JP5723212B2 - Cleaning device, cleaning method and temper rolling mill - Google Patents

Description

  The present invention relates to a cleaning device, a cleaning method, and a temper rolling mill.

When temper rolling is performed on a steel strip in a continuous hot dip galvanizing line, a part of the galvanized layer is peeled off to generate foreign matters such as zinc powder, which may adhere to the work roll surface. If zinc powder adheres to the surface of the work roll, it may be transferred to the steel strip during rolling, and the appearance quality of the steel strip may be impaired.
Moreover, the unevenness | corrugation for providing the steel plate roughness requested | required by the user to the surface of a steel plate is formed in the work roll surface of a temper rolling mill with the roughness corresponding to a steel plate roughness. When foreign matter such as zinc powder adheres and accumulates in the concave and convex portions, the roughness of the work roll surface is lowered and a state called “clogging” is brought about. If the work roll is clogged, the hot-dip galvanized steel strip after temper rolling cannot be provided with the required steel plate roughness, and the required press formability and sharpness cannot be ensured when used as automotive parts. There's a problem.
For such a problem, various methods have been proposed for removing foreign matters on the surface of the work roll when temper rolling the hot dip galvanized steel strip and for preventing clogging of the work roll.

In Patent Document 1, a high-pressure fluid of 15 kg / cm ² (15 MPa) or more is applied to the work roll surface over its entire length on the work roll exit side (the side on which the rolled rolled sheet is fed from between the work rolls). In addition, a work roll surface cleaning method that is constantly sprayed during rolling is described. Examples of the high pressure fluid used in this work roll surface cleaning method include rolling oil, air, oil mist, hot water and the like.
Patent Document 2 describes a method of rolling by forming a water film between a work roll and a galvanized steel sheet. The water film suppresses heat generation at the contact portion between the work roll and the steel sheet, and suppresses a phenomenon in which foreign matter such as zinc powder adheres to the work roll surface and roll roughness is lowered.

In addition, a method of cutting or peening a workpiece by an air cavitation jet has been proposed.
Cutting nozzles for injecting an air cavitation jet are described in, for example, Patent Documents 3 to 5. This cutting nozzle has a high-pressure jet nozzle in the center, and a low-pressure jet nozzle that surrounds the high-pressure jet nozzle in a concentric double ring shape and forms a low-pressure water flow path having an annular cross section on the inner surface. And a low pressure water jet is injected so that the circumference | surroundings of a high pressure water jet may be enclosed, and a cavitation phenomenon is produced.

  As yet another method, Patent Document 6 describes a method of cleaning the surface of an object to be processed by projecting dry ice or the like at high speed using a high-pressure and low-temperature liquefied inert gas as a projection medium.

Japanese Patent No. 3039895 JP 2004-21697A JP 2000-202326 A JP-A-10-113871 Japanese Patent No. 2957976 JP 61-152368 A

However, the cleaning method using the high-pressure fluid described in Patent Document 1 has a problem that foreign matters such as zinc powder deposited in the recesses on the surface of the work roll cannot be sufficiently removed. Further, since the high-pressure fluid is constantly ejected over the entire length in the axial direction of the work roll during rolling, a large amount of cleaning waste liquid containing the removed foreign matter is generated. And there also exists a problem that the processing cost of this washing | cleaning waste liquid is high.
Furthermore, in the method described in Patent Document 2, since it is necessary to continuously form a water film between the work roll and the galvanized steel sheet, there is a problem that a large amount of waste liquid is generated and the waste liquid treatment cost is high. is there.
Further, in the method using the air cavitation jet described in Patent Documents 3 to 5, the effect of cutting or peening is superior to the method using only a high-pressure fluid, but a large amount of low-pressure is generated to cause the cavitation phenomenon. Fluid is required. As a result, a large amount of waste liquid is generated.
And in the cleaning method described in patent document 6, since the high pressure low temperature liquefied inert gas is used as a projection medium and dry ice etc. are used as a projection material, although the processing cost of washing | cleaning waste liquid can be suppressed, a work roll There exists a problem which cannot fully remove the said foreign material adhering to the recessed part of the surface.

  An object of the present invention is to provide a cleaning device, a cleaning method, and a temper rolling mill that can suppress the adhesion of foreign matters while removing foreign matters on the surface of the work roll, and can reduce the amount of cleaning waste liquid.

The cleaning device of the present invention is a cleaning device for cleaning a work roll of a temper rolling mill,
A blasting material containing sublimable solid particles less than 0 ° C. and a jetting medium, a high-pressure fluid having a pressure of 20 MPa or more and 30 MPa or less, and a washing nozzle capable of jetting a low-pressure fluid having a pressure of 0.03 MPa or more and 0.06 MPa or less;
Blast material supply means for supplying the blast material to the cleaning nozzle;
High-pressure fluid supply means for supplying the high-pressure fluid to the cleaning nozzle;
Low pressure fluid supply means for supplying the low pressure fluid to the cleaning nozzle,
The cleaning nozzle has a first jet port that jets the high-pressure fluid, and a second jet port that surrounds the first jet port and jets the low-pressure fluid and the blast material.
Between the cleaning nozzle and the blast material supply means, a first adjustment means for adjusting the supply amount of the blast material is provided,
Between the cleaning nozzle and the high-pressure fluid supply means, a second adjustment means for adjusting the supply amount of the high-pressure fluid is provided,
A third adjusting means for adjusting a supply amount of the low-pressure fluid is provided between the cleaning nozzle and the low-pressure fluid supply means.

