Gas phase reactor terminator multi-point injection apparatus and method

Abstract

The application relates to the technical field of polymer production, and is a gas-phase reactor terminator multi-point injection device and method.The former comprises a gas-phase reactor and a terminator storage bottle;the gas-phase reactor is fixedly connected with a raw material pipeline at a top feeding end;the gas-phase reactor is fixedly connected with a reflux pipeline between the top and the bottom;the terminator storage bottle is fixedly connected with a terminator main pipe at a discharging end;the first discharging end of the terminator main pipe is fixedly connected with a bottom injection pipeline between the bottom feeding end of the gas-phase reactor; and the second discharging end of the terminator main pipe is fixedly connected with an upper injection pipeline between the upper feeding end of the gas-phase reactor.The application realizes rapid, uniform and accurate injection of the terminator by arranging injection points in multiple key areas, significantly improves termination efficiency and reliability, reduces the amount of the terminator, effectively reduces equipment damage and the rate of defective products, and guarantees long-period safe and stable operation of the device.

Description

Technical Field

[0001] This invention relates to the field of polymer production technology, and is a device and method for multi-point injection of a gas phase reactor terminator. Background Technology

[0002] In existing polypropylene production, raw materials propylene, ethylene, and hydrogen are refined to remove impurities before entering prepolymerization, loop polymerization reactors, and gas-phase polymerization reactors. The main catalyst and activator are continuously added to the prepolymerization loop reactor, after which the material enters the loop reactor for liquid-phase bulk polymerization. The product path varies depending on the type: for homopolymer and random products, the slurry from the loop reactor directly enters the gas-phase reactor; for impact-resistant products, the material needs to be heated and subjected to gas-solid separation before the resulting PP powder enters the gas-phase reactor for further reaction. The polypropylene powder discharged from the gas-phase reactor undergoes further processing to obtain the final product. The gas-phase fluidized bed reactor is one of the core pieces of equipment. In traditional gas-phase reactor designs, the method of adding the terminator has significant limitations. The core issue is the single injection point, typically only one. This makes it difficult for the terminator to diffuse quickly and uniformly within the large reaction space, failing to promptly suppress excessive reactions caused by localized "hot spots," ultimately leading to polymer agglomeration.

[0003] Setting a single terminator injection point at the bottom discharge line or top of the gas-phase reactor has the following significant drawbacks: Uneven terminator diffusion and slow response: A single injection point makes it difficult for the terminator to diffuse quickly and evenly throughout the entire reaction area, especially in the highly active zone near the distribution plate and the upper part of the fluidized bed. The terminator may take several minutes to reach the far end, leading to persistent localized reactions, forming "hot spots" and lumps. Poor adaptability to operating conditions: When producing high melt index products or complex impact copolymers, different areas within the reactor have varying requirements for the terminator, and a single injection point cannot achieve precise and rapid targeted control, limiting the plant's production adjustment capabilities. Low termination reliability: Some existing systems rely on the turbine system of the circulating gas compressor to maintain fluidization in case of failure, but the high turbine start-up failure rate leads to termination program failure. Simultaneously, insufficient reserve of terminator cylinders necessitates manual switching, delaying the process. High terminator dosage: To ensure that the termination concentration is reached even in the blind zone, traditional processes have to inject excessive amounts of terminator, resulting in resource waste and increased costs.

[0004] In his paper "A Discussion on the Reaction Termination System of Low-Pressure Polyethylene Plant," Liu Yifei introduced the process flow and control logic of Type I, Type II, Type III, and small-scale termination systems in low-pressure polyethylene plants. He emphasized that the amount of termination agent needed should be 40 to 80 times the theoretical value, and that fluidization should be maintained by a circulating gas compressor or turbine system. However, the termination system described in this paper still has drawbacks: a single termination agent injection point (usually located in the circulating gas pipeline or above the reactor), making it difficult to achieve rapid and uniform diffusion and resulting in a "coverage blind zone"; the system relies on turbine start-up, leading to a high failure rate and poor termination reliability; the large amount of termination agent used results in serious resource waste and a lack of precise control capabilities.

