Novel horizontal multi-shaft spiral sheet unfolding and folding self-cleaning kneading devolatilization machine

Abstract

The utility model discloses a novel horizontal type multi-shaft screw sheet unfolding and folding self-cleaning kneading devolatilization machine which comprises a transmission system, a machine barrel assembly, a kneading stirring shaft assembly and a movable lathe bed, the machine barrel assembly is formed by connecting a plurality of sections of barrel bodies in series and installed on the movable lathe bed, the kneading stirring shaft assembly is installed in the machine barrel assembly, and the movable lathe bed is installed on the movable lathe bed. The transmission system is connected with and drives the kneading and stirring shaft assembly, the machine barrel assembly is provided with a vacuum exhaust chamber, the kneading and stirring shaft assembly comprises screw sheet kneading units and mandrels, the screw sheet kneading units penetrate through and are fixed outside the mandrels, and a plurality of mandrels are horizontally arranged. According to the novel devolatilization machine, multiple shafts of a double-shaft devolatilization machine are arranged in a horizontal line, so that the width of the devolatilization machine is greatly increased. And the rotor has larger working volume and heat exchange area under the same specification. In addition, due to the fact that multiple shafts in the horizontal direction bring multiple sets of meshing areas, better interface updating and mixing dispersion functions are achieved, the devolatilization efficiency is further improved, and better and all-dimensional kneading and self-cleaning effects are achieved.

Description

Technical Field

[0001] The utility model relates to a devolatilizer, in particular to a novel horizontal multi-axis screw blade expanding self-cleaning kneading devolatilizer. Background Art

[0002] When devolatilizing high-viscosity polymer materials, various devolatilization equipment are currently commonly used, including thin-film evaporators, falling-stripe devolatilizers, and twin-screw extruders. Thin-film and falling-stripe evaporators offer high heat transfer efficiency and rapid evaporation rates, but are only suitable for processing low-viscosity materials (viscosity <150,000 mPa·s). When processing high-viscosity materials (viscosity >150,000 mPa·s), their mass transfer, heat transfer, and interface renewal capabilities are poor, resulting in significantly lower devolatilization efficiency and a high risk of pipe blockage and stalling. Devolatilization twin-screw extruders rely on the screw to mix and stir the material. While they offer excellent mass transfer, heat transfer, and interface renewal, their working volume and heat exchange area are very small, and residence time is very short. This results in very low production capacity when producing materials with high solvent content (solvent content >40%).

[0003] In recent years, several manufacturers, both domestic and international, have developed various horizontal twin-shaft devolatilizers. These devolatilizers utilize one-sided structures, such as "E-shaped claws" and tooth-shaped rotors, in their working components, which can address the aforementioned devolatilization challenges for high-viscosity materials. However, limitations in the twin-shaft structure and manufacturing process prevent the manufacture of large-scale twin-shaft devolatilizers due to limitations in the outer diameter and length of the twin-shaft rotors. Consequently, the heat exchange area and working volume required for large-scale production lines are insufficient, limiting the widespread adoption and application of these horizontal reactors in high-volume projects. Furthermore, the planar structure of the rotor's mixing section also prevents effective self-cleaning and mixing of ultra-high-viscosity materials (viscosity > 5 million mPa·s). Summary of the Invention

[0004] In order to solve the problem of small working volume and heat exchange area of ​​the above-mentioned double-shaft reactor, the utility model provides a novel horizontal multi-shaft screw blade expanding self-cleaning kneading devolatilizer.

[0005] The utility model provides the following technical solutions:

[0006] A novel horizontal multi-axis screw blade spreading self-cleaning kneading devolatilizer comprises a transmission system, a barrel assembly, a kneading stirring shaft assembly and a movable bed. The barrel assembly is composed of multiple barrel sections connected in series and mounted on the movable bed. The kneading stirring shaft assembly is mounted inside the barrel assembly. The transmission system connects and drives the kneading stirring shaft assembly. The barrel assembly is equipped with a vacuum exhaust chamber. The kneading stirring shaft assembly comprises a screw blade kneading unit and a core shaft. The screw blade kneading unit is sleeved and fixed to the outside of the core shaft. Multiple core shafts are arranged horizontally.

[0007] Furthermore, the transmission system includes a main motor, a coupling and a transmission box. The main motor is connected to the transmission box input shaft through the coupling, and the output shaft of the transmission box is connected to the tail end of the core shaft of the kneading and stirring shaft assembly.

