A high-efficiency air-locking blanking system

Abstract

The application discloses a high-efficiency air locking discharging system, relates to the technical field of polyolefin chemical production equipment, and solves the technical problems of poor air locking of the existing equipment and mutual interference of gas phase components in the upper and lower process sections.The technical scheme comprises an expansion bag filter / steam generator, the top of which is connected with a recovery pipeline, the bottom of which is connected with a material collecting cylinder, the material collecting cylinder is provided with a material level meter, the bottom is provided with a degassing bin / dryer, a rotary discharging valve A and a rotary discharging valve B are arranged between the material collecting cylinder and the degassing bin / dryer, and a gas seal feeding valve is arranged between the material collecting cylinder and the rotary discharging valve A, and the gas seal feeding valve is provided with a spiral air inlet channel.The multiple air locking effects of the rotary discharging valve A, the rotary discharging valve B and the gas seal feeding valve are achieved, the mutual interference of the gas phase components in the upper and lower process procedures is effectively prevented, the production abnormality caused by the poor air locking of the discharging system is solved, the continuous, quantitative and controllable transfer of the powder is met, and the continuity and stability of production are improved.

Description

Technical Field

[0001] This invention relates to the field of polyolefin chemical production equipment technology, and more specifically to a feeding system that can achieve efficient "air lock" to prevent cross-contamination of gas between upstream and downstream processes in the powder deactivation and drying unit of polyolefin processes. Background Technology

[0002] In the production processes of polyolefins such as polypropylene (ST, Spheripol, SPG) and polyethylene (UNIPLO), polymer powder is generated in the reactor and then fed into an expansion bag filter or steam generator via pressure differential. It is then transferred to subsequent degassing chambers and dryers to achieve degassing, deactivation, drying, and quantitative transfer of the polymer powder, thereby ensuring the continuous and stable polymerization reaction. To facilitate feeding and ensure effective gas-solid phase separation in the polymer powder, the pressure inside the expansion bag filter / steam generator is generally controlled at a low level. During the transfer of powder in the expansion bag filter / steam generator, due to the use of conventional regulating valves or the lack of control and monitoring devices, it is difficult to ensure both production capacity and efficient gas lock in the feeding system. This easily leads to crosstalk between gaseous components in upstream and downstream processes, severely affecting the smooth progress of the polymerization reaction, reducing reaction yield, and impacting the company's production efficiency.

[0003] For example, when polymer powder enters the degassing chamber for catalyst deactivation, nitrogen and water vapor are typically introduced to remove residual catalyst, co-catalyst, or unreacted polymer monomers. If the feeding system lacks proper gas lock, wet nitrogen can leak into the expansion bag filter from subsequent processes and, along with the gaseous components separated from the powder, pass through the filter bag into the recycling unit for reuse. The presence of wet nitrogen significantly reduces the activity of the recycled catalyst, even killing the reaction. Simultaneously, wet nitrogen entering the expansion bag filter causes residual catalyst in the powder to react with water, producing corrosive gases (such as HCl), accelerating equipment corrosion. Furthermore, wet nitrogen entering the filter bag causes residual co-catalyst (TEAL) in the powder to react with water, burning the filter bag and causing unfiltered fine powder to enter the compressor unit of the recycling unit, leading to compressor malfunction and shutdown. The presence of water vapor also causes fluctuations in compressor operation. Additionally, water vapor entering the expansion bag filter increases the viscosity of fine powder in the powder, easily causing filter bag blockage. Therefore, wet nitrogen entering the expansion bag filter will reduce the effect and efficiency of gas-solid phase separation of powder, seriously affecting the normal progress of the polymerization reaction and reducing the polymerization yield.

[0004] For example, when polymer powder enters the steamer for drying, hot nitrogen is usually introduced to remove the moisture separated during the drying process and fluidize the material. If the feeding system has poor airlocking, the separated moisture can easily seep into the subsequent dryer along with the powder, resulting in high moisture content and excessive humidity in the powder within the dryer. This increases the heat load on the dryer and affects powder conveying, making it prone to bridging, sticking to the walls, corrosion, and other abnormalities. It also increases the heat load on the extruder in the subsequent granulation process. Moreover, severe moisture intrusion can lead to significant "water bubbles" after granulation in the extruder, seriously affecting the quality of the polymer product. In addition, during winter production, if the moisture content of the powder after steam treatment exceeds the standard, it can cause freezing and blockage in the relevant powder transfer system, ultimately leading to reaction fluctuations, equipment overpressure, and production interruption.

