SU900895A1 - Apparatus for feeding technological lubricant on hot rolling mill rolls - Google Patents

Description

I

The invention relates to rolling production, and specifically to devices for supplying lubricant to hot rolling mill rolls, and improves the design of process lubricant supply systems.

During hot rolling, the rolls operate under severe conditions at high pressures and temperatures. It is possible to improve the working conditions of the rolls by applying technological grease.

Experience in operating lubrication systems at hot rolling mills showed that the most acceptable should be considered as lubrication for the surface of the rolls in the form of an oil-water mixture. ,

To prepare an oil / water mixture, various process lubrication systems and various roller lubrication devices are used.

A device for feeding technological lubricant is known, which contains a line for supplying oil and water under

pressure, mixture supply pump, mixture supply line to nozzles, mixers, pressure regulator flj.

A disadvantage of the known device is that it does not allow the formation of a lubricating layer on the rolls of a certain composition during the periods of the device start-up.

The closest in technical essence to the proposed is

10 a device for feeding the process lubricant to the rolls, containing lines for supplying oil and water under pressure, a pump for feeding the mixture, a looped supply and pressure mains were holed with shut-off valves, a pressure regulator installed in the supply lines before the check valve, and mixers for supply and pressure highways 2.

X

The known device uses oil-water mixture as a process lubricant. When the mixing of water and oil is stopped, the mixture is exfoliated within seconds. Therefore, the known device operates in the continuous mixing mode of the process lubricant in a looped line to maintain it in a dispersed state. In the lubricant supply lines, from the loopback line to the nozzles, the lubrication of the lubricant during the movement of the lubricant does not occur. However, lubrication is applied to the rolls only during rolling. At the time of pauses and when the mill stops, the rolls are not lubricated. At this time, in the lines supplying the lubricant to the injectors, a separation of the water – oil mixture into oil and water occurs. During the subsequent supply of delaminated lubricant onto the rolls, clean oil enters, which leads to oiling of the surface of the rolls, which may cause the rollers to slip and break.

In addition, the length of the lubrication lines to the injectors is usually 10-30 m and there is a significant amount of lubricant 5 15 l. This amount of lubricant is usually sufficient for rolling about 50 m of strip. And since the lubricant is stratified in the main line x of the inlet, the lubricant of unknown composition and concentration gets onto the rollers. As a result, optimal conditions for forming a lubricating layer on the rolls are violated, which leads to an incomplete use of the effectiveness of the lubricant. The separation of lubrication leads to blockage of shut-off and metering valves.

It is possible to prevent the separation of water-oil mixture in the pipelines by organizing a continuous movement of lubricant, as is done in a looped highway. However, it is not possible to loop the pipelines over all the mill cages. The looped pipe of the mixture supply pump must have a diameter of at least 50 mm in order ... to provide the necessary dynamic characteristics of the lubricant flow and to prevent the fluid pressure in the pipelines from falling. The diameter of the lines for supplying lubricant to the nozzles does not exceed 20 mm, and the line itself bends with sharp turns and bends, since it is located on the rolling stand and must repeat its configuration. Therefore include this highway in

a common loop-back line of the pump cannot be, as this will lead to a significant complication of the entire lubrication supply system and will preclude reliable operation of the system.

The purpose of the invention is to improve the reliability of the device by imparting lubrication to the nozzles when it is being brought in to prevent delamination.

The goal is achieved by the fact that a device containing a supply line of oil and water under pressure, a mixture supply pump with a looped supply and pressure line, with a check valve in the supply line, a mixture supply line to the nozzles with shut-off valves, a pressure regulator in the supply line before return the valve, mixers in a loop-backed line, equipped with an additional mixer designed as an ejector, mounted in the supply line between the pressure regulator and the inlet of the feed pump, see You can also connect pipelines with supply lines to the injectors at the inlet of the shut-off valve.

The drawing shows the proposed device.

