JPH0824933A - Method and device for feeding rolling oil - Google Patents

Abstract

PURPOSE:To automatically separate and remove the scum from the used rolling oil. CONSTITUTION:The used rolling oil is stored in a scum separating tank 4 to float and separate the dirt such as metallic powders and oxide powders as the scum. A gate 8 is provided in the scum separating tank 4. The liquid level in the scum separating tank 4 is set lower than the level of the gate 8 during the rolling. When the scum is discharged, a first pump 1 and a second pump 2 are stopped for the prescribed period of time, and the scum is sufficiently separated from the rolling oil, the second pump 2 is operated with a small volume to slowly increase the liquid level in the scum separating tank 4. The scum overflows the gate 8, and is automatically separated. It is unnecessary to manually scrape up and remove the scum from the liquid surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling mill for rolling a metal strip, and a rolling oil supply method and device for cooling a rolling roll, lubricating and removing dirt.

[0002]

2. Description of the Related Art Conventionally, during cold rolling of a metal strip containing a special steel such as ordinary steel or stainless steel, a steel material such as a high alloy iron or a non-ferrous material, cooling of a rolling roll, a metal strip and a rolling roll. Rolling oil is used for the lubrication of the interface of the, or the removal of dirt generated by rolling.
The rolling oil includes oily ones such as mineral oils, emulsions in which oil droplets are emulsified and dispersed in water, and rolling agents that are not necessarily oily such as aqueous solutions, and are used properly according to their properties. During the rolling of the metal strip, the rolling oil is spray-injected from the nozzle or the like provided in the rolling mill toward the biting portion of the rolling roll, and the used rolling oil is used in the oil pan or the like provided below the rolling mill. Collected in a saucer, collected, circulated and reused. Since the used rolling oil contains dirt generated during rolling of the metal strip, it is necessary to remove and clean the dirt in the middle of the circulation use route.

The dirt in the rolling oil is mainly dust remaining after the oxide scale on the surface of the metal strip or a part of the metal surface is mechanically removed from the surface of the metal strip by a rolling roll. When the rolling oil after use is stored, such metal powder or oxide powder floats as scum on the liquid surface over time. Therefore, the rolling oil after use is
Once stored in a scum separation tank also called a dirty tank, float the scum on the liquid surface to separate it, and then clean the liquid that has separated the scum with a filter and store it in another clean tank, also called a clean tank. A configuration in which the oil is supplied to the rolling mill again as rolling oil is often used.

In the dirty tank, scum increases as the operation of the rolling mill continues, and eventually the rolling oil supply path may be clogged in the dirty tank. Therefore, it is necessary to perform scum-out work to remove scum before the scum increases so much. Conventionally, scum-out work is performed by manually scraping scum from the liquid surface.

[0005]

[Problems to be Solved by the Invention] Tandem rolling mills, etc.
Since a rolling mill having a plurality of stands is used and a scum separation tank provided in a rolling oil supply path for the rolling mill has a considerably large capacity, the manual scum-out work requires considerable labor. Further, a scum separation tank is provided in the vicinity of the rolling mill that continuously passes the metal strip. Even if the rolling of the metal strip is stopped during the scum-out work, it is not always possible to secure a sufficient space for the work. During the work, it may fall into the scum separation tank, which is a very dangerous work. Also, the scum separation tank, which is also called a dirty tank, is considerably dirty and is not good as a working environment.

It is an object of the present invention to automate the work of scouting and improve the work environment and work efficiency.

[0007]

According to the present invention, rolling oil after use is collected and temporarily stored in a scum separation tank, sucked from the scum separation tank by a first pump, and cleaned by a filter. Oil is stored in the cleaning tank, the rolling oil sucked from the cleaning tank by the second pump is injected to the rolling rolls of the rolling mill, and the recovered rolling oil is circulated for use in the rolling oil supply method. The weir is provided to keep the liquid level in the scum separation tank lower than that of the weir during rolling, and when discharging scum, the first pump is stopped and the second pump is operated with a small capacity to separate scum. This is a rolling oil supply method characterized in that the level of the liquid level in the tank is slowly raised until it reaches the level of the weir.

Further, the present invention is characterized in that when the scum is discharged, the rolling oil supply path is switched so that the rolling oil flows into the scum separation tank without being injected into the rolling rolls of the rolling mill.

