JPH0626730B2 - Metal strip pickling equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for pickling metal strips, and more particularly to an apparatus suitable for pickling steel strips.

(Prior Art) For example, in order to remove the scale of the hot-rolled steel strip, the steel strip is passed through a pickling tank filled with a pickling solution to dissolve and remove the scale. As this pickling tank, a horizontal type that normally passes a steel strip horizontally is widely used.

As an example of a conventional horizontal pickling tank of this type, it is known that a continuous pickling tank 3 is arranged as shown in FIG. The flow of the pickling solution 18 is only the flow caused by the overflow and the flow caused by the progress of the steel strip 1. Therefore, the non-uniformity of the descaling process on the upper and lower surfaces of the steel strip 1 and the slow processing speed become problems. Was there.

In order to solve the above problems, a structure is adopted in which the pickling solution flows in from the upper and lower parts of the horizontal tank with both ends or one end through which the steel strip passes, and the pickling solution flows out from both ends or one open end. Japanese Patent Publication No. 51-32582 discloses that a pickling tank is used to improve the flow rate in the tank, the reaction rate between the steel strip and the pickling solution, and shorten the reaction time.

Further, Japanese Patent Laid-Open No. 60-61112 discloses a method shown in FIG. 3 as a high-speed pickling technique. That is, as shown in FIG. 3, the steel strip 1 enters the closed type pickling tank 3 and reacts with the pickling solution which flows out from the pickling solution discharge ports 12 and 13 by the pickling solution supply pump 15 at a predetermined flow rate. , Descaled. The pickling solution is configured to return to the bottom storage tank 17 by its own weight.

(Problems to be solved by the invention) However, in the conventional pickling apparatus, since all the pickling solutions are treated together as described above, the basic unit of the pickling solution is considered due to the problem of the pickling solution usage efficiency. , And steam or electricity etc.
There was the inconvenience that the basic unit for heat retention was significantly deteriorated.

The present invention can eliminate such disadvantages of the conventional technology, can smoothly supply the pickling solution and perform the waste acid treatment, and can greatly improve the pickling solution basic unit and the temperature rise / heat retention basic unit. An object is to provide a pickling device for a metal strip.

(Means for Solving the Problems) The pickling apparatus of the present invention for achieving this object is configured as follows. That is, a plurality of pickling tanks having a structure in which the pickling solution flows in from the upper and lower portions of a horizontal tank having open both ends through which the metal strip passes and flows out from the open end of one end or the other end is arranged in series. In a device for performing continuous pickling of a metal strip, each pickling tank has an independent pickling solution storage tank and pickling solution recovery device, respectively. It is a device.

(Function) The pickling solution can be arbitrarily supplied and collected by the storage tank and the recovery device in each pickling tank, whereby the pickling solution concentration can be balanced for each tank.
In addition, by moving the pickling solution between the storage tanks as needed, it suffices to raise and maintain the temperature of the pickling solution only in the high-concentration side tank.

(Examples) Examples of the present invention will be described below with reference to the drawings. As shown in FIG. 1, in the pass line of the metal strip 1 such as a steel plate,
A preheating tank 2 for preheating the metal strip from the upstream side in the traveling direction of the metal strip,
A plurality of continuous pickling tanks 3 are arranged in series. Preheating tank 2
Is for heating the metal strip 1 to a required temperature prior to pickling to improve the reaction rate of the pickling solution and the metal strip. The preheating tank 2 is provided with a pump 4 and hot water for supplying and collecting hot water. It is connected to the tank 6. That is, the pump 4 is provided in the hot water supply pipe 2A having one end connected to the upper and lower parts of the tank body and the other end connected to the hot water tank 6, and the discharge pipe 2B for collecting the hot water in the tank 6 is connected to the tank. It is provided between the main body and the hot water tank 6.

The plurality of pickling tanks 3 have the same structure, and each pickling tank is provided with an independent pickling solution storage tank and an independent pickling solution recovery device. That is, the pickling tank body is the pickling solution supply pipe
The pickling solution storage tank 7 is connected via 3A and the discharge piping 3B to form a pickling solution circulating system, and the supply pump 5 is provided in the supply piping 3A.
Is provided. The pickling solution supply pipe 3A is connected at the upper and lower parts of the downstream end of the tank main body in the direction of movement of the metal strip, and the solution is fed from the upper and lower parts of the tank so that it flows countercurrently to the metal for efficient pickling. Carry out processing.

Each of the storage tanks 7 of the pickling tanks 3 arranged in series is arranged so that the pickling solution overflows into the subsequent tanks sequentially from the NO.1 storage tank or is forcibly transferred by using a pump or the like. . In addition, the replenishment of new pickling solution is NO.1
Therefore, the new acid tank 11 is connected to the NO.1 storage tank via the pump 10 as shown in the figure. Further, a recovery acid tank 9 is connected to the final storage tank (NO.i) via a recovery pump 8.

Since the present invention is configured as described above, by appropriately supplying the pickling solution to the pickling tank from the pickling solution storage tank 7 in each pickling tank 3 and collecting the pickling solution to the storage tank 7, The concentration balance of the pickling solution can be maintained in an optimum state for each pickling tank. Further, since it is possible to transfer the acid solution between the tank storage tanks 7 for balancing the concentration of the pickling solution, it is sufficient to raise and keep the temperature of the pickling solution only in the high concentration tank.

(Effects of the Invention) As described above, according to the apparatus of the present invention, stable pickling operation can be performed, a high descaling rate can be obtained, the pickling solution usage efficiency is increased, and the pickling solution basic unit is improved. To do. Further, the temperature of the pickling solution may be raised and kept warm only in the high-concentration bath of the pickling tank, and the effect of improving the basic unit for raising and keeping the temperature can be expected.

[Brief description of drawings]

FIG. 1 is an overall layout drawing showing an embodiment of the device of the present invention, and FIG.
FIG. 3 and FIG. 3 are explanatory views showing an example of a conventional pickling apparatus. 1 ... Metal strip, 2 ... Hot water tank, 3 ... Pickling tank, 4, 5,
8, 10 ... Pump, 6 ... Warm water tank, 7 ... Pickling solution storage tank, 9 ... Recovery acid tank, 11 ... New acid tank.

Claims (1)

[Claims] 1. A plurality of pickling tanks having a structure in which a pickling solution flows in from the upper and lower parts of a horizontal tank having open both ends through which a metal strip passes, and the pickling solution flows out from both ends or one open end. An apparatus for performing continuous pickling of metal strips arranged in series, wherein each of the pickling tanks has an independent pickling solution storage tank and pickling solution recovery device. Pickling equipment.