US2316104A - Noncondensable gas purger - Google Patents

Description

APFG, 1943- L. P. Rl-:lss

NONCONDNSABLE GAS PURGER 2 Sheets-Sheet l Filed Nov. 28, 1940 P Pr/ss INV April s, 1943. L P, REISS 2,316,104

' NONCONDENSABLE GAS PURGER Filed Nov. 28, 1940 2 sheets-sheet 2 Patented Apr. 6, 1943 UNITED -STATES `PATENT OFFICE p ,2,316,104l NoNcoNDENsABLE Gas BURGER Louis P. Reiss, Marshall, Tex. Application November 28, 1940, Serial No. 367,557

' `5 Claims. (Cl. 62-115) This invention relates to commercial refrigera- -tion and it has particular reference to a method and apparatus designed to purge a refrigerating system of objectionable non-condensable gases.

One object of the invention is to provide apparatus of an extremely simple and easily operated construction which is adaptable to that type of system in which a liquid refrigerant is employed and is extremely effective in purging the system of accumulated non-condensable gases entrained with the refrigerating fluid.

Still another object of the invention is to provide an apparatus and method for the purpose specified in which the refrigerating system may be purged of objectionable gases without interfering with the normal operation of the plant.

`A further object of the invention is to provide a gas purger for use in a refrigerating system which purging unit does notrequire a reduction of the amount of refrigerating fluid used in normal operation to accomplish its results.

Still another object of the invention is to provide a purging device that subjects a thin layer `of fluid refrigerant and non-condensable gases to a low temperature, effected by passing the fluid through a refrigerated zone containing water which is held at a temperature substantially that of ice or slightly above.

The invention has for another and important object, the provision of a purging system which may employ ice as its own refrigerating medium, produced either commercially or by direct expansion, the latter being desirable where commercial ice is difficult or expensive to obtain and in the use of automatic cooling, automatic Valve means is provided to maintain uniform temperature of the refrigerating medium or zone. n -A construction designed to carry out the invention will be hereinafter described together with other features of the invention.

` The invention will be more readily understood vfrom a reading of the following specification and by reference to the accompanying drawings, in which an example of the invention is shown, and wherein:

Figure 1 shows a-purging system constructed in laccordance with the present invention, 'employing commercial ice as the cooling medium, and

-Figure 2 is a modified form of the invention through which the refrigerant is passed. f

Since refrigerating systems employing carbon.

dioxide, ammonia and like fluids as the refrigerating medium are well known to the art, it is not considered necessary to describe such a system. It is, however, important to mention that in the operation of any such refrigerating system, the results obtained or the temperature maintained, depends entirely on the suction pressure maintained. When any type of purger is put into operation requiring a refrigerant to obtain the desired temperature, the amount of such refrigerant will necessarily have to be reduced in order to maintain the suction pressurev for the desired temperature. The travel of the refrigerant in an ordinary type of purger after it passes through 'the expansion valve until it enters the suction line to the compressor is generally very short. If no means of heat exchange between the refrigerant used and the gases to be cooled is provided other than the metal contact, much of the refrigerant will pass over to the compressor unevaporated. The unevaporated refrigerant passes to the compressor and reduces the capacity of the compressor, quite often forming frost on the cylinder walls as it will evaporate after it has entered the cylinder. By placing the refrigerat` ing coil in a fluid such as is provided, and previously mentioned, a more rapid heat exchange between the gases to be cooled and the refrigerant is set up. This is brought about by convection currents which are set up in the water surrounding the coils.

`In the foregoing it has been mentioned that purgers in which direct expansion is employed and which have a short travel for the refrigerant, some of the refrigerantl is carried over into the cylind-ers of the compressor frequently causing frost to form on the cylinder walls which results in undue mechanical wear and lcss of power. That ammonia or other refrigerant which passes oi with the suction gases and whose refrigerating effect is greatly reduced thereby is not only detrimental to the normal operation of the system, the efficiency of the machine and causing undue wear, but this surplus refrigeration is a complete loss.

The present invention, as' previously stated, utilizes la tank in which a predetermined water level is maintained, saidwater being maintained at a constant temperature through the medium of crushed ice wherein the separation of the condensed ammonia gases and other undesirable non-condensable gases is accomplished. It is a l well-known fact that in the present art that the --best time to purge non-condensable gases from --a system vis that time when there are no disturbances in the system such as is caused by a compressor operating and the gas and refrigerant moving in the regular cycle. The present invention is so constructed as to allow a purging operation to be performed at such time as the balance of the plant is shut down but which may also be used if the plant is running.

