JP2009197945A - Slurry liquid mechanical seal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slurry liquid mechanical seal capable of certainly preventing follow-up performance of a stationary hermetically-sealing ring from deteriorating (failing in operation) owing to a slurry liquid containing hard solid particles such as a sintered hard alloy or the like. <P>SOLUTION: There is provided a whose seal case 5 is fitted on a device housing 1 with a hermetically-sealing ring holder 5b of the seal case exposed in a slurry liquid region A. In the slurry liquid mechanical seal, an outer circumferential-side end 19a is fixed between the hermetically-sealing ring holder 5b and the housing 1 in a sandwiched and pressed manner, while an inner circumferential-side end 19b is allowed to be in pressure-contact with an outer circumferential surface 7b of the stationary hermetically-sealing ring 7. An annular rip seal 19 is arranged in such a state as to be in contact with an apical surface 5e of the hermetically-sealing ring holder 5b to seal a portion between the seal case 5 and the housing 1 with the outer circumferential-side end 19a. Besides, the slurry liquid is restrained from entering an O ring 16 arranged space 17 and from coming in contact with the hermetically-sealing ring holder 5b by the inner circumferential-side end 19b and the connecting section 19c between inner and outer circumferential-side ends 19b, 19a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is for a slurry liquid equipped as a shaft sealing means in a rotary device such as a ball mill (wet pulverizer), a pump, a stirrer, etc. that handles a slurry liquid containing hard solid particles (for example, ceramic or cemented carbide fine particles). It relates to mechanical seals.

  As a conventional mechanical seal for slurry liquid, as shown in FIG. 6 or FIG. 7, a cylindrical structure in which a sealing ring holding part 105b is attached to a housing 101 of a rotating device that handles slurry liquid in a state where it is exposed to the slurry liquid area A. A seal case 105, a rotary seal ring 106 disposed on the slurry liquid region A side from the seal ring holding portion 105b and fixed to the rotary shaft 102 passing through the seal case 105, and an inner peripheral portion of the seal ring holding portion 105b The stationary seal ring 107 fitted and held so as to be movable in the axial direction through the O-ring 116 engaged and held in the O-ring groove 117 formed therein, and the stationary seal ring 107 to the rotary seal ring 106. And a spring member 108 that is urged to be brought into press contact with each other by the relative rotational sliding contact action of the sealing end faces 106a and 107a, which are the opposing end faces of the sealing rings 106 and 107. An end surface contact type configured to shield and seal the slurry liquid area A that is the outer peripheral side area of the relative rotational sliding contact portions 106a and 107a and the atmospheric area B that is the inner peripheral side area is well known (for example, , See Patent Document 1).

  By the way, in the mechanical seal, since the slurry is in communication with the slurry liquid region A in the space in which the O-ring 116 is disposed, that is, the space in the O-ring groove 117, the slurry liquid enters and the slurry component is introduced. As a result, the axial movement of the stationary seal ring 107 through the O-ring 116, that is, the followability is deteriorated and impeded, and the contact surface pressure of the sealed end faces 106a and 107a becomes inappropriate. There is a problem that the mechanical seal function is deteriorated.

Therefore, in the mechanical seal shown in FIG. 6 (hereinafter referred to as “first conventional seal”), the lip seal 119 is fitted and fixed to the outer peripheral portion of the stationary seal ring 107, and the lip portion 119b is fixed to the tip of the seal ring holding portion 105b. By keeping pressure contact with the surface 105e, the axial movement of the stationary seal ring 107 is allowed by elastic deformation of the lip portion 119b, while the space in the O-ring groove 117 is shielded from the slurry liquid region A to the space. (See FIG. 9 of Patent Document 1). In the mechanical seal shown in FIG. 7 (hereinafter referred to as “second conventional seal”), the O-ring groove 117 is filled with a viscous material 100 such as grease, thereby allowing the stationary seal ring 107 to move in the axial direction. However, it is devised to prevent the slurry liquid from entering the O-ring groove 117 (see FIGS. 1 and 2 of Patent Document 1).
JP 2005-048819 A

However, in the first conventional seal, as the stationary seal ring 107 moves in the axial direction (follow-up operation), the sealing force by the lip portion 119b (the contact force to the front end surface 105e of the seal ring holding portion 105b) changes. For this reason, it is difficult to reliably prevent the slurry liquid from entering the O-ring groove 117, and the reliability as a mechanical seal for the slurry liquid is poor. Further, the elastic force of the lip seal 119 (the contact force with the front end surface 105e of the sealing ring holding portion 105b) acts as a pressing force that presses the stationary sealing ring 107 against the rotary sealing ring 106, similarly to the spring member 108. In addition, since the pressure varies depending on the pressure of the slurry liquid region A, there is a problem that the contact pressure of the sealing end faces 106a and 107a of the stationary seal ring 107 becomes higher than necessary under the condition that the slurry liquid region A becomes high pressure.

