JP2002226052A - Rotary valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary valve capable of holding a sealing performance even if the sealing performance is deteriorated by the development of abrasion of components such as rotary vanes, etc., improving the sealing performance more than the conventional ones, and avoiding troubles in a pneumatic pumping system and a storage hopper of powder and granular materials. SOLUTION: This rotary valve 20 is provided with a casing 1 having a supply part 1a and a delivery part 1b, multiple rotary vanes 3 fixed to a rotary shaft 2 inside the casing 1, and a seal pad 4 movably disposed in the casing 1, formed with a columnar space 4a communicated with the supply part 1a and the delivery part 1b, and rotating the multiple rotary vanes 3 with their tips being in slide contact with or approaching to its internal circumferential surface 4b. At least, a part of the seal pad 4 may be movable or energized in the extension direction of the rotary vanes 3, the seal pad 4 can be formed of a different quality material from that of the rotary vanes 3, and the seal pad 4 can be divided into a plurality of numbers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary valve, and more particularly, to a rotary valve which can maintain its sealing performance even when its sealing performance is deteriorated due to the progress of wear of components such as rotary blades. The present invention relates to a rotary valve having improved sealing performance.

[0002]

2. Description of the Related Art Conventionally, a rotary valve (also referred to as a "rotary feeder") has been used for the purpose of supplying or discharging a granular material to a location having a pressure difference.

As shown in FIG. 5, this rotary valve includes a cylindrical casing 51 having a supply section 51a, a discharge section 51b, and a body section 51c.
A cover 54 for covering the openings on both side surfaces of the casing 51, and a rotating shaft 52 extending horizontally in the body 51c of the casing 51.
A plurality of rotating blades 53 fixed to the
3 rotates while sliding or approaching the inner peripheral surface of the body portion 51c of the casing 51. Improving the sealing performance of the rotary valve is the most technically important issue in handling powder and granular materials.

Generally, when the material of the casing 51 and the rotating blade 53 in FIG. 5 is metal, the casing 51 and the rotating blade 53 have a minimum clearance between them so as not to cause galling. I'm making it. The value of the clearance varies depending on the particle diameter of the powder or other various conditions, but is usually limited to about 0.1 mm to 0.05 mm.

[0005] In addition, if contamination of foreign matter is not a problem, that is, if there is no problem even if a small amount of foreign matter is contained in the supplied material, as shown in FIG.
In some cases, rubber, plastic resin, non-ferrous metal used for bearing material, or the like may be attached as the seal piece 55, whereby the clearance between the casing 51 and the rotary blade 53 is set close to zero, In some cases, the sealing piece 55 may be used in contact with the casing.

[0006] As described above, in the past, in order to improve the sealing performance, for the sake of convenience, the rotor side has been mostly modified in some way, and a countermeasure against wear is usually taken on the casing side. For example, insert a sleeve (pipe) -like thing, hard chrome plating,
2. Description of the Related Art Abrasion resistance treatment such as hardfacing, thermal spraying, and ceramic upholstery is performed.

[0007]

However, even if the rotary valve is constructed as described above, if the pressure to be sealed becomes high, blow-through occurs and wear of the rotating blades and the inner peripheral surface of the casing progresses. The sealing property is reduced, and the intended purpose cannot be achieved. For example, in the pneumatic transportation system of a granular material, the performance of shutting off the pressure difference is reduced, the blow-up amount is significantly increased, and the transportation efficiency is reduced.
Further, in a storage hopper or the like above the rotary valve, a problem such as formation of a bridge due to pushing up of the granular material by blowing up occurs.

In view of the above, the present invention has been made in view of the above-mentioned problems in the conventional rotary valve, and maintains the sealing performance even when the sealing performance is deteriorated due to the progress of wear of the components such as the rotating blades. It is an object of the present invention to provide a rotary valve that can improve the sealing performance as compared with the conventional one and can avoid troubles in a pneumatic transportation system, a storage hopper, and the like.

[0009]

In order to achieve the above object, an invention according to claim 1 is a rotary valve, comprising: a casing having a supply section and a discharge section; and a rotary shaft in the casing. A plurality of fixed rotating blades and a cylindrical space that is movably disposed in the casing and communicates with the supply unit and the discharge unit, and has an inner peripheral surface that is a tip of the plurality of rotating blades. And a seal pad that rotates in close contact with or in close proximity thereto.

