A non-driving end sealing device for a large horizontal reactor

Abstract

The application provides a large horizontal reactor non-driving end sealing device, which is installed on a flange seat of a horizontal reactor and comprises a transition cavity installed on the flange seat, a sealing cavity in sealing butt joint with the transition cavity and a shaft sleeve in the sealing cavity and sleeved on a stirring shaft of the horizontal reactor, an end cover matched with the sealing cavity, a sliding groove on the shaft sleeve and matched with a key on the stirring shaft, the transition cavity sleeved on the shaft sleeve, stationary mechanical seals and rotary mechanical seals installed on both sides of the transition cavity and double-row tapered roller bearings sleeved between the shaft sleeve and the sealing cavity. Compared with the prior art, the large horizontal reactor non-driving end sealing device uses the slidable matching of the key and the sliding groove between the stirring shaft and the shaft sleeve and the double-row tapered roller bearings on the shaft sleeve, meets the requirement of using mechanical seals, uses the stationary mechanical seals and the rotary mechanical seals in combination, is safe and reliable and is modularized as a whole, thereby ensuring the installation performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of petrochemical production, in particular to a sealing device for the non-driving end of a large horizontal reactor. BACKGROUND

[0002] Since the end of last century, various chemical production processes have developed rapidly, especially in the field of petrochemical industry, the demand for large-scale high-parameter working conditions is increasing, and the demand for large horizontal reactor is one of the most prominent examples. It is mainly used in resin synthesis such as polypropylene synthesis horizontal reactor. High pressure, large volume, long stirring shaft, large driving power. There are liquid, gas and solid in the medium. The sealing of the non-driving end of the stirring shaft is often a very difficult problem. The key is to solve the sealing performance and reliability of the non-driving end bearing, so that solid materials cannot enter the rolling bearing and cause bearing damage. If the seal fails, it will often cause sudden stop. Once the sudden stop occurs, the production loss is great. It is very difficult to replace the seal and bearing, and the processing time is long, the construction cost and replacement cost are high.

[0003] Although the performance and service life of mechanical seal are better than that of packing, the requirements for equipment and environment are relatively strict, that is, certain rotation accuracy requirements and environmental requirements must be met; at present, the general method to solve the sealing problem of the non-driving end of such large horizontal reactor is to use labyrinth seal + packing seal, plus external flushing system, with short service life and unable to operate for a long period, which is determined by the characteristics of this combined seal. The main reason why mechanical seal is not used is that the influence of long stirring shaft thermal expansion (more than 40 mm) on mechanical seal has not been solved, that is, the axial movement requirement of mechanical seal for sealing shaft or shaft sleeve (generally, the axial movement amount cannot exceed 0.1 mm) cannot be met. Moreover, using this labyrinth seal + packing seal method, there are many inspection points, the use and maintenance cost is high, it is a scattered part without pre-assembly, and the disassembly requires tooling, the inspection and maintenance is complex and requires high technical level. In addition, the non-driving end generally uses spherical self-aligning roller bearing, which has no limit to the radial swing of the shaft and the shaft sleeve, that is, the radial runout requirement of mechanical seal for sealing shaft or shaft sleeve (generally, the radial runout amount cannot exceed 0.05 mm) cannot be met, which is one of the main reasons why mechanical seal is not used. SUMMARY

[0004] In view of the above problems, the present application provides a sealing device for the non-driving end of a large horizontal reactor, which can eliminate the mutual influence of the stirring shaft and the shaft sleeve during thermal expansion, meet the requirement of using mechanical seal, and improve the sealing performance by combining static mechanical seal and rotating mechanical seal.

[0005] The technical scheme adopted by the present application is:

[0006] The utility model provides a large -scale horizontal reactor non -driven end sealing device, install on the flange seat of horizontal reactor, its characterized in be including install on the transition cavity of flange seat, with the sealed cavity of transition cavity sealed butt joint and be in the shaft sleeve of sealed cavity inside set on the stirring shaft of horizontal reactor, the end cap of sealed cavity's last end cooperation has, be equipped with with the sliding slot of key cooperation on the stirring shaft on the shaft sleeve, transition cavity sleeve on the shaft sleeve, transition cavity's both sides are equipped with stationary mechanical seal and rotary mechanical seal for sealing the clearance between transition cavity and shaft sleeve respectively, the shaft sleeve with sealed cavity between still sleeve for to the shaft sleeve and the mechanical seal of installing on the shaft sleeve carries out axial and radial positioning double -row tapered roller bearing.

