A low-carbon resin granulation system and method

Abstract

The application discloses a low-carbon resin granulation system, which comprises a resin granulation device and a molten resin tank; the upper end of the molten resin tank is provided with a feeding port and a circulating feeding port, the lower end of the molten resin tank is provided with a discharging port, the discharging port is connected with a pre-filter, a circulating pipeline is connected between the outlet of the pre-filter and the circulating feeding port, and a conveying pipeline is connected between the outlet of the pre-filter and the resin granulation device; a first filter is arranged on the circulating pipeline, a second filter and a third filter are sequentially arranged on the conveying pipeline, and the filtering precision of the pre-filter, the first filter, the second filter and the third filter is sequentially increased. Therefore, the removal efficiency of black points in the molten resin can be improved, the number of black points in the molten resin can be effectively reduced, the quality of resin products can be improved, meanwhile, the amount of chemical additives such as antioxidants can be reduced, and the consumption of materials and production cost can be reduced. The application further discloses a low-carbon resin granulation method.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical production technology, specifically relating to a low-carbon resin granulation system and method. Background Technology

[0002] C5 petroleum resin is a thermoplastic resin produced from the C5 fraction, a byproduct of petroleum cracking, through a series of pretreatment, polymerization, and distillation processes. Its main chain segments are aliphatic hydrocarbons, and its molecular weight is typically between 1000 and 2500. C5 petroleum resin has advantages such as low price, good miscibility, low softening point, water resistance, ethanol resistance, and chemical corrosion resistance, and can be widely used in various industries and fields such as rubber, adhesives, coatings, papermaking, and inks. With the continuous expansion of domestic production capacity and the gradual saturation of the market, in order to ensure that resin products maintain sufficient competitiveness in the industry, the production process of resin products not only needs to meet the strategic policy of energy conservation and emission reduction, but also needs to continuously promote the technological upgrading of the production system.

[0003] C5 petroleum resin, as an intermediate product, typically requires granulation in a granulation system before further processing into the final product. The C5 petroleum resin entering the granulation system is usually in a molten state. During production and transportation, carbonization inevitably occurs in the molten resin, resulting in black spots (carbide particles). Excessive black spots can severely affect the quality of the final product.

[0004] In existing technologies, to reduce the number of black spots in molten resin, the molten resin entering the granulation system is usually mixed with antioxidants and other additives to reduce carbonization. Before entering the granulation device, it is filtered to remove some large-diameter black spots. While these methods can reduce the number of black spots in the molten resin, the removal efficiency is not high, and the removal effect is still unsatisfactory. Furthermore, the need to use large amounts of antioxidants and other additives to inhibit carbonization significantly increases material consumption and production costs, hindering energy conservation and emission reduction. Summary of the Invention

[0005] To address the shortcomings of the prior art, this invention provides a low-carbon resin granulation system. By combining circulating filtration with multi-stage filtration, the system improves the removal efficiency of black spots in molten resin, effectively reducing the number of black spots. The efficient physical sieving method of multi-stage filters removes black spots, effectively reducing the amount of antioxidants and other chemical additives used, thus reducing consumables and production costs. This invention also provides a low-carbon resin granulation method.

[0006] The technical effects to be achieved by this invention are realized through the following technical aspects:

[0007] In a first aspect, the present invention provides a low-carbon resin granulation system, comprising a resin granulation apparatus and a molten resin tank for supplying molten resin to the resin granulation apparatus.

[0008] The upper end of the molten resin tank is provided with a feed inlet and a circulating feed inlet, and the lower end of the molten resin tank is provided with a discharge outlet. The discharge outlet is connected to a pre-filter, and a circulation pipeline is connected between the outlet of the pre-filter and the circulating feed inlet. A conveying pipeline is connected between the outlet of the pre-filter and the resin granulation device.

[0009] A first filter is installed on the circulation pipeline, and a second filter and a third filter are installed sequentially on the delivery pipeline. The filtration accuracy of the pre-filter, the first filter, the second filter and the third filter increases sequentially.

