Flow path switching device

Abstract

To provide a flow path switching device that ensures operability and watertightness while minimizing disruption to the water flow. [Solution] The flow path switching device 6 comprises a first flow path 11 and a second flow path 12, a door body 20 capable of selectively closing the first flow path 11 and the second flow path 12, and a moving mechanism 30 for moving the door body 20 to close the first flow path 11 and the second flow path 12. Each of the first flow path 11 and the second flow path 12 consists of an open channel and is formed in a trapezoidal cross-section in which the distance between a pair of inner surfaces widens from bottom to top. The door body 20 has a trapezoidal shape that allows the first flow path 11 and the second flow path 12 to be opened and closed by a lifting operation. The movable mechanism 30 includes a lateral movement mechanism 32 capable of moving the door body 20 between a first position P1 capable of closing the first flow path 11 and a second position P2 capable of closing the second flow path 12 in the space above the flow path, and a lifting mechanism 40 for lifting the door body 20 up and down.

Description

Technical Field

[0001] The present invention relates to a flow path switching device that switches flow paths between a plurality of flow paths each composed of an open channel.

Background Art

[0002] In sewage treatment facilities and water purification facilities, raw water is pretreated with a grit chamber and a dust collector and then transferred to a plurality of solid-liquid separation devices. The pretreated raw water is generally transferred to each solid-liquid separation device through a groove-shaped water channel (open channel) called a trough.

[0003] In these facilities, the operation of some solid-liquid separation devices may be stopped due to failures or inspections. In this case, it is necessary to switch the flow path so that the raw water transferred to the solid-liquid separation device to be stopped is transferred to the operating solid-liquid separation device.

[0004] For this reason, conventionally, a connecting passage that can be opened and closed by a corner gate is provided in the middle of two troughs connected to each solid-liquid separation device, and the position on the downstream side of the connecting passage in each trough is configured to be closable by a corner gate. The corner gate is one of the gate structures that closes the flow path with one or a plurality of detachable plate-shaped door bodies.

[0005] That is, when stopping one solid-liquid separation device, the trough connected to the solid-liquid separation device is closed and the connecting passage is opened, so that the water flow in the trough connected to the solid-liquid separation device to be stopped is merged into the water flow in the other trough through the connecting passage.

[0006] However, in the configuration of closing the trough with a corner gate, when closing or opening the flow path, the door body is often moved manually, which requires labor and time. Therefore, for example, as disclosed in Patent Document 1, it has been considered to perform flow path switching of the trough with a gate that rotates the door body (hereinafter sometimes referred to as a swing gate).

Prior Art Documents

Patent Documents

[0007] [Patent Document 1] Japanese Patent Publication No. 2005-9274 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] Swing gates are considered to be more advantageous than drop gates in terms of the effort and time required to switch the flow path.

[0009] However, swing gates have the following challenges. Swing gates need to maintain a watertight seal between the gate body and the inner surface and inner bottom surface of the trough. In this case, a configuration in which a sealing member provided on the gate body is pressed against each surface of the trough from the inside of the trough, in other words, a configuration in which the sealing member is pressed against each surface in a direction perpendicular to the direction of water flow in the trough cross-section (transverse plane), may not be able to adequately ensure a watertight seal. This is because, from the viewpoint of the gate body's opening and closing operation, it is difficult to firmly press the sealing member against each surface (especially the inner bottom surface).

[0010] On the other hand, a configuration can be considered in which steps are provided on the inner surface and inner bottom surface (especially the inner bottom surface) of the trough, and a door body (watertight member) is pressed against the stepped portion from the upstream side along the direction of the water flow. However, in this case, the cross-sectional area of ​​the flow path changes in the middle of the trough, which may cause turbulence in the water flow during normal operation and adversely affect the processing in the solid-liquid separation device.

[0011] Therefore, sewage treatment and water treatment facilities require flow path switching devices that ensure good operability of the door body and watertightness when the water is stopped, while minimizing disruption to the water flow. It should be noted that similar or comparable challenges may exist not only in sewage treatment and water treatment facilities, but also in agricultural waterways, river waterways, experimental facilities, and other similar structures.

[0012] This invention has been made in view of the above circumstances, and aims to provide a flow path switching device that can ensure good operability of the door body and watertightness when water is stopped, and that does not easily disturb the water flow. [Means for solving the problem]

[0013] [Aspect 1] To solve the above problems, a flow path switching device according to one aspect of the present invention comprises a plurality of flow paths including at least a first flow path and a second flow path, a door body capable of selectively closing either the first flow path or the second flow path, and a moving mechanism for moving the door body to close the first flow path and the second flow path, wherein each of the first flow path and the second flow path consists of an open channel having an inner bottom surface and a pair of inner surfaces, and is formed in a trapezoidal cross-section in which the distance between the pair of inner surfaces widens from bottom to top, the door body has a trapezoidal shape that can open and close the first flow path and the second flow path by a lifting operation, and the movable mechanism includes a lateral movement mechanism capable of moving the door body between a first position in the space above the plurality of flow paths in which the first flow path can be closed and a second position in which the second flow path can be closed, and a lifting mechanism for raising and lowering the door body.

[0014] This flow path switching device allows for the selective closure (water stoppage) of either the first or second flow path by moving the door body between a first and second position and lowering it at either position. This selection allows for the switching of the flow path.

[0015] In this case, the first and second channels consist of open channels with a trapezoidal cross-section, and the gate body has a trapezoidal shape that allows it to open and close the first and second channels, respectively, by raising and lowering it. Therefore, by lowering the gate body and bringing it into contact with the inner bottom and inner surfaces of each channel, each channel can be closed while keeping the space between the inner bottom and inner surfaces and the gate body watertight. In other words, each channel can be closed while keeping the space between the inner bottom and inner surfaces and the gate body watertight, without having to create steps in the inner bottom or other surfaces to change the channel area of ​​each channel midway. Moreover, when the gate body is raised from the closed state, it can be completely separated from the inner bottom and inner surfaces, so the gate body can be easily moved between the first and second positions.

[0016] Therefore, this flow path switching device makes it possible to provide a flow path switching device that ensures good operability of the door body and watertightness when water is stopped, while also being less likely to disturb the water flow.

[0017] [Aspect 2] In the flow path switching device of embodiment 1, the first flow path and the second flow path are connected by a connecting passage, the connecting passage consists of an open channel having an inner bottom surface and a pair of inner surfaces, and is formed to have the same cross-sectional shape as the first flow path and the second flow path, the lateral movement mechanism is configured to move the door body in the upper space between a reference position where the connecting passage can be closed, the first position and the second position, the first position is the position where the flow in the first flow path merges with the flow in the second flow path through the connecting passage when the door body closes the first flow path, and the second position is the position where the flow in the second flow path merges with the flow in the first flow path through the connecting passage when the door body closes the second flow path.

[0018] This flow path switching device allows for selective closure (water stoppage) of the first flow path, the second flow path, and the connecting passage by moving the door body between a reference position, a first position, and a second position, and lowering it at any of these positions. This selection allows for switching of the flow path. Specifically, under normal circumstances, closing the connecting passage allows for the formation of independent flows in the first and second flow paths. On the other hand, closing the first flow path allows the water flow in the first flow path to merge with the water flow in the second flow path through the connecting passage, and closing the second flow path allows the water flow in the second flow path to merge with the water flow in the first flow path through the connecting passage.

[0019] In this case, the communication passage consists of an open water channel having the same cross-sectional shape as the first flow path and the second flow path. Therefore, by lowering the door body and making it contact the inner bottom surface and the inner side surface of the communication passage, the communication passage can be closed in a watertight sealed state between the inner bottom surface and the inner side surface and the door body. Further, when the door body is raised from the closed state, the door body can be completely separated from the inner bottom surface and the inner side surface. Therefore, the door body can be easily moved between the reference position, the first position, and the second position.

[0020] [Aspect 3] In the flow path switching device of Aspect 2, the lateral movement mechanism may include a beam member movable in the upper space of the first flow path, the second flow path, and the communication passage, and the lifting mechanism may be provided on the beam member and configured to lift and lower the door body with respect to the beam member.