[0005] Therefore, solving the problem of poor airlock in the feeding system is the key to avoiding the above-mentioned abnormalities in the production process, and it is a key technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0006] In summary, the purpose of this invention is to address the shortcomings of existing polyolefin production processes, such as the defective design of the feeding system in the powder deactivation and drying unit, poor gas-locking effect, and easy crosstalk between gaseous components in the upstream and downstream process sections, which leads to the aforementioned abnormalities during production. The invention provides a high-efficiency gas-locking feeding system that is simple in structure, rationally laid out, highly efficient in operation, and has a good gas-locking effect.

[0007] To address the shortcomings of the technology proposed in this invention, the following technical solution is adopted:

[0008] A high-efficiency, air-locking feeding system includes an expansion bag filter / steamer for gas-solid phase separation in polymer powder, a recovery pipeline connected to its top for discharging gaseous components, and a collection cylinder connected to its bottom outlet for leakage to subsequent processes. The collection cylinder has a level gauge on its wall and a degassing chamber / dryer at its bottom outlet for powder deactivation or drying. The system further comprises:

[0009] Rotary discharge valve A and rotary discharge valve B are arranged sequentially between the collecting cylinder and the degassing chamber / dryer. They are interlocked with the level gauge and are opened and closed intermittently in sequence under the control of the DCS control system. They are used to quantitatively transfer powder to the next process in sequence under airlock isolation.

[0010] An air-sealed feeding valve is located between the collecting cylinder and the rotary feeding valve A. At least two spiral air inlets are evenly distributed within the valve body, allowing air to be blown from one end of the collecting cylinder to the other end of the rotary feeding valve A. This valve is used to connect to an external air source to form an air film between the collecting cylinder and the rotary feeding valve A, or to pneumatically convey powder from the rotary feeding valve A and the rotary feeding valve B to the degassing chamber or drying chamber.

[0011] Furthermore, the rotary feeder valve A and rotary feeder valve B are connected in a vertically opposite manner.

[0012] Furthermore, the air-sealed feed valve includes:

[0013] The butterfly valve body is connected to the rotary feed valve A at its rear end. It is opened and closed under the control of the DCS control system and is used to control the discharge of the material collection cylinder.

[0014] The air seal cylinder is a flat cylindrical structure with openings at both ends. Its front end is connected to the discharge end of the collecting cylinder, and its rear end is connected to the front end of the butterfly valve body. The air inlets of the spiral air inlet are evenly distributed at the front end of its outer wall, and the purge ports of the spiral air inlet are evenly distributed at the rear end of its inner wall.

[0015] The air distribution duct is a hollow ring structure, which is fixedly connected to the front end of the outer wall of the air seal cylinder through the air inlet, and has at least one air inlet for connecting to an external air source.

[0016] Preferably, the purge port is arranged along the tangential direction of the inner wall of the gas seal cylinder.

[0017] Furthermore, the system also includes:

[0018] At least three feed inlets are evenly arranged along the tangential direction of the upper inner wall of the expansion bag filter / steamer cylinder for intermittent entry of polymer powder generated by the reactor for gas-solid phase separation.

[0019] At least three level switches are evenly distributed on the outer wall of the bottom of the funnel-shaped cone of the expansion bag filter / steamer, used to detect the level of powder in the bottom of the cone and report it to the DCS control system.

[0020] At least three air hammer devices are evenly distributed on the outer wall of the bottom of the funnel-shaped cone of the expansion bag filter / steamer. They are interlocked with the material level switch and are used to knock on the cylinder wall under the control of the DCS control system when the material level is abnormal, so as to prevent powder from sticking to the wall or clogging the discharge end.

[0021] Furthermore, the system also includes:

[0022] The backflush device includes backflush ports evenly distributed on the inner wall of the expansion bag filter / steamer, which are connected to an external air source to blow clean air to the top of the expansion bag filter / steamer.

[0023] Furthermore, the system also includes:

[0024] An online water analyzer, located on the recovery pipeline at the top of the expansion bag filter / evaporator, is used to detect the humidity of the discharged gas phase components and report it to the DCS control system.