[0008] Furthermore, the barrel assembly is provided with feed ports and discharge ports at both ends. The barrel assembly is a double-layer structure with a heating medium passing through the interior, and is provided with a plurality of barrel heat medium feed ports 112 and barrel heat medium discharge ports.

[0009] Furthermore, a heating medium flows through the interior of the core shaft, and the core shaft is provided with a core shaft heat medium inlet and a core shaft heat medium outlet.

[0010] Furthermore, the vacuum exhaust chamber is installed at the opening on the devolatilizer barrel, and the vacuum exhaust chamber includes an exhaust chamber body, a front valve, a bellows compensator, a filter, a rear valve and a condensate collection tank. An upper cover window is installed on the exhaust chamber body, and the exhaust chamber body is connected to the front valve, the bellows compensator and the filter in sequence. The upper end of the filter is connected to the rear valve, and the lower end of the filter is connected to the condensate collection tank.

[0011] Compared to existing technologies, the present invention offers the following advantages: This new multi-shaft, self-cleaning, kneading devolatilizer upgrades a two-shaft devolatilizer to a three- or four-shaft design. This multi-shaft design, arranged horizontally in a straight line, significantly increases the devolatilizer's width. Compared to conventional two-shaft devolatilizers, it offers the same continuous production and self-cleaning capabilities, while boasting a larger working volume and heat exchange area within the same rotor specifications, thus reducing the design and manufacturing complexity of large-scale equipment. Furthermore, the multiple horizontal axes provide multiple meshing areas, resulting in superior interface renewal and mixing and dispersion capabilities, further improving devolatilization efficiency and providing enhanced, all-around kneading and self-cleaning effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is the appearance diagram of the horizontal multi-axis screw blade expansion self-cleaning kneading devolatilizer of the utility model.

[0013] Figure 2 This is a diagram of the barrel and screw blade kneading unit of the utility model.

[0014] Figure 3 This is a diagram of the diameter and gap between the barrel and the screw blade of this utility model.

[0015] Figure 4 This is a structural diagram of the kneading and stirring shaft assembly of the utility model.

[0016] Figure 5 This is a schematic diagram of the structure of the vacuum exhaust chamber component of the utility model.

[0017] In the figure: 101, main motor, 102, coupling, 103, transmission box, 104, feed port, 105, kneading stirring shaft assembly, 106, barrel, 107, vacuum exhaust chamber, 108, discharge port, 109, movable bed, 110, screw kneading unit, 111, mandrel, 112, barrel heat medium inlet, 113, barrel heat medium outlet, 114, mandrel heat medium inlet, 115, mandrel heat medium outlet, 116, exhaust chamber body, 117, upper cover window, 118, front valve, 119, bellows compensator, 120, filter, 121, rear valve, 122, condensate collection tank, 123, barrel jacket. Implementation Method

[0018] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] See also Figure 1-5 The utility model is a novel horizontal multi-axis screw blade expanding self-cleaning kneading devolatilizer, which includes a transmission system, a barrel assembly, a kneading stirring shaft assembly and a movable bed 109. The barrel assembly 106 is composed of multiple barrel sections connected in series and is installed on the movable bed 109 through a bracket. A feed port 104 and a discharge port 108 are provided at both ends of the barrel assembly. The kneading stirring shaft assembly is installed in the barrel assembly, and the transmission system is connected to and drives the kneading stirring shaft assembly.

[0020] The barrel assembly is equipped with a vacuum exhaust chamber 107. Both the barrel assembly and the kneading and stirring shaft assembly are connected to the on-site thermal oil / steam heating system via pipes. This new multi-shaft, self-cleaning, kneading devolatilizer is used to remove solvents from high-viscosity materials under heating and vacuum conditions.

[0021] The transmission system consists of a main motor 101, a coupling 102, and a transmission case 103. The main motor 101 is connected to the input shaft of the transmission case 103 via the coupling 102. The output shaft of the transmission case 103 is connected to the tail end of the core shaft 111 of the kneading and stirring shaft assembly 105. The transmission system drives the rotation of the vane rotor (kneading and stirring shaft assembly 105) and also withstands torque loads. The transmission case 103 is equipped with an oil cooler to cool the bearings and lubricating oil within the case.

[0022] The main motor 101 is an AC variable frequency motor. According to the application requirements, high-voltage AC variable frequency motor, explosion-proof AC variable frequency motor and other types can be selected. The main motor is fixed on the bed, and the output shaft of the main motor 101 is connected to the input shaft of the transmission box 103 through the coupling 102.

