US1698939A - Refrigerating apparatus - Google Patents

Description

Jan. 15, 1929.

R. W. DAVENPORT REFRIGEHATING APPARATUS Filed March 18, 1926 INVENTOR. Ransom W. Davenporf Jim (i W ATTORNEY.

Patented Jam 15, 1929.

UNITED STATES PATENT OFFICE.

RANSOM W. DAVENPORT, OF DETROIT, MICHIGAN, ASSIGNOR TO CHICAGO PNEUMATIC TOOL COMPANY, 01 NEW YORK, N. Y., A CORPORATION 01! NEW JERSEY.

REIRIG-ERATING APPARATUS.

Application filed March 18, 1926. Serial Ito. 95,531.

This invention relates to apparatus for transforming heat. It has special application to refrigerating machines for household use although by no means confined thereto. The apparatus of the present invention ,is particularly adapted and intended for use with lubricating working substances or refrigerants of the type disclosed and claimed in my copending application Serial N 0. 60,311 filed October 3, 1925.

One object of the invention is to provide apparatus which will successfully utilize lubricating working substances in the transforming of heat. -Another object is to provide such a paratus operating with the crank case 0? the compressor considerably below atmospheric pressure. Another ob ject is to provide a concentrating evaporator for the lubricating working substance. Still another object is to provide an improved packing arrangement for the shaft of the compressor. Other objects relating generally to improvements in prior apparatus willbe apparent from the detailed description which follows:

In order to illustrate the invention one concrete embodiment thereof is indicated somewhat diagrammatically in the accompanying drawings in which:

Fig. 1 discloses a refrigerating system in accordance with the present invention, cer tain parts of the apparatus being shown in section, other parts in elevation, and the remaining parts diagrammatically indicated.

Fig; 2 is a sectional view through the cFompressor, substantially on the line 22 of The heat transforming or refrigerating system disclosed in Fig. 1, comprises an evaporator 2 which is disposed in the chamber from which heat is extracted such as a refrigerator chamber A indicated by broken lines, a compressor 3 connected to evaporator 2, and a condenser 4 into which compressor 3 discharges to condense the vapor of the refrigerant and to return it to the evaporator through expansion device 5. The elements are suitably connected-together, as indicated to form a closed cycle system especially adapted to utilize a lubricating refrigerant of the type disclosed in my copending application above identified.

he compressor 3 is of the reciprocating piston type having a crank case 3 in which rotates a crank shaft 3*, arranged to be driven by a prime mover, such as an elec-' trical motor, (not shown) through a suitable driving connection such as a belt over a pulley 3. A connection 6 from evaporator 2 to compressor 3 opens directly into crank case 3 so that the latter-forms a part of the low pressure side of the system. The inlet valve 3 of the compressor is mounted in piston 3 and the discharge valve 3 is in the cylinder head. Suitable means are provided for sealing the projecting end of shaft 3* against loss of the working substance through leakage. To this end the crank case 3 is provided with spaced walls 3 and 3, through which the crank shaft extends and in which suitable bearings are provided.

Spaced packing glands 7 and 8 for shaft 3 i.

are provided in walls 3 and 3 and a restrict-ed chamber 9 is formed sealed off from the crank case 3 on the one hand and from the atmosphere in the other in a substantially fluid-tight manner. The discharge duct 10 leading from the cylinder head of compressor 3 to condenser 4 has a branch connection 11 to chamber 9, so that the latter is under high side pressure. Thus low side and high side pressure obtains on opposite sides of the inner packing 7 and since the high side pressure in the system disclosed is approximately that of atmosphere, leakage along crank shaft3" tends to be from chamber 9 to the crank case. i. e., within the refrigerating system, so that loss of the working substance is avoided. Moreover the high side pressure in chamber 9 assists in maintaining a fluid-tight 'seal forthe crank shaft.

Since the inlet connection from the evaporator to the compressor is directly to the .crank case of the latter there is a natural tinually to feed concentrated lubricant thereto. This is accomplished by providing a concentrating evaporator, or a concentrator in relation to the evaporator, so arranged that a body of the lubricating refrigerant is subjected to the vaporizing effects of the system for a sufiicient period to drive off the member 12 providing a chamber of substantial size wh1ch member is disposed adjacent the top or warmest part of the refri erating chamber A. The connection 6 to t e com lpressor 3 extends from member 12, being connected thereto intermediate the top and bottom of the same. By preference the connection 6 is downwardly inclined so that any in condition for operation pure re rigerant all liquid having access thereto will find its way by gravity to crank case 3*. The evaporator coil 2 opens'into the chamber of concentrator 12 abo e 'thevopening of connection 6 so that agitated liquid in the evaporator overflows into the concentrating chamber forming a body of liquid up to the opening of connection 6. The body of liquid 1n concentrator 12 remains in the warmest part of the refrigerating chamber for a considerable period subjected "to the vaporizing effect produced by the operation of pump 3, thus giving ample opportunity for the volatile ingredients thereof to pass off as vapor leaving lubricant in highly concentrated form to pass by gravity through connection 6 to the crank case. 1