According to the present invention as described above, three types of jetting materials, that is, a blasting material containing high-pressure fluid, low-pressure fluid, and sublimable solid particles of less than 0 ° C. can be sprayed onto the work roll surface. Then, the supply and stoppage of the ejection material to the cleaning nozzle can be switched by the first adjustment means, the second adjustment means, and the third adjustment means.
For this reason, first, if cleaning is performed with a blast material containing sublimable solid particles of less than 0 ° C., foreign matter adhering to the surface of the work roll due to the impact when the blast material is sprayed can be removed.
Moreover, since the blast material contains solid particles having a low temperature of less than 0 ° C., the work roll surface can be cooled. The cooling effect is better for the blast material than when the rolling oil is sprayed as a high-pressure fluid. As a result, since heat generation at the contact portion between the work roll surface and the steel sheet is suppressed, adhesion of foreign matter such as zinc powder to the recesses on the work roll surface can be suppressed.
Here, when the blast material is sprayed and the cleaning power is insufficient and the foreign matter cannot be completely removed, the foreign matter can be removed by switching to spraying the high-pressure fluid having higher cleaning power.
Further, when the foreign matter or the like cannot be completely removed even by spraying the high pressure fluid, the low pressure fluid is ejected at the same time to generate an air cavitation jet. Since this air cavitation jet has a higher cleaning power than a high-pressure fluid, foreign substances can be more reliably removed.
As described above, since the cleaning apparatus of the present invention can eject while switching between three types of ejecting materials having different cleaning powers, an appropriate cleaning method is selected according to the state of the work roll surface to remove foreign matters on the work roll surface. In addition, adhesion of foreign matters can be suppressed.

Further, since the blast material has sublimation properties, it does not remain as a waste liquid after washing the work roll.
Therefore, during normal temper rolling, cleaning with this blast material reduces the amount of cleaning waste liquid, and switching to cleaning with high-pressure fluid or air cavitation jet when foreign matter can no longer be removed Compared to regular cleaning with an air cavitation jet, the amount of cleaning waste liquid can be reduced.

  In the cleaning apparatus of the present invention, it is preferable to use a liquefied inert gas as the ejection medium for the blast material.

In this case, since the blast material contains sublimable solid particles of less than 0 ° C. and a liquefied inert gas, the blast material is in a sol form. The blast material sprayed on the work roll surface removes foreign matters on the work roll surface and cools the work roll surface. In particular, since the liquefied inert gas tends to spread on the work roll surface as compared with the solid particles, the cooling effect is improved. Therefore, the effect which suppresses the foreign material adhesion to the recessed part of the work roll surface improves.
Furthermore, since the liquefied inert gas is vaporized after being sprayed on the work roll surface, the amount of washing waste liquid can also be reduced.

  In the cleaning apparatus of the present invention, the sublimable solid particles of less than 0 ° C. of the blast material are preferably dry ice.

  In such this invention, since the solid particle contained in a blast material is dry ice, the surplus carbon dioxide in a factory can be used effectively.

In the cleaning apparatus of the present invention,
Detecting means for detecting the state of the surface of the work roll;
Control means for controlling the first adjustment means, the second adjustment means, and the third adjustment means according to the state of the work roll surface detected by the detection means,
When temper rolling is performed while the blast material is ejected from the second ejection port and sprayed onto the surface of the work roll, foreign matter adheres to the concave and convex portions on the surface of the work roll by the detecting means. When it is detected that the foreign matter cannot be completely removed by spraying the material, the control means controls the first adjustment means to stop the supply of the blast material to the cleaning nozzle, and the second adjustment By controlling the means and starting the supply of the high-pressure fluid to the cleaning nozzle, the high-pressure fluid is ejected from the first ejection port and sprayed on the work roll surface,
Further, when the detection means detects that the foreign matter cannot be completely removed by spraying the high pressure fluid, the control means controls the third adjustment means to supply the low pressure fluid to the cleaning nozzle. Preferably, the high pressure fluid is ejected from the first ejection port and the low pressure fluid is ejected from the second ejection port at the same time to form a cavitation jet and spray the surface of the work roll.

  In the present invention as described above, the state of the work roll surface can be detected by the detecting means, and each adjusting means can be controlled by the control means in accordance with the detected surface state. The surface of the work roll can be cleaned with an appropriate jetting material selected according to the surface state. Therefore, foreign matter removal on the surface of the work roll, suppression of foreign matter adhesion, and reduction of the amount of cleaning waste liquid can be more reliably performed.

