TW494004B - Magnetic filter device - Google Patents

Abstract

A magnetic filter device comprises permanent magnets installed opposedly to each other on both sides of a container so that magnetic lines of force are generated in the direction orthogonal to the moving direction of the fluid in the container, wherein the relation between the installation interval L (mm) for the filter device and the residual induction B(T) of the permanent magnets meets the requirement of the expression Bx100 ≤ L ≤ Bx250 under the condition that the filter passing time of the fluid is 0.5 sec. to 1.5 sec. When the general-purpose permanent magnets such as ferrite magnets and neodymium magnets are used, the device can be reduced in size at a low cost by deriving the maximum filter performance.

Description

494004 A7 B7 V. Description of the invention (1) (Industrial fields of use) (Please read the precautions on the back before filling out this page) The present invention relates to magnetic filter devices, especially the rolling oil used in the cold rolling of steel plates Related to the magnetic filter device used to continuously separate the magnetic particles mixed in the fluid during the purifying process of various fluids, such as the washing liquid used to remove the rolling oil after cold rolling. (Prior technology) When you want to clean the rolling oil used in cold-rolled steel sheet, or to clean the cleaning liquid used to remove the rolling oil remaining on the surface of cold-rolled steel sheet, magnetic filters are commonly used. , As a means of removing magnetic particles in the fluid. An example of a typical magnetic filter device in the past will be described using a cross-sectional view of FIG. 1 (a) and a side view of the same figure (b). The numbers in the figure indicate that 1 is the container, 2 is the permanent magnet, 3 is the filter, 4 is the rear plate, 5 is the fluid inlet, and 6 is the fluid discharge. Consumption cooperation with employees of the Intellectual Property Bureau of the Ministry of Economic Affairs' Printing Normally, ferromagnetic materials such as steel or JISSUS 4 3 0 ferrous grain iron stainless steel metal mesh are used as magnetic filters 3 in the container 1 . Permanent magnets 2 are disposed on the outside of the container 1 so as to face each other across the container 1 so as to generate magnetic lines of force in a direction where the flow of the fluid belonging to the liquid to be treated intersects substantially perpendicularly. The liquid to be treated is introduced into the container 1 from the fluid introduction port 5 and passes through the magnetic filter body 3 and is discharged from the discharge port 6. Magnetic particles such as iron powder mixed in the liquid to be processed pass through the magnetic filter body 3 and are adsorbed by the magnetism of the magnetic filter body 3 magnetized by the permanent magnet 2 to be separated from the liquid towel to be processed. This paper scale is in accordance with Chinese National Standard (CNS) A4 specification (21〇'〆297mm) -4- 494004 A7 B7 V. Description of the invention (2) In the process of capturing magnetic particles by magnetic filter device, from The attractive force F m of the thin line or the metal mesh constituting the filter body can be expressed by the following equation.

