The research and development background to the environmental problems of natural draught cooling towers

Abstract The paper traces the development of eliminators in the early 1950s and their satisfactory performance in C.E.G.B. cooling towers. More recently, significant droplet carry-over (drift) has been detected at two new 2000 MW stations; relevant factors are that more spray is created in the bigger installations and that longer residence time in the larger towers increases droplet growth. However, the two recent occurrences were principally due to the use of eliminators which differed from the originally recommended designs in construction in one case, and in installation in the other. There is a prima facie case for adopting eliminators of a higher standard for future installations. It seems very possible that a closer pitched ( 1 3 4 in.) asbestos-cement louvre type would meet the need without penalizing the thermal performance of the tower. Blow-out and stripping of spray from the air inlets in high winds and at exposed sites remains a problem of conventional hyperbolic towers for which there is no complete solution.