How to Maintain Your Polymer Blending Unit
How emulsion polymer works
To understand why polymer blending units need periodic maintenance, it is helpful to know how polymer works. A polymer is a large organic molecule formed into a chain with either positive or negative charge sites. When polymer chains are introduced into sludge, it causes a magnetic attraction; think of putting a magnet in a bucket of nails. It is this reaction that allows for water–solids separation. In its emulsified state, the active polymer is highly concentrated with the chains tightly compacted. Blending units use water and energy to strip away the emulsion oils and unwind the polymer chains.
Blending units
Polymer blending units generally employ either mechanical or static mixers, a few use both methods. Mixing provides the energy to break the emulsion and unwind the polymer chains. Over time polymer deposits build up on the internal components of the blending unit. The buildup can cause reduced mixing energy and reduce the effectiveness of the polymer. Think about it this way. If a blending unit is partially clogged with polymer deposits, it won’t fully unwind polymer chains. You will only be using part of the polymer, with the rest wasted. It is like filling your truck up with gas and only being able to use ½ the tank.
Cleaning Blending Units
Fortunately, there is an easy way to clean your blending unit and keep it performing like new. We have developed a blending unit flush that will safely strip away polymer deposits while lubricating pump seals and fittings. Our Poly-Solv 02™ is safe to use with all brands of blending units. To use, add Poly-Solv 02™ into your blending unit's calibration column. Activate the unit and run until Poly-Solv 02 has saturated the system. The product has a blue tint to help you know when your system is full. Turn the unit off and let it sit overnight or over the weekend. Poly-Solv 02™ will slowly loosen and dissolve polymer deposits. Doing this weekly will keep your blending unit running at peak efficiency and save you money on polymer.
How do we know that it works?
Polymer activation can be measured using viscosity. The fully activated polymer has a defined maximum viscosity that can be obtained from the manufacturer. A viscometer is used to measure it.
Case Study
During the development of Poly-Solv 02™ we performed many before and after testing of blending units cleaned with our product. The following are results from a recent test that we performed with a client.
This client uses two belt filter presses for biosolids dewatering and processes 90,000 gallons of sludge per day. For polymer activation, they are using a VeloDyne blending unit. Their current polymer is a branched high-charge cationic emulsion. We obtained the maximum viscosity of a .5% solution from the manufacturer, >12,000 mPas. A sample of the polymer solution was collected from the blending unit before cleaning. A reading of 11,021 mPas was obtained. The blending unit was then cleaned and allowed to sit overnight. The next morning a new sample of the polymer solution was analyzed, with a result of 12,275 mPas. This is an 11% increase in activation, which translates to fewer polymer pounds consumed for dewatering. This particular client cleans their unit every other week. We see much more dramatic results from clients that have never cleaned their blending units.
Added Benefits
Polymer blending units periodically need pump rebuilds. Regular use of Poly-Solv 02™ will extend the life of pump wear parts, seals, and check valves, extending the time between rebuilds. Regular cleaning will save you money on both polymer and pump maintenance. The following pictures are two examples of polymer deposits found in a blending unit that we recently cleaned:
