Patent ID: 8791230

Claim:
A method of producing a particulate water absorbent resin, the method comprising: polymerizing an aqueous solution of unsaturated monomer; and drying a particulate water-containing gel-like cross-linked polymer having a solids concentration of 30% by weight or greater that is obtainable by a gel grain refining step during polymerization or after polymerization, with one or more apparatuses for aerating any one of the particulate water-containing gel-like cross-linked polymer, a dried product, a pulverization product, or a classification product thereof as a water absorbent resin with a high temperature gas stream in the drying and/or in at least one of the subsequent steps, wherein in the aerating apparatus, the high temperature gas stream used for aeration is passed through a filter and then a portion or all of the high temperature gas stream is reused in the same step as the step where the aerating apparatus is installed, or in a different step.