[0023] The coupling 102 is configured such that when an unexpected situation such as the screw-type kneading and stirring shaft 105 stalls and causes excessive load, the safety clutch in the coupling 102 is disengaged, thereby protecting the main motor 101 and the transmission box 103.

[0024] The transmission case 103, consisting of a housing, drive shafts, gears, and bearings, is used to reduce the input speed of the main motor 101 and carry torque. The internal structure of the transmission case allows the output shafts to rotate in the same direction at differential speeds. The differential speed ratio of the three-shaft output speeds is 4:5:4, and the differential speed range of the three-shaft output speeds is 2 / 2.5 / 2-40 / 50 / 40 rpm. The transmission case is equipped with a forced lubrication device, mainly consisting of pipelines, an oil pump, and a cooler. It is used for forced spray lubrication of bearings and gear meshing, and is equipped with an external cooler to cool the lubricating oil within the case.

[0025] The kneading and stirring shaft assembly 105 comprises a spiral kneading unit 110 and a core shaft 111. The spiral kneading unit 110 is sleeved and fixed to the outside of the core shaft 111. The tail end of the core shaft 111 is connected to the output shaft of the transmission box 103. The ends of the core shaft 111 are supported by bearings and mechanical seals as dynamic seals. The core shaft 111 is a parallel 2-4 axis with co-directional differential rotation.

[0026] Overall technical parameters of kneading stirring shaft assembly:

[0027] 1. The core shaft 111 is 2-4 shafts arranged horizontally.

[0028] 2. The outer diameter d of the core shaft and the outer diameter D of the kneading stirring shaft. The ratio coefficient of the stirring shaft depth , the design value range of i is 2-2.7.

[0029] 3. Center distance between two adjacent kneading and stirring shafts , the design range of center distance L is 80-1100mm.

[0030] 4. According to the above center distance formula, the outer diameter of the core shaft is obtained .

[0031] 5. The outer diameter of the kneading stirring shaft D = i·d. The minimum value of the outer diameter D of the kneading stirring shaft is 2×43=86mm, and the maximum value is 2.7×733≈1979mm. The range of the outer diameter D of the kneading stirring shaft is 86-1979mm.

[0032] 6. The gap between the outer diameter of the kneading stirring shaft and the inner diameter of the barrel is e=1-25mm (the design value of the gap increases with the increase of equipment specifications)

[0033] 7. The length-to-diameter ratio of the kneading and stirring shaft is L / D = 4:1-8:1;

[0034] 8. The static sealing parts connecting the various sets of screw kneading units on the kneading stirring shaft are all designed with high temperature resistant sealing gaskets (graphite metal spiral wound gaskets) and welded structure sealing.

[0035] Structural features of the screw blade kneading unit 110:

[0036] 1. Each screw kneading unit is equipped with a heat medium flow channel, which is heated by thermal oil / steam to improve the heat transfer efficiency of the outer surface to the contact material;

[0037] 2. The screw slice kneading unit consists of a support and a screw slice. The screw slice mainly includes 6 surfaces, namely the outer curved surface, the inner curved surface, the long surface of the tail, the short surface of the tail and the two side surfaces. The direction of the sharp corners of all the screw slice claws is the same as the direction of rotation. It is fixed to the support by building block connection or welding.

[0038] Mandrel 111:

[0039] 1. Made of high-quality alloy steel with high toughness and high bending resistance, it has good hardenability and stability against overheating.

[0040] 2. The core shaft and the screw claw are connected and fixed by keyway.

[0041] 3. The heating medium (thermal oil / steam) flows through the core shaft and is connected to the on-site thermal oil / steam heating system through the core shaft heat medium inlet 114 and the core shaft heat medium outlet 115.

[0042] Barrel assembly:

[0043] The barrel assembly 106 consists of two to four barrel sections connected in series, each containing a barrel jacket 123. The barrel is mounted on a movable bed 109 via a bracket. A feed port 104 is located on the left side of the barrel, connected to a feed pipe and valve. This port allows the mixed rubber solution to enter the devolatilizer for devolatilization. A discharge port 108 is located on the right side of the barrel assembly, connecting to downstream equipment. Two to four vacuum exhaust chambers 107 are located on the barrel, connected to the vacuum condensation system via vacuum pipes and valves. The barrel assembly is a double-layered structure, with a heating medium (thermal oil / steam) flowing through it. Several barrel heat medium feed ports 112 and discharge ports 113 are located accordingly.

[0044] The main technical parameters of the barrel assembly are as follows:

[0045] 1. The number of barrel holes is 2-4 parallel cross holes, and the center distance L between two adjacent holes is the same as the center distance of the stirring shaft.

