JPH0450842B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] This invention forms a filtration layer made of a large number of fibers by an upward water flow in a waterway such as a sewage channel, and raises water in the waterway containing fine solids to form a filtration layer in the filtration layer. This relates to a horizontal filter bed type low pressure drop upward flow filtration device which is capable of filtering a large amount of water with low pressure drop by passing through the water, and which can maintain an appropriate upward flow velocity even when the flow rate changes. It is. [Prior Art] Conventionally, as a device for filtering water containing fine solids by upward flow using a filter medium having floating properties, as disclosed in Japanese Patent Application Laid-Open No. 48-25259, A perforated blocking body is provided at the upper part of the filter tank, and a current plate is provided at the bottom of the filter tank, and a floating filter material is accommodated between the perforated blocking body and the current plate, and the lower part of the current plate A filtration device is known in which a raw water supply pipe is opened in a filter tank and a wash water supply pipe is provided below the perforated blocking body. [Problems to be Solved by the Invention] When the conventional filtration device is used to filter water in a waterway, if the flow rate of the waterway changes greatly, the flow velocity of the upward water flow also changes greatly, so it is difficult to obtain high-performance filtration. The problem is that it cannot be done. [Means for Solving the Problems] In order to achieve the above object, in the horizontal filter bed type low pressure drop upward flow filtration device of the first invention, an upstream weir 2 provided in a waterway 1 and a waterway bottom 3 are provided. A water passage opening 4 is provided between the upstream weir 2 and the upper part of the downstream weir 5 provided in the waterway 1 on the downstream side of the upstream weir 2. An upper perforated plate 6 for receiving fiber lumps and a lower perforated plate 7 for receiving fiber lumps, which are located underwater, are arranged between the downstream weir 5 and the upper perforated plate 6 and the lower perforated plate 7, respectively. A fixed partition plate 11 extending in the width direction of the waterway is provided, and an elevating partition plate 12 is provided above the fixed partition plate 11. A fiber lump filtration layer 9 consisting of a large number of fiber lumps 8 is formed, and a space 10 for allowing the fiber lumps to float and fall is formed between the lower part of the fiber lump filtration layer 9 and the lower porous plate 7 for receiving fiber lumps.
It is provided. Further, in the horizontal filter bed type low pressure drop upward flow filtration device of the second invention, the upstream weir 2 provided in the water channel 1
A water passage opening 4 is provided between the upstream weir 2 and the water channel bottom 3, and an overflow part is provided at the upper part of the downstream weir 5 provided in the water channel 1 on the downstream side of the upstream weir 2. Between the side weir 2 and the downstream weir 5, an upper perforated plate 6 for receiving fiber lumps and a lower perforated plate 7 for receiving fiber lumps, which are located underwater, are disposed, respectively, and extend in the waterway width direction. Upper perforated plate for receiving lumps 6
A plurality of fixed partition plates 11 are provided at intervals in the longitudinal direction of the water channel and extend from the upper end of the fixed partition plate 11 to the lower perforated fiber block receiving plate 7. The level of the perforated plate 6 gradually decreases from the upstream side to the downstream side, and a fiber agglomerate filtration layer 9 consisting of a large number of fiber agglomerates 8 floating by an upward water flow is formed below the upper perforated plate 6 for receiving the fiber agglomerates.
is formed, and a space 10 for allowing floating and falling of the fiber lumps is provided between the lower part of the fiber lump filtering layer 9 and the lower porous plate 7 for receiving the fiber lumps. Further, in order to wash the fiber lumps, an aeration pipe 13 for washing the fiber lumps is provided in the water below the lower porous plate 7. [Function] Water flowing from the upstream side of the waterway 1 through the water passage opening 4 into the lower chamber 37 between the waterway bottom 3 and the lower perforated plate 7 passes through the lower perforated plate 7 and the upper perforated plate 6. The upward water flow causes each fiber mass 8 to float toward the upper perforated plate 6 to form a fiber mass filtration layer 9 under the upper perforated plate 6, and the upward water flow It is filtered when passing through the fiber mass filtration layer 9. As filtration progresses, fine solid matter in the upward water flow adheres to the lower layer fiber mass 8 in the fiber mass filtration layer 9, resulting in a fiber mass 8 to which a certain amount or more of fine solid matter has adhered.
