US1501858A - Expansion valve for refrigerating machines and the like - Google Patents

Description

July 15 1924. I 1,591,858

c. L. M cuE EXPANSION VALVE FOR REFRIGERATING MACHINES AND THE LIKE] Filed Nov. 1 1919 rm 29 4/8 P p z W 7 Mir-so; STAT-ES.

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Application filed November 1, 191a Serlal No. 335,032.

- To all whom it may concern."

' boils at atmospheric pressure.

whence the refrigerant enters from the com- Be it"known thatI, CHARLES L. MoCUnN, a citizen of the iUnited States, residinsg at Evanston, in the county of Cook and tate of-Illinois, have invented certain new and useful Improvements-in Expansion Valves for Refrigerating Machines and'the like, ofwhich the following is a specification. The invention relates to an improved form p): expansion valve particularly designed to paratus of thecom there is employed t e usual compressor, a condenser and an expansion chamber, the said valve embodying my invention being introducedinto the system in the connections between the condenser and the expansionchamber, and the invention is particularly adapted for use in systems. of this character employing a refrigerant which Expansion valves for controlling the flow of refrigerant from the condenser coil to the expansion coil have been heretofore used and one form of such' valve is shown and described in Patent No..1,291,334 of January 14, 1919, F. W. Wolf.v

One of the difficulties-encountered in the use of expansion valves of this character resides in the tendency of foreign. materials,

which may find their way into the refriger-r ant, to accumulate on the side of the valve pressor, audit is one of the objects of\my chamber which has a nism for thuslocating the valve controlling 1nvention to provide an expansion valve which will not be revented from properly functioning by or inary accumulations of foreign'materials therein.

My improved ex ansion valve is designed to be controlled by tile-normal pressure of the atmosphere, the valve stem being connected to ,one wall or portion of a collapsible chamber positioned and secured within the valve port communicating with a pipe leading to the expansion chamber. The aforesaid collapsible chamber. which operates the valve is arranged so that the interior thereof is pheric pressure, and it is one of the objects of fmyiiivention to provide suitable mecha- ,mechanism' and also to provide suitable means for shou'ld the preventing injurious collapsing of the collapsible valve operating chamber, same be subjected to unexpectedly used in connection with refrigerating apression type in which at substantially atmosthe-preferred embodiment of the-invention as hereinafter described, with reference to the drawing forming a part of the specifica tion, and finally more particularly pointed out in the claims.

In the said drawing, Fig. sectional view through my improved expansion valve, and Fig. 's a sectional view illustrating a detail of construction of the Valvecasing of an expansion valveof the character to which the invention relates being designed for use in the system between the condenser and the expansion chamber, and preferably being constructed so it may be inserted in the pipe line, forming means of communication between the condenser and the expansion chamber orexpansion coil and hence may consist of a closed chamber provided with nipples for connectionwith the pipe leading with the pipe leading .to the expansion chamber or coil, thenipple for the former' being indicated in the drawing Fig. 1, by the reference character 15 and the nipple for the latter by the reference character 16, both of said nlpplesbeing screw threaded for attachment to the ducts in the said system in the usual manner.

