US2171698A - Pressure regulating apparatus - Google Patents

Description

Sept, 5, 1939. R. A, HETZER PRFssuRra' REGULATING AFPARATus Filed Jan. 25, 1958 INVENTOR YRUSSELL A. HETZER @mM/j Patented Sept. 5, 1939 UNITEDI STATES PATENT OFFICE PRESSURE REGULATIN G APPARATUS Application January 25, 1938, Serial No. 186,848

4 Claims.

'Ihis invention relates to a vessel' or system in which a-volatile liquid or solvent is being storedY or'utilized and more particularly to an improved means for regulating pressure conditions within they vessel or system.

TheV object of4 theA invention is to provide an improved apparatus for automatically compensating for otherwise wide fluctuations of pressure within a vessel'or system, or in other words, for maintaining a fairly uniform pressure so that the-parts of the apparatus can be designed and made of material of the proper strength but with minimum weight and cost as well as for further advantages which will more fully appear hereinafter.

Iny the drawing which represents one suitable embodiment of my invention, Fig. lY is a diagrammatic view of a dry cleaning system, showing'my improved regulator in diagrammatic form applied thereto, parts of the dry cleaning system being broken away to show the internal structure; and Fig. 2 is a cross sectional view of the pressure regulator, parts being shown in elevation.

One common form of dry cleaning apparatus utilizing volatilevdetergents-c-omprises a chamber or casing within which garments or fabrics to be treated are subjected to theefiects of a quantity of a liquid detergent, following which the liquid detergent is drained oi andextracted from thefabric as much as possible and any remaining detergent is removed by the use of an air current, is condensed and returned to the liquid and theusedliquid detergent is cleaned or claried by distillation'and condensation. While any 'n volatile detergentmay be employed, one common detergenty suitable for the purpose is carbon tetrachloride.

Systems of'this kind if entirely closed or sealed against escapeof vapors to the atmosphere necessarily must-be made ofv heavy material. This is true not only of the casing or walls of the treating compartment but also of the walls of containers for liquid, stills, condensers and the like. The reason is Vthat the chambers within the sevs `eral vessels necessarily are subjected to widely varying uctuations of pressure if the entire system is sealed or closed-due to the application of heat for distillation, the variations in temperature of the outside air and alsoy variations in temperature ofthe cooling medium, such as water and the like. As the result, most systems are provided with an open vent4 to the'atmosphere to maintain atmospheric pressure or nearly so with the disadvantage of possible loss of valuable detergent by free escape to the atmosphere.

The present invention is designed to prevent loss of valuable detergent by escape tothe atmosphcreiincident to thev use of a vent by closing or sealing`- avessel or system against venting or escape to theY atmosphere except during loading or unloading and at the same time providing the vessel or system with means which automatically compensates for the wide fluctuations in pressure which otherwise would be produced in such a vessel or system. In case of abnormal pressure conditions existing in the vessel or system, my improved apparatus also acts as a vent and permits vapors to escape when the pressure becomes abnormally high or allows atmospheric air to enter the system if the pressure becomes abnormally low.

While my improved pressure regulating means may be employed with any vessel or system in which a volatile solvent or detergent is being stored or utilized, for purposes of illustration the system shoWn in the drawing comprises a treating unit I, a detergent storage tank 2, a still 3 and a condenser 4 suitably connected and associated with each other.

The treating unit I is somewhat similar to an ordinary washing machine or drying tumbler comprising an outer casing 5 and an inner rotatable foraminous drum 6 mounted within the chamberv of the casing. Connected in circuit with the casing is a condenser 'I, whose inlet side communicates by a conduit 8 with the casing 5,- an air moving device, such as a fan 9, the inlet side of which is connected to the condenser by conduit lil, and a heater II, the inlet side of which is connected to the outlet side of the air l moving device by a conduit I2 and the delivery side ofl which is connected to the casing by a conduit I3.

Liquid detergent is supplied to the treating chamber by way of a' supply pipe I/I having a valve I5' and communicating with the storage tank 2; The used liquidin the treating chamber I may be drained therefrom to a sump tank IS by way of a pipe I l' provided with a valve I8. Sump tank I6 communicates by means of a pipe I9 havinga valve 2li with the evaporator or still 3 which may be heated by steam circulated through coil 2| located in the still or evaporator 3. The vapors or gases produced by the distilling operation in still 3 rise through conduit 23to chamber 24 within condenser 4, there being condensed Yto'liquid form by the effect of cooling coil 26Y through which cold water may be circulated. The liquid thus condensed flows by way of pipe 21 to thestorage reservoir 2.

With this arrangement the material to be treated is first loaded into the rotating drum S and a quantity of liquid detergent is run into the treating compartment by opening valve l5 which is then closed. The drum 6' is rotated for the proper period of time to produce a thorough agitation of the material in the detergent with a consequent washingV or cleaning thereof. Finally the drum 6 is stopped and the liquid in chamber I is drained to the sump tank I6 by opening valve I8. When as much liquid has been extracted and drained from the work as is .reasonably possible, the fan 9 is started, air from treat- .ing chamber I is circulated through the condenser 1 by the fan 9, returning by the way of heater II and conduit I3 to the treating chamber, solvent vapors being condensed and flowing by the way of conduit 28 to the sump tank I6. This drying operation is continued until substantially all of the detergent has been recovered.

