CN113478780A

CN113478780A - Temperature control system of mixing extruder

Info

Publication number: CN113478780A
Application number: CN202110860100.1A
Authority: CN
Inventors: 钟小平; 钟良
Original assignee: Shanghai Meiheng Machinery Co ltd
Current assignee: Shanghai Meiheng Machinery Co ltd
Priority date: 2021-07-28
Filing date: 2021-07-28
Publication date: 2021-10-08
Anticipated expiration: 2041-07-28
Also published as: CN113478780B

Abstract

The invention relates to the technical field of high polymer material mixing, in particular to a temperature control system of a mixing extruder, which comprises a material conveying pipe, an extrusion assembly and a filtering device which are sequentially connected. Be provided with heating system in the filter equipment, extrude the subassembly including the mixed section of plastify of connecting the conveying pipeline and the pressure boost section of connecting filter equipment, and extrude the outside temperature regulating device that all wraps up of subassembly, control system for control heating system and temperature regulating device carry out reasonable preheating temperature control to mixing extruder through heating system and temperature regulating device, and temperature variation is reasonable, and temperature control is stable, has less to mixing extruder's damage, and mixing effectual advantage.

Description

Temperature control system of mixing extruder

Technical Field

The invention belongs to the technical field of high polymer material mixing, and particularly relates to a temperature control system of a mixing extruder.

Background

The blending modification and extrusion molding technology of high molecular polymer materials has been growing as an important technology in the polymer processing industry, with the development of the technology in the polymer processing industry. The total volume of the world high molecular polymer material exceeds that of a metal material, the high molecular polymer can be a product with use value only through blending modification and extrusion molding processing, and a mixing extruder is a main device for blending modification and extrusion molding of the high molecular polymer material.

In the process of extrusion molding of the high molecular polymer material, the high molecular polymer material needs to be smelted at high temperature, so that the high molecular polymer material is in a viscoelastic state, and extrusion mixing of an extruder is facilitated; on the other hand, the high temperature is beneficial to the volatilization of gas and water in the high molecular polymer material, so that the mixed finished product has excellent purity.

The traditional high molecular polymer mixing extruder usually adopts an oil heating mode, an infrared heating mode and an electric heating mode, wherein the oil heating mode is realized by adding a heating oil channel in a cylinder of the extruder and injecting high-temperature heating oil into the heating oil channel to heat the interior of the cylinder of the extruder, and the extruder has the advantages of stable and controllable heating and lower cost, but is limited by heating oil materials, the temperature of the heating oil can only reach about 280 ℃ at most, and the high molecular polymer with high temperature resistance is difficult to process, for example, the mixing temperature of a PC material needs to reach more than 380 ℃; in addition, the strength of the extruder pipeline is reduced due to the increase of the heating oil passage, and the upper limit of the extrusion pressure of the extruder is lower.

And the electrical heating mode is through the heating methods who adds heating device in extruder barrel outside, current heating device generates heat for circular telegram coil, then through screw rod barrel contact conduction heat, it is fast to melt the plastic granules, it is fast to have a rate of heating, the operation of being convenient for, install the advantage that this is lower, but the mode through screw rod barrel contact conduction heat makes, the heating efficiency of this mode is lower, the energy consumption is high, heating temperature is difficult to control simultaneously, heating temperature is inhomogeneous, cause the harm to the extruder barrel easily.

The infrared heating mode is that infrared rays emitted by an infrared radiator in the heater irradiate the barrel of the extruder to heat the barrel, meanwhile, a part of infrared rays penetrate through the barrel and are absorbed by plastic to be processed in the barrel, molecules and atoms in the plastic resonate under the influence of the infrared rays, strong vibration and rotation are generated, the temperature of the plastic is increased, and the purpose of heating is achieved.

Therefore, a temperature control system for a mixing extruder, which can realize stable heat preservation and uniform heating in a larger temperature interval, is needed at present.

Disclosure of Invention

1. Technical problem to be solved by the invention

The invention aims to solve the problem of how to control the constant temperature of a mixing extruder in the running process of the mixing extruder in the prior art.

2. Technical scheme

In order to achieve the purpose, the technical scheme provided by the invention is as follows: a temperature control system of a mixing extruder comprises a material conveying pipe, an extrusion assembly and a filtering device which are connected in sequence;

a heating system is arranged in the filtering device;

the extrusion assembly comprises a plasticizing mixing section connected with the conveying pipe and a pressurizing section connected with the filtering device, and temperature control devices are wrapped outside the extrusion assembly;

the control system is used for controlling the heating system and the temperature control device;

the control process is as follows:

s1, starting the heating system to preheat the filtering device, simultaneously starting a temperature control device outside the pressurizing section, and preheating the pressurizing section according to a set rate;

s2, after preheating to a set time or a set temperature, starting a temperature control device outside the plasticizing and mixing section to heat the plasticizing and mixing section;

s3, after the filtering device and the pressurizing section are heated to a set temperature value, starting to preserve heat of the filtering device and the pressurizing section;

s4, heating the plasticizing and mixing section to a set temperature, and preserving heat;

and S5, starting a material conveying pipe to feed, and controlling the temperature of the plasticizing and mixing section through the temperature control device.