The operation of the apparatus may be describedas follows: To place the a paratus (such for example as methylene chloride) is placed in evaporator 2 and a pure lubri=, cant which is miscible with or soluble in the' refrigerant (such for example as a blend of castor oil) is placed in the crank case 3 The remainder of the system may be filled with air or any other gas substantially inertv to and insoluble in both the refrigerant and the lubricant so that the system will operate in its heat transforming effects after the manner disclosed in my copending application, Serial No. 15,172, filed March 12,

1925 now Patent No. 1,619,196. When the compressor is started the passing of vapor of the refrigerant into the crank case 3 will cause dilution of the lubricant, and the lubricant carried over into the high side of the system will find its ,way eventually through expansion, device 5 into evaporator 2 and become mingled with the refrigerant. The extent of dilution of the lubricant will depend upon the temperature and pressure in the crank case, the lower the pressure and the higher the temperature the less the dilution. The liquid refri erant in evaporator 2 tends to,decrease y the amount remaining in solution. in the crank case. When the dilution or mingling of the liquid ingredients has become constant and the system is in stable operation the concentrator 12 is filled te the overflowing point with the castor oil blend and refrigerant mixture so that a limited amount of the mixture passes through pipe 6 into the crank case 3 along with the cool vaporized refrigerant. The concentrated lubricant mixture is splashed about in the crank case and some of it is carried over into the discharge pipe '10. Part of the carried over lubricant passes on to the condenser and part goes into branch 11 and into the high side chamber 9. The proportion of the lubricant going to the condenser 4 and to chamber 9 may be varied 'as desired by suitable separating means (not shown). In the condenser the concentrated lubricant mixture is diluted by 3 ancTthis concentration is greatly increased) in concentrator 12 since the liquid trapped therein cannot flow back into the evaporator 2 and theliquid body. remains at the top of the refrigerator .for a considerable period, during which periodit is subjected to the vaporizing ac-tion of compressor 3.

That portion of the concentrated lubricant 1 mixture which passes into branch 11 and thence into-the stufling box chamber 9 serves to; lubricate and seal the packing glands 7 and 8 {and gradually works back into the crank case by reason of the lower pressure obtaining in the crank case as compared with that in chamber 9.

--Byreason of the presence of the inert gas in the stream of fluid circulated through the system, which gas expands through member 5 into and through the liquid in evaporator 2 carrying or blowing some of the liquid into member 12, a free boiling effect is produced resulting in energetic va orizing of the volatile parts of the liquid, thus producing a marked heat absorbing effect and at progressively higher temperatures as the top of the evaporator'is approached. As disclosed in my aforementioned'process application, Serial No. 15,172, the high side pressure of the system does not greatly exceed atmospheric pressure so that the sealing arrangement for thecrank shaft including the high side pressure chamber 9 intermediate crank case 3 and atmosphere overcomes any tendencies toward leakage outside of the system.

From the above it will be apparent that the herein described apparatus provides for the efficient utilization of refrigerants having atmospheric boiling points, that such refrigerants may be successively used with compressors whose crank cases are operated below atmosphere, that any leakage which adequate lubrication of the compressor. Processes for transforming heat with lubricating refrigerants are disclosed and claimed in my copending applications Serial No. 85,580, filed February 2, 1926 and Serial No. 88,164, filed Februar Y 15, 1926.

While the invention has been herein described in what is now considered to be. its

preferred form, it is to be understood that it is not limited to the specific details thereof bnt covers all changes, modifications and adaptations within the scope of the appended claims.

I claim as my invention:

1. In a heat transforming system of the closed cycle type having compressing and condensing means in which a lubricant is diluted with a solvent working fluid while ejecting heat, means for absorbing heat comprising a series of vessels arranged and .connected to form a fractional still, means for feeding dilute fluid from said condensing means into the first of said series. and means for feeding concentrated liquid by gravity from the last of the series into said compressing means, while vapor is being taken from all said vessels into said compressing means.

2. In a heat transforming system of the closed c cle type a compressor, a condenser in which a lubricant is diluted wit-h a solvent working fluid while ejecting heat, means for absorbing heat comprising a series of vessels arranged and connected to form a fractional still, means for feeding dilute fluid from said condenser to the-first of said vessels, a connection from the last vessel of said evaporator series to the crank case of the compressor for vapor of the solvent working fluid and arranged to move concentrated lubricant by gravity to said crank case, and a connection from said compressor to said condenser.

3. A refrigerating system utilizing a 111- bricating refrigerant, an evaporator comprising a series of vessels connected to form a fractional still and including a conccntrating chamber, a compressor having a crank case, a connection from said chamber to said crank case arranged to pass vapor from said evaporator together with a limited amount of concentrated lubricant by gravity to said ci'ank case, a condenser into which said compressor discharges, and a connection from said condenser to said'evaporator thereby to form a closed cycle system.

