JPH02304270A - Horizontal type shaft sealing device - Google Patents

Abstract

PURPOSE:To prevent a mechanical seal from being damaged by connecting a cleaning fluid feeding device to a cleaning fluid filling hole provided in a casing between a mechanical seal unit part an an oil seal unit part. CONSTITUTION:When a valve 34 and pressure control valves 38 and 39 are opened in washing, a cleaning fluid in a cleaning pot 35 flows into a space 41 between an oil seal 4 and a mechanical seal 5. In this case, the pressure control valves 38 and 39 are so opened that a pressure in the cleaning fluid pot 35 may be increased higher than that in a vessel and a pressure in a shaft seal fluid pot 31 may be increased further. By this, the cleaning fluid in the space 41 flows into the internal side of the vessel, but will not flow into a shaft seal chamber 12. Accordingly, though the TEG liquid solution of high temperature and low viscosity in the vessel reaches near the oil seal 4 through a screw seal 3, the hot solution 21 in the vessel will not come in contact with the oil seal 4 and the mechanical seal 5 since the cleaning fluid of room temperature flows out of the oil seal 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a horizontal shaft sealing device, and particularly to a horizontal shaft sealing device suitable for a horizontal stirring device for high-temperature, high-viscosity liquids.

[Conventional technology]

Examples of horizontal stirring devices for high-temperature, high-viscosity liquids include horizontal continuous polymerization devices for PgT (polyethylene terephthalate);
Figure C.2-1 "Shaft seal using liquid viscosity" on page 721 and Figure C.2-194 "Example of mechanical seal (double static type)" on page 724 of There are combinations of screw seals and mechanical seals.

An example of its structure is shown in FIG. In Figure 5, axis 1
A screw seal 3 and a mechanical seal 5 are provided in the portion where the casing 2 passes through the casing 2 in this order from the container side. The mechanical seal 5 is composed of a rotating ring 6, a pin 7, a fixed ring 8, a spring 9, and an O-ring 10.11. A shaft sealing liquid container is contained in a space 12 (hereinafter referred to as a "shaft sealing chamber") between the mechanical seal 5 and the casing 2.

The casing 2 of the shaft sealing chamber t2S has a shaft sealing liquid inlet hole 13 and a shaft sealing liquid outlet hole 14, each of which is connected to a pressurized shaft sealing liquid supply device 17 via a pipe 16. As the shaft sealing liquid pressurized supply device It17, a combination of a shaft sealing liquid pot and a nitrogen cylinder, or an oil pressure unit is used.

In the structure shown in FIG. 5, the screw seal seals the high temperature and high viscosity content liquid, and the mechanical seal seals the atmosphere. Therefore, during normal operation, the high temperature and high viscosity content liquid comes into contact only with the screw seal and does not come into contact with the mechanical seal. Note that related devices of this type include, for example, Japanese Patent Application Laid-open No. 187173/1986. The above-mentioned conventional technology does not take into account countermeasures when cleaning containers, and when cleaning containers, high-temperature cleaning liquid and foreign matter are mechanically removed. It could have come into contact with the seal and caused damage due to heat and foreign objects.

For example, in the case of PfiiT's horizontal continuous polymerization apparatus, the container may be cleaned with a TgG (triethylene glycol) solution at 1IiL degree close to 300° C. in order to remove PWT stuck to the wall inside the container. Since the TgG liquid has a much lower viscosity than the PgT liquid, it cannot be sealed with a screw seal that uses the viscosity of the liquid to perform sealing. Therefore, when cleaning the container, the high-temperature TgG liquid comes into contact with the mechanical seal together with foreign matter, and there is a risk that the mechanical seal may be damaged by the heat and foreign matter.

An object of the present invention is to provide a horizontal shaft seal device that prevents high temperature cleaning liquid from coming into contact with a mechanical seal together with foreign matter, thereby preventing damage to the mechanical seal.

[Means to solve the problem]

In order to achieve the above purpose, an oil seal is provided between the screw seal and the mechanical seal, and a cleaning fluid injection hole is provided between the oil seal and the mechanical seal to inject cleaning fluid that does not trap foreign matter at room temperature. It is something.

