CN219518779U - Loop reactor - Google Patents

Abstract

The utility model provides a loop reactor, which comprises a first reactor and a second reactor which are connected in series, wherein the first reactor and the second reactor are in mirror symmetry, the loop reactor is a closed loop, the first reactor and the second reactor comprise a transverse short pipe, an L-shaped elbow, a first straight pipe section, a first 180-degree elbow, a second straight pipe section, a U-shaped elbow, a third straight pipe section, a second 180-degree elbow, a fourth straight pipe section and a vertical short pipe which are sequentially communicated, one end of the transverse short pipe is connected with a first axial flow pump, the other end of the vertical short pipe is connected with a second axial flow pump, a suction inlet is arranged on the first straight pipe section, and a discharge outlet is arranged on the fourth straight pipe section; the discharge outlet of the first reactor communicates with the suction inlet of the second reactor. Compared with the prior art, the utility model provides the loop reactor, which is characterized in that the first reactor and the second reactor are connected in series, the main structures of the first reactor and the second reactor are in mirror symmetry, the whole structure is simple, the heat transfer efficiency is high, and the flow field distribution is uniform.

Description

Loop reactor

Technical Field

The utility model relates to the field of loop reactors, in particular to a loop reactor of polyethylene and polypropylene.

Background

The loop reactor is mainly used in the polyolefin industry, is one of main equipment for producing Polyethylene (PE) and polypropylene (PP), is key core equipment in a loop polypropylene process device, and the performance of the loop reactor directly influences the normal operation of the whole device and the quality of products. In the working process, propylene slurry in the equipment circularly flows in an annular pipeline, mass and heat transfer are realized in the flowing process, and propylene polymerization reaction is completed under the action of an efficient catalyst from a prepolymerization reactor. The produced polypropylene product accounts for more than 40% of the polypropylene productivity in China, and is an important upstream device in polypropylene production and processing.

After the loop reactor was successfully applied to polypropylene industrial production in the 60 th century of 19 th year, the structure of the loop reactor was changed continuously along with the process updating, the loop reactor was changed from the first two-leg (two straight pipe sections) loop reactor to the four-leg loop reactor, and then the loop reactor was developed into the eight-leg loop reactor, and even the twelve-leg loop reactor was achieved in recent years, but the main stream structure was also the eight-leg loop reactor in terms of long-term use data.

The polypropylene loop reactor (short for large loop) consists of 2 four-leg loop reactors (namely a first reactor and a second reactor) which are mirror symmetrical left and right, and the propylene polymerization reaction is completed in the first reactor by 65 percent and is completed in the second reactor by 35 percent under the action that catalyst is continuously supplied into the loop reactor by a prepolymerization reactor (short for small loop). The reactor is a closed and unique annular tube type combined structure, consists of a closed annular pipeline and an inlet and an outlet of the reactor, and belongs to the category of low-temperature pressure containers.

The loop reactor is not only a reactor, but also a supporting steel column of a reaction frame and a ladder platform, and the ultra-long straight pipe section (a heat exchange jacket and an inner cylinder body) also has certain concentricity. An axial flow pump is arranged at the lower end connecting section of the reactor, so that the reaction materials can circularly flow in the reactor and play a role in stirring the reaction materials. The inner wall of the inner cylinder body of the reactor is subjected to semi-fine polishing treatment until the roughness Ra2.5 is reached, so that the phenomenon of explosion aggregation caused by sticking of reaction materials to the wall is prevented. In addition, the propylene polymerization reaction is a strong exothermic reaction when the reactor works, a large amount of heat transfer exists, and in order to enable the propylene polymerization reaction to be carried out at a constant temperature, the reaction heat needs to be removed, so in actual production, a heat exchange jacket is usually arranged outside the inner cylinder body, and circulating water is led between the heat exchange jacket and the inner cylinder body for cooling. In order to relieve the thermal stress of the heat exchange jacket, an expansion joint is usually arranged at the upper end of the heat exchange jacket, so as to play a role in compensating the thermal expansion of the heat exchange jacket. However, due to the pressure difference between the inside and outside, the expansion displacement between the heat exchange jacket and the inner tube is caused, and the connection position of the lower end of the heat exchange jacket is easy to displace. In addition, since the loop reactors are high, close to 60 meters in height, and weigh about 900 tons, how to stably support the loop reactors is also a problem to be solved.

