JPS62258716A - Apparatus for filtering magnetic liquid - Google Patents

Abstract

PURPOSE:To obtain the title apparatus operable for a long time, by providing a stirrer having a stirring blade rotating along the surface of the filter material in a filter housing in close vicinity to the surface of said filter material. CONSTITUTION:A turbine type stirring blade 4a moving along the surface of the filter material 3a of the filter housing 5a of a cylindrical filter is arranged in the vicinity of the filter material 3a. That is, a shearing speed is uniformly imparted to the liquid on the surface of the filter material 3a to eliminate the stagnation part or low shearing part in the upper part of the filter separated from a liquid supply port 1a or in the side opposite to the liquid supply port 1a and the formation of the accumulation layer on the surface of the filter material 3a is prevented. As a result, the continuous operation time of the filter can be made long to make it possible to contribute to the enhancement of the production efficiency of a magnetic material and the reduction in equipment and maintenance cost as well as the stability and enhancement of the product quality of the magnetic material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a continuous filter used before applying a magnetic liquid in the production of magnetic materials. In particular, it relates to a magnetic liquid filtration device MK that can perform constant pressure and stable filtration of footsteps for a long period of time.

[Conventional technology]

In conventional continuous filtration devices, it has been customary to provide a large filtration area in order to operate continuously for a long time.

[Problem that the invention seeks to solve]

However, when a large filtration area is provided, when the liquid being sent enters the filter housing, the flow rate decreases rapidly, and the difference in speed across the entire door surface increases, resulting in a large number of foreign substances being separated. In the case of the liquid present in the eagle,
In the case of liquids that tend to react or aggregate to form foreign substances under low shear rates, or in the case of thixotropic liquids where the liquid viscosity changes greatly depending on the shear rate distribution, it is necessary to A layer of solid content in the liquid is formed on the surface of the F# coating, reducing the effective filtration area and shortening the continuous operation time of the filter.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic liquid filtration device that eliminates the conventional drawbacks, prevents the formation of a deposited layer on the surface of a door material, and is capable of long-term operation.

[Means and effects for solving the problem] In the #i magnetic liquid filtration device of the present invention, by increasing the shear rate in the filter housing, especially on the surface of the door material, the liquid stagnation area is eliminated and the liquid is prevented from forming due to reaction or aggregation. In addition to preventing the formation of foreign matter, foreign matter generated upstream is redistributed under high shear rates, reducing the load on the filter.

That is, the present invention provides a continuous filter that removes foreign substances while continuously pumping a magnetic liquid using a pump, etc., in which a stirring blade that rotates while bathing the surface of the F material is provided in close proximity to the surface of the furnace material in the filter housing. This is a dispensing liquid filtration device characterized in that it is equipped with a stirrer.

The continuous filter for magnetic liquid in the present invention includes a cylindrical filter as shown in FIG. 1 and a disc-shaped filter as shown in FIG. 2.6.

The present invention will be explained based on the drawings. In Fig. 1, a turbine type stirring blade 4a that moves along the surface of the furnace material is installed close to the F material 6a of the filter housing 5a of the cylindrical filter, and uniformly applies a shear rate to the liquid on the surface of the P material. , the upper part of the filter away from the liquid supply port 1a and the liquid retention part and low shear part on the side opposite to the liquid supply port 1a are eliminated to prevent the formation of a deposited layer on the surface of the furnace material 6a. Stirring blades 4a and F
Preferably, the shear rate between the surfaces of the material 6a is kept higher than the shear rate in the piping entering the filter housing.

Figure 2 shows a system in which a high-speed circulation system is used in conjunction with the cylindrical filtration device shown in Figure 1 to further increase the flow velocity on the filter surface.The amount of supply from the metering pump 12 is increased and the circulation is activated to achieve a fixed amount of filtration. Flowmeter 8 to obtain stock tank 11
The autonomalp 9 is controlled based on the value of , which is effective in systems where there are a large amount of foreign matter to be separated by a filter.

FIG. 3 has a conical disk-shaped filter for the same purpose as FIG. 1, and a seed-shaped stirring blade 4b is installed when a disk-shaped F material 6b is used. The seed type stirring blade 4b is close to the furnace material 6b, rotates along the surface of the furnace material 3b, and imparts a shear rate to the F# coating surface liquid.

Figure 4 shows a case where a cylindrical disk-shaped filter is used, and when dealing with a liquid that is prone to agglomeration and fc reaction under low shear speed, it is necessary to prevent the reaction and agglomeration within the filter housing 5C, or to prevent the reaction that has already occurred. A high-speed sawtooth stirring blade 4C is installed to redisperse the agglomerates that have formed. The shearing rate generated by the sawtooth stirring blade 4C does not need to be extremely high in the case of reaction and prevention of agglomeration, but if redispersion of the liquid is required, it is necessary to obtain a shearing stress that breaks the agglomerates.
Depending on the type of liquid, ultrahigh speed is required, so it is necessary to be careful about heat generation and use a cooling jacket 6 or the like.