In constructing the expansion valve mechanism I prefer that the connecting ni ples 15, 16 be a part of an irregular metallic plate 10 which is provided with a valve chamber or opening 17 and a valve housing 18- forming a supplementary chamber 19 connected with the chamber 17 and leading to a valve seat 20. In this seat there is mounted aconical shaped valve 21 formed preferably as an integral part and enlargement at one end of a valve stem 22, the latter being threaded at its other extremity for adjustable connection with a threaded socket 100 v 1 is a vertical I from the condenser and and construction for the purpose of allowing the desired expansion and contraction and consequent separation and approximation of the heads 23 and 24 of the valve controlling device is obtained by brazing, soldering or otherwise securing the extremities of the copper cylinder 25 to the heads 23 and 2 1. These heads are preferably circular in form corresponding with the circular shape in cross section of the cylindrical copper bellows 25, the bellows effect being obtained in the usual manner by giving the wall of the cylindrical member the sinuous form indicated by the cross section taken through the same, as illustrated in Fig. 1. The head 24.- of the expansion chamber for controlling the valve 21 is provided with an extended shank, preferably screw threaded on its exterior as indicated at 26 and beyond the screw threaded part 26 there is a shank 27 of a contracted diameter so that a shoulder is formed at 28 at the outer extremity of the threaded portion adapted to co-operate with suitable packing 29 contained in a gland or housing. The stem or shank 26, 27 is provided with a longitudinally extending canal or duct 30 affording communication between the atmosphere and the interior of the valve controlling expansion chamber. The casting 10 containing the nipple 15, 16 and the primary valve chamber 17 is preferably formed approximately circular in form with the nipples 15 and 16 extending radially from the periphery thereof on diametrically opposite sides of the center occupied by the valve 21. A closed compartment is formed on each side of the valve and valve seat 20, the outer compartment designated by the reference character 31 being closed by a substantially circular and spherical like cap plate 32 the outer periphery of which is mined to the periphery of the main valve casting 10 and there being a passageway 33 communicating between the chamber 31 and the duct 34 in the nipple 15. On the other side of the main valve casting 10 there is a peripheral seat adapted for the attachment of a cylindrical chamber surrounding the aforesaid collapsible valve controlling chamber, the walls of which are indicated generally by the reference character 35. These walls have a peripheral horizontal flange 36 around the edge thereof adapted to be clamped to form a gas tight joint with the main valve casting 10, the union, as in the case of the plate 32 on the outer side of the valve castin being secured first by interposing suita le gaskets as indicated at 37 38 and applying a circular ring 39 to the outer side of the horizontal flange portion 36 of the chamber 35.

There are preferably a plurality of threaded openings in the circular ring 39 adapted to receive corres ondingly threaded ends of suitable fastening devices as the neonate threaded bolts 40 which may be provided with heads 41 at their other extremities constructed to take a suitable tool for mani ulating the same and passing through suita le registering openings in the cap plate 32 and locked in their adjusted positions by the lock washer 42. There will be a plurality of these screw threaded locking bolts 40 spaced around the periphery of the device as may be needed for securing gas tight joints between the described parts.

The nipple 16 like the nipple 15 will be provided with a passageway as indicated by the reference character 43, furnishing means of communication with the pipe leading to the expansion chamber. tremity of the casing 35 for the purpose of forming a gas tight closure and adjusting means for the threaded shank 26 of the ex pansion valve controlling head 24 may be perforated and providedwith the cylindrical shaped part 45 having the radial flange- 46 preferably formed integral thereon and offset. from the inner end thereof to form a seat for the attachment of the inner turned end. of the chamber 35, the union being secured by a plurality of rivets passed through the last said parts as indicated by the reference character 47. Beyond the opening in the part 45 where it is screw threaded to re ceive the threaded part 26 of the expansion valve controlling device is the enlargement or gland opening for receiving the packing 29 already referred to, the outer end of the opening being closed by a sleeve 48 surrounding the stem 27 and engaged by an adjusting cap 49, screw threaded on the corresponding threaded outer periphery ofthe part 45, so that any desired pressure may be secured upon the packing 29 of the gland to render the same gas tight throughout all adjustments of the valve controlling mechanism of the device.

