JP7042482B2 - Filtration device and filtration method - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Law Announced at the 20th Anniversary Event of the Kinki Branch of the Simple Spraying Law Frame Association held at the Nisshoku Research Field on November 25, 2016.

Patent Law Article 30 Paragraph 2 Applicable December 20, 2016 Dosan Line Tsubojiri-Hashikura 32k760m Slope improvement work, test implementation for performance verification

The present invention relates to, for example, a filtration device and a filtration method for removing an admixture from a fluid such as cement sewage containing an admixture (specifically, cement washing water (sludge water), wastewater from a concrete factory, etc.). ..

At construction sites where cement is used, cement sewage (sewage containing cement) is generated as the tools are washed. If this cement sewage is poured directly into a drainage ditch or the like, it may cause clogging.

Therefore, for example, it is conceivable to use a filter using a filter cloth disclosed in Patent Document 1 for purifying cement sewage.

Japanese Unexamined Patent Publication No. 2006-305468

However, cement sewage often contains an admixture such as a water reducing agent, and most of the admixtures (chemical admixtures for concrete) currently on the market may contain a surfactant as a main component. In a filter, the filter cloth is quickly clogged by an admixture that adsorbs to cement particles or disperses in cement sewage, and the amount of cement sewage that can be filtered is limited to a small amount, resulting in poor filtration efficiency. There's a problem. It is also considered that the dispersion effect of the admixture disperses the colored particles in the sewage, making it difficult to filter with a filter cloth.

The present invention has been made with the above-mentioned matters in mind, and an object of the present invention is to provide a filtration device and a filtration method capable of efficiently filtering a fluid containing an admixture.

In order to achieve the above object, the filtration device according to the present invention is a filtration device for removing an admixture from a fluid containing an admixture, and is a first filtration tank and a fluid that has passed through the first filtration tank. The first filtration tank is provided with a second filtration tank for filtering the particles, and the first filtration tank accommodates and holds the flocculant layer and the fine aggregate layer in this order from the upstream side, and has a water permeation hole in the downstream portion. The second filtration tank has a plurality of stacked cloth filters, and stackable mesh box pallets are stacked in three stages of upper, middle and lower, and the first filtration tank is contained in the upper mesh box pallet. The mesh box pallet in the middle stage has the cloth filter installed inside it to serve as the second filtration tank, and the mesh box pallet in the lower stage has a non-permeable sheet installed along its inner wall to store fluid. The mesh box pallets are provided with four legs that are configured to be lockable on the upper edge of the lower mesh box pallets when stacked (claim 1).

In the filtration device, the mesh box pallet may be foldable (claim 2).

On the other hand, in order to achieve the above object, the filtration method according to the present invention is a filtration method for removing an admixture from a fluid containing an admixture, and the filtration device according to claim 1 or 2 is used. The step of filtering the fluid containing the admixture and the step of removing the filtration residue solidified on the fine aggregate layer are provided (claim 3).

In the present invention, a filtration device and a filtration method capable of efficiently filtering a fluid containing an admixture can be obtained.

That is, if it is attempted to remove the admixture in the cement sewage by coagulation sedimentation, a worker who stirs after adding the coagulant to the cement sewage is required, which requires a lot of labor. In the filtration device and filtration method of the present invention, the fluid containing the admixture can be efficiently filtered by using the filtration tank having the flocculant layer, which also contributes to the simplification of the work.

Further, the flocculant of the flocculant layer is cured together with the cement paste remaining on the surface of the fine aggregate layer after filtration to form a plate and can be easily separated from the fine aggregate layer. The plate-shaped filtration residue thus separated may be crushed to reduce the volume and treated as industrial waste, and the treatment is simple. On the other hand, if the cement content increases in the fine aggregate layer due to filtration, it can be reused for mortar / concrete spraying work, so industrial waste can be reduced.

In the filtration device of the invention according to claim 1 , since the cloth filter of the second filter tank is less likely to be clogged by the admixture, the cloth filter can be used for a long period of time without replacement, and the filtration efficiency can be improved. Can be done. If the cloth filter gradually becomes clogged and the filtration speed slows down, turn the cloth filter over in a dry state and tap it to remove the clogging, and then use it as a cloth filter again. Compared to the case where it can be used and is thrown away, it saves resources, and even if an expensive cloth filter is used, economic rationality can be obtained by long-term use.

