Switching valve

A regenerative thermal oxidizer for processing a gas, comprising:

• a combustion zone;
• a first heat exchange bed containing heat exchange media and in communication with said combustion zone;
• a second heat exchange bed containing heat exchange media and in communication with said combustion zone;
• a valve for alternating the flow of said gas between said first and second heat exchange beds, said valve comprising:
• a first valve port in fluid communication with said first heat exchange bed and a second valve port separate from said first valve port and in fluid communication with said second heat exchange bed;
• a flow distributor having an inlet passageway and an outlet passageway, said flow distributor being movable with respect to said first and second valve ports between a first position in which gas entering said inlet passageway flows into said first heat exchange column through said first valve port and out of said outlet passageway through said second heat exchange column and said second valve port, and a second position in which gas entering said first passageway flows into said second heat exchange column through said second valve port and out said outlet passageway through said first heat exchange column and said first valve port;
• said flow distributor comprising a blocking portion for blocking the flow of gas through a portion of said first and second valve ports when said flow distributor is between said first and second positions.