Key Advantages to Using Shell & Tube Technology

In addition to the advantages of distillation using waste heat recovery, there are key advantages to using shell & tube technology over a plate-type distiller.  While both have comparable upfront capital costs, the key advantages are found in the cost of maintenance of a shell & tube unit.

Tube bundles are structurally sound and easy to remove for inspection and cleaning with a low risk of damage.  Plate-type exchangers are composed of many thin plates separated by gaskets.  Disassembly can be extremely difficult without damaging the plates. After inspection and/or cleaning, a tube bundle can be easily reinstalled with only two gaskets needing replacement.  Reassembly of a plate pack requires the insertion of many thin and delicate gaskets and a careful realignment of the entire plate assembly.

With shell & tube, heat transfer surfaces are uniformly exposed to the turbulent boiling feed water, helping to eliminate dead spots on heat exchanger surfaces and discouraging scale formation.  With a plate-type distiller, the feed water flows diagonally across the plate.  Dead spots in the opposing corners lead to scaling which are hard to clean and lead to long-term loss of heat transfer efficiency.

Finally, in the event there is a need to replace the heat exchanger's elements with a shell & tube unit, the cost amounts to only 10% of the original equipment cost.  With a plate-type distiller, the heat exchangers and the boiling chamber are all in one.  Replacement cost equals 90% of the original equipment cost.