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US 4,985,122 AGranted
Vacuum distillation apparatus and method with pretreatment
AssigneeVaqua Limited
InventorColin W. Spencer
Life of this patent
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AssigneeVaqua Limited
InventorColin W. Spencer
Estimating the term…
Method and apparatus for separating volatile contaminants from a liquid to be continuously distilled. A continuous still comprises evaporator (1) having a heating coil (2), and condensor coil (6), and distillate collector (5). An entrainment device (11) removes distillate (13) from collector (5) via line (10) and reduces pressure in evaporator (1). Feed liquid (21) containing volatile contaminants is charged batchwise to a pre-chamber (20) at sub-atmospheric pressure which is then sealed (valve 22) from feed supply (21). Volatile contaminants are extracted from the charge in prechamber (20) via line (26) and entrainment device (32). Pre-chamber (20) is subsequently placed in communication (via valve 25) with evaporator (1) whereby to equilibrate pressure between evaporator (1) and pre-chamber (20). Liquid levels in pre-cheamber (20) and evaporator (1) then equilibrate whereby decontaminated liquid is automatically transferred (line 36) from the pre-chamber (20) to evaporator (1) to make up for distillate removed from evaporator (1). Valve (25) is then closed and the cycle repeated. The valves are automatically operated in a timed sequence.
A method for pretreating a liquid to be supplied to an evaporator of a continuous vacuum still which vaporizes liquid to produce a vapor and condenses said vapor to produce a distillate, said method comprising the steps of:
A continuous still comprising evaporator means for vaporizing liquid to produce a vapor, condensor means for condensing said vapor to produce a distillate, first means to maintain the evaporator at a sub-atmospheric pressure, evaporator feed means including a pre-chamber, means for repetitively admitting a liquid to the pre-chamber from a supply, second means for reducing pressure in the pre-chamber whereby to extract volatiles and/or gases from the liquid in the pre-chamber in isolation from the evaporator and said distillate, means for removing extracted volatiles and/or gases from the prechamber, and means for transferring at least part of the resultant residual liquid from the pre-chamber to the evaporator.
Dependencies are inferred from the claim text.