JP2640901B2 - Liquid filtration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid, such as a cleaning liquid, an organic solvent, a cutting liquid, oil, or water, containing impurities such as fine particles and oil. The adsorbent consisting of the granular or powdered material is passed through the gap between the particles, the distance between the impurity particles is reduced to the distance where the impurity particles are aggregated, and the impurities are aggregated. The present invention relates to a liquid filtration apparatus in which each of impurity particles is filtered through a sufficiently coarse filter layer after being formed into a large mass.

[0002]

FIG. 9 shows a conventional apparatus. In the figure, the liquid flowing into the container 10 from the inflow port 10 a is connected to the first mesh electrode 15 a of the electrode cassette 15 and the container 10.
When a voltage is applied between the electrodes, the impurity particles in the liquid are electrostatically agglomerated and become larger, and those larger than the mesh of the first mesh electrode 15a are filtered by the first mesh electrode 15a. The adsorbent 3 such as activated clay, zeolite, or activated carbon stored in the cassette 15 is reached. Since the adsorbent 3 is surrounded by the first and second mesh electrodes 15a and 15b, its surface potential rises to the voltage applied to the first mesh electrode 15a and dramatically increases the electrostatic adsorption force. To electrostatically adsorb the impurity particles in the liquid. In addition, the impurity particles which have passed through the adsorbent 3 and become electrostatically agglomerated accumulate on the outer periphery of the coarse filter 4, are cake-filtered, and then flow out of the outlet 10 b to the outside of the container 10. I do.

[0003]

The conventional apparatus is constructed as described above, and uses activated clay, zeolite and activated carbon as the adsorbent 3. These have a large number of holes on the surface, and only when the impurity particles come into strong contact with the holes, the impurity particles are taken into the holes and adsorbed and removed. For this reason, there is a problem that most of the impurity particles do not come into strong contact with the surface of the adsorbent 3 due to the flow velocity of the liquid, and are not directly absorbed and removed. In addition, the impurity particles that have passed through are in a state of being individually separated from each other, and there is a problem that there is no ability to aggregate these impurity particles into a large lump. Further, when the conventional adsorbent 3 is to be provided with an aggregating ability, the adsorbent 3 itself is made into, for example, ultrafine particles of 0.1 μm or less, and a liquid is caused to flow through a gap between the ultrafine particles, so that the There is no method other than to make the distance between the impurity particles extremely small and to aggregate the impurity particles. However, when the adsorbent 3 itself is made of ultrafine particles, the gap between the ultrafine particles becomes extremely small, and the adsorbent 3 itself is immediately clogged, and there is a problem that the adsorbent 3 cannot be used at all. Further, a precoat filter using activated clay or the like is commercially available, but generally, oil is mixed with fine particles in a liquid to be purified. Activated clay itself absorbs oil, so it becomes sticky, does not disperse evenly in the liquid, pre-coating is not performed well, and sticky activated clay etc. gets into the eyes of the filter, Clogged and unusable. That is, there was a problem that it was not possible to simultaneously purify both the fine particles and the oil in the liquid. Furthermore,
A method has been proposed in which magnesium hydroxide is used as the adsorbent 3 to adsorb and remove the oil component and the surfactant from the magnesium hydroxide. However, commercially available magnesium hydroxide is a needle-like fiber having a size of 30 μm. When this fiber is used as the adsorbent 3, the gap between the magnesium hydroxides is very narrow, and the magnesium hydroxide is immediately clogged and cannot be used at all. There were challenges. Magnesium hydroxide absorbs and removes an oil component and a surfactant having a weight of one-half its own weight, but immediately saturates. Therefore, it is necessary to frequently replace magnesium hydroxide.
There was a problem that could not be used.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and comprises a granule formed by assembling crystalline magnesium fibers as an adsorbent.
Alternatively, using a powdery material, the liquid is passed through the gap between the adsorbents, and the distance between the fine particles in the liquid and the impurity particles such as oil is reduced to a distance at which the respective impurity particles aggregate with each other, The impurity particles are aggregated to form a large mass. When the impurities are fine particles, the large impurity particles are filtered through a sufficiently coarse filter layer for each impurity particle. On the other hand, if the impurities are oil, even if the oil becomes a large lump, it will be pushed and elongated by the pump, and will pass through the coarse filtration layer. It is an object of the present invention to provide a liquid filtration device adapted to collect.