The cleaning method of the present invention is a cleaning method using the above-described cleaning apparatus,
The cleaning apparatus includes a detection unit that detects a state of the surface of the work roll,
When performing temper rolling while spraying the blast material from the second jet nozzle and spraying it on the surface of the work roll, foreign matter adheres to the concave and convex portions on the surface of the work roll and the blast material sprays the When the detection means detects that the foreign matter cannot be completely removed, the first adjustment means is controlled to stop the supply of the blast material to the cleaning nozzle, and the second adjustment means is controlled. Starting the supply of the high-pressure fluid to the cleaning nozzle, and spraying the high-pressure fluid from the first ejection port and spraying the surface of the work roll,
Further, when the detection means detects that the foreign matter cannot be removed by spraying the high pressure fluid, the third adjustment means is controlled to start the supply of the low pressure fluid to the cleaning nozzle, and A jet of the high-pressure fluid from one jet outlet and a jet of the low-pressure fluid from the second jet outlet are simultaneously performed to form a cavitation jet and spray it onto the work roll surface.

In the present invention, the state of the work roll surface is detected, and the work roll can be cleaned while controlling each adjusting means according to the detected surface state. Clogging can be prevented more reliably. While foreign matter does not adhere to the recesses on the surface of the work roll, clean it with blasting material. If clogging occurs and the blasting material cannot be removed, switch to high-pressure fluid ejection, and further remove with high-pressure fluid. If not, it is possible to switch to simultaneous ejection of the high-pressure fluid and the low-pressure fluid and control to remove foreign matter by the air cavitation jet.
Therefore, since it is difficult to remove with a blasting material, it is switched to a jetting material with a strong removal capability, so that clogging can be reliably prevented and a large amount of waste liquid is generated even when there is almost no clogging (high-pressure fluid The amount of waste liquid generated can also be reduced compared with the case of employing cleaning and air cavitation jet cleaning).

  In the cleaning method of the present invention, it is preferable that the blast material, the high-pressure fluid and the low-pressure fluid are ejected intermittently.

  In this invention, since three types of jetting materials are ejected intermittently, the amount of waste liquid generated can be reduced compared to the case of jetting continuously.

  A temper rolling mill according to the present invention includes the above-described cleaning device and a work roll.

In the present invention, since the cleaning device of the present invention is used, as described in the description of the cleaning device, it is possible to suppress the adhesion of foreign matter while removing the foreign matter on the surface of the work roll, and to reduce the amount of cleaning waste liquid. .
As a result, it is possible to prevent appearance damage and roughness reduction of the steel strip during temper rolling.

The structure schematic of the temper rolling mill which concerns on embodiment of this invention. The upper surface schematic of the temper rolling mill which concerns on the said embodiment. The partial cross section schematic of the washing | cleaning apparatus which concerns on the said embodiment. The 1st graph which shows the washing | cleaning experiment result performed with the washing | cleaning apparatus which concerns on the said embodiment. The 2nd graph which shows the washing | cleaning experiment result performed with the washing | cleaning apparatus which concerns on the said embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Configuration of temper rolling mill]
As shown in FIG. 1, the temper rolling mill 1 includes a pair of upper and lower work rolls 2, a backup roll 3 disposed above and below each work roll 2, and a cleaning device 5 for cleaning the surface of the work roll 2. And an exhaust hood 6 and a duct 7.
The pair of work rolls 2 temper-roll the hot-dip galvanized steel strip 4 supplied from the entry side (left side in FIG. 1) of the work roll 2 and send it out from the exit side (right side in FIG. 1). .

[Configuration of cleaning equipment]
The cleaning device 5 sprays three types of ejection materials, that is, a blast material including sublimable solid particles of less than 0 ° C. and an ejection medium, a high-pressure fluid and a low-pressure fluid onto the surface of the work roll 2 to clean the surface. Is for.
The cleaning device 5 includes a cleaning nozzle 51, a blast material supply unit 52, a high-pressure fluid supply unit 53, a low-pressure fluid supply unit 54, a cleaning nozzle moving unit 55, a detection unit 56, and a control unit 57. .

As shown in FIG. 1, the cleaning nozzle 51 is disposed on the exit side of each work roll 2. The cleaning nozzle 51 is connected to the blast material supply means 52 via the pipes P1 and P3, to the high-pressure fluid supply means 53 via the pipe P2, and to the low-pressure fluid supply means 54 via the pipe P3. The pipe P1 may be directly connected to the cleaning nozzle 51 without joining the pipe P3.
Further, as shown in FIG. 2, the cleaning nozzle 51 is attached to the cleaning nozzle moving means 55, and one cleaning nozzle 51 is arranged along the axial direction of the work roll 2.
Furthermore, as shown in FIG. 3, the cleaning nozzle 51 includes a tubular first nozzle 511 and a tubular second nozzle 512 surrounding the first nozzle 511.
The 1st nozzle 511 has the 1st jet nozzle 513 which can eject the high pressure fluid supplied from the high pressure fluid supply means 53 in the front end side.
The second nozzle 512 is provided so as to surround the first nozzle 511 in a concentric double tubular shape, and is supplied from the blast material supplied from the blast material supply means 52 and the low-pressure fluid supply means 54 to the tip side thereof. A second outlet 514 capable of ejecting the low-pressure fluid to be ejected.

