Flexible & Cost-Effective Thermal Oxidizers - Over 95% Destruction Efficiency for VOCs

For very low VOC concentrations, Met-Pro Systems recommends a Regenerative Thermal Oxidizer (RTO) that is capable of 95% destruction efficiency and up to 95% heat recovery. A two-chamber, industrial RTO is the most cost effective selection. Individual heat recovery chambers are filled with ceramic heat sink media. Incoming VOC laden air enters one of the chambers where the gas is raised close to the light-off temperature by heat stored in the ceramic heat sink media. The heated gas is then burned in the top combustion chamber. These hot gases are then routed through a second chamber where the heat is again stored in the ceramic media. During the next operating cycle of the RTO, the gas flow through the unit is reversed by a proprietary switching valve.

• Met-Pro Systems RTOs are applied in applications where VOC concentrations are as low as 3% of the Lower Explosive Limit (LEL) or as high as 25% LEL.  We employ various methods of heat rejection to maintain optimum performance. As VOC concentration increases, the natural gas is reduced to the burner - all the way to zero if needed.  If VOC concentration continues to increase, a dilution air damper allows fresh air into the RTO for cooling.  When VOC concentrations are very high, a hot-gas by-pass damper opens so that hot gases are directed directly from the combustion chamber to the exhaust stack.
  
  
• Exhaust gases containing dilute concentrations of VOCs are delivered to the RTO via a forced draft fan that is controlled by a VFD to maintain constant draft control. A proprietary single-blade switching valve directs the gases to one of  two heat recovery chambers where the gases are preheated by heat stored in structured ceramic media. Once preheated, the gases are brought up to oxidation temperature in a combustion chamber with heat from a small supplemental burner.  From the combustion chamber, the cleaned gases pass down through the second heat recovery chamber where the gases give up heat that is stored in the structured ceramic media in the second heat recovery chamber.  The cooled, clean gases pass again through the switching valve and out to atmosphere via an exhaust stack.
  
  
• Sophisticated PLC controls determine the optimum time to switch the position of the switching valve reversing the flow of gases through the RTO.  The heat recovery chamber that was the inlet chamber now become the outlet chamber and vice versa.