US2192258A - Compressor system - Google Patents

Description

March 5, 1940. G, w N R 2,192,258

COMPRESSOR SYSTEM Filed Dec. 17, 1937 3 Sheets-Sheet l INVENTOR WW. 0% W ATTO RNEYS G. w. CHANDLER COMPRESSOR SYSTEM March 5, 1940;

Filed Dec. 17, 1937 3 Sheets-Sheet 2 36 38" 9 7 9.8 l a n/3,2,

INVENTOR WW mm, 2

ATTORNEYS March 1940 G. w. CHANDLER I 2,192,258

COMPRESSOR SYSTEM Filed Dec. l7, 1937 3 Sheets-Sheet 3- ATTO RNEYS Patented Mar. 5, 1940 UNITED STATES 2,192,258 COMPRESSOR SYSTEM George W. Chandler, Elkins Park, Pa., assignor to Brunner Manufacturing Company, Utica, N. Y., a corporation of New York Application December 17, 1937, Serial No. 180,310

4 Claims.

This invention relates to a compressor system.

The general purpose of my present invention is to provide in such system. a check valve of new and improved construction and operation and especially one to render the system free from noise, hammering and vibration.

A further purpose is to provide a check valve coacting in such system that has a new mode of construction and operation in that the valve seat faces downwardly and the movable valve member moves upwardly to closed position and downwardly to opened position and in that the movable valve member moves upwardly to closed position against the force of gravity and without the help of a spring or the like but by the use of a constantly available pressure (as from the tank already charged through the check valve) exerted against the bottom of the movable valve member and the downwardly facing parts of a plunger rigidly carrying the movable valve member against a temporary lower or lack of pressure on top of the said plunger. 1

A further purpose of this invention is to provide a check valve coacting in such system wherein the movable valve member moves up to close, and down to open, the valve and wherein the said movable valve member is steadily and reliably held down in open position by the action of gravity upon the valve member and its fixedly attached plunger and with the pressure of the system balanced on the upper and lower faces of the valve member and the plunger, and wherein the plunger is mounted and operated in a separate cylinder so that pressure from the system builds up on top of the plunger during normal operation and helps to hold the movable valve member down and open and wherein provision is made for temporarily deflating the pressure above said plunger cotemporaneously with the system reaching its maximum pressure, whereby the pressure forces tending to raise the movable valve member are effective to at once raise the valve member to its seat and thereafter to hold it shut while the means provided to independently deflate the cylinder of the plunger functions thereafter to unload the pressure from the discharge side of the compressor.

Another object of this invention is to provide a system using the check valve mentioned wherein the plunger is fixedly connected to the movable valve member and wherein there is a plunger cylinder separate from either compartment Bf the check valve but formed as' an extension of the compartment on the inlet side of the valve through which compartment the shank or lower portion of the plunger extends with the" plunger head or plunger proper thereabove slidingly mounted in the cylinder with an air-leak fit so that pressure from the inlet side of the valve leaks past the plunger and during normal open position of the valve and normal running of the compressor, builds up and maintains the pressure in the upper end of the cylinder and so on top of the plunger to the same extent as present in the inlet compartment of the valve so that this running pressure on top of the plunger together with the weight of the movable valve member and the plunger first pushes the movable valve member open from its closed position and then operates to hold itv steadily open until the system reaches its adjusted maximum pressure whereupon the pressure controlled switch mechanism not only opens the electric switch to the motor operating the compressor and so allows the motor to stop, but cotemporaneously a bleeder valve is opened which through suitable pipe connections to the top of the said plunger cylinder deflates the pressure in the upper end of the cylinder and so allows the then pressure coming back from the tank to the outlet side of the valve and overbalancingly operating on the downwardly facing surfaces of the movable valve member and of the plunger to raise the movable valve member and plunger and close .the valve.

It will be understood that when the bleeder valve is open and the compressor stopped the air cannot leak upwardly past the plunger fast enough to maintain any but a much lower pressure or no pressure at all against the top of the plunger whereas the indefinitely greater amount of air under high pressure .from the tank coming back into the compartments of the check valve is not appreciably reduced by the temporary leaking of the small amount of air past the plunger.

