Background

Precipitated solids are solid states of matter formed in a solution as a result of a chemical reaction. This solid, formed during the purification process, is known as the “precipitate”. Often there are excess reactants (products of the reaction) mixed in with the .
Methods for purifying the precipitate include filtration, decanting and centrifuging.  These methods are generally co-current and require a significant amount of washing fluid to adequately purify the precipitates.

The Crown Advantage

Crown Iron’s extractors use counter current washing and a shallow bed approach for purification of precipitated solids. Counter current washing minimizes the amount of liquid required for purification by as much as 40 – 50%. In addition, the washing action is gentle, preventing the breakup of the solids and minimizing product loss. 

Crown’s Specialty Extractors

Crown Iron has two percolation extractor models and one immersion extractor model; each designed for purification of specific products. The features and use of each are outlined below.

Crown’s Immersion Extractor (Model IV)

• Used for processing solids that are either too dense or too fine for percolation-type extractors. Special features include:
  • Complete immersion which ensures good product contact with the solvent
  • Complete bed turnover that prevents compaction and packing of solids
  • Gentle motion and bed turnover which minimizes product breakage

Crown’s Percolation Extractors (Models III and V)

• Model III is suited for high volume extractions such as vegetable proteins, wood chips & polymers; while Model V is designed to handle flakes, crushed beans or leafy materials.  Both models have the following features:
  • Shallow material beds which allow for expansion of wet materials
  • En-masse conveyors that minimize product breakage
  • Gentle paddle motion over stationary relieved screens that prevents screen plugging
  • Easy clean and CIP able design

• Additional features of the Model III Extractor include:
  • High throughputs
  • Complete bed turnover which promotes good drainage
  • Screen cleaning set-ups that do not require plant shutdown