[0005] Chinese patent document CN101165018A discloses a method for producing ethylene and propylene. The patent includes the following steps: (a) the raw material first enters from the bottom of the first fluidized bed reactor, and the terminator enters from the top of the first fluidized bed reactor. The raw material and the terminator react with catalyst I to generate effluent I containing ethylene, propylene, C4 and above hydrocarbons. Effluent I and unreacted materials are discharged from the top of the first fluidized bed reactor to enter the subsequent process section; (b) the unregenerated catalyst II in the first fluidized bed reactor enters the regenerator and is regenerated by contacting the regeneration gas from the bottom of the regenerator. The regeneration flue gas is discharged from the top of the regenerator; (c) the regenerated catalyst III from the regenerator enters the second fluidized bed reactor and contacts the passivating agent that can cause the regenerated catalyst III to produce carbonaceous deposits; (d) the passivated catalyst IV from the second fluidized bed reactor is returned to the first fluidized bed reactor for reaction. This patent proposes using water, C2-C5 alcohols, or C4+ hydrocarbons as terminators in the methanol-to-olefins process, injected from the top of the fluidized bed reactor to terminate secondary reactions and improve ethylene-propylene selectivity. However, this terminator is injected only from a single location at the top of the reactor, failing to cover the initial catalyst contact zone, the core fluidized bed reaction zone, and the active powder zone in the loop; it lacks optimization of the terminator diffusion path and efficiency, making it difficult to handle localized reaction runaway; and it does not address rapid response and multi-point coordinated control logic under emergency conditions.

[0006] Chinese patent document CN116966833A discloses a method and apparatus for one-click injection of an emergency termination agent in a reaction polymerization reactor. When an abnormal situation occurs in the reactor, the reactor's ESD controller is activated; then, the reactor's mechanical seal water shut-off valve automatically closes, and the automatic valve for injecting the emergency termination agent nitric oxide automatically opens; finally, when the reactor pressure is ≥1.995 MPa, the reactor's rupture disc breaks, and the emergency termination agent nitric oxide is automatically injected into the reactor, terminating the polymerization reaction. This invention targets polyvinyl chloride (PVC) polymerization reactors and proposes a one-click injection system based on an ESD controller, achieving automatic nitric oxide injection through rupture disc rupture. However, it still suffers from a single injection point (entering only through the mechanical seal water pipeline), poor mixing uniformity due to the reliance on gas bubbling for the distribution of the termination agent within the reactor, and a lack of multi-region targeted injection design, making it difficult to cope with the complex flow fields within large fluidized bed reactors.

[0007] In summary, existing technologies generally suffer from the following common shortcomings: a single injection point leads to uneven diffusion of the terminating agent and a slow response; large amounts of terminating agent are used, resulting in low resource utilization; and insufficient automation and intelligence prevent rapid, safe, and traceable emergency responses. Therefore, there is an urgent need for a system and method capable of achieving rapid, uniform, precise, and reliable termination of reactions, particularly suitable for emergency safety control of large-scale gas-phase fluidized bed reactors. Summary of the Invention

[0008] This invention provides a multi-point injection device and method for a gas phase reactor terminator, which overcomes the shortcomings of the prior art and can effectively solve the problems of single injection point, uneven diffusion, slow response, large amount of terminator, and low resource utilization of existing terminators.