Further purposes and advantages of the invention will appear from the specification and claims herein. 7

Fig. l is a side elevation of a compressed air system wherein a check valve embodying this invention is interposed between the air-compressor and the air-receiving and storage tank.

Fig. '2 is a side elevation of the check valve shown in Fig. 1.

Fig. 3 is a central vertical sectional view longitudinally through the check valve shown in Fig. 2 and showing the movable valve member open.

Fig. 4 is a sectional view similar to Fig. 3' but showing the valve member closed.

Fig. 5 is a vertical sectional view through said valve when open butwith the section at right angles to that shown in'Fig. 3.

Fig. 6 is a view partly in section and partly in side elevation of a condensing unit wherein a check valve embodying this invention is interposed between the compressor and the condenser that in Fig. l the check valve I0 is shown in an air-compressor system as being interposed in the line between the air-compressor H and the airreceiving and storage tank l2. It will be understood that this is a typical and very useful and effective employment of the check valve embodying this invention but the showing of the check valve between an air-compressor and air-receiving tank is simply illustrative of the invention and is, not to be taken as limiting the use of the check valve of this invention to that use because the said check valve can be used in many other places and in many other situations.

For the purpose of definiteness and clearness in description and as illustrating one typical use and a typical operation of the check valve of this invention the system shown in Fig. 1 will be described in some detail. The air compressor system illustrated comprises the air-receiving or storage tank I2 of conventional construction and of proper size and conveniently having rigidly secured to its upper surface the base l3 of the air compressor II, which also will be of any of the conventional types and of proper size for the system. The air compressor is driven by any desired means, but most conveniently by a separate electrically driven motor 24, indicated diagrammatically upon the drawings by the symbol I therefor. This method of driving the compressor is the most convenient for control of the motor by the pressure control switch 23 hereinafter referred to. Ordinarily the air drawn into the compressor is received through the air strainer I4 and the air after being compressed in the compressor II is conducted therefrom through the pipeline I5. This pipe line is shown in Fig. 1 as passing to the right and then downwardly and connected by a proper fitting IE to the inlet side or port 39 of the check valve l0, shown in all the drawings of this application at the left hand side of the check valve. From the opposite or right hand side and from the outlet port 40 of the check valve the air passes to the air tank l2 by suitable pipes and connections such as short pipe l9, T fitting 20 and pipe 2| extending downwardly to the tank. From the other or upper end of the Tfitting 20 there extends upwardly a pipe 22 conducting the air to the pressure controlled switch generally designated by the 50 numeral 23 which is of conventional or any proper construction, such as by having a dia-, phragm member 25 which moves when the air pressure in the tank l2 (which is also at the same pressure as the air in pipe 22 leading to the diaphragm) reaches the maximum pressure at which the system is to work. Upon such maximum pressure being reached the said diaphragm member either i directly or through intermediate means operates the switch proper, which thereupon shuts olf or opens the electric circuit 24a used to drive the motor 24, which drives the air compressor.

' casing 30, a movable valve member 3|, a plunger bleeder line 21 is connected at its other end to the upper part, preferably the top, of the plunger cylinder 29 of the checkvalve, which check valve will now be described in detail. The check valve as a whole comprises a valve plunger 32.

32 fixedly secured to and upstanding from the middle portion of the movable valve member, and a cap 33 for the lower end of the casing.

The valve casing 30 is conveniently formed by an initial casting or forging process and has a main chamber which is-divided by a generally horizontally arranged partition 34 into upper and lower compartments 35 and 36 respectively, 'Axially arranged relative to the valve there is an The outlet port the lower compartment 36. Ordinarily the outlet port is arranged at the same level as, and

most conveniently directly opposite to, the inlet port 39. Conveniently therefor there is provided a short passage 4| in the valve casing extending upwardly and to the right from the upper part of the lower compartment to the inner end of the outlet port 40.