[0021] According to this configuration, by moving the beam member in the upper space of the first flow path, the second flow path, and the communication passage, it becomes possible to move the door body between the reference position, the first position, and the second position as the beam member moves. Therefore, the door body can be easily moved between the reference position, the first position, and the second position. <{

[0022] [Aspect 4] In the flow path switching device of Aspect 3, the lateral movement mechanism may further include a support column erected between the first flow path and the second flow path and configured to horizontally support the beam member rotatably, and be configured to move the door body between the reference position, the first position, and the second position as the beam member rotates.

[0023] According to this configuration, by rotating the beam member with the support column as a fulcrum, the door body can be moved between the reference position, the first position, and the second position. That is, it becomes possible to open and close the first flow path, the second flow path, and the communication passage with a relatively simple configuration similar to a swing gate.

[0024] [Aspect 5] In any of the flow path switching devices according to Aspects 1 to 4, the movable mechanism may be configured to move the door body by manual operation.

[0025] According to this configuration, it becomes possible to switch the flow path without difficulty even in a situation where power cannot be secured, such as during a disaster.

[0026] [Aspect 6] In any of the flow path switching devices according to Aspects 2 to 5, a configuration including a locking mechanism that restrains the beam member at each of the reference position, the first position, and the second position may be employed.

[0027] According to this configuration, the door body can be raised and lowered while the beam member is restrained at each of the reference position, the first position, and the second position, that is, while the door body is stably arranged at each position. Therefore, the raising and lowering operability of the door body is improved.

[0028] [Aspect 7] In any of the flow path switching devices according to Aspects 2 to 6, the door body may be configured to close the first flow path and the second flow path at a position inclined with respect to the longitudinal direction of the flow paths of the first flow path and the second flow path.

[0029] According to this configuration, when closing the first flow path, the door body functions as a guide for guiding the water flow of the first flow path to the communication path, and when closing the second flow path, the door body functions as a guide for guiding the water flow of the second flow path to the communication path. Therefore, it becomes possible to more smoothly merge the water flow on one side to be closed of the first flow path and the second flow path into the water flow on the other side.

[0030] [Aspect 8] In any of the flow path switching devices according to Claims 1 to 7, the door body includes a door main body and a seal member made of a rubber material that seals between the inner bottom surface and the pair of inner side surfaces, and the seal member may be composed of a pair of unit members having a P-shaped cross section that are arranged in the thickness direction of the door main body, fixed to the door main body, and each having a hollow portion at the tip end.

[0031] With this configuration, when the sealing member comes into contact with the inner bottom surface and inner surface of the flow path, the entire unit of the member elastically deforms and presses against the inner bottom surface, and the hollow portion also elastically deforms in a way that compresses its internal space. As a result, it becomes possible to highly seal the space between the door body and the inner bottom surface and inner surface of each flow path by the sealing member.

[0032] [Aspect 9] Furthermore, a flow path switching device according to one aspect of the present invention comprises a first region having a first flow path, a second region comprising a plurality of second flow paths adjacent to the upstream or downstream side in the longitudinal direction of the first region and each communicating with the first flow path, a door body capable of closing one or more of the plurality of second flow paths to the first flow path, and a movable mechanism for moving the door body to close the one or more of the second flow paths, wherein the movable mechanism includes a lateral movement mechanism capable of moving the door body between a retracted position in the space above the flow path where all of the plurality of second flow paths can communicate with the first flow path and a predetermined position where the one or more of the second flow paths can be closed to the first flow path, and a lifting mechanism for raising and lowering the door body, wherein the door body has a trapezoidal shape with a lower side shorter than the upper side, and the flow path cross-sectional shape at the predetermined position is a trapezoidal shape corresponding to the door body, capable of opening and closing the one or more of the second flow paths in accordance with the lifting and lowering operation of the door body.

[0033] In this flow path switching device, the door body is moved between a retracted position and a predetermined position in the space above the flow path, and by lowering it at the predetermined position, one or more second flow paths can be simultaneously closed (water stopped) from the first flow path. Furthermore, by raising the door body from this closed state, the door body can be easily moved between the retracted position and the predetermined position. [Effects of the Invention]

[0034] As described above, the flow path switching device of the present invention makes it possible to provide a flow path switching device that ensures good operability of the door body and watertightness when water is stopped, and that does not easily disturb the water flow. [Brief explanation of the drawing]

[0035] [Figure 1] This is a plan view of a water treatment system to which a flow path switching device according to the first embodiment of the present invention is applied. [Figure 2] This is a plan view of the flow path switching device during normal operation (when the connecting passage is closed). [Figure 3] This is a cross-sectional view of the flow path switching device (a cross-sectional view along the line III-III in Figure 2). [Figure 4] This is a cross-sectional view of the flow path switching device (a cross-sectional view along the line IV-IV in Figure 2). [Figure 5] This is a cross-sectional view of the flow path switching device (corresponding to Figure 4) with the door body positioned in the water-stop release position. [Figure 6] Figure 3 is an enlarged view (cross-sectional view) of the sealing member. [Figure 7] This is a plan view of the flow path switching device during normal operation. [Figure 8] This is a plan view of the flow path switching device when the first flow path is closed. [Figure 9] This is a plan view of the flow path switching device when the second flow path is closed. [Figure 10] This is a schematic plan view showing a flow path switching device according to the second embodiment. [Figure 11] This is a schematic plan view showing a flow path switching device according to the third embodiment. [Figure 12] This is a schematic plan view showing a modified example of a flow path switching device. [Figure 13] This is a schematic plan view showing a flow path switching device according to the fourth embodiment. [Figure 14] This is a schematic plan view showing a flow path switching device according to the fifth embodiment. [Modes for carrying out the invention]

[0036] Embodiments of the present invention will be described in detail below with reference to the drawings.

[0037] [Configuration of Water Treatment System 1] Figure 1 is a plan view of a water treatment system 1 to which the flow path switching device 6 according to the present invention is applied. The water treatment system 1 shown in Figure 1 is equipment that performs pretreatment for water purification and wastewater treatment, that is, treatment to separate impurities (debris, dust) from raw water.

[0038] The water treatment system 1 comprises a raw water intake 2, a debris remover 4 installed at the intake 2, a solid-liquid separator 8, a trough 5 that guides the raw water that has passed through the debris remover 4 to the solid-liquid separator 8, and a flow path switching device 6.

[0039] The debris remover 4 is equipment that captures and removes relatively large impurities from the raw water. In this example, four debris removers 4A to 4C, numbered 1 to 4, are arranged in parallel in this order relative to the direction of raw water flow (white arrows). Each debris remover 4, for example, rotates a long, narrow porous endless belt (screen S) in the vertical direction, capturing and removing impurities from the raw water with the screen S. The raw water flows into the inside of the screen S, passes through the screen S, and is introduced into the trough 5. The trough 5 is a channel-shaped waterway (open channel) that guides the raw water that has passed through the debris remover 4 to the solid-liquid separator 8.

[0040] This water treatment system 1 is provided with two troughs, a first and a second, 5A and 5B, which extend in the direction of the arrangement of the dust removal machines 4. The first trough 5A is connected to the first dust removal machine 4A and the second dust removal machine 4B, and the second trough 5B is connected to the third dust removal machine 4C and the fourth dust removal machine 4D. Both troughs 5A and 5B are formed in a trapezoidal cross-section, with the width increasing from bottom to top, and they are arranged parallel to each other in adjacent regions Ar.

[0041] The solid-liquid separator 8 is equipment that separates and removes relatively small impurities that cannot be captured by the dust remover 4. The solid-liquid separator 8 consists of, for example, a centrifugal sedimentation machine that separates solid components in raw water by the action of centrifugal force. This water treatment system 1 is equipped with two solid-liquid separators, the first and second 8A and 8B, respectively, with the first trough 5A connected to the first solid-liquid separator 8A and the second trough 5B connected to the second solid-liquid separator 8B. As a result, during normal operation, raw water that has passed through the first dust remover 4A and the second dust remover 4B is treated in the first solid-liquid separator 8A, and raw water that has passed through the third dust remover 4C and the fourth dust remover 4D is treated in the second solid-liquid separator 8B.

