US1942427A

US1942427A - Feed water regulator

Info

Publication number: US1942427A
Application number: US513289A
Authority: US
Inventors: William L Hunter; Kennedy B Whitley
Original assignee: NORTHERN EQUIPMENT CO
Current assignee: NORTHERN EQUIPMENT Co
Priority date: 1931-02-04
Filing date: 1931-02-04
Publication date: 1934-01-09
Anticipated expiration: 1951-01-09

Description

Jan. 9, 1934. w. L. HUNTER Er AL 1,942,427

FEED WATER REGULATOR Filed Feb. 4, 1951 2 Sheets-Sheet l Jan.

W. L. HUNTER ET AL FEED WATER REGULATOR Filed Feb. 4,

1931 2 Sheets-Sheet 2 fA/vsA/ro/as: h ////'am A. Hun/er Ken/magi? h fif/ /ey Patented Jan. 9, 1934 FEED WATER REGULATOR William L. Hunter and Kennedy B. Whitley, Erie, Pa., assignors to Northern Equipment Coinpany, Erie, Pa., a corporation of Pennsylvania Application February 4, 1931. Serial No. 513,289

18 Claims.

This invention relates to feed water regulators for boiler systems, and it has for its object providing means for regulating the flow of the feed water to boiler systems, in accordance with the flow of steam from the boiler, the water level in the boiler itself, and also the rate of flow of the water to the boiler. The system is particularly applicable to batteries of boilers which are operated at high capacities and steampressures, and a further purpose is to provide a suitable regulator system in cases where superheaters or economizers or both are employed.

Of the accompanying drawings, Fig. 1 is a diagrammatic elevation of a feed water regulator system connected to a boiler, which embodies the features of our invention; and Fig. 2 is an enlarged sectional view of the main elements of the system of Fig. 1.

In view of the operation, of late years, of boiler systems at high capacities and steam pressures, and the operation of a number of boilers in batteries receiving water from a common pump system and delivering steam to a common main, and the use in such systems of superheaters, economizers and steam purifiers and the like, it becomes more and more desirable and necessary to have very complete and sensitive automatic control of the flow of water to the boilers. We have sought, in connection with the present invention, to provide such control and, while we have herein described the system as applicable to certain definite apparatus, it will be understood that application of the same may be made to other systems embodying other apparatus. As illustrating, we have shown a portion of the system applicable to use with superheaters and economizers, but these may be omitted and other apparatus, such as steam purifiers, may be substituted therefor, as will be obvious to those skilled in the art.

The system of Fig. l is applicable to a single boiler or a battery of boilers in which the boiler 61 is supplied with feed water through the pipe '73, any suitable pump or other system being used for supplying the water to the pipe under pressure to this boiler alone or with others in a battery of boilers. The boiler supplies steam through a main 67, which may or may not be connected to a common main of the battery of boilers. In this system, it is desired to control the flow of water to the boiler, in accordance with variations in water level in the boiler, and in accordance with the rate of flow of steam from the boiler and the rate of flow of water to the boiler. For convenience, the controllers or regulators for the purpose are herein referred to as the water level apparatus, the steam flow apparatus, and the water flow apparatus. While boiler systems inthe past have been controlled by these three characteristics of the boiler system, yet, what we claim as new comprises the means by which this control is brought about and the particular application of the means to boiler systems.

The control of the flow of water to the boiler, in accordance with the elevation of the water level in the boiler itself, may be by the use of any ordinary or suitable means. We prefer for the purpose the use of water level apparatus comprising a thermostatic tube which has its ends operatively connected with the steam space and. the water space of the boiler, as is common. As the water level in the boiler and, hence, in the tube, rises or sinks, the contraction or expansion of the tube operates means which are operatively connected more or less indirectly with the feed water valve 62 of the boiler system. In general, as the water level in the boiler sinks, the tube 60 will expand and the means operatively connecting it with the valve 62 will tend to open the valve more and allow more water to pass to the boiler.

