US 3300174 A
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Description (OCR text may contain errors)
1967 D. c. URBAN ETAL 3,300,174
GAS VALVE Filed May 10, 1963 United States Patent Ofiice Patented Jan. 24, 1967 3,380,174 GAS VALVE Donald C. Urban, Florissant, and Carl A. Smith, Lemay, Mo., assignors, by mesne assignments, to Emerson Electric (10., a corporation of Missouri Filed May 10, 1963, Ser. No. 279,490 2 Claims. (Cl. 251-29) This invention relates to gas valves for controlling the operation of gas burners and particularly concerns fluid pressure operated valves including regulating means for regulating the fluid pressure applied to the valve operator in a manner to maintain a predetermined gas pressure at the burner metering orifice. 7
An object of the invention is to provide a generally new and improved fluid pressure operated gas valve which when operated from closed to open position automatically sup-plies gas to a burner initially at a relatively low rate for a predetermined relatively short period of time and thereafter at a relatively high rate until the valve is operated to a closed position.
A further object is to provide a valve of this character which includes adjustable pressure regulating means whereby the relatively low initial flow rate as Well as the subsequent higher flow rate may be preselected and maintained irrespective of variations in supply line pressure.
These and further objects and advantages will appear from the following description when read in connection with the accompanying drawing.
In the drawing, the single figure is a schematic view of a valve constructed in accordance with the present invention, shown associated with main and pilot gas burners.
Referring to the drawing, a valve body is generally indicated at 10 and comprises a lower main valve section 11, three successive overlying sections 12, 13, and 14, and a cover member 15, all suitably connected. The main lower valve section 11 is provided with an inlet passage 16 leading to a chamber 17 and a main burner fuel out-let passage 18 leading from chamber 17. A supply conduit 19 is connected to inlet 16, and a conduit 20 is connected to outlet 18 and leads to a main burner 21 which is provided with the usual fuel metering orifice 22. The main valve section 11 is further provided with an annular valve seat 23 with which a main disc valve 24 cooperates to control the flow of gas to the main burner 21. The valve 24 is attached to and is movable with the central portion of a flexible diaphragm member 25 which forms the flexible upper wall of chamber 17.
Interposed in inlet passage 16 is a manually rotatable plug valve 26 having main transverse ports 27 therethrough and an arcuate groove 28 at the lower end thereof forming a pilot burner fuel port. The arcuate groove 28 extends somewhat more than 180 around the plug valve 26 so as to permit the plug valve to be rotated to a position in which fuel is permitted to flow through a pilot burner fuel passage 29 when the ports 27 are in a position to cut off flow through main inlet passage 16. The plug valve 26 may therefore be moved to three positions, one, in which all flow is cut off through both the main inlet 16 and the pilot burner fuel passage 29, two, in which fuel is permitted to flow through pilot passage 29 only, and, three, in which fuel is permitted to flow through both the main inlet passage 16 and the pilot burner fuel passage 29. The pilot burner fuel passage 29 extends from a point in the main inlet passage 16 anterior to plug valve 26 to an outlet in the first overlying body section 12 controlled by a valve 38. A conduit 31 connected to the outlet of pilot burner fuel passage 29 leads to a pilot burner 32 arranged to ignite gas issuing from main burner 21.
Body section 12 has a lower cavity forming a chamber 33 opposed to inlet chamber 17 and separated therefrom by flexible diaphragm 25. A spring 34 in chamber 33 biases the central part of diaphragm 25 downward and valve 24 on its seat 23. Body section 12 is further provided with an upper cavity forming a smaller chamber 35. A flexible diaphragm 36 clamped between sections 12 and 13 forms the flexible upper wall of chamber 35. Body section 13 in turn has a lower cavity forming a chamber 37 opposed to chamber 35 which is separated from chamber 35 by the flexible diaphragm 36. The body section 13 is further provided with an upper cavity forming a chamber 38, and a flexible diaphragm 39 clamped between body sections 13 and 14 forms the flexible upper wall of chamber 38.
Body section 14 is again in turn provided with a lower cavity forming a lower chamber 40 opposed to chamber 38 and is separated therefrom by the flexible diaphragm 39. Body section 14 is further provided with an upper cavity forming an upper chamber 41. A flexible diaphragm 42 clamped between body section 14 and cover 15 forms the upper flexible wall of chamber 41.