[0042] The flow path switching device 6 is a component of the trough 5 and is used to merge the raw water from one of the two troughs 5A and 5B with the raw water from the other, as needed. Such flow path switching is necessary, for example, in the event of a malfunction or inspection of the first solid-liquid separator 8A or the second solid-liquid separator 8B. As a result, during the period of malfunction or inspection, all raw water that has passed through the first to fourth dust collectors 4A to 4D will be treated in either the first solid-liquid separator 8A or the second solid-liquid separator 8B.

[0043] [Configuration of the flow path switching device 6] Figure 2 is a plan view of the flow path switching device 6. More specifically, it is a plan view of the flow path switching device 6 during normal operation (when the connecting passage 13 described later is closed). Figure 3 is a cross-sectional view of the flow path switching device 6 along line III-III in Figure 2, and Figure 4 is a cross-sectional view of the flow path switching device 6 along line IV-IV in Figure 2.

[0044] The flow path switching device 6 is integrated into the trough 5 and, as previously described, constitutes a part of the trough 5 in the middle of region Ar where the two troughs 5A and 5B are arranged parallel to each other.

[0045] The flow path switching device 6 comprises a first flow path 11 that constitutes part of the first trough 5A, a second flow path 12 that constitutes part of the second trough 5B, a connecting passage 13 that connects the first flow path 11 and the second flow path 12, a door body 20 that can selectively close the first flow path 11, the second flow path 12, and the connecting passage 13, and a movable mechanism 30 that moves the door body 20.

[0046] The connecting passage 13 is a short passage that connects the first passage 11 and the second passage 12 in a direction perpendicular to their longitudinal direction X (see Figure 1). In other words, the passage switching device 6 has a passage that is H-shaped in plan view. In the following description, the longitudinal direction X is synonymous with the flow direction of raw water (direction of water flow) in the troughs 5 (5A, 5B) and each of the passages 11 and 12.

[0047] Each of the first channel 11, the second channel 12, and the connecting passage 13 consists of an open channel with a trapezoidal cross-section, similar to the rest of the trough 5. As shown in Figures 2 and 3, the first channel 11 is composed of an inner bottom surface 11a and a pair of inner surfaces 11b, the second channel 12 is composed of an inner bottom surface 12a and a pair of inner surfaces 12b, and the connecting passage 13 is composed of an inner bottom surface 13a and a pair of inner surfaces 13b.

[0048] The first channel 11 and the second channel 12 have symmetrical cross-sectional shapes in the region Ar. On the other hand, the connecting passage 13 is formed with a width W3 (dimension parallel to the longitudinal direction X) that is larger than the widths W1 and W2 of the first channel 11 and the second channel 12 (dimensions perpendicular to the longitudinal direction X).

[0049] The inner bottom surfaces 11a, 12a, and 13a of each channel 11, 12 and connecting passage 13 are continuous flat surfaces. The inner bottom surfaces of the troughs 5 (5A, 5B) are inclined downwards from upstream to downstream in the longitudinal direction X. Therefore, the inner bottom surfaces 11a, 12a, and 13a of each channel 11, 12 and connecting passage 13 are also inclined downwards from upstream to downstream by an angle θ (see Figure 4) with respect to the horizontal plane, so as to be continuous with the inner bottom surfaces of the other parts of the trough 5.

[0050] The door body 20 is formed in a trapezoidal shape that allows each of the flow paths 11, 12 and the connecting passage 13 to be opened and closed, and the flow paths 11, 12 and the connecting passage 13 are opened and closed by a lifting motion.

[0051] More specifically, as shown in Figure 4, in a side view from the watertight surface side, the gate body 20 is formed in a trapezoidal shape, comprising a lower edge portion 20a and a pair of side edges 20b extending upward from both ends of the lower edge portion 20a. Note that the left and right surfaces of the gate body 20 in Figure 3, that is, the surfaces on both sides in the thickness direction of the gate body 20, are the watertight surfaces of the gate body 20.

[0052] As shown in Figures 3 and 4, the door body 20 comprises a door body 21 made of metal with a rectangular cross-section, and a sealing member 22 made of rubber that is fixed to the edge of the door body 21 and forms the lower edge 20a and side edge 20b. As shown in Figures 3 and 6, the sealing member 22 consists of a pair of unit members 23 that are fixed to the flange portion of the door body 21, back to back in the thickness direction of the door body 21. Each unit member 23 has a P-shaped cross-section, with its base end 23a fixed to the door body 21 and a hollow pipe portion 23b at its tip. The unit members 23 are sometimes called P-type watertight rubber.

[0053] The movable mechanism 30 includes a lateral movement mechanism 32 for moving the door body 20 horizontally in the space above the first flow path 11, the second flow path 12, and the connecting passage 13, and a lifting mechanism 40 for raising and lowering the door body 20.

[0054] The lateral movement mechanism 32 comprises a vertically extending support column 34 and a beam member 33 supported by the support column 34 so as to be able to pivot freely around the axis Ax of the support column 34. The beam member 33 extends linearly in the horizontal direction and is cantilevered to the support column 34 at one end in its longitudinal direction. The door body 20 is positioned below the beam member 33 and is suspended from the beam member 33.

[0055] With this configuration, as the beam member 33 rotates, the door body 20 can move between a reference position P0 where the connecting passage 13 can be closed, a first position P1 where the first flow path 11 can be closed, and a second position P2 where the second flow path 12 can be closed, as shown in Figure 2. The reference position P0, the first position P1, and the second position P2 are the positions of the door body 20 when the flow path switching device 6 is viewed from above. In other words, these are positions where the connecting passage 13, the first flow path 11, and the second flow path can be closed by lowering the door body 20 from the water-stopping release height position to the water-stopping height position described later.

[0056] The reference position P0 is the position where the door body 20 crosses the connecting passage 13 in a straight line in its width direction. In contrast, the first position P1 is the position where the door body 20 crosses the first flow path 11 diagonally with respect to its width direction, and the second position P2 is the position where the door body 20 crosses the second flow path 12 diagonally with respect to its width direction.

[0057] More specifically, the first position P1 is the position where the door body 20 crosses the first channel 11 at a 45° angle to the longitudinal direction X, such that the end of the door body 20 located on the side of the support column 34 is located downstream of the end located on the opposite side of the support column 34 (opposite the support column 34). The second position P2 is the position where the door body 20 crosses the second channel 12 at a 45° angle to the longitudinal direction X, such that the end of the door body 20 located on the side of the support column 34 is located downstream of the end located on the opposite side of the support column 34. By arranging the door body 20 to cross each channel 11 and 12 at an angle to their width, the connecting passage 13 and the narrower channels 11 and 12 can be opened and closed using a common door body 20.

[0058] As shown in Figures 2 and 3, a V-shaped recess 15 is formed in plan view on the inner surface 11b of the outer side of the first channel 11, that is, the inner surface 11b on the side away from the second channel 12, at the position corresponding to the first position P1, which is recessed outward. Similarly, a V-shaped recess 16 is formed in plan view on the inner surface 12b of the outer side of the second channel 12, that is, the inner surface 12b on the side away from the first channel 11, at the position corresponding to the second position P2, which is recessed outward.

[0059] The recess 15 is formed by an upstream surface 11u facing downstream and a downstream surface 11d facing upstream, with the upstream surface 11u facing the support column 34. The cross-sectional shape of the first channel 11 at the first position P1, more specifically as shown in Figure 2, is a trapezoidal cross-section that is approximately the same as the cross-sectional shape of the connecting passage 13 shown in Figure 4 (though not shown in the figure).

[0060] Similarly, the recess 16 is formed by an upstream surface 12u facing downstream and a downstream surface 12d facing upstream, with the upstream surface 12u facing the support column 34. Furthermore, the cross-sectional shape of the second channel 12 at the second position P2, more specifically as shown in Figure 2, is formed as a trapezoidal cross-section, which is approximately the same as the cross-sectional shape of the connecting passage 13 shown in Figure 4 (though not shown in the figure).