Claims (2)

The device contains lines 1 and 2 of the supply of oil and water under pressure. Regulators 3 and C of pressure and check valves 5 and 6 are installed in the mains. The oil and water supply lines are connected by a fifth line 7 to the mixture supply pump 8. The delivery line 9 of the mixture pump is looped to its supply line through the pressure regulator 10. The line 11 of the nozzle 12 for supplying lubricant to the rollers with a shut-off valve 13 is connected to a looped pump line between the pump outlet and the pressure regulator 10. Pressure control valve 1 is installed in the discharge line of the mixture pump in front of the nozzle line. A check valve 15 is installed in the ring line between the regulator and lines 1 and 2. A mixer 16 is installed in the supply line, and a mixer 17 in the supply line, connected by non-return valves 18 and 19 to the steam line 20. Directly at the valve 13 on the line 11. the start of the pipeline 21 is connected to the mixer ejector 22. A valve 23 is installed in front of the ejector 22 to regulate the vacuum value. The device works as follows. In lines 1 and 2, oil and water are supplied to the line under the same pressure, for example, 0.2 MPa, but with a different predetermined flow rate. The pump 8 is turned on and it creates pressure in the pressure head of the 9 set by the regulator 10. The water-and-oil mixture continuously circulates through a looped highway. After the signal is given, the valve 13 is opened and the technological lubricant is fed to the work rolls through the nozzle 12. In this case, of course, the pressure in line 7 drops and begins to feed the oil and water from the hot rods 1 and 2. The amount of the newly supplied oil and water corresponds to the amount of lubricant consumed by the nozzle. The line 20 supplies steam to the mixer 16 at a pressure not lower than the pressure in the feed line x 1 and 2. The steam heats the process lubricant circulating along the ringed line, and if necessary, it is fed to the mixer 17 The ring line is made of large diameter pipes to reduce loss of movement of the mixture. A line 11 for withdrawing the mixture to the nozzle is made of a pipe of relatively smaller diameter, but of considerable length. Looped onto the main line at the operating hot rolling mill is installed away from the stands, so the pipeline for venting the mixture to the nozzle has a length of several tens of meters. With open shut-off valve I in line 11, a pressure determined by the regulator 10 is created. When lubricant moves in a looped-out line in the mixer 22, an ejection effect occurs and from pipe 21 the lubricant enters the ringed trunk. In this case, a lubricant movement occurs in line 11, regardless of whether the shut-off valve 13 is open or closed. This lubricant movement prevents its separation, which in turn increases the reliability of the entire system. An intensive fluid flow always takes place in the loop-shaped line of the mixture feed pump. Therefore, installation in a looped highway with a moving liquid of an additional mixer in the form of an ejector will allow the pressure of the medium always at the inlet to the ejector to be substantially lower than the pressure in the looped line due to the ejection effect. The effect of ejection will be observed regardless of the location of the mixer in a looped highway, however, installing an ejector in the supply line between the pump inlet and the pressure regulator will ensure that the pressure at the inlet to the ejector is much less than the pressure in the back. ringed fluid before the pressure regulator. The connection of the supply lines to the nozzles and the additional ejector by the pipeline makes it possible to have a constant lubricant movement in the line, regardless of whether the lubricant is fed to the rolls or not. This prevents the lubricant from splitting up in the lubricant supply area from the looped road to the cells and ensures a stable lubricant composition in front of the nozzles during the entire period of operation of the system. The constant movement of the lubricant in the pipeline is determined by the presence of a pressure differential at the junction of the mixture supply line to the nozzles with the looped-in line and the entrance to the ejector. This pipeline maintains the lowest pressure throughout the entire system, and can be used as a drainage pipeline for collecting and returning to the lubrication system from those parts of the system where lubricant separation is possible. Apparatus of the Invention A device for supplying technological lubricant to the rolls of a hot rolling mill, comprising an oil and water supply line under pressure, a mixture supply pump with a looped supply and pressure line, with a check valve in the supply line, a mixture supply line to nozzles with shut-off valves, the torus of pressure in the supply line before the check valve, the mixers in the looped line, in order to improve the reliability of the device by imparting lubrication to the lubricant when supplying nozzles to prevent delamination, but it is equipped with an additional mixer designed as an ejector installed in the supply line between the pressure regulator and the mixture supply pump inlet and connected pipes with 900 mixture supply lines to the nozzles at the inlet of the shut-off valve. Sources of information taken into account in the examination 1. US patent number 3837199, cl. 72-21, 197. 2. USSR author's certificate W 7303S7, cl. B 21 B 27/10, 1978. 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