JP2005090674A - Flow passage switching valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow passage switching valve capable of frequently and reliably switching its flow passage so as not to be fully closed for a long period even if air is supplied from a blower and enabling the construction of a piping system at a proper cost. <P>SOLUTION: This flow passage switching valve comprises an internally cylindrical housing 2, a valve element 3 rotating around its axis in the housing, and a flange 7 closing both ends of the housing. The housing comprises a fluid inlet P and a plurality of fluid outlets A and B formed in the outer peripheral part thereof in the axial direction. The valve element comprises partition plates 5a and 5b having V-ring packings coming into contact with the inner surface of the housing to separate, airtight, the inner space of the housing. The partition plates are installed so that the inlet is allowed to communicate with the outlets in order and allowed to always communicate with at least one outlet. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flow path switching valve for switching the discharge direction of a supplied fluid, and in particular, a flow path suitable for membrane cleaning of a membrane filtration device used in water treatment such as sewage, middle water, industrial wastewater, and sewage. It relates to a switching valve.

  Conventionally, aeration according to the processing content has been performed in water treatment, and the aeration apparatus basically has a configuration in which a blower and an air diffuser are connected by piping. In submerged membrane devices that are frequently used in recent sewage treatment devices, aeration is also used for cleaning filtration membranes, for example, Japanese Patent No. 3341428 (Patent Document 1) is disclosed. That is, in Patent Document 1, a plurality of membrane units are arranged in a treatment tank separated by a partition plate, and each of the air diffusers is provided in an immersion membrane device in which an air diffuser is provided below each of the membrane units. Is connected to a common blower with a branch pipe and can be operated individually with each on-off valve provided on the pipe, and the aeration device can be operated alternately by opening and closing the on-off valve every predetermined time, for example every 15 minutes. Has been described. As a result, air bubbles and upward flow are generated between the membranes of the membrane unit on the operating diffuser, and downward flow is generated between the membranes of the membrane unit on the non-operated diffuser. It is explained that the non-filtered substance that occurs and adheres to the membrane surface of the membrane unit is peeled off by these actions.

Japanese Patent No. 3341428 (paragraph number 0006, FIG. 1)

  The immersion membrane device in Patent Document 1 is a device in which the membrane unit is separated by a vertical partition plate, and in the conventional immersion membrane device in which the membrane unit is not separated by the vertical partition plate, the upper part of the air diffuser that is not in operation Since neither air bubbles nor downward flow acts on the membrane unit, there is a problem that, for example, if left unattended for 15 minutes, dirt adheres. For this reason, most conventional diffusers are always operated. However, since it consumes a lot of energy if it is always operated, it is preferable to perform an alternate operation in order to save energy. However, in order to obtain a cleaning action equivalent to continuous aeration by intermittent aeration, the aeration cycle needs to be shortened to 3 to 30 seconds, for example.

  Since Patent Document 1 uses an on-off valve for switching a diffuser, in order to prevent an abnormal pressure from being applied to the blower when the valve is switched, the air supply from the blower is always supplied to any one of the diffusers. Must be supplied. For this purpose, it is desirable to use a responsive valve. Patent Document 1 does not specifically describe the on-off valve, but a butterfly valve or a ball valve is usually used for controlling the direction of fluid from the blower, and the same valve is used. Inferred. However, since the valve takes time to open and close, it is not suitable for the high frequency switching as described above.

  As a directional control valve capable of high-frequency switching and high-speed response, there is a valve for pneumatic control, and not only an on-off valve but also a flow switching valve such as a three-way valve is provided. The air diffuser can be operated alternately. However, the directional control valve for normal air pressure control has a high pressure and a small capacity specification, and if this is used, high pressure air must be prepared. For this reason, the air must be compressed using a compressor, and the air diffuser and the piping system must be high-pressure specifications, which is a problem in terms of cost. Further, the valve is required to operate at the above frequency for at least two years, and there is a concern in terms of durability.

  Therefore, according to the present invention, even if air is supplied from the blower, the flow path can be switched frequently and reliably over a long period so as not to be in a fully closed state. It aims at providing the flow-path switching valve which can construct | assemble a system.