Upper chamber 41 and lower chamber 33 both communicate with the inlet chamber 17 through a common passage 43 and branched passage 44. A filter 45 and a restricting orifice 46 are interposed in common passage 43. The lower end of branch passage 44 opens directly into lower chamber 33, but the upper end thereof opens into an extension passage 47 before entering chamber 41 and passage 47 is controlled by a valve 48. The valve 48, which will be hereinafter referred to as the full flow regulator valve, is attached to the central portion of diaphragm 42 forming the upper flexible wall of chamber 41. A chamber 49 formed in cover 15 opposed to chamber 41 and separated therefrom by the diaphragm 42 is vented to atmosphere through vent 50. An adjustable compression spring 51 in cover 15 bearing downward on diaphragm 42 biases the valve 48 openward.
A port 52 providing communication between chamber 41 and next lower chamber 40 is controlled by valve 53. The valve 53, which will hereinafter be referred to as the low flow regulator valve, is connected to the central portion of flexible diaphragm 39 which forms the lower flexible wall of chamber 40. Chambers 38 and 37 underlying the chamber 40 are both vented to atmosphere 7 through a side opening 54. An adjustable compression spring 55 acting on the underside of diaphragm 39 biases valve 53 openward. The spring 55 bears at its lower end on a hollow threadedly adjustable member 56 threadedly engaged in a partition 57 separating chambers 38 and 37. Access for adjustment of member 56 is provided by side opening 54. A vertical pin 58 slidable in hollow member 56 abuts the lower side of diaphragm 39 under certain conditions to move valve 53 openward. The lower end of pin 58 is connected to the central portion of diaphragm 36. The pin 58 and diaphragm 36 are biased downward by a spring 60.
Chamber 4t communicates with main fuel outlet passage 18 through a port 61 opening into a chamber 62, a passage 63 having a port 63a leading to a chamber 64, and a passage 65 leading from chamber 64 to outlet passage 18. Chamber 40 also communicates with chamber 35 through port 61, passage 63, passage 66, and through passage 68 parallel with passage 63. Passage 68 is unrestricted while passage 63 has a calibrated restriction 69 therein between chamber 64 and common passage 66. It will be seen that chamber 35 is also in communication with the main fuel outlet passage 18 via passage 65, chamber 64, port 63a, passage 63 with restriction 69, and passage 66.
The passage 61 leading from chamber 48 to chamber 62 is formed with a valve seat on the chamber 62 side as is the upper end of passage 68. These valve seats are axially aligned and opposed and are controlled by a double throw valve 70. The valve 70 is operated by a solenoid actuator 71 which when energized moves valve 70 from the position shown to a position wherein it opens with respect to port 61 and closes the upper end of passage 68. When solenoid 71 is de-energized a spring 72 returns valve 78 to the position shown, closing port 61 and opening the upper end of passage 68.
A valve 73 controls port 63a leading to chamber 64. The valve 73 controlling port 63a and valve 30 controlling the outlet of pilot burner fuel passageway 29 are operated simultaneously by a lever 74. The lever 74 is biased by a spring 75 in a direction to move valves 73 and 30 to a closing position with respect to port 63a and the pilot outlet. Lever 74 is provided with an armature 76 which is moved into contact with the core of an electromagnet 77 by a push pin 78, and when moved to this position opens valves 73 and 30. Electromagnet 77 is energized by current generated at a thermocouple junction 79 arranged to be impinged by a flame at pilot burner 32. Therefore, armature 76 will remain against the core of electromagnet 77 and valves 73 and 30 will remain open so long as there is pilot burner flame to generate electric current.
The energization of electromagnet 71, which actuates double throw valve 78, is effected through a circuit connected to commercial power source terminals 80 and 81 and controlled by a thermostat 82.
Operation The elements of the device are shown in the positions they assume when the main and pilot burners are inoperative. The manual plug valve 26, however, for the pur pose of better illustration, is shown in a position to admit fuel to inlet chamber 17 and to the pilot burner fuel pas-sage 29. Under these conditions supply line pressure is applied to both sides of main valve diaphragm 25 inasmuch as chamber 33 is in open communication with chamber 17 through passages 43 and 44. The area on the lower side of diaphragm 25 exposed to this pressure being somewhat less than the exposed area on the upper side thereof due to the valve port area, the valve 24 will be biased on its seat. The closing spring 34 adds further seat pressure. The high and low fiow regulator valves 48 and 53, respectively, will be closed, as shown, due to supply line pressure acting on their respective operating diaphragms 42 and 39.