Disclosure of Invention

Aiming at the problems, the utility model provides a loop reactor, which is formed by connecting a first reactor and a second reactor in series, wherein expansion joints are arranged at the upper end and the lower end of a heat exchange jacket cylinder simultaneously so as to compensate the axial displacement of the heat exchange jacket cylinder and eliminate the temperature difference pressure; adopts a connecting structure (comprising a connecting beam bracket, an I-shaped connecting beam, a connecting plate and the like) to carry out connection and reinforcement and firmly support.

The utility model adopts the technical scheme that:

the loop reactor comprises a first reactor and a second reactor which are connected in series, the first reactor and the second reactor are in mirror symmetry, the loop reactor is a closed loop, the first reactor and the second reactor comprise a transverse short pipe, an L-shaped elbow, a first straight pipe section, a first 180-degree elbow, a second straight pipe section, a U-shaped elbow, a third straight pipe section, a second 180-degree elbow, a fourth straight pipe section and a vertical short pipe which are sequentially communicated, one end of the transverse short pipe is connected with a first axial flow pump, the other end of the vertical short pipe is connected with a second axial flow pump, a suction inlet is arranged on the first straight pipe section, a discharge outlet is arranged on the fourth straight pipe section, safety valves are arranged on the first 180-degree elbow and the second 180-degree elbow, and guide plates are arranged at the connection positions of the straight pipe section, the 180-degree elbow, the U-shaped elbow and the L-shaped elbow; the discharge outlet of the first reactor is communicated with the suction inlet of the second reactor; each straight pipe section comprises an inner barrel and a heat exchange jacket barrel sleeved on the inner barrel, a guide base plate and a wash-resistant plate are further arranged in the heat exchange jacket barrel, an upper expansion joint is arranged at the upper end of the heat exchange jacket barrel, a lower expansion joint is arranged at the lower end of the heat exchange jacket barrel, the two heat exchange jacket barrels are connected through a heat exchange jacket connecting pipe, and the heat exchange jacket connecting pipe is provided with a heat exchange jacket connecting pipe expansion joint; the heat exchange jacket cylinder bodies are provided with annular supports, and radial support plates are arranged in the annular supports and are fixed with the inner cylinder bodies in the jacket cylinder bodies into a whole; a plurality of I-shaped connecting beams are arranged between the adjacent heat exchange jacket cylinders, connecting beam brackets are arranged outside the heat exchange jacket cylinders, and two ends of each working connecting beam are connected with the connecting beam brackets through connecting plates.

Preferably, cooling water inlets are formed in the heat exchange jacket cylinders of the first straight pipe sections in the first reactor and the second reactor, and cooling water outlets are formed in the heat exchange jacket cylinders of the second straight pipe sections; a cooling water inlet is formed in the heat exchange jacket cylinder of the third straight pipe section, and a cooling water outlet is formed in the heat exchange jacket cylinder of the fourth straight pipe section; the top end part of each heat exchange jacket cylinder is also provided with a jacket vent, and the bottom end part of each heat exchange jacket cylinder is also provided with a jacket vent; and each jacket connecting pipe is also provided with a connecting pipe emptying port.

Preferably, a killing agent injection port is also arranged on the loop reactor.

Preferably, a nitrogen inlet is also provided on the loop reactor.

Preferably, a slurry inlet is also provided on the loop reactor.

Preferably, a feed port is also provided on the loop reactor.

Preferably, a temperature control valve is also arranged on the loop reactor.

Preferably, a temperature measuring port is also arranged on the loop reactor.

Preferably, a temperature alarm port is also arranged on the loop reactor.

Preferably, a reactor discharge and a reactor bottom discharge are also provided on the loop reactor.

Preferably, a reactor drain is also provided on the loop reactor.