The flow path switching valve of the present invention has a cylindrical housing inside, a valve body that rotates around the shaft center inside the housing, and a flange that closes both ends of the housing. The valve body has a partition plate provided with a V-shaped ring packing that contacts the inner surface of the housing and separates the internal space of the housing from each other in an airtight state. The plate is attached so that the inflow port sequentially communicates with each of the outflow ports as the valve body rotates, and the at least one outflow port is maintained in communication.
The flow path switching valve of the present invention has a cylindrical housing inside, a valve body that rotates around the shaft center inside the housing, and a flange that closes both ends of the housing. In addition, the valve body includes a V-shaped ring packing that contacts the inner surface of the housing and separates the internal space of the housing from each other in an airtight state. The partition plate has a member that traverses the inlet in the circumferential direction, and the space communicating with the inlet when the valve body rotates is separated from the space facing the one outlet. It is characterized by switching to the space where the exit faces. In addition, it is preferable that the partition plate has a member that divides the internal space where the outflow port faces with the inflow port interposed therebetween. However, even if it is not necessarily configured as a separate member, the single member has both functions. It may be.

The present invention has the following effects.
(1) Air leakage is small due to high airtightness.
(2) Since the operation of the flow path switching valve of the present invention is only to switch the flow path by continuously rotating the valve body in one direction, the service life is long, the reliability is high, and the driving power may be small.
(3) Since the switching time can be changed simply by changing the rotational speed of the valve body, the control is simple.
(4) Since the positional relationship between the valve body, the inflow port, and the outflow port is mechanically defined so as not to be fully closed, an overload such as an abnormal pressure rise is not applied to the fluid supply means such as a blower.
(5) The structure is simple and the packing ring can be easily replaced. Since no special precision processing is required, the manufacturing cost can be reduced, and a large structure can be easily manufactured.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited by these Examples.

Hereinafter, an example in which the flow path switching valve of the present invention is provided as a three-way valve for intermittent aeration will be described.
The flow path switching valve is installed below the membrane module of the hollow fiber microfiltration membrane immersed in the sewage treatment reactor and connected to a plurality of aeration devices used for aeration cleaning of the membrane. Air is supplied. The air supply pipe from the blower is connected to the inlet P of the flow path switching valve, the pipe from the outlet A is connected to one air diffuser group, and the pipe from the outlet B is connected to the remaining air diffuser group Connected. Therefore, the air diffuser is divided into two systems connected to the outlet A and the outlet B, and the air diffusers of each system alternately generate bubbles at the timing described later defined by the flow path switching valve.

FIG. 1 is an axial sectional view showing a schematic structure of a flow path switching valve 1 of the present embodiment, FIG. 2 is a transverse sectional view shown in an arrow direction in FIG. 1, and (a) is an HH section, (B) is an II cross section. The flow path switching valve 1 has a housing 2 whose inner surface is cylindrical, and a valve body 3 that rotates around an axis within the housing 2.
On the outer periphery of the housing 2, an inflow port P and outflow ports A and B are provided in the axial direction across the inflow port P. Both ends of the housing 2 are sealed with flanges 7 (7a, 7b), and bearings 8 that support the valve body 3 are installed on the flanges 7.
The valve body 3 has a rotating shaft 4 and a compartment plate attached to the rotating shaft 4. The partition plate is sandwiched between two vertical partition plates 5a and 5b, and the two circular vertical partition plates 5a and 5b, which are arranged at a predetermined interval, with the rotation shaft 4 passing through the center of the partition plate. It consists of two horizontal compartment plates 6a and 6b which are axisymmetrically joined to both the vertical compartment plates 5a and 5b and the rotary shaft 4 so as to divide the space into two in the radial direction. The vertical compartment plate 5a is located between the outlet A and the inlet P, and the vertical compartment plate 5b is located between the inlet P and the outlet B.

  1, the left side space between the inner peripheral surface of the housing 2 and the flange 7a and the vertical partition plate 5a is the chamber C, and the right side space between the vertical partition plate 5b and the flange 7b is the chamber D and the vertical partition. A central space between the plates 5a and 5b is a chamber E. The chamber E is further divided into two chambers E1 and E2 in the circumferential direction by a horizontal partition plate 6. Accordingly, the aforementioned inlet P faces the chamber E, and the outlets A and B face the chambers C and D, respectively. The vertical compartment plate 5a is formed with a flow passage hole 10 for communicating the chambers E1 and C, and the vertical compartment plate 5b is formed with a flow passage hole 11 for communicating the chambers E2 and D. Further, a rotational force transmitting means is attached to one end side of the rotating shaft 4 so that the valve body 3 can be rotated. In this example, the variable speed motor 9 is attached to the right flange 7b, and the shaft and the right end of the rotary shaft 4 are directly connected.