In the drawings, the numeral I designates an elongated cylindrical tank or container and having a separator II extending axiallyvtherethrough. A Constant water level L is maintained through the medium of an overflow pipe I2 which is connected onto a drain line I3 located in the extreme bottom of the tank and which drain is ordinarily closed by valve ill. A core I5 is disposed within the separator I I and is provided with a wire I5 of suitable gage spirally wound therearound. rPhe outer ldiameter of the core is slightly less than the inner diameter of the separator l! while the wire I5 is of sufficient weight to close the space between the pipe and core. n

The lower end of the separator l I iseonnected Ato a receiving tank Il by means of a pipe I8 having an angle cut-oif valve IQ mounted `there- Yin intermediate said tank and said separator i l. Condensed refrigerating iiuid enters the tank il through a pipe 2B from the condenser (not shown) and is normally passed on through theV gases accumulated above the liquor level `inthe receiver I?, due to deferential temperatures, they are immediately drawn off through the pipe 'L8 -with some ammonia gases and transferred into the separator II, it 'being understood that the valve Sil yis opened to carry out this operation.

As the gases attempt upward travel aroundl the spiralled core l5 through the cooledarea, the ammoniaV gases are suiilciently cooled .to transform these gases into liquid and allow the same in liquid form to travel spirally down the core through the line Idand backto the receiver l1 `to be further utilized in the system.

The non-condensable gases .usually consist of air andY gases which are found in the system and which may enter `in anumber of ways. 4The noncondensable gases and air are drawnoff from the separator Il through the medium of an exhaust pipe 22 preferably inclined, as shown, and Lcornmunicates with a valve 23, connected toene end of a flexible exhaust means 2li,.the latter terminating adjacent the bottom of a small glass container 25 which islled approximatelyto its top with water or other liquid suited to the purpose. The function of this container of liquid is to enable the operator to view the gases as theyv escape the exhaust member 2li and pass arator at such a rate that the ammonia gases will have suicient time to condense and thereby be conserved.

In operation: water is placed in the tank I0 up to a pre-determined level and then crushed ice A is deposited in the container to float on or near the surface of said water so that the 10W- est temperature will be near the top of the tank. As the ice melts, the liquid therefrom will be drawn off from the tank IIJ through the overflow drain I2.

When the purger has cooled suiflciently, the valve 23 may be opened to allow 40 to 50y bubbles per minute Ito escape through the exhaust hose 2li, considered to be suicient to determine the condition of the system and to purge the same of foul gases. When no bubbles appear, it is assumed that all non-condensable gases and air have escaped, whereupon the valve 23 is closed and after suicient time has elapsed to allow all liquid ammonia in the separator II to-drain back into the receiver, the valve I9 may then be closed. Y Y Y f n When it is desired to drain the tank Il) for repairs or to prevent freezing in cold weather, the valve I4 may be opened to completely drain the said tank and overflow pipe I2.

From the foregoing,` it may be seen that a purging. system of extreme simplicity of construction and operation maybe had. This system may be easily connected to any ammonia system,

`and the only important requirement ls to place the device at a higherievel than the receiver so `that the liquefied ammonia may return by gravity to the receiver. The overilow pipe l2 will keep the water at a pre-determined level at all times.

Further, due to the provision of the spirals about the core i5 disposed inthe separator II, a thin layer of ammonia and non-condensable gases are subjected to a low temperature which temperature is maintained constant through the ,medium of commercial crushed ice.

Attention is directed to the Vfact that while the core I5 within the separator I I has spirals formed thereon by means of a wire` securedvto'the outer peripheryof said core this spiral core could be formed in any number of ways.

Referring now to Figure 2, showing the slightly modi ed form of theinvention, the same charactors of reference will be employed for indicating parts therein identical to those of the earlier .described form vof the invention, and since the essary` The Yone feature of this latter form of invention whichdiilers from that just described, lies l'ill upwardly `through the liquid withintheccntainer in the form of bubbles.