Further, according to the present invention, the rolling oil after use is collected and temporarily stored in the scum separation tank, sucked from the scum separation tank by the first pump, and the rolling oil cleaned through the filter is transferred to the cleaning tank. In the method of supplying rolling oil in which the rolling oil that is stored and sucked by the second pump from the cleaning tank is injected to the rolling rolls of the rolling mill and the collected rolling oil is circulated, there is a gap on the liquid surface in the scum separation tank. It is a method of supplying rolling oil, which is characterized in that it is left floating and the scum is collected by a gap and separated.

Further, according to the present invention, the rolling oil after use is collected and temporarily stored in the scum separation tank, sucked by the first pump from the scum separation tank, and the rolling oil cleaned through the filter is cleaned in the cleaning tank. In the scum separation tank in a rolling oil supply device in which the rolling oil stored in the cleaning tank and sucked by the second pump is injected to the rolling rolls of the rolling mill and the recovered rolling oil is circulated. And a liquid level gauge that detects the liquid level in the scum separation tank, and responds to the output from the liquid level gauge, and operates the first pump and the second pump so that the liquid level becomes lower than the weir during rolling. When the scum is discharged, the first pump is stopped so that the liquid level rises slowly to reach the level of the weir, and the second pump is controlled to operate at a small capacity. Supply of rolling oil It is the location.

[0011]

According to the present invention, the weir for overflow is provided in the scum separating tank interposed in the rolling oil circulating system.
During rolling, the level of the liquid level in the scum separation tank is kept lower than that of the weir, so that the rolling oil will not overflow from the weir even if the liquid level changes. During scum discharge, the liquid level in the scum separation tank is slowly increased until it reaches the level of the weir, so the separation of rolling oil and scum proceeds,
Scum that floats and floats on the liquid surface overflows the weir and is removed. It is not necessary to manually scrape scum on the liquid surface.

According to the invention, when scum is discharged,
Since the rolling oil flows into the scum separation tank without being sprayed onto the rolling rolls of the rolling mill, the liquid level of the rolling oil in the scum separation tank can be controlled more accurately.

Further, according to the present invention, since the scum is scraped off and separated by the gap left floating on the liquid surface in the scum separation tank, it is not necessary to manually scrape the scum on the liquid surface.

Further, according to the present invention, a scum separation tank provided with a weir for overflow is interposed in the rolling oil circulation supply system, and the liquid level of the scum separation tank is detected by a liquid level gauge. From the scum separation tank, rolling oil is sent to a cleaning tank through a filter by a first pump, and from the cleaning tank, rolling oil purified by a second pump is injected to a rolling roll of a rolling mill. The control means controls the first and second pumps during rolling so that the liquid level of the scum separation tank becomes lower than that of the weir. During scum discharge, the first pump is stopped and the second pump is controlled to operate with a small capacity so that the liquid level slowly rises and reaches the level of the weir. The first pump and the second pump are operated according to the rolling condition to control the liquid level in the scum separation tank. When scum is discharged, the scum is discharged over the weir, so the scum on the liquid surface is manually discharged. There is no need to perform a scraping operation.

[0015]

Embodiments of the present invention will be described below with reference to FIGS. 1 shows a basic piping system of an embodiment of the present invention, FIG. 2 shows the operation of the embodiment of FIG. 1 as a time chart, and FIG. 3 shows a more specific piping system of the embodiment of FIG. 4 to 6 show the configuration of the device related to the scum separation tank, FIG. 7 shows the operation of the embodiment of FIG. 1 as a flowchart, and FIG. 8 shows the configuration of the liquid level gauge used in the embodiment of FIG. 9 to 11 show a piping system, an arrangement of air nozzles, and a liquid level in another embodiment of the present invention, respectively.

In FIG. 1, a first pump 1 and a second pump 2 are provided in the rolling oil supply path. The rolling oil is sprayed onto the rolling rolls in the rolling mill 3 by the second pump 2. The used rolling oil recovered from the rolling mill 3 is stored in the scum separation tank 4. The rolling oil stored in the scum separation tank 4 is sucked by the first pump 1, cleaned by a filter 5 realized by a Hoffman filter or the like, and stored in a cleaning tank 6 also called a clean tank. The rolling oil stored in the cleaning tank 6 is sucked by the second pump 2 and sent to the rolling mill 3.

