A spiral blade unfolding and kneading self-cleaning device for multi-shaft horizontal reactor

Abstract

The application discloses a novel spiral blade type unfolding and kneading self-cleaning device for a multi-shaft horizontal reactor, which comprises 2-4 groups of kneading stirring shaft assemblies, the kneading stirring shaft assembly is composed of a spiral blade kneading unit and a mandrel, the mandrel has 2-4 roots and is arranged in a linear type in a horizontal direction, the mandrels rotate in the same direction, and 5-20 spiral blade kneading units are fixed on each mandrel along the axial direction at equal intervals, the spiral blade kneading unit is composed of a support and spiral blades distributed on the edge of the support, the spiral blade mainly comprises a spiral blade tip angle and six surfaces, namely a spiral blade outer curved surface, a spiral blade inner curved surface, a spiral blade tail long surface, a spiral blade tail short surface and two spiral blade side surfaces, the direction of the spiral blade tip angle is the same as the rotating direction, the spiral blade tip angle faces forward during rotation, and the joint of the spiral blade tail short surface and the spiral blade tail long surface is at the rear. The three-dimensional spiral blade type unit reduces the resistance, and when the mandrel rotates, the rotation scraping capacity of the spiral blade is stronger, compared with a plane type rotor which has a dead zone on the back of the rotor, the spiral blade can realize omnidirectional self-cleaning, and effectively prevents material from depositing on the device.

Description

TECHNICAL FIELD

[0001] The present application relates to a spiral blade type unfolding and folding kneading self-cleaning device, in particular to a spiral blade type unfolding and folding kneading self-cleaning device for a multi-shaft horizontal reactor. BACKGROUND

[0002] In the process of devolatilization or polymerization, the commonly used reaction and devolatilization equipment includes a tubular reactor, a stirred tank reactor, a reaction / devolatilization type double screw extruder and a horizontal reactor.

[0003] The horizontal reactor is particularly suitable for the reaction or devolatilization of high-viscosity materials, because it has a larger working volume and heat exchange area, excellent interface renewal capacity, mass transfer and heat transfer capacity and self-cleaning capacity.

[0004] The working unit of the horizontal reactor for stirring and mixing materials currently includes a flat rotor structure such as a harrow, a spiral belt, a tooth shape and an E-shaped rotor. The E-shaped hook has better mixing and self-cleaning functions, but still has the following shortcomings: such a rotor has defects when producing materials with extremely high viscosity and melt strength, and cannot form complete self-cleaning between the hook and the hook, and between the hook and the shaft.

[0005] Due to insufficient rotor self-cleaning capacity, a certain amount of high-viscosity material will still stick to the rotor; or the material will stick to the back of the hook, forming a dead zone of accumulated material. The long-term residence of the accumulated material will cause uneven product polymerization degree, or cause the material to decompose for a long time. When the material accumulation is serious, the entire pair of rotors will be wrapped in the material, which will affect the film drawing effect on the material and reduce the reaction / devolatilization effect. Meanwhile, the large thickness of the material layer will also increase the resistance to the rotor and the motor load. Therefore, a new self-cleaning device is needed to solve the above problems. SUMMARY

[0006] To solve the problem of the self-cleaning capacity limitation of the reactor rotor, the present application provides a spiral blade type unfolding and folding kneading self-cleaning device for a multi-shaft horizontal reactor.

[0007] The present application provides the following technical solutions:

[0008] A kind of screw blade type unfolding and closing kneading self-cleaning device for multi-shaft horizontal reactor, including 2-4 groups of kneading stirring shaft assemblies, the kneading stirring shaft assembly is composed of screw blade kneading unit and mandrel, mandrel has 2-4, in horizontal direction, in a straight line type is arranged, mandrel same direction operation, 5-20 screw blade kneading units are fixed along the axis direction on each mandrel and are equally spaced, screw blade kneading unit is composed of support and the screw blade that support edge circumferential distribution, screw blade includes screw blade sharp angle and 6 faces, respectively screw blade outer curved surface, screw blade inner curved surface, screw blade tail long face, screw blade tail short face and two screw blade side, the direction of screw blade sharp angle is same with the direction of rotation, when operating, screw blade sharp angle is towards front, the joint of screw blade tail short face and screw blade tail long face is in back.