The apparent specific gravity of the fibers increases and it becomes impossible to form the filtration layer 9, and the fibers float in the space 10 for allowing the floating and falling of the fibers or the lower porous plate 7
sediment to the top. Therefore, a new fiber mass 8 is always exposed at the bottom of the fiber mass filtration layer 9, and low pressure drop upward flow filtration by the horizontal filter bed is continued. When the elevating partition plate 12 is lowered onto the fixed partition plate 11, even when the amount of water flowing in the water channel 1 decreases, the flow velocity of the upward water flow becomes equal to or higher than a certain level. Moreover, between the upstream side weir 2 and the downstream side weir 5, an upper perforated plate 6 extending in the channel width direction and for receiving fiber lumps is provided.
A plurality of fixed partition plates 11 extending from the fiber mass receiving lower perforated plate 7 are provided at intervals in the longitudinal direction of the waterway, and the level of the upper end of each fixed partition plate 11 and the level of the upper perforated plate 6 are If the value is gradually lowered from the upstream side to the downstream side, even if the flow rate of the waterway is very large, the width of the waterway is narrow, and the flow rate changes, low pressure drop upward flow filtration by the horizontal filter bed can be achieved. can be done. Furthermore, by blowing out air from the fiber mass cleaning aeration pipe 13 provided in the water below the lower perforated plate 7, an upward flow of air-mixed water is generated, and the upward flow of the air-mixed water causes the upward flow of the air-mixed water. Perforated plate 6
The fiber mass 8 between the lower porous plate 7 and the lower porous plate 7 can be stirred and washed in water. [Example] Next, the present invention will be explained in detail using illustrated examples. FIGS. 9 and 10 show a filtering fiber mass 8 made of a crimped fiber mass used in an embodiment of the present invention. A large number of crimped fibers 20 are assembled into a bundle, and the center portion of the bundle of crimped fibers is made of a rigid synthetic fiber thread, a hard plastic band, or a corrosion-resistant metal wire such as an aluminum wire. The bundled crimped fibers are bundled so as to be squeezed by a binding material 21, and the bundled crimped fibers are rolled into a substantially spherical shape with a diameter of 10 to 50 mm. The synthetic fibers constituting the crimped fibers 20 are optimally fibers with a higher specific gravity than water, such as polyvinylidene chloride fibers, but polyvinyl chloride fibers, polyethylene fibers, or other synthetic fibers may also be used. good. In the case of a fiber mass with a diameter of approximately 3.5 cm using polyvinylidene chloride crimped fibers with a true specific gravity greater than 1,
The sedimentation rate in water is approximately 90-100 m/hr. Therefore, in a uniform upward water flow that is faster than the settling speed of the fiber mass in water, the fiber mass floats to the surface. 1 to 3 show a horizontal filter bed type low pressure loss upward flow filtration device according to an embodiment of the first invention using the fiber mass 8, which is installed on the upstream side of the water channel 1. A weir 2 is integrally connected to both side walls 22 of the waterway 1, and a water passage opening 4 is provided between the bottom 3 of the waterway 1 and the lower end of the upstream weir 2. A downstream weir 5 having an overflow part at the upper part is provided on the downstream side, and the downstream weir 5 is integrally connected to the bottom part 3 and both side walls 22 of the waterway 1, and further connected to the upstream weir 2 and the downstream weir. 5, fixed partition plates 11 extending in the width direction of the waterway are arranged at intervals in the longitudinal direction of the waterway at the middle part in the height direction of the waterway, and both ends of each fixed partition plate 11 in the width direction are arranged as follows. It is fixed by bolts to a vertical support member 23 fixed to the side wall 22. At a level slightly lower than the upper surface of the downstream weir 5, a horizontal fiber mass receiving upper perforated plate 6 made of wire mesh is installed between each adjacent fixed partition plate 11, and between the upstream side weir 2 and the fixed partition plate 11. between and the downstream weir 5
and the fixed partition plate 11, and the peripheral portion of each fiber mass receiving upper perforated plate 6 includes the upstream weir 2, the downstream weir 5, the fixed partition plate 11, and the side wall 22.
