| 摘要 |
<p>A vacuum distn. unit has a feed reservoir (A), vented to atmospheric pressure, linked to a second reservoir (C) at least 10 m higher under vacuum and primed from the lower reservoir by a thermo syphon effect due to a heated jacket (B) on one of two liq. filled legs connecting the reservoirs A,C. Concentrates which collect in (A) by recirculation may be drained off and replaced by fresh input. Vapour from the upper reservoir (C) is condensed (D) and collected in another high level reservoir (F), under vacuum, which can drain to a low level reservoir (G) vented to atmos. from which the prod. may be removed via a drain or overflow system. Air entrained from soln. may be relieved, by conventional traps (E) either from the condenser (D) or the low pressure receiver (F). Used for purificn. of e.g. sea water, without involving use of extn. pumps to remove either concentrates from the still bottoms or prod. from an evacuated receiver, thus reducing operating energy requirements, esp. if the thermal syphon (B) is effected by a waste heat source at e.g. 60-80 deg.C. Suitable for low technology countries.</p> |
