JPH0512002B2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The present invention is applicable to municipal tap water, sewage water, river water, lake water,
It enhances suspended solids in flocculation-sedimentation supernatant water, intermediate water in various processes, various recovered water such as recovered water in paper manufacturing processes, various wastewaters, treated water from biological treatment equipment, liquids containing valuables, alcohol, oil, etc. The present invention relates to a filtration tower using long fiber bundles for removal at a flow rate, and particularly relates to the filtration tower with an improved support structure for the lower part of the long fiber bundles.

<Prior Art> The applicant of the present invention previously disclosed a filtration tower using long fiber bundles in Japanese Patent Applications No. 146,989/1980 and No. 131,715/1983.

As shown in Fig. 5, the filter tower is constructed by installing a perforated plate horizontally in the filter tower A, fixing the lower end of the long fiber bundle inside the filter tower A, and using the upper end as a free end. Long fiber bundles are installed throughout the interior, and when filtering undiluted solutions containing suspended matter,
At the same time as valves N and E are opened, the stock solution flows into the stock solution inflow pipe and passes through the long fiber bundle C in a downward flow. is taken out from the filtrate outflow pipe.

In addition, when pressure loss increases due to the capture of suspended matter, valves D and H are closed, valves CH and E are opened, compressed air flows in from the air inlet pipe N, and the long fiber bundle C is stirred. , vibrate, then open the valve with compressed air flowing in, or stop the inflow, and let the backwash water flow in from the backwash water inlet pipe and drain the suspended matter from the backwash water discharge pipe. It is.

The filtration tower is constructed by relatively densely storing long fiber bundles of 0.4 m to 3.0 m in length, which are usually aggregates of untwisted single fibers such as acrylic fibers, polyester fibers, and polyamide fibers with a thickness of 10 μm to 80 μm. Since the filter is made to stand upright by being filled with the filter, the suspension can be filtered at a high flow rate without increasing pressure loss.

In addition, since the lower end of the long fiber bundle is fixed, when high-flow compressed air or backwash water flows upward during backwashing, the long fiber bundle becomes like a windsock with the lower end fixed. Since the long fiber bundle vibrates as it stretches, trapped suspended matter can be effectively removed.

However, when this filtration tower was first developed, the lower end of the long fiber bundle was fixed as shown in Figure 6, by bending the long fiber bundle, gathering the bent portions together with a ring, and closing each hole in the perforated plate. However, since the bending portion was positioned and the long fiber bundle was fixed by a support rod and a bolt using a bolt communicating with a ring bolt, it had the following drawbacks.

In other words, in the case of such a structure, the long fiber bundles in the part held together by the ring filter are quite dense, and the liquid always passes through this part during filtration.
The dense area is easily clogged with suspended matter, and once the suspended matter is clogged, it is difficult to remove it even if the backwashing described above is performed.

This is because, in the structure shown in Figure 6, even if fluid such as compressed air or backwash water is passed through each hole, it is preferentially distributed from the contact area between the upper surface of the perforated plate and the long fiber bundle. This is because it is difficult for the fluid to pass through the important part, that is, the dense part. In addition, when the nut is strongly tightened and the degree of contact between each hole and the long fiber bundle is increased, priority is given to holes having long fiber bundles whose dense portions are relatively free of suspended matter. A phenomenon also occurs in which the fluid passes through and does not pass through the holes that have long fiber bundles that are clogged with suspended matter, that is, the areas that are desired to be cleaned.

Therefore, if this condition continues, suspended matter will gradually remain in the dense area, which will gradually increase the initial pressure difference in filtration, and in some cases, it may seriously impede the filtration process itself. becomes.

Another disadvantage is that even if the long fiber bundle is fixed so as to bite into the hole, there will be a small gap between the periphery of the hole and the long fiber bundle, which causes suspension of the fibers due to increased pressure loss. material leaks and the quality of the filtrate decreases in the latter half of the filtration process.

