JPH0332608B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for on-line removing deposits adhering to the circumferential surface of a strip conveying roll used in various metal strip processing lines.

[Conventional technology]

A large number of transport rolls are used in various processing lines for metal strip, and oxides and the like may adhere to these rolls and cause scratches on the metal strip.

For example, a continuous annealing and pickling line for stainless steel strip has a horizontal direct-fired furnace and a pickling tank, but oxidized scale from the strip adheres and grows on the conveyor rolls in the furnace, causing the strip to become damaged. It will cause damage. For example, if two rolls are used in the furnace, one roll is lowered below the pass line and used as a spare roll.If oxide scale grows on the roll being used, the spare roll can be raised to the pass line position. Then, the rolls used up until now are taken out and cleaned (for example, Japanese Patent Application Laid-Open No. 80310/1983).

In addition, in the pickling tank, rolls are used to immerse the stainless steel strips in acid solution. For example, when the concentration of FeSO is high, crystals precipitate and form sludge, which adheres to the immersion rolls. This will cause scratches on the stainless steel strip. In this case, the solution is to drain the acid solution in the pickling tank and perform maintenance, or to replenish new acid and melt the sludge.

In addition to the above, for example, Utility Model No. 59-133666
There are scraper-based roll care methods, such as those disclosed in .

[Problem that the invention seeks to solve]

However, for example, regarding furnace rolls,
Care of the roll is difficult. In addition, in order to increase production capacity, there is a recent tendency to raise the temperature inside the furnace, which increases the frequency of oxide scale deposition.
The burden of roll care is increasing.

Furthermore, it is difficult to maintain the immersed rolls in a pickling tank, etc., and the liquid consumption rate also deteriorates.

A scraper-type roll care device used for products other than immersed rolls and furnace rolls also requires the device for each roll, which increases equipment costs.

An object of the present invention is to provide a simple method for solving these problems.

[Means for solving problems]

In the present invention, when driving a strip conveying roll used in a metal strip processing line, the circumferential speed of the roll is adjusted such that a temporary difference appears between the moving speed of the metal strip and the circumferential speed of the roll. The characteristic technical means is to drive the motor by intermittently varying it.

[Effect]

According to the present invention, since the moving speed of the metal strip and the circumferential speed of the roll are intermittently different from each other, a temporary sliding action occurs between the strip and the circumferential surface of the roll, and the circumference of the roll Even if foreign matter adheres to the surface, it can be removed from the roll without allowing it to grow.

〔Example〕

An example in which the present invention is implemented in a continuous annealing furnace for stainless steel strip will be explained.

FIG. 1 shows in-furnace conveyance rolls provided in a catenary-type direct-fired furnace 5. As shown in FIG. There are six rolls 1 in total, and they catenally support the stainless steel strip 6. The roll 1 is connected to a drive motor 4 via a joint 2, a clutch 3, and a joint 2a.
is combined with Further, 7 indicates foreign matter attached to the roll.

Figure 2 shows clutch 3 of these six rolls.
This is a time chart showing ON and OFF operation, and the solid line is
ON state, blank indicates OFF state.

As shown in Figure 2, the six rolls are placed on the furnace entry side.
Clutch 3 is turned on and off intermittently in order from No. 1 roll to No. 6 roll on the furnace outlet side. When the operation was carried out by temporarily creating a speed difference between the moving speed of the strip 6 and the circumferential speed of the roll, as shown in Fig. 3, the number of coils with defects due to adhesion of foreign matter increased. It decreased dramatically.

In the above embodiment, the clutch 3 is turned ON and OFF, but it may also be done by changing the rotation speed of the motor, or in this case, the circumferential speed of the roll may be made slower than the moving speed of the strip. ,
On the contrary, the same effect can be obtained by increasing the speed.

〔Effect of the invention〕

In the present invention, since roll deposits can be automatically removed online during operation, defects caused by foreign matter can be reduced without reducing production volume.

In addition, roll maintenance work is reduced, leading to improvements in the acid consumption rate of pickling.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of the method of the present invention, FIG. 2 is a time chart of the embodiment, and FIG. 3 is a graph showing the effects of the present invention. 1... Roll, 2... Joint, 3... Clutch, 4... Motor, 5... Catenary type direct-fired furnace,
6...Strip, 7...Adherence.

Claims (1)

[Claims] 1. When driving a strip conveying roll used in a metal strip processing line, the peripheral speed of the roll is intermittently varied so that there is a temporary difference between the moving speed of the metal strip and the peripheral speed of the roll. A method for removing deposits on a roll, characterized in that the roll is driven by rotating the roll.