According to the first aspect of the present invention, even when the sealing performance is deteriorated due to the progress of wear of the components such as the rotary blades, the seal pad is moved to move between the tip of the rotary blades. By making the clearance zero or extremely small, the sealing performance can be maintained, and the sealing performance can be improved as compared with the related art.
Thereby, in the pneumatic transportation system of the granular material, the performance of shutting off the pressure difference is improved, so that the blow-up amount is greatly reduced, the transportation efficiency is increased, and the transportation unevenness is reduced, so that the transportation accuracy is improved. In addition, in a storage hopper or the like disposed above the rotary valve, troubles such as formation of a bridge due to pushing up of the granular material by blowing up can be eliminated.

According to a second aspect of the present invention, as a preferred mode of the rotary valve according to the first aspect, at least a part of the seal pad is movable in a direction in which the rotary blade extends.

According to a third aspect of the present invention, there is provided the rotary valve according to the second aspect, further comprising an urging means for urging at least a part of the seal pad in an extending direction of the rotary blade. .

According to the third aspect of the present invention, the clearance between the seal pad and the tip of the rotary blade can be constantly maintained at zero, so that the sealing performance is further improved. Further, even when the seal pad is worn, the seal pad automatically moves in the direction approaching the tip of the rotary blade, so that it is not necessary to manually adjust the position of the seal pad, thereby improving maintainability.

According to a fourth aspect of the present invention, in the rotary valve according to the first, second or third aspect, the seal pad is formed of a material different from the material of the rotary blade. Then, as a material of the seal pad, carbon, ceramic, resin, or the like, which has good lubricity and does not seize even when it comes into contact with the rotating blades, can be used for the whole or a part of the seal surface.

According to a fifth aspect of the present invention, in the rotary valve according to any one of the first to fourth aspects, the seal pad can be divided into a plurality of parts.

According to the fifth aspect of the present invention, since the seal pad can be divided into a plurality of parts, the seal pad can be partially adjusted or replaced, thereby improving maintainability.

[0017]

Next, a specific example of an embodiment of a rotary valve according to the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show an embodiment of a rotary valve according to the present invention.
Is a casing 1 having a supply section 1a and a discharge section 1b.
A rotor 10 integrated with a plurality of rotating blades 3 fixed to a rotating shaft 2 in a casing 1, and a seal pad 4 movably disposed in the casing 1; The seal pad 4 rotates in contact with or close to the inner peripheral surface 4b of the seal pad 4.

The casing 1 is composed of a top plate 1d having a supply portion 1a formed therein, a bottom plate 1e having a discharge portion 1b formed therein, and a side plate 1c. The rotating shaft 2 passes through the cover 9.

The rotor 10 is a so-called pocket type rotor having a side wall 10 a and integral rotating blades 3, and rotates together with the rotating shaft 2.

The seal pad 4 is provided inside the casing 1 with the rotating blades 3 and the sidewalls 10a of the rotor 10.
And a cylindrical space 4a communicating with the supply portion 1a and the discharge portion 1b is formed, and the tip of the rotary blade 3 is slidably contacted or rotated on the inner peripheral surface 4b thereof.

As the material of the seal pad, there can be used carbon, ceramic, resin or the like which has good lubricity and does not seize even when it comes into contact with the rotating blades.
Note that all of the seal pads 4 can be made of the same material, and the above material can be used for a part of the seal surface. If there is a problem with foreign matter in the supply,
The seal pad 4 is made of the same material as the rotary blade 3.

The seal pad 4 is configured to be movable in the extending direction of the rotary blade 3 by the fixing member 6, the screw 7, and the fixing member 8. That is, the side plate 1 of the casing 1
(c) is provided with a male screw portion (7a) screwed with the female screw portion (6a) of the fixing member (6), and by operating a screw (7) whose tip is inserted into a concave fixing member (8) provided on the outer peripheral surface of the seal pad (4). The seal pad 4 can be moved in the direction in which the rotary blade 3 extends.

The basic usage of the rotary valve 20 having the above-described structure is the same as that of the conventional one. However, by making the seal pad 4 movable, the sealability is improved due to the progress of wear of the rotary blades 3 and the seal pad 4. Even in the case of a decrease, as shown in FIG. 3A, the sealing performance can be maintained by moving the seal pad 4 to make the clearance between the tip of the rotating blade 3 zero or minimal. At the same time, the sealing performance can be improved more than before. In addition, depending on the type of the granular material to be handled, as shown in FIG. 3B, the operation may be performed with a certain clearance C provided between the inner peripheral surface 4b of the seal pad 4 and the tip of the rotary blade 3. it can. Furthermore, since the clearance C can be adjusted from outside the casing 1, it can be adjusted during operation without stopping the equipment.

