JP2017018888A - Filtration apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filtration apparatus configured such that turbid matter can be properly discharged during washing while maintaining turbid matter capturing performance.SOLUTION: A filtration apparatus comprises: a filtration tank 10; a perforated plate 2 provided on an upstream in the filtration tank 10 and a perforated plate 3 provided on a downstream in the filtration tank 10; and filter materials 4 formed of filament bundles whose upper end parts and lower end parts are bound by binding members 31 and 32, and which comprise fixing strings 5a and 5b on the upper end parts and the lower end parts. Each filter material 4 is arranged inside the filtration tank 10 in such a manner that each fixing string 5a on the upper end part is attached to the perforated plate 2 provided on the upstream side and the fixing string 5b on the lower end part is attached to the perforated plate 3 on the downstream side. The fixing string 5a and the fixing string 5b of the filter material 4 are different in length.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a filtration device used for capturing turbidity from irrigation water, wastewater or other raw water.

  Conventionally, as a filtration device for capturing turbidity from raw water, a filtration device in which a long fiber filter medium is used as a filter medium and the long fiber filter medium is disposed along the flow direction of the raw water is known (Patent Document 1). To 3).

  In Patent Document 1, one end of a core member of a filter medium made of a material that can be bent and deformed along the longitudinal direction of a plant fiber, a resin fiber, or the like at an appropriate position of a perforated plate such as a face plate constituting a filter medium support floor of a filtration chamber And a filter device comprising a suitable number of the filter media in the filtration chamber, and the filter media comprising the core member and an infinite number of trapping yarns radially attached to the core member along the longitudinal direction thereof. Have been described.

  Patent Document 2 has a long fiber bundle disposed on a perforated plate horizontally installed in a tower main body, the lower end side of which is supported by a support member. In the filtration tower using the long fiber bundle, a filtration device is described in which the long fiber bundle is bent at one or more sites and the bent portion is positioned on the upper end side.

  In Patent Document 3, an appropriate amount of fiber filter medium is placed in a filtration chamber between a perforated plate constituting a filter medium supporting bed and an upstream perforated plate facing the perforated plate in the flow direction of raw water, and one end of the perforated plate In addition, the other end is fixed to the upstream perforated plate and filled, and the fiber filter medium is longer by a predetermined amount than the length in the flow direction of the raw water in the filtration chamber, and the peripheral side of the core material Filtration that is made up of countless Wooled resin fibers that are radially projected in countless loops, and the core material is provided with a portion of the core material that does not have resin fibers on the peripheral side for a predetermined length. An apparatus is described.

JP-A-8-299707 JP 2001-219008 A JP2013-653A

  In the devices described in Patent Document 1 and Patent Document 2, one end of the core material is fixed, and the free end is the upstream side. In this device, the filter medium is compressed during water flow and the filtration layer becomes thin, so that the amount of trapped turbidity is reduced. In addition, since the compression load is applied more than necessary, the filter medium becomes hazy, making it difficult to return to the original state, and the filter medium is easily entangled during the second filtration operation, and turbidity adheres, creating a waterway. There is a drawback that it is easy.

  The device described in Patent Document 3 has an advantage that the filtration rate is high and the trapped amount of turbidity is large compared to sand, but depending on the water flow rate, there is a problem that the turbidity is not sufficiently discharged during cleaning even in actual equipment. is there. This is because the advantage of the filter medium is that the porosity is high, conversely, depending on the fiber filling condition and trapped state of turbidity, a part where water easily flows and a part where water does not flow easily are formed. It can be inferred that the initial water supply pressure increased due to the fact that the air and the air did not contact the filter media evenly, and turbidity remained in the areas where water did not flow easily.

  Therefore, an object of the present invention is to provide a filtration device in which turbidity is discharged well during washing while maintaining the trapping power of turbidity.

