JPH037122B2 - - Google Patents
Info
- Publication number
- JPH037122B2 JPH037122B2 JP57026082A JP2608282A JPH037122B2 JP H037122 B2 JPH037122 B2 JP H037122B2 JP 57026082 A JP57026082 A JP 57026082A JP 2608282 A JP2608282 A JP 2608282A JP H037122 B2 JPH037122 B2 JP H037122B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- magnetic fluid
- magnetic field
- fluid
- strength
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000011553 magnetic fluid Substances 0.000 claims description 38
- 230000005291 magnetic effect Effects 0.000 claims description 31
- 238000000034 method Methods 0.000 claims description 9
- 230000005294 ferromagnetic effect Effects 0.000 claims description 7
- 239000003302 ferromagnetic material Substances 0.000 claims description 3
- 238000007670 refining Methods 0.000 claims description 3
- 239000012530 fluid Substances 0.000 claims 1
- 239000002245 particle Substances 0.000 description 13
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 8
- 238000000746 purification Methods 0.000 description 7
- 238000012856 packing Methods 0.000 description 6
- 239000011362 coarse particle Substances 0.000 description 5
- 229910052742 iron Inorganic materials 0.000 description 4
- 230000005415 magnetization Effects 0.000 description 4
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 230000002269 spontaneous effect Effects 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000005119 centrifugation Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 239000002612 dispersion medium Substances 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 239000000945 filler Substances 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 239000006249 magnetic particle Substances 0.000 description 2
- 239000013049 sediment Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- NBVXSUQYWXRMNV-UHFFFAOYSA-N fluoromethane Chemical compound FC NBVXSUQYWXRMNV-UHFFFAOYSA-N 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000003350 kerosene Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229920002545 silicone oil Polymers 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 235000015112 vegetable and seed oil Nutrition 0.000 description 1
- 239000008158 vegetable oil Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Lubricants (AREA)
- Soft Magnetic Materials (AREA)
- Compounds Of Iron (AREA)
- Sealing Material Composition (AREA)
Description
この発明は磁性流体の精製方法に関するもので
ある。
磁性流体は粉砕または湿式合成法によつて得ら
れたマグネタイト或いは鉄以外の金属を含むフエ
ライトの微粒子を炭化水素、エステル類、シリコ
ーンオイル、フツ化炭素、植物油又は水等の液体
に安定分散されたもので、回転軸のシール、比重
差分離、磁性インク、スピーカー用ダンパその他
に用いられており、いずれも強い磁場中で使用さ
れる点が共通している。したがつて磁性流体中に
磁場で凝集したり、沈降したりし易い粒子が含ま
れると、沈降物の堆積と磁性粒子濃度の低下が起
り好ましくない。
一般に強磁性体粒子は、粒径のある限界値以下
では磁化履歴（ヒステリシス）現象を示さず、所
謂超常磁性の挙動を示すが、その限界値以上の粒
径になると自発磁化を示す。磁性流体中に自発磁
化をもつた粒子が含まれると、磁気凝集を起す原
因となる。また自発磁化を有し得ない粒径の粒子
であつても、磁気力或いは重力による沈降速度を
考慮すると粒径は小さい方が望ましい。
粉砕法もしくは湿式合成法によつて得られたマ
グネタイト或いは鉄以外の金属を含むフエライト
微粒子は一般に広い粒度分布をもつており、安定
な磁性流体を得るためには、これらの粒子を分散
媒中に分散させた後に精製を行うのが普通の方法
である。
従来より行われてきた磁性流体の精製方法はそ
のほとんどの遠心分離によるものである。しかし
遠心分離法は磁性流体中から粗大な粒子を分離除
去する効果的な方法であるが、設備が高価である
こと、運転に多くの動力を要すること、運転に長
時間を要することに加えて連続的操業が困難であ
ること等の欠点があり、磁性流体の生産に要する
費用を引き上げる一因となつている。
一方、特開昭56−163169号公報には“磁性イン
クの精製方法″と題した磁性流体の精製方法が開
示されているが、これは集中磁界を多数の永久磁
石により磁性板の下部から加え、該磁性板を傾け
てその上に磁性流体を硫化させるものであるた
め、磁性流体の精製に長時間を要する。
この発明は上記実情に鑑み、簡便且つ迅速に磁
性流体を精製することができる方法を開発する目
的で鋭意研究の結果、非強磁性体容器に強磁性体
充填物を充填し、これを磁場中に置いて磁性流体
を通じると、磁性流体中の粗大な粒子が充填物に
吸引付着され、急速に分離除去されて磁性流体の
精製が行われることを見出したものである。
そしてこの発明によれば充填物の形状、磁場の
強さ、および通過させる磁性流体の流速を適当に
選択することにより例えば比較的低磁場中で使用
される磁性流体では、分散安定性の悪い粗大粒子
だけを分離除去すればよいで、本発明における磁
場の強さを低くし、通過させる磁性流体の速度も
速くてよい。また、高磁場中で使用される磁性流
体では、無磁場中或いは低磁場中では安定に分散
するような一定粒径以上の磁性粒子も凝集し易く
なるので、この一定粒径以上の磁性粒子を分離除
去するために本発明における磁場の強さを高く
し、通過させる磁性流体の速度も遅くすればよ
