JPH0623944U - Rotary valve - Google Patents

Abstract

(57) [Abstract] [Purpose] In a rotary valve equipped with a rotary rotor having pockets in a cylindrical casing, it is possible to reliably prevent the powder particles from entering the gaps and leaking the lower pressure in stages. It is to provide a rotary valve. [Structure] A side purge air supply mechanism is connected to a gap between the side cover 5 of the casing 1 and the side plate 15 of the rotating rotor 11, and the side cover 5 and the rotating shaft 2 are connected.
A pressure control that connects a shaft seal purge air supply mechanism to the shaft seal member portion arranged between 0 and controls so that the side purge air pressure is higher than the lower pressure and the shaft seal purge air pressure is higher than the side purge air pressure. A valve is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotary valve for discharging a certain amount of powder or granular material into, for example, an air transportation pipe by rotating a rotor.

[0002]

[Prior art]

 This type of rotary valve has side covers on both sides in the axial direction, a cylindrical casing with an inlet for powder and granules on the upper side, and an outlet for applying a lower pressure on the lower side, and a cylindrical casing in the circumferential direction. A cylindrical rotor that has a plurality of pockets at intervals and has side plates on both sides in the axial direction and is rotatably fitted in the casing; and an inner peripheral surface of the side cover that is fixed to the rotor. The rotary shaft is rotatably supported via a shaft seal member, and the powder and granules charged from the charging port are sequentially supplied to the pockets of the rotor. It is designed to be discharged to.

[0003]

[Problems to be solved by the device]

 Conventionally, there are various gaps in a rotary valve. For example, the gap between the side plate of the rotor and the side cover of the casing, the gap between the cylindrical outer peripheral surface of the rotor and the inner peripheral surface of the casing, or the gap between the rotary shaft and the inner peripheral surface of the cover. Due to the existence of such various gaps and the fact that lower pressure is applied to the discharge port from the lower air transport pipe, etc., the following are important issues in the field of rotary valves. There is. In other words, the lower pressure causes powder particles (particularly powder) near the outlet to enter various gaps, causing abnormal noise, or being crushed and sticking to the rotating part, which makes it worth reusing. There is a risk that the rotation speed of the rotor will become unstable, etc. Further, the compressed air for transportation of the air transportation pipe leaks through the above-mentioned gaps, so that the transportation performance is deteriorated or disturbed.

To address these problems, a rotary valve has been developed in which a side purge air supply mechanism is connected to the gap between the side cover and the side plate, and by supplying compressed air to the gap, In addition to blocking the intrusion of powder, the lower pressure is prevented from leaking through the gap. Also, a rotary valve in which a purge air supply mechanism is connected to the gap between the rotating shaft and the case cover has been developed. However, each of them has its own purge air supply mechanism, and the rotary valve as a whole does not have a sufficient function of preventing powder particles (particularly powder) from entering or preventing leakage of lower pressure.

An object of the present invention is to provide a rotary valve capable of reliably preventing the intrusion of powdery or granular material into each gap and the leakage of lower pressure in a stepwise manner.

[0006]

[Means for Solving the Problems]

 The present invention is provided with side covers on both sides in the axial direction, a cylindrical casing having an inlet for powder and granules on the upper side, and an outlet for applying a lower pressure on the lower side. A cylindrical rotor having a plurality of pockets and side plates on both sides in the axial direction, which is rotatably fitted in the casing, and a shaft seal member fixed to the rotor and provided on the inner peripheral surface of the side cover. In a rotary valve equipped with a rotary shaft that is rotatably supported via a shaft, a side purge air supply mechanism is connected to the gap between the side cover and side plate, and a shaft seal purge air supply mechanism is connected to the shaft seal member. Connected and equipped with a pressure control valve that controls the side purge air pressure to be higher than the lower pressure and the shaft seal purge air pressure to be higher than the side purge air pressure. A rotary valve according to claim.

[0007]

[Action]

 A side purge air supply mechanism supplies side purge air at a pressure higher than the lower pressure to the gap between the casing side cover and the rotor side plate. It prevents entry and also prevents underpressure from leaking through the gap. Further, at the position where the shaft seal member is arranged, the shaft seal purge air supply mechanism supplies the shaft seal purge air at a pressure higher than the side purge air pressure, so that the shaft seal performance at the shaft seal portion is further improved. It is possible to reliably prevent the side purge air from leaking, and to further improve the effect of preventing the intrusion of the granular material by the side purge air.