[0009] One of the technical solutions of the present invention is achieved through the following measures: a multi-point injection method apparatus for a gas phase reactor terminator, comprising: a gas phase reactor and a terminator storage bottle; a raw material pipeline is fixedly connected to the top feed end of the gas phase reactor, a return pipeline is fixedly connected between the top and bottom of the gas phase reactor, a terminator main pipe is fixedly connected to the discharge end of the terminator storage bottle, a bottom injection pipeline is fixedly connected between the first discharge end of the terminator main pipe and the bottom feed end of the gas phase reactor, an upper injection pipeline is fixedly connected between the second discharge end of the terminator main pipe and the upper feed end of the gas phase reactor, a compressor and a heat exchanger are fixedly installed on the return pipeline along the direction of medium flow, and a return injection pipeline is fixedly connected between the third discharge end of the terminator main pipe and the return pipeline between the gas phase reactor and the heat exchanger.

[0010] The following are further optimizations and / or improvements to one of the above-mentioned technical solutions:

[0011] The aforementioned bottom injection pipeline includes a first bottom injection pipeline and a second bottom injection pipeline; the first discharge end of the terminator main pipe is fixedly connected to the first injection port at the bottom of the gas phase reactor, and the second bottom injection pipeline is fixedly connected to the second injection port at the bottom of the gas phase reactor.

[0012] The aforementioned upper injection pipeline includes an upper first injection pipeline, an upper second injection pipeline, and an upper third injection pipeline; the upper first injection pipeline is fixedly connected to the second discharge end of the terminator main pipe and the upper first injection port of the gas phase reactor, the upper second injection pipeline is fixedly connected to the upper second injection port of the gas phase reactor, and the upper third injection pipeline is fixedly connected to the upper third injection port of the gas phase reactor.

[0013] The aforementioned terminator storage cylinders include multiple supply cylinders and backup cylinders, which are connected in parallel to the terminator main pipe.

[0014] A bus valve is fixedly installed on the aforementioned terminator main pipe. The bus valve includes a first bus valve and a second bus valve, which are installed in parallel.

[0015] A discharge pipeline is fixedly connected to the stop agent main pipe between the aforementioned bus valve and the discharge end of the stop agent main pipe.

[0016] The second technical solution of the present invention is achieved through the following measures: a multi-point injection method for a gas-phase reactor terminator, comprising:

[0017] In case of an emergency, the stop agent is injected into the bottom and top of the gas phase reactor through the bottom injection line and the top injection line, and the stop agent is injected into the reflux line through the reflux injection line.

[0018] The following are further optimizations and / or improvements to the second technical solution of the above invention:

[0019] The volume ratio of the terminator injected into the bottom, top and reflux lines of the above-mentioned gas phase reactor is (3 to 5): (4 to 6): (1.5 to 2.5).

[0020] This invention provides a multi-point injection device and method for a gas-phase reactor terminator. By setting injection points in multiple key areas and controlling the injection of the terminator, the device achieves rapid, uniform, and precise injection of the terminator, significantly improving termination efficiency and reliability, reducing the amount of terminator used, effectively reducing equipment damage and defect rate, and ensuring long-term safe and stable operation of the device. Attached Figure Description

[0021] Appendix Figure 1 This is a schematic diagram of the process flow of Embodiment 1 of the present invention.

[0022] The codes in the attached diagram are as follows: 1 is the gas phase reactor, 2 is the gas supply storage cylinder, 3 is the spare storage cylinder, 4 is the raw material pipeline, 5 is the reflux pipeline, 6 is the terminator main pipe, 7 is the bottom first injection pipeline, 8 is the bottom second injection pipeline, 9 is the upper first injection pipeline, 10 is the upper second injection pipeline, 11 is the upper third injection pipeline, 12 is the reflux injection pipeline, 13 is the compressor, 14 is the heat exchanger, 15 is the first main valve, 16 is the second main valve, 17 is the discharge pipeline, 18 is the discharge valve, 19 is the first injection valve, 20 is the second injection valve, 21 is the third injection valve, 22 is the fourth injection valve, 23 is the fifth injection valve, 24 is the sixth injection valve, and 25 is the pressure sensor. Detailed Implementation