That is, the configuration of the present invention relates to a filtration device as described below.
(1) a filtration tank;
A perforated plate provided on the upstream side in the filtration tank; a perforated plate provided on the downstream side in the filtration tank;
A filter medium comprising a long fiber bundle in which an upper end portion and a lower end portion are bound by a binding member, and having a fixed string at the upper end portion and the lower end portion;
With
The filter medium is disposed in the filtration tank by attaching the fixed string at the upper end to the porous plate provided on the upstream side, and attaching the fixed string at the lower end to the porous plate on the downstream side,
There is a difference in the length of the fixed string of the filter medium.
(2) The filtration device according to (1), wherein the length of the fixed string is different between adjacent filter media.
(3) The filtration device according to the above (1) or (2), wherein the long fibers constituting the long fiber bundle are woolly-processed long fibers.

  According to the filtration device of the present invention, a sufficient cleaning effect can be obtained by reducing the residual turbidity at the time of backwashing without reducing the trapping power of the turbidity at the time of raw water treatment.

It is a conceptual diagram which shows the structure of the filtration apparatus of this invention. It is a figure which shows the structure of the filter medium used in the filtration apparatus of this invention. It is a figure which shows the state of the filter medium in the filtration apparatus of this invention.

The present invention will be described in detail below with reference to embodiments, but the technical scope of the present invention is not limited to the following embodiments.
Details of the filtration device of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a conceptual diagram showing the configuration of the filtration device of the present invention.
As shown in FIG. 1, the porous plate 2 is provided in the upper part of the filtration tank 10 constituting the filtration device 20, and the porous plate 3 is provided in the lower part of the filtration tank 10. A space defined by the inner wall 10 a of the filtration tank 10 and the perforated plate 2 and perforated plate 3 forms a filtration chamber 1. As the perforated plates 2 and 3, a punching metal or a wire mesh can be used.

A supply port 11 for the raw water W1 is provided on the upstream side of the perforated plate 2. The raw water W1 supply port 11 also serves as a cleaning drainage B2 and an air discharge port when the filtration device 20 is backwashed.
On the downstream side of the perforated plate 3, an outlet 12 for the filtered water W2 is provided. The outlet for the filtered water W2 also serves as a supply port for the cleaning water B1 and air during backwashing.
The supply port 11 for the raw water W1 and the discharge port 12 for the filtered water W2 communicate with the filtration chamber 1 through the perforated plates 2 and 3.

In the filtration chamber 1, a filter medium 4 composed of a fiber bundle in which both ends of long fibers 41 are bundled with a binding member is disposed. As the binding member, an appropriate one such as a string or a binding band can be used.
FIG. 2 shows an example of a binding member.
2A is a view showing a single filter medium 4, and FIG. 2B is a view showing a cross section of the binding portion 30 at the lower end of the filter medium 4 shown in FIG. 2A. 2 (c) is a view showing a longitudinal section of the binding portion 30.
As shown in FIG. 2, the upper end portion and the lower end portion of the long fiber 41 are arranged on the outer periphery of the disc-shaped core member 31 having a hole 33 for attaching the fixed strings 5 a and 5 b at the center. By using a bundling member composed of the ring-shaped member 32, the bundling member 32 is bound and fixed in a space formed between the outer peripheral surface of the core member 31 and the inner peripheral surface of the ring-shaped member 32.

The filter medium 4 is held in the filtration chamber 1 by fixing the fixed string 5 a to the porous plate 2 and fixing the fixed string 5 b to the porous plate 3.
The fixing straps 5a and 5b may be attached to the perforated plates 2 and 3 by linking the fixing straps to the base material portions of the perforated plates 2 and 3, or the fixing straps 5a and 5b may be attached using a locking tool. You may carry out by latching to the perforated plates 2 and 3. FIG.
The fixing straps 5a and 5b are preferably provided separately on the upper end portion and the lower end portion of the filter medium 4, respectively, and the length thereof is sufficient to fix the upper end portion and the lower end portion of the filter medium 4 to the perforated plates 2 and 3. It is sufficient if it is long, and there is no need to provide a margin.
In this way, by fixing the upper and lower ends of the filter medium 4, the filter medium 4 is not compressed too much at the time of water flow. Therefore, an increase in the primary pressure can be suppressed even at high-speed water flow, and all layers of the filter medium 4 The filtration function can be demonstrated.

