US2670902A - Fluid heater control apparatus - Google Patents

Description

R. F. DQTSON FLUID HEATER CONTROL APPARATUS March 2, 1954 3 Sheets-Sheet 1 Filed Jan. 15, 1951 w, M 0 u a m0 mfi W m w e 8 6 mg r a m 6 M a z 6 M m 2 l\ 2 w w 2 6 8 JMMM 216 BY I I ATTORNEY March 2, 1954 R. F. DOTSON FLUID HEATER CONTROL APPARATUS Filed Jan. 15) 1951 3 Sheets-Sheet 2 INVEN I'OR- 803.5224 I 00710 ATTORNEY March 2, 1954 R. F. DOTSON FLUID HEATER CONTROL APPARATUS 3 Sheets-Sheet 3 Filed Jan. 15, 1951 INVENTOR 6055544 5 00750,

ATTORNEY Patented Mar. 2, 1954 UNITED STATES PATENT OFFICE FLUID HEATER-CONTROL APPARATUS Russell FlDotson, Kankakee, Ill. Application January-15, 1951;: Serial No. 206,028"

scl ims; (01. 236-21 -'I'his"invention relates" to fluid heater control apparatusand is particularly well adapted for gas fired installations. The invention relates to apparatus of the same general type as that disclosed in an application of the same inventor, serialaNo; 131,473, filed December 6, 1949 which has matured into Patent No. 2,628,033, of which this application constitutes a continuation-inpa-rti' Assetforth in the earlier application, appa- 1atus-of=the typehere involved usually comprises a--main burne'r and'a' pilot burner, and it is of fundamental importance that no fuel be supplied to the main-burner" while an attendant is lighting the'pilot burner; In this case as in the earlier one, the mainburner valve is controlled by bleeding fuel from one side of a diaphragm more rapidly than it-is replaced from' the fuelsource, as result of which, the control of--the-'bleed"fuel will determine the opening and closingoperations of the mainburner valve. Accordingly, an arrangement has been provided herein to 'preventkindling of the pilot burner'at the-time that gas can be bled from behind the diaphragman'd at the same time reopening of the I bleed passage isprevented until after such time that thepil'ot burner fuel primer has been removed from its a pilot valve opening position. In-the present case the-operator performing these functions of primingand obstructing the bleed passage; is-prefera-blya single member performing-the two functions;

When'the fluid being heated has reacheda temperature exceeding a predetermined safe value,=the*flowof both bleed and pilot fuel'will be interrupted, requiring manual priming to reestablish'thefiow of fuel to eitherthe main or pilot a burner;

A-thermocoupleexposed to the pilot burner flamesupplies current to" an electromagnet at a value sufficientto maintain a valve in its openpositien but insufiicient of itself to open thevalve from a closed position;- hence, a manual primeris provided to initiate theopening of this valve, whereupon the pilot burner can-be" started and the resulting thermocouple current will then hold-thevalvein its'op'e position. In order to keep the'currentrequirements of the thermo couple circu'it at a' minimum consistent with depcn'd'able operation; the forhi' of the valve and its 's'afbeome 'slgilificanti It has been found that the "valve: is assigned 5 the forth of a .paramagrieti all, a smaller force rescues to holdi it elvated contact with an inclined plane thanwould baa-necessary were the r1194 I that of assuring proper seating of the valve in its 10" closed position. This is accomplished by havingthe valve port at the bottom of the welldefined byarelatively sharp edge to provide a line contactwith the ba-lLand'the edge is spaced from the: longitudinal wall or walls of the well by a small distance which will always be less than the radius of the ball.

When the temperature of the fluid'beingheateddrops below a preset value, a thermo-sensitive element responds to permit the flow-of bleed gas, and similarly, when the fluid temperature achieves a predetermined elevated value, the element closes a valve in the bleed gas line. A- preferred'type of actuator for-this purpose assumes the form of a permanent magnet influencing a paramagnetic valve, themagnet being attached' 'to a thermally actuated arm which travels in an arcuate path to transmit small movements of a' remote thermo-sensitive element, accompanied by a magnification of such movementato a control element which in turn controls the fuel supply. The transmitting member traveling in such an arcuate path will assume the form of a pendulum in a preferred embodiment of this invention, the free end of which carries a permanent magnet for cooperation with the valve orvalves under its influence. When the safe upper temperature has been exceeded, the permanent magnet'assu'mes a position in which its flux opposes that of the thermocouple supplied electromagnet to an extent sufiicient to at least partially neutralize the effect of the electromagnet causingth'eva'lveto close and interrupt the flow of both pilot and bleed gas.

