US2475473A - Cooling system for electron tubes and other devices - Google Patents

Description

July 5, 1949. w. E. BROWN 5,

COOLING SYSTEM FOR ELECTRON TUBES AND OTHER DEVICES Filed Jan. 10, 1947 Kh i 6 CONTROL.

BOX

Patented July 5, 1949 COGLING SYSTEM FOR ELECTRON TUBES AND OTHER DEVICES William E. Brown, Pewaukee, Wis., assignor to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Application January 10, 1947, Serial No. 721,325

9 Claims.

This invention relates to fiuid cooling systems for electron tubes and other devices, and more particularly to improved protective means which detects and responds to cooling system abnormalities.

An object of the invention is to provide simple and inexpensive protective means which responds to temperature and coolant flow rate abnormalities.

Other objects and advantages of the invention will hereinafter appear.

The accompanying drawings show an embodiment of the invention, it being understood that the embodiment illustrated may be altered in various ways without departing from the scope of the appended claims.

In the drawings,

Figure 1 is a schematic showing of a cooling system for an electron tube, which incorporates the improved protective means;

Fig. 2 is a vertical sectional View of a part shown in Fig. 1, sectioning being along line 2-.-2, Fig.

Fig. 3 is a horizontal section along line 33, Fig.

Fig. 4 is a perspective view of a bimetallic element shown in Figs. 2 and 3.

Referring to Fig. 1, this shows an electron tube l and protective means therefor comprising a switch 2 under the control of a bucket type variable weight 3. Tube I, assumed to be of a known liquid cooled type, has a coolant inlet 4 and an outlet 5. It also is shown as having an anode lead 6, a cathode lead I and an igniter lead 8.

A housing 9 of suitable metal or plastic construction is provided for supporting the switch 2 and for enclosing said switch and the variable weight 3. The housing 9 shown only in vertical section may be assumed to be circular in cross section. The top of the housing is preferably closed except for a hole provided to receive a pipe -l| projecting into the interior of the housing. 'Pipe H is connected to the outlet 5 of tube I. The bottom .of the housing 9 is closed except for an outlet l2 from which leads a Waste pipe 13. The housing 9 and pipe I l are preferably secured together as by brackets within the housing having straps l4 and I5 embracing and clamping that portion .of pipe H which projects into the interior of the housing. Preferably the pipe II is located substantially coaxially with the lower portion of the housing.

The .protective switch ;2 shown as enclosed, is fastened to the housing in a suitable position as by screws I1 and I8 threading into a Wall of the housing or a bracket thereon. Terminal screws l9 and 20 are provided for electrical connection of the switch 2 in any of the well known protective relations to the tube 1. The switch has an actuator button 2| which is normally biased in one direction by a spring lever 22. The lever 22 is a flat strip of spring metal and is fastened to the housing of the switch as by screw 23. It has a hook or groove 24 at its free end which forms a saddle for supporting the bail 25 of the bucket type weight 3.

Under normal conditions with little or no weight exerted downwardly on the end of the lever 22, said lever flexes to move the switch 2 into a given position through the medium of the actuator button 2!. Switch 2 may be assumed to be a so-called microswitch biased to a given position and movable into another position through the medium of button 2|. As is well known, switches so designated are capable of handling substantial currents while requiring only very minute move ents of their actuators. Such switches are commercially available in various types and sizes.

The variable weight 3 comprises a thin walled cylindrical bucket 26 constructed of a light metal and containing a bimetallic sleeve 27, said bucket being suspended to receive the discharge of coolant from pipe H. Bucket 2.6 has a plurality of holes 29 drilled through its cylindrical wall near the bottom thereof, said holes preferably being evenly spaced. The bimetallic sleeve 21 is mounted inside the bucket with its outer side conforming to the inside circumference of the bucket wall to tightly cover the holes 29.

Referring to Fig. 2, it shows the bucket in vertical cross section and shows a preferred form of bail 25 hooked into small holes 30 and 3i and having free pivotal movement therein. Fig. 2 also shows the bucket as having a small hole or orifice 32 in the bottom wall thereof.

Referring to Fig. 3, it shows the bucket in horizontal cross section and shows in full lines the bimetallic sleeve 21 in its normal state pressing against the bucket wall. Sleeve 21 is preferably fastened to the bucket wall near one end as by rivet 33.

Reierring to Fig. 4, this shows in perspective a preferred form of the bimetallic sleeve 21. The drawing is exaggerated in respect to the thickness of the sleeve to more clearly indicate its bimetallic construction. The sleeve is fabricated from a thin strip of bimetal and shaped in the form of a circular band with overlapping ends. The sleeve is so formed that the metal having the high coefiicient of expansion is on the outside circumference. It is sized to conform to the internal circumference of the container at normal temperatures. Increasing the temperature above normal will cause the sleeve to de crease in circumference, and conversely the sleeve will tend to increase in circumference when the temperatures are below normal.

When the bucket has no liquid therein its weight will be insufficient to relieve the force exerted on the actuator button 2| by the lever 22. The switch above described will thus be retained in a given position, which may be open position or closed position, as preferred. However, when the cooling system is in operation and the normal rate of coolant is circulating about the electron tube I the coolant will be discharged into the bucket 26 through pipe I Coolant will normally accumulate in the bucket to a certain level, with excess coolant passing out through the orifice 32. The added weight of the accumulated coolant reduces the force exerted by the lever 22 on the actuator button 2| sufiiciently to cause the switch 2 to move to its normal position, thereby permitting the operation of the electron tube I. If the rate of coolant flow falls below a predetermined rate, the rate of coolant flow from the bucket through the orifice 32 will be sufiicient to reduce the weight of accumulated coolant below the value required to restrain the lever 22 from biasing the actuator button upwardly, thereby actuating the switchv The liquicl flowing from the bucket 26 is discharged to a sewer by the waste pipe l3 or can be recirculated through a closed cooling system.

