JP2004269966A - Device for removing bottom dross - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cut and remove bottom dross 3 from a plating pot 1 in the state of containing a hot-dip plating metal 2. <P>SOLUTION: This removing device has an elevatable shaft 22 which retains a rotary cutter 21 in the bottom end and is installed in a carrier 10 travellable to X-direction and Y-direction, and cuts and removes a bottom dross 3 depositing in the plating pot 1 while rotating the rotary cutter 21 with a motor 23. The cut bottom dross 3 is carried away by an inert gas spouted from a nozzle 26, and is discharged from the plating pot 1. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
[Industrial applications]
The present invention relates to an apparatus for mechanically cutting and removing bottom dross deposited in a plating pot installed in a continuous hot-dip galvanizing line by hot heat.
[0002]
[Prior art and problems]
In the continuous hot-dip galvanizing line, the steel strip to be plated annealed is continuously fed into a plating pot containing hot-dip metal, and is rotated around a sink roll and pulled up from the hot-dip, and an excessive amount of hot-dip Is manufactured by hot-dip galvanized steel strip with the basis weight adjusted by gas wiping or the like. When the dross accompanies the hot-dip plated metal pulled up from the plating pot, defects caused by the dross are introduced into the plating layer. Above all, in a zinc plating bath to which a large amount of Al, Mg or the like is added for the purpose of improving corrosion resistance, a large amount of intermetallic compounds is generated, and as a result, a large amount of dross is easily generated. When a large amount of dross accumulates on the plating pot, it causes unstable running of the steel strip to be plated and troubles of the sink roll.
[0003]
Therefore, the maintenance of the plating pot is performed by manually drawing out hot-dip metal from the plating pot and periodically removing the deposited bottom dross. The operation of mechanically removing the bottom dross is also partially adopted (Japanese Patent Application Laid-Open Nos. 8-61867 and 8-92710). However, depending on the type of bottom dross, the cohesive force is strong and cutting and removal are not easy. Further, since the bottom dross is cut and removed after at least most of the hot-dip plated metal has been pumped out of the plating pot, a temperature drop of the plating pot is inevitable and workability is poor.
[0004]
[Means for Solving the Problems]
The present invention has been devised in order to solve such a problem, and it is possible to cut and remove a bottom dross while holding a hot-dip metal in a plating pot, and reduce a time required until a continuous plating line is started up again. The purpose is to shorten it.
A bottom dross removing apparatus according to the present invention includes a movable gantry on which a X-direction rail is movably mounted on a Y-direction rail arranged along opposing edges of a plating pot, and a movable carrier mounted on the X-direction rail. And a rotary blade fixed to a lower end of a shaft provided on the carrier so as to be movable up and down. An inert gas spray nozzle that moves up and down in conjunction with the shaft may face the rotary blade.
[0005]
Embodiment
The apparatus for removing bottom dross according to the present invention includes a movable carrier 10 provided on a plating pot 1, and a cutting tool 20 is provided on the carrier 10 so as to be able to move up and down (FIG. 1).
In a state where the continuous hot-dip plating line is operating, a circling sink roll (not shown) is immersed in the plating pot 1, and a steel strip to be plated (not shown) annealed by reduction is placed in the plating pot 1. It is continuously fed into the hot-dip metal 2 and is pulled up from the hot-dip metal 2 around the sink roll. When the plating operation is continued, dross is generated by a reaction between alloy components of the hot-dip metal 2 and a reaction with the atmosphere or a reaction between the hot-dip metal 2 and the steel strip to be plated. 1 settles and deposits at the bottom.
[0006]
When the deposition amount of the bottom dross 3 reaches the set value, the continuous hot dipping line is stopped, the sink roll is pulled up from the plating pot 1, and the bottom dross removing device is placed on the plating pot 1. The deposition amount of the bottom dross 3 measured by inserting a measuring rod into the plating pot 1 can be used as an index, but the continuous dipping line is stopped using the deposition amount estimated from the line operation results as an index, and the bottom dross is stopped. The removing device may be mounted on the plating pot 1.
[0007]
The bottom dross removing device connects the ends of a Y-direction rail 11 (FIG. 2) arranged at opposing edges of the plating pot 1 with beams to form a movable gantry, and can travel along the Y-direction rail 11. The X-direction rail 12 is mounted on the Y-direction rail 11. The carrier 10 includes wheels 13 that roll on an X-direction rail 12, and extends an X-direction shaft 15 provided with a pulley 14 to which power is transmitted or a power transmission gear to one side. The carrier 10 travels along the Y-direction rail 11 together with the X-direction rail 12 by forward and backward movement of the Y-direction shaft 16, and travels along the X-direction rail 12 with the power transmitted to the pulley 14. Since the Y table can be used, the details of the power transmission mechanism will not be described.
