Polyaluminum Chloride Dosing System Design
Stock
Polyaluminum Chloride (PAC) solution is stored in a plastic jug near the peristaltic pump. The pump draws solution out of this jug through a tube.
Peristaltic Pump
The peristaltic pump near the Aguaclara desktop computer pumps alum from the plastic jug to the flocculation tank. This pump can be turned on and off, but its speed can be changed only by changing the "alum dose" in Process Controller. (See "Starting the alum pump" on the Troubleshooting Start-up page.
Mixing
The peristaltic pump send PAC through a thin tube to the first baffle spacing of the flocculator (which serves as a mixing chamber), where the turbulence from the water entering the flocculator serves to disperse the PAC uniformly.