Under normal operating conditions with normal rate of coolant flow being maintained, the temperature of the coolant will be such that the bimetallic sleeve 21 will conform to and exert a pressure against the bucket wall to close the holes 29, thereby preventing any appreciable escape of coolant through these holes. The bucket 26 can be adjusted to maintain the same weight of accumulated liquid at a different normal flow rate as by changing the size of the orifice 32.

If the temperature of the coolant fluid leaving the tube I should increase above a certain Value due, for example, to abnormal electrical loads on the tube the sleeve 21 wil respond to the increase in temperature of the coolant and will contract away from the bucket wall, thus permitting coolant to escape from the bucket at an increased rate through the holes 29. This reduces the weight of accumulated coolant in the bucket and a given reduction in weight thereof permits the lever 22 to bias the actuator button 2| upwardly, thereby actuating the switch as above described.

The above described protective means is simple and yet affords adequate protection against coolant temperature flow rate abnormalities.

What I claim as new and desire to secure by Letters Patent is:

1. In apparatus responsive to abnormality of a stream of liquid, the combination with a yieldingly mounted container supplied with liquid at a rate varying with the rate of flow of the aforementioned stream, said container having an outlet for the liquid therewithin, of means to regulate the outlet of said container, said means comprising thermally responsive means subjected to thei mal conditions varying with the temperature of liquid in said container.

2. In apparatus responsive to abnormality of a stream of liquid, the combination with a. yieldingly mounted container supplied with liquid at a rate varying with the rate of flow of the aforementioned stream, said container having an outlet for the liquid therewithin, of means to regulate the outlet of said container, said means comprising thermally responsive means subjected to thermal conditions varying with the temperature of liquid in said container, and said container affording the liquid therewithin a given outlet free from restriction by said thermally responsive means.

3. In apparatus responsive to abnormality of a stream of liquid, the combinations with a yieldingly supported container supplied with liquid at a rate varying with the rate of flow of the aforementioned stream, said container having an outlet for the liquid therewithin, of means to regulate escape of liquid from said container, said means comprising thermally responsive means subjected to thermal conditions varying with the temperature of the liquid in said container, thereby to accelerate or retard escape of liquid according to the temperature of liquid in said container, said container under the control of said regulating means aifording escape of liquid such as to establish and maintain therewithin a given liquid level and thus to assume and maintain a given position if and While supplied with liquid at a given rate and a given temperature but subject to change in such liquid level and to change in its position as a function of changes in either rate of flow or temperature of the liquid supplied thereto.

4. In apparatus responsive to abnormality of a stream of liquid, the combination with a yieldingly supported container supplied with liquid at a rate varying with the rate of flow of the aforementioned stream, said container having an outlet for the liquid therewithin, of means to regulate escape of liquid from said container, said means comprising thermally responsive means subjected to thermal conditions varying with the temperature of the liquid in said container, thereby to accelerate or retard escape of liquid according to the temperature of liquid in said container,

. said container under the control of said regulating means affording escape of liquid such as to establish and maintain therewithin a given liquid level and thus to assume and maintain a given position if and while supplied with liquid at a given rate and a given temperature but subject to change in such liquid level and to change in its position as a function of decrease in rate of flow of the liquid supplied or increase in tempera ture of such liquid.

5. In apparatus responsive to abnormality of a stream of liquid, the combination with a yieldingly mounted container supplied with liquid at a rate varying with the rate of flow of the aforementioned stream, said container having an outlet for the liquid therewithin, of means to regulate the outlet of said container, said means comprising thermally responsive means immersed in the liquid in said container and subjected to the variations in temperature of said liquid.

6. In apparatus responsive to abnormality of a stream of liquid, the combination with a yieldingly mounted container supplied with liquid at a rate varying with the rate of flow of the aforementioned stream, said container having an outlet for the liquid therein, of a bimetallic strip subjected to the temperature of the liquid in said container and overlying the outlet in said container to close or open said outlet as a function of change in the temperature of the liquid.

7. In a cooling system the combination with conducting means for a flow of coolant liquid, said means including a movably mounted element which assumes difieren't positions according to the quantity of coolant liquid accumulating therein, of means for rendering the escape of liquid from said element variable with the temperature of coolant liquid in said element and protective means under the control of said element.

8. In a cooling system the combination with conducting means for a flow of coolant liquid, said means including a movably mounted container which assumes different positions according to quantity of coolant liquid accumulating therein, of thermally responsive means immersed in the coolant for varying the rate of escape of liquid from said container in accordance with the temperature of the coolant liquid in said container and protective means under the control of said container.

9. In a cooling system the combination with conducting means for a flow of coolant liquid, said means including a movable mounted container which assumes different positions according to the quantity of coolant liquid accumulating therein, of a thermostatic device for varying the effective opening of an outlet in said container for rendering the escape of liquid from said element variable with the temperature of the coolant liquid in said container and a protective device under the control of said movable container to assume selectively two difierent positions,

WILLIAM E. BROWN.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 951,563 Hatch Mar. 8, 1910 1,420,045 Lippert June 20, 1922 1,951,697 Klein Mar. 20, 1934 2,157,470 Adlam May 9, 1939 FOREIGN PATENTS Number Country Date 9,861 Great Britain 1906

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