(A) is an explanatory diagram schematically showing the configuration of a filtration device used in the filtration method according to the embodiment of the present invention, and (B) is a vertical sectional view schematically showing the configuration of a main part of the filtration device. be. It is a perspective view which shows schematic structure of the 2nd filtration tank of the said filtration apparatus. (A) is a perspective view schematically showing the configuration of a mesh box pallet used in the filtration device according to the modified example of the present invention, and (B) is a perspective view schematically showing the configuration of the modified example.

Embodiments of the present invention will be described below with reference to the drawings.

The filtration method according to the present embodiment is performed using the filtration device shown in FIG. 1A, and the filtration device filters the fluid that has passed through the first filtration tank 1 and the first filtration tank 1. It is provided with a second filtration tank 2 for the purpose.

Of these, the first filtration tank 1 accommodates and holds the flocculant layer 3 and the fine aggregate layer 4 in this order from the upper side (upstream side), and is provided by the storage holding body 6 having a water permeation hole 5 at the bottom (downstream part). It is configured and held above the second filtration tank 2 by appropriate means.

Here, the fine aggregate layer 4 is a layer in which sand or the like at the site is filled as fine aggregate from the bottom of the accommodating holding body 6, and the coagulant layer 3 is a layer in which the coagulant is contained in the accommodating holding body 6. It is a layer filled on the upper side (upstream side) of the fine aggregate layer 4, and as the flocculant, clay minerals such as sepiolite and bentonite, PAC (polyaluminum chloride), alum and the like can be used. The amount of the flocculant may be smaller than that of the fine aggregate. For example, when 300 L of sand is used as the fine aggregate, and if alum that acts as an electrolyte is used as the flocculant, the amount used can be about 300 to 500 g. ..

By the way, in the case where the flocculant layer 3 is arranged on the upper side and the fine aggregate layer 4 is arranged on the lower side as shown in the illustrated example, the fine aggregate having a smaller particle size than the flocculant (for example, myoban) of the flocculant layer 3 (for example, myoban). For example, if the fine aggregate layer 4 is constructed using sand), the flocculant layer 3 and the flocculant layer 3 can be formed due to the Brazilian nut effect (a phenomenon in which the largest particles float on the surface when powder particles of different sizes are shaken). Even if a partition net or the like is not arranged between the fine aggregate layers 4, the flocculant does not sink into the fine aggregate layer 4, and the flocculant layer 3 and the fine aggregate layer 4 are separated from each other. Can be kept.

However, a partition may be provided between the flocculant layer 3 and the fine aggregate layer 4 to prevent the two layers 3 and 4 from being mixed. In this case, the partition may be configured to allow water to pass through but not the flocculant and fine aggregate, and the flocculant solidified with the cement paste remaining on the surface of the fine aggregate layer 4 after filtration. If a partition (for example, a perforated plate made of synthetic resin or metal) that can be easily separated and removed from the filtration residue composed of the layer 3 is used, the recycling of the filtration residue can be facilitated and ensured. .. Further, a partition that allows water to pass through and does not allow the coagulant to pass through may be provided on the upper side (upstream side) of the coagulant layer 3, and if this partition has a certain strength, the coagulant layer 4 may be provided. The inflow impact of raw water is mitigated to prevent the formation of a relatively large dent in a part of the coagulant layer 4, and such an inflow impact structure is not used as a partition but separately above the coagulant layer 3. It may be provided.

On the other hand, as the storage holding body 6, for example, a flexible container bag (capacity 350L) that is lightweight and easy to fold, a water-impermeable sheet (vinyl sheet, etc.) is laid inside, or a resin barrel or the like is used. A plurality of water-permeable holes 5 are provided at the bottom to allow fluid to flow out and prevent the fine aggregate of the fine aggregate layer 4 from flowing out. That is, when the accommodating holding body 6 is composed of a flexible container bag and a sheet, for example, a through hole may be provided between the flexible container bag and the sheet, and the through hole may be a water permeation hole 5. When a resin barrel is used, the through hole may be provided. The through hole provided in the bottom wall may be a water permeation hole 5. In addition, a bottom plate having the water permeable hole 5 may be laid on the upper side of the bottom wall of the accommodation holding body 6, and the bottom wall of the housing holding body 6 may be provided with a through hole larger than the water permeable hole 5.