  On the other hand, the second conventional seal can surely prevent the slurry liquid from entering the O-ring groove 117 without causing such a problem, but there is a limit to the rotary device that can be applied as the shaft seal means. For example, when a second conventional seal is used as a shaft sealing means in a rotary device such as a wet pulverizer that handles a slurry liquid containing hard solid particles (such as cemented carbide fine particles and ceramic fine particles), There is a possibility that the packed layer of the viscous material 100 is eroded by contact with the hard solid particles, and the packed layer is damaged or disappears within a short period of time, and the slurry liquid intrusion prevention effect by the viscous material 100 may be impaired.

  In the first and second conventional seals, the seal ring holding portion 105b of the seal case 105 and the seal rings 106 and 107 come into contact with the slurry liquid. In the case of containing hard solid particles such as fine particles, damage due to contact with the hard solid particles becomes a problem, but such a problem is caused by contact of the seal rings 106 and 107 with contact with the hard solid particles. This can be dealt with by using a hard material (cemented carbide, ceramics, etc.) that does not work. However, since the sealing case 105 must be made of a metal material such as steel from the viewpoint of production economy, the solid particles contained in the slurry liquid are harder than such a sealing case constituent material. In the case of cemented carbide, ceramics, etc., the seal case portion that comes into contact with the slurry liquid (in the first conventional seal, it is the portion that is not covered with the lip seal 119 on the tip surface 105e of the seal ring holding portion 105b, , The entire surface of the front end surface 105e of the sealing ring holding portion 105b) is damaged, and the life of the mechanical seal is significantly reduced.

  The present invention solves such a problem and reliably prevents the followability (operation failure) of the stationary seal ring by the slurry liquid and the damage of the seal case, so that hard solid particles such as cemented carbide and ceramics can be obtained. It is an object of the present invention to provide a mechanical seal for slurry liquid that can be suitably used as a shaft sealing means for rotating equipment such as a wet pulverizer (ball mill) that handles the contained slurry liquid.

  The present invention relates to a cylindrical seal case attached to a housing of a rotating device that handles slurry liquid containing hard solid particles in a state where the seal ring holding portion is exposed to the slurry liquid region, and the slurry liquid region from the seal ring holding portion. A rotating seal ring that is arranged on the side and fixed to a rotating shaft that penetrates the seal case, and a stationary seal ring that is fitted and held on the inner peripheral portion of the seal ring holding portion via an O-ring so as to be movable in the axial direction. And a spring member for urging the stationary seal ring to press contact with the rotary seal ring. An annular lip seal with an inner peripheral end pressed against the outer peripheral surface of the stationary seal ring is disposed in contact with the distal end surface of the seal ring holding portion, Sealing cable by side edge Sealing between the housing and the housing, and connecting portions between the inner peripheral end and inner and outer peripheral ends prevent entry of slurry liquid into the O-ring arrangement space and contact between the sealing ring holding section and the slurry liquid. It is suggested that it is configured to do so.

  In a preferred embodiment of such a slurry liquid mechanical seal, a distal end surface of the sealing ring holding portion is formed with an intermittent or continuous recess concentric with the lip seal. Further, when the hard solid particles contained in the slurry liquid are harder than the constituent material of the seal case (for example, cemented carbide particles or ceramic particles having an average particle diameter of 0.05 to 1.0 mm), each sealing The ring is made of cemented carbide or ceramics, while the seal case is made of metal, which is a common component.