[0061] This configuration allows the first flow path 11 to be opened and closed at the first position P1, and the second flow path 12 to be opened and closed at the second position P2, both by the door body 20.

[0062] The lifting mechanism 40 is composed of a so-called screw-feed mechanism. Specifically, a horizontally extending operating shaft 43 is supported on the beam member 33 via a bracket 41 and a bearing, and a vertically extending screw shaft 45 is connected to the tip of the operating shaft 43 via a gearbox 44, and this screw shaft 45 is screwed into and inserted into a nut member 46 fixed to the upper part of the door body 20. A handle 42 is attached to the base end of the operating shaft 43, and the operating shaft 43 is configured to be rotatable via the handle 42. In addition, a pair of vertically extending guide shafts 47 are provided on both sides of the nut member 46 of the door body 20, and the door body 20 is supported on the beam member 33 via the screw shaft 45 with these guide shafts 47 guided by the beam member 33.

[0063] In other words, the lifting mechanism 40 is configured such that when the operating shaft 43 is rotated via the handle 42, this rotation is transmitted to the screw shaft 45 via the gearbox 44, and the door body 20 moves up and down as the screw shaft 45 rotates.

[0064] As a result, for example, at the reference position P0, the door body 20 can be manually raised and lowered between a watertight height position where the lower edge 20a and side edges 20b of the door body 20 are pressed against the inner bottom surface 13a and inner side surface 13b of the passageway 13, closing the passageway 13, as shown in Figure 4, and a watertight release height position where the lower edge 20a and side edges 20b of the door body 20 are separated from the inner bottom surface 13a and inner side surface 13b of the passageway 13, releasing the closed state of the passageway 13, as shown in Figure 5. This is basically the same for the first position P1 and the second position P2.

[0065] The flow path switching device 6 further includes a locking mechanism that restrains the beam member 33 at each of the aforementioned reference position P0, first position P1, and second position P2.

[0066] The locking mechanism consists of a beam member side bracket 33a provided at the tip of the beam member 33, a flow path side bracket 18 provided at a position overlapping with the beam member side bracket 33a at each of the reference position P0, first position P1, and second position P2, and a locking pin 35 which is removably inserted into pinholes formed in the brackets 18 and 33a at the position where the two brackets 18 and 33a overlap.

[0067] In other words, the locking mechanism is configured to restrain the beam member 33 in place by inserting the locking pin 35 into both brackets 18 and 33a at any of the following positions: reference position P0, first position P1, and second position P2.

[0068] [Flow path switching by flow path switching device 6] (During normal operation) During normal operation of the water treatment system 1, the door 20 is positioned at the reference position P0, and the connecting passage 13 is closed by the door 20. Figure 7 is a plan view of the flow path switching device 6 showing the state in which the connecting passage 13 is closed by the door 20.

[0069] With the connecting passage 13 closed, the first channel 11 and the second channel 12 are independent, and independent flows of raw water are formed in each of the first channel 11 and the second channel 12. Therefore, as previously described, the raw water that has passed through the first dust remover 4A and the second dust remover 4B is sent to the first solid-liquid separator 8A through the first trough 5A, and the raw water that has passed through the third dust remover 4C and the fourth dust remover 4D is sent to the second solid-liquid separator 8B through the second trough 5B.

[0070] When the passageway 13 is closed, as shown in Figure 4, the lower edge 20a and side edges 20b of the door body 20 are positioned at a predetermined watertight height position (the position shown in Figure 4) where they are pressed against the inner bottom surface 13a and inner side surface 13b of the passageway 13. When the door body 20 is positioned at the watertight height position, the entire tip of each unit member 23 is elastically deformed and pressed against the inner bottom surface 13a and inner side surface 13b, and the pipe portion 23b is elastically deformed so as to crush the internal space due to the water pressure. As a result, the space between the door body 20 and the inner bottom surface 13a and inner side surface 13b is sealed in a watertight state by the sealing member 22, and the passageway 13 is reliably closed.

[0071] (During maintenance of the first solid-liquid separation unit 8A) During maintenance of the first solid-liquid separator 8A, the door body 20 is moved from the reference position P0 to the first position P1. This opens the connecting passage 13 and closes the first flow path 11 with the door body 20. The switching procedure in this case is as follows.

[0072] First, the lock pin 35 is pulled out to release the restraint on the beam member 33 relative to the reference position P0. Next, the handle 42 is rotated to raise the door body 20 from the watertight height position to the watertight release height position. This opens the connecting passage 13.

[0073] Subsequently, by pressing the beam member 33 towards the first channel 11, the support column 34 is rotated around its axis Ax, moving the door body 20 from the reference position P0 to the first position P1. At this time, as shown in Figure 5, the door body 20 is not in contact with either the inner bottom surface 13a or the inner side surface 13b of the connecting passage 13, and the door body 20 is subjected to the pressure of the water flow in the first channel 11. Therefore, the door body 20 can be easily moved from the reference position P0 to the first position P1.

[0074] Next, the beam member 33 is restrained in the first position P1 with the lock pin 35, and then the handle 42 is rotated to lower the door body 20 from the water-stop release height position to the water-stop height position. This closes the first flow path 11.

[0075] Figure 8 is a plan view of the flow path switching device 6 showing the state in which the first flow path 11 is closed by the gate 20. In this way, by opening the connecting passage 13 and closing the first flow path 11, the raw water flow in the first flow path 11 can be merged with the raw water flow in the second flow path 12 through the connecting passage 13. In this case, as previously described, the gate 20 closes the first flow path 11 at a position that crosses the first flow path 11 diagonally with respect to its width (i.e., a position that is inclined with respect to the longitudinal direction X). Therefore, the gate 20 functions as a guide that directs the flow from the upstream side of the first flow path 11 into the connecting passage 13, and as a result, the flow in the first flow path 11 can be smoothly merged with the second flow path 12.

[0076] In this example, as shown in Figures 2 and 8, the inner surface 13b of the connecting passage 13 located on the support column 34 side is formed in an arc shape in plan view, and the door body 20, more precisely, closes the first flow path 11 by being pressed against one inner surface 11b of the first flow path 11 and one inner surface 11b of the connecting passage 13.

[0077] (During maintenance of the second solid-liquid separation unit 8B) During maintenance of the second solid-liquid separator 8B, the door body 20 is moved from the reference position P0 to the second position P2. This opens the connecting passage 13 and closes the second flow path 12 with the door body 20. This switching procedure is the same as the procedure described above for opening the connecting passage 13 and closing the first flow path 11 with the door body 20, except that the door body 20 is moved to the second position P2.

[0078] Figure 9 is a plan view of the flow path switching device 6 showing the state in which the second flow path 12 is closed by the gate 20. In this way, by opening the connecting passage 13 and closing the second flow path 12, the raw water flow in the second flow path 12 can be merged with the raw water flow in the first flow path 11 through the connecting passage 13. In this case as well, the gate 20 closes the second flow path 12 at a position that crosses the second flow path 12 diagonally with respect to its width (i.e., a position that is inclined with respect to the longitudinal direction X), so the gate 20 functions as a guide that directs the flow from the upstream side of the second flow path 12 into the connecting passage 13. Therefore, the flow in the second flow path 12 can be smoothly merged with the first flow path 11.

[0079] In this case as well, similar to the first position P1, the door body 20 is precisely pressed against one inner surface 12b of the second flow path 12 and one inner surface 12b of the connecting passage 13, thereby closing the second flow path 12.

[0080] After maintenance of the solid-liquid separator 8 is completed, the door body 20 is basically returned from the first position P1 or second position P2 to the reference position P0 in the reverse order of the procedure described above, and the connecting passage 13 is closed with the door body 20. This allows the raw water to be guided to each solid-liquid separator 8A, 8A through the first flow path 11 and the second flow path 12, respectively.

