The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 10, 1999
Filed:
Apr. 21, 1998
Masayoshi Takiura, Aizuwakamatsu, JP;
Seizo Masukawa, Aizuwakamatsu, JP;
Haruo Kohno, Aizuwakamatsu, JP;
Shunroku Sukumoda, Aizuwakamatsu, JP;
Mitsubishi Shindoh Co., Ltd., Tokyo, JP;
Abstract
The present invention has the object of increasing the heat exchanging performance of heat transfer tubes having grooved inner surfaces. In order to achieve this object, the heat transfer tubes having grooved inner surfaces according to the present invention have fins which are formed consecutively in a circumferential direction on the inner surface of a metallic tube. The inner surface of the metallic tube is divided into regions R1.about.R4 in the circumferential direction. The inclination angle .alpha. with respect to the axis of the heat transfer tube of the fins 2 in odd-numbered regions when counting from one of the regions is 10.about.25.degree., and the inclination angle .beta. with respect to the axis of the heat transfer tube of the fins 2 in even-numbered regions when counting from the region is -10.about.-25.degree.. The pitch of the fins 2 is 0.3.about.0.4 mm, the height of the fins from the inner circumferential surface of the metallic tube is 0.15.about.0.30 mm, and the angle formed between the side surfaces of each fin is 10.about.25.degree..