When it is desired to operate the pilot burner, the push pin 78 is depressed and held down. This action rotates lever 74, moving armature 76 into contact with the core of electromagnet 77 and opening control valve 73 and pilot burner outlet valve 38, thereby permitting fuel to flow from passage 29 through conduit 31 to the pilot burner 32. The pilot burner is then lighted and push pin 78 is held down until sufficient electrical energy is generated at thermocouple junction 79 to hold lever 74 in the set position. With pilot burner 32 in operation and valve 73 being held in the open set position, the main valve 24 may now be operated to an open position by the closing of thermostat 82.
The closing of thermostat 82 energizes electromagne-t 71 moving double throw valve 70 to a position to open port 61 and close passage 68. Opening of port 61 permits the existing supply line pressure in chambers 41 and 40 to exhaust at a relatively rapid rate to the instant existing atmospheric pressure in outlet passage 18 through port 61, chamber 62, passage 63, port 6311, chamber 64, and passage 65. When this occurs the pressure drop permits springs 51 and 55 to move high and low flow regulator valves 48 and 53 openward. As valves 48 and 53 move openward chamber 33 is also permitted to exhaust to main outlet passage 18 at a relatively rapid rate, thereby permitting the line pressure existing in chamber 17 and acting on the underside of main diaphragm 25 to move valve 24 openward. It will be seen that while chambers 33, 41, and 40 are thus exhausting to main outlet passage 18, they are also being supplied with gas at line pressure through passages 43 and 44, but this flow is restricted by orifice 46 to such extent that the net eitect is a substantial drop in pressure in chambers 33, 41, and 40.
As main valve 24 moves open gas flows through outlet passage 18 and conduit 20 to burner metering orifice 22 which restricts the fiow and causes the pressure in conduit 20 and outlet passage 18 to rise above atmospheric. When the pressure in outlet passage 18 rises to a predetermined pressure (above atmospheric), the pressure again increases in chamber 40 causing diaphragm 39 to depressdownward to move the low flow regulator valve 53 toward a closed position. The low flow regulator valve now assumes that partially open position which permits chamber 33 to exhaust at a sufiiciently greater rate than the input thereto through restriction 46 to position main valve 24 so as to maintain that predetermined pressure in outlet passage 18. This predetermined pressure in outlet passage 18 corresponds to a predetermined low flow rate through orifice 22.
This pressure increase in outlet passage 18, due to partially opening valve 24, also acts of course on diaphragm 42 which actuates the high flow regulator valve 48, but the spring 51 urging valve 48 openward is con siderably stronger than spring 55 urging the low flow regulator valve 53 open so that, at the lower outlet pressures, the low flow regulator valve is the controlling point. In this connection the diaphragm 39 may be made of considerably larger area than diaphragm 42, if desired, so that it responds to close valve 53 at a lower pressure than that required to act on diaphragm 42 to close valve 48.
Under these :low flow conditions the predetermined pressure existing in outlet passage 18 is slowly communicated to chamber 35 through the highly restricting orifice 63 the valve 73 being open. The passage 68 is closed at its upper end by double throw valve 70 under these conditions so that communication between main outlet passage 18 and chamber 35 is limited to orifice 69. As the pressure in chamber 35 attains that in main outlet passage 18, diaphragm 36 bulges upward, moving sliding pin 58 upward into engagement with diaphragm 39, and further so as to move diaphragm 39 upward and the attached low flow regulator valve 53 openward to a position in which it is no longer controlling. It will be understood that regulator spring 58, in any adjusted position is considerably stronger than diaphragm return spring 60. The elapsed time :between the partial opening of main valve 24 and opening of valve 53 to a non-controlling position is in the order of five seconds, This time, of course, may be varied by providing an adjustable needle valve for orifice 69, which is contemplated. The purpose of providing an initial low flow f'uel rate to the main burner for a short period is to allow time for a natural draft to develop through the burner combustion chamber before permitting a high or full flow rate to the burner to occur.
When the limiting low flow regulator valve 53 is moved openward to a non-controlling position, the chamber 33 above main diaphragm 25 may now be exhausted at a higher rate, permitting valve 24 to move .farther open to a position which results in a higher predetermined pressure (above atmospheric) in main outlet passage 18. When this higher predetermined pressure in chamber 18 occurs, high flow regulator valve 48 is moved toward a closed limiting position which permits chamber 33 to exhaust at that rate which positions valve 24 so as to maintain the higher predetermined pressure in main outlet passage 18. This higher predetermined pressure in passage 18 corresponds to a predetermined higher flow rate through burner metering orifice 22.
