Chemical Cleaning on fouled tubes

Hi,

I have a evaporator with water on the shell side and R22 inside the tubes. The tubes are stainless steel, 304.

Recently, i open up a chamber that receives chilled water from this evaporator. The tank was very dirty and filled with sludge.

As a result, is seriously think that evaporator needs some cleaning. I cant remove the tube bundle in this case.

I think that chemical cleaning is the best option. What type of chemical (acid/alkaline) that i can use? What is this effect of this chemicals on the stainless steel tubes.
Please help.

Regards,
jaya

Not sure if these export . Their coolflow HSC1 is a alkaline based cleanser which will do exactly what you need

http://coolflowfx.co.uk/index.html