Oil-skimming devices are rotary cylinder units mounted at the water surface level in the tanks. These units require heat protection to prevent freezing in the winter. The sludge is recovered; since it consists primarily of mill scale, it can be sold as blast furnace charging material.
Strainers are 0.005 in units with 5,000 gpm capacity each. These are in the system for insurance in the event of heavy overloading of the settling tanks. This might occur if one of the two parallel systems was shut down for pump or ejection mechanism repairs when the mill is operating at peak capacity.
Until now, the system has performed well, except for minor startup and training problems. Mill operating personnel are pleased, because return water quality is far better than the raw river water they were using.
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