The control of the flow of Water to the boiler by means of the steam fiow, in this instance, may be produced by any suitable apparatus. We prefer for the purpose steam flow apparatus comprising a flexible bellows 1'7 enclosed in the easing 18. As is well understood, when opposing pressures are applied to the opposite sides of the plate 20 of the bellows, the plate will be moved one Way or the other as the pressures vary relatively. In this instance, we connect the chamber 21 on the upper side of the plate 20, by means of pipes '71, with the steam space of the boiler, and connect the chamber 23 on the other side of the plate 20, by means of pipes '70 with the steam main, at such a point therein as to provide a drop in pressure in the steam between the two points of connection of the pipes.

In this case, we have inserted a superheater in the system and also an economizer 66. The regulator 63 is thus connected to the pipe 68 which connects the superheater with the main, and is also connected to the boiler. In this way, the difference in pressure in the apparatus 63 is equal to the drop in pressure from the boiler to the steam main with the superheater intervening.

In case of the water flow apparatus 64 which may be similar to 63, the lower side of the bellows is connected to the boiler by the pipe "71, and the upper side is connected, by means of the 'will elevate the piston 108 in the pilot '78.

pipe '72, to the feed water pipe 73, preferably between the feed water valve 62 and the economizer 66. In this way, the water flow control is subject to the drop in pressurebetween the feed water pipe and the boiler, with the economizer intervening.

The operating means connecting the apparatus with the valve comprises a motor 75. Also, there is a master pilot valve 76 and a water level pilot valve 77, and a fluid flow pilot valve 78.

In normal operation, the piston 81 of the master valve 76 is maintained substantially in the position indicated by Fig. 2, so that fluid under pressure is at liberty to flow through the pipe 82, port 83, pipe 84, and port 85, into the chamber 86 of the water level pilot '77. When, in such a case, the water level in the boiler sinks so as to cause the tube 60 to expand, the arms 89 and 87 are lowered, carrying with them the piston 88, andthis allows thepressure fluid to flow from the chamber 85 through the port 90, pipe 91, and passageway 92, into the chamber 93, beneath the piston 94 in the motor 75. At the same time, the fluid in the chamber 95 of the motor is free to flow through the various ports 99 and 99' and .pipes 96 and 97 to the exhaust or waste pipe 98.

The result is that the piston 94 is forced upwardly, carrying with it the plunger 100 of the feed water valve 62, and opening more the valve so as to bring the water level back to the desired elevation.

Obviously, in such a case, if there were no compensation provided for, the piston 9 would be raised the maximum amount and the valve would be opened wide. But the arm 101 or" the lever 102 ispivoted to the stem 103 of the motor and, as the stem is elevated, the arm 101 is elevated and forces the piston 88 back to the neutral position, so as to stop the movement of the valve plunger 100. By proper adjustments of the various parts, the movement of this valve will be stopped by this compensating means as soon as the valve has opened suniciently to raise the water level in the boiler to the desired elevation.

It will thus be seen that the water level apparatus provides its own compensating means, which limits the action of the apparatus, so as to prevent over-running, and this is entirely irrespective of the action of either of the flow apparatus.

However, the water flow apparatus also tends to prevent over-running of the water level apparatus and also affects the position of the feed water valve more or less. The apparatus 64 is subject to the drop in pressure from the feed Water valve to the boiler through the economizer and, as the valve 100 is opened more, this drop will be increased. As a consequence, in such a case, the arm 105 will be elevated. The elevation of the arm 105 will result in elevating the arms 106 andlO'l, and the elevation of the arm 10'? As a consequence, pressure fluid will be free to flow through the port 110, and the pipe 111., and the chamber 112 and port 113, into the chamber 95 of the motor. If, at this time, the piston 88 has not been moved back to normal by the piston rod 103, the exhaust will be free to flow from both ends of the cylinder through the port 120 and the pipe 97. This will produce substantially uniform pressures on both sides of the piston 94:, thus bringing the plunger 100 to rest. This compensation of the water flow apparatus may be greater or less than that of the water level apparatus, and may act more quickly or more slow- 1y, depending upon the special conditions which are effective.

