1. SRAPPA 2014 Moving Forward in the 21st Century 63rd Annual Conference
Marshall University, Huntington, West Virginia

2. LaMotte Water Management and present

3. Energy Conservation Through the Removal of Bio-film
The intent of this study is to demonstrate the impact of biofilm on water cooled condenser heat transfer surfaces in an electric driven chiller plant and the associated increase in electrical usage.

4. Green Technology by Zentox

5. The demonstration is a study of the use of Ozone as a stand alone treatment system to provide superior Bio-film control and resultant increase in heat transfer efficiency.
The study will measure Fouling Factors and Bio-film on operational water chillers.

6. Process Description
Tower water is recirculated from/to the tower sump in a bypass loop
Tower water is dosed with Ozone in the recirculating loop
Ozone is manufactured on site by feeding dry, oxygen rich gas to a plasma block Ozone generator
Ozone gas is drawn into the bypass loop by negative presure via a venturi
Ozone production is regulated by a feedback loop from an ORP sensor
ORP set point is maintained by varying electrical charge in the Ozone generator
Conductivity of the cooling water is controlled by a TDS/Conductivity monitor and bleed valve
Conductivity set point is calculated to maintain
Langelier Saturation Index and
Phosphate Saturation Point

7. Process Description Monthly service requirements
On site make-up water and tower water chemistry
Clean ORP probe
Test oxygen generator feed gas concentration
Visually inspect cooling tower
Check Approach Temperature
Optical Bacteria and/or Corrosion Coupon Testing

8. Washington & Lee University Chiller Plant Study
System Components
Ozone Treatment Package
Two 300 gpm circulation pumps
Four Oxygen generators providing 36 LPM
Two Plasma Block Ozone generators providing 120 gm/hr
ORP controller for linier control of Ozone production
pH Control
Replace 66˚ Baume` Sulfuric Acid with CO2

11. Washington & Lee University Chiller Plant Study
Facility
4 Electrically Driven Chillers
3 – 1,200 Ton Chillers
1 – 600 Ton Chiller
1 Flooded Sump, Field-erected, Ceramic Counter Flow Tower
augmented by a dry sump Evapco cross-flow tower
Water Supplied by City Water and 2 Auxiliary Wells
Controlled with 2 level controls with well water always the primary source. City water designed to supliment when wells can not keep up with evaporation

13. Why use Fouling Factor?
Our primary concern is Bio-film and it’s ability to foul and insulate condenser tubes.
With measured and recorded Fouling Factor we get demonstrable, not theoretical, energy savings.

14. Fouled vs. Clean

15. Concept for Use of Fouling Factor
The Fouling Factor is independent of loadings, demands and degree days. Less Bio-film on the tubes, lower Fouling Factor with measurable improvement on heat transfer and energy consumption.

16. The Fouling Factor Formula Used
F (Fouling Factor) = 1/U – 1/Uc
Where U is the Heat Transfer Coefficient and the Clean/New Heat Transfer Coefficient respectively.
U = Q/(A x F x LMTD) is used to calculate the actual Heat Transfer Coefficient
Where Q is the Condenser Load, A is the Condenser Heating Area, F is the Temperature Correction Factor, and LMTD is the Log Mean Temperature Difference.

18. Significance of Bio-Film to Energy Loss
Old thinking:
Bio-film was a concern.
Current understanding:
New data and studies indicate that Bio-film is the single biggest contributor to energy loss.

19. Power of Bio-Film
Bio-film is almost 5 times more insulating that scale.
Thermal Conductivity
Calcium Carbonate
Calcium Phosphate
Calcium Sulfate
Iron Oxide
Bio-film

20. Porous Mixture of Organic and Inorganic Material

21. Ozone Bio-film’s Worst Enemy
Biofilm Prevention and Removal
Ozone Bio-film’s Worst Enemy

22. What is Ozone? 03 - an unstable form of oxygen with three atoms
Powerful oxidizing biocide
500% more effective than chlorine
Short life in evaporative cooling water (around 20 minutes)
Environmentally Safe- breaks down to oxygen

23. Biofilm Prevention and Removal
Keep system clean
Mechanically- physical removal
Chemically- micro-biocides, dispersants
Reduce Food
Filtration
Oxidation
Location of Equipment
Process Leaks

24. Biological Control and Standards
Chemically – must use dual biocide program to prevent development of immunity
Standard – maintain growth below 10,000 CFU (Colony Forming Units per ml)
Ozone – uses cold combustion to destroy cell wall and oxidize waste – impossible for bacteria to develop immunity
Standard – maintain growth below 100 CFU

27. Data Collection Fouling Factor Bio-film
Data collected prior to changeover to Ozone
Data collected after changeover to Ozone
Bio-film
Readings collected with the use of a coupon and results from a 15 minute reaction – all readings in BMR, or Bio-Mass Reading
Range – from <0.2 indicating no problem to >4.0 indicating severe Bio-fouling
Average readings prior to changeover to Ozone
Average readings after changeover to Ozone

28. Data Points, Calculations and Display
The Chiller Plant maintains sensors on the Chillers installed to monitor all necessary data – system temperatures, lift, approach temperatures – necessary to calculate the FF.
Since some of the necessary constants are considered proprietary by the Chiller manufacturer, they have built the calculation into their programming so that we can log FF for before and after comparison.
The data collection software provides a readout of this calculated number on the Dashboard of the University’s monitoring programs, allowing University personnel to see the FF at any given time.

29. BioMass Readings - Biofilm Testing
Washington & Lee University Chiller Plant
Lexington, VA
Before Ozone Treatment
After Ozone Treatment
Date
BMR
Coupon Location
12/27/2011
1.03 1
1/10/2012
0.71 2
1/24/2012
0.31
2/14/2012
2.27
3/8/2012
0.88
3/15/2012
0.47
4/18/2012
2.11
5/8/2012
2.08
6/4/2012
1.72
6/15/2012
1.36
7/13/2012
0.49 *
* Acid over feed on day of sample - pH at Removing this reading results in an average BMR of 1.38
7/25/2012
0.72
8/21/2012
1.26
9/12/2012
10/3/2012
***
*** Turned on Ozone system 10/13/2
10/22/2012
0.26
11/28/2012
0.19
12/11/2012
0.16
1/16/2013
0.17
3/12/2013
0.67
4/15/2013
0.28
5/1/2013
0.79
5/16/2013
1.31
5/29/2013
1.33
6/18/2013
4.02 **
**Allowed Bromine to run out
7/1/2013
7/16/2013
0.55
8/1/2013
0.85
8/13/2013
*** Turned on Ozone system 8/13/13
9/5/2013
9/17/2013
0.33
10/3/2013
0.41
10/23/2013
11/20/2013
1.16
Average Biofilm Reading Before Ozone
0.29
Average Biofilm Reading After Ozone
1.29
Average Biofilm Reading During Chemical Re-evaluation
Average Biofilm Reading After Ozone Re-start

31. Program Results Electrical Savings of 3.58%
Fouling Factor Improvement of 17% Over Chemical Program
Significantly Higher Savings When Chiller Load Above 840 Tons (on a 1200 Ton Chiller)
Bio-film Readings Significantly Reduced
Corrosion Rates Maintained in the Excellent Range
Eddy Current Test Results Identify No Impact
Results of Test Backed by Excellent Copper Corrosion Results

35. Picture of W&L Dashboard

36. Chiller Tonnage vs Fouling Factor

37. Chiller Tonnage vs Fouling Factor

38. Are there any questions?
Clean Streams™ is another Environmentally Friendly Product of the Zentox Corporation