Interlocking spacer members for coiled tube assembly

DETAILED DESCRIPTION I claim: 1.
A heat exchanger comprising a coil assembly having a plurality of coaxial layers of helically coiled tubes, a respective spacer body for each of said layers, said bodies being all identical and constituting the sole means for holding said coils in spaced apart relation said bodies each being elongated and formed with a multiplicity of recesses receiving respective turns of the respective layer and mating formations on opposite sides of each body enabling the weld-free interconnection of said bodies to space said layers apart by relative longitudinal displacement of two adjacent bodies, each of said bodies being formed along an underside with a continuous T-section rail constituting one of said formations, each body being provided between each two of the respective recesses with a wall lying in a plane perpendicular to the rail and having a free end remote therefrom, all of said free ends being formed with T-shaped windows which are aligned with one another parallel to the respective rail for accommodating the rail of an adjacent body, said bodies being connected to one another solely by the fitting of a rail of one body into the windows of another.
2.
The heat exchanger defined in claim 1 wherein each of said recesses is a groove extending transversely to the longitudinal axis of the body, said grooves each having axes inclined to the axis of said body such that the small angle included between each groove axis and longitudinal axis of said body is between 70.
degree.
and 90.
degree.
.
3.
The heat exchanger defined in claim 2 wherein said body of the outermost layer receives a bar closing its grooves and forming a runner enabling insertion of said layers in a housing of the heat exchanger.
4.
The heat exchanger defined in claim 3, further comprising a core tube, said layers being disposed around said core tube, the body of the innermost layer being attached to said core tube, said body of said innermost layer being welded to said core tube, for each of said layers a plurality of such bodies being angularly spaced around said core tube