USRE20964E

USRE20964E - Distributor head

Info

Publication number: USRE20964E
Authority: US
Publication date: 1939-01-03

Description

Jan. 3, 1939. H.l E. MoRTQN R'20964 DISTRIBUTOR HEAD Original Fi'led July 5, 1934 Remued l .im4 3, 1939 uNlrsos'rA'rss PATENT OFFICE.

DISTRIBUTOR HEAD Harry E. Morton, Boston, Mass., asslgnor to B. F. Sturtevant Company, Inc., Boston, Mass.

Orkinl'No. 1,985,617, dated December 25, 1934, I

Serial No. 733,844, July 5, 1934. Application for reissue May 14, 1936, Serial N0. 79,781

16Claims.

cooled, it is necessary to provide not only ex- Y tended surface on the coils, but to provide a large l number of separate coils extended crossways the air stream, and also a` large number of coils in multiple or parallel relationship. Where so many coils are used, it has been foundthat the ordinary expansion valve is not suitable for expanding 20 refrigerant into cooling coils because ofthe problems of unequal distribution. In a small number of the coilsy gas may enter, in another group of the coils a mixture of gas and liquid, and some of l the coils will contain liquid. This is not satisfac- 26 tory, of course, because in order for efllcient operation, an equal amount of liquid and gas should be supplied to each of the evaporator coils. In the past, in order to overcome these difllcultiea a number of expansion valves have been provided,

A30 one for each row or pair of rows of coils.

According to the present invention, a single expansion valve is provided with a single distributor head. The distributor head is provided with a series of small orifices, each connecting with a 36 row of air cooling evaporator coils. With this ar'- rangement, onlypartial expansion of the refrigerant at the regulating expansion valve is permitted, and the passages on the low pressure side of this regulating valve have insufllcient area to 40 permit complete expansion to the evaporator,

pressure. Thus, thev intermediate pressure is maintained up 'to the distributor head, andthe final expansion takes place in the individual tubes leading to the evaporator coils.

45 An object of ...this invention is to regulate the now of a refrigerant through a single expansion valve and to apportion it equally to each of aplurality of rows of evaporator coils. l

Another object of the invention is to supply y 50 to each of a plurality of rows of evaporatorcoils,

' an ,equal quantity of a uniform mixture of gas and lllllil'L` Other objects of theinvention will be apparent from the following description taken together 6l 'with the drawing.

In order, however, to obtain.

The invention will now be described with reference to the drawing, of which:

Fig. l is a side view of an assembly of extended surface, evaporator coils used as'air cooling coils for air conditioning purposes, with each horizon- 5 tal row of coils attached to a separate tube leading to the distributor head of a single 'expansion valve;

Fig. 2 is an end, view, with a portion ,of the side u-l`removed, of the coil assembly of Fig. 1;

Fig. 3 is a side view, partially in section, of the expansion valve anddistributor head of Fig. 1,

Fig. 4 is an end view of the distributor head of Fig. 3.

The evaporator coil assembly of Fig. 1 comprises the rows of coils 5, which are provided with the extended surfaces ii, and which are arranged in a plurality of both horizontal and vertical rows. Each horizontal row of ooilsis supplied with expanded refrigerant through an individual tube 1, leading from the distributor head 8 of the yexpansion valve indicated generally by 9. Each horizontal row of coils discharges into the common header I0, from which the pipe Ii conducts the low pressure gas after the complete evaporation of the refrigerant in the coils. The pipe Il contains the ordinary thermostat element I2, connected by tube I3 to the valve mechanism in the a0 expansion valve 9, this control mechanism serving, as is well known, to control the rate of flow of the refrigerant in accordance with the temv perature of the low pressure gas leaving the coils. Details-of this control will be discussed in connectionJ with the description of Fig. 3 ofthe drawing.