The operation of the expansion valve is as follows:

The interior of the expansion chamber controlling the movement of the valve 21 in relation to the valve seat 20 for the purpose of causing the valve to seat or be unseated in allowing portions or slugs of the refrigerant to pass from the chamber 31 into the chamber 17 and consequently from the condenser into the expansion chamber is initially open to the atmosphere through the duct 30. When the pressure on the expan- The outer 'exsion chamber side of the valve falls below atmosphere the consequent effect of the atmousse mined quantity of the refrigerant has been allowed to enter tothe expansion chamber side of the valve, will build up the pressure within the chamber 17 on the exterior of the valve controlling device suflicient to overcome the internal substantially atmospheric pr hessure and force the valve 21 to its seat. en, copper or analogous material for making the sinuous wall of the expansion chamber 25 is used there will be so little inherent'resiliency in the walls of same as to cause no appreciable tendency toward contraction or expansiofifrom a given condition, and hence I prefer to insert on the interior of the expansion chamber a suitable coil spring as indicated by the reference character 50, having normal tendency to expand the chamber and consequently unseat the valve, the respective extremities of, this spring bearing against the heads 23 and 24 of the expansion chamber. Such ajspring will also tend to prevent the injurious collapsing of the'expansion chamber due to excessive and unexpected pressures on the expansion chamber side and the valve and as a guide for the spring and as a further means of preventing injurious collapsing should the valve stem break or get out of proper adjustment with head 72, I rovide a boss 52 around the upper end of t educt 30 in the head 24 of the expansion chamber, and secure over the same the tubular part 53, the free extremity of which willserve as a bufier or stop when the upper head 72 of the ex ansion chamber has reached a predetermined position, under the collapsing efl'ect of the pressure.

An expansion valve of the described character is very delicate in its operation ,and consequently somewhat diflicult of proper adjustment. Consequently, I prefer that the'valve mechanism be sent out properly adjusted and that adjustment subsequent to, the final factory adjustment of the valve shall be made from the exterior of the same and without removing the packed coveringplates which render the valve chambers gas tight. For this reason, while the outer extremity of the valve stem 22 is shown provided with means for adjustment by the use of a tool as a screw driver, I prefer after the same has been adjusted at the factory to lock the valve stem 22 and the head 23 of the expansion valve chamber by passing a pinior key as indicated at 55 through the valve stem and head. This will lock the parts together so that the only necessary and possible adjustment may be made by the use of a wrench or other tool applied to the specially formed lower extremity of the stem 27 beyond the gland nut 49. When the valve stem 22 is locked to the head 23, obviously,

to its seat so that any desired adjustment may be made from the exterior without disturbing the highly volatile refrigerant in the system;

It will be seenthat; the valve seat 20 is formed with-a very sharp .or knife lik'e edge providing'a seat engaging the conical surface of the valve.

In a mechanism of the described character, I prefer this form of seat as an aid in securing an efliciently seating valve with freedom from the tendency of the valve to unseat upon the introduction of any foreign material.

In a valve mechanism of the described in position thereon the inner peripheral edge of a cylindrical screen as indicated by the reference character 60, the outer extremity of which may be extendedso' as to approximately engageithe lower surface of the ca or closure plate 32. By the use of this screen, through which all the refrigerant to the valve must pass, foreign particles as rust and other materials that might cause difiiculty in the valve or pump vmechanism will be kept from approaching "or passing the valve seat. f

In the normal 0 ration of my improved valve there will a ways be condenser pressure maintained on the valve 21.. The pressure of the expansion chamber or coil and in the chamber 17 of the valve mechanism will be exerted on the exterior of the collapsible valve controlling mechanism. consistingof the bellows-like cylinder 25 and the heads 23 and 24 connected therewith, tending to cause the collapsing of the same, while substantially atmospheric pressure will constantly maintain on the interior of the latter. Thus the operation of the valve controlling chamber and of the valve 21 itself 'will dependv upon thedifferential of pressure between the atmosphere and the gressure in the expansion coil or chamber. ince the atmospheric pressure will be approximately constant it follows that theopening and closing of the valve will de-' pend upon the variation of the pressure in the expansion coil or chamber. Since the difference'in area between the valve 21 and. the movable surface of the collapsible valve operating chamber is very great the latter will be sensitive to influence by pressure in the expansion chamber or coil, and hence the valve itself will be very sensitiveto every slight variation in the relative pressures in the expansion coil and entrapped atmosphere While the interior of the collapsible valvecontrolling chamber comprising the heads 23, 24 and the bellows-like cylindrical wall 25 is at all times at substantially atmospheric pressure, I prefer to provide the outer extremity of the duct in the shank 26, 27 with a threaded detachable plug 80,