  According to the mechanical seal for slurry liquid of the present invention, it is possible to reliably prevent the slurry liquid containing hard solid particles from entering the space where the O-ring, which is the secondary seal of the stationary seal ring, enters for a long time. In addition, the followability of the stationary seal ring is not deteriorated to cause malfunction, and the mechanical seal function can be satisfactorily exhibited over a long period of time. Further, the seal case cannot be made of a hard material like a seal ring and is easily damaged by contact with hard solid particles in the slurry liquid. According to the present invention, the seal case and the slurry liquid Can be prevented, damage to the seal case can be avoided, and the life of the mechanical seal can be improved.

  The configuration of the present invention will be specifically described below based on the embodiment shown in FIGS.

  FIG. 1 is a longitudinal side view showing an example of a mechanical seal for slurry according to the present invention, and FIG. 2 is a detailed view showing an enlarged main part of FIG. In the following description, front and rear refer to the left and right in FIG.

  The shaft seal device shown in FIG. 1 is equipped in a rotating device such as a ball mill that handles slurry liquid containing hard solid particles (for example, cemented carbide particles or ceramic particles having an average particle diameter of 0.05 to 1.0 mm). Between the housing 1 of the rotating device (for example, the housing of the mill portion) 1 and the rotating shaft (for example, the rotor shaft) 2 that concentrically penetrates the shaft seal opening 1a. A slurry liquid region A and a housing outer region which are regions inside the housing (region inside the machine) by a primary seal 3 and a secondary seal 4 which are parallel to the axis, and are simply arranged in parallel in the following “axial direction”) (Outside machine area) It is configured so as to seal with the atmosphere area B as a sealant via a sealing area C formed between the seals 3 and 4.

  As shown in FIG. 1, the primary seal 3 is a mechanical seal for slurry liquid according to the present invention, and is fixed to a cylindrical seal case 5 attached to the shaft seal opening 1 a of the housing 1 and the rotary shaft 2. The rotary seal ring 6, the stationary seal ring 7 held in the seal case 5 so as to be movable in the axial direction (front-rear direction), and the spring member 8 that urges the stationary seal ring 7 to press and contact the rotary seal ring 6. The slurry liquid region A, which is the outer peripheral side region of the relative rotational sliding contact portions 6a, 7a, and the inside thereof by the relative rotational sliding contact action of the sealing end surfaces 6a, 7a that are the opposite end surfaces of the sealing rings 6, 7 It is an end surface contact type mechanical seal configured to shield and seal between the sealed liquid region C which is the peripheral region. In addition, a sealing liquid 30 having a higher pressure than the slurry liquid area A is circulated and supplied to the sealing liquid area C as will be described later.

  The seal case 5 has a cylindrical structure made of a steel material such as carbon steel or stainless steel (SUS304 in this example). As shown in FIG. 1, the seal case 5 protrudes from the main body portion 5a and the inner peripheral front end portion. It comprises a ring holding portion 5b and a spring holding portion 5c connected to the rear end portion on the inner circumference side, and the front end surface (front end surface) of the main body portion 5a collides with the base end surface (rear end surface) of the shaft seal opening 1a. At the same time, the outer peripheral surface of the sealing ring holding portion 5b is attached to the housing 1 in a state of abutting (fitting) with the circular inner peripheral surface 1b of the shaft seal opening 1a. In addition, the rotating shaft 2 has penetrated each part 5a, 5b, 5c of the seal case 5 concentrically.

As shown in FIG. 1, the rotary seal ring 6 is made of cemented carbide or ceramics (in this example, cemented carbide) having a front end surface (rear end surface) formed as a sealed end surface 6 a which is an annular smooth surface orthogonal to the axis. It is a ring-shaped body made of metal, and is fitted and fixed to the rotary shaft 2 in the shaft seal opening portion 1a at a position closer to the slurry liquid region A (front side) than the seal ring holding portion 5b. A sleeve 2a made of steel (SUS304 in this example) is fitted and fixed to the rotary shaft 2 by a stopper ring 10 fitted to the rear end portion thereof and an appropriate number of set screws 11 and 12 screwed to the stopper ring 10. ing. The rotary seal ring 6 is fitted and fixed to the front end portion of the sleeve 2 a via an O-ring 13, a key 14 and a snap ring 15. As shown in FIG. 1, the fitting structure between the sleeve 2a and the rotary seal ring 6 is such that the front end surfaces of both sleeves 2a and 6 are flush with each other so that the front end surfaces of both sleeves 2a and 6 are flush with each other. Is designed to be as small as possible.

