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# c12) United States Patent 

# Minnich et al. 

# (54) METHOD AND APPARATUS FOR HIGH EFFICIENCY EVAPORATION OPERATION 

(75) Inventors: Keith R. Minnich, Pewaukee, WI (US); Ramkumar Karlupudi, Waukesha, WI (US); Richard M. Schoen, Hartland, WI (US) 

(73) Assignee: Aquatech International Corporation, Cannonsburg, PA (US) 

( *) Notice: Subject to any disclaimer, the term ofthis patent is extended or adjusted under 35 U.S.C. 154(b) by 1075 days. 

(21) Appl. No.: 10/531,752 

(22) PCT Filed: Oct. 17, 2003 (Under 37 CFR 1.47) 

(86) PCT No.: PCT/US03/33066 § 371 (c)(l), (2), ( 4) Date: Jun.12,2006 

(87) PCT Pub. No.: WO2004/035479 

PCT Pub. Date: Apr. 29, 2004 

## (65) Prior Publication Data 

US 2008/0099154 Al May 1, 2008 

(60) Provisional application No. 60/419,549, filed on Oct. 18, 2002, provisional application No. 60/419,552, filed on Oct. 18, 2002. 

(51) Int. Cl. 

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## Related U.S. Application Data 

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# (IO) Patent No.: US 8,092,656 B2 

# Jan.10,2012 (45) Date of Patent: 

(52) U.S. Cl. ....... 203/10; 159/49; 159/901; 159/DIG. 8; 203/12; 203/72; 203/84; 203/88; 203/89; 203/98; 210/639; 210/664; 210/665; 210/681; 210/687; 210/718; 210/737; 210/774; 210/806 

(58) Field of Classification Search ................... 159/2.1, 159/24.1, 49, 901, DIG. 8, DIG. 13, DIG. 27, 159/DIG. 28; 203/10, 12, 39, 40, 72, 84, 203/88, 89, 98; 210/634, 639, 660, 664, 210/665,681,685, 687,713,718,737,774, 210/806; 423/659 See application file for complete search history. 

## (56) References Cited 

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Primary Examiner - Virginia Manoharan 

(74) Attorney, Agent, or Firm -Andrus, Sceales, Starke & Sawall, LLP 

## (57) ABSTRACT 

A process for treatment of an aqueous stream to produce a low solute containing distillate stream and a high solute/solids containing blowdown stream utilizing a method to increase the efficiency of an evaporator while providing an essentially scale free environment for the heat transfer surface. Multi› valent ions and non-hydroxide alkalinity are removed from aqueous feed streams to very low levels and then the pH is increased preferably to about 9 or higher to increase the ionization oflow ionizable constituents in the aqueous solu› tion. In this manner, species such as silica and boron become highly ionized, and their solubility in the concentrated solu› tion that is present in the evaporation equipment is signifi› cantly increased. The result of this is high allowable concen› tration factors and a corresponding increase in the recovery of high quality reusable water with essentially no scaling. 

US008092656B2 

## U.S. PATENT DOCUMENTS 

## 15 Claims, 6 Drawing Sheets 

(Continued) 

