end of said housing and adjacent to and outwardly of the path of movement of said upper draft control portion of the gate and between the outer end r of the housing" and the general-planeextended of said upper draft "control portion "when said upper draft control portionis opened outwardly beyond'the outer end'of the housing'durlng an outdr'aft, whereby the heated gases from the housing during an 'outdraft' are" directed onto 'the thermal switch to* actuate the same to control supported by said second supporting-element from the bracket on the housing.

means on said gate disposed to effect a closing torque on the gate, an arm mounted on said gate above its pivotal axis and projecting outwardly therefrom, a bracket projecting forwardly from said housing, an auxiliary weight for producing additional closing torque on the gate when the gate opens inwardly due to an indraft, a first weight supporting element connecting said auxiliary weight to said arm, a flexible second supporting element connected to said auxiliary weight and to said bracket and of such length as to support the auxiliary weight when the gate opens outwardly due to an outdraft, and burner valve control means comprising a thermal switch, an electrically controllable fuel supply valve and a circuit having therein said thermal switch and said electrically controllable fuel supply valve, said thermal switch being disposed adjacent to the outer end of the housing and adjacent to and outwardly of the path of movement of said upper draft control portion of the gate and between the outer end of the housing and the general plane extended of said upper draft control portion when said upper draft control portion is opened outwardly beyond the outer end of the housing during an outdraft; whereby the heated gases from the housing due to an outdraft are directed onto the thermal switch to actuate the same to control said circuit to actuate said electrically controllable fuel supply valve to shut off the supply of fuel to a burner, said thermal switch operating through said circuit to close said valve when the thermal switch is heated by the gases from the housing and when said auxiliary weight is being supported by said second supporting element from the bracket on the housing.

3. In a barometric draft regulator and burner control, an open ended gate housing, a control gate disposed in said housing adjacent to the open end thereof and pivotally mounted to swing,

about an approximately horizontal axis, and hav ing an upper draft control portion above said axis opening inwardly during an indraft and outwardly beyond the outer end of the housing during an outdraft, said gate being disposed approximately vertical when closed and disposed for its upper portion to swing inwardly and outwardly of the housing, weighting means on said gate disposed to effect a closing torque on the gate, an arm mounted on said gate above its pivotal axis-and projecting outwardly therefrom; a

bracketprojecti-ng' forwardly fromsaid housing,

an auxiliary'weight for producing additional closingtorque on-the gate when the gate opens inwardly' dueto an'indraft, a first'weight supporting elementconnecting-said auxiliary weight to said arm, a fiexible-second supporting element connectedto said auxiliary weight and to said bra cket and or suchlength as tosupport the auxiliaryweight when-the gate opens outwardly "due to' an o'utdraft, and burner valve control means comprising a thermal switch, an electrically controllablefuel supply valve and a-circuit having therein said thermal switch and said electrically controllable fuel supply valve, said thermal switch being disposed adjacent to the outer-end of the housing and adjacent to and outw'ai'dly of thepath of movement of said upper draft control portion of the gate and between the outer end of the housing and the general plane extended of said upper draft control portion when said upper draft control portion is opened outwardly beyond the outer end of the housing during an outdraft; whereby the heated gases from the housing due to an outdraft are directed onto the thermal switch to actuate the same to control said circuit to actuate said electrically controllable fuel supply valve to shut off the supply of fuel to a burner, said thermal switch operating through said circuit to close said valve when the thermal switch is heated by the gases from the housing and when said auxiliary weight is being supported by said second supporting element from the bracket on the housing, the gate having an outwardly inclined segmental flangelike top portion facilitating the directing of the outdraft gases upon the switch.

4. In a barometric draft regulator and burner control, an open ended gate housing, a pivotally mounted control gate disposed in said housing and having a draft control portion on one side of the pivotal axis of the gate disposed adjacent to the outer end of the housing for opening inwardly during an indraft and outwardly beyond the outer end of the housing during an outdraft,

weighting means on said gate acting to effect a closing torque thereon, an auxiliary Weight for producing additional closing torque on the gate when the draft control portion of the gate opens inwardly due to an indraft, means for supporting said auxiliary weight from said housing when the gate opens outwardly, and burner control means comprising a thermal switch, an electrically controllable fuel supply valve and a circuit having therein said thermal switch and said electrically controllable fuel supply valve, said thermal switch being disposed adjacent to the outer end of the housing and adjacent to and outwardly of the path of movement of said draft control portion of the gate and between the outer end of the housing and the general plane extended of said draft control portion when the draft control ortion is opened outwardly beyond the outer end of the housing during an outdraft whereby the heated gases from the housing due to an outdraft are directed onto the thermal switch to actuate the same to control said circuit to actuate said electrically controllable fuel supply valve to shut off the supply of fuel to a burner, said thermal switch operating through said circuit to close said valve when the thermal switch is heated by said gases from the housing and when said auxiliary weight is being supported by said supporting means from the housing.

5. In a barometric draft regulator and burner control, a gate housing, a pivotally mounted control gate disposed in said housing and having a draft control portion on one side of the pivotal axis of the gate disposed adjacent to the outer end of the housing for opening inwardly during an indraft and outwardly beyond the outer end of the housing during an outdraft, weighting means on said gate acting to effect a closing torque thereon when opening inwardly during an indraft and when opening outwardly beyond the outer end of the housing during an outdraft,

and burner control means comprising a thermal switch, an electrically controllable fuel supply valve and a circuit having therein said thermal switch and said electrically controllable fuel supply valve, said thermal switch being disposed adjacent to the outer end of the housing and adjacent to and outwardly of the path of movement of said draft control portion of the gate and between the outer end of the housing and the general plane extended of said draft control portion when said draft control portion is opened outwardly beyond the outer end of the housing during an outdraft whereby the heated gases from the housing during an outdraft are directed onto the thermal switch to actuate the same to control said circuit to actuate said electrically operable fuel supply valve to shut off the supply of fuel to a burner.

References Cited in the file of this patent UNITED STATES PATENTS Walker Aug. 13, 1946

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