Rotating joint structure at upper end of body polymerization kettle
By designing an improved rotary joint structure on the polymerization reactor, the problems of easy damage to the upper rotary joint and difficulty in temperature control are solved, and more efficient equipment use and production stability is achieved.
Patent Information
- Application Number
- CN202421197081.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-29
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2034-05-29
AI Technical Summary
In the polymerization reactor, the upper rotary joint is easily damaged, resulting in a short service life of the equipment, affecting the production progress, and difficult temperature control, which easily leads to explosive polymerization and resin quality degradation.
A rotary joint structure at the upper end of the body polymer kettle is designed, using two-stage sealing and bearing liquid separator ring, which increases the stability and sealing effect of the bearing, is easy to use, reduces the frequency of maintenance, and improves the service life of the equipment.
It realizes easy installation and reliable use of rotary joints, reduces maintenance frequency, extends the service life of the equipment, ensures smooth production, and improves the reliability of temperature control, avoiding the risk of explosive polymerization.
Smart Images
Figure CN222255487U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of chemical industry, specifically to a rotary joint structure at the upper end of a bulk polymerization kettle. Background Art
[0002] Polyvinyl chloride resin (PVC for short) is one of the five general-purpose resins with the largest output. It is widely used in industrial and agricultural production and people's lives. In addition, PVC is a product that consumes a lot of chlorine. The development of PVC production plays an important role in the chlorine balance of the chlor-alkali industry and the development of the chlor-alkali industry. At present, there are three methods for producing PVC: suspension method, emulsion method and bulk method. The bulk method is a patented technology of France's Atto Company. Its production characteristics are that no water and dispersant are required during the polymerization process. There are only two basic raw materials, vinyl chloride monomer and initiator. The "two-step method" process is used to directly obtain PVC powder in the polymerization kettle. The process flow is short, the equipment is small, the operation is simple, the product quality is good, the purity is high, the processing performance is good, the raw materials and energy consumption are low, the land is small, the investment is low, there is basically no three wastes discharged, and the environmental pollution is small. Therefore, it has been widely promoted and used.
[0003] The polymerization temperature has a great influence on the polymerization speed. The increase in temperature accelerates the movement of vinyl chloride molecules, thereby accelerating the speed of the entire reaction and releasing more heat. If the reaction heat is not removed in time, it will cause difficulties in operation control and even the risk of explosive polymerization. At the same time, as the temperature increases, the molecular weight of PVC resin decreases and the viscosity decreases. In addition, the increase in temperature can also increase the degree of chain branching, increase the activity of chlorine atoms, easily cause HCL removal, and deteriorate the thermal stability and processing properties of the resin. Therefore, in industrial production, the polymerization temperature is almost the only factor that controls the molecular weight of PVC.
[0004] The polymerization reactor is equipped with upper and lower double stirring. Hot water should be introduced into the stirring shaft at the beginning of the reaction to quickly increase the reaction temperature and allow the monomer to reach the reaction conditions. During the polymerization process, cooling water should be introduced to remove the reaction heat to avoid explosive polymerization and affect product quality. The upper end rotary joint is a device that connects the stirring shaft of the reactor and the water inlet and outlet at the outer end. Since the upper end stirring shaft is relatively long, exceeding 5 meters, in actual operation, the rotary joint is damaged after a short period of use, which greatly affects the production progress and needs to be modified. Utility Model Content
[0005] Therefore, in order to solve the above-mentioned shortcomings, the utility model provides a bulk polymerization kettle upper end rotating joint structure, which is an improvement of the bulk polymerization reactor upper end rotating joint, easy installation, reliable use, reduces the maintenance frequency, increases the service life of the equipment, and ensures the smooth progress of production.
