High speed pickling device and high speed pickling method

Abstract

A high speed pickling device for causing a thin plate to travel in acid fluid and removing through pickling oxidized scales which are formed on the surfaces of the thin plate, a plurality of weir members which dam wakes of the acid fluid flowing along the surfaces of the thin plate over substantially the entire width of the thin plate are provided in the traveling direction of the thin plate with a predetermined interval and close to the thin plate. The weir members are provided close to the surfaces of the thin plate for damming and stripping off wakes of the acid fluid flowing along the surface of the thin plate at the inlet sides of these weir members, the acid fluid is caused to deflect in the opposite direction away from the thin plate, and fresh acid fluid is sucked onto its surface at the outlet sides of the weir members along with the traveling of the thin plate. According to the present invention indicated above, by providing the weir members close to the thin plate, wakes of the acid fluid which flows along the thin plate is dammed and the most part thereof is stripped off from the thin plate. This stripped acid fluid flows in an opposite direction away from the thin plate and is drained along the weir members. The remaining wakes which were not stripped off by the weir members pass through a narrow clearance between the thin plate and the weir members and proceeds to the outlet sides of the weir members in the form of thin layered wakes. At the outlet sides of the weir members thickness of the wakes along the thin plate again tends to increase and fresh acid fluid is sucked to increase the wake thickness. By these draining and sucking of the acid fluid, replacement of the acid fluid is surely performed and pickling effect is enhanced and the pickling time is shortened.