US2688460A

US2688460A - Automatic drain valve

Info

Publication number: US2688460A
Application number: US203451A
Authority: US
Inventors: William F Borgerd
Original assignee: International Harverster Corp
Current assignee: Navistar Inc
Priority date: 1950-12-29
Filing date: 1950-12-29
Publication date: 1954-09-07
Anticipated expiration: 1971-09-07

Description

SePt- 7, 1954 w. F. BoRGL-:RD 2,688,450

AUTOMATIC DRAIN VALVE Filed Dec. 29, 1950 5 Sheets-Sheet l sn 1 grr "nm w. F. BORGERD AUTQMATIC DRAIN VALVE sept. 7, 1954 3 Sheets-Sheet 2 Filed Dec. 29, 1950 w. F. BORGERD v AUTOMATIC DRAIN VALVE Sept. 7, 1954 3 Sheets-Sheet 5 Filed Dec. 29, 1950 Patented Sept. 7, 1,954

2,688,460 AUTOMATIC DRAIN VALVE William F. Borgerd, Evansville, Ind., assigner to International Harvester Company, a corporation' of New Jersey Application December 29, 1950, Serial No. 203,451- 4 4 Claims. l

This invention relates generally to a thermostatic drain valve and more particularly to a valve which will automatically drain the liquid from a coolinglsystem when the system issubjected to freezing conditions.

The present invention provides a valve which is particularly adaptable for draining water from a water cooled condenser of an air conditioning system. During sudden periods of unusually cold weather, tremendous damage is often done to Water cooled condensers since the air conditioning systems are ordinarily placed in enclosed rooms which are heated only by heat leakage from adjacent heated rooms. The temperature of the condenser will be lowered below the freezing point of water during such cold weather, which results in the freezing of the water in the condenser. As the water freezes, it expands and bursts the condenser. Accidents of this kind are quite common in business buildings, especially if the cold weather occurs on a week-end when attendants are absent from the building. When the condenser has burst, water runs all through the refrigeration system and the job of cleaning the system costs nearly as much as a new condensing unit because of the repeated purging with refrigerant that is necessary and the multitude of chemical dryers that must be used. By providing` automatic means for draining the condenser, serious damage to the air conditioning system Will be prevented.

One object of the present invention is to provide a drain valve which automatically cuts olf the supply of cooling Water to a water cooled condenser and completely drains water from the condenser When the temperature of the condenser approaches the freezing point of water.

Another object of the invention is to provide a drain valve with electrical means for operating the valve in response to ambient temperatures.

A further object of the invention is to provide an automatic drain valve which may be manually reset and which may be easily checked to determine if it is in proper operating condition.

Another object of the invention is to provide an automatic drain valve with signal means for warning an operator when the valve has moved to drain position.

Another object of the invention is to provide a cooling system with a drain valve which will positively and rapidly operate to drain the system when the system is subjected to freezing tem.- peratures.

With the above and the other objects in view the invention consists in certain novel details of construction and combinations of parts hereinafter fully described and claimed, it being understood. that various modiiications may be resorted to within the scope of the appended claims without departing from the spirit or sacrificing any of the advantages of the invention.

. In the accompanying drawings` forming part ofthis specication:

Fig. l is a diagrammatic view of a refrigeration system with an enlarged side elevational view of the drain valve. n

Fig.. 2 is an enlarged horizontal sectional View of the drain valve taken on line 2-2 of Fig. 2.

Fig. 3 is a vertical sectional View of the valve taken on line 3--3 of Fig. 2'.

Fig. 4 is a vertical sectional view of the valve With the movable parts in drainage position.

Referring specifically to the drawings, numeral Il] designates generally a drain valve which is connected to the water inlet Il of a water cooled condenser I2 by hose I3. The water outlet i4 of condenser l2 is connected to a suitable wastev pipe by hose i5. The condenser l2 is a member of a refrigeration system comprising motor-compressor unit i6 and evaporator Il. After the refrigerant is compressed by motorcompressor unit I6, it flows through conduit I8 into a seriesof tubes in condenser I2 where it is cooled by the water owing into Water inlet Il, around the tubes and out the water outlet ill. The refrigerant flows from condenser I2y throughconduit i9 into expansion valve 2i), then through conduit 2l into evaporator l'l. The air to be conditioned is passed over the evaporator and is cooled by the refrigerant passing therethrough. From the evaporator I'l, the refrigerant returns to the motor-compressor unit It through conduit 22v and repeats the cycle.