In addition, when injecting the cleaning liquid, the pressure of the cleaning liquid must be lower than the pressure of the shaft sealing liquid in the shaft sealing chamber to prevent the cleaning liquid from entering the shaft sealing chamber and adversely affecting the sealing performance of the mechanical seal. Similarly, a mechanism for adjusting the pressure of the cleaning liquid and the shaft sealing liquid is also provided.

In addition, as an alternative to injecting cleaning liquid, a cooling jacket having a small gap with the shaft is provided in the casing between the screw seal and the mechanical seal, and an oil seal is provided at the end of the cooling jacket on the mechanical seal side. It is something.

[For production]

If an oil seal is provided between the screw seal and the mechanical seal, it is possible to prevent the high-temperature cleaning liquid from coming into contact with the mechanical seal together with foreign matter until the oil seal deteriorates due to heat. Furthermore, if a cleaning liquid injection hole is provided between the oil seal and the mechanical seal and the cleaning liquid at room temperature flows out from the oil seal into the can, the temperature of the cleaning liquid near the oil seal can be lowered, so the temperature of the cleaning liquid near the oil seal can be lowered. It protects from deterioration caused by water and seals high-temperature cleaning fluids for a long period of time. In addition, if the space between the oil seal and the mechanical seal is filled with cleaning fluid that does not contain foreign matter at room temperature, even if the oil seal loses its sealing properties for some reason, the high-temperature cleaning fluid will be able to clean the mechanical seal along with foreign matter. No contact with the seal.

Also, as an alternative to injecting cleaning liquid, if a cooling jacket is provided, the high temperature cleaning liquid in the container will pass through the threaded seal and flow toward the mechanical seal, but the cooling jacket will The mechanical seal is cooled as it passes through the small gap between the shafts, so the cleaning fluid comes into contact with the mechanical seal at a lower temperature. Although oil seals are not suitable for sealing high-temperature liquids, they can seal low-temperature cleaning liquids after passing through the small gap between the cooling jacket and the shaft. If so, the cleaning fluid will not come into contact with the mechanical seal.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained based on the first factor. 1st
1 is an example of a shaft sealing device of a horizontal continuous coupling device for PgT. In the figure, a shaft 1 is provided at a portion passing through the casing 2, and a screw seal 3, an oil seal 4, and a mechanical seal 5 are provided on the shaft 1 in this order from the container side. The mechanical seal 5 includes a rotating ring 6, a pin 7, and a fixed ring 8.
and spring 9 and 0 ring 10. Consists of u.

A shaft sealing liquid field is contained in the shaft sealing chamber 4 between the mechanical seal 5 and the casing 2. The casing 2 of the shaft sealing chamber has a shaft sealing liquid inlet hole 13 and a shaft sealing liquid outlet hole 14, each of which is connected to a shaft sealing liquid pot 31 via a pipe 16. In addition, oil seal 4 and mechanical seal 5
There is a cleaning liquid injection hole in the casing 2 between the piping and the cleaning liquid pot A, which is connected to the cleaning liquid pot through a valve. 37 and a nitrogen cylinder ψ are connected via pressure adjustment valves 38 and 39. The shaft sealing liquid pot 31 contains gG (ethylene glycol) liquid as the shaft sealing liquid 4. Inside the cleaning liquid pot The container contains TgG at room temperature as a cleaning liquid.The liquid in the container is PgTM with high temperature and high viscosity during normal operation, and becomes high temperature and low viscosity TgG liquid during cleaning.

First, the operating method and operation of this device during normal operation will be explained. During normal operation, valve 10 and pressure regulating valve I are closed, and only pressure regulating valve α is closed. The opening degree of the pressure Il regulating valve is set so that the pressure in the shaft sealing liquid pot 31 is higher than the pressure in the container, and an appropriate pressure is applied to the sliding movement of the mechanical seal. During normal operation, the liquid inside the container is a high-temperature, high-viscosity PgT liquid, so the liquid inside the container is pushed back into the container by the action of the screw seal 3, and the oil seal 4 and mechanical seal 5
never come into contact with.