Preferably, a pressure differential port is also provided on the loop reactor.

Preferably, a reactor balance port is also provided on the loop reactor.

Preferably, a vent port is also provided on the loop reactor.

Preferably, a sampling port is also provided on the loop reactor.

Preferably, a discharge to a belt interface is also provided on the loop reactor.

Compared with the prior art, the utility model has the beneficial effects that: the utility model provides a loop reactor, which has the following advantages:

1) The first reactor and the second reactor are connected in series, the main structures of the first reactor and the second reactor are mirror symmetry, the propylene polymerization reaction is completed in the first reactor by 65 percent, and the propylene polymerization reaction is completed in the second reactor by 35 percent;

3) The 'double-peak' product can be produced, and the product has uniform quality and is not easy to generate hot spots and the like;

4) The structure is simple, the heat transfer efficiency is high, and the flow field is uniformly distributed;

5) Automatic control and continuous operation are easy to realize;

6) The space assembly precision is high, and the interface sealing performance is good;

7) The material residence time is short, the reaction volume is better utilized, and the production efficiency is improved;

8) The hydrogen content inside the reactor can be adjusted to change the range of melt index (MFR).

Drawings

FIG. 1 is a perspective view of a loop reactor provided by the present utility model;

FIG. 2 is a schematic plan view of a loop reactor according to the present utility model;

FIG. 3 is an enlarged view of a loop reactor, A-A, provided by the present utility model;

FIG. 4 is an enlarged view B-B of a loop reactor according to the present utility model.

Detailed Description

The preferred embodiments of the present utility model will be described in detail with reference to the accompanying drawings.

Fig. 1 to 4 show a preferred embodiment of a loop reactor according to the present utility model. As shown in fig. 1 to 4, the loop reactor comprises a first reactor and a second reactor which are connected in series, the first reactor and the second reactor are in mirror symmetry, the loop reactor is a closed loop, the first reactor and the second reactor comprise a transverse short pipe 53, an L-shaped elbow 57, a first straight pipe section 10001, a first 180-degree elbow 1-1, a second straight pipe section 10002, a U-shaped elbow 89, a third straight pipe section 10003, a second 180-degree elbow 1-2, a fourth straight pipe section 10004 and a vertical short pipe 47 which are sequentially communicated, one end of the transverse short pipe 53 is connected with a first axial flow pump 70-1, the other end of the vertical short pipe 47 is connected with a second axial flow pump 70-2, the first straight pipe section 10001 is provided with a suction inlet 58, the fourth straight pipe section 10004 is provided with a discharge outlet 50, the first 180-elbow 1 and the second 180-elbow 1 are provided with a safety valve 3/8/14/19, and the connection positions of the straight pipe section, the 180-elbow, the U-shaped elbow and the L-shaped elbow are provided with a deflector plate/51/100; the discharge outlet 50 from the first reactor communicates with the suction inlet 58 from the second reactor; each straight pipe section comprises an inner cylinder 27 and a heat exchange jacket cylinder 23 sleeved on the inner cylinder, a guide backing plate 24 and a shock-proof plate 29 are further arranged in the heat exchange jacket cylinder, an upper expansion joint 22 is arranged at the upper end of the heat exchange jacket cylinder 23, a lower expansion joint 94 is arranged at the lower end of the heat exchange jacket cylinder, the two heat exchange jacket cylinders are connected through a heat exchange jacket connecting pipe 97, and a heat exchange jacket connecting pipe expansion joint 98 is arranged on the heat exchange jacket connecting pipe; the annular supports 95 are arranged on the jacket cylinder bodies of each heat exchange, and radial support plates 28 are arranged in the annular supports 95 and are fixed with the inner cylinder body 27 of the jacket cylinder body 23 into a whole; a plurality of I-shaped connecting beams 96 are arranged between the adjacent heat exchange jacket cylinders 23, the connecting beam brackets 26 are arranged outside the heat exchange jacket cylinders, and two ends of each I-shaped connecting beam 96 are connected with the connecting beam brackets 26 through connecting plates 25. The whole loop reactor is formed by sequentially connecting 8 straight pipe sections, 8 annular supports, 4 1-8-degree elbows, 2L-shaped elbows, 2U-shaped elbows, 2 vertical short pipes, 2 horizontal short pipes and an axial flow pump into a circulating whole. The annular support is fixed on the foundation to achieve the purpose of fixedly supporting the whole loop reactor. The 8 straight pipe sections are connected and reinforced through a connecting structure (comprising connecting beam corbels, I-shaped connecting beams, connecting plates and the like). The materials are driven by an axial flow pump to circularly reciprocate in the system through structures such as an inner cylinder, a 180-degree elbow, an L-shaped elbow, a U-shaped elbow, a transverse short pipe, a vertical short pipe and the like in the loop reactor, and propylene polymerization reaction occurs; stay for about 90 minutes and go to the next process.

