ak1965
Mechanical
- Jul 28, 2007
- 158
We have Milisecond furnace in our olefin plant. The tubes are high NI CR alloy. Tubes handles hot gases with hydrocarbons & TMT is around 850 Deg. C . the furnace isbottom fired. Tube dia is 50.8 mm & Tube ID is 38.1 mm. During the process, these tubes are subjected to coking, that is removed through decoking process on regular intervals. With the given sevreity in service,gradually carburisation takes place in the tubes & TETRA FITTINGS ON THE TOP OF TUBES. As a result, these become prone for failure. it is understood that the tubes having a vlaue of carburisation >130 mV should be replaced.
My question :
1)Is the criterian taken for replacement is good enough to replace the tube ?
2)Which are the methods available for the measurment of carburisation in the tubes & which one is the best method ? plz give the details of instrument used.
3) What is the best alternative to reduce decoking frequency ? lot of production time goes waste in deoking process. Also frequent start ups & shut downs are not good for the health of the heater.
My question :
1)Is the criterian taken for replacement is good enough to replace the tube ?
2)Which are the methods available for the measurment of carburisation in the tubes & which one is the best method ? plz give the details of instrument used.
3) What is the best alternative to reduce decoking frequency ? lot of production time goes waste in deoking process. Also frequent start ups & shut downs are not good for the health of the heater.
