US1544195A - Method of controlling flow of fluid from the high to the low pressure lines of a fluid-circulating system - Google Patents

Description

June 30, 1925. 1,544,195

3 C. STEWART ET AL METHOD OF CONTROLLING FLOW OF FLUID FROM THE HIGH TO THE LOW PRESSURE LINES OF A FLUID CIRCULATING SYSTEM Original Filed Dec. 16, 1918 2g Ens. 7 g. 2

gmlanlozs Barf 0. Slevari. Clarence )f. Holley.

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Patented June 30, 1925.

- UNITED STATES PATENT OFFICE.

BURT C. STEWART, OF BIRMINGHAM, AND CLARENCE M. HOLLEY, OF HIGHLAND PARK, MICHIGAN, ASSIGNORS, BY MESNE ASSIGNMENTS, TO THE HOOVER COM PANY, OF NORTH CANTON, OHIO, A CORPORATION OF OHIO.

METHOD OF CONTROLLING" FLOW OF FLUID FROM THE HIGH TO THE LOW PRESSURE LINES OF A FLUID-CIRCULATING SYSTEM.

Original application filed December 16, 1918, Serial .No. 266,848. Divided and this application filed October 14, 1922.

To all whom it may concern:

Be it known that we, BURT C. STEWART and CLARENCE M. HoLLEY, citizens of the United States, residin at, respectively, Birmingham, Oakland County, and Highland Park, Wayne County, State of Michigan, have invented a certain new and useful Improvement in Methods of- Controlling F low of Fluid from the High to the Low Pressure Lines of a Fluid-Circulating System, and declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

This invention relates to method of discharging fluidl from th high to the low pressure line of a' fluid circulating system, its object being to provide a method whereby the fluid is discharged in such manner that the pressure of the low pressure side of thesystem remainspractically constant.

This application is a division of our joint application for Letters Patentof the United States for automatic expansion valve, Serial No. 266,848, filed December 16, 1918. The method is particularly adapted for use in the circulating system of artificial refrigerating apparatus or other fluid circulating systems particularly in such systems as those in which a compressor is utilized to withdraw fluid from the low pressure side and discharge the same to the high pressure side. In some well known fluid circulating systems utilizing an expansion valve, the pressure of the low pressure side of the system is utilized to close the highpressure line stopping the flow to the low pressure line until the pressure therein has been reduced to some extent. Such. methods, however, vary the pressure of'the low pressure side to a material extent as the flow to the low pressure line continues until the entire low pressure side of the system, from the valve to the pump, is filled with fluid under pressure sufliciently great to cause closing of the high pressure line which remains closedv until the low pressure or expansion side of I Serial No. 594,497.

' a the system is again reduced to the predetermined low pressure. This invention diflers particularly from such previous methods, the object being to prevent any material variation in the pressure of the expansion line and to holdv the pressure therein practically constant by first discharging only a very small volume of fluid, in comparison to the capacity of the expansion or low pressure side, into a chamber, the pressure of which acts to close the high pressure line and to open the low pressure line to the chamber permitting the small volume of fluid to discharge into the low pressure side. Although such volume discharged into the chamber is of apressure somewhat higher than that in the expansion side, yet, due tothe very small volume, there is practically no increase in the pressure of the expansion or low pressure side of the system. By such method the beneficial result is obtained of maintaining the low pressure side of the system at asubstantially constant low temperature, which temperature by previous methods is varied to a material extent especially in small household installations. Greater efficiency is attained through use of our improved method in which the temperature of the low pressure side is maintained practically constant.

