Heat Recovery System Capturing Heat from Exhaust Gases
February 1, 2007
A process heat recovery system from Megtec Systems, De Pere, Wis., uses the heated air from process dryers, ovens and air pollution control systems to help processors reduce operating costs by capturing waste heat.
“Thermal air management provides many opportunities to save energy and cut operating costs,” said Tim Golden, manager of Megtec’s Engineering Services Group.
The system extracts wasted heat energy and uses it to heat areas of a plant or process. The robust system, designed for efficient installation, is fully assembled and requires minimal space. Megtec has developed an online energy savings calculator to help potential users of the heat recovery system determine the approximate value of energy saved based on specific conditions.
The flow arrangement consists of a slipstream of heated air drawn from an exhaust duct or stack and passed through a heat exchanger, then returned to the exhaust duct or stack. Fresh outdoor air is drawn in and passed through the heat exchanger, where it is heated and controlled to a setpoint of 70 to 125oF to provide supplemental heating or summer cooling.
Using the preengineered system, energy recovery is possible with source temperatures as low as 200oF or as high as 700oF. Safety features include temperature protection of the delivered airstream as well as isolating it from the process and facility anytime the unit is turned off.
Standard features include the ability to interface with existing building climate controls for “on command” operation as well as automatic interface with oxidizer or other heat sources to prevent interference with existing processes. It also prevents condensation from forming from the regulated airstream, which in turn eliminates the need of having to dispose of collected condensate and having to comply with any related regulatory issues.