As shown by Fig. 2, each of the horizontal rows of coils is interconnected at each end to form several extended surface cooling coils arranged in series relationship, and, as shown by Figs. 1 and 2 taken together, each ofthe horizontal rows of coils is connected in multiple or parallel relationship with every other horizontal row of coils. With this series-parallel arrangement of the plurality of coils provided with extended surfaces, a considerable cooling surface vis provided for extracting heat from the air to be conditioned, which is moved past the outer surface of the coils 50 by a fan or blower. As stated before, the dlfli- `culty in the past has been to provide an equal amount of refrigerant to each of a large number of coils, but this is accomplished by the present invention by the distributing arrangement which will now be described in connectionwith Figs. 3 and 4 of the drawing. i

Asin ordinary practice, thel liquid refrigerant underhigh pressure is forced into the expansion valve 9 through the high pressure inlet il. The 'expansionvalve i5 is moved under control of the Athermostat element I2 (Fig. 1) to permit the takes place, andthe-resultant change in pressureY partial expansion of the refrigerant past the valve piston `l5 into the intermediate pressure channel 16. As temperature `variations take place in the outlet pipe Il, shown by Fig. l, evaporation or condensation of suitable liquid in the tube I3,

causes movement of the diaphragm I'i of Fig'.,3 againstthe lower portion of which the member iB isin contact andk is moved by the movement of the diaphragm I1 to move the 4expansion valve pistony i5 from its seat to permit the high pressureliquid enteringthe expansion valve to pass to the high pressure passage Il, past the valve,` piston i5, and into the intermediate gas pressure passage IB. Movement of the member lI8 is communicated to the piston I5 throughthe intermediate rod 2U, and movement of the vpiston I5 is opposed by the usual spring control2i.

The'distributor head B" contains eight small openings i9, which are tapped to receive the threaded ends `of the tubes.1,which connect the distributor head with the horizontal rows of coils (Fig. 1). To the rear of each of the ends of the tubesfl, which are screwed into the distributor head 8, are the open spaces 22, which communicate not only with the inlets `tothe tubes 1, vbut `to the space beneath the diaphragm i8 through the intermediary of thechannels 23, 24, 25 and 26, i

and also to the intermediate gas pressure channel IG on the output side of the expansion `valve through the intermediaryof the channels 21, the

A chamber 28, ythe space` surrounding the spinner 29, the channel 30, and chamber 3i. y

The channels l21 serve as oriilcesthrough which ilnai expansion Aof the refrigerant takes place into the spaces 22 and the individual tubes l.

The ispinner 29 is a metal strip, twistedy to as- `sume the shape shown by Figs. 3 and 4,so asto form the spinning channels I2 through which the refrigerant leaving the ychamber 30 passes in a' spinning movement, which prevents the segregation of the liquid from the gas and consequent uneven distribution of the liquid at thetimethat it enters the individual annees 21.

-Through each of the individual rices 21, the Amixed gas and liquid is fed in substantially equal amounts, and upon passing into the chambers ,'22 andA tubes 1, a portion of the remainder of the f liquid is expanded into gaswith the result that gas and liquid passes into eachof thetubes 1.

compressed refrigerant enters through the, high l' v70 valve, and beyond that "point a mixture of gais4 and liquid is handled; Under most operating con- The passagesleading from ythe low pressure channel 'IB to the evaporator tubes are made t'o rhave insufilcient areato permit complete expansion to .the evaporator pressure, with the result that the complete expansion finally takes place in the individual tubes 1, where itis desired. yThe oriilces 21fshould be so proportioned as to `provide a total area not 'exceeding 125% of the area of channelsfit and 3U, which latter arev of the same diameter.`

With the arrangement above described,` the pressure channel i 4 as liqui l,part of it is converted into gas as it passes thepiston of the expansion ditions,the ratioby volume of liquid to gasgis low,y and to prevent the liquid from` separating by fsopes gravity or other'forces from the gas, it is found necessary, for most ei'ilcient operation, to insert 'the spinner 22, which prevents segregation of the y liquid from the gas up to the time ture is fed into the ilnal orifices 21. K

` In order that'the control pressure acting `upon the piston of the expansion valve be the pressure in theevaporator and not the intermediate pressure, this invention provides the passages, 24, 2l and 26 leading -from the evaporator tubes to that the mixa space on the under side of the diaphragm `i1.

