US1850907A - Refrigeration - Google Patents

Description

March 22, 1932. G. AND ESEN' 1,850,907

REFRIGERATION Filed Jul .29, 1929 s Sheets-:Sheet 1 March 22,1932. 3 ANDRESEN 1,850,907

' REFRIGERATION Filed July 29, 1929 3 Sheets-Sheet 2 Patented Mar. 22, 1932 UNITED v,STATES PATENT OFFICE GEORGE ANDRESEN, OF CHICAGO, ILLINOIS; ASSIGNOR '10 W. B. PABKYN, OI CHICAGO, ILLINOIS REFRIGERATION Application filed I111y 29, 1929. Serial No. 881,862.

case of a compressor having intermeshing compressing elements, in advance of, or substantially at, the point of mesh of such elements) to effect the discharge, to a reservoir, of the compressed gas and the sealing fluid.

To secure the desired high operating efficiency of the compressor it is desirable that the pressure in the compressor should be confined to the area effecting compression and proportionately to the progressive closing of the space or the spaces in which the gaseous refrigerant to be compressed is entrapped.

The compressor serves to compress the gasified refrigerant and deliver it to a condenser from which the refrigerant in liquefied condition is supplied to an evaporator for eflecting the desired refrigerating action, the refrigerant passing from the evaporator back to the compressor forflrecompression, provision being made in the apparatus for' separating the sealing liquid from the refrigerantdischarged from'theucompressor, the sealing liquid thus separated being returned to the compressor by subjection to ,the head pressure produced by the compressor. I y

In such apparatus the passage of compressed gaseous refrigerant from the separator referred to to the condenser is effected by a differential of pressure between the condenser and the separator, due to the contained heat of friction and compression in the compressed gas discharged into the separator which latter is removed from cooling influences.

It is characteristic of compressors and especially rotary compressors, that as the differential between the head pressure and the 5 pressure of the gaseous refrigerant at the point at which the sealing liquid contacts with the compressing element increases, the quantity of sealing liquid delivered to the compressor increases and the volumetric displacement of gaseous compressed refrigerant decreases.

As the compressed gaseous refrigerant in its passage from the compressor to the condenser extracts heat from the sealing liquid, and as the total amount of heat extracted therefrom varies in proportion to the sealing liquid and the gaseous refrigerant discharged from the compressor, an increase in the differential between the head pressure and the pressure of the gaseous refrigerant at the point at which it is contacted by the returned sealing liquid in the com ressor results in i the return of the sealing liquid to the compressor in a larger volume'and at a substantially higher temperature, the presence of this heat resulting in the overheating of the compressor and impairing the proper functioning thereof.

In accordance with methods as hitherto practiced in apparatus as'hitherto provided, the sealing liquid is introduced into the compressor, throughout the range of the operatingcycle at temperatures either substan- I tiallyf lower or higher than that of the gasig0 fied refrigerant at its point of discharge from the compressor, due to variations in temperatures of the cooling medium and variations in the condenser temperatures, with the disadvantages that when the temperature of the sealing liquid introduced intot'he compressor is lower than the gasified refrigerant discharged from the compressor, objectionable drag due to the relatively low viscosity of the sealing liquid, results, and the cooling effect of the sealing liquid on the gas being compressed results in further lowering the efliciencyof the compressor due to an added duty being imposed thereon in the raising of the temperature of the mixture of the gaseous refrigerant and the noncompressible sealing fluid in the compressor'to the thermal heat required to effect discharge from the compressor against the high side pressure.

When the sealing liquid is introduced into the compressor at a temperature substantially higher than the temperature of the refrigerant at the point of discharge from the compressor, the generation of objectionable gas-pressure in the compressor, due to the premature heating of the gaseous refrigerant, results, with the disadvantage of gencrating high friction in the compressor resulting in objectionable high pressure on a large portion of the faces of the compressing elements and consequent objectionable braking effect on said faces, requiring the compressor to operate against the resistance of such high internal pressure, and subjecting the bearings of the compressor to excessive stress with con sequent friction and loss in efiiciency due to the increase of pressure on the faces of the compressing elements over that of the progressive pressure produced by the progressive compressing action.

One of my ob] ects is to overcome the ob ections above set forth and to provide for the introduction of the sealing liquid into the compressor at a temperature substantially that of the compressed gaseous refrigerant at the point of discharge from the compressor, regardless of variations in temperature of the gaseous refrigerant on the high side of the apparatus. i

Another object is to accomplish the purpose above stated byapparatus which shall operate automatically to cause the temperature of the sealing liquid to rise and fall responsive to the rise and fall ofthe temperature of the gaseous refrigerant at the point of discharge from the compressor; and by apparatus which shall be of simple, compact,

and economical construction and operable at the minimum cost.

. Another object is to effectively stabilize the condensing of gaseous refrigerant and the temperature-conditioning of the sealingliquid throughoutthe entire range of volumetric displacement of the compressor; and other objects as will be manifest from the follow- Figure 3 is a sectional view of the compressor comprising an element of the apparatus shown, the section being taken at the lines 3 on Figs. 1 and 4 and viewed in the direction of the respective arrows.

Figure 4 is a section taken at the line 4 on Fig. 3 and viewed in the direction of the ar row.

Figure 5 is a section taken at the line 5 on F ig. 3 and viewed in the direction of the arrow; and

Figure 6, a broken sectional View of the side wall-forming portion of the casing of the compressor with the gears omitted, this view being taken at the line 5 on Fig. 3 and viewed in the direction of the arrow.

