KR20010067881A - Acid-resistant apparatus for sealing up the spindle of a centerifugal pump - Google Patents

Abstract

PURPOSE: A stuffing device for an acid-proofing centrifugal pump is provided to prolong the life of the centrifugal pump and a mechanical seal by cooling friction heat generated from a contact portion between a fixed ring and a rotating ring of the mechanical seal and improve efficiency of the pump by largely improve a rotational speed of a motor. CONSTITUTION: A stuffing device for an acid-proofing centrifugal pump includes a mechanical seal mounting space(18) communicating with the inside space of a casing at a front part of a connection bracket(17) connected to a rotating shaft mounted between a rear part of the casing and a motor(2), a mechanical seal(10) mounted in the mechanical seal mounting space for preventing leakage of fluid of the casing to a rear part of the rotating shaft, An O-ring(19a) is mounted on the outside of the rotating shaft at a rear part of the mechanical seal mounting space, a fixed ring(19) is mounted at a prescribed gap between the mechanical seal and the rotating shaft, a contact sealing ring(20) molded at the rear part of the rotating shaft in front of the fixed ring, a rotating ring(23) mounted at the center and a rotating ring cover(25) mounted at a front and outer side of the rotating ring to wrap the rotating ring. The rotating ring has a bellows(22) and a slant head part(21) and is in contact with the rotating shaft.

Description

Acid-resistant apparatus for sealing up the spindle of a centerifugal pump}

The present invention relates to an acid resistant shaft rod device of a centrifugal pump, and more particularly, a mechanical seal installed on a rotating shaft of a centrifugal pump for transferring an acid solution or an alkaline solution to prevent leakage of a fluid to an acid solution or an alkaline solution. It is a rubber material that can withstand a bellows shape, and the rubber bellows type mechanical seal is installed behind the impeller so as to be immersed in the fluid pumped from the pump casing. The frictional heat generated at the contact point of the pump is cooled by the fluid pumped from the pump casing to extend the life of centrifugal pumps including mechanical seals, and to significantly improve the rotational speed of the motor to improve the efficiency of the pump. It is to.

As shown in FIG. 1, the centrifugal pump is provided with a pump 4 in front of the motor 2 by a rotating shaft 3, and the pump 4 discharges the inlet 5 through which the fluid is introduced and the fluid. It consists of a casing (7) having a discharge port (6) to be formed, and an impeller (8) freely installed by the rotating shaft (3) inside the casing (7).

In addition, while the rotary shaft 3 is installed with the rotary shaft 3 long for the quiet rotation of the impeller 8, this long rotary shaft 3 is supported by the shaft support (9), the casing (7) The mechanical seal 10 is installed on the rotating shaft 3 behind the impeller 8 in order to prevent the fluid being pumped through from leaking to the rotating shaft 3 side.

1 and 2, the mechanical seal 10 has a fixed ring 12 at a casing back cover 11 behind the casing 7 with a predetermined clearance and an outer circumference of the rotating shaft 3. It is fixedly installed, the rotating ring 13 is fixedly installed by the fixing screw 14 at a predetermined interval from the fixing ring 12 on the rotating shaft 3 behind the fixing ring 12, the rotating ring 13 Between the fixing ring 12 and the rotating ring 13, the sealing ring 16, the tip of which is in close contact with the rear end of the fixing ring 12 is elastically installed with the spring 15 interposed therebetween. It is.

In this conventional pump, as the motor 2 starts, the rotational force of the motor 2 rotates the impeller 8 through the rotation shaft 3, and the impeller 8 rotates as the impeller 8 rotates. The fluid flows into the casing 7 through the inlet 5 by the centrifugal force and is discharged to the outside through the discharge port 6.

In this way, the fluid flows into the inlet 5 and is transported through the outlet 6 so that fluid may leak to the outside through a gap between the casing back cover 11 and the rotating shaft 3 behind the casing 7. There is a mechanical seal 10 installed at the rear of the casing back cover 11 to prevent the leakage of the fluid.

As shown in FIG. 2, the mechanical seal 10 is fixed to the casing back cover 11 while the rotating ring 13 and the sealing ring 16 are the same as the rotating shaft 3. Since the rear end of the fixing ring 12 and the front end of the sealing ring 16 are in close contact with the elasticity of the spring 15 because it is in a rotating state, heat due to friction is generated at this contact portion.

In preparation for the friction, the front end portion of the sealing ring 16 uses a carbon ring which can be self-lubricated, and even when the carbon ring of the sealing ring 16 is worn on the friction portion, the spring 15 is closed. 16 is continuously applied to the fixing ring 12 side, so that the rear end of the fixing ring 12 and the tip of the sealing ring 16 are in intimate contact with each other, and the sealing ring 16 of the rotary shaft 3 Since it is closely inserted in the outer circumference, the fluid is prevented from leaking to the rear of the rotating shaft 3.