In the present invention, the rotating speed of the stirring blade installed in the filter housing can be sufficiently effective by increasing the shearing speed of the P material surface as fast as possible, but it is not appropriate for the system in terms of heat generation and cost. It is desirable to adopt

The three types of stirring blades listed above are turbine type, paddle type, sawtooth type, etc., but the blade structure, installation position, rotation speed, etc. should be selected appropriately depending on the enemy characteristics and purpose of use. . For liquids that react or coagulate at low shear rates, it is necessary to rotate sawtooth stirring blades with high shear force at high speeds, but this may simply result in the formation of a deposited layer in the stagnation area or the presence of a large amount of foreign matter to be separated. For liquids that contain liquids, it is sufficient to simply install a seed-shaped blade near the surface of the F material and slowly rotate it many times. That is, the shear rate near material F needs to be selected depending on the liquid properties and usage.

〔Example〕

Next, the present invention will be specifically explained using examples.

(Example (6)) Using the cylindrical disk-shaped PiA device shown in FIG. 4, changes in the differential pressure before and after the filter during continuous filtration of a magnetic liquid were investigated.

Specifications of OF4 device...The effective diameter of the disc F material of the filter is 70 mm, the stirring blade has a sawtooth blade diameter of 40 cmgJ,
0 Magnetic liquid composition (parts by weight) Ferromagnetic alloy powder... (Fe-N4 alloy N1 approx.
i1. Specific surface area [5-BET, ]: 555m/, 9
) 100 parts vinyl chloride/vinyl acetate/maleic anhydride copolymer (manufactured by Nippon Zeon ■: 400xllOA) 12 parts urethane resin (manufactured by Nippon Polyurethane @: N-2601) 12 parts polyinsyanate (manufactured by Nippon Polyurethane ■: Coronate L) 8 parts carbon black (average particle size 0.04 μm) 2
Part a-Fe20g (average particle size 0.4 μm)
5 parts methyl ethyl ketone 600
In addition to the above conditions, F material made of cellulose + epoxy resin with a nominal removal rate of 2 μm was used, and the lower surface of the stirring blade and the furnace were Between the material surface and the blade stirring speed 6 Or
Filtration was performed under the conditions of , p, and m, and compared with that without using a stirring blade. The results are shown in FIG. 5(a).

Examples are indicated by A1, and comparative examples are indicated by B.

(Example-2) Bronze filter steel with a nominal removal rate of 5 μm was used as the furnace material, and the gap between the stirring blade and the door material surface was maintained at 10 iua, and the stirring speed of the blade was set to K 1.30 Or, p, and P. Fig. 5 Φ
). The example is shown as A2, and the comparative example is shown as 82.

In all of the above cases, stirring reduced the rise in the differential pressure across the filter, making it possible to significantly lengthen the continuous operation time.

〔Effect of the invention〕

As explained above, the present invention prevents reactions and agglomeration in the liquid that occur when the shear rate is low by installing rotating stirring blades close to the F material in the filter housing and swamped on the surface of the furnace material. By being able to prevent the formation of a deposited layer on the surface of the F material, it was possible to extend the continuous operation time of the filter. This greatly contributes to improving production efficiency of magnetic materials, reducing equipment and maintenance costs, and stably improving product quality of magnetic materials.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an apparatus in which a turbine-type stirring blade is installed in a cylindrical filter as an embodiment of the present invention, FIG. 2 is a system diagram of an apparatus using the present invention in combination with high-speed liquid circulation, and FIG. FIG. 4 is a cross-sectional view when a seed-shaped stirring blade and a sawtooth-shaped stirring blade are respectively installed in a disc-shaped filter as another embodiment of the present invention. FIG. 5(a)(t)1 is a chart comparing the change in the differential pressure before and after the filter with respect to the continuous operation processing time of the filtration apparatus of the present invention and the conventional technology. 1a, 1b, ic...liquid supply port, 2a, 2b, 2c...
...Liquid discharge port, 3a, 3b, 3C--Furnace material, 4a, 4
k). 4C... Stirring blade, 5a, 5b, 5c... Filter housing, 6... Jacket, 7... Commercial pressure type seal, 8... Flow meter, 9... Automatic pulp, 10...
・Liquid supply tank, 11°...Stock tank. (a) Time (minutes) Figure 5 (b) Shoranukiginmagin)

Claims (1)

[Claims] In a continuous type filter that removes foreign substances while continuously pumping a magnetic liquid using a pump, etc., a stirrer is installed close to the surface of the filter medium in the filter housing and has stirring blades that rotate along the surface of the filter medium. A magnetic liquid filtration device featuring: