Hot rolling mill lubrication apparatus and process

Claim 2

Apparatus for applying a hot rolling mill lubricant of water and a difficultly dispersible oil to a roll stand during the presence of a workpiece in the stand, said apparatus comprising spray header means at the roll stand from which the lubricant is discharged onto the roll stand during the presence of a workpiece, a common lubricant water line connected to said spray header means, a pressurized water supply connected to saId common line to continuously provide water thereto at a given pressure range, means for injecting oil into the common line to mix with the water and form a lubricant dispersion, said injection means including an oil injection line connected into the common line, a pump having a suction port and a discharge port, an oil supply connected to the suction port, an oil recirculating line connected on one side to said supply, a discharge line connected from the pump discharge port to the other side of the oil recirculating line and to the oil injection line, and valve means between the discharge line, the oil injection line, and the oil recirculating line for selectively closing communication between the discharge line and the recirculating line to raise the pressure in the oil injection line above the water pressure in said common line and cause injection of oil into the water.

Claim 3

Apparatus as defined in claim 1, which further includes a return line between said oil injection line and said supply, and a pressure regulating valve in said return line set so that the oil pressure in the oil injection line when said valve means is closed exceeds the water pressure.

Claim 4

Apparatus as defined in claim 2, which further includes a pressure regulating valve in said oil recirculating line set to maintain maximum flow through said return line when the valve means is open without causing injection of oil into the water.

Claim 5

Apparatus as defined in claim 3, which further includes means detecting the presence and absence of a workpiece at the roll stand for controlling said valve means to cause injection of oil into the common line during the presence of a workpiece.

Claim 6

Apparatus as defined in claim 4, which further includes means for heating the oil supply.

Claim 7

Apparatus for applying a hot rolling mill lubricant of water and difficulty dispersible oil to a roll stand during the presence of a workpiece in the stand, said apparatus comprising spray header means at the roll stand from which lubricant is discharged onto the roll stand during the presence of a workpiece and from which water is discharged onto the stand during the absence of a workpiece, a common lubricant-water line connected to said spray header means, a pressurized water supply connected to said common line to continuously provide water thereto, means for injecting oil into the common line to mix with the water and form a lubricant dispersion, said injection means including a continuously operating pump having a suction port and a discharge port, an oil injection line between said pump discharge port and said common line, an oil supply, an oil supply line connected between the oil supply and the pump suction port, a recirculating line between the suction and discharge ports, an oil injection control valve means in the recirculating line and connected to the oil injection line for selectively stopping oil flow in the recirculating line and causing the injection of oil through the oil injection line into the common line, a mixing device in the oil injection line at the common line to cause mixing of the oil into the water during oil injection, check valve means in the oil injection line upstream of the mixing device preventing backflow of water through the oil injection line, an oil return line connecting between the oil supply and the oil injection line upstream from said check valve means, a pressure regulating valve in said return line set so the oil pressure in the oil injection line exceeds the water pressure in the common line when said oil injection control valve means is closed to then cause oil injection into the common line while bleeding oil back to said oil supply, wherein the oil pressure in the oil injection line is less than the water pressure in the common line when the oil injection control valve means is open and oil is being recirculated in both the oil recirculation line and the return line.

Claim 8

Apparatus for applying a hot rolling mill lubricant of water and difficulty dispersible oil to a roll stand during the presence of a workpiece in the stand, said apparatus comprising spray header means at the roll stand from which lubricant is discharged onto the roll stand during the presence of a workpiece and from which water is discharged onto the stand during the absence of a workpiece, a common lubricant-water line connected to said spray header means, a pressurized water supply connected to said common line to continuously provide water thereto, means for injecting oil into the common line to mix with the water and form a lubricant dispersion, said injection means including a continuously operating pump having a suction port and a discharge port, an oil injection line between said pump discharge port and said common line, an oil supply, an oil supply line connected between the oil supply and the pump suction port, a recirculating line between the suction and discharge ports, an oil injection control valve means in the recirculating line and connected to the oil injection line for selectively stopping oil flow in the recirculating line and causing the injection of oil through the oil injection line into the common line, a mixing device in the oil injection line at the common line to cause mixing of the oil into the water during oil injection, check valve means in the oil injection line upstream of the mixing device preventing backflow of water through the oil injection line, an oil return line connecting between the oil supply and the oil injection line upstream from said check valve means, a pressure regulating valve in said return line set so the oil pressure in the oil injection line exceeds the water pressure in the common line when said oil injection control valve means is closed to then cause oil injection into the common line while bleeding oil back to said oil supply, wherein the oil pressure in the oil injection line is less than the water pressure in the common line when the oil injection control valve means is open and oil is being recirculated in both the oil recirculation line and the return line.

Claim 9

Apparatus as defined in claim 6, wherein said oil injecting means further includes means for heating thE oil supply.

Claim 10

Apparatus as defined in claim 6, wherein said oil injecting means further includes a pressure regulating valve in said oil recirculating line set to maintain maximum flow through said return line when the oil injection control valve means is open without causing injection of oil into the water.

Claim 11

Apparatus as defined in claim 8, which further includes means detecting the presence and absence of a workpiece at the roll stand for controlling said oil injection valve means to cause injection of oil into the common line only during the presence of a workpiece.