The present disclosure relates to a workpiece cleaning device and a cleaning method. The workpiece cleaning device comprises: a frame (1); and a plurality of cleaning tanks disposed on the frame (1) side by side, comprising a molten salt cleaning tank (2) for cleaning a workpiece with molten salt, a first rinsing tank (5) for rinsing the workpiece cleaned with the molten salt, a de-rusting cleaning tank (6) for cleaning the workpiece rinsed in the first rinsing tank (5) with a de-rusting agent, a second rinsing tank (7) for rinsing the workpiece cleaned with the de-rusting agent, and an anti-rust cleaning tank (8) for cleaning the workpiece rinsed in the second rinsing tank (7) with anti-rust liquid, which are sequentially disposed from upstream to downstream in terms of procedure.

There is provided a liquid removal device that removes liquid attached to a surface of a steel sheet, the device including a slit nozzle that jets gas to the surface of the sheet, the slit nozzle being installed so as to jet gas from a downstream side toward an upstream side in a movement direction of the sheet that moves relatively to the slit nozzle and being configured in a manner that a jet angle θ, a back face inclination angle β, and a back face length L of a nozzle back face of the slit nozzle satisfy, β+θ≥60° and L≥20mm, and a gap h between a jetting port of the slit nozzle and the sheet, a slit width d, and nozzle pressure P.sub.n of the slit nozzle satisfy the following relationship: P.sub.n≥2.0×10.sup.10(h/d).sup.0.6{1/(1+exp(β+θ−58)+1}.sup.−4L.sup.−7.

A pickling apparatus includes a plurality of pickling tanks in which a scale of a steel plate is removed while the steel plate is advanced and sequentially dipped; an intermediate spraying unit, disposed between a pickling tank at the front end and a pickling tank at the rear end, for spraying a pickling solution onto the steel plate; and a pickling solution supply means configured to provide a pickling solution of a concentration used in the pickling tank at the rear end to the intermediate spraying unit, wherein a wringer roll disposed between the plurality of pickling tanks is removed.

A pickling apparatus includes a plurality of pickling tanks in which a scale of a steel plate is removed while the steel plate is advanced and sequentially dipped; an intermediate spraying unit, disposed between a pickling tank at the front end and a pickling tank at the rear end, for spraying a pickling solution onto the steel plate; and a pickling solution supply means configured to provide a pickling solution of a concentration used in the pickling tank at the rear end to the intermediate spraying unit, wherein a wringer roll disposed between the plurality of pickling tanks is removed.

[Object] To provide a liquid removal device capable of removing liquid on a steel sheet without using wringer rolls and a drier.

[Solution] A liquid removal device that removes liquid attached to a surface of a sheet-like member that moves relatively, the liquid removal device including: a slit nozzle that jets gas to the surface of the sheet-like member; and a gap measurement device that measures a gap between a jetting port of the slit nozzle and the sheet-like member. The slit nozzle is installed so as to jet gas from a downstream side toward an upstream side in a movement direction of the sheet-like member that moves relatively to the slit nozzle, and is configured in a manner that a jet angle , a back face inclination angle , a back face length L of a nozzle back face, a gap h, a slit width d, and nozzle pressure P.sub.n of the slit nozzle satisfy the following relational formulas.

[00001]$\begin{array}{cc}{P}_{n}2.0{10}^{10}.Math.{\left(h.Math.\text{/}.Math.d\right)}^{0.6}.Math.{\left(\frac{1}{1+\exp \left(+-58\right)}+1\right)}^{-4}.Math.L^{-7},+60.Math.,L20.Math..Math.\mathrm{mm}& \left[\mathrm{Math}..Math.1\right]\end{array}$

A method of producing a cold rolled steel strip includes: subjecting a steel strip that has been cold rolled and subsequently continuously annealed to pickling by continuously feeding the steel strip into a mixed acid solution containing a first acid that is oxidizing and a second acid that is non-oxidizing to immerse the steel strip; and subsequently subjecting the steel strip to repickling by continuously feeding the steel strip into an acid solution containing a third acid that is non-oxidizing to immerse the steel strip. The concentration of the first acid in the mixed acid solution is lowered and the concentration of the second acid in the mixed acid solution is raised as the iron ion concentration in the mixed acid solution rises.

A manufacturing method of a support for a planographic printing plate including at least an alkaline etching step of dissolving an aluminum surface layer of an aluminum web with an alkaline solution during a surface roughening treatment on a surface of the aluminum web continuously traveling, the manufacturing method comprising: a circulating step of cyclically using the alkaline solution between a treatment tank for the etching and an alkaline solution reservoir during adjusting composition concentration of the alkaline solution; and a filtering step of filtering the alkaline solution cyclically used so as to remove solid matter in the alkaline solution.

A device and method for post-treating a metal strip, wherein a pickled metal strip (2) coming from a pickling zone is advanced continuously through a rinsing zone (4) in which residues of a pickling agent adhering to the surface (11) of the metal strip (2) are removed by spraying the metal strip with rinsing fluid. At least one device (8) for generating a liquid mist (9) is provided in the rinsing zone (4). The device (8) can moisten the surface (14) of the metal strip (2) during an interruption of the continuous operation or of a sharply reduced speed of the strip. The device (8) has mist spraying jets above the surfaces of the metal strip.

A high-grade non-oriented silicon steel and a production method are provided. The non-oriented silicon steel includes the following chemical components in percent by mass: 0.002-0.004% of C, not greater than 0.003% of S, 1.4-1.7% of Si, 0.7-0.95% of Mn, not greater than 0.03% of P, 0.015-0.035% of Sn; and 11([Si]-1.4%)=14([Mn]-0.7%). In the production method, the heating temperature of a continuous casting billet is 1,120-1,150 C.; the finishing temperature in finish rolling is 89015 C.; the rolling reduction of the last pass of finish rolling is not less than 30%, the total rolling reduction of the last two passes of finish rolling is not less than 50%, and the coiling temperature is 65020 C.; normalizing treatment is avoided before acid continuous rolling.