US1819861A

US1819861A - Refrigeration

Info

Publication number: US1819861A
Application number: US503847A
Authority: US
Inventors: John G Bergdoll
Original assignee: YORK ICE MACHINERY CORP
Current assignee: YORK ICE MACHINERY Corp
Priority date: 1930-12-20
Filing date: 1930-12-20
Publication date: 1931-08-18
Anticipated expiration: 1948-08-18

Description

Aug 18, 19317- J. G. BERGDOLL 1,819,861

REFRIGERATION n Filed Dec. 20. 195o Patented Aug. 18, 1931 u UNITED STATES- PATENT OFFICE JOHN G. BERGDOLL, 'OF YORK, PENNSYLVANIA, ASSIGNOR T0 YORK ICE MACHINERY CORPORATION, 0F YORK, PENNSYLVANIA, A CORPORATION 0F DELAWARE REFRIGERATION Application led December 20, 1930. Serial No. 503,847.

This' invention relates to refrigeration, and

particularly to means for controlling the feedI of liquid refrigerant to flooded evaporators.

In my allowed 'application Serial No. 408,- 363, filedrNovember 19, 1929, I describe and claim an arrangement of float control valve for feeding liquid refrigerant to a flooded evaporator in which the float valve is located at a level above the liquid level in the evaporator.

`Generally stated, the float responds to the riseand fall of a column' of liquid, preferably refrigerant, which balances a liquid column in the evaporator, the'two columns reactlng against each other through a pressure transmitting link of refrigerant vapor.

In the structure of the prior application, no means was provided forvvarying the liquid level maintain-ed in the evaporator, and the yobject of the present invention is to provide such means.

The present invention contemplates the adjustment of the vertical height of the pressure transmitting link of refrigerant vapor. This may be done in various ways, for exam# ple, the vertical height of the upper end of the link may be varied, in which case the height of both liquid columns willvary to correspond.

lAccording to another embodiment of the invention the vertical height of thev lower end of the vapor column is varied, -in which case the height of both liquid columns remains the same, but the datum plane for the liquid column :in the evaporator varies as the lower end of the vapor column varies in height.

Two embodiments of the invention, one embodying each of the general @operative principles above outlined, are illustrated in the accompanying drawings, inI which,-

Fig. 1 isa vertical elevation of a portion .Y of an evaporator including a suction trap with the invention applied in that form in whichthe vertical height of the upper end of the vapor column is adjustable. In this view, portions are sectioned to show 'the internal construction, and the parts are shown -in the position for maintaining the lowest available liquid level in the trap.

Fig. is a section on line 2-2 of Fig. 1.

In this view there is shown in full lines the adjustment for the lowest available liquid level, and lindotted lines an adjustment for .a higherlevel.

a. modified form-in which the level of the lower end of the vapor column is adjustable..

suction trap. The lower or liquid headers of the evaporator are indicated atl 7 and the upper or gas headers at 8. These are horizontal and are connected by riser tubes 9, of

` any suitable form,for example, the V-shaped riser` tubes characteristic of the patent above 'identied The form, or even the presence of the riser tubes, is not, however, material to the invention. l

The minimum liquid operating level in and another higher liquid level which may le aintained is indicated by the line Connected to theupper end of the drum 6 is a suction line 11 which leads t0 the suction of the compressor, not shown. 'The liquid 'supply line 12 is connected to deliver liquid refrigerant to the drum 6 either through a float control valve (normal operation) or through an expansion valve, but before describing the connections, the construction and arrangement of the yfloat control valve will be explained.

The float valve mechanism includes a float chamber housing 13. From the top of this there leads a pressure equalizing connection 14 to the interior of the drum 6 above the highest liquid level to be maintained therein.

open stop valve 15. From the bottom' of the Itheevaporator is indicated by the line A-A i' float chamber housing 13 a pipe 16 leads to the lowest liquid level to be. maintained in tlie interior of the drum 6, at a point below i ss Flg. 3 1s a vlew similar toFlg. 1, showingthe drum. A liquid sealed trap is interposed between the pipe 16 and the drum 6, and, vin the embodiment of the invention here illustrated, this takes the form o f an inverted U, 17, having at its ends alined mpples 18 and 19, one of which swivels in the gland 21 at the lower end of the pipe 16, and the otherof which swivels in a similar gland 22 connected directly to the interior of the drum below the lowest liquid level to be maintained therein. A brace is shown at 20.