Preferably, the temperature control device comprises a heat insulation layer, and the heat insulation layer is wrapped outside the extrusion assembly; a plurality of heating elements are arranged on the inner surface of the heat insulation layer; a flow guide channel is arranged between the heat insulation layer and the plurality of heating members; two ends of the diversion channel are connected with cooling systems, and each cooling system comprises a cooling liquid circulating device and a gas circulating device;

the cooling liquid circulating device is used for circularly conveying cooling liquid to the diversion channel;

the gas circulating device is used for circulating gas in the flow guide channel.

Preferably, a vacuum mixing section is arranged between the plasticizing mixing section and the pressurizing section, and a vacuumizing device is arranged on the side wall of the vacuum mixing section;

the vacuum mixing section and the plasticizing mixing section are synchronously heated and controlled in temperature;

and the vacuumizing device is synchronously started when the vacuum mixing section is started and heated, and vacuumizing operation is carried out on the interior of the mixing extruder.

Preferably, the cooling liquid circulating device is provided in combination with the gas circulating device.

Preferably, the cooling liquid circulating device comprises a liquid storage bin, a circulating pump and a cooling device, wherein the liquid storage bin, the circulating pump and the cooling device are connected through pipelines and are connected to two ends of the flow guide channel; the transfusion port of the liquid storage bin is arranged at one end of the diversion channel, and one end of the liquid storage bin, which is far away from the transfusion port, is connected with the cooling device;

the gas circulating device adopts the same circulating pump and cooling device and is provided with a gas guide pipe, one end of the gas guide pipe is communicated with the infusion port, and the other end of the gas guide pipe is communicated with a pipeline connected with the liquid storage bin and the cooling device; and a three-way valve is arranged at the joint of the air duct and the infusion port.

Preferably, the temperature control mode of the plasticizing and mixing section is as follows:

s5.1, calculating a heating rate Q1 during mixing of the plasticizing mixing section;

s5.2, calculating the input speed of the cooling liquid by the cooling liquid circulating device according to the heating value;

s5.3, starting the gas circulating device, and driving the cooling liquid to circulate in the flow guide channel by using gas;

s5.4, the cooling liquid is completely gasified in the flow guide channel, the heat absorption rate Q2 of the gasification of the cooling liquid is equal to the heat generation rate Q1, and the cooling liquid flows back to the cooling liquid circulating device through the gas circulating device.

3. Advantageous effects

Compared with the prior art, the technical scheme provided by the invention has the following beneficial effects:

the temperature control system of the mixing extruder comprises a material conveying pipe, an extrusion assembly and a filtering device which are connected in sequence. Be provided with heating system in the filter equipment, extrude the subassembly including the mixed section of plastify of connecting the conveying pipeline and the pressure boost section of connecting filter equipment, and extrude the outside temperature regulating device that all wraps up of subassembly, control system for control heating system and temperature regulating device carry out reasonable preheating temperature control to mixing extruder through heating system and temperature regulating device, and temperature variation is reasonable, and temperature control is stable, has less to mixing extruder's damage, and mixing effectual advantage.

Drawings

FIG. 1 is a schematic view of the extrusion assembly of the present invention;

FIG. 2 is a schematic diagram of the cooling system of the present invention in cooperation with a plenum section;

FIG. 3 is a schematic structural view of a vacuum mixing section according to the present invention;

FIG. 4 is a schematic structural diagram of a plasticizing mixing section of the present invention;

FIG. 5 is a schematic view of a rotary screen according to the present invention;

fig. 6 is a schematic view of the internal structure of the rotary screen of the present invention.

The reference numerals in the schematic drawings illustrate:

100. an extrusion assembly; 110. a plasticizing and mixing section; 111. a mixing barrel; 112. a planetary main shaft; 113. a planetary layshaft; 120. a vacuum mixing section; 121. a vacuum cylinder; 122. a vacuum main screw; 123. a vacuum auxiliary screw; 130. a pressurizing section; 131. a pressurizing cylinder; 132. a pressurizing screw; 140. a vacuum pumping device; 150. isolating the net plate; 200. a filtration device; 210. a feeding port; 211. a first coarse filter screen; 212. heating the net; 220. a discharge port; 221. a second coarse filter screen; 230. rotating the filter screen; 231. rotating the disc; 232. a rotating shaft; 233. a filter screen; 234. a heating unit; 235. a drive device; 300. a temperature control device; 310. a thermal insulation layer; 320. a heating member; 330. a flow guide way; a cooling system; 341. a liquid storage bin; 3411. an infusion port; 342. a circulation pump; 343. a cooling device; 344. an air duct; 400. and (5) controlling the system.

