Cryogenic bayonet connection
An improved system is provided for connecting thermally insulated cryogenic delivery piping including a bayonet coupler comprising a thermally insulated section of dual walled piping, said dual walled piping having an annular space between the walls of said piping, the annular space maintained at high vacuum, said bayonet coupler sized to be securely received by internal sleeves disposed at the to-be-joined ends of said cryogenic delivery piping.
1 . A thermally insulated cryogenic coupler including:
a section of inner piping having a first and second end;
a section of outer piping having a first and second end, the first and second ends substantially coterminous with the first and second ends of the said section of inner piping, wherein the internal diameter of said outer section of piping is larger than the outer diameter of said inner section of piping, said section of inner piping positioned within said section of outer piping;
the said sections of said inner and outer piping joined one to the other at their first and second ends to define a closed, hermetically sealed annular space between said inner and outer sections of piping; whereby,
a condition of vacuum is provided and maintained between the inner and outer sections of said piping.
2 . The insulated cryogenic coupler of claim 1 wherein the vacuum is a high vacuum.
3 . The insulated cryogenic coupler of claim 2 wherein the high vacuum is between 10 −2 torr to 10 −4 torr.
4 . The insulated cryogenic coupler of claim 1 wherein the section of inner piping is wrapped with one or more layers of an insulating material.
5 . The insulated cryogenic coupler of claim 4 wherein the insulating material is a reflective foil.
6 . The insulated cryogenic insulated coupler of claim 1 wherein the inner and outer sections of said piping are joined at their first and second ends by an annular-ring type spacer plug whose inner diameter is sized to receive the outer wall of said section of inner piping, and whose outer diameter is sized to be received by the inner wall of said section of outer of piping, the spacer plug fixedly secured in place.
7 . The insulated cryogenic coupler of claim 1 wherein the said inner section of piping is outwardly flared at its first and second ends, said outwardly flared ends sized to be of a diameter slightly smaller than the inner diameter of said outer piping section, whereby said inner and outer sections of piping are joined at their first and second ends by welding of said flared ends to the inner wall of said outer section of piping.
8 . The insulated cryogenic coupler of claim 3 wherein within the space between the inner and outer sections of piping contains a gettering material.
9 . The insulated cryogenic coupler of claim 1 wherein the longitudinal center point of the pipe is indicated by a central marking.
10 . The insulated cryogenic coupler of claim 9 wherein said central marking is a radially extending post.
11 . In a cryogenic fluid delivery system, a connecting assembly having a first section of insulated transport pipe, including an internal receiving sleeve, and a second section of insulated transport pipe including an internal receiving sleeve, each of said first and second sections of insulated pipe terminating in a flanged end section, and means for coupling the two said pipe sections together at their flanged ends, the improvement comprising:
a jacketed piping insert, said piping insert comprising a section of pipe including an inner pipe and an outer pipe, the inner pipe spaced from the outer pipe to define an annular space between them, said jacketed piping insert vacuum sealed to define a vacuum within said annular space, the jacketed piping insert having a diameter sized so as to be received by each of said receiving sleeves of said sections of insulated pipe.
12 . The connecting assembly of claim 11 wherein the jacketed piping insert extends equidistant into each of the receiving sleeves of said insulated transport pipe sections.
13 . A method for fabricating the thermally insulated cryogenic coupler of claim 1 wherein:
the sections of inner and outer piping are first sealed in atmosphere at a first end;
the annular space between the pipes is next evacuated; and,
the second ends of the pipes are thereafter sealed one to the other in vacuum.
14 . The method of claim 13 in which the second ends of the pipes are sealed in vacuum by an e-beam weld carried out in vacuum.
15 . The method of claim 13 in which the first and second ends of pipe are hermetically sealed.
16 . The method of claim 13 wherein the annular spaced is evacuated to high vacuum prior to sealing of the pipes at their second ends.
17 . The method of claim 15 wherein the annular space is evacuated to 10 −2 to 10 −4 Torr prior to sealing.