A new type of co-rotating parallel multi-screw deep devolatilization extruder

Abstract

The present invention provides a novel parallel multi-screw deep devolatilization extruder in the same direction, comprising: a barrel, a screw installed in the barrel, a drive mechanism connected to the end of the screw, multiple groups of screws arranged in a straight line in the barrel, multiple screws meshing with each other, and the material is mixed, homogenized, and sheared in the meshing area, and a vacuum exhaust devolatilization component is installed on the barrel 3, and the vacuum exhaust devolatilization component includes: an exhaust chamber, a buffer tank, and a connecting pipe. The present invention installs multiple screws arranged in a straight line in the barrel, adaptively adjusts to increase the inner hole cross-section of the barrel, so that the volume ratio of the barrel is increased, and the extra screw and barrel volume bring more working volume. At the same time, due to the increase in the cross-sectional area of ​​the barrel in the devolatilization exhaust section, a high-efficiency deep devolatilization effect is produced.

Description

Technical Field

[0001] The invention relates to the field of polymer material production equipment, in particular to a co-rotating parallel multi-screw deep devolatilization extruder. Background Art

[0002] During the polymerization and blending modification of polymer materials, organic volatiles will be generated. These organic volatiles need to be devolatilized to make the final product meet the use standards. The most common dynamic continuous devolatilization equipment is the twin-screw extruder.

[0003] Since the above-mentioned organic volatiles have the characteristics of high boiling point, low content and good compatibility with polymers, the traditional twin-screw extruder has a small volume ratio and needs to increase the aspect ratio and residence time. However, the increase in residence time is very limited, so it is impossible to meet the volatile content requirements. Passively increasing the thermal history and time will cause the polymer material to be easily decomposed by heat, affecting the comprehensive performance of the material. Summary of the invention

[0004] In view of the problems in the background technology, the present invention provides a novel co-directional parallel multi-screw deep devolatilization extruder, comprising: a barrel, a screw is installed in the barrel, a driving mechanism is connected to the end of the screw, the material enters from the head end of the barrel, the material in the barrel is slowly extruded along the barrel through the screw, and the material is heated and devolatilized while moving in the barrel, characterized in that the screws are arranged in groups in a straight line in the barrel, the multiple screws are meshed in pairs, the material is mixed, homogenized and sheared in the meshing area, and a vacuum exhaust devolatilization component is installed on the barrel 3, The vacuum exhaust and devolatilization component includes: an exhaust chamber, a buffer tank, and a connecting pipe. An exhaust hole is opened on the side wall of the barrel, and the exhaust chamber is docked and installed on the exhaust hole. The exhaust chamber is vertically arranged upward, and an opening is provided on the top of the exhaust chamber and a sealing cover is installed at the opening. A sight glass is provided on the sealing cover. The connecting pipe is installed on the side wall of the exhaust chamber and the end of the connecting pipe is tilted downward. The buffer tank is installed at the end of the connecting pipe. The top of the buffer tank is connected to the vacuum equipment through a hose, and a liquid phase pipeline one-way valve is installed at the bottom of the buffer tank.

[0005] As a preferred solution of the present invention, the volume of the exhaust chamber>the exhaust opening cross-sectional area of ​​the barrel×flow rate×allowed bubbling time.

[0006] As a preferred solution of the present invention, the volume of the buffer tank is determined by the following formula:

[0007] ;

[0008] Where P0 is the standard atmospheric pressure, P1 is the devolatilization pressure, P2 is the devolatilization stop pressure, Q is the volatile flow rate, and T is the vacuum gauge reaction time.

[0009] As a preferred solution of the present invention, the driving mechanism includes: a main motor, a transmission box, and the main motor, transmission box, and barrel are installed on a horizontally arranged bed in sequence. The input shaft of the transmission box is connected to the rotating shaft of the main motor through a safety coupling, and the transmission box is equipped with multiple output shafts, and the multiple output shafts are respectively connected to multiple screws.

[0010] As a preferred solution of the present invention, the barrel is composed of a plurality of unit barrels connected together, and the unit barrels are provided with independent temperature control mechanisms for heating and cooling temperature control treatments.

[0011] As a preferred solution of the present invention, the temperature control mechanism includes: an electric heater, a cooling water flow channel, a thermocouple temperature measuring device, and a circulating water tank. The electric heater is installed outside the unit tube, the cooling water flow channel is arranged around the inner hole of the unit tube, the circulating water tank is connected to both ends of the cooling water flow channel, and the unit tube is also equipped with a thermocouple temperature measuring device.

