US2919858A

US2919858A - Flow control device

Info

Publication number: US2919858A
Application number: US516604A
Authority: US
Inventors: Russell B Matthews
Original assignee: Baso Inc
Current assignee: Baso Inc
Priority date: 1955-06-20
Filing date: 1955-06-20
Publication date: 1960-01-05
Anticipated expiration: 1977-01-05

Description

Jan. 5, 1960 R. B. MATTHEWS 2,919,353

FLOW CONTROL DEVICE Filed June 20, 1955 .94 INVENTOR. jZusseZZ B Maizheazs United States Patent FLOW CONTROL DEVICE Russell B. Matthews, Wauwatosa, Wis., assignor to 'Baso Inc., a corporation of Wisconsin Application June 20, 1955, Serial No. 516,604

12 Claims. (Cl. 236-1) This invention relates to improvements in modulating flow control devices, and more particularly to thermoelectrically powered devices affording modulating control of the flow of gaseous fuel.

In the control of fuel flow to a gaseous fuel burner, it is necessary to provide a relatively large volume fuel flow to safely ignite the burner, but once the burner is ignited, a stable flame can be maintained even though the fuel flow is reduced to a substantially lesser amount. The minimum amount of fuel needed to maintain a safe flame is often designated as the minimum safe flow and the amount of fuel necessary for safe ignition is often designated as the safe ignition flow.

It is a general object of the present invention to provide a modulating fuel control device having fuel control means movable to said minimum safe flow and safe ignition positions, said control means being movable to said minimum (safe flow position only after the burner is ignited.

Another object of the invention is to provide an improved fuel flow control device of the character described which employs two operators for the flow control means, the first of said operators being operable to move the control means from a first or off position to full flow or safe ignition position, and the other of said operators being operable to move the control means from said safe ignition to a reduced or minimum safe flow position.

Another of the objects of the invention is to provide a device as above characterized having embodied therein means for energizing the first operator responsive to a first condition, and means for energizing the second operator responsive to a second condition.

A more specific object of the invention is to provide a control device of the type described for controlling the flow of fluid fuel to a fluid fuel burning apparatus having main and pilot burners, the first operator of said device being responsive to the heat of burning fuel at the pilot burner, and the second operator thereof being responsive to heat of burning fuel at the main burner, whereby energization of the second operator, and hence movement of the flow control means to the reduced flow permitting position, cannot take place until a stable flame exists at said main burner, thereby insuring safe ignition of said main burner.

A further object of the invention is to provide a device of the aforementioned character wherein the flow control means is biased toward an off position and utilizes first and second electromagnetic operators for movement against said bias to the various controlling positions, said second electromagnetic operator being capable of moving said flow control means to and holding the latter in said reduced flow permitting position only when energized simultaneously with said first electromagnetic operator, wherefore on deenergization of said first operator, for example on pilot burner outtage, said flow control means moves to said off position under said bias regardless of energization of said second operator, thereby affording safety shut-off of the fuel.

Another object of the invention is to provide the aforementioned fuel control device with a first circuit controlling device in circuit with the first of said operators and operable to effect deenergization of the latter in response to a predetermined high limit temperature, said fuel control device also having a second circuit controlling device in circuit with said second operator operable to cycle the latter in response to normal fluctuations in the temperature, cycling of said second operator moving said flow control means between said full flow and reduced flow positions to thereby afford modulation of the fuel flow.

A specific object of the invention is to provide a modulating fuel control device of the class described wherein the valve means comprises first and second spaced opposing valve seats serially arranged in the fuel stream, and a double-acting valve member provided with first and second spaced surfaces cooperable with said valve seats.

Still another object of the invention is to provide a device of the type described embodying an operative connection between the valve member and the two operators, said operative connection including a pair of relatively movable lost motion members between said valve member and first operator permitting movement of said valve member to reduced flow permitting position by said second operator after said first operator has moved said valve member to full flow permitting position.

A further specific object of the invention is to provide a device wherein the above-described operative connection comprises a pivotal actuating member for moving the valve member, said actuating member being operatively connected to two annatures each forming a part of one of the two electromagnetic operators, energization of the first operator affording movement of the first armature to an attracted position and through said actuating member moves the second armature from an inoperative position to an intermediate position for attraction by the second operator. Subsequently energization of said second operator effecting movement of the second armature to attracted position to thereby actuate said valve member from full flow-permitting position to reduced flow-permitting position.

