MBF wreaks

MBF Wreaks further: Middle Burden feeder of Module # 4, HBI plant, stalls at 22:40 hrs, causing restriction of high temperature material flow, the reduced Iron. The Top gas temperature began to shoot up. The shaft is powered by two Push-Pull hydraulic cylinders and senses their “end of Stroke” and change direction using two inductive proximites. Since the shaft was out of alignment for past two to three months, the crack opening at shaft got wide day by day. The furnace gas was jetting out from this gas. This gas is highly inflammable with high concentration of CO [carbon monoxide]. So any one approaching near will go unconscious. The explosive limit was also very very high. So doing any electrical signal wiring, welding in the area will result in fire. Further the CO gas which was oozing out itself has a tendency to catch fire on its own as its temperature was above its Self Ignition Temperature.Huge water spraysg were required to prevent reoccurrence of fire.

Why did MBF stall?
Since hot gas was oozing out at regular intervals and water mixed with reduced iron dust , the proximites were failing to respond to actual target . Further the high temperature in the region also reduced its life. But one more important reason was that the local JB , kept below almost 6 inches above the floor, was completely drenched with water. This JB dint even had a cable duct gland. So the voltage to Proximty might also got failed.

Approaching to this Local JB was not possible in the above said condition. During this crisis two timers simulated MBF “end of stroke”.

So it was finally decided to continue the MBF running with out proximites to sense their end of stroke, and instead timers simulating them.

But in next shutdown care must taken to shift the Local JB to a comfortable higher position, and re-routing the lead cables of each proximity in full length. It should not be kept wound as presently kept. Cable gland must be used to prevent any water entry or dust entry inside the JB.