The above described operation occurs under loads when the drop in pressure through the superheater is such as to hold open the port 83 to the pressure fluid from the pipe 82. But, in case of material load increases, the increased drop in presure through the superheater will cause the steam flow apparatus 63 to operate,

by forcing downwardly the plate 115, thus forcing upwardly the arm 116 and the piston 81. This will close the port 83, so that the pressure fluid is no longer efiective on the pilot 77. At the same time, the movement of the plate 115 downwardly'will force downwardly the

arms

117, 118 and 107, and thus will force downwardly the piston 108 and allow the pressure fluid to flow through the port 110 and pipe 111 and chamber 112, through the

ports

114 and 120 into the chamber 93, and this will elevate more the valve plunger 100. This will compensate for the increased load on the boiler. Then, the increased ficw of water through the feed water pipe will increase the drop in pressure therethrough .and operate the apparatus 64. This will result in forcing upwardly the arms 106 and 107, and the piston 108 will be moved back to the neutral position, thus stopping the effect of the steam flow apparatus on the motor '75.

It is frequently desired to elevate the water level in the boiler as the load on the boiler inpanied by ahigh elevation of water, and a light load by a low elevation of water in the boiler. As

a consequence, when a material change in load occurs, there is less danger or" the water in the boiler temporarily sinking too low as the light load comes on, or rising too high as the heavy load comes on. This increase in water elevation with increased load, or the reverse, may be accomplished by adjusting the leverages of the two flow apparatus. As illustrated, the steam flow apparatus leverage is such as to cause the change in load to affect the position of the plunger 100 more thanit is affected by the increased water flow, by means of the apparatus 64. As a consequence, the piston 108 will not be returned to the neutral position until the valve 62 is opened sufliciently to provide. the desired increased water level elevation when the heavy load becomes constant. V

'In this connection, it will be noted that the water level apparatus also is arranged to com- 'pensate for the water flow effect of the increased load when the load is not large enough to close the port 83. The increased elevation of the Water in the boiler will cause a contraction of the tube 60, and an elevation of the arms 89 and 8'7. This will raise the piston 88 and allow pressure fluid to enter the chamber 95; and it will also, by means of the arm 109, assist the water flow regulator in moving the piston 108 back to neutral. This latter occurs whether or not port 83 is closed.

If, at. any time, the Water level in the boiler varies materially from the normal elevation, the expansion or contraction of the tube 60 will be sufiicient to lower or raise the arm 109 sufiiciently to operate the piston 108 so as to bring it back to neutral and stop the movement of the plunger 100, or, if the change in level elevationis suffi: cient, the position of the piston will be reversed and this willallow pressurefluid to pass into the cylinder 75 and, thus, reverse the movement of the valve plunger 100. .This will prevent any dangerous elevation of the water level.

In general, it will be understood, that by suitable adjustments the water level elevation in the boiler with reference to the load may be varied so as to produce a substantially constant water level for all loads, or a low level or high level for heavy loads, as may be desired.

Finally, when the pressure in the feed water pipe 73 is abnormally increased, or the pressure in the boiler materially decreased, the effect also will be to elevate the arms 106 and 107. The piston 108 will then be elevated above the neutral position, allowing the pressure fluid to flow into the chamber 95, and forcing downwardly the plunger 100 of the valve, so as to decrease the flow of water therethrough, until the drop in pressure through the feed water pipe is reduced sufficiently to cause the apparatus 64 to lower the piston 108 and stop the action of the apparatus on the valve.

When the load on the boiler is sufliciently light, the piston 81 will be forced down slightly, so as to close the passage of the pressure fluid into the pipe 111, but not sumciently to close the pipe 84, means being provided to prevent the movement downward of the piston 81 sufficiently to close pipe 84. In this manner, with light loads, the water level responsive apparatus alone controls the position of the valve plunger 100.

It will be understood that various modifications may be made in these systems by those skilled in the art, without departing from the spirit of our invention, as disclosed by the following claims. Also, various adjusting means may be used. For instance, the action of the flexible bellows used in connection with the flow apparatus may be controlled in an ordinary manner, by means of springs 125 positioned between the plates 20 and the casing of the apparatus.

In the following claims it is to be understood that water level apparatus refers to apparatus of the nature of a governor or regulator which is responsive to changes in the water level elevation in the associated boiler. Similarly with reference to steam flow and Water flow apparatus; steam flow apparatus relates to a regulator responsive to steam flow changes in the flow of steam to the boiler; and water flow apparatus refers to a regulator responsive to changes in the flow of water to the boiler.

