US2138903A - Feed water control - Google Patents

Description

Dec. 6, 1938. F BRADFORD FEED WATER CONTROL Filed June 26, 1935 Patented Dec. 6, 1938 UNITED STATES PATENT OFFICE I Application June 26,

3 Claims.

The present invention relates generally to co-ntrols and regulators and is particularly concerned With certain improvements in control devices for boilers and the like arranged to be responsive to 5 the liquid level therein, and the present invention is especially concerned with devices for controlling theoperation of a steam boiler feed pump and similar arrangements.

'I'he principal object of the present invention 1u is the provision of liquid level responsive means acting through compound leverage means for accurately controlling a valve and moving the same to the proper position, irrespective of pressure conditions to which the valve may be subjected, either on one side only or on both sides.

Another object of the present invention, particularly in connection with controlling the operation of feed pumps, is the provision of a regulator which serves to throttle down the pump to the slowest possible speed for maintaining the desired water level in the boiler.

Still further, another important object of the present invention, having to do with both feed pump controls and feed water regulators, as well as other devices, is the utilization of a compound lever principle in liquid level responsive means, whereby the contro, eiected by such responsive means is bot-h sensitive and highly eicient, even when operating against substantial pressure difierences, and' is capable of securing a positive and effective controlling action under all conditions.

These and other objects of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description of the preferred embodiment, taken in conjunction with the accompanying drawing illustrating such embodiment.

In the drawing:

Figure l is a central section taken through o-ne form of my control device;

Figure 2 isl a view, more or less diagrammatic, illustrating one method of installing the device shown in Figure l; and

Figure 3 shows the open position of the valve means.

Referring now to the drawing, more particularly to Figure 2, the reference nuberal l indicates the boiler and the reference numeral 2 indicates 50 my improved control device in its entirety. rThe upper portion of the controller, containing the steam space thereof as will be referred to later, is connected with the steam space of the boiler by conduit or pipe means including a vertical 55 section l connected with the controller through 1935, Serial N0. 28,489

a valve 5, and a horizontal connection 6 leading into the boiler and connected with the upper end of the pipe section 4 by a T 1. The lower or water space of the controller 2 carries a short connection l0 which, at its lower end, receives a coupling l l and communicates with a lower horizontal connection l2 leading to the water space of the boiler, as at I3, andy including a valve hl and, if necessary, a blow-oir i5. The feed water is supplied to the boiler l by means of a steam feed pump of conventional construction (not shown), and the latter receives steam through a connection 2B which is. in communication with the upper portion of the controller 2 through a T 2| .and a valve 22, the latter com-v municating with the steam space of the controller 2 through conventional fittings or conduit means 23. For bypassing the controller 2 I may provide connections 25, including a controlling valve 26.

The details of my improved controller are best shown in Figure 1, and as there shown, the controller consists of a float housing 35 including a lower section 38 having an open upper end surrounded by a flange 3l and covered by a closure member 39 having a flange 4t by which, through cap screws lil, the closure member is secured in leak-tight relation and serves thereby to complete the fluid-tight iioat housing 35. The lower portion of the float housing 35 includes a boss 45 having a threaded conduit receiving opening 45 therein, the lower connection lll being threaded into this opening, as indicated in Figure 2. The upper closure member 39 includes two-laterally spaced threaded openings il and 48, the former receiving the nip-ple 5B (Figure 2) by which the valve 5. is connected with the iloat housing. The other conduit receiving opening receives the connections 23 and is provided with an interiorly disposed apertured boss 52 having a anged portion encircling and extending a short distance below the opening 48. Preferably, although not necessarily, the float housing and the closure member 39 are formed of cast iron, but any other suitable material may be employed and, in addition, suitable gasket means 55 may be employed to secure a tight connection between the upper and lower parts of the loat chamber.

A valve mechanism frame t@ is secured to the under side of the closure member 39 by any suitable means, such as a plurality of cap screws 6l, and the valve frame includes a pair of laterally spaced openings 53 and an opening 64 spaced apart to conform generally to the spacing of the threaded conduit receiving openings 41 and 48.