The blast material supply means 52 is for producing a blast material and supplying it to the second nozzle 512. As shown in FIG. 1, the first storage means 521, the second storage means 522, and the particle production means. 523, a mixing unit 524, a first adjusting unit 525, a compressor 526, and a pressure reducing valve 527.
The blast material supplied by the blast material supply means 52 includes sublimable solid particles (hereinafter referred to as sublimable solid particles) of less than 0 ° C. and an ejection medium.
The sublimable solid particles have a temperature of less than 0 ° C. and have sublimability at normal temperature and pressure, and examples thereof include dry ice.
Examples of the ejection medium include compressed air and low-temperature liquefied inert gas. The low-temperature liquefied inert gas is in a liquid state that is liquefied by cooling the inert gas in a gaseous state at room temperature, and includes liquefied gases such as carbon dioxide, nitrogen, argon, and helium.
In the present embodiment, the blast material is in the form of a sol because it contains a low-temperature liquefied inert gas as an ejection medium in addition to the sublimable solid particles.

Examples of the first storage unit 521 and the second storage unit 522 include a tank and a cylinder.
The first storage means 521 is connected to the particle production means 523 and stores the raw material for producing sublimable solid particles in the state of high-pressure gas or liquefied gas. An adjustment unit 521a is connected between the first storage unit 521 and the particle production unit 523. The adjusting means 521a is connected to the control means 57, and adjusts the supply amount and supply pressure of the raw material for producing sublimable solid particles from the first storage means 521 to the particle producing means 523 under the control of the control means 57. . Examples of the adjusting means 521a include a pressure regulator provided with a valve and a pressure gauge.
Here, when the sublimable solid particles are dry ice, the first storage means 521 stores high-pressure carbon dioxide or compressed and liquefied carbon dioxide.

  The 2nd storage means 522 is connected to the mixing means 524, and stores the low temperature liquefied inert gas as an ejection medium. An adjusting means 522a is connected between the second storage means 522 and the mixing means 524. The adjusting means 522a is connected to the control means 57, and adjusts the supply amount and supply pressure of the low-temperature liquefied inert gas from the second storage means 522 to the mixing means 524 under the control of the control means 57. Examples of the adjusting means 522a include a pressure regulator provided with a valve and a pressure gauge.

  Here, when the low-temperature liquefied inert gas is a liquefied carbon dioxide gas obtained by liquefying carbon dioxide and the sublimable solid particles are dry ice, the first storage means 521 and the second storage means 522 are made common. You can also. In this case, when the liquefied carbon dioxide gas is ejected into the particle production means 523 from a tank or the like for storing the liquefied carbon dioxide gas, the liquefied carbon dioxide gas is adiabatically expanded and changed into solid dry ice. The blast material obtained by mixing the dry ice and the stored liquefied carbon dioxide gas by the mixing means 524 can be supplied to the second nozzle 512.

  The particle production means 523 is connected to the mixing means 524, and is composed of a tank or a cylinder. The particle manufacturing unit 523 manufactures sublimable solid particles by adiabatic expansion of the high-pressure gas or liquefied gas supplied from the first storage unit 521 and supplies the sublimable solid particles to the mixing unit 524.

  The mixing unit 524 is connected to the second nozzle 512 by a pipe P1 and a pipe P3, and includes a tank, a cylinder, and the like. This mixing means 524 is connected to the sublimable solid particles produced by the particle production means 523 and the low temperature liquefied inert gas which is the ejection medium stored in the second storage means 522, or the pressure reducing valve 527. The blast material is manufactured by mixing with the compressed air supplied from the compressor 526 and supplied to the pipe P1.

  The first adjusting means 525 is provided in the pipe P <b> 1 and adjusts the supply amount and supply pressure of the blast material sent out from the mixing means 524 under the control of the control means 57. As this 1st adjustment means 525, the pressure regulator provided with the valve | bulb and the pressure gauge etc. are mentioned.

  In the case where the blast material is composed of sublimable solid particles and a low-temperature liquefied inert gas, the low-temperature liquefied inert gas can also serve as the ejection medium. The material can be sent to the cleaning nozzle 51 by the pressure feeding means.

  The compressor 526 and the pressure reducing valve 527 are connected via a fourth adjustment unit 528 having the same configuration as the first adjustment unit 525, and supply the ejection medium to the mixing unit 524 under the control of the control unit 57. .

The high-pressure fluid supply unit 53 is for supplying a high-pressure fluid to the first nozzle 511, and includes a cleaning fluid storage unit 531, a first pumping unit 532, and a second adjustment unit 533.
The cleaning fluid storage means 531 is a tank or a cylinder that stores cleaning fluid such as water or rolling oil, and is connected to the first nozzle 511 by a pipe P2.

  The 1st pumping means 532 is a high pressure pump, and is provided in the piping P2. The first pumping unit 532 pressurizes the cleaning fluid supplied from the cleaning fluid storage unit 531 and supplies it to the first nozzle 511 as a high-pressure fluid under the control of the control unit 57. The pressure of the high-pressure fluid supplied to the first nozzle 511 is large enough to generate an air cavitation jet, which will be described later, and is specifically 20 MPa to 30 MPa. Moreover, the pressure in the case of washing with a high-pressure fluid is also 20 MPa or more and 30 MPa or less.