The second filtration tank 2 is arranged below the first filtration tank 1, and in the examples shown in FIGS. 1A and 2, it is made of a metal having a bottom surface of 1 m × 1 m, which is generally called a mesh box pallet (in this example). A cloth filter 8 (high in this example) in which a plurality of sheets (three in this example) are stacked so that they can be separated from each other (along the inner wall) inside a net cage (an example of a storage tank having a water permeation hole) 7 (made of iron). (Uses woven fabric made of dense polyester material) is installed. The cloth filter 8 may be installed only on the inside of the net cage 7, or the cloth filter 8 may be attached to the net cage 7 by an appropriate means such as a fastener. Further, the mesh size of the cloth filter 8 may be set according to the size of the particles to be filtered. The plurality of cloth filters 8 have the same configuration, and may be configured using, for example, a non-woven fabric, or may be configured without using a non-woven fabric. Further, the shape of the mesh (water permeation hole) of the net cage 7 can be various, such as a rectangular shape (square shape), a rhombic shape, and a polygonal shape.

The second filtration tank 2 is housed in the neutralization tank 10 while being placed on the table 9, and the lower surface of the second filtration tank 2 is separated upward from the bottom surface of the neutralization tank 10. .. The table 9 may be a dedicated one, an appropriate one such as a brick block, or may be provided (integrated) on the bottom surface of the neutralization tank 10 or the bottom surface of the net cage 7. May be good. Further, as the neutralization tank 10, it is conceivable to use, for example, a vessel made of metal or resin and having a capacity of about 200 L.

In the filtration device having the above configuration, by injecting a fluid into the first filtration tank 1, the fluid is supplied to the first filtration tank 1 (aggregator layer 3 and fine aggregate layer 4) and the second filtration tank 2 (cloth filter). It is filtered through 8). For example, when cement sewage containing an admixture (for example, a surfactant such as a water reducing agent, an antifreeze agent, etc.) and a colorant that may be generated at a construction site is injected into the first filtration tank 1, the first filtration tank 1 is used. , The admixture is largely removed from this cement sewage, and the cement and colorants are also removed to some extent. Further, in the second filter tank 2, the remaining cement and the colorant are also removed, and the filtered water passing through the first filter tank 1 and the second filter tank 2 contains almost no cement, the colorant and the admixture. Such filtration is performed if the cement sewage passes through the second filtration tank 2 (cloth filter 8) in a state where the admixture (for example, a water reducing agent) is contained, the admixture is the cloth filter 8. At the same time as causing clogging, the colorant is dispersed to make it difficult for the cloth filter 8 to capture the colorant. However, in the present embodiment, the admixture is used by the first filter tank 1 before passing through the second filter tank 2. It is considered that by removing the above, not only the clogging of the cloth filter 8 is prevented, but also the dispersibility of the colorant is lowered, and the aggregated colorant can be captured by the cloth filter 8. If the fluid to be filtered contains coarse aggregate, for example, the fluid may be passed through a coarse wire mesh or a flexible container bag with holes of appropriate size to allow the fluid to pass through in advance. The material or the like may be removed.

Then, the coagulant of the coagulant layer 3 of the first filtration tank 1 is hardened together with the cement paste remaining on the surface of the fine aggregate layer 4 after filtration, becomes a plate, and is easily separated and removed from the fine aggregate layer 4. can do. The plate-shaped filtration residue thus separated and removed may be crushed to reduce the volume and treated as industrial waste.

In addition, if the cement content increases in the fine aggregate layer 4 of the first filtration tank 1 due to filtration, this can be reused for mortar / concrete spraying work, and industrial waste can be reduced. can.

In the filtration device of the present embodiment, since the cloth filter 8 of the second filter tank 2 is less likely to be clogged by the admixture, the cloth filter 8 can be used for a long period of time without replacement, and the filtration efficiency is improved. Can be done. If the cloth filter 8 is gradually clogged and the filtration speed becomes slow, for example, the cloth filter 8 is turned inside out in a dried state and tapped to remove the clogged portion and regenerate it. If this is the case, the filtration speed can be increased again, which saves resources as compared with the case where the cloth filter 8 is thrown away, and even if an expensive cloth filter is used, economic rationality can be obtained by long-term use. It is also possible to improve economic efficiency.

