US3905385A

US3905385A - Steam trap

Info

Publication number: US3905385A
Application number: US465090A
Authority: US
Inventors: Edwin Laurence Green
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-04-29
Filing date: 1974-04-29
Publication date: 1975-09-16
Anticipated expiration: 1992-09-16

Abstract

A steam trap to be utilized on exit tubing from steam appliances to permit return of condensed water to a boiler while simultaneously preventing return of pressurized steam. The trap comprises a sealed holding tank having a steam pipe leading from the appliance into the tank, and an upright standpipe extending vertically into the tank. The lower end of the standpipe includes a bottom opening through which the water condensate is free to pass. The upper end of the standpipe includes an electrode that is situated within the standpipe adjacent the top of the tank. A portion of the standpipe extends vertically above the top of the holding tank and is connected to a drainpipe. The pipe includes a solenoid-operated valve connected in an electrical circuit with the electrode. The electrode is located within the standpipe so that buildup of condensate within the holding tank must reach a certain level before the electrode is engaged by the accumulating condensate. Once engaged, the circuit is completed and the solenoid valve is actuated to open, allowing the condensate within the holding tank to be forced vertically through the standpipe and out the drainpipe. As the tank empties, the condensate leaves engagement with the electrode and the circuit is broken. This releases the solenoid valve and the pressurized steam is prevented from leaving the confines of the holding tank.

Description

United States Patent [451 Sept. 16, 1975 Green 1 STEAM TRAP [76] Inventor: Edwin Laurence Green, P.O. Box

1127, Twin Falls, Idaho 83301 [22] Filed: Apr. 29, 1974 Appl. No.: 465,090

Primary ExaminerAlan Cohan Attorney, Agent, or Firm-Wells, St. John & Roberts [57] ABSTRACT A steam trap to be utilized on exit tubing from steam appliances to permit return of condensed water to a boiler while simultaneously preventing return of pressurized steam. The trap comprises a sealed holding tank having a steam pipe leading from the appliance into the tank, and an upright standpipe extending vertically into the tank. The lower end of the standpipe includes a bottom opening through which the water condensate is free to pass. The upper end of the standpipe includes an electrode that is situated within the standpipe adjacent the top of the tank. A portion of the standpipe extends vertically above the top of the holding tank and is connected to a drainpipe. The pipe includes a solenoid-operated valve connected in an electrical circuit with the electrode. The electrode is located within the standpipe so that buildup of condensate within the holding tank must reach a certain level before the electrode is engaged by the accumulating condensate. Once engaged, the circuit is completed and the solenoid valve is actuated to open, allowing the condensate within the holding tank to be forced vertically through the standpipe and out the drainpipe. As the tank empties, the condensate leaves engagement with the electrode and the circuit is broken. This releases the solenoid valve and the pressurized steam is prevented from leaving the confines of the holding tank.

2 Claims, 1 Drawing Figure L9 ,r/f

STEAM TRAP BACKGROUND OF THE INVENTION The present invention is related to steam systems and more particularly condensing to mechanisms for recovering water condensate from steam systems. Such apparatus is commonly associated with steam appliances such as those used in dry cleaning operations. In such systems, a steam trap is required to enable return of condensed water to a boiler without permitting return of pressurized steam.

Most conventional steam traps utilize a mechanical float that operates a flap valve or small disc that raises in response to condensate level within a holding tank. Most conventional steam traps have very small exit orifices that prevent quick release of the collected condensate. Further, most of these devices permit steam to escape along with the condensate each time the trap opens. This is undesirable since steam pressure is sacrificed along with the heat value of the escaped steam.

A United States patent granted to Williams US. Pat. No. 2,368,509 discloses a water control discharge with an electrode contacted by collected water to operate a valve. The valve permits discharge of the collected water under steam pressure. The arrangement does not include an upright standpipe to assure discharge of a comparatively large volume of water under steam pressure and appears incapable of differentiating between escaping water condensate and steam exiting from the tank and associated steam system.

The apparatus of the present invention comprises a sealed holding tank connected to the steam system and having an upright standpipe extending downwardly into the holding tank to a bottom end adjacent the bottom of the holding tank. An upper end of this standpipe extends vertically outward from the holding tank and includes a drainpipe fixed thereto. The drainpipe includes a solenoid-operated valve that is connected in circuit to an electrode mounted within the standpipe and having an exposed tip adjacent to the top of the holding tank. As condensate reaches the level within the holding tank, the exposed electrode tip is engaged and a circuit completed to operate the solenoid valve to open the drainpipe and allow steam pressure to evacuate the holding tank of the water condensate. Once the exiting condensate leaves engagement with the exposed electrode tip, the solenoid valve automatically closes, preventing escape of steam from the holding tank and the steam system.