<Problems to be Solved by the Invention> The present invention solves the above-mentioned drawbacks of filtration towers using long fiber bundles, and allows the entire long fiber bundle to be sufficiently washed by backwashing, and also allows the filtrate to It is an object of the present invention to provide a filtration tower that can maximize the advantages of long fiber bundles by preventing suspensions from leaking as much as possible.

<Means for solving the problems> A filtration tower using long fiber bundles according to the present invention, which has been made to achieve the above object, fixes the lower end of the long fiber bundles on a perforated plate installed horizontally inside the tower. At the same time, a long fiber bundle is set upright throughout the inside of the tower with its upper end as a free end, and when the concentrate is passed downward from the upper end of the long fiber bundle to the lower end, the long fiber bundle becomes Although the height of the filtration tower is reduced, it does not bend horizontally and stands entirely upright within the tower.A downward flow of raw solution is introduced from above the filtration tower, and suspended particles are formed in the voids within the long fiber bundle. In a filtration tower that captures the A support for long fiber bundles with continuous bodies is placed in each hole of a perforated plate installed horizontally in the tower, with the upper lid-like body facing above the perforated plate, and the lower cylindrical body facing below the perforated plate. This is a filtration tower using long fiber bundles, characterized in that the long fiber bundles are attached so as to face each other, and the lower ends of the long fiber bundles are fixed around the side trunks of each of the upper lid-shaped bodies.

The present invention will be explained in detail below.

FIG. 1 is an overall view showing the flow of the filtration tower of the present invention, FIG. 2 is a cutaway sectional view showing a support for a long fiber bundle used in the present invention, and FIG. FIG. 3 is a partial external view showing the support of FIG.

The filtration tower of the present invention has a filtration tower 1 as shown in FIG.
A perforated plate 2 is installed horizontally in the lower part of the frame, a support 3 for the long fiber bundle, which will be described later, is attached to the perforated plate 2, and the lower end of the long fiber bundle 4 is fixed by the support 3. The long fiber bundle 4 is erected in the filtration tower 1 by making the upper end of the bundle 4 a free end and filling the tower with the long fiber bundle 4 relatively densely.

Further, a stock solution inflow pipe 5 is provided above the filtration tower 1, and a backwash water discharge pipe 6 is branched and communicated with the stock solution inflow pipe 5.

Further, a backwash air inflow pipe 7 is communicated below the perforated plate, and a filtrate outflow pipe 8 is provided at the bottom of the filtration tower, and a backwash water inflow pipe 9 is branched and communicated with the filtrate outflow pipe 8.

In this embodiment, the backwash air inflow pipe 7 is divided into two and communicated with each other so as to face the tower wall of the filtration tower 1, but the present invention is not limited to this, and one backwash air inflow pipe 7 may be used. There is no problem. Furthermore, 10 to 1
4 each indicates a valve.

Next, the support 3 for the long fiber bundle used in the filtration tower of the present invention will be explained.

The support body 3 is the most important part in the present invention, and as shown in FIGS. 2 and 3, it basically consists of an upper lid-like body 16 having a large number of holes 15 in the upper and side body parts, and a side body. It consists of a lower cylindrical body 18 which has a slit 17 in its body and is open at its upper and lower ends.

The support 3 is attached to each hole 19 in the perforated plate 2 as follows.

First, a pair of holes (not shown) are drilled in the upper side wall of the lower cylindrical body 18, and the T-bolts 20 are inserted into the holes.
The lower cylindrical body 18 is suspended on the T-shaped bolt 20 by inserting the lower T-shaped portion of the lower cylindrical body 18. Note that the outer diameter of the lower cylindrical body 18 is made smaller than the diameter of the holes 19 in the perforated plate 2, and
The thickness is such that the lower cylindrical body 18 can be inserted therein.

Next, the lower cylindrical body 18 is inserted into the hole 19 by inserting the tip of the T-shaped bolt 20 from the lower part of the hole 19.
After inserting the nut 22 with legs 21 into the T-bolt 20, the legs 21 tighten the T-bolt 2.
0 is fixed in the hole 19.

