1) Adsorption and concentration of the VOCs using a hydrophobic Zeolite Rotor
2) Desorption of the VOCs from the Rotor with a hot slip-stream of air
3) Destruction of the concentrated VOCs by a Thermal Oxidizer
A Rotor wheel is a temperature swing adsorption device, designed to continuously remove VOC from a low concentration, high volume air stream by adsorbing the VOCs onto a hydrophobic Zeolite media. After the VOCs have been collected, they are then released from the Rotor by a heated low volume air stream to be treated by the thermal oxidizer. By concentrating the VOCs into the low volume air stream, considerable energy savings, both electric and fuel gas, are achieved.
The Rotor cassette(s) [wheel(s)] shall be mounted on a shaft and bearings, and is rotated slowly in the air stream. As the Rotor turns, it passes through sealed sections, used for adsorption, desorption, and cooling. The Rotor(s) will turn at a speed of two (2) to eight (8) revolutions per hour.
The VOC-laden exhaust stream is drawn from the supply ductwork and pushed into the Rotor housing by the main process fan. As the exhaust stream enters into the Rotor housing, it slowly passes through the Rotor media and the VOC molecules that are contained in the air stream are adsorbed (collected) by the Zeolite material. As the Rotors continuously turns a small volume of cooling air passes through another portion of the Rotor to pre-heat and subsequently blend with a slip stream from the thermal oxidizer to reach the desorption temperature. This heated volume passes through a 3rd ‘pie-cut’ of the Rotor in the opposite direction of the process air flow and the collected VOCs are removed from the Zeolite material. The hot air causes the Zeolite pore structure to release the VOC molecules from the media while concentrating the VOCs in the air stream. The concentrated air stream then exits the rotor with the VOCs, and is directed to the Thermal Oxidizer system for destruction.