Detailed Description

In order to facilitate an understanding of the invention, the invention will now be described more fully hereinafter with reference to the accompanying drawings, in which several embodiments of the invention are shown, but which may be embodied in many different forms and are not limited to the embodiments described herein, but rather are provided for the purpose of providing a more thorough disclosure of the invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present; when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present; the terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs; the terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention; as used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Example 1

Referring to fig. 1 to 6, the present embodiment provides a technical solution: a temperature control system of a mixing extruder comprises a material conveying pipe, an extrusion assembly 100 and a filtering device 200 which are connected in sequence;

be provided with heating system in filter device 200, filter device 200 is provided with pan feeding mouth 210 and discharge gate 220, pan feeding mouth 210 with be provided with rotation filter screen 230 between the discharge gate 220, pan feeding mouth 210 is provided with coarse filter screen 211, heating system including set up in pan feeding mouth 210 heating screen 212 with set up in rotate filter screen 230's heating unit 234

The extrusion assembly 100 comprises a plasticizing mixing section 110 connected with the conveying pipe and a pressurizing section 130 connected with the filtering device 200, and the outside of the extrusion assembly 100 is wrapped with a temperature control device 300;

a control system 400 for controlling the heating system and the temperature control device 300;

the control process is as follows:

s1, starting the heating system to preheat the filtering device 200, simultaneously starting the temperature control device 300 outside the pressurizing section 130, and preheating the pressurizing section 130 according to a set rate; the set rate is 100-,

s2, after preheating to a set time or a set temperature, starting a temperature control device 300 outside the plasticizing and mixing section 110, and heating the plasticizing and mixing section 110;

the set time and the set temperature are confirmed according to the characteristics of the mixing materials, if the melting temperature interval of the mixing materials is from T to T + N, the set temperature is from 0.5T to 0.8T, and the set time is obtained by dividing the set temperature by the set rate; the preheating is carried out by the set time, so that the operation and the control are convenient, and the function of controlling the preheating time can be realized by only adding timing equipment; and through it is more accurate to set for the temperature preheating then preheat the effect, the change of temperature when can accurate reaction preheats, but need additionally increase temperature real-time detection device in equipment for equipment structure is more complicated, and receives under high temperature real-time detection device life's restriction.

The heating rate for heating the plasticizing and mixing section 110 is greater than the preheating rate for the filtering device 200 and the pressurizing section 130, the heating rate for heating the plasticizing and mixing section 110 is preferably set to be 200-,

s3, heating the filtering device 200 and the pressurizing section 130 to a set temperature value, and then starting to keep the filtering device 200 and the pressurizing section 130 warm; the set temperature value is set within a melting temperature interval T to T + N of the mixing material. The holding time t is at least more than 20 minutes.

S4, heating the plasticizing and mixing section 110 to a set temperature, and preserving heat; the set temperature value is set to be within a melting temperature interval T to T + N of the mixing material, and the heating rate of the plasticizing mixing section 110 is set as follows:

v＝(T-T1)/t

t1 is the current temperature value of the plasticizing and mixing section 110;

the T1 is obtained by measuring with a temperature detector, or by adding the product of heating rate and heating time to the temperature of normal temperature.

And S5, starting a material conveying pipe to feed, and controlling the temperature of the plasticizing and mixing section 110 through the temperature control device 300. The conveying pipe is connected with a vacuum feeding device, the vacuum feeding device is used for carrying out vacuum feeding on the conveying pipe, and the conveying pipe transmits materials to the plasticizing and mixing section 110.

In a preferred embodiment, temperature control device 300 includes a thermal insulation layer 310, where thermal insulation layer 310 is wrapped and disposed outside extrusion assembly 100; a plurality of heating elements 320 are arranged on the inner surface of the heat insulation layer 310; a flow guide 330 is arranged between the heat insulation layer 310 and the plurality of heating elements 320; two ends of the flow guide channel 330 are connected with a cooling system, and the cooling system comprises a cooling liquid circulating device and a gas circulating device;

the cooling liquid circulating device is used for circularly conveying cooling liquid to the flow guide channel 330;

the gas circulation device is used for circulating the gas in the flow guide 330.

The heating elements 320 are arranged by heating coils, are uniformly distributed and arranged outside the extrusion assembly 100, different heating elements 320 are filled by the heat insulation layer 310, the flow guide channel 330 is isolated from the outside of the extrusion assembly 100 by the heating elements 320 and the heat insulation layer 310, the flow guide channel 330 is spirally arranged and continuously sleeved on the outer rings of the heating elements 320, so that the contact area between the flow guide channel 330 and the outside of the extrusion assembly 100 is increased, and the heat transfer efficiency is improved; because the coolant liquid direct contact that flows in the water conservancy diversion way 330 extrude the outside of subassembly 100, arouse quick temperature change, it is easy right extrude the damage that subassembly 100 caused the difference in temperature, consequently water conservancy diversion way 330 sets up in a plurality of heating member 320 outer lane is through good to the heat conductivity heating member 320 cools down, thereby it is right to extrude subassembly 100 and stabilize the cooling.

The cooling liquid circulating device is used for circularly conveying cooling liquid to the flow guide channel 330; the cooling liquid contacts the heating member 320 to absorb heat of the heating member 320 and is discharged to the outside of the flow guide 330, so that heat inside the thermal insulation layer 310 is lowered.