[0012] As a preferred solution of the present invention, the temperature control mechanism is specifically an independently arranged thermal oil heating system, and independent temperature control in the unit cylinder is achieved through the thermal oil heating system.

[0013] As a preferred solution of the present invention, the barrel is provided with a liquid metering and feeding device, and there are two liquid metering and feeding devices, which are installed on a group of spaced-apart unit barrels.

[0014] As a preferred embodiment of the present invention, 3-6 screws are installed in the barrel and arranged in a straight line, and the outer diameter of the screws is φ72~160mm.

[0015] As a preferred solution of the present invention, according to the material properties, 3-10 vacuum exhaust chamber devolatilization components are configured on the barrel.

[0016] Compared with the prior art, the present invention provides a novel co-rotating parallel multi-screw deep devolatilization extruder, which has the following beneficial effects:

[0017] 1. The present invention installs a plurality of screws arranged in a straight line in the barrel, and adaptively adjusts and increases the inner hole cross-section of the barrel, so that the volume ratio of the barrel is increased. The extra screws and barrel volume bring more working volume. At the same time, due to the increase in the cross-sectional area of ​​the barrel in the devolatilization exhaust section, a high-efficiency deep devolatilization effect is produced.

[0018] 2. The multiple screws of the present invention mesh with each other and have more than two meshing areas. Each rotation of the screw increases the number of times the material is mixed, homogenized, and sheared. The mixing, dispersing, and mixing capabilities of the equipment are stronger, which is more conducive to the release of volatile components inside the material.

[0019] 3. The present invention configures a high-efficiency vacuum exhaust devolatilization component on the barrel, and the vacuum exhaust devolatilization component consists of a high-efficiency vacuum exhaust chamber and supporting components, which effectively improves the devolatilization effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is an overall schematic diagram of a new type of co-rotating parallel multi-screw deep devolatilization extruder.

[0021] Figure 2 This is a side view of the vacuum exhaust devolatilization component.

[0022] Figure 3 This is the front view of the vacuum exhaust devolatilization component.

[0023] Figure 4 It is a schematic diagram of the barrel of a novel co-rotating parallel multi-screw deep devolatilization extruder embodiment 1.

[0024] Figure 5 It is a schematic diagram of the barrel of a novel co-rotating parallel multi-screw deep devolatilization extruder embodiment 2.

[0025] Among them: 1-main motor; 2-transmission box; 3-barrel; 4-vacuum exhaust and devolatilization component; 401-exhaust chamber; 402-buffer tank; 403-connecting pipe; 404-hose; 405-liquid phase pipeline one-way valve; 5-liquid metering and feeding device; 6-circulating water tank; 7-screw. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0027] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] Example 1

[0029] like Figure 1-3As shown, the present invention provides a novel co-directional parallel multi-screw deep devolatilization extruder, comprising: a barrel 3, a screw 7 is installed in the barrel 3, a driving mechanism is connected to the end of the screw 7, the material enters from the head end of the barrel 3, the material in the barrel 3 is slowly extruded along the barrel 3 through the screw 7, and the material is heated and devolatilized while moving in the barrel 3, the screw 7 has multiple groups and is arranged in a straight line in the barrel 3, specifically 3-6 screws 7 are configured, the multiple screws 7 are meshed in pairs, the material is mixed, homogenized, and sheared in the meshing area, and a vacuum exhaust devolatilization component 4 is installed on the barrel 3, The vacuum exhaust devolatilization component 4 includes: an exhaust chamber 401, a buffer tank 402, and a connecting pipe 403. An exhaust hole is opened on the side wall of the barrel 3, and the exhaust chamber 401 is docked and installed on the exhaust hole. Specifically, 3-10 exhaust chambers are configured, and each exhaust chamber 401 is vertically arranged upward. An opening is provided at the top of the exhaust chamber 401 and a sealing cover is installed at the opening. A sight glass is provided on the sealing cover. The connecting pipe 403 is installed on the side wall of the exhaust chamber 401 and the end of the connecting pipe 403 is tilted downward. The buffer tank 402 is installed at the end of the connecting pipe 403. The top of the buffer tank 402 is connected to the vacuum equipment through a hose 404, and the bottom of the buffer tank 402 is installed with a liquid phase pipeline one-way valve 405. The present invention installs a plurality of screws 7 arranged in a straight line in the barrel 3, and adaptively adjusts and increases the inner hole cross-section of the barrel 3, so that the volume ratio of the barrel 3 is increased. The extra screws 7 and the volume of the barrel 3 bring more working volume. At the same time, due to the increase in the cross-sectional area of ​​the barrel 3 in the devolatilization and exhaust section, a high-efficiency deep devolatilization effect is produced. The plurality of screws are meshed in pairs and have more than two meshing areas. Each rotation of the screw increases the number of times the material is mixed, homogenized, and sheared. The mixing, dispersing and mixing capabilities of the equipment are stronger, which is more conducive to the release of volatile components in the material. In addition, an efficient vacuum exhaust devolatilization component is configured, and the vacuum exhaust devolatilization component consists of a high-efficiency vacuum exhaust chamber and supporting components, which effectively improves the devolatilization effect.

