US2508132A - Automatic drain valve - Google Patents

Description

Filed April 24, 1947 INVENTOR Burton SAilmmn QM awa A ATTORNEY Patented May 16, 1950 AUTOMATIC DRAINVALVE" Burton S. Aikman, Wilkinsburg Pa., assignor to The Westinghouse Air Brake Company, Wilmet-ding, Pa., a corporation of Pennsylvania- Application April 24, 1947, Serial No. 743,533

This invention relates to automatic drain. valve devices and more particularly to the type employed with the reservoir or receiverof a fluid pressure system to drain moisture which accumulates in the reservoir or receiver.

In the operation of fiuid pressure systems, air from the atmosphere is compressed and is stored in a reservoir or receiver from which fluid is withdrawn as required.

Fluid under pressure supplied to a reservoir or receiver by a fluid compressor is usually cooled while being stored therein, with theresult that a substantial amount of its vapor content condenses in the reservoir. If this condensate is allowed to accumulate in the reservoir, it not only reduces the fluid pressure volume of said reservoir, but may find its way into a system utilizing fluid under pressure therefrom and cause operational failure or damage to the equipment com prised in said system.

It is an object of this invention to provide a drain valve device adapted to be employed with the reservoir of a fiuid'pressure system to automatically prevent accumulation of condensate in chamber to actuate a valve device to drain the condensate from said chamber.

Another object of the invention is to provide an improved drain valve device of the type hereinbefore mentioned which may be easily attached L to a reservoir of the type employed in fluid pressure systems.

Other objects and advantages of the invention will become apparent from the-followingmore detailed description taken in connection with the accompanying drawing, the single figure of which is a. sectional view of a portion eta reservoir equipped with the drain valve device embodying the invention.

Description Referring to'the' drawing, there is illustrated a-portion of a reservoir l for a fluid pressure sys tem which is adapted to be supplied with fluid under pressure by a suitable compressor (not shown) and from which fluid may-flow by way of a suit- 5 Claims. (Cl. 13'768) able pipe (not shown) for use'in controlling fluid pressure devices or the like.

The reference numeral 2 designates a drain valve device, embodying the invention, and comprises a hollow body portion 2a, a magnet valve device 3 and a fixed mounting'base or bracket 4 upon which are mounted the body portion 2a and the magnet valve device 3. This drain valve device 2 is located below the reservoir I and the interior of the reservoir is in constant open communication with a condensate collecting chamber 5 in the body portion 2a by way of a drain pipe 6 which preferably has screw-threaded connections with both the reservoir and top of the body portion 2a-whereby bygravity condensate may drain from the reservoir into said chamber.

Disposedwithin the hollow body portion 2a is a float 1 loosely mounted on a guide rod 8 to provide a clearance space 30 therebetween. The

' rod 8 is secured tothe mounting base 4 at 29 andis encircled by an annular space or cavity 2'! formed in saidbase, which cavity is open to a passage 23. Encircling cavity 2! is a seat 29 for the float L Mountedon the upper face of the float! is an electrical contact in the form of a metallic contact ring "9 adapted to engage a pair of spaced contact fingers In which are mounted in suitable insulating members ll secured in the body portion 2a adjacent the drain pipe 5.

One of the contact fingers iii is connected to a circuit wire Illeadlng from one of the terminals of a battery l3. The other contact finger fl! is connected to-a wire i241 leading to the magnet valvedevice 3.

The magnet valve device '3 may comprise a casing I 4 havinga chamber l5 arranged at one side of a flexible diaphragm I! which is clamped between said casing and the mounting base 4. At the opposite side of diaphragm I! is a chamber 15 in the base 4. The magnet valve device also comprises a-coil or winding H! which has one end connected to the wire l2a leading from one of the contact fingers"). The'ot-her end of the coil l 3 is connected "to a wire ls'which is connected to the other terminal of the battery l3. The magnet valve devicefurther 'comprises'an armature 29 connected to the center of diaphragm l1 and having formed on one end a valve 22 disposed in chamber I6 for cooperation with a seat on the mounting base 4 for controlling communication between chamber lfi and a passage '23 leading to float chamber 5. Uponenergization of coil .8 the armature ibis adapted to unseat the valve 22. A spring '2! acting-onzthe armature is provided to seat valve 22.. upon deenergization. of 1 coil I8.

Chamber I 8 is open to atmosphere through a choke 24 and passage 25.