The gas circulation device is used for circulating the gas in the flow guide 330. The gas contacts the heating member 320 to absorb heat of the heating member 320 and is carried out of the flow guide 330, so that heat inside the thermal insulation layer 310 is reduced. On the other hand, the gas circulation device can also be used to drive a fixed amount of the cooling liquid to circulate in the flow guide 330.

In a preferable scheme, a vacuum mixing section 120 is arranged between the plasticizing mixing section 110 and the pressurizing section 130, and a vacuumizing device 140 is arranged on the side wall of the vacuum mixing section 120;

the vacuum mixing section 120 and the plasticizing mixing section 110 are synchronously heated and controlled in temperature;

the vacuum pumping device 140 is synchronously started when the vacuum mixing section 120 is started to heat, and performs vacuum pumping operation on the interior of the mixing extruder.

In a preferred embodiment, the cooling liquid circulating device is provided in combination with the gas circulating device. Thereby simplifying the structure of the device and reducing the installation cost.

In a preferable scheme, the cooling liquid circulation device includes a liquid storage bin 341, a circulation pump 342 and a cooling device 343, and the liquid storage bin 341, the circulation pump 342 and the cooling device 343 are connected through a pipeline and are connected to two ends of the diversion tunnel 330; an infusion port 3411 of the liquid storage bin 341 is arranged at one end of the flow guide channel 330, and one end, far away from the infusion port 3411, of the liquid storage bin 341 is connected with the cooling device 343;

the gas circulating device adopts the same circulating pump 342 and cooling device 343, and is provided with a gas-guide tube 344, one end of the gas-guide tube 344 is communicated with the infusion port 3411, and the other end is communicated with a pipeline connecting the liquid storage bin 341 and the cooling device 343; a three-way valve is arranged at the joint of the air duct 344 and the infusion port 3411. The three-way valve is used to control the diversion channel 330 to communicate with the infusion port 3411 only, the gas-guide tube 344 only, or the gas-guide tube 344 and the infusion port 3411 at the same time.

In a preferred embodiment, the temperature control manner of the plasticizing and mixing section 110 is as follows:

s5.1, calculating a heating rate Q1 when the plasticizing and mixing section 110 is used for mixing; the heating rate Q1 is obtained by comprehensively calculating according to the properties of the materials, the mixing speed and the quality of the mixed materials; in a preferred mode, a specific material is mixed for a certain time according to a preset mixing speed and a preset material input speed, and the temperature change in the plasticizing mixing section 110 is actually measured, so that the heat generation rate Q1 of the specific material under the condition is calculated.

S5.2, calculating the input speed of the cooling liquid by the cooling liquid circulating device according to the heating speed Q1;

the input rate of the cooling fluid is calculated as follows:

and obtaining the heat absorption amount when the unit cooling liquid is completely gasified, wherein the input rate of the cooling liquid is the heat generation rate Q1 divided by the heat absorption amount when the unit cooling liquid is completely gasified.

The principle is illustrated as follows: the heat generation rate Q1 × time is an input rate of the coolant × time per unit endothermic amount of the coolant at the time of complete vaporization.

S5.3, starting the gas circulation device, and driving the cooling liquid to circulate in the flow guide channel 330 by using gas;

s5.4, the cooling liquid is completely gasified in the flow guide channel 330, and the heat absorption rate Q2 of the gasification of the cooling liquid is equal to the heat generation rate Q1, and the cooling liquid flows back to the cooling liquid circulating device through the gas circulating device.

Example 2

Referring to fig. 1 to 6, the present embodiment provides a technical solution: the high-temperature planetary mixing extruder comprises a material conveying pipe, an extrusion assembly 100 and a filtering device 200 which are sequentially connected, wherein a temperature control device 300 is wrapped outside the extrusion assembly 100.

In a preferred embodiment, the extrusion assembly 100 comprises a plasticizing mixing section 110, a vacuum mixing section 120 and a pressurizing section 130 which are connected in sequence; a vacuumizing device 140 is arranged on the side wall of the vacuum mixing section 120 close to one end of the plasticizing mixing section 110, an isolation screen plate 150 is arranged between the vacuum mixing section 120 and the vacuumizing device 140, and the isolation screen plate 150 is used for preventing materials from entering the vacuumizing device 140; the isolation net plate 150 comprises a plurality of layers of grid plates, and the meshes of the plurality of layers of grid plates are arranged in a staggered manner.

A vacuum feeding device is communicated above the conveying pipe, and the interior of the vacuum feeding device is kept in a sealed state in the feeding process; after the extruder is started, the vacuumizing device 140 performs vacuumizing operation on the inside of the extruder system, so that the inside of the extruder system is in a vacuum state.

