JPH07224365A - Device for washing and removing dross sticking to apparatus immersed in plating bath - Google Patents

Abstract

PURPOSE:To efficiently wash and remove the dross sticking to the surface of a sink roll. CONSTITUTION:Only the lower part of the sink roll 6 is immersed into a phosphoric acid soln. 10 housed in a washing tank 7 and the phosphoric acid soln. 10 in the washing tank 7 is introduced through a sub-tank 2 into a header nozzle 5 and is sprayed from the header nozzle 5, by which the dross sticking to the sink roll is washed away. The dross is removed by the jet pure water injected from a jet washing nozzle 9 in the state of once interrupting the washing by the header nozzle 5. At this time, the sink roll 6 is inverted by using a handle 13 and the dross sticking over the entire surface of the roll is removed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to the attachment of plating bath dipping equipment such as sink rolls and support rolls used for dipping steel sheets in a plating bath in continuous hot dip galvanizing. The present invention relates to a dross cleaning and removing device.

[0002]

2. Description of the Related Art Hot-dip galvanized steel sheets are used as inexpensive rust-preventive steel sheets in various products such as building materials and furniture, and alloyed hot-dip galvanized steel sheets have come to be used for automobile exteriors. By the way, in hot dip galvanizing, dross is generated in the hot dip galvanizing bath, and this dross is Fe-Zn or Fe-Zn-Al compound in the hot dip galvanizing bath.

Dross adhering to the surface of a sink roll or a support roll axially supported in a state of being immersed in a hot dip galvanizing bath is peeled off from the surface during continuous hot dip galvanizing, especially in the sink roll, which is It adheres to the surface and causes surface defects. In order to prevent such dross from adhering to the sink roll, it is disclosed in Japanese Patent Laid-Open No.
In the gazette, in a step of continuously performing hot metal plating on a steel sheet, a part of the molten metal in the plating bath is sampled, the sampled molten metal is heated to a temperature higher than the temperature of the plating bath, and the molten metal is provided in the plating bath. There is proposed a method for preventing dross from adhering by spraying the surface of the sink roll.

In order to prevent dross from adhering to the sink roll in such a continuous hot metal plating process,
Although it is possible to extend the period until the dross adheres to the roll surface and grows, it is impossible to prevent the dross from completely adhering by such means alone. Therefore, finally, it is necessary to remove the dross attached to the sink roll outside the line to remove the dross attached to the sink roll. Conventionally, when removing dross attached to plating bath immersion equipment such as sink rolls and support rolls immersed in the plating bath outside the line for maintenance, generally work dross attached to the surface of plating bath immersion equipment such as rolls. It is carried out by the primitive means of manual scraping by a person using chisel or the like and scraping off by using a grinder.

Further, recently, a means for immersing in a phosphorus-based solution for a long period of time has been adopted, which is less susceptible to corrosion of a plating bath applied to the surface of a roll, for example, a sprayed ceramic, and has less effect on the human body. Has been done. Such a means is adopted as a means for removing the dross adhering to the roll chock like the roll.

[0006]

Among the above-mentioned prior art, in the scraping work of the attached dross using chisel and the scraping work using the grinder, the sprayed surface applied to the roll is scratched or peeled. To do. Therefore, when the roll is reused, there is a problem that the life of the plating bath dipping device is shortened because the condition that the dross is easily wound around the roll is created. In addition, there is a problem that the removal work requires one to two full-time workers and requires a working time of 8 hours × 3 days = 24 hours.

The means for immersing and removing the plating bath immersing device such as a roll in a phosphorus-based solution varies depending on the dross adhesion state until the dross is completely removed, but it requires 4 to 7 days.
For this reason, the rotation of plating bath dipping equipment becomes a bottleneck, and it is necessary to have a large number of plating bath dipping equipment such as rolls, which increases the cost. Since it is immersed in the solution of the system, a large amount of the solution is required, and the equipment itself becomes large, which increases the equipment cost.

The present invention has been made in view of the above circumstances, and completely removes the attached dross of a plating bath dipping device by a relatively simple means in a short time without requiring a dedicated worker. It is an object of the present invention to provide a device for cleaning and removing adhered dross of a plating bath dipping device that can be used.

[0009]

Means for Solving the Problems The present invention for achieving the above-mentioned object is an adhering dross cleaning / removing device for a plating bath dipping device immersed in a continuous hot dip galvanizing bath, which comprises a phosphoric acid solution for cleaning. A cleaning tank to house, a reversing support device that supports the plating bath dipping device in which only the lower part is immersed in the phosphoric acid solution housed in this cleaning tank, and a circulation path for the phosphoric acid solution housed in this cleaning tank. Through the spray bath dipping device to a header nozzle disposed above the plating bath to circulate by spraying a phosphoric acid solution circulating and spraying device, and jet water from the jet cleaning nozzle toward the dross adhering to the plating bath dipping device. An adhering dross cleaning / removing device for a plating bath dipping device, comprising a jet cleaning device.