Another object of the above described invention is to provide a device of the aforementioned type which is relatively simple in construction and inexpensive to manufacture and is otherwise well adapted for the purpose described.

The novel features that I consider characteristic of my invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation together with additional objects and advantages thereof will best be understood by the following description of a specific embodiment when read in connection with the accompanying drawing, in which:

The sole figure is a sectional view of a fuel control device constructed in accordance with the invention and operatively associated with a fuel burning apparatus, the electrical circuit of said device and parts. of said apparatus being shown semi-diagrammatically.

While the invention may take a number of forms, the modulating fuel control device selected for illustration in the drawing is generally indicated by the numeral 10 and comprises a valve body or casting 7 having an inlet connection 12 and an outlet connection 14, there being an annular inlet valve seat 13 and an annular outlet valve seat 11. A main fuel burner 16 is supplied with fluid fuel through a supply pipe 19, contiguous sections of which are connected to the inlet 12 and outlet 14 as shown.

A valve member generally indicated by the numeral .24 coacts with the seats 11 and 13 and controls the flow of fuel to the burner 16, said valve member being under the dual influence of a pair of

electromagnetic operators

65 and 67 to afford modulation of the fuel flow as will later be described. A minimum safe fuel flow by-pass 15 is formed in the valve body 7 and by-passes the inlet valve seat 13. A set screw 17 adjusts the capacity of the by-pass 15.

A cup-shaped housing member 8 is sealingly attached to the valve body 7 through a gasket 21, and is secured to said body, as by a plurality of bolts 22. The member 8 provides a chamber 23 to house the

operators

65 and 67 out of the direct path of the fuel stream. An actuating member or lever arm 36 provides an operative connection between the valve member 2 5 and the

operators

65 and 67 for positioning the valve member in various controlling positions. One end 38 of the actuating member 36 is pivotally attached to a suitable lug or bracket 39 formed in the cup-shaped housing member 8.

The valve member 24 may comprise a stem 26 provided with an integral shoulder 32 and having valve disks 28 and 3t) pivotally connected to opposite ends thereof. The arm 36 is formed with an aperture which may have a diameter slightly larger than the stem 26 and smaller than that of the shoulder 32. The stem 26 extends through the aperture 29, and a loading spring 34 surrounding said stem biases the valve disk away from the arm 36 and the shoulder 32 into engagement with said arm. The valve disks 28 and 30 have sealing surfaces 28a and 30a respectively cooperable with the seats 11 and 13, and the pivotal connections of said valve disks with the stem 26 permit said disks to accommodate themselves to said seats.

The electromagnetic operator 65 is formed of a generally U-shaped permeable core 68 having an energizing winding 74-, one end of which is connected to a terminal 75 which sealingly and insulatingly extends through the housing member 3 as shown. The core 68 is fixedly attached to a portion of the side wall of the housing member 8, for example by a tubular connection 73 having an insulated terminal member 73 extending therethrough and externally exposed. The other end of the winding '74 is connected in circuit with the terminal 78.

The legs of the core 68 each terminate in a pole face, and an armature 46 is movable to attracted and retracted positions with respect to said pole faces. Disposed between the legs of the core 68 is a coiled compression spring 60 one end of which abuts the inner bottom surface of said core, and the other end of which abuts the armature 4-6 to bias the latter toward its retracted position.

The armature 4-6 is carried by the arm 36 and is connected thereto by a stem 44 having a terminal shoulder 50. The armature 46 is formed with a central aperture 48 which may have a diameter smaller than the shoulder 50 and slightly larger than the armature stem 44, which projects therethrough. interposed between the lever arm 36 and the upper surface of the armature 46 is a compression spring 52 which biases the armature into engagement with the terminal shoulder Stl. As shown, this provides a spring loaded lost-motion connection which permits relative movement of the lever arm 36 and the armature 36 along stem 44.