[0005]

[Means for Solving the Problems]

The invention of claim 1 is provided with an adsorbent which is provided between a first filtration layer and a second filtration layer, and is composed of a granular material or a powder material formed by assembling magnesium crystalline fibers, The liquid is passed through the inter-gap of the adsorbent through the first filtration layer, the distance between the impurity particles in the liquid is reduced to a distance where the impurity particles are aggregated with each other,
After the impurity particles are aggregated to form a large lump, the individual impurity particles are filtered through the second filter layer, which is sufficiently coarse.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a side sectional view showing one embodiment of the present invention.
In the figure, a first cylindrical body 1 that is a first filtration layer has:
For example, the first tubular body 1a is formed of a resin such as polypropylene or plastic, and is formed in a porous body or a mesh body, and is made of, for example, synthetic paper attached to the first tubular body 1a. First mesh or filter 1
b. The second cylindrical body 2 is installed coaxially with the first cylindrical body 1 and is made of, for example, a resin such as polypropylene or plastic, and is formed in a porous body or a mesh-like body. It comprises a second tubular body 2a having a smaller diameter than the body 1a, and a second mesh body or a filter-like body 2b made of, for example, synthetic paper attached to the second tubular body 2a. And the second cylindrical body 2
A blind portion 2c made of, for example, a plate-like body is provided at the upper end portion of “a”. The adsorbent 3 is accommodated between the first cylindrical body 1 and the second cylindrical body 2, and is made of, for example, a granular body or a powdery body formed by assembling crystalline magnesium fibers. The filter 4 as the second filtration layer is, for example, a cylindrical body, is installed in a hollow portion of the second cylindrical body 2 so as to be replaceable, and is in contact with the inner peripheral surface of the second cylindrical body 2. hand,
The strength of the second cylindrical body 2 is reinforced. The cylindrical electrode 5 is formed of a porous body or a mesh-like body, and is installed coaxially with the first cylindrical body 1 so as to house the first cylindrical body 1. The supporting member 6 is made of, for example, an insulating material, and integrally supports the first cylindrical body 1, the second cylindrical body 2, the filter 4, and the cylindrical electrode 5. The holding plate 7 integrally presses and supports the first cylindrical body 1, the second cylindrical body 2, and the filter 4 on the support plate 6. The spring receiver 8 is provided on the hollow shaft core of the filter 4 and closes the upper end opening of the hollow part of the filter 4.
The spring 9 is installed on the spring receiver 8, and presses the spring receiver 8 against the upper end surface of the filter 4 by the holding plate 7. The container 10 includes a container portion 10c having an inlet 10a and an outlet 10b, and a lid 10e having an air vent 10d. The support plate 1 for supporting the support material 6 is provided at the outlet 10b.
0f is attached. The spring 11 holds the holding plate 7
And is pressed by the lid 11e to press the holding plate 7. The electrode 12 contacts the cylindrical electrode 5 and applies a voltage between the cylindrical electrode 5 and the container 10.

Next, this operation will be described with reference to FIG. Figure 2 shows the potential property curve, the repulsive force P ₁ and the attraction P ₂ on the vertical axis, taking impurity particles A, the inter-particle distance L B on the horizontal axis. When the impurity particles A and B are mixed in the liquid,
The potential of the liquid molecules around the impurity particles A and B,
A zeta potential is generated around the impurity particles A and B due to a potential difference from the potentials of the impurity particles A and B themselves. The impurity particles other than the metal have a negative potential and are repelled by the zeta potential of the negative potential, and the repulsive force P ₁ is 0 at the distance L ₁ .
It is stable. In this state, joined by some kind of force, the impurity particles A, the closer the distance between B, and repulsive force P ₁ as curve i in FIG. 2 is increased, the distance L
It approaches to ₂ or less, cause the aggregation working attractive force P _2. When the liquid is oil, to apply high voltage DC450V,
Both the oil molecules and the impurity particles A and B have a DC voltage of 450 V, the zeta potential is cancelled, and aggregation occurs immediately as shown by the characteristic curve iii in FIG. When the liquid is water-based, oxygen gas is generated when the energizing current value exceeds 10 mA, and hydrogen gas is generated when the energizing current value exceeds 23 mA. Therefore, for example, only low voltage DC2V can be applied. At DC2V, there is no big difference from earth potential.
Aggregation does not occur as shown by the characteristic curve ii in FIG. In order to cause agglomeration under any conditions, the distance L between the impurity particles A and B is adjusted by the action of the special adsorbent 3.
If the distance L ₂ or less, it is possible to cause agglomeration without application of voltage.