[0008]

【Example】

 FIG. 1 is a front view showing a partial cross section of a rotary valve to which the present invention is applied. In FIG. 1, the casing 1 is formed in a cylindrical shape and has an inlet 2 for powder particles at the upper end. A discharge port 3 is provided at the lower end, and side covers 5 are fixed on both sides in the axial direction. A bearing case 6 is fixed to each side cover 5, and a bearing cover 7 that closes these axial ends is fixed to each bearing case 6. The bearing cover 7 on one side (right side of FIG. 1) completely closes the bearing case 6, while the bearing cover 7 on the other side (left side of FIG. 1) has a hole 19 for inserting the rotary shaft. The rotary shaft 20 is fitted with a seal.

As shown in FIG. 3, the inlet 2 is connected to the lower end of the hopper portion 10 a of the powder and particle supply silo 10, and the outlet 3 is connected to the upper end of the inclined branch pipe 12 a of the lower air transport pipe 12. Therefore, the powder or granules discharged from the discharge port 3 into the transportation pipe 12 through the branch pipe 12a are transported to the destination by the transportation air flowing in the transportation pipe 12.

In the casing 1 of FIG. 1, a cylindrical rotor 11 is rotatably arranged. The rotor 11 is integrally provided with side plates 15 on both sides in the axial direction, and is also provided with a plurality of powdery or granular material storage pockets 16 at equal intervals in the circumferential direction. A horizontal rotary shaft 20 is fixed to the center of rotation of the rotor 11, and both ends of the rotary shaft 20 penetrate through the side covers 5 and reach the inside of the bearing case 6, respectively, and bearings are provided through a pair of tapered roller bearings 22 respectively. The case 6 is rotatably supported. One (left) end of the rotary shaft 20 penetrates the bearing cover 7 and projects to the outside, and is connected to an appropriate drive source such as a drive motor with a reduction gear (not shown).

A pair of annular shaft seal members 25 are fitted on the inner peripheral surface of each side cover 5, and a ring 27 having an H-shaped cross section is sandwiched between the shaft seal members 25. There is. The inner peripheral surface of the shaft seal member 25 and the inner peripheral surface of the ring 27 are slidably in contact with the outer peripheral surface of the rotary shaft 20 to rotatably support the outer peripheral surface of the rotary shaft 20, thereby sealing the outer peripheral surface of the rotary shaft 20.

Each side cover 5 is formed with a side purge air passage 30 that opens into a gap S between the side cover 5 and the side plate 15, and an inlet portion of each side purge air passage 30 is provided with an outside of the casing. The side purge air supply pipe 31 is connected. Each side purge air passage 30 is formed at a position below the axis of rotation.

In FIG. 2, the H-shaped ring 27 divides the space between the shaft seal members 25 into an outer annular space portion 27a and an inner annular space portion 27b. A plurality of air circulation holes 27c are formed in the partition wall portion between the spaces 27b at intervals in the circumferential direction, and the circulation holes 27c communicate between the space portions 27a and 27b. A shaft seal purge air passage 33 opening to the outer annular space 27a is formed in the side cover 5 in an inclined shape, and an upper end inlet of the side purge air passage 33 has a shaft seal purge air supply pipe outside the casing. 34 is connected.

The pair of tapered roller bearings 22 are inclined in opposite directions, and an annular spacer 23 is arranged between the bearings 22.

FIG. 3 shows an air piping diagram, in which the air transportation pipe 12 is connected to a first air pressure control valve (pressure reducing valve) 36 via an air transportation air supply pipe 43, and a side purge air supply pipe is connected. 31 is connected to the second air pressure control valve (pressure reducing valve) 37, the shaft seal purge air supply pipe 34 is connected to the third air pressure control valve (pressure reducing valve) 38, and the air pressure control valves 36, 37 are connected. , 38 are connected to the air compressor 39 on the inlet port side. Each pressure control valve 36, 37, 38 is provided with a control unit 36a, 37a, 38a to which a pilot pressure is input, and the pressure of discharge air is set to a predetermined pressure value relative to each pilot pressure. It can be set. The first air pressure control valve 36 detects the pressure at the discharge port of the valve 36 as a pilot pressure and controls so that the pressure inside the transport pipe 12, that is, the lower pressure P0 is always maintained at a predetermined pressure. . The control portion 37a of the second air pressure control valve 37 is connected to the discharge port 3 of the rotary valve V via the pilot passage 40, and the lower pressure P0 is input to the control portion 37a as the pilot pressure. The pressure P1 of the side purge air supplied to the side purge air supply pipe 31 is adjusted so that it is always higher than the lower pressure P0 by a constant value. The control portion 38a of the third air pressure control valve 38 is connected to the side purge air supply pipe 31 via the pilot passage 41, and the side purge air pressure P1 is input to the control portion 38a as pilot pressure. The pressure P2 of the shaft seal purge air supplied to the shaft seal purge air supply pipe 34 is always adjusted to be higher than the pressure P1 of the side purge air by a constant value. That is, the control valves 36, 37 and 38 are adjusted so that the relationship of P0 <P1 <P2 is always maintained.

