Continuous auxiliary feeding device for improving whiteness and fisheye of polyvinyl chloride

Abstract

The utility model discloses a continuous auxiliary feeding device for improving whiteness and fisheye of polyvinyl chloride. A discharge port of a relieving gas-liquid interface agent storage tank is respectively connected with a feed port of the relieving gas-liquid interface agent storage tank and a feed port pipeline of a polymerization kettle; a discharge port of the stabilizer storage tank is respectively connected with a feed port of the stabilizer storage tank and a feed port pipeline of the polymerization kettle; the relieving gas-liquid interface agent regulating valve is arranged on a pipeline between a discharge port of the relieving gas-liquid interface agent storage tank and a feed port of the relieving gas-liquid interface agent storage tank, and the pH regulator regulating valve is arranged on a pipeline between a discharge port of the pH regulator storage tank and a feed port of the pH regulator storage tank; the pH regulator reflux valve is arranged on a pipeline between the discharge port of the pH regulator storage tank and the feed port of the polymerization kettle; and the stabilizer return valve is arranged on a pipeline between the discharge port of the stabilizer storage tank and the feed port of the polymerization kettle. According to the utility model, a gas-liquid interface relieving agent, a pH regulator and a stabilizer can be continuously added into the polymerization kettle, so that the polymerization reaction efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of polymer polymerization technology, and in particular to a continuous feeding device for additives that improve the whiteness and fish-eye appearance of polyvinyl chloride. Background Technology

[0002] Polyvinyl chloride (PVC), one of the five major engineering plastics, is widely used in industry, construction, and daily life. Currently, due to differences in processes and formulations, different PVC manufacturers (including those abroad) all exhibit issues such as excessive fish-eye defects and poor stability of the PVC chain in their products. Poor stability leads to a decrease in whiteness (including processed whiteness and apparent whiteness).

[0003] Traditional methods for improving fisheye appearance include increasing the product's oil absorption rate and adding anti-fisheye agents. However, increasing the product's oil absorption rate significantly reduces the apparent density of polyvinyl chloride (PVC). Adding anti-fisheye agents significantly hinders the initial reaction rate and consumes excessive initiator.

[0004] Traditional methods for improving the stability of polyvinyl chloride (PVC) include replacing low-polymerization-degree products with high-polymerization-degree products and adding stabilizers initially. Improving stability by increasing the polymerization degree, i.e., lowering the product grade, is not suitable for fixed-grade products but is appropriate for lowering the grade. However, grade changes bring a series of processing changes, generally making industrial use impractical. Adding stabilizers initially can improve stability, but stabilizers are typically polymerization inhibitors, antioxidants, or terminators, which significantly hinder the initial reaction rate.

[0005] As downstream processing companies place increasingly higher demands on PVC quality, they need to improve indicators such as fisheye appearance, whiteness, and so on to adapt to changes in the market and demand. Utility Model Content

[0006] The purpose of this invention is to provide a continuous feeding device for additives that improve the whiteness and fish-eye appearance of polyvinyl chloride.

[0007] This utility model is implemented by the following technical solution: a device for adding an auxiliary agent, comprising:

[0008] Gas-liquid interface agent storage tank, pH adjuster storage tank, stabilizer storage tank, first valve assembly, second valve assembly, third valve assembly and controller;

[0009] The first valve assembly includes a gas-liquid interface agent regulating valve and a gas-liquid interface agent reflux valve; the second valve assembly includes a pH adjuster regulating valve and a pH adjuster reflux valve; the third valve assembly includes a stabilizer regulating valve and a stabilizer reflux valve.

