| 摘要 |
<p>Primary solns. are concd. by passing them through a series of membranes with a high solid rejecting power while subjecting them to a first working pressure, the dilute soln. passing through the membrane being thrown away, passing the concd. soln., which has not passed through the membranes whilst being subjected to a second working pressure, through a second series of membranes with a lower solid rejecting power than the first series of membranes, and recovering as product soln. the part of the feed to the second membranes which has not passed through these membranes. The first and second working pressures are greater than R2 pi1 (where R is the rate of rejection of the corresponding membranes; and pi1 is the osmotic pressure of the soln. on the membranes).</p> |