The first 180-degree elbow 1-1 and the second 180-degree elbow 1-2 are formed by connecting two straight pipe sections of the loop reactor at the top to form a closed loop, so that propylene polymerization reaction can be smoothly carried out.

The loop reactor is provided with a vertical pipe stub 47 for connecting the reactor straight pipe section to the second axial flow pump 70-2 at the bottom to form a closed loop so that propylene polymerization can be smoothly carried out.

The loop reactor is provided with a short transverse pipe 53 in order to connect the reactor L-shaped elbow 57 with the first axial flow pump 70-1 at the bottom to form a closed loop, so that propylene polymerization can be smoothly carried out.

The loop reactor is provided with an L-shaped elbow 57, and the purpose of the loop reactor is to connect the inner cylinder 27 of the reactor with the transverse short pipe 53 and the first axial flow pump 70-1 at the bottom to form a closed loop, so that propylene polymerization can be smoothly carried out.

The loop reactor is provided with a first axial flow pump 70-1 and a second axial flow pump 70-2 in order to provide power for the circulating flow of the material in the reactor and also to play a role in stirring the material.

The loop reactor is provided with a U-shaped elbow 89, and the U-shaped elbow 89 is connected with the straight pipe sections of the reactor at the two ends, so that the reactor forms a closed loop, and the propylene polymerization reaction can be smoothly carried out.

The loop reactor is provided with a suction inlet 58, and the suction inlet 58 is arranged on a first straight pipe section 10001, so that during the internal circulation of the reactor, the material flows back to the first axial flow pump 70-1 through the suction inlet 58 and then flows upwards through the vertical short pipe 47 for circulation.

The loop reactor is provided with a discharge outlet 50, the discharge outlet 50 is arranged in a fourth straight pipe section 10004, in order that the material is circulated upwards through the vertical short pipe 47 by the second axial flow pump 70-2 in the process of circulating the inside of the reactor, and the material is discharged through the discharge outlet due to the higher pressure when flowing out of the second axial flow pump 70-2 through the vertical short pipe 47 due to factors such as gravity and viscosity of the material, so as to reduce the pressure.

The loop reactor is provided with baffles 51 in order to prevent non-uniform flow of material during the circulating flow inside the reactor.

The loop reactor is provided with a safety valve 3 in order to prevent the pressure of the medium inside the apparatus from exceeding a prescribed value and to avoid safety accidents due to excessive pressure.

The loop reactor is provided with an inner cylinder 27 for the purpose of enabling the polymerization of propylene to be completed smoothly inside it, forming a closed loop with 180 ° elbow 1, U-elbow 89, L-elbow 57, vertical stub 47, lateral stub 53.