Moreover, in the regeneration process from the drying of the cloth filter 8 to the removal of the clogging, for example, only the innermost cloth filter 8 (the most clogged cloth filter 8) among the plurality of stacked sheets is (that is, a part). It is preferable that the cloth filter 8) can be removed to perform filtration (temporary filtration step) by another cloth filter 8 during the regeneration step. By doing so, it is possible to eliminate the stagnation of filtration and improve the filtration performance and the filtration efficiency. Then, the cloth filter 8 that has undergone the above-mentioned regeneration step may be stacked on the outermost side of the other cloth filter 8, for example. Considering such a usage method, it is usually preferable to use three or more cloth filters 8 in a stack. In particular, when four or more cloth filters 8 are stacked and used, it is conceivable to regenerate two or more cloth filters 8 at a time by the above-mentioned regeneration step. In this case as well, while the inner cloth filter 8 which is considered to be relatively clogged is sent to the regeneration process, the remaining (outer) cloth filter 8 can be used for filtration (temporary filtration step). preferable. The method of regenerating the cloth filter 8 is not limited to the above, and may be performed by using an appropriate tool such as a brush.

If the first filtration tank 1 is omitted and the admixture in the cement sewage is to be removed by coagulation sedimentation, a worker who stirs after adding the coagulant to the cement sewage is required, which requires a lot of labor. However, in the present embodiment, by using the first filtration tank 1, it is possible to save the trouble of stirring cement sewage and simplify the work. And, basically, it suffices if there is an empty space for installing the neutralization tank 10, and the filtration device of the present embodiment is also useful in that filtration can be performed in a limited space such as a construction site.

On the other hand, the fluid filtered through the first filtration tank 1 and the second filtration tank 2 accumulates in the neutralization tank 10, and a neutralizing agent is added to the neutralization tank 10 to neutralize the fluid, thereby creating an environment. Countermeasures can be taken, and the neutralized fluid may be discharged from the neutralization tank 10 and appropriately treated. Then, in order to facilitate this discharge, for example, an on-off valve (not shown) may be provided at the bottom of the neutralization tank 10 so that the on-off valve can be opened and discharged at the time of discharge.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention can be variously modified and implemented without departing from the gist of the present invention. For example, the following modification examples can be given.

In the filtration device of the above embodiment, the fluid to be filtered (cement sewage) is basically configured to flow from top to bottom, but the present invention is not limited to this, and the direction in which the fluid flows is appropriate. It can be changed, and for example, a portion where the fluid flows sideways may be provided. Further, in the example shown in FIG. 1A, the first filtration tank 1 is separated above the second filtration tank 2, but the present invention is not limited to this, and for example, the lower part of the first filtration tank 1 is the second filtration tank. The second filter tank 2 may be arranged so as to cover the bottom portion (downstream portion) of the first filter tank 1 so as to enter the portion 2 to some extent.

In the filtration device of the above embodiment, one layer each of the flocculant layer 3 and the fine aggregate layer 4 is provided in the accommodation holding body 6, but one or both of them are provided in two or more layers. May be good.

Further, in the filtration device of the above embodiment, the first filtration tank 1 and the second filtration tank 2 are provided one by one, but one or both of them may be provided in two or more. For example, two first filtration tanks 1 may be provided so that the fluid passes through the two first filtration tanks 1 and then heads toward the second filtration tank 2.