[0010] The outlet of the gas-liquid interface agent storage tank is connected to the inlet of the gas-liquid interface agent storage tank and the inlet of the polymerization reactor, respectively; the outlet of the pH adjuster storage tank is connected to the inlet of the pH adjuster storage tank and the inlet of the polymerization reactor, respectively; the outlet of the stabilizer storage tank is connected to the inlet of the stabilizer storage tank and the inlet of the polymerization reactor, respectively; the gas-liquid interface agent regulating valve is installed on the pipeline between the outlet of the gas-liquid interface agent storage tank and the inlet of the gas-liquid interface agent storage tank; the gas-liquid interface agent reflux valve is installed on the pipeline between the outlet of the gas-liquid interface agent storage tank and the inlet of the polymerization reactor; the pH adjuster... A pH adjuster regulating valve is installed on the pipeline between the outlet and inlet of the pH adjuster storage tank; a pH adjuster reflux valve is installed on the pipeline between the outlet of the pH adjuster storage tank and the inlet of the polymerization reactor; a stabilizer regulating valve is installed on the pipeline between the outlet and inlet of the stabilizer storage tank; a stabilizer reflux valve is installed on the pipeline between the outlet of the stabilizer storage tank and the inlet of the polymerization reactor; the controller is electrically connected to the gas-liquid interface agent regulating valve, the gas-liquid interface agent reflux valve, the pH adjuster regulating valve, the pH adjuster reflux valve, the stabilizer regulating valve, and the stabilizer reflux valve.

[0011] The controller is used to control the regulating valve of the gas-liquid interface agent to regulate the first gas pressure in the pipeline between the outlet of the gas-liquid interface agent storage tank and the inlet of the gas-liquid interface agent storage tank, so that the first gas pressure reaches the preset gas pressure. The controller is used to control the gas-liquid interface agent reflux valve to open when the first gas pressure reaches the preset gas pressure and when the reaction time reaches the early stage of polymerization reaction or the middle and late stage of polymerization reaction.

[0012] The controller is used to control the pH adjuster regulating valve to adjust the second air pressure of the outlet and inlet pipes of the pH adjuster storage tank, so that the second air pressure reaches a preset air pressure. The controller is also used to control the pH adjuster reflux valve to open when the second air pressure reaches the preset air pressure and the reaction time reaches the end of the polymerization reaction. The controller is also used to control the stabilizer regulating valve to adjust the third air pressure of the outlet and inlet pipes of the stabilizer storage tank, so that the third air pressure reaches a preset air pressure. The controller is also used to control the stabilizer reflux valve to open when the third air pressure reaches the preset air pressure and the reaction time reaches the end of the polymerization reaction.

[0013] Furthermore, the additive addition device also includes: a first addition pump, a second addition pump, a third addition pump, a first pressure gauge, a second pressure gauge, a third pressure gauge, a flow meter for the gas-liquid interface mitigation agent, a flow meter for the pH adjuster agent, and a flow meter for the stabilizer agent;

[0014] The first addition pump, the first pressure gauge, and the flow meter for the gas-liquid interface agent are sequentially installed on the pipeline between the outlet of the gas-liquid interface agent storage tank and the inlet of the polymerization reactor. The second addition pump, the second pressure gauge, and the flow meter for the pH adjuster are sequentially installed on the pipeline between the outlet of the pH adjuster storage tank and the inlet of the polymerization reactor. The third addition pump, the third pressure gauge, and the flow meter for the stabilizer are sequentially installed on the pipeline between the outlet of the stabilizer storage tank and the inlet of the polymerization reactor. The first addition pump, the second addition pump, the third addition pump, the first pressure gauge, the second pressure gauge, and the third pressure gauge are all electrically connected to the controller.

[0015] Advantages of this utility model:

[0016] In this embodiment, by setting up regulating valves for the gas-liquid interface agent, pH regulator, and stabilizer, the first, second, and third gas pressures are adjusted respectively, facilitating the entry of the gas-liquid interface agent into the polymerization reactor. Furthermore, by controlling the reflux valves for the gas-liquid interface agent, pH regulator, and stabilizer, the gas-liquid interface agent can be continuously added to the polymerization reactor in the early or later stages of the polymerization reaction, and the pH regulator and stabilizer can be continuously added to the polymerization reactor in the late stage of the polymerization reaction, eliminating the need for batch addition of the gas-liquid interface agent and improving the efficiency of the polymerization reaction. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a continuous feeding device for additives to improve the whiteness and fish-eye appearance of polyvinyl chloride, provided in an embodiment of this utility model.