The loop reactor is provided with a heat exchange jacket cylinder 23, and is cooled by circulating water between the loop reactor and an inner cylinder 27, so that propylene polymerization reaction can be smoothly carried out. The loop reactor is provided with a heat exchange jacket upper expansion joint 22 and a heat exchange jacket lower expansion joint 94, wherein the heat exchange jacket upper expansion joint 22 compensates the axial displacement of the upper heat exchange jacket cylinder 23 and the inner cylinder 27 of the loop reactor due to thermal expansion so as to eliminate larger temperature difference stress generated by asynchronous axial displacement of the inner tube and the outer tube; the expansion joint 94 at the lower end of the heat exchange jacket compensates the axial displacement of the heat exchange jacket cylinder 23 and the inner cylinder 27 at the lower end of the ring seat of the ring pipe reactor due to thermal expansion, so as to eliminate the larger temperature difference stress generated by asynchronous axial displacement of the inner pipe and the outer pipe. The heat exchange jacket of the loop reactor has the length of about 70 m, and the expansion joint is arranged at the lower end of the heat exchange jacket, so that the thermal stress of the lower end part of the heat exchange jacket cannot be effectively relieved, and the expansion joint is also arranged at the lower end of the heat exchange jacket through simulation calculation and analysis.

The loop reactor is provided with a heat exchange jacket connecting pipe 97, and the two heat exchange jacket cylinders 23 are connected by the heat exchange jacket connecting pipe 97, so that circulating cooling water can smoothly circulate inside the heat exchange jacket cylinders. The two heat exchange jackets are connected by the heat exchange jacket connecting pipe 97, and the condition that the heat exchange jacket connecting pipe 97 is thermally expanded due to the influence of temperature is considered, so that the heat exchange jacket connecting pipe 97 is provided with the heat exchange jacket connecting pipe expansion joint 98, and the transverse expansion displacement of the heat exchange jacket cylinder 23 at the two ends caused by the thermal expansion and the axial expansion displacement of the heat exchange jacket connecting pipe 97 are compensated, so that the temperature difference stress caused by the thermal expansion is eliminated.

A guide backing plate 24 and a shock-proof plate 29 are arranged in the heat exchange jacket cylinder 23. The guide pad 24 is used for fixing the position of the inner cylinder 27 in the heat exchange jacket cylinder 23, ensuring certain straightness of the inner cylinder and preventing the deformation of the inner cylinder caused by long-term use of the equipment; the anti-flushing plate 29 relieves the impact of the circulating cooling water on the inner cylinder 27 in the process of circulating flow in the heat exchange jacket cylinder 23, and plays a role in reinforcing the inner cylinder.

A cooling water inlet is formed in the heat exchange jacket cylinder of the first straight pipe section in the first reactor and the second reactor, and a cooling water outlet is formed in the heat exchange jacket cylinder of the second straight pipe section; a cooling water inlet is formed in the heat exchange jacket cylinder of the third straight pipe section, and a cooling water outlet is formed in the heat exchange jacket cylinder of the fourth straight pipe section; the top end part of each heat exchange jacket cylinder is also provided with a jacket vent 5, and the bottom end part of each heat exchange jacket cylinder is also provided with a jacket vent 31; and each jacket connecting pipe is also provided with a connecting pipe emptying port 4.

The loop reactor is provided with a jacket vent 5, and aims to discharge redundant gas in the heat exchange jacket at the position of the jacket vent at the uppermost part of the heat exchange jacket after circulating cooling water is introduced into the heat exchange jacket, so that the circulating water in the heat exchange jacket can be filled with the redundant gas.

The loop reactor is provided with a jacket water inlet 30, and is used for filling circulating cooling water between the heat exchange jacket cylinder 23 and the inner cylinder 27 so as to take away heat generated by propylene polymerization reaction; the circulating cooling water enters at the jacket water inlet and exits through the jacket water outlet 44, completing a complete cycle. The loop reactor is provided with a jacket water outlet 44 where the circulating cooling water is discharged, which serves as a complete cycle, taking away the heat generated by the propylene polymerization reaction.

The loop reactor is provided with a jacket drain 31 for draining the circulating cooling water between the heat exchange jacket cylinder 23 and the inner cylinder 27.

The loop reactor is provided with a heat exchange jacket connecting pipe emptying port 4. The purpose is to discharge the redundant gas in the heat exchange jacket connecting pipe position after circulating cooling water is introduced into the heat exchange jacket, so that the inside of the heat exchange jacket is filled with the circulating cooling water.

