Tubular structure

Claim 1

An industrial cooling tower comprising a support structure resting on a ground surface and a waisted tubular envelope consisting of a continuous membrane having an unbroken surface of saddle shape and made of a material which is capable of supporting tension in all directions in its plane, said membrane being pre-tensioned and carried with its tubular axis upright from said support structure, an open latticework anchoring the lower border of said membrane to the ground surface and providing an inlet for entry of cooling air into the interior of said membrane, said membrane having an open upper end serving as an air outlet opening and a ring connected to the upper border of said membrane and to said support structure with said envelope stretched in an axial direction between its upper and lower borders, and with said support structure providing the vertical component of said pre-tensioning, said support structure being of sufficient strength to support said membrane in a sufficiently stretched condition to cause said pre-tensioning to create tensile forces in said membrane in all directions in the plane of said waisted envelope, with said tensile forces being greater than the compression forces created by the wind externally to said shell, whereby said tensioned membrane becomes a self-supporting membrane shell.