[0006] Specifically, a rotary joint structure at the upper end of a bulk polymerization kettle comprises:
[0007] Inlet and outlet water components, an inlet flange and an outlet flange, wherein the inlet flange and the outlet flange are fixedly connected via a sealing head;
[0008] The water inlet and outlet pipe fittings include a water outlet pipe and a water inlet pipe, wherein the water inlet pipe is sleeved inside the water outlet pipe, the water inlet pipe is communicated with the water inlet flange, a water inlet channel communicated with the water inlet flange is formed inside the water inlet pipe, a water outlet channel is formed between the water inlet pipe and the water outlet pipe, the upper portion of the water outlet pipe extends to the water outlet flange, and the water outlet channel is communicated with the water outlet flange through a circle of holes opened at the upper portion of the water outlet pipe;
[0009] One side of the water outlet flange is connected to the sealing head, an upper end seal is provided between the sealing head and the water outlet pipe, and the other side of the water outlet flange is connected to a bearing box, a bearing is installed in the bearing box, and a bearing cover connected to the bearing box is provided on the outer side of the bearing;
[0010] A lower mechanical seal located in the water outlet flange is installed between the bearing box and the water outlet pipe.
[0011] Furthermore, the upper end seal includes a bearing, a pressure plate and lip seals installed on the upper and lower ends of the bearing. The bearing is installed on the sealing head through the pressure plate, and the pressure plate is fixedly connected to the sealing head through screws. A partition is installed between the lip seal and the bearing.
[0012] Furthermore, the upper end seal is provided with a grease injection hole.
[0013] Furthermore, the lower mechanical seal includes a dynamic ring, a static ring and a pushing assembly, the dynamic ring is installed on the outer wall of the water outlet pipe through the pushing assembly, the static ring contacts the dynamic ring, and the static ring is installed on the bearing box through a static ring seat.
[0014] Furthermore, the pushing assembly includes a spring seat, a spring and a push ring, the spring seat is fixedly mounted on the water outlet pipe by screws, the push ring is mounted on the spring seat by a plurality of springs, and is pushed by the spring force to be close to the moving ring, and the moving ring is rotationally connected to the spring seat. The rotational connection is achieved by inserting the radial convex part into the radial concave part to realize the transmission of torque.
[0015] Furthermore, a bearing fluid spacer ring is installed between the bearing box and the water outlet pipe and is located below the lower mechanical seal.
[0016] Furthermore, the upper and lower ends of the bearing are both provided with skeleton oil seals installed in the bearing box, and the bearing box is provided with grease injection holes adapted to the bearing.
[0017] Furthermore, a mechanical seal leakage observation hole opened in the bearing box is provided below the bearing fluid spacer ring. The mechanical seal leakage observation hole is adapted to the skeleton oil seal and the bearing fluid spacer ring and is located between the upper skeleton oil seal and the bearing fluid spacer ring.
[0018] When the rotary joint structure at the upper end of the bulk polymerization kettle is implemented, the water inlet and outlet components are first welded: the water inlet flange, the water outlet flange, the sealing head, and the sealing cavity are welded together; the water inlet and outlet pipe fittings are welded: the water outlet pipe, the water inlet pipe, the spacer ring, the support ring, and the connecting plate are welded together. The bearing cover is placed on the outside of the water inlet and outlet pipe fittings, the skeleton oil seal is placed in the bearing cover, the lower end clamp ring is placed on the water outlet pipe, the bearing is hot-mounted, and the upper end clamp ring is placed; after the skeleton oil seal is placed in the bearing box, the entire bearing box is placed on the outside of the bearing, and the bearing box and the bearing cover are connected; the O-ring is placed in the bearing liquid separator ring, and then placed on the outside of the water outlet pipe. Pay attention to the opening direction of the bearing liquid separator ring during assembly, and push the liquid separator ring to the step on the water outlet pipe. The static ring is sealed and installed in the bearing box with an O-ring. When installing, pay attention to the correspondence between the static ring gap and the anti-rotation pin of the bearing box, and install it in place; assemble the dynamic ring assembly: a group of springs, push rings, and dynamic rings are placed in the spring seat in sequence, and finally the clamp ring is placed in the spring seat slot. Fasten the assembled dynamic ring assembly to the outside of the water outlet pipe with a set of screws. During assembly, pay attention to aligning the spring seat with the pre-marked line on the water outlet pipe to ensure the spring compression. In the sealing head of the water inlet and outlet assembly, install the lip seal, partition, bearing, partition, and lip seal in sequence. Pay attention to the direction of the lip of the lip seal during installation. Finally, use a set of screws to fix the upper seal in the sealing head; install the water inlet and outlet assembly with the upper seal on the outside of the water inlet and outlet pipe fittings, seal with an O-ring, and fix it to the upper end of the bearing box with a set of bolts. During assembly, you can pre-apply grease in the bearing. After installation, install oil cups on the sealing cavity and the outside of the bearing box to facilitate online greasing of the bearing.