4. In a heat transforming system of the closed cycle type utilizing a lubricating working substance and having a high side pressure which is substantially atmospheric, in combination, a condenser, an evaporator, a compressor having a crank case, a crank shaft in said crank case, a packing for one end of said shaft, a connection from said evaporator to said crank case, and means subjecting the exterior of said packing to the pressure of'the discharge line of said compressor. v

5. In a heat transforming system of: the closed cycle type utilizing a lubricating working substance and having a high side pressure which is substantially atmospheric in combination, a condenser, an evaporator,

a compressor having a crank case, ,a crank shaft in said crank case, spaced packings for one end of said shaft providing therebe tween a chamber, a connection from said evaporator'to said crank case, and a connection from the discharge line of said compressor to said chamber.

6. In a refrigerating system utilizing a.

lubricating refrigerant and operating with a high side pressure which is substantially atmospheric and with a low side pressure much below atmospheric, an 'evaporator comprising a series of vessels connected together to form a fractional still and including a concentrating chamber, a compressor having a crank case, a crank shaft in said case, a connection from said chamber to said crank case arranged to pass vapor from said evaporator along with a limited amount of concentrated lubricant to said crank case. a condenser into which said compressor discharges, a connection from said condenser to said evaporator thereby to form a closed cycle system, spaced packings for said crank shaftv providing therebetween a chamber, and a connection from the discharge line of said compressor to said chamber, thereby to improve the sealing of said shaft and to confine leakage along said shaftto the system itself 7.- In apparatus of the class described including an evaporator, a compressor connected thereto and having a crank case, a crank shaft rotatably mounted therein, spaced packings for said shaft providing therebetween a chamber, and means subjecting said crank case and said chamber to differential pressures so that leakage along said shaft is internal.

8, In a closed cycle system, in combination, an evaporator, a compressor connected thereto and having a crank case, a crank shaft rotatably mounted therein, spaced packings for said shaft providing therebetween a chamber, and means subjecting said chamber to approximately atmospheric pressure and said case to a lower pressure, both said pressures being supplied by the system whereby leakage along said shaft is into said case and internal of the system.

a 9. In combination in a closed cycle refrigerating system of the compressor-condenser-evaporator type having a low side pressure much below atmospheric and a high side pressure substantially atmospheric, an evaporator, a compressor connected thereto and having a crank case,

a crank shaft rotatable therein, packing means for the end of the shaft issuing .from said case comprising spaced packings'providing therebetween a chamber, and means connecting said crank case to the low side of said system and said chamber to the-high side thereof so as to seal said shaft opening and direct any leakage that Y i '1 may develop into said crank case. I

10. In combination in a closed cycle refrigerating system of the compressor-condenser-evaporator type utilizing a lubricatng refrigerant, said system having a substantially atmospheric high side pressure and a low side pressure-much below atmospheric, an evaporator," a "compressor connected thereto and having a crank case, a crank shaft rotatable therein, sealing means for an end of the shaft issuing from said case comprising spaced packings providing therebetween a chamber, a connection from the low side of said system to said crank case arranged to feed concentrated lubricant thereto, and a connection from the high side of said system to said chamber.

11. In combination in a closed cycle refrigerating system of the compressor-con-. denser-evaporator type ut1l1z1ng a lubricat ing refrigerant, said system having a sub stantially atmospheric high side pressure anda low side pressure much below atmospheric, an evaporator, a compressor connected thereto and having a crank case, a crank shaft rotatable therein, sealing means foran end of the shaft issuing from said case comprising a low side pressure much below atmospheric, an evaporator, av compressor connected thereto and having a crank case, a crank shaft rotatable therein, sealing means for an end of the shaft issuing from said case comprising spaced packings proyiding therebetween a chamber, a connection from the low-side of said system to said crank case arranged to feed concentrated lubricant thereto, and a connection from the high side of said system to'said chamber arranged to feed lubricant thereto to assist said packings in sealing said shaft.

' 13. A concentrating evaporator for heat transforming systems having a elongate passage terminating in a chamber, said chamber havin a single outlet for the contents thereof, sa1d outlet being intermediatethe top and bottom of the chamber to enable a predetermined quantity of liquid to remain in said chamber, the terminal of said passage bein above the liquid level determined by sai outlet.

14,. The combination with the evaporator of a heat transforming system, of a concentrating chamber disposed above the evaporator, said chamber havin a single outlet for the contents thereof, sai outlet being intermediate the top and bottom of said chamber to enable a body of liquid to gather in the same, and an overflow inlet from the evaporator opening into said chamber, above the level of such liquid body.

15. A concentrator for use with an evaporator in heat transforming systems comprising a hollow member providing a chamber arranged to be placed above the evaporator, a single outlet connection-for the contents of said chamber above the bottom of the same to enable a body of evaporating liquid to gather therein, and an lnlet arranged for connection to the evaporator and terminating above said outlet.

Signed by me at Detroit, Wayne County, Michigan, this 15th day of March, 1926.

RANSOM W. DAVENPORT.

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