Next, operation | movement of the flow-path switching valve 1 is demonstrated based on FIG.
FIG. 3 shows the HH cross section of FIG. 1. The inlet P and the outlet A are shown by solid lines, but the outlet B is not visible on the near side, but for reference only in FIG. 3 (a). It is indicated by a two-dot chain line. The valve body 3 is continuously rotated at a predetermined rotational speed by the variable speed motor 9, and the rotational speed is about 1 to 12 rpm. In this example, the rotation is 6 rpm and one rotation is performed in 10 seconds.
3A shows a state in which the valve body 3 rotating in the direction of the arrow W is in the state shown in FIGS. 1 and 2, and the horizontal compartment plate 6 is in the center of the inflow port P. FIG. The air supply from the blower is indicated by lightly colored hatching, divided into horizontal compartment plates 6b and entering both the chambers E1 and E2, flowing into the chambers C and D through the channel holes 10 and 11, It discharges to the outlet A and the outlet B.

  Next, when the valve body 3 is rotated to the position shown in FIG. 3B, the horizontal compartment plate 6b is separated from the inlet P, and the supply air flows only into the chamber E2 side, and passes through the passage hole 11 (not shown). It flows into chamber D and discharges to outlet B. Until the valve body 3 reaches the position shown in FIG. 3C, the supply air flows only into the chamber E2 and is discharged from the outlet B. FIG. 3 (d) shows a state in which the valve body 3 is rotated by 180 ° from FIG. 3 (a). This time, the horizontal compartment plate 6a is located at the center of the inlet P, and the supply air is on the chamber E1 side. Then, the air flows into the chambers C and D through the flow path holes 10 and 11, and is discharged to the outlet A and the outlet B.

  Next, when the valve body 3 is rotated to the position shown in FIG. 3 (e), the horizontal partition plate 6a is separated from the inlet P, and the supply air flows only into the chamber E1, and passes through the channel hole 10 to the chamber C. Into the outlet A and discharged to the outlet A. Until the valve element 3 reaches the position shown in FIG. 3 (f), the supply air flows only into the chamber E1 and is discharged from the outlet A, and eventually returns to the position shown in FIG. 3 (a). Thereafter, the above operation is repeated in a cycle of 10 seconds. That is, air is intermittently discharged to the outlet A and the outlet B about every 5 seconds. At the time of discharge switching to the outlet A and the outlet B, for example, between FIGS. 3C to 3E, air is discharged to both outlets. If the diameter of the inlet P is 70 mm, the time between them is about 0.4 seconds.

  Seal members are attached to the outer peripheral portions of the vertical compartment plates 5a and 5b in FIG. 1 so as to slide with the housing 2 (not shown). The portion surrounded by the one-dot chain line in FIG. The enlarged detail view is shown in FIG. The seal member 12 is preferably a packing ring (V-shaped ring) having a V-shaped cross-sectional shape. When using a V-shaped ring, it is attached so that the V-groove 12b faces the chamber E side. The distal end portion (sliding surface 12c) of the outer peripheral surface of the lip 12a of the V-shaped ring is slid with the housing 2. When the air pressure is applied to the chamber E by adopting the V-shaped ring, the lip 12a of the V-shaped ring pressed by the pressure is pressed against the inner surface of the housing 2 as shown by the arrow in the figure and is tightly sealed. To increase. Further, even if the ring sliding surface 12c is worn out over a long period of operation, the airtightness can be maintained by the lip 12a being pressed against the inner surface of the housing. When the normal O (O) ring is worn, the airtightness cannot be maintained. In addition, since the V-shaped ring having the above-described mechanism can obtain high confidentiality even with a small contact area, it does not generate a large frictional resistance when the valve body is rotated, and the valve body can be rotated with small power. it can. Since the V-shaped ring is a consumable part, it needs to be replaced periodically. However, since the structure of the device is simple, there is no need for adjustment work after replacement and the apparatus can be immediately restarted.

  In the state where the rotational phase of the valve body is shown in FIGS. 3B, 3C, 3E and 3F, the chamber E1, which is partitioned by the horizontal partition plate 6 by the inflow of pressurized air from the inlet P. Only one of E2 is pressurized. However, since the chambers E1 and E2 communicate with each other by the V-shaped groove 12b of the V-shaped ring, air leaks from the pressurized chamber to the other chamber, thereby impairing the function as a switching valve. In order to prevent this, a structure in which the V groove 12b of the V-shaped ring is partially filled can be employed. The structure is shown in FIGS. FIG. 5 is a partially enlarged view of the HH sectional view in FIG. The chambers E1 and E2 are partitioned by a horizontal compartment plate 6 having an elastic plate 13 (material is rubber, resin, etc.) that slides on the housing 2 at its end. However, since the chambers E1 and E2 communicate with each other by the V-groove 12b, the V-groove 12b is filled with the filler 12d to disconnect the communication. The seal member 12 may be manufactured in such a structure from the beginning. 6 is a cross-sectional view taken along line JJ in FIG. Thus, the V groove 12b of the sealing member is partially filled with the filler 12d at a position corresponding to the position of the horizontal compartment plate 6.