[0023] Example 1: As Figure 1 As shown, the multi-point injection device for the gas phase reactor terminator includes: a gas phase reactor 1 and a terminator storage bottle; a raw material pipeline 4 is fixedly connected to the top feed end of the gas phase reactor 1, a return pipeline 5 is fixedly connected between the top and bottom of the gas phase reactor 1, a terminator main pipe 6 is fixedly connected to the discharge end of the terminator storage bottle, a bottom injection pipeline is fixedly connected between the first discharge end of the terminator main pipe 6 and the bottom feed end of the gas phase reactor 1, an upper injection pipeline is fixedly connected between the second discharge end of the terminator main pipe 6 and the upper feed end of the gas phase reactor 1, a compressor 13 and a heat exchanger 14 are fixedly installed on the return pipeline 5 along the direction of medium flow, and a return injection pipeline 12 is fixedly connected between the third discharge end of the terminator main pipe 6 and the return pipeline 5 between the gas phase reactor 1 and the heat exchanger 14.

[0024] Example 2: As Figure 1 As shown, as an optimization of the above embodiment, the bottom injection pipeline includes a bottom first injection pipeline 7 and a bottom second injection pipeline 8; the bottom first injection pipeline 7 is fixedly connected between the first discharge end of the terminator main pipe 6 and the bottom first injection port of the gas phase reactor 1, and the bottom first injection pipeline 7 is fixedly connected between the bottom second injection port of the gas phase reactor 1 and the bottom second injection pipeline 8. The first and second injection ports at the bottom of the gas phase reactor 1 are respectively located on both sides of the bottom of the gas phase reactor 1.

[0025] Example 3: As Figure 1As shown, as an optimization of the above embodiment, the upper injection pipeline includes an upper first injection pipeline 9, an upper second injection pipeline 10, and an upper third injection pipeline 11; the upper first injection pipeline 9 is fixedly connected to the second discharge end of the terminator main pipe 6 and the upper first injection port of the gas phase reactor 1, the upper second injection pipeline 10 is fixedly connected to the upper second injection port of the gas phase reactor 1, and the upper third injection pipeline 11 is fixedly connected to the upper third injection port of the gas phase reactor 1. The upper first injection port, second injection port, and third injection port of the gas phase reactor 1 are located above the distribution plate inside the gas phase reactor 1 and are evenly distributed.

[0026] Example 4: Figure 1 As shown, as an optimization of the above embodiment, the terminating agent storage cylinder includes multiple supply cylinders 2 and backup cylinders 3, which are connected in parallel to the terminating agent main pipe 6. Both the supply cylinders 2 and the backup cylinders 3 are carbon monoxide cylinders with a volume concentration of 10%, and the cylinder pressure range is 10 MPa to 20 MPa. Depending on the needs, there can be 4 to 6 supply cylinders 2.

[0027] Example 5: Figure 1 As shown, as an optimization of the above embodiment, a bus valve is fixedly installed on the terminal agent main pipe 6. The bus valve includes a first bus valve 15 and a second bus valve 16, which are installed in parallel.

[0028] Example 6: As Figure 1 As shown, as an optimization of the above embodiment, a discharge line 17 is fixedly connected to the stop agent main pipe 6 between the bus valve and the discharge end of the stop agent main pipe 6. The discharge line 17 leads to the flare and is used to release residual pressure in the pipeline.