The provision of an adjustable needle valve for varying the restriction at orifice 46 is contemplated. The use of an interlocking arrangement between manually rotatable plug valve 26 and push pin 78, which prevents the manual operation of push pin 78 to open valves 73 and 30 when plug valve 26 is in a position to permit flow from inlet 16 to chamber 17, is also contemplated. Arrangements of this kind are well known and understood in the art.
When heat produced by main burner 21 satisfies thermostat 82, it opens breaking the circuit energizing electromagnet 71. When this occurs double throw valve 70 move-s to a position to close port 61 and open passage 68. The closing of port 61 again results in a pressure buildup in chambers 40, 41, and 33 equal to supply line pressure, whereupon main valve 24 closes. Unrestricted passage 68 now being open, chamber 35 is rapidly restored to the atmospheric pressure again existing in outlet passage 18 thereby permitting rapid recycle operation of the device. If the pilot burner is extinguished at any time, the supply of electrical energy to electromagnet 77 is no longer generated at thermocouple 79 and, therefore, valves 73 and 30 are closed. The closing of valves 30 cuts oil how to the pilot burner, and the closing of valve 73 cuts off all communication between chambers 33, 41, and 40 and the main outlet passage 18. Under these conditions the pressure in chamber 33 attains that of inlet chamber 17 and main valve 24 closes.
It will be seen from the foregoing that we have provided a fluid pressure operated gas valve which functions automatically when operated from closed to open or from off to on position to supply an initial relatively small flow of gas to a burner for a predetermined relatively short period of time and, thereafter, supplies gas to the burner at a relatively high flow rate until the valve is operated to an oil or closed position. It will also he seen that gas at both the initial small flow rate and the subsequent relatively high flow rate is supplied to the burner at a predetermined pressure irrespective of variations in supply line pressure.
Adjustment of the low flow regulator spring 55 to a stronger biasing position will result in a higher pressure in main outlet passage 18 and therefore a greater initial flow to the burner through metering orifice 22, and adjustment of the high flow regulator spring 51 to a stronger biasing position will likewise increase the pressure in outlet passage 18 and therefore increase the subsequent higher flow rate to the burner.
Inasmuch as the position of main valve 24 is dependent on the pressure in outlet passageway 18 when the valve is operating, the substitution of a larger diameter burner orifice will cause valve 24 to open wider under both low and high flow operating conditions and thereby permit greater flow at the same predetermined pressures.
6 We claim: 1. In a gas valve, a valve body having an inlet passage, an outlet passage, and a valve chamber therebetween, a biased closed valve in said chamber controlling the flow from said inlet to outlet passage including a pressure responsive actuator operative to move said valve openward when greater fluid pressure is applied to one side thereof than to the other, means providing communication between said inlet passage and one side of said actuator, means providing relatively restricted communication between said inlet passage and said other side of said actuator, a bleed passage providing relatively unrestricted communication between said other side of said actuator and said outlet passage, a control valve movable to open and close said bleed passage, two pressure regulating valves arranged in series in said bleed passage, one of which is operative to maintain a higher fluid pressure on said other side of said actuator than the other, pressure responsive means in communication with said outlet passage and operative in response to an increase in pressure in said outlet passage to move said one pressure regulating valve to an inoperative position, and said communication between said pressure responsive means and said outlet passage comprising a highly restricted passage whereby the response to said pressure responsive means to an increase in pressure in said outlet passage is delayed. 2. A gas valve as set :torth in claim 1 which further includes a second passage providing relatively unrestricted communication between said pressure responsive means and said outlet passage, and valve means movable with said control valve to close said second passage when said control valve is moved to open position with respect to said bleed passage and movable therewith to open said second passage when said control valve is moved to a closed position with respect to said bleed passage, whereby said pressure responsive means is permitted to exhaust rapidly into said outlet passage when said bleed passage is closed to effect closure of said main valve.
References Cited by the Examiner UNITED STATES PATENTS 2,262,825 11/1941 Welliver 2369 2,765,029 10/1956 Wolff.
2,876,951 3/1959 Matthews 23 684 3,036,778 5/1962 Dillman 236-8O 3,064,900 11/ 1962 Atges 236-- X 3,235,180 2/1966 Graham et al 23680 EDWARD J. MICHAEL, Primary Examiner.