[0010] As a further description of the technical solution of the present invention, the pre-filter is provided with a 300-400 mesh filter screen, the first filter is provided with a 500-600 mesh filter screen, the second filter is provided with an 800-1000 mesh filter screen, and the third filter is provided with a 1200-1400 mesh filter screen.

[0011] As a further description of the technical solution of the present invention, the pre-filter is provided with a 400-mesh filter screen, the first filter is provided with a 600-mesh filter screen, the second filter is provided with an 800-mesh filter screen, and the third filter is provided with a 1340-mesh filter screen.

[0012] As a further description of the technical solution of the present invention, a heat exchanger is also provided on the conveying pipeline. The heat exchanger is located upstream of the second filter. The hot side of the heat exchanger is used for the flow of molten resin, and the cold side of the heat exchanger is used for the flow of cooling water.

[0013] As a further description of the technical solution of the present invention, the low-carbon resin granulation system further includes a resin circulation pump and a resin delivery pump. The resin circulation pump is disposed on the circulation pipeline and located upstream of the first filter, and the resin delivery pump is disposed on the delivery pipeline and located upstream of the heat exchanger.

[0014] As a further description of the technical solution of the present invention, the low-carbon resin granulation system further includes a backup filter, which is connected in parallel with the third filter, and the filtration accuracy of the backup filter is the same as that of the third filter.

[0015] As a further description of the technical solution of the present invention, the low-carbon resin granulation system further includes a vacuum stripping tower and an antioxidant tank. The bottom of the vacuum stripping tower is equipped with a resin extraction pump, and the outlet of the antioxidant tank is equipped with an antioxidant output pump. Both the resin extraction pump and the antioxidant output pump are connected to the feed inlet.

[0016] As a further description of the technical solution of the present invention, the low-carbon resin granulation system further includes a static mixer, which is provided with a first inlet, a second inlet and a mixture outlet. The resin discharge pump is connected to the first inlet, the antioxidant output pump is connected to the second inlet, and the mixture outlet is connected to the feed port.

[0017] As a further description of the technical solution of the present invention, the static mixer is provided with a plurality of SX-type mixing units, which are located between the first inlet and the mixture outlet.

[0018] Secondly, the present invention provides a method for granulating low-carbon resin, comprising the following steps:

[0019] The molten resin and antioxidant are mixed and then fed into a molten resin tank for heating and stirring.

[0020] The molten resin output from the molten resin tank first enters the pre-filter for primary filtration, then enters the first filter for secondary filtration, and is then circulated back to the molten resin tank.

[0021] The molten resin output from the molten resin tank re-enters the pre-filter for supplementary filtration, then passes through a heat exchanger for cooling, and then enters the second filter for tertiary filtration, and then enters the third filter for quaternary filtration. The molten resin that has completed quaternary filtration is directly transported to the resin granulation unit for granulation.

[0022] The filtration accuracy of the pre-filter, the first filter, the second filter, and the third filter increases sequentially.

[0023] In summary, the present invention has at least the following advantages:

[0024] The low-carbon resin granulation system provided by this invention features both a circulation pipeline and a conveying pipeline outside the molten resin tank. Molten resin output from the molten resin tank is first circulated back into the molten resin tank via the circulation pipeline, and then enters the resin granulation device for granulation via the conveying pipeline. Molten resin re-entering the molten resin tank via the circulation pipeline undergoes primary filtration by the pre-filter and secondary filtration by the first filter, removing large and medium-sized black spots. Furthermore, the circulating conveying loop formed between the molten resin tank and the circulation pipeline reduces the residence time of the molten resin in the molten resin tank, further reducing carbonization and inhibiting the formation of new black spots. Molten resin entering the conveying pipeline from the molten resin tank can re-enter the pre-filter for supplementary filtration, followed by tertiary filtration by the second filter and quaternary filtration by the third filter, removing small and micro-sized black spots. The low-carbon resin granulation system of the present invention significantly improves the removal efficiency of black spots in molten resin by combining circulating filtration and multi-stage filtration, effectively reducing the number of black spots in molten resin, thereby effectively improving the quality of resin end products. At the same time, the removal of black spots in molten resin by the efficient physical sieving method of multi-stage filters can significantly reduce the amount of chemical additives such as antioxidants, effectively reducing consumables and production costs.