[0019] During on-site installation, connect the connection plate of the inlet and outlet water pipes to the rotating end of the equipment through a set of fasteners, connect the bearing cover to the fixed end of the equipment with a set of fasteners, and connect the inlet and outlet water flanges to the external inlet and outlet of the equipment through hoses.
[0020] The utility model has the following advantages:
[0021] The utility model is an improvement on the upper end rotary joint of a bulk polymerization reactor, which is easy to install and reliable to use, reduces the maintenance frequency, increases the service life of the equipment, and ensures smooth production; the improved rotary joint constructs a two-stage seal, adds a bearing spacer ring, and selects a bearing that can withstand a larger radial force. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 It is a structural schematic diagram of the rotary joint structure at the upper end of the bulk polymerization kettle of the utility model;
[0023] Figure 2 yes Figure 1 A is a partial enlarged schematic diagram;
[0024] Figure 3 yes Figure 1 A partial enlarged schematic diagram of B in the middle;
[0025] Figure 4 yes Figure 1 A partial enlarged schematic diagram of C in the middle. DETAILED DESCRIPTION
[0026] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.
[0027] In this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises", or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article, or apparatus.
[0028] As described in the background technology, the polymerization temperature has a great influence on the polymerization speed. The temperature rise accelerates the movement of vinyl chloride molecules, thereby accelerating the speed of the entire reaction and releasing more heat. If the reaction heat is not removed in time, it will cause difficulties in operation control and even the danger of explosive polymerization. At the same time, the increase in temperature will reduce the molecular weight of PVC resin and reduce viscosity. In addition, the increase in temperature can also increase the branching degree of the chain, increase the activity of chlorine atoms, easily cause HCL removal, and deteriorate the thermal stability and processing properties of the resin. Therefore, in industrial production, the polymerization temperature is almost the only factor controlling the molecular weight of PVC.
[0029] The polymerization reactor is equipped with upper and lower double stirring. Hot water should be introduced into the stirring shaft at the beginning of the reaction to quickly increase the reaction temperature and allow the monomer to reach the reaction conditions. During the polymerization process, cooling water should be introduced to remove the reaction heat to avoid explosive polymerization and affect product quality. The upper end rotary joint is a device that connects the stirring shaft of the reactor and the water inlet and outlet at the outer end. Since the upper end stirring shaft is relatively long, exceeding 5 meters, in actual operation, the rotary joint is damaged after a short period of use, which greatly affects the production progress and needs to be modified.
[0030] Based on the above reasons, this embodiment provides a rotary joint structure at the upper end of a bulk polymerization reactor, such as Figure 1-Figure 4 The structure comprises a water outlet assembly, an inlet and outlet pipe fitting, a bearing seat 6, and a bearing cover 14. The inlet and outlet assembly is welded by an inlet flange 1, an outlet flange 4, a sealing head 2, and a sealing chamber 3; the inlet and outlet pipe fitting is welded by an outlet pipe 17, an inlet pipe 18, a spacer ring 13, a support ring 19, and a connecting plate 11; the inlet and outlet pipe fitting is on the inner side of the inlet and outlet assembly. The bearing box 6 is located outside the inlet and outlet pipe fitting, sealed by an O-ring 5, and a group of bolts 16 are connected to the lower end of the inlet and outlet assembly; the bearing cover 14 is located outside the inlet and outlet pipe fitting, and is connected to the lower end of the bearing box 6 by a group of bolts 10. There is an upper seal at the upper end between the water inlet and outlet assembly and the water inlet and outlet pipe fittings. A lower mechanical seal is installed at the upper end of the bearing box 6 between the water inlet and outlet assembly and the water inlet and outlet pipe fittings. A bearing 9 is installed outside the water outlet pipe 17 in the bearing box 6. The inner ring of the bearing 9 is fixed to the water outlet pipe 17 by upper and lower clamp rings 8. The upper skeleton oil seal 7 is located between the bearing box 6 and the water outlet pipe 17, and the lower skeleton oil seal 7 is located between the bearing cover 14 and the water outlet pipe 17. A grease injection hole is provided at the upper end of the water inlet and outlet assembly to facilitate grease injection to the upper sealed bearing; a grease injection hole is provided on the outer side of the bearing box 6 to facilitate grease injection to the bearing 9 in the bearing box 6. Between the mechanical seal and the bearing 9, the outer side of the water inlet and outlet pipe fittings is sealed by an O-ring, and a bearing liquid spacer ring is installed. A leakage observation hole is provided on the outer bearing box 6 to facilitate online observation of the operation of the mechanical seal and reasonable arrangement of maintenance time. The connection plate 11 at the bottom of the rotary joint is sealed by an O-ring 12, and a set of fasteners is connected to the rotating end of the equipment to drive the inlet and outlet pipes to rotate. The bearing cover 14 is connected to the fixed end of the equipment through a set of fasteners to keep the inlet and outlet components and the bearing box 6 and the bearing cover 14 fixed and not rotating. The inlet and outlet flanges on the inlet and outlet components are connected to the external water inlet and outlet through hoses to achieve online water circulation.