[0081] [effect] As described above, in the flow path switching device 6 of the embodiment, the door body 20 can be moved between the reference position P0, the first position P1, and the second position P2 to selectively close (stop the water flow) any of the first flow path 11, the second flow path 12, and the connecting passage 13. Therefore, the flow path can be switched between a state in which the connecting passage 13 is closed to form independent water flows in the first flow path 11 and the second flow path 12, a state in which the first flow path 11 is closed and the water flow in the first flow path 11 is merged with the water flow in the second flow path 12, and a state in which the second flow path 12 is closed and the water flow in the second flow path 12 is merged with the water flow in the first flow path 11.

[0082] In this case, the flow path switching device 6 of the embodiment consists of open channels with trapezoidal cross-sections for each of the flow paths 11, 12 and connecting passage 13, and the gate body 20 is formed in a trapezoidal shape. The first flow path 11, the second flow path 12 and the connecting passage 13 can be opened and closed by the gate body 20 as the gate body 20 moves up and down. Therefore, the first flow path 11 and the second flow path can be closed by sealing the space between the inner bottom surfaces 11a, 12a, etc. of the first flow path 11 and the second flow path 12 and the gate body 20 in a watertight manner, without having to create steps in the inner bottom surfaces 11a, 12a, etc. of the first flow path 11 and the second flow path 12 to change the flow path area midway. Furthermore, when the door body 20 is raised from the water-stopping height position to the water-stopping release height position, the door body 20 is completely separated from the inner bottom surfaces 11a, 12a, 13a, etc. of the first flow path 11, the second flow path 12, and the connecting passage 13 (see Figure 5). Therefore, when moving the door body 20 between the reference position P0, the first position P1, and the second position P2, the door body 20 can be easily moved.

[0083] Therefore, according to the flow path switching device 6 of the embodiment, it is possible to provide a flow path switching device that ensures good operability of the door body 20 and watertightness when water is stopped, and that does not easily disturb the water flow during normal operation of the water treatment system 1.

[0084] Furthermore, in the flow path switching device 6 of the embodiment, the lateral movement mechanism 32 includes a beam member 33 that can move in the space above the first flow path 11, the second flow path 12, and the connecting passage 13, and the lifting mechanism 40 is provided on the beam member 33 and is configured to raise and lower the door body 20 relative to the beam member 33.

[0085] Therefore, according to the flow path switching device 6 of the embodiment, by moving the beam member 33 in the space above the first flow path 11, the second flow path 12, and the connecting passage 13, the door body 20 can be easily moved between the reference position P0, the first position P1, and the second position P2 as the beam member 33 moves.

[0086] In this case, the flow path switching device 6 of the embodiment further includes a support column 34 erected between the first flow path 11 and the second flow path 12 to support the beam member 33 so that it can rotate horizontally, and the beam member 33 rotates relative to the support column 34 to move the door body 20 between a reference position P0, a first position P1, and a second position P2.

[0087] Therefore, according to the flow path switching device 6 of this embodiment, the opening and closing of the first flow path 11, the second flow path 12, and the connecting passage 13 can be performed with a relatively simple configuration similar to a swing gate.

[0088] Furthermore, in the flow path switching device 6 of this embodiment, the movable mechanism 30 is configured to allow the door body 20 to be moved by manual operation. Therefore, even in situations where power cannot be secured, such as during a disaster, the flow path switching described above can be performed without difficulty.

[0089] Furthermore, the flow path switching device 6 of this embodiment is equipped with a locking mechanism that allows the beam member 33 to be restrained at the reference position P0, the first position P1, and the second position P2 by inserting a locking pin 35. As a result, the door body 20 can be raised and lowered while the beam member is restrained at each of the reference position P0, the first position P1, and the second position P2, that is, while the door body 20 is stably positioned at each of the positions. Consequently, the operability of raising and lowering the door body 20 is improved.

[0090] Furthermore, in the flow path switching device 6 of the embodiment, the door body 20 is configured to close the first flow path 11 and the second flow path 12 in an inclined position with respect to the longitudinal direction X of the first flow path 11 and the second flow path 12. Therefore, when the first flow path 11 is closed, the door body 20 functions as a guide to direct the water flow of the first flow path 11 to the connecting passage 13, and when the second flow path 12 is closed, the door body 20 functions as a guide to direct the water flow of the second flow path 12 to the connecting passage 13. As a result, it becomes possible to more smoothly merge the water flow on one side of the first flow path 11 and the second flow path 12 that is closed with the water flow on the other side.

[0091] Furthermore, in the flow path switching device 6 of the embodiment, the door body 20 comprises a door body 21 and a rubber sealing member 22 that seals the space between the door body 21 and the inner bottom surfaces 11a, 12a, 13a, etc. of the first flow path 11. The sealing member 22 is composed of a pair of P-shaped unit members 23, each fixed to the door body 21 and arranged in the thickness direction of the door body 21, and each having a pipe portion 23b (hollow portion) at its tip.

[0092] Therefore, as described above, when the sealing member 22 comes into contact with the inner bottom surfaces 11a, 12a, 13a, etc. of the connecting passage 13, the entire unit member 23 is elastically deformed and pressed against the inner bottom surface, etc., and the pipe portion 23b is elastically deformed in such a way that it compresses its internal space. As a result, the space between the door body 20 and the inner bottom surfaces 11a, 12a, 13a, etc. of the connecting passage 13 can be highly sealed by the sealing member 22.

[0093] [Second Embodiment] Next, the flow path switching device 6A according to the second embodiment will be described with reference to Figure 10. Figure 10 is a schematic plan view showing the flow path switching device according to the second embodiment. The flow path switching device 6A according to the second embodiment is not used as a replacement for the flow path switching device 6 described above that is applied to the water treatment system 1. The same applies to the flow path switching devices 6B, 6C, and 6D according to the third to fifth embodiments described later.

[0094] The flow path switching device 6A according to the second embodiment includes first to fourth flow paths 51 to 54 that intersect in a cross shape, a door body 60 that can selectively close the first flow path 51 and the second flow path 52, and a movable mechanism 70 for moving the door body 60.

[0095] Each channel 51-54 consists of an open channel with a trapezoidal cross-section, formed by an inner bottom surface and a pair of inner surfaces, more specifically, a trapezoidal cross-section in which the width dimension widens from bottom to top.

[0096] The basic configuration of the door body 60 and the movable mechanism 70 is the same as that of the door body 20 and the movable mechanism 30 in the first embodiment. That is, the door body 60 is formed in a trapezoidal shape that allows the first flow path 51 and the second flow path 52 to be opened and closed, and comprises a door body and a sealing member.

[0097] Furthermore, the movable mechanism 70 includes a lateral movement mechanism 72 for moving the door body 60 horizontally in the space above the first channel 51 and the second channel 52, and a lifting mechanism (not shown) for raising and lowering the door body 60. The lateral movement mechanism 72 comprises a support column 74 positioned at the joint between the side wall of the first channel 51 and the side wall of the second channel 52, and a beam member 73 supported so as to be rotatable around the axis of the support column 74. With this configuration, as shown in Figure 10, the door body 60 can move between a first position P11 in which the first channel 51 can be closed and a second position P12 in which the second channel 52 can be closed, in conjunction with the rotational movement of the beam member 73. The lifting mechanism is configured to raise and lower the door body 60 between a water-stopping height position and a water-stopping release height position relative to the beam member 73.

[0098] Although not shown in the diagram, the second embodiment is also provided with a locking mechanism similar to that of the first embodiment. The beam member 73 can be restrained in either the first position P11 or the second position P12 by inserting a locking pin into the bracket.

[0099] In the flow path switching device 6A of the second embodiment described above, the flow path can be switched between a state in which the first flow path 51, the third flow path 53, and the fourth flow path 54 are in communication with each other by positioning the door body 60 at the second position P12 and closing the second flow path 52 with the door body 60, and a state in which the second to fourth flow paths 52 to 54 are in communication with each other by positioning the door body 60 at the first position P11 and closing the first flow path 51 with the door body 60.

[0100] In addition, the flow path switching device 6A according to the second embodiment may further include a door body 60 that can selectively close the third flow path 53 and the fourth flow path 54, and a movable mechanism 70 for moving the door body 60.

