June 16, 2009—Plant operators with Cooling Towers who struggle with the twin demands of continuously reliable operation versus maintenance costs will find the rack-mounted Model 2122 Cooling Tower Control System from Electro-Chemical Devices reduces waste and cost by eliminating expensive excess chemical feeds.Water-based wet Cooling Towers are commonly made of concrete, steel, or fiberglass and operate based on the evaporative principle of cooling. They are widely utilized in the process industries as well as in HVAC systems supporting large institutional or commercial buildings.
Various types of corrosion from common rust to scaling and fouling are a constant maintenance concern, which requires expensive chemical treatment with biocides and corrosion inhibitors that also create pollutants.ECD’s plug-and-play Model 2122 Cooling Tower Control System (CTCS) is designed to apply the various chemicals utilized to prevent corrosion, scaling and fouling. A biocide timer is built into the system for ease of maintenance. It is simple to install, set-up and operate right out of the box. The Model 2122 is an integrated system, which controls acid feed, blowdown and inhibitor feed in cooling processes.
Acid feed is controlled via pH monitoring, blowdown is controlled via conductivity (TDS) and the inhibitor is fed on a user selected time basis.The highly advanced Model 2122 CTCS features a unique timer-based overfeed function that locks out the blowdown cycle or the acid/base feed function. It triggers a process alarm if the acid feed or blowdown cycle proceeds longer than the operator’s predetermined cycle time. The overfeed alarm function allows plant operators to prevent excessive harsh chemical treatments, which are costly and also over time can affect the life of the tower, piping, pumps and other ancillary cooling system equipment.The advanced Model 2122 CTCS consists of ECD’s Model 22 Controller, a Model PHS10 pH sensor and a Model CS10 conductivity sensor.
The C22 Controller is an intelligent analyzer with control logic and failsafe interlocks, which are utilized to inhibit excess chemical feed. Both the period and dose time are easily controlled by the system operator via a backlit LCD graphical display with membrane switch touch control. The C22 features four SPDT relays and is rated NEMA 4X for rugged environments. An optional digital input card also can be added to alarm no-flow conditions for extra safety. The PHS10 pH sensor and the CS10 conductivity sensor are easily installed and serviceable insertion style devices.
Their signal conditioned outputs provide a reliable noise-free signal to the C22 Controller’s analyzer for precise measurement and control. The PHS10 measures pH from 0 to 14 pH at 80C and withstands pressures from 0 to 100 psig. The CS10 measures conductivity from 500 us to 20 ms at 80C and withstands pressures from 0 to 100 psig.
