U-shaped heat exchanger tube with a concavity formed into its return bend

Abstract

A heat exchanger tube includes a tube body that forms a hollow passageway and has a U-shaped tube section defining a return bend and a pair of straight tube sections. Respective ones of the straight tube sections are connected to the U-shaped section at respective connection locations and extend generally parallel to one another to define an internal space disposed between and among the U-shaped tube section and the straight tube sections connected to the U-shaped tube section. The U-shaped tube section has a concavity formed thereinto with the concavity defining a portion of the internal space. A heat exchanger serpentine tube includes a plurality of straight tube sections arranged in a plurality of generally parallel rows and disposed in a common plane and a plurality of U-shaped tube sections connected to the plurality of straight tube sections to form a serpentine configuration.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a U-shaped heat exchanger tube. More particularly, the present invention is directed to a U-shaped heat exchanger tube with a concavity formed into a return bend of the U-shaped heat exchanger tube. BACKGROUND OF THE INVENTION [0002] Commonly known in the art in the fabrication of the heat exchangers, straight tubes are bent in an approximate range of bend angles of 170° and 190° so as to form a unitary construction of two straight tube sections integrally connected with a return bend formed at a selected bend angle. A skilled artisan would appreciate that if the straight tube is bent precisely 180°, the two straight tube sections would extend parallel to one another while if the straight tube is bent at a selected bend angle anywhere in the approximate range other than 180°, the straight tube sections would extend generally parallel with one another. For simplicity, the term “generally parallel” shall refer to the relat...

AI Technical Summary

Benefits of technology

The present invention provides a heat exchanger tube with a U-shaped tube section that has a tight return bend and a concavity formed thereinto. This results in a reduced pressure loss of the heat exchange fluid as it flows through the tube. The heat exchanger tube is also wrinkle-free and made from a material difficult to bend. The invention also includes a heat exchanger serpentine tube with a plurality of straight tube sections and U-shaped tube sections that form a serpentine configuration. The U-shaped tube sections have a concavity formed thereinto with the concavity defining a portion of the internal space. The heat exchanger includes an inlet header, an inlet connection, an outlet header, and a plurality of heat exchanger serpentine tube bodies that interconnects the inlet and outlet headers. The technical effects of the invention include improved heat exchange efficiency, reduced pressure loss, and reduced likelihood of fouling.

Problems solved by technology

Depending upon the metal material used for the fabrication of the heat exchanger tubes, difficulty may arise.

For instance, it is difficult to bend straight stainless steel tubes into U-shaped heat exchanger tubes particularly when a relatively tight return bend is desired.

Such wrinkling is sometimes considered unsightly and sometimes customers who purchase heat exchangers question whether the structural integrity of the stainless steel heat exchanger tubes with relatively tight, wrinkled bends is compromised.

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