Patent ID: 8795598

Claim:
An exhaust treatment device, comprising: a housing defining an axis with an inlet opening and an outlet opening with the openings being disposed along the axis; a first catalyst brick and a second catalyst brick each having an inlet end and an outlet end, the first catalyst brick being disposed within a first segment adjacent the inlet opening of the housing and the second catalyst brick being disposed within a second segment adjacent the outlet opening of the housing with the segments being disposed along the axis, the first segment having an inner periphery that is not equal to an inner periphery of the second segment, the first and second catalyst bricks each having nonuniform dimensions with respect to one another, the first and second segments of the housing being independently dimensioned in proportion to the first and second catalyst bricks respectively; a first insulating support cover disposed within the first segment of the housing in a first annular space between an inner surface of the housing and an exterior surface of the first catalyst brick with the first insulating support cover having a first material, a first basis weight, a first resistance to thermal gas erosion, and a first rate of thermal expansion; and a second insulating support cover disposed within the second segment of the housing in a second annular space between the inner surface of the housing and an exterior surface of the second catalyst brick with the second insulating support cover having a second material, a second basis weight, a second resistance to thermal gas erosion, and a second rate of thermal expansion, the first and second insulating support covers being independently dimensioned in proportion to the first and second catalyst bricks respectively; wherein one or more of: the first and second materials are different from each other; the first basis weight is greater than the second basis weight; the first resistance to thermal gas erosion is greater than the second resistance to thermal gas erosion; and the first and second rates of thermal expansion are different from each other.