JPS6334349B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a mechanical seal for slurry liquid, and an object of the present invention is to provide a mechanical seal suitable for shaft sealing of highly concentrated pulp liquid and the like.

[Conventional technology]

Conventionally, asbestos packing has been commonly used to seal high viscosity pulp liquids. By the way, when using asbestos packing, it is necessary to supply a large amount of water for cooling and lubrication, but bleaching efficiency decreases when a large amount of water enters, so it is necessary to develop a shaft sealing device that does not require large amounts of water injection. desired.

[Summary of the invention]

The present invention was made in response to the above-mentioned needs, and aims to provide a mechanical seal suitable for shaft sealing of high-viscosity pulp liquid.

Double seals are generally suitable mechanical seals for shaft sealing of high viscosity fluids such as slurry liquids, but double seals have the disadvantage of having a long shaft length. Therefore, in the present invention, a radial double seal configuration having two sealing end faces on the outer circumferential side and the inner circumferential side is adopted, and the thermal deformation of the seal ring, which is a drawback of this type of double seal, is effectively reduced This was to prevent this.

That is, the present invention includes one rotating ring and two non-rotating rings. The non-rotating rings are each arranged concentrically, and the rotating ring is in sliding contact with the outer circumferential side and the inner circumferential side to form two sealed end surfaces. A liquid higher in pressure than the sealing liquid is injected between the non-rotating rings from outside the stuffing box. A passageway is formed in the rotating ring and/or the first non-rotating ring on the outer circumferential side, through which the high-pressure liquid is ejected into the inside of the machine from the outer circumferential side surface thereof. This passageway may be a hole formed in the ring, or it may be something like a groove. This jet of high-pressure liquid infiltrates the outer circumferential side of the rotating ring and the first non-rotating ring and the vicinity of the outer circumferential sealed end surface, reducing the frictional resistance caused by the solids contained in the sealing liquid, and at the same time cooling the rotating ring. is being carried out.

In the second invention, a gland packing is attached to the first and second non-rotating rings further toward the atmosphere.
This gland packing is a secondary seal for preventing sealing liquid from leaking to the outside when the mechanical seal consisting of the rotating ring and the non-rotating ring is damaged. This gland packing comes into contact with the rotating shaft and generates sliding heat and wears out. To prevent this, a leakage mechanism is provided to leak a small amount of the high-pressure liquid to the gland packing side. Examples of this leakage mechanism include a configuration in which the surface pressure of the sealed end surface formed by the second non-rotating ring is reduced to allow a small amount of leakage from this sealed end surface.

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, X is the rotation axis and Y is the stuffing box.

A rotating ring 1, first and second non-rotating rings 2 and 3, and a gland packing 4 are fitted into the stuffing box Y in this order from the inside of the machine.

The rotating ring 1 is directly fitted onto the axis X, and a spacer 10 is attached to the back end thereof, and a sleeve 11 is attached to the sealed end surface thereof, so that the rotary ring 1 is fixed in a non-driven manner. A tapered surface 12 is formed on the outer peripheral side of the rotating ring 1 and is tapered toward the rear end surface.

Non-rotating rings 2 and 3 are mounted concentrically on the outside of the sleeve 11 and are in sliding contact with the rotating ring 1, forming two sealed end surfaces S and S'.

The non-rotating rings 2 and 3 are driven rings, and the spring 2 mounted on the stuffing box Y side
0 and 30, respectively, are pressed toward the rotating ring 1 side. There are grooves 21 and 31 in stuffing box Y.
are formed, respectively, and springs 20, 30 and non-rotating rings 2, 3 are fitted therein. 22, 32
are each an O-ring.

The contact pressure of the non-rotating ring 2 on the outer circumferential side is increased to prevent solid matter such as pulp from entering the sealed end surface on the outer circumferential side. On the other hand, the inner non-rotating ring 3
The contact surface pressure is made small, and the structure is such that a small amount of high-pressure water (described later) leaks to the gland packing 4 side.

The stuffing box Y is provided with an inlet 5 and a drain 6 for high-pressure water, and the inlet 5 communicates with the groove 21. High-pressure water is injected from the injection port 5 from the sealing liquid on the inside A side of the machine, and this high-pressure water passes through the groove 21 to fill the space between the non-rotating rings 2 and 3 and circulates. The non-rotating ring 3 on the inner peripheral side functions to maintain the pressure of high-pressure water in this space. An end face of the rotating ring 1 facing the space, that is, a sealed end face S,
A high pressure water passage hole 7 is formed in the end face between S'.
The water passage hole 7 forms openings 70 at a plurality of locations on the side circumference of the rotating ring 1. It is desirable that this opening 70 be located as close to the sealed end surface as possible. The water passage hole 7 and the opening 70 allow high pressure water to pass through the rotating ring 1.
The liquid is ejected from the outer circumferential side into the machine, cooling the rotating ring 1, washing away solid matter, and preventing friction with the solid matter.

In the embodiment shown in FIG. 1, the water passage hole 7 and the opening 70 are used as a passageway through which high-pressure water is jetted from the outer peripheral surface of the rotating ring, but the invention is not limited to this and various embodiments are possible. be. For example, in the embodiment shown in FIGS. 2 and 3, the sealed end surface S on the outer peripheral side
Four water passage grooves 8 are formed in the radial direction. One end of this water passage groove 8 opens on the outer peripheral side surface of the rotary ring 1, and the other end extends inward from the sealed end surface S and opens between the sealed end surfaces S and S'. As a result, high-pressure water is ejected from the outer circumferential side of the rotating ring 1.

Further, these water passage holes 7 or water passage grooves 8 may be provided on the first non-rotating ring 2 side, or may be provided on both the rotating ring 1 and the non-rotating ring 2.

