Scraped Surface Plate Heat Exchangers

InKorr supplies continuous scraped surface heat exchangers through our partnership with Armstrong Chemtec Group, built for cooling crystallisation and viscous cooling duties. The process fluid is cooled across the inner pipe wall as coolant flows through the annulus between the inner and outer pipe, while rotating blades inside the inner pipe keep the fluid mixed and stop build-up on the pipe wall. Pilot units are available for rent or hire, making it easy to scale a process from lab testing through to full commercial production.

How it works

A warm process fluid runs through the shell side, counterflow to a cooling fluid in the surrounding jacket. Heat transfer through the shared pipe wall causes wax or crystals to form on the inside of the shell, where continuously rotating scraper blades remove them before they can build up. Downstream filters then separate the crystals from the rest of the process fluid. Units are typically supplied as stands of several double-pipe sections connected in series to suit the process duty.

Advantages

Runs for extended periods without clogging, reducing the need for hot washing
Continuous scraping overcomes the fouling tendencies of many slurries
Handles higher MTDs than shell and tube equipment
Operating range from -75°C to 250°C
Handles solids concentrations up to 65% by weight
Suited to viscosities in excess of 10,000 cP
Near plug flow profile allows an easy transition from batch to continuous operation
More cost effective than vacuum crystallisation for larger installations
Gentle enough for delicate crystals, rugged enough for tough ones
Simple, self-contained design without the excessive instrumentation, condensers or vacuum systems that other crystallisation methods require

Applications

Scraped surface exchangers are used across a wide range of crystallisation, dewaxing and deoiling processes, including hydrocarbon wax removal for lubricating oil production. Typical process fluids include benzoic acid, caffeine, fatty acids, lactose, menthol, naphthalene, paraxylene, potassium chloride, sodium sulfate, tall oil and tallow fatty acids, waxes, and many other organic and inorganic compounds. Get in touch to check compatibility with your specific fluid.

Sizes and materials

Inner and outer shells are typically carbon steel, 304/304L or 316/316L stainless steel, with alternate materials available on request for specialised duties. Scraper blade material is selected to be softer than the inner shell (to avoid damaging the pipe) but strong enough to remove built-up crystals, and sample blades can be supplied for compatibility testing in your process fluid.

Inner shell sizes of 6″, 8″, 10″ or 12″ nominal pipe are available, in stands of up to 14 shells and scraped lengths up to 13 m.

Want to Know More?

Talk with our team about your process heat transfer needs.