Although the seal pad 4 is moved by the screw 7 in the above embodiment, the seal pad 4 is always moved by using a coil spring or the like instead of the screw 7.
May be configured to be urged in the direction of. With this configuration, even when the inner peripheral surface 4b of the seal pad 4 or the tip of the rotary blade 3 is worn, the seal pad 4 automatically moves in the direction approaching the tip of the rotary blade 3, so that hand There is no need to adjust the position of the seal pad 4 during the operation, and maintainability is improved. In addition, as means for urging the seal pad 4, pneumatic pressure, hydraulic pressure, magnet, or the like can be used in addition to the coil spring.

Further, in the above embodiment, the seal pad 4
Is divided into two parts. However, the seal pad 4 may be divided and arranged in more parts in order to partially adjust or replace the seal pad 4.

In the above-described embodiment, a pocket-type rotor with a side wall is used in order to enhance the sealing property. However, a generally used open-type rotor may be used.

FIG. 4 shows another embodiment of the rotary valve according to the present invention, in which an open type rotor is provided.
It is formed integrally with the rotary blade 33 without a sidewall. Further, the rotary valve 40 includes a seal pad 34 movably disposed in the casing 1, and the tip of the rotary blade 33 is slidably in contact with or close to the inner peripheral surface 34 b of the seal pad 34 and rotates. Components other than the rotor 30 and the seal pad 34 are the same as those in the above embodiment.

The seal pad 34 is arranged in the casing 1 so as to surround the rotary blade 33 and the rotor 30, forms a cylindrical space 34a communicating with the supply section 1a and the discharge section 1b, and has an inner peripheral surface thereof. The tip of the rotating blade 3 is slidably in contact with or close to the rotating blade 4b.

The seal pad 34 is movable in the direction in which the rotary blade 33 extends in the same manner as in the first embodiment. The sealing performance can be maintained even in a case where the sealing performance is lowered, and the sealing performance can be improved as compared with the conventional case. Further, depending on the type of the granular material to be handled, the operation can be performed with a certain clearance provided between the inner peripheral surface 34b of the seal pad 34 and the tip of the rotary blade 33.

[0031]

As described above, according to the present invention,
Even when the sealing performance is deteriorated due to the progress of wear of the components such as the rotating blades, the sealing performance can be maintained, and the sealing performance can be improved as compared with the conventional one. A rotary valve capable of avoiding troubles in a storage hopper or the like can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a rotary valve according to the present invention.

FIG. 2 is a sectional view taken along a section perpendicular to the section of the rotary valve of FIG. 1;

FIGS. 3A and 3B are enlarged views of a portion A in FIG. 1; FIG. 3A shows a case where a clearance between a seal pad and a rotating blade tip is zero; FIG. 3B shows a clearance between a seal pad and a rotating blade tip; Indicates the case where exists.

FIG. 4 is a sectional view showing another embodiment of the rotary valve according to the present invention.

FIG. 5 is a partial sectional view showing an example of a conventional rotary valve.

FIG. 6 is a cross-sectional view showing another example of a conventional rotary valve, showing a state where a seal piece is attached to a rotary blade.

[Explanation of symbols]

 Reference Signs List 1 casing 1a supply unit 1b discharge unit 1c side plate 1d top plate 1e bottom plate 2 rotating shaft 3 rotating blade 4 seal pad 4a cylindrical space 4b inner peripheral surface 6 fixing member 6a female screw portion 7 screw 7a male screw portion 8 fixing member 9 side cover Rotor 10a Side wall 20 Rotary valve 30 Rotor 33 Rotating blade 34 Seal pad 34a Columnar space 34b Inner peripheral surface

Claims (5)

[Claims] A casing provided with a supply section and a discharge section; a plurality of rotating blades fixed to a rotating shaft in the casing; a supply section and the discharge section movably disposed in the casing; And a seal pad that forms a cylindrical space communicating with the seal portion, and has an inner peripheral surface that is rotated by the tips of the plurality of rotating blades in sliding contact or close proximity. 2. The rotary valve according to claim 1, wherein at least a part of said seal pad is movable in a direction in which said rotary blade extends. 3. The rotary valve according to claim 2, further comprising: urging means for urging at least a part of said seal pad in a direction in which said rotary blade extends. 4. The rotary pad according to claim 1, wherein the seal pad is formed of a material different from that of the rotary blade.
4. The rotary valve according to 2 or 3. 5. The rotary valve according to claim 1, wherein said seal pad can be divided into a plurality of parts.