[0008]
The cutting tool 20 mounted on the carrier 10 extends a shaft 22 having a rotating blade 21 fixed to a lower end thereof downward, and faces an inert gas spray nozzle 26 for flushing the bottom dross 3 cut by the rotating blade 21 to the rotating blade 21. Not. As the rotary blade 21, a blade made of cemented carbide, which is much harder than the bottom dross 3, is used. The nozzle 26 is provided so as to move up and down in synchronization with the shaft 22.
The shaft 22 has a power transmission mechanism (not shown) such as a belt or a chain stretched between the shaft 22 and a shaft 25 having a handle 23 at one end, and is rotated in the Z direction by rotating the handle 23 manually or by motor power. Can be moved up and down. The upper end of the shaft 22 is connected to the output shaft of a blade rotating motor 24, and the rotating blade 21 is rotated by power from the motor 24.
[0009]
When removing the bottom dross 3 deposited on the plating pot 1, the sink roll is pulled up from the plating pot 1, and the molten metal 2 is basically not pumped out (while the molten metal surface 4 is kept at a certain height). ) The Y-direction rails 11 are positioned on both edges of the plating pot 1 and the bottom dross removing device is placed on the plating pot 1. At this time, the rotary blade 21 is moved to the upper end position by raising the shaft 22.
[0010]
Next, the carrier 10 is set at a predetermined position by traveling along the Y-direction rail 11 and the X-direction rail 12, and the shaft 22 is lowered while rotating the rotary blade 21. When the rotary blade 21 comes into contact with the bottom dross 3, the load on the handle 23 for lowering the shaft 22 increases. Therefore, the rotation speed of the rotary blade 21 is increased according to the detection of the load. Further, an inert gas is blown from the nozzle 26 toward the rotary blade 21. As a result, the bottom dross 3 deposited on the plating pot 1 is cut by the rotary cutter 21, flushed from the bottom of the plating pot 1 with an inert gas, and passed through a gutter (not shown) attached to the plating pot 1. It is discharged out of the system.
[0011]
When the bottom dross 3 is removed by cutting, the load applied to the handle 23 is reduced. Therefore, the load is reduced, the shaft 22 is lowered, and the bottom dross 3 is dug down. When the amount of lowering of the shaft 22 reaches the set value, it is determined that the bottom dross 3 at that position has been removed by cutting, the shaft 22 is raised, the carrier 10 is moved in the X direction, and the vicinity is moved in the same operation procedure. The bottom dross 3 is removed by cutting. Alternatively, it is also possible to continuously cut and remove the bottom dross 3 while moving the carrier 10 in the X direction while keeping the rotary blade 21 at a fixed depth position.
[0012]
After one step of cutting and removing the bottom dross 3 along the X direction is completed, the carrier 10 is moved along with the X direction rail 12 along the Y direction. Then, the cutting and removal of the bottom dross 3 are repeated while moving the carrier 10 in the X direction at different positions in the Y direction.
As described above, the bottom dross 3 is cut and removed by the rotary blade 21 while moving the carrier 10 in the X direction and the Y direction, and is discharged from the plating pot 1. Moreover, since there is no need to pump out the hot-dip metal 2, the temperature drop is small and the time required for restarting the continuous hot-dip plating line is reduced.
[0013]
【The invention's effect】
As described above, in the method of cutting and removing the bottom dross 3 with the rotary blade 21 fixed to the lower end of the shaft 22 that can be raised and lowered, the bottom dross 3 can be cut and removed without having to pump out the hot-dip metal 2. Therefore, compared with the conventional method in which the bottom dross 3 is removed in a cold state after the entire amount of the hot-dip metal 2 has been drawn out, the plating pot is compared with the method in which the bottom dross 3 is removed while leaving a portion of the hot-dip metal 2. 1 is much smaller. As a result, the time for injecting new hot-dip plating metal 2 into the plating pot 1 after removing the bottom dross 3 and raising the temperature to the required plating temperature is reduced, and the rapid re-starting of the continuous hot-dip plating line becomes possible. Become.
[Brief description of the drawings]
FIG. 1 is a side view in which a bottom dross removing device is arranged in a plating pot. FIG. 2 is a plan view of the bottom dross removing device.
1: Plating pot 2: Hot-dip metal 3: Bottom dross 4: Hot surface 10: Carrier 11: Y-direction rail 12: X-direction rail 13: Wheel 14: Pulley 16: Y-direction shaft 20: Cutting tool 21: Rotary blade 22: Shaft 23: Handle 24: Blade rotating motor 26: Inert gas spray nozzle

Claims (2)

A movable gantry in which an X-direction rail is movably mounted on a Y-direction rail arranged along opposing edges of a plating pot; a movable carrier mounted on the X-direction rail; And a rotary blade fixed to the lower end of the provided shaft, wherein the carrier is moved in the X and Y directions to cut and remove bottom dross accumulated in the plating pot with the rotary blade. 2. The bottom dross removing device according to claim 1, wherein an inert gas spray nozzle that moves up and down in association with the shaft faces the rotary blade.

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