The second electromagnetic operator 67 is substantially identical to operator 65, having similar elements such as a U-shaped core 70, a winding 72, an armature '42, and a biasing spring rsl. One end of the winding 72 is connected to the common terminal post 75, and the core 70 is fixed within the housing member 8 by a tubular connection member 76a having an insulated terminal member 76 extending therethrough, said terminal being connected in circuit with the other end of the winding 72. The armature 42 is also carried by the lever arm 36 for coaction with the pole faces of core 79. A stem 41) connects the armature 42 and arm 35, one end of the stem being fixed to said arm the other end being loosely fixed to the armature, as at 41, in a manner to allow a slight tilting movement of the armature, so that it may readily accommodate itself to the pole faces of the core 70.

The source of electric power for the electro-magnetic operator 65 may be a thermoelectric generator 58, which in the illustrated embodiment takes the form of a thermocouple. The main burner 16 is provided with a pilot burner 54 in igniting relation thereto, and the thermocouple 53 is mounted in a position to have its hot junction subject to the heat of the flame at said pilot burner. A second thermocouple 56 may be the power source for the electro-magnetic operator 67 and is preferably positioned so that its hot junction is subject to the heat of the flame at the main burner 16.

Temperature responsive circuit controlling means may be provided for controlling the energization of both of the electromagnetic operators, and one form of such means is indicated generally by the numeral 99. The circuit controlling means 99 may include a thermostat 93 for controlling the first operator 65, and a thermostat ItOtl for controlling the operator 67. The circuit controlling means 99 includes a bracket 69 on which the thermostats 9S and ltlt) are mounted. The thermostat 98 may comprise an expansible and contractible hermetically sealed enclosure 101 having

contacts

86 and 84 encapsulated therein. The enclosure llbl may take the form of a bellows having fixed and

movable end walls

87 and 88 respectively, and having a thermally expansible and contractible volatile fluid fill therein. The

contacts

86 and 84 are fixed respectively to the

end walls

87 and 88, the contact 86 being connected in circuit with the terminal post through the adjacent arm 6% of the bracket 69 and a conductor 77. The contact 84 is insulated fro-m the end wall 88, as by a glass seal 34a, and is connected in circuit with one terminal of the thermoelectric generator 58 by a conductor 82. The electrical circuit for the operator 65 is completed by a conductor connecting the other terminal of the generator 58 in circuit with the terminal 78.

The illustrated thermostat 1% comprises an expansible and contractible hermetically sealed enclosure 102, having contacts 96 and 94' encapsulated therein. The enclosure 102 may take the form of a bellows having fixed and movable end walls 83 and 85 respectively, and having a thermally expansible and contractible volatile fluid fill therein. The

contacts

96 and 94 are fixed respectively to the end walls 85 and 83, the contact 96 being connected in circuit with the terminal post 75 through the adjacent arm 69a of the bracket 69 and a conductor 77. The contact 96 may be insulated from the end wall 85, as by a glass seal 96a, and is connected in circuit with one of the terminals of the thermoelectric generator 56 by a conductor 81. The electrical circuit for the operator 67 is completed by a conductor 79 which connects the other terminal of the generator 56 in circuit with the terminal 76.

Means is provided for adjusting the temperature control points of the

thermostats

98 and 100 comprising the pressure plate 91 having a stem 91:: slidable in bearings 71 formed on the bracket 69. Interposed between the end wall 88 of thermostat 98 and the pressure plate 91 is a loading spring @tl which biases the contact 84 toward engagement with the contact 86. Interposed between the end wall 85 of thermostat 1% and the pressure plate 91 is a spring 92 which biases contact 96 away from engagement with the contact 94. A cam Va is fixed to a shaft 103 which is rotatably mounted on an arm can of the bracket 69. The shaft ms may be provided with a knob or finger piece (not shown) for effecting rotation of said shaft and hence of the cam 93 for adjustment of the position of the pressure plate 91 to thereby adjust the biasing force of springs and 92 .5 and the temperature control points of the

thermostats

98 and 100.

The thermostat 98 is preferably of the type that has a thermal lag of approximately F. while thermostat 100 is preferably of the type that has a thermal lag near 4 F. It is also preferable that the two thermostats have substantially identical median thermal lag points, i.e. if the temperature range of thermostat 98 is 70 to 80 F., the median thermal lag point is 75 F., and with the aforementioned range and median of thermostat 98, it is then preferable for the thermostat 100 to have a 77 to 73 F. range, thus providing thermostat 100 with the same median lag point of 75 F.

