Patent ID: 8986517
Filing Date: 2015-03-24
Classification: B01D,C01D,C02F,C25B,Y02P

Abstract:
1. An apparatus for making and concentrating an aqueous caustic alkali comprising: an electrolytic cell having a cell membrane, a cathode in a cathode chamber, and an anode in an anode chamber; the cell membrane located between the cathode chamber and the anode chamber; the cathode chamber connected to a first piping means for conveying aqueous caustic alkali with a first alkali concentration; the first piping means branching into a second piping means for conveying aqueous caustic alkali with the first alkali concentration and a third piping means for conveying aqueous caustic alkali with the first alkali concentration; the second piping means connected to a first heat exchanger; the first heat exchanger connected to a fourth piping means for conveying aqueous caustic alkali with the first alkali concentration; the fourth piping means connected to the cathode chamber; the third piping means connected to a third effect evaporator; the third effect evaporator connected to a fifth piping means for conveying aqueous caustic alkali with a second alkali concentration, whereby the second alkali concentration is greater than the first alkali concentration; the fifth piping means connected to a flash evaporation chamber; the flash evaporation chamber connected to a sixth piping means for conveying aqueous caustic alkali with a third alkali concentration, whereby the third alkali concentration is greater than the second alkali concentration; the sixth piping means branching into a seventh piping means for conveying aqueous caustic alkali with the third alkali concentration and an eighth piping means for conveying aqueous caustic alkali with the third alkali concentration; the seventh piping means connected to the first heat exchanger; the first heat exchanger connected to a ninth piping means for conveying aqueous caustic alkali with the third alkali concentration; the ninth piping means connected to the flash evaporation chamber; the eighth piping means connected to a second effect evaporator; the second effect evaporator connected to a tenth piping means for conveying aqueous caustic alkali with a fourth alkali concentration, whereby the fourth alkali concentration is greater than the third alkali concentration; the tenth piping means connected to a first effect evaporator; the first effect evaporator connected to an eleventh piping means for conveying steam having a first temperature; the first effect evaporator connected to a twelfth piping means for conveying water vapor having a second temperature; the twelfth piping means connected to the second effect evaporator; the second effect evaporator connected to a thirteenth piping means for conveying water vapor having a third temperature; the thirteenth piping means connected to the third effect evaporator; and the first effect evaporator connected to a fourteenth piping means for conveying aqueous caustic alkali with a final alkali concentration and a fourth temperature, whereby the final alkali concentration is greater than the fourth alkali concentration.