Please help solve this problem: A supply tank requires a vaporizer to generate sufficient pressure to pump stored fluid up into a vehicle or tank. The available head is limited as the tank level falls and it is important to minimize the system pressure drop to maintain the desired flow rate.
When installing Multi Layer Insulation (MLI) blankets on VJ line joints or cryo storage tanks should they be wrapped and tied down tight or loose? These are usually pre-cut to size. Also should they have an access hole at the point of where the molecular sieve is installed to help the evacuation of the sieve?
I want to know that why there are different layers of ice over a pipe carrying a cryogenic fluid, each layer separated with clear marks / lines? What do these layers signify?
Is it possible to achieve -200˚C using nitrogen as a cryogen?
I am doing a bit of market research on the use of fiberglass in the LNG market. What is the type and weave of fiberglass used in LNG manufacturing? Is it used aesthetically or is there an actual technical purpose for the fiberglass, such as insulation? Can you name the top picks to get the … Continue reading Use of fiberglass in the LNG market
I was looking for suppliers of regenerator materials. Can you please provide a list of vendors for: • Lead spheres • Bronze screen discs • Rare earth materials and spheres Thank you in advance for any help you can provide.
We are implementing a system to recover helium from our Janis ST-500 continuous flow LHe cryostat. The recovery system uses standard 1/4" plastic tubing, which we connect directly to the cryostat's exhaust port. The problem with this setup is that the gas is still quite cold as it leaves the cryostat. The tube quickly ices … Continue reading Containing ice accumulation while recovering helium
I am looking for some advice regarding cryogenic modeling in ANSYS FEA software. I have been trying to use the Transient Thermal module, in workbench 14.5, to model the cooling of a device in a dilution fridge. I have approximate values for the cooling power of each plate in the fridge, and I have the … Continue reading Looking for some advice regarding cryogenic modeling in ANSYS FEA software
We use liquid nitrogen at our power station to freeze light and heavy water in piping. The ice plug formed within the piping acts as a "valve" and allows us to work on a section of the piping system that otherwise cannot be isolated. The liquid nitrogen enters a jacket that surrounds the piping. The … Continue reading Problem sending LN2 through hoses – need to minimize heat leak
Are there any rules of thumb for the design length of transition tubes in order to prevent condensation at the room temperature end? By “transition tube,” I mean some standard size (O.D. and wall thickness) type 304 stainless steel tube with either 4 K or 80 K at one end and room temperature (300 K) … Continue reading Rules of thumb for the design length of transition tubes
Are compensators and/or accumulators, high or low pressure, used in cryogenics? Are they used in space?
I would like to measure vibrations in small LHe cryostats. Could anybody recommend commercial sensors which would be suitable for the purpose? I am interested in the frequency range between 1Hz and a couple of KHz, with particular attention to the low frequency side.
In order to perform an indicative cost assessment of our helium cryogenic plant (still in the design phase), I need an estimation of the cost of carbon steel room temperature pure helium storage tanks. The storage pressure is 20 bar. Can anyone give me suggestions about how to estimate the cost of these tanks? We … Continue reading Estimating cost of carbon steel, pure helium storage tanks
I have to perform a cost estimation of our helium cryogenic plant design. I based it on the formula discussed in the following article "THE COST OF HELIUM REFRIGERATORS AND COOLERS FOR SUPERCONDUCTING DEVICES AS A FUNCTION OF COOLING AT 4 K" by M. A. Green: C(M$) = 2.6 [R(kW)]^0.63 This is an updated version … Continue reading Estimating cost for components of a helium plant
In an actual experiment we would like to measure the static pressure in a cryostat in the range between one and four bar. Therefore we are looking for some (more or less) cheap pressure sensors that work in liquid helium in the pressure range up to five bar. Unfortunately all sensors mentioned in the literature … Continue reading Supplier of pressure sensor that works down to 4.2 K
Can you suggest some reference textbooks for practical thermodynamics applications in cryogenic fields? I need textbooks with cryogenics calculations and examples, dimensioning procedures, second principle applications in cryogenics, heat load calculations, cryogenic pump application, etc. Do such books exist? Does any similar source of information exist?
A recent project highlighted to me that closed cycle cryogenic cooling systems use far more electrical power to reduce temperatures by a few watts than regular refrigerators. I am sure it must be something to do with the extra difficulty of removing the heat from the liquid nitrogen or similar but I was wondering if … Continue reading Power usage: cryogenic systems vs. regular refrigerators
I was wondering what kind of redundancy strategies are people using for their mechanical -80C freezers? I am aware of the following. Please add if you are doing something different. 1) 1 Backup freezer for every 10 freezers - Empty and maintained at -80C at all times 2) Backup C02 sensor and tank 3) Backup … Continue reading Redundancy strategies for mechanical -80C freezers
I am looking for any safety guidelines for handling cryogenic vessels of nitrogen indoors and outdoors. I am especially interested in recommendations for area monitors to detect leaks, flow detection devices, etc.
I would like to know how much heat energy liquid nitrogen contains per lb. In other words, per lb. of liquid, how many BTUs of heat would N2 absorb in the process of coming up to about 60F? I want to capture the cold energy of nitrogen as it vaporizes and store that cold energy … Continue reading How much heat energy does LN2 contain per lb.?