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Heat Exchanger World Europe 2022 Conference Series
Inside the tubes
Around the tubes Examples of where thermal cleaning could be applied .
Between the tubes and the shell Inside tubes with static mixers
very important asset today . It automatically results in far fewer maintenance shutdowns and also makes a huge difference to the energy consumption of the production process . This can really save hundreds of thousands of euros or dollars per year per cleaned heat exchanger ; a nice result for an initially slightly more expensive cleaning method . A clean bundle transfers heat much better and , as a result , much less energy is needed to keep production running properly .
Practical considerations When using this cleaning method , it is of course important that the parts can withstand the temperatures used . A normal treatment is generally carried out between 400 and 450 ° C ( 752 ° F and 842 ° F ), and the metal components of the material must be able to withstand this . Aluminium exchangers are thus already ruled out for thermal cleaning . For special alloys which cannot withstand this temperature , such as duplex steel or Monel , two-stage cleaning is often performed . Here , the contamination is first thermally cracked at a lower temperature , after which the residue will be removed by hydro blasting . As the
fouling becomes somewhat more brittle due to the thermal treatment , it is relatively easy to completely remove the residue using water blasting . A thermal test with the fouling will soon reveal whether this is a feasible cleaning option or not .
Ideal candidates The broad range of parts can be treated by thermal cleaning : heat exchangers with pollution in and between the tubes ; heat exchangers with fixed housings and pollution between tubes and the shell ; compablocs , heat exchangers plates , spiral heat exchangers ; vane decks , demisters , mellow packs ; pipe work ( also with static mixers ); extruder screws & parts ; polymer & refinery pumps ; flame arrestors , sieve packs , valves ; filters , spin packs , die plates , hot runners , and so on . In principle , all parts resistant to the temperatures used , polluted with organic material , can be thermally cleaned . Note : inorganic fouling can only be removed if it is part of a fouling mix with organic components . In such cases , thermal cleaning will remove the organic part ( the adhesive in this case ), leaving the inorganic part loose and ready to be removed by the post-treatment technique .
Before thermal cleaning
After thermal cleaning
+/ -1 hour HP cleaning Final result Before and after thermal cleaning .
44 Heat Exchanger World April 2023 www . heat-exchanger-world . com