By Mahendra Singh
Incinerators burn off sludge
We use incinerators on board ships for burning off the sludge, oily rags, paper and cardboard. The important associates of the incinerators are the waste oil tanks where we evaporate the water content by opening steam to the coils of these tanks.
It is important to check from bottom to top to understand what other fittings are there, if any, connected with uptakes of these tanks, such as the exhaust fan to aid evaporation and homogenizers fitted on these tanks to churn the sludge for making it more burnable.
Minimizing accidents in incinerators
We have been successful in minimizing accidents involving incinerators by ensuring that these are run only during day time when more manpower is available in the engine room to keep a regular watch on them. Things could go wrong quickly such as burning failure, breaking of a copper pipe, overheating at the burner mouth, uptake temperature
going high etc; burning failure can occur if oil pressure is not correct, if water finds its way or oil temperature (sludge temperature too high or too low, a good temp experienced was at 90 degC). Failure of the V belt also has contributed to failures. The Forced Draft (FD) fan should be kept in well maintained condition because there is no substitute for this one.
On one particular incinerator, the furnace temperature sensor used to get burnt because of its close proximity to flames. We had to provide sheathing to it by locating a suitable tube, inside in which to fix the sensor. Overheating of refractory due to flame impingement has also contributed to failures on many occasions. The refractory needs to be inspected and rebuilt from time to time. Filters in the system need to be kept clean.
Logging the evaporation and sludge burning
Logging the evaporation and sludge burning in oil record books need to be done carefully besides burning of the oily rags (indicate quantity), according to the instructions given in
the beginning of the Oil record book itself. Check up with the owners if you are using the latest book prescribed by your flag state.
Follow the instructions given in the operation manual
And finally, when evaporation capacity reduces, we need to clean the coils of the waste oil tank. Check if the high temperature alarm functions correctly (normally set at 125 degC). The condition of uptake exhaust fan bearings should be checked as well as the uptake high temperature alarm and furnace high temp alarm. There is also an indicator to show the furnace temperature and it should be kept in good operational condition. Follow the instructions given in the operation manual on method and periodicity of checking the alarms and log it too in the oil record book under the maintenance heading.