which after the expansion device or chamber is constructed and adjusted may be mserted in the opening at the lower end of the duct 30 to hermetically seal the interior and moisture, which is an important fea-,

ture of my invention and one of its primary objects, since it is found in diaphram controlled expansion valves where the refrigerant comes in contact with the metallic diaphragm, there is such cooling of the diaphragm exposed on one side to the atmosphere that there is a tendency for injurious condensation of moisture and freezing, with the result that as the valve continues in use there will be an ultimate accumulation and freezing that may render the diaphragm and consequently the valve inoperative or greatly impede its normal functioning. With the expansion chamber thus hermetically sealed as described, after its construction and adjustment and enclosing a suflicient quantity of air at substantially atmospheric pressure to insure proper functioning and with such.

expansion chamber enclosed and sealed as by the valve casing 35, it will be seen that condensation and freezing of moisture on movable or operating parts of the valve mechanism will be obviated.

It is obvious from the foregoing that the valve 21 is responsive only to the difierence of pressure within the collapsible chamber and that within the expansion valve. The collapsible chamber being sealed is not affected by the changes in pressure external to the expansion valve and therefore operates the valve independently of the pressure conditions external to the refrigerant circulatory system.

In order that the invention might be understood I have shown and particularly described the preferred embodiment thereof,

but it will be seen that persons skilled in the art may modify the details without departing from the purpose and spirit of my invention.

I claim:

1. In a refrigerating apparatus of the described character, the combination with a valve chamber provided with p w menses adapted to have operative connection with the refrigerant circulatory system, a wall dividing the said chamber into two compartmcnts, each of which is in communication with one of the said passages, a valve seat adjacent an opening in the said wall,

a valve cooperating with said valve seat,

a collapsible chamber secured in one of the adapted to have operative connection with the refrigerant circulatory system, a wall. dividing the said chamber into two compartments, each of which is in communication with one of the said passages, a valve seat adjacent an opening in the said wall, a valve cooperating with said valve seat, a collapsible chamber secured in one of the compartments of the said valve chamber, there, being a passageway extending from the interior of said collapsible chamber to the atmosphere, a removable closure plug in the outer end of said passageway, and a connection between saidcollapsible chamber and said valve for controlling the latter.

3. In a refrigerating apparatus of the described charactenthe combination with a plate or disk provided with a valve seat surrounding an opening therein, a valve stem in said opening being provided with a valve adapted to engage said valve seat, cover plates secured to the said plate and providing closed compartments on each side of the said plate adjacent the valve seat, a collapsible chamber connected with the wall of one of said compartments and having operative connection with the said valve stem, and means accessible on the exterior of the valve compartment for adjusting the connection between the said collapsible chamber and the compartment wall whereby to adjust the said valve.

4. In a refrigerating apparatus of the described character, the combination with a plate having a valve seat therein, a valve co operating with said seat, a valve stem connected with said valve, means for controlling said valve comprising a metallic cylinder having the walls thereof in the form of a bellows capable of elongation and contraction, means for closing and scaling the ends of said bellows-like chamber comprising heads at each end thereof, a. connection between one of the said. heads and the valve stem, an elongated shankpn the other head.

of the said chamber, a closed compartment surrounding the said bellows-like chamber, and adjustable connections in the wall of the said compartment for supporting the said shank.

5. In a refrigerating apparatus of the described character, the combination with a valve plate being provided with an opening therein, a valve-seat surrounding said opening, a valve adapted to cooperate with said seat, detachable cover plates secured to the said valve plate on opposite sides of the opening therein and forming closed compartments, and a hermetically sealed collapsible chamber secured to the wall of one of the compartments and having operative connection with the said valve.