Next, the lower end of the long fiber bundle 4 is tightened around the entire circumference of the side trunk of the upper lid-shaped body 16 in advance, and the band 2
3, the T-shaped bolt 20 is inserted into the mounting hole 25 of the upper lid-shaped body 16 to which the long fiber bundle 4 is fixed, and the hole 19 is covered with the upper lid-shaped body 16. The upper lid-shaped body 16 is fixed to the upper part of the hole 19 by screwing into the bolt 20.

By the installation procedure as described above, the perforated plate 2
A support 3 for a long fiber bundle is attached to each hole 19 of the fiber bundle.

Note that the hole 15 in the upper lid-like body 16 allows the filtrate,
Although this is a portion through which fluids such as compressed air and backwash water pass, it does not necessarily have to be provided above the lid-shaped body 16. However, at least a large number of holes may be provided around the side body portion of the lid-like body 16, and a large number of slits may be provided in place of the holes 15.

Furthermore, although the slit 17 provided in the lower cylindrical body 18 is mainly a portion through which compressed air passes, the slit 17 may be replaced by a plurality of small holes arranged in the vertical direction.

The structure of the long fiber bundle support 3 and its attachment method shown in FIGS. 2 and 3 are just one example. Basically, the structure of the support 3 for the long fiber bundle shown in FIGS. A long fiber bundle support 3 formed by communicating a lid-like body 16 with a lower cylindrical body 18 having open upper and lower ends and having a slit or a plurality of small holes arranged in the vertical direction in the side body is placed in the column. The upper lid-like body 16 is attached to each hole 19 of the horizontally installed perforated plate 2 so as to face above the perforated plate 2, and the lower cylindrical body 18 is attached to each hole 19 of the perforated plate 2 so as to face below the perforated plate 2. Any detailed structure may be used as long as the lower end of the long fiber bundle is fixed around the side trunk of the body 16.

<Effect> Next, the operation of this filtration tower will be explained.

First, when filtering a stock solution containing suspended matter,
The valves 10 and 14 are opened to allow the stock solution to flow downward from the stock solution inflow pipe 5. The raw solution flows down along the long fiber bundles 4 set upright in the tower, and the suspended matter is captured in the voids formed by the long fiber bundles 4, and the filtrate is passed through the hole 15 in the upper cover 16 to the support. 3 Go inside,
The filtrate then flows out from the filtrate outflow pipe 8 via the lower cylindrical body 18 . In the filtration tower of the present invention, since the long fiber bundle 4 is attached so as to cover the hole 15 of the upper lid-like body 16, unlike the conventional structure, no gap is formed, so even if the pressure loss increases. No suspended matter leaks into the filtrate.

When a large amount of suspended matter is trapped in the voids of the long fiber bundle 4 due to the continuation of such filtration, the pressure loss gradually increases, and as the pressure loss increases, the long fiber bundle starts to stand upright from the lower part. The long fiber bundles begin to bend,
A phenomenon occurs in which the upright height of the long fiber bundle gradually decreases.

When the increase in pressure loss reaches a predetermined value, valves 10 and 14 are closed to stop filtration, and the following backwashing is performed.

That is, the valves 11 and 12 are opened to allow compressed air to flow in from the backwash air inflow pipe 7.

Since the lower part of the perforated plate 2 is filled with the filtrate, the filtrate first flows out from each hole 15 of the upper lid-like body 16 due to the inflow of compressed air, but the second part immediately flows under the perforated plate 2. As shown in the figure, a liquid level L is formed, and a compressed air layer A is formed above the liquid level L. The compressed air is then passed through the slit 17 located above the liquid level L to the lower cylindrical body 1.
8 and then ejects from each hole 15 of the upper lid-like body 16.

The jet of compressed air agitates the water in the filter tower 1 and vibrates the long fiber bundles 4, destroying the voids formed between the fibers and destroying the aggregates of suspended matter. The suspended matter adhering to the fiber bundle 4 is peeled off.

Especially in the early stage of inflowing compressed air, the perforated plate 2
The liquid present below is pushed up all at once by the compressed air, becomes a powerful piston flow, and flows out from each hole 15 of the upper lid-shaped body 16.Then, as the compressed air flows out, the surrounding area of the upper lid-shaped body 16 is The densely packed portions of long fiber bundles in the tube are also effectively cleaned by the passage of the fluid.