[0046] 2. The inner diameter of the barrel hole φ is determined by the outer diameter D of the kneading and stirring shaft blades and the gap e. The size of the gap e is determined by the outer diameter D of the kneading and stirring shaft blades, and the value range is 1-25mm;

[0047] 3. The inner material of the barrel is selected according to the type of material, which can be various types of stainless steel, titanium or Hastelloy;

[0048] 4. Each section of the barrel is a double-layer design with heat transfer oil / steam flowing inside;

[0049] 5. The barrel assembly consists of 2-4 barrel sections connected in series, with a length-to-diameter ratio of L / D = 4:1-8:1;

[0050] 6. The static sealing parts of each section of the barrel assembly are all equipped with high temperature resistant sealing gaskets (graphite metal spiral wound gaskets) and special structural design to ensure reliable sealing of gas and liquid media.

[0051] Vacuum exhaust chamber 107 components:

[0052] The vacuum exhaust chamber 107 is installed at the opening on the devolatilizer barrel. The vacuum exhaust chamber 107 includes an exhaust chamber body 116, a front valve 118, a bellows compensator 119, a filter 120, a rear valve 121 and a condensate collection tank 122. An upper cover window 117 is installed on the exhaust chamber body 116. The exhaust chamber body 116 is connected to the front valve 118, the bellows compensator 119 and the filter 120 in sequence. The upper end of the filter 120 is connected to the rear valve 121, and the lower end of the filter 120 is connected to the condensate collection tank 122. Finally, it is connected to the vacuum system through the main gas phase pipeline.

[0053] Main technical parameters:

[0054] Depending on the volatile matter content, the devolatilizer barrel is equipped with 2-4 vacuum exhaust chambers 107. Each vacuum exhaust chamber 107 is equipped with pipes, valves, filters and other accessories, and is connected to the vacuum condensation system. The vacuum degree range is 100Pa-50KPa (A).

[0055] The exhaust chamber body 116 is designed to be elevated and sandwiched, with internal heating by thermal oil / steam, and a temperature range of 20-300°C.

[0056] The main body and upper cover of the exhaust chamber are made of 316 stainless steel and are equipped with an observation window.

[0057] A gas phase outlet is provided on the exhaust chamber body and is connected to the bellows compensator 119 to offset the displacement caused by thermal stress after the pipeline and the main machine are heated.

[0058] A basket filter is provided inside the filter 120 to filter the materials carried by the vacuum exhaust.

[0059] The front air inlet of the filter 120 is connected to the front valve 118, and the upper outlet of the filter 120 is connected to the rear valve 121. By closing the front valve and the rear valve at the same time, the filter can be temporarily disconnected from the vacuum system, and then the basket filter inside the filter is cleaned. After cleaning, the front and rear valves are opened to restore normal devolatilization and exhaust conditions.

[0060] A condensate port is provided at the bottom of the filter and is connected to the condensate collection tank 122 at the bottom. During the devolatilization process, a small amount of solvent condensed into liquid phase in the entire gas phase pipeline eventually flows back along the pipeline and falls into the condensate collection tank 122 for storage, collection and regular treatment.

[0061] Movable bed 109:

[0062] The movable bed consists of a bed, bracket, and movable slides. The bed has a base that secures the motor and transmission case, while the bracket supports the barrel. The entire bed is divided into sliding and fixed components. During normal operation, the bracket bottom is fixed. During shutdown and kettle cleaning, the barrel and transmission case mountings are removed, and the bolts securing the sliding component are loosened. The sliding component then disengages along the track, allowing the barrel assembly to be pulled out along with the movable components, exposing the internal agitator assembly for cleaning or maintenance.

[0063] The bed is divided into sliding parts and fixed parts;

[0064] The fixed parts are the main motor, transmission box, and transmission box connecting rotor;

[0065] The sliding parts are a barrel and its bracket. A pulley is provided under the barrel bracket and can slide on the track.

[0066] The utility model has the following advantages:

[0067] 1. The new multi-shaft, self-cleaning, kneading devolatilizer utilizes a horizontally arranged multi-shaft structure, significantly increasing its width. Compared to a twin-shaft devolatilizer with the same rotor diameter, the multi-shaft, self-cleaning, kneading devolatilizer boasts a volumetric capacity increase of over 30%, resulting in a higher working volume and greater gas phase space. This allows for higher throughput and production efficiency in high-solvent devolatilization polymerization processes.

