Why are there no backup units for the blowers and exhaust fans in the delayed coking heater? What happens if a failure occurs?
Thread Content
I’m a newcomer here. Why aren’t backup units provided for the blowers and exhaust fans in delayed coking heaters, just like in other pumps and machinery? If there’s a problem, isn’t the only option to stop work? I seek advice from experts.
Well, there’s also natural ventilation, and it has interlock protection. . . It’s something very basic; it should be available everywhere.
Production can also be achieved through natural ventilation; the height of the chimney is designed with regard to the amount of negative pressure that needs to be created. Exhaust fans are used for forced ventilation, and they also allow for the reuse of heat
Quickly open the air damper to supply air directly; use the flue sealing baffle to control negative pressure
Currently, there are no backup units for the main fans in the catalytic unit, which means that these critical devices must be disassembled and inspected during maintenance. Moreover, lifetime inspections are necessary; even if some components are not damaged, they still need to be replaced once their service life is reached
Without a backup unit, it is a rather troublesome issue to inspect the main fan while it is in operation; it is not possible to ensure its long-term continuous operation. After all, scaling on the blades of the exhaust fan can very likely affect the operation of the main fan and lead to shutdowns, and this becomes a significant problem in the absence of a backup unit.
If the exhaust fan fails, it can be removed and the main fan can be driven directly by the motor; in this case, the electrical consumption of the device increases significantly
So the smoke extractor still can’t be repaired. It would be good if it had a device similar to a clutch that’s connected to the main fan, so that the smoke extractor could be taken apart for maintenance; otherwise, power consumption will increase significantly.
The forced draft fans in the heating furnaces of coking units do not require backup units; in the event of problems during normal operation, a system interlock is in place that activates these fans automatically. The forced draft fans are equipped with quick-opening dampers, while the exhaust fans have smoke traps. These elements are sufficient to ensure normal operation. We have encountered such situations before – the forced draft fans were repaired during normal production.
Heating furnaces in refining units generally do not require a backup exhaust fan, as the flue gas bypass dampers and chimney can also serve as an exhaust fan, albeit at the cost of reduced thermal efficiency. For blowers, if a quick-opening damper is installed, there is no need to have a backup blower. However, opening the air valve quickly has many disadvantages: one is that it may lead to air leakage, resulting in lower efficiency of the furnace, and another issue is the potential safety hazard. Therefore, some systems do not include quick-open dampers, but instead use multiple blowers.