6. In a refrigerating apparatus of the described character, the combination with a valve plate of an opening therein, a valve seat surrounding said opening, a valve cooperating with said seat, a collapsible chamber comprisin a bellows-like cylinder of flexible material having two rigid heads connected therewith, one of said heads be-- ing operatively connected with said valve and the other head being provided with a shank, there bein a duct leading through the last said bee and shank providing a passage from the interior of the collapsible chamber to the atmosphere, a closure for said passage, and means to prevent the collapsing of the said chamber beyond a predetermined degree.

7. In a refrigerating apparatus combination with a valve plate having valve chambers formed on opposite sides thereof with a valve opening therein, a valve seat surrounding said opening, nipples formed on the said plate, there being passageways through said nipples leading to said valve chambers, cove-r plates over the said valve chambers and secured to the walls of said valve plate on 0ping of said chamber, a coil spring of. cylindrical form within the said collapsible chamber and surrounding the said cylindrical stop therein, the extremities of the spring engaging the heads of the said collapsible chamber, and an operative connection between the said collapsible chamber and said valve. v

9. In a refrigerating apparatus of the described character, the combination with a valve plate having an opening therein, a valve seat surrounding said opening, a valve co-operating with said seat, a collapsible chamber comprisinga bellows-like cylinder of flexible material having one of the walls thereof operatively connected with the valve and another wall of said collapsible chamber operatively connected with a tubular shank extending to atmosphere, there being a passageway through the said shank adapted to furnish communication between the inchamber having communication with the refrigerant circulatory system, a valve controlling such communication, and a hermetically sealed collapsible chamber arranged within the valve chamber and operativelyconnected with the valve and adapted to actuate same.

11. In a-' refrigerating apparatus of the described character, the combination of a valve chamber having communication with the refrigerant circulatory s stem, a valve controlling such communication, and a collapsible hermetically sealed chamber filled posite sides thereof, a collapsible 'chamberawith air at substantially atmospheric presterior thereof filled with air, said co lapsible chamber comprising a cylinder of flexible material the walls of which have a sinus or bellows-like formation, heads secured to the opposite ends of said bellows-like chamber, one of said heads being provided with a boss, a cylindrical member engaging the boss and providing a stop against injurious collapssure and arranged within the valve chamber said collapsible chamber being operatively connected with thevalve and adapted to actuate same.

12. In a refrigerating apparatus of thedescribed character, the combination with a valve chamber provided with passages adapted to have operative connection with the refrigerant circulatory system, a valve, a valve seat for the valve within said chamber, a hermetically sealed collapsible chamher within said valve chamber, said collapsible chamber being filled with air at sub stantially atmospheric pressure, and opera tive connections between one of the walls of said collapsible chamber and said valve for operating the latter in relation to its said seat.

14. In a refrigerating apparatus of the described character, the combination with a valve chamber provided with passages adapted to have operative connection with the refrigerant circulatory system, a valve, a valve seat for the valve within said chamber, a hermetically sealed collapsible chamber within said valve chamber, being filled with a cushioning and expansible fluid, and operative connections between the walls of said collapsible chamber and said valve for operating the latter, said collapsible chamber operating independently of pressures external to the said refrigerant circulatory system.

15. In a refrigerating apparatus of the described character, the combination with a valve chamber provided with passages menses adapted to have operative connection with the refrigerant circulatory a stem, a valve, a valve seat for the valve wit in said chamber, means within said valve chamber and hermetically sealed for actuating said valve,-

said means being responsive to pressure conditions within said chamber and operating independently of pressure conditions external to the said refrigerant circulatory system.

16. In a refrigerating apparatus of the character described, the combination with a valve chamber provided with passages adapted to have operative connection with the refrigerant circulatory system, a valve, a valve seat for the valve within the chamher, a collapsible chamber within said valve chamber having an end wall having connection with the valve for operating same and an end wall adjustably secured to one of the walls of said valve chamber.

In testimony where-oil have signed my name to this specification on this 24th day of October, A. D. 1919. a

CHARLES L. MGCUEN.

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