US2759336A - Pressure fluid release device - Google Patents

Description

Aug. 21, 1956 F. c. SEEFELDT PRESSURE FLUID RELEASE DEVICE Filed July 1, 1952 2 Sheets-Sheet l III/III ATTORNEYS.

Aug. 21, 1956 Filed July 1, 1952 fgqg 2 Sheets-Sheet 2 INVENTOR.

ATTORNEYSL United States Patent PRESSURE FLUID RELEASE DEVICE Fred C. Seefeldt, Tenafly, N. J., assignor to The Liquid Carbonic Corporation, Chicago, Ill., a corporation of Delaware Application July 1, 1952, Serial No. 296,609

3 Claims. (CI. 62-92) This invention relates to a pressure fluid release device. The invention is particularly useful in the release of CO2 and the like and in keeping the discharge nozzle or valve orifice substantially free of plugging by C02 snow or water crystals, etc. The invention is further useful in refrigerting systems in which the refrigerating liquid is chilled by contact with CO2, a fluid pressure release being employed for bringing the CO2 into contact with the refn'gerant without blocking or plugging the discharge nozzle or release orifice, etc. The invention is clearly applicable to other uses.

An object of the invention is to provide a discharge nozzle or expansion valve structure in which means are provided for keeping the nozzle or valve seat from being blocked or plugged when CO2 is being released therethrough. A further object is to provide a pressure fluid release device which is highly effective in the discharge of carbon dioxide and the release of pressure thereon while keeping the discharge port open continuously during the discharge of the carbon dioxide. Yet another object is to provide a refrigerating system in which the refrigerant employed for chilling areas is itself chilled by contact with carbon dioxide which is released from a liquid state to a gaseous state through the employment of a pressure release device equipped with means for keeping the discharge port or orifice clear. A still further object is to provide in such a structure a nozzle equipped with a rotary vane for clearing the nozzle of snow or ice while at the same time providing a valve control conduit for supplying CO2 to the nozzle discharge port. A still further object is to provide in an expansion valve structure for the release of CO2 maintained under high pressure, a valve device which is connected to power means for moving the valve to maintain the valve seat or orifice constantly open. Other specific objects and advantages will appear as the specification proceeds.

The invention is shown in illustrative embodiments by the accompanying drawings, in which Figure 1 is a vertical sectional view of a refrigerant chilling receptacle, a container for CO2, and connecting means therebetween, including a pressure fluid release device embodying my invention; Fig. 2, an enlarged broken sectional view showing the fluid pressure release device; Fig. 3, a transverse detail sectional view, the section being taken as indicated at line 33 of Fig. 2; and Fig. 4, a broken vertical sectional view of a modified form of the device.

In the illustration given in Figs. 1 to 3, inclusive, designates an insulating refrigerant container adapted to hold therein a body 11 of secondary liquid refrigerant such as methyl alcohol, acetone, etc. The top of the container is closed with an insulated closure 12 having therein a vent pipe 13 for the escape of CO2 gas, etc. It is common practice to circulate by a pump, the secondary refrigerant 11 through finned heat exchangers. The exchangers are part of a closed insulated duct system in which a blower recirculates air which is chilled as it passes through the exchanger and in turn refrigerates the test chamber. For example, such apparatus may be used for maintaining test chambers for various types of devices at very low temperatures, such as, for example, 70 F. Since a temperature differential must exist between the test chamber and the refrigerating fluid, the fluid temperature should be lower than F.

Heretofore it has been common to introduce blocks of solid carbon dioxide into the liquid body 11 as a means for chilling the fluid, but this practice is expensive and it has been desired to use liquid CO2 as a means for cooling the refrigerant 11. When, however, liquid CO is employed, it is found that as the pressure upon the discharged CO2 is released, there is formed in the discharge nozzle or orifice crystalline material which brings about a blocking or plugging of the discharge device. This plugging may be due to the forming of carbon dioxide snow in the nozzle or the forming of water ice crystals, or possibly to a combination of both.

In the structure shown in Figs. 1 to 3, inclusive, I provide an insulated container 14 containing liquid CO2 15, and from the container 14 extends a conduit 16 which is provided with a stop valve 17. The conduit 16 has a forward portion 18 extending downwardly at an angle and communicating with the bore 19 of the nozzle 20. The nozzle 20 is threaded at its forward end to receive an attachment member 21 having a threaded portion 22 threadably engaging the inner threaded walls of the opening 23 of container 10.