'I'his arrangement isbelieved to be'the most del sirable one, but, obviously, equivalent arrangements are the substitution of an external connection fron'rthe evaporatorto the` chamber of the diaphragm, or a connection fromv the outlet end yoi' theevaporator tubes 'to the chamber underneath the diaphragm, it only being` necessary, as stated above, that the control pressure be the evaporator pressure and not the intermediate Preme- In the foregoing, each of a plurality of rows Ior evaporator coils has been` described as. being provided, according to this invention, with an equal quantityofgas and liquid. v,This repre-` sents, however. ideal conditions where each row of coils is under equal load. In some cases, however, the air load may be denitely less on some individual coils, due to their location with vre- While one embodiment oi" the invention has been described for the should 'be understood limited tothe details described, since manymodications may be made by those skilled in the art zvithout departing from the spirit of the invenion. i What is claimed is: c

1. Refrigeration apparatus, comprising anexpansion valve. a distributor head, a' plurality of purpose of illustration, it

each of said evaporators, means connecting said openings and said evaporators. means forming a that the invention is not evaporators, means rforming a plurality of out- `lei: openings in said head for connection. one to substantially horizontal channel connecting said head with the output side of said valve, means forming a plurality of constricted oriilces with axes substantially perpendicular to the axes of said'openings, one for eachv of said evaporators.

. means connecting said orifices `with said outlet l openings, and means in-said channel for preventing the segregation of unevaporated liquid fromV theevapo'rated liquid in its travel between said valve and said orinces,

2. Refrigeration apparatus. comprising an expansion valve, a distributor head, a plurality of groupsof evaporators. means forming a plurality `o`f outlet openings having substantially `parallel axes in saidv head for connection, one to ,each of said groups of evaporators,means connecting said openings and said evaporators. means forming a channel' connectingy said head with the output side of said valve, means formina plurality of constricted orifices, one for each ci' said evaporators, connecting with said channel and having axes substantially` perpendicular tov said axes of said openings, and-means connecting saidorifice `with said outlet openings.

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. pansion valve adapted 3. An expansion mechanism for refrigerant evaporators, comprising in combination, an exto be supplied with high pressure refrigerant, a distributor head, a plurality of substantially similar evaporators, a plurality of substantially similar tubes connecting said head with said evaporator means in said valve for expanding the' high pressure refrigerant into a fluid of gas and liquid at an intermediate pressure, means forming a plurality of substantially similar constricted orifices, one for each ofr said tubes, each having a cross sectional area substantially less than the cross sectional area of the opening in its associated tube for substantially expanding said fiuid into its associated tube, and

means for maintaining the iiuid at' a pressure not less than said intermediate pressure in its travel between said valve and said orifices. 4. An expansion mechanism for refrigeran evaporators, comprising an expansion valve. a distributor head, means'forming a plurality of outlets in said head for connection to a plurality of evaporators, means forming a plurality of orifices between said outletsand the output side of said valvefa diaphragm, a thermostat exposed to gas from said evaporators, means acting on one side of said ,diaphragm for moving same proportional to variations in said thermostat, means connecting said diaphragm and valve whereby said valve is moved proportional to the movement of said diaphragm, and means transmitting gas pressure from between said orifices and saidl outlets to the other side of said diaphragm.

`5. An expansion mechanism for refrigerant evaporators, comprising an expansion valve, a

distributor head having a plurality of outlets for connection to evaporators, means. forming a plurality of orifices between said valve and said outlets, and a spiral spinner between said valve and said orifices for mixing liquid refrigerant and gas in its travel between said valve and said outlets. 6. An. expansion mechanism for refrigerant evaporators, comprising an expansion valve, a distributor head having a plurality of outlets for connection to evaporators, means forming a plurality of orifices between said valve and said outlets, means forming a channel between said valve and said orifices, and means in said channel for ycausing the refrigerant to pass therethrough in an advancing spiral.

7. An expansion mechanism for refrigerant evaporators, lcomprising an expansion valve, a distributor head having a pluralityof outlets for connection to evaporators, means forming a plurality of orifices between said valve and said outlets, means forming a channel between said valve and said orifices, and means comprising a spiral spinner in said channel for causing the refrigerant to pass therethrough in an advancing spiral.

