Abstract A heat transfer pipe having in an inner surface thereof a plurality of first internal grooves formed in parallel with each other and having a generally rectangular cross sectional shape, and a plurality of second internal grooves formed in parallel with each other and crossing the first internal grooves, the second internal grooves having a cross section which is generally in the shape of an inverted trapezoid, the heat transfer pipe further having the following portions defined by the above first and second internal grooves; tunnel portions formed in the portions where the first internal grooves cross the second internal grooves, the tunnel portions each having a space; discontinuous projecting portions formed at the portions crossing the portions between the first internal grooves, the discontinuous projecting portions being parallel to the second internal grooves and each having a generally triangular cross section; and including opening portions of the first internal grooves formed in the intermittent portions of the projecting portions.
A heat transfer pipe having formed in an inner surface portion thereof: a plurality of first internal grooves formed in parallel with each other and having a generally rectangular cross sectional shape; and a plurality of second internal grooves formed in parallel with each other and crossing said first internal grooves, said second internal grooves having a cross section which is generally in the shape of an inverted trapezoid; and further comprising the following portions defined by said first and second internal grooves; tunnel portions formed in portions where said first internal grooves cross said second internal grooves, said tunnel portions each having a space; discontinuous projecting portions formed at portions crossing the portions between said first internal grooves, said discontinuous projecting portions being parallel to said second internal grooves and each having a generally triangular cross section; and opening portions of said first internal grooves formed in intermittent portions of said projecting portions.
Claim 2
Dependent Claim
154 words
A heat transfer pipe having formed in an inner surface portion thereof: a plurality of first internal grooves formed in parallel with each other and having a generally rectangular cross sectional shape; and a plurality of second internal grooves formed in parallel with each other and crossing said first internal grooves, said second internal grooves having a cross section which is generally in the shape of an inverted trapezoid; and further comprising the following portions defined by said first and second internal grooves; tunnel portions formed in portions where said first internal grooves cross said second internal grooves, said tunnel portions each having a space; discontinuous projecting portions formed at portions crossing the portions between said first internal grooves, said discontinuous projecting portions being parallel to said second internal grooves and each having a generally triangular cross section; and opening portions of said first internal grooves formed in intermittent portions of said projecting portions.