US2604902A - Boiler feed water regulating apparatus - Google Patents

Description

July 29, 1952 WEINING Er AL 2,604,902

BOILER FEED WATER REGULATING APPARATUS Filed Oct. 5, 1945 2 SHEETS-SHEET 1 1N VEN TORS H/MRY H. WElN/NG H/MOLD ASCHL/EDER F1 6. z f-wk H 7'7'OANE Y 29, H. H. WElNlNG El-AL BOILER FEED WATER REGULATING APPARATUS Filed Oct. 5, 1945 2 SHEETS-SHEET 2 INVENTORS HHARYH. WEINING' Hfl/FOLD 14. SCHL/EDER fl T TORNE Y Patented July 29, 1952 BOILER FEED WATER REGULATING APPARATUS Harry H. Weining and Harold A. Schlieder, Erie, 7 Pa., assignors to Continental Foundry and Machine Company, East Chicago, Ind., a corporation of Delaware Application October 3, 1945, Serial No. 619,936

1 Claim. l

This invention relates to boiler feed water regulating apparatus, and more particularly to apparatus of this type wherein the feed water valve is actuated by feed water pressure.

We are aware that it has previously been proposed to utilize the pressure of a feed water line to a boiler for actuating the feed water valve with the supply of feed water to a fluid pressure motor operatively connected to the feed Water valve being generally responsive to water level variation in the'boiler. However, with few exceptions in prior apparatus of this general type with which we are familiar the feed water valve has been responsive both to water level variations and feed water line pressure variations resulting-in undesirable continuous actuation of the feed water valve with variations in line pressure. In cases where the prior apparatus might'be considered substantially uninfluenced by line pressure variations, the apparatus has been relatively complicated.

According to our invention, a fluid pressure motor is operatively connected to the feed water valve and the pressure drop across the valve or difierential pressure at the upstream and downstream side of the valve .is utilized to actuate the fluid pressure motor. Communication between the feed water line and fluid pressure motor is controlled through a pilot valve responsive to water level variations. At a constant water level in the boiler the pilot valve occupies a neutral position cutting off communication between the feed water line and fluid pressure motor so that the feed water valve is uninfluenced by variations in feed water line pressure. Upon a predetermined rise or fall in water level communication from the feed water line to the fluid pressuremotor is' established thereby moving the feed water valve towards closed or open position and this movement of the feed water valve re-sets the pilot valve to neutral position thereby holding the feed water valve in its actuated position until there is a further predetermined variation in water level.

Manual means are provided for adiusting the amount of feedwater' valve movement for a given variation in water level while maintaining the flow of feed water to thefiboiler or without requiring that the boiler be temporarily taken out of service.

It is a primary object f our invention to provide improved feed water regulating apparatus for-boilers wherein the feed -water valve is actuated byieed water line pressure but is uninfluenced 'bv-variati'ons in. teed wat r line p sure.

Another object of our invention is to provide improved feed water regulating apparatus for boilers wherein the feed water valve is actuated by feed water line pressure but is solely responsive to a predetermined variation in boiler water level.

Another object of our invention is to provide apparatus'of the above type and wherein the amount of feed water valve movement for a predetermined variation in boiler water level can be quickly and easily adjusted without taking the boiler out of service. v

Another object of our invention is to provide apparatus of the above type having a manual jacking device for opening or closing the. feed water valve in an emergency or when the unit is out of service.

Another object of ourinvention is-to provide a feed water valve unit wherein the feed water valve is actuated by feed water line pressure and which can be installed merely by connecting the feed water valve in the feed water line in a conventional manner and connecting the unit to a conventional water level responsive means associated with the boiler. I

Another object of the invention is to provide apparatus of the above type which is relatively compact, economical of construction, easy to install, and easily adjustable. Y

Other objects of the invention and the invention itself will become increasingly apparent from a consideration of the following description and drawings wherein: v a,

Fig. 1 is a diagrammatic end elevational view of a boiler and a conventional type boiler water level responsive means which we may employ for operating the pilot valve.