The loop reactor is provided with annular supports 95 for the purpose of supporting and fixing the overall structure of the reactor, where it is welded to the inner reactor shell 27 by means of radial support plates 28 in the form of fillet welds. The radial support plates 28 are arranged in the loop reactor, and the purpose is to weld the radial support plates and the annular support 95 together in the form of fillet welds, so as to fix and limit the inner cylinder 27.

The loop reactor is provided with I-shaped connecting beams 96 which are connected with the connecting beam corbels 26 and the heat exchange jacket cylinder 23, and have the functions of fixing and reinforcing the integral frame of the reactor, so that the reactor is safer and more reliable in operation, and is an important component of the steel structure of the loop reactor. The loop reactor is provided with a connection plate 25 for the purpose of connecting and fixing the connection beam corbels 26 to the i-shaped connection beams 96. The loop reactor is provided with a connecting beam bracket 26. The purpose is to connect, fix and strengthen the whole loop reactor by connecting with the heat exchange jacket cylinder 23 and the I-shaped connecting beam 96, which is an important component of the loop reactor steel structure. The connecting beam bracket 26, the I-shaped connecting beam 96, the connecting plate 25 and the like form a connecting structure.

The loop reactor is further provided with a killing agent injection port 34 for injecting a killing agent into the reactor, thereby enabling the propylene polymerization reaction to proceed smoothly.

The loop reactor is also provided with a nitrogen inlet 35 for injecting nitrogen into the reactor so as to smoothly carry out propylene polymerization.

Preferably, the loop reactor is provided with a slurry inlet 10, and after the propylene monomer has been prepolymerized in a prepolymerization reactor (abbreviated as "small loop"), the material is fed into the loop reactor by connecting the slurry inlet via a polishing pipe.

The loop reactor is provided with a feeding port 83, and the purpose is to provide materials for the inside of the reactor through the feeding port, so that the materials in the reactor are always in a full state, and the purpose that propylene polymerization can be successfully completed is achieved.

The loop reactor is provided with a temperature control valve 32 in order to control the temperature of the propylene polymerization reaction inside the reactor so that the propylene polymerization reaction can be carried out at a proper temperature.

The loop reactor is provided with a temperature measuring port 48 for measuring the temperature of the propylene polymerization reaction inside the reactor.

The loop reactor is provided with a temperature alarm port 42, so that when the pressure of propylene polymerization reaction in the reactor exceeds a limit value, a temperature alarm system can be triggered, and the temperature of propylene polymerization reaction in the reactor can be reminded and controlled in time, so that propylene polymerization reaction can be smoothly carried out.

The loop reactor is provided with a reactor discharge 36 and a reactor bottom discharge 38/54/55/67/82 for the purpose of discharging the material for the next process step.

The loop reactor is provided with a reactor evacuation port 68 for evacuating the reactor interior.

The loop reactor is provided with a pressure differential port 33 for controlling the pressure of the propylene polymerization reaction inside the reactor so that the propylene polymerization reaction can be carried out at a suitable pressure.

The loop reactor is provided with a reactor balance port 37 for balancing the pressure inside the reactor with the external atmospheric pressure.

The loop reactor is provided with a vent to boundary zone port 2, so that overpressure caused by the influence of outside air temperature is avoided, and the pressure is prevented from being too high in the operation and use process and can be used as a pressure relief port.

The loop reactor is provided with a sampling port 81 in order to observe the reaction of the material by the material in the reactor withdrawn from the sampling port.

The loop reactor is provided with a discharge to belt interface 84 for connection to a belt.

In summary, the technical solution of the present utility model can fully and effectively achieve the above-mentioned objects, and the structural and functional principles of the present utility model have been fully verified in the embodiments, so as to achieve the intended effects and purposes, and various changes or modifications may be made to the embodiments of the present utility model without departing from the principles and spirit of the present utility model. Accordingly, this utility model includes all modifications encompassed within the scope of the utility model as described in the claims and any equivalent thereof as would be within the scope of the utility model as expressed in the claims.

