Information of Helium Gas Recovery Technology

Installation of the check valve and the recovery gas meter

Refer to the figure down below, please install the check valve and the recovery gas meter correctly. If your laboratory installs that equipment, please, confirm with cryogenic laboratory. If you have not confirmed with Cryogenic Laboratory, we won't be able to supply Liquid Helium. We provide check valve and a gas meter. We also have stock in standard installation apparatus and parts. If you need those items, please make sure and consult with us about note below.

Check valve (ball floating type)・Figure of gas meter installation model.

Check valve (ball floating type) is able to use all of the gas meters.

※Click here for enlarge the picture.

Check valve (diaphragm type)・ Figure of gas meter installation model

Check valve (diaphragm type) is only usable for gas meter sized N5.

※Click here for enlarge the picture.

Information of Helium Gas Recovery Technique and General Equipment

About Recovery Helium Gas and SQUID Magnetometer

Usually, QuantunDesign of SQUID magnetometer is not design for recovering the Helium Gas. For recovering Helium Gas correctly, please make a refinement on your equipment.

［Problems］

  1. The pressure control valve (1psi) has to remove whenever refilling Liquid Helium.
    The pressure control valve has attached to the Helium feeder.→ It would make about 1psi gas to escape.
  2. Enable to recover vaporized Helium Gas.
    The pressure control valve is facing outside (It is not connected to recovery line.)that is why it can't recover naturally vaporized gas.

［Computation of the vaporized gas］

  1. Filling the Liquid Helium makes liquid evaporation such as flash loss.
    Liquid volume has changed to approximately 95% →1.4litter of liquid loss
    Evaporation of gas is approximately 1m3
    If a filling filling has occurred once a week, gas evaporates approximately 4m3 per month.
    ※ Filling frequency may increase when measuring the gas.
  2. Natural vaporization and air pump
    A day of vaporization volume is approximately 4litters by liquid.(Standby mode)→ That will make total of 112litters by liquid per month.
    That makes gas evaporate 78.4m3 per month minimum.
    ※　The case of measuring gas makes increase the vaporization. In this connection, magnetic field dependence measuring case, evaporation might occur approximately 60litters by liquid per week.

［Supply feeder improvement plan］

Liquid Helium supply needs to improve to recover naturally vaporized liquid, and take out inner pressure of Helium Gas then able to insert the transfer tube. Also, recover air pump, it is mostly helium.

We think it is best to prove the equipment as image below in this page, to not connecting directly to Liquid Helium feeder and pressure control valve. In fact, it is working well as directed as picture below.

Image

LHe feeder

Sample 1

Sample 2

Instructions for using helium

We sometimes hear the information that some people letting go the gas to the atmosphere from pre-cool down transfer tube when transferring liquid helium to the test equipment. We predict that is trying to reduce vaporization of liquid helium in the equipment. Even though, transfer without pre-cool down it doesn't make too much difference of vaporization. Although, some people might think it is wasting to letting the gas to the atmosphere makes lower the recovery rate and that makes unit price goes up for Liquid Helium. Please consider and use liquid helium wisely.

Transferring Liquid Helium to the test equipment

  1. At the time of pre-cool down the transfer tube, you must put tip of transfer tube to recovery line or bag,then recovery the Helium Gas.
  2. Use transfer tube without pre-cool down.
    1. There would be small volume of Liquid Helium vaporization inside equipment when its slowly transferred.
    2. It is possible to transfer without Liquid Helium vaporization inside equipment.Remodel the tipof transfer tube to prevent spout out to the down side.

Helium gas recovery inlet

  1. Separating Helium Gas inlet for several forms or placing the several equipment, please use check valve and prevent regurgitate Helium Gas to the equipment.

About the purity of helium recovery

　When the recovering Helium Gas has low purity, liquefier machine and other equipment have bad affect.Therefore, we measure recovery gas purity by each building. But for the best result, please make sure at your laboratory,also. Special attention is needed when testing under decompression; there might be possibility of entering the oil and the air to the pump system.

　It is able to measuring recovery gas's purity by placing the Helium Gas purity meter to the outlet of decompression pipe, test equipment,and recovery piping. The common purity meter is expensive , so that makes difficult to place it at each laboratory. But, it is possible to place the simple purity meter that had been developed at the University of Tokyo cryogenic center;it works well and cost is cheaper.

　We had a number of requests from many laboratories about mass purchasing the purity meter. The result of survey, we decided to purchase purity meters by large order. The details about result of survey and purchasing purity meters are individually written in following sentences.

  1. The result of survey about recovery gas meter.
  2. About purchasing a Helium Gas purity meter.

About management in a laboratory of Liquid Helium

To manage Liquid Helium at your laboratory, you must know the volume of Liquid Helium left in the vessel, at any time.A user measures volume of liquid, before use and after use, then leaves a record. Doing that would avoid the trouble, such as warming the vessel by transferring too much and empty it.計測して記録し、常に液量を把握しておけば、トランスファーしすぎて空にして容器を暖めてしまう等のトラブルを避けることもできます。

研究室内でも簡単に容器内のヘリウムの量を計測する方法としては、気柱振動液面計があります。以下に気柱振動液面計の図面と容器の在庫を記録しておくメモ用紙を用意しましたので、ヘリウム容器の管理に活用してください。

Figure of a column of air vibration level guage


Click to open the pdf file.

この気柱振動液面計の上部部品に3mmのパイプを銀蝋付けして使用します。
パイプには液面をマークするためのo-ring(I.D. 3mm以下)を二個通しておきます。

How to use：

Memo pad for the liquid volume in the vessel

Excel and pdf are provided. Please download and use it.

Memo pad for the liquid volume in the vessel(Excel)
Memo pad for the liquid volume in the vessel(pdf)

An introduction of low temperature technology - related books

Introducing low temperature technology - related books. We are able to lend these books for people who are in the ISSP only. If you are interested, please contact us.
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