い。さらに、高磁場中で使用され、且つ細管など
に使用される磁性流体は、より高い精製精度を求
められるので、本発明における磁場の強さをより
高くし、通過させる磁性流体の速度より遅くすれ
ばよい。しかも運転は完全に連続的に行うことが
できる。また磁場を取り除いたり、或いは遮断す
ることにより充填物は吸引付着機能を失つて粗大
粒子が脱離するので、溶剤洗浄等により容易に洗
浄再生することができる。
以下、図示の実施例に基いてこの発明を説明す
ると、１は磁性流体を通過させる非強磁性体容器
であつて、非強磁性体容器１は両端を開口して一
端には磁性流体注入口２、他端には流量調製バル
ブ３を介して磁性流体流出口４を設け、更に中央
部には充填室５を設けるとともに、該充填室５内
には強磁性体充填物６を充填し、更に充填物６の
両端にはフイルター７ａ，７ｂを設ける。
なお充填物６としては鉄、コバルト、ニツケル
等の強磁性金属単体もしくは合金、強磁性酸化物
等の粉末、網状、球状、棒状或いは繊維状にした
もの等が良好な性能をもたらす。
以上のように構成される非強磁性体容器１は例
えば充填室５内を磁性流体が流化するように縦方
向に設置するとともに、充填室５の外側には電磁
石もしくは永久磁石等の磁石７，７を対向状に設
置し、磁性流体は注入口２より注入し、充填物６
間を通過させる。
このようにすると、強磁性体で構成される充填
物６は磁石７，７により磁化されているため、磁
性流体は充填物６の間隙を通過する間に、その中
に含まれる粒径の大きなもの等は充填物６の表面
に吸引、付着して磁性流体より分離される。した
がつて磁性流体は精製された状態で流出口４より
流出される。
なおこの発明において磁場源は永久磁石、電磁
石いずれも有効であるが、例えば電磁石を用いる
と、容易に磁界の強さを変化させることができ、
また、磁場を遮断して充填物を洗浄することによ
り吸着物を容易に除去することができる。
次に、ケロシンを分散媒とし、マグネタイトを
分散質とした粗製磁性流体をこの発明による方法
で精製した結果を示す。精製結果は、この発明に
より精製した原試料中の固型分濃度と原試料を更
に超遠心分離（30000G）に30分間かけて粗大粒
子を沈降させて得られた磁性流体中の固型分濃度
の差、即ち粗大粒子濃度をもつて表わした。
第１表は磁場の強さ（Oe）を変化させた場合
の精製結果を示すもので、充填物は平均径30μの
鉄繊維を充填度150ｇ／で用い、充填層中の磁
性流体の平均流速は0.5cm／secとし、磁場の強さ
は充填容器を取り外した時の向き合つた両磁極
（永久磁石）の中心を結ぶ線の中間点で測定した
ものである。
The present invention relates to a method for purifying magnetic fluid. Magnetic fluid is made by stably dispersing fine particles of magnetite or ferrite containing metals other than iron, obtained by crushing or wet synthesis, in a liquid such as hydrocarbons, esters, silicone oil, fluorocarbon, vegetable oil, or water. It is used in seals for rotating shafts, specific gravity separation, magnetic ink, dampers for speakers, etc., and all have in common that they are used in strong magnetic fields. Therefore, if particles that tend to aggregate or settle in a magnetic field are included in the magnetic fluid, this is undesirable because sediment will accumulate and the concentration of magnetic particles will decrease. In general, ferromagnetic particles do not show a magnetization history (hysteresis) phenomenon when the particle size is below a certain limit value and exhibit so-called superparamagnetic behavior, but when the particle size exceeds the limit value, they exhibit spontaneous magnetization. When particles with spontaneous magnetization are included in the magnetic fluid, it causes magnetic aggregation. Furthermore, even if the particle size is such that it cannot exhibit spontaneous magnetization, it is desirable that the particle size be small in consideration of the sedimentation rate due to magnetic force or gravity. Magnetite or ferrite fine particles containing metals other than iron obtained by pulverization or wet synthesis generally have a wide particle size distribution, and in order to obtain a stable magnetic fluid, these particles must be placed in a dispersion medium. The usual method is to perform purification after dispersion. Most conventional methods of purifying magnetic fluids are based on centrifugation. However, although centrifugation is an effective method for separating and removing coarse particles from magnetic fluids, it requires expensive equipment, requires a lot of power to operate, and takes a long time to operate. There are drawbacks such as difficulty in continuous operation, which is one of the reasons for increasing the cost required to produce magnetic fluids. On the other hand, JP-A-56-163169 discloses a method for purifying magnetic fluid entitled "Method for Purifying Magnetic Ink," which involves applying a concentrated magnetic field from the bottom of a magnetic plate using a large number of permanent magnets. Since the magnetic plate is tilted and the magnetic fluid is sulfurized thereon, it takes a long time to purify the magnetic fluid. In