Partial Separation of Argon from a Helium‐Argon Mixture by Sampling Capillary Flow

摘要

The partial separation of helium and argon in a sample withdrawn through a tube at right angles to a capillary through which the mixture is flowing at high velocity is measured. With a helical capillary the effect is greater by at least a factor of 4 than can be accounted for by the centrifugal field due to the average velocity along the helix, even if no mixing or turbulence is assumed. The effect in a straight capillary is somewhat smaller and is about that expected to be produced by a stable eddy near the entrance to the sampling tube. The helix results depend in sign as well as magnitude on the flow conditions. Separations up to 0.7% are observed. The effect vanishes at small withdrawal rates, indicating an interaction between any possible effect of the helix and the demonstrated effect at the withdrawal hole.