[0019] Figure 1 In the container, 1-a gas-liquid interface agent storage tank, 2-pH adjuster storage tank, 3-stabilizer storage tank, 4-first valve assembly, 5-second valve assembly, 6-third valve assembly, 7-first inlet pump, 8-second inlet pump, 9-third inlet pump, 10-gas-liquid interface agent flow meter, 11-pH adjuster flow meter, 12-stabilizer flow meter, 13-first pressure gauge, 14-second pressure gauge, 15-third pressure gauge, 16-polymerization reactor, 40-gas-liquid interface agent regulating valve, 41-gas-liquid interface agent reflux valve, 50-pH adjuster regulating valve, 51-pH adjuster reflux valve, 60-stabilizer regulating valve, 61-stabilizer reflux valve. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Figure 1This is a schematic diagram of a continuous feeding device for additives to improve the whiteness and fish-eye appearance of polyvinyl chloride (PVC) according to an embodiment of the present invention. The continuous feeding device includes: a gas-liquid interface agent storage tank 1, a pH adjuster storage tank 2, a stabilizer storage tank 3, a first valve assembly 4, a second valve assembly 5, a third valve assembly 6, and a controller. The first valve assembly 4 includes a gas-liquid interface agent regulating valve 40 and a gas-liquid interface agent reflux valve 41; the second valve assembly 5 includes a pH adjuster regulating valve 50 and a pH adjuster reflux valve 51; the third valve assembly 6 includes a stabilizer regulating valve 60 and a stabilizer reflux valve 61; the outlet of the gas-liquid interface agent storage tank 1... The feed inlet is connected to the feed inlet of the gas-liquid interface agent storage tank 1 and the feed inlet of the polymerization reactor 16, respectively; the discharge outlet of the pH adjuster storage tank 2 is connected to the feed inlet of the pH adjuster storage tank 2 and the feed inlet of the polymerization reactor 16, respectively; the discharge outlet of the stabilizer storage tank 3 is connected to the feed inlet of the stabilizer storage tank 3 and the feed inlet of the polymerization reactor 16, respectively; the gas-liquid interface agent regulating valve 40 is installed on the pipeline between the discharge outlet and the feed inlet of the gas-liquid interface agent storage tank 1; the gas-liquid interface agent reflux valve 41 is installed on the pipeline between the discharge outlet and the feed inlet of the polymerization reactor 16; the pH adjuster regulating valve 50 is installed in the pH adjuster storage tank 2. The controller is electrically connected to the gas-liquid interface agent regulating valve 40, the gas-liquid interface agent reflux valve 41, the pH regulating valve 50, the pH regulating valve 51, the stabilizer regulating valve 60, and the stabilizer regulating valve 61. The controller is used to control the gas-liquid interface agent regulating valve 60. The throttle valve 40 regulates the first air pressure in the pipeline between the outlet and inlet of the gas-liquid interface agent storage tank 1, so that the first air pressure reaches the preset air pressure. The controller is used to control the gas-liquid interface agent reflux valve 41 to open when the first air pressure reaches the preset air pressure and the reaction time reaches the early stage or the middle and late stage of the polymerization reaction. The controller is used to control the pH adjuster regulating valve 50 to regulate the second air pressure in the pipeline between the outlet and inlet of the pH adjuster storage tank 2, so that the second air pressure reaches the preset air pressure. The controller is used to control the pH adjuster reflux valve 51 to open when the second air pressure reaches the preset air pressure and the reaction time reaches the middle and late stage of the polymerization reaction.The controller is used to control the stabilizer regulating valve 60 to regulate the third air pressure in the outlet and inlet pipes of the stabilizer storage tank 3, so that the third air pressure reaches the preset air pressure. The controller is also used to control the stabilizer reflux valve 61 to open when the third air pressure reaches the preset air pressure and the reaction time reaches the end of the polymerization reaction.

