Polyolefin device devolatilization system
By designing a combined system of heating, devolatilization and cooling components in a polyolefin device, the continuous devolatilization operation of polyolefin particles is achieved, which solves the problem of difficulty in reducing VOC content in the prior art, and improves product quality and production efficiency.
Patent Information
- Application Number
- CN202420932810.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-30
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2034-04-30
AI Technical Summary
The existing polyolefin devices have poor results in reducing the content of volatile organic compounds (VOCs). Especially for large devices, the existing drying and devolatilization process has uneven effects and is difficult to meet the requirements of international standards ≤80ppm.
A polyolefin device devolatilization system is designed, including material heating assembly, devolatilization assembly and material cooling assembly. Through the combination of heater, degassing silo, fan and cooler, the continuous devolatilization of polyolefin particles is achieved. Operation, use a rotary valve to control the heating, devolatilization and cooling process of the material to ensure that the required devolatilization temperature and time are achieved and the VOC content is reduced.
It effectively reduces the VOC content in polyolefin particles, improves product quality, saves energy consumption and space, improves production efficiency, and reduces public engineering consumption and costs.
Smart Images
Figure CN222286389U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a devolatilization system of a polyolefin device. Background Art
[0002] Polypropylene (PP) and polyethylene (PE) are the two most widely produced and used polymer resins in polyolefins. The most advanced production processes in the world are mainly bulk-gas phase combined process and gas phase process. However, no matter how advanced the production process is, polyolefin products inevitably have residual volatile matter (also known as VOC). Reducing the VOC content of polyolefin products used in the automotive, home appliance, food and pharmaceutical fields has become a top priority for manufacturers.
[0003] The main methods of devolatilization (reducing VOC content) in large-scale polyolefin plants are flash devolatilization, melt devolatilization and dry devolatilization in the late stage of polymerization. Although the first two methods can reduce the VOC content to 100ppm, they still cannot meet the international standard of ≤80ppm. It is necessary to continue to use dry devolatilization to deeply remove the VOC contained in polyolefins.
[0004] There are two forms of dry devolatilization at present. One is to devolatilize polyolefin powder, such as the degassing tank in the JPP (gas phase polymerization) process, and the other is to devolatilize polyolefin particles. However, the treatment effects of these two processes are uneven, especially for large-scale polyolefin plants. The effect is not good and the product quality is not high. Therefore, a polyolefin plant devolatilization system is proposed to solve the above problems. Utility Model Content
[0005] The utility model aims to overcome the existing defects and provide a polyolefin device devolatilization system to improve product quality.
[0006] The technical solution to achieve the above-mentioned purpose is: a devolatilization system for a polyolefin device, comprising a material heating component, a devolatilization component and a material cooling component; the upper end of the devolatilization component is connected to the material heating component, and the lower end is connected to the material cooling component; the material heating component is used to heat the material to reach the required devolatilization temperature; the devolatilization component is used to devolatilize the heated material; and the material cooling component is used to cool the devolatilized material.
[0007] Preferably, the material heating assembly includes a material heater and a material heater outlet rotary valve;
[0008] The lower end of the material heater is connected to the material heater outlet rotary valve, and the lower end of the material heater outlet rotary valve is connected to the devolatilization component.
[0009] Preferably, the devolatilization assembly comprises a degassing silo, a degassing fan, a heat exchanger and a degassing silo outlet rotary valve;
[0010] The upper end of the degassing silo is connected to the material heater outlet rotary valve, the lower end is connected to the degassing silo outlet rotary valve, and the lower end of the degassing silo outlet rotary valve is connected to the material cooling component;
[0011] The degassing fan is connected to the heat exchanger, and the other end of the heat exchanger is connected to the degassing silo.
[0012] Preferably, the material cooling assembly includes a material cooler and a material cooler outlet rotary valve;
[0013] The upper end of the material cooler is connected to the degassing silo outlet rotary valve, and the lower end of the material cooler is connected to the material cooler outlet rotary valve.
[0014] Preferably, the upper end of the material heater is connected to the first rotary valve.
[0015] Preferably, the lower end of the degassing silo is conical.