[0025] Furthermore, the system also includes:

[0026] The heat tracing device includes a heat exchange jacket disposed on the outer wall of the bottom of the funnel-shaped cone of the expansion bag filter / steamer, which is connected to an external heat source to circulate a gaseous or liquid heat exchange medium to promote the separation of gaseous components in the powder or to promote the drying of the powder.

[0027] Several temperature sensors are evenly distributed on the outer wall of the bottom of the funnel-shaped cone of the expansion bag filter / steamer to detect the temperature of the powder and report it to the DCS control system.

[0028] Preferably, the temperature sensors are located at different heights on the outer wall of the funnel-shaped cone bottom of the expansion bag filter / steamer, for detecting the temperature at different material levels of the powder.

[0029] Furthermore, the exhaust devices of the rotary discharge valve A and rotary discharge valve B are connected to the upper cylindrical part of the expansion bag filter / steamer through the gas collection chamber.

[0030] The beneficial effects of this invention are as follows:

[0031] 1. The feeding system of this invention solves the problems of poor gas lock-in and abnormal powder conveying in the production processes of polyolefins such as polypropylene (ST, Spheripol, SPG) and polyethylene (UNIPLO), specifically in the degassing, deactivation, and drying of powder. This invention replaces conventional regulating valves with rotary feeding valves A and B, both interlocked with level gauges to achieve cascade control. Under the control of the DCS control system, the system intermittently opens and closes sequentially through feeding control and timing control, continuously and quantitatively conveying the gas-solid phase separated powder to subsequent processes. Rotary feeding valve B performs powder conveying and primary gas blocking, working in conjunction with rotary feeding valve A and the gas-sealed feeding valve to achieve multiple gas lock functions. This ensures strict gas phase isolation between upstream and downstream processes, achieving efficient gas lock-in while continuously and quantitatively transferring powder, guaranteeing the continuous and stable operation of the polymerization reaction.

[0032] Meanwhile, the added air-sealed feeding valve not only achieves overall control of the material discharge from the collecting cylinder, but also uses the spiral air inlet channel in its valve body to blow air to the rotary feeding valves A and B, and the degassing chamber / dryer. This creates an air-locking isolation film between the collecting cylinder and the rotary feeding valve A, effectively preventing gaseous components from the rotary feeding valves A and B from entering the expansion bag filter / steamer. This further improves the air-locking isolation effect of the feeding system of this invention, and completely solves the problems caused by wet nitrogen interference, such as reduced activity of recycled catalyst, killing of polymerization reaction, corrosion of equipment pipelines, burning of filter bags, compressor unit failure, and filter bag blockage. This is conducive to the continuous, stable, and efficient polymerization reaction, increases polymer product yield, reduces equipment failure rate, reduces the frequency of downtime maintenance, and improves the efficiency of production enterprises.

[0033] In addition, while the air-sealed feeding valve of the present invention prevents the gas phase components in the downstream degassing chamber / dryer from rising upwards, the purging air blown into the rotary feeding valves A and B can also act as a flow aid, fluidizing the powder so that its transfer between the two rotary feeding valves is smoother and more efficient. This improves the air-locking effect of the feeding system of the present invention and the continuity, stability and reliability of powder transfer, thereby improving the working efficiency of the feeding system.

[0034] 2. This invention combines multiple air-locking effects—material level air-locking, rotary valve air-locking, and air-sealed feeding valve air-locking—to achieve a highly efficient air-locking function in the feeding system. This effectively prevents moisture separated from the powder in the steam generator from entering the subsequent dryer and granulation process, improving the powder drying effect. It solves problems such as high heat load on the dryer and extruder, conveyor bridging, wall adhesion, self-polymerization, corrosion, and poor polymer product quality caused by high powder moisture content and excessive humidity during the transfer process. This improves the efficiency of powder conveying and the quality of polymer products, facilitates low-level control in each system, increases the operational flexibility of each system, and reduces equipment failure rate and downtime maintenance frequency. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0036] Figure 2 This is an exploded view of the overall structure of the air-sealed feed valve of the present invention.