[0101] [Third Embodiment] Next, the flow path switching device 6B according to the third embodiment will be described with reference to Figure 11. Figure 11 is a schematic plan view showing the flow path switching device 6B according to the third embodiment. Note that the configuration of the flow path switching device 6B according to the third embodiment is the same as the configuration of the flow path switching device 6A of the second embodiment, except for the specific flow path configuration. Therefore, in the following description, common components will be denoted by the same reference numerals and their descriptions will be omitted or simplified.

[0102] The flow path switching device 6B according to the third embodiment includes an upstream main flow path 50, a first flow path 51 and a second flow path 52 branching from the main flow path 50, a door body 60 capable of selectively closing the first flow path 51 and the second flow path 52, and a movable mechanism 70 for moving the door body 60.

[0103] The first channel 51 and the second channel 52 are formed by a partition wall 50a provided in the widthwise center of one channel that forms the main channel 50, which divides the downstream portion of the channel into two channels.

[0104] The first channel 51 and the second channel 52 consist of open channels with a trapezoidal cross-section, specifically a trapezoidal cross-section whose width increases from bottom to top, composed of an inner bottom surface and a pair of inner surfaces. The main channel 50 (upstream of the first channel 51 and the second channel 52) also consists of an open channel with a trapezoidal cross-section. The white arrows in Figure 11 indicate the direction of water flow.

[0105] The movable mechanism 70 includes a lateral movement mechanism 72 and a lifting mechanism (not shown) for raising and lowering the door body 60. The lateral movement mechanism 72 comprises a support column 74 positioned at the upstream end of the partition wall 50a and a beam member 73 that is pivotably supported around the axis of the support column 74. With this configuration, as the beam member 73 rotates, the door body 60 can move between a first position P11 in which the first flow path 51 can be closed and a second position P12 in which the second flow path 52 can be closed, as shown in Figure 11.

[0106] In the flow path switching device 6B of the third embodiment described above, the flow path can be switched between a state in which all the flow from the main flow path 50 is introduced into the first flow path 51 by positioning the door body 60 at the second position P12 and closing the second flow path 52 with the door body 60, and a state in which all the flow from the main flow path 50 is introduced into the second flow path 52 by positioning the door body 60 at the first position P11 and closing the first flow path 51 with the door 60.

[0107] In the example shown in Figure 11, the first position P11 and the second position P12 are positions where the gate body 20 crosses the flow paths P11 and P12 in a straight line in their width direction; in other words, the watertight surface of the gate body 20 is perpendicular to the flow direction of the main flow path 50.

[0108] However, the first position P11 and the second position P12 may be, for example, the positions shown in Figure 12. That is, the first position P11 and the second position P12 may be positions in which the gate body 60 is oblique to the direction of water flow, such that the end of the gate body 20 located on the column 74 side is located downstream of the end located on the opposite side of the column 74 (opposite the column 74). With this configuration, the gate body 60 functions as a guide to direct the flow of the main channel 50 into the first channel 51 and the second channel 52. This has the advantage of facilitating the introduction of flow to the other side when one side of the first channel 51 and the second channel 52 is closed by the gate body 60.

[0109] In the example shown in Figure 11, the direction of the water flow is to the left (see the white arrow), but it may be in the opposite direction. That is, the flow path switching device 6B may be configured to switch between a state in which only the flow from the first flow path 51 is introduced into the main flow path 50 by positioning the door body 60 at the second position P12 and closing the second flow path 52 with the door body 60, and a state in which only the flow from the second flow path 52 is introduced into the main flow path 50 by positioning the door body 60 at the first position P11 and closing the first flow path 51 with the door 60.

[0110] [Fourth Embodiment] Next, the flow path switching device 6C according to the fourth embodiment will be described with reference to Figure 13. Figure 13 is a schematic plan view showing the flow path switching device 6C according to the fourth embodiment. Note that the configuration of the flow path switching device 6C according to the fourth embodiment is the same as the configuration of the flow path switching device 6B of the third embodiment, except for the specific flow path configuration. Therefore, in the following description, common components will be denoted by the same reference numerals and their descriptions will be omitted or simplified.

[0111] The flow path switching device 6C according to the fourth embodiment comprises a first downstream region DAr having a main flow path 100, a second region UAr consisting of three sub-flow paths 101 to 103 adjacent to the upstream side of the first region DAr and each connected to the main flow path 100, a door body 60 capable of closing one or more of the first to third sub-flow paths 101 to 103 to the main flow path 100, and a movable mechanism 70 for moving the door body 60 to close the one or more sub-flow paths.

[0112] The first to third sub-channels 101 to 103 are formed by dividing the main channel 100 into three channels of approximately the same width upstream from a certain point, by two partition walls 120 and 121 provided within the main channel 100. Therefore, the bottom surface of the main channel 100 and the bottom surfaces of the sub-channels 101 to 103 are formed as a continuous flat surface. In the following description, the bottom surface of the main channel 100 and the bottom surfaces of the sub-channels 101 to 103 will not be distinguished and will simply be referred to as the channel bottom surface.

[0113] The basic configuration of the door body 60 and the movable mechanism 70 is the same as that of the door body 20 and the movable mechanism 30 in the first embodiment. That is, the door body 60 has a trapezoidal shape in which the lower side is shorter than the upper side, and comprises a door body and a sealing member.

[0114] Furthermore, the movable mechanism 70 includes a lateral movement mechanism 72 for moving the door body 60 horizontally in the space above the flow path, and a lifting mechanism (not shown) for raising and lowering the door body 60.

[0115] The lateral movement mechanism 72 includes a support column 74 provided on the upper part of the side wall 110 on one side of the main flow path 100, and a beam member 73 that is supported so as to be able to rotate around the axis of the support column 74. With this configuration, as the beam member 73 rotates, the door body 60 can move between the retracted position P00 and the first to third positions P21 to P23 (corresponding to the "predetermined positions" of the present invention), as shown in Figure 13. The retracted position P00 is the position in which all sub-flow paths 101 to 103 are in communication with (opened to) the main flow path 100. The first position P21 is the position in which only the first sub-flow path 101 can be closed to the main flow path 100. The second position P22 is the position in which both the first sub-flow path 101 and the second sub-flow path 102 can be closed to the main flow path 100. Furthermore, the third position P23 is a position that allows all sub-channels 101 to 103 to be closed off relative to the main channel 100.

[0116] The lifting mechanism is configured to raise and lower the door body 60 between a watertight height position and a watertight release height position relative to the beam member 73.

[0117] As shown in Figure 13, at the first position P21, the door body 60 is positioned between one side wall 110 of the main flow path 100 and the downstream end of the partition wall 121; at the second position P22, the door body 60 is positioned between the one side wall 110 and the downstream end of the partition wall 120; and at the third position P23, the door body 60 is positioned between one side wall 110 and the other side wall 111 of the main flow path 100 so as to cross the main flow path 100.

[0118] Furthermore, the cross-sectional shape of the flow path along the door body 60 located at the first position P21, that is, the cross-sectional shape of the portion of the flow path formed by the downstream end of the partition wall 121, one side wall 110 of the main flow path 100, and the bottom surface of the flow path, along the door body 60 (the cross-sectional shape at the position along the dashed line indicating the first position P21 in Figure 13), is the shape corresponding to the door body 60, and is shaped as a trapezoid that can close the first sub-flow path 101 as the door body 60 descends.

[0119] Furthermore, the cross-sectional shape of the flow path along the door body 60 located at the second position P22, that is, the cross-sectional shape of the portion of the flow path formed by the downstream end of the partition wall 120, one side wall 110 of the main flow path 100, and the bottom surface of the flow path, along the door body 60 (the cross-sectional shape at the position along the dashed line indicating the second position P22 in Figure 13), is a shape corresponding to the door body 60, and is shaped as a trapezoid that can close the first sub-flow path 101 and the second sub-flow path 102 as the door body 60 descends.