The adsorbent 3 of the embodiment shown in FIG. 1 is a special adsorbent satisfying the above conditions, and is composed of a granular material or a powdery material formed by assembling crystalline magnesium fibers.
The liquid is passed through the gap between the adsorbents 3 so that the distance between the impurity particles A and B is reduced to a distance at which the impurity particles A and B aggregate. That is, the impurity particles A, the distance B, by approximating the following distance L ₂ shown in FIG. 2, the impurity particles A, to aggregate B cross, after the big lumps hundreds of impurities particles A, B each Is filtered through a sufficiently coarse filter 4. Therefore, the adsorbent 3 is a special substance which causes a completely different phenomenon from the conventional activated clay, zeolite, activated carbon, and magnesium fiber alone.

That is, activated clay, zeolite,
An adsorbent such as activated carbon has a large number of holes on its surface, and only when the impurity particles come into contact with the holes strongly, the impurity particles are taken into the holes to be adsorbed and removed. For this reason, most of the impurity particles do not come into strong contact with the surface of the adsorbent due to the flow rate of the liquid, and are not adsorbed and removed as they are. Also, the impurity particles that passed through
It is in a discrete state and does not cause any agglutination. When magnesium crystalline fiber alone is used as an adsorbent, since the crystalline fiber itself is about 30μ, the gap between them is very narrow, causing immediate clogging, and it can be used as an adsorbent at all. Absent. Further, the magnesium crystalline fiber alone has a property of absorbing and removing an oil component mixed in the liquid by の of its own weight.
However, since it becomes saturated immediately, it is necessary to frequently replace the crystalline magnesium fiber alone, and it cannot be used as an adsorbent at all.

On the other hand, in the case of the adsorbent 3 composed of a granular material or a powdery material constituted by assembling magnesium crystalline fibers of the present invention, the particle size is about 250 μm,
Infinite gaps of about μ are formed. Therefore, the fine particles hardly clog the adsorbent 3, and when the liquid passes through the gap between the adsorbents 3, the fine particles in the liquid and the emulsified oil coagulate. All issues will be resolved. Note that the adsorbent 3 of the present application also has the property of absorbing and removing half of the oil of its own weight and, after saturation, agglomerating and extruding the oil.

One example of a method for producing the adsorbent 3 containing magnesium as a main component is to react magnesium luteate and magnesium hydroxide in the presence of a special phosphate to produce fibrous crystals by a hydrothermal reaction. The adsorbent 3 thus configured has a pilling shape of about 250 μ in which fibers of about 30 μ are entangled, and the surface thereof is in a state where fibers of 10 μ to 15 μ project innumerably. Therefore, the innumerable adsorbents 3 housed between the first cylindrical body 1 and the second cylindrical body 2 form an innumerable inter-gap of about 50 μ, and 10 μ to 15 μ fibers are present in the inter-gap. It is in a state protruding countlessly. When the liquid passes through the gap between the adsorbents 3, the impurity fine particles A and B in the liquid and the oil of about 1 μm which has been emulsified and mixed into the liquid are absorbed by the adsorbent 3 itself and adsorbed. The fibers are entangled with the fibers of 10 μ to 15 μ protruding from the surface of the agent 3, and the distance between them becomes less than the distance L ₂ shown in FIG. The oil mixed into the liquid is initially absorbed and removed by the adsorbent 3 by the adsorbent 3 as described above, but when the absorption is saturated, the above-mentioned coagulation action is performed and the oil is removed. Extrude into large chunks. The components of the adsorbent 3 are, for example, in terms of% by weight, basic magnesium sulfate> 94%, magnesium hydroxide <6%, magnesium sulfate <0.5%, and basic magnesium sulfate: 85% to 98%. , Magnesium hydroxide: 1% to 10%, magnesium sulfate:
0.1% to 1% is appropriate.

