Patent ID: 7506681

Claim:
A brazed headerless core assembly and a pre-existing heat exchanger assembly from which a core assembly has been removed such that header members with spaced-apart apertures therein remain of the pre-existing heat exchanger, the brazed headerless core assembly having a tube end spacing pattern corresponding to the spacing of the apertures of the header members to enable the brazed headerless core assembly to be assembled with the header members and fluidically sealed thereto with resilient sealing means, the brazed headerless core assembly comprising: substantially parallel tubes, each of the tubes having an oblong cross-section defining oppositely-disposed planar surfaces that are spaced from a longitudinal axis of the tube, each of the tubes having oppositely-disposed tube ends so that each adjacent pair of tubes has adjacent pairs of tube ends having a predetermined distance therebetween that together define the tube end spacing pattern of the brazed headerless core assembly; centers between the tubes, substantially parallel to the tubes, and brazed to the planar surfaces of the tubes with a braze material; and means for maintaining the predetermined distances and the tube end spacing pattern defined thereby, the maintaining means comprising the centers and excluding a plate or other structural member secured transverse to the tubes to maintain the predetermined distances and the tube end spacing pattern, whereby the tube ends are unrestricted and the predetermined distances and the tube end spacing pattern are exclusively determined by the centers; and wherein the braze material has a melting temperature so as to be molten at about 600° C. and below melting temperatures of the tubes and centers; the predetermined distances and the tube end spacing pattern enable the tube ends to be simultaneously received in and sealed with the resilient sealing means in the apertures in the header members of the pre-existing heat exchanger assembly; and the tube ends are sized to be smaller than the apertures of the header members to accommodate the resilient sealing means therebetween.