Showa Denko K.k.

Hokuto Mine

Naohisa Higashiyama

Motoyuki Takagi

A double-wall-tube heat exchanger has outer and inner tubes. A clearance between the outer and inner tubes and the interior of the inner tube serve as refrigerant flow paths. Opposite end portions of the inner tube project from opposite ends of the outer tube. The outer tube includes expanded portions formed near the opposite ends. Contracted portions are formed on the outer tube to be located on the outer sides of the expanded portions, and are brazed to the inner tube. Longitudinally extending ridges project radially inward from the inner circumferential surface of the outer tube at predetermined circumferential intervals. The ridges on the inner circumferential surfaces of the expanded portions and the contracted portions are crushed. The clearances between the inner tube and portions of the contracted portions of the outer tube where the ridges are not formed are filled with a brazing filler metal.

Double-wall-tube heat exchanger

An evaporator includes a refrigerant inlet header section, a refrigerant outlet header section, and a refrigerant circulation path connecting the two header sections. A refrigerant inlet-outlet member composed of a first plate, a second plate, and an intermediate plate is joined to the two header sections. The refrigerant inlet-outlet member has an inflow channel whose one end communicates with the refrigerant inlet of the refrigerant inlet header section and whose other end is opened to a rear edge of the refrigerant inlet-outlet member, and an outflow channel whose one end communicates with the refrigerant outlet of the refrigerant outlet header section and whose other end is opened to the rear edge. The first and second plates each have inflow-channel-forming and outflow-channel-forming outward swelled portions. Cutouts and a through hole are formed in the intermediate plate such that the inflow channel and the outflow channel cross each other.

Growing community of inventors

Oyama, Japan

Hokuto Mine