A gland packing 4 is further mounted on the sleeve 11 on the side of the atmosphere B from the non-rotating rings 2 and 3, and is held down by a gland presser 40. This packing 4 is provided as a secondary seal to prevent the sealing liquid and high pressure water from leaking out of the stuffing box Y at once if the mechanical seal is damaged. As mentioned above, since the contact pressure of the inner non-rotating ring 3 is reduced, some high-pressure water leaks and wets the seal 4. Therefore, the packing 4 does not have dry sliding.
Abrasion is suppressed and it can withstand long-term use.

As a mechanism for leaking high-pressure water to the gland packing 4 side, various mechanisms are possible in addition to the above. You can also do it.

Note that if a mechanism for leaking high-pressure water is not provided, loosen the gland presser 40 during normal operation to reduce the friction between the gland packing 4 and sleeve 11, and remove the presser foot 4 in case of mechanical seal damage.
Consideration must be taken, such as tightening the 0.

In the present invention, in addition to the above configuration, the space between the tapered surface 12 of the rotating ring 1 and the outer periphery of the spacer 10 and the inner periphery of the stuffing box Y is configured to be narrow, and the thread 101 is formed on the outer periphery of the spacer 10. This is configured to push solid matter back into the inside of the machine.

Further, a cleaning hole 9 is provided in the vicinity of the rotating ring 1, so that solid matter adhering to the outer circumference of the rotating ring 1 can be washed away by injecting high-pressure water when the device is in operation. In this embodiment, the high pressure water source 50 to be supplied to the high pressure water inlet 5 is connected to the cleaning hole 9.
A solenoid valve 51 is interposed between the high-pressure water source and the solenoid valve 51 is switched and controlled by a control device 52 to supply high-pressure water to the high-pressure water inlet 5 or the cleaning hole 9. ing.

The control device 52 receives a signal indicating the operating status of the device to which this mechanical seal is installed, and at the same time starts water injection from the inlet 5 a certain time before the start of the device, it also starts cleaning from the cleaning hole 9. Apply water to wash away solids. The supply of cleaning water is stopped after a certain period of time, and thereafter only water is continued to be supplied from the water inlet 5. When the equipment is stopped, washing water is supplied again from the washing hole 9, and the equipment is stopped after a certain period of time. At the same time, the water supply from the inlet 5 is also stopped, and all water supplies are stopped.

In the above configuration, the sealed end surface S by the non-rotating ring 2 on the outer circumferential side has a high contact surface pressure, so that good sealing can be performed without getting solid objects. Further, since the circumferential speed is high on the outer peripheral side, the amount of heat generated is large, but since it is cooled by the high pressure water passing through the water passage hole 7 and the high pressure water jetting out from the opening 70, no thermal deformation occurs. In addition, solid matter is washed away by the high-pressure water that is ejected, so
Entrapment of solid matter into the sealed end surface S is further suppressed. Furthermore, solid matter is prevented from sticking, wear resistance is reduced, and rotational torque can be reduced. Furthermore, since a gland packing is provided on the atmospheric side of the mechanical seal, even if the mechanical seal is damaged, a large amount of sealing fluid and high-pressure water will not leak out at once, making it safe. In addition, since the gland packing 4 is constantly kept in a wet state due to a small amount of leaked high-pressure water, seizing does not occur and the service life can be extended.

〔Effect of the invention〕

As explained above, in the mechanical seal of the present invention, solid matter does not get caught in the sealed end face or adhere to the rotating ring, and since cooling is performed well, thermal deformation of the rotating ring does not occur. In addition, there is no need to use a large amount of water as with conventional gland packings, and the shaft length does not become long as with ordinary double seals.

In addition, in the second aspect of the invention, the gland packing can prevent danger in the event of damage to the mechanical seal, and the life of the gland packing can be extended.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG.
The figure is a partial sectional view showing another embodiment, and FIG. 3 is an explanatory view showing the state of the groove formed in the sealed end surface of the rotating ring. 1...Rotating ring, 2 and 3...Non-rotating ring, 4...Gland packing, 5...High pressure water inlet, 6...High pressure water drain port, 7...Water hole, 70...Opening, 8 …
...Water channel.

Claims (1)

[Claims] 1. A rotating ring mounted on the inside of the machine, and a first non-rotating ring mounted on the atmosphere side of the rotating ring and forming a sealed end surface by slidingly contacting the outer peripheral side of the end surface of the rotating ring. a second non-rotating ring attached to the atmosphere side of the rotating ring and forming a sealed end surface by slidingly contacting the inner peripheral side of the end surface of the rotating ring; and the first and second non-rotating rings. A mechanical device for slurry liquid, comprising: a device for circulating high-pressure liquid between the rotating ring and/or the first non-rotating ring; and a passageway for spouting the high-pressure liquid from the outer circumferential side of the rotating ring and/or the first non-rotating ring to the inside of the machine. sticker. 2. A rotating ring mounted on the inside of the machine; a first non-rotating ring mounted on the atmosphere side of the rotating ring and forming a sealed end surface by slidingly contacting the outer peripheral side of the end surface of the rotating ring; and the rotating ring. a second non-rotating ring mounted on the atmospheric side of the rotary ring and forming a sealed end face by slidingly contacting the inner circumferential side of the end face of the rotating ring; and supplying high pressure liquid between the first and second non-rotating rings. a circulation device; a water passageway for ejecting the high-pressure liquid from the outer circumferential side of the rotating ring and/or the first non-rotating ring to the inside of the machine; and a water passage installed further to the atmosphere side of the first and second non-rotating rings. A mechanical seal for slurry liquid, characterized in that it has a gland packing having a high pressure and a leakage structure that leaks a small amount of the high-pressure liquid to the gland packing.