US2608202A - Boiler feed system - Google Patents

Description

Patented Aug. 26, 1952 srr BOELER FEED SYSTEM Eugene J. Le Claire and Bernard J. Heinzinan, St. Paul, Minn., assignors to Harry Ii. J costing,

St. Paul, Minn.

11 Claims.

Our invention relates to an improvement in boiler feed systems wherein it is desired to employ a relatively low water pressure to feed a boiler operating at substantiallyhigher pressure.

In the feeding of boilers it is usual practice to I provide some means of building up suficient pressure behind the feed water to force the feed water into the boiler. There are two common means of building up this pressure. A boiler water feed pump is sometimes provided to produce the necessary water pressure. In other instances an injector is employed to force the water into the boiler under pressure. Both of these means are costly to operate and maintain in proper operation.

It is the object of thepresent invention to provide a means of using a relatively low pressure water supply to feed a relatively high pressure boiler. This we accomplish by feeding low pressure water into a supply tank, equalizing pressure on both sides of said tank, and allowing the water to feed into the boiler by gravity. As 'a result the water will feed properly into the boiler regardless of the fact that the feed water is supplied at extremely low pressure.

A feature of the present invention resides in the fact that our feed water'system is entirely automatic. As soon as the level of Water in the supply tank drops below a desired level more Water is fed thereinto. When suiiicient water is in the supply tank the water supply is automatically cut oil and the pressure on opposite sides of the supply tank equalized, allowin the water to feed by gravity into the boiler. r

A further feature of the present invention resides in the factthat there are no manualcontrols which must be actuated to supply water to the boiler. The steam connections remain constantly connected to the water supply tank to avoid the necessity of cutting off the steam supply in order to reduce the pressure in the supply tank.

A further feature of the present invention resides in the fact that the steam pressure above the water in the water supply tank is reduced by opening a vent therein to permit the pressure to drop below the pressure of the water supply. By opening a passage between the pressure tank and the atmosphere, the top of the water supply tank may be reduced to atmospheric pressure, allowing water to enter the tank under any pressure in excess of atmospheric pressure.

A further feature of the present invention resides in the use of a novel type of Weight for assisting the float operation of the venting valve in the Water supply tank. A float holds this venti valve closed when the Water in the tank is at the proper level and the weight of the float and valve tends'to open the valve when the water level in the supply tank drops. In order to assist the weight of the float and valve in opening the valve ,a water container having an opening in the top thereof is supported on the valve mechanism. Whenthis container is submerged in water there is little weight exerted upon the valve. However. when the level of water outwardly'of the container falls, the weight of waterwithin the container is added to the weight of the container These and other objects and novel features of our invention will be more clearly and'fully set forth in the following specification and claims.

In'thedrawings forming a part of our specification:

Figure 1 is a'dia-grammatic view of our water supply tank, boiler and float valve regulating the level of water within the boiler. I

Figure 2 is a vertical section through the water supply tank showing the construction thereof.

Figure 3 isa sectional view through thewater supply tank .nearthe bottom thereof.

As best indicated in Figure 1 of the drawings the boiler A is supplied with water from a water supply tank B. A float valve C is provided in the water supply line from the tank to the boiler to regulate the water level within the boiler.

The boiler A is provided with a steam outlet it which may provide steam to any'desired apparatus. A pipe line H leads to a check valve 12. The check valve 52 permits steam to pass through the pipe line H in a direction away from the boiler A toward the water supply tank B, but prevents a reverse flow of steam or water. The check valve [2 is connected by the pipe line 13 to the T I l. The opposite end of the T M is connected to the inlet tube or connection [5.

The water supply line it is connected to the T M and includes a check valve [7. The check valve ll permits a flow of water into the water supply tank B, but prevents the flow of water or steam rearwardly into the water supply line. The

water supply tank B is connetced to the feed line I9 leading to the float valve C. The top of the float valve is connected by the connection to the top of the boiler A, thus communicating steam pressure to the top of the float valve. The bottom of the float valve C is connected by the boiler feed line 2I to the boiler A.

