US5351750A — Tubular element for a heat exchanger

Claim 1

Independent Claim 226 words

A tubular element for a heat-exchanger comprising: a tubular core composed of a first aluminum alloy comprising up to 0.3 wt % maximum of silicon, up to 0.5 wt % maximum of iron, from 0.50 to 0.70 wt % of copper, from 0.65 to 1.0 wt % of manganese, from 0.1 to 0.30 wt % of magnesium, up to 0.05 wt % maximum of zinc, from 0.08 to 0.10 wt % of titanium, and the balance aluminum and unavoidable impurities; an inner layer on the tubular core and composed of a second aluminum alloy comprising up to 0.70 wt % maximum in total of silicon and iron, up to 0.10 wt % maximum of copper, up to 0.10 wt % maximum of manganese, up to 0.10 wt % maximum of magnesium, from 0.80 to 1.3 wt % of zinc, up to 0.05 wt % maximum of titanium and the balance aluminum and unavoidable impurities; and an outer brazable layer on the tubular core and composed of a third aluminum alloy comprising from 6.8 to 8.2 wt % of silicon, up to 0.80 wt % maximum of iron, up to 0.25 wt % maximum of copper, up to 0.10 wt % maximum of manganese, up to 0.10 wt % maximum of zinc, up to 0.05 wt % maximum of titanium, and the balance aluminum and unavoidable impurities.

Claim 2

Dependent Claim 226 words

A tubular element for a heat-exchanger comprising: a tubular core composed of a first aluminum alloy comprising up to 0.3 wt % maximum of silicon, up to 0.5 wt % maximum of iron, from 0.50 to 0.70 wt % of copper, from 0.65 to 1.0 wt % of manganese, from 0.1 to 0.30 wt % of magnesium, up to 0.05 wt % maximum of zinc, from 0.08 to 0.10 wt % of titanium, and the balance aluminum and unavoidable impurities; an inner layer on the tubular core and composed of a second aluminum alloy comprising up to 0.70 wt % maximum in total of silicon and iron, up to 0.10 wt % maximum of copper, up to 0.10 wt % maximum of manganese, up to 0.10 wt % maximum of magnesium, from 0.80 to 1.3 wt % of zinc, up to 0.05 wt % maximum of titanium and the balance aluminum and unavoidable impurities; and an outer brazable layer on the tubular core and composed of a third aluminum alloy comprising from 6.8 to 8.2 wt % of silicon, up to 0.80 wt % maximum of iron, up to 0.25 wt % maximum of copper, up to 0.10 wt % maximum of manganese, up to 0.10 wt % maximum of zinc, up to 0.05 wt % maximum of titanium, and the balance aluminum and unavoidable impurities.

Claim 3

Dependent Claim 47 words

A tubular element according to claim 1, wherein the first and second aluminum alloys are selected so that the corrosion potential difference between the tubular core and the inner clad layer is in the range from about 170 to about 200 mV versus a saturated calomel electrode.

Claim 4

Dependent Claim 40 words

A tubular element according to claim 1, wherein the first and second aluminum alloys are selected so that the corrosion potential difference between the tubular core and the inner clad layer is about 185 mV versus a saturated calomel electrode.

Claim 5

Dependent Claim 43 words

A tubular element according to claim 1, wherein the tubular core has a grain size falling within the range about ASTM 5 to about ASTM 6 and the grains have a morphology which is elongated in the axial direction of the tubular core.

Claim 6

Dependent Claim 51 words

A tubular element according to claim 1, wherein the thickness of the inner clad layer is about 12 percent of the total wall thickness of the tubular element and the thickness of the outer clad layer is from 9 to 12 percent of the total wall thickness of the tubular element.

Claim 7

Dependent Claim 31 words

A tubular element according to claim 1, further comprising external fin members brazed thereto, said fin members being composed of the aluminum alloy "AA3003" which additionally includes 1.5 wt % zinc.

Claim 8

Dependent Claim 95 words

A tubular element for a heat exchanger, the tubular element comprising: a tubular core composed of a first aluminum alloy; and an inner layer clad on the tubular core, the inner clad layer being composed of a second aluminum alloy and being adapted, in use, to act as a sacrificial anodic layer for the tubular core, the first and second aluminum alloys being chosen so that the corrosion potential difference between the tubular core and the inner clad layer is in the range from about 170 to about 200 mV versus a saturated calomel electrode.

Claim 9

Dependent Claim 95 words

A tubular element for a heat exchanger, the tubular element comprising: a tubular core composed of a first aluminum alloy; and an inner layer clad on the tubular core, the inner clad layer being composed of a second aluminum alloy and being adapted, in use, to act as a sacrificial anodic layer for the tubular core, the first and second aluminum alloys being chosen so that the corrosion potential difference between the tubular core and the inner clad layer is in the range from about 170 to about 200 mV versus a saturated calomel electrode.

Claim 10

Dependent Claim 40 words

A tubular element according to claim 7, wherein the first and second aluminum alloys are chosen so that the corrosion potential difference between the tubular core and the inner clad layer is about 185 mV versus a saturated calomel electrode.