Conduit I2 is provided with a connection 29 to the atmosphere adapted to be opened and closed by a valve or damper 36. Conduit I3 is also provided with a valve or damper 3| and the two valves 30 an-d 3| are operatively connected by means of a link 32 and may thus he jointly operated. During the washing and drying operation before referred to the valves lie in the full line position as shown in Fig. 1. When the drying operation is finished, valve 3l is moved to open position and valve 38 shutsv o" communication between the air moving means 9 and the heater II. Therefore when the drying operation is concluded, the ian continues to operate for deodorizing, drawing fresh air in through the conduit I3 and delivering it through the condenser 1 from which it flows to the atmosphere through pipe 29. Valve 26 is now opened and the liquid in sump tank I6 is drained into the evaporator, is there distilled and is conveyed as a gas to condenser 4 fromv which as a liquid it drains to storage tank 2.

As illustrated in the drawing the pressure within the various vessels o the system is eq'ualized and means are provided to regulate fluctuations in pressure within the system. As shown, a vent pipe 33 leads from the sump tank I6 and is pro- '\vided with a branch 34 which is connected to. casing 5 and a branch 35 which is connected to y the storage tank 2.

When liquid is passed into the treating vessel I from tank 2, the gases displaced in the treating vessel pass through pipes 34 and 35 to tank 2,v and when liquid is passed from treating vessel I -jto sump tank I6, gases displaced in sump tank I6 pass to the treating Vessel through pipe 34.I In a like manner when liquid is drained from sump tank I6 into evaporator 3, the gases, displaced in the evaporator pass through conduits 23, 21 and 35 to sump tank I6.

My present invention provides means for regulating the pressure conditions within the sys-. tem and alsol acts as a vent when abnormal pressure conditions occur within the system. As shown in Fig.1 2, myirnproved apparatus comprises a tank 36 containing any suitable liquid,v such as water.y Arranged within the tank is a container 31 mounted for vertical movement and having a bottomv opening 3,8, the lower endv of which normally extends below thel level ot the liquid in the tank 36. thereby forming a sas chamber 39 into which the pipe 3Y fromthe system extends and a liquid sealbetween chamber 33 and the EL'CIHQSpllere.y 'Ijhe level of the liquid in the tank 36 isgsuch that, an effective liquid seal is maintained during the rise and fall of thercontainer 31 caused by the normal iiuctua- ..46 for a cable 41, one end of which is attachedY to a weight 48 and the other end of which is attached to the container 31. The weight 48 normally balances the weight of the container 31 when the pressure within air chamber 39 is normal. In the event, however, that the pressure within the chamber 39 tends to rise due to the tendency of pressure in the vessel or system to increase, container 31 moves upwardly while on the other hand if the pressure in chamber 39 tends to fall, due tothe tendency of pressure in the vessel or system to decrease, container 31 moves downwardly, thereby maintaining a substantially uniform pressure within the Vessel or system. Suitable means are provided to limit the movement of the container 31. As illustrated in the drawing, stops 49 on brackets 42 and 43 are provided to limit the upward movement of container 31 and the upper end 50 of pipe 33 limits its downward movement. The upper end 58 of pipe 33 is also provided with side apertures 5I to provide a passageway for the air when the container 31 rests on the end of pipe 33.

My improved pressure regulating means also acts as a vent when abnormal pressure conditions occur in the vessel or system. As shown in the drawing, the side walls of the container 31 are spaced from the walls of tank 36 and the amount of liquid in tank 36 is maintained at such a level that if abnormally high pressure conditions occur in the system, the pressure within the air chamber 39 forces the Water below the opening in the bottom of the `container 31 and the vapors from the vessel or system escape to the atmosphere through the space between container 31 and tank 36. On the other hand if the pressure within the tank or system becomes abnormally low, atmospheric air forces the liquid downwardly between the walls of tank 36 and container 31 and air from the atmosphere bubbles up through the water in container 31. The height of tank 36, container 31, vent tube 33 and the level of the sealing liquid in tank 36 are such that when abnormally high pressure conditions exist in the vessel or system, the liquid will not overilow the edge of tank 36 and when abnormally low pressure conditions exist in the Vessel or system, the liquid will not rise high enough to enter the oriuce oi vent tube 33.

Means are also provided to maintain the liquid in tank 36 at a substantially constant level and to compensate for any liquid which evaporates. For this purpose a liquid supply conduit 52 having a valve 53 is provided, said valve being actllated by a ,float 54 when the liquid in tank 36 falls below a predetermined level. An overflow pipe 5.6 is also provided to prevent the liquid in tank 36 fromv risingabove a predetermined level.

