JP2001281044A - Level measuring device for reverse washing fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a level measuring device that can continuously use for a long time by preventing the clogging the device. SOLUTION: The level measuring device, which measures the level of the reverse washing fluid 7 in a reverse washing fluid tank 8, is provided with a level gauge 10 and a conduction passage 12 that communicates the fluid of the lower part of the tank 8 to the level gage 10. A metal powder retaining part that precipitate the metal powder is installed on the way of the passage 12. A powder exhausting pipe that communicates a position above an opening and closing valve 21, which opens and closes an exhausting pipe 9 on the exhausting pipe 9, to an iron powder precipitation part of the metal powder retaining part is placed. The passage of the part, on which the exhaust pipe is communicated on the exhausting pipe 9, is throttled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for backwashing a metal powder removing filter such as an electromagnetic filter with a backwashing liquid contained in a backwashing liquid tank, and to apply the metal powder filter to the backwashing liquid tank. The present invention relates to a level measuring device that is used in a circulation type backwashing device that collects captured metal powder and that measures the level of the backwashing solution in the backwashing solution tank.

[0002]

2. Description of the Related Art For example, since iron powder is adhered to a steel strip 1 after cold rolling, a cleaning step of cleaning the steel strip 1 after rolling with a cleaning liquid 2 as shown in FIG. After passing, the steel strip 1 is sent to an annealing step. The cleaning with the cleaning liquid 2 is performed by immersing the steel strip 1 in a cleaning tank 3 containing the cleaning liquid 2 or spraying the cleaning liquid 2 on the surface of the steel strip 1. FIG. 1 illustrates only the case of immersion.

The cleaning liquid 2 in the cleaning tank 3
Is circulated by being sent into the process liquid tank 4 and at the same time the clean liquid 2 in the process liquid tank 4 is sent to the cleaning tank 3. Further, the cleaning liquid 2 in the process liquid tank 4 continuously or intermittently circulates in an iron powder removing filter 5 (for example, an electromagnetic filter) in a filtering direction to remove iron powder mixed in the cleaning liquid 2. are doing. Reference numeral 6 denotes a filtration pump for pressure feeding. The cleaning liquid 2 is generally an alkaline liquid containing no oil.

When the iron powder removing filter 5 is clogged, the circulation for filtration from the process liquid tank 4 is temporarily stopped, and the iron powder removing filter 5 is backwashed. Backwashing refers to washing a filter by flowing a washing liquid in a direction opposite to a filtration direction. In FIG. 1, backwashing moves the inside of an iron powder removal filter 5 from an outlet side to an inlet side, that is, the filtration. This is performed by feeding backwash liquid 7 made of warm water into filter 5 in the direction B opposite to direction A, and discarding backwash liquid 7 containing iron powder discharged from the inlet side of filter 5. At this time, in the backwashing device shown in FIG. 1, in order to use the backwashing solution 7 economically, the backwashing solution 7 contained in the backwashing solution tank 8 is circulated and used, and when the backwashing is completed, The drain pipe 9 provided at the bottom of the backwash liquid tank 8 is opened to discharge all the backwash liquid 7 and iron powder in the backwash liquid tank 8. When the discharge is completed, the backwash liquid supply valve 11 is opened and the backwash liquid tank 8 is opened.
The inside is filled with a backwash liquid 7 to a predetermined level. At this time, in order to measure the level of the backwash liquid 7 to be filled, a level measuring device is used to control the amount of the backwash liquid 7 to be filled.

The level measuring device communicates the pressure of the backwashing liquid 7 at the lower part of the backwashing tank 8 to the levelmeter 10 by connecting the lower part of the backwashing liquid tank 8 and the level meter 10 by a conduction path 12. The backwash liquid 7 is transmitted by the level meter 10 based on the pressure.
Is measuring the level. The level meter 10 is composed of, for example, a water pressure gauge.