Next, the operating method and operation of this apparatus during cleaning will be explained. During cleaning, valve U and pressure regulating valve blades 39 are all opened. Valve and pressure All! !
! When the valve is bent, the cleaning liquid in the cleaning pot flows into the space 41 between the oil seal 4 and the mechanical seal 5 through the valve U and the pipe (and the cleaning liquid injection hole 5). The opening degrees of the regulating valves 38 and 39 are such that the pressure inside the cleaning liquid bot 3 is higher than the pressure inside the container, and the pressure inside the shaft sealing liquid bot 31 is even higher than the pressure inside the cleaning liquid pot 3. With such an opening, the cleaning liquid 2 in the space 41 will flow out into the container through the oil seal 4, but will flow between the fixed ring 8 of the mechanical seal 5 and the rotating shaft 1116 and into the shaft seal. It does not flow into the chamber ν.During cleaning, the liquid n in the container has a high temperature and low viscosity T.
Since it is a 13G liquid, the container liquid 21 passes through the screw seal 3 and reaches the vicinity of the oil seal 4. but,
Since the cleaning liquid at room temperature flows out from the oil seal 4, the high temperature liquid 4 in the container is 1IIIi! It does not come into contact with the oil seal 4 and mechanical seal 5 while remaining IL.

FIG. 2 shows another embodiment of the invention. ′! In diagram J3,
The shaft sealing liquid pot 31 and the cleaning liquid pot share a common piping 42.
Although it is connected to the nitrogen cylinder via the pressure chest adjustment valve 0, the installation position of the shaft sealing liquid pot 31 is higher than the position of the cleaning liquid pot.

First, during normal driving! The operating method and operation of J2el's Ml will be explained. During normal operation, the valve control valve is closed and only the pressure regulating valve C is opened. The opening degree of the pressure regulating valve 43 is set so that the pressure inside the shaft sealing liquid pot 31 is higher than the pressure inside the container, similar to the device shown in FIG. If the operation is carried out in this manner, the high temperature liquid gas in the container will be transferred to the oil seal 4 and the mechanical seal by the same action as the apparatus shown in Fig. 1. explain. When cleaning, open both the valve adjustment and the pressure g4 adjustment valve. The opening degree of the pressure regulating valve 4 is set such that the pressure inside the cleaning liquid pot 35 is higher than the pressure inside the container. At this time, the cleaning liquid δ in the space 41 is
The oil flows out into the container through the seal, but the shaft sealing liquid pot 31 is located higher than the cleaning liquid pot and there is a head difference, so the mechanical seal 5 is fixed.]
! 18 and rotation 1f6 and does not flow into the shaft sealing chamber. Therefore, if you operate as described above, the gt! Due to the same effect as above, the high-temperature container liquid 4 does not come into direct contact with the oil seal 4 and mechanical seal 5.

Figure m3 is another embodiment of the present invention. In the jlIa diagram,
The cleaning liquid injection hole is connected to the cleaning liquid oil pressure unit 51 via piping (and a valve).

Further, a shaft sealing liquid oil pressure unit 61 is connected to the shaft sealing liquid inlet hole and the shaft sealing liquid outlet hole 14 via pipes 15 and 16, respectively. The cleaning liquid oil pre-spring unit 51 is composed of a cleaning liquid pot 52 and a cleaning liquid pump housing. The shaft sealing liquid oil pressure unit q is composed of a nitrogen cylinder C, a shaft sealing liquid pot 8, a shaft sealing flow pump, and a heat exchanger 6.

First, the operating method and operation of the apparatus shown in FIG. 3 during normal operation will be explained. During normal operation, the valve joint is closed, the cleaning liquid oil pressure unit 51 is stopped, and only the shaft sealing liquid oil pressure unit 61 is operated. At that time, the discharge pressure of the shaft sealing liquid pump 6 is set higher than the pressure inside the container. If operated in this manner, the temperature inside the high temperature container will be reduced due to the same effect as the device shown in Figure m1. The liquid gas does not come into contact with the oil seal 4 and mechanical seal 5.

Next, the operating method and operation of the apparatus shown in FIG. 3 during cleaning will be explained. During cleaning, the valve is opened and both the cleaning liquid oil pressure unit 51 and the shaft sealing liquid oil pressure unit 61 are operated. At this time,
The discharge pressure of the cleaning liquid pump group is higher than the pressure inside the container, and the discharge pressure of the shaft sealing liquid pump is higher than the discharge pressure of the shaft sealing liquid pump group. If the system is operated in this manner, the high temperature liquid inside the container will not come into contact with the oil seal 4 and the mechanical seal 5 due to the same effect as in the device shown in FIG.