The opening 64 is preferably in exact axial alignment with the opening 48 and is threaded to receive a valve seat or port 66 of stainless steel or similar material set into the frame 50. The frame 60 carries spaced bracket means carrying pairs of apertured ears 68 and 69, and preferably, but not necessarily, formed integral with the body of the frame 60. The pair of ears E8 are disposed adjacent the aligned openings 48 and 64, and the other pair of ears 69 are disposed on the frame 6U adjacent the opening 63 thereof.

A valve 1I, preferably conical and formed of stainless steel or the like, cooperate with the valve port 66 to open and close the same, the valve 'H being disposed on the steam space side of the port 66. The valve il is carried for limited rocking movement by a lever in the form of a valve arm 13 which is pivotally connected at one end with the apertured ears B8 by a pin 'F4 or the like and carries the Valve il at a point relatively close thereto, asV best shown in Figures l and 3, the valve 'il being pivoted to the lever arm 'i3 by a pin 25 or other suitable means. The other or outer end of the arm 'i3 is extended to a pointl closely adjacent the other pair of apertured ears 69 and is connected by means of a link T16 with a lug H formed on a float arm iS closely adjacent the pivot connection 'i9 of the latter with the ears 69. The outer end of the oat arm i8 carries a float 88 formed of copper or the like.

It will be noted that the float 8S is carried at the outer end of the float arm 'i8 While the link 16, which transmits the power thereof to the valve arm T3, is connected closely adjacent the pivot 79 of the oat arm '58, and it will .also be observed that the link is, in turn, pivot-ally connected with the outermost end of the valve arm 13 while the valve 'H is itself carried by the arm closely adjacent the pivot 'I4 of the valve arm i3. Thus, in the first instance, the power of the float is multiplied and, in the second instance, this multiplied power is further multiplied by virtue of the fact that the link 'I6 is connected so much farther away from the pivot of the arm 13 than the valve 1l.

Thus, both the valve arm 13 and the float arm 18 constitute levers of the second class and are so interconnected that they form a compound leverage by which relatively small changes in the iiotation of the fioat 8i] will apply relatively large forces or pressures to the valve il, insuring that the same will be closed tight when the iioat is up and opened, even against the pressure of the steam within the steam space of the float chamber, when the oat is down. This last feature is of considerable importance for, noting that the valve 'H is on the steam spaceside of the valve port 66, it will be seen that when the water level falls from the high level towards low water level position, the relatively light weight of the float 80, acting through the compound leverage above referred to, will develop ample power to open the valve 1I against the steam pressure, irrespective of whether or not there is assisting pressure on the other side of the valve. By virtue of this arrangement, and particularly by utilization of the compound lever principle employed in the arrangement illustrated, the valve is controlled, opened and closed, as determined by the water level in the float chamber under all operating conditions.

When the controller is installed as illustrated in Figure 2, the opening and closing of the valve 'il controls the flow of steam from the steam space of the float chamber through the conne- ctions 23, 2| and 29 to the pump which operates to force ordirect feed water into the boiler. Due to the positive and yet highly responsive control of the valve 'Il effected by virtue of the aforesaid compound leverage, the water level in the boiler, and therefore in the oat chamber itself, varies only a relatively small amount so that the pump is usually operated continuously at the slowest possible speed to maintain the desired water level in the boiler, thus not only insuring high efficiency fo-r the boiler, but, in addition, preventing any damage thereof by reason of the water becoming too low.

The levers or arms i3 and 78, and the frame 6|] as well, are preferably formed of brass, cast bronze, or the like, but obviously any suitable materials may be used if and where desired. The frame 6i] is fastened to the closure member 39 over the valved opening 64 and sealed in fluidtight relation against the circular flange 52 by any suitable means such as a gasket or the like. It is to be observed that no stufng boxes are used, consequently there is no drag or friction affecting the valve movement.