Next, the operation will be described. The granules charged from the silo 10 of FIG. 3 to the charging port 2 of FIG. 1 are sequentially supplied into the pocket 16 of the rotating rotor 11. Then, by the rotation of the rotor 11, it reaches the lower end discharge port 3, is dropped and supplied into the air transport pipe 12, and is transported to a target location by the air for air transport flowing in the transport pipe 12.

The side purge air having a pressure P1 higher than the lower pressure P0 is supplied to the gap S between the side cover 5 and the side plate 15 from the side purge air passage 30. However, it prevents the lower pressure from entering the gap S and prevents the air for air transportation of the transportation pipe 12 from leaking to the outside. Further, as shown in FIG. 2, the ring seal portion 25 between the shaft seal members 25 is supplied with the shaft seal purge air having a pressure P2 higher than the pressure P1 of the side purge air. From the space 27a into the inner annular space 27b through the flow holes 27c, the side purge air or powder is prevented from entering the bearing 22 side in combination with the sealing function of the shaft seal member 25. . This indirectly strengthens the lower pressure leakage prevention and prevents the powder from entering the bearing 22 and deteriorating the rotating function. The pressure P0 of the transportation air in the transportation pipe 12 may change due to the adjustment of the discharge amount of the powder or the like. Even in this case, the second air pressure control valve 37 and the third air pressure control valve 38 By the pressure control action of, the relationship of P0 <P1 <P2 is always maintained, and the above sealing function can be maintained.

[0018]

[Another embodiment]

 (1) FIG. 4 shows a modified example of the shaft seal member 25, which is an example in which an annular ring having a hollow rectangular cross section is mounted as the ring 27, and the outer wall and the inner wall are respectively provided. The air circulation hole 27c is formed. (2) The side purge air passage 30 may be formed in the side cover 5 portion above the rotary shaft core. (3) An O-ring may be attached as the shaft seal member 25. (4) The ring 27 between the shaft seal members 25 is made of resin or metal.

[0019]

[Effect of device]

 As described above, according to the present invention, (1) a side purge air having a pressure P 1 higher than the lower pressure P 0 is provided in the gap S between the side cover 5 of the casing 1 and the side plate 15 of the rotor 11 by the side purge air supply mechanism. Since it is supplied, it is possible to prevent the granular material (particularly the powder) in the vicinity of the discharge port from entering the gap S due to the lower pressure, which results in the generation of abnormal noise and the deterioration of the rotation performance. Can be prevented. Moreover, by preventing the lower pressure from leaking through the gap, it is possible to effectively prevent the pressure loss of the transport air such as the air transport pipe 12 which is the source of the lower pressure. (2) At the location of the shaft seal member 25, the shaft seal purge air supply mechanism supplies the shaft seal purge air at a pressure P2 higher than the pressure P1 of the side purge air. Further, it is possible to reliably prevent the side purge air from leaking, and further improve the effect of preventing the invasion of the granular material by the side purge air and the leakage prevention of the lower pressure.

[Brief description of drawings]

FIG. 1 is a front view showing a partial cross section of a rotary valve to which the present invention is applied.

FIG. 2 is an enlarged view of a shaft seal portion of FIG.

FIG. 3 is an air piping diagram of a rotary valve to which the present invention is applied.

FIG. 4 is an enlarged vertical cross-sectional view showing a modified configuration example of the shaft seal member.

[Explanation of symbols]

 1 Casing 2 Input Port 3 Discharge Port 5 Side Cover 6 Rotor 12 Air Transport Pipe 15 Side Plate 20 Rotating Shaft 22 Bearing 25 Shaft Seal Member 30 Side Purge Air Passage 31 Side Purge Air Passage Pipe 33 Shaft Seal Purge Air Passage 34 Shaft Seal Purge Air Supply Pipe 36 , 37, 38 Pressure control valve

Claims (1)

[Scope of utility model registration request] 1. A cylindrical casing having side covers on both sides in the axial direction, an inlet for the powder or granules on the upper side, and an outlet for applying a lower pressure on the lower side, and a circumferentially spaced casing. A cylindrical rotor having a plurality of pockets and having side plates on both sides in the axial direction and rotatably fitted in the casing, and a shaft seal member fixed to the rotor and provided on the inner peripheral surface of the side cover. In a rotary valve having a rotary shaft that is rotatably supported via a side purge air supply mechanism, the side seal air supply mechanism is connected to the gap between the side cover and the side plate, and the shaft seal purge air supply mechanism is connected to the shaft seal member portion. The pressure control valve that controls the side purge air pressure to be higher than the lower pressure and the shaft seal purge air pressure to be higher than the side purge air pressure. Characteristic rotary valve.