In the rolling oil circulation system as described above, the switching valve 7 is provided in the supply pipe line to the rolling mill 3, and the rolling oil fed from the second pump 2 is sprayed on the rolling mill 3. It is possible to switch between the supply route and the supply route for flowing into the scum separation tank 4 without spraying the rolling mill 3. The scum separation tank 4 is provided with a weir 8 so that the scum floating on the liquid surface of the stored rolling oil can be overflowed and separated. The liquid level of the rolling oil in the scum separation tank 4 is detected by the liquid level gauge 9. The output from the liquid level gauge 9 is input to the control device 10. Control device 10
While monitoring the liquid level in the scum separation tank 4
The operating states of the pump 1 and the second pump 2 are controlled. The overflowed scum is stored in the scum tank 11.

FIG. 2 shows the operating state of the embodiment of FIG.
The time t0 to t1 is the operation state during rolling, and the time t1 to t4 is the scum-out operation during scum discharge. 2 (1) shows the operating capacity of the first pump 1, FIG.
2 (2) shows the operating capacity of the second pump 2, and FIG. 2 (3) shows the liquid level in the scum separation tank 4. During the rolling, the first pump 1 and the second pump 2 each have a constant capacity V
Operated at 1, V2, the liquid level in the scum separation tank 4 is L
At 1, it is set lower than the level L2 of the weir. The liquid level fluctuates due to various factors during operation, but the weir level L
The level of L1 is set as a level that does not reach 2.

In the scum out from the time t1, first, the pumps 1 and 2 are stopped for, for example, 1 to 2 hours until the time t2, and the liquid level L1 of the scum separation tank 4 is kept constant. Time t when the separation of scum and rolling oil has progressed sufficiently
From 2, the control device 10 operates the second pump 2 with the small capacity V3 while keeping the first pump 1 stopped. The small capacity operation of the second pump 2 can be realized by various methods such as using a variable capacity pump, operating a part of a plurality of pumps, performing inverter control, or the like. By time t3, the level of the liquid level in the scum separation tank 4 gradually rises, and overflow is started before reaching the level L2 of the weir. Since the scum exists above the level of the liquid surface, it overflows beyond the weir and is stored in the scum tank 11 of FIG. 1 before the time when the level of the liquid surface reaches L2. At time t3, the small-capacity operation of the second pump 2 is stopped, and left until time t4. From time t2 to t
Up to 4 is a time within 30 minutes, for example.

FIG. 3 shows the piping path of the embodiment of FIG. 1 in more detail. The rolling oil is supplied to each of the plurality of rolling mills 3a and 3b that rolls the metal strip 15. Each rolling mill 3a, 3
Switching valves 7a and 7b are provided at b, and it is possible to switch between a supply path for spraying the rolling roll and a supply path without spray. Roll 16 for rolling the metal strip 15 is sprayed with rolling oil from a nozzle 17. The sprayed rolling oil is placed in a pan 18 below the roll 16.
And is returned to the scum separation tank 4.

The scum separation tank 4 is provided with an agitator 20, a heater 21, a liquid level gauge 9, a weir 8 and the like. The first pump 1 that sucks rolling oil from the scum separation tank 4 is realized by parallel operation of a plurality of pumps 1a, 1b, 1c. First
The rolling oil delivered from the pump 1 is filtered by the filter element 25 which forms the filter 5 as a Hoffman filter, and is delivered to the cleaning tank 6. The scum that overflows beyond the weir 8 is stored in the scum tank 11. Since the rolling oil overflows beyond the weir 8 together with the scum, the rolling oil is sucked by the return pump 26 in the scum tank 11 and returned to the scum separation tank 4 via the filter 27. The rolling oil that is not separated from the scum flows from the scum tank 11 to the waste liquid tank 2
Sent to 8. In the waste liquid tank 28, the waste liquid pump 29 sends the waste liquid to a facility for waste liquid treatment.