' The right hand leg of the inverted U-trap 17 is li uid filled, and the left hand leg is lled with refrigerant gas or vapor, as is clearly indicated in- Fig. 1. The verticalA height defined by this tra is indicated by the line C--C and may be a justed 'to vary the vertical height of the vapor column by tilting the member 17 from the vertical position indicated in full lines in Fig. 2 to an iiiclined position, one of which'is indicated in dotted lnes in that ligure. q

The presence of vapor in the left hand leg of the trap 17 is assured by the .fact that the vapor evolvedfrom any liquid mthis leg is trapped against escape, and, consequently, displaces the liquid downward and into the drum 6, until the left hand leg of the trap 17 is free of liquid. f 0

The liquid level maintained in the trap chamber 13 is indicated by the line D-D.

When thel liquid rises in the chamber 13 to' the level D-D, the float valve stops the feedI and prevents thelevel from rising: higher.

A. normally open stop valve 23 controls low lthrough the pipe 16.

In theposit-ion illustratedin Fig. 1, and in thefu'll line position of Fig. 2, the liquid column H balances the liquid column H2,

the pressure between the columns being transmitted through thevapor. The vapor co1- umn Serves as a substantially weightless fessure-transmitting m'edium interposed etween the two columns H', H2. n

If itis desired to raise the liquid level 1n the drum 6, the trap 17' is swung toan iiiclined position (one ofvwhich is indicated in dotted lines in Fig. 2). In the position shown in dotted lines, the liquid column H3, which is higher than the liquid column I-I, balances an equalliquid column H4, which,

' consequently, is higher than the liquid column H2. Thus.the angular adjustment' of the trap member 17 permits adjustment of the liquid level in the drum 6. I

While the fioat valve mechamsm might assume various forms and be variously connected, the following construction and arrangement is preferred:4

Within the ioat chamber 13 is a. float 24 carried by a. rod 25 which is pivoted at 26.v

The rod 25 has an offset arm 27 which is connected to rcciprocate'a balanced piston .slide valve 28. This valve is conventionally illustrated as provided with a port 'groove 29,

which, in the lower position of the ioat,con-

nects an inlet port 31 with an outlet port 32. Leading from the outlet vport 32 is a bleed port 33, which, when they valve 29 is in its open position, delivers a small flow of liquid refrigerant to the interior of the chamber 13. When the liquid in the chamber 13 falls below the level D-D, descent of the float 24 shifts the valve 28 to the left so that the port 29 connects the ports 31 and 32. At the level D-.D the valve 28 laps the port 32 and-stops the flow. i

Liquid refrigerant arriving by the high pressure liquid line 12' passes through a normally open stop valve 34 to a strainer 35 and thence by pipe 36 to the port 31. When the Valve* 28 is open,all the liquid except the small part which passes through the port 33 to the chamber 13,-lows through the pipe 37 and normally open stop valve 38 tothe pipe 39,and thence to the interior of the drum 6. A normally closed by-pass valvev 41 which may be used as an expansion valve is provided, so` that if it is desired to suspend the flow, the controlling valves 34 and 38 may be closed and the valve'4l may be o ened, in which case liquid'refrigerant will fed to the drum directly.