Either continue the inflow of compressed air as described above, or close the valve 12 to stop the inflow of compressed air.
3 is opened, and backwash water flows in from the backwash water inflow pipe 9.

The inflowing backwash water mainly enters into the cylindrical body 18 through the lower end opening of the lower cylindrical body 18, and then flows out from each hole 15 of the upper lid-shaped body 16.

The lower end of the long fiber bundle 4 is fixed, and
Since its upper end is a free end, the upward flow of backwash water causes the long fiber bundle 4 to elongate like a windsock, and each fiber vibrates.

Therefore, the suspended matter separated from the long fiber bundle 4 by the shock caused by the inflow of the compressed air is washed away, and backwash wastewater containing a large amount of the suspended matter flows out from the backwash water discharge pipe 6.

In addition to the method described above, as a backwashing procedure, there is also a method in which a certain amount of backwash water flows in from the backwash water inflow pipe 9 and compressed air intermittently flows in from the backwash air inflow pipe 7. .

In this case, each time compressed air flows in, the strong piston flow described above is formed, so backwashing can be performed more effectively.

FIG. 4 shows another embodiment of the long fiber bundle support used in the present invention, which is a conical valve receiver 2 having a large number of passage holes 26 inside and above the upper lid-like body 16.
7, and a conical valve membrane 28 that can tightly close the passage hole 26 is provided inside the valve receiver 27, and the other structure is the same as that in FIG. The upper end of the valve membrane 25 is fixed to the upper inner surface of the upper lid-like body 16, and the lower end is opened in the shape of a flap and is made of a flexible material.

The functions of the valve receiver 27 and the valve membrane 28 are as follows.

That is, during filtration, the filtrate passes through the hole 15,
Since the valve membrane 28 is pushed inward by the fluid, it has no effect during filtration and does not cause any hindrance during the filtration process.

However, during backwashing, it works as follows.

That is, the upward flow of compressed air or backwash water flowing through the lower cylindrical body 18 causes the valve membrane 28 to
are pushed apart, and the valve membrane 28 comes into close contact with the valve receiver 27. Therefore, the only hole for compressed air or backwash water is the hole 15A located below.

Therefore, compressed air or backwash water can be preferentially discharged from the lowermost end of the fixed portion of the long fiber bundle 4, and the lowermost end of the long fiber bundle 4, which is difficult to clean, can be more effectively cleaned. can.

Next, the long fiber bundle 4 used in the present invention will be explained below. Even if the stock solution is passed through in a downward flow at a relatively high flow rate, the lower part of the long fiber bundle is slightly bent at the initial stage, and its height is lowered. The fiber bundle 4 shrinks slightly, and as the liquid continues to flow, the bending part in the lower part increases, and the long fiber bundle 4 gradually
Although the upright height of the fibers decreases, the long fiber bundles do not bend horizontally and remain erect as a whole even when the liquid is flowing in the filter tower 1, and
A certain amount of filling is required, and synthetic fibers such as acrylic fibers, polyester fibers, and polyamide fibers, or cotton,
Natural fibers such as wool can be used.

It is preferable to use an aggregate of untwisted single fibers made of these synthetic fibers or natural fibers with a thickness of 80 μm or less, usually around 35 μm.

However, it does not bend horizontally during liquid flow,
As long as it is a long fiber bundle that stands upright within the filter tower 1, an aggregate of twisted yarns may be used.

As the aggregate density of the long fiber bundles used in the present invention increases, even fine suspended matter can be removed and the quality of the filtrate water improves, but on the other hand, the pressure loss increases.

Furthermore, as the aggregate density decreases, the quality of the filtrate decreases, but conversely, the pressure loss decreases.

Therefore, it is preferable to select and use a long fiber bundle having the most suitable aggregate density depending on the quality or quantity of the suspension in the raw water. For example, when using a long fiber bundle consisting of an aggregate of untwisted single fibers with a length of 1000 mm to 3000 mm, the packing density is such that the long fiber bundle has a weight of 25 to 110 kg (dry weight) per 1 m ³ of filtration tower volume. It's good to do that.

