JPH03232510A - Method for judging clogging of filter in cleaning solution tank filter in continuous surface polishing device for metallic strip - Google Patents

Abstract

PURPOSE:To judge the clogging state of a filter in a tank filter from the cumulative quantity of a recovered cleaning soln. by recovering a cleaning soln. overflowing the tank filter due to the clogging of the filter in an overflow recovery tank. CONSTITUTION:The tank filter 2 provided with a filter 3 for filtering a cleaning soln. is provided on the return side of a cleaning soln. circulating line in the continuous surface polishing devices 12 and 13 for a metallic strip 15, and the soln. overflows the tank filter. The soln. overflowing the tank filter 2 due to clogging of the filter 3 is recovered in the overflow recovery tank 7. The clogging state of the filter in the tank filter 2 is judged from the cumulative quantity of the soln. recovered in the tank 7. As a result, the periodic inspection of the clogging of the filter by an operator is not needed, and the trouble caused by the spillage of the overflowing soln., etc., is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for determining filter clogging in a cleaning liquid filtration tank provided on the return side of a cleaning liquid circulation system in a continuous plate surface polishing apparatus for metal strips.

<Prior art> A continuous plate surface polishing or polishing device for metal strips (hereinafter collectively referred to as a continuous plate surface polishing device) is used to remove oxide films, adhering carbon, etc. formed on the surface of metal strips such as thin steel plates. Generally, as shown in FIG. 2, the surface of a metal plate 15 moving in the direction of the arrow is polished by upper and lower brush rolls 12 to remove oxide films, carbon, etc.

The upper and lower brush rolls 12 are each sprayed with a cleaning liquid from the spray nozzles 12 to be cleaned. The cleaning liquid used for cleaning is guided to a filtration tank 2 installed on the return side of the scrubber tank 1, and the cleaning liquid after foreign matter has been filtered by a filter 3 in the filtration tank 2 is collected from a return pipe 4 into a scrubber subtank 5. The cleaning liquid collected in the scrubber sub-tank 5 is circulated from a spray pump 11 through a pipe 14 to a spray nozzle 13 and sprayed thereon.

However, the filter (wire mesh) 3 of the filtration tank 2 provided on the return side of the polishing liquid circulation system gradually becomes clogged, and especially when the filter (wire mesh) 3 of the filtration tank 2 is clogged with brush debris from the brush roll 12, the returned cleaning liquid flows from the filtration tank 2. This will overflow, resulting in water leakage from the equipment and failure of the cleaning liquid to return to the scrubber sub-tank 5, which will impede the polishing work of the metal strip by the continuous plate surface polishing device.

Therefore, the operator must periodically check whether the filter 3 of the filtration tank 2 is clogged or replace the filter early, resulting in waste. In particular, in plate surface polishing equipment, the condition of the metal band and the plate speed,
The amount of liquid accepted into the filtration tank 3 and the concentration of the cleaning liquid vary greatly depending on operating conditions such as the amount of cleaning liquid associated with the amount of polishing. It would be too wasteful to maintain the filter 3 in a state where it does not overflow even with the maximum load in order to deal with such large fluctuations.

As a means for detecting clogging of a filter, a method of measuring resistance during filtration using pressure or the like is generally adopted (see, for example, Japanese Patent Laid-Open No. 134022/1983).

<The invention tries to solve i! l! g> However, in order to detect clogging of the filter and measure the resistance during filtration using pressure, etc., sophisticated instrumentation and equipment are required, which not only increases equipment costs but also requires time and effort to maintain the instrumentation equipment. was there.

The present invention has been made in view of the above circumstances,
The object of the present invention is to provide a method for determining filter clogging of a cleaning liquid filtration tank in a continuous plate surface polishing apparatus for metal strips, which can automatically determine the clogging of the filter of the filtration tank using a simpler and cheaper device. be.

Means for Solving the Problem> A method for determining filter clogging of a cleaning liquid filtration tank in a continuous sheet polishing apparatus for metal strips in order to achieve the above object is a method for determining the clogging of the filter of a cleaning liquid filtration tank in a continuous sheet polishing apparatus for metal bands. A filtration tank equipped with a filter for filtering the cleaning liquid provided on the side is made to be overflowable, and the cleaning liquid that overflows the filtration tank due to clogging of the filter is collected in an overflow recovery tank, and the accumulation of cleaning liquid collected in the overflow recovery tank. The present invention is characterized in that the filter clogging state of the filtration tank is determined based on the amount of liquid.