Operation Assuming that winding I8 of the magnet valve device 3 is deenergized and the several parts of the drain valve device are in the position in which they are shown in the drawing, and that fluid under pressure is being supplied to the reservoir I and thence through pipe 6 to the chamber 5. From the chamber 5 fluid under pressure will flow through the clearance space 30 between the guide rod 8 and the float "I to the space 21 between the undersuriace of the float and the adjacent surface of the base portion 4 so as to partially counterbalance the pressure of fluid acting over the upper surface of the float. Fluid under pressure from space 21 will flow through passage 23 to the seated magnet valve 22.

Condensate as it collects in the reservoir I drains through pipe 6 into chamber 5. Now when the condensate in chamber 5 reaches a certain level it will lift the float from contact with the base 4 and open chamber 5 directly to cavity 2'! and passage 23. When the accumulated condensate in chamber 5 is suflicient to cause the float I to move the ring 9 into engagement with both contact fingers ID, the electric circuit through the winding I8 of the magnet valve device and battery I3 is closed thus energizing the winding I 8. With the winding I8 energized the armature 20 is caused to move upwardly against the o pposing pressure of the spring 2I, flexing the diaphragm I! upwardly and unseating the valve 22.

With the valve 22 unseated the accumulated condensate in the passage 23 and chamber 5, which is under the pressure of fluid from the reservoir I, will flow to chamber IE and thence to atmosphere through choke 24 and exhaust port 25. As the condensate from chamber 5 is discharged to atmosphere, the level of condensate in said chamber will fall and along with it the float 1 and ring 9 until said ring moves out of engagement with the contact fingers I and opens the circuit through the winding I8 of the magnet valve device and battery I3 thus deenergizing the coil. However, the valve 22 will remain open upon deenergization of the magnet until the float I engages the base 4, since the choke 24 so restricts discharge of condensate from chamber It as to maintain sufficient pressure on the lower face of flexible diaphragm I1, as to hold said diaphragm deflected against spring 2| and thus hold valve 22 unseated against the opposing pressure of said spring until substantially all of the condensate has been discharged from chamber and float I has returned to its lower most position in chamber I3 contacting seat 28. With the float I in contact with seat 28, the flow of condensate from chamber 5 to passage 23 is restricted by the clearance space 30 to a rate less than the rate at which fluid flows from chamber IE to atmosphere by way of the choke 24 and exhaust port 25 and, as a result, the pressure of fluid in chamber I6 will promptly reduce and permit the spring 2I to move the armature downward to seat the valve 22, the diaphragm I! returning to its normal position with the armature.

Summary From the above description it will now be seen that the improved drain valve device will operate each time chamber 5 becomes sufliciently filled with condensate to cause energization of magnet valve device 3 to discharge such condensate and 4 thereby prevent condensate from accumulating in the reservoir I.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:

1. An automatic drain valve device for discharging condensate from a fluid pressure system, comprising a casing having a condensate collecting chamber in constant open communication with said fluid pressure system, a condensate drainage communication leading from said chamber, electromagnetic valve means normally closing said condensate drainage communication and operative upon energization to open said com munication, switch means comprising a guide rod in said chamber, a float slidably mounted on said guide rod, an electrical contact carried by said float, and a pair of contact fingers carried by said casing and adapted to be engaged by said electrical contact in response to a predetermined increase in the amount of condensate collected in said chamber for efiecting energization of said valve means and being responsive to the partial discharge of collected condensate from said chamber to move said electrical contact out of engagement with said fingers to effect deenergization of said valve means, control means responsive to the pressure of condensate discharged from said chamber for maintaining said valve means in its condensate drainage communication opening position, said float being responsive to substantially complete discharge of condensate from said chamber for restricting flow of fluid under pressure from said chamber to said drainage communication to a rate less than the rate of flow of condensate from said drainage communication to effect a reduction in the pressure of condensate on said control means, and means operative upon said reduction in the pressure of the condensate acting on said control means for actuating said valve means to close said drainage communication.