Referring to the particular illustrated construction the apparatus comprises a compressor 7 which may be, and preferably is, of the well known intermeshing herring-bone gear type, the inlet of the compressor com municating with a pipe 8 and its outlets, lo-

cated at opposite ends of the compressor, with a pipe 9, the compressor being shown as driven by an electric motor 10 the armature shaft of which is provided with a fan 11 l0- cated between the motor and compressor. The pipe 9 leads to a separator device 12 for directing the compressed gas and entrained sealing liquid into this device which latter is provided with a gas outlet pipe 13 which communicates with the upper end of a condenser element 14 shown aslocated in alinement with the compressor 7 and motor 10, a housing 15, opening at its opposite ends being arranged about the compressor 7 and the condenser 14. The condenser discharges at its lower end into a liquid-refrigerant receiver 16 which is in the form of a tank located within the housing 15, the tank 16 communicatin at its upper end with a pipe 17.

The refrigerating element of the apparatus is represented generally at 18 and is shown as comprising a plurality of yokeshaped pipes 19 which may extend into the space to be cooled, or into a bath of circulating brine, as is well known in the art. The pipes 19 -open upwa'rdlythrough the bottom 20 of a float chamber 21 having an inlet 22 in its side wall, valved at 23, and communicating with the pipe 17, the valve 23 cooperating with a float-lever 24 and operating to close the chamber 21 to the pipe 17 when the level of the liquid refrigerant rises in this chamber toa predetermined point, and to establish communication betweenthe pipe 17 and this chamberwhen the level of the liquid therein drops below such predetermined .point, the refrigerating liquid filling the pipeslfi. The

chamber 21 contains a gas outlet 25 shown as opening into this chamber close to the top thereof and communicating with the pipe 8. v The arrangement shown and described is thus of the closed circuit type, the gasified refrigerant, which becomes gasified in-the refrigerating element 18, in performing the refrigerating function, being sucked into the compressor 7 from which it is discharged in compressed condition through the pipe 9, the separator 12, and into the condenser 14, in which latter it is liquefie'd and collected in the liquid receiver 16, the liquefied refrigerant feeding to the float chamber 21 under the control of the valve 23.

As further description of the construction and operation of the gear compressor shown, it may be stated that it comprises a casing 26 chambered as represented at 27 to receive herringbone gears 28 journalled in the casing at shafts 29 thereof one of which shafts connects with the armature shaft of themotor 10, the gears 28 rotating in the direction of the respective arrows in Fig. 3. The passage in the casing 26 through which the gas pass ing through the pipe 8 to the compressor discharges into the spaces between the teeth of the gears, is represented at 30 and is shown as located midway between the ends of the gears. The gas introduced into the gears, in

the rotation of the latter as stated, is caused by the intermeshing of the gears to be compressed and in such condition discharged at the ends of the gears through the outlets 31 in the casing which communicate with the pipe 9. v

The casing 26 contains an inlet 32 for sealing liquid such as for example .oilcommon- 1y used for sealing compressors and of particular import-ancein a compressor of the type shown ,to provide a sealing film between the peripheries of the gears and the casing in which they rotate, this inlet being shown as located midway between the ends of the gears 26 and so positioned as to communicate with the spaces between the gears at their points of initial intermesh, the passage 32 communicating with a pipe 33 opening into the lower portion of the tank 12 and thus in communication with the body of sealing liqui'd in the latter, the arrangement shown being such that the sealing liquid 1s forced through the pipe 33 and into the compressor by reason of the head pressure exerted against the sealing liquid in the tank 12.

In accordance withthe preferred embodi ment of my invention and as I prefer to practice it, the sealing liquid in its passage from the separator 12 to the compressor is subjected to the temperature-controlling action of the liquefied refrigerant as liquefied in the condenser, it .being preferred that the pipe 33 be formed with a coil section 34 immersed in the body of liquefied refrigerant in the tank 16. I n

The temperature of the sealing liquid flowing to the compressor is thus caused to besubstantially that of the gaseous refrigerant at the point of dischar e from the compressor, the temperature of t e sealing liquid rising and falling with the temperatlire of the gaseous refrigerant and thereby the objections above noted in describing the effect of the introduction of the sealing liquid into the compressor in either. too cold or too heated a condition, are prevented, the compressor thus functioning closely in accord with the law of adiabatic heat generation.

It has been found in practice that this stabilization of the heat dissipation generated in the compressor may be effected without 0 requiring the use of a condenser of greater capacity than hitherto provided in apparatus in which the sealing liquid, separated from the compressed refrigerant, has its temperature controlled otherwise than by the action of the condenser, it being noted that as the differential between the pressure on the high able to a proportionate degree for the desired.

temperature conditioning of the increased volume of sealing liquid.

What I claim as new, and desire to secure by Letters Patent is:

1. In refrigerating apparatus the combination of a compressor employing a sealing liquid, a separator for the compressed refrigerant and thesealing liquid delivered by said compressor, a condenser for condensing the compressed refrigerant, an evaporator in communication with said condenser and with the inlet of the compressor, anda conduit through which the sealing liquid separated from the refrigerant is returned to said compressor, said conduit being so disposed that it is subjected to the temperature-controlling effect of the refrigerantcooled by said condenser. t

2. In refrigerating apparatus the combination of a compressor employing a sealing liquid, a separator for the compressed refrigerant and the. sealing liquid delivered by said compressor, a condenser for"condensing the compressed refri erant, a receptacle for the frigerant receiver; the combination of a separator for the compressed refrigerant and a sealing liquid delivered by the compressor, and a conduit through which the sealing liquid separated from the refrigerant is returned to said compressor, said conduit being so disposed in the body of liquefied refrigerant in said liquid receiver as to cause the seal ing liquid to be subjected to the temperaturecontrolling effect of-the condensed refrigerant.

GEORGE ANDRESEN.

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