[0006]

In the level measuring apparatus having the above-mentioned structure, the level meter 10 and the conduction path 12 are clogged with the movement of the iron powder in the backwashing liquid 7 with the passage of time. The measured value by 10 becomes lower than the actual value, and the measurement accuracy is deteriorated. Therefore, it is necessary to periodically clean the level measuring device.

When the level measuring device is cleaned, the level of the backwashing liquid 7 in the backwashing liquid tank 8 cannot be controlled, so that the backwashing cannot be performed during that period. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a level measurement device capable of preventing a level measurement device from being clogged and capable of measuring a level over a long period of time.

[0008]

In order to solve the above-mentioned problems, the present invention as set forth in claim 1 of the present invention is directed to a method in which a backwashing liquid in a backwashing liquid tank is washed with metal powder in a direction opposite to a filtration direction. By circulating in the removal filter, the metal powder captured by the metal powder removal filter is recovered together with the backwash liquid in the backwash liquid tank, and then a discharge pipe connected to the bottom of the backwash liquid tank is provided. Used in a backwashing device that opens and discharges the backwashing solution and metal powder from the backwashing solution tank, a level meter that measures the level of the backwashing solution in the backwashing solution tank, and a lower part of the backwashing solution tank. A conductive path for communicating the liquid with the level meter, wherein a metal powder reservoir for capturing and precipitating metal powder is interposed in the middle of the conductive path. .

Next, according to a second aspect of the present invention, in the configuration according to the first aspect, a position of the discharge pipe on the upstream side of an opening / closing valve for opening and closing the discharge pipe and a metal in the metal powder reservoir are provided. A powder discharge path communicating with the powder sedimentation section is provided, and a flow path of a portion of the discharge pipe communicating with the powder discharge path is narrowed.

[0010]

Next, embodiments of the present invention will be described with reference to the drawings. It should be noted that the same devices and the like as those in the above-described conventional example are denoted by the same reference numerals and described. In the present embodiment, a level measuring device used in the backwashing liquid tank 8 of the backwashing device for backwashing the iron powder removing filter 5 described in the above-described conventional example will be exemplified.

As shown in FIG. 2, the level measuring device of the present embodiment includes a level
And an iron powder reservoir 20, which is a metal powder reservoir, and a powder discharge tube 22 forming a powder discharge passage. Conduction path 12
Communicates the pressure of the backwash liquid 7 to the level meter 10 by communicating the lower part of the backwash liquid tank 8 with the level meter 10.

The iron powder reservoir 20 is interposed in the conduction path 12. As shown in FIG. 3, the iron powder reservoir 20 has two chambers 20a and 20b defined by a partition wall 20c and communicates with an upper portion thereof, and the first chamber 20a communicates with the backwash liquid tank 8. The second chamber 20b communicates with the level meter 10. And the first chamber 20a on the tank side
, Only the liquid moves to the second chamber 20b on the level side, and the iron powder having a large specific gravity is trapped in the first chamber 20a to precipitate and deposit. In addition, the iron powder pool 20
The configuration is not limited to the above configuration as long as it can trap and precipitate iron powder.

One end of a powder discharge pipe 22 communicates with the bottom of the first chamber 20a.
It is connected to a discharge pipe 9 communicating with the backwash liquid tank 8.
The connection position may be on the upstream side of the on-off valve 21, but in the present embodiment, the flange portion 23 on the upstream side of the on-off valve 21
Connected to The flow path of the discharge pipe 9 at the position of the flange portion 23 is narrowed as shown in FIG. 4 so that the flow velocity is high, that is, suction from the powder discharge pipe 22 side is promoted by negative pressure. ing.

In the backwash liquid tank 8 provided with the level measuring device having the above structure, the iron powder accumulates even if the iron powder in the backwash liquid 7 in the backwash liquid tank 8 moves to the conduction path 12 side. 20 first
It is prevented from being trapped in the chamber 20a and moving to the level meter 10. The iron powder trapped in the first chamber 20a
The particles settle on the bottom of the first chamber 20a and fall in the powder discharge pipe 22 communicating with the bottom.