Fig. 2 is a fragmentaryend elevational view showing the level responsive meansof Fig. 1 associated with a unit embodying our invention and wherein the fluid pressure motor islshown partially in section.

Fig. 3 is a diagrammatic view showing the level responsive means stationary and with the pilot valve inneutral position whereby communication between the feed water line and the fluid pressure motor is cut off.

Fig. 4 is a view similar to Fig. 3 but .wherein the pilot valve has been moved to a position permitting flow to the lower diaphragm chamber and concurrently permitting discharge from the upper diaphragm chamber.

Fig. 5, is a viewsimilarto Fig. 3 but wherein the pilot valve "has been returned to neutral position with the level responsive means remaining in the position of ig- 3. Z

Fig. 6 is a left and elevational view of the unit illustrated in Fig. 2.

Fig. 7 is a staggered vertical sectional view taken generally along the line 'l--'| of Fig. 6.

Fig. 8 is a horizontal sectional view taken along the line 88 of Fig. 6, and

Fig. 9 is a top plan view of the unit illustrated in Fig. 7.

Referring now to the drawings, and particularly Fig. 1, we have indicated at 15, the end or drum head of a conventional boiler and at H a feed water line supplying the boiler. Extending laterally from the steam space of the boiler is a conduit l2 which is adapted to communicate with a lateral conduit l3 extending from the water space of the boiler through an inclined tube l4 formed of thermally expansible material. Tube i4 is supported between two channel members 16, the near channel member being omitted for illustration, with the lower end of the tube being secured to the channel members as indicated at ll and the upper end being free to move under thermal change. An L-shaped lever I8 is fulcrumed on the channel members as indicated at l9 with its upstanding short arm pivoted to the upper end of the tube [4, as indicated at 2|, and its generally horizontally extending long arm pivotally connected to a strut 22, as indicated at 23. Strut 22 is preferably provided with tension relief means 24.

Strut 22 will be moved upwardly or downwardly in accordance with relative amount of steam and water in tube l4 or variation in boiler water level since the channel members 16 are relatively unaffected by thermal change in tube l4.

The level responsive means so far described are well known and constitute no essential part of our invention and any suitable means wherein movement is imparted to an element adapted to transmit movement in accordance with boiler water level variations may be used.

Referring now particularly to Figs. 2 and '7 a conventional feed water valve is generally indicated at 26, and comprises an inlet 21, a main port 28 controlled by a piston type valve element 29. and an outlet 3| to the boiler. The casing of valve 26 includes a horizontal annular flange 32 which seats and sealingly engages the lower flange 33 of a fluid pressure motor generally indicated at 34. Flange 33 supports a generally cupshaped upper flange 33 by a pair of spaced upstanding arms 31. Sealingly secured between flange 3B and a co-operating flange 38 of inverted cup form is a flexible diaphragm 39 forming an upper chamber 4| and a lower chamber 42. Secured to valve element 29 is a stem 43 which projects upwardly and is secured to diaphragm 39 by stiffening plates 44 and a nut 45. Conventional stuffing boxes 4] prevent leakage where stem 43 projects through flanges 33 and 35.

It will now be apparent that as fluid pressure difierential is created in chambers 4i and 42 that diaphragm 39 will be moved upwardly or downwardly and resultantly move stem 43 and valve element 29. v

A pilot valve generally indicated at 48 controls the supply and discharge of feed water to and from the chambers 4| and 42. The pilot valve comprises an outer fixed cylinder 49 and a wear resistant inner .fixed cylinder 51 sealed at their ends and having three generally radial ports therethrough. Port 52 communicates with upper chamber 4| through a line 53, port .54 communicates with lower chamber 42 through a line 56, and port 51 communicates with the at the downstream or low pressure side of port 28.