2. An automatic drain valve device for discharging condensate from a fluid pressure system, comprising a casing having a condensate collecting chamber in constant open communication with said fluid pressure system, a condensate drainage communication leading from said chamber, an electrically controlled valve device comprising a flexible diaphragm, a valve operatively associated with said diaphragm normally closing said condensate drainage communication and operative to open the communication, a magnet operative upon energization to actuate said valve to open said communication, a spring for actuating said valve to close said communication, a source of electrical energy, switch means operative to connect said source of electrical energy into circuit with said magnet to effect the energization of said magnet winding and operative to open said circuit to effect deenergization of said magnet, said switch means compris ing a guide rod disposed in said chamber, a float slidably mounted on said guide rod, an electrical contact carried by said float, and a pair of contact fingers carried by said casing and adapted to be engaged by said electrical contact ring in response to a predetermined increase in the amount of condensate collected in said chamber for closing said circuit, and being responsive to the partial discharge of collected condensate from said chamber to move said electrical contact out of engagement with said contact fingers to open said circuit, said flexible diaphragm being responsive to pressure of condensate being discharged from said chamber for maintaining said valve opening said condensate drainage communication against the opposing pressure of said spring upon deenergization of said magnet, and said float being responsive to substantially complete discharge of condensate from said chamber for restricting the flow of fluid under pressure from said chamber to said drainage communication to a rate less than the rate of flow of condensate from said drainage communication to thereby eflect a reduction in the pressure oicondensate acting on said flexible diaphragm for rendering said spring effective.

3. An automatic drain valve device for discharging condensate from a fluid pressure system, said device comprising a casing having a condensate collecting chamber in constant open communication with said fluid pressure system, a condensate drainage communication leading from said chamber, electromagnetic valve means normally closing said condensate drainage communication and operative upon energization to open said communication, a source of electrical energy, a normally open electric circuit associated with said electromagnetic valve means and said source of electrical energy, a float movably mounted in said condensate collecting chamber, an electric switch member operative to open and close said circuit, said float being movable in response to a certain increase in the amount of condensate in said condensate collecting chamber to cause said switch member to close said electric circuit through said electromagnet valve device and said source of electrical energy to thereby efiect the energization of the electromagnetic valve means, means responsive to the pressure of condensate discharged from said chamber for actuating said valve means to maintain said condensate discharge communication open, said float being responsive to the substantially complete discharge of condensate from said chamber for restricting the flow of fluid under pressure from said chamber to said drainage communication to a rate less than the rate of flow of condensate from said drainage communication to efiect a reduction in the pressure of the condensate acting on said valve means, and means responsive to the reduction in pressure of condensate on said valve means for actuating said valve means to close said drainage communication.

4. An automatic drain valve device for discharging condensate irom a fluid pressure system, said device comprising a casing having a condensate collecting chamber in constant open communication with said fluid pressure system, a condensate drainage communication leading from said chamber, an electrically operated valve device comprising a flexible diaphragm, a valve operatively associated with one side of said diaphragm and normally closing said condensate drainage communication, a magnet operative upon energization to efiect operation of said valve to open said communication, a source of electrical energy, a normally open electrical circuit associated with said source of electrical energy and said electrically operated valve device, switch means operative to open and close said circuit, and a float responsive to a certain increase in the amount of condensate collected in said chamber for effecting the operation of said switch means to close said circuit to thereby effect the energization of said magnet and responsive to a partial discharge of collected condensate from said chamber to effect the operation of said switch means to open said circuit to thereby effect the deenergization of said magnet, said flexible diaphragm being responsive to the pressure of the condensate being discharged from said chamber for maintaining said valve open, said float being responsive to substantially complete discharge of condensate from said chamber for restricting flow of fluid under pressure from said chamber to said drainage communication to a rate less than the flow of condensate from said drainage communication to effect a reduction in the pressure of condensate acting on said diaghragm, and spring means acting on said diaphragm for actuating said valve to close said drainage communication upon eflecting said reduction in the pressure of the condensate on said diaphragm.

5. An automatic drain valve device for discharging condensate from a fluid pressure system, said valve device comprising a casing having a condensate collecting chamber in open communication with said system, valve means controlling a condensate discharge communication from said chamber, an electromagnet operable upon energization to efiect operation of said valve means to open said communication, a source of electrical energy, a normally open electrical circuit associated with said source of electrical energy and said electromagnet, switch means operative to open and close said circuit, and a float responsive to a certain amount of condensate in said chamber to effect the operation of said switch means to close said circuit to thereby effect the energization of said magnet and responsive to a reduction in the amount of condensate in said chamber to efiect the operation of said switch means to open said circuit to thereby efiect the deenergization of said magnet, said float being operative upon the substantially complete discharge of condensate from said chamber to restrict such discharge, control means for maintaining said valve means in its communication opening position upon deenergization of said magnet, said control means being rendered ineifective upon the restricting of the discharge of condensate from said chamber by said float, and means for actuating said valve means to close said communication upon rendering said control means ineffective.

BURTON S. AIKMAN.

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

UNITED STATES PATENTS Number Name Date 1,529,334 Winkeleer Mar. 10, 1925 1,747,498 Archibald Feb. 18, 1930

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