The above example is an example in which the cleaning liquid and the shaft sealing liquid are different. However, if the cleaning liquid and the shaft sealing liquid are the same liquid, even if the cleaning liquid enters the shaft sealing chamber, the sealing performance of the mechanical seal will be affected. Since this has no effect, it is also possible to omit the mechanism that increases the pressure of the cleaning liquid and the shaft sealing liquid by 14:1 so that the pressure of the cleaning liquid is lower than the pressure of the shaft sealing liquid in the shaft sealing chamber.

In addition, the above embodiment is an example of an apparatus in which the liquid in the container is a high-viscosity liquid during normal operation, and the liquid in the container becomes a low-viscosity cleaning liquid during cleaning. The same structure can be adopted as long as the viscosity of the viscosity changes from low to high. For example, in the case of a GT system that handles a liquid that has a low viscosity at the initial stage of the reaction, but gradually changes to a high viscosity liquid by adding an additive and causing a reaction, the cleaning liquid may be mixed with additives. The same structure as in the above embodiment can be adopted by simply replacing . In that case, at the beginning of the reaction, the same operations as those during washing in the above embodiments are performed, and at the end of one reaction, the same operations as during normal operation in the above embodiments are performed. If the operation is carried out in this manner, at the beginning of the reaction when the liquid in the container is a low-viscosity liquid, the high-temperature liquid in the container will come into contact with the oil seal and the mechanical seal due to the additive flowing from the oil seal to the inside of the container. At the end of the reaction, the screw seal can prevent the high temperature liquid in the container from coming into contact with the oil seal and mechanical seal.

Further, as another embodiment of the present invention, a case in which a cooling jacket is provided as an alternative to injecting the cleaning liquid will be described with reference to FIG.

FIG. 4 is an example of a shaft sealing device for a horizontal continuous polymerization apparatus for PgT. In FIG. 4, a shaft 1 is provided at a portion passing through the casing 2, and a screw seal 3 and a mechanical seal 5 are provided on the shaft 1 in this order from the container side. The mechanical seal 5 is composed of a rotation 3j16, a pin 7, an identification ring 8, a spring 7, and an O-ring 10.11. The casing 2 between the screw seal 3 and the mechanical seal 5 is provided with a cooling jacket n having a small gap with respect to the shaft l. The casing 2 of the cooling jacket 71 section has a cooling water inlet hole n and a cooling water outlet hole n, to which piping 74 and 75 are connected, respectively, through which cooling water is supplied and discharged. Further, an oil seal 4 is provided at the end of the cooling jacket 71 on the mechanical seal 5 side. The oil seal 4 is installed as necessary. First, when the oil seal 4 is omitted, the container liquid 4 passes through the screw seal 3 during cleaning because the container liquid 4 becomes a high-temperature, low-viscosity TBG liquid.

It flows towards the mechanical seal 5. However, since the liquid contained in the container is cooled while passing through the small gap between the cooling rack q and the shaft 1, even if it comes into contact with the mechanical seal 5, it will not be damaged by heat. Next, when the oil seal 4 shown in Fig. 4 is installed, the oil seal will deteriorate due to heat when it comes into contact with high-temperature liquid, and the sealing performance will decrease, so it is not very effective as a seal for high-temperature liquid. If the cleaning liquid passes through the small gap between the cooling jacket n and the shaft l, the sealing performance will not deteriorate because the temperature has decreased. Since the cleaning liquid contains foreign matter, even if it is at a low temperature, if foreign matter gets into the sliding surface of the mechanical seal, there is a risk of damaging the mechanical seal.
If the cleaning liquid is sealed with an oil seal to prevent the cleaning liquid from coming into contact with the mechanical seal, the mechanical seal will not be damaged by foreign objects.

The horizontal shaft sealing device of the present invention described above can be applied to a horizontal stirring device as a shaft sealing device for high-temperature, high-viscosity liquids. Furthermore, it is particularly suitable as a polymerization apparatus for synthetic resins, especially for polyethylene terephthalate.