The lower end of the valve casing is provided with a large vertically arranged aperture, circular in form and interiorly screw-threaded and so adapted to receive the exteriorly-threaded upstanding flange 42 of casing cap 33, whichis of larger diameter than the flange 42 and thus provides an upwardly-facing shoulder 43, which is opposite the annular bottom edge 44 'of the valve casing. An annular gasket 45 of proper .size and material is interposed between the shoulder 43 and the annular bottom edge of the valve casing so that when this valve cap. is screwed on v to the casing the casing will be air tight at its lower end. Within the exteriorly-threaded flange 42 of the casing cap said cap is cut away forming a relatively deep cup-shaped space 46 for a purpose that will presently appear.

There is provided and located within the lower compartment 36 the movable valve member 3| conveniently consisting of the valve disc 41 and the valve disc retainer 48. The valve disc retainer consists of a central strong plate of metal having an upstanding peripheral flange 49 adapted to enclose the periphery of the valve disc 48 in the usual manner of such valve members. Through the valve disc and the valve retainer, there are provided centrally disposed aligned holes preferably circular in form through which extends the finger50'downwardly extending from the lower end of the shank 5| of the The lower end of this finger 50 is screw-threaded to receive below the valve disc retainer 48 a nut 52 and therebelow preferably a lock nut 53. In the open position of the movable valve member the lower face of the valve retainer 48 rests near its periphery upon the upwardly facing surface of the annular flange 42 of the cap 33,"but the engagement at this point between these two members is not an airtight engagement even'at the lowered position of the movable valve member sothat the pressure of the fluid passing through the checkvalve is at all times communicated to the bottom surface of the valve retainer and so to the movable valve member as a whole, so that a pressure upon the top of the movable'valve member; is pounterbalanced by the same pressure upon its lower side or the lower sideof'the parts fixed thereto as the nuts 52 and; 53:and the lower end of the plunger finger 50. It will be understood that even the shank 5| of the plunger is of somewhat larger diameter than the finger 50 projecting downwardly therefrom and so the shank of the plunger provides a downwardly facing shoulder bearing upon the valve discand cooperating with the said nuts to hold the movable valve member in fixed relation to the plunger and its shank. It will now be seen that the cup-shaped space 46 in the middle of the upper face of the casing cap provides space for the upper and lower nuts 52 and 53 and the lower end of the finger 50 to project into without any of theseparts touching the cap. The plunger 32 has its upper end circular in form and cylindrical in outline and slidingly fits in the cylinder 29 provided in the valve casing as extending vertically upward from the upper part of the upper compartment 35. This cylinder is somewhat longer than the enlarged diametered upper portion or plunger head 32a of the plunger 32. As already mentioned the upper part or top of the plunger cylinder 29 is provided with a bleeder or relief opening 54 into which is fitted this end of the bleeder line or tube 2'! at the other end of which is the pressure controlled or equivalent mechanically controlled bleeder valve 26, which it will be understood is closed when the compressor is running and forcing air or other fluid through the check valve. The plunger proper or the plunger head and the interior diameter of the plunger cylinder 32 are of such relative size that the said plunger is guided by the cylinder to reciprocate easily in a vertical direction. The fit between these two parts however is not an air-tight fit but is such as to allow air or other fluid to slowly pass upwardly by the plunger head from the upper compartment of the valve when the valve is either open or shut and so for such air or other fluid to accumulate in the portion of the plunger cylinder above the plunger and in the bore of the bleeder line tube 21 to the extent of the pressure then present in the upper compartment of the valve. On the other hand the fit of these parts is close enough so that the air only slowly passes from said upper compartment past the plunger head into the upper end of the plunger cylinder 29 so that when the bleeder valve is opened and the air in said bleeder valve is allowed to escape to the atmosphere the air pressure in the cylinder above the plunger will be almost instantaneously greatly reduced and notwithstanding the slow leakage of air past the plunger head will remain at-either no pressure or at a greatly less pressure than is present below the plunger head.