[0009] Further, the screw blade is distributed on the edge of the support, and is fixed on the edge top of the support in the form of mechanical connection or welding, 3-6 screw blades are arranged on the edge of the support of each screw blade kneading unit in the circumferential direction, the screw blade sharp angle is towards the same rotation direction, and the supports on each mandrel are arranged in the axial direction of the mandrel, and the supports on the adjacent two mandrels are staggered.

[0010] Further, the screw blade thrust surface on the kneading stirring shaft assembly and the mandrel axis direction exist an angle θ, the angle θ is in the range of 5-20°, the screw blade outer curved surface and the side shaft mandrel gap f is in the range of 1≦f≦20mm, and the screw blade side and the support end surface gap g of the side shaft is in the range of 1≦g≦20mm.

[0011] Further, the screw blade kneading unit and the mandrel are both provided with heat medium flow channels, and hot medium is passed in the flow channels to heat the kneading stirring shaft assembly.

[0012] Further, the relationship between the outer diameter D of the kneading stirring shaft assembly and the outer diameter d of the mandrel is D=i×d, i is the depth ratio coefficient of the screw blade kneading stirring shaft assembly, the design value of i is in the range of 2-2.7, the outer diameter D of the kneading stirring shaft is determined according to the center distance L, and the relationship between the center distance L and the outer diameter D of the kneading stirring shaft and the outer diameter d of the mandrel is center distance L= , the length-diameter ratio of the kneading stirring shaft is l / D=4:1-8:1, l is the length of the kneading stirring shaft, the rotation mode of the kneading stirring shaft assembly is same direction differential speed rotation, the speed ratio between the shafts is 4:5 for double-shaft differential speed ratio, 4:5:4 for three-shaft differential speed ratio, and 4:5:4:5 for four-shaft differential speed ratio, the design range of the center distance L is 80-1100mm, and the rotation speed range of the kneading stirring shaft assembly is 2-100rpm.

[0013] Further, the length of each screw blade is determined according to the lead S, the lead S is in the range of 2300-42000mm, and the angle θ between each screw blade and the axis direction is 5-20°, the larger the lead S length is, the smaller the angle θ is.

[0014] Compared with the prior art, the beneficial effects of the present application are:

[0015] For ultra-high viscosity materials and lumpy materials, this invention replaces the original planar hooks, such as E-type and toothed structures, with three-dimensional spiral blade units. Specifically, the spiral blade mixing unit adopts a three-dimensional structure with sharp corners and multiple curved surfaces. This structure facilitates the insertion and cutting of ultra-high viscosity materials or lumpy materials, reducing the resistance of the materials to the mixing unit. By replacing the unit with a three-dimensional spiral blade unit, the resistance is reduced, and the spiral blades have a stronger scraping ability when driven by the rotating spindle. Compared with the planar rotor, which has a dead zone on the back of the rotor, the spiral blades can achieve all-round self-cleaning, effectively preventing materials from depositing on the device.

[0016] The curved three-dimensional structure of the spiral blades can also perform excellent mixing, stretching / film stretching, and cutting / shearing of high melt strength agglomerated melts, forming a unique "spreading and kneading" function, further improving its reaction / volatilization efficiency. Attached Figure Description

[0017] Figure 1 This is a structural diagram of the four-claw screw-blade kneading unit of the screw-blade type spreading and kneading self-cleaning device of the present invention.

[0018] Figure 2 This is a front view of the four-claw screw-blade kneading unit of the screw-blade type spreading and kneading self-cleaning device of the present invention.

[0019] Figure 3 This is a top view of the four-claw screw-blade kneading unit of the screw-blade type spreading and kneading self-cleaning device of the present invention.

[0020] Figure 4 This is a left view of the four-claw screw-blade kneading unit of the screw-blade type spreading and kneading self-cleaning device of the present invention.