As described above, in the process of preventing the leakage of fluid which may leak to the rear side of the casing 7 as the mechanical seal 10 while the impeller 8 rotates as described above. The rear end of the 12 and the front end of the sealing ring 16 generates friction heat while continuously rubbing, and if left without cooling the friction heat, the friction part is easily damaged to the rear of the rotating shaft 3. There is a problem that the fluid leaks.

Therefore, in the related art, as shown in FIGS. 1 and 2, the frictional heat is cooled by air cooling by opening a portion on which the mechanical seal 10 is mounted, but there is a limit to cooling by air cooling. In view of such a problem, there have been cases in which cooling water is supplied to the friction part, but in this case, there is a troublesome problem of separately installing a cooling water supply means and a cooling device part on one side of the mechanical seal 10.

In the present invention, the fluid transferred from the centrifugal pump 1 relates to the use of chemicals such as an acidic solution or an alkaline solution. The conventional mechanical seal 10 is made of a metal material, and thus, an acidic solution or an alkaline solution is used. When used in a centrifugal pump for transporting chemicals such as solutions, special care must be taken to ensure that such chemicals do not come into contact with the metallic mechanical seal (10).

When the chemical seal such as an acidic solution or an alkaline solution is buried in the metallic seal 10 made of the metal material, the mechanical seal 10 is corroded by the chemical agent and thus the inherent function of the mechanical seal 10 is caused. Since the conventional mechanical seal 10 made of metal had to be installed on the outside where the fluid is not in contact with each other, as shown in FIGS. 1 and 2, it occurred at the frictional part of the mechanical seal 10. The cooling of the frictional heat to be cooled was cooled by air cooling.

By cooling the frictional heat generated in the frictional portion of the mechanical seal 10 in the air-cooled manner as described above, a motor having a low cooling efficiency and a low-speed rotation cannot be mounted, and a motor having a rotation speed of 1500 to 1700 rpm is typically used. As it is installed and used, it is not suitable for pumping at high speed.

The present invention is to solve the above problems, the mechanical seal is installed on the rotary shaft of the centrifugal pump for pumping chemicals such as acidic solution or alkaline solution to prevent the leakage to the rear of the rotary shaft acid solution or alkaline solution After forming the bellows shape using a rubber material that can withstand chemical chemicals such as bellows, the bellows type mechanical seal formed of the rubber material is installed so as to be immersed in a chemical fluid such as an acid solution. The technical problem is that the frictional heat generated from the frictional part is cooled by the chemical fluid so that the fluid does not leak to the outside.

The present invention for achieving the above object is provided in the rotary shaft behind the impeller of the centrifugal pump for pumping chemical fluids, such as acidic solution or alkaline solution, to prevent the fluid in the casing from leaking to the outside of the rotating shaft, the casing The connecting bracket is connected and installed between the rear of the motor and the rotating shaft of the motor, and the mechanical seal installation space is formed in the front center of the casing back cover formed at the front of the connecting bracket so as to communicate with the inner space of the casing. The mechanical seal installation space is provided with a mechanical seal that prevents the fluid in the casing from leaking to the rear of the rotating shaft, and the mechanical seal is outside the rotating shaft outside the closed space at the rear of the mechanical seal installation space. O-ring is inserted in the periphery and ceramic ring is installed with a certain gap between the rotating shaft The rotating ring in front of the fixed ring is formed with a contact sealing ring in close contact with the front end of the fixed ring and a slanted head formed at the front end thereof, and a rotating ring having a bellows formed at the center thereof in close contact with the rotating shaft. It is characterized in that the front outer side of the rotating ring cover formed to form a slanted groove to be mated with the inclined head is extrapolated to be wrapped.

1 is a structural diagram showing a conventional general centrifugal pump.

Fig. 2 is an enlarged view of an essential part of “A” of Fig. 1, showing a structure of a conventional mechanical seal.

Figure 3 is a partial cross-sectional view showing a centrifugal pump in which the present invention is installed.

4 is an enlarged excerpt view showing the enlarged portion "B" of FIG.

5 is a cross-sectional view showing another example of installation of the present invention.

<Explanation of symbols for main parts of drawing>

1 Centrifugal Pump 2 Motor 3 Rotary Shaft

4 pump 5 inlet port 6 outlet port

7: casing 8: impeller 9: shaft support

10 Mechanical Seal 11 Casing Back Cover 12 Retaining Ring

13: rotating ring 14: fixing screw 15: spring

16: sealing ring 17: connecting bracket 18: mechanical seal installation space

19: fixing ring 20: contact sealing ring 21: inclined head

22: bellows 23: rotary ring 24: inclined groove

25: rotary ring cover 26: O-ring 27: bearing

27: boss portion 29: snap ring

Hereinafter, with reference to the accompanying drawings, Figures 3 to 5 for the acid-proof shaft device of the centrifugal pump according to the present invention.