A horizontal fiber mass receiving lower part made of a wire mesh is placed on an upper horizontal support member 24 fixed to the upper horizontal support member 24 and fixed with bolts, and is located between the water channel bottom 3 and the fiber mass receiving upper perforated plate 6. The porous plate 7 is provided between the lower parts of the adjacent fixed partition plates 11, between the lower part of the upstream weir 2 and the lower parts of the fixed partition plate 11, and between the lower parts of the downstream weir 5 and the fixed partition plate 11. The lower horizontal support member 25 fixed to the upstream side weir 2, the downstream side weir 5, the fixed partition plate 11, and the side wall 22 is arranged around the lower perforated plate 7 for receiving fiber agglomerates.
It is placed on and fixed with bolts. A large number of fiber lumps 8 are accommodated between the upper perforated plate for receiving fiber lumps 6 and the lower perforated plate for receiving fiber lumps 7, and between the upstream side weir 2 and the downstream side weir 5, from below to above. Due to the upward water flow, each fiber mass 8 is floated toward the upper perforated fiber mass receiving plate 6, and a fiber mass consisting of a large number of fiber masses 8 is placed under the upper perforated fiber mass receiving plate 6. A filtration layer 9 is formed,
Moreover, a space 10 for allowing floating and falling of the fiber lumps is provided between the lower part of the fiber lump filtering layer 9 and the lower porous plate 7. A vertical elevating partition plate 12 disposed above each of the fixed partition plates 11 is inserted between a pair of guide beams 26 fixedly installed across the upper part of each side wall 22, and A vertical blocking plate 28 whose upper end is connected to a lifting fluid cylinder 27 and which is disposed at the upper part of the downstream weir 5 is placed between a pair of guide beams 29 that are fixedly installed across the upper part of each side wall 22. The upper end of the blocking plate 28 is connected to a lifting fluid cylinder 30. A perforated algae removal plate 31 made of a wire mesh is disposed upstream of the water passage opening 4 to prevent algae from entering the lower part of the lower perforated plate 7. A fiber mass cleaning aeration pipe 13 is fitted into a holding member 32 having a vertical groove-shaped cross section fixed to both side walls 22 and has a large number of aeration holes at the lower part of the lower perforated plate 7. 13 is connected to a blower 34 via an air pipe 33, and furthermore, a water intake port in a water suction pipe 36 of a pump 35 for discharging cleaning waste water is connected to the upper perforated plate 6 between the fixed partition plate 11 on the downstream side and the downstream weir 5. placed at the top. The thickness of the fiber agglomerate filtration layer 9 is set to, for example, 200 mm, and it is sufficient that the distance between the upper perforated plate 6 and the lower perforated plate 7 is about twice the thickness of the agglomerate filtration layer 9. When performing filtration, the water channel bottom 3 and the lower perforated plate 7
If the flow velocity of the upward water flow flowing from the lower chamber 37 to the upper part of the upper perforated plate 6 is 100 m/hr or more, each fiber mass 8 is floated toward the upper perforated plate 6 and A fiber mass filtration layer 9 can be formed in close contact with the lower part of the plate 6. Further, by using binding materials 21 made of materials with different specific gravity, the settling speed of the fiber mass 8 can be adjusted. If the flow velocity of the upward water flow is less than 100 m/hr, the ascending/lowering partition plate 12 at an appropriate position is lowered and brought into contact with the upper part of the fixed partition plate 11 to reduce the filtration area appropriately and reduce the flow rate of the upward water flow. Flow velocity 100m/
It can be more than hr. When raising and lowering the lifting partition plate 12, the flow rate of the waterway is measured by a measuring device, and the lifting fluid cylinder 27 is expanded and contracted via a control device based on a signal from the measuring device, so that the lifting partition plate 12 is automatically moved. It may be raised and lowered. Next, the operation of the waterway water filtration device according to the embodiment of the first invention will be explained. Water flowing from the upstream side of the waterway 1 through the water passage opening 4 into the lower chamber 37 between the waterway bottom 3 and the lower perforated plate 7 passes upward through the lower perforated plate 7 and the upper perforated plate 6. The upward water flow causes each fiber mass 8 to float toward the upper perforated plate 6 to form a fiber mass filtration layer 9 under the upper perforated plate 6, and the upward water flow causes the fiber mass filtration layer to form a fiber mass filtration layer 9 under the upper perforated plate 6. It is filtered as it passes through layer 9. As filtration progresses, fine solid matter in the upward water flow adheres to the lower layer fiber mass 8 in the fiber mass filtration layer 9, resulting in a fiber mass 8 to which a certain amount or more of fine solid matter has adhered.