[0037] In the diagram: 1. Expansion bag filter / steamer, 11. Feed inlet, 12. Level switch, 13. Air hammer device, 14. Backflush port, 15. Heat exchange jacket, 16. Temperature sensor, 2. Recovery pipeline, 21. Online water analyzer, 3. Collection cylinder, 31. Level gauge, 4. Degassing chamber / dryer, 5. Rotary discharge valve A, 6. Rotary discharge valve B, 7. Air-sealed feed valve, 71. Butterfly valve body, 72. Air-sealed cylinder, 73. Air distribution duct, 74. Air inlet, 75. Purge port, 76. Air inlet, 8. Exhaust device, 9. Gas collection chamber. Detailed Implementation

[0038] The structure of the present invention will be further described below with reference to the accompanying drawings and preferred embodiments.

[0039] Reference Figures 1 to 2 As shown, this invention discloses a high-efficiency air-locking feeding system, comprising an expansion bag filter / steamer 1 for gas-solid phase separation in polymer powder, a recovery pipeline 2 for discharging the separated gas phase components connected to the top of the expansion bag filter / steamer 1, and a collection cylinder 3 for leakage to subsequent processes connected to the bottom discharge end of the expansion bag filter / steamer 1. A level gauge 31 for detecting the material level inside the cylinder is installed on the cylinder wall of the collection cylinder 3, and a degassing chamber / dryer 4 for powder deactivation or drying is installed at the bottom discharge end of the collection cylinder 3. The feeding system of this invention also includes a rotary feeding valve A5, a rotary feeding valve B6, and an air-sealed feeding valve 7.

[0040] Rotary feeding valves A5 and B6 are arranged sequentially between the collecting cylinder 3 and the degassing chamber / dryer 4, and both are interlocked with the level gauge 31 on the collecting cylinder 3. In actual use, rotary feeding valves A5 and B6 are opened and closed intermittently in sequence under the control of the DCS control system, and are used to quantitatively transfer powder to the subsequent process in a time-sequenced manner under the airlock isolation state.

[0041] Specifically, the air-sealed feeding valve 7 is located between the collecting cylinder 3 and the rotary feeding valve A5. Three spiral air inlets are evenly distributed around its axis within the valve body, blowing air from one end of the collecting cylinder 3 to the other end of the rotary feeding valve A5. These spiral air inlets are connected to an external air source and are used to blow purge air (usually hot nitrogen) from one end of the collecting cylinder 3 to the other end of the rotary feeding valve A5, thereby forming an air film between the collecting cylinder 3 and the rotary feeding valve A5. This prevents gaseous components in the degassing chamber / dryer 4 from rising into the expansion bag filter / steamer 1, thus achieving the efficient air-locking function of the feeding system of this invention.

[0042] Meanwhile, the purging air blown out by the spiral air inlet of the air-sealed feed valve 7 can also act as a flow aid, making it easier to send the powder to the degassing chamber or drying chamber by the rotary feed valves A5 and B6.

[0043] By adopting the above technical solution, the present invention has the following beneficial effects.

[0044] This invention's feeding system solves the problems of poor gas lock-in and abnormal powder conveying in the production processes of polyolefins such as polypropylene (ST, Spheripol, SPG) and polyethylene (UNIPLO), specifically in the degassing, deactivation, and drying of powder. The invention replaces conventional regulating valves with rotary feeding valves A5 and B6, both interlocked with level gauge 31 to achieve cascade control. Under the control of the DCS control system, the system intermittently opens and closes sequentially through feeding control and timing control, continuously and quantitatively conveying the gas-solid phase separated powder to subsequent processes. Rotary feeding valve B6 performs powder conveying and primary gas blocking, working in conjunction with rotary feeding valve A5 and gas-sealed feeding valve 7 to achieve multiple gas lock functions. This ensures strict gas phase isolation between upstream and downstream processes, achieving efficient gas lock-in while continuously and quantitatively transferring powder, guaranteeing the continuous and stable operation of the polymerization reaction.

[0045] Meanwhile, the added air-sealed feeding valve 7 not only achieves overall control of the discharge from the collecting cylinder 3, but also uses the spiral air inlet channel in its valve body to blow air to the rotary feeding valves A5 and B, and the degassing chamber / dryer 4, so that an air film for airlock isolation is formed between the collecting cylinder 3 and the rotary feeding valve A5. This effectively prevents gaseous components in subsequent processes such as rotary feeding valves A5 and B6 from entering the expansion bag filter / steamer 1, further improving the airlock isolation effect of the feeding system of this invention. It completely solves the problems caused by wet nitrogen interference, such as reduced activity of recycled catalyst, killing of polymerization reaction, corrosion of equipment pipelines, burning of filter bags, compressor unit failure and filter bag blockage. It is conducive to the continuous, stable and efficient polymerization reaction, improving polymer product yield, reducing equipment failure rate, reducing the frequency of downtime maintenance, and improving the efficiency of production enterprises.