[0007] Preferably, a positioning sleeve for positioning the double-row tapered roller bearing is further provided in the sealed cavity, and the side surface of the positioning sleeve is attached to the end cap.

[0008] Preferably, a pressing sleeve for locking the double-row tapered roller bearing is further provided on the shaft sleeve, and the pressing sleeve is bolted to the tail end of the shaft sleeve.

[0009] Preferably, a first pipe for flushing the stationary mechanical seal and a second pipe and a third pipe for the rotary mechanical seal are further provided in the sealed cavity.

[0010] More preferably, the first pipe is butt-jointed with a first pipe flange, the second pipe is butt-jointed with a second pipe flange, and the third pipe is butt-jointed with a third pipe flange.

[0011] Preferably, the end cap is bolted to the sealed cavity by high-strength studs and nuts.

[0012] Compared with the prior art, the utility model has the beneficial effects that: the utility model provides a large -scale horizontal reactor non -driven end sealing device, and the key and the sliding slot are used for the slidable cooperation between the stirring shaft and the shaft sleeve, so that the mutual influence of the stirring shaft and the shaft sleeve during thermal expansion is eliminated; the double-row tapered roller bearing on the shaft sleeve accurately positions the shaft sleeve and the mechanical seal installed on the shaft sleeve, has very high rotation precision, and meets the requirements of using the mechanical seal; the stationary mechanical seal and the rotary mechanical seal are combined to improve the sealing performance and ensure safety and reliability; the overall modular design ensures the installation performance and facilitates installation and maintenance. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 The utility model provides a large -scale horizontal reactor non -driven end sealing device's schematic view. DETAILED DESCRIPTION

[0014] The preferred embodiments of the utility model are described in detail according to the drawings.

[0015] Figure 1This is a preferred embodiment of a non-driven end sealing device for a large horizontal reactor provided by the present invention. For example... Figure 1 As shown, the non-drive end sealing device of this large horizontal reactor is installed on the flange seat 100 of the horizontal reactor. It includes a transition cavity 10 installed on the flange seat, a sealing cavity 20 that seals with the transition cavity, and a bushing 30 that is fitted inside the sealing cavity and sleeved on the stirring shaft of the horizontal reactor. The end of the sealing cavity is fitted with an end cap 21. The bushing 30 is provided with a groove 31 that mates with the key 2001 on the stirring shaft 200. The transition cavity 10 is fitted on the bushing 30. A static mechanical seal 11 and a rotary mechanical seal 12 for sealing the gap between the transition cavity and the bushing are respectively installed on both sides of the transition cavity 10. A bushing 30 for sealing the gap between the bushing 30 and the sealing cavity 20 is also fitted between them. The double-row tapered roller bearing 40 provides axial and radial positioning for the bushing and the mechanical seal mounted on it. This allows for a sliding fit between the agitator shaft 200 and the bushing 30 using a key and groove, eliminating the mutual influence between the agitator shaft 200 and the bushing 30 during thermal expansion. The double-row tapered roller bearing 40 on the bushing 30 provides accurate axial and radial positioning for both the bushing 30 and the mechanical seal mounted on it, exhibiting high rotational accuracy and meeting the requirements for using a mechanical seal. The combination of a static mechanical seal 11 and a rotary mechanical seal 12 improves sealing performance and ensures safety and reliability. The overall modular design guarantees installation performance and facilitates installation and maintenance.

[0016] The sealed cavity 10 is also provided with a positioning sleeve 13 for positioning the double-row tapered roller bearing, and the side of the positioning sleeve 13 fits against the end cap; the bushing 30 is also fitted with a clamping sleeve 32 for locking the double-row tapered roller bearing. The clamping sleeve 32 is bolted to the tail end of the bushing 30. In this way, the double-row tapered roller bearing will not be radially or axially displaced under the action of the positioning sleeve 13 and the clamping sleeve 32, ensuring that the bushing 30 and the mechanical seal installed on the bushing 30 are axially and radially positioned, so as to meet the requirements for the use of the mechanical seal.

[0017] The sealing cavity 20 also houses a first piping for flushing the stationary mechanical seal 11 and second and third piping for flushing the rotary mechanical seal 12. The transition cavity 10 uses a hard alloy plate on the medium side to flush the hard alloy stationary mechanical seal 11. The first piping is connected to a first connecting flange 51, forming a flushing system loop that effectively blocks particulate media and creates a favorable operating environment for the other rotary mechanical seal. The rotary mechanical seal 12 in the transition cavity 10 is located on the non-medium side (bearing side). The second piping 202 is connected to a second connecting flange 52, and the third piping 203 is connected to a third connecting flange 53, forming a sealing fluid circulation system. The sealing flushing auxiliary system uses white oil as the circulating fluid, ensuring that the sealing face and bearing are simultaneously in a good oil bath lubrication condition. The first connecting flange 51, the second connecting flange 52, and the third connecting flange 53 respectively use high-pressure resistant connecting pipes and loose flange assemblies, which are high-pressure resistant, easy to install, and have reliable sealing performance.

