ShellJeTT removes hard deposit from tube nest
Shell side fouling consisted of hard coke like deposits which needed removing from deep within the shell side of an ethylene dichloride heater on a large UK petrochemical plant. The unit had historically provided poor performance as all deposits had never been effectively removed.
- Ethylene Dichloride heater with five baffles at even distances along the nest.
- Square pitch tubes with 9.5mm gap between tubes.
- Hard coke like deposit with some bridging but mainly evenly coated.
- Previously tried alternative cleaning systems could not penetrate into the bundle so the deposits had not removed to the client’s satisfaction.
- Possibility of HCL forming when product contacted air or water.
Unfortunately, due to the excessive fouling on the bundle, some of the tubes were damaged while another contractor was extracting the bundle. This meant that some of the tubes at the end of the bundle were buckled and some completely flattened. Tube Tech was able to spread some of these bent tubes to enable access. This highlights the need for Tube Tech’s approach to in situ shell side cleaning and the savings it can deliver to its clients.
- Having successfully cleaned the shell side of Texas Towers (VCFE/Platformer) and other types of heat exchangers fouled with polymer and hydrocarbon coke, Tube Tech was certain that its bespoke ShellJett cleaning system would remove the stubborn deposit from the heater.
- The unique design of the Shell JeTT oscillated between the tubes to reach and remove the tightly packed deposit within the tube bundle. The combination of mechanical, ultrasonic and polymeric water ensure the deposits were removed effectively.
- Tube Tech used its hands free ShellJett to ensure operatives could work remotely to avoid contact to the black hard carbon like substance which produced HCL and emitted a pungent unpleasant smell.
- Despite the damage at the end of the bundle Tube Tech successfully removed the hard coke like deposits and the client could see daylight between all the tubes of the heater.
Tube Tech Comment
Peter Lord, Technical Sales: “Our client was very pleased with the results our ShellJeTT system produced. So often shell side cleaning is performed ineffectively and the effect of poor cleaning on heat transfer rates can be significant. Tube Tech’s shell side cleaning techniques are recognised by industry leaders who want to ensure a ‘complete’ shell side clean.”