The apparent specific gravity of the fibers increases and it becomes impossible to form the filter layer 9, and the fibers float in the space 10 for allowing the floating and falling of the fibers or the lower porous plate 7
sediment to the top. Therefore, a new fiber mass 8 is always exposed at the bottom of the fiber mass filtration layer 9, and low pressure drop upward flow filtration by the horizontal filter bed is continued. As the number of fine solid matter adhering fiber lumps 8 floating or settling in the space 10 for allowing floating/falling of fiber lumps increases,
When it becomes necessary to wash the fiber mass 8, the blocking plate 28 is lowered to the upper part of the downstream weir 5, and air is blown out from the fiber mass cleaning aeration pipe 13.
An upward flow of air-mixed water is generated, and the upward flow of the air-mixed water destroys the fiber mass filtration layer 9, and the fiber mass 8 is transferred between the upper perforated plate 6 and the lower perforated plate 7 by the air-mixed water flow. Stir and float, fiber mass 8
Wash and remove fine solid matter adhering to the Further, the cleaning drainage water is discharged from the upper part of the upper porous plate 6 to the outside of the water channel by the cleaning drainage discharge pump 35. When the cleaning wastewater is discharged to the outside of the waterway, cleaning water automatically flows into the cleaning section from the upstream side of the upstream weir 2. In a sewage treatment plant, washing wastewater is sent to an upstream part such as a settling basin to treat concentrated fine solids in the washing wastewater. The horizontal filter bed-type low-pressure-drop upward flow filtration purifying device for channel water according to the embodiment of the first invention is installed, for example, in an intermediate channel that collects final sedimentation tank treated water in a sewage treatment plant. Note that by removing the algae removal perforated plate 31 and installing a blocking plate in its place, the upstream weir 2
It may be configured such that the water channel 1 is partitioned at a portion, a gate (not shown) provided at the lower opening of the downstream weir 5 is opened, and water on the downstream side of the water channel is used as cleaning water. Next, the operation of the water filtration apparatus according to the embodiment of the first invention will be explained with reference to the principle diagram shown in FIG. When an upward water flow (100 m/hr or more) is generated from the lower perforated plate 7 side toward the upper perforated plate 6, the fiber mass 8 floats toward the upper perforated plate 6 as shown in FIG. 4A. As shown in FIG. 4B, a fiber mass filtration layer 9 is formed under the upper perforated plate 6. As the filtration of the upward water flow through the fiber mass filtration layer 9 progresses, the fiber mass 8 to which a certain amount or more of fine solid matter has adhered floats within the space 10 or settles on the lower porous plate 7, At the end of the filtration, as shown in FIG. 4C, a relatively thin fibrous mass filtration layer 9 remains under the upper porous plate 6, and the fibrous mass 8 also exists under the space 10. Next, as shown in FIG. 4D, air is ejected from the diffuser pipe 13 to generate an upward flow of air-mixed water,
The fiber mass 8 is stirred and suspended between the upper perforated plate 6 and the lower perforated plate 7, and the fiber mass 8 is washed. After the cleaning is completed, the fiber mass 8A containing a large amount of air bubbles is floating near the upper perforated plate 6, as shown in FIG. 4E. From this state, filtration using upward water flow is resumed. FIG. 5 shows an embodiment of the second invention implemented when the water flow rate of the waterway 1 is very large and the width of the waterway 1 is narrow. The edge, a large number of upper perforated plates 6, and a large number of lower perforated plates 7 are arranged so as to become lower from the upstream side to the downstream side, and the area of the water passage opening 4 at the lower part of the upstream weir. The pressure drop is 20
