Problems with chelating resin columns
Thread Content
At 20 minutes, both Wash 2 and Wash 3 of the chelating resin column met the requirements for acidity and alkalinity; then why was it necessary to complete the 1.5 hours required for Wash 2 and the 1 hour required for Wash 3?
This post was last edited by pzhhuagong on 2019-12-30 at 19:51; after \"water washing 2\" comes alkali regeneration. The resin tower has a certain volume; for washing with water, it is generally required that the amount of pure water used be twice the volume of the tower, in order to completely displace the acidic water. If only a 20-minute replacement is carried out, most of the acidic water remains in the resin tower, rendering alkali regeneration meaningless. After the 3 washes, saltwater replacement takes place, which involves replacing the pure water inside the tower with saltwater, so as to keep the saltwater concentration within acceptable levels and prepare for the switchover of the tower. Therefore, for washing 3, using an amount of pure water equal to one time the volume of the resin column is sufficient. If the replacement is carried out over only 20 minutes, there will still be a large amount of alkaline water in the resin tower, which will result in a high pH level of the brine inside the tower after the replacement. This brine with a high pH then enters the electrolysis sump, which hinders the process control of the electrolyzer.