The ProMdryTM system by ProMinent Fluid Controls is designed to 

mix dry chemicals into solution prior to adding to the water treatment 

process. The volumetric feeder dispenses dry chemical into the mix 

tank while the flow switch is monitoring water entering the mix tank. 

The dry chemical and the water are introduced directly into the 

prop style tank mixer, where they are mixed into solution.  The solution 

is then drawn from the opposite side of the tank to the process.