It is set large enough to maintain around ~30mmAq. In the case of the embodiment of the second invention, at the water level 38 when the waterway flow rate decreases, filtration is performed by the fiber mass filtration layer 9 on the downstream side of the waterway, and the waterway flow rate gradually increases and the water level rises. As the flow progresses, the fiber mass filtration layer 9 that performs filtration spreads toward the upstream side. Therefore, in the case of the embodiment of the second invention, even if the flow rate of the waterway decreases, an upward flow velocity of 100 m/hr or more can be obtained, and the lifting partition plate 12 in the embodiment of the first invention can be obtained. Can be omitted. When performing filtration using upward water flow as mentioned above, if there is a water level difference of about 200 mmAq, the
Since an upward water flow velocity of 300 m/hr can be obtained, fine solids in the flowing water of the waterway can be attached to the fiber mass 8 and removed. Table 1 shows the results of a comparative test of low pressure drop upward water flow filtration and downward water flow filtration using the apparatus of the present invention for treated water from a final sedimentation tank of a sewage treatment plant.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below. Water flowing from the upstream side of the waterway 1 through the water passage opening 4 into the lower chamber 37 between the waterway bottom 3 and the lower perforated plate 7 passes upward through the lower perforated plate 7 and the upper perforated plate 6. As each fiber mass 8 floats toward the upper perforated plate 6 due to the upward water flow, a fiber mass filtration layer 9 is automatically formed under the upper perforated plate 6 to perform upward water flow filtration. can be done,
In addition, as the filtration progresses, fine solids in the upward water flow adhere to the lower layer fiber lumps 8 in the fiber lump filtration layer 9, and the fiber lumps 8 to which a certain amount or more of fine solids have adhered
The apparent specific gravity of the fibers increases and it becomes impossible to form the filtration layer 9, and the fibers float in the space 10 for allowing the floating and falling of the fibers or the lower porous plate 7
Since the fiber lumps 8 settle upward, new fiber lumps 8 are constantly exposed at the bottom of the fiber lump filtration layer 9, and low pressure drop upward flow filtration can be performed continuously for a long time using the horizontal filter bed. The entire fiber mass constituting 9 can be effectively utilized. In addition, in the case of the first invention, by lowering the elevating partition plate 12 onto the fixed partition plate 11, even when the flow rate decreases, the flow velocity of the upward water flow can be kept above a certain level, resulting in high performance. can be filtered. In the case of the second invention, there is a groove extending in the waterway width direction between the upstream weir 2 and the downstream weir 5 and extending from the upper perforated plate 6 for receiving fiber lumps to the lower perforated plate 7 for receiving fiber lumps. A plurality of fixed partition plates 11 extending along the
The water channels are provided at intervals in the longitudinal direction, and the level of the upper end of each fixed partition plate 11 and the level of the upper perforated plate 6 are gradually lowered from the upstream side to the downstream side, so that the flow rate of the water channel is very large and Even when the width of the waterway is narrow and the flow rate changes, low pressure drop upward flow filtration can be performed, so high performance filtration can be performed. Furthermore, in the first or second invention, air is jetted out from the fiber mass cleaning aeration pipe 13 provided in the water below the lower perforated plate 7 to generate an upward flow of the air-mixed water. The fiber mass 8 between the upper perforated plate 6 and the lower perforated plate 7 is stirred in the water by the upward flow of the air-mixed water, and can be easily and quickly washed.

[Brief explanation of drawings]

1 to 3 show an embodiment of the first invention, in which FIG. 1 is a longitudinal sectional side view of a horizontal filter bed type low pressure drop upward flow filtration device, FIG. 2 is a longitudinal sectional front view thereof, FIG. 3 is a longitudinal sectional front view showing an enlarged part of FIG. 2. FIG. FIG. 4 is a principle diagram for performing upward water flow purification and fiber mass washing, FIG. FIG. 7 is a longitudinal sectional side view showing a first modification of the cleaning drainage discharge means, FIG. 7 is a longitudinal sectional front view showing a second modification of the cleaning drainage discharge means, and FIG.
