GB1014594A - Improvements in and relating to dehydrators - Google Patents

Abstract

Dissolvable granular porous pellets comprise a major proportion of a low hygroscopicity soluble substance as the integral porous core thereof and a minor proportion of a soluble higher hygroscopicity substance impregnated on at least the surface of the porous core. The low hygroscopicity substance may be sucrose, NaCl, KCl, KNO3, NaNO3, or tartaric acid whilst the higher hygroscopicity substance may be CaCl2, LiCl, ZnCl2, CaBr2 or glycerine. The pellets may be of dimensions from 1/64 -1 inch but preferably 1/2 -1 inch and have a composition comprising 90-97% low hygroscopicity and 3-10% higher hygroscopicity substances. A minor proportion of a rust inhibiting compound e.g. sodium dichromate or metallic Zn or Mg, may be incorporated; also a substance to mitigate corrosion effects e.g. trisodium phosphate. The pellets may be made by impregnating the porous core portion with a solution of the higher hygroscopicity substance which may be done by first heating the core portion to at the most 500 DEG F. Specific constituents for pellets are sucrose and calcium chloride; sodium chloride, calcium chloride, sodium dichromate and trisodium phosphate. A gas, e.g. air, may be dehumidified by passage through pellets containing 90-97% NaCl and 3-10% CaCl2, whereby the moisture goes into solution with the compounds and accumulates in a sump below the pellets as a solution. Apparatus for the above process are disclosed, comprising an inlet, outlet and means for supporting pellets of the above composition. In one embodiment, the support is shaped like the frustum of a cone and in another, a baffle is placed below two parallel flat supports.