Lubricant removal system for cold rolling stand

In an apparatus for cold rolling of nonferrous metal, said apparatus of the type including a roll stand having an inlet side and an outlet side, opposed work rolls in the stand for rolling metal as the metal form passes between the rolls in a direction from the inlet side to the outlet side, coolant application means in the roll stand for applying coolant to the metal and rolls during rolling;

• a gas discharge assembly mounted on the stand to impinge gas on the form passing from the rolls;
• suction boxes mounted on the stand on opposite sides of the metal form at the outlet side of the mill at a position upstream from the gas discharge assembly, the improvement comprising, in combination;
• a hood collection assembly for collecting coolant and the gas from the suction boxes and from the roll stand, for separating and recovering coolant, and for supressing any combustion of the effluent coolant and gas collected by the assembly, said assembly including a shroud positioned on the inlet and outlet side of the roll stand to substantially enclose the rolled metal form in the roll stand prior to entry into the rolls and upon exit from the rolls;
• a plurality of suction lines connected to the suction boxes and the hood, said lines connected to a common single suction passage;
• at least one trap in the passage;
• a fluid pump upstream from the traps for drawing coolant and gas into the hood and suction boxes;
• a gas discharge outlet upstream from the fluid pump;
• combustible gas sensors located in the suction box and roll stand hood for sensing a combustible mixture in the fluid and gas mixture drawn into the assembly through fluid lines;
• and means for feeding a non-combustible gas into said fluid lines to suppress potential combustion.