[0021] Figure 5 This is a structural diagram of the five-claw screw-blade kneading unit of the screw-blade type spreading and kneading self-cleaning device of the present invention.

[0022] Figure 6 This is a front view of the five-claw screw-blade kneading unit of the screw-blade type spreading and kneading self-cleaning device of the present invention.

[0023] Figure 7 This is a top view of the five-claw screw kneading unit of the screw-type spreading and kneading self-cleaning device of the present invention.

[0024] Figure 8 This is a left view of the five-claw screw-blade kneading unit of the screw-blade type spreading and kneading self-cleaning device of the present invention.

[0025] Figure 9 The parameters and clearance diagram of the spiral-type spreading and kneading self-cleaning device of the present invention (taking a horizontal triaxial reactor as an example).

[0026] Figure 10This is a diagram of the main body of the spiral-type spreading and kneading self-cleaning device of the present invention (circles indicate the meshing area between the spiral blades and the support; taking a three-axis device as an example, the same applies below).

[0027] Figure 11 This is a schematic diagram of the operation of the spiral-type spreading and kneading self-cleaning device of the present invention.

[0028] Figure 12 This is a cross-sectional view showing the operating position of the spiral-type spreading and kneading self-cleaning device of the present invention.

[0029] In the diagram: 101, Support component; 102, Sharp corner of the screw blade; 103, Outer curved surface of the screw blade; 104, Inner curved surface of the screw blade; 105, Long surface of the tail of the screw blade; 106, Short surface of the tail of the screw blade; 107, Side surface of the screw blade; 108, Barrel; 109, Barrel jacket; 201, Mandrel 1; 202, Screw blade 1 of mandrel 1; 203, Screw blade 2 of mandrel 1; 204, Screw blade 3 of mandrel 1; 205, Screw blade 4 of mandrel 1 206. Mandrel 1, Screw 5; 207. Mandrel 1 support; 301. Mandrel 2; 302. Mandrel 2, Screw 1; 303. Mandrel 2, Screw 2; 304. Mandrel 2, Screw 3; 305. Mandrel 2, Screw 4; 306. Mandrel 2, Screw 5; 307. Mandrel 2, Screw 6; 308. Mandrel 2 support; 401. Mandrel 3; 402. Mandrel 3, Screw 1; 403. Mandrel 3, Screw 2. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings (taking a three-axis embodiment as an example). Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Figure 10 , 11 As shown in Figure 12, a spiral-type kneading self-cleaning device for a multi-axis horizontal reactor of the present invention includes 2-4 sets of kneading stirring shaft assemblies. The kneading stirring shaft assembly consists of spiral kneading units and mandrels. There are 2-4 mandrels arranged in a straight line in the horizontal direction. The mandrels rotate in the same direction. Each mandrel has 5-20 spiral kneading units equidistantly sleeved along the axial direction. The arrangement can be either integrally welded or modular.

[0032] The screw kneading unit consists of a support component and screw blades distributed circumferentially around its edge. A heating medium (heat transfer oil / steam / hot water) flows inside the mandrel, which is connected to the on-site heat transfer oil / steam / hot water heating system via a mandrel heat transfer medium inlet pipe and a mandrel heat transfer medium outlet pipe. Each screw kneading unit has an internal heat transfer medium channel for heating, improving the heat transfer efficiency of the outer surface to the material in contact with it.

[0033] The screw blades are distributed circumferentially around the edge of the support component and are fixed to the top edge of the support component by mechanical connection or welding. Each screw blade kneading unit has 3-6 screw blades on the circumferential direction of the top edge of the support component, with the pointed corners of the screw blades facing the same direction of rotation. These components can be installed and adjusted according to specific conditions. The support components on each mandrel are arranged axially along the mandrel direction, and the arrangement method is either integral welding or modular structure, with the support components on adjacent mandrels arranged alternately.

[0034] During operation, due to the misalignment of the screw reeling units on two adjacent spindles, the screw of one spindle can smoothly pass through the gap between two adjacent supports on the side shaