Problem
It is critical that the shower water temperature be maintained at precisely 92 degrees Fahrenheit. If the water is too cool, the hazardous material in question may not be removed. If the water is too hot, people can be scalded, or the pores of their skin may open, increasing their exposure to the very chemicals that the process is designed to remove. ACSI has developed three and four-boiler trailers to increase decontamination capacity, but control of this number of boilers proved to be difficult.

Solution
Watlow's CPC400 multi-loop temperature controller with the new TRU-TUNE+^TM adaptive algorithm tunes control loops automatically, minimizing setup time and effort. In addition, the product ensures optimal performance by fine tuning loops more precisely than auto-tune features, and provides stable control through set point and load changes. ACSI's earlier systems with more than two boilers experienced unacceptable water temperature fluctuations when showers were turned on or off. Because the system includes numerous showers that can be independently turned on and off, the water flow can change quickly and by a large amount. Prior attempts with other products failed to control this very dynamic system at ACSI's test facility. When deployed, the decontamination equipment will have to provide precise water temperature regardless of whether the emergency happens at a blazing hot afternoon football game in the Texas summer or a frigid midnight concert in the Minnesota winter. With the TRU-TUNE+ algorithm the controller recognizes the changing dynamics of the system and adapts on the fly while maintaining the temperature well within the customer's specifications even with different inlet water temperatures. The CPC400 controller's custom logic capability is used to interlock the control outputs with the water flow. Watlow's SERIES SD controllers are used as redundant backups for control and are integrated through the CPC400 controller's logic software.