Brazed heat exchanger and production method
AssigneeModine Manufacturing Company
InventorWolfgang Schatz-Knecht
Life of this patent
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Abstract
A brazed heat exchanger includes plates that are stacked or nested to define flow channels for multiple media. Inserts are arranged within at least some of the flow channels. Two different braze alloys having compositions based on different metals are used to form braze joints between the plates and the inserts. In some cases, a copper-based braze alloy is used for joints corresponding to flow channels for one of the media in order to provide high pressure-resisting strength to those flow channels, while an iron-based braze alloy is used for joints corresponding to flow channels for another of the media where dissolved copper is undesirable.
Claims20
A brazed heat exchanger, comprising:
- stacked plates defining a plurality of ducts for two or more media to flow between the plates, the plurality of ducts including a first plurality of ducts for a first one of the media and a second plurality of ducts for a second one of the media, the first and second plurality of ducts being alternatingly arranged in the stack of plates;
- a first braze material providing braze joints within a first set of the plurality of ducts;
- and
- a second braze material different in composition from the first braze material providing braze joints within a second set of the plurality of ducts, the first braze material and the second braze material having matching melting temperature ranges, wherein some of the plurality of ducts are in either the first set or the second set but not both,
- wherein all of the first plurality of ducts belongs to the first set of ducts,
- wherein all of the second plurality of ducts belongs to the second set of ducts, and
- wherein at least one of the most distal ones with respect to a stack direction of the second plurality of ducts additionally belongs to the first set of ducts.
A brazed heat exchanger for cooling oil, comprising:
- a brazed stack of plates defining alternating oil ducts and coolant ducts;
- oil inserts arranged within the oil ducts and joined to adjacent ones of the plates by way of a first braze material;
- first coolant inserts arranged within the coolant ducts and joined to adjacent ones of the plates by way of a second braze material that is different in composition from the first braze material;
- and
- second coolant inserts arranged within the coolant ducts and joined to adjacent ones of the plates by way of the first braze material.
A method of making a brazed heat exchanger, comprising:
- providing a plurality of plates, each of the plates including a middle portion surrounded by a peripheral portion, the peripheral portion being oriented at at least one oblique angle to the middle portion;
- providing a first braze alloy having a first composition to a bottom surface of the middle portion of a first plate of the plurality of plates;
- providing a second braze alloy having a second composition different from the first composition to a bottom surface of the middle portion of a second plate of the plurality of plates;
- providing the first braze alloy to a top surface of the middle portion of the second plate;
- providing the first braze alloy to top surface of the peripheral portion of the second plate;
- arranging the plurality of plates into a stack in a stacking direction wherein each plate of the plurality of plates is arranged on either side of a duct to form a plurality of ducts within the stack, and wherein the first plate is arranged adjacent to the second plate;
- and
- heating the stack in a brazing furnace to a temperature that exceeds the melting temperature of both the first and the second braze alloys to at least form braze joints within each duct of the plurality of ducts and between adjacent plates of the plurality of plates.
Dependencies are inferred from the claim text.