[0046] Furthermore, while the air-sealed feeding valve 7 of this invention prevents the gas phase components in the downstream degassing chamber / dryer 4 from rising upwards, the purging air blown into the rotary feeding valves A5 and B can also act as a flow aid, fluidizing the powder so that its transfer between the two rotary feeding valves is smoother and more efficient. This improves the air-locking effect of the feeding system of this invention and the continuity, stability and reliability of powder transfer, thereby improving the working efficiency of the feeding system.

[0047] Furthermore, this invention combines multiple air-locking effects—material level airlock, rotary valve airlock, and air-sealed feeding valve 7—to achieve a highly efficient air-locking function in the feeding system. This effectively prevents moisture separated from the powder in the steamer from entering the subsequent dryer and granulation process. The optimization of the rotary feeding valve at the bottom discharge end of the steamer, replacing the regulating valve, improves the powder drying effect, significantly reduces water vapor entrainment in the dryer, enhances the fluidization effect of the dryer, shortens the drying residence time, and ensures smooth downstream powder conveying. It solves problems such as high heat load on the dryer and extruder, conveyor bridging, wall adhesion, self-polymerization, corrosion, freezing blockage, and poor polymer product quality caused by high powder moisture content and excessive humidity during the transfer process. This improves the efficiency of powder conveying and the quality of polymer products, facilitates low material level control in each system, increases the operational flexibility of each system, reduces equipment failure rate and downtime maintenance frequency, and ensures stable and smooth production.

[0048] Preferred, refer to Figure 1 As shown, the rotary discharge valves A5 and B6 of the feeding system of the present invention are connected in an up-down relative manner. This connection method reduces the obstruction of the pipeline between the two valves to the transfer of powder. Under the premise of airlock isolation, the combined effect of the air-assisted flow of the air-sealed feed valve 7 and gravity promotes the efficiency of powder transfer, thereby reducing the failure rate of the feeding system of the present invention during the powder transfer process and improving the working efficiency.

[0049] Furthermore, refer to Figure 2 As shown, the air-sealed feeding valve 7 of the present invention includes a butterfly valve body 71, an air-sealing cylinder 72, and an air distribution pipe 73.

[0050] Specifically, the butterfly valve body 71 is an electrically controlled valve, and its rear end is connected to the rotary feed valve A5. It is opened and closed under the control of the DCS control system and is used to control the discharge of the material collection cylinder 3.

[0051] Specifically, the air seal cylinder 72 is a flat cylindrical structure with openings at both ends. Its front end is connected to the discharge end of the collecting cylinder 3, and its rear end is connected to the front end of the butterfly valve body 71. The spiral air inlet is located on the cylinder wall of the air seal cylinder 72, and the air inlets 74 (not shown in the figure) of the spiral air inlet are evenly distributed on the front end of the outer wall of the air seal cylinder 72. The purge ports 75 of the spiral air inlet are evenly distributed on the rear end of the inner wall of the air seal cylinder 72. The main body of the spiral air inlet is located inside the inner wall of the air seal cylinder 72.

[0052] Specifically, the air distribution duct 73 is a hollow annular structure, which is fixedly connected to the front end of the outer wall of the air seal cylinder 72 through the air inlet 74, and has three air inlets 76 evenly distributed on it for connecting to an external air source.

[0053] Preferably, the purge port 75 of the spiral air intake is arranged along the tangential direction of the inner wall of the air seal cylinder 72 to facilitate the purge air entering in a cyclone form.

[0054] Preferably, the three air inlets 76 and the three air inlets 74 are arranged in a staggered manner to facilitate uniform air distribution in the air distribution duct 73.