Operation The operation of the illustrated modulating fuel control system is as follows:

The fuel pressure and the springs 60 and 61 bias the valve member 24 toward an oif or flow-preventing position wherein the valve disk 28 sealingly engages outlet valve seat 11. When the temperature surrounding the thermostat 98 is above the predetermined high limit temperature for which it is set, thermoelectric current flow through the

contacts

84 and 86 is interrupted so that there is no energization of operator 65. Operator 67 is also deenergized, since with the fuel flow to the main burner 16 shut off, there is no flame at said burner and hence the generator 56 is not heated.

With the valve member 24 in the aforementioned off position, a drop in the temperature surrounding thermostat 98 causes contraction of the enclosure 101, thereby moving the end wall 88 toward the wall 87 to move the contact 84 toward the contact 86 to complete the circuit to the operator 65. Since thermocouple 58 is heated by the flame of the pilot burner 54, operator 65 immediately becomes energized to attract armature 46 and thereby move lever arm 36 to actuate the valve member 24 to its full open position shown, wherein the valve disks 28 and 30 are spaced from their respective seats substantially the same amount. Full fuel flow to the main burner 16 is thereby provided, thus insuring safe ignition of the fuel at the main burner. On ignition of the main burner 16, the latter heats the generator 56 to render the same operative. The aforementioned movement of the lever arm 36 by attractive movement of the armature 46 also moves the armature 42 from an inoperative retracted position (not shown) to the operative retracted position shown.

As the temperature surrounding thermostats increases due to the heat produced by a high flame existing at the main burner 16, expansion of the enclosure 102 moves the contact 96 toward the contact 94 to complete the circuit between the generator 56 and the operator 67 and effect energization of said operator. Due to the energization of operator 67, the armature 42 is attracted from the operative retracted position shown to an attracted position in engagement with the pole faces of the core 70. This attraction of armature 42 moves the valve member 24 to a reduced flow-permitting or low fire position indicated in dot and dash lines and wherein the valve disk 30 is seated on the seat 13 to prevent fuel fiow through the inlet 12. Fuel can now flow through the by-pass 15 only, the latter having a capacity which affords the minimum flow of fuel for maintenance of a stable flame at the burner 16. It is of course obvious that by-pass 15 can be omitted and in its place means can be provided to limit closure of the valve disk 30 to that affording the aforementioned minimum. safe flow of fuel.

If the room temperature drops as a result of the reduced flame at the main burner, enclosure 102 contracts, and the corresponding movement of the end wall 85 toward the end wall 83 causes separating movement of the

contacts

94 and 96 sufficient to interrupt the current flow to the operator 67 and deenergize the latter. The

armature 42 is thereupon biased to its operative retracted position by the spring 61, and the corresponding movement of the arm 36 returns the valve member 24 to the full flow-permitting position shown.

If, however, the main burner fuel input at the low fire position produces suflicient heat so ahthtt ETAOIN fire position produces sufiicient heat so that the temperature continues to rise, thermostat 98 expands and separates the

contacts

84 and 86 sufficient to deenergize operator 65, such deenergization allowing the biasing forces to move the valve member 24 to the flow-preventing or off position.

It is to be noted, that when the valve member 24 is in off position and the armature 42 is in the inoperative retracted position (not shown) the air gap separating the said armature from the pole faces of core 70 is too large for said armature to be attracted by energization of the operator 67. For this reason the operator 67 cannot move the valve member '24 to reduced flowpermitting position unless and until the air gap between said operator and armature 42 is reduced and the bias of the spring 60 has been overcome by attraction of the armature 46 to the pole faces of the core 68, which attraction also moves lever arm 36 as previously described. Also of special note is the lost-motion connection between the armature stem 44 and armature 46 which permitsthe lever arm 36 to be moved to low fire position by attractive movement of the armature 42 while the armature 46 is in engagement with the pole faces of the core 68.

Although only one specific embodiment of the invention has been shown and described, it is with full awareness that many modifications are possible. .The scope of the invention, therefore, is not to be restricted except by the terms of the appended claims.