[0016] The beneficial effects of the utility model are as follows: the devolatilization system of the polyolefin device is arranged so that the polyolefin particles are sent into the material heater through the pneumatic conveying system, and under the action of the material heater, the temperature of the polyolefin particles finally reaches the required devolatilization temperature, and then the rotary valve of the heater discharge port is started to discharge the materials into the degassing silo below; after the materials enter the degassing silo, the degassing fan is started to input hot air reaching the devolatilization temperature into the degassing silo, and the continuous devolatilization operation of the materials is started. When the required devolatilization time is reached, the rotary valve at the outlet of the degassing silo is started to discharge the materials that have completed the devolatilization process into the downstream material cooler; after the materials are cooled to a certain temperature, they are discharged into the downstream process through the rotary valve, which can further reduce the VOC content in the polyolefin pellets, thereby improving the product quality. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the devolatilization system of the polyolefin device of the utility model.
[0018] In the figure: 1. first rotary valve; 2. material heater; 3. material heater outlet rotary valve; 4. degassing silo; 5. degassing fan; 6. heat exchanger; 7. degassing silo outlet rotary valve; 8. material cooler; 9. material cooler outlet rotary valve. DETAILED DESCRIPTION
[0019] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.
[0020] The utility model will be further described below in conjunction with the accompanying drawings.
[0021] like Figure 1 As shown, a devolatilization system of a polyolefin device includes a material heating component, a devolatilization component and a material cooling component; the upper end of the devolatilization component is connected to the material heating component, and the lower end is connected to the material cooling component; the material heating component is used to heat the material to reach the required devolatilization temperature; the devolatilization component is used to devolatilize the heated material; the material cooling component is used to cool the devolatilized material.
[0022] Specifically, the material heating component, the devolatilization component and the material cooling component are arranged vertically from top to bottom, which effectively saves land area and improves space utilization.
[0023] Specifically, the material heating component includes a material heater 2 and a material heater outlet rotary valve 3; the lower end of the material heater 2 is connected to the material heater outlet rotary valve 3, and the lower end of the material heater outlet rotary valve 3 is connected to the devolatilization component. The upper end of the material heater 2 is connected to the first rotary valve 1.
[0024] Specifically, the material heater 2 adopts a vertical gravity flow mode, and the material moves slowly through the gap between the heat transfer plates to ensure sufficient heat transfer time. The cooling water circulates in the heat transfer plates, and the countercurrent design improves the heat transfer efficiency.
[0025] Specifically, the devolatilization component includes a degassing silo 4, a degassing fan 5, a heat exchanger 6 and a degassing silo outlet rotary valve 7; the upper end of the degassing silo 4 is connected to the material heater outlet rotary valve 3, and the lower end is connected to the degassing silo outlet rotary valve 7, and the lower end of the degassing silo outlet rotary valve 7 is connected to the material cooling component; the degassing fan 5 is connected to the heat exchanger 6, and the other end of the heat exchanger 6 is connected to the degassing silo 4. The lower end of the degassing silo 4 is conical.
[0026] Specifically, the material flow form in the degassing silo 4 adopts the overall flow, and the silo is designed as a cone-in-cone type to ensure that the gas flow rate on each cross section of the silo is the same, and the gas is evenly distributed in the silo to avoid dead corners and non-flowing areas. In addition, the cone angle of the silo must be below 60° to avoid the formation of funnel flow.
[0027] Specifically, the material cooling assembly includes a material cooler 8 and a material cooler outlet rotary valve 9; the upper end of the material cooler 8 is connected to the degassing silo outlet rotary valve 7, and the lower end of the material cooler 8 is connected to the material cooler outlet rotary valve 9.
[0028] Specifically, the material falls into the material heater 2 by gravity through the rotary valve 1. The material heater 2 uses low-pressure steam as a heat source, so that the material is heated to the devolatilization temperature, and then the material is discharged to the degassing bin 4 through the material heater outlet rotary valve 3 for degassing. The material flow form in the degassing bin adopts an integral flow, and the bin is designed as a cone-in-cone type to ensure that the gas flow rate on each cross section of the bin is the same, and the gas is evenly distributed in the bin to avoid dead corners and non-flowing areas. In view of this, the cone angle of the bin must also be below 60° to avoid the formation of funnel flow. After the material enters the degassing bin, the degassing fan 5 is started to input hot air reaching the devolatilization temperature into the degassing bin to start continuous devolatilization of the material; the heat exchanger 6 is used to increase the degassing temperature, so that the temperature reaches the devolatilization temperature, and removes VOC (volatile organic compounds) in the material. When the required devolatilization time is reached, the rotary valve 7 at the outlet of the degassing bin is started to discharge the material that has completed the devolatilization process into the downstream material cooler 8; after the material is cooled to a certain temperature, it is discharged into the downstream process through the rotary valve 9. At this point, the devolatilization process of the material is completely completed.
