Scraped Surface Heat Exchangers

Armstrong Chemtec’s continuous scraped surface heat exchanger is generally used in cooling crystallization and viscous cooling duties. The process fluid is cooled across the inner pipe wall as coolant flows in the annulus between the inner and outer pipe. Rotating blades inside the inner pipe mix the process fluid and prevent build-up on the inner pipe ID. These heat exchangers are well suited for scaling up from pilot testing to commercial production. Armstrong Chemtec has pilot scraped surface heat exchangers that are available for rent or hire.

Armstrong Chemtec continuous scraped surface heat exchangers offer many advantages over other crystallization methods:

  • The exchangers are designed to run without clogging for extended periods between hot washings.
  • Fouling tendencies of some slurries are overcome by continuous scraping of the heat transfer surface.
  • The design is capable of handling higher MTDs than shell and tube equipment.
  • Operating temperatures range from -75°C ( -103 °F) to + 250°C (482°F).
    Weight percent solids as high as 65% have been handled.
    Can handle process fluids with viscosities in excess of 10,000 cP.
    Near plug flow profile allows for easy transition from batch to continuous process.
  • Scraped surface crystallizers are more cost effective for larger installations where vacuum crystallization may seem attractive.
  • The design minimizes shear stress on delicate crystals but is rugged enough to handle tough crystals.
  • Simple, self-contained construction eliminates the need for excessive instrumentation, condensers, vacuum systems, etc.