Abstract A vapor generating tube of the two-phase type which is operated at a pressure between sub-critical and critical pressure of the vapor has a tube-like body through which fluid is passed. The inner wall surface of the tube is crossed-rifled to provide a plurality of quadrilaterally shaped projections uniform and regularly spaced along the cross-rifled axes. The minor inside diameter d1, the projection height h of each projection, the projection pitch P, projection width b, and spiral lead angle Alpha and Beta have the following relationships: P/h is from 5 to 4 h/d1 is from 0.005 to 0.08, b/P is in the range of 0.2 to 0.8, and the spiral lead angles Alpha + Beta are from 20* to 80* .
A vapor generating tube of the two-phase type operated at a pressure above sub-critical pressure and below critical pressure of the vapor and sub-jected to high heat flux, comprising; a tube-like body for passing fluid therethrough and having an inner wall surface, said inner wall surface is cross-rifled and has a plurality of projections uniformly and regularly spaced thereon along the cross-rifling axes, and each of said projections having a quadrilateral shape.
Claim 2
Dependent Claim
72 words
A vapor generating tube of the two-phase type operated at a pressure above sub-critical pressure and below critical pressure of the vapor and sub-jected to high heat flux, comprising; a tube-like body for passing fluid therethrough and having an inner wall surface, said inner wall surface is cross-rifled and has a plurality of projections uniformly and regularly spaced thereon along the cross-rifling axes, and each of said projections having a quadrilateral shape.
Claim 3
Dependent Claim
90 words
A vapor generating tube as in claim 1 wherein said tube-like body has a minor inside diameter d1, and each of saiD projections have a projection height h, a projection pitch P, and a projection width b, wherein P/h is in the range of 5 to 40, h/d1 is in the range of 0.005 to 0.08, and b/P is in the range of 0.2 to 0.8, the spiral lead angles of the cross-riflings are Alpha and Beta , and Alpha + Beta is in the range of 20* to 80*.
Claim 4
Dependent Claim
48 words
A vapor generating tube as in claim 2 wherein P/h is in the range of 8 to 25, h/d1 is in the range of 0.01 to 0.07, b/P is in the range of 0.3 to 0.6 and Alpha + Beta is in the range of 30* to 75*.
Claim 5
Dependent Claim
15 words
A vapor generating tube as in claim 2 wherein 20* Alpha <43* and Beta 0*.