Heat exchanger for physiological fluids
First Claim
1. A heat exchanger capable of maintaining sterility during temperature variation comprising an inner conduit, an outer conduit partially covering said inner conduit and forming a fluid flow channel between an outer surface of said inner conduit and an inner surface of said outer conduit, and end cap means for securing and fluid sealing one end of said outer conduit and for communicating a first fluid with said channel, wherein said inner conduit has a thermal coefficient of expansion larger than that of said outer conduit and said outer conduit is elastic for at least partially accommodating expansion or contraction of said inner conduit, and wherein said end cap means is elastic for at least partially accommodating expansion or contraction of said inner conduit and comprises a first hollow portion cemented to said one end of said outer conduit and a second hollow portion having a hoop strength adequate to tightly grip said outer surface of said inner conduit to provide a pressure tight seal between said second hollow portion and said inner conduit and to provide a location of said pressure tight seal which remains substantially fixed with respect to said inner conduit during normal thermal expansion or contraction of said inner conduit.
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Accused Products
Abstract
A heat exchanger preferably for use in heating physiological fluids includes an inner conduit, an outer conduit, and end caps which seal the outer conduit to the inner conduit to form a flow channel. The inner conduit is preferably of aluminum and the outer conduit and end caps are of an elastomeric material. The end caps are designed to tightly engage the inner conduit and to be solvent bonded to the outer conduit. When the inner conduit elongates because of thermal expansion, the outer conduit elastically deforms so that there is no relative movement between the end cap and the inner conduit. This preserves sterility during temperature variation.
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Citations
13 Claims
- 1. A heat exchanger capable of maintaining sterility during temperature variation comprising an inner conduit, an outer conduit partially covering said inner conduit and forming a fluid flow channel between an outer surface of said inner conduit and an inner surface of said outer conduit, and end cap means for securing and fluid sealing one end of said outer conduit and for communicating a first fluid with said channel, wherein said inner conduit has a thermal coefficient of expansion larger than that of said outer conduit and said outer conduit is elastic for at least partially accommodating expansion or contraction of said inner conduit, and wherein said end cap means is elastic for at least partially accommodating expansion or contraction of said inner conduit and comprises a first hollow portion cemented to said one end of said outer conduit and a second hollow portion having a hoop strength adequate to tightly grip said outer surface of said inner conduit to provide a pressure tight seal between said second hollow portion and said inner conduit and to provide a location of said pressure tight seal which remains substantially fixed with respect to said inner conduit during normal thermal expansion or contraction of said inner conduit.
- 10. An end cap for sealing an end of an outer conduit to an inner conduit comprising a first hollow portion for receiving said end of an outer conduit and having an inner wall for engaging an outer wall portion of said end of an outer conduit, a second hollow portion for receiving said inner conduit, said second hollow portion having an inner wall for engaging an outer wall of said inner conduit, said second hollow portion having a protuberance extending radially inwardly for tightly engaging said outer surface of said inner conduit wherein said first and second hollow portions and said protuberance are integrally formed of elastomeric material.
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12. A heat exchanger comprising an inner conduit, an outer conduit partially covering said inner conduit to form a flow channel between said inner and outer conduits, and two end caps, each of said end caps comprising a first hollow portion having an inner wall cemented to a portion of the outer wall of said outer conduit and a second portion comprising a second hollow portion tightly and sealingly engaging a portion of the outer wall of said inner conduit and a protuberance engaging said outer surface of said inner conduit, wherein said end caps are made of elastic material and wherein said first and second hollow portions and said protuberance are integrally formed of elastomeric material.
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13. A heat exchanger capable of maintaining sterility during temperature variations comprising a metal inner conduit, an outer conduit having a length less than that of said inner conduit, an end cap at each end of said outer conduit for providing a fluid path between said inner and outer conduits, wherein each said end cap is of elastic material for at least partially accommodating expansion or contraction of said inner conduit and comprises a first hollow portion cemented to said outer conduit and a second hollow portion having a hoop strength adequate to tightly grip said inner conduit to provide a pressure tight seal at a location substantially fixed with respect to said inner conduit during expansion or contraction of said inner conduit.
Specification