The flow path switching valve of the present invention shown in FIGS. 1 to 6 was produced, and the discharge flow rate from the outlets A and B was measured. The inner diameter of the housing was 250 mm, the rotational speed of the valve body 3 was 10 rpm, and the internal pressure of the chambers E1 and E2 by supplying pressurized air was 0.5 kgf / cm ² . The sliding surface was non-lubricating oil because the V-shaped ring was self-lubricating, and the ambient temperature was 50 ° C.

As is apparent from Table 1, it can be seen that in the embodiment, the air leakage to the other outlet is small even if it is discharged from either outlet A or B.
In Comparative Example 1, there is much air leakage to the other outlet. This is because O-ring packing is used, and the pressing action of the packing by air pressure does not work and the airtightness is insufficient. In Comparative Example 1, sufficient airtightness can be obtained by increasing the pressure of the O-ring packing against the housing 2 by increasing the diameter of the vertical compartment plate 5, but since wear progresses faster, Airtightness decreases.
In Comparative Example 2, the gap between the vertical compartment plate 5 and the housing 2 was set to 0.1 mm. Even if there is no seal, if the gap is made as small as possible, the airtightness is enhanced, but such precision processing is difficult and impractical.

  As described above, the flow path switching valve of the present invention can switch the supply air in a short time and send it to the diffuser, so that the membrane cleaning effect can be improved even with a small capacity blower. And energy saving can be achieved. In addition, since a large-capacity product can be easily manufactured, when switching the operation / non-operation of the air diffuser to two systems, it is possible to cope with one. Moreover, if it combines suitably and sets the rotation speed of a valve body appropriately, air can be sequentially supplied to multiple systems.

  The present invention relates to a flow path switching valve for switching the discharge direction of a supplied fluid, and in particular, a flow path suitable for membrane cleaning of a membrane filtration device used in water treatment such as sewage, middle water, industrial wastewater, and sewage. Can be used as a switching valve.

It is sectional drawing which shows the 1st Example of the flow-path switching valve of this invention. It is a figure which shows the cross sections HH and II of FIG. It is sectional drawing for demonstrating operation | movement of the flow-path switching valve of FIG. FIG. 2 is an enlarged detail view of a portion surrounded by a one-dot chain line in FIG. 1. It is a partially expanded view of the HH cross section arrow view in FIG. FIG. 6 is a sectional view taken along line JJ in FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,20,30 Flow path switching valve 2 Housing 3 Valve body 4 Rotating shaft 5a, 5b Vertical compartment plate 6 Horizontal compartment plate 7 Flange 8 Bearing 9 Variable speed motor 10, 11 Channel hole 12 Seal member (V-shaped ring) Packing)
12a Lip 12b V groove 12c Sliding surface 12d Filler 13 Elastic plate A, B Outlet E1, E2 Chamber P Inlet

Claims (3)

The inside has a cylindrical housing, a valve body that rotates around the axis within the housing, and a flange that closes both ends of the housing,
The housing has a fluid inlet and a plurality of outlets in the axial direction of the outer periphery,
The valve body has a compartment plate provided with a V-shaped ring packing that contacts the inner surface of the housing and divides the internal space of the housing into an airtight state,
The partition plate is attached so that the inflow port sequentially communicates with each outflow port and the at least one outflow port is maintained in communication with the rotation of the valve body. . The inside has a cylindrical housing, a valve body that rotates around the axis within the housing, and a flange that closes both ends of the housing,
The housing has a fluid inlet and a plurality of outlets located across the inlet in the axial direction of the outer periphery.
The valve body has a compartment plate provided with a V-shaped ring packing that contacts the inner surface of the housing and divides the internal space of the housing into an airtight state,
The partition plate has a member that crosses the inlet in the circumferential direction, and switches the space that communicates with the inlet when the valve body rotates from the space that faces one outlet to the space that faces another outlet. A flow path switching valve characterized by that. The flow path switching valve according to claim 2, wherein the partition plate has a member that divides an internal space where the outflow port faces with the inflow port interposed therebetween.

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