  As shown in FIG. 1, the stationary seal ring 7 is a circle made of cemented carbide or ceramics (in this example, ceramics) having a tip end surface (front end surface) formed as a sealed end surface 7a which is an annular smooth surface orthogonal to the axis. It is an annular body, and is fitted and held in an inner peripheral portion of the sealing ring holding portion 5b through an O-ring 16 made of an elastic material such as rubber (perfluoro rubber in this example) so as to be movable in the axial direction. As shown in FIG. 1, the stationary seal ring 7 is an annular body having an outer peripheral surface 7b having a constant diameter that is the same as the outer diameter of the rotary seal ring 6, and a secondary seal is provided between this and the seal ring holding portion 5b. In the state where the O-ring 16 is interposed, the seal ring holding portion 5b is fitted and held so as to be movable in the axial direction. The O-ring 16 is engaged and held in an annular O-ring groove 17 formed in the inner peripheral portion of the sealing ring holding portion 5b, and is pressed against the outer peripheral surface 7b of the stationary sealing ring 7 so as to be capable of relative movement.

  As shown in FIG. 1, the spring member 8 is composed of an appropriate number of coil springs loaded with a stationary seal ring 7 and a spring holding portion 5 c of the seal case 5 positioned behind the stationary seal ring 7. It is urged forward to press contact with the sealing ring 6. The stationary seal ring 7 is sealed while allowing movement in the axial direction within a predetermined range by engaging a drive pin 18 projecting from the spring holding portion 5c with a recess 7c formed in the inner peripheral portion of the rear end. Relative rotation with respect to the case 5 is prevented.

  Thus, in the primary seal 3, according to the present invention, as shown in FIGS. 1 and 2, the mounting portion 19a, which is the outer peripheral end, is clamped and fixed between the sealing ring holding portion 5b and the housing 1. In addition, an annular lip seal 19 in which the lip portion 19b which is the inner peripheral side end portion is brought into pressure contact with the outer peripheral surface 7b of the stationary seal ring 7 is disposed in contact with the front end surface (front end surface) 5e of the seal ring holding portion 5b. Then, the space between the seal case 5 and the housing 1 is sealed by the mounting portion 19a, and the arrangement space (inside the O-ring groove 17) of the O-ring 16 is formed by the connecting portion 19c between the lip portion 19b and the inner and outer peripheral end portions 19a and 19b. And the contact between the sealing ring holding portion 5b and the slurry liquid is prevented.

  That is, the lip seal 19 is made of an elastic material such as rubber (perfluoro rubber in this example), and is configured as an annular plate in which the connecting portion 19c is thinner than the mounting portion 19a and the lip portion 19b. As shown in FIG. 2, the outer peripheral surface 5d of the tip end portion of the seal ring holding portion 5b has a smaller diameter than the inner peripheral surface 1b of the shaft seal opening 1a, and an annular groove 20 is formed between the opposing peripheral surfaces 1b, 5d of both portions 1a, 5b. By forming and mounting the mounting portion 19a into the annular groove 20 in a sandwiched state, the lip seal 19 is brought into contact with the front end surface 5e of the sealing ring holding portion 5b and the lip portion 19b is statically sealed. It is attached to the housing 1 or the sealing ring holding portion 5b in a state of being pressed against the outer peripheral surface 7b of the ring 7. Note that the front end surface 5e of the sealing ring holding portion 5b and the connecting portion 19c are orthogonal to the axis.

As shown in FIG. 2, the mounting portion 19a of the lip seal 19 extends rearward from the outer peripheral end of the connecting portion 19c, and between the opposed peripheral surfaces 1b and 5d of the shaft seal opening 1a and the seal ring holding portion 5b. By being clamped and fixed, it functions as a fixed portion of the lip seal 19 and also functions as a seal portion that seals (secondary seal) between both portions 1a and 5b. Since the attachment portion 19a also functions as a seal portion in this way, in this example, as shown in FIG. 1, the secondary seal between the housing 1 and the seal case 5 is performed only by the attachment portion 19a, and a special two No next seal member (O-ring or the like) is provided. As shown in FIG. 2, the outer peripheral surface 19 g of the mounting portion 19 a has an uneven surface as shown in FIG. 2 in order to increase the pressure contact force of the mounting portion 19 a to the housing inner peripheral surface 1 b and to more effectively exert its function as a seal portion. It is configured. Further, as shown in FIG. 2, the mounting portion 19a includes an annular convex portion 19 that engages with an annular concave portion 5f formed on the front end outer peripheral surface 5d of the sealing ring holding portion 5b.
f is formed, and detachment of the lip seal 19 from the annular groove 20 is prevented by the engagement of the uneven portions 5f and 19f.

