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1. A method for recovery of liquid desiccant from a cool air drying system comprising the steps of:spraying liquid desiccant from desiccant holding area into an air stream, wherein said desiccant absorbs water from said air forming wet desiccant;removing said wet desiccant and preheating it in an economizing heat exchanger;moving preheated wet desiccant from said economizing heat exchanger into a concentrator;boiling said preheated wet desiccant in the concentrator producing a mixed vapor;causing said mixed vapor to enter a distillation column at a bottom end, wherein almost pure water vapor exits said distillation column at a top end;condensing said almost pure water vapor to liquid water in a condenser;causing a predetermined amount of said liquid water to be refluxed back into the top end of said column;returning purified desiccant from said concentrator through said economizing heat exchanger and into said desiccant holding area.
2. The method for recovery of liquid desiccant of claim 1 further comprising disposing of all remaining liquid water.
3. The method for recovery of liquid desiccant of claim 1 wherein said mixed vapor contains around 20% to 30% desiccant.
4. The method for recovery of liquid desiccant of claim 1 wherein water refluxed back into said column scrubs desiccant from said column.
5. The method of recovery of liquid desiccant of claim 1 wherein said desiccant is a glycol.
6. The method of recovery of liquid desiccant of claim 1 wherein said glycol is chosen from the group consisting of propylene glycol, ethylene glycol and triethylene glycol.
7. The method of recovery of liquid desiccant of claim 1 wherein said concentrator is heated with steam.
8. The method of recovery of liquid desiccant of claim 1 wherein said concentrator is heated by natural gas.
9. The method of recovery of liquid desiccant of claim 1 wherein said condenser is water cooled.
10. A system for recovering desiccant in an air cooling system comprising:a desiccant spray wherein high concentration liquid desiccant is sprayed through a cool air flow;a concentrator coupled to a first end of a distillation column;a condenser coupled to a second end of said distillation column;a refluxer located in said distillation column near said second end;wherein wet desiccant from said spray is caused to enter said concentrator where it is boiled causing mixed vapor to enter said distillation column, and where almost pure water vapor leaves said distillation column and enters said condenser where it condenses to liquid water, and wherein a portion of said liquid water is caused to enter said refluxer.
11. The system of claim 10 further comprising an economizing heat exchanger located between said desiccant spray and said concentrator, wherein returning hot dry desiccant from said concentrator preheats cold wet desiccant entering said concentrator.
12. The system of claim 10 wherein said concentrator is steam heated.
13. The system of claim 10 wherein said concentrator is natural gas heated.
14. The system of claim 10 wherein said desiccant is a glycol.
15. The system of claim 14 wherein said glycol is chosen from the group consisting of propylene glycol, ethylene glycol and triethylene glycol.
16. The system of claim 10 wherein said condenser is water cooled.
17. The system of claim 10 wherein said desiccant is purified up to around 97%.
18. A method for recovering liquid desiccant in a closed loop comprising: 1) mixing liquid desiccant with an air flow so the desiccant absorbs moisture from the air flow; 2) causing the desiccant with gained water to pass into a concentrator where it is boiled to produce a mixed vapor wherein this mixed vapor passes into a distillation column in which most of the desiccant is removed by column action and by refluxing a stream of liquid water into the column to scrub the glycol from the column; 3) returning the purified glycol for further use.
19. The method of claim 18 wherein the desiccant is a glycol.
20. The method of claim 19 wherein the glycol is chosen from the group consisting of propylene glycol, ethylene glycol and triethylene glycol.
21. The method of claim 18 further comprising condensing almost pure water vapor exiting said distillation column.
22. An apparatus for recovering liquid desiccant comprising;a means for spraying an air flow with said liquid desiccant from a holding area wherein moisture is removed from said air flow;a means for boiling said liquid desiccant causing vapor to enter a distillation column;a means for refluxing said distillation column with almost pure water scrubbing said column of desiccant;a means for returning said desiccant back to said holding area.
22. The apparatus of claim 20 further including a means for preheating said desiccant with an economizing heat exchanger before boiling it.
23. The apparatus of claim 20 wherein said desiccant is chosen from the group consisting of propylene glycol, ethylene glycol and triethylene glycol. |
