Air filter

An air filter comprising:

• a honeycomb rotor which carries a porous adsorbent and is configured to be rotated in a circumferential direction;
• a drive means configured to rotate the honeycomb rotor;
• a first gas introduction section disposed on one side of the honeycomb rotor;
• a second gas introduction section disposed on another side of the honeycomb rotor, the first and second gas introduction sections configured to introduce counter-currently flowing two types of gases into different conduits;
• a first gas exhaust section which is disposed on the other side of the honeycomb rotor and configured to introduce the gas which is introduced from the first gas introduction section and to be exhausted through the honeycomb rotor;
• a second gas exhaust section which is disposed on the one side of the honeycomb rotor and configured to introduce the gas which is introduced from the second gas introduction section and to be exhausted through the honeycomb rotor;
• a heater disposed at an inlet port of the first gas introduction section;
• a drive controller for controlling a drive means so that the honeycomb rotor can rotate intermittently by every part of a regenerative-purge zone opposing to the first gas introduction section in the filter surface of the honeycomb rotor;
• and
• a heater controller configured to put said heater in an ON-state during a regenerative period of the first half of a regenerative/purge period starting from the time when said honeycomb rotor stops rotating until it starts rotating and puts said heater in an OFF-state during the latter half purge period.