A pickling facility includes: a pickling tank for storing an acid solution; a conveyance part for continuously conveying a steel plate immersed in the acid solution; a measurement part for measuring at least one parameter which has a correlation with a heat transfer coefficient between the acid solution and a reference surface disposed in the acid solution so as to face the steel plate; and a conveyance speed decision part configured to decide a conveyance speed of the steel plate conveyed by the conveyance part, on the basis of a measurement result of the at least one parameter.

A method for pickling a steel plate having a first steel plate portion and a second steel plate portion which is connected to a tail end of the first steel plate portion and which requires a longer time for pickling than the first steel plate portion when pickled under the same condition includes: a step of pickling the steel plate by immersing the steel plate in an acid solution in at least one pickling tank while conveying the steel plate; a step of circulating the acid solution, through a circulation line connected to any of the at least one pickling tank, between the pickling tank and an oxidizing device disposed in the circulation line; a step of oxidizing Fe.sup.2+ in the acid solution to Fe.sup.3+ by the oxidizing device using a gaseous oxidant; and a feeding start step of, upon switching from pickling of the first steel plate portion to pickling of the second steel plate portion, starting feeding of a liquid oxidant for oxidizing Fe.sup.2+ in the acid solution to Fe.sup.3+ to any of the at least one pickling tank or to the circulation line.

A method for continuously cleaning a moving strip in a cleaning installation including a tank containing an aqueous solution, at least a roll immerged in the aqueous solution for guiding the strip into the tank, at least an ultrasound emitter a feed for feeding an aqueous solution inside the tank, a tank emptier for emptying the tank, an aqueous solution estimator for estimating the aqueous solution level in the tank, a distance calculator for calculating, for each ultrasound emitter, its distance to the aqueous solution level and a power controller for controlling the power of the at least one ultrasound emitter including the following steps, performed continuously: —estimating the aqueous solution level in the tank, —calculating for each ultrasound emitter its distance to the aqueous solution level, —comparing for each ultrasound emitter its distance to the aqueous solution level to a determined threshold.

A water-based grinding machine for polishing a surface of a metal strip includes an unwinding wheel, a polishing mechanism, a cleaning mechanism, a drying mechanism and a winding wheel. The polishing mechanism includes a first polishing wheel and a first workbench. The metal strip is drawn from the unwinding wheel into a gap between a polishing wheel and a pad, and then is drawn to the cleaning mechanism. The cleaning mechanism includes a third workbench and a cleaning liquid storage tank. At least one pair of felt wheels is arranged above the third workbench. The metal strip passes through a gap between the at least one pair of felt wheels. An outer circumference of the at least one pair of felt wheels is covered with a wool layer. The cleaning liquid storage tank is provided with a cleaning pipe. The drying mechanism includes an oven.

A pickling facility includes: a pickling tank for storing an acid solution; a conveyance part for continuously conveying a steel plate immersed in the acid solution; a measurement part for measuring at least one parameter which has a correlation with a heat transfer coefficient between the acid solution and a reference surface disposed in the acid solution so as to face the steel plate; and a conveyance speed decision part configured to decide a conveyance speed of the steel plate conveyed by the conveyance part, on the basis of a measurement result of the at least one parameter.

The invention relates to a method for pickling steel sheets 8, the steel sheets being continuously dipped in a pickling bath 1, containing a pickling solution 10, the bath being connected to a treatment unit including a recirculation tank 3, circulators 12 and 13, a continuous entering flow 11 of the solution being fed into an ultrafiltration device 2 from the recirculation tank 3 and two flows exiting the ultrafiltration device, one filtered exiting flow 21 being then fed back inside the recirculation tank 3 and one unfiltered flow 22, the treatment unit including no storage tank.

Methods, systems and apparatuses are disclosed for treating aluminum desmutting solutions by reacting, mixing and filtering an aluminum desmutting solution flow from an aluminum desmutting solution tank and controlling the amount of copper ions in an aluminum desmutting solution tank by directing a portion of the desmutting solution from a desmutting solution tank to a treatment line, reacting a portion of the desmutting solution in the treatment line and recirculating a filtered aluminum desmutting solution to the aluminum desmutting solution tank during active desmutting operation of the aluminum desmutting solution tank.

To prevent over-pickling of a steel strip during pickling pause, and shorten the time required to switch between pickling operation and pickling pause, a pickling device includes: a pickling tank for storing acid solution and for pickling a steel strip by allowing the steel strip to travel therethrough while the steel strip is immersed in the acid solution; a heat exchanger for heating the acid solution in the pickling tank; a circulation tank for storing the acid solution, provided separately from the pickling tank; an acid-solution circulation unit configured to circulate the acid solution between the pickling tank and the acid-solution storage tank; and a control device configured to control the acid-solution circulation device to maintain a liquid level of the acid solution in the pickling tank at a level below a traveling height of the steel strip.

Continuous annealing equipment (1) including a cleaning device (11, 12) for performing a cleaning treatment on a steel strip (S) and an annealing device (12) for performing an annealing treatment on the steel strip (S) comprises an exhaust gas passage (31, 41) through which an exhaust gas discharged from the annealing device (12) flows, a solution circulation passage (32, 51) through which a cleaning solution used in the cleaning device (11, 12) circulates, and a heat exchanger (53) which forms a part of the solution circulation passage (32, 51) and contacts with the exhaust gas.

A plant for cleaning rolled metal strips provided with a superficial layer of oxide, the plant comprising unwinding means for unwinding at least one coil of rolled strip and pickling means for pickling said rolled strip; wherein there are provided measuring means for measuring the thickness of the superficial layer of oxide, arranged between said unwinding means and said pickling means. A relating cleaning method is also claimed.