The cleaning tank 6 also includes an agitator 30, a heater 31,
Liquid level gauges 32 are provided respectively. Fine iron and the like may be mixed in the cleaned rolling oil, and in order to remove such fine iron and the like, the concentration of the iron content is sucked by the pump 33 and the iron content is adjusted by using the electromagnetic filter 34. It can be reduced. The second pump for sucking the rolling oil from the cleaning tank 6 also has a plurality of pumps 2a, 2b, 2c, and the small capacity operation is realized by operating a part of them. The rolling oil delivered from the second pump 2 is cooled by the cooler 40 and supplied to the rolling mills 3 a and 3 b via the flow meter 41. Heaters 21, 31
Controls the oil temperature by flowing steam.

FIG. 4 shows a scum separation tank 4 and a scum tank 11.
1 is a front view of the embodiment of FIG. 1, FIG. 5 is a plan view of the scum separation tank 4 of FIG. 4, and FIG. 6 is a right side view of the scum separation tank 4 of FIG. Length LL of scum separation tank 4 in the longitudinal direction
Is, for example, 10 m, the width LW is, for example, 3 m, and the height H is, for example, 3 m. A gutter 45 is provided on one side wall of the scum separating tank 4, and a bottom surface of the gutter 45 is inclined so as to become lower toward a side where the scum tank 11 is provided. On the wall surface of the boundary between the gutter 45 and the scum separation tank 4, a plurality of square holes are provided as weirs 8. Scum separation tank 4
Is a large-scale facility like this, and manually scraping off the scum from the liquid surface to separate the scum is extremely inefficient. According to this embodiment, the scum can be automatically separated by controlling the liquid surface level, so that the working efficiency is greatly improved.

FIG. 7 shows the operation of this embodiment. The operation is started from step a1, and the first pump 1 is started at step a2.
And the second pump 2 is stopped. In step a3, as shown between time t1 and time t2 in FIG. 2, a separation time for separating scum and rolling oil is provided. Step a
In 4, the switching valve 7 is switched so that the rolling oil supply path is switched from the state of spraying to the rolling mill 3 to the path of directly flowing to the scum separation tank 4. At step a5, the second pump 2 is operated in a small capacity to gradually raise the liquid level in the scum separation tank 4.

At step a6, it is judged whether the liquid level in the scum separation tank 4 reaches the level of the weir 8. When the liquid level reaches the level of the weir 8, the small-volume operation of the second pump 2 is stopped in step a7, and step a
In step 8, holding is further performed for a certain period of time, and in step a9, the operation of scout is ended.

FIG. 8 shows the structure of the liquid level gauge used in the embodiment of FIG. In the scum separation tank 4, the scum 51 floats on the liquid surface of the rolling oil 50. FIG. 8 (1) shows the configuration of a liquid level gauge 9a in which the elongated electrode 52 is inserted into the rolling oil 50 and the liquid level of the rolling oil 50 is detected by the detector 53. 8 (2), in the center body 54, the differential pressure between the measurement pressure side unit 55 mounted near the bottom surface of the scum separation tank 4 and the reference pressure side unit 56 that detects the pressure of the atmosphere is detected, and the transmission unit 57 keeps it constant. It is transmitted as a standard signal. According to such an electronic differential pressure transmitter type liquid level gauge 9b, the pressure corresponding to the height of the oil level of the rolling oil 50 can be detected.

FIG. 9 shows the configuration of another embodiment of the present invention. In this embodiment, parts corresponding to the embodiment of FIG. 1 are denoted by the same reference numerals. It should be noted that the skimmer 60 is floated on the liquid surface of the scum separation tank 4 and the motor 61 drives the skimmer 60 to scrape and discharge the scum floating on the liquid surface. The rolling oil supply path switched by the switching valve 7 passes through the pan 18.

FIG. 10 shows an air nozzle 62 arranged for efficiently performing the operation by the skimmer 60. Operate each air nozzle 62 in order to remove the scum on the liquid surface.
Collect on the 0 side and discharge efficiently.

FIG. 11 shows the optimum liquid level for providing the skimmer 60.

[0030]

As described above, according to the present invention, the operating states of the first pump and the second pump are controlled to adjust the level of the liquid level in the scum separation tank with respect to the level of the weir, and the automatic Scum discharge can be performed. Since it is not necessary to manually scrub the scum, it is possible to improve the work environment and work efficiency.

According to the present invention, when scum is discharged,
Since the rolling oil supply path is switched so that the rolling oil is not injected into the rolling rolls of the rolling mill, the liquid level in the scum separation tank can be accurately controlled, and the scum can be efficiently overflowed from the weir and separated. In addition, rolling oil can be prevented from flowing out of the weir.