[0055] The air-sealed feeding valve 7 of this invention is based on a butterfly valve body 71, to which an air-sealed cylinder 72 is detachably connected. It has a simple structure, is easy to disassemble and use, and facilitates subsequent maintenance. The butterfly valve allows for overall control of the material discharge from the collecting cylinder 3, and has a low failure rate. The spiral air inlet is connected to an external air source through the air inlet 76 of the air distribution pipe 73. The purge ports 75 are evenly distributed at the rear end of the inner wall of the air-sealed cylinder 72 and are tangentially positioned to the inner wall, causing the blown-in gas to purge and deliver air to the rear end in a cyclone manner. This improves the air-film locking effect, effectively prevents powder from sticking to the wall, and promotes powder transfer.

[0056] Furthermore, refer to Figure 1 As shown, the feeding system of the present invention also includes a feed inlet 11, a material level switch 12, and an air hammer device 13.

[0057] Preferably, three feed inlets 11 are provided, which are evenly arranged along the tangential direction of the upper inner wall of the cylindrical expansion bag filter / steamer 1. The polymer powder generated in the reactor enters the expansion bag filter / steamer 1 in an intermittent feeding manner under the control of the DCS control system driven by pressure difference, thereby separating the gas phase components (mainly catalyst and unreacted polymer monomers) in the powder and realizing the separation of the gas and solid phases of the powder.

[0058] Preferably, three level switches 12 are provided, evenly distributed on the outer wall of the bottom of the funnel-shaped cone of the expansion bag filter / steamer 1, to detect the level of powder in the bottom of the cone of the expansion bag filter / steamer 1 and report it to the DCS control system.

[0059] Preferably, three air hammer devices 13 are provided, evenly distributed on the outer wall of the bottom of the funnel-shaped cone of the expansion bag filter / steamer 1, and are interlocked with the material level switch 12 for control. They are used to knock on the cylinder wall under the control of the DCS control system when the material level is abnormal, so as to prevent powder from sticking to the wall or clogging the discharge end.

[0060] The air inlet 74 of the expansion bag filter / steamer 1 of this invention is tangentially aligned with the upper inner wall. Under the control of the DCS control system, polymer powder enters tangentially via differential pressure and intermittent feeding, resulting in more uniform powder distribution, reduced vibration during material transport, and improved efficiency of gas-solid phase separation. Simultaneously, the DCS control system enables fully automatic feeding control, ensuring the powder level within the expansion bag filter / steamer 1. This guarantees the material sealing effect of the feeding system of this invention while improving the stability of the powder level.

[0061] Meanwhile, the material level switch 12 and the air hammer device 13 installed on the outer wall of the cone bottom of the expansion bag filter / steamer 1 of the present invention are electrically connected to the DCS control system in an interlocking manner. When the material level alarm occurs, the interlock triggers the solenoid valve of the air hammer device 13, thereby starting the air hammer device 13 to knock on the cylinder wall, thereby effectively preventing the powder from sticking to the wall and hanging, avoiding the occurrence of abnormal situations such as powder self-aggregation and clumping that affect the transfer to its downstream processes, and ensuring that there is "no material" at the bottom of the cone.

[0062] Furthermore, refer to Figure 1 As shown, the feeding system of the present invention also includes a backflushing device, which includes backflushing ports 14 evenly distributed on the upper inner wall of the cylindrical expansion bag filter / steamer 1. The backflushing device is connected to an external air source to blow clean air into the recovery pipeline 2 at the top of the expansion bag filter / steamer 1 through the backflushing ports 14.

[0063] Furthermore, the backflush port 14 is positioned lower than the feed inlet 11. In actual use, the backflush device can operate synchronously with the feed, thereby using the clean air blown out by the backflush port 14 to evenly distribute the powder entering through the feed inlet 11, thereby fluidizing the powder and facilitating the separation of gaseous components in the powder, thus improving the effect of gas-solid phase separation of the powder.

[0064] When applied to expandable bag filters, the backflushing device can also be operated after feeding to increase the blowing pressure and use the clean air blown out of the backflushing port 14 to sweep and clean the filter bag, preventing fine powder and other particles from clogging the filter bag and affecting the normal operation of the equipment.

[0065] Preferably, the backflush port 14 and the feed port 11 are staggered to facilitate the uniform backflush of the powder by the clean air.

[0066] It is important to note that the type of purified gas blown out from backflush port 14 needs to be selected according to whether it is used in an expansion bag filter or a steam generator. For example, when used in an expansion bag filter, the purified gas introduced into backflush port 14 can be one of the gas-phase catalysts, while when used in a steam generator, the purified gas blown out from backflush port 14 can be hot nitrogen.