By rnanipulating` ythe valve the iiow of escaping gases, as well as` the speed of their exhaust may be regulated whereby the gases enltering the lower end of the separator II will be A constrained Vto pass upwardly'through said sepin the use of direct expansion as a refrigerating means for the liquid in tank It instead of cracked ice A. The refrigerating .medium in this modification conssts of a coil of pipe 2,55*, surrounding the Vvertically disposed separator il and whose `coils are spaced midway between the exterior walls oi the separator Il and the interior wall of tank l@ in order that suflicient space will be provided for the accumulation of ice on the coils tothe greatest possible thickness before touching either the separator I I or tank walls. Thisiheavy formation of ice will store the greatest amount of refrigeration :in a given lsized tank and will also` prevent distortion of either the separator Ii or 7theside walls of tank IB in the event an operator -should failto inspect the unit or failure of the automatic valve, later identified, t0 function. s

The pipe 26, serving the coil 25 is connected to the high side of the ammonia system while the pipe 21, opposite, extends to the suction side of the system.

It has been stated that uniformity of temperature of the liquid in the tank I is a desideratum for efficient operation of the purger. In this connection, it is pointed out that the thermostatically operated valve 28 is incorporated between pipe 26 and coil 25' in order that the temperature of the liquid in the tank I0 will be 38 or below. It is to be understood that use of this automatic valve 28 is optional since in some cases it may not be found expedient to employ the same.

The operation of the refrigerating medium need not be continuous asit is apparent that operation for but ashort time will be sufficient to lower the temperature of the liquid, to remain as stored refrigeration through a range of 32 to 38 for several hours, after which, the refrigerating system will be automatically set into operation through the action of valve 28.

This modified arrangement has been found to be highly advantageous in localities where water ice is not immediately available or where automatic refrigeration is more desirable.

Manifestly the construction as shown and described is capable of some modification and such modification as may be construed to fall within the scope and meaning of the appended claims is also considered to be within the spirit and intent of the invention. Y

What is claimed is:

l. Apparatus for the removal of non-condensable gases from a refrigerating system comprising a refrigerant container having a separator therein, said separator comprising a pipe positioned vertically within said container, a core disposed Within said pipe, means cooperating with said core and the inner surface of said pipe deflning a spiral passage therethrough, means effecting communication between said spiral passage and the receiver of said system whereby the vaporized refrigerating fluid and entrained noncondensable gases from said receiver are subjected to the cold inner surface of said pipein thin layers to effect condensation of said vaporized refrigerating fluid, an exhaust line for non-condensable gases connected to the upper end of said pipe, and a transparent container having liquid therein, receiving the outlet end of said exhaust line to produce a means for observing the escape of said non-condensable gases from said pipe.

2. Apparatus for the removal of non-condensable gases from a refrigerating system including a receptacle having a cooling medium therein maintained at a constant temperature, a separator comprising a pipe disposed within said receptacle and submerged in said cooling medium,

a core in said pipe, means interposed in the space between said core and pipe and cooperating therewith to deilne a spiral passage within said pipe for subjecting thin layers of vaporized refrigerating fluid and entrained non-condensable gases introduced into said pipe from the receiver of said refrigerating system to said cooling medium, to effect condensation of said refrigerating fluid, means into which said non-condensable gases are exhausted to observe the speed of exhaust thereof, and a common means for conveying gas laden fluid from and returning condensate to said receiver.

3. Apparatus for the removal of non-condensable gases from a refrigerating system, in combination with the receiving tank of said system, a receptable containing a refrigerant at a constant temperature, a pipe axially disposed in and extending substantially the full length of said receptac1e a core coaxially disposed in said pipe but of a diameter slightly less than the inner diameter of said pipe, means intermediate the walls of said core and pipe, cooperating with each to define a spiral passage substantially the length of the latter and through which vaporized fluid is passed in thin layers to effect condensation, means effecting communication between said pipe and receiving tank and connected to the upper end of said spira] passage and means communicating with means exteriorly of said receptacle for receiving and releasing extracted gases.

4. Apparatus for extracting non-condensable gases from a refrigerating system in combination with the receiver of said system, a receptacle adapted to contain a refrigerant, a pipe disposed centrally in said receptacle in heat exchange relation with said refrigerant, having communication with said receiver at its lower end and provided with a gas release at its upper end, means lwithin said pipe to constrain fluid from said ren ceiver to flow against the wall of said pipe spirally and in a thin stream to effect separation of the gas and fluid and means exteriorly of said receptacle for observing the rate of release of said gases.

5. An extractor for non-condensable gases in a refrigerating system, comprising in combination with the receiver of said system, a hollow, tubular body having one end in fluid exchange communication with said receiver and a gas exhaust at its opposite end, means within said body to constrain vaporized fluid to flow against the inner walls of said body in a thin spiral stream, means for maintaining the exterior of said body at a constant low temperature to effect condensation of said fluid and means communieating with the exhaust of said body for observing the rate of said exhaust.

LOUIS P. REISS.

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