JPS6332461Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a mechanical seal for slurry liquid such as pulp slurry liquid.

In mechanical seals that seal slurry liquid, solids in the slurry such as pulp may get caught in the sealed end surface formed by the rotating ring and the non-rotating ring, or between the rotating ring and the shaft or between the rotating ring and the equipment body. There was a problem that the liquid got stuck in between, resulting in incomplete sealing and liquid leakage.

One way to solve this problem is to supply clean liquid to prevent slurry from accumulating near the sealed end face or between the rotating ring and the shaft, but in this case, the effect of removing solids is not sufficient. In addition, the problem arises that the clean liquid dilutes the sealing liquid.

The present invention has been made to improve the above-mentioned drawbacks of the prior art, and has the effect of constantly discharging slurry from the vicinity of the sealed end surface by forming a threaded portion or vanes on the outer periphery of the rotating ring. ,
Furthermore, since the slurry gradually accumulates with only this pumping action, cleaning liquid is supplied intermittently as appropriate.

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

FIG. 1 is a half-sectional view of an embodiment of this invention, in which 1 is the main body of the device, 2 is a rotating shaft, 3 is a non-rotating ring,
4 is a rotating ring, 5 is a stopper, 6 is a spring, 7 is an annular cover, and 15, 16, and 17 are O-rings.

The non-rotating ring 3 is fitted into the annular cover 7 via an O-ring 16, and is a non-rotating, non-driven fixed ring.

The rotating ring 4 is fitted onto the shaft 2 via an O-ring 17, and is a rotating-driven ring that is pressed toward the non-rotating ring 3 by a spring 6. The other end of the spring 6 is locked to a stopper 5 fixed on the shaft 2. This stopper 5 is also a rotating ring.

A threaded portion 8 is formed on the outer peripheral surface of the rotating ring 4 . The threaded portion 8 is a right-handed screw when the shaft 2 rotates to the right when viewed from the right direction in FIG. 1, and a left-handed screw when the shaft 2 rotates to the left. The threaded portion 8 may be formed on the outer peripheral surface of the stopper 5, which is also a rotating ring, or may be formed on both the rotating ring 4 and the stopper 5.

Note that instead of the threaded portion 8, protruding blades 20 may be formed as shown in FIG.

The outer circumferential surface of the rotating ring 4 is aligned with the outer circumferential surface of the non-rotating ring 3 in the vicinity of the sliding sealing end surface 9, that is, in this embodiment, the outer circumferential surface of the protrusion 3' of the non-rotating ring 3, and forms a continuous surface. There is no recess near the end face 9 where the slurry liquid would accumulate, and the slurry liquid can flow smoothly.

A flushing hole 10 is formed near the sealed end surface 9, into which clean flushing fluid is supplied from a flushing fluid source 12 via a valve 11. The valve 11 is opened at appropriate intervals to supply flushing liquid intermittently. The opening and closing of the valve 11 may be done manually or at predetermined intervals by providing a timer 13 or the like. Furthermore, the temperature rise in the slurry liquid may be detected by the temperature measuring device 14, and the valve 11 may be opened when the temperature reaches a predetermined temperature or higher. Further, a plurality of the above-mentioned means may be employed in parallel.

In the above configuration, the rotation of the shaft 2 also rotates the rotary ring 4 having the threaded part 8, and the threaded part 8 generates a force in the direction of arrow c in the sealing liquid, and the slurry near the sealing end face 9 is moved in the direction of c. is discharged to. This action is always performed while the shaft 2 is rotating.

Then, the valve 11 is opened by the timer 13 or manually or by a signal from the temperature measuring device 14, whereby the flushing liquid supplied from the flushing hole 10 displaces the slurry liquid near the sealed end face 9 and flows into the threaded portion 8. Since residual slurry that has not yet been discharged by the pumping action is discharged, clogging can be prevented, and at the same time, overheating can be prevented by the cooling action. Since the flushing liquid is supplied intermittently, the slurry liquid is not diluted.

Further, since the threaded portion 8 causes the flushing liquid to flow in the direction of arrow C, the cleaning effect of the flushing liquid is promoted, and the effect of preventing the slurry liquid from stagnation is increased.

Further, in this embodiment, the outer circumferential surface of the rotary ring 4 is flush with the outer circumferential surface of the protrusion 3' and forms a continuous surface, thereby facilitating the removal of solid matter. Furthermore, in this embodiment, since the rotary ring 4 is also used as a driven ring, a force in the direction of arrow F is applied to the rotary ring 4 by the threaded portion 8, increasing the pressing force and improving the sealing performance.

As described above, according to the present invention, the slurry is constantly discharged from the vicinity of the sealed end surface by the spiral portion or the blade provided on the rotating ring, and clean slurry is supplied to the vicinity of the sealed end surface at appropriate intervals. Flushing fluid facilitates slurry drainage. Moreover, since the flushing liquid itself is subjected to a pumping action by the spiral portion or vanes, its cleaning effect is enhanced. As a result, clogging of the sealed end face can be prevented extremely efficiently and sealing performance can be improved. Furthermore, since the flushing liquid is supplied intermittently, there is an effect that the slurry liquid is not diluted.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention;
The figure is a perspective view showing another embodiment. 8...Threaded portion, 10...Flushing hole, 11
... Valve, 12 ... Flushing liquid source, 13 ... Timer, 14 ... Temperature measuring device, 20 ... Vane.

Claims (1)

[Scope of utility model registration request] A flushing device is provided near the sealed end surface formed by the rotating ring and the non-rotating ring to intermittently supply a clean flushing liquid different from the sealing liquid at appropriate intervals, and a threaded portion or blade is provided on the outer peripheral surface of the rotating ring. A mechanical seal for slurry liquid, characterized in that it forms a force in the sealing liquid in a direction away from the sealing end face.