[0120] Furthermore, the cross-sectional shape of the flow path along the door body 60 located at the third position P23, that is, the cross-sectional shape of the portion of the flow path formed by one side wall 110 of the main flow path 100, the other side wall 110, and the bottom surface of the flow path, along the door body 60 (the cross-sectional shape at the position along the dashed line indicating the third position P23 in Figure 13), is the shape corresponding to the door body 60, and is shaped as a trapezoid that can close all of the first to third sub-flow paths 101 to 103 as the door body 60 descends.

[0121] In the flow path switching device 6C of the fourth embodiment described above, the flow path can be switched between the following states: 1) positioning the door body 60 at the retracted position P00 to open all first to third sub-flow paths 101, thereby introducing the flow of all sub-flow paths 101 to 103 into the main flow path 100; 2) positioning the door body 60 at the first position P21 to close the first sub-flow path 101 with the door body 60, thereby introducing the flow of the second and third sub-flow paths 102 and 103 into the main flow path 100; 3) positioning the door body 60 at the second position P22 to close the first sub-flow path 101 and the second sub-flow path 102 with the door body 60, thereby introducing only the flow of the third sub-flow path 103 into the main flow path 100; and 4) positioning the door body 60 at the third position P23 to close all sub-flow paths 101 to 103 with the door body 60, thereby blocking the introduction of flow from the upstream side to the main flow path 100.

[0122] In the retracted position P00, the door body 60 is positioned within the recess 110a formed in the side wall 110. As a result, all sub-channels 101 to 103 are fully open relative to the main channel 100.

[0123] In the example shown in Figure 11, the water flow is directed to the right (see the white arrow), but it can also be directed in the opposite direction. In other words, the flow path switching device 6C can switch the flow path to a state in which the door body 60 is placed in the retracted position P00 to open all sub-flow paths 101, thereby introducing the flow of the main flow path 100 into all sub-flow paths 101 to 103; a state in which the door body 60 is placed in the first position P21 to close the first sub-flow path 101 with the door body 60, thereby introducing the flow of the main flow path 100 into the second and third sub-flow paths 102 and 103; a state in which the door body 60 is placed in the second position P22 to close the first sub-flow path 101 and the second sub-flow path 102 with the door body 60, thereby introducing the flow of the main flow path 100 only into the third sub-flow path 103; and a state in which the door body 60 is placed in the third position P23 to close all sub-flow paths 101 to 103 with the door body 60, blocking the introduction of flow from the main flow path 100 into all sub-flow paths 101 to 103.

[0124] [Fifth Embodiment] Next, the flow path switching device 6D according to the fifth embodiment will be described with reference to Figure 14. Figure 14 is a schematic plan view showing the flow path switching device 6D according to the fifth embodiment. Note that the configuration of the flow path switching device 6D according to the fifth embodiment is the same as that of the flow path switching device 6C of the fourth embodiment, except for the specific flow path configuration. Therefore, in the following description, common components will be denoted by the same reference numerals and their descriptions will be omitted or simplified.

[0125] The flow path switching device 6D according to the fifth embodiment comprises an upstream first region UAr having two main flow paths 100a and 100b, a first region DAr adjacent to the downstream side of the first region UAr and connected to the two main flow paths 100a and 100b, a second region DAr consisting of three sub-flow paths 101 to 103, a first to third region 101 to 103, a door body 60 capable of closing one or more of the first to third sub-flow paths 101 to 103 to the two main flow paths 100a and 100b, and a movable mechanism 70 for moving the door body 60 to close the one or more sub-flow paths.

[0126] The first and second main channels 100a and 100b are formed when a single channel is divided into two channels of the same width by a partition wall 130 provided within that channel. The first to third sub-channels 101 to 103 are formed downstream of the first and second main channels 100a and 100b by two partition walls 120 and 121 provided within the same channel, which forms the first and second main channels 100a and 100b, when that channel is divided into three channels of the same width.

[0127] The movable mechanism 70 includes a lateral movement mechanism 72 and a lifting mechanism (not shown). The lateral movement mechanism 72 includes a support column 74 provided at the downstream end of the partition wall 130 and a beam member 73 that is pivotably supported around the axis of the support column 74. With this configuration, the door body 60 can move between the first to fourth positions P31 to P34 as shown in Figure 14, in conjunction with the pivoting movement of the beam member 73. The first position P31 is the position in which all sub-flow channels 101 to 103 are connected to (opened) the first main flow channel 100a. The second position P32 is the position in which only the first sub-flow channel 101 can be closed to the first main flow channel 100a. The third position P33 is the position in which both the first sub-flow channel 101 and the second sub-flow channel 102 can be closed to the first main flow channel 100a. The fourth position P34 is a position where all sub-channels 101-103 can be closed off to the first main channel 100a.

[0128] On the other hand, the first position P31 is a position in which all of the first to third sub-channels 101 to 103 can be closed to the second main channel 100b. The second position P32 is a third position P33 in which the second sub-channel 102 and the third sub-channel 103 can be closed to the second main channel 100b. The third position P33 is a position in which only the third sub-channel 103 can be closed to the second main channel 100b. The fourth position P34 is a position in which all of the sub-channels 101 to 103 are connected to (open to) the second main channel 100b.

[0129] As shown in Figure 13, at the first position P31, the door body 60 is positioned between the downstream end of the partition wall 130 and the side wall 110 of the second main flow path 100b; at the second position P32, the door body 60 is positioned between the downstream end of the partition wall 130 and the upstream end of the partition wall 121; at the third position P33, the door body 60 is positioned between the downstream end of the partition wall 130 and the upstream end of the partition wall 120; and at the fourth position P34, the door body 60 is positioned between the downstream end of the partition wall 130 and the side wall 111 of the first main flow path 100a.

[0130] Furthermore, the cross-sectional shape of the flow path along the door body 60 located at the first position P31, that is, the cross-sectional shape of the portion of the flow path formed by the downstream end of the partition wall 121, the side wall 110 of the second main flow path 100b, and the bottom surface of the flow path, along the door body 60 (the cross-sectional shape at the position along the dashed line indicating the first position P31 in Figure 14), is the shape corresponding to the door body 60, and is shaped into a trapezoid that can close all sub-flow paths 101 to 103 to the second main flow path 100b as the door body 60 descends.

[0131] Furthermore, the cross-sectional shape of the flow path along the door body 60 located at the second position P32, that is, the cross-sectional shape of the portion of the flow path formed by the upstream end of the partition wall 120, the downstream end of the partition wall 130, and the bottom surface of the flow path, along the door body 60 (the cross-sectional shape at the position along the dashed line indicating the second position P32 in Figure 14), is the shape corresponding to the door body 60, and is shaped as a trapezoid that can close the first sub-flow path 101 to the first main flow path 100a as the door body 60 descends.

[0132] Furthermore, the cross-sectional shape of the flow path along the door body 60 located at the third position P33, that is, the cross-sectional shape of the portion of the flow path formed by the upstream end of the partition wall 120, the downstream end of the partition wall 130, and the bottom surface of the flow path, along the door body 60 (the cross-sectional shape at the position along the dashed line indicating the third position P33 in Figure 14), is the shape corresponding to the door body 60, and is shaped as a trapezoid that can close the first sub-flow path 101 and the second sub-flow path 102 to the first main flow path 100a as the door body 60 descends.

[0133] Furthermore, the cross-sectional shape of the flow path along the door body 60 located at the fourth position P34, that is, the cross-sectional shape of the portion of the flow path formed by the side wall 111 of the first main flow path 100a, the downstream end of the partition wall 130, and the bottom surface of the flow path, along the door body 60 (the cross-sectional shape at the position along the dashed line indicating the fourth position P34 in Figure 14), is the shape corresponding to the door body 60, and is shaped as a trapezoid that can close all sub-flow paths 101 to 103 to the first main flow path 100a as the door body 60 descends.