In the filtration device of the above embodiment, the net cage 7 is used for the second filtration tank 2, but the present invention is not limited to this, and instead of the net cage 7, for example, one having the same configuration as the accommodation holding body 6 or the like. A larger one may be used. However, for example, when a net cage 7 is used, the vertical and horizontal size d (see FIG. 1 (B)) of the gap (water permeation hole) of the mesh is 5 to 15 cm, preferably 10 to 15 cm (10 cm or more and 15 cm or less). ), The cloth filter 8 arranged inside the net cage 7 appropriately protrudes to the outside of the mesh due to the water pressure of the fluid flowing into the inside of the net cage 7, and the mesh of the cloth filter 8 is formed. Since it spreads, the filtration speed can be increased. If the vertical and horizontal size d of the gap is less than 5 cm, the mesh size of the cloth filter 8 does not widen and the filtration speed decreases. There is. Therefore, even when a cage having the same structure as that of the accommodation holder 6 having the water permeable hole 5 is used instead of the net cage 7, the vertical and horizontal size d of the hole corresponding to the water permeable hole 5 is set to 10 to 15 cm. Is preferable. As the shape of the hole corresponding to the water permeable hole 5 in this case, various shapes such as a rectangular shape (square shape), a rhombic shape, a polygonal shape, a circular shape, and an elliptical shape can be considered.

Cement sewage may contain hexavalent chromium, which cannot be discharged unless it falls below environmental standards. Therefore, an adsorbent that adsorbs hexavalent chromium is charged into at least one of the first filtration tank 1, the second filtration tank 2, and the neutralization tank 10, and hexavalent chromium is adsorbed and removed from the cement sewage. You may do so. As the adsorbent, for example, an environmental purification material described in JP-A-2009-11900 can be considered.

The fluid to be filtered is not limited to cement sewage, but may be muddy water, for example, and the filtration device of the present embodiment can also be used for treating turbid water generated during anchor drilling, for example.

The filtration device of the present invention may be configured by using the stackable type mesh box pallet 11 shown in FIG. 3 (A). That is, the four legs 12 of the mesh box pallet 11 are configured to be lockable to the upper edge of the lower mesh box pallet 11 when stacked. Then, as shown in FIG. 3B, when the mesh box pallets 11 are stacked in the upper, middle, and lower three stages, the first filtration tank 1 is placed in the upper mesh box pallet 11 and the middle stage mesh box is placed. A cloth filter 8 is installed inside the pallet 11 to form a second filtration tank 2, and a non-permeable sheet (for example, a blue sheet) 13 is installed along the inner wall of the lower mesh box pallet 11 to store fluid. The neutralization tank 10 may be used. When the lower mesh box pallet 11 is used in the neutralization tank 10, for example, the peripheral edge of the impermeable sheet 13 is made to protrude to the outside of the mesh box pallet 11, and the protruding portion is made to protrude from the mesh box pallet 11 with an appropriate member. It may be fixed to 11.

When the filtration device is configured as shown in FIG. 3B, if the mesh box pallet 11 is foldable, the transportability of the filtration device to the site is dramatically improved, and the filtration device is stored compactly when not in use. It is also possible to keep it.

Needless to say, the modifications given in the present specification may be combined as appropriate.

1 1st filter tank 2 2nd filter tank 3 Coagulant layer 4 Fine aggregate layer 5 Water permeable hole 6 Containment holder 7 Net cage 8 Cloth filter 9 units 10 Neutralization tank 11 Mesh box pallet 12 Leg 13 Non-permeable sheet d Vertical and horizontal size of the water permeation hole

Claims (3)

A filtration device for removing an admixture from a fluid containing an admixture.
A first filtration tank and a second filtration tank for filtering the fluid that has passed through the first filtration tank are provided.
The first filtration tank is composed of an accommodating and holding body that accommodates and retains the flocculant layer and the fine aggregate layer in this order from the upstream side and has a water permeation hole in the downstream portion.
The second filtration tank has a plurality of stacked cloth filters .
Stackable mesh box pallets are stacked in three stages, upper, middle and lower, the first filtration tank is placed in the upper mesh box pallet, and the cloth filter is installed inside the middle mesh box pallet. The second filtration tank, the lower mesh box pallet is a neutralization tank in which a non-permeable sheet is installed along the inner wall to store fluid, and the mesh box pallet is the mesh on the lower side when stacked. A filtration device characterized by having four legs that are configured to be lockable on the upper edge of a box pallet . The filtration device according to claim 1, wherein the mesh box pallet is foldable . A filtration method for removing an admixture from a fluid containing an admixture.
A step of filtering a fluid containing an admixture using the filtration device according to claim 1 or 2.
A filtration method comprising a step of removing a filtration residue solidified on the fine aggregate layer.

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