[0030] In order to ensure a good devolatilization effect, to reduce the gas flow rate in the exhaust chamber 401 and prevent the volatilization from carrying materials into the exhaust chamber 401 due to too fast flow rate, the cross-sectional area of ​​the exhaust chamber 401 is 3 to 10 times the cross-sectional area of ​​the barrel 3. The gas flow rate in the exhaust chamber 401 is controlled at 2 to 5 m / s through the above design. The length × width or diameter of the exhaust chamber 401 is slightly larger than the length × width or diameter of the exhaust port opened by the barrel 3, so as to fully utilize the gas phase space opened by the barrel 3 for exhaust. In order to prevent the material from overflowing to the pipe opening of the connecting pipe 403, the connecting pipe 403 of the present invention needs to be designed to be higher to increase the volume of the exhaust chamber 401. The volume of the exhaust chamber is greater than the cross-sectional area of ​​the barrel exhaust opening × flow rate × the allowable bubbling time. The allowable bubbling time is usually less than 30s.

[0031] The buffer tank 402 of the present invention is in the shape of a disc and is perpendicular to the pipeline. The radius of the disc is 1.5 to 2 times the diameter of the connecting pipe 403, and the thickness is 2 times the diameter of the connecting pipe 403. In specific implementation, the volume of the buffer tank 402 is determined by a formula, and the specific formula is as follows:

[0032] ; Wherein P0 is standard atmospheric pressure, P1 is devolatilization pressure, P2 is devolatilization stop pressure, Q is volatile flow rate, T is vacuum gauge reaction time, and the upper end of buffer tank 402 is designed with air pressure stabilization port and hose as well as connecting auxiliary facilities. The hose part is convenient for connecting to vacuum pipe system installation.

[0033] All components of the vacuum exhaust devolatilization assembly 4 are made of stainless steel anti-corrosion materials;

[0034] The following is a specific description of the driving mechanism of the present invention, which specifically includes: a main motor 1, a transmission box 2, the main motor 1, the transmission box 2, and the barrel are sequentially installed on the horizontally arranged bed, the input shaft of the transmission box 2 is connected to the rotating shaft of the main motor 1 through a safety coupling, and the transmission box 2 is equipped with multiple output shafts, and the multiple output shafts are respectively connected to multiple screws 7. The main motor 1 of the present invention adopts an AC or DC motor, an AC inverter is configured for AC, and a DC inverter is configured for DC, and the output speed of the main motor is controlled by the inverter. Explosion-proof motors can be configured according to the on-site working conditions, and the explosion-proof grades are Class II and Class III. The transmission box 2 adopts one-axis input and multiple-axis (three to six axes) output, the transmission ratio i=15 / 7.5 / 5 / 3.75 / 3 / 2.5, the output speed is 100~600rpm, and the transmission torque level is up to 10T / A³. The input shaft is equipped with a safety coupling to connect the motor shaft and the transmission box input shaft. When the rotor is stuck or other unexpected situations occur, resulting in excessive load, the safety clutch in the safety coupling will be disengaged to protect the motor and transmission box. Through the self-developed high-performance gear transmission box, the shaft system and bearing selection design have been optimized and improved, and the life of key radial bearings has been greatly extended; low-speed transmission is transmitted through two axial splits, and the load-bearing capacity is 70% higher than the conventional type, which improves the adaptability of equipment processing; at the same time, the transmission box 2 is equipped with an oil-immersed lubrication and circulation cooling device, auxiliary spraying, forced filtration, and no oil interruption design, which improves reliability. The oil lubrication cooling device consists of an oil pump and a high-efficiency heat exchanger to cool the lubricating oil in the transmission box; the gears of the transmission box 2 are made of high-performance materials and hardened tooth surface design, with tooth surface hardness: HRC58-62 and gear grinding accuracy level 6.

[0035] The screw 7 of the present invention is designed by the principle of meshing building block combination, and the special screw elements with different functions are reasonably designed and combined, and the combination is completed by the core shaft optimization structure series combination. It can be adjusted according to different material properties and process requirements to adapt to various complex processes and material requirements. In actual implementation, the number of screws is usually 3 to 6, and the material of the screw 7 is suitable for various types of corrosion-resistant and wear-resistant alloy steel materials. The outer diameter of the screw 7 is φ=71mm~160mm, the aspect ratio of the screw 7 is L / D=28:1-60:1, and the outer diameter of the screw 7 and the screw groove ratio is D / d=1.5-1.7. The screw element is connected to the core shaft by splines, and the core shaft is made of high-toughness, high-bending, high-strength high-quality alloy steel with a quenched and tempered hardness of HB300-350.

[0036] The barrel 3 of the present invention adopts the building block principle design. The barrel 3 is composed of multiple unit barrels connected together. Each unit barrel section usually has the same length and interface form. According to different functional requirements, there are a variety of barrel unit types with different structures and material systems for selection. The length-to-diameter ratio of each unit barrel is L / D=4 or L / D=6, and each barrel section is connected by a flange. The inner hole of the barrel is a multi-hole form of parallel and equidistant intersection, and the number of holes is matched with the meshing screw. The unit barrel material is selected from various types of corrosion-resistant and wear-resistant alloy steel materials.

[0037] The present invention grooves the connecting end faces of adjacent unit tubes and fills them with high temperature resistant sealing materials to ensure reliable sealing of gas-liquid phase media.

[0038] The unit tube 3 of the present invention is provided with an independent temperature control mechanism for heating and cooling temperature control processing. The specific temperature control mechanism includes: an electric heater, a cooling water flow channel, a thermocouple temperature measuring device, and a circulating water tank 6. The electric heater is installed outside the unit tube, and the cooling water flow channel is arranged around the inner hole of the unit tube. The circulating water tank 6 is connected to the two ends of the cooling water flow channel. The unit tube is also equipped with a thermocouple temperature measuring device. The electric heater and the circulating water tank 6 are regulated according to the thermocouple temperature measuring device to cool the over-temperature unit tube to achieve heat exchange balance.

[0039] The present invention is provided with a liquid metering feeding device. For the high-boiling-point additive that is difficult to overflow, a certain amount of solvent is added to swell and dilute the high-boiling-point volatiles that are difficult to overflow, and then devolatilize, so as to meet the requirements of the volatile content. Specifically, a liquid metering feeding device 5 is provided on the barrel 3. There are two liquid metering feeding devices 5, and the two liquid metering feeding devices 5 are installed on a group of spaced-apart unit barrels. Figure 4 As shown, the present invention sets the feed port on the first unit cylinder, and connects the liquid metering feeding device 5 (such as Figure 4 as shown).

[0040] Example 2

[0041] The present invention provides a novel co-rotating parallel multi-screw deep devolatilization extruder. Compared with Example 1, the present invention sets the feed port on the second unit barrel, connects the liquid metering feeding device 5 to the ninth and eleventh unit barrels, and configures the vacuum exhaust devolatilization component 4 (such as Figure 5 As shown in the figure), when the liquid feed contains a low boiling point solvent (more than 10%), the above design can improve the devolatilization efficiency and prevent the gas phase from entraining the material.

[0042] The rest of the structure is the same as that of Example 1.

[0043] Example 3

[0044] The present invention provides a novel co-directional parallel multi-screw deep devolatilization extruder. Compared with Example 1, the temperature control mechanism is specifically an independently arranged heat transfer oil heating system, and the heat transfer oil heating system is used to realize independent temperature control in the unit barrel, and the heat transfer oil is regulated by an oil mold temperature controller.

[0045] The rest of the structure is the same as that of Example 1.

[0046] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should be included in the scope of the claims of the invention.