The drain valve lil-comprises a generally tubularshaped valve body 23 provided with three interconnecting cylindrical

shaped chambers

24, 25 and 26 which extend through the central portion of the body. These chambers will hereinafter be referred to as inlet chamber 24 outlet chamber 25 and power chamber 26. One end of inlet chamber 24 is internally threaded into which an externally threaded nipple 2l is threaded. The valve body 23l is provided with an outlet nozzle 2R hav-ing a passageway 29 which extends into communication with inlet chamber Ell. A drain nozzle 3'0'is provided on the lower part. of valve body 23 having a passageway 3i which extends into outlet chamber 25. An annular shoulder 32'A surrounds a valve port lili and provides a valve seat 33 between valve chamber 2li. and outlet chamber 2li. Nipple Z1 is provided with an annular shoulder 3d which surrounds valve port 024 and forms a second valve seat 3'5. A valve member or disc 36 is secured to one end of a valve stem 37 and positioned within valve chamber 2li. Secured in an annular groove 47V in valve member 363 is a serrated ring 38 whichhel'psY to support theA end of valve sternV 3l andinsures concentric seating of valve member 365 against valve seats 33 and 35.

Valve stem 3l extends through outlet chamber 2 5 intopower chamber 26. Between these chambersis a wall memberl 39y which is secured in valve. bo'dy'23v by washer lll and is provided with a: central. opening d. through which the valve stem 3:7 extendsinsliding relationshipthereto.

A compressible coiled spring 42 encircles valve stem 31 with one end abutting wall member 39 and the other end abutting an annular shoulder 43 formed Aon valve stem 31. A hollow cylindrical shaped piston 44 is tted in power chamber 25 in sliding relationship thereto so that it is adapted for reciprocating movement therein. The closed end 45 of the piston is provided with an opening through which the valve stem 31 extends. The forward edge 46 of the piston is beveled to provide a surface inclined approximately 45. Slidably received within piston 44 is a cylindrical shaped sleeve 48 having an internal bore 49 extending therethrough. The end of valve stem 31 extends into bore 49 and is xedly secured to the sleeve 48 by pin 50. A horizontally extending cross pin 5| is fixedly secured to piston 44.

Slots

52 and 53 are provided in Valve body 23 through which the ends of the fcross pin I extend. Sleeve 48 is provided with

slots

54 and 55 through which the pin 5| extends. The

slots

54 and 55 are made a length which is approximately twice the diameter of pin 5|, whereas the length of

slots

52 and 53 is considerably greater. A compressible coiled spring 56 encircles valve stem 31 with one end abutting the closed end 45 of `piston 44 and the other end abutting the forward end of sleeve 48.

A portion of valve body 23 is cut away to provide an opening 51 which communicates with the top portion of power chamber 26. A projection 58 is formed as part of valve body 23 along one edge of opening 51. Pivotally secured to projection 58 by pivot Ipin 59 is a trigger member 68 having a substantially vertically extending handle 6I and a leg 62 which extends into opening 51. A notch 63 is provided in leg 62 which nts over the beveled edge 46 of piston 44. Secured to valve body 23 by screws 64 is a bracket 65 having an upstanding portion spaced from handle 6|. Secured to bracket 65 by screw 66 is a solenoid 61 having a metallic core 68 surrounded by an electrical winding 69. Insulating plates 10 and 1I are positioned at each end of winding 69 with end 12 of core 68 extending through an aperture in plate 18.

Valve body 23 is provided with two

bosses

13 and 14 to which housing 15 is secured by

bolts

16 and 11. Secured within housing 15 is a thermostat 18 which will be responsive to temperature changes. The thermostat 18 comprises a bimetallic strip 19 having a fixed end 88 secured to the Ihousing 15. Secured to the movable end of strip 19 is an electrical contact 8| which is positioned between two

iixed contacts

82 and 83. Contact 83 is connected in an electrical circuit to solenoid 61. Contact 82 is connected in an electrical circuit to an electric alarm bell 84 and an electric relay 85 which will operate as hereinafter described.