<Effects> As explained above, the filtration tower using long fiber bundles according to the present invention does not simply have long fiber bundles attached to each hole of a perforated plate, but also has a large number of holes or slits at least around the side body. an upper lid-like body;
Each hole of a perforated plate installed horizontally in the tower is connected to a support body for long fiber bundles that communicates with a lower cylindrical body whose upper and lower ends are open and which has slits or a plurality of small holes arranged in the vertical direction in the side body. Then, the upper lid-like body is attached so as to face above the perforated plate, and the lower cylindrical body is attached so as to face below the perforated plate, and the lower end of the long fiber bundle is attached around the side trunk of each of the upper lid-like bodies. Since it is fixed, the hole in the upper lid-like body is reliably covered by the long fiber bundle, so it is difficult for suspended matter to leak into the filtrate.
In addition, during backwashing, fluids such as compressed air and backwash water can flow out evenly from each hole around the upper lid, making it particularly effective in areas where long fiber bundles are concentrated near the perforated plate, which is difficult to clean. can be washed,
There is no possibility of insufficient backwashing.

In addition, a conical valve receiving body having a large number of passage holes is attached to the upper part of the inside of the upper lid-like body, and a valve membrane is attached to the inside thereof, which can tightly close the passage holes by upward flow during backwashing. By doing so, the backwashing fluid can be ejected preferentially from the bottom end of the fixed long fiber bundle, which is more effective in preventing suspended matter from remaining during backwashing. .

[Brief explanation of the drawing]

Figures 1 to 4 are drawings showing embodiments of the present invention, in which Figure 1 is an overall diagram showing the flow of the filtration tower of the present invention, and Figure 2 is a diagram showing the long fibers used in the present invention. FIG. 3 is an enlarged cross-sectional view showing a support for a bundle of filaments, FIG. 3 is a cutaway external view of a support for a filament bundle used in the present invention, and FIG. FIG. 2 is an enlarged cross-sectional view showing an embodiment of the invention. Moreover, FIG. 5 is an overall view showing the flow of a conventional filter tower using long fiber bundles, and FIG. 6 is an enlarged sectional view showing the lower structure of the conventional filter tower. 1... Filter tower, 2... Perforated plate, 3... Support for long fiber bundle, 4... Long fiber bundle, 5... Stock solution inflow pipe,
6... Backwash water discharge pipe, 7... Backwash air inflow pipe, 8
...Filtrate outflow pipe, 9...Backwash water inflow pipe, 10,
11, 12, 13, 14... Valve, 15... Hole, 1
6... Upper lid-like body, 17... Slit, 18...
Lower cylindrical body, 19...hole, 20...T-shaped bolt,
21... Leg, 22... Nut, 23... Tightening band, 24... Nut, 25... Mounting hole,
26... Passing hole, 27... Valve receiver, 28... Valve leaflet.

Claims (1)

[Claims] 1 The lower end of the long fiber bundle is fixed to a perforated plate placed horizontally inside the tower, and the upper end of the long fiber bundle is set as a free end, and the long fiber bundle is set upright throughout the inside of the tower, and from the upper end to the lower end. When the raw solution flows downward toward the filter, the long fiber bundles shrink in height, but do not bend horizontally, but instead descend from the top of the filtration tower, which stands upright within the tower. A filtration tower that receives a stream of raw liquid and traps suspended matter in the voids in the long fiber bundle has an upper lid-like body having at least a number of holes or slits around the side body, and a slit or slit in the side body. A support for a long fiber bundle formed by communicating with a lower cylindrical body having a plurality of vertically arranged small holes and open at the upper and lower ends is inserted into each hole of a perforated plate installed horizontally in the tower, and an upper lid-like body is connected to the support body. is attached so as to face above the perforated plate, and the lower cylindrical body is attached so as to face below the perforated plate, and further, the lower end of the long fiber bundle is fixed around the side trunk of each of the upper lid-like bodies. A filtration tower using long fiber bundles.