Spiral heat exchangers are one of the most fouling-resistant designs available for slurries and other solids-laden fluids, because their single continuous curved channel produces consistent turbulence across the entire flow path at almost any flow rate. That geometry is the main reason they are specified ahead of shell-and-tube units in pulp, mining, and wastewater services.
Why a Single Curved Channel Resists Fouling
Unlike a tube bundle, where flow distribution can vary significantly between individual tubes, a spiral exchanger forces the entire fluid stream through one channel of constant width. This keeps velocity and shear uniform along the full length, which prevents the low-velocity dead zones where slurry solids typically settle and cake.
Handling Solids and Coarse Particulates
Spiral units can be built with wider channel gaps than a typical tube bundle, allowing coarse particulates to pass through without plugging, which is a common failure mode in tube-and-shell designs handling slurries. If the design does eventually foul, the single-channel geometry can usually be cleaned in place with a straight run-through flush rather than a full mechanical teardown.
Pressure and Temperature Limits to Check
Spiral exchangers are generally rated for lower pressures than shell-and-tube units of comparable size, so it is worth confirming the pressure rating early in the selection process for high-pressure slurry duties. Channel spacing also needs to be matched to the actual particle size distribution in the slurry, not just its nominal solids content.
Specifying a Spiral Exchanger for Your Process
Correct channel spacing and material selection make the difference between a spiral unit that runs for years and one that fouls immediately. GreyTec supplies spiral heat exchangers engineered around the actual slurry characteristics of each project, supported by our engineering and consultancy team.