[0010]

[Function] The dross attached to the equipment in the cleaning tank is immersed in the phosphoric acid solution (concentration: about 10 to 30% by weight) contained in the cleaning tank while only the lower part of the equipment such as sink roll is immersed in the plating bath. The phosphoric acid solution is circulated and pickled with a phosphoric acid solution sprayed from the header nozzle to remove it. Since such pickling is the main component, it is possible to remove the adhering dross by pickling without causing scratches on the surface of the thermal sprayed ceramic applied to the surface of the roll or the like or causing peeling.

Further, during pickling with the phosphoric acid solution, the dross surface is exposed by jet cleaning with pure water ejected from a jet cleaning nozzle to activate the pickling reaction of the phosphoric acid solution. By this activation, the time until the dross attached to the equipment is completely removed can be shortened to 10 to 20 hours, so that not only can we reduce the number of equipment that we have, but also we plan to use equipment for rotation. it can.

[0012] The plating dipping equipment includes a lower part that is immersed in the cleaning tank by occasionally reversing to an appropriate angle intermittently using a reversing support device, a portion directly exposed to the phosphoric acid solution sprayed from the header nozzle, and By replacing the part that receives the pure water jet from the jet cleaning nozzle, the dross attached to the equipment is pickled and removed in a balanced manner. Furthermore, in the pickling by spraying the phosphoric acid solution by circulation, only the lower part of the equipment is immersed in the cleaning tank, so the amount of phosphoric acid solution can be reduced to about 1/3 compared to the case where the entire equipment is immersed. The capacity of the cleaning tank can be reduced, and the overall size of the equipment can be reduced accordingly.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system diagram relating to the apparatus of the present invention. In FIG. 1, a case where the dross adhering to the sink roll 6 of various plating bath dipping equipment is removed by a cleaning / removing apparatus will be described. It can be applied to support rolls and other various equipment used by being immersed in a hot dip galvanizing bath.

As shown in FIG. 1, the cleaning tank 7 contains a phosphoric acid solution (concentration: 10 to 30% by weight) 10. The rotating shafts 11 provided at both ends of the sink roll 6 are supported by bearings 12, and only the lower portion of the sink roll 6 thus supported is immersed in the phosphoric acid solution 10 in the cleaning tank 7. ing. A handle 13 is attached to one end of the rotary shaft 11, and the sink roll 6 can be manually rotated using the handle 13. The sink roll 6 may be rotated by an electric motor.

Circulation piping taken out from the bottom of the cleaning tank 7
14 is connected to the lower part of the sub tank 2 and the circulation piping 14
By operating the circulation pump 15 provided on the way, the phosphoric acid solution in the cleaning tank 7 can be taken out and supplied to the sub tank 2 through the circulation pipe 14. The liquid supply pipe 16 taken out from the bottom of the sub tank 2 is connected to the header nozzle 5 arranged above the sink roll 6.

A shutoff valve 1 is provided from the upstream side in the middle of the liquid supply pipe 16.
7, a liquid supply pump 4 and a shutoff valve 18 are provided. In addition, the supply pipe 19 taken out from the lower part of the main tank 1
The shutoff valve 17 is connected to the feed pump 4 between the feed pump 4 and the supply pipe 19 is also provided with a shutoff valve 20. Also, waste liquid pipe taken out between the liquid supply pump 4 and the shutoff valve 18.
Reference numeral 21 is connected to the waste liquid tank 3, and a cutoff valve 22 is also provided in the waste liquid pipe 21.

Further, a jet cleaning device 8 is installed on the side of the cleaning tank 7, and a jet cleaning nozzle 9 is attached to the tip of a hose 23 connected to the jet cleaning device 8. Pure water is sprayed from 9 to the sink roll 6. Next, the operation of the attached dross cleaning / removing device of the present invention will be described.
In this case, a new phosphoric acid solution (concentration 20
The description will be started assuming that a predetermined amount of (wt%) 10 is contained.

After the sink roll 6 with the dross is conveyed above the washing tank 7 by using a crane or the like, the sink roll 6 is suspended and the rotating shaft 11 of the sink roll 6 is set on the bearing 12, so that the lower portion of the sink roll 6 is washed. Phosphoric acid solution contained in 7 10
Be immersed in. Initially, the shutoff valve 20 installed in the supply pipe 16
The shutoff surface 22 provided on the waste liquid pipe 21 is closed, while the shutoff valves 17 and 18 provided on the liquid supply pipe 16 are open.

The circulation pump 15 is operated to supply the phosphoric acid solution 10 in the cleaning tank 7 to the sub tank 2 through the circulation pipe 14. When the appropriate amount of the phosphoric acid solution 10 is accumulated in the sub tank 2, the liquid supply pump 4 is continuously operated. The phosphoric acid solution 10 in the sub tank 2 passes through the liquid supply pipe 16 because the shutoff valves 17 and 18 are open. And reaches the header nozzle 5, and the header nozzle 5
To the Syncroll 6

The phosphoric acid solution 10 sprayed from the header nozzle 5 to the sink roll 6 flows along the surface of the sink roll 6 to wash adhering dross, and then is circulated to the phosphoric acid solution 10 in the washing tank 7. On the other hand, since the lower part of the sink roll 6 is immersed in the phosphoric acid solution 10 in the cleaning tank 7, it is cleaned in the same manner as the immersion method. After such a circulation of the phosphoric acid solution, the cleaning by the spraying method from the header nozzle 5 and the cleaning by the immersion method of the cleaning tank 7 in the phosphoric acid solution are performed for a certain period of time, for example, for about 2 hours, and then the liquid supply is performed. The operation of the pump 4 and the circulation pump 15 is stopped, and the circulation of the phosphoric acid solution 10 is stopped.

