PK post-treatment system and process

Abstract

A PK post-treatment system comprises a crusher, a polymer dryer, an extruder and an underwater granulator, a feed port of the crusher is connected with a PK polymerization unit, a discharge port of the crusher supplies materials to the polymer dryer, the polymer dryer is connected with a negative pressure source, a discharge port of the polymer dryer supplies materials to the extruder through a powder cooler, and the underwater granulator is connected with the powder cooler. A mixing feed hopper is further arranged at the feed end of the extruder and connected with an anti-aging agent source, and a discharge port of the extruder supplies materials to the underwater granulator through a melt pump. The device is simple in structure and convenient to operate, and PK products with stable quality can be obtained.

Description

Technical Field

[0001] The present invention relates to the field of chemical industry, and in particular to a PK post-processing system and process. Background Art

[0002] PK is polyketone resin, a hard and dense material with a smooth, white and shiny surface. It has a high elastic modulus, high rigidity and hardness, and its specific strength and specific rigidity are close to those of metals. It also has a low friction coefficient, is wear-resistant, and has good dimensional stability. Polyketone resin can partially replace copper, zinc, aluminum, steel and other metals and is widely used in automobiles, machinery manufacturing, precision instruments, office appliances, military and other industries. Polyketone resin has the characteristics of high hardness and wear resistance, so it is widely used in the manufacture of various gears, rollers, bearings, conveyor belts, springs, cams, bolts, and various pump bodies, housings, impeller friction bearings and other mechanical equipment structural parts.

[0003] PK is a linear crystalline polymer obtained by alternating copolymerization of carbon monoxide, ethylene and propylene. The material obtained after copolymerization contains solvents and impurities that need to be removed. In addition, since PK polyketone resin is a crystalline plastic, once it reaches the melting point, the melt viscosity drops rapidly. At the same time, if the melt is heated for too long, it will lead to severe thermal degradation and produce more impurities. The above factors cause the quality of the PK plastics currently processed to be unstable.

[0004] Therefore, designing a device that can stably post-treat PK polyketone resin to enhance the competitiveness of PK products is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] One of the purposes of the present invention is to provide a PK post-processing system in view of the deficiencies in the prior art, which has a simple structure, is easy to operate, and can ensure that a PK product with stable quality is obtained.

[0006] The second object of the present invention is to provide a process for treating PK polymers using the above-mentioned post-treatment system, which has a simple process and low treatment cost, can obtain PK products with stable quality, and enhance the market competitiveness of PK products.

[0007] The technical solution for achieving one of the purposes of the present invention is: a PK post-processing system, including a crusher, a polymer dryer, an extruder, and an underwater pelletizer, the feed port of the crusher is connected to the PK polymerization unit, the discharge port of the crusher supplies the polymer dryer, the polymer dryer is connected to a negative pressure source, the discharge port of the polymer dryer supplies the extruder through a powder cooler, the feed end of the extruder is also provided with a mixing feed hopper, which is connected to an antioxidant source, and the discharge port of the extruder supplies the underwater pelletizer through a melt pump.

[0008] The polymer dryer is a jacketed horizontal spiral dryer. The gas phase outlet of the polymer dryer is connected to a gas-liquid separator via a condenser. The gas phase outlet of the gas-liquid separator is connected to a negative pressure source. The liquid phase outlet of the gas-liquid separator is used to recover the solvent via a crude solvent pump.

[0009] The extruder is connected to an induced draft fan, and the downstream end of the induced draft fan is emptied to the outside through a spray washing tower.

[0010] The technical solution for achieving the second object of the present invention is: a process for synthesizing a PK catalyst using any of the above-mentioned production systems comprises the following steps:

[0011] 1) The slurry containing PK polymer discharged from the polymerization unit is sent to a crusher and crushed to a particle size of less than 0.5 mm;

[0012] 2) The crushed slurry is sent to the polymer dryer at a pressure of 50 mmH 2 O. Drying treatment at 165℃, residence time is 10min;

[0013] 3) After the dried material is cooled, it is mixed with an anti-aging agent and then enters the extruder, and the extrusion temperature is controlled at 180-200°C and the screw speed is 200r / min;

[0014] 4) The extrudate is pelletized underwater to obtain the target product.

