Honeycomb heater having a portion that is locally quickly heated

摘要

A honeycomb heater comprising a honeycomb structure and a catalyst layer supported on partition walls of the honeycomb structure. The honeycomb heater includes a first portion that is resistance adjusted such that the first portion is adapted to heat more quickly than a second portion of the honeycomb heater. The first portion includes at least an inlet end of the honeycomb that receives gas that flows therethrough. In addition, the first portion has an area along the gas inlet within a range of 5 to 50% of the sectional area of the gas inlet. The first portion may extend through the honeycomb structure and terminate before reaching the gas outlet of the heater. The partition walls of the first portion may have a different hydraulic diameter, different thickness or different cell density than the second portion of the honeycomb heater.