[0022] The preset air pressure is 1.2 MPa. The gas-liquid interface agent regulating valve 40 is used to regulate the first air pressure in the pipeline between the outlet and inlet of the gas-liquid interface agent storage tank 1, and the gas-liquid interface agent reflux valve 41 is used to control the flow rate of the gas-liquid interface agent entering the polymerization reactor 16. The pH adjuster regulating valve 50 is used to regulate the second air pressure in the pipeline between the outlet and inlet of the pH adjuster storage tank 2, and the pH adjuster reflux valve 51 is used to control the flow rate of the pH adjuster entering the polymerization reactor 16. The stabilizer regulating valve 60 is used to regulate the third air pressure in the pipeline between the outlet and inlet of the stabilizer storage tank 3, and the stabilizer reflux valve 61 is used to control the flow rate of the stabilizer entering the polymerization reactor 16.

[0023] Initially, the controller opens the gas-liquid interface agent regulating valve 40, causing the first air pressure in the pipeline between the outlet and inlet of the gas-liquid interface agent storage tank 1 to reach the preset air pressure. The controller then opens the pH adjuster regulating valve 50, causing it to adjust the second air pressure in the pipeline between the outlet and inlet of the pH adjuster storage tank 2 to reach the preset air pressure. Finally, the controller opens the stabilizer regulating valve 60, causing the third air pressure in the pipeline between the outlet and inlet of the stabilizer storage tank 3 to reach the preset air pressure.

[0024] When the controller reaches the preset pressure in the first gas pressure and the reaction time reaches the early stage or the middle and late stage of the polymerization reaction, it controls the gas-liquid interface agent reflux valve 41 to open, allowing the gas-liquid interface agent to enter the polymerization reactor 16. When the controller reaches the preset pressure in the second gas pressure and the reaction time reaches the middle and late stage of the polymerization reaction, it controls the pH adjuster reflux valve 51 to open, allowing the pH adjuster to enter the polymerization reactor 16. When the controller reaches the preset pressure in the third gas pressure and the reaction time reaches the middle and late stage of the polymerization reaction, it controls the stabilizer reflux valve 61 to open, allowing the stabilizer to enter the polymerization reactor 16.

[0025] In this embodiment, by setting the gas-liquid interface agent regulating valve 40, the pH adjuster regulating valve 50, and the stabilizer regulating valve 60, the first gas pressure, the second gas pressure, and the third gas pressure are respectively adjusted, which facilitates the entry of the gas-liquid interface agent into the polymerization reactor 16. Furthermore, by controlling the gas-liquid interface agent reflux valve 41, the pH adjuster reflux valve 51, and the stabilizer reflux valve 61, the gas-liquid interface agent can be continuously added to the polymerization reactor 16 in the early stage or the middle and late stage of the polymerization reaction, and the pH adjuster and stabilizer can be continuously added to the polymerization reactor in the middle and late stage of the polymerization reaction, without the need to add the gas-liquid interface agent in batches, thus improving the efficiency of the polymerization reaction.