  The second adjusting means 533 is a pressure regulator provided with a valve and a pressure gauge, and is provided on the first nozzle 511 side of the first pressure feeding means 532 in the pipe P2. The second adjusting means 533 adjusts the supply amount and supply pressure of the high-pressure fluid delivered from the first pressure feeding means 532 under the control of the control means 57.

The low-pressure fluid supply means 54 is for supplying a low-pressure fluid to the second nozzle 512, and includes a cleaning fluid storage means 531, a second pressure-feed means 542, and a third adjustment means 543. In the present embodiment, since the same cleaning fluid is used for the high-pressure fluid and the low-pressure fluid, the cleaning fluid storage unit 531 described in the high-pressure fluid supply unit 53 can be used. Therefore, the cleaning fluid storage unit 531 is also connected to the second nozzle 512 by the pipe P3.
In addition, when using the cleaning fluid different from a high pressure fluid as a low pressure fluid, the storage means for storing the cleaning fluid for a low pressure fluid is provided separately.

  The 2nd pumping means 542 is a low pressure pump, and is provided in the piping P3. The second pumping unit 542 pressurizes the cleaning fluid supplied from the cleaning fluid storage unit 531 and supplies it to the second nozzle 512 as a low-pressure fluid under the control of the control unit 57. The pressure of the low-pressure fluid supplied to the second nozzle 512 is a magnitude for generating an air cavitation jet, which will be described later, specifically, 0.03 MPa to 0.06 MPa.

  The 3rd adjustment means 543 is a pressure regulator provided with the valve and the pressure gauge, and is provided in the 2nd nozzle 512 side of the 2nd pumping means 542 in the piping P3. The third adjusting means 543 adjusts the supply amount and supply pressure of the low-pressure fluid sent out from the second pressure feeding means 542 under the control of the control means 57.

The cleaning nozzle moving means 55 moves the cleaning nozzle 51 under the control of the control means 57 while keeping the distance between the cleaning nozzle 51 and the work roll 2 constant.
As shown in FIG. 2, the cleaning nozzle moving means 55 includes a nozzle support portion 571 that supports each cleaning nozzle 51 and a nozzle moving lead screw 572 that passes through the nozzle support portion 571 and is screwed into the nozzle support portion 571. And a drive unit 573 that rotates the nozzle moving lead screw 572 in the forward and reverse directions.
When the drive unit 573 rotates the nozzle moving lead screw 572 in the forward and reverse directions, the nozzle support unit 571 that is screwed with the nozzle moving lead screw 572 runs along the axial direction of the work roll 2. Therefore, the cleaning device 5 is configured such that there are no blind spots in the spray region of the three types of ejected material on the surface of the work roll 2.

The detection unit 56 detects the surface state of the work roll 2 and sends information corresponding to the detected surface state to the control unit 57. Examples of the element indicating the surface state of the work roll 2 include surface roughness, surface color, surface temperature, and the state of foreign matter adhesion to the surface. The detection means 56 can detect one or more surface state elements. To detect.
For example, when detecting the roughness of the surface of the work roll 2, the detection means 56 includes a surface roughness measuring device, measures the change in the unevenness of the surface of the work roll 2, and foreign matter adheres to or accumulates in the recess. Detect whether or not.
For example, when detecting the color of the surface of the work roll 2, the detection unit 56 includes an image processing device including a camera and an image analysis unit. Is detected.
In addition, for example, when detecting the temperature of the work roll 2 surface, the detection means 56 is provided with a non-contact temperature sensor, and whether the surface temperature is higher than the temperature at which the action of suppressing the adhesion of zinc powder works. To detect.

Furthermore, the detecting means 56 may be used separately in order to detect the surface condition such as surface roughness and surface wrinkles of the hot-dip galvanized steel strip 4 after temper rolling.
In this case, the detection means 56 is arranged so as to be able to detect the surface state of the work roll 2 and the hot-dip galvanized steel strip 4 after temper rolling, and is connected to the control means 57.

  The control means 57 includes a detection means 56, a first adjustment means 525, a second adjustment means 533, a third adjustment means 543, a first pressure feeding means 532, a second pressure feeding means 542, a cleaning nozzle moving means 55, a compressor 526, a pressure reducing valve. 527, the adjusting unit 521a and the adjusting unit 522a are connected to the adjusting unit 522a through the electric wiring Cb, and based on the surface state detected by the detecting unit 56, the switching state of the ejected material by the cleaning device 5, the fluid pressure and flow rate, The position and swing of the cleaning nozzle 51 are controlled.

The exhaust hood 6 is disposed in the vicinity of the cleaning nozzle 51 and collects the gas generated by vaporizing the sublimable solid particles and the inert gas generated by vaporizing the low-temperature liquefied inert gas.
The duct 7 is connected to the exhaust hood 6, conveys the collected gas, and exhausts it outside the factory by an exhaust fan (not shown). If the collected gas is carbon dioxide, it may be changed to liquefied carbon dioxide gas as a raw material for the blast material.

