JPS6316934Y2 - - Google Patents

Description

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

When using a slurry liquid such as pulp slurry as the sealing liquid, various problems may occur such as solid matter getting stuck in the sealing surface or clogging the spring, etc., resulting in abrasion of the sealing surface and incomplete sealing due to poor follow-up of the driven ring. Are known.

For this reason, conventional methods have been used such as injecting clean liquid from the outside and creating a double mechanical seal.

Although the above-mentioned drawbacks can be overcome by injecting a cleaning fluid, a new problem arises in that the sealing fluid is diluted by the cleaning fluid. On the other hand, if the amount of cleaning liquid to be injected is reduced in order to avoid this, there is a problem in that the above-mentioned drawbacks cannot be solved satisfactorily.

Further, in the case of a double mechanical seal, although there is no problem such as dilution of the sealing liquid, there is a drawback that the structure is complicated and the cost is high.

The present invention has been made to improve the above-mentioned conventional drawbacks, and is intended to prevent clogging due to solids in the slurry liquid with a relatively simple structure.

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

FIG. 1 is a half-sectional view showing an example in which the present invention is applied to a mechanical seal for a slurry pump.
is the rotating shaft, A is the casing, 1 is the fixed ring, 2 and 3
are rotating rings, 2 is a driven ring, 3 is a collar, and 4 is a pressing spring. An annular protrusion 10 is provided on the casing side corresponding to the collar 3, and a constriction part 11 is formed between the protrusion 10 and the collar 3. In this embodiment, the protrusion 10 is formed by attaching an annular push to the casing A, but if there is a neck push B at the collar 3 position, it may be used.

A thread 12 is formed on the outer peripheral surface of the collar 3 so that a flow in the direction of the arrow is formed in the constricted portion 11. This thread 12 may be formed so as to cause a flow in the direction of the arrow depending on the direction of rotation of the axis X.

Instead of this thread 12, a blade 13 may be formed as shown in FIG.

It is preferable that the blade 13 is formed into a protrusion having a rectangular or trapezoidal cross section as shown in the figure, since this increases the discharge effect. Further, as shown in the figure, it is preferable that the blades 13 be provided obliquely rather than parallel to the axis, and may also be curved in a helical shape. This diagonal direction varies depending on the direction of rotation of the rotary ring, and may be a direction that causes flow in the direction of the arrow in FIG.

In this embodiment, a thread 12 is also formed on the outer periphery of the driven ring 2 in order to discharge solid matter from the vicinity of the sealing surface S. Also in this case, instead of the thread 12, a blade as shown in FIG. 2 may be used.

Further, in this embodiment, in addition to the above configuration, the spring 4 is exposed without being covered, and the flow in the direction of the arrow is also formed by this spring 4. Further, the cross-sectional shape of the spring 4 may be round, but by making it square, the flow forming force can be further strengthened.

When this spring 4 forms a flow in the direction of the arrow, if the spring 4 transmits the rotational force from the collar 3 to the driven ring 2, the spring 4 will receive a force in the opening direction, which is not preferable. Therefore, in this embodiment, a plurality of protrusions 20 and 30 extending in the axial direction are formed at the base of the driven ring 2 and the collar 3.
30 are engaged with each other to transmit rotational force. FIGS. 3 and 4 show front views of the driven ring 2 and collar 3.

In the above configuration, the thread 12 or the blade 13 acts as a pump in the constriction part 11, and the solid matter in the space P from the protrusion 10 to the sealing surface S moves from the protrusion 10 toward the inside of the machine. As a result, the concentration of solids in the space P is reduced, and solids are prevented from getting caught in the sealing surface S and clogging the spring 4.

Furthermore, in this embodiment, the spring 4 is exposed and has a rectangular cross-section, so that the pumping action is enhanced. Further, since the driven ring 2 is also formed with a thread 12 or a blade 13, the discharge of solid matter from the vicinity of the sealing surface S is promoted, and the entrapment of solid matter into the sealing surface S is further suppressed.

As explained above, the mechanical seal of the present invention is configured to cause a pumping action using the constriction part and the screw or vane, thereby discharging solids from the mechanical seal part. There are advantages such as being able to suppress troubles.

[Brief explanation of drawings]

Fig. 1 is a half-sectional view showing one embodiment of the mechanical seal of the present invention, Fig. 2 is a perspective view showing another embodiment of the collar or driven ring, Fig. 3 is a front view of the driven ring, and Fig. 4 is a front view of the collar. In the figure, 1 is a fixed ring, 2 is a driven ring, 3 is a collar,
4 is a spring, 10 is a protrusion, 11 is a diaphragm, 12 is a thread, and 13 is a blade.

Claims (1)

[Claims for Utility Model Registration] A mechanical seal for slurry liquid having a fixed ring, a driven ring, a spring that presses the driven ring toward the fixed ring, and a collar that locks the spring, which corresponds to the collar on the casing side. 1. A mechanical seal for slurry liquid, characterized in that an annular protrusion is formed at a position where a constriction is formed between the ring-shaped projection and the collar, and a thread or a blade is provided on the outer peripheral surface of the collar.