RECLAIMING MICROELECTRONICS WASTEWATER FOR USE IN COOLING TOWERS

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RECLAIMING MICROELECTRONICS WASTEWATER FOR USE IN
COOLING TOWERS

Darell Rogers Sandia National Laboratories Albuque
rque New Mexico
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Reclaim Spent Rinse-Water for Cooling Towers

• Send portion of spent microelectronics water to
  adjacent cooling towers
• High make-up water quality allows increasing
  concentration cycles from 2.8 to 10
• Intel had already pioneered the way

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Microelectronics Development Lab
Annual Use 190 MG WCOs Identified 50 MG
Recycle Treatment
40 gpm
DI
140 gpm
Loop
MDL processes
100gpm
acid waste neutralization
domestic potable water
treatment
183.8 gpm
245 gpm
64 gpm
5.5 gpm
108.4 gpm
8.4 gpm
RO Reject Recovery 50
25 gpm
32 gpm
RO water loop
27.8 gpm
cooling tower
RO Reject / Backwash
80.6 gpm
blowdown
sewer
32 gpm
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PROJECT DESCRIPTION

• Install pump in basement of AWN room
• Pump is on when conductivity is less than 1100
  mmhos
• Install 3 storage tanks to equal peak day usage
• Connect storage tanks to cooling tower sumps
• Install control valves to open based on sump
  level
• Sumps are filled by gravity drain from storage
  tanks
• Install control valve to feed well water as
  backup supply

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Three Tower Cells
Three Reclaim Water Storage Tanks
Three 1600 Ton Chillers
Chlorine Analyzer
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CHEMICAL CONTROL
Work with your chemical service company to
collect water data and design a cost effective
water treatment program corrosion control and
biological control
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Reclaim Spent Rinse-Water for Cooling Towers
Unit Cost
Gallons
Total
Water Use
1.25/1000
21,000,000
26,250
Sewer Discharge
1.25/1000
21,000,000
26,250
Chemicals
-10,000
Operations
0
Annual Savings
42,500
Total Project Costs
165,000
Simple Payback in Years
3.9
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Cooling Tower Project

• Install corrosion monitor and coupon rack
• AWN water is more aggressive than well water

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How to Read a SANI-CHECK Bacteria TestAWN Water
has a higher biological demand
1,000 10,000 100,000
1,000,000 10,000,000
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858 Cooling Tower Bio-Control
Date 9/7 AWN MU CT Bacteria 1000-10000
STABREX Usage 2 gal, Settings 20 Speed,
50 Stroke, 90 min duration
Cooling Tower
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858 Cooling Tower Bio-Control
Date 9/27 AWN MU Bacteria 1000-10000
CT Bacteria 100,000 STABREX Usage 2.5
gal Settings 20 Speed, 50 Stroke, 90 min
duration
Cooling AWN-Make-up Tower
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Chlorine Demand
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Chlorine Demand
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Conclusions

• Start-up is always harder than you anticipate so
  work closely with operations
• Need to have automated system with City Water as
  back-up supply
• Work closely with your chemical supplier to get
  the proper chemical treatment for corrosion
  protection and biological control.
• AWN Reclaim works!!!

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THE END