  As shown in FIG. 2, the lip portion 19b of the lip seal 19 has a front surface slightly protruding from the front surface of the connecting portion 19c and is thicker than the connecting portion 19c, and hinders movement of the stationary seal ring 7 in the axial direction. To the extent that it does not, it is in pressure contact with the outer peripheral surface 7 b of the stationary seal ring 7. As shown in FIG. 2, the radial width H of the lip portion 19b is the radial distance between the front wall portion 5g of the O-ring groove 17 formed by the inner peripheral side tip portion of the sealing ring holding portion 5b and the stationary sealing ring 7. The radial interval h is set as small as possible on condition that the front wall portion 5g of the O-ring groove 17 can prevent the O-ring 16 from jumping out from the O-ring groove 17. It is set large. In this example, the radial interval h is set equal to or slightly smaller than 1/2 of the radial interval between the groove bottom surface of the O-ring groove 17 and the outer peripheral surface 7b of the stationary seal ring 7 as shown in FIG. Has been. The corner 19h at the rear end of the inner periphery of the lip 19b is an arc surface, and the corner 5h at the front end of the inner wall 5g of the O-ring groove 17 is a chamfered inclined surface.

  When the pressure in the slurry liquid region A (hereinafter referred to as “process pressure”) increases, the lip portion 19b of the lip seal 19 bites into the outer peripheral surface 7b of the stationary seal ring 7 as illustrated in FIG. The shape is deformed and the degree of deformation changes depending on the process pressure, and increases as the process pressure increases. Accordingly, the contact pressure of the lip portion 19b to the stationary sealing ring 7, that is, the sealing force increases as the process pressure increases, and a sealing force corresponding to the process pressure is obtained.

  Since the mechanical seal 3 for slurry liquid according to the present invention as the primary seal is configured as described above, the entry of the slurry liquid into the O-ring arrangement space (the space in the O-ring groove 17) prevents the lip seal. The solid solid particles contained in the slurry liquid enter and accumulate between the stationary seal ring 7 and the O-ring 16 as a result of the sealing action of the 19 lip portions 19b. Occurrence of a situation that lowers or impedes followability is reliably avoided. Further, since the seal case portion exposed in the slurry liquid region A, that is, the sealing ring holding portion 5b is isolated from the slurry liquid region A by the lip seal 19 and does not come into contact with the slurry liquid, even if the hard solid particles are in the seal case. Even if it is harder than the constituent material, the seal case 5 is not damaged by contact with the hard solid particles contained in the slurry liquid.

  By the way, the deformation of the lip portion 19b described above for exhibiting the sealing function with the stationary seal ring 7 is not caused by the elastic deformation of the lip portion 19b itself, and the connecting portion 19c is sealed as shown in FIG. This is caused by elastic deformation in a direction (front) away from the front end surface 5e of the ring holding portion 5b. However, as shown in FIG. 5, when the front end surface 5e of the sealing ring holding portion 5b is a flat surface, the connecting portion 19c is pressed and adhered to the entire front end surface 5e by the process pressure. Even if an attempt is made to elastically deform in a direction away from the front end surface 5e, the space formed between the two 5e and 19c becomes negative pressure, which may hinder the elastic deformation. Therefore, the above-described deformation of the lip portion 19b is not performed smoothly, and the sealing force by the lip portion 19b may not be in accordance with the process pressure. On the other hand, when the fluid pressure to be sealed is high enough to elastically deform the connecting portion 19c despite the occurrence of the negative pressure, the deformation of the lip portion 19b becomes larger than necessary. The pressure contact force of the lip portion 19b to the stationary seal ring 7 becomes higher than necessary, and as a result, the axial movement of the stationary seal ring 7 is hindered. There is a possibility that the sealing function may not be exhibited.