[0067] This invention utilizes the backflush port 14 of the backflush device to blow clean gas back into the expansion bag filter / evaporator 1, which disperses the incoming powder and achieves the effect of fluidizing the powder. Simultaneously, the clean gas blown back to the recovery pipeline 2 can clean the filter bags of the expansion bag filter, preventing clogging and ensuring effective gas-solid phase separation. Furthermore, the clean gas blown out of the backflush port 14 can also remove moisture separated from the powder in the evaporator, thereby promoting powder drying and reducing the powder's moisture content.

[0068] Furthermore, refer to Figure 1As shown, the feeding system of the present invention also includes an online water analyzer 21, which is installed on the recovery pipeline 2 at the top of the expansion bag filter / steamer 1, and is used to detect the humidity of the discharged gas phase components and report it to the DCS control system.

[0069] This invention utilizes an online water analyzer 21 to detect the humidity of the gas phase components in the recovery pipeline 2 to verify the airlock effect of the feeding system. It can monitor and guide the operator to control and adjust the material level at any time, ensuring the airlock effect while also ensuring the stable operation of the tail gas recovery compressor, extending the service life of the compressor inter-stage filter, and extending the service life of key components such as compressor valves.

[0070] Furthermore, refer to Figure 1 As shown, the system of the present invention also includes a heat tracing device and a temperature sensor 16. The heat tracing device includes a heat exchange jacket 15 disposed on the outer wall of the bottom of the funnel-shaped cone of the expansion bag filter / steamer 1. The heat exchange jacket 15 is a cavity structure and is connected to an external heat source to circulate a gaseous or liquid heat exchange medium inside its cavity to promote the separation of gaseous components in the powder or to promote the drying of the powder.

[0071] Three temperature sensors 16 are preferably provided, distributed at different heights on the outer wall of the bottom of the funnel-shaped cone of the expansion bag filter / steamer 1, to detect the temperature of the powder and report it to the DCS control system.

[0072] The heat tracing device of this invention utilizes the circulating heat exchange medium in the heat exchange jacket 15 to provide additional heat to the powder distributed within the expansion bag filter / steamer 1, thereby promoting the separation of the gas-solid phase in the powder or accelerating the drying of the powder. This improves the discharge efficiency of the feeding system of this invention, reduces the moisture content of the dried powder, and improves the quality of the polymer product. Furthermore, the heat tracing device of this invention uses temperature sensors 16 at different locations to monitor the temperature of the powder within the expansion bag filter / steamer 1, resulting in more accurate monitoring results. This allows the DCS control system to adapt the temperature and circulation time of the heat exchange medium according to the actual powder temperature, ensuring the degree of dryness of the powder entering the collection cylinder 3.

[0073] Furthermore, refer to Figure 1 As shown, the exhaust device 8 of the rotary discharge valve A5 and rotary discharge valve B6 of the feeding system of the present invention is connected to the upper cylindrical part of the expansion bag filter / steamer 1 through the air collection chamber 9.

[0074] The exhaust device 8 of the rotary discharge valves A5 and B6 of the present invention is connected to the upper cylindrical part of the expansion bag filter / steamer 1 through the gas collection chamber 9. In actual use, it exhausts the gas phase components of the powder in the rotary valve, which can prevent the conveying capacity from being affected by the wear of the rotary valve rotor and the decrease in the filling rate, reduce the failure rate of the rotary valve, improve its service life, and ensure the stability of the powder transfer of the feeding system of the present invention.