view of the above circumstances, this invention was developed as a result of intensive research for the purpose of developing a method that can easily and quickly purify magnetic fluid. It has been discovered that when the magnetic fluid is passed through the magnetic fluid, coarse particles in the magnetic fluid are attracted to the packing and are rapidly separated and removed, thereby purifying the magnetic fluid. According to the present invention, by appropriately selecting the shape of the packing, the strength of the magnetic field, and the flow rate of the magnetic fluid to be passed through, for example, the magnetic fluid used in a relatively low magnetic field can be used in a coarse manner with poor dispersion stability. It is only necessary to separate and remove particles, and the strength of the magnetic field in the present invention may be low, and the speed of the magnetic fluid passed may be high. In addition, in magnetic fluids used in high magnetic fields, magnetic particles with a certain particle size or more that are stably dispersed in no magnetic field or in a low magnetic field tend to aggregate. In order to separate and remove the particles, the strength of the magnetic field in the present invention may be increased and the speed of the magnetic fluid passed may be reduced. Furthermore, since the magnetic fluid used in a high magnetic field and used in thin tubes etc. requires higher purification precision, the strength of the magnetic field in the present invention is made higher and the speed of the magnetic fluid to be passed is lower than that of the magnetic fluid. Bye. Moreover, the operation can be carried out completely continuously. Furthermore, by removing or blocking the magnetic field, the filling loses its suction and adhesion function and the coarse particles are detached, so it can be easily washed and regenerated by solvent washing or the like. The present invention will be described below based on the illustrated embodiment. Reference numeral 1 is a non-ferromagnetic container through which a magnetic fluid passes, and the non-ferromagnetic container 1 has both ends open and one end has a magnetic fluid inlet. 2. A magnetic fluid outlet 4 is provided at the other end via a flow rate adjustment valve 3, and a filling chamber 5 is provided in the center, and the filling chamber 5 is filled with a ferromagnetic material filling 6. Furthermore, filters 7a and 7b are provided at both ends of the packing 6. As the filler 6, ferromagnetic metals such as iron, cobalt, nickel, etc. alone or alloys, powders of ferromagnetic oxides, etc., or those in the form of nets, spheres, rods, or fibers provide good performance. The non-ferromagnetic container 1 configured as described above is installed vertically, for example, so that the magnetic fluid flows inside the filling chamber 5, and a magnet 7 such as an electromagnet or a permanent magnet is placed outside the filling chamber 5. , 7 are installed facing each other, the magnetic fluid is injected from the inlet 2, and the filling 6
pass between. In this way, since the filling 6 made of ferromagnetic material is magnetized by the magnets 7, 7, while the magnetic fluid passes through the gap of the filling 6, the large particles contained therein are The objects are attracted and attached to the surface of the filler 6 and are separated from the magnetic fluid. Therefore, the magnetic fluid is discharged from the outlet 4 in a purified state. In this invention, both permanent magnets and electromagnets are effective as the magnetic field source, but for example, if an electromagnet is used, the strength of the magnetic field can be easily changed.