Fm = x * V * H · (dH / dx) Here, Z: magnetic susceptibility of particles V: volume of particles Η: intensity of magnetic field d H / d X: magnetic gradient (spatial change of magnetic field) In the formula, because of the characteristics of Z and V-based magnetic particles, it is necessary to increase the magnetic field or increase the magnetic gradient in order to increase the attractive force F m and improve the filtering performance. However, the magnetic gradient d H / d X is a coefficient that depends on the material and shape of the ferromagnetic body constituting the filter, and the magnetic gradient d H / d X is also subjected to a magnetic field after determining the material and shape of the ferromagnetic body. The strength dominates, so how to maintain a strong magnetic field in the filter body becomes the most important issue to improve the filtration performance, that is, to increase the attractive force. (Problems to be Solved by the Invention) In the past, due to insufficient research on the relationship between the filtering performance and the magnetic field, disadvantages such as deterioration of the filtering performance occurred whenever the magnetic field in the filter body became smaller. In addition, regarding the selection of magnets, it is not necessary to use magnets with the strength of a river to achieve the required filtering performance. The shape of the filter body is in accordance with the Chinese National Standard (CNS) A4 specification (210X297 mm). ) (Please read the notes on the back before filling out this page), 11 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs, printed 494004 A7 B7 V. Description of the invention (3), the flow rate of the fluid to be treated, etc., and the strength of the magnet The relationship between them is not clear, resulting in the lack of desired filtering performance and other shortcomings. (Please read the precautions on the back before filling out this page.) That is, even if a powerful magnet is used, it will not necessarily have good results depending on its design and specifications. In addition, when a powerful magnet is used, an appropriate effect can be expected ′, but there is a disadvantage that cost increase cannot be avoided. (Means for solving the problems) The present invention is a person who can solve the above problems, and its object is to provide a magnetic filter device, especially when a widely used permanent magnet such as a ferrite magnet and a samarium-based magnet is used. Also, by extracting the highest performance, it is possible to make a magnetic filter device that achieves the lightness and miniaturization of the device on the premise of low cost. The inventors of our company investigated the relationship between the magnetic field strength and the filtering performance in the magnetic filtering device, and investigated its influence and various factors on the filtering performance. This time, we successfully filtered the various factors on the filtering performance. The impact of performance is clarified, and based on this, we develop low-cost and high-efficiency magnetic filter economic and intellectual property bureau employees' consumer cooperation 11 bucket manufacturing device. That is, the present invention is a magnetic filter device. A filter body made of an elastic magnetic body is provided in a container provided with a fluid inlet and a discharge port, and a permanent magnet used to magnetize the filter body is oriented. A magnetic filter device that generates magnetic lines in a direction that is substantially perpendicular to the direction of fluid movement in the container. The magnetic filter device is arranged opposite to each other across the container. It is characterized in that the filtration time of the fluid 趵 is 0.5 seconds or more and low. Applicable to Chinese paper standard (CNS) A4 specification (210X297 mm) at this paper scale -6- Intellectual Property Bureau, Ministry of Economic Affairs, Consumer Cooperation Du printed 494004 A7 B7 V. Description of the invention (4) Within 1 and 5 seconds The above-mentioned permanent magnet is set as follows: The relationship between the interval L (mm) and the residual magnetic field line density B (τ ^) of the permanent magnet conforms to the following relationship: BX100SLSBX250. In the present invention, it is used to magnetize the filter body. For permanent magnets, ^ 1: It is ideal to use a residual magnetic line density of 0. 4 T or more. (Best Embodiment of the Invention) With regard to the content of the present invention, The physical description is as follows. First, the analysis of the present invention is explained. In addition, in terms of factors related to filtration performance, items such as γ are conceivable. • Magnet strength • Distance between magnets • Material and shape of the filter body • Fluid speed, length of filter body, and properties of the fluid. At the beginning of experiments on factors related to filtration performance, 'the most commonly used ferrous iron-based stainless steel JIS -S υ 〇 4.0 metal Gang (1 Q Hi esh, plain line: 1 rn in 'Guangben paper size applies Chinese National Standard (CNS) A4 specification (210X297 public director)

{Please read the notes on the back before filling in this page. J% -line-494004 Employees' cooperation of Intellectual Property Bureau of the Ministry of Economic Affairs. 4'print A7 B7 V. Description of the invention (5)) Fill the container as a filter, In addition, an alkaline cleaning solution that is generally used in a cold-rolled steel sheet cleaning process is selected as a fluid. The alkaline cleaning solution is usually reusable, and the concentration of iron powder on the side before passing through the filter body is in the range of 60ma s s ppm to 100ma s s P P m. The filtration performance was evaluated by the following formula. Iron powder scavenging rate = (F — E) / Fx100 (%) In the formula, F: the concentration of iron powder on the entry side and E: the concentration of iron powder on the discharge side. When the rate of iron powder scavenging is more than 60% It can be said that the filtration performance is good. In contrast, when the iron powder removal rate Θ is less than 60%, as will be described later, the circulation flow rate to ensure the cleanliness of the fluid is increased, and as a result, the filtering equipment is increased, so it is not a good policy. In addition, when confirming the filtration performance, the measurement of the iron powder removal rate of 7? Is based on the backwash of the filter body, waiting for 10 minutes to 20 minutes, and taking a stable filtration, take a test Samples are measured. In addition, in the case of permanent magnets, ferrite magnets or neodymium-based magnets whose residual magnetic field line density B is in the range of about 0.2 T to 0.6 T are used. As shown in Fig. 1 (a), focusing on the distance L between the permanent magnets and the magnet is a very important data for obtaining the desired performance in the magnetic filter device. 3 5 mm change to this paper size applies Chinese National Standard (CNS) A4 specification (210X297 mm) Sound port (Please read the precautions on the back before filling this page)

-8-494004 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the invention (6) 2000 mm, and measure the iron powder removal rate 々. Fig. 2 shows the results of an investigation on the effect of the residual magnetic field density β (τ) of the permanent magnet used and the distance L (m m) between the magnets on the iron powder removal rate. In addition, the time for the fluid to pass through the filter is set to 1.0 second. As can be understood from the same figure, when the residual magnetic line density B (T) of the permanent magnet and the distance L (mm) between the magnets can satisfy the following formula :

In the case of the relationship of L ^ 2 5 Ο X B, it was found that high filtration performance can be stably obtained. Secondly, the situation of reducing the distance L between the magnets is also reviewed. When L is less than B X 100, although the iron powder removal rate π can be stably maintained at a high value, it is determined that the cross-sectional area of the filter body It becomes too small. As a result, in order to ensure the circulation flow, it is necessary to prepare most filtering devices. In addition to complicate the equipment and troublesome maintenance, it will cause a significant increase in equipment costs. Figure 3 shows that in the alkaline cleaning of steel plates that are actually used for rolling. In the equipment, the cleaning liquid volume of the cleaning steel plates is set: about 20 m 3 and the circulation flow rate is 0 · 2 m 3 / Under the condition of minutes, the equipment cost of the filter when L / B is changed by many parties is investigated. In the same figure, the equipment cost is set to 1 · 0 when L / B = 150, and then the equipment cost is relatively compared. It can be seen from the same figure that when L / B becomes smaller, ’even if the iron of the filter body is applicable to China National Standard (CNS) A4 (210 X297 mm) (please read the precautions on the back before filling this page)

-9-Consumption Cooperation by Employees of the Intellectual Property Bureau of the Ministry of Economic Affairs, printed 494004 A7 B7 V. Description of the Invention (7) The powder removal performance will be improved. However, in order to ensure the circulation flow, it is necessary to increase the number of devices in the filter body. Fees will rise. Especially when L / B is less than 100, it will cause a sharp increase in equipment costs. Therefore, in the present invention, as shown in Fig. 4, the distance L between the residual magnetic flux density B of the permanent magnet and the magnet must be determined as follows:

The condition of the relationship of 100 × B ^ L ^ 25 × B. In addition, in the above experiment, although the concentration of iron powder on the fluid inlet side of the fluid is specified to be 60ma ss ppm to 100ma ss PP m, the filtration system is usually recycled for constant use. For the cleanliness of circulating fluids, iron powder concentration: 30 mass ppm or less is the target. Figure 5 shows that in the actual alkaline steel cleaning equipment for rolled steel plates, the set conditions are: the amount of cleaning liquid for the steel plates: about 20 m 3, and the average iron powder concentration on the entry side of the filter: In the alkaline cleaning solution path of about 150 massppm, set the circulating flow rate: 0.2 m 3 / min filter, and maintain the iron powder concentration of the alkaline cleaning solution at about 20 ppm. The result of investigating the relationship between the filtration performance (iron powder removal rate) of each single device and the equipment cost of the filter body. Also, in the same figure, the lie fee is 1. c in the case where the iron powder removal rate is 7/270%, and then the equipment cost is relatively compared. This paper size applies to China National Standard (CNS) A4 (210X297 mm) (Please read the precautions on the back before filling this page)

-10- 494004 A7 B7 V. Description of the invention (8) As shown in the figure, if the iron powder removal rate of the filter body of each device does not reach 60%, a large-scale filter body is required to maintain The liquid was at the required cleanliness, which caused an increase in equipment costs. Therefore, when considering the efficiency of the equipment, the iron powder removal rate π of the overspray is the best solution if the value is more than 60%. Next, the flow rate, flow rate, and transit time of the treatment liquid passing through the filter were investigated. The flow velocity of the treatment liquid was changed from 100 m / s to 300 m / s. For the filter passing length, four cases of 50 mm, 100 mm, 150 mm, and 200 mm were used to measure the iron powder removal rate π. Fig. 6 shows the length A of the filter body and the fluid flow velocity V in the filter body, and the passage time t of the filter body here is

t = A / V t: time of fluid passing through the filter body (seconds) A: length of filter body (mm) V: flow velocity of the fluid in the filter body (m m / second) Expressed. According to the above investigation, it is understood that the filtration performance, that is, the iron powder removal rate of 77 can be sorted by the passage time of the filter body. The younger figure 7 is the result of checking the relationship between the passage time t of the sprinkler body and the iron powder removal rate 7 / in S week. As shown in the same figure, it is understood that no matter what the case is, when the filter passes the time mo · 5 seconds, the iron powder removal rate drops sharply, and this paper size applies the Chinese National Standard (CNS) Α4 specification (210X297 public director) (please read the precautions on the back before filling this page), ^ 1 Consumption Cooperation between Employees and Intellectual Property Bureau of the Ministry of Online Economics Du Yin-11-494004 A7 B7 V. Description of the invention (9) The filtering performance will be greatly Ground down. In addition, even if the filter passing time t exceeds 1.5 seconds, a significant improvement in the iron powder removal rate of 7% cannot be seen. (Please read the precautions on the back before filling out this page.) Next, Figure 8 shows that in the actual alkaline steel cleaning equipment for rolled steel plates, the set conditions are: the amount of cleaning liquid to clean the steel plates ... About 20 m 3, the average iron powder concentration on the inlet side of the filter: about 150 massppm in the alkaline cleaning solution path, set the circulation flow rate: 0.2 m 3 / min, the passing time: 1.0 seconds The filter body whose iron powder removal rate is 70%, and the iron powder concentration of the alkaline cleaning solution is maintained at about 20 ppm. The result of investigation on the relationship between the filtration passage time t and the equipment cost of the filter body . Also, in the same figure, the equipment cost at the time of filter passing time t = 1 · 0 seconds is set to 1 · 0, and then the equipment cost is relatively compared. As shown in the same figure, when the filter passing time t exceeds 1.5 seconds, the necessary iron powder removal can be ensured even when the residual magnetic line density of the permanent magnet is slightly smaller or the distance between the magnets is slightly wider. Rate, but in order to maintain the cleanliness of the cleaning solution, the filter body will eventually become a large-scale person, so it is determined that the equipment cost will increase. Therefore, from the viewpoint of equipment efficiency, it is best to set the filter passing time t to within 1.5 seconds. From the results of Figures 7 and 8 shown above, the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs prints the results. It can be understood that the effective filtering passing time t, including filtering performance and equipment costs, ranges from 0.5 seconds to 1 · Between 5 seconds. Therefore, in the present invention, the filtration passage time of the restricted fluid is more than 0.5 seconds and less than 1.5 seconds. / ^ mr,