Claims

1. A novel co-rotating parallel multi-screw deep devolatilization extruder, comprising: A barrel (3) is provided with a screw (7) installed in the barrel (3), and a driving mechanism is connected to the end of the screw (7). The material enters from the head end of the barrel (3), and the material in the barrel (3) is slowly extruded along the barrel (3) through the screw (7). The material is heated and devolatilized while moving in the barrel (3). The invention is characterized in that the screws (7) are arranged in a straight line in the barrel (3) in a plurality of groups, and the plurality of screws are meshed in pairs. The material is mixed, homogenized, and sheared in the meshing area. A vacuum exhaust devolatilization component (4) is installed on the barrel 3. The vacuum exhaust devolatilization component (4) comprises: an exhaust chamber (401), a buffer tank (402), and a connecting pipe (403); an exhaust hole is provided on the side wall of the barrel (3); the exhaust chamber (401) is butt-mounted to the exhaust hole; the exhaust chamber (401) is arranged vertically upward; an opening is provided at the top of the exhaust chamber (401) and a sealing cover is installed at the opening; a sight glass is provided on the sealing cover; the connecting pipe (403) is installed on the side wall of the exhaust chamber (401) and the end of the connecting pipe (403) is tilted downward; the buffer tank (402) is installed at the end of the connecting pipe (403); the top of the buffer tank (402) is connected to the vacuum equipment via a hose (404); and a liquid phase pipeline one-way valve (405) is installed at the bottom of the buffer tank (402); The volume of the exhaust chamber (401) is greater than the cross-sectional area of ​​the exhaust opening of the barrel (3) × flow rate × allowed material emitting time, the cross-sectional area of ​​the exhaust chamber 401 is 3-10 times the cross-sectional area of ​​the barrel 3, and the length × width or diameter of the exhaust chamber 401 is greater than the length × width or diameter of the exhaust opening of the barrel 3; The volume of the buffer tank (402) is determined using the following formula: ; Wherein P0 is standard atmospheric pressure, P1 is devolatilization pressure, P2 is devolatilization stop pressure, Q is volatile flow rate, and T is vacuum gauge reaction time; buffer tank 402 is disc-shaped and perpendicular to the pipeline, the radius of the disc is 1.5-2 times the diameter of connecting pipe 403, and the thickness is 2 times the diameter of connecting pipe 403.

2. A novel co-rotating parallel multi-screw deep devolatilization extruder according to claim 1, characterized in that: The driving mechanism comprises: a main motor (1), a transmission box (2), the main motor (1), the transmission box (2), and a barrel being sequentially mounted on a horizontally arranged bed, the input shaft of the transmission box (2) being connected to the rotating shaft of the main motor (1) via a safety coupling, the transmission box (2) being equipped with a plurality of output shafts, the plurality of output shafts being respectively connected to a plurality of screw rods (7).

3. A novel co-rotating parallel multi-screw deep devolatilization extruder according to claim 1, characterized in that: The barrel (3) is composed of a plurality of unit barrels connected together, and the unit barrel (3) is provided with an independent temperature control mechanism for performing temperature control processing for heating and cooling.

4. A novel co-rotating parallel multi-screw deep devolatilization extruder according to claim 3, characterized in that: The temperature control mechanism comprises: an electric heater, a cooling water flow channel, a thermocouple temperature measuring device, and a circulating water tank (6); the electric heater is mounted outside the unit tube; the cooling water flow channel is arranged around the inner hole of the unit tube; the circulating water tank (6) is connected to both ends of the cooling water flow channel; and the unit tube is also equipped with a thermocouple temperature measuring device.

5. A novel co-rotating parallel multi-screw deep devolatilization extruder according to claim 3, characterized in that: The temperature control mechanism is specifically an independently arranged heat transfer oil heating system, and independent temperature control in the unit cylinder is achieved through the heat transfer oil heating system.

6. A novel co-rotating parallel multi-screw deep devolatilization extruder according to claim 1, characterized in that: The barrel (3) is provided with a liquid metering and feeding device (5), and there are two liquid metering and feeding devices (5). The two liquid metering and feeding devices (5) are installed on a group of unit barrels arranged at intervals.

7. A novel co-rotating parallel multi-screw deep devolatilization extruder according to claim 1, characterized in that: The barrel (3) is provided with 3 to 6 screws arranged in a straight line, and the outer diameter of the screws is φ72 to 160 mm.

8. A novel co-rotating parallel multi-screw deep devolatilization extruder according to claim 1, characterized in that: According to the material properties, 3 to 10 vacuum exhaust chamber devolatilization components (4) are arranged on the barrel (3).

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