Claims (16)

1. The loop reactor is characterized by comprising a first reactor and a second reactor which are connected in series, wherein the first reactor and the second reactor are in mirror symmetry, the loop reactor is a closed loop, the first reactor and the second reactor comprise transverse short pipes, L-shaped elbows, first straight pipe sections, first 180-degree elbows, second straight pipe sections, U-shaped elbows, third straight pipe sections, second 180-degree elbows, fourth straight pipe sections and vertical short pipes which are sequentially communicated, one end of each transverse short pipe is connected with a first axial flow pump, the other end of each vertical short pipe is connected with a second axial flow pump, a suction inlet is formed in each first straight pipe section, a discharge outlet is formed in each fourth straight pipe section, safety valves are arranged on each first 180-degree elbow and each second 180-degree elbow, and guide plates are arranged at the connecting positions of each straight pipe section, each 180-degree elbow, each U-shaped elbow and each L-shaped elbow; the discharge outlet of the first reactor is communicated with the suction inlet of the second reactor; each straight pipe section comprises an inner barrel and a heat exchange jacket barrel sleeved on the inner barrel, a guide base plate and a wash-resistant plate are further arranged in the heat exchange jacket barrel, an upper expansion joint is arranged at the upper end of the heat exchange jacket barrel, a lower expansion joint is arranged at the lower end of the heat exchange jacket barrel, the two heat exchange jacket barrels are connected through a heat exchange jacket connecting pipe, and the heat exchange jacket connecting pipe is provided with a heat exchange jacket connecting pipe expansion joint; the heat exchange jacket cylinder bodies are provided with annular supports, and radial support plates are arranged in the annular supports and are fixed with the inner cylinder bodies in the jacket cylinder bodies into a whole; a plurality of I-shaped connecting beams are arranged between the adjacent heat exchange jacket cylinders, connecting beam brackets are arranged outside the heat exchange jacket cylinders, and two ends of each working connecting beam are connected with the connecting beam brackets through connecting plates.

2. Loop reactor according to claim 1, characterized in that: a cooling water inlet is formed in the heat exchange jacket cylinder of the first straight pipe section in the first reactor and the second reactor, and a cooling water outlet is formed in the heat exchange jacket cylinder of the second straight pipe section; a cooling water inlet is formed in the heat exchange jacket cylinder of the third straight pipe section, and a cooling water outlet is formed in the heat exchange jacket cylinder of the fourth straight pipe section; the top end part of each heat exchange jacket cylinder is also provided with a jacket vent, and the bottom end part of each heat exchange jacket cylinder is also provided with a jacket vent; and each jacket connecting pipe is also provided with a connecting pipe emptying port.

3. Loop reactor according to claim 1, characterized in that: and a killing agent injection port is also arranged on the loop reactor.

4. Loop reactor according to claim 1, characterized in that: the loop reactor is also provided with a nitrogen inlet.

5. Loop reactor according to claim 1, characterized in that: a slurry inlet is also provided on the loop reactor.

6. Loop reactor according to claim 1, characterized in that: and a feeding port is also arranged on the loop reactor.

7. Loop reactor according to claim 1, characterized in that: and a temperature control valve opening is also arranged on the loop reactor.

8. Loop reactor according to claim 1, characterized in that: and a temperature measuring port is also arranged on the loop reactor.

9. Loop reactor according to claim 1, characterized in that: and a temperature alarm port is also arranged on the loop reactor.

10. Loop reactor according to claim 1, characterized in that: the loop reactor is also provided with a reactor discharge port and a reactor bottom discharge port.

11. Loop reactor according to claim 1, characterized in that: the loop reactor is also provided with a reactor emptying port.

12. Loop reactor according to claim 1, characterized in that: the loop reactor is also provided with a pressure difference port.

13. Loop reactor according to claim 1, characterized in that: the loop reactor is also provided with a reactor balance port.

14. Loop reactor according to claim 1, characterized in that: the loop reactor is also provided with a vent zone port.

15. Loop reactor according to claim 1, characterized in that: and a sampling port is also arranged on the loop reactor.

16. Loop reactor according to claim 1, characterized in that: the loop reactor is also provided with a discharge-to-belt interface.