1. Automating Your Water Treatment Program Presented by:

2. Cooling Tower Controllers 5 Major Control Functions: Dissolved Solids Control Scale & Corrosion Inhibitor Feed Biocide Feed pH Control ORP Control

3. Dissolved Solids (TDS) Control Key Facts: Only pure water evaporates Dissolved solids (TDS) are left behind in recirculating water TDS accumulate and fall out of solution in the form of scale

4. Scale Buildup vs. Energy Loss 1/1000” of scale can reduce heat transfer efficiency by up to 10% This translates into a proportionate increase in energy costs

5. Bleed-Off = Scale Prevention “Bleed-off” refers to removing water with high TDS and replacing it with fresh makeup water This process lowers the overall TDS to a safe, non- scale forming level. Manual bleed-off can result in high and low TDS spikes (forms scale or wastes water)

6. Results of Manual TDS Control Tendency to Form Scale Deposits TARGET MAXIMUM Excess Water Usage

7. The Solution: Automated Bleed-Off Two common forms of automated bleed-off are “conductivity control” and “proportional bleed” Bleed-off valves should be installed downstream of the heat exchanger for optimum energy efficiency

8. Conductivity Control Systems TDS in the water conduct electricity Conductivity controllers measure the ability of the water to conduct electricity Conductivity controllers automatically open a bleed- off valve when TDS levels approach scale forming levels

9. Conductivity Control Systems Conductivity controllers keep TDS levels near the target maximum at all times Automated controllers account for changes in load demands and atmospheric conditions -- manual bleed does not Target Maximum

10. Conductivity Control Systems Installation Guidelines: Bypass assembly with 3-10 gpm flow rate No air pockets Upstream of chemical injection points Probe should be mounted near controller for ease of cleaning/calibration, but wire extensions in excess of 300’ are permissible Conductivity probe wire must be separated from high voltage lines

11. Conductivity Control Systems Pros: Extremely accurate Easy to use Cons: Maintenance required (periodic probe cleaning and calibration) Installation requirements (piping/wiring)

12. Proportional Bleed Systems Also called “water meter timer” systems Bleeds-off proportionally to the volume of incoming makeup water Contacting head water meter initiates timed bleed-off cycle

13. Proportional Bleed Systems Pros: Very little maintenance Ease of installation Cons: Doesn’t account for changes in makeup water quality Leakage or “windage” can lead to excess bleed-off

14. Proportional Bleed Systems Installation Guidelines: Water meter wire can be extended up to 1000’ Low voltage water meter wire must be separated from other high voltage lines

15. Automated Inhibitor Feed “Feed With Bleed” Chemical is injected as bleed valve opens Potentially wastes chemical “Feed After Bleed” Chemical is injected after bleed valve closes Feed is proportional to bleed-off

16. Automated Inhibitor Feed “Percentage Timer” Chemical is fed on a repeating time cycle Doesn’t correspond to water usage “Pulse Timer” Signal from makeup water meter initiates feed cycle Chemical is fed proportioanlly to makup water Most accurate way to dose inhibitors

17. Automated Biocide Addition Biocides should not be handled or added manually (health and safety hazard) Biocides are typically “slug fed” using a chemical pump (or brominator) and timer A 28-day timer initiates the biocide feed cycle Bleed-off is typically “locked out” during biocide feed cycles

18. pH Control Hard water can be “softened” using controlled acid feed pH controllers allow acid to be fed at safe and consistent levels

19. ORP Control ORP = oxidation-reduction potential ORP is a relative measurement of the amount of free chlorine or bromine in a system using a measurement similar to pH ORP control is not used widely compared to “slug-feeding” biocides as it is relatively costly and more maintenance intensive

20. pH/ORP Guidelines Routine cleaning of probes is essential Probe wire shouldn’t exceed 15’ in length without a signal amplifier Probe wires should never be spliced All chemicals should be inject downstream of pH or ORP sensors pH/ORP probes have a serviceable lift of approximately 12 months

21. Analog Controllers Feature analog meter readout of conductivity Limited functionality (1 or 2 control functions) Easy to operate Economical choice No modem or Internet communication

22. Microprocessor Controllers Keypad programmable Digital display Combines many functions Slight operational learning curve Initially more expensive Capable of all forms of remote communication

23. Chemical Metering Pumps Most water treatment applications use solenoid- driven diaphragm pumps Metering pumps are specified by: –Type of chemical being pumps –Desired output –Required injection pressure

24. Chemical Metering Pumps Most common pumps have a suction lift of five feet Injection valves should be installed vertically into the bottom side of a pipe A foot valve is placed in the chemical drum to help a pump keep its prime

25. Degassing Considerations Some “off-gassing” chemicals (bromine, chlorine, etc.) produce gases that can vapor- lock the pump When vapor-locked, a pump loses its prime and will not pass chemical through the head Utilize a “degassing valve” to allow gas to escape the pump head and prevent priming problems

26. Typical System Installation

27. Equipment Trends Side Stream Filtration “Smart” Pumps Multi-System Controllers Remote Monitoring Online Service Reporting Chemical Volume Measurement Direct Chemical Measurement ???

28. Side Stream Filtration Reduces energy costs by making heat exchangers more efficient Reduces fouling and improves water clarity Typically installed in bypass line sized to 10% of system volume

29. “Smart” Metering Pumps Combine pump and controller features into a single pump housing Inexpensive control option for simple applications Limited to 2 control features

30. Multi-System Controllers Early controllers featured only one or two relay outputs Modern controllers feature up to 20 control relays Sophisticated units can control up to four independent water treatment systems

31. Remote Monitoring 4-20 mA signals and dry contact switch closures can be sent to building management systems Modem-to-modem communication allows off-site monitoring and control with custom software Cutting-edge controllers are using the Internet to transmit data and alarm conditions

32. Web Based Remote Monitoring Snapshot of WebAdvantage Controller Status

33. Web Based Remote Monitoring Uses facility’s existing Ethernet for remote access Eliminates need for phone lines and proprietary software “Always on” connection detects power interruptions Allows simultaneous multiple user access No need to download data

34. Online Service Reporting Combine water treatment test results with controller operating data Receive automated services reports at user-defined intervals Receive e-mail alarms when operating parameters are out of spec

35. Chemical Volume Measurement Volume-activated pulse output device is installed on discharge side of chemical pump Chemical volume is combined with water meter volume to calculate PPM concentration of chemical

36. Direct Chemical Measurement Using specialized probes, direct measurement of phosphonates and other chemicals will be possible Using proportional control technology, precise chemical levels will be maintained in a system Precise dosing will maximize water treatment program efficiency

37. Any Questions?