摘要 |
A heater unit includes a metallic casing, and a honeycomb heater held in the casing, comprising a metallic honeycomb structure having a large number of parallel passages extending in the direction of the flow of a gas passing through the heater unit and at least one electrode for electrical heating of the honeycomb structure, attached to the honeycomb structure. A fastening member is fitted to part of the outer surface of the honeycomb heater to stabilize the shape of the honeycomb heater and a holding member is fitted to the outer periphery of the honeycomb heater to connect the honeycomb heater with the inner surface of the casing via the holding member. This heater unit can be suitably used for purification of the exhaust gas emitted from an automobile engine, because, in the heater unit, the unpurified exhaust gas which passes through the gap between the casing and the honeycomb heater, i.e. the by-pass flow, is minimized.
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