Hi, Gene Heskett wrote: > Have you ever seen a cardox compressor?
No. I never compressed helium to ~500 bar pressure. Did you have a chance to check the temperature at the pressured outlet ? > This one had intercoolers bigger > than the cylinders. Fitst cylinder was around a cubic foot per stroke, next > on about a quart, till the 6th one was about 2 cc's. The internet data about heat production during compression of helium indicate that there is a lot of heat to dispose. If "cc" means cubic centimeters then a cylinder of that volume has few surface to get rid of hundreds of Kelvins. So it is not outruled that the compressed gas reached the pressure storage hotter than boiling water. The internet gives no technical data which would put the diffusion coefficient of helium higher than the one of hydrogen. In contrary: https://en.wikipedia.org/wiki/Helium states "helium diffuses through solids at a rate three times that of air and around 65% that of hydrogen. [30] ... [30] Hampel, Clifford A. (1968). The Encyclopedia of the Chemical Elements. New York: Van Nostrand Reinhold. pp. 256–268. ISBN 978-0-442-15598-8." (I have seen hydrogen tanks under high pressure.) In a previous mail, Gene Heskett wrote: > What are we going to do when we run out? Mine a star? We wait until alpha-decay of radiocative elements in the earth has produced more helium. Alpha particles are helium atoms without electrons. When the particles slow down they catch electrons from the environment and become complete helium atoms. https://en.wikipedia.org/wiki/Helium states "Most helium on Earth is a result of radioactive decay. Helium is found in large amounts in minerals of uranium and thorium, [...] Because helium is trapped in the subsurface under conditions that also trap natural gas, the greatest natural concentrations of helium on the planet are found in natural gas" Have a nice day :) Thomas
