Tubes cleaning, hydroblasting

Clean the tubes by hydroblasting, but could not establish a water flow through the tubes. 

Each individual tube can now be cleaned by one person with a long tube and a hydroblast machine. 

If the deposits are soluble in a solvent, the shell may be soaked in a chemical bath. Sometimes this bath must be kept hot to dissolve the deposits, at a reasonable rate. Sometimes, the deposits must be attacked with a hydroblast machine. If the design engineer has selected a correct tube pitch, cleaning the shell side of an exchanger with a hydroblast machine may be a reasonable proposition. 

This all results in reduced capital cost. The disadvantage of this tube pitch is that, except for the outer few rows of tubes, the shell side cannot be cleaned by hydroblasting. Obviously, this sort of arrangement should never be used in a fouling service, unless the deposits can be chemically removed. 

Hydroblasting U-tube bundles may or may not completely clean the tubes. However, there is a method that is certain to completely clean even a badly plugged and fouled tube—pigging. 

The Fixotal inserts have been used in single- and two-phase flow applications— that is, condensation and evaporation. Only the Fixotal inserts are used in air coolers and are intended to reduce fouling, particularly with paraffin coating or water cooler scaling. We also note that Fixotal has been used in U tubes, and can now be left in place during hydroblasting for cleaning. 

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