I would highly recommend a static mixer. There are many different designs available and the selection will need to be based on the flow, pipe size and available head loss. Call some static mixers manufacturer's to discuss the application. Try TAH, Koch, Kenics, Koflo.
Kevin
I used to work for a major mixer manufacturer and I know for a fact that the three major manufacturers have publications addressing "portable" mixer configurations.
Some of the basics are:
For fluid with viscosities under 10,000 Cp, baffles are highly recommended. There should be...