In the mechanical seal 3 in this embodiment, in order to surely avoid such a problem, as shown in FIG. 2, an annular concentric with the lip seal 19 is provided on the front end surface 5e of the sealing ring holding portion 5b. An intermittent or continuous recess 21 is formed. That is, since the connecting portion 19c does not come into full contact with the front end surface 5e of the sealing ring holding portion 5b due to the presence of the concave portion 21, the contact area is reduced. Therefore, the connecting portion 19c described above is between the both 5e and 19c. A large negative pressure that prevents elastic deformation does not occur (the air bleeding effect by the recess 21). Therefore, the above-described deformation of the lip portion 19b (deformation that easily bites into the outer peripheral surface 7b of the stationary seal ring 7 as shown in FIG. 3) is smoothly performed, and the sealing force by the lip portion 19b according to the process pressure. Is obtained.

  Further, when the lip portion 19b is deformed as shown in FIG. 3, if the process pressure is high, the pressure contact force of the lip portion 19b against the stationary seal ring 7 may be increased more than necessary. However, such a fear is also avoided by the presence of the recess 21. That is, due to the presence of the recess 21, as shown in FIG. 4, the connecting portion 19c is elastically deformed so as to be immersed in the recess 21 due to the action of the process pressure, that is, the degree of deformation of the lip portion 19b (the outer periphery of the stationary seal ring 7). The degree of deformation in the case of biting into the surface 7b and deforming in the desired direction) is reduced, and as a result, the pressure contact force of the lip portion 19b against the stationary seal ring 7 hinders the followability of the stationary seal ring 7. It will not grow. In addition, even if the recessed part 21 makes the concentric annular shape with the lip seal 19, and interrupts (forms the several recessed part 21 parallel to the circumferential direction in the front end surface 5e of the sealing ring holding | maintenance part 5b), the said Even if it is continuous in an annular shape (one annular recess 21 is formed on the front end surface 5e of the sealing ring holding portion 5b), any of them may be used, but the cross-sectional shape thereof is a static sealing of the lip portion 19b. The connecting portion 19c can be elastically deformed so as to be immersed in the recess 21 as shown in FIG. 4 so that the pressure contact force on the ring 7 does not increase to such an extent that the followability of the stationary sealing ring 7 is inhibited as described above. As a condition, it is set appropriately.

  In this way, by forming the recess 21 in the front end surface 5e of the sealing ring holding portion 5, the sealing force by the lip portion 19b is appropriately adjusted according to the level of the process pressure. Regardless of the height, the followability of the stationary seal ring 7 can be reliably ensured while always preventing the slurry liquid from entering the O-ring groove 17 and contacting the seal ring holding portion 5b.

  Further, in the mechanical seal 3 described above, an annular space between the stationary seal ring 7 and the seal ring holding portion 5b, which is sealed by the O-ring 16 and the lip seal 19 (see FIG. 2). Is filled with a lubricant such as grease in order to reduce the contact resistance between the seal members 16 and 19 and the stationary seal ring 7.

  As shown in FIG. 1, the secondary seal 4 includes a seal case 5 that is also used as the primary seal 3 and a holding ring that is arranged in a rear direction from the spring holding portion 5c of the seal case 5 and is fitted and fixed to the sleeve 2a. 23 and a movable seal ring 25 which is engaged with the sleeve 2a so as not to rotate relative to the sleeve 2a and is fitted and held through an O-ring 24 so as to be movable in the axial direction. A fixed sealing ring 26 fitted and fixed to the rear end of the case 5, and loaded between the holding ring 23 and the movable sealing ring 25, and urged to press the movable sealing ring 25 against the fixed sealing ring 26. And a sealed region which is an outer peripheral side region of the relative rotational sliding contact portions 25a and 26a by the relative rotational sliding contact action of the sealing end surfaces 25a and 26a which are the opposite end surfaces of both sealing rings 25 and 26. C and its inner circumference area It is configured end surface contact type mechanical seal to shield seals the atmosphere region B. The shaft seal device composed of the primary seal 3 and the secondary seal 4 is attached to the seal case 31 with an appropriate number of set claws 31 engaged with the stopper ring 10 as shown by a chain line in FIG. It is configured in a cartridge type that can be integrated when the shaft seal device is attached to and detached from the rotating device. During operation of the shaft seal device, the set claw 31 is removed from the stopper ring 10 and attached to a position that is an appropriate place for the seal case 31 and does not hinder the operation (for example, a position indicated by a solid line in FIG. 1). .