8. An expansion mechanism for refrigerant evaporators, comprising an expansion valve, a -distributor head having a plurality of outlets with substantially horizontal axes, means forming a plurality of orifices with substantially radial axes between said valve and said outlets, means form-` ing a plurality of chambers between said outlets and said o rices, `means forming a substantially horizontal channel arranged centrally with respect to said orifices and between same land said valve, and a spinner in said channel for intimately mixing the gas and liquid in its travel between said valve and said orifices. K

9. An expansion mechanism for refrigerant evaporators, comprising an expansion valve, a

distributor head having a plurality of outlets with substantially horizontal axes, means forminga plurality of orifices dial axes between said valve means forming a plurality of chambers between said outlets and said orifices, means forming a substantially horizontal channel arranged centrally with respect to said orifices and between same and said valve, a diaphragm, a thermostat exposed to gas from said evaporators, means connecting one side of said diaphragm and said thermostat for moving said diaphragm proportional to temperature changes in said thermostat, means connecting said diaphragm yand valve whereby said valve is moved with movements in said diaphragm, and means forming gas passages from said chambers to thel other side of said diaphragm. l

and said outlets,

10. An expansion mechanism` for refrigerant substantially horizontal channel arranged centrally with respect to said oricesrand between same and said valve, a spinner in said channel for intimately mixing the gas and liquid in its travel between said valve and said orifices, a

diaphragm, a` thermostat exposed to gas from said evaporators, said diaphragm and said thermostat for moving said diaphragm proportional to temperature lchanges inV said thermostat, means connecting said diaphragm and valve whereby said valve is moved with movements in said diaphragm, and .means forming gas passages from said chambers to the other side of said diaphragm.

11.,An expansion mechanism for refrigerant evaporators, comprising an expansion valve, a distributor head having a plurality of outlet openings for connection to evaporators, said head including a plurality of chambers, one connecting with each of said outlets, means in said head forming a plurality of orifices connecting one with each of said chambers, and means connecting said orifices with said valve.

s evaporators, comprising an expansion valve, a

distributor head having a plurality of outlet openings for connection to evaporators, said head including a plurality of chambers, one connecting with each of said outlets, means in said-head forming a plurality of orifices having radial axes arranged in a substantiallyvertical plane connecting one with each of said chambers, and means forming a central channel connecting said orifices with said valve. 13. An expansion mechanism for refrigerant evaporators comprising an expansion valve, a distributor head having a` plurality of outlet openings for connection to evaporators,-said head including a plurality of chambers, one connecting with each of said outlets, means in said head forming a plurality of orifices having radial axes arrangedv in a substantially vertical plane connecting one with each` of said chambers,l means forming a central channel connecting said ori'- flces with said valve, and means in said channel for preventing the segregation of unevaporated liquid from the gas passing therethrough. n 14. An expansion mechanism for refrigerant means connecting one side of evaporators comprising au expansion valve, a distributor head having a plurality of outlet open-y l ings'for connection to evaporators, said head including a pluralityoi chambers, one connecting with each of said outlets, means in said head forming?y a plurality of orices having radialaxes connecting one with Veach of said chambers,

'means' forming a central channel `connecting said orifices -with said valve, and means comprising a spiral spinner in said channel fonpreventing the segregation of unevaporated liquid from the gas passing therethrough. f

15, An' expansion mechanism for refrigerant evaporators,y comprisingr an` expansion valve, a distributor head having `a kplurality oi outlet openings for connection to evaporators, said head including a plurality of chambers, one connecting with each of said outlets, means in said head forming a plurality oforiilces connecting `one with each of said chambersmeans connecting Asaid orices vwithhsaid valve, a diaphragm, a thermostat exposed to' gas from said evaporators, meansconnecting one side of said diaphragm and said thermostat for moving said diaphragm proportional to temperature changes in said thermostat, means connecting said diaphragm and valve and said milices.

valve, whereby said valve is moved with movements in said diaphragm, and means forming gas passages Eirom saidgchambers to the other side of said diaphragm. p v

16. An' expansion mechanism for refrigerant evaporators, comprising in combination, an ex- 4pansin valvey adapted to be supplied with high pressure refrigerant. ay distributor head, a `plurality of vsubstantially similar evaporators, a plurality of substantially similar tubes connecting said headwith said vevaporators, means yin said valve for expanding the high pressure refrigerant into a fluid of gas and liquid at an intermediate pressure,`means forming a plurality offsubstan-