Mounted within the bore 19 and the reduced passage 24 in extension 21 is a vane 25 of thin, blade-like cross section, as shown more clearly in Fig. 3, the blade conforming at its rear to the increased diameter of the bore 19 and at its forward end to the reduced passage 24 of the extension 22.

Any suitable means for rotating the vane 25 may be employed. In the illustration given, a shaft 26 is secured at its forward end to the vane 25 and extends rearwardly through a packing and stufiing box 27 to a drive wheel 28. A drive arm 29 is eccentrically connected to the wheel 28 at one end and at its other end is eccentrically connected to a small drive Wheel 30 mounted on the shaft of motor 31. With this structure, the wheel 28 is rotated through an arc of approximately degrees as the smaller drive wheel 30 is rotated. If desired, the vane may be rotated continuously by a geared motor.

In the operation of the apparatus, the valve 17 is operated to cause the desired flow of CO2 downwardly at an angle into the nozzle bore 19. As the CO2 passes forwardly through the outlet portion of the nozzle, the crystals formed are engaged by the rotating vane 25 and swept clear from attachment to the inner surface of the nozzle so that such material is swept forward by the pressure of the fluid into the refrigerant 18. Thus, as the cooling operation starts, it is found that there is no tendency for the material to plug during the cooling period. Intermittent flow is eliminated and a continuous drop in temperature is obtained down to the sublimation temperature of solid carbon dioxide, namely, 1l0 F.

In the foregoing operation, the CO2 flows through a rather large conduit 18 into the relatively large bore 19 of the nozzle, and when it reaches the discharge portion of the nozzle where the diameter is substantially reduced, the rotating vane 25 is effective in keeping the ice particles from blocking the passage while at the same time enabling the dislodged crystal material to be carried forwardly through the reduced nozzle opening.

In the modification illustrated in Fig. 4, there is provided a valve casing 32 providing an inner valve seat 33. A threaded member 34 provides an outwardly-flaring passage 35 communicating with the valve orifice. The member 34 also has an outer threaded portion 36 which is adapted to engage the threaded wall of the opening 23 in the container 10. The valve casing 32 provides an inner chamber 37 to which liquid carbon dioxide is fed through the opening 38. A conduit (not shown) from the source of supply and preferably equipped with a stop valve, is adapted to threadably engage the threaded boss 39 about opening 38. The valve seat 33 is tapered and a tapered or needle valve 40 is supported for engagement with the seat upon the valve stem 41. The valve stem 41 is threaded at 42 and engages threads in the valve casing 43 so that upon rotation of the valve stem the valve 40 is moved toward or away from the valve seat 33. The valve stem 41 passes through a packing and stuffing box 44 and thence through a bearing 45 provided by a support 46. To the end of stem 41 is secured a wheel 47 and eccentrically connected to the wheel is an arm 48. The arm 48 is eccentrically connected at its other end to a drive disc 49 mounted upon a motor shaft 50. The loose connections between the parts enable the wheel 47 to be oscillated through a short are as the motor shaft '0 is rotated, and the valve 40 thus has a partly rotating movement and a partly longitudinal movement toward and away from the valve seat 33.

In order to change the quantity of gas flowing through the orifice it is necessary to first remove the connecting rod 48 stud in disc 47 and then turn the valve stem 41 counterclockwise to enlarge the valve opening after which the stud and connecting rod are again assembled.

In the operation of the expansion valve structure shown in Fig. 4, it is probable that the solid carbon dioxide is not formed until the liquid has expanded into the divergent cone 35 of the discharge nozzle, and it seems likely that the plugging of the annular conical space between the needle and the orifice or valve seat may be caused by water ice crystals. In any event, the oscillating needle of the valve apparently crushes the minute crystals and keeps the orifice clear for flow. Thus, the valve 40, which rotates as well as moves longitudinally, is effective in causing the flow of the CO2 into the expanding cone 35 of the discharge nozzle and a continuous drop in temperature is obtained in the operation of the device for cooling the refrigerating fluid in vessel 10. The stem 41 may be oscillated through an angle of approximately 40 degrees, or through any other desired angle, using any suitable linkage to a gear motor shaft and the motor shaft may rotate at approximately R. P. M., the gear motor output not being critical.