Next, the operation of the jet cleaning device 8 is started, pure water that does not adversely affect the phosphoric acid solution is supplied to the jet cleaning nozzle 9 via the hose 23, and the dross attached to the sink roll 6 is removed from here. Remove with jet pure water. At this time, by manually reversing the sink roll 6 little by little using the handle 13, the adhered dross is removed from the entire surface of the sink roll 6 by the jet pure water sprayed from the jet cleaning nozzle 9.

Even if the jet cleaning device 8 is used, it is difficult to remove the dross attached to the sink roll 6 all at once.
After stopping the operation of the jet cleaning device 8 at an appropriate stage,
Start the operation of the circulation pump 15 and the liquid supply pump 4 again,
Wash with phosphoric acid solution. At this time, it is preferable to return the lower portion of the sink roll 6 previously immersed in the phosphoric acid solution 10 stored in the cleaning tank 7 to the atmosphere and immerse another portion.

According to the above-described procedure, the adhered dross is sprayed from the header nozzle 5 by spraying the phosphoric acid solution and the adhering dross is removed from the jet cleaning nozzle by the jet pure water. The removed dross can be removed efficiently. In addition, when the cleaning ability is lowered due to the circulating use of the phosphoric acid solution 10 contained in the cleaning tank 7, the shutoff valve 22 is opened and the shutoff valve 18 is closed, so that the phosphoric acid solution 10 in the wash tank 7 is stored in the subtank 2 And it collects in the waste liquid tank 3 via the waste liquid pipe 21.

Next, the shutoff valves 18 and 20 are opened, the shutoff valves 17 and 22 are closed, and the new phosphoric acid solution 10 stored in the main tank 1 is supplied to the header nozzle via the replenishment pipe 19 and the liquid feed pipe 16. 5 is supplied to the cleaning tank 7 from the header nozzle 5. After the replenishment of the phosphoric acid solution 10 from the main tank 1 to the cleaning tank 7 as described above, the work of cleaning and removing the adhered dross by circulating water sprinkling is performed by the above-described procedure.

As a result of cleaning the ceramic spray-coated sink roll with a phosphoric acid solution and removing it with jet pure water using the adhered dross cleaning / removing apparatus of the present invention, the surface ceramic of the sink roll conventionally peeled off with a chisel or the like was peeled off. About 70 cases of less than 10 mm ^{2 and} about 30 cases of more than 10 mm ² were absent. Further, according to the present invention, it takes 15 hours to completely remove the adhered dross without much manual work.
Since it was just repeated, it was possible to perform other maintenance work in that time, and the dedicated work as in the past became unnecessary.

[0026]

As described above, according to the present invention, the cleaning of adhering dross by spraying a phosphoric acid solution and the removal of adhering dross by jet pure water are performed in combination. It is possible to completely prevent the thermal spray ceramics from peeling off.

Further, since the spraying of the phosphoric acid solution and the dipping in the phosphoric acid solution are used in combination, the size of the cleaning tank can be reduced, the solution amount of the phosphoric acid solution can be reduced, and the entire equipment can be made compact. . Further, not only a dedicated worker is not required, but also maintenance work can be reduced.

[Brief description of drawings]

FIG. 1 is a system diagram showing an apparatus of the present invention.

[Explanation of symbols]

 1 Main Tank 2 Sub Tank 3 Waste Liquid Tank 4 Liquid Supply Pump 5 Header Nozzle 6 Sink Roll 7 Cleaning Tank 8 Jet Cleaning Device 9 Jet Cleaning Nozzle 10 Phosphoric Acid Solution 11 Rotating Shaft 12 Bearing 13 Handle 14 Circulation Piping 15 Circulation Pump 16 Supply Piping 17 Shutoff valve 18 Shutoff valve 19 Supply pipe 20 Shutoff valve 21 Waste liquid pipe 22 Shutoff valve 23 Hose

Claims (1)

[Claims] 1. A deposition dross cleaning and removing device for a plating bath dipping device that is dipped in a continuous hot-dip galvanizing bath, the cleaning bath containing a phosphoric acid solution for cleaning, and the phosphoric acid contained in the cleaning bath. A reversing support device for reversibly supporting a plating bath dipping device in which only the lower part is dipped in a solution, and a header nozzle in which the phosphoric acid solution contained in this cleaning tank is arranged above the plating bath dipping device via a circulation path. And a jet cleaning device for ejecting pure water from a jet cleaning nozzle toward the dross attached to the plating bath dipping device, and a phosphoric acid solution circulating and spraying device for circulating the solution by spraying. Equipment dross cleaning and removing device.