The figure is a longitudinal side view, and Figure 9 is a front view of the fiber mass.
FIG. 10 is a sectional view thereof. In the figure, 1 is a water channel, 2 is an upstream weir, 3 is a bottom of a channel, 4 is an opening for water passage, 5 is a downstream weir, 6 is an upper perforated plate for receiving fiber lumps, and 7 is for receiving fiber lumps. Lower porous plate, 8 is a fiber mass, 9 is a fiber mass filter layer, 10 is a space for allowing the fiber mass to float and fall, 11 is a fixed partition plate,
12 is an elevating partition plate, 13 is a diffuser pipe for cleaning fiber lumps,
20 is a crimped fiber, 21 is a binding material, 22 is a side wall, 2
3 is a vertical support member, 24 is an upper horizontal support member, 2
5 is a lower horizontal support member, 26 is a guide beam, 2
7 is a lifting fluid cylinder, 28 is a blocking plate, 29 is a guide beam, 30 is a lifting fluid cylinder, 31
is a perforated plate for algae removal, 33 is an air pipe, 34 is a blower,
35 is a cleaning drainage discharge pump, 36 is a water suction pipe, 3
9 is a cylindrical box body, 40 is a drainage introduction tube, 41 is a drain pipe, 42 is a drainage channel, and 43 is an on-off valve.

Claims (1)

[Claims] 1. A water passage opening 4 is provided between an upstream weir 2 provided in the waterway 1 and a waterway bottom 3, and a water passage opening 4 is provided in the waterway 1 on the downstream side of the upstream weir 2. An overflow part is provided at the upper part of the downstream weir 5, and between the upstream weir 2 and the downstream weir 5, an upper perforated plate 6 for receiving fiber lumps and an upper perforated plate 6 for receiving fiber lumps, which are located underwater, are provided. A fixed partition plate 11 extending in the channel width direction is provided between the upper perforated plate 6 and the lower perforated plate 7, and the fixed partition plate 11
An elevating partition plate 12 is provided above, and a fiber lump filtration layer 9 consisting of a large number of fiber lumps 8 floating by an upward water flow is formed below the fiber lump receiving upper perforated plate 6. A horizontal filter bed type low pressure drop upward flow filtration device in which a space 10 for allowing floating and falling of fiber lumps is provided between the lower part of layer 9 and the lower perforated plate 7 for receiving fiber lumps. 2. A water passage opening 4 is provided between the upstream weir 2 provided in the waterway 1 and the waterway bottom 3, and a downstream weir 5 provided in the waterway 1 on the downstream side of the upstream weir 2. An overflow part is provided at the upper part of the dam, and between the upstream weir 2 and the downstream weir 5, there are an upper perforated plate 6 for receiving fiber lumps and a lower perforated plate 7 for receiving fiber lumps, which are located underwater, respectively. are arranged, and a plurality of fixed partition plates 11 extending in the width direction of the waterway and extending from the upper perforated plate 6 for receiving fiber lumps to the lower perforated plate 7 for receiving fiber lumps are arranged at intervals in the longitudinal direction of the waterway. The level of the upper end of each fixed partition plate 11 and the level of the upper perforated plate 6 for receiving the fiber lumps gradually decrease from the upstream side to the downstream side, and the lower part of the upper perforated plate 6 for receiving the fiber lumps gradually decreases from the upstream side to the downstream side. A fiber lump filtration layer 9 consisting of a large number of fiber lumps 8 floating by the upward water flow is formed, and between the lower part of the fiber lump filtration layer 9 and the lower porous plate 7 for receiving fiber lumps, the fiber lumps floating are formed. Space for descent allowance 1
0 horizontal filter bed type low pressure drop upward flow filtration device. 3. The horizontal filter bed type low pressure drop upward flow filtration device according to claim 1 or 2, wherein a fiber agglomerate cleaning aeration pipe 13 is provided in the water below the fiber agglomerate receiving lower porous plate 7.