What is claimed as the invention is:

1. A control device for fluid fuel burning apparatus having main and pilot burners, comprising main burner fuel flow controlling means having flow-preventing, full flow-permitting and reduced flow-permitting positions, means including first operator means responsive to heat of burning fuel at said pilot burner for moving said flow controlling means from said flow-preventing position to said full flow-permitting position, and means including second operator means responsive to heat of burning fuel at said main burner for moving said flow controlling means from said full flow-permitting position to said reduced flow-permitting position.

2. A control device for modulating fuel comprising, means defining a fuel passage having first and second spaced valve seats serially arranged therein, and valve means having a first sealing surface cooperable with said first valve seat, and a second sealing surface fixed with respect to said first sealing surface and cooperable with said second valve seat, said valve means being biased to a first position wherein said first sealing surface engages said first valve seat to prevent fluid flow through said passage, said valve means having a second position wherein said sealing surfaces are spaced respectively from said valve seats sufliciently to permit full fluid flow through said passage, said valve means also having a third position wherein said second sealing surface is in reduced flow-permitting relation with said valve seat, first temperature responsive operator means operable to move said valve means from said first position to said second position against said bias in response to a first predetermined temperature, and second temperature responsive operator means responsive to a second predetermined temperature operable only to move said valve means from said second position to said third position against said bias whereby to modulate the fuel flow.

3. A fuel burning and control system comprising in combination a main burner, a pilot burner positioned adjacent to said main burner, a first thermoelectric generator positioned to be heated by said pilot burner, a second thermoelectric generator positioned to be heated by said main burner, means for controlling the flow of fuel to said main burner having ofi, high, and low controlling positions, first operator means for said flow controlling means in circuit with said first generator, second operator means for said flow controlling means in circuit with said second generator, said first operator means when energized being operable to move said flow controlling means from said off to said high position and said second operator means when energized being operable, only after movement of said flow control means to said high position, to move said flow controlling means from said high to said low position.

4. A fuel burning and control system comprising in combination, a main burner, a pilot burner positioned adjacent to said main burner, a first thermoelectric generator positioned to be heated by said pilot burner, a second thermoelectric generator positioned to be heated by said main burner, means for controlling the flow of fuel to said main burner having ofi, high and low controlling positions, first operator means for said flow controlling means in circuit with said first generator, first circuit controlling means in circuit with said first operator means and generator for controlling energization of said operator means by said generator, second operator means for said flow controlling means in circuit with said second generator, second circuit controlling means in circuit with said second operator means and generator for controlling energization of said second operator means by said second generator, said first operator means when energized being operable to move said flow controlling means from said off to said high position and said second operator means when energized being operable, only after movement of said flow controlling means to said high position, to move said flow controlling means from said high to said low position.

5. A fluid fuel burning and flow control device having main and pilot burners comprising, fiow control means biased toward a first position, and also having second and third positions, first electromagnetic operator means energizable in response to heat of burning fuel at said pilot burner for moving said flow control means from said first position to said second position against said bias, and second electromagnetic operator means operatively associated with said flow control means and energizable in response to heat of burning fuel at said main burner to aiford predetermined limited power capable of moving said flow control means to its said third position but only after said first electromagnetic operator means has positioned said flow control means in its said second position.

6. A fluid flow control device comprising, flow control means having off, high and low positions, first operator means having a member operatively associated with said flow control means and movable from a first position to a second position to move said flow control means from said off position to said high position, second operator means having a member operatively associated with said flow control means and movable from a first position to a. second position to move said flow control means from its said high position to its said low position, and lost-motion means interposed between said flow control means and the member of said first operator means to permit the latter member to remain in its second position during movement of said flow control means from its high to its low position by said second operator means following movement of said flow control means from its low to its high position by said first operator means.

7. A fuel burning and control system comprising, a main burner, a pilot burner positioned adjacent said main burner, means for controlling the flow of fuel to said main burner having off, high and low controlling positions, means including operator means responsive to a given condition while said flow controlling means is in its high position to successively move said flow controlling means from said high to said low position and from said low to said otf position for interruption of fuel flow to said main burner, and means responsive to a flame at said pilot burner and associated with said operator means to cause said operator means to move said flow control means directly to its off position upon outage of the flame at said pilot burner regardless of the position of said flow control means at the time of said pilot flame outage.