The port 3 3 has an important function. Since the space within the chamber 13 is connected with the vapor space in the drum 6 by the equalizing connection 14, some refrigi erant will evaporate in the chamber 13. 4The port 33 is designed to, feed refrigerant to the' lchamber 13 at a rate slightly in excess of the maximum loss of refrigerant from the chainber by evaporation." The excess, which .is slight, Hows down the pipe 16, up the right hand leg 'of the trap 17, and then passes `through the gasfilled leg of the trap 17 to the lower end of the dru'm 6.-

frigerant so fed passes oli' as vapor through .the connection 14. The slight excess whichl is provided is not sufficient to flood the gas flled leg of the member 17 'and thus -exerts no disturbing effect. v

The construction of the float valve has been illustrated in a simple and somewhat diagrammatic form, and maybe departed from in practice., For example, I contemplate the use ofthe float valve illustrated in` detail in my allowed application, above referred to,- but as the function of that valve' is in no way different from the function of `thevalve just described, it is unnecessary to vThe supply ofliquid to the chamber `13 is.- ery limited, so limited that most of the rethe lower end of the gas filled pipe. One

the feature that the vertical hei-ght of the gas such structure is illustrated in Fig. 3, and in this particular embodiment, the effective length of the gas filled pipe, only, is'varied,

5 the height of the two balanced liquid columns remaining constant. However, this varies the datum plane, from which the column in the evaporator is measured, with the result that the actual level in the evaporator drum is changed.

InFig. 3 the construction and arrangement of many parts are unchanged, and accordingly they bear the same reference numerals as identicalparts in Figs. 1 and 2. Such identical parts are those numbered 6 to 16 inclusive, 23, and 34 to 41 inclusive. In- Fig. 3 the internal constructionof the float valve mechanism, indicated generally by the numeral 13, is not shown, but it is to 20 be understood that it conforms to the showing in Fig. 1 and contains the parts 24 to 33 inclusive. l

The pipe 16 instead of leading to a swinging inverted trap 17, is formed`with a trap loop 42, which leads by an offset 43 intothe relatively large vertical pipe 44 which communicates at its lower end with the drum 6, at.a level lower than the lowest level to be maintained in the drum. The upper end of the pipe 44, above the offset 43, is provided with a packing gland 45, through which is slidably adjustable. in a vertical direction, a dip pipe 46. The upper end of the dip pipe 46 is connected by a flexible tube 47 with the interior of `the drum 6 above the highest liquid level to be maintained therein. A convenient way of making the connection is to connect the flexible pipe 47 directly with the pressure equalizing pipe 14, as shown in Fi 3.

rgn annular space is afforded between the outside of the di-p pipe 46 and the inner side of the vertical pipe 44. Consequently, refrigerant vapor evolved in the pipe 44 is trapped and displaces liquid refrigerant in the pipe. 44 down to the level of the lower end of the dip pipe 46. It follows, therefore, that the effective liquid column in the trap 13, which is represented atl-I5, is balanced by the eective liquid column H6 in the drum 6.

The datum line E-E is determinedby the lower end of the dippipe 46, foras soon as the gas displaces the liquid downward in the pipe 44 to this datum line, the ldisplacement will be arrested b the escape ofthe gas upwardly through t e dip pipe 46. In thls arrangement the column ,H5 1s constant, and bein equal to the column H6 they latter must also e a constant, but sincethe column H is measured from the datum plane E-E and since the datum plane may be adjusted vertically by adjusting the dip pipe 46 vertically, itis possible to establish different levels in the drum 6 by moving the dip pipe 46 up i and down.

Both these arrangements have in common or vapor leg which serves asa pressure transmitting link between the two liquid columns, is adjustable.

Various other arrangements within the scope of the. invention are possible,`and are contemplated. The gist of the invention is the use of a float control valve located at al fixed level, and preferably at a level above the liquid level to be maintained in the evaporator, to maintain various desired levels in thev evaporator, the. result being secured by cont-rol of the gas filled link which serves as a pressure transmitting medium betweenathe two liquid columns, i. e., that controlled by the float, and that existing in the evaporator.

In certain of the claims the portion of pipe 16 above the. seal afforded by the inverted U-trap 17 (Figs. 1 and 2), or above the seal 'aorded by the loop 42 (Fig. 3), together with the liquid-filled portion of chamber 13,

are referred to as a liquid-containing manometer fo-r in effect such liquid column functions as a manometer. I

What is claimed is,-

1. The combination with an evaporator, of

means for maintaining a desired liquid levely therein, comprising a liquid containing manorneter;v a valve controlling the supply of liquid refrigerant to the evaporator; operating means for said valve responsive to the height of the liquid in said manometer; a pressure transmitting connection between said manometer and a point within the evaporator below the liquid level therein; means for developing in said connection a vapor pressure at least equal to the head of the liquid refrigerant at .said point; and means for varying the vertical height of the vapor filled portion of said pressure transmitting connection.