[0026] See Figure 1 Furthermore, based on the above embodiments, the additive addition device further includes: a first addition pump 7, a second addition pump 8, a third addition pump 9, a first pressure gauge 13, a second pressure gauge 14, a third pressure gauge 15, a flow meter for mitigating gas-liquid interface agent 10, a flow meter for pH adjuster 11, and a flow meter for stabilizer 12; the first addition pump 7, the first pressure gauge 13, and the flow meter for mitigating gas-liquid interface agent 10 are sequentially arranged on the pipeline between the outlet of the mitigating gas-liquid interface agent storage tank 1 and the inlet of the polymerization reactor 16; the second addition pump 8, the second pressure gauge 14, and the flow meter for pH adjuster 11 are sequentially arranged on the pipeline between the outlet of the pH adjuster storage tank 2 and the inlet of the polymerization reactor 16; the third addition pump 9, the third pressure gauge 15, and the flow meter for stabilizer 12 are sequentially arranged on the pipeline between the outlet of the stabilizer storage tank 3 and the inlet of the polymerization reactor 16; the first addition pump 7, the second addition pump 8, the third addition pump 9, the first pressure gauge 13, the second pressure gauge 14, and the third pressure gauge 15 are all electrically connected to the controller.

[0027] The system includes a first pressure gauge 13 for measuring the first air pressure in the pipeline between the outlet of the gas-liquid interface agent storage tank 1 and the inlet of the polymerization reactor 16; a second pressure gauge 14 for measuring the second air pressure in the pipeline between the outlet of the gas-liquid interface agent storage tank 1 and the inlet of the polymerization reactor 16; and a third pressure gauge 15 for measuring the third air pressure in the pipeline between the outlet of the stabilizer storage tank 3 and the inlet of the stabilizer storage tank 3. A gas-liquid interface agent flow meter 10 is used to measure the gas-liquid interface agent flow rate in the pipeline between the outlet of the gas-liquid interface agent storage tank 1 and the inlet of the polymerization reactor 16. A pH adjuster flow meter 11 is used to measure the pH adjuster flow rate in the pipeline between the outlet of the pH adjuster storage tank 2 and the inlet of the polymerization reactor 16. A stabilizer flow meter 12 is used to measure the stabilizer flow rate in the pipeline between the outlet of the stabilizer storage tank 3 and the inlet of the polymerization reactor 16.

[0028] Specifically, the controller starts the first feed pump 7, the second feed pump 8, and the third feed pump 9, creating a pressure difference in the pipes on both sides of the first feed pump 7, the second feed pump 8, and the third feed pump 9. The first pressure gauge 13 measures the first pressure value in the pipe between the outlet of the gas-liquid interface agent storage tank 1 and the inlet of the polymerization reactor 16. Based on the first pressure value measured by the first pressure gauge 13, the controller controls the opening of the gas-liquid interface agent regulating valve 40 to ensure the first pressure reaches the preset value. The second pressure gauge 14 measures the second air pressure value in the pipeline between the outlet of the pH adjuster storage tank 2 and the inlet of the polymerization reactor 16. The controller adjusts the opening of the pH adjuster regulating valve 50 according to the second air pressure value measured by the second pressure gauge 14 so that the second air pressure value reaches the preset air pressure. The third pressure gauge 15 measures the third air pressure in the pipeline between the outlet of the stabilizer storage tank 3 and the inlet of the stabilizer storage tank 3. The controller adjusts the opening of the stabilizer regulating valve 60 according to the third air pressure value measured by the third pressure gauge 15 so that the third air pressure reaches the preset air pressure.