[0029] As needed, valves, thermometers, pressure gauges, and other instruments to ensure the normal operation of the gas phase reactor terminator multi-point injection device are fixedly installed on each pipeline. Specifically, a discharge valve 18 is fixedly installed on the discharge pipeline 17; a first injection valve 19 is fixedly installed on the bottom first injection pipeline 7 between the gas phase reactor 1 and the bottom second injection pipeline 8; a second injection valve 20 is fixedly installed on the bottom second injection pipeline 8; a third injection valve 21 is fixedly installed on the upper first injection pipeline 9 between the gas phase reactor 1 and the upper second injection pipeline 10; a fourth injection valve 22 is fixedly installed on the upper second injection pipeline 10 between the gas phase reactor 1 and the upper third injection pipeline 11; a fifth injection valve 23 is fixedly installed on the upper third injection pipeline 11; and a sixth injection valve 24 is fixedly installed on the reflux injection pipeline 12. The multi-point injection device for the gas-phase reactor terminator is also equipped with a DCS controller. The first bus valve 15, the second bus valve 16, the discharge valve 18, the first injection valve 19, the second injection valve 20, the third injection valve 21, the fourth injection valve 22, the fifth injection valve 23, and the sixth injection valve 24 are all solenoid valves, and all six injection valves are electrically connected to the DCS controller. Simultaneously, a pressure sensor 25 can be installed in the terminator main pipe 6. When the pressure in the terminator main pipe 6 is lower than 3.5 MPa, all injection valves are automatically closed; when the pressure recovers to above 4 MPa, the injection valves are reopened to ensure that the terminator is injected under stable pressure.

[0030] Example 7: The multi-point injection method for the gas phase reactor terminator includes:

[0031] In case of an emergency, the terminator is injected into the bottom and top of the gas phase reactor 1 through the bottom injection line and the top injection line, and into the reflux line 5 through the reflux injection line 12.

[0032] Emergency situations include: abnormally high temperature and cooling system failure, rapid pressure increase and inability to release pressure in time, failure and shutdown of the circulating compressor, blockage of reactor discharge, and power outage of the unit.

[0033] Example 8: As an optimization of the above example, the volume ratio of the stop agent injected into the bottom, top and reflux line 5 of the gas phase reactor 1 is (3 to 5): (4 to 6): (1.5 to 2.5).

[0034] In case of an emergency, the control procedure for emergency injection of terminator into gas phase reactor 1 via DCS controller is as follows: first, close the discharge valve 18 on the discharge line 17 to the flare; 3 seconds later, open the first bus valve 15 and the second bus valve 16 on the terminator main pipe 6; 3 seconds later, simultaneously open the first injection valve 19, the second injection valve 20, the third injection valve 21, the fourth injection valve 22, the fifth injection valve 23, and the sixth injection valve 24 to inject terminator into gas phase reactor 1.

[0035] The device for multi-point injection of the gas-phase reactor terminator of the present invention employs a combination of multiple parallel gas supply cylinders 2 and spare cylinders 3. The terminator is supplied through a main terminator pipe 6 and distributed to six independent injection points after passing through a bus valve. These six independent injection points are distributed in three key areas of the reaction system. First, the bottom injection point of the gas-phase reactor 1 injects the terminator at the bottom of the distribution plate within the gas-phase reactor 1. This injection covers the "region where the catalyst initially contacts propylene," where the catalyst active centers are most concentrated. The terminator can directly react with the highly active catalyst, preventing reaction propagation at its source. Second, the upper injection point of the gas-phase reactor 1 injects the terminator at the upper part of the distribution plate within the gas-phase reactor 1. This injection covers the "core reaction zone of the fluidized bed," where the polymerization reaction is most intense. Injection here effectively replenishes the terminator concentration in the middle of the bed, avoiding localized concentration deficiencies caused by fluidized gas disturbance. In addition, an injection point is set in the fluidized loop (return line 5), and the injection of the terminator covers the "active powder area carried by the circulating gas". This directly terminates the active powder that still has polymerization capacity in the fluidized loop, without waiting for the terminator in the reactor to be carried out by the circulating gas, thus improving termination efficiency and protecting downstream equipment. The entire multi-point injection device for the gas phase reactor terminator can be fully automatically controlled by a DCS controller, ensuring the accuracy and safety of operation. The terminator can diffuse to all areas of the reactor within 10 to 15 seconds, which is more than 70% more efficient than the traditional single injection point (60 to 90 seconds), completely avoiding the problems of explosive agglomeration or agglomeration caused by local reaction runaway.