2. 'The combination with an evaporator, of means for maintaining a desired liquid level therein, comprising a liquid containing manometer; a valve controlling the'supply of liquid refrigerant to the evaporator; operating means foi` said valve responsive to the height of the liquid in saidmanometer; a

pressure equalizing connection between the upper end of the manometer andthe vapor space above the liquid in the evaporator;l a

'pressure transmitting connection between saidvmanometer and a'point within the evap orator below the liquid level therein; means for developing in said connection a vapor pressure at least equal to the head ofthe liquid refrigerant at said point; and means for varying the vertical height of the vaporfilled portion of said pressure transmitting connection. j

3. The combinationwith an evaporator, `of meansau for maintaining a desired liquid level therein, comprising wa manomer con- `taining a column of liquid refrigerant; a

valve controlling the supply of liquid refrigerant to the evaporator; operating means for said valve responsive to the height of the liquid column in said manometer; a pressure transmitting connection between said manometer and a point within the evaporated below the liquid levelv therein; means for developing in said connection 'a refrigerant vapor pressure at least equal to the head of the liquid refrigerant at said point; and means for varying the vertical height of the vapor filled portion of said pressure transmitting connection.

4. The combination with an evaporator, of means for maintaining a desired liquid level therein, comprising a manometer containing a column of liquid refrigerant, a valve controlling the supply of liquid refrigerant to the evaporator; operating means for said valve responsive to the height of the liquid column in said manometer; a pressure equalizing connection between the upper end of the manometer and the vapor space above the liquid in the evaporator; a pressure transmitting connection between said manometer and a point within the evaporator below the liquid level therein; means for developing in said connection a refrigerant vapor pressure at least equal to the head of the liquid refrigerant at said point; and means for varying the vertical height of the vapor filled portion of said pressure transmitting connection.

5. The combination with an evaporator, of means for maintaining a desired constant .liquid level therein, comprising a manometer containing a column of liquid refrigerant; a valve controlling the supply of liquid refrigerant to the evaporator; operating means for said valve responsive to the height of the liquid column in said manometer; a pressure equalizing connection between the upper end of the manometer and the vapor space above the liquid in the evaporator; a pressure transmitting connection between said manometer and a point within the evaporator below thev liquid level therein; means fon developing insaid connection a refrigerant vapor pressure at least equal to the head of the liquid refrigerant at said point; means for varying the vertical height vof the vapor filled portion of said pressure transmitting connection and means for supplying liquid refrigerant to said manometer column at a restricted rate.

6. The combination with an evaporator, of means for maintaining a desired constant liquid level therein, comprising a valve controlling the supply of liquid refrigerant to the evaporator; a fioat chamber and a liquid sealed trap arranged to define a manometer column; a pressure equalizing connection from the float chamber to the vapor space of the evaporator; a pressure transmitting vapor filled connection between the trap the evaporator; a float chamber and a liquid.

sealed trap arranged to define a manometer column; means for adjusting the vertical height of said trap, whereby the height of the manometer column is varied; a pressure equalizing connection from the float chamber to the vapor spaceof the evaporator; a pressure transmitting connection between the trap and a point within the evaporator below the liquid level therein; and a float in said float chamber connected to close said valve upon 'a riseof liquid level in said chamber. l

8. The combination with an evaporator, of means for maintaining a substantially constant liquid level therein comprising a valve controlling the supply of liquid refrigerant to the evaporator; a float chamber andra liquid sealed trap arranged to define a manometer column: a pressure equalizing connection from the float chamber to the vapor space of the evaporator; a pressure transmitting vapor filled connection between 'the trap and a point within the evaporator bclow the liquid level therein; means for variably, defining the lower end of said vapor filled connection; and a iioat in said fioat chamber connected to close said valve upon a rise of liquid level in said chamber.