The materials are input into the material conveying pipe from the vacuum feeding device, and reach the plasticizing and mixing section 110 through the material conveying pipe, the plasticizing and mixing section 110 mixes the materials, the materials are sheared, rubbed and extruded in the plasticizing and mixing section 110 from dry powder or blocks to form viscous flow, moisture and gas in the materials are extruded, and a large amount of heat is released; meanwhile, the vacuum pumping device 140 keeps the vacuum pumping operation, so that the vacuum state in the extruder system is kept, and simultaneously, the water vapor or other gases generated by mixing materials are discharged. The materials are fully sheared and mixed by the vacuum mixing section 120, and further drained and exhausted to be fully and uniformly enter the pressurizing section 130, the pressurizing section 130 pushes the mixed and melted materials to the filtering device 200, a certain pressure is applied to extrude the materials from the filtering device 200, and the filtering device 200 filters solid impurities in the materials to obtain the viscous fluid materials which are fully mixed and have high purity.

The temperature control device 300 comprises a heat insulation layer 310, the heat insulation layer 310 is wrapped outside the extrusion assembly 100, and the heat insulation layer 310 can be respectively wrapped on the plasticizing mixing section 110, the vacuum mixing section 120 and the pressurizing section 130; a plurality of heating elements 320 are arranged on the inner surface of the heat insulation layer 310; the heat insulation layer 310 is used for improving the heating efficiency of the heating element 320 on the outside of the extrusion assembly 100, and has the effect of preserving heat on the outside of the extrusion assembly 100, thereby having the advantage of energy saving.

The insulating layer 310 is made by high temperature resistant thermal insulation material, insulating layer 310 includes relative heat insulating part one and heat insulating part two that sets up, heat insulating part one with heat insulating part two centre gripping in it is outside to extrude the subassembly, just heat insulating part one with the edge that heat insulating part two meet can be dismantled the connection, can dismantle the mode and include heat insulating part one with one side that heat insulating part two meet rotates the connection, and the another side that meets is through dismantling a fixed connection, perhaps heat insulating part one with the edge that heat insulating part two meet all is through dismantling a fixed connection, can dismantle the structure that is used for dismantling the connection including screw nut or buckle spare etc..

And the control system 400 is connected with the plurality of heating members 320 and is used for respectively controlling the opening and closing of the plurality of heating members 320. The control system 400 can individually control a plurality of the heating elements 320 so that the control system 400 can control the temperature outside the extrusion assembly 100 in stages according to the local temperature state of the extrusion assembly 100.

In a preferred scheme, the plasticizing and mixing section 110 comprises a mixing cylinder 111 and a planetary mixing assembly arranged inside the mixing cylinder 111, wherein the planetary mixing assembly comprises a planetary main shaft 112 and a plurality of planetary auxiliary shafts 113, and the plurality of planetary auxiliary shafts 113 are arranged around the planetary main shaft 112; the rotation direction of the planetary auxiliary shafts 113 is opposite to that of the planetary main shafts 112, so that dry powdery or blocky materials can be fully extruded, rubbed and sheared between the planetary main shafts 112 and the interior of the mixing cylinder 111, and meanwhile, shearing force between the planetary main shafts 112 and a plurality of planetary auxiliary shafts 113 can be applied, and the mixing cylinder has the advantages of high shearing efficiency and good mixing effect, so that the materials are converted into viscous flow from powdery or blocky materials, and simultaneously, moisture and gas in the materials can be fully extruded and sheared;

the vacuum mixing section 120 comprises a vacuum cylinder 121 hermetically connected with the mixing cylinder 111, a vacuum main screw 122 in transmission connection with the planetary main shaft 112 is arranged in the vacuum cylinder 121, and a plurality of vacuum auxiliary screws 123 are arranged around the axis of the vacuum main screw 122;

the pressurizing section 130 comprises a pressurizing cylinder 131 and a pressurizing screw 132 tightly matched with the inner wall of the pressurizing cylinder 131; the pressurizing screw 132 is a single screw or a double screw, and has a good pressurizing effect. And the pitch of the pressurizing screw 132 is gradually reduced along the direction of the material propulsion, so that the pitch of the pressurizing screw 132 near one end of the vacuum mixing section 120 is larger, the speed of driving the material to propel is higher, and the material is prevented from being accumulated at the joint of the pressurizing section 130 and the vacuum mixing section 120, thereby influencing the effect of vacuumizing. On the other hand, the tooth pitch of the end, close to the filtering device 200, of the pressurizing screw 132 is small, so that the pushing speed of the pressurizing screw 132 is reduced, the maximum pushing pressure of the pushing material is increased, the effect of pushing the material at high pressure is achieved, the material can smoothly pass through the filtering device 200, and the extrusion efficiency of the material is improved.

In a preferred embodiment, a plurality of material guiding grooves are disposed at one end of the main vacuum screw 122 close to the pressurizing section 130, the plurality of material guiding grooves correspond to the auxiliary vacuum screws 123 one by one, the material guiding grooves are connected to the ends of the auxiliary vacuum screws 123, and the other ends of the material guiding grooves are connected to the pressurizing screws 132. The material guide chute is used for conveying the material mixed by the vacuum auxiliary screw 123 into the pressurizing screw 132. The material guide chutes are spirally arranged and guide materials towards the rotating axis of the pressurizing screw 132, so that the material mixed by the vacuum auxiliary screw 123 can be directed towards the rotating axis of the pressurizing screw 132 by the material guide chutes and enter the pressurizing screw 132 in a twist shape, and the material is not easy to accumulate at the joint of the pressurizing section 130 and the vacuum mixing section 120, thereby affecting the vacuum pumping effect; on the other hand, the material is twisted into a twist shape by the guide chutes, which is beneficial to discharging water vapor and gas in the material, and the water vapor and gas are discharged by the vacuumizing device 140, so that the content of water and gas in the material is reduced, and the quality of material molding is improved.