[Description of cleaning method]
Next, a method for cleaning the work roll 2 will be described.
First, as shown in FIG. 1, the cleaning nozzle 51 is arranged on the exit side of each work roll 2, and one is arranged along the axial direction of the work roll 2 as shown in FIG. 2. Then, the hot dip galvanized steel strip 4 is temper-rolled with a pair of upper and lower work rolls 2 while being conveyed in the direction of the arrow in FIG. Drive along the direction.
And the control means 57 selects an ejection material as shown below based on the detection state by the detection means 56. FIG.

(Cleaning with blast material)
When the detecting means 56 detects that no foreign matter adheres to the surface of the work roll 2, the control means 57 performs temper rolling while ejecting the blast material. By spraying the blast material onto the surface of the work roll 2, foreign matters such as zinc powder adhering to the surface due to the impact at the time of spraying are removed, and the surface is cooled to prevent the foreign matter from adhering to the recesses on the surface of the work roll 2. In cleaning with such a blast material, the blast material is vaporized and thus does not become a waste liquid.

(Cleaning with high-pressure fluid)
When it is detected by the detection means 56 that a foreign material of an amount that cannot be removed by the blasting material is attached to the concave portion on the surface of the work roll 2, the control means 57 removes the ejected material from the blasting material and has a higher cleaning power. Switch to fluid.
In this case, the control unit 57 controls the first adjustment unit 525 to stop the supply of the blast material to the cleaning nozzle 51. And the control means 57 controls the 2nd adjustment means 533, the supply of the high pressure fluid to the washing nozzle 51 is started, a high pressure fluid is ejected from the 1st jet nozzle 513, and it sprays on the work roll 2 surface. Foreign matter is removed by spraying this high-pressure fluid.

(Cleaning with air cavitation jet)
When the detection unit 56 detects that an amount of foreign matter that cannot be removed by spraying the high-pressure fluid is detected by the detection unit 56, the control unit 57 switches from the ejection of the high-pressure fluid to an air cavitation jet with higher cleaning power.
Specifically, the control unit 57 controls the third adjustment unit 543 to start supply of the low pressure fluid to the second nozzle 512, and ejects the high pressure fluid from the first ejection port 513 and the second ejection port 514. And the pressure of the high pressure fluid sent from the first pressure feeding means 532 is controlled to 20 MPa or more and 30 MPa or less, and the pressure of the low pressure fluid sent from the second pressure feeding means 542 is set to 0.03 MPa or more. Control to 0.06 MPa or less. A cavitation jet is formed and sprayed onto the surface of the work roll 2 by simultaneously ejecting a high-pressure fluid and a low-pressure fluid having different pressures and speeds. Since the bubbles contained in this air cavitation jet burst on the surface of the work roll 2, the impact pressure of the cleaning fluid is increased, so that foreign matter adhering to and accumulating in the recesses can be removed with a higher cleaning power than the blast material or high-pressure fluid. it can.
The term “simultaneous” here means that the time zone in which the high-pressure fluid is ejected overlaps the time zone in which the low-pressure fluid is ejected.

[Effects of Embodiment]
According to the above embodiment, the following effects can be obtained.
Since the cleaning device 5 can eject while switching three types of ejecting materials having different cleaning powers, an appropriate method can be selected according to the state of the surface of the work roll 2, and the adhesion of the foreign matters can be suppressed while removing the foreign matters.

  Since the sublimable solid particles contained in the blast material have sublimation properties, they do not remain as waste liquid after washing the work roll 2. For this reason, the amount of cleaning waste liquid can be reduced as compared with the case where cleaning is always performed with a high-pressure fluid or an air cavitation jet.

Since the blast material contains sublimable solid particles and liquefied inert gas, the blast material is in a sol form. The blast material sprayed on the surface of the work roll 2 removes foreign matters and cools the surface. In particular, since the liquefied inert gas easily spreads on the surface of the work roll 2 as compared with the solid particles, the cooling effect is improved. Therefore, the effect which suppresses the foreign material adhesion to the recessed part of the work roll 2 surface improves.
Furthermore, since the liquefied inert gas is vaporized after being sprayed on the surface of the work roll 2, the amount of cleaning waste liquid can also be reduced.

  The detecting means 56 detects the state of the surface of the work roll 2, and the control means 57 controls the first adjusting means 525, the second adjusting means 533, and the third adjusting means 543 in accordance with the detected surface condition. Therefore, the surface of the work roll 2 can be cleaned with an appropriate jetting material selected according to the surface state from the three types of jetting materials. Therefore, foreign matter removal on the surface of the work roll 2, suppression of foreign matter adhesion, and reduction of the amount of cleaning waste liquid can be more reliably performed.

  Since the temper rolling is performed while cleaning the work roll 2 using the cleaning device 5, it is possible to prevent appearance damage and roughness reduction of the hot-dip galvanized steel strip 4 during the temper rolling.

[Modification]
In addition, this invention is not limited to embodiment mentioned above, The deformation | transformation etc. in the range which can achieve the objective of this invention are included.
For example, a plurality of the cleaning nozzles 51 described in the above embodiment can be arranged, and at least one of running and swinging along the axial direction of the work roll 2 can be performed.

  Further, without providing the mechanism for running the nozzle support portion 571 of the cleaning nozzle moving means 55 described in the above embodiment, more cleaning nozzles 51 are attached to the nozzle support portion 571, and three types of the surface of the work roll 2 are attached. It can also comprise so that there may be no blind spot in the blowing area | region of a blowing material.