Claim 11

Dependent Claim 75 words

A tubular element according to claim 7, wherein the first aluminum alloy comprises up to 0.3 wt % maximum of silicon, up to 0.5 wt % maximum of iron, from 0.50 to 0.70 wt % of copper, from 0.65 to 1.0 wt % of manganese, from 0.1 to 0.30 wt % of magnesium, up to 0.05 wt % maximum of zinc, from 0.08 to 0.10 wt % titanium, and the balance aluminum and unavoidable impurities.

Claim 12

Dependent Claim 72 words

A tubular element according to claim 7, wherein the second aluminium alloy comprises up to 0.70 wt % maximum in total of silicon and iron, up to 0.10 wt % maximum of copper, up to 0.10 wt % maximum of manganese, up to 0.10 wt % maximum of magnesium, from 0.80 to 1.3 wt % of zinc, up to 0.05 wt % maximum of titanium and the balance aluminium and unavoidable impurities.

Claim 13

Dependent Claim 43 words

A tubular element according to claim 7, wherein the tubular core has a grain size falling within the range about ASTM 5 to about ASTM 6 and the grains have a morphology which is elongated in the axial direction of the tubular core.

Claim 14

Dependent Claim 81 words

A tubular element according to claim 7, further comprising an outer brazable layer clad on the tubular core and composed of a third aluminum alloy comprising from 6.8 to 8.2 wt % of silicon, up to 0.80 wt % maximum of iron, up to 0.25 wt % maximum of copper, up to 0.10 wt % maximum of manganese, up to 0.10 wt % maximum of zinc, up to 0.05 wt % maximum of titanium, and the balance aluminum and unavoidable impurities.

Claim 15

Dependent Claim 51 words

A tubular element according to claim 12, wherein the thickness of the inner clad layer is about 12 percent of the total wall thickness of the tubular element and the thickness of the outer brazable layer is from 9 to 12 percent of the total wall thickness of the tubular element.

Claim 16

Dependent Claim 84 words

A tubular element for a heat exchanger, the tubular element comprising: a tubular core comprised of a first aluminum alloy; an inner layer on the tubular core and composed of a second aluminum alloy; and an outer layer composed of a third aluminum alloy clad on the tubular core; the tubular core having a grain size falling within the range about ASTM 5 to about ASTM 6 and the grains having a morphology which is elongated in the axial direction of the tubular core.

Claim 17

Dependent Claim 84 words

A tubular element for a heat exchanger, the tubular element comprising: a tubular core comprised of a first aluminum alloy; an inner layer on the tubular core and composed of a second aluminum alloy; and an outer layer composed of a third aluminum alloy clad on the tubular core; the tubular core having a grain size falling within the range about ASTM 5 to about ASTM 6 and the grains having a morphology which is elongated in the axial direction of the tubular core.

Claim 18

Dependent Claim 76 words

A tubular element according to claim 14, wherein the first aluminum alloy comprises up to 0.3 wt % maximum of silicon, up to 0.5 wt % maximum of iron, from 0.50 to 0.70 wt % of copper, from 0.65 to 1.0 wt % of manganese, from 0.1 to 0.30 wt % of magnesium, up to 0.05 wt % maximum of zinc, from 0.08 to 0.10 wt % of titanium, and the balance aluminum and unavoidable impurities.

Claim 19

Dependent Claim 72 words

A tubular element according to claim 14, wherein the second aluminum alloy comprises up to 0.70 wt % maximum in total of silicon and iron, up to 0.10 wt % maximum of copper, up to 0.10 wt % maximum of manganese, up to 0.10 wt % maximum of magnesium, from 0.80 to 1.3 wt % of zinc, up to 0.05 wt % maximum of titanium, and the balance aluminum and unavoidable impurities.

Claim 20

Dependent Claim 68 words

A tubular element according to claim 14, wherein the third aluminum alloy comprises from 6.8 to 8.2 wt % of silicon, up to 0.80 wt % maximum of iron, up to 0.25 wt % maximum of copper, up to 0.10 wt % maximum of manganese, up to 0.10 wt % maximum of zinc, up to 0.05 wt % maximum of titanium, and the balance aluminum and unavoidable impurities.

Claim 21

Dependent Claim 47 words

A tubular element according to claim 14, wherein the first and second aluminum alloys are selected so that the corrosion potential difference between the tubular core and the inner clad layer is in the range from about 170 to about 200 mV versus a saturated calomel electrode.

Claim 22

Dependent Claim 40 words

A tubular element according to claim 18, wherein the first and second aluminum alloys are selected so that the corrosion potential difference between the tubular core and the inner clad layer is about 185 mV versus a saturated calomel electrode.

Claim 23

Dependent Claim 51 words

A tubular element according to claim 14, wherein the thickness of the inner clad layer is about 12 percent of the total wall thickness of the tubular element and the thickness of the outer clad layer is from 9 to 12 percent of the total wall thickness of the tubular element.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1997-10-03	1998-04-04	1998-10-04	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2001-10-03	2002-04-04	2002-10-04	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2005-10-03	2006-04-04	2006-10-04	$7700.00	Window Closed / Lapsed

Tubular element for a heat exchanger

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