In the operation of my improved apparatus, when the vessel or system. is open to the atmosphere, for instance when fabric is being introduced into the drum 6 through doors or openings in the casing and drum, not shown, the weight 48 is set at such a position that the top of container 31 is approximately midway between stops 49 and the upper end of pipe 33. For convenience in ascertaining this position, the counterweight 48 slides through an opening in a guide 51 attached to the bracket 43, the guide being provided with a pointer 58 which registers with the arrow 53 impressed upon the counterweight when the counterweight is in the desired position. At this time the pressure within the vessel or system is at normal or Vatmospheric pressure and the level of liquid in tank 36.is the same as the level of liquid in container 31.

Let us assume that the drum door is now closed and that the pressure within the system and chamber 39 tends to rise due to the heat from the atmosphere or that caused by distillation. Container 31l will therefore rise and the volume of the air or vapor chamber 39 will increase, thus maintaining the pressure within the vessel or system substantially normal. In the event that the pressure within the vessel or system and air chamber'39 tends to fall below normal due to cooling or other causes, the weight of the container is sufficient to overcome the counterweight and the container therefore descends, reducing the volume of air or vapor chamber 39 and maintaining the air pressure within the system substantially normal. A breathing action thus takes place which under ordinary conditions is sufficient to regulate the iiuctuations of pressure within the system.

In case abnormally high pressure conditions develop within the tank or system, however, which cannot be accommodated by the ordinary breathing action, the container 31 is forced upwardly against stops 49 and the pressure in air chamber 39` forces the liquid below the opening in container 31 and allows the vapors to escape through the passageway between the walls of the tank and the walls of the container. On the other hand, if abnormally low pressure conditions occur within the vessel or system, tank 31 falls until the top of the tank engages the end of pipe 33. Atmospheric air then forces the liquid between the walls of the container and the tank downwardly and permits air to flow into the air chamber 39 through the bottom opening of the container from whence it passes through the side apertures l into the vessel or system and relieves the partial vacuum conditions existing therein. This action generally occurs suddenly and consequently the small amount of water which flows through conduit 52 as the level of the liquid in the space between the tank 36 and container 31 is lowered will not be suflicient to raise the level of the liquid in container 31 sufficient to cause liquid to flow through the orifice of tube 33 before the vacuum conditions within the vessel or system are relieved.

What I claim is:

1. Apparatus of the class described, comprising a vessel or system having a chamber containing a volatile solvent and subjected to inuences tending to vary the pressure in said chamber, means for maintaining substantially uniform pressure in said chamber during normal use of said vessel or system which acts as a vent when abnormal pressure conditions occur in said chamber, including a tank containing a predetermined amount of liquid, a container having a bottom opening and a lower end portion mounted for vertical movement in said liquid in spaced relation to the walls of said tank during the normal tendency of the pressure within said vessel or system to vary, thereby forming a chamber above said liquid, communicating means between said chambers including conduit means having an orifice extending above the liquid in said container, means for limiting the upward movement of said container at such a position that the bottom opening of said container is only a short distance below the surface of the liquid in said tank, whereby abnormally high pressure conditions within said vessel or system may be relieved, and means for limiting the downward movement of said container at a substantial distance above the bottom of said tank, thereby permitting air to pass between the walls of said tank and container and upwardlyinto the chamber above said liquid and through said conduit means to relieve abnormally low pressure conditions occurring in said vessel or system.

2. Apparatus according to claim l, including means for automatically maintaining the predetermined amount of liquid in said tank.

3. Apparatus of the class described, comprising a vessel or system having a chamber containing a volatile solvent and subjected to influences tending to vary the pressure in said chamber, and means for maintaining substantially uniform pressure in said chamber during normal use of said vessel or system and for preventing abnormally low pressure from developing therein, including a tank containing a predetermined amount of liquid, a container having a bottom opening and a lower end portion mounted for vertical movement in said liquid in spaced relation to the walls of said tank during the tendency of the pressure to vary from normal in said vessel or system, thereby forming a chamber above said liquid, conduit means providing communication between said chambers, one end of said conduit means extending a substantial distance above the liquid in said tank, and means for limiting the downward movement of said container at such a point that the container is a substantial distance above the bottom of said tank, the amount of liquid in said tank being insuflicient to cause the surface of the liquid in the chamber of the container to rise a sufficient distance to cause the liquid to pass through the conduit means communicating between the two chambers before the liquid seal is broken when abnormally low pressure conditions occur in said vessel or system.

4. Apparatus of the class described, including a vessel having a chamber containing a volatile solvent subjected to iniiuences tending to vary the pressure in said chamber when said vessel is closed, the walls of the vessel being provided with a door adapted to be periodically opened, means for maintaining substantially uniform pressure in said chamber when said door is closed, comprising a ,tank containing a predetermined amount of liquid, an inverted bucket-form container having its bottom open and being mounted for vertical movement in said liquid, said container being spaced from the walls of said tank and having a chamber above the liquid, communicating means between said chambers independent of said door, stops for limiting upward and downward movement of said container, the bottom of said container being located only a short distance below the liquid in said tank when said container reaches the upper stop and a substantial distance above the bottom of said tank when said container reaches the lower stop, and movable balancing means adapted to hold said container stationary at any position between said stops when said door is open, and said container being responsive by movement to variations in pressure in said vessel when said door is closed.

RUSSELL A, HETZER.

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