It will be seen that the top and bottom of the float valve C is subjected to the same pressure. Thus in the event the water level in the boiler A should drop somewhat, water may feed thereinto by gravity.

The water supply tank B is best illustrated in Figure 2 of the drawings. The tank B is shown as having side walls 22, a bottom closure 23 and a top closure 24. One end of the tank B is preferably removably secured and in Figure 2 the tank end 24 is shown connected to the flange 25 on the tank side walls 22 by means of bolts 26.

A bushing or nipple 21 having a central aperture 28 therethrough is secured extending through the top closure plate 24. The lower end of this bushing or nipple 21 is provided with a tapered valve seat 30 which may be engaged by the tapering end 3I of the vent valve rod 32. The valve rod 32 is slidably supported by a guiding frame 33 secured depending from the top closure plate 24 and at its lower end is supported by a guide disc 34. The rod or stem 32 extends centrally through the disc 34 and angularly spaced apertures 35 are provided in this disc to permit the free flow of liquid therethrough into the upper extremity 36 of the feed line I9.

A float 31 is secured to the valve rod 32 to actuate the same. The float 31 is shown comprising a hollow spherical shell 39 having a central tube 40 extending therethrough. The valve rod 32 extends through the tube 40. Shoulders or projections H and 42 on the rod 32 hold the float 31 from sliding relative to the valve rod 32.

Secured to the valve rod 32 above the level of the float 31 we provide a container 43 which is secured to the valve rod for movement therewith. The container 43 is shown as having cylindrical side walls 44 and a convex bottom 45. A flat top 46 having an opening 41 therethrough closes the major portion of the top of the container 43. The inlet tube I5 extends into this opening 47, thereby preventing the rotation of the container 43 and valve rod 32. Perforations 49 are provided through the inlet tube I5 above the level of the container 43 and the bottom end of the tube I5 is closed as indicated at 50.

In operation the boiler is filled to the desired level by the float valve C, this float valve C receiving liquid through the feed connection I 9 from the supply tank B. The supply tank B is fed from the water supply line I6. Before the boiler has been started no steam has been developed and there is no pressure in the steam lines II and I3, thus permitting fluid to flow freely into the supply tank B.

The boiler is now started into operation and steam under pressure flows through the pipe lines II and I3 as well as the check valve I2, thus providing a pressure above the liquid in the tank B. Steam pressure is also equalized within the float valve C, permitting water to flow from the float valve into the boiler. The water supplied to the float valve C is drawn through the feed line I9 from the tank B. Thus gradually the level of liquid in the tank B drops.

When the tank'B is nearly full of water the container 43 is submerged so that only the weight of the tank itself exerts a downward pressure upon the valve rod 32. Even the weight of the tank 43 is partially overcome by the surrounding water. However, as the level of water in the tank B drops, less and less of the container 43 remains submerged. If the container 43 remains full of water the efiective weight acting upon the rod 32 greatly increases until this downward force is suflicient to lower the valve rod 32.

As the valve rod 32 moves into the open position shown in full lines in Figure 2 of the drawings the steam pressure within the top of the tank B is vented to atmosphere, thereby quickly dropping the pressure within the top of the tank B. If as an example the steam pressure in the top of the tank B is initially seventy pounds and if the city water pressure is fed to the tank at thirty-five pounds pressure, as soon as the P sure within the top of the tank B drops below thirty-five pounds the check valve I! will open and water will feed through the inlet I 5 and into the interior of the tank B.

When the vent valve 21 opens steam also passes through the lines II and I3 and through the check valve I2. However, the steam pressure within the top of the tank drops faster than the entering steam can build it up, due to the restriction 5I in the steam line I3, thus allowing water to enter through the supply line I6. When the steam passing through the lines I I and I3 strikes the water entering through the water supply line IS, the steam is condensed, thereby losing its pressure. v

Water continues to feed through the inlet tube I5 until the float 31 again raises the valve rod 32 to close the vent valve. This closure of the vent valve will not take place until the container 43 is at least partially submerged in liquid thus lowering the effective weight of the container 43.