As shown in FIG. 1, the fixed strings 5 a and 5 b have a difference in the length of the fixed strings 5 a and 5 b between the filter media 4. It is preferable that there is a difference in the lengths of the fixed strings 5a and 5b between adjacent filter media.
FIG. 3 conceptually shows the state of the filter medium 4 with different lengths of the fixed strings 5a and 5b when the filter medium is filled, during filtration, and backwashing.
FIG. 3A is a view showing a state in which the filter medium 4 is filled in the filtration chamber 1. Since the filter medium 4 is densely packed, it is in a state of floating in the air in the filtration chamber 1.
FIG.3 (b) is a figure which shows the state of the filter medium 4 at the time of filtration. The filter medium 4 receives water pressure by the water flow W1 and is biased downward. Further, the fixed string 5a prevents the filter medium 4 from being crushed by water pressure and prevents the occurrence of a short circuit flow.
FIG.3 (c) is a figure which shows the state of the filter medium 4 at the time of backwashing. The filter medium during backwashing moves upward as a whole by the washing water B1, but the movement of the filter medium 4 varies between the filter mediums due to the difference in the length of the fixed string 5b.

  By making the lengths of the fixed strings 5a, 5b different between the filter media 4 as described above, not all the filter media 4 move in the same way during water flow and backwashing, but the vertical direction of each filter media 4 The relative position of the baffle fluctuates and the position of the bundling member fluctuates, which prevents the occurrence of short-circuit flow during water flow, and the adjacent filter media 4 rub against each other during backwashing, thereby eliminating turbidity. It will be easier.

  As the long fibers 41 constituting the filter medium 4, it is preferable to use those subjected to Woolley processing in order to make the filter medium 4 bulky. The fiber material is not particularly limited, and polypropylene fiber, acrylic fiber, polyester fiber, polyamide fiber, and the like can be used. These resin fibers are hydrophobic and are excellent in detergency because they are easily peeled off.

  The thickness of the long fiber 41 can be variously selected according to the type of filtration tower to be applied, the type of water to be treated, etc., as in the conventional case, but is preferably about 10 μm to about 100 μm. Moreover, it is preferable that the length of the long fiber 41 is equivalent to the length of the filtration chamber 1, and it is preferable to use the thing of the range of 1000 mm-1500 mm.

DESCRIPTION OF SYMBOLS 1 Filtration chamber 2 Perforated plate 3 Perforated plate 4 Filter medium 5a Fixed string 5b Fixed string 10 Filtration tank 10a Filtration tank inner wall 11 Raw water supply port, washing waste water discharge port 12 Filtration water discharge port, washing water supply port 20 Filtration device 30 Binding part 31 Core material 32 Ring-shaped member 33 Hole 41 Long fiber W1 Raw water W2 Filtration water B1 Washing water B2 Washing drainage

Claims (3)

A filtration tank;
A perforated plate provided on the upstream side in the filtration tank;
A perforated plate provided on the downstream side in the filtration tank;
A filter medium comprising a long fiber bundle in which an upper end portion and a lower end portion are bound by a binding member, and having a fixed string at the upper end portion and the lower end portion;
With
The filter medium is disposed in the filtration tank by attaching the fixed string at the upper end to the porous plate provided on the upstream side, and attaching the fixed string at the lower end to the porous plate on the downstream side,
There is a difference in the length of the fixed string of the filter medium.   The filtration apparatus according to claim 1, wherein there is a difference in the length of the fixed string between adjacent filter media.   The filtration apparatus according to claim 1 or 2, wherein the long fibers constituting the long fiber bundle are Wooly long fibers.