[0025] The low-carbon resin granulation method provided by this invention efficiently removes black spots from molten resin through a combination of circulating filtration and multi-stage filtration. Simultaneously, circulating filtration reduces the residence time of the molten resin in the molten resin tank, minimizing carbonization and thus inhibiting the formation of new black spots. Furthermore, the molten resin is cooled before undergoing third- and fourth-stage filtration, further reducing its temperature and suppressing carbonization. This prevents the formation of new black spots during third- and fourth-stage filtration, ensuring efficient black spot removal. This low-carbon resin granulation method reduces the number of black spots in molten resin primarily through physical elimination and secondarily through chemical inhibition, significantly reducing the amount of antioxidants used, lowering consumables and costs, and better aligning with energy-saving and consumption-reducing production policies. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the low-carbon resin granulation system of Embodiment 1 of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of the low-carbon resin granulation system of Embodiment 2 of the present invention;

[0028] Figure 3 This is a schematic diagram of the static mixer in Embodiment 2 of the present invention.

[0029] Marked in the image:

[0030] 1. Resin granulation equipment;

[0031] 2. Molten resin tank; 21. Inlet; 22. Circulating inlet; 23. Outlet;

[0032] 3. Pre-filter; 4. First filter; 5. Second filter; 6. Third filter; 7. Heat exchanger; 8. Resin circulation pump; 9. Resin transfer pump; 10. Backup filter; 11. Vacuum stripping tower; 12. Antioxidant tank; 13. Resin collection pump; 14. Antioxidant output pump;

[0033] 15. Static mixer; 151. First inlet; 152. Second inlet; 153. Mixture outlet; 154. SX type mixing unit;

[0034] A. Circulation pipeline; B. Delivery pipeline. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are some, but not all, of the embodiments of the present invention.

[0036] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0037] Example 1

[0038] refer to Figure 1 The low-carbon resin granulation system provided in this embodiment includes a resin granulation device 1 and a molten resin tank 2 for supplying molten C5 petroleum resin to the resin granulation device 1. The upper end of the molten resin tank 2 is provided with an inlet 21 and a circulating inlet 22, and the lower end of the molten resin tank 2 is provided with an outlet 23. The outlet 23 is connected to a pre-filter 3. A circulation pipeline A is connected between the outlet of the pre-filter 3 and the circulating inlet 22, and a conveying pipeline B is connected between the outlet of the pre-filter 3 and the resin granulation device 1. That is, the molten resin output from the pre-filter 3 can selectively enter either the circulation pipeline A or the conveying pipeline B. A first filter 4 is provided on the circulation pipeline A, and a second filter 5 and a third filter 6 are sequentially provided on the conveying pipeline B. The filtration accuracy of the pre-filter 3, the first filter 4, the second filter 5, and the third filter 6 increases sequentially.

[0039] During operation, molten C5 petroleum resin is mixed with an antioxidant and fed into the molten resin tank 2 through inlet 21 for heating, heat preservation, and stirring. Then, it enters the pre-filter 3 through outlet 23 for primary filtration. Next, it enters circulation pipeline A and undergoes secondary filtration through the first filter 4 before being circulated back into the molten resin tank 2. Molten resin output from the molten resin tank 2 then re-enters the pre-filter 3 for supplementary filtration. Afterward, it enters the conveying pipeline B and undergoes tertiary and quaternary filtration sequentially through the second filter 5 and the third filter 6, finally entering the resin granulation unit 1 for granulation. It should be noted that circulation pipeline A and conveying pipeline B can operate simultaneously, thereby enabling simultaneous molten resin feeding, circulation filtration, multi-stage filtration, and granulation. This reduces the residence time of the molten resin in the molten resin tank 2 and in each pipeline, minimizing the possibility of carbonization of the molten resin before entering the resin granulation unit 1.