8. A fluid flow control device comprising, flow control means having olf, high and low flow positions and being biased to ofi position, first operator means operatively connected to said flow control means, said operator means including an armature movable from a retracted position to an attracted position by energization of the first operator means to thereby move the flow control means from said off position to said high flow position against said bias, second operator means operatively connected to said flow control means and having a second armature movable to first and second retracted positions and to an attracted position relative thereto, said second armature being movable from its first to its second retracted position by movement of said flow control means from its off to high flow position, said second operator means when energized being operable to move said second armature from said second retracted position to its attracted position to thereby move said flow control means from said high flow position to said low flow position against said bias.

9. A fluid flow control device comprising, flow control means biased to off position, and having high and low flow positions, an actuating member for moving said flow control means, first operator means operatively connected to said actuating member, said operator means including a first armature having a relative lost-motion connection to said actuating member, said lost motion connection including biasing means for biasing said actuating member and said first armature to a separated relation, said first armature being movable from a retracted position to an attracted position by energization of the first operator means to thereby move the flow control means from said oil position to said high flow position against said bias, second operator means operatively connected to said actuating member, said second operator means including a second armature operatively associated with said actuating member and movable to first and second retracted positions and to an attracted position relative thereto, said second armature being movable from its first to its second retracted position by movement of said flow control means by said actuating member from its off to high flow position, and said second operator means when energized being operable to move said second armature from said second retracted position to its attracted position and simultaneously move said actuating member to thereby move said flow control means from said high flow position to said low flow position against said bias, said lost motion connection permitting movement of sad actuating member relative to said first armature against said bias.

10. A fluid flow control device comprising, flow control means biased toward an off position, and also having high flow and low flow positions, first electromagnetic operator means for said flow control means operable when energized to move said flow control means from said off position to said high flow position against said bias, and second electromagnetic operator means operatively associated with said flow control means and energizable to aliord predetermined limited power capable of moving said flow control means to its said low flow position but only after said first electromagnetic operator means has positioned said flow control means in said high flow position.

11. A fluid flow control device comprising, flow control means biased toward an off position, and also having high flow and low flow positions, first electromagnetic operator means for said flow control means, a first condition responsive energizing circuit for energizing said first operator, said operator being operable when energized by said circuit to move said flow control means from said off position to said high flow position against said bias in response to a first condition, second electromagnetc operator means operatively associated with said flow control means, and a second condition responsive energizing circuit for energizing said second operator means in response to a second condition to afford predetermined limited power capable of moving said flow control means to its said low flow position but only after said first electromagnetic operator means has positioned said flow control means in its said high flow position.

12. A fluid flow control device comprising, flow control means biased toward an off position, and also having high flow and low flow positions, first electromagnetic operator means for said flow control means, a first condition responsive circuit controlling device and a first energizing circuit for energizing said first operator, said operator being operable when energized by said circuit to move said flow control means from said off position to said high flow position against said bias in response to a first condition, second electromagnetic operator means operatively associated with said flow control means, and a second condition responsive circuit controlling device and a second energizing circuit for energizing said second operator in response to a second condition to afiord pre determined limited power capable of moving said flow control means to its said low flow position but only after said first electromagnetic operator means has positioned said flow control means in its said high flow position.

References Cited in the file of this patent UNITED STATES PATENTS 1,845,999 Breese Feb. 16, 1932 1,849,163 Wilhjelm Mar. 15, 1932 1,932,269 Harrington Oct. 24, 1933 2,224,705 Stringer Dec. 10, 1940 2,317,639 Ray Apr. 27, 1943 2,329,682 Alfery Sept. 14, 1943 2,377,517 Ray June 5, 1945 2,396,205 Russell Mar. 5, 1946 2,495,226 'Crago Jan. 24, 1950 FOREIGN PATENTS 4,827 Norway Aug. 10, 1896 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,919,858

Russell B. Matthews January 5, 1960 Itis hereby certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 39, for "Subsequently" read Subsequent column 6, line 6, strike out "fire position produces sufficient heat so ahthtt Efl'AOIN"; column 8, line 60, for "of sad actuating member" read of said actuating member Signed and sealed this 28th day of June 1960.

(SEAL) Attest: KARL H. AXLINE ROBERT C. WATSON Attesting Officer Commissioner of Patents