The manner of operating the pilot valve 48 willnow be described. The plug element 59 of the pilot valve has a shaft portion 64 extended through the end of the valve to which is fixed a rock lever 66. A link 61 is adjustably pin connected to rock lever 66 and a lever 68 which is adjustably pivoted at one end to an arm 69 fixed to stem 43 'of valve 29. The opposite end: of lever 68 is pivotally connected to strut 22 of the level responsive means. As illustrated in Fig. 7, lever 68 is adjusted to pivot about an axis 1 l. Assuming that the parts are positioned as illustrated in Fig. 3 with both ports 52 and-54 closed thereby holding valve element 29 stationary and lever 68 extending substantially horizontally, a drop in boiler water level causes strut 22 to move downwardly and this movement is aided by a pair of tension springs 12 secured to lever 58 and a fixed support 13. Lever B8 is rocked counter-clockwise about the axis H and through link 61 and dock lever 66 plug element 59 is rotated clockwise placing the parts in the position illustrated in Fig. 4 whereby lower chamber 42 communicates with the high pressure feed water and upper chamber 4| communicates with the low pressure feed water. The resultant pressure differential acting on diaphragm 39 lifts the diaphragm, stem 43, and valve element 29 upwardly increasing the feed water flow to the boiler. v

The upward movement of stem 43 is substan tially instantaneous when pressure differential is effected on the diaphragm 39 and this upward movement of the stem rocks lever 38 counterclockwise about its pivotal connection with strut 22. This movement of lever 68 rotates plug element 59 in a counter-clockwise direction thereby re-setting the pilot valve to neutral position and holding valve element 29 in its relatively upward or more opened position. The feed water valve will remain in such position until a variation of water level again causes movement of valve element 29. If the water level rises the strut 22 is elevated and through the linkage previously described plug 59 of the pilot valve is rotated counter-clockwise from neutral position whereby upper chamber 44 communicates with the high pressure side of the feed water valve and lower chamber 42 with the low pressure side thereof. Diaphragm 39, stem 43, and valve element 29 are. resultantly lowered reducing the flow of feed water tothe boiler. The substantially instantaneous downward movement of stem 43 re=sets the pilot valve to neutral position.

Thus, it will be observed that we have provided a feed water valve responsive to boiler water level variation and wherein the feed water line pressure is utilized for moving the valve under the control of a pilot valve automatically re-set to neutral position by responsive movement of the feed water valve. 'Morespeciiically; the pressure drop across the feed water valve is controlling the feed water valve and operationorthe feed water valve is independent of pressure variation in thefeed water line sincewhen the pilot valve is in neutral position communication is shut offwith'the feed water line 'and line pressure variation is inefiective to ac'tuate the pilot valve, fluid motor, or-feed water valve.

It is true that the pressure drop across the feed water valve will. vary with line pressure variation and when the feed valve is being actuated a greater pressure difierential on diaphragm 39 may increase the rate of valve response but the position of strut 22 controls the amount which plug element 59 is rotated from neutral position independently of the pressure drop across the feed water valve. Thus, a greater or less pressure drop across the feed water valve merely efiects the rate at which the pilot valve is reset to neutral position since upon reaching neutral position further actuation of the feed water valve is stopped until the cycle is repeated due to further water level variation.

Support 13 forms a guide and limiting member which is bolted or otherwise secured to flange 33 and comprises an upstanding portion, slotted at its upper end asindicated at 14, and spaced horizontally extending arms 76. Arms 15 have a plurality of transversely aligned elongate slots ll therein adapted to slidably receive a pin 78 which pivotally interconnects link 67 and lever 68. These slots limit the upward or downward movement of link 61 responsive to movement of strut 22 and resultantly the relative rotation of plug element 59 in either direction from neutral position. The tension relief means provided in strut 22 permits this limiting movement. As illustrated in Fig. 7, lever 68 pivots around axis H and link 6? is disposed so that pin :8 ope-rates in the extreme left slots 11. However, link 6'! may be bodily moved to the right by disposing pin 78 in the middle or extreme right slots ll, it being understood that additional holes are provided in lever 58 and rock lever 66 so that link 5? will be disposed substantially vertically in any adjusted position with the pilot valve in neutral position. The pin connecting lever 68 with arm 58 will be correspondingly moved so that the distance between pin it and the pivotal axis H or the total allowable movement of plug 59 will be maintained substantially constant.