Moreover, the adsorbed matter can be easily removed by cutting off the magnetic field and washing the filling. Next, the results of purifying a crude magnetic fluid using kerosene as a dispersion medium and magnetite as a dispersoid using the method according to the present invention will be shown. The purification results are the solid content concentration in the original sample purified by this invention and the solid content concentration in the magnetic fluid obtained by further ultracentrifuging the original sample (30000G) for 30 minutes to sediment coarse particles. The difference is expressed as the coarse particle concentration. Table 1 shows the refining results when the strength of the magnetic field (O e ) was changed. Iron fibers with an average diameter of 30μ were used as the packing at a packing degree of 150g/, and the average amount of magnetic fluid in the packed bed was The flow rate was 0.5 cm/sec, and the strength of the magnetic field was measured at the midpoint of the line connecting the centers of the two opposing magnetic poles (permanent magnets) when the filled container was removed.
【表】
以上の結果より明らかな如く、磁場の強さに比
例して精製度の向上が見られる。
第２表は第１表と同様な方法で同一試料につい
て流速のみを変化させて行なつた精製試験の結果
である。なお磁場の強さは3450Oeである。
第３表は第２表の同様な方法で、同一試料につ
いて充填物を交換して行なつた精製試験の結果で
ある。なお磁場の強さは3450Oe、平均流速0.5
cm／secである。[Table] As is clear from the above results, the degree of purification is improved in proportion to the strength of the magnetic field. Table 2 shows the results of a purification test conducted on the same sample in the same manner as in Table 1 by varying only the flow rate. The strength of the magnetic field is 3450O e . Table 3 shows the results of a purification test conducted on the same sample using the same method as in Table 2, but with different packings. The strength of the magnetic field is 3450O e and the average flow rate is 0.5
cm/sec.
【表】【table】
図面はこの発明に使用する精製装置の概略図で
ある。
The drawing is a schematic diagram of a purification apparatus used in this invention.
Claims (1)
ことのできる構造を有する非強磁性体容器内に充
填して該容器を磁場の強さを可変とした磁場中に
置き、容器内に設けた充填物内に磁性流体を通過
させ、磁場の強さ及び通過する磁性流体の流速を
選択することにより、精製精度を可変としたこと
を特徴とする磁性流体の精製方法。1 A filling made of ferromagnetic material is filled in a non-ferromagnetic container having a structure that allows fluid to pass through, and the container is placed in a magnetic field with variable magnetic field strength. A method for refining a magnetic fluid, characterized in that the refining accuracy is made variable by passing the magnetic fluid through a filling and selecting the strength of the magnetic field and the flow rate of the passing magnetic fluid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2608282A JPS58145623A (en) | 1982-02-22 | 1982-02-22 | Purification of magnetic fluid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2608282A JPS58145623A (en) | 1982-02-22 | 1982-02-22 | Purification of magnetic fluid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58145623A JPS58145623A (en) | 1983-08-30 |
| JPH037122B2 true JPH037122B2 (en) | 1991-01-31 |
Family
ID=12183698
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2608282A Granted JPS58145623A (en) | 1982-02-22 | 1982-02-22 | Purification of magnetic fluid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58145623A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8475985B2 (en) * | 2005-04-28 | 2013-07-02 | Xerox Corporation | Magnetic compositions |
| CN102976414B (en) * | 2012-11-22 | 2015-01-07 | 云南云天化股份有限公司 | Preparation method of silicone oil nano iron oxide suspension |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5344970A (en) * | 1976-10-06 | 1978-04-22 | Nittetsu Mining Co Ltd | Method of collecting dispersoid in dilute water base magnetic fluid |
| JPS56163169A (en) * | 1980-05-20 | 1981-12-15 | Matsushita Electric Ind Co Ltd | Purifying method for magnetic ink |
-
1982
- 1982-02-22 JP JP2608282A patent/JPS58145623A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5344970A (en) * | 1976-10-06 | 1978-04-22 | Nittetsu Mining Co Ltd | Method of collecting dispersoid in dilute water base magnetic fluid |
| JPS56163169A (en) * | 1980-05-20 | 1981-12-15 | Matsushita Electric Ind Co Ltd | Purifying method for magnetic ink |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58145623A (en) | 1983-08-30 |
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