Enhancements to a heat exchanger manifold block for improving the brazeability thereof

A heat exchanger manifold block brazed to a jumper tube and a heat exchanger manifold, the manifold block having a longitudinal axis substantially parallel to a longitudinal axis of the manifold, the manifold block comprising:

• a longitudinal surface substantially parallel to the longitudinal axes of the manifold block and the manifold;
• a lateral end surface substantially perpendicular to the longitudinal surface of the manifold block;
• a mounting flange mated with and brazed to the manifold, the mounting flange being spaced longitudinally from the lateral end surface of the mounting block;
• a port hole in the lateral end surface of the manifold block, the jumper tube being received in and brazed to the port hole;
• longitudinal fins projecting from the longitudinal surface of the manifold block and lateral fins projecting from the lateral end surface of the manifold block, the lateral fins and the longitudinal fins promoting convective and radiative heat transfer to the manifold block so as to increase the heating rate of the manifold block during brazing of the manifold block to the jumper tube and the manifold;
• a counterbore surrounding the port hole, the counterbore being sized to serve as a reservoir for molten braze metal and to prevent molten braze metal from flowing away from the jumper tube and toward the fins during brazing of the jumper tube to the port hole;
• and
• a cylindrical boss within the counter bore and surrounding the port hole, the cylindrical boss having a distal end that does not project beyond the lateral end surface of the manifold block, the jumper tube being brazed to the cylindrical boss.

A method of brazing a heat exchanger manifold block to a heat exchanger manifold and a jumper tube, the method comprising the steps of:

• forming the manifold block to have a longitudinal axis, a longitudinal surface substantially parallel to the longitudinal axis of the manifold block, a second surface substantially perpendicular to the longitudinal surface of the manifold block, a port hole in the second surface of the manifold block, fins projecting from at least one of the longitudinal and second surfaces of the manifold block, and a counterbore surrounding the port hole;
• and
• assembling the manifold block, the jumper tube and the manifold by installing the jumper tube in the port hole and mating the manifold block with the manifold so that the manifold block is oriented to have the longitudinal axis thereof substantially parallel to a longitudinal axis of the manifold;
• and then
• brazing the manifold block to the jumper tube and the manifold, the fins promoting convective and radiative heat transfer to the manifold block so as to increase the heating rate of the manifold block, the counterbore serving as a reservoir for molten braze metal and preventing molten braze metal from flowing away from the jumper tube and toward the fins.