As shown in FIG. 1, a sealing liquid 30 having a pressure higher than the process pressure is circulated and supplied to the sealing liquid region C through supply / discharge passages 28 and 29 formed in the sealing case 5. As the sealing liquid 30, water, oil, a solvent, or the like that does not interfere with the slurry liquid is used. By this sealing liquid 30, lubrication between the sealing end surfaces of the primary seal 3 and the secondary seal 4 is performed satisfactorily, and the sealing between the slurry liquid area A and the atmospheric area B is performed satisfactorily.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately improved and changed without departing from the basic principle of the present invention. For example, the mechanical seal of the present invention is used as the primary seal 3 in the shaft seal device having the above-mentioned double mechanical seal structure, and also a single seal that seals the slurry liquid region A as the in-machine region and the air region B as the out-of-machine region. Can be used, and the same effects as the above-described embodiment can be obtained. Further, the mechanical seal of the present invention is particularly preferably used in a rotating machine containing cemented carbide alloy particles and ceramic particles harder than the seal case constituent material, but the slurry containing softer solid particles than these. Of course, it can also be used to seal the liquid.

It is a vertical side view which shows an example of the mechanical seal for slurry liquids concerning this invention. FIG. 2 is an enlarged detailed view showing a main part of FIG. 1. It is action explanatory drawing equivalent to FIG. 2 which shows the deformation | transformation form of a lip seal. FIG. 4 is an operation explanatory diagram corresponding to FIG. 2 and showing a modified form of the lip seal different from FIG. 3. It is a vertical side view equivalent to FIG. 2 of the principal part of the said mechanical seal which shows the example which does not form a recessed part in the front end surface of a sealing ring holding | maintenance part. It is a vertical side view which shows a 1st conventional seal | sticker. It is a vertical side view which shows a 2nd conventional seal | sticker.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing of rotary device 1a Shaft seal opening of housing 2 Rotating shaft of rotary device 5 Seal case 5b Seal ring holding portion 5e End face of sealing ring holding portion 6 Rotating sealing ring 6a Sealing end surface of rotating sealing ring 7 Stationary sealing ring 7a Sealing end face of stationary sealing ring 7b Outer peripheral surface of stationary sealing ring 8 Spring member 16 O-ring 17 O-ring groove (O-ring arrangement space)
19 Lip seal 19a Mounting part (outer edge of lip seal)
19b Lip (inner side of lip seal)
19c Connecting part 21 Recessed part A Slurry liquid area B Atmospheric area C Sealed liquid area

Claims (3)

A cylindrical sealing case (5) attached to a housing (1) of a rotating device that handles slurry liquid containing hard solid particles in a state where the sealing ring holding portion (5b) is exposed to the slurry liquid region (A); A rotary seal ring (6) disposed on the slurry liquid region (A) side of the seal ring holding part (5b) and fixed to the rotary shaft (2) passing through the seal case (5); and the seal ring holding part A stationary seal ring (7) fitted and held on the inner periphery of (5b) via an O-ring (16) so as to be movable in the axial direction, and the stationary seal ring (7) pressed against the rotary seal ring (6) In a mechanical seal for slurry liquid comprising a spring member (8) biased to contact,
The outer peripheral side end (19a) is clamped and fixed between the sealing ring holding portion (5b) and the housing (1), and the inner peripheral side end (19b) is fixed to the outer peripheral surface (7b) of the stationary sealing ring (7). An annular lip seal (19) brought into pressure contact with the sealing ring holding portion (5b) is disposed in contact with the tip end surface (5e), and the outer peripheral side end portion (19a) is connected to the seal case (5) and the housing. (1) and the connecting portion (19c) between the inner peripheral end (19b) and the inner and outer peripheral ends (19a, 19b) to the arrangement space (17) of the O-ring (16). The slurry liquid mechanical seal is configured to prevent the slurry liquid from entering and the seal ring holding portion (5b) from contacting the slurry liquid. The front end surface (5e) of the sealing ring holding portion (5b) is formed with a concave portion (21) that is intermittently or continuously formed in an annular shape concentric with the lip seal (19). Mechanical seal for slurry liquid described in 1. The seal case (5) is made of metal, each sealing ring (6, 7) is made of cemented carbide or ceramics, and the hard solid particles contained in the slurry liquid are cemented carbide or ceramics. The mechanical seal for slurry liquid according to claim 1 or 2, characterized by the above.