[0029] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An aid continuous feeding device for improving the whiteness and fisheye of polyvinyl chloride, characterized in that, The application relates to a polyolefin production system. The first valve assembly comprises a relieving gas-liquid interface agent regulating valve and a relieving gas-liquid interface agent backflow valve; the second valve assembly comprises a pH adjusting agent regulating valve and a pH adjusting agent backflow valve; and the third valve assembly comprises a stabilizing agent regulating valve and a stabilizing agent backflow valve. The outlet of the relieving gas-liquid interface agent tank is connected with the inlet of the relieving gas-liquid interface agent tank and the pipeline of the polymerizer inlet; the outlet of the pH adjusting agent tank is connected with the inlet of the pH adjusting agent tank and the pipeline of the polymerizer inlet; the outlet of the stabilizing agent tank is connected with the inlet of the stabilizing agent tank and the pipeline of the polymerizer inlet; the relieving gas-liquid interface agent regulating valve is arranged on the pipeline between the outlet of the relieving gas-liquid interface agent tank and the inlet of the relieving gas-liquid interface agent tank; the relieving gas-liquid interface agent backflow valve is arranged on the pipeline between the outlet of the relieving gas-liquid interface agent tank and the polymerizer inlet; the pH adjusting agent regulating valve is arranged on the pipeline between the outlet of the pH adjusting agent tank and the inlet of the pH adjusting agent tank; the pH adjusting agent backflow valve is arranged on the pipeline between the outlet of the pH adjusting agent tank and the polymerizer inlet; the stabilizing agent regulating valve is arranged on the pipeline between the outlet of the stabilizing agent tank and the inlet of the stabilizing agent tank; and the stabilizing agent backflow valve is arranged on the pipeline between the outlet of the stabilizing agent tank and the polymerizer inlet. The controller is electrically connected with the relieving gas-liquid interface agent regulating valve, the relieving gas-liquid interface agent backflow valve, the pH adjusting agent regulating valve, the pH adjusting agent backflow valve, the stabilizing agent regulating valve and the stabilizing agent backflow valve. The controller is used for controlling the relieving gas-liquid interface agent regulating valve to adjust the first gas pressure of the pipeline between the outlet of the relieving gas-liquid interface agent tank and the inlet of the relieving gas-liquid interface agent tank, so that the first gas pressure reaches a preset gas pressure; the controller is used for controlling the relieving gas-liquid interface agent backflow valve to open when the first gas pressure reaches the preset gas pressure and when the reaction time reaches the early stage or the middle-late stage of the polymerization reaction. The controller is used for controlling the pH adjusting agent regulating valve to adjust the second gas pressure of the pipeline between the outlet of the pH adjusting agent tank and the inlet of the pH adjusting agent tank, so that the second gas pressure reaches a preset gas pressure; the controller is used for controlling the pH adjusting agent backflow valve to open when the second gas pressure reaches the preset gas pressure and when the reaction time reaches the late stage of the polymerization reaction; and the controller is used for controlling the stabilizing agent regulating valve to adjust the third gas pressure of the pipeline between the outlet of the stabilizing agent tank and the inlet of the stabilizing agent tank, so that the third gas pressure reaches a preset gas pressure; the controller is used for controlling the stabilizing agent backflow valve to open when the third gas pressure reaches the preset gas pressure and when the reaction time reaches the late stage of the polymerization reaction.

2. The continuous feeding device of an auxiliary agent for improving the whiteness and fisheyes of polyvinyl chloride according to claim 1, characterized in that, The application further relates to a polyolefin production system. The first adding pump, the second adding pump, the third adding pump, the first pressure gauge, the second pressure gauge, the third pressure gauge, the relieving gas-liquid interface agent flowmeter, the pH adjusting agent flowmeter and the stabilizing agent flowmeter are arranged on the pipeline between the outlet of the relieving gas-liquid interface agent tank and the inlet of the relieving gas-liquid interface agent tank. The first adding pump, the first pressure gauge and the buffer gas-liquid interface agent flow meter are sequentially arranged on the pipeline between the discharge port of the buffer gas-liquid interface agent storage tank and the polymerizer inlet; the second adding pump, the second pressure gauge and the pH adjusting agent flow meter are sequentially arranged on the pipeline between the discharge port of the pH adjusting agent storage tank and the polymerizer inlet; the third adding pump, the third pressure gauge and the stabilizer flow meter are sequentially arranged on the pipeline between the discharge port of the stabilizer storage tank and the polymerizer inlet; the first adding pump, the second adding pump, the third adding pump, the first pressure gauge, the second pressure gauge and the third pressure gauge are electrically connected with the controller.

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