[0040] The molten resin passes through a circulating conveying loop formed between the molten resin tank 2 and the circulation pipeline A. This loop not only completes the primary filtration of the pre-filter 3 and the secondary filtration of the first filter 4, removing large and medium-sized black particles and achieving a circulating filtration process, but also reduces the residence time of the molten resin in the molten resin tank 2, reducing carbonization and inhibiting the formation of new black particles. The molten resin, having completed the primary and secondary filtration, then passes through the conveying pipeline B to complete the tertiary filtration of the second filter 5 and the quaternary filtration of the third filter 6, further removing small and micro-sized black particles, achieving a multi-stage filtration process before granulation. The combination of circulating filtration and multi-stage filtration significantly improves the removal efficiency of black particles in the molten resin, effectively reducing the number of black particles and thus improving the quality of the final resin product. Simultaneously, the efficient physical sieving method of multi-stage filtration significantly reduces the amount of antioxidants used, effectively reducing consumables and production costs.

[0041] In some embodiments, the pre-filter 3 is equipped with a 300-400 mesh screen, the first filter 4 with a 500-600 mesh screen, the second filter 5 with an 800-1000 mesh screen, and the third filter 6 with a 1200-1400 mesh screen. In a preferred embodiment, the pre-filter 3 is equipped with a 400 mesh screen, the first filter 4 with a 600 mesh screen, the second filter 5 with an 800 mesh screen, and the third filter 6 with a 1340 mesh screen. The pre-filter 3 can remove black spots with a particle size of 38 μm or larger, the first filter 4 can remove black spots with a particle size of 23 μm or larger, the second filter 5 can remove black spots with a particle size of 15 μm or larger, and the third filter 6 can remove black spots with a particle size of 10 μm or larger, ultimately ensuring that only a few black spots with a particle size smaller than 10 μm exist in the molten resin entering the resin granulation device 1. By using multi-stage filters for progressively finer filtration, the number of black spots in the molten resin can be reduced to the greatest extent, effectively improving the quality of the resin end product.

[0042] In some implementations, the pre-filter 3, the first filter 4, the second filter 5, and the third filter 6 can all be made of stainless steel. Each filter can have 15 to 20 filter cartridges inside, and the specific number of filter cartridges can be determined according to the actual flow requirements. The filter screen can be set on the filter cartridge, and the filter screen can be made of high-temperature resistant PTFE woven fabric. Each filter can also use an internal-inlet and external-outlet filtration method.

[0043] As a further optimization, a heat exchanger 7 is also installed on the conveying pipeline B. The heat exchanger 7 is located upstream of the second filter 5. The hot side of the heat exchanger 7 is used for the flow of molten resin, and the cold side of the heat exchanger 7 is used for the flow of cooling water. In this embodiment, the cooling water is constant-temperature hot water at 100°C. Through heat exchange, the temperature of the molten resin before granulation can be kept constant at around 175°C.

[0044] Since the molten resin entering the conveying pipeline B will be directly conveyed to the resin granulation device 1 for granulation, a heat exchanger 7 is set upstream of the second filter 5. This allows for timely cooling of the molten resin before it enters the second filter 5, thereby preventing the formation of new black spots in the molten resin under prolonged high-temperature conditions. At the same time, it can also reduce the temperature of the molten resin during granulation, resulting in better molding effects during the granulation process. In addition, through heat exchange in the heat exchanger 7, the steam generated on the cold side of the heat exchanger 7 can be conveyed to the steam utility system for use in the production of other products. This can effectively reduce the steam consumption of the steam utility system and further promote low-energy production.

[0045] In some embodiments, the low-carbon resin granulation system further includes a resin circulation pump 8 and a resin delivery pump 9. The resin circulation pump 8 is located on circulation pipeline A and upstream of the first filter 4, while the resin delivery pump 9 is located on delivery pipeline B and upstream of the heat exchanger 7. In practical applications, the direction of molten resin delivery can be controlled by the resin circulation pump 8 and the resin delivery pump 9, thus selectively controlling whether the molten resin enters circulation pipeline A or delivery pipeline B.

[0046] In some embodiments, the low-carbon resin granulation system also includes a backup filter 10, which is connected in parallel with the third filter 6 and is also connected to the resin granulation device 1. The specific structure and filtration accuracy of the backup filter 10 are the same as those of the third filter 6. When the third filter 6 malfunctions and needs to be repaired, the connection pipeline of the backup filter 10 can be switched to continue production, thereby ensuring the continuity of the production process.

[0047] Example 2

[0048] As a further optimization of Example 1, in Figure 1 Based on, refer to Figures 2 to 3 The low-carbon resin granulation system also includes a vacuum stripping tower 11 and an antioxidant tank 12. The vacuum stripping tower 11 is equipped with a resin extraction pump 13 at its bottom for extracting C5 petroleum resin from the bottom of the tower. The antioxidant tank 12 is equipped with an antioxidant output pump 14 at its outlet. Both the resin extraction pump 13 and the antioxidant output pump 14 are connected to the feed inlet 21. By directly extracting the molten C5 petroleum resin produced by the vacuum stripping tower 11 into the molten resin tank 2, the molten resin collection path can be shortened, avoiding the increase in black spots due to prolonged transport of the molten resin, thus helping to reduce black spots in the molten resin.

[0049] In this embodiment, the antioxidant tank 12 is used to store isooctyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate. Isooctyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate has high antioxidant properties, effectively delaying the oxidative degradation of C5 petroleum resin. It also has low volatility, is not easily volatilized at high temperatures, and exhibits strong stability. Furthermore, isooctyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate has good compatibility with the hydrocarbon structure of C5 petroleum resin, is not easily precipitated, and has long-term stability. In this embodiment, the antioxidant output pump 14 is a metering pump, which can accurately measure and control the amount of antioxidant added, avoiding excessive addition of antioxidant and resulting in waste of consumables, thus effectively controlling production costs.

[0050] In some embodiments, the low-carbon resin granulation system further includes a static mixer 15, which has a first inlet 151, a second inlet 152, and a mixture outlet 153. A resin discharge pump 13 is connected to the first inlet 151, an antioxidant discharge pump 14 is connected to the second inlet 152, and the mixture outlet 153 is connected to the feed inlet 21. By setting up the static mixer 15, the mixing uniformity of the molten resin and antioxidant can be improved, allowing the molten resin and antioxidant to fully contact each other, effectively improving the antioxidant effect.

[0051] In this embodiment, the static mixer 15 is internally equipped with multiple SX-type mixing units 154, which are located between the first inlet 151 and the mixture outlet 153. Since both β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate isooctyl ester and C5 petroleum resin have high viscosity, using SX-type mixing units 154 can achieve a more ideal mixing effect, ensuring thorough mixing of the antioxidant and the molten resin.

[0052] Example 3

[0053] refer to Figures 1 to 3 The low-carbon resin granulation method provided in this embodiment can be implemented using the low-carbon resin granulation system of Embodiment 1 or 2, and includes the following steps:

[0054] Molten C5 petroleum resin and antioxidant β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate isooctanol ester are mixed together and fed into molten resin tank 2 through inlet 21 for heating and stirring.

[0055] The molten resin output from the outlet 23 of the molten resin tank 2 first enters the pre-filter 3 for primary filtration, then enters the circulation pipeline A, undergoes secondary filtration through the first filter 4, and is then circulated back into the molten resin tank 2 through the circulation inlet 22.

[0056] The molten resin discharged from the outlet 23 of the molten resin tank 2 re-enters the pre-filter 3 for supplementary filtration, then enters the conveying pipeline B, is cooled by the heat exchanger 7, and then enters the second filter 5 for tertiary filtration, and then enters the third filter 6 for quaternary filtration. The molten resin that has completed quaternary filtration is directly conveyed to the resin granulation device 1 for granulation.

[0057] The filtration precision of the pre-filter 3, first filter 4, second filter 5, and third filter 6 increases sequentially. In this embodiment, the pre-filter 3, with a 400-mesh screen, can remove black spots with a particle size of 38μm or larger; the first filter 4, with a 600-mesh screen, can remove black spots with a particle size of 23μm or larger; the second filter 5, with an 800-mesh screen, can remove black spots with a particle size of 15μm or larger; and the third filter 6, with a 1340-mesh screen, can remove black spots with a particle size of 10μm or larger. Ultimately, only a few black spots with a particle size of less than 10μm exist in the molten resin entering the resin granulation device 1.

[0058] The low-carbon resin granulation method of this embodiment efficiently removes black spots from molten resin through a combination of circulating filtration and multi-stage filtration. Simultaneously, circulating filtration reduces the residence time of the molten resin in the molten resin tank, minimizing carbonization and thus inhibiting the formation of new black spots. Furthermore, the molten resin is cooled before undergoing third- and fourth-stage filtration, further reducing its temperature and suppressing carbonization. This prevents the formation of new black spots during third- and fourth-stage filtration, ensuring efficient black spot removal. This low-carbon resin granulation method of the present invention reduces the number of black spots in molten resin primarily through physical elimination and secondarily through chemical inhibition, significantly reducing the amount of antioxidants used, lowering consumables and costs, and better aligning with energy-saving and consumption-reducing production policies.

[0059] Comparative Example

[0060] (1) Comparison of antioxidant consumption

[0061] Multiple batches of molten resin granulation were carried out using a resin granulation system without the first and third filters (the structure is the same as in Example 2 except that it does not have the first and third filters, and is referred to as the existing resin granulation system) and the low-carbon resin granulation system of Example 2, respectively. The amount of antioxidant consumed in each production batch and the number of black spots (carbide particles) in the molten resin before entering the resin granulation device 1 were counted. The results are shown in Table 1.

[0062] Table 1

[0063]

[0064] As shown in Table 1, the low-carbon resin granulation system of Example 2, used for granulation of molten resin, reduces both the amount of antioxidant required and the number of black spots in the molten resin before granulation. This demonstrates that combining circulating filtration with progressive, staged fine filtration effectively reduces the number of black spots in the molten resin and also reduces the amount of antioxidant required. This improves the quality of the final resin product while reducing consumables and production costs, demonstrating high practical value and economic benefits in real-world applications.

[0065] (2) Comparison of the number of black spots (carbide particles) after each stage of filtration

[0066] Multiple batches of molten resin granulation were carried out using a resin granulation system without the first and third filters (the structure is the same as in Example 2 except that it does not have the first and third filters, and is referred to as the existing resin granulation system) and the low-carbon resin granulation system of Example 2, respectively. The number of black spots in the molten resin after different levels of filtration in each production batch was counted. The results are shown in Table 2.

[0067] Table 2

[0068]

[0069] As can be seen from Table 2, the number of black spots in the molten resin produced by the low-carbon resin granulation system of Example 2 is significantly reduced after four-stage filtration. Furthermore, the particle size of the black spots in the molten resin that finally enters the resin granulation device for granulation can be basically below 10μm. This can minimize the impact of carbonization on the resin end product and effectively improve the quality of the resin end product. It also proves the authenticity and reliability of the present invention in achieving high-efficiency removal of black spots by combining circulating filtration and multi-stage filtration.

[0070] (3) Comparison of steam consumption

[0071] The resin granulation system without the first and third filters (the structure is the same as in Example 2 except that it does not have the first and third filters, and is referred to as the existing resin granulation system) and the low-carbonized resin granulation system of Example 2 were used to produce melt resin granulation. The steam consumption of the steam utility system was counted and the results are shown in Table 3.

[0072] Table 3

[0073]

[0074] As can be seen from Table 3, using the low-carbon resin granulation system of Example 2 for molten resin granulation production can reduce the steam consumption of the steam utility system by 28%, proving that using the low-carbon resin granulation system of the present invention for resin granulation production can effectively reduce production energy consumption and production costs, and has important application value.

[0075] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0076] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0077] In this invention, unless otherwise expressly specified and limited, "above or below" a first feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on" the first feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the first feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0078] Although the description of the invention has been given in conjunction with the specific embodiments described above, it will be apparent to those skilled in the art that many substitutions, modifications, and variations can be made based on the foregoing. Therefore, all such substitutions, modifications, and variations are included within the spirit and scope of the appended claims.

Claims

1. A low-carbon resin granulation system, characterized in that, It includes a resin granulation device (1), a molten resin tank (2) for supplying molten resin to the resin granulation device (1), a vacuum stripping tower (11), an antioxidant tank (12), and a static mixer (15). The upper end of the molten resin tank (2) is provided with a feed inlet (21) and a circulating feed inlet (22), and the lower end of the molten resin tank (2) is provided with a discharge outlet (23). The discharge outlet (23) is connected to a pre-filter (3). A circulation pipeline (A) is connected between the outlet of the pre-filter (3) and the circulating feed inlet (22). A conveying pipeline (B) is connected between the outlet of the pre-filter (3) and the resin granulation device (1). The circulation pipeline (A) is provided with a first filter (4), and the delivery pipeline (B) is provided with a second filter (5) and a third filter (6) in sequence. The filtration accuracy of the pre-filter (3), the first filter (4), the second filter (5) and the third filter (6) increases in sequence. A heat exchanger (7) is also provided on the conveying pipeline (B). The heat exchanger (7) is located upstream of the second filter (5). The hot side of the heat exchanger (7) is used for the flow of molten resin, and the cold side of the heat exchanger (7) is used for the flow of cooling water. The vacuum stripping tower (11) is equipped with a resin extraction pump (13) at its bottom, and the antioxidant tank (12) is equipped with an antioxidant output pump (14) at its outlet. Both the resin extraction pump (13) and the antioxidant output pump (14) are connected to the feed inlet (21). The static mixer (15) is provided with a first inlet (151), a second inlet (152) and a mixture outlet (153). The resin extraction pump (13) is connected to the first inlet (151), the antioxidant output pump (14) is connected to the second inlet (152), and the mixture outlet (153) is connected to the feed inlet (21). The static mixer (15) is provided with a plurality of SX type mixing units (154) inside, and the plurality of SX type mixing units (154) are located between the first inlet (151) and the mixture outlet (153).

2. The low-carbon resin granulation system according to claim 1, characterized in that, The pre-filter (3) is equipped with a 300-400 mesh filter screen, the first filter (4) is equipped with a 500-600 mesh filter screen, the second filter (5) is equipped with an 800-1000 mesh filter screen, and the third filter (6) is equipped with a 1200-1400 mesh filter screen.

3. The low-carbon resin granulation system according to claim 2, characterized in that, The pre-filter (3) is equipped with a 400-mesh filter, the first filter (4) is equipped with a 600-mesh filter, the second filter (5) is equipped with an 800-mesh filter, and the third filter (6) is equipped with a 1340-mesh filter.

4. The low-carbon resin granulation system according to claim 1, characterized in that, It also includes a resin circulation pump (8) and a resin delivery pump (9), the resin circulation pump (8) being disposed on the circulation pipeline (A) and located upstream of the first filter (4), and the resin delivery pump (9) being disposed on the delivery pipeline (B) and located upstream of the heat exchanger (7).

5. The low-carbon resin granulation system according to claim 1, characterized in that, It also includes a backup filter (10), which is connected in parallel with the third filter (6), and the filtration accuracy of the backup filter (10) is the same as that of the third filter (6).

6. A method for low-carbon resin granulation, implemented using the low-carbon resin granulation system according to any one of claims 1-5, characterized in that, Includes the following steps: After the molten resin and antioxidant are mixed, they are put into the molten resin tank (2) for heating and stirring; The molten resin output from the molten resin tank (2) first enters the pre-filter (3) for primary filtration, then enters the first filter (4) for secondary filtration, and then is circulated back to the molten resin tank (2); The molten resin output from the molten resin tank (2) re-enters the pre-filter (3) for supplementary filtration, then is cooled by the heat exchanger (7) and enters the second filter (5) for tertiary filtration, and then enters the third filter (6) for quaternary filtration. The molten resin that has completed quaternary filtration is directly transported to the resin granulation device (1) for granulation. The filtration accuracy of the pre-filter (3), the first filter (4), the second filter (5), and the third filter (6) increases sequentially.

Images