9. The 'combination with an evaporator. of means for maintaining a desired liquid level therein comprising a valve controlling the supply ofliquid refrigerant to the evaporator; a fioat chamber and a liquid sealed trap arranged to define a manometer column; means for adjusting the vertical height of said tra-p; a pressure-equalizing connection from the float chamberpto the vaporspace of the evaporator; a pressure transmitting connection between the trap and a point within theievaporator below the liquid level therein-fa` fioat in said float chamber connected to close said valve upon a rise of liquid level in said chamber; and means for feeding liquid refrigerant .at a restricted rate to said chamber.

1,0. The combina-tion with'an evaporator, of means for maintaining a desired liquid level therein comprising a' valve controlling the supply of liquid refrigerant to the evaporator; a float chamber and a liquid sealed trap arranged to define a manometer column; a pressure e'qualizing connection from the float chamber to the vapor space of the-evaporator; a vapor filled pressure transmitting connectionbetween the trapand a point within the evaporator below the liquid level therein; means for varying the vertical height of said vapor filled connection; a float in said float chamber connected to close'said valve upon a rise of liquid level in said chamber; and means for feeding liquid refrigerant at a restricted rate to said chamber.

11. The combination with an evaporator, of means for maintaining a desired liquid level therein comprising a valve controlling the supply of liquid refrigerant to the evaporator; a float chamber and a liquid sealed trap arranged to define a manometer column; a pressure equalizing connection from the float chamber to the vapor space of the evaporator; a vapor filled pressure transmitting connection between the trap and a point within the evaporator below the liquid level therein; means for adjusting vertically', the lower end of said vapor filled connection; a float in said float chamberl connected to close saidvalve upon a rise of liquid level in said chamber; and means for feeding liquid refrigerant at a restricted rate to said chamber.

12.- The combination with an evaporator,`

. mitting-connection and the lower end of the manometer column; means for adjusting the trap to vary the height of the lowerend of the manometer column; and means responsive to the height of the upper end of the manometer column for opening and closing said valve as said upper end falls and rises.

13. The combination with an evaporator, of means for maintaining a desired liquid level therein, comprising a valve controlling the supply of liquid refrigerant tothe evaporator; a manometer column; a pressure equalizing connection from the top of the manometer column to the vapor space of the evaporator; a partially vapor-filled pressure transmitting connection between the lower end of the manometer column and a point in the evaporator below the desired liquid level therein; a trap interposed between the pressure transmitting connection and thelower end of the manometer column; an adjustable vent leading from the lower portion of the pressure transmitting connection to the vapor space in the evaporator and serving when adjusted to determine at will the lower end of the vapor filled portion thereof; and means responsive to the height of the upper end of the manometer column for opening and closng said valve as said upper end rises and alls.

14. The combination with an evaporator, of means for maintaining a desired liquid level therein, comprising a 'fixed manometer containing a column of liquid refrigerant; a valve controlling the supply of liquid refrigerant to the evaporator; operating means for said valve responsive to the height of the liquid column in said manometer; a pressure transmitting connection between said manometer and a point within the evaporator below the liquid level therein; means for developing in said connection a refrigerant vapor pressure at least equal to the head of the. liquid refrigerant at said point; and means associated with said pressure transmitting connection for varying the relation between the liquid column in the manometer and the height .of liquid in the evaporator.

15. The combination with an evaporator, of means for maintaining a desired liquid level therein, comprising a fixed manometer containing a column of liquid refrigerant; `a valve controlling the supply of liquid refrigerant to the evaporator; operating means for said valve responsive to the helght of the liquid column in said manometer; a pressure equalizing connection between the upper end of the manometer and the vapor space above the liquid in the evaporator; a pressure transmitting connection between said manometerv and a point within theevaporator below the liquid level therein; means for developingin said connection a refrigerant vapor pressure at least equal to the head of theliquid refrigerant at said point; and means associated with said pressure transmitting connection for varying the relation between the liquid column in thevmanometer and the height of li uid in the evaporator n testimony whereof I have signed my name to this specification.

JOHN G. BERGDOLL.