VM JM b'j J This paper size is applicable to Chinese National Standard (CNS) A4 (210X297 mm) 494004 A7 B7 V. Description of the invention (10) It is used in the actual cleaning equipment shown in Figure 9 The magnetic filter device of the present invention performs the cleaning treatment of the cleaning solution. (Please read the precautions on the back before filling this page.) As shown in the figure, the rolled steel plate 7 passes through the rough cleaning tank 8 commonly known as the soaking tank, and then uses the first brush scrubber 9 Brush, and then formally wash in a gutter 10. Corresponding to the immersion tank 8 and the cleaning tank 10, circulating tanks 1 1 and 12 are respectively set, and a cleaning liquid mainly composed of an alkaline cleaning liquid is circulated for use by pumps 1 3 and 1 4. In the magnetic filter device 15 and 16 of the present invention, there is a cleaning liquid introduced from the circulation tank 11 or 12 by a pump 17 and 18, and iron is removed from the steel plate through the cleaning process. The powder is removed by adsorption. The specifications of the magnetic filter device 16 for the cleaning tank circulation tank, the filtration passing time of the cleaning solution and the iron powder concentration on the entry side are shown in Table 1. In Table 1, the results of investigating the iron powder concentration on the discharge side of the cleaning liquid and the iron powder removal rate 77 after the cleaning treatment of the cleaning liquid according to the above conditions are described. As shown in the same table, when the magnetic filter device according to the present invention is used to process the consumption cooperation of employees of the Intellectual Property Bureau of the Ministry of Economic Affairs, the iron powder removal rate 7? Is more than 60%, and good results are obtained. Then, when the magnetic filter device 15 for the immersion tank circulation tank and the magnetic filter device of the present invention were used for purification treatment, it was investigated, and it was confirmed that a good result was obtained. (Effects of the invention) This paper size applies Chinese National Standard (CNS) A4 specification (210X297 mm) -13- 494004 A7 B7 V. Description of the invention (11) (Please read the notes on the back before filling this page) According to the invention, the highest filtering performance can be exhibited when the plutonium purification treatment of the fluid is performed using a general-purpose permanent magnet, and as a result, Ken has achieved a compact and lightweight device at a low cost. In addition, in the past, during the continuous annealing process after cleaning, the iron powder on the surface of the steel plate will adhere to the surface of the roller, and the so-called unevenness of the roll marks repeatedly occurs, so the product yield rate has to be 0. The reduction is about 2 to 0.5%. However, after using the magnetic filter device of the present invention, iron powder can be strongly and stably removed after washing treatment. As a result, the defect is successfully eradicated. (Brief description of the drawings) Fig. 1 shows an example of a conventional representative magnetic filter device, in which (a) is a cross-sectional view, and (b) is a side view. Figure 2 is a graph showing the effect of the residual magnetic field density B (T) of the permanent magnet and the distance L (m m) between the magnets on the iron powder removal rate 7 ?. Fig. 3 is a graph showing the relationship between the distance between magnets and the ratio of the residual magnetic field line density (L / B) to the cost of the filtering equipment. Figure 4 shows the relationship between the residual magnetic field line density B and the distance L between the magnets of a permanent magnet that can achieve a good iron powder removal rate. Fig. 5 is a graph showing the relationship between the filtration performance (iron powder removal rate) of each unit and the cost of filtration equipment. Fig. 6 shows the filter length A and the fluid flow velocity V in the filter. Fig. 7 shows the relationship between the filtration passing time t and the iron powder removal rate 7? ΓΗ〇- = t = r. Gj iMj ^ This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -14- 494004 A7 B7 V. Description of the invention (12) Figure 8 is a graph showing the relationship between the filtering passage time t and the filtering equipment cost. Fig. 9 shows in a pattern form the cleaning equipment prepared by the present invention in a magnetic filter device printed by a consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. 0 (illustration of the drawing number) 1 container 2 permanent magnet; iron 3 magnetic cm mm body 4 rear plate 5 fluid introduction □ 6 fluid discharge j outlet P 7 steel plate 8 immersion tank (rough washing tank) 9 first brush: scrubber 1 〇 淸 cleaning tank 1 1, 1 2 rm tank 1 3, 1 4 pumps 1 5 1 6 magnetic filter 1 7 1 8 pumps 0 This paper size is applicable to China National Standard (CNS) A4 specifications (210X297 mm) (Please read the precautions on the back before filling this page} Binding-booking line -15- 494004 A7 B7 V. Description of the invention

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This paper size applies to China National Standard (CNS) A4 (210X297 mm)

Claims (1)

494004 Α8 Β8 C8 D8 κ, patent application scope 1 · A magnetic filter device is provided in a container provided with a fluid inlet and an α outlet, and a filter body made of a ferromagnetic body is provided, and the filter body will be supplied magnetically. The permanent magnet used is capable of generating magnetic lines of force in a direction that intersects with the fluid moving force in the container in a direction that intersects at a substantially perpendicular direction. The magnetic barrier device disposed opposite to each other through the container is characterized by: Under the limiting conditions of more than 0.5 seconds and less than 1.5 seconds, the above permanent magnets are set such that the relationship between the setting interval L (mm) and the residual magnetic field line density B (T > of the permanent magnets is in accordance with the following Relational formula: Bxi〇〇 $ LSBx250. (Please read the precautions on the back before filling in this page.) 稽 | Order · Printed by the Intellectual Property Bureau of the Ministry of Online Economics and Consumer Cooperatives The paper is printed in accordance with China National Standard (CNS) A4 specifications (21 OX297 mm)-