Heat Exchanger White Paper0 pages

WHITE PAPER
by Neil Cathie, Kenics™ Global Business Development Manager

The design of static mixer heat transfer equipment
for adhesives, sealants, resins and polymers.
The fluids handled within the adhesives and sealant industries are
amongst the most difficult to handle of any in the main process
industries globally. The characteristics which make them
particularly difficult to handle include:
•t High viscosities (typically 1-2000 Pa.s, or 1000 to
2 million cP).
•t Often non-Newtonian (viscosity is not constant and
varies with shear rate).
•t Some must be processed at temperatures close to their
solidification/hardening points where they are close to
changing phase from liquid to solid (e.g. hot melt adhesives).
•t Almost all have low thermal conductivities, often intentionally.
This makes them particularly resistant to being heated or cooled.
•t Their high viscosity requires that they be pumped at high pressures to be moved from A to B and through all required process
equipment and process stages.
•t To keep fluids flowing, they must often be processed at temperatures well above ambient.
•t Some of the fluids processed are for food related use and require the alloy and non-alloy materials in contact with the fluids
to be FDA approved (e.g. gaskets).
•t Equipment can be difficult to clean safely, causing shutdowns and maintenance delays.
•t Many fluids processed are susceptible to degradation if “cooked” for too long.
•t Controlling the “thermal history” of a product by avoiding excessive ranges of residence times (and thereby reducing the
potential for degradation) becomes more difficult as soon as flow becomes laminar.
•t Process lines are often designed to handle a variety of process fluids and flow rates, which adds further complication.

Heating and Cooling
Heating and cooling are key processes in the adhesives and sealants industry and ones into which most of
the above challenges inevitably fall. Many products need to be processed or formed at high temperatures
(e.g., within a reactor or mix vessel) but later cooled to facilitate further processing or handling.

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