In a preferable scheme, a flow guide 330 is arranged between the heat insulation layer 310 and the plurality of heating elements 320; two ends of the flow guide channel 330 are connected with a cooling system, and the cooling system comprises a cooling liquid circulating device and a gas circulating device; the heating elements 320 are arranged by heating coils, are uniformly distributed and arranged outside the extrusion assembly 100, different heating elements 320 are filled by the heat insulation layer 310, the flow guide channel 330 is isolated from the outside of the extrusion assembly 100 by the heating elements 320 and the heat insulation layer 310, the flow guide channel 330 is spirally arranged and continuously sleeved on the outer rings of the heating elements 320, so that the contact area between the flow guide channel 330 and the outside of the extrusion assembly 100 is increased, and the heat transfer efficiency is improved; because the coolant liquid direct contact that flows in the water conservancy diversion way 330 extrude the outside of subassembly 100, arouse quick temperature change, it is easy right extrude the damage that subassembly 100 caused the difference in temperature, consequently water conservancy diversion way 330 sets up in a plurality of heating member 320 outer lane is through good to the heat conductivity heating member 320 cools down, thereby it is right to extrude subassembly 100 and stabilize the cooling.

In a preferable scheme, a first temperature sensor is arranged inside the extrusion assembly 100; the temperature sensors are respectively arranged inside the plasticizing and mixing section 110, the vacuum mixing section 120 and the pressurizing section 130.

The control system 400 is connected with the first temperature sensor and the cooling system, and the control system 400 is used for controlling the opening and closing of the heating element 320 and the cooling system according to a signal of the first temperature sensor. The thermostatic control of the control system 400 is performed in such a manner that the heating member 320 is activated to heat as soon as the temperature sensor detects that the temperature is lower than a set temperature; when the temperature detected by the temperature sensor is higher than or equal to the set temperature, the heating element 320 is closed, heat is preserved through the heat insulation layer 310, and when the temperature detected by the temperature sensor is too high due to heat generated by extrusion, mixing and heating of materials, the cooling system is started to cool the extrusion assembly 100.

In a preferred embodiment, the cooling liquid circulation device includes a flow monitor and a liquid storage bin 341, an infusion port 3411 of the liquid storage bin 341 is disposed at one end of the diversion channel 330, the flow monitor is disposed at the infusion port 3411, the flow monitor is connected to the control system 400, and the control system 400 is configured to control the on/off of the cooling liquid circulation device according to a signal of the flow monitor.

the gas circulation device comprises a gas guide tube 344, one end of the gas guide tube 344 is communicated with the infusion port 3411, the other end of the gas guide tube 344 is communicated with a pipeline connected with the liquid storage bin 341 and the cooling device 343, and the gas guide tube 344 is arranged obliquely upwards to prevent cooling liquid from entering.

In the operation process of the cooling system, when the cooling liquid circulation device is started, the cooling liquid in the liquid storage bin 341 flows into the flow guide channel 330 through the liquid inlet 3411 to cool the interior of the heat insulation layer 310, meanwhile, the circulation pump 342 pumps the heated cooling liquid out of the flow guide channel 330 to the cooling device 343, and the cooling device 343 cools the cooling liquid and then returns to the liquid storage bin 341 again;

when the gas circulation device is started, the circulation pump 342 pumps the high-temperature gas inside the flow guide channel 330 to enter the cooling device 343 for cooling, and the cooled gas bypasses the liquid storage bin 341 through the gas guide pipe 344 and enters the flow guide channel 330 through the liquid delivery port 3411 to cool the inside of the heat insulation layer 310.

The cooling method of the cooling liquid circulating device and the cooling method of the gas circulating device are as follows:

1. the circulating pump 342 circulates cold air into the flow guide channel 330, so that heat in the flow guide channel 330 is taken out, and the cooling device has the advantages of energy conservation, environmental protection, low cooling speed, mild cooling mode and low damage to equipment.

2. The circulation pump 342 circulates cooling liquid into the flow guide 330, and the cooling liquid includes cooling water, cooling oil and the like, so that heat in the flow guide 330 is rapidly taken out, and the cooling effect and the cooling speed are high.

3. The biphase temperature control is realized, the cooling liquid adopts liquid with the boiling point lower than the set temperature, the heat absorbed during the gasification of the liquid with a certain volume and temperature is basically constant, and the calorific value of the material in the mixing process is determined by the material, the feeding speed and the mixing speed of the material, so the control system 400 can control the feeding speed of the material according to the calorific value in the mixing process of the material, thereby calculating the total amount of the required cooling liquid, introducing a certain amount of the cooling liquid into the flow guide 330, and the cooling liquid is pushed to flow and gasify in the guiding flow passage 330 by the gas circulation device, and finally the cooling liquid is discharged from the guiding flow passage 330 as a gas state, by balancing the heat generated during the mixing process and the heat absorbed by the gasification of the cooling liquid, the dual-phase temperature control method can stably maintain the extrusion assembly 100 at the set temperature.