  Further, unlike the above embodiment, the low pressure fluid and the blast material may be ejected from the second nozzle 512 at the same time.

  Moreover, unlike the said embodiment, supply of the sublimable solid particle of a blast material may be stopped, and only the liquefied inert gas of an ejection medium may be ejected. In this case, the supply of sublimable solid particles is stopped by the adjusting means 521a.

  Moreover, the cleaning apparatus and the cleaning method of the present invention can be applied to a steel plate processing line other than the continuous hot dip galvanizing line.

  Moreover, the cleaning apparatus and the cleaning method of the present invention can be applied to a roll of a rolling mill other than the temper rolling mill.

  Moreover, the cleaning apparatus and the cleaning method of the present invention can also be applied to removal of foreign matter from intermediate rolls and backup rolls other than work rolls.

  Moreover, in the cleaning apparatus and the cleaning method of the present invention, the cleaning nozzle is disposed on the work roll exit side in the embodiment, but may be disposed on the entry side.

  Moreover, in the cleaning apparatus and the cleaning method of the present invention, in the above-described embodiment, the presence / absence of use of a blast material or a high-pressure fluid, and the switching are determined according to the surface state of the work roll confirmed by the detection means. However, even if there is no detection means, it may be carried out by visually confirming the state of the steel plate and the roll.

(Confirmation of cleaning effect)
4 to 5 are graphs showing the results of a work roll cleaning experiment performed by the cleaning device 5. The cleaning experiment was performed on a work roll which was used for temper rolling in a continuous hot dip galvanizing line and a clogged state occurred.

Experiment 1: Comparison of blasting material cleaning, high-pressure fluid cleaning, and air cavitation jet cleaning A work roll was attached to a test machine, and cleaning was performed by repeatedly moving the cleaning nozzle at the same speed in the roll width direction at the same speed. . In Experiment 1, the roll was not rotated during cleaning.
First, the amount of zinc present per unit area of the roll surface in the initial clogging state in the area where the blasting material was cleaned was measured with a fluorescent X-ray analyzer before cleaning. After the cleaning nozzle is set at the start position, cleaning is started and the vehicle is run while cleaning. When the stroke limit of the cleaning nozzle is reached, the cleaning is stopped. The amount of zinc in the area measured before cleaning was measured after each traveling cleaning was completed.
After the measurement was completed, the cleaning nozzle was returned to the start position, the next running cleaning was performed, and the amount of zinc in the same area was measured. The relationship between the number of times that the blasting material was washed by repeating this process and zinc on the roll surface was measured.
Next, the roll was rotated 90 ° to perform high-pressure fluid cleaning on the newly clogged roll surface. Before starting cleaning, the amount of zinc deposited on the roll surface was measured, running cleaning was performed with a cleaning nozzle, and the amount of zinc on the roll surface was measured by the same method as blasting material cleaning.
Further, the roll was rotated 90 °, and cleaning was carried out in the same manner using an air cavitation jet.
Dry ice was used as the blasting material for blasting, and compressed air was used as the ejection medium. In the high-pressure fluid cleaning and the air cavitation jet cleaning, water pressurized was used as the fluid, and the high-pressure water pressure was the same.
・ Work roll diameter: φ410mm
・ Nozzle travel speed: 3mm / sec
・ Nozzle travel distance: 100mm
-Roll rotation speed: No roll rotation during cleaning

  The results are shown in FIG. In FIG. 4, the horizontal axis indicates the number of traveling cleanings, and the vertical axis indicates the amount of decrease from the roll surface zinc (Zn) amount in the initial clogging state. In FIG. 4, DI indicates blast material cleaning using dry ice, CV indicates air cavitation jet cleaning, and HW indicates high-pressure fluid cleaning. Hereinafter, in the examples, blast material cleaning using dry ice is referred to as dry ice cleaning.

  As shown in FIG. 4, in the dry ice cleaning, the amount of zinc removed in the first cleaning was large, but the amount of zinc removed in the second and subsequent times did not increase greatly. On the other hand, with high-pressure fluid cleaning and cleaning with an air cavitation jet, the amount of zinc removed increased with repeated cleaning.

  As shown in FIG. 4, it can be seen that the cleaning by the air cavitation jet exceeds the attached zinc removing ability as compared with the high pressure fluid cleaning.

Experiment 2: Switching cleaning between blasting material cleaning and air cavitation jet cleaning The work roll surface was first cleaned with dry ice, and then the air was subjected to air cavitation jet cleaning.
In Experiment 2, the same work roll as in Experiment 1 was used, but the cleaning location was different from that in Experiment 1, and cleaning was performed from the initial clogging state. Further, in Experiment 2, the work roll was rotated at the same rotation speed as that during operation, and the cleaning was performed at a fixed position without running the cleaning nozzle.
・ Work roll diameter: φ410mm
・ Nozzle travel speed: No nozzle travel (fixed position)
・ Nozzle travel distance: 0mm
・ Roll rotation speed: 112rpm

  The results are shown in FIG. In FIG. 5, the horizontal axis indicates the cleaning time, and the vertical axis is the same as in FIG. Further, in FIG. 5, DI cleaning indicates dry ice cleaning, and CV cleaning indicates air cavitation jet cleaning.

