Seal assembly in rotary regenerative heat exchanger

In a rotary regenerative heat exchanger having a heat-transferring member which is cylindrical and rotatable on the longitudinal axis thereof and a stationary block member having a surface opposite to and spaced from an end face of the heat-transferring member, a seal assembly for providing seal between said end face and said surface, comprising:

• a loop-shaped seal member having a substantially rectangular configuration of a heat-resistant and substantially rigid material having an outer surface, an inner surface, a flat front surface stretched between said inner and outer surfaces and a back surface;
• a loop-shaped groove having a substantially rectangular configuration formed in said surface of the block member to have a width larger than the width of said seal member, said groove having an inner wall;
• a loop-shaped back-up having a substantially rectangular configuration member of a resilient material tightly received in said groove, said seal member being received in said groove such that said front surface and said back surface of said seal member are kept in contact with said end face of the heat-transferring member and said back-up member, respectively, said back-up member being sandwiched with a compressive force between said back surface of said seal member and the bottom of said groove when said front surface is in contact with said end face, at least one of said groove and said back-up member being shaped such that a loop-shaped space is formed in said groove partly defined by said inner wall and an inner extreme region of said back surface, so that part of an inner surface of said back-up member comes into no contact with part of said inner wall of said groove;
• said bottom wall of said groove being shaped to have a shoulder portion contiguous to said inner wall, said back-up member extending from said outer wall to the outer end of said shoulder portion;
• and
• a loop-shaped auxiliary seal member of a resilient material arranged in said groove to provide seal between an outer wall of said groove and said outer surface of said seal member and keep said inner surface of said seal member in intimate contact with said inner wall of said groove with a compressive force.