SU947565A1 - Device for feeding cryogenic liquid from dewar flask - Google Patents

Description

The invention relates to a cryogenic technique, mainly to devices for supplying a cryogenic liquid from Dewar vessels.

A device for supplying a cryogenic liquid from a Dewar vessel, including a line for supplying liquid to a consumer, a supply pipeline, the lower end of which is located in the lower part of the vessel, and an evaporation chamber connected to the vessel by means of a transfer pipe

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The disadvantages of this device are the impossibility of ensuring the continuous supply of refrigerant to the consumer and the increased loss of refrigerant, due to the continuous flow of the latter through the chamber lacking thermal insulation.

The purpose of the invention is to provide a continuous supply and reduce the loss of cryogenic liquid.

To achieve this goal, a device for feeding a cryogenic liquid from a Dewar vessel, including a main line for feeding a liquid. These consumers, the supply pipeline, the lower end of which is located in the lower part of the vessel, and evaporative

the chamber connected to the vessel by means of a flow tube; the evaporation chamber provided with means for connecting the chamber to the atmosphere; the end of the flow tube is located in the lower part of the vessel and the supply line is directly connected to the main line for supplying fluid to the consumer.

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The drawing is a schematic diagram of the device.

The device contains a line 1 for supplying liquid to a consumer, a supply pipe 2, the lower end

15 which is located in the lower part of the Dewar vessel 3, and the evaporation chamber 4 connected to the vessel 3 by means of a transfer pipe 5. The evaporation chamber 4 is equipped with means 6 for connecting it to the atmosphere in the form of a neck 7, an associated valve 8 and installed in the neck 7 float 9 with a pointer.

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The end of the transfer pipe 5 is located in the lower part of the vessel 3, and the supply pipe 2 is directly connected to the line 1.

The device also contains a cover

Claims (1)

30 10, which serves as the base of chamber 4, with flanges 11 for sealing the vessel Dewar 3, the valve 12 connected to it, the valve 13 and the pressure gauge 14, an accumulator 15 is fixed to the lower end of the supply pipe 2. The device operates as follows. The cap 10 is sealed to the Dewar vessel 3. Part of the liquid refrigerant in vessel 3 Dewar evaporates under the effect of heat accumulated in accumulator 15, resulting in an increase in pressure, which means supplying refrigerant to the consumer (via pipeline 2 and line 1) and into the cavity of chamber 4 through tube 5. Others refrigerant into chamber 4 (short-term until the pressure of the refrigerant evaporated in it is not equal to the pressure in the Dewarg vessel 3. If the pressure in the Dewar vessel 3 is lower than the specified value and does not provide the required refrigerant delivery rate to the consumer ( At relatively large distances to the last or at small sections of the channels, for example, cryosurgical instruments connected to line 1), valve 8 is lifted, opening the outlet. of chamber 4 to the atmosphere. At the same time, the liquid refrigerant flows from chamber 4, raising the float 9. As soon as chamber 4 is filled with a liquid refrigerant (the indicator of the float 9 comes out of the neck 7, the valve 8 is returned to me, sealing the neck 7. Since chamber 4 is devoid of heat insulation, the heat supply to it from the environment causes an intense boiling of the liquid refrigerant and, therefore, an increase in pressure compared to the pressure in the Dewar vessel 3. Therefore, the refrigerant comes through the tube 5 into the Dewar vessel 3, increasing the pressure in the latter to a predetermined value determined by the valve 12, and ensuring the required flow rate of the refrigerant to the consumer. Shutting off the refrigerant supply is done by depressurizing the Dewar vessel 3, for example, by opening the valve 13. Thus, by installing the evaporation chamber separately from the line and equipping it with the first means to connect it to the atmosphere, allowing the pressure in the Dewar to be maintained at a predetermined level, continuous flow is provided and loss of cryogenic fluid is reduced. Thus, to create a 16 l pressure of 200 kPa in a Dewar vessel, it is necessary to evaporate about 0.18 l of liquid nitrogen, which makes it possible to quickly prepare the proposed device for operation and to supply the refrigerant stably to the consumer. Apparatus of the Invention A device for supplying a cryogenic liquid from a Dewar vessel, comprising a line for supplying liquid to a consumer, a supply pipe, the lower end of which is located in the lower part of the vessel, and an evaporation chamber connected to the vessel through a flow tube, in order to ensure continuous supplying and reducing the loss of cryogenic liquid; the evaporation chamber is equipped with a means for connecting it to the atmosphere; the end of the overflow pipe is located in the lower part of the vessel and is prepared the conduit is directly connected to the line for supplying the fluid to the consumer. Sources of information taken into account in the examination 1. US patent 3440829, cl. R 17 C 7/00, 1969. 15 P