As shown in FIG. 5, in the dry ice cleaning, although the amount of zinc decrease increases at the initial stage when dry ice is ejected, it gradually reaches its peak after about 500 seconds. Then, after 630 seconds, when switching to air cavitation jet cleaning, the amount of zinc reduction began to increase again.
For this reason, although dry ice cleaning has the ability to remove zinc, it cannot remove the attached zinc, but it can be further removed by switching to air cavitation jet cleaning from the middle. I understood. Therefore, the blasting material cleaning is performed in a state where no zinc adheres or accumulates on the surface of the work roll, and is suitable for suppressing adhesion or removing a small amount of adhering zinc, such as an air cavitation jet. It can be said that cleaning with strong cleaning power is suitable for use when the blasting material cannot be completely removed. By switching the cleaning method, the amount of waste liquid generated can be reduced.

  DESCRIPTION OF SYMBOLS 1 ... Temper rolling mill, 2 ... Work roll, 5 ... Cleaning apparatus, 51 ... Cleaning nozzle, 52 ... Blast material supply means, 53 ... High pressure fluid supply means, 54 ... Low pressure fluid supply means, 56 ... Detection means, 57 ... Control means, 513... First ejection port, 514... Second ejection port, 525... First adjustment means, 533... Second adjustment means, 543.

Claims (6)

A cleaning device for cleaning a work roll of a temper rolling mill,
A blasting material containing sublimable solid particles less than 0 ° C. and a jetting medium, a high-pressure fluid having a pressure of 20 MPa or more and 30 MPa or less, and a washing nozzle capable of jetting a low-pressure fluid having a pressure of 0.03 MPa or more and 0.06 MPa or less;
Blast material supply means for supplying the blast material to the cleaning nozzle;
High-pressure fluid supply means for supplying the high-pressure fluid to the cleaning nozzle;
Low pressure fluid supply means for supplying the low pressure fluid to the cleaning nozzle,
The cleaning nozzle has a first jet port that jets the high-pressure fluid, and a second jet port that surrounds the first jet port and jets the low-pressure fluid and the blast material.
Between the cleaning nozzle and the blast material supply means, a first adjustment means for adjusting the supply amount of the blast material is provided,
Between the cleaning nozzle and the high-pressure fluid supply means, a second adjustment means for adjusting the supply amount of the high-pressure fluid is provided,
A cleaning device, wherein a third adjusting means for adjusting a supply amount of the low-pressure fluid is provided between the cleaning nozzle and the low-pressure fluid supply means. The cleaning device according to claim 1,
A sublimation solid particle of less than 0 ° C. of the blast material is dry ice. The cleaning apparatus according to claim 1 or 2,
Detecting means for detecting the state of the surface of the work roll;
Control means for controlling the first adjustment means, the second adjustment means, and the third adjustment means according to the state of the work roll surface detected by the detection means,
When temper rolling is performed while the blast material is ejected from the second ejection port and sprayed onto the surface of the work roll, foreign matter adheres to the concave and convex portions on the surface of the work roll by the detecting means. When it is detected that the foreign matter cannot be completely removed by spraying the material, the control means controls the first adjustment means to stop the supply of the blast material to the cleaning nozzle, and the second adjustment By controlling the means and starting the supply of the high-pressure fluid to the cleaning nozzle, the high-pressure fluid is ejected from the first ejection port and sprayed on the work roll surface,
Further, when the detection means detects that the foreign matter cannot be completely removed by spraying the high pressure fluid, the control means controls the third adjustment means to supply the low pressure fluid to the cleaning nozzle. The cleaning is characterized in that it is started, and the ejection of the high-pressure fluid from the first ejection port and the ejection of the low-pressure fluid from the second ejection port are simultaneously performed to form a cavitation jet and spray the surface of the work roll. apparatus. A cleaning method using the cleaning device according to claim 1 or 2,
The cleaning apparatus includes a detection unit that detects a state of the surface of the work roll,
When performing temper rolling while spraying the blast material from the second jet nozzle and spraying it on the surface of the work roll, foreign matter adheres to the concave and convex portions on the surface of the work roll and the blast material sprays the When the detection means detects that the foreign matter cannot be completely removed, the first adjustment means is controlled to stop the supply of the blast material to the cleaning nozzle, and the second adjustment means is controlled. By starting the supply of the high-pressure fluid to the cleaning nozzle, the high-pressure fluid is ejected from the first ejection port and sprayed onto the work roll surface, and further, the foreign matter can be removed by spraying the high-pressure fluid. If the detection means detects that there is not, the third adjustment means is controlled to start the supply of the low-pressure fluid to the cleaning nozzle, A cleaning method comprising: simultaneously ejecting the high-pressure fluid and ejecting the low-pressure fluid from the second ejection port to form a cavitation jet and spraying the surface of the work roll. The cleaning method according to claim 4, wherein
The cleaning method, wherein the blast material, the high-pressure fluid, and the low-pressure fluid are ejected intermittently.   A temper rolling mill comprising the cleaning device according to any one of claims 1 to 3 and a work roll.

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