Patent ID: 8602089

Claim:
A heat exchanger apparatus comprising: a first outer shell having an open end and an end wall; an inner shell haying a longitudinal axis and a cavity, the inner shell extending through the end wall of the first outer shell; a first tube sheet having an inner region and a rim portion, the rim portion having a design feature for allowing the rim portion to act as an expansion joint, the design feature comprising a circumferential groove in an outer lateral surface of the rim portion, a first flange extending from the inner region in a direction of the longitudinal axis and a second flange extending from the inner region in a direction transverse to the longitudinal axis; the second flange of the first tube sheet connected to the first outer shell so as to enclose the open end of the first outer shell and form a first header cavity between the first outer shell and the inner shell; a clearance existing between the inner shell and the first tube sheet; a plurality of holes in the inner shell that form passageways between the first header cavity and the cavity of the inner shell; a first end cap connected to the first flange of the first tube sheet, an inner surface of the first end and an inner surface of the first flange collectively defining a first plenum on a side of the first tube sheet opposite the first header cavity; a plurality of tubes located in the cavity of the inner shell and operably connected to the first tube sheet; an opening in the first outer shell for flowing a shell-side fluid into and/or out of the first header cavity; an opening in the first end cap for flowing a tube-side fluid into and/or out of the first plenum; and wherein the circumferential groove comprises a floor that is spaced a first distance from the longitudinal axis and the inner surface of the first flange is spaced a second distance from the longitudinal axis, the second distance being greater than the first distance.