It will be apparent that by the adjustment means described the amount of movement of valve element 29 of the feed valve can be varied for a given movement of strut 22. In other words, under a given line pressure the rate at which feed water is supplied in response to a given drop in boiler water level can be varied.

To effect the adjustment described we provide a by-pass line is extending from a T 8!, connecting port 52 with line 53, to the passage 83 connecting chamber l2 with line 56. A normally closed equalizing valve 84 prevents passage of liquid through the bypass line during normal operation of the apparatus- However, when it is desired to adiustably move link 61, valve 84 is opened effecting direct communication between chambers 42 and 44 thereby equalizing the pressure on both sides of the diaphragm 39 whereby the diaphragm and associated parts may be moved relatively easily. Since adjustment requires holding or movement of stem 43 and arm 69 we provide a manual jacking device comprising a pair of spaced bearing lugs 86 integral with arms 31 which support a shaitB'I, Mounted on shaft 81 is a jacking element- 88'having a tubular portion; encircling the; shaft: from which extends a handle 89 and a lug 90 provided with aligned holes 8|. Arm 59 Whichis fixedtostem 43 has a pin projected there'throughand "e'ccentrically into holes 9 I which are su'fficiently large to pernormalstem movement without rocking handle'89; When it is-desired- -tomove-'- stem 43 for-adjustment this can be easilyeffected after the'eq-ualizing valve 84 is opened by manually rocking handle 89.

As pointed out above, handle 89 provides a convenient means for adjusting the linkage described but its primary purpose is as a manual jacking device for closing or opening the feed water valve in an emergency or when the unit is out of service.

To insure that there will be sufiicient pressure drop across the feed water valve when wide open to operate the fluid pressure motor or diaphragm 39, the ports 28 must have less area than the feed water line to always ofifer some resistance to flow. In practice we prefer to design the valve and port areas to produce a resistance of twentyfive pounds per square inch with the valve wide open.

Although we have shown and described a preferred form of the invention we contemplate that numerous and extensive departures may be made therefrom without departing from the spirit of the invention and the scope of the appended claim.

What we claim is as follows:

A feed water valve unit for regulating the supply of feed water to a boiler of the type having means movably responsive to boiler water level variation, said unit comprising a feed water valve adapted to be inserted in the boiler feed water line, a fluid pressure motor associated with the valve comprising a pair of chamberswith a movable element therebetween, the movable element being operably connected to the feed water valve, a pilot valve adapted to be operably connected to the level responsive means, a conduit eifecting communication between the pilot valve and the upstream side of the feed water valve, a conduit effecting communication between the pilot valve and the downstream side of the feed water valve, conduit means extending from the pilot valve to each of said chambers whereby when the pilot valve is in one position the differential pressure across the feed water valve is communicated to the chambers, the pilot valve being operably connected to the feed water valve whereby movement of the feed water valve in response to differential pressure on the movable element moves the pilot valve to a position cutting off communication with the feed water line until the level responsive means is'again moved, a normally closed conduit effecting direct commun'ication between the chambers, valve means controlling fluid flow through said conduit adapted to be opened to equalize pressure on each side of the movable element, and manual means for moving the feed water valve with the pressure equalized to permit adjustment of the connection between the feed water valve and pilot valve.

HARRY H. WEINING. HAROLD A. SCHLIEDER.

(References on following page) 7. 8 V 1 v Number Name Date REFERENCES C E 1,864,850 Nordberg June 28, 1932 'The following references are of record in the 1,390,472 p e 13, 1932 file of this patent: 1,959,890 Wunsch May 22, 1934 v 5 2,032,426 Magis Mar. 3, 1936 UNITED STATES PATENTS 7 2,057,172 Veenschoten Oct. 13, 1936 Nuggzrn B1 Name Dz' gt leos 2,105,196 McCauley Jan. 11, 1938 00m e 987,048 Connet Mar. 14, 1911 FORExGN PATENTS 1,154,591 Dodge Sept. 21, 1915 10 Number Country Date 1,449,472 Sullivan Dec. 13, 1932 1 214 351 Great Britain of 1924

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