[0015] Step 1) The concentration of the polymer in the slurry is 70 wt %, and the remainder is solvent.

[0016] Step 2) The polymer dryer uses 2.5 MPa (G) saturated steam to provide heat.

[0017] Step 3) Nitrogen is used as a circulating cooling carrier, and the flow ratio of the dried material and the anti-aging machine is 1280:1.

[0018] The above technical solution has the following beneficial effects:

[0019] 1. The PK post-processing system includes a crusher, a polymer dryer, an extruder, and an underwater pelletizer. The crusher is used to crush the materials in the slurry so that the particle size of each material is uniform and within the specified range, ensuring the subsequent drying effect, mixing effect and melting effect. The feed port of the crusher is connected to the PK polymerization unit, and the slurry discharged from the PK polymerization unit can be directly used as a raw material to reduce the intermediate processing cost. The discharge port of the crusher feeds the polymer dryer, and the polymer dryer is connected to a negative pressure source, so that the operating temperature of the dryer can be reduced and the solvent therein can be fully recycled. The discharge port of the polymer dryer feeds the extruder through a powder cooler to avoid the high-temperature powder from directly contacting and reacting with the anti-aging agent, ensuring that the subsequent anti-aging agent is in uniform contact with the powder, and then ensuring the quality stability of the PK product. The feed end of the extruder is also provided with a mixing feed hopper, which is connected to the anti-aging agent source, and the discharge port of the extruder feeds the underwater pelletizer through a melt pump.

[0020] 2. The polymer dryer is a jacketed horizontal spiral dryer. The gas phase outlet of the polymer dryer is connected to a gas-liquid separator through a condenser to convert the vaporized solvent into a liquid phase and separate it through the gas-liquid separator. The gas phase outlet of the gas-liquid separator is connected to a negative pressure source, and the liquid phase outlet of the gas-liquid separator is recovered through a crude solvent pump. This can not only provide vacuum for the polymer dryer, but also realize the recycling of solvents, meeting the actual needs of enterprises.

[0021] 3. In the post-processing process of the present invention, the slurry containing PK polymer is first crushed into a particle size of less than 0.5 mm by a crusher, which is beneficial to the downstream drying process, mixing effect and extruder melting effect, and the high temperature is cooled before feeding to the extruder for melting, so as to avoid direct reaction of some high-temperature powder with the anti-aging agent, but to melt and extrude after sufficient mixing, so as to ensure the quality stability of PK products. By controlling the temperature of the extruder to 180-200°C and shortening the extruder residence time to 15min, the decomposition of PK during the modification process can be effectively avoided, and the material yield can be improved.

[0022] Further description is given below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a connection schematic diagram of the post-processing system of the present invention.

[0024] In the attached drawings, 1 is a crusher, 2 is a polymer dryer, 3 is an extruder, 4 is an underwater pelletizer, 5 is a powder cooler, 6 is a mixing feed hopper, 7 is a melt pump, 8 is a condenser, 9 is a gas-liquid separator, and 10 is an induced draft fan. DETAILED DESCRIPTION

[0025] In the present invention, the antioxidant IR245 (triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate) is used.