The thermo-sensitive element is preferably of the surface contact type,and provision has been temperatures, a safety feature has been incorporated to avoid excessive heating even though such adjusting member might become damaged or separated'from' the assembly; V 7 Among its many aspects, the present inven-' tier?contemplatesfluid. heater control apparatus comprising a valve casing, a diaphragm dividing the casing into two chambers, fuel inlet and outlet tubes having ports communicating with the first of the chambers, a valve connected with the diaphragm for registry with one of the ports, means interconnected with one of the tubes defining a pilot fuel passage, means defining a bleed fuel passage communicating with the second of the chambers for controlling the diaphragm and valve, a control valve interposed in the pilot fuel passage, and an operator movable to a position opening the control valve and closing the bleed fuel passage. The operator is preferably provided with means for biasing it towards a position opening the bleed fuel passage, which may assume the form of a coil spring.

The apparatus preferably comprises a selecting valve carried by the casing interposed between the fuel inlet tube on the one hand and the first chamber and passages on the other, for selectively supplying fuel to either the first chamber or passages or both. The valve may be of the rotary type having two interconnected ports in communication with the fluid inlet tube, for distribution of fuel to the pilot fuel and bleed fuel passages only, or to these passages and the first chamber jointly. The valve also has a position in which there will be no passage of fluid from the fuel inlet tube to either the first chamber or the passages.

The invention also contemplates means defining a reduced passage extending and converging from the first chamber to the outlet port, the diaphragm connected valve being received in this passage for registry with the outlet port. The cross-section of the passage adjacent the outlet port preferably approximates that of the valve so that as the valve approaches its seat there is a progressively increasing biasing efiect, due to fuel flow, tending to close the valve.

A more complete understanding of the invention will follow from a detailed description of the attached drawings wherein:

Fig. 1 is a side elevation, partially in section, depicting a form of the invention applied to a domestic gas water heater;

Fig. 2 is a front elevation, on a somewhat larger scale, of the control apparatus of Fig. 1;

Fig. 3 is a sectional elevation on a further enlarged scale taken along line 3--3 of Fig. 2;

Fig. 4 is a fragmentary sectional elevation, on an enlarged scale, taken along line 4-4 of Fig. 2;

Fig. 5 is a fragmentary sectional view taken along line 5-5 of Fig. 4, having a pilot fuel ad justing valve superimposed thereon to indicate its function;

Fig. 6 is a fragmentary sectional elevation taken along line 6-6 of Fig. 2;

Fig. 7 is a fragmentary sectional view taken along line 'I-! of Fig. 6;

Fig. 8 is a fragmentary sectional elevation taken along line 8-8 of Fig. 3;

' the upper portion of the valve casing, and is pro- Fig. 9 is a fragmentary sectional elevation pan i8, enclosing a firebox 20 which receives a main burner 22 provided with the usual bottle mixer 24. Suitable brackets 26 support the main burner above the pan in a position to receive an orifice spud 28 provided with an orifice 38, Fig. 3. The orifice spud is secured to a portion of the skirt or a mounting plate 32 between an adjustable nut 34 and a flange 36 carried by the spud. The orifice spud is threadedly received in a valve casing 38, the reduced and 39 of the spud defining a valve seat for a flexible body or disk 40 which is carried by a diaphragm 44 for movement in a convergent passage 46 to and from its closed position depicted in Fig. 3 of the drawings. The disk is supported by a rigid backing washer 4| carried by a stem 42 suitably secured thereto and to the diaphragm.

The diaphragm 44 is clamped between the easing 38 and a cover plate 48 suitably secured together by fastening means 50 such as rivets or screws. The diaphragm and its valve 40 are biased towards the valve seat by means of a sprin 5! interposed between the diaphragm and the cover 48.

A thermal control housing 52 is mounted on vided with a head '54 secured thereto by means of a screw 56 and containing a spirally wound thermo-sensitive bimetallic element 58 which is .presented towards the surface whose temperature is to be controlled through an open side 50.

A control knob 62 provided with limiting stops 64 and 66 is employed to adjust the thermo-sen-' sitive element where higher or lower temperatures are desired. As indicated in Fig. 2 of the drawings, when the knob 62 is moved to its extreme position in a counterclockwise direction, the high heating condition is permitted. On the other hand, if the maximum temperature is to be the lowest for which the system is designed, the knob will be turned to its extreme clockwise position.

