Swivel Hood Technology for capturing emissions

Introduction:

Clair has supplied hot gas fume extraction system for a reputed client manufacturing steel at their unit located in Pune. The hot gas fume extraction system supplied is extracting fumes generated during the operation of Electric Arc Furnace (EAF) of 50 tons capacity. The fumes from the EAF were connected to the primary fumes extraction system of Ladle Refining Furnace (LRF), which has its own fumes extraction system and dedicated de-dusting system. Clair was entrusted with design, engineering, manufacture and supply of secondary fume extraction system dedicated for EAF and a separate de-dusting system.

The electric arc furnace recycles used iron scrap by melting it in the furnace. Graphite electrodes used inside the furnace melts the iron. Graphite has high thermal conductivity and is very resistant to heat and impact. It also has low electrical resistance, which helps to conduct the large electrical currents needed to melt iron. When the EAF is in operation, hot fumes are generated. The fumes generated are captured in the hood which is placed on top of the EAF. When the EAF is not in operation, the electrodes used for melting need to changed. Hence a swiveling hood arrangement is provided so that when the EAF needs to be charged with graphite rods, the hood can be moved. After the graphite rods are charged in the EAF, the hood is moved back into the position to capture the hot fumes generated.

Observations:

Clair has successfully installed the hot gas fume extraction system with the swiveling hood arrangement, ducting, bag filter, ID fan and stack. The fumes extracted from the swiveling hood passes through the bag filter to filter out the dust. The system has been successfully running since 2016 with effective capture of hot gas fumes from the EAF. The bag filter is achieving an emission of ≤ 30 mg/Nm³ since its commissioning.

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