[0134] In the flow path switching device 6D of the fifth embodiment described above, the door body 60 is positioned at the first position P31 to introduce the flow of the first main flow path 100a into all sub-flow paths 101 to 103, while blocking the flow from the second main flow path 100b to all sub-flow paths 101 to 103. Alternatively, the door body 60 is positioned at the second position P32 to introduce the flow of the first main flow path into the second and third sub-flow paths 102 and 103, while introducing the flow of the second main flow path 100b only into the first sub-flow path 101. The flow path can be switched between two states: one where the door body 60 is positioned at the third position P33, allowing the flow from the first main flow path 100a to be introduced only into the third sub-flow path 103, while the flow from the second main flow path 100b is introduced into the first and second sub-flow paths 101 and 102; and another where the door body 60 is positioned at the fourth position P34, blocking the flow from the first main flow path 100a to all sub-flow paths 101-103, while the flow from the second main flow path 100b is introduced into all sub-flow paths 101-103.

[0135] In the example shown in Figure 11, the direction of the water flow is leftward (see white arrow), but it may be in the opposite direction. In this case, the flow path switching device 6C can be configured to have two states: 1) position the door 60 at the first position P31, introducing the flow of all sub-channels 101-103 only into the first main channel 100a, and blocking the flow from the sub-channels 101-103 to the second main channel 100b; and 2) position the door 60 at the second position P32, introducing the flow of the second and third sub-channels 102 and 103 into the first main channel 100a, and introducing the flow of the first sub-channel 101 into the second main channel 100b. The flow path can be switched between two states: one where the door body 60 is positioned at the third position P33, allowing the flow from the third sub-channel 103 to be introduced into the first main channel 100a, and the flows from the first and second sub-channels 101 and 102 to be introduced into the second main channel 100b; and another where the door body 60 is positioned at the fourth position P34, blocking the flow from all sub-channels 101 to 103 to the first main channel 100a, and introducing the flow from all sub-channels 101 to 103 only into the second main channel 100b.

[0136] [Differentiations, etc.] The flow path switching devices 6, 6A to 6D described above are examples of preferred embodiments of the flow path switching device according to the present invention, and their specific configurations can be modified as appropriate without departing from the spirit of the present invention. For example, the following configuration can also be applied.

[0137] (1) In the first embodiment, the first position P1 and the second position P2 are positions where the door body 20 is inclined at a 45° angle with respect to the longitudinal direction X, that is, positions that traverse each flow path 11 and 12 in the width direction. However, the first position P1 and the second position P2 are not limited to these. The first position P1 and the second position P2 can be changed as appropriate based on the relationship between the widths W1 and W2 of the first flow path 11 and the second flow path 12 and the width W3 of the connecting passage 13.

[0138] For example, in the first embodiment, the width W3 of the connecting passage 13 is wider than the widths W1 and W2 of the first flow path 11 and the second flow path 12, but the width W3 of the connecting passage 13 may be the same as the widths W1 and W2 of the first flow path 11 and the second flow path 12. In this case, the positions where the door body 20 is positioned perpendicular to the longitudinal direction X of the first flow path 11 and the second flow path 12 are designated as the first position P1 and the second position P2, and the respective flow paths 11 and 12 can be closed at these positions.

[0139] (2) In the first embodiment, the lateral movement mechanism 32 is configured to move the door body 20 between a reference position P0, a first position P1, and a second position P2 by pivoting the door body 20 together with the beam member 33 using the support column 34 as a pivot point. However, the configuration of the lateral movement mechanism 32 is not limited to the configuration of the embodiment as long as it can move the door body 20 between the reference position P0, the first position P1, and the second position P2. This point is also true for the second to fifth embodiments.

[0140] (3) In the first embodiment, the movable mechanism 30 is configured to move the door body 20 manually. However, either one or both of the lateral movement mechanism 32 and the lifting mechanism 40 may be configured to be driven by a motor. That is, the beam member 33 can be driven to rotate by a motor and / or the door body 20 can be driven to move up and down by a motor. This is also true for the second to fifth embodiments. [Explanation of Symbols]

[0141] 1. Water treatment system 4 Dust remover 4a 1st dust remover 4b 2nd dust remover 4c 3rd dust remover 4d 4th dust remover 5 Trough 5 5a First Trough 5b Second trough 6, 6A, 6B, 6C, 6D Flow path switching device 8 Solid-liquid separator 8A 1st solid-liquid separator 8B 2nd solid-liquid separator 11. First channel 11a, 12a, 13a Inner bottom surface 11b, 12b, 13b inner surface 12 Second channel 13 Communication path 15, 16 Recess 20, 60 Door Body 21 Door body 22 sealing member 30, 70 movable mechanism 32, 72 Lateral movement mechanism 33, 73 Beam members 34, 74 pillars 40 Lifting mechanism P0 reference position P1 1st position P2 2nd position

Claims

1. A plurality of channels including at least a first channel and a second channel, A door body capable of selectively closing either the first channel or the second channel, The device comprises a moving mechanism for moving the door body to close the first and second flow paths, Each of the first and second channels consists of an open channel having an inner bottom surface and a pair of inner surfaces, and is formed in a trapezoidal cross-section in which the distance between the pair of inner surfaces widens from bottom to top. The door body has a trapezoidal shape that allows the first and second flow channels to be opened and closed by a lifting motion. The aforementioned movable mechanism is A lateral movement mechanism is provided that allows the door body to be moved between a first position in which the first flow path can be closed and a second position in which the second flow path can be closed, in the space above the plurality of flow paths. A flow path switching device including a lifting mechanism for raising and lowering the aforementioned door body.

2. In the flow path switching device according to claim 1, The first channel and the second channel are connected in part through a connecting passage. The aforementioned connecting passage consists of an open channel having an inner bottom surface and a pair of inner surfaces, and is formed to have the same cross-sectional shape as the first channel and the second channel. The lateral movement mechanism is configured to move the door body between a reference position in the upper space that can close the passageway, and the first and second positions. The first position is the position where the door body closes the first flow path, causing the flow in the first flow path to merge with the flow in the second flow path through the connecting passage. The second position is a flow path switching device in which the door body closes the second flow path, causing the flow in the second flow path to merge with the flow in the first flow path through the connecting passage.

3. In the flow path switching device according to claim 2, The lateral movement mechanism includes a beam member that can move in the space above the first channel, the second channel, and the connecting passage. The aforementioned lifting mechanism is a flow path switching device provided on the beam member, which raises and lowers the door body relative to the beam member.

4. In the flow path switching device according to claim 3, The lateral movement mechanism further comprises a support column erected between the first flow path and the second flow path to support the beam member so as to be able to rotate horizontally, and the flow path switching device moves the door body between the reference position, the first position and the second position as the beam member rotates.

5. In a flow path switching device according to any one of claims 1 to 4, The aforementioned movable mechanism is configured to move the door body by manual operation, and is a flow path switching device.

6. In the flow path switching device according to claim 2 or 3, A flow path switching device comprising a locking mechanism for restraining the beam member at the reference position, the first position, and the second position, respectively.

7. In the flow path switching device according to any one of claims 2 to 4, The door body is a flow path switching device that closes the first flow path and the second flow path at a position inclined with respect to the longitudinal direction of the flow paths of the first and second flow paths.

8. In the flow path switching device according to any one of claims 1 to 4, The door body comprises a door body and a sealing member made of rubber material that seals the space between the inner bottom surface and the pair of inner surfaces. The sealing member is a flow path switching device comprising a pair of P-shaped unit members fixed to the door body in the thickness direction of the door body and each having a hollow portion at its tip.

9. A first region having a first channel, and a second region consisting of a plurality of second channels adjacent to the upstream or downstream side in the longitudinal direction of the first region and each communicating with the first channel, A door body capable of closing one or more of the aforementioned plurality of second channels to the first channel, The device comprises a movable mechanism for moving the door body to close the one or more second flow paths, The aforementioned movable mechanism is A lateral movement mechanism is provided that allows the door body to move between a retracted position in the space above the flow path, where all of the plurality of second flow paths can be connected to the first flow path, and a predetermined position where one or more of the second flow paths can be closed off from the first flow path. The door body includes a lifting mechanism for raising and lowering it, The aforementioned door body has a trapezoidal shape in which the lower side is shorter than the upper side. A flow path switching device wherein the cross-sectional shape of the flow path at the predetermined position is a trapezoidal shape corresponding to the door body, and the one or more second flow paths can be opened and closed in accordance with the raising and lowering movement of the door body.

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