The rubber hose I3 connects the outlet nozzle 28 to condenser inlet Il and rubber hose 86 connects nipple 21 to a suitable water supply. Drain nozzle 38 is connected to a suitable waste pipe by hose 81. The drain valve I8 is positioned adjacent the condenser I2 so that they will both be subjected to the same ambient temperature. When the refrigeration system is operating under normal conditions, the bimetallic strip 19 maintains movable contact 8| in engagement with xed contact 83 which completes the circuit to solenoid 61 from a suitable power supply through wire 88, strip 19, contact 8|, contact 83, wire 89, solenoid winding 59, and wire 98. As the solenoid 61 is energized, a magnetic pull is created which holds the trigger 68 in cocked position with handle 6| contacting end 12 of core 68 and notch 63 engaging the beveled edge 46 of piston 44 as seen in Figs. 2 and 3. Spring 56 is ,stiffer than spring 42 so that sleeve 48 is forced to the right by spring 56. "Since valve stem 31 is secured to the sleeve 48 by pin 50, the valve stem will be moved to the right until valve member 36 is in contact with Valve seat 33. This opens valve port |02 so that cooling water will pass through nipple 21, valve chamber 24, passageway 29, and hose I3 into condenser I2. With the drain valve mechanism in this position, the condenser I2 will be properly cooled by the cooling water. Spring 56 is strong enough to overcome spring 33 so that the valve member 36 is securely seated against valve seat 33 which prevents water from running into outlet chamber 25. The cross pin 5| is positioned proximate the rear edges of

slots

52, 53, 54, and 55.

When the temperature of the air surrounding condenser I2 and the drain valve I0 is lowered to approximately 38, the bi-metallic strip 19 will bend and move Contact 8| away from xed contact 83 into engagement with fixed contact 82 which breaks the circuit to solenoid 61. As the solenoid is de-energized the magnetic force will cease and handle 6| of trigger member 69 will be released. Both springs 56 and 42 will be acting to force the piston 44 forward which will force the trigger 60 in a counter-clockwise direction about pin 59 until notch 63 is above beveled edge 46. This releases piston 44 and the entire valve mechanism moves forwardly impelled by spring 42 to the position shown in Fig. 4. Valve member 36 is forced away from valve seat 33 and is moved into engagement with valve seat 35. As the sleeve 48 is carried forwardly by valve stem 31, it carries cross pin 5| and piston 44 with it. When valve member 36 contacts valve seat 35, the spring 55 will abut against fixed sleeve 48 and force piston 44 forwardly until cross pin 5| `contacts the front edges of

slots

54 and 55 in sleeve 48. The handle 6| is provided with projection |88 which abuts against valve body 23 and acts as a stop for trigger 60.

With the valve mechanism moved to the drainage position as shown in Fig. 4, the water supply through nipple 21 will be shut o, and communication between outlet chamber 25 and valve chamber 24 is provided through valve port Il. The water in condenser I2 will drain through hose I3, passageway 29, valve chamber 24, outlet chamber 25, passageway 3|, and hose 81 into a suitable waste pipe. A slot 8| is provided in the upper portion of valve chamber 24 which connects with passageway 29 to insure rapid drainage of water past the valve member 36. Since the drain valve In is positioned below the condenser I2, all the water `will drain from the condenser which will prevent damage to the condenser as the temperature falls below 32.

As the bi-metallic strip 19 moves contact 8| into engagement with fixed Contact 82 the circuit is completed to alarm bell 84 and relay 85 from a suitable supply source through wire 8B, strip 19, contact 8|, contact 82, wire 9|, relay coil 92, wire 93, alarm bell 84, and wire 94. The resultant current ow will energize the alarm bell 84 and the alarm bell will begin to ring which will warn an operator that the condenser I2 is approaching freezing conditions. As the relay coil 92 is energized, arm 95 will be moved away from contact 96 and the current to motor-compressor unit I6 will be broken. This condition prevails until an operator comes to investigate. If the operator wants to use the air conditioner .to solenoid 61. up so that the valve does not again trip to drain in the immediate future, he may recock the valve tended ends of cross .pin 5|. As the cross pin is forced to the right, it carries sleeve 48 and piston 44 with it so that trigger member 60 may be rotated until notch 63 is in engagement with beveled edge 46. The bi-metallic strip 19 is then warmed so that contact 8| is moved into engagement with contact 83 which completes the circuit The room must then be warmed position. As contact 8| is moved away from fixed contact 82 the circuit to alarm bell 84 and relay 85 is broken. As the relay is de-energized, arm 95 will move into engagement with contact 96 and the circuit will be completed to motor-compressor unit I6 through wire 99, contact 96, arm 95, Wire 98, motor I6, and wire 91.