These objects and novel features of our invention may be accomplished by various types of mechanism, only one of which is shown in the drawing which is a vertical section of an expansion valve for use between the high and low pressure lines of a fluid circulatlng system adapted to operate upon our improved method. 1

In the construction shown, the device consists of a lower preferably cylindrical member 1 and a cap member 2 therefor each of such complemental shape as to provide a chamber therebetween. To the cap member 2 is secured a hollow stem 3 to which is to be connected the high pressure line of a circulating system, and the member 1 at the bottom is provided with a threaded inlet 4: to which is to be attached the piping forming part of thelow pressure side of the system. The tubular member 3 is provided with a channeled extension 5 which extends downward into the chamber fbrmed between the members 1 and 2 as shown. To this tubular member 3 at the upper end. which is shaped to receive the same, is secured a corrugated cylinder preferably formed of copper. The upper end of this cylinder is secured by soldering the same to i a shoulder formed at the upper end of the part 5and the lower end of the cylinder is secured to a hub 6" of a plate 7 as shown. This plate is preferably cylindrical in form .and to the periphery thereof is secured a practically expand or contract to an equal extent. The lower end of the part 5 extends into the apertured hub of the plate 7 but is spaced from the wall thereof as indicated. This plate is provided also with an external hub 9 threaded to receive the threaded body of a coned valve 10. This valve is provided with a lock'nut 11 and the parts 6 and 8 and tube 3 have been assembled on the part 2 of the casing, the valve is set to cause expansion to a greater or less degree of the corrugated cylinders whereby the natural tendency of the cylinders to contract tends to hold the valve closed, and it is to be understood that the area of the channel in the part 5 is so small that the presure exerted on the face of the valve open to the pressure line is insuflicient to expand the cylinders 6 and 8 and open the valve to-fiow therethrough.- By the construction described, there is a small chamber 12 provided inside the cylinder 6 and between the cylinder and the tubular member 5, and this chamber is open to the chamber 14 formed between the plate 7 and cylinder 8, and the case lby means-of the apertures 13 formed in the hub member 9. This chamber 14 is thus open at all times to the chamber 12 and forms the first expansion chamber of the system. It is to be noted in passing, that the casing is formed of two parts 1 and 2 for the purpose of allowing the cylinders to be assembled and the valve tobe set while the two parts, aredisengaged, and that in securing the parts together by means of the bolt 15, the ring 90 provides a gasket and revents any leakage through the interstice between the meeting surfaces of the two parts whereby the vacuum in the chamber 14 might be broken. This construction allows the several parts to be readily assembled or disassembled. The

valve body has a valve 10 at one end and a valve 16 at the opposite end which extends downward through the threaded stem 4. A seat for the valve 16 is provided in the threaded plug 17 in the stem 4. This plug has a central channel 18 therethrough adapted to be closed by the valve 16, and the plug, 17 may be varied in position relative to the valve 16 by turning the same in the threaded stem and thus provide for a greater or less movement of both the valves 10 and 16. The threads in the stem and plug should be fine incharacter in order that a minute adjustment of the plug may be secured and, by such adjustment, the degree of vacuum to be maintained in the expansion system may be varied. After the plug is once set, however, and the system connected up, it is evident, by reason of the 'plug being on the interior of the piping,

that it is impossible to disarrange the valve from the exterior and thus the disarrangement by unauthorized persons is prevented as is desirable in systems in general public use.

' The operation of the device is as follows, it being understood that a pump ordinarily used with a system of this character is utilized to compress the fluid on the pressure side of the system and to draw the fluid from the vacuum side. Vith the pump in operation in a system of this character involving the valve described, a vacuum is produced on the vacuum side of the system and in the chambers 14 and 12 and the pressuretherein is reduced until the pressure of atmosphere on the outside of the corrugated members 6 and 8 which is the chamber 20 open to atmosphere through an aperture '19 in the case 2), expands the said cylinders and opens the valve 10. This movement of the valve 10 closes the valve 16 and thus closes the vacuum side of the system to the chamber 14. By this arrangement, fluid under pressure will be discharged from the pressure line into the chamber 14 and relieve the degree of vacuum therein to an extent to allow the natural contraction of the cylinders 6 and 8 to again close the valve 10. The closing of the valve 10 opens the chamber 14 to the vacuum side of the system, and the fluid in the chamber 14 is thus discharged into the vacuum coils and, by reason of its small volume in comparison to the capacity of the coils, is immediately expanded to its greatest extent. By this arrangement also and due to the fact that the chamber 14 is small in volume in comparison to the volume of the expansion-side of the system, the degree of vacuum therein is not. relieved by this discharge and thus, although there is practically continual discharge of fluid from the high to the low pressure side of the system, it is at no instant of time of such volume asto cause mate-.

rially evident fluctuation in the degree of vacuum maintained. Furthermore, there is not a gradual expansion of fluid'when discharged from thechamber but in fact the expansion is almost instantaneous, and therefore is highly efficient as it is instantly 1n condition to take up heat. The principal object of the invention is involved in this feature of construction by means of which a small quantity of fluid under pressure is first discharged into a chamber to relieve the vacuum therein which closes the pressure side of the system and opens the chamher to the expansion side, and this operation in practice is found to be very rapid, the valve fluctuating so rapidly as to cause a continuous sound.