Fuel is supplied to the casing 38 through a tube 68 threaded into the lower portion thereof, and through a selecting or distributing valve H1 into the chamber 12 defined on the right side of the diaphragm 44 as viewed in Fig. 3. With the valve 42 closed as shown in Fig. 3, there can be no passage of gas through the main burner supply port 14, but depending upon the position of the selecting valve 10, gas might flow through a passage I6 formed, on the periphery of the valve 10 and pass through a filter supply passage (8 into the filter chamber 80, passing upwardly therethrough, and through suitable filtering material 82 to a pilot fuel port 84 and a bleed fuel supply port 86. Th upper end of the filter chamber is closed by a plug 88 threaded therein as clearly shown in Fig. 4. Fuel entering the pilot supply port 84 travels through a pilot fuel passage 94, at an intermediate point of which it encounters a pilot adjusting valve 92 in the form of a screw containing a fixed orifice 94 serving as the upper limit for the amount of fuel that can be delivered to the pilot under normal operating conditions. From this point, the pilot fuel passage extends into the chamber 96 of the ball valve 98 which serves to cut off both pilot fuel and bleed fuel under emergency conditions. Under normal operating conditions, the ball 98 will be elevated above its seat Hill, in a manner to be described, permitting fuel from th -pilot gas passage to enter the pilot gas delivery passage I92 connected by means of a fitting I04 with a pilot tube 146 whose tip H18 wards the right until it approaches the ball chamber 96, and if the temperature is sufficiently high, the influence of the permanent magnet I04 will at least partially neutralize the effect of the electromagnet I46 so that the ball 98 will drop and shut ofi both the bleed fuel and pilot fuel. When the passage of bleed fuel has been terminated, as will be evident to those skilled in the art, the fuel pressure on opposite sides of the main diaphragm 44 will becom equal and the burner valve will close. If operation of the apparatus is to be restored, it will be necessary to prime the apparatus manually under which conditions, the main burner will remain inoperativ and there will be no flow of bleed fuel until the primer I30 has been retracted.

The inner end of the thermo-sensitive element 58 is secured to a shaft I90 which is rotatably supported in suitable bearings provided by the head 54. The shaft I90 may be retained against axial movement by means of one or more suitable screws I92 threaded into the casing or head 54. The shaft I90 is provided with a transverse bore through which a pin or screw I94 is threaded, the head I95 of th screw cooperating with an abutment I98 whose position can be adjusted by manipulation of the screw 200 on which it is carried. The screw 260 is threaded in a boss 202 provided by the head 54, and externally, carries a lock nut 204 to secure the knob 62 in an adjusted position. As the temperature to be controlled increases, the head I96 of the screw will move towards the abutment I08, at which point further deformation of th thermo-sensitive element 58 will be reflected in movement of its free end I88 and consequently, the permanent magnet I84. As the temperature drops below the value for which the control apparatu is intended, deformation of the thermo-sensitive element will occur and will first return th permanent magnet I84 to its extreme left hand position as viewed in Fig. 3. Further deformation due to low temperature will result in movement of the threaded end of the screw I94 against a resilient abutment or spring 206 seated in a bore 208 provided by the head 54 so that, even under extremely low temperature conditions, there will be no damage to the thermo-sensitive element itself or to the members connected thereto. In the event that the adjusting screw 200 should be retracted excessively, or its abutment I98 damaged in any way, it will be noted, that the head I96 of the screw I94 will engage the end cf the boss 202 as the temperature conditions increase, thus assuring that safe temperature conditions cannot be exceeded.

In assembling the apparatus on a portion of the skirt or mounting plate of a heater, it may be desirable to have a second point of attachment, for which purpose a bolt 2 I0 can be threaded into the lower portion of th valve casing 38 and can receive a pair of nuts 2I2 which can be adjusted into contact with opposite sides of the skirt or cover plate in substantially vertical alignment with the flange 36 and nut 34 carried by the orifice spud 28.

Whereas only one embodiment of the present invention has been illustrated for purposes of providing a complete understanding of the invention, variations will occur to those skilled in the art just as they have occurred already to the present inventor, and accordingly, the invention should not be restricted to this single form beyond the scope of the appended claims.

I claim:

1. Fluid heater control apparatus comprising a valve casing, a diaphragm dividing said casing into two chambers; fuel inlet and outlet tubes having ports communicating with the first of said chambers; a valve connected with said diaphragm for registry with one of said ports, means interconnected with one of said tubes defining a pilot fuel passage, means defining a bleed fuel passage communicating with the second of said chambers for controlling said diaphragm and valve, a control valve interposed in said pilot fuel passage, and an operator comprising a rod having an end movable to a position engaging and opening said control valve, said rod having a portion accessible externally of said casing for manual operation and having an intermediate portion simultaneously projecting into and closing said bleed fuel passage.