While I have shown two specific modifications in which the CO passes through an orifice or through a restricted discharge passage, the orifice or restricted passage being kept free of clogging through the employment of an oscillating, rotating or longitudinally-movable member, it will be understood that various other forms of fluid pressure release devices may be used having different forms of crystal breakers or movable members for eliminating the formed crystals. Such movable members may be rotated continuously or oscillated or moved back and forth or moved in other ways to break the crystal formations and prevent them from building up in the reduced diameter area to cause plugging of the apparatus. The freezing difficulties or plugging are aggravated in the smaller size of nozzles, and the moving or oscillating crystal breakers are of great value in connection with such nozzles to permit a continuous drop in temperature down to the sublimation temperature of solid carbon dioxide without any break in the fiow of the carbon dioxide.

In the drawing, as shown in Fig. 1, the insulation extends about the valve structure 20 and the inclined portion of pipe 18. If desired, the thickness of insulation shown may extend about the entire chamber containing the chilled liquid 11.

While in the foregoing specification I have set forth specific embodiments of the invention in considerable detail for the purpose of illustrating the invention, it will be understood that such details of structure may be varied widely by those skilled in the art without departing from the spirit of my invention.

I claim:

1. In a refrigeration system in which a liquid refrigerant is chilled by contact with expanded CO2 and in which the refrigerant is contained within an insulated vessel, a nozzle secured within an opening in the side wall of said vessel and having its discharge port communicating with the refrigerant in said vessel, a conduit leading from a source of liquid CO2 to the bore of said nozzle, means for controlling the flow of CO2 in said bore, a movable member adjacent the discharge portion of said nozzle, and power means for moving said member to break crystals forming within the bore of said nozzle adjacent said discharge portion.

2. In combination with a vessel containing liquid refrigerant, a nozzle having an enlarged bore portion and a reduced bore portion secured to a wall of said vessel and communicating with the refrigerant therein, a conduit leading from a source of CO2 to the enlarged bore portion of said nozzle, a member rotatably mounted in said nozzle adjacent the discharge portion thereof and being substantially enclosed within said nozzle, and power means for continuously oscillating said rotatably mounted member.

3. In a nozzle structure for use in combination with a vessel containing liquid refrigerant, a nozzle having an enlarged bore portion and a reduced bore portion for securance to such a vessel with the reduced portion thereof in communication with the refrigerant within that vesscl, a conduit leading from a source of CO2 to the enlarged bore portion of said nozzle, a member rotatably mounted in said nozzle adjacent the discharge portion thereof and being substantially enclosed within the nozzle, and power means for continuously oscillating said rotatably mounted member.

References Cited in the file of this patent UNITED STATES PATENTS 1,287,756 Rork Dec. 17, 1918 1,470,974 Hardinge Oct. 16, 1923 1,594,176 Knauf July 27, 1926 1,869,346 Comer July 26, 1932 1,997,651 Paramor et al Apr. 16, 1935 2,011,550 Hasche Aug. 13, 1935 2,344,758 Welsh Mar. 21, 1944 2,520,430 Pearson Aug. 29, 1950

Claims (1)

1. IN A REFRIGERATION SYSTEM IN WHICH A LIQUID REFRIGERANT IS CHILLED BY CONTACT WITH EXPANDED CO2 AND IN WHICH THE REFRIGERANT IS CONTAINED WITHIN AN INSULATED VESSEL, A NOZZLE SECURED WITHIN AN OPENING IN THE SIDE WALL OF SAID VESSEL AND HAVING ITS DISCHARGE PORT COMMUNICATING WITH THE REFRIGERANT IN SAID VESSEL, A CONDUIT LEADING FROM A SOURCE OF LIQUID CO2 TO THE BORE OF SAID NOZZLE, MEANS FOR CONTROLLING THE FLOW OF CO2 IN SAID BORE, A MOVABLE MEMBER ADJACENT THE DISCHARGE PORTION OF SAID NOZZLE, AND POWER MEANS FOR MOVING SAID MEMBER TO BREAK CRYSTALS FORMING WITHIN THE BORE OF SAID NOZZLE ADJACENT SAID DISCHARGE PORTION.

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