The chamber 20 formed between the exterior of the cylinder 6 and interior of the cylinder Sand case 2, as before stated, is open to atmosphere through the port 19.

By this arrangement airat normal temperature may enter the'chamber 20 and maintain the temperature of the walls of the cylinders and plate 7, and consequently the valve 10 at such degree as to prevent congealing of any foreign substance, as oil or other matter, at the point of discharge into the chamber 14. Thus, freezing of the valve on its seat is prevented. It is furthermore necessary to open this outsideof the cylinder 6 and inside of the cylinder 8 to atmosphere in order that the pressure thereof may be utilized to open the valve upon suflicient reduction in pressuretin the chamber. Further, by opening the outside of the cylinder to atmosphere no material temperature change takes place in the air outside the cylinder. I

In the device illustrated the construction is such that atmospheric pressure is util-. ized in opening the high pressure line to the chamber 14. So far as this method is concerned, however, means may beemployed in the structure to require greater than atmospheric pressure to open the high pressure line or less than atmospheric pressure in the chamber 14 to close the high pressure line, the structure here shown being more particularly illustrative of the method involving the two-stage expansion described discharging a small volume of fluid from the high pressure side to a chama manner to maintain the pressure of the low pressure line substantially constant,

which consists in expanding a relatively small volume of the fluid to a partial degree, and then introducing the partially expanded charge into the low pressure line.

3. The method of discharging fluid from the high to the low pressure side of a fluid circulating system, which consists in first discharging aquantity of fluid under pressure and small in volume in comparison to the volume of the low pressure side into av small volume of the fluid .from the high pressure line to a partial degree, then opening the low pressure line, and closing the high pressure line to the chamber by means of the introduced charge. i 5. The method of regulating the pressure of a fluid by controlling its fiow from the high to the low pressure side of a fluid circulating system, which consists in repeatedly passing relatively small volumes of fluid from the high to the low pressure line by a-multi-stage expansion of each volume through influence of the pressure of the low pressure line and regulating the rapidity of I introduction to the low pressure line by in-' fluence of the pressure thereof.

6. The method of regulating the pressure of a fluid by controlling its flow from the high to the low pressure side of a fluid circulating system in which the fluid is mechanically withdrawn from the low pres' sure side and discharged into the high pressure side under pressure, which consists in the provision of a chambered body into' 'the low pressure of the said low pressure 1., The method of discharging fluid from side a volume of fluid from the high pressure and closing the high pressure line and opening the low pressure line to the chamber by influence of the pressure of the introduced volume.

. 7. The method of discharging a refriger- Q ati ng fluid from the high to the low pressure side of a fluid circulating system, comprising the steps of admitting to a chamber a quantity ofthe fluid, vaporization and initial expansion of the fluid therein, whereby the initial expansion operates means preventing admission of further fluid to the chamber and causes transfer of the initially expanded fluid to the low pressure side of the system.

8. The method ing the volatilization and expansion of a refrigerating fluid in a plurality of stages of expansion.

0fnefrigeration compris consisting of ,volati wing and initially expanding a refrigeration fluid and the subsequent admission of the volatilized and initially expanded fluid into an expansion systerm for further expansion and the production of refrigeration.

10. The method of refrigeration comprising the introduction of a quantity of refrigeration fluid intoa chamber for volatilization and initial expansion Whereby the volatilization of the fluid operates means admitting the initially expanded refrigerant to an expansion system for further expansion.

In testimony whereof, We signthis specification. K

BURT'C. STEWART. CLARENCE M. HOLLEY.

9. The method of roduci'ng refrigeration

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