As soon as the vent valve is closed the entering steam again brings up suflicient pressure to close the check valve I! and to equalize pressure on opposite sides of the supply liquid. Thereupon liquid may drain from the tank B into the fluid chamber as required.

It will be seen that a relatively low water pressure may thus automatically feed into a boiler operating at considerably higher pressure. If the fluid and check valves are sturdy, there is little or nothing to go out of operation in the device described. The tapering valve 3| can not easily clog up due to the fact that each time this valve opens steam under pressure passes through the vent aperture 29. We have found our boiler feed apparatus extremely reliable, simple in construction, and entirely automatic in operation. Furthermore, we have found that the small amount of steam entering the water supply tank heats the tank considerably, thereby permitting water to be fed to the boiler in a preheated condition.

In accordance with the patent statutes, we have described the principles of construction and operation of our boiler feed systems, and while we have endeavored to set forth the best embodiment thereof, we desire to have it understood that obvious changes may be made within the scope of the following claims without departin from the spirit of our invention.

We claim:

1. A liquid feed apparatus comprising a closed chamber, a discharge passage therefrom including means for at times blocking discharge therethrough, an inlet thereto, a relatively high pressure steam line connected to said inlet, means for limiting the flow of steam through said steam line, a liquid supply line to said chamber, check valve in said liquid supply line to prevent a reverse flow away from said chamber, the pressure of said liquid supply line being smaller than the pressure of steam in said steam line, a vent, opening in said chamber of larger cross-sectional area than saidsteam flow limiting means, and means for controlling the opening and closing of said vent opening, said vent opening when open acting to reduce the pressure in said chamber below the pressure of liquid in said liquid feed line to permit liquid to flow into said chamber.

2. A liquid feed apparatuscomprising a closed chamber, a discharge passage therefrom including means for at times blocking discharge therethrough, and a relatively high pressure steam line continuously connected to said chamber above the liquid level therein, a relatively lower pressure liquid feed line connected to said chamber, a check valve in said liquid feed line to prevent the flow of fluid away from said chamber, a restriction in said steam line to restrict the steam flow to the chamber, vent means for connecting said chamber to atmosphere, said vent means being of larger cross-sectional area than said restriction, and means controlling the opening and closing of said vent means, lowering of pressure in said chamber allowing liquid to enter from said liquid feed line.

3. A liquid feed apparatus comprising a closed chamber, a discharge passage therefrom including means for at times blocking discharge therethrough, an inlet thereto, a relatively high pressure gas pressure line connected to said inlet, means for limiting the flow of gas pressure through said gas pressure line, a liquid supply line to said chamber, check valve in said liquid supply line to prevent a reverse flow away from said chamber, the pressure of said liquid supply line being smaller than the pressure of gas pressure in said gas pressure line, a vent opening in said chamber, said vent opening being large relative to said flow limiting means, and said vent permitting a greater flow of gas than the gas flow limiting means, and means for controlling the opening and closing of said vent opening, said vent opening when open acting to reduce the pressure in said chamber below the pressure of liquid in said liquid feed line to permit liquid to flow into said chamber, said vent opening allowing pressure in said chamber to drop faster than said gas pressure line can supply pressure.

4. A pressure feed device comprising a closed float chamber, conduit means leading from said chamber to discharge liquid therefrom into a pressure region including means for at times blocking discharge through said discharge conduit, gas pressure supply conduit means extendin into said chamber above the surface of the liquid therein for equalizing the pressure in the chamber with the pressure in said region, a liquid feed line extending into said conduit means for supplying liquid at a pressure below the gas pressure in said conduit means, check means respectively in said conduit means and said liquid line to prevent flow of fluid away from said chamber through said conduit means and feed line, vent means above the liquid level in said chamber, said vent means having a greater effective crosssectional area than said conduit means to thereby lower the pressure in said chamber below that of the water feed line upon opening or the vent means, and float actuated valve means for closing said vent means.