SUMMARY OF THE INVENTION A steam trap is disclosed for separating pressurized steam from water condensate. The steam trap comprises an enclosed holding tank for receiving pressurized steam and water condensate from a steam pipe leading into the tank. An upright standpipe extends into the tank and includes a bottom opening adjacent the bottom of the tank and an upper end extending outwardly from the top of the tank. Sensing means is located within the standpipe adjacent the upper end thereof for sensing a prescribed level of condensate within the standpipe. A drainpipe openly communicates with the upper end of the standpipe and includes a valve means mounted thereon responsive to the sensing means for opening the drainpipe as the condensate reaches said prescribed level and closing the drainpipe when said condensate is full or not engaging the sensing means. The condensate is thereby automatically drained by force of said pressurized steam to the level of the bottom opening of the standpipe.

It is a first object of my invention to provide a steam trap for effectively allowing evacuation of water condensate from a steam system without allowing accompanied escape of pressurized steam.

It is another object to provide such a steam trap that will facilitate evacuation of substantially large amounts of condensate from a steam system in a relatively short period of time.

It is an additional object to provide such a steam trap that is very economical to utilize in conjunction with present steam systems.

A yet further object is to provide such a steam trap that is simple in construction and substantially maintenance free.

These and other objects and advantages will become apparent upon reading the following disclosure which, taken with the accompanying drawing, disclose a preferred form of my invention.

BRIEF DESCRIPTION OF THE DRAWING A preferred form of the present invention is illustrated in the accompanying drawing which is a substantially diagrammatic representation of a longitudinal cross section of my invention and associated circuitry.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing in greater detail, a preferred form of my invention is shown basically comprising a holding tank 10, a steam pipe 11 leading into the holding tank 10, an upright standpipe 18 and an attached drainpipe 30 leading from the holding tank. A sensing means 23 is positioned within the standpipe l8 and is connected by a normally open electric circuit 35 to a valve means 31. The sensing means 23 and valve means 31 are operative to detect a prescribed level of water condensate within the holding tank 10 and to allow the condensate to be drained from the holding tank under pressure from steam entering through pipe 11..

The holding tank 10 is comprised of a sealed container formed with a bottom wall 13, a top wall 14, side walls 19 and end walls 15. The steam pipe 11 openly communicates with the hollow interior of tank 10 by connection through one of the end walls 15. The steam pipe 11 may be an integral portion of a steam system such as those commonly utilized in a dry cleaning operation. The attached steam system is not shown in the accompanying drawing. It may be understood however that steam and water condensate are directed under pressure from the steam system through the steam pipe 11 and into the holding tank 10.

The standpipe 18 is located adjacent the end 15 opposite that connected to the steampipe 11. Standpipe 18 is upright and extends vertically into the tank 10, leading downward to a bottom opening 20 adjacent tank bottom wall 13. Standpipe 18 further includes an upper end 21 that extends upwardly and outwardly from the top wall 14 of holding tank 10. Standpipe 18 may be provided as an integral element of the holding tank 10, as illustrated, or may be threadably engaged or otherwise attached to the holding tank in a position as illustrated in the drawing. The drainpipe 30 is similarlybonnected to the upper end 21 of standpipe 18 to openly communicate with the hollow interior thereof. Thus, any condensate evacuated from holding tank must first move upwardly from open end to the drainpipe 30. The level of opening 20 thereby determines the level of condensate after the evacuation process.

The sensing means 23 is basically comprised of an electrode 24 mounted within the upper end of standpipe 18 and extending downwardly into the holding tank 10. The electrode 24 is partially encased by an insulator 26 so that only a small portion or tip is exposed within the holding tank 10. Sensing means 23 is attached to the standpipe 18 by means of a threaded plug 27 engaged within the otherwise open top end 21 of standpipe 18. Electrode tip 25 defines a prescribed level at which the condensate is allowed to reach before the valve means 31 is operated to release the condensate through drainpipe 30 under steam pressure.

Valve means 31 may be comprised of a conventional valve plunger 32 mounted to a solenoid 33. The plunger 32 is vertically movable between an open position wherein a passage is opened to allow free movement of the condensate through drainpipe 30, and a normally closed position (illustrated in the drawing) maintained by a compression spring 34.

Solenoid 33 is operated by sensing means 23 and a power means 37 in the form of a battery or other power source connected in the circuit 35. Solenoid 33 is insulated to prevent electrical contact with drainpipe 30. Therefore, connection is made to the power means 37 and sensing means 23 solely through means of connecting wires.

A first wire 38 extends from solenoid 33 to the electrode 24, and a second wire 40 extends from the solenoid 33 to power means 37. The holding tank 10 and pipes connected thereto are utilized by the circuit as a common ground. It may be noted in the drawing that valve means 31 is normally closed since the solenoid 33 and sensing means 23 are both insulated from the com mon ground. The circuit to valve means 31 is completed, however, once the water condensate reaches the level of exposed electrode tip 25. When this occurs, the condensate becomes a conductor and solenoid 33 is operated to move plunger 32 to the open position, allowing condensate to be forced by steam pressure through drainpipe 20.