[0026] Antioxidant Standard and Purity

[0027]

[0028] Example 1

[0029] See also Figure 1 , the PK post-processing system includes a crusher 1, a polymer dryer 2, an extruder 3, and an underwater pelletizer 4. The feed port of the crusher 1 is connected to the PK polymerization unit, and the discharge port of the crusher 1 feeds the polymer dryer 2. The polymer dryer 2 is connected to a negative pressure source, and the discharge port of the polymer dryer 2 feeds the extruder 3 through a powder cooler 5. In this embodiment, the polymer dryer 2 is a jacketed horizontal spiral dryer, and the gas phase outlet of the polymer dryer 2 is connected to a gas-liquid separator 9 through a condenser 8. The gas phase outlet of the gas-liquid separator 9 is connected to a negative pressure source, and the liquid phase outlet of the gas-liquid separator recovers the solvent through a crude solvent pump. The feed end of the extruder 3 is also provided with a mixing feed hopper 6, which is connected to an antioxidant source, and the discharge port of the extruder 3 feeds the underwater pelletizer 4 through a melt pump 7. Specifically, the extruder 3 is connected to an induced draft fan 10, and the downstream end of the induced draft fan 10 is emptied to the outside through a spray washing tower.

[0030] The specifications of each device are as follows:

[0031]

[0032]

[0033] Example 2

[0034] The post-treatment system of Example 1 was used to treat the PK slurry:

[0035] 1) The slurry containing 70 wt% PK polymer discharged from the PK polymerization unit, with a flow rate of 9.238 t / h, is sent to a crusher for crushing to make the polyketone resin powder particle size less than 0.5 mm;

[0036] 2) The crushed material is sent to the polymer dryer, the working condition is 50mmH 2 O and 165°C, 2.5MPa(G) saturated steam was used to provide heat, and the residence time was 10min;

[0037] 3) The powder after drying has a flow rate of 6.4 t / h, which enters the powder cooler. Nitrogen is used as a circulating cooling carrier, and the powder is cooled here. The gas phase outlet flow rate of the polymer dryer is 2.792 t / h. After condensation, the gas phase outlet (non-condensable gas) of the gas-liquid separator has a flow rate of 0.006 t / h, which enters the negative pressure source. The liquid phase outlet flow rate is 2.786 t / h, which is sent to the solvent recovery unit;

[0038] 4) The cooled powder is mixed with an anti-aging agent (IR245, flow rate is 0.005 t / h) and then fed into an extruder. The residence time of the extruder is 15 min, the pressure is 0.02 MPa (A), and heat transfer oil is used as the heating medium. The inlet temperature is 230°C and the outlet temperature is 220°C. The extruder temperature is maintained between 180-200°C.

[0039] 5) The molten slurry is sent to the underwater pelletizer, sheared into granular PK pellets, and sent to the product silo after liquid-solid and drying.

[0040]

[0041]

[0042] Example 3

[0043] Dryer and extruder operating conditions 1

[0044] Dryer operating conditions unit Numeric Dryer residence time minute 12 Annual operating time Hour 8000 Dryer production capacity Tons / year 62500 Dryer temperature ℃ 165 Dryer vacuum pressure <![CDATA[mmH 2 The]]> 50 Dryer steam inlet temperature ℃ 231℃ Dryer steam inlet pressure (saturated) MPa(G) 2.5 Extruder operating conditions unit Numeric Extruder residence time minute 8 Annual operating time Hour 8000 Extruder production capacity Tons / year 62500 Extruder temperature ℃ 200 Extruder vacuum pressure MPa(A) 0.02 Thermal oil extruder inlet temperature ℃ 230 Thermal oil extruder outlet temperature ℃ 220

[0045] Dryer and extruder operating conditions 2

[0046]

[0047]

[0048] Dryer and extruder operating conditions 3

[0049] Dryer operating conditions unit Numeric Dryer residence time minute 15 Annual operating time Hour 8000 Dryer production capacity Tons / year 50000 Dryer temperature ℃ 165 Dryer vacuum pressure <![CDATA[mmH 2 The]]> 50 Dryer steam inlet temperature ℃ 231℃ Dryer steam inlet pressure (saturated) MPa(G) 2.5 Extruder operating conditions unit Numeric Extruder residence time minute 10 Annual operating time Hour 8000 Extruder production capacity Tons / year 50000 Extruder temperature ℃ 185 Extruder vacuum pressure MPa(A) 0.02 Thermal oil extruder inlet temperature ℃ 230 Thermal oil extruder outlet temperature ℃ 220