5. A pressure feed apparatus comprising a closed float chamber, a pressure discharge line means leading therefrom into a pressure region including means for at times blocking discharge through said discharge line, an inlet extending thereinto above the liquid level therein, a steam pressure line connected to said inlet for equalizing the pressure in said chamber with the pressure in said regiomfa 'liquidfeed line connected to said inlet supplying water at a pressure below normal steam pressure in said steam line, check valves respectively in said steam line and said liquid feed line to prevent the flow'of fluid away from said chamber, avent in said chamber above liquid level, said vent having ra larger effective cross sectional area than said steam line, and float actuated means for closing said vent opening. f H i 6. A pressure feed apparatus comprising a closed float chamber, a discharge passage means therefrom leading into a pr'essure'region including means for at times blocking discharge through said discharge passage, an inlet thereto above liquid level, a relatively high steam pressure line and'a relatively lower water pressure line connected to said inlet, a check valve insaid water line to-pr'event a reverse flow away from said chamber, a vent opening above liquid level in said chamber, said vent having a relatively greater effective cross-sectional area than said steam line, and a float actuated valve for closing said vent opening.

7. A liquid feed device comprising a closed float chamber, a discharge passage means ex tending therefrom into a pressure region including means for at times blocking discharge through said discharge passage, an inlet passage extending thereto, a relatively high pressure steam line and a relatively lower pressure liquid feed line connected to said inlet, a check valve in said liquid feed line to prevent the flow of fluid away from said chamber, a vent valve above liquid level in said chamber, said vent having a relatively greater effective cross-sectional area than said steam line, and float actuated valve means for closing saidvent opening.

8. A pressure feed device comprising a closed float chamber, a discharge passage means there from leading into a pressure region including means for atv times blocking discharge through said discharge passage, an inlet passage thereto above liquid level, a T connection on said inlet, a relatively high pressure steam line connected to one outlet of said T connection, a relatively lower pressure liquid feed line connected to the other T outlet, a check valve in said liquid feed line to prevent the flow of fluid away from said chamber, and means for relieving pressure within said chamber comprising a vent opening in said chamber, said vent having a relatively greater efiective cross-sectional area than said steam line, and a float valve for closing said vent opening.

9. A pressure feed apparatus comprising a closed pressure chamber, a pressure discharge passage means therefrom including means to at times block flow therethrough, an inlet thereto, relatively high pressure steam and relatively lower pressure liquid lines connected to said inlet, a

steam line soas to destroy the pressure effect thereof.

10. A pressure feed apparatus comprising a closed feed chamber, a pressure discharge means therefrom including means to at times block flow therethrough, an inlet thereto above the liquid level, a relatively high pressure steam line and a relatively low pressure water line connected to said inlet, a check valve in said liquid supply line to prevent liquid from flowing away from said chamber, a vent valve in said chamber, and means for closing said vent valve, said vent valve being of larger eifective cross-sectional area than the steam pressure line to thereby be capable of lowering the pressure in said pressure chamber below the pressure of the liquid supply when the vent is open, thereby allowing liquid to enter said chamber, the liquid acting to condense the steam and to substantially destroy the pressure thereof.

11. A liquid feed apparatus comprising a closed pressure chamber, a discharge means therefrom including means at times to block flow therethrough, an inlet thereto, a relatively high pressure steam line and a relatively lower pressure liquid feed line connected to said inlet, a check valve in said liquid feed line to prevent the flow of fluid in a reverse direction away from said chamber, means for at times lowering the pressure in said chamber, and means for restricting the flow of steam through said steam line, said pressure restricting means cooperating with said pressure lowering means to reduce pressure faster than said steam feed line may build pressure up so as to drop the pressure in said chamber sufficiently to permit said liquid feed line to deliver liquid to said chamber.

EUGENE J. LE CLAIRE. BERNARD J. HEINZMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,252,967 'I'rane Jan. 8, 1918 1,362,150 Shealy Dec. 14, 1920 1,672,610 Goff June 5, 1928

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