[0068] 2. The new multi-shaft screw-fleeting, self-cleaning, kneading devolatilizer offers superior mixing and interface renewal capabilities, contributing to improved devolatilization efficiency. Compared to a twin-shaft devolatilizer with only one meshing area, the multi-shaft screw-fleeting, self-cleaning, kneading devolatilizer has two or more meshing areas. The meshing areas between the multiple shafts stretch and mix highly viscous materials, enhancing the removal of volatile components such as solvents and monomers from the highly viscous polymer, and improving the devolatilization and drying effects.

[0069] 3. The multi-shaft screw blade self-cleaning kneading devolatilizer has a large heat transfer area. Each shaft can be heated by a heat medium. The shaft and the screw blades on the shaft are in direct contact with the material. This further improves the mass and heat transfer capacity during the kneading and stretching of high-viscosity materials, and improves the efficiency of removing volatile components such as solvents.

[0070] 4. The mixing unit on each shaft utilizes a screw-type structure, further enhancing the equipment's self-cleaning capabilities for extremely high-viscosity materials while also reducing resistance to the screw and the load on the main motor. The screw features a sharp angle on the front and a curved outer surface, allowing it to more easily penetrate high-viscosity and high-melt-strength materials during rotation, achieving a slitting, mixing, and film-forming effect.

[0071] This new multi-shaft, spiral-flanged, self-cleaning kneading devolatilizer upgrades a two-shaft devolatilizer to three or four shafts. These multiple shafts are arranged horizontally in a straight line, significantly increasing the devolatilizer's width. Compared to conventional two-shaft devolatilizers, this not only offers the same continuous production and self-cleaning capabilities, but also boasts a larger working volume and heat exchange area within the same rotor specifications, thus simplifying the design and manufacturing of large-scale equipment. Furthermore, the multiple horizontal shafts provide multiple meshing areas, resulting in superior interface renewal and mixing and dispersion, further improving devolatilization efficiency and providing enhanced, all-round kneading and self-cleaning effects.

[0072] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A new type of horizontal multi-shaft screw blade self-cleaning kneading devolatilizer, characterized by: The invention comprises a transmission system, a barrel assembly, a kneading and stirring shaft assembly and a movable bed (109), wherein the barrel assembly (106) is composed of multiple barrel sections connected in series and is installed on the movable bed (109), the kneading and stirring shaft assembly is installed in the barrel assembly, the transmission system is connected to and drives the kneading and stirring shaft assembly, the barrel assembly is equipped with a vacuum exhaust chamber (107), the kneading and stirring shaft assembly (105) comprises a spiral kneading unit (110) and a core shaft (111), the spiral kneading unit (110) is sleeved and fixed on the outside of the core shaft (111), and the core shaft (111) has multiple horizontally arranged ones.

2. A novel horizontal multi-shaft screw blade expansion self-cleaning kneading devolatilizer according to claim 1, characterized in that: The transmission system comprises a main motor (101), a coupling (102) and a transmission box (103); the main motor (101) is connected to an input shaft of the transmission box (103) via the coupling (102); and the output shaft of the transmission box (103) is connected to the tail end of a core shaft (111) of a kneading and stirring shaft assembly (105).

3. The novel horizontal multi-shaft screw blade self-cleaning kneading devolatilizer according to claim 1, characterized in that: The barrel assembly is provided with a feed port (104) and a discharge port (108) at both ends. The barrel assembly is a double-layer structure with a heating medium passing through the interior. A plurality of barrel heat medium feed ports (112) and barrel heat medium discharge ports (113) are correspondingly provided.

4. The novel horizontal multi-shaft screw blade expansion self-cleaning kneading devolatilizer according to claim 1, characterized in that: A heating medium flows through the core shaft (111), and the core shaft (111) is provided with a core shaft heat medium inlet (114) and a core shaft heat medium outlet (115).

5. The novel horizontal multi-shaft screw blade expansion self-cleaning kneading devolatilizer according to claim 1, characterized in that: The vacuum exhaust chamber (107) is installed at the opening of the devolatilizer barrel. The vacuum exhaust chamber (107) includes an exhaust chamber body (116), a front valve (118), a bellows compensator (119), a filter (120), a rear valve (121) and a condensate collection tank (122). An upper cover window (117) is installed on the exhaust chamber body (116). The exhaust chamber body (116) is connected to the front valve (118), the bellows compensator (119) and the filter (120) in sequence. The upper end of the filter (120) is connected to the rear valve (121), and the lower end of the filter (120) is connected to the condensate collection tank (122).

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