[0031] External water enters from the upper water inlet flange 1, enters the water equipment through the water inlet pipe 18, returns to the lower end of the rotary joint after circulation, enters the channel between the outer side of the water inlet pipe 18 and the inner side of the water outlet pipe 17 through a group of holes opened on the spacer ring 13, and flows out from the water outlet flange 4 through a group of holes opened on the water outlet pipe 17. The upper seal isolates the water inlet and water outlet, and the mechanical seal prevents the water outlet from leaking. Therefore, the rotary joint realizes the circulation of water in the shaft when the stirring shaft of the equipment rotates, realizes heat exchange, and achieves the temperature control of the reaction process by the process.
[0032] The upper end rotary joint structure of the bulk polymerization kettle is provided with a new upper end seal at the upper end of the rotary joint mechanical seal, between the outlet pipe and the sealing head; for example, Figure 2As shown, the upper seal includes a bearing 101, a pressure plate 104, and lip seals 102 installed at the upper and lower ends of the bearing. The bearing 101 is installed on the sealing head 2 through the pressure plate, and the pressure plate is fixedly connected to the sealing head through screws. A partition 103 is installed between the lip seal and the bearing, and the upper seal is provided with a grease injection hole. The upper seal uses a bearing 101 to increase the stability of the far end. A partition 104 and back-to-back lip seals 102 are set at both ends of the bearing to achieve isolation of water inlet and outlet. The installed oil cup 105 can regularly grease the bearing to ensure the operation of the bearing. Finally, a set of screws are used to fasten the pressure ring in the sealing head.
[0033] For example, Figure 3 As shown, the lower mechanical seal includes a dynamic ring 202, a static ring 201 and a push assembly. The dynamic ring 202 is installed on the outer wall of the water outlet pipe 17 through the push assembly. The static ring 201 contacts the dynamic ring 202. The static ring 201 is installed on the bearing box through the static ring seat. The push assembly includes a spring seat 206, a spring 205 and a push ring 204. The spring seat is fixedly installed on the water outlet pipe by screws. The push ring is installed on the spring seat by several springs and is pushed by the spring force to be close to the dynamic ring. The dynamic ring is rotatably connected with the spring seat. The rotational connection method is to realize the transmission of torque by inserting the radial convex part into the radial concave part.
[0034] The lower mechanical seal is composed of a sealing surface formed by a dynamic and static ring on the outside of the water outlet pipe to prevent water from leaking out of the water outlet. The static ring 201 is sealed by an O-ring and anti-rotation pin 207 to prevent rotation. It is installed on the upper end of the bearing box. The dynamic ring is sealed by an O-ring. A group of compressed springs installed in the spring seat push the push ring to be close to the static ring. The spring seat is fixed on the water outlet pipe by a group of screws. With the rotation, a group of convex R on the spring seat corresponds to a group of concave R on the dynamic ring (the rotating connection method), driving the dynamic ring to rotate. At the same time, in order to prevent the dynamic ring from falling out during installation, a card slot is also set on the spring seat, and a card ring 203 is installed. The utility model is improved, and the axial distance L between the spring and the spring seat is increased compared with the original mechanical seal, which can better deal with the axial movement of the rotary joint caused by long use time, bearing wear, and other reasons on site.