It will be seen that when the movable valve member is in lowered position and the valve is in so-called open position the air pressure upon the downwardly facing parts of the movable valve member and its attached plunger will be equal to the total air pressure upon the upwardly facing surfaces of said two parts, namely the movable valve member and the plunger, it being recalled that during normal operation or open position of the valve.

of the valve there will be the same pressure operating downwardly upon the upper end of the plunger head as is present in the upper chamber It is obvious therefrom that the air pressure bearing upon the movable valve member and its fixedly attached plunger will be inoperative to move the valve member and therefore gravity acting upon the movable valve memher and plunger will retain the movable valve member at lowered or open position.

However when the system in which the check valve is being used reaches its maximum pressure and the pressure-controlled switch shuts off the current to the motor and thereby allows the motor to stop and the compressor provides no further current of air under pressure coming to the check valve, the bleeder valve 26 is opened allowing the air to escape from the bleeder line 21 and thereby from the part of the plunger cylinder 29 that is above the plunger. This sharp, great reduction or absence of pressure acting upon the top of the plunger head will not be neutralized by the slow leakage of air past the plunger head and so the pressure in the valve compartments maintained at maximum pressure by backward pressure from the tank to the valve will move the movable valve member and the.

plunger upwardly and the valve member is closed and rests in air-tight position against the valve seat 38 in which position it will be held by the continued back pressure from the tank H2. The upward movement of the valve member will be caused by the bleeder valve opening cotemporaneously with the stopping of the compressor, which opening of the bleedervalve will greatly reduce or entirely relieve the pressure that up to that time has been exerted by the air pressure against the top of the plunger head. When there is no longer downward pressure upon the top of the plunger head the opposing upwardly and downwardly acting forces of air pressure upon the movable valve member and the plunger become unbalanced by the area of the plunger head; it is no longer receiving any substanial downwardly acting air pressure and therefore the plunger and movable valve member will move upward. As soon as the movable valve member comes to rest and securely rests against the valve seat 38 no more air will move backwardly through the check valve and so there will be no leak from the tank up through the valve past the plunger head. The check valve will now act in the ordinary manner of a check valve by using the accumulated storage to hold the check valve closed. The opened bleeder valve with its communicating bleeder line 27 and the slow leakage of air past the plunger head will operate as an unloading device to allow the air pressure that was present in the upper compartment 35 of the check valve and the length of pipe line l 5 leading back to the last check valve of the compressor nine hundredths (.49") of an inch and to have the plunger cylinder provided with an interior diameter of fifty hundredths of an inch (.50"). This difference of one hundredth (.01") of an inch allows a satisfactory mechanical sliding fit and also provides the slow leakage of air or fluid past the piston head that is required.

.Assuming that use of the air or other fluid has occurred to an extent that brings the tank pressure down to the minimum pressure at which the system is to have the compressor start again, there will be a reverse movement of the diaphragm member so as to put it in position to be again moved when the air pressure again reaches maximum pressure and there will be a closing of the bleeder valve or relief device, and.

there .will be a movement of the electric switch controlling the circuit to the compressor motor so as to close said circuit and start the motor and therewith the compressor. The details of these actions of the pressure-controlled switch are well known and need not be outlined here further. As already mentioned the check valve has operated as an unloader device so that the compressor can easily start up without pressure in the pipe [5 leading to the check valve. As the compressor gets under way and pressure is accumulated in the upper compartment of the check valve it will soon accumulate to the point where its pressure is greater than that on the under side of the movable valve member which as yet is in the position as shown in Fig. 4 against the valve'seat. As the accumulating air pressure from the working air compressor produces a greater pressure in the upper compartment of the check valve and also above the top of the. plunger head that is in the upper part of the plunger cylinder through air leaking past said plunger head and raising the pressure in said cylinder and of course in the bleeder line 21, the downwardly acting air pressure together with the weight of the cylinder and its attached movable valve member will cause the valve member and plunger to move from the valve seat downwardly to open position. The check valve is then in position to continue in this open position as alrady described until the maximum air,

pressure has been again reached.