It was pointed out above that while the valve 7i is subjected to the steam pressure of the boiler on its inner side, whereby the pressure in the steam space tends to hold the valve 'Il closed, yet by virtue of the aforesaid compound leverage, the float develops suicient effective power to open the valve against such steam pressure. However, where steam feed pumps are employed, the connections 23, 22, 2l and 2li, disposed on the other side of the valve 1i, are under whatever pressure is necessary to operate the pump, and this pressure is opposed to the pressure on the steam side of the valve 1l, whereby the tendency of the steam in the upper space of the cat housing to hold the valve 'H closed is thereby reduced. Thus, the valve 'H serves more as a throttle valve than as a shut-off valve, being positioned in various positions by the float 80. However, by virtue of the very efficient linkage, the construction shown in Figure l may be used wherever a shut-on valve is desired, as for venting the same space above the liquid level in a conduit or space, such as the chamber 35, to release air and other gases whenever the liquid level falls to a predetermined position, corresponding to the position indicated low Water level in Figure l. Such devices are usually termed air release Valves. Obviously, of course, my invention is also capable of many other uses.

While I have thus shown and described above the preferred structure in which the principles of the present invention have been embodied, it is to be understood that my invention is not to be limited to the specific details shown and described above, but that, in fact, widely different means may be employed in the practice of the broader aspects of my invention.

W'hat I claim, therefore, and desire to secure by Letters Patent is:

- l. A control device for boilers and the like, comprising a iioat chamber including a part having an openupperendandaclosuredisposedoversaidopen end and having spaced conduit receiving openings, one adapted to communicate with the steam space of a boiler and the other having an inwardly extending flange encircling the opening and adapted to lead to a point exterior of the boiler, a frame fastened to said closure member on the interior of said iioat chamber in spaced relation with respect to said one opening and securely sealed to the ange encircling said other opening,

a oat disposed within said chamber and including a iioat arm pivotally connected with and carried by said frame adjacent said one opening, a valve port in said frame registering with said other opening, a lever pivotally connected with and carried by said frame laterally outwardly of said valve port and including a valve secured thereto in a position to' open and close said port, and means connecting the end of said lever opposite its point of pivotal connection with said frame with said float arm adjacent its point of pivotal connection with said frame.

2. A control device for boilers and the like, comprising a float chamber including a part having an open upper end and a closure disposed over said open end and having spaced conduit receiving openings, one adapted to communicate with the steam space of a boiler and the other having an inwardly extending ange encircling the opening and adapted to lead to a point exterior of the boiler, a frame fastened to said closure member on the interior of said float chamber in spaced relation with respect to said one opening and securely sealed to the ange encircling said other opening, a oat disposed within said chamber and including a float arm pivotally connected with and carried by said frame adjacent said one opening, there being a threaded opening in said frame registering with said other conduit receiving opening in the closure member, a Valve seat member threaded into said frame opening from the closure side of the latter, al

lever pivotally connected with and carried by said frame laterally outwardly of said valve seat member, a valve secured to said lever in a position to seat against said member, and means connecting the end of said lever opposite its point of pivotal connection with said frame with said float arm adjacent its point of pivotal connection with said frame.

3. A control device for boilers and the like, comprising a float chamber including a part having an open upper end and a closure disposed over said open end and having spaced conduit receiving openings, one adapted to communicate with the steam space of a boiler and the other having an inwardly extending flange encircling the opening and adapted to lead to a point exterior of the boiler, a frame fastened to said closure member on the interior of said float chamber and securely sealed to the flange encircling said other opening, a iioat disposed within said chamber and including a iioat arm pivotally connected with and carried by said frame adjacent said one opening, a valve port in said frame registering with said other opening, a lever pivotally connected with and carried by said frame laterally outwardly of said valve port and including a Valve secured thereto in a. position t0 open and close said port, and means connecting the end of said lever opposite its point of pivotal connection with said frame with said float arm adjacent its point of pivotal connection with said frame.

FREDERICK I-I. BRADFORD.

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