[0029] The main equipment of the devolatilization system of the polyolefin device, namely the material heater 2, the degassing silo 4 and the material cooler 8, are arranged in a line from top to bottom, and the flow of materials is achieved by gravity. There is no need to use other methods to move or transport materials, which saves energy and avoids wear and tear of materials during transportation.
[0030] Specifically, the material flow form in the degassing silo 4 adopts the overall flow, and the silo is designed as a cone-in-cone type to ensure that the gas flow rate on each cross section of the silo is the same, and the gas is evenly distributed in the silo to avoid dead corners and non-flowing areas. In view of this, the cone angle of the silo must be less than 60° to avoid the formation of funnel flow.
[0031] Specifically, due to the high specific heat capacity of polypropylene PP and polyethylene PE materials, traditional heating methods are not only inefficient but also consume a lot of energy. The material heater uses hot water to exchange heat with polyolefins, so that the materials are quickly preheated to the required temperature, greatly reducing energy consumption. The material cooler 8 achieves efficient cooling through circulating water. This innovative method not only significantly reduces the consumption of utilities such as water, electricity, and gas, improves production efficiency, but also reduces costs for enterprises and improves economic benefits.
[0032] Specifically, the material heater 2 and the material cooler 8 adopt a vertical gravity flow mode, and the material moves slowly through the gap between the heat transfer plates to ensure sufficient heat transfer time. The heat exchange medium circulates in the heat transfer plates, and the countercurrent design improves the heat transfer efficiency. The best heat transfer state can be achieved when the material is fully loaded.
[0033] In another embodiment, a PLC (Programmable Logic Controller) controller may be included to control the operation of each device and the opening and closing of each valve through the PLC, thereby achieving full automation and seamless connection with upstream and downstream units. The PLC controller is an existing device, and the model may be FX3U-16MT.
[0034] The above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model is described in detail with reference to the above embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the above embodiments, or replace some or all of the technical features therein with equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.
Claims
1. A devolatilization system for a polyolefin device, characterized in that: It includes a material heating component, a devolatilization component and a material cooling component; the upper end of the devolatilization component is connected to the material heating component, and the lower end is connected to the material cooling component; the material heating component is used to heat the material to reach the required devolatilization temperature; the devolatilization component is used to devolatilize the heated material; the material cooling component is used to cool the devolatilized material.
2. The devolatilization system of a polyolefin device according to claim 1, characterized in that: The material heating component comprises a material heater (2) and a material heater outlet rotary valve (3); The lower end of the material heater (2) is connected to the material heater outlet rotary valve (3), and the lower end of the material heater outlet rotary valve (3) is connected to the devolatilization component.
3. The devolatilization system of a polyolefin device according to claim 2, characterized in that: The devolatilization component comprises a degassing silo (4), a degassing fan (5), a heat exchanger (6) and a degassing silo outlet rotary valve (7); The upper end of the degassing silo (4) is connected to the material heater outlet rotary valve (3), and the lower end is connected to the degassing silo outlet rotary valve (7), and the lower end of the degassing silo outlet rotary valve (7) is connected to the material cooling component; The degassing fan (5) is connected to the heat exchanger (6), and the other end of the heat exchanger (6) is connected to the degassing silo (4).
4. The devolatilization system of a polyolefin device according to claim 3, characterized in that: The material cooling assembly comprises a material cooler (8) and a material cooler outlet rotary valve (9); The upper end of the material cooler (8) is connected to the degassing silo outlet rotary valve (7), and the lower end of the material cooler (8) is connected to the material cooler outlet rotary valve (9).
5. The devolatilization system of a polyolefin device according to claim 2, characterized in that: The upper end of the material heater (2) is connected to the first rotary valve (1).
6. The devolatilization system of a polyolefin device according to claim 3, characterized in that: The lower end of the degassing silo (4) is conical.