System for recycling water soluable waste liquids

• US 4,080,247 A
• Filed: 03/15/1976
• Issued: 03/21/1978
• Est. Priority Date: 03/15/1976
• Status: Expired due to Term

• Current Assignee: Robert P. Malakul
• Original Assignee: Robert P. Malakul
• Inventors: Malakul, Robert P.
• Primary Examiner(s): Bernstein, Hiram H.
• Application Number:
  US05/666,903
• Time in Patent Office: 736 Days
• Field of Search: 159/17 R, 159/28 C, 159/23, 159/24 A, 203/3, 203/75, 203/76, 203/77, 202/185 D, 202/174, 202/235, 202/181, 202/176
• US Class Current: 159/17.1
• CPC Class Codes: B01D 1/26 Multiple-effect evaporating
• CPC Class Codes: C07C 29/80 by distillation
• CPC Class Codes: C07C 31/202 Ethylene glycol
• CPC Class Codes: C12C 11/02 Pitching yeast

Abstract

A system for reclaiming solutions of waste chemicals such as ethelene glycol is provided. The water in the ethelene glycol is distilled or evaporated off at temperatures below the boiling point of the glycol. The system includes two or more interconnected evaporating stages each having a heating coil therein. The last or final evaporating stage is provided with an aqueous solution sensing loop for removing portions of reclaimed solution at predetermined concentration levels and is provided with water sensing station for removing condensed steam or returning contaminated water to the input of the system.

Claims

1. A system for reclaiming waste chemicals diluted in aqueous solutions comprising:

a storage tank for storing the waste chemical solution to be refined,

a first evaporating stage connected to said storage tank for receiving said waste chemical solution,

first level control means on said first evaporating stage for maintaining a predetermined level of said waste chemical solution therein,

fluid heating means inside said first evaporating stage for generating low pressure steam from said waste chemical solution,

first steam and condensate collecting means inside said first evaporating stage,

a second evaporating stage containing waste chemical solution and having a steam heating coil therein connected to said first steam and condensate collecting means,

second steam and condensate collection means inside said second evaporating stage,

said second steam and condensate collection means being connected to said steam heating coil inside said second evaporating stage,

condensing coil means inside said second evaporating stage for condensing steam generated in said second evaporating stage,

liquid conduit means connecting the aqueous solutions in said first and said second evaporating stages,

second level control means on said second evaporating stage for opening and closing said liquid conduit means to maintain a predetermined level of said waste chemical solution in said second evaporating stage,

vacuum means connected to said second evaporating stage for reducing the pressure in said second evaporating stage below atmospheric pressure,

an aqueous solution sensing loop having an inlet and an outlet connected to the waste chemical solution in said second evaporating stage, said aqueous solution sensing loop comprising a liquid circulating pump, bypass valve control means and sensing control means for determining the amount of waste chemical in the solution being pumped in said sensing loop, a water sensing station connected to said second steam and condensate collection means, said water sensing station comprising, a liquid circulating pump, diversion valve control means and a purity sensing control for determining the amount of chemical impurity in the condensed steam being pumped in said water sensing station and

collection storage means connected to said by pass valve control means for receiving portions of said waste chemical solution from said second evaporating stage when a predetermined concentration of waste chemical is sensed by said sensing control means, whereby reclaimed waste chemical is intermittently provided at said collection storage means.

2. A system as set forth in claim 1 which further includes, a return pipe connected to said water sensing station and to said storage tank for returning condensed steam to said storage tank when the condensed steam contains excessive impurity as determined by said sensing control.

3. A system as set forth in claim 2 which further includes,

an exhaust pipe connected to said water sensing station and to an outlet drain for exhausting condensed steam when the condensed steam contains only a predetermined allowable impurity as determined by said sensing control.

4. A system as set forth in claim 3 which further includes,

manual control means on said purity sensing control for selecting said return pipe or said exhaust pipe.

5. A system as set forth in claim 3 which further includes,

a water filter bank connected to said exhaust pipe for removing chemical impurities from said condensed steam.

6. A system as set forth in claim 1 wherein said waste chemical solution comprises an aqueous solution of ethelene glycol, and said system further includes,

a hot fluid supply connected to said heating means in said first evaporating stage,

temperature control means in said hot fluid supply, and

a thermostat control in said first evaporating stage for controlling the supply of hot fluid to said heating means.

7. A system as set forth in claim 6 wherein said thermostat control maintains said ethelene glycol solution at a temperature of approximately 160°

fahrenheit and said vacuum means connected to said second evaporating stage pulls a vacuum in said first evaporating stage through said heating coil and said first steam collecting means sufficient to produce steam and condensate in said first evaporating stage at approximately 140°

fahrenheit.

8. A system as set forth in claim 6 wherein said vacuum means pulls a vacuum in said second evaporating stage sufficient to produce steam in said second evaporating stage at approximately 120°

fahrenheit.

9. A system as set forth in claim 6 wherein said hot fluid supply is further connected to a heating coil in said storage tank for preheating said waste chemical solution of ethelene glycol.

10. A system as set forth in claim 9 wherein said preheated solution of ethelene glycol is filtered before being connected to said first evaporating stage.

11. A system as set forth in claim 1 wherein said waste chemical solution comprises an aqueous solution of ethelene glycol, and said system further includes,

a filter bank connected to by pass control means between said collection storage means for filtering and aqueous solution of ethelene glycol, and

wherein said sensing control means are set to bypass an approximate 50 percent by volume filtered solution of ethelene glycol to said collection storage means.