2. Fluid heater control apparatus comprising a valve casing, a diaphragm dividing said casing into two chambers; fuel inlet and outlet tubes having ports communicating with the first of said chambers; a valve connected with said diaphragm for registry with one of said ports, means interconnected with one of said tubes defining a pilot fuel passage, means defining a bleed fuel passage communicating with the second of said chambers for controlling said diaphragm and valve, a control valve interposed in said pilot fuel passage, an operator comprising a unitary rod having an end movable to a position engaging and opening said control valve, said rod having an intermediate portion simultaneously projecting into and closing said bleed fuel passage, and means biasing said operator towards a position opening said bleed fuel passage.

3. Fluid heater control apparatus comprising a valve casing, a diaphragm dividing said easing into two chambers; fuel inlet and outlet tubes having ports communicating with the first of said chambers; a valve connected with said diaphragm for registry with one of said ports, means interconnected with one of said tubes defining a pilot fuel passage, means defining a bleed fuel passage communicating with the second of said chambers for controlling said diaphragm and valve, a magnetically actuated control valve interposed in said pilot fuel passage, a condition responsive member movable in a path adjacent said control valve, a magnet carried by said member for shifting said control valve, and valve means carried by said casing interposed between said fuel inlet tube and said first chamber.

4. Fluid heater control apparatus comprising a valve casing, a diaphragm dividing said casing into two chambers; fuel inlet and outlet tubes having ports communicating with the first of said chambers; a valve connected with said diaphragm for registry with one of said ports, means interconnected with one of said tubes defining a pilot fuel passage, means defining a bleed fuel passage communicating with the second of said chambers for controlling said diaphragm and valve, and a selecting valve carried by said casing interposed between said inlet tube on the one hand and said first chamber and passages on the other.

5. Fluid heater control apparatus comprising a valve casing, a diaphragm dividing said easing into two chambers; fuel inlet and outlet tubes having ports communicating with the first of said chambers; a valve connected with said diaphragm for registry with one of said ports, means interconnected with one of said tubes defining a pilot fuel passage, means defining a bleed fuel passage communicating with the second of said chambers for controlling said diaphragm and valve, a magnetically actuated control valve interposed in one of said passages, a condition responsive member movable in a path adjacent said control valve, a magnet carried by said member for shifting said control valve, and a rotary selecting valve carried by said casing between said inlet tube on the one hand and said first chamber and passages on the other for selectively supplying fuel to either said first chamber or passages or both.

6. Fluid heater control apparatus comprising a valve casing, a diaphragm dividing said casing into two chambers; fuel inlet and outlet tubes having ports communicating with the first of said chambers; a valve connected with said diaphragm for registry with one of said ports, means interconnected with one of said tubes defining a pilot fuel passage, means defining a bleed fuel with the second of said chambers for controlling said diaphragm and valve, a control valve interposed in said bleed fuel passage, a thermo-responsive element remotely spaced from said control valve, an arm secured to said element, said arm having a remote end movable through an arcuate path adjacent said control valve, and magnetic means establishing a coupling between said arm and control valve.

7. Fluid heater control apparatus comprising a valve casing, a diaphragm dividing said casing into two chambers; fuel inlet and outlet tubes having ports communicating with the first of said chambers; a valve connected with said diaphragm for registry with one of said ports, means interconnected with one of said tubes defining a pilot fuel passage, means defining a bleed fuel passage communicating with the second of said chambers for controlling said diaphragm and valve, a control valve interposed in said bleed fuel passage, a thermo-responsive element remotely spaced from said control valve, a pendulous arm secured to said element, said arm having a remote end movable through an armate path in a vertical plane adjacent said control valve, and magnetic means establishing a coupling between said arm and control valve.

8. Fluid heater control apparatus comprising a valve casing, a diaphragm dividing said easing into two chambers; fuel inlet and outlet tubes having ports communicating with the first of said chambers; a valve connected with said diaphragm for registry with one of said ports, means interconnected with one of said tubes defining a pilot fuel passage, means defining a bleed fuel passage communicating with the second of said chambers for controlling said diaphragm and valve, a control valve having a chamber inclined to the vertical interposed in said pilot fuel passage, a shoulder in a lower portion of said chamber defining a substantially linear valve seat, a ball received in said chamber for cooperation with said seat, said ball having a radius exceeding the width of said shoulder, and magnetic means for holding said ball away from said seat.

RUSSELL F. DOTSON.

References Cited in the file of this patent UNITED STATES PATENTS

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