RPA Engineering Offers Unique Energy-Saving Dynamic Control System for Process Cooling

RPA Engineering has developed the Dual Cooling Tower Spillover Temperature Control System, a new, high efficiency dual programmable logic controller-driven (PLC-driven) system for chilled water processes that allows two or more cooling towers to be individually controlled for optimum cost and energy savings.

Traditionally, a single-temperature controller operates two or more cooling towers’ fans in tandem. However, cooling towers are very sensitive to changes in process temperatures, as well as fluctuations in humidity and ambient conditions. In systems with multiple cooling towers, this sensitivity can result in wasted energy as the secondary cooling towers sometimes are forced to run unnecessarily in response to subtle atmospheric and process changes.
The new Dual Cooling Tower Spillover Temperature Control System allows the controller to establish different set points for each cooling tower.  In this way, the first tower operates its fan only as needed to regulate the temperature, while the additional tower fans are engaged only as needed to regulate the broad range of temperatures required by the process plant equipment. This variable control option helps processing plants continuously reduce energy costs.
The system utilizes an Allen-Bradley RS Logix 5000 PLC with a unique proprietary ladder-logic and structured text program in conjunction with variable frequency drives to control the fans speed.
According to Jack M. Guitas, P.E., manager of electrical and controls engineering for RPA Engineering, “The Dual Cooling Tower Spillover Temperature Control System is ideal for use in any facility that uses a chilled or cool water process, such as oil refineries, chemical plants, power stations, iron and steel foundries and other process manufacturing plants. It effectively helps to eliminate waste heat from induction furnaces, arc furnaces, induction coils, power supplies and quench tanks, while managing the fans, pumps, valves and temperature control loops.  It can be adapted to any manufacturer’s fan-controlled cooling tower.”
The Dual Cooling Tower Spillover Temperature Control System is ideal for both new and retrofit applications. To date, RPA Engineering has installed the new system at a number of manufacturing and foundry locations.