3 and 4 show a preferred embodiment of the present invention, Figure 5 shows another embodiment of the present invention.

First, in the present invention shown in FIGS. 3 and 4, a connecting bracket 17 is connected between the rear opening of the casing 7 and the motor 2. At this time, the rotating shaft 3 is penetrated to the casing 7 side in the center of the connecting bracket 17, and the impeller 8 is freely installed at the tip of the rotating shaft 3 penetrating into the casing 7.

The mechanical seal installation space 18 is formed in the front center of the casing back cover 11 of the connecting bracket 17 so as to communicate with the internal space of the casing 7, and the mechanical seal installation space 18 has a casing (7). The mechanical seal 10 is installed to block the fluid in the cylinder from leaking to the rear of the rotation shaft (3).

The mechanical seal 10 has an O-ring 19a fitted to an outer circumference of the outer side of the rotating shaft 3 of the closed space of the mechanical seal installation space 18, and the fixing ring 19 made of ceramic material rotates the rotating shaft. (3) and a predetermined clearance is provided, the contact sealing ring 20 is molded in the rear end of the fixed ring 19 in close contact with the front end of the fixed ring 19, the inclined head portion At the same time as the 21 is formed, the rotating ring 23 having the bellows 22 formed at the center thereof is installed to be in close contact with the rotating shaft 3, and the inclined head 21 is disposed at the front outer side of the rotating ring 23. Rotating ring cover 25 is formed to be extrapolated to form the inclined groove 24 to be joined with.

Another embodiment of the present invention shown in Figure 5 shows that the mechanical seal 10, which is a major component of the present invention is installed to be exposed to the outside of the casing (7), the rear of the casing back cover (11) After forming the boss portion 28 open to the rear side, the fixing ring 19 made of ceramic material is fixedly coupled to the inside of the boss portion 28, and on the rotating shaft 3 behind the fixing ring 19, Rotating ring 23 having a contact sealing ring 20 formed of carbon or cemented carbide on the contact portion with the fixing ring 19, and having an inclined head 21 formed at the rear end thereof and a bellows 22 at the center thereof. It is inserted in close contact with the rotary shaft (3), the outer side of the rotary ring 23 is extrapolated to surround the rotary ring cover 25 having an inclined groove 24 therein, the rotary ring cover 25 The rear rotation shaft (3) is provided with a snap ring 29 to prevent the rotary ring cover 25 from retreating.

In the drawing, reference numeral 26 denotes an O-ring, and 27 denotes a bearing.

Referring to Figures 3 and 4 the working relationship of the present invention configured as described above is as follows.

When the motor 2 is driven, the rotational force of the motor rotates the rotary shaft 3, and thus the impeller 8 in the casing 7 rotates, and the inlet is caused by the centrifugal force generated when the impeller 8 rotates. Through (5) the fluid is introduced into the casing (7). At this time, it is clear that the fluid to be pumped is to inject and discharge chemicals such as acidic solutions or alkaline solutions.

As described above, the fluid introduced into the casing 7 is discharged to the discharge port 6 through the entire casing 7, and the mechanical seal 10, which is a main component of the present invention, is the casing 7. The mechanical seal 10 is also locked in the circulating fluid.

Thus, as the rotary shaft 3 and the impeller 8 rotate in the process of discharging the fluid circulated in the casing 7 through the mechanical seal 10, the fluid is circulated closely to the rotary shaft 3. Since the rotary ring cover 25 is installed on the front outer side of the rotary ring 23 to surround the rotary ring 23, the rotary ring cover 25 is in close contact with the rear of the impeller 8 and the rotary ring 23. The rotary ring cover 25 is rotated together with the rotary shaft (3).

In addition, the rotary ring 23 has a bellows 22 freely stretched at the center thereof, and a contact sealing ring 20 which is formed of carbon or a small alloy at the rear end thereof without lubrication has a mechanical seal installation space ( 18 is in contact with the fixing ring 19 fixed to the closed inner wall of the rotating ring 23 is provided with a bellows 22 at the center of the rotary ring 23 due to the expansion force of the bellows 22. The rear end contact sealing ring 20 and the front end of the fixed ring 19 is rotated in close contact.

As described above, since the rear contact sealing ring 20 of the rotary ring 23 is rotated in close contact with the distal end of the stationary ring 19, friction heat is generated while rotating friction at the contact portion. The mechanical seal 10 including) is submerged in the fluid passing through the casing 7 as described above, so that the frictional heat is cooled.

