HEAT EXCHANGER TUBE

• US 20100116472A1
• Filed: 01/20/2010
• Published: 05/13/2010
• Est. Priority Date: 05/06/2003
• Status: Active Grant

• Current Assignee: MA Aluminum Corporation
• Original Assignee: Mitsubishi Aluminum Company Limited (Mitsubishi Materials Corporation)
• Inventors: WATANABE, Akira, KATSUMATA, Masaya, HYOGO, Yasunori
• Granted Patent: US 8,640,766 B2
• Time in Patent Office: Days
• US Class Current: 165/133
• CPC Class Codes: B23K 1/0012 Brazing heat exchangers
• CPC Class Codes: B23K 1/008 Soldering within a furnace B23K1/012 takes precedence
• CPC Class Codes: B23K 1/012 Soldering with the use of hot gas
• CPC Class Codes: B23K 1/203 Fluxing, i.e. applying flux onto surfaces
• CPC Class Codes: B23K 2101/06 Tubes
• CPC Class Codes: B23K 2101/14 Heat exchangers
• CPC Class Codes: B23K 2101/34 Coated articles , e.g. plated or painted; Surface treated articles
• CPC Class Codes: B23K 2103/10 Aluminium or alloys thereof
• CPC Class Codes: B23K 35/286 Al as the principal constituent
• CPC Class Codes: B23K 35/3603 Halide salts
• CPC Class Codes: B23K 35/3605 Fluorides
• CPC Class Codes: F28F 19/02 by using coatings, e.g. vitreous or enamel coatings
• CPC Class Codes: F28F 19/06 of metal
• CPC Class Codes: F28F 21/084 from aluminium or aluminium alloys
• CPC Class Codes: F28F 2255/16 extruded

Abstract

A heat exchanger tube comprising an Al alloy extruded tube, and a flux layer including Si powder, Zn-containing flux, and binder formed on an outer surface of the Al alloy extruded tube, wherein an amount of the Si powder applied on the Al alloy extruded tube is in a range of 1 g/m² or more and 5 g/m² or less, an amount of the Zn containing flux applied on the Al alloy extruded tube is in a range of 3 g/m² or more and 20 g/m² or less, and the Si powder has a particle diameter distribution such that 99% particle diameter is 5 μm or more and 20 μm or less, and an amount of coarse particle having a diameter of not smaller than 5 times (D₉₉) is less than 1 ppm by volume.

Claims

1. A heat exchanger tube comprising an Al alloy extruded tube, and a flux layer including a Si powder, a Zn-containing flux, and a binder formed on an outer surface of the Al alloy extruded tube,

wherein

an amount of the Si powder applied on the Al alloy extruded tube is in a range of 1 g/m² or more and 5 g/m² or less,

an amount of the Zn containing flux applied on the Al alloy extruded tube is in a range of 3 g/m² or more and 20 g/m² or less, and

the Si powder has a particle diameter distribution such that 99% particle diameter (D₉₉) is 5 μ

m or more and 20 μ

m or less, and an amount of coarse particles having diameters of not smaller than 5 times (D₉₉) is less than 1 ppm by volume,

where (D₉₉) denotes a critical diameter defined such that cumulative volume of particles not larger than (D₉₉) constitute 99% by volume of all the particles.

2. A heat exchanger tube according to claim 1, wherein 50% particle diameter (D₅₀) of the Si powder is (D₉₉)×

0.05 or more and (D₉₉)×

0.7 or less, where (D₅₀) denotes a critical diameter defined such that cumulative volume of particles not larger than (D₅₀) constitute 50% by volume of all the particles.

3. A heat exchanger tube according to claim 1, wherein the Zn-containing flux contains at least one selected from ZnF₂, ZnCl₂, and KZnF₃.

4. A heat exchanger tube according to claim 1, wherein the Al alloy extruded tube is constituted of an alloy containing Si of 0.05% or more and 1.0% or less by weight, Mn of 0.05% or more and 1.2% or less by weight, and the balance being consisting of Al and inevitable impurities.

5. A heat exchanger tube according to claim 2, wherein the Al alloy extruded tube is constituted of an alloy containing Si of 0.05% or more and 1.0% or less by weight, Mn of 0.05% or more and 1.2% or less by weight, and the balance being consisting of Al and inevitable impurities.

6. A heat exchanger tube according to claim 3, wherein the Al alloy extruded tube is constituted of an alloy containing Si of 0.05% or more and 1.0% or less by weight, Mn of 0.05% or more and 1.2% or less by weight, and the balance being consisting of Al and inevitable impurities.