[0035] At the same time, because the bearing is located at the lower end of the mechanical seal, in order to prevent the mechanical seal from leaking water into the bearing and causing bearing damage, such as Figure 4As shown, between the machine seal and the bearing, an O-ring seal is used to install a bearing spacer ring 20 (the specific implementation of the bearing spacer ring can refer to the utility model with application number CN201721801603.7). When the machine seal is damaged and water leaks out, it will flow into the outside of the bearing spacer ring, enter the leakage observation hole opened in the bearing box, and flow out of the rotary joint. On the one hand, it prevents the leaked water from entering the bearing, and on the other hand, it can remind the user that the machine seal is damaged and needs to be replaced. A bearing is installed at the lower end of the bearing box 6 to withstand the radial swing of the long shaft, improve the radial runout at the machine seal, and extend the service life of the machine seal. For this purpose, a bearing that can withstand greater radial force is selected.
[0036] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A rotary joint structure at the upper end of a bulk polymerization reactor, characterized in that: include Inlet and outlet water components, an inlet flange and an outlet flange, wherein the inlet flange and the outlet flange are fixedly connected via a sealing head; The water inlet and outlet pipes include a water outlet pipe and a water inlet pipe, wherein the water inlet pipe is sleeved inside the water outlet pipe, the water inlet pipe is communicated with the water inlet flange, a water inlet channel communicated with the water inlet flange is formed inside the water inlet pipe, a water outlet channel is formed between the water inlet pipe and the water outlet pipe, the upper portion of the water outlet pipe extends to the water outlet flange, and the water outlet channel is communicated with the water outlet flange through a circle of holes opened at the upper portion of the water outlet pipe; One side of the water outlet flange is connected to the sealing head, an upper end seal is provided between the sealing head and the water outlet pipe, and the other side of the water outlet flange is connected to a bearing box, a bearing is installed in the bearing box, and a bearing cover connected to the bearing box is provided on the outer side of the bearing; A lower mechanical seal located in the water outlet flange is installed between the bearing box and the water outlet pipe.
2. According to claim 1, a rotary joint structure at the upper end of a bulk polymerization reactor is characterized in that: The upper end seal includes a bearing, a pressure plate and lip seals installed on the upper and lower ends of the bearing. The bearing is installed on the sealing head through the pressure plate, and the pressure plate is fixedly connected to the sealing head through screws. A partition is installed between the lip seal and the bearing.
3. According to claim 2, a rotary joint structure at the upper end of a bulk polymerization reactor is characterized in that: The upper end seal is provided with a grease injection hole.
4. The rotary joint structure at the upper end of a bulk polymerization reactor according to claim 1, characterized in that: The lower mechanical seal comprises a dynamic ring, a static ring and a driving assembly. The dynamic ring is installed on the outer wall of the water outlet pipe through the driving assembly. The static ring contacts the dynamic ring. The static ring is installed on the bearing box through a static ring seat.
5. The rotary joint structure at the upper end of a bulk polymerization reactor according to claim 4, characterized in that: The pushing assembly includes a spring seat, a spring and a push ring. The spring seat is fixedly installed on the water outlet pipe by screws. The push ring is installed on the spring seat by several springs and is pushed tightly against the moving ring by the spring force. The moving ring is rotatably connected to the spring seat.
6. The rotary joint structure at the upper end of a bulk polymerization reactor according to claim 5, characterized in that: The rotational connection is achieved by inserting a radial convex portion into a radial concave portion to transmit torque.
7. The rotary joint structure at the upper end of a bulk polymerization reactor according to claim 1, characterized in that: A bearing fluid spacer ring located below the lower mechanical seal is also installed between the bearing box and the water outlet pipe.
8. The rotary joint structure at the upper end of a bulk polymerization reactor according to claim 7, characterized in that: The upper and lower ends of the bearing are both provided with skeleton oil seals installed on the bearing box, and the bearing box is provided with grease injection holes adapted to the bearing.
9. The rotary joint structure at the upper end of a bulk polymerization reactor according to claim 8, characterized in that: A mechanical seal leakage observation hole opened in the bearing box is arranged below the bearing fluid spacer ring. The mechanical seal leakage observation hole is adapted to the skeleton oil seal and the bearing fluid spacer ring and is located between the skeleton oil seal and the bearing fluid spacer ring above.