In addition, the contact sealing ring 20 integrally molded to the rear of the rotary ring 23 is formed of carbon or sintered alloy that does not need to be lubricated, and the fixing ring 19 in contact therewith is not easily worn. It is formed of a ceramic material that is strong and resistant to acidic or alkaline solutions and does not corrode. The contact sealing ring 20 has a lower hardness than the fixing ring 19, so that the contact sealing ring has a low hardness at the rotational frictional region due to long-term use. 20 is worn, but the contact sealing ring 20 and the fixed ring (19) despite the contact sealing ring 20 is worn by the expansion of the bellows 22 formed in the center of the rotary ring (23) This intimate contact is to prevent the leakage of the fluid flows into the fixing ring (19) side.

In addition, the inclined head portion 21 is formed to be inclined to the front end portion of the rotary ring 23, the outer side of the rotary ring cover formed with an inclined groove portion 24 corresponding to the inclined head portion 21 ( When the pressure is applied to the rotary ring cover 25 by the inflow pressure through which the fluid is introduced through the inlet port 25, the rotary ring cover 25 is applied when the force to push the rotary ring cover 25 to the rear side is installed. Of the inclined groove 24 of the rotating ring 23 pushes the inclined groove 24 of the rotary ring 23 in the direction perpendicular to the inclined surface, so as to contact the inside of the inclined head 21, that is, the rotating shaft 3. The rotary shaft 3 is in intimate contact to prevent sliding of the rotary ring 23.

As the rotating ring 23 is slidably coupled to the outer side of the rotating shaft 3 as described above, the bellows 22 expands while the penetrating portion of the inner rotating shaft 3 of the inclined head 21 is firm and held in place. The contact sealing ring 20 acts in close contact with the contact sealing ring 20 and the fixing ring 19 made of ceramic material, thereby preventing the fluid from leaking to the rear of the rotation shaft 3.

In the present invention, the rotary ring 23 is formed of a rubber material that is resistant to acidic or alkaline solutions, so that the rotary ring 23 does not corrode even when the rotary ring 23 is immersed in the acidic or alkaline solution. It can function properly.

In another embodiment of the present invention shown in Figure 5 shows a case in which the rotary ring 23 made of rubber material and the fixing ring 19 made of ceramic material is exposed to the outside of the casing (7), Since the mechanical seal 10 is also installed inside the casing 7 and has the same function as preventing leakage of the fluid, detailed description of other embodiments will be omitted.

As described above, in the acid resistant shaft rod device of the centrifugal pump, the rotary ring of the mechanical seal is formed of a rubber material capable of withstanding acidic or alkaline solutions such as sulfuric acid or hydrochloric acid, thereby for conveying acidic or alkaline solutions. It can be installed inside the casing of the centrifugal pump. As the mechanical seal mounted inside the casing rotates at high speed, the frictional heat generated at the frictional part is cooled by the fluid circulating through the casing and the top of the mechanical seal This can be prevented.

As the fluid in the casing cools the heat generated from the frictional part of the mechanical seal, a centrifugal pump, which has a mechanical seal installed on the outside, cannot employ a motor that rotates more than about 1700 rpm. In the case of the present invention, it is possible to employ a motor having a rotational speed of 3400 to 3500 rpm, so that the pumping capability of the centrifugal pump for pumping chemicals is improved.

Claims (1)

In the rotational shaft 3 behind the impeller 8 of the centrifugal pump for pumping chemical fluids such as an acidic solution or an alkaline solution, the fluid in the casing 7 is prevented from leaking to the exterior of the rotational shaft 3. , A mechanical seal installation space 18 communicating with the inner space of the casing 7 is provided in front of the connecting bracket 17 through which the rotating shaft 3 is connected between the rear of the casing 7 and the motor 2. Is formed to be open to the front, The mechanical seal installation space 18 is provided with a mechanical seal 10 to prevent the fluid in the casing (7) from leaking to the rear of the rotating shaft (3), The mechanical seal 10 has an O-ring (19a) is fitted to the outside of the rotary shaft 3 of the closed space of the mechanical seal installation space 18, the fixing ring 19 made of ceramic material is the rotary shaft (3) Is installed with a small gap, In the rotating shaft 3 in front of the fixing ring 19 is formed a contact sealing ring 20 in close contact with the front end of the fixing ring 19, the inclined head portion 21 is formed at the front end and at the same time a bellows ( Rotating ring 23 formed 22 is installed in close contact with the rotating shaft (3), Axial rod for acid resistance of the centrifugal pump, characterized in that the front and outer side of the rotary ring 23 is wrapped around the rotary ring cover 25 formed with the inclined groove portion 24 to be mated with the inclined head 21. Device.