We claim as our invention:

1. In a boiler system, a feed water regulator system therefor, a steam main, a water pipe and a feed water valve in said pipe, said regulator system comprising a steam flow apparatus operatively connected with said main and said valve, a boiler water level apparatus operatively connected with said boiler and said valve, and means actuated by said steam flow apparatus for rendering inoperative said water level apparatus when the load on the boiler is relatively large.

2. In a boiler system as claimed in claim 1,

means actuated by said steam flow apparatus for rendering said water level apparatus operative when said load becomes light.

apparatus, and pilot valves operatively connected with each apparatus for passing pressure fluid to said motor.

4. In a boiler system as claimed in claim 1, a master pilot valve operatively connected with said steam flow apparatus for controlling the flow of pressure fiuid to the pilot valve of said Water level apparatus.

5. In a boiler system, a feed waterregulator system therefor, a steam main, a water pipe and a feed water valve in said pipe, said regulator system comprising a steam flow apparatus operatively connected with said main, a water flow apparatus operatively connected with said pipe, a water level apparatus operatively connected with said boiler, a pressure fluid motor operatively connected with said valve, 'a pilot valve for passing pressure fluid to said motor operatively connected with said water level apparatus, and a second pilot valve operatively connected with said motor and with each of said flow apparatus.

6. Ina boiler system as claimed in claim 5, a master pilot valve operatively connected with said steam flow apparatus for controlling the passage of pressure fluid to said first-mentioned pilot valve.

7. In a boiler system as claimed in claim 5, said water flow apparatus being arranged to limit the action of said steam flow apparatus.

8. In a boiler system as claimed in claim 5, said water flow apparatus being arranged to limit the action of said steam flow apparatus, and said water level apparatus being arranged to assist said water flow apparatus in limiting the action of said steam flow apparatus.

9. In a boiler system, an apparatus for controlling the flow of water to the boiler in which the flow of steam from the boiler, the flow of water to the boiler, and the water level in the boiler coact to control the water flow to the boiler when the steam flow is large and the water level is abnormal and in which the water level alone controls when the steam flow is small.

10. In a boiler system as claimed in claim 9, a power motor controlled to operate the valve in the feed line, said power motor being controlled by the steam flow, water flow, and water level, when the steam flow is large, and by the water level alone when the steam flow is small, the movement of the power motor compensating for the movement of the water level apparatus when the steam flow is small.

11. In a boiler system, means for operating the feed water valve of the system, said means comprising boiler water level responsive means operable at light loads only, and other boiler water level responsive means operable at abnormal boiler water levels.

12. In a boiler system, means for operating the feed water valve of the system, said means comprising boiler steam flow responsive means, and boiler water level responsive means, and means operable by said steam flow means for rendering inoperable said water level means.

13. In a boiler system, means for operating the feed water valve of the system, said means comprising boiler steam flow responsive means operable at large loads only, and boiler Water level responsive means operable at light loads only.

14. In a boiler system as claimed in claim 13, other boiler water level responsive means operable at abnormal water levels. I

15. In a steam boiler system, a floating bar, a motor responsive to the steam flow from the boiler operatively associated with one end of said bar, a motor responsive to the water flow to the boiler operatively associated with the other end of said bar, and means operatively associating an intermediate portion of said bar with the feed water valve of said system, said means comprising a second floating bar, said intermediate portion being operatively associated with one end of said second bar, a third motor operatively connected to thesaid valve, a fourth motor responsive to the water level elevation of the boiler of said system and operatively associated with the other end of said second bar and with the third motor, and an intermediate portion of said second bar being operatively associated with the third motor.

16. In a boiler system, a feed water regulator system therefor, a steam main, a water pipe and a feed water valve in said pipe, said regulator system comprising a steam flow apparatus 0peratively connected with said main and said valve, a boiler water level apparatus operatively connected with said boiler and said valve, and means actuated by said steam flow apparatus for rendering inoperative said water level apparatus when the load on the boiler is relatively large and the Water level is substantially normal.

boiler water level responsive means, and means operable by said steam flow means for rendering inoperable said water level means when the water level is substantially normal.

WILLIAM L. HUNTER, KENNEDY B. WHITLEY.