The Total Solution ... for Recycling Water and Chemicals
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
FAQ : No Recycle System vs. Closed-Loop Water Recycling System
What are the Costs of Operating a No Recycle System vs.
a Closed-Loop Water Recycling System?Purpose: To analyze some costs of operating an in-line aqueous cleaner that drains to a sewer (no recycle) compared to an aqueous cleaner with all of its water reused in a closed-loop water recycling system. Energy calculations are based on the use of an electric heater.
Operating Assumptions:
| Rinse flow (gpm) 4 | Water/sewage fees($/gal) $0.005 |
| Operating hours(weekly) 30 | Cost of power($KWH) $0.050 |
| Weeks/year 48 | Recycle system dumps(gal/yr) 10,000 |
| Operating temerature(degrees F) 140 | Evaporation loss in cleaner(% total throughout) 4% |
| Tap water Temperature(degrees F) 50 | Energy loss(estimated) 10% |
| Heat Capacity 1 BTU/1B-degree F | Cleaner drain temperature(degrees F) 135 |
Note: Other values more specific to your application can be used for the above operating assumptions.
A. No-recycle water/heat costs
1. Water cost
Minutes/yr = 30hr/wk x 60 min/hr x 48 wk/yr = 86,400 minutes/yr
Gallons/yr = 86,400 min/yr x 4 gal/min = 245,600 gallons/yr
Water cost = 345,600 gallons/yr x $0.005 (water/sewage fees/gal) = $1,728.00/yr2. Heat cost
Heat required = 1 lbs tap water/yr x heat capacity x (oper. temp - tap temp)
Heat required = 345,600 gals/yr x 8.33 lbs/gal x 1 x (140 -50) = 259,096,320 BTU
Heat cost = 259,096,320 BTU/yr x 0.0002923 kwh/BTU x $0.05/KWH = $5,514.69/yrTotal water and heat costs = Water cost + heat cost = $1,728.00 + $3,786.69 = $5.514.69/yr
B. Recycle water/heat costs
1. Water cost
Gallons/yr - Dumps + Evaporation losses = gal water dumped/yr + (% loss x gal/yr for
no-recycle system) = 1000 gal/yr + 4% (345,600/yr) = 14,824 gal/yr.
Water cost = 14,824 gal/yr x $0.005 (water/sewage/fees/gal) = $74/yr.
2. Heat cost
Heat for tap water = tap water (lbs/yr) x heat capacity x (oper temp - tap temp) = 123,484 x 1 x (140 -50) = 11,113,560 BTU/yr
Heat required for recycled water:
Lbs recycled/yr = total rinse flow (lbs/yr) - evaporation losses = 345,600 gals/yr x 8.33
lbs/gal - 10%(2,878,848) = 2,590,963 lbs/yrHeat for recycled - lbs/yr recycled x heat capacity x (oper temp - drain temp) = 2,590,963 x 1 x (140 -135) = 12,954,815 BTU/yr
Total heat required = heat for tap water + heat for recycled water = 11,113,560 +
12,954,815 = 24,068,375 BTU/yrHeat cost = 24,068,375 BTU/yr x 0.0002923 KWH/BTU x $0.05/KWH = $352/yr
Total water and heat costs = Water cost + Heat cost = $74 + $352 = $426/yrC. Summary
Recycled No-recycle Savings
Water/sewage $74 - $1,728 = $1,654
Heat $352 - $3,787 = $3,435Total $426 - $5,515 = $5,089
Copyright 2003 Separation Technologists, Inc. AquaChemical, AquaCycler, AquaMembrane, AquaZero, and Separation Technologists are trademarks and registered trademarks of Separation Technologists, Inc. All other names are trademarks of their respective companies.