Scrub pro© Attrition Mills
Customize to suit your application
Single or Multiple Stages
Opposing with Different Pitches
Removable and Replaceable Liners
Custom Designed Systems Available
As defined by Taggart, “Scrubbing is disintegration effected by forces which are relatively light but are sufficient to break down soft unconsolidated materials such as clay, or to sever the bonding between grains.” There are many methods available to achieve the scrubbing action, but the most common and effective method today is attrition scrubbers, sometime called attrition mills.
How do attrition mills work?
A sand slurry, typically -¼”, is fed into the scrubber vessel at relatively high solids, 72% SBW +/-. Inside the vessel is a vertical rotating shaft, driven by an electric motor and speed reducer. On this shaft are propellers or mixing blades. The propellers are arranged with some being up-thrust and some being down-thrust. When the slurry is forced between the propellers, particles are thrust against particles, thereby causing the scrubbing action. The scrubber vessel is a flow-through design so material enters on one side and exits on the other for a continuous flow. More than one cell is often needed, depending on the required residence time, so cells can be arranged so that the slurry can flow from one cell to the next. Once the slurry exits the final cell, it is ready to be washed and the liberated contaminants removed.
What advantages does the Scrub Pro attrition mill have over others?
- Heavy-duty propeller design instead of mixing ‘blades’. The propellers thrust against each other with one propeller having a 100-degree pitch and the other having a 150-degree pitch to help move slurry from one vessel to the other. The propeller design is the most efficient and robust in our experience.
- Oversized mixer drives. Our drives typically have a 3-to-1 service factor which allows you to operate 24 hours a day without concern for excessive fatigue or oil temperature.
- Urethane lined to protect the inside from wear. We use the same high quality urethane to line our attrition mills as we do for our cyclones, pump parts, and other wear parts.
Common FAQs when considering attrition mills?
- What is the working capacity of each cell in cubic feet? Capacity will relate back to residence time.
- How much horsepower is installed? Efficient scrubbing takes horsepower to force particle-on-particle at high solids. It is attractive sometimes to be able to install less horsepower, but having too little installed can lead to a failed installation.
- What size of reducer is used? Service factor means a lot here. If you don’t have at least Class 2 service the life of the reducer will be limited.
- What style of mixers are used? Propeller style or blade/paddle style are used.