This prevents the measurement accuracy of the level meter 10 from deteriorating due to the clogging of the iron powder.
After the backwashing of the iron powder removing filter 5 is performed in a circulating manner, and after the iron powder captured by the filter 5 is captured in the backwashing liquid tank 8, the on-off valve 21 is opened and the backwashing is performed through the discharge pipe 9. The backwash liquid 7 and the iron powder in the liquid tank 8 fall down and are discharged.

At this time, since the flange portion 23, that is, the connection portion of the powder discharge tube 22 is narrowed, a negative pressure is applied and the iron powder in the powder discharge tube 22 is sucked, so that the discharge tube 9 and the powder 1
The iron powder deposited in the chamber 20a and the liquid in the passage 12 are automatically drained. As a result, the cleaning of the conduction path 12 is performed automatically, so that the level measuring device can be used continuously for a long time.

In this embodiment, the iron powder pool 20
Although the first chamber 20a is communicated with the discharge pipe 9, the present invention is not limited to this. For example, a valve may be provided in the first chamber 20a, the valve may be opened as appropriate, and the liquid may be drained to remove the iron powder precipitated in the first chamber 20a. In the above embodiment, iron powder is exemplified as the metal powder, but the present invention is also applicable to a tank for backwashing the filter 5 for removing other metal powder such as aluminum powder.

[0018]

As described above, the backwash liquid level measuring apparatus of the present invention has an effect that the level of the backwash liquid in the backwash liquid tank can be stably detected for a long period of time. In particular, when the invention according to claim 2 is adopted, there is an effect that the conduction path of the level measurement device is cleaned when the backwash liquid is discharged into the backwash liquid tank.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating filtration by a filter and circulating backwashing of the filter.

FIG. 2 is a diagram showing a level measuring device according to an embodiment based on the present invention.

FIG. 3 is a diagram showing an iron powder pool according to an embodiment according to the present invention.

FIG. 4 is a view showing a discharge pipe portion connecting a powder discharge pipe according to an embodiment according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel strip 2 Cleaning liquid 3 Cleaning tank 4 Process liquid tank 5 Iron powder removal filter 6 Filtration pump 7 Backwash liquid 8 Backwash liquid tank 9 Discharge pipe 10 Level meter 11 Valve 12 Conduction path 20 Iron powder pool 20a First chamber 20b Second chamber 20c Partition wall 21 Open / close valve 22 Powder discharge pipe 23 Flange part A Filtration direction B Backwash direction C Level measurement device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Koji Kawashima 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba F-term in the Chiba Works, Chiba Works (reference) 2F014 AA17 AB01 4D066 BB12 EA06 EA12 FA02

Claims (2)

[Claims] 1. A backwash liquid in a backwash liquid tank is circulated through a metal powder removal filter in a direction opposite to a filtration direction,
After collecting the metal powder trapped in the metal powder removal filter in the above-mentioned backwashing liquid tank together with the backwashing liquid, open the discharge pipe connected to the bottom of the above-mentioned backwashing liquid tank to remove the backwashing liquid and the metal powder. Used in a backwashing device that discharges from the backwashing liquid tank, a level meter for measuring the level of the backwashing liquid in the backwashing liquid tank, and a liquid at a lower portion of the backwashing liquid tank communicates with the level meter. A level measuring device having a conduction path, wherein a metal powder reservoir for capturing and precipitating metal powder is interposed in the middle of the conduction path. 2. A powder discharge path communicating between a position of the discharge pipe upstream of an on-off valve for opening and closing the discharge pipe and a metal powder sedimentation section of the metal powder reservoir, and a powder discharge passage in the discharge pipe. 2. The level measuring device for a backwash liquid according to claim 1, wherein a flow passage at a portion where the body discharge passage communicates is narrowed.