[0018] The end cap 21 at the end of the sealing cavity 20 is installed on the sealing cavity using a high-strength stud 22 and a nut to improve the sealing performance.

[0019] During installation, the transition chamber 10, the static mechanical seal 11, the rotary mechanical seal 12, the sealing chamber 20, the double-row tapered roller bearing 40, and the end cover 21 are assembled into a single sealing assembly using a bushing 30, screws, bolts, a positioning sleeve 13, and a clamping sleeve 32. Next, the key 2001 is installed on the stirring shaft 200. Then, the entire sealing assembly is installed onto the flange 100 and the stirring shaft 200 using studs 22 and nuts. Finally, the first pipe 201 is connected to the first connecting flange 51 to form a flushing system circuit. The second pipe 202 is connected to the second connecting flange 52, and the third pipe 203 is connected to the third connecting flange 53 to form a sealing liquid circulation system. The entire sealing assembly is pre-assembled before installation, allowing for sealing performance testing, such as dynamic and static pressure testing, to be completed before installation. This reduces uncertainty and ensures sealing performance before and reliability after installation. Furthermore, it simplifies installation, reduces the level of skill required, shortens installation time, lowers costs, and makes it easier to guarantee installation quality.

[0020] During operation, the rotating agitator shaft 200 drives the bushing 30 to rotate, which in turn drives the inner ring of the bearing 40 to rotate. Simultaneously, the agitator shaft 200 can slide within the bushing 30. The axial movement and thermal expansion of the agitator shaft 200 do not exert force on the bushing 30. The axial and radial positions of the bushing 30 are determined solely by the bearing 40, ensuring high rotational accuracy and minimal axial displacement, thus providing excellent operating conditions for the mechanical seal. Meanwhile, the sealing face of the static mechanical seal 11 is flushed through a circuit, effectively blocking the medium, especially particulate media, creating a clean environment for the rotary mechanical seal 12 on the other side. The rotary mechanical seal 12 then uses a sealing fluid circulation system to provide white oil with appropriate parameters (including pressure and temperature) to lubricate and seal the sealing face and bearing, thereby achieving long-term operation.

[0021] In summary, the technical solution of this invention can fully and effectively achieve the above-mentioned objectives. Furthermore, the structure and functional principles of this invention have been fully verified in the embodiments, achieving the expected effects and objectives. Without departing from the principles and essence of this invention, various changes or modifications can be made to the embodiments. Therefore, this invention includes all substitutions within the scope mentioned in the patent application claims, and any equivalent changes made within the scope of this patent application are within the scope of the patent application.

Claims

1. A non-drive end sealing device for a large horizontal reactor, installed on a flange seat of the horizontal reactor, characterized in that, It includes a transition cavity mounted on a flange seat, a sealing cavity that seals with the transition cavity, and a bushing inside the sealing cavity that is fitted onto the stirring shaft of the horizontal reactor. The end of the sealing cavity is fitted with an end cap, and the bushing has a sliding groove that matches the key on the stirring shaft. The transition cavity is fitted onto the bushing. A static mechanical seal and a rotary mechanical seal are respectively installed on both sides of the transition cavity to seal the gap between the transition cavity and the bushing. A double-row tapered roller bearing is also fitted between the bushing and the sealing cavity to provide axial and radial positioning for the bushing and the mechanical seal installed on the bushing. The sealed cavity is also provided with a positioning sleeve for positioning the double-row tapered roller bearing, and the side of the positioning sleeve fits against the end cap. The bushing is also fitted with a clamping sleeve for locking the double-row tapered roller bearing, and the clamping sleeve is bolted to the tail end of the bushing. The sealed cavity is also equipped with a first pipe for flushing the static mechanical seal and a second and third pipe for flushing the rotary mechanical seal. The first pipe is connected to a first connecting flange, the second pipe is connected to a second connecting flange, and the third pipe is connected to a third connecting flange.

2. The sealing device for the non-driven end of a large horizontal reactor according to claim 1, characterized in that: The end cap is installed on the sealed cavity using high-strength studs and nuts.

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