A flow guide 330 is arranged between the heat insulation layer 310 outside the plasticizing and mixing section 110 and the plurality of heating elements 320; the infusion port 3411 is disposed at one end of the flow guide channel 330 close to the material conveying pipe, when dual-phase temperature control is adopted, the quantitative cooling liquid enters from the infusion port 3411, absorbs heat and gasifies rapidly, so that heat can be absorbed rapidly, the mixing action of one end of the plasticizing mixing section 110 close to the material conveying pipe is most intense, and the heat generation is relatively more, so that when the cooling liquid enters from one end of the flow guide channel 330 close to the material conveying pipe, the heat generated by friction and extrusion under the mixing action can be taken away more rapidly, and along with the continuous flow of the cooling liquid in the flow guide channel 330, the temperature of the cooling liquid is increased and gasified, the cooling effect of one end of the plasticizing mixing section 110 far away from the material conveying pipe is reduced, meanwhile, the material mixing of one end of the plasticizing mixing section 110 far away from the material conveying pipe is relatively sufficient, so that the heat generated by friction and extrusion is relatively less, therefore, the whole plasticizing and mixing section 110 is in a uniform temperature state, the temperature stability is guaranteed, and the material mixing effect and quality are improved.

In a preferred scheme, filter device 200 includes pan feeding mouth 210 and discharge gate 220, be provided with rotation filter screen 230 between pan feeding mouth 210 and the discharge gate 220, pan feeding mouth 210 is provided with coarse filter screen one 211, discharge gate 220 is provided with coarse filter screen two 221. And extruding the mixed material into the first coarse filter screen 211 and the filtering device 200, filtering solid impurities in the material, finally extruding the material from the second coarse filter screen 221 and conveying the material into a forming device.

In a preferred embodiment, the rotary filter screen 230 includes a rotary disc 231, a rotary shaft 232 disposed at the center of the rotary disc 231, and a plurality of filter screens 233 disposed around the rotary shaft 232, wherein the plurality of filter screens 233 are detachably disposed on the rotary disc 231; the rotary filter screen 230 adopts a fine filter screen 233 for fine filtering of impurities in the material.

The rotating shaft 232 is arranged deviating from the material inlet 210 and the material outlet 220 and is connected with a driving device 235; the single filter screen 233 on the rotating disc 231 is arranged between the feeding port 210 and the discharging port 220; the driving device 235 is used for controlling the rotation of the rotating disc 231, so as to replace the filter screen 233 arranged between the material inlet 210 and the material outlet 220. When the filter screen 233 arranged between the feeding port 210 and the discharging port 220 needs to be replaced, only the rotating disc 231 needs to be rotated to enable the adjacent filter screen 233 to rotate to the position between the feeding port 210 and the discharging port 220, and the filter screen 233 which needs to be replaced is detached and replaced without influencing the normal operation of the equipment.

In a preferred embodiment, a heating system is disposed in the filtering device 200, and the heating system includes a heating net 212 disposed at the feeding port 210 and a heating unit 234 disposed at the rotating filter screen 230; the heating net 212 is arranged on the first coarse filter screen 211.

A plurality of heating units 234 are arranged and correspond to the plurality of filter screens 233 one by one; each of the heating units 234 is disposed around its corresponding filter mesh 233; the material around the filter screen 233 can be heated sufficiently and kept in a molten state, and the material fluidity is prevented from being too low, so that the extrusion pressure is too high, and the service life of the filter screen 233 and the equipment is influenced.

The feeding port 210 is provided with a second temperature sensor, a pressure sensor and a viscosity sensor;

the second temperature sensor, the pressure sensor, the viscosity sensor, the heating unit 234 and the driving device 235 are all connected to the control system 400, and the control system 400 controls the heating net 212, the heating unit 234 and the driving device 235 to be opened or closed according to signals of the second temperature sensor, the pressure sensor and the viscosity sensor. When the temperature measured by the second temperature sensor is lower than a set value, the heating unit 234 and the heating net 212 are started; when the temperature measured by the second temperature sensor is higher than the set value, the heating unit 234 and the heating net 212 are turned off. When the pressure measured by the pressure sensor exceeds a set value and the temperature measured by the temperature sensor II is higher than the set value, the driving device 235 is controlled to rotate the rotating disc 231 to replace the filter screen 233.