In the embodiment shown in FIG. 1, the liquid flowing into the container 10 from the inlet 10a reaches the adsorbent 3 through the cylindrical electrode 5 and the first cylindrical body 1. When the liquid passes through the adsorbent 3, the fine particles in the liquid, the impurity particles such as oil, and the like, have a distance between each other due to the action of the special adsorbent 3.
Aggregate close to the distance L ₂ less shown in, the large lumps hundreds of. When the impurity particles are fine particles, the large agglomerated impurity particles accumulate on the outer peripheral surface of the filter 4 which is sufficiently coarse for each of the impurity particles, and are cake-filtered. On the other hand, when the impurity particles are oil, even if they become a large mass, they are elongated and deformed, and pass through the filter 4 together with the liquid. Like this
The liquid from which the fine particles are filtered by the filter 4 flows out of the container 10 from the outlet 10b together with the oil that has become a large lump,
Return to the liquid tank. The oil returned to the liquid tantalum floats on the liquid surface due to the difference in specific gravity and is collected. In addition, the replacement of the adsorbent 3 and the filter 4 is performed by taking out the first cylindrical body 1 and the second cylindrical body 2 together with the support member 6 and the holding plate 7 out of the container 10.
Dispose of with. Further, the adsorbent 3 has a fiber ball shape of about 250 μ in which fibers of about 30 μ are intertwined, and the surface thereof is in a state in which fibers of 10 μ to 15 μ protrude innumerably. For this reason, when the adsorbent 3 is wetted by the liquid and pressure is applied, 50
Infinitely protruding fibers having a size of 10-15 μm are crushed in the gap of about μ, the mutual gap between the adsorbents 3 is reduced, and the volume of the adsorbent 3 as a whole is reduced and reduced. Due to this reduction in volume, a case occurs where a cavity is formed above the adsorbent 3 and the liquid does not pass through the adsorbent 3. For this reason, the blind portion 2c is provided, and even if the adsorbent 3 is reduced and the liquid flows through the cavity formed on the blind portion 2c, the liquid does not directly reach the filter 4 due to the blind portion 2c and the liquid is adsorbed. 3 is prevented from passing through. Furthermore, as a countermeasure against loss of the adsorbent 3, if the granular material having a specific gravity close to that of the adsorbent 3, such as polypropylene, cork, and activated carbon, is mixed, the loss can be improved. The mixing volume ratio is as follows: adsorbent: contaminant = 1 to 1
0.5: 5 is desirable. Further, when polypropylene is mixed, the adsorbent 3 can be prevented from being reduced by heat fusion with the adsorbent 3. In this case, the blind part 2c can be omitted.

FIG. 3 shows another embodiment of the present invention. That is, in the embodiment shown in FIG.
And a voltage was applied between the cylindrical electrode 5 and assisted the cohesive action of the adsorbent 3, but in the embodiment of FIG. 3, the cylindrical electrode 5 was omitted,
No voltage is applied, and the impurity particles in the liquid are agglomerated only by the action of the adsorbent 3.

FIG. 4 shows still another embodiment of the present invention. That is, in the embodiment of FIG. 4, the first and second cylindrical bodies 1 and 2 and the adsorbent 3 are integrated into a cassette by the support member 6 and the pressing member 13, and the exchange of the adsorbent 3 is performed. It is a more simplified one.

FIG. 5 shows still another embodiment of the present invention. In FIG. 5, the third cylindrical body 14 is made of a porous body such as expanded metal or a mesh-like body, and is installed in contact with the inner peripheral surface of the second cylindrical body 2. Is to reinforce the strength. That is, in each of the embodiments of FIGS. 1, 3 and 4, the strength of the second cylindrical body 2 is reinforced by providing the filter 4 in contact with the inner peripheral surface of the second cylindrical body 2. In the embodiment of FIG. 5, the third cylindrical body 1
4, the strength of the second cylindrical body 2 is reinforced. Note that the filter 4 is housed in the third cylindrical body 14 in a replaceable manner.

