Blocked serpentine furnace coils cleared in one day
The client asked Tube Tech to develop a technology and method to clear a single fully blocked serpentine furnace tube measuring 100mm diameter x 45m.
Initially the client wanted to follow the traditional route of unblocking the furnace by cutting off the bends, unblocking the tube by using water jets and re-welding. However this meant switching off all 4 furnaces at a cost of many millions of dollars.
Tube Tech a globally renowned engineering solutions provider suggested unblocking both lines whilst the unit was online at 430 degrees centigrade so as to avoid incurring these costly production downtime for the plant.
- As with many projects this would be another challenging first for Tube Tech. A replica furnace was constructed, directly linked to a heater at their UK headquarters. The tube was blocked with concrete to simulate harder than average fouling and the temperature raised to 430C on-line.
- An independent, globally recognised petrochemical consultant witnessed the trial on behalf of the client and approved its use.
- The trial was were carried out in three stages.
- Heat eat was quenched by a constantly-monitored injection of water with steam being safely contained and vented.
- The furnace tubes were navigated by means of a modified high-pressure jetting lance, modified to withstand the severe temperatures and high torque which it would encounter within the furnace tubes. Buoyancy pockets would assist the drill in reaching the “coal face.”
- Mike and his team practiced the procedure many times with military precision at over 430 degrees C.
- When on site the client had reduced the temperature to 120 degrees due to other site conditions. As a result the blockage was cleared in 1 day instead of the anticipated 3.
Tube Tech Comment
“We appreciated the importance of a uniform clean when decoking furnace tubes and have first hand experience of using traditional 1000 and 2500 bar water pressure which in many cases is not enough to de-coke the layers of coke within the tubes. Our WysperJet furnace decoking system combines 3 systems in one cleaning head in other words what one system doesn’t remove, the next system will. This decoking system ensures 100% tube heat transfer surface area is cleaned.”