Further, in the present invention, the filter clogging state of the filtration tank may be determined based on the cumulative number of overflows of the cleaning liquid that overflows the filtration tank due to filter clogging.

<Function> Since the present invention has the above-described configuration, when the cumulative amount of cleaning liquid collected from the filtration tank to the overflow recovery tank reaches a predetermined amount, an alarm is emitted, or an overflow accumulation of the cleaning liquid overflowing from the filtration tank is activated. If a warning is issued when the number of times reaches a predetermined number, clogging of the filter can be automatically determined.

<Example> An embodiment of the present invention will be described below based on No. 1117.

In Fig. 1, the same parts as those in Fig. 2 are given the same reference numerals, and the explanation will be simplified. After removing brush waste etc. in step 3, it is collected into the scrubber sub-tank 5 through the return pipe 4 as before.
An overflow recovery tank 7 surrounding the filtration tank 2 is installed, and a level switch 6 is provided in the recovery tank 7.

When the filter 3 of the filtration tank 2 becomes clogged and overflows, the overflowing wash water is collected and stored in the overflow recovery tank 7. When the cumulative amount of cleaning liquid collected in the overflow collection tank 7 reaches a predetermined level, that is, the L level of the level switch 6, an alarm is issued to notify that the filter 3 is close to its clogging limit. Then, measures are taken such as replacing the filter 3 before the level switch 6 reaches the H level.

n'l A level switch 6 is installed in the overflow recovery tank 7.
Providing a filter is suitable when the cleaning liquid overflows from the filtration tank 2 with a relatively small amount of fluctuation, but if the amount of cleaning liquid received in the filtration tank 3 or the concentration of the cleaning liquid changes significantly, In the case of loss-of-business conditions that repeatedly overflow or not, the accumulated Mi/
, 1tffi, it may be preferable to make the determination based on the number of times the cleaning liquid overflows from the filtration tank 2.

In such a case, it is desirable to provide a level switch 6' in the filtration tank 2.The level switch 6' is set at a level at which the cleaning liquid overflows from the filtration tank 2. It is possible to detect the number of times the cleaning liquid overflows into the overflow collection tank 7, and when this cumulative number reaches a predetermined number of times or a predetermined cumulative number of times within a certain period of time, an alarm is issued and it is determined that the filter is clogged. .

It is also possible to set the filter replacement cycle by appropriately setting the alarm level of the cumulative amount of cleaning liquid collected in the collection tank 7 or the cumulative number of overflows in the filtration tank 2 based on experience.

When the cleaning liquid collected in the overflow recovery tank 7 reaches the overflow level, it passes through the overflow bypass pipe 8 and passes through the filter 3' of the overflow filtration tank 9.
The overflow is filtered through the overflow return pipe 10, joins the return pipe 4, and is collected in the scrubber subtank 5.

<Effects of the Invention> As explained above, according to the present invention, an automatic check for clogged filter tank filters can be achieved using a simple device instead of a manual check, thereby eliminating the need for the operator to periodically check for clogged filters. Since the cleaning liquid that overflows the filtration tank is collected in the overflow recovery tank, troubles caused by spillage of the overflow liquid can be solved.

[Brief explanation of drawings]

FIG. 1 is a flowchart including a schematic side view showing the overall configuration of an embodiment of the present invention, and FIG. 2 is a flowchart including a schematic side view showing the overall configuration of a conventional example. ■...Scrubber tank, 2...Did tank, 3.
3'...Filter, 4...Return pipe, 5...Scrubber sub tank, 6.6'...Level switch, 7...Overflow collection tank, 8...Overflow bypass pipe, 9...・Overflow filtration tank, IO... Overflow return pipe, 11... Spray pump, 12... Brush roll, 13... Spray nozzle, 14... Piping, 15
...Metal band.

Claims (1)

[Claims] 1. A filtration tank equipped with a filter for filtering the cleaning liquid provided on the return side of the cleaning liquid circulation system in a continuous plate surface polishing apparatus for metal strips is made to be overflowable, so that the filtration tank is closed due to clogging of the filter. An apparatus for continuous sheet polishing of metal strips, characterized in that overflowing cleaning liquid is collected in an overflow recovery tank, and the clogging state of the filter in the filtration tank is determined based on the cumulative amount of cleaning liquid collected in the overflow recovery tank. Method for determining filter clogging in cleaning liquid filtration tank. 2. The method according to claim 1, wherein the filter clogging state of the filtration tank is determined based on the cumulative number of times the cleaning liquid overflows the filtration tank due to filter clogging.