First we need to talk about what is a rotary scrubber.  Depending on where you are and what you are trying to process, different devices are called rotary scrubbers.  In small scale (artisanal) mining a rotary scrubber is often simple trammel with internal baskets. In other operations in looks like a rotary dryer or rod mill with a large trammel at the end.

In any case, since the general purpose is to break up clay and dirt balls and wash them away from the coarser material, two sizing criteria are involved.  For small scale operations (artisanal) using typical rotary screen sizing with sprays would work.  For the larger sizes, assuming a rod mill with no media would give a satisfactory answer.

Thanks for your reply. This scrubber is used in an iron ore beneficiation plant, please find the details below

Drum Type - Rotary washing drum for iron ore, Drum speed  10 rpm

Feed material - iron ore fines
Design feed capacity - 200 Tons / hour dry
Bulk density of feed material - 2.2 Tons/ cum.(Including moister)
Bulk angle of material - approx. 40 °
Material feed temperature -  max. 45 °C,  Grain size - 0-18 mm

Now supplier has mentioned 75KW  & 2m X 6m (dia & length) of drum scrubber.

I want to know how the supplier has calculated it. please share the calculation

regards

Sam