〔Effect of the invention〕

According to the present invention, since the cleaning liquid at room temperature can be injected into the space between the oil seal and the mechanical seal, the high temperature cleaning liquid in the container will not come into contact with the mechanical seal together with foreign matter, and the mechanical seal will not be damaged by heat and foreign matter. can be prevented.

Furthermore, if the cleaning liquid is cooled, the temperature of the cleaning liquid that comes into contact with the mechanical seal can be lowered, so that damage to the mechanical seal due to the heat of the cleaning liquid can be prevented.

Furthermore, if the cleaning liquid is sealed with an oil seal, the cleaning liquid will not come into contact with the mechanical seal, thereby preventing damage to the mechanical seal due to foreign matter in the cleaning liquid.

[Brief explanation of drawings]

#A side view, Figures 2 and 3 are longitudinal sectional views of a horizontal shaft sealing device according to another embodiment of IW Koumyo, and Figure 4 is a horizontal shaft sealing device provided with a cooling jacket according to another embodiment of the present invention. FIG. 5 is a longitudinal sectional view of a conventional horizontal shaft sealing device. 1...shaft, 2...casing, 3...
-...Screw seal, 4...Oil seal, 31...Shaft sealing liquid pot, F...Cleaning liquid injection hole, 2...Cleaning liquid pot, 38, blade,
43...Pressure m regulating valve, 71...Cooling jacket agent Patent attorney Masaru Ogawa Male l Figure/--Ichi glaze 4--11 years old 4 Lucille J2
----; I sweat i 瀻入几2 ----→-shin 7 5
---Mercy tlJ5---kneeling dot 3---hU', -tl/31---m3-+
IL Bo? ) 38,! 'lーーLka t14 vertical t(tl
y7-'Az Eye A3 Figure

Claims (1)

[Claims] 1. A shaft passing through the casing, a mechanical seal installed between the shaft and the casing, a screw seal installed at a position closer to the container than the mechanical seal installation part, and the In a horizontal shaft seal device comprising a shaft seal liquid supply device connected to a mechanical seal, an oil seal is installed on the casing and the shaft between the mechanical seal installation section and the threaded seal installation section, and
A horizontal shaft sealing device, characterized in that a cleaning liquid injection hole is provided in a casing between the mechanical seal device section and the oil seal installation, and a cleaning liquid supply device is connected to the cleaning liquid injection hole. 2. The horizontal shaft sealing device according to claim 1, wherein the shaft sealing liquid supply device and the cleaning liquid supply device have a pressure adjustment mechanism. 3. The shaft sealing liquid supply device is a shaft sealing liquid pot, and
Claim 1 or Claim 2, characterized in that the cleaning liquid supply device is a cleaning liquid pot, and the shaft sealing liquid pot and the cleaning liquid pot are each connected to a pressure source via a suitable pressure regulating valve. Horizontal shaft sealing device as described in . 4. The shaft sealing liquid supply device is a shaft sealing liquid pot, and
Claim 1, characterized in that the cleaning liquid supply device is a cleaning liquid pot installed at a lower position than the shaft sealing liquid pot, and the shaft sealing liquid pot and the cleaning liquid pot are connected to a pressure source via a common piping. or claim 2. 5. Claim 1 or 2, wherein the shaft sealing liquid supply device is an oil pressure unit for shaft sealing liquid, and the cleaning liquid supply device is an oil pressure unit for cleaning liquid. shaft sealing device. 6. A shaft penetrating the casing, a mechanical seal installed between the shaft and the casing, a screw seal installed at a position closer to the container than the mechanical seal installation part, and a screw seal connected to the mechanical seal. A horizontal shaft sealing device comprising a shaft sealing liquid supply device, characterized in that the casing between the mechanical seal installation part and the screw seal installation part is provided with a cooling jacket having a small gap between it and the shaft. Horizontal shaft sealing device. 7. The horizontal shaft sealing device according to claim 6, wherein an oil seal is installed at the mechanical seal side end of the cooling jacket. 8. The horizontal shaft sealing device according to claim 1, claim 2, claim 6, or claim 7, which is a polymerization device for polyethylene terephthalate.