FIG. 6 shows still another embodiment of the present invention.
In the embodiment of FIG. 6, the adsorbent 3 and the filter 4 are integrated into a cassette, and the second cylindrical body 2 is omitted. In this case, as a countermeasure against loss due to a decrease in the volume of the adsorbent 3, the upper end of the filter 4 is, for example, 2 cm from the upper end.
A tape of, for example, polypropylene or the like is wound over about 10 cm to prevent the liquid from reaching the filter 4 without passing through the adsorbent 3.

FIG. 7 shows still another embodiment of the present invention.
In the embodiment shown in FIG. 7, the adsorbent 3, the filter 4, and the cylindrical electrode 5 are integrally made into a cassette. Also in this case, similarly to the embodiment of FIG. 6, a measure for reducing the amount of the adsorbent 3 can be taken.

FIG. 8 shows an example of purifying waste liquid using the embodiment of FIG. The vertical axis indicates the scale of 0 to 10, and the horizontal axis indicates the purification time. The liquid to be purified is a coolant for a machine tool used for iron grinding, Matsumura Sekiyu: M Cool, capacity: 150
1, purification circulation flow rate: 50 l / min. In addition, how to read the scales 0 to 10 on the vertical axis is as follows. Test Results a, Fine particles were removed, and the emulsified oil was flocculated and separated by flotation. b. In the measurement of the concentration, the amount of mixed oil was large, and it was not possible to measure until 1 hour. However, after 2 hours, the oil was separated and removed, so that the concentration could be measured. became. c, The total number of bacteria was reduced and the odor was eliminated.

The adsorbent 3 may be manufactured by any method.

[0020]

As described above,

According to the first aspect of the present invention, as an adsorbent, a granular material or a powdery material formed by assembling crystalline magnesium fibers is used, and a liquid is passed through the gap between the adsorbents. The distance between the fine particles in the liquid and the impurity particles such as oil is brought close to the distance at which the respective impurity particles aggregate, and the impurity particles are aggregated into a large lump. The resulting impurity particles are filtered through a sufficiently coarse filter layer for each impurity particle. On the other hand, if the impurities are oil, even if the oil becomes a large lump, it will be pushed and elongated by the pump, and will pass through the coarse filtration layer. , It is possible to remove ultra-fine particles mixed in the liquid and oil which has been emulsified and mixed, and to process several hundreds of ultra-fine particles individually. Ultra-fine particles can be removed by the twice coarser filtration layer, and clogging of the filtration layer is extremely reduced.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of a liquid filtration device according to the present invention.

FIG. 2 is a potential energy characteristic diagram illustrating the operation of FIG.

FIG. 3 is a side sectional view showing another embodiment of the liquid filtration device according to the present invention.

FIG. 4 is a side sectional view showing still another embodiment of the liquid filtration device according to the present invention.

FIG. 5 is a side sectional view showing still another embodiment of the liquid filtration device according to the present invention.

FIG. 6 is a side sectional view showing another embodiment of the cassette used in the liquid filtering device according to the present invention.

FIG. 7 is a side sectional view showing still another embodiment of the cassette used in the liquid filtering device according to the present invention.

8 is a purification characteristic curve diagram showing an example of purification of waste liquid using the liquid filtration device of the embodiment of FIG.

FIG. 9 is a side sectional view showing a conventional liquid filtering device.

[Explanation of symbols]

 1: 1st cylindrical body 1a: 1st cylindrical body 1b: 1st mesh-like body or filter-like body 2: 2nd cylindrical body 2a: 2nd cylindrical body 2b: 2nd Reticulated or filtered 3: adsorbent 4: filter 10: container

Claims (1)

(57) [Claims] 1. The method according to claim 1, wherein the first filter layer and the second filter layer are provided between the first filter layer and the second filter layer.
Condyles composed of crystalline magnesium fibers
A particulate material, or an adsorbent in a powder state , wherein a liquid is passed between the adsorbents through the first filtration layer.
Through the gap, the distance between the impurity particles in the liquid,
Approaching the distance that the impurity particles aggregate with each other,
After the impurity particles are aggregated to form a large lump,
A liquid filtration apparatus characterized in that each of the pure particles is filtered through the second filter layer, which is sufficiently coarse .