The Wash Stations (WS-1401 and WS-2401) are used to remove silicon particles from the bell jars between reactor runs. Each Wash Station can wash one bell jar at a time. Tanks and pumps for washing and rinsing the reactors are shared between the two Wash Stations.
The wash program consists of five steps: Leak Detection/Nitrogen Purge, Caustic Wash, Rinse (2nd Use), Demin Water Rinse, and Drying Cycle. Both Wash Stations can operate simultaneously but, because the storage tanks and pumps are shared between the two Wash Stations, both cannot be on the same step. An additional program step called “Regen” is used to limit the accumulation of dissolved solids in the wash tank by moving a portion of the caustic solution to the dump tank and replenishing the wash tank with fresh caustic and demin water. The wash stations are interlocked so that neither can run during the Regen process.