[0036] Example 9: The implementation of the device for multi-point injection of the gas phase reactor terminator is as follows:

[0037] Taking a 100,000-ton / year polypropylene plant using the "dual-loop + gas-phase fluidized bed" process as an example, the original process only had a terminator injection point at the top of gas-phase reactor 1, and the compressor in the fluidized loop was equipped with a turbine. If the circulating gas compressor suddenly stops, the termination procedure is immediately initiated, the turbine starts, and the terminator is injected into gas-phase reactor 1, requiring the injection of 80 Nm³ of 10% CO gas. 3 (equivalent to 8 Nm³ of pure CO) 3 Only then can the reaction be completely terminated.

[0038] The device for multi-point injection of the gas phase reactor terminator according to the present invention is provided with three sets of injection points: the upper part of the distribution plate, the bottom of the distribution plate, and the fluidization loop. The compressor turbine is eliminated, and the injection volume distribution at each injection point is optimized as follows:

[0039] 20 Nm of water was injected into the bottom of the distribution plate. 3 (Covering the initial region of the catalyst)

[0040] 25 Nm of water was injected into the upper part of the distribution plate. 3 (Covering the core area of ​​the catalyst bed)

[0041] 10 Nm injected into the fluidized loop 3 (Covering the active powder area).

[0042] In an emergency, the DCS controller executes the injection process in the following order: closing the discharge valve 18 → opening the bus valve → opening all injection valves.

[0043] The total injection volume is 55 Nm 3 (equivalent to 5.5 Nm of pure CO) 3 The total dosage was reduced by 31.25%, and the reaction termination time was shortened from 120 seconds to 60 seconds. At the same time, the risk of local agglomeration caused by insufficient CO in the lower part of the bed in the original process was avoided, as well as other problems caused by turbine start-up failure.

[0044] Example 10: The implementation of the device for multi-point injection of the gas phase reactor terminator is as follows:

[0045] Taking a 450,000-ton / year polypropylene plant using a combination of liquid phase bulk and gas phase fluidized bed process as an example, the original process set up a terminator injection point at the top and bottom of the gas phase reactor 1.

[0046] During a certain overheating incident, 120 Nm³ of 10% CO gas was injected into the bottom and part of the distribution plate, respectively. 3 and 130Nm 3 (Total pure CO is 25 Nm) 3 The fluidization circuit was not injected. After 20 minutes, the temperature of the return line rose from 80°C to 110°C, and polymer adhered to the inner wall of the line. Cleaning took 48 hours.

[0047] After implementing this invention, when the device overheats, a terminator of 60 Nm³ is injected into the upper part of the distribution plate, the bottom part of the distribution plate, and the fluidization loop respectively, following the method of multi-point injection of terminator in a gas-phase reactor. 3 100Nm 3 35Nm 3 The total injection volume is 195 Nm. 3 (equivalent to 19.5 Nm³ of pure CO) 3 The total dosage was reduced by 22%, the passivation time of the terminator was shortened from 8 to 12 minutes to less than 3 minutes, the temperature of the return pipeline was kept below 85°C, no adhesive polymer was formed on the inner wall of the pipeline, and no cleaning was required.

[0048] The core of a gas-phase reactor is the full contact between the gas and solid phases in a fluidized state, and the fluidization loop is the key channel for maintaining catalyst particle circulation and heat removal. A comparison before and after implementation of this invention in this embodiment shows that injecting the terminator only at the bottom and top of the distribution plate has significant drawbacks. Under emergency conditions (such as overheating or feed runaway), a large number of polypropylene particles with active centers and unreacted monomers will remain in the fluidization loop. Injecting only the terminator into the reactor will cause these particles to continue to polymerize and release heat within the loop, and the circulating gas compressor will exacerbate the local reaction, leading to a surge in circulating gas temperature, exceeding the heat exchanger's heat exchange load limit, and causing coking and blockage in the circulating pipeline. Moreover, injecting the terminator only at the bottom and top of the distribution plate only effectively covers 60% to 70% of the gas-phase reactor volume, leaving an active center residue rate of >40% in the uncovered areas. This means the reaction's exothermic rate cannot be effectively reduced, and the risk of overheating persists.