The control system 400 is controlled as follows:

inputting a set temperature a into the control system 400 according to the temperature required by material processing in advance, and after the extruder is started, performing vacuum pumping operation on the interior of the extruder by using the vacuum pumping device 140 to keep the interior of the extruder in a vacuum state;

firstly, the control system 400 controls the heating element 320 outside the pressurizing section 130 to preheat the pressurizing section 130 to the temperature of a/3 to 2a/3, when the pressurizing section 130 is preheated to the temperature of a/3 to 2 a/3;

secondly, the control system 400 controls the heating element 320 to preheat the vacuum mixing section 120 and the plasticizing mixing section 110, and controls the heating system to preheat the interior of the filtering device 200, and at the same time, slowly preheats the pressurizing section 130 to the temperature a;

thirdly, the control system 400 keeps the temperature of the pressurizing section 130, and at the same time, heats the vacuum mixing section 120, the plasticizing mixing section 110 and the filtering device 200 to a set temperature a;

then, after the interior of the extruder reaches a set temperature, the vacuum feeding device feeds materials to the material conveying pipe in a vacuum mode, and the extrusion assembly 100 performs mixing and extrusion on the materials;

finally, the control system 400 controls the cooling system to control the temperature of the plasticizing and mixing section 110 through the two-phase temperature control.

The above-mentioned embodiments only express a certain implementation mode of the present invention, and the description thereof is specific and detailed, but not construed as limiting the scope of the present invention; it should be noted that, for those skilled in the art, without departing from the concept of the present invention, several variations and modifications can be made, which are within the protection scope of the present invention; therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The temperature control system of the mixing extruder is characterized in that: comprises a material conveying pipe, an extrusion component (100) and a filtering device (200) which are connected in sequence;

a heating system is arranged in the filtering device (200);

the extrusion assembly (100) comprises a plasticizing mixing section (110) connected with the conveying pipe and a pressurizing section (130) connected with the filtering device (200), and the outside of the extrusion assembly (100) is wrapped with a temperature control device (300);

a control system (400) for controlling the heating system and the temperature control device (300);

the control process is as follows:

s1, starting the heating system to preheat the filtering device (200), starting a temperature control device (300) outside the pressurizing section (130) at the same time, and preheating the pressurizing section (130) according to a set rate;

s2, after preheating to a set time or a set temperature, starting a temperature control device (300) outside the plasticizing and mixing section (110), and heating the plasticizing and mixing section (110);

s3, heating the filtering device (200) and the pressurizing section (130) to a set temperature value, and then starting to carry out heat preservation on the filtering device (200) and the pressurizing section (130);

s4, heating the plasticizing and mixing section (110) to a set temperature, and preserving heat;

s5, starting a material conveying pipe to feed, and controlling the temperature of the plasticizing and mixing section (110) through the temperature control device (300).

2. The temperature control system of a mixing extruder according to claim 1, wherein: the temperature control device (300) comprises a heat insulation layer (310), and the heat insulation layer (310) is wrapped outside the extrusion assembly (100); a plurality of heating elements (320) are arranged on the inner surface of the heat insulation layer (310); a flow guide channel (330) is arranged between the heat insulation layer (310) and the plurality of heating elements (320); two ends of the flow guide channel (330) are connected with a cooling system, and the cooling system comprises a cooling liquid circulating device and a gas circulating device;

the cooling liquid circulating device is used for circularly conveying cooling liquid to the flow guide channel (330);

the gas circulation device is used for circulating gas in the flow guide channel (330).

3. The temperature control system of a mixing extruder according to claim 1, wherein: a vacuum mixing section (120) is arranged between the plasticizing mixing section (110) and the pressurizing section (130), and a vacuumizing device (140) is arranged on the side wall of the vacuum mixing section (120);

the vacuum mixing section (120) and the plasticizing mixing section (110) are synchronously heated and controlled in temperature;

and the vacuumizing device (140) is synchronously started when the vacuum mixing section (120) is started and heated, and performs vacuumizing operation on the interior of the mixing extruder.

4. The temperature control system of a mixing extruder according to claim 2, wherein: the cooling liquid circulating device is combined with the gas circulating device.

5. The temperature control system of the mixing extruder according to claim 4, wherein: the cooling liquid circulating device comprises a liquid storage bin (341), a circulating pump (342) and a cooling device (343), wherein the liquid storage bin (341), the circulating pump (342) and the cooling device (343) are connected through pipelines and are connected to two ends of the diversion channel (330); an infusion port (3411) of the liquid storage bin (341) is arranged at one end of the flow guide channel (330), and one end, far away from the infusion port (3411), of the liquid storage bin (341) is connected with the cooling device (343);

the gas circulating device adopts the same circulating pump (342) and the same cooling device (343), and is provided with a gas guide pipe (344), one end of the gas guide pipe (344) is communicated with the infusion port (3411), and the other end is communicated with a pipeline connected with the liquid storage bin (341) and the cooling device (343); a three-way valve is arranged at the joint of the air duct (344) and the infusion port (3411).

6. The temperature control system of a mixing extruder according to claim 2, wherein: the temperature control mode of the plasticizing mixing section (110) is as follows:

s5.1, calculating a heat generation rate Q1 when the plasticizing and mixing section (110) mixes;

s5.3, starting the gas circulation device, and driving the cooling liquid to circulate in the flow guide channel (330) by using gas;

s5.4, the cooling liquid is completely gasified in the guide flow channel (330), and the heat absorption rate Q2 of the gasification of the cooling liquid is equal to the heat generation rate Q1, and the cooling liquid flows back to the cooling liquid circulating device through the gas circulating device.