[0075] The above embodiments are merely for illustrating one specific implementation of the present invention and are not intended to limit the scope of the invention. Those skilled in the art can deduce and summarize other adjustments or modifications to the expansion bag filter / steamer 1, recovery pipeline 2, collection cylinder 3, level gauge 31, degassing chamber / dryer 4, rotary discharge valve A5, rotary discharge valve B6, air-sealed feed valve 7, feed inlet 11, level switch 12, air hammer device 13, backflushing device, online water analyzer 21, heating device, temperature sensor 16, etc., based on the present invention, which will not be listed here. Any modifications, substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A high-efficiency, air-locking feeding system, comprising an expansion bag filter / steamer for gas-solid phase separation in polymer powder, a recovery pipeline connected to its top for discharging gaseous components, and a collection cylinder connected to its bottom discharge end for leakage to subsequent processes, wherein a level gauge is provided on the cylinder wall of the collection cylinder, and a degassing chamber / dryer is provided at the bottom discharge end for powder deactivation or drying, characterized in that, The system also includes: Rotary discharge valve A and rotary discharge valve B are arranged sequentially between the collecting cylinder and the degassing chamber / dryer. They are interlocked with the level gauge and are opened and closed intermittently in sequence under the control of the DCS control system. They are used to quantitatively transfer powder to the next process in sequence under airlock isolation. An air-sealed feeding valve is located between the collecting cylinder and the rotary feeding valve A. At least two spiral air inlets are evenly distributed within the valve body, allowing air to be blown from one end of the collecting cylinder to the other end of the rotary feeding valve A. This serves to connect to an external air source to form an air film between the collecting cylinder and the rotary feeding valve A, or to pneumatically convey powder from the rotary feeding valves A and B to a degassing chamber or drying chamber. The rotary feeding valves A and B are connected in a vertically opposite manner. The butterfly valve body is connected to the rotary feed valve A at its rear end. It is opened and closed under the control of the DCS control system and is used to control the discharge of the material collection cylinder. The air seal cylinder is a flat cylindrical structure with openings at both ends. Its front end is connected to the discharge end of the collecting cylinder, and its rear end is connected to the front end of the butterfly valve body. The air inlets of the spiral air inlet are evenly distributed at the front end of its outer wall, and the purge ports of the spiral air inlet are evenly distributed at the rear end of its inner wall. The air distribution duct is a hollow ring structure, which is fixedly connected to the front end of the outer wall of the air seal cylinder through the air inlet, and has at least one air inlet for connecting to an external air source.

2. The high-efficiency airlock feeding system according to claim 1, characterized in that, The purge port is arranged tangentially to the inner wall of the gas seal cylinder.

3. The high-efficiency airlock feeding system according to claim 1, characterized in that, The system also includes: At least three feed inlets are evenly arranged along the tangential direction of the upper inner wall of the expansion bag filter / steamer cylinder for intermittent entry of polymer powder generated by the reactor for gas-solid phase separation. At least three level switches are evenly distributed on the outer wall of the bottom of the funnel-shaped cone of the expansion bag filter / steamer, used to detect the level of powder in the bottom of the cone and report it to the DCS control system. At least three air hammer devices are evenly distributed on the outer wall of the bottom of the funnel-shaped cone of the expansion bag filter / steamer. They are interlocked with the material level switch and are used to knock on the cylinder wall under the control of the DCS control system when the material level is abnormal, so as to prevent powder from sticking to the wall or clogging the discharge end.

4. The high-efficiency airlock feeding system according to claim 1, characterized in that, The system also includes: The backflush device includes backflush ports evenly distributed on the inner wall of the expansion bag filter / steamer, which are connected to an external air source to blow clean air to the top of the expansion bag filter / steamer.

5. The high-efficiency airlock feeding system according to claim 1, characterized in that, The system also includes: An online water analyzer, located on the recovery pipeline at the top of the expansion bag filter / evaporator, is used to detect the humidity of the discharged gas phase components and report it to the DCS control system.

6. The high-efficiency airlock feeding system according to claim 1, characterized in that, The system also includes: The heat tracing device includes a heat exchange jacket disposed on the outer wall of the bottom of the funnel-shaped cone of the expansion bag filter / steamer, which is connected to an external heat source to circulate a gaseous or liquid heat exchange medium to promote the separation of gaseous components in the powder or to promote the drying of the powder. Several temperature sensors are evenly distributed on the outer wall of the bottom of the funnel-shaped cone of the expansion bag filter / steamer to detect the temperature of the powder and report it to the DCS control system.

7. The high-efficiency airlock feeding system according to claim 6, characterized in that, The temperature sensors are located at different heights on the outer wall of the funnel-shaped cone bottom of the expansion bag filter / steamer, and are used to detect the temperature at different material levels of the powder.

8. The high-efficiency airlock feeding system according to claim 1, characterized in that, The exhaust devices of the rotary feed valve A and rotary feed valve B are connected to the upper cylindrical part of the expansion bag filter / steamer through the gas collection chamber.

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