[0050] Dryer and extruder operating conditions 4

[0051] Dryer operating conditions unit Numeric Dryer residence time minute 16.5 Annual operating time Hour 8000 Dryer production capacity Tons / year 45455 Dryer temperature ℃ 168 Dryer vacuum pressure <![CDATA[mmH 2 The]]> 50 Dryer steam inlet temperature ℃ 231℃ Dryer steam inlet pressure (saturated) MPa(G) 2.5 Extruder operating conditions unit Numeric Extruder residence time minute 11 Annual operating time Hour 8000 Extruder production capacity Tons / year 45455 Extruder temperature ℃ 182 Extruder vacuum pressure MPa(A) 0.02 Thermal oil extruder inlet temperature ℃ 230 Thermal oil extruder outlet temperature ℃ 220

[0052] Dryer and extruder operating conditions 5

[0053] Dryer operating conditions unit Numeric Dryer residence time minute 18 Annual operating time Hour 8000 Dryer production capacity Tons / year 41667 Dryer temperature ℃ 169 Dryer vacuum pressure <![CDATA[mmH 2 The]]> 50 Dryer steam inlet temperature ℃ 231℃ Dryer steam inlet pressure (saturated) MPa(G) 2.5 Extruder operating conditions unit Numeric Extruder residence time minute 12 Annual operating time Hour 8000 Extruder production capacity Tons / year 41667 Extruder temperature ℃ 180 Extruder vacuum pressure MPa(A) 0.02 Thermal oil extruder inlet temperature ℃ 230 Thermal oil extruder outlet temperature ℃ 220

Claims

1. A PK post-processing system, characterized in that: It comprises a crusher (1), a polymer dryer (2), an extruder (3), and an underwater pelletizer (4). The feed port of the crusher (1) is connected to the PK polymerization unit, and the discharge port of the crusher (1) supplies materials to the polymer dryer (2). The polymer dryer (2) is connected to a negative pressure source, and the discharge port of the polymer dryer (2) supplies the extruder (3) via a powder cooler (5). The feed end of the extruder (3) is also provided with a mixing feed hopper (6) connected to an antioxidant source, and the discharge port of the extruder (3) supplies the underwater pelletizer (4) via a melt pump (7).

2. The PK post-processing system according to claim 1, characterized in that: The polymer dryer (2) is a jacketed horizontal spiral dryer. The gas phase outlet of the polymer dryer (2) is connected to a gas-liquid separator (9) via a condenser (8). The gas phase outlet of the gas-liquid separator (9) is connected to a negative pressure source. The liquid phase outlet of the gas-liquid separator is used to recover the solvent via a crude solvent pump.

3. The PK post-processing system according to claim 1, characterized in that: The extruder (3) is connected to an induced draft fan (10), and the downstream end of the induced draft fan (10) is emptied to the outside through a spray washing tower.

4. A process for treating PK polymers using any post-treatment system according to any one of claims 1 to 3, characterized in that: The following steps are involved: 1) The slurry containing PK polymer discharged from the polymerization unit is sent to a crusher and crushed to a particle size of less than 0.5 mm; 2) The crushed slurry is sent to a polymer dryer and dried at a pressure of 50 mmH2O and 165°C for 10 minutes; 3) After the dried material is cooled, it is mixed with an anti-aging agent and then enters the extruder, and the extrusion temperature is controlled at 180-200°C and the screw speed is 200r / min; 4) The extrudate is pelletized underwater to obtain the target product.

5. The process according to claim 4, characterized in that Step 1) The concentration of the polymer in the slurry is 70 wt %, and the remainder is solvent.

6. The process according to claim 4, characterized in that Step 2) The polymer dryer uses 2.5 MPa (G) saturated steam to provide heat.

7. The process according to claim 4, characterized in that Step 3) Nitrogen is used as a circulating cooling carrier, and the flow ratio of the dried material and the antioxidant is 1280:1.

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