Further, according to the present invention, since a skimmer is floated on the liquid surface of the scum separation tank and the scum scrapes the scum from the liquid surface to remove it, the scum on the liquid surface is manually scraped and separated. do not have to.

Further, according to the present invention, the controller controls the first pump and the second pump while monitoring the liquid level in the scum separation tank with the liquid level gauge, and is provided in the scum separation tank when the scum is discharged. It is possible to gradually raise the liquid level to the level of the weir to be spilled and overflow the scum to separate it from the rolling oil.

[Brief description of drawings]

FIG. 1 is a schematic piping system diagram of an embodiment of the present invention.

FIG. 2 is a time chart showing the operation of the embodiment of FIG.

FIG. 3 is a more detailed piping system diagram of the embodiment of FIG.

FIG. 4 is a front view showing a configuration related to the scum separation tank of the embodiment of FIG.

FIG. 5 is a plan view of a scum separation tank.

FIG. 6 is a right side view of the scum separation tank.

FIG. 7 is a flowchart showing the operation of the embodiment of FIG.

FIG. 8 is a simplified front view showing the configuration of a liquid level gauge used in the embodiment of FIG.

FIG. 9 is a piping system diagram of another embodiment of the present invention.

FIG. 10 is a simplified front sectional view of the embodiment of FIG.

FIG. 11 is a simplified side sectional view of the embodiment of FIG.

[Explanation of symbols]

 1, 1a, 1b, 1c 1st pump 2, 2a, 2b, 2c 2nd pump 3, 3a, 3b rolling mill 4 scum separation tank 5 filter 6 cleaning tank 7, 7a, 7b switching valve 8 weir 9, 9a, 9b Liquid level gauge 10 Control device 15 Metal band 16 Roll 17 Nozzle 18 Pan 25 Filter element 34 Electromagnetic filter 40 Cooler 45 Gutter 50 Rolling oil 51 Scum 52 Electrode 55 Measuring pressure side unit 60 Skimmer

Claims (4)

[Claims] 1. Rolling oil after use is collected and temporarily stored in a scum separation tank, sucked from the scum separation tank by a first pump, and the rolling oil purified through a filter is stored in a cleaning tank. In the method for supplying rolling oil in which the rolling oil of the rolling mill is injected by the rolling oil sucked by the second pump from the cleaning tank and the collected rolling oil is circulated, the weir for overflow is provided in the scum separation tank. Inside, keep the liquid level in the scum separation tank lower than that of the weir, and when discharging scum, stop the first pump and operate the second pump with a small capacity to keep the liquid level in the scum separation tank low. A method for supplying rolling oil, which comprises slowly increasing the level until reaching the level of a weir. 2. The method for supplying rolling oil according to claim 1, wherein the rolling oil supply path is switched so that the rolling oil is not jetted to the rolling rolls of the rolling mill but is allowed to flow into the scum separation tank when the scum is discharged. . 3. Rolling oil after use is collected and temporarily stored in a scum separation tank, sucked from the scum separation tank by a first pump, and the rolling oil purified through a filter is stored in a cleaning tank. In the method of supplying rolling oil, in which the rolling oil sucked from the clean tank by the second pump is jetted to the rolling rolls of the rolling mill, and the recovered rolling oil is circulated, leaving a gap on the liquid surface in the scum separation tank. A method for supplying rolling oil, characterized in that scum is collected by a gap and separated. 4. The rolling oil after use is collected and temporarily stored in a scum separation tank, sucked from the scum separation tank by a first pump, and the rolling oil purified through a filter is stored in a cleaning tank. In the rolling oil supply device that injects the rolling oil sucked by the second pump from the clean tank to the rolling rolls of the rolling mill and circulates the recovered rolling oil, the weir for overflow provided in the scum separation tank and the scum separation In response to the output from the liquid level gauge that detects the liquid level in the tank and the level gauge, the first pump and the second pump are operated so that the liquid level becomes lower than the weir during rolling, and the scum is discharged. Sometimes, a control means for controlling the first pump to stop and the second pump to operate at a small capacity so that the liquid level rises slowly to reach the level of the weir is provided. Supply device.