It will now be seen that the check valve of this invention is well adapted to accomplish the purposes set out in detail at the beginning of this specification and particularly that it is free from noise, hammering and vibration. This latter general result is obtained because this .check valve definitely opens when it is once called into operation and then stays definitely open until the system in which it is used requires the change of position of the movable part of the check valve and that when the conditions of the system require the movable valve member to change it does change definitely to the other position. It will be noted especially as already pointed out that when the valve opens it does so as soon as the accumulating compressed air forces operating on the upper part of the movable valve member and its plunger together with the weight of the movable valve member and plunger are great enough to overcome the back pressure from the tank tending to hold the valve shut. that even during the opening operation the valve will move on a very slight margin of effective pressure and weight and so the metal bottom of the valve will not engage the co-operating part of the check valve so violently as to make an appreciable noise. the deflation of the air pressure operating upon the top of the valve plunger takes an appreciable though very short time to let the valve close and so .the valve will close quietly, especially considering the fact that the valve disc forming the contacting surface of the movable valve- .member is not metallic but isslightly resilient and not anywhere near as noisy as would be the,

case were two metal surfaces to engage.

While I have illustrated the bleeder valve, or relief device as being opened by mechanical motion directly or indirectly obtained from the pressure-controlled diaphragm which also controls the main switch to the motor, it will be obvious that a check valve embodying this in It .will thus be seen In something the same way vention and constructed and connected as above described, will operate in the same way when the bleeder valve or relief device is operated cotemporaneously or substantially cotemporaneously with the main switch to the motor as by the bleeder valve being controlled by a speedcontrolled device operatively connected to some rotating part of the compressor. With such a speed-controlled device, the bleeder valve is held shut during normal running of the compressor but is opened by the compressor stopping or slowing down to below normal or predetermined speed.

Now that the detailed construction of the ,check valve of this invention has been described and its use and operation in detail illustratedin connection with one typical use, namely that of a check valve in an air-compressor system, it will be obvious to persons skilled in the art that a check valve embodying this invention can be used for many purposes and in many situations either without any variations in construction or connection at all or with such variations in construction and connection, as will be made almost automatically by persons skilled in the art.

As an instance of such a modified use a check valve 55 constructed precisely as above described in detail -may' be used very advantageously in a condensing unit such as is used in an electrically operated refrigerating system as illustrated in Fig. 6. In such a system the check valve 55 of this invention will be interposed between the outgoing side 56 of the compressor 51 and the adjacent end or portion of the condenser 58, and will occurring on the low side of the system which is that part of the system immediately preceding the compressor or at least before the piston or pistons of the compressor and the operation of. the compressor is stopped when the desired low pressure or low temperature is reached upon such low side of the condensing unit. Accordingly the pressure or temperature-control, in this case a pressure-controlled switch 59, is placed in such a system on the low side of the unit (rather than upon the high side or storage tank as was the case in the air-compressor sys-- tem). 6| will be a part of such control device or at least simultaneously controlled as by being operated by a magnetic control 60 which in turn is controlled by the main switch 59 and accordingly the bleeder line 62 from the top of the plunger cylinder 63 of the check valve used in this system will be connected over to said bleeder valve 6| and the gas or fiuid under pressure that has accumulated in the check valve so as to allow the movable valve member to change its position. i

It will be seen that the using of the check valve embodying this invention in-such a condensing unit does not require any change whatever in the construction of the check valve but only involves a variation in its connection to the system which is common to any check valve used in such a system and a variation in the connection of the valve to a bleeder upon the low side of a condensing unit, which is the obvious place and method for relieving or unloading the compressor when it has been acting upon a refrigerating gas that cannot be wasted but can be exhausted into the low side of the system.

