US 5,928,477 A · Method and apparatus for removing water from an aqueous fluid mixture

Abstract

A method and apparatus permits concentration of a water-miscible organic liquid in a mixture of such liquid and water, with recovery of a desired concentrate of the water-miscible organic liquid and water, and a relatively clean water containing only a very low content of the water-miscible organic liquid which enables disposal of the water in sewage systems, the method and apparatus thus enhancing the ability to satisfy environmental concerns; the method has particular application to the recovery of a reusable glycol/water mixture from diluted spent aircraft deicer fluid (ADF). The diluted spent ADF is heated in a plate heat exchanger with steam to form a hot frothing mass of liquid and steam which is delivered to a cyclone concentrator, the hot frothing mass in the plate heat exchanger and the cyclone concentrator are maintained at a first pressure and a steam phase including steam bubbles in the hot frothing mass is efficiently separated from and withdrawn from a hot liquid phase which represents a more concentrated glycol/water mixture. The steam withdrawn from the hot frothing mass is compressed to a second pressure higher than the first pressure and cycled back to provide the steam input of the plate heat exchanger. After start-up the operation proceeds, with maintenance of the pressure differential, exploiting the heat of the compressed steam with no requirement for external heating. The method and apparatus may be applied to other aqueous fluid mixtures.

Claims20

Dependent claims

A method of removing diluent water from spent deicing fluid to provide a re-usable fluid comprising:

a) heating, with hot steam, a spent deicing fluid containing diluent water to produce a hot frothing mass of liquid deicing fluid containing bubbles of steam vapor, at a first pressure,
b) feeding said hot frothing mass into a separating chamber of a cyclone,
c) separating the hot frothing mass cyclonically in said separating chamber at said first pressure with formation of a discrete hot liquid deicing fluid phase and a discrete steam vapor phase, in said separating chamber,
d) recovering said hot liquid deicing fluid phase from said separating chamber,
e) recovering said steam vapor phase from said separating chamber,
f) compressing said steam vapor phase in at least one compression stage to develop a hot compressed steam at a second pressure, and
g) recycling said hot compressed steam at said second pressure from step f) to step a) for said heating of the spent deicing fluid in step a),
said first pressure being below said second pressure.

5 more elements

Apparatus for removing diluent water from an aqueous fluid mixture comprising:

A) a heat exchanger having a first flow passage therethrough for an aqueous fluid mixture containing diluent water, said first passage being in heat exchange relationship with a second flow passage for steam, said first passage having an inlet port and an outlet port, and said second flow passage having an inlet port and an outlet port;
B) a cyclone having a separating chamber with liquid inlet port and a first conduit for liquid flow communication of said outlet port of said first passage with said inlet port of said cyclone;
a steam outlet port in said cyclone and a liquid outlet port communicating with said separating chamber in said cyclone;
C) at least one compressor for compressing steam having a steam inlet port and a second conduit for steam flow communication of said steam outlet port of said cyclone with said steam inlet port of said at least one compressor;
a compressed steam outlet port and a third conduit for steam flow communication of said compressed steam outlet port with said inlet port of said second flow passage of said heat exchanger, and
D) means for maintaining said first flow passage, said first conduit, said separating chamber, said steam outlet port of said cyclone and said second conduit at a pressure below the pressure within said second flow passage of said heat exchanger, said at least one compressor and said third conduit.

3 more elements

Dependencies are inferred from the claim text.

Method and apparatus for removing water from an aqueous fluid mixture

Life of this patent

Method and apparatus for removing water from an aqueous fluid mixture

Life of this patent

Abstract

Claims20