From the foregoing it can be seen that a drain valve is provided which will automatically operate to drain water from a water cooled condenser when the condenser is subjected to freezing temperatures. The valve may be easily checked to determine if all parts are free and in good working order by simply bumping the extended end of sleeve 48. The resultant squirt of Water out the drain hose 81 will also indicate that the water supply is normal. Since the drain valve is accurately responsive to temperature changes, there is no danger that the water in the condenser will be frozen even if the refrigeration system is located in an unheated room.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, therefore, desired to conne the invention to the exact form herein shown and described, but it is desired to include all such as a trigger member for engaging said piston, spring means interposed between said piston and said sleeve which forces said valve member to closed position when said trigger member engages said piston, a lever arm rigidly mounted to said trigger member, said lever arm formed of a magnetically attractable material whereby an electrical magnet is positionable in cooperation with said lever arm to control the operation of said trigger member, and spring means for forcing said valve member to open position `when said trigger member is released.

2. A valve for a Water system comprising a valve body having a valve chamber and a drain port communicating with said valve chamber, a valve stem, a valve member secured to one end of said valve stem and adapted to open and close said drain port, a sleeve secured to the opposite `end of said valve stem, a piston slidably secured within said valve body, a pivotable trigger secured to said valve body and engaging said piston in the cocked position, resilient means interposed between said piston and said sleeve which holds said valve member in closed position when said trigger is engaging said piston in the cocked position, a lever arm rigidly mounted to said trigger,

said lever arm formed of a magnetically attractable material so that an electric magnet is mountable in cooperation with said lever arm to control the cocking and uncocking of said trigger, said resilient means being made inoperative when said trigger is uncocked, and means for moving said valve member to open position when said trigger is uncocked.

3. A valve for a Water system comprising a valve body having a valve chamber, said valve body provided with a drain port which communicates with said valve chamber, a valve stem, a valve member secured to one end of said valve stem which is adapted to open and close said port, a sleeve secured to the opposite end of said valve stem, a piston, a trigger member movably secured to said valve body and operable to the cocked position to engage said piston and to the uncooked position to release said piston, resilient means interposed between said piston and said sleeve and operating responsive to the engagement of said piston by said trigger member for holding said valve member in the closed position, said trigger member formed to have a leg projecting therefrom, said leg formed of a magnetically attractable material so that an electro-magnet is mountable in cooperation with said leg to attract and release said leg whereby said trigger member is maintainable in the cocked and uncooked positions, and means for forcing said valve member to open position when said trigger member is released.

4. A valve for a water system comprising a valve body having a valve chamber, said valve body being provided with a drain port which communicates with said valve chamber, a valve stem having a valve member secured to one end thereof, said valve member adapted to open and close said drain port, a piston operable to one position, resilient means in engagement with said valve stem and said piston and operating when said piston is operated to said one position for moving said valve member to close said port, a trigger member movably secured to said valve body, said trigger member movable to one position to operate said piston to said one position whereby said valve member is moved to close said drain port, said trigger member formed to have a lever arm mounted rigidly thereto, said lever arm formed of a magnetically attractable material whereby an electro-magnet is mountable in cooperation with said lever arm to attract said lever arm to cock said trigger member to said one position and to release said lever arm to uncock said trigger member, and means for forcing said valve member to open position when said trigger member is released.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,350,550 Hoffman Aug. 24, 1920 1,395,203 Olsen Oct. 25, 1921 1,443,592 Richmond et'al. Jan. 30, 1923 1,510,164 Ruegger Sept. 30, 1924 1,526,718 Opp Feb. 17, 1925 1,539,667 Halagarda May 26, 1925 1,786,878 Van Keuren Dec. 30, 1930 1,912,843 Holmes June 6, 1933 1,924,250 McGuire Aug. 29, 1933 1,924,251 McGuire Aug. 29, 1933 2,144,399 Betz Jan. 17, 1939 2,236,227 Wantz Mar. 25, 1941 2,301,876 Hurlburt Nov. 10, 1942