The condensate will continue to be forced by steam pressure from the holding tank so long as it remains a conductor between electrode tip 25 and ground. Further, the position of bottom opening 20 of standpipe 18 facilitates removal of almost all of the condensate within holding tank 10 since it is located adjacent the bottom wall 13. The condensate must drain to a level below the bottom opening 20 before steam is allowed to enter the standpipe 18.

Any steam or air existing within the tank, before the condensate level begins to rise, is exhausted through a small escape aperture 36 located adjacent the top wall 14 of tank 10. The escape aperture 36 extends through the standpipe and openly communicates between the hollow interior of the standpipe and the interior of holding tank 10. Any air within standpipe 18 is thereby forced into the holding tank 10 as the condensate 12 rises.

It may be understood that the escape of steam from the holding tank 10 is prevented at the instant the condensate leaves engagement with the exposed electrode tip 25. As the condensate disengages tip 25, the circuit 35 is again opened and solenoid 33 is deactivated, allowing compression spring 34 to return plunger 32 to the closed position. This step is accomplished almost instantaneously so that no steam is allowed to escape the holding tank or associated steam system.

On occasion the device is temporarily disabled by an air lock within tank 10. This can be remedied by adding an air vent 42 open to the interior of tank 10. The air vent 42 is a pressure-operated valve, normally closed. It is pre-set to open at a pressure slightly greater than the operating steam pressure. If air in the tank 10 is compressed, vent 42 will open and allow the air (and steam) to escape momentarily, thereby making room for incoming condensate. Alternately, a small air line (not shown) running to the high point of the pipe 11 can also be used to bleed trapped air within tank 11.

It may have become apparent from the above description and attached drawings that various modifications may be made therein without departing from the intended scope of this invention. It is for this reason that only the following claims are to be taken as definitions of my invention.

What I claim is:

l. A steam trap for separating pressurized steam from water condensate comprising:

an enclosed holding tank for receiving pressurized steam and water condensate from a steam pipe leading into the tank,

an upright standpipe extending into the tank and having a bottom opening adjacent the bottom of the tank;

sensing means within the standpipe and elevationally located within the tank for sensing presence of condensate at a prescribed level within the standpipe and tank;

a drainpipe openly communicating with said standpipe at a location elevationally above said prescribed level;

a relief aperture formed through said standpipe elevationally above said prescribed level for allowing escape of gas from within said standpipe as condensate raises therein:

valve means mounted on said standpipe for opening the drainpipe and closing said drainpipe; and

power supply means operatively interconnecting said sensing means and said valve means responsive to said sensing means for actuating said valve means to open said drainpipe as said condensate reaches said prescribed level and engages .said sensing means, and to actuate said valve means to close said drainpipe when said condensate passes beyond the sensing means and becomes disengaged with said sensing means.

2. The invention set out in claim 1 wherein said power supply means is comprised of an electrical circuit with a source of electrical energy; and

wherein said sensing means comprises an electrode, connected to said electrical circuit and electrically insulated from said standpipe and tank and having an exposed tip at said prescribed condensate level; and

wherein said valve means includes a solenoid operated valve connected in said circuit to said source of electrical energy and to said electrode, said source of electrical energy being connected in said circuit to said condensate, whereby engagement of said condensate with said electrode completes said circuit and disengagement of said electrode and condensate opens said circuit to thereby operate said solenoid operated valve to open and close said drainpipe.

Claims

1. A steam trap for separating pressurized steam from water condensate comprising: an enclosed holding tank for receiving pressurized steam and water condensate from a steam pipe leading into the tank, an upright standpipe extending into the tank and having a bottom opening adjacent the bottom of the tank; sensing means within the standpipe and elevationally located within the tank for sensing presence of condensate at a prescribed level within the standpipe and tank; a drainpipe openly communicating with said standpipe at a location elevationally above said prescribed level; a relief aperture formed through said standpipe elevationally above said prescribed level for allowing escape of gas from within said standpipe as condensate raises therein: valve means mounted on said standpipe for opening the drainpipe and closing said drainpipe; and power supply means operatively interconnecting said sensing means and said valve means responsive to said sensing means for actuating said valve means to open said drainpipe as said condensate reaches said prescribed level and engages said sensing means, and to actuate said valve means to close said drainpipe when said condensate passes beyond the sensing means and becomes disengaged with said sensing means.

2. The invention set out in claim 1 wherein said power supply means is comprised of an electrical circuit with a source of electrical energy; and wherein said sensing means comprises an electrode, connected to said electrical circuit and electrically insulated from said standpipe and tank and having an exposed tip at said prescribed condensate level; and wherein said valve means includes a solenoid operated valve connected in said circuit to said source of electrical energy and to said electrode, said source of electrical energy being connected in said circuit to said condensate, whereby engagement of said condensate with said electrode completes said circuit and disengagement of said electrode and condensate opens said circuit to thereby operate said solenoid operated valve to open and close said drainpipe.