Assuming that the condensing unit of this refrigerating system is stopped, the check valve will have its movable valve member 65 in upper or closed position against thevalve seat 86 as shown in Fig. 6. Incident to the unloading operation that occurred when the compressor ceased operating there will be only the low pressure of the low side of the condenser unit present above the plunger 64 and the same also in the pipe 61 from the outlet side of the compressor to the check valve 55 and in the compartment of the check valve above the movable valve member 65 due to the slow leak of refrigerent gas as already described in detail as to the check valve perse. When the refrigerating system develops the high pressure (which corresponds to high temperature) upon the low side which includes the evaporator or freezing unit 68 at which the system is set to go into operation, the pressure controlled switch 59 closes the circuit 69 to the motor I0 and also closes the circuit H to the magnetic control 60. Upon said control 60 being magnetized its solenoid I2 is raised allowing the movable valve member 13 of the bleeder valve 6| to close. The motor 10 now being energized and the bleeder valve 6| closed, the first work of the compressor 51 accumulates pressure of gas 01' the refrigerant in the inlet side of the check valve and also above the plunger 64 and in the bleeder line 62 until this pressure with the help of the weight of the movable valve member and its attached plunger 64 overcomes the iorce exerted upon the bottom of the movable valve member 65 by the back pressure from the condenser tube 58 which with the receiver l4 and expansion valve 15 and'pipe It thereto represent the high side 01! the condenser unit. 'I'hereupon the movable valve member quietly moves down from the valve seat to opened position and stays open steadily and without vibration or hammering until the system develops the predetermined low pressure on the low side to actuate the pressure-controlled switch 59. Upon this switch being so moved it interrupts the circuit 69 to the motor and the-circuit H to the electrically operated bleeder valve control device 60 whereupon the compressor stops, the bleeder valve opens and the consequent reduced pressure upon the top of the check valve plunger 64 allows the movable valve member 65 to move quietly up to closed position, thus completing an entire cycle of operations of the system and of the check valve.

what I claim as new and desire to patent is: 1. In combination, a compressor, a receiver, a fluid line irom'the compressor to the receiver,

a connected check valve and plunger, said plunger having a leak fit connection in the line and being located so as to be subject to pressure on one side from the compressor through said'leak fit connection and the check valve being located in theline subject to receiver pressure and adapted to open by pressure from the compressor acting against said plunger, starting and stopping means, and means operated by said starting and stopping means for relieving pressure on said plunger whereby receiver pressure may close the valve upon a stopping of the compressor.

2. In a compressor system, a compressor, a receiver, a fluid line connecting the compressor with the receiver, a check valve in. said line, said check valve including a valve member, a chamber having means communicating with the discharge pressure from the compressor and a second chamber located above said first chamber, a valve member-position-controlling plunger in said second chamber, there being a restricted passage past said plunger into said second chamber for permitting pressure from the compressor to balance in said first and second chambers and permit the valve member to open communication from the compressor to the receiver, a bleed line communicating with said second chamber, venting means for said bleed line, means for starting and stopping the compressor, and means actuated by said last named means for operating said venting means to relieve pressure above said plunger and thereby permit receiver pressure to move said valve member to its closed position.

3. In a compressor system, a compressor, a receiver, a fluid line connecting the compressor with the receiver, a check valve in said fluid line, means for starting and stopping the compressor, said check valve comprising a chamber communicating at one side with the compressor and at,

the other side with the receiver, a plunger, a valve carried by said plunger, a valve seat in said chamber, a cylinder above said chamber, said plunger extending into said cylinder, a second chamber, said second chamber being above the plunger, said plunger having a loose fit in said cylinder to permit slow passage of fluid from said first chamber to said second chamber to balance the plunger and permit it to open said valve by gravity, a bleed line for relieving pressure above said plunger and communicating with the second chamber, and means operative upon a stopping of said compressor for venting the bleed line to thereby unbalance the pressures in said chambers and lines and render receiver pressure effective for closing said valve.

4. In combination, a compressor, a receiver, a fluid line from the compressor to the receiver, a check valve in said line adapted'to open in the direction of flow of pressure fluidfrom the compressor and subject to compressor pressure at one side and to receiver pressure on the other side, a bleeder line communicating directly with the said fluid line through a restricted opening about a portion of the valve at the side thereof subject to compressor pressure, starting and stopping means, and means operated by said last named means for relieving pressure from the fluid line through said restricted opening and bleeder line, whereby receiver pressure may close the valve upon stopping of the compressor.

GEORGE CHANDLER.

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