[0049] Furthermore, in emergency situations, the gas-phase reactor needs to complete the entire process through the steps of "terminating the reaction → cooling and depressurizing → restoring fluidization." Injecting the terminator only into the upper and lower parts of the gas-phase reactor will disrupt the stability of the fluidization system, causing localized agglomeration and blockage of the distribution plate, uneven distribution of fluidizing gas, coking in the fluidization loop, and a sharp drop in the efficiency of the circulating fan. First, the continuous aggregation of unpassivated active particles in the dense phase region will form hard polymer agglomerates, blocking the openings in the distribution plate. During subsequent restoration of fluidization, the fluidizing gas cannot pass through the distribution plate evenly, leading to "channeling" and "surging" in the bed, or even bed collapse, further damaging the distribution plate support structure. Second, the unterminated reaction in the fluidization loop will produce fine powder and molten polymer, which adhere to the heat exchanger tube walls and fan impeller, causing the heat exchanger heat transfer coefficient to decrease by 30% to 50%, failing to effectively remove heat; scaling on the fan impeller leads to dynamic imbalance, excessive vibration (>8 mm / s), and in severe cases, fan shaft breakage.

[0050] In addition, uneven distribution of terminator residues leads to a surge in subsequent degassing load, affecting the stability of the granulation process, resulting in high secondary treatment costs, extended production cycle, and the risk of explosive polymerization, threatening the safety of personnel and equipment.

[0051] In summary, the fluidized loop acts as a "circulating carrier" of active particles and heat. In emergency situations of a gas-phase reactor, injecting terminator only at the bottom and top of the distribution plate is equivalent to treating only the reactor body, neglecting the extended reaction area. This ultimately leads to a chain reaction of consequences: incomplete termination → localized reaction runaway → equipment damage → prolonged restart cycle → escalating safety risks. The implementation results of this embodiment demonstrate that, compared to injecting terminator only at the top and bottom of the gas-phase reactor, adding terminator injection points in the fluidized loop effectively promotes the flow of terminator within the reactor, reduces the total amount of terminator used, and allows only a small amount of terminator to be injected into the fluidized loop, enabling rapid diffusion of the terminator with the fluidizing gas to all areas of the reactor and the loop, achieving "full-area, rapid, and uniform passivation."

[0052] The present invention has the following outstanding beneficial effects:

[0053] (1) Significantly improved termination efficiency: Through multi-point targeted injection, the terminator can diffuse to all areas of the gas phase reactor 1 within 10 to 15 seconds, which is more than 70% more efficient than the traditional single injection point (60 to 90 seconds), and completely avoids local reaction runaway.

[0054] (2) Significantly reduced dosage of terminator: Due to the achievement of precise coverage and the elimination of “ineffective injection”, the total dosage of terminator can be reduced by 15% to 35%.

[0055] (3) Improved equipment reliability and lifespan: The reactor agglomeration rate was reduced from approximately 30% to below 5%, and the equipment damage rate was reduced by 80%. The fluidized loop injection point prevented the agglomeration of powder in the compressor 13 and heat exchanger 14, extending the maintenance cycle of heat exchanger 14 from 3 months to 12 months. Annual equipment maintenance and cleaning costs can be reduced by RMB 800,000 to RMB 1.2 million (based on a 450,000-ton / year plant).

[0056] (4) Improved product quality and yield: Taking a 450,000-ton / year polypropylene plant as an example, after the implementation of this invention, the amount of defective products caused by reaction runaway was reduced from 5 to 10 tons per instance to 1 to 2 tons, and the raw material utilization rate was increased by 80%. The product defect rate decreased from 1.5% to 2% to 0.3% to 0.5%. The qualified rate of high-end grades increased from 85% to 95%, resulting in significant annual revenue increases. Enhanced plant operation stability: The number of unplanned shutdowns decreased from an average of 3 to 4 times per year to 0.5 to 1 time, reducing annual shutdown losses by approximately RMB 6.72 million. The annual operating hours of the plant increased from 8,000 hours to 8,200 hours, resulting in additional production capacity and an annual revenue increase of approximately RMB 9 million.

[0057] In summary, the multi-point injection device and method for gas-phase reactor terminator of the present invention, by setting injection points in three key areas of the reaction system and controlling the injection of terminator, comprehensively covers the high-activity area of ​​the catalyst, the area of ​​intense polymerization reaction, and the active powder area, realizing rapid, uniform, and precise injection of terminator, significantly improving termination efficiency and reliability, reducing the amount of terminator used, effectively reducing equipment damage, and improving product quality and profitability.

[0058] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A gas phase reactor terminator multi-point injection device characterized by The application relates to a gas phase reactor and a terminator storage bottle; a raw material pipeline is fixedly communicated with a top feeding end of the gas phase reactor; a reflux pipeline is fixedly communicated between the top and the bottom of the gas phase reactor; a terminator main pipeline is fixedly communicated with an outlet end of the terminator storage bottle; a bottom injection pipeline is fixedly communicated between a first outlet end of the terminator main pipeline and a bottom feeding end of the gas phase reactor; an upper injection pipeline is fixedly communicated between a second outlet end of the terminator main pipeline and an upper feeding end of the gas phase reactor; a compressor and a heat exchanger are fixedly installed on the reflux pipeline along the medium flow direction; a reflux injection pipeline is fixedly communicated between a third outlet end of the terminator main pipeline and the reflux pipeline between the gas phase reactor and the heat exchanger; The bottom injection pipeline comprises a bottom first injection pipeline and a bottom second injection pipeline; The bottom first injection pipeline is fixedly communicated between the first outlet end of the terminator main pipeline and a bottom first injection port of the gas phase reactor; and the bottom second injection pipeline is fixedly communicated between the bottom first injection pipeline and a bottom second injection port of the gas phase reactor; the upper injection pipeline comprises an upper first injection pipeline, an upper second injection pipeline and an upper third injection pipeline; The upper first injection pipeline is fixedly communicated between the second outlet end of the terminator main pipeline and an upper first injection port of the gas phase reactor; the upper second injection pipeline is fixedly communicated between the upper first injection pipeline and an upper second injection port of the gas phase reactor; and the upper third injection pipeline is fixedly communicated between the upper second injection pipeline and an upper third injection port of the gas phase reactor. The terminator storage bottle comprises a plurality of gas supply storage bottles and standby storage bottles, which are connected in parallel to the terminator main pipeline.

2. The gas phase reactor terminator multi-point injection apparatus of claim 1, wherein A bus valve is fixedly installed on the terminator main pipeline; the bus valve comprises a first bus valve and a second bus valve; and the first bus valve and the second bus valve are installed in parallel.

3. The gas phase reactor terminator multi-point injection apparatus of claim 2, wherein A discharge pipeline is fixedly communicated between the bus valve and the outlet end of the terminator main pipeline.

4. The gas phase reactor terminator multi-point injection apparatus of claim 3, wherein When an emergency occurs, the terminator is injected into the bottom and the upper part of the gas phase reactor through the bottom injection pipeline and the upper injection pipeline, and the terminator is injected into the reflux pipeline through the reflux injection pipeline.

5. A method of multi-point injection of a gas phase reactor terminator according to any one of claims 1 to 4, characterized in that The volume ratio of the terminator injected into the bottom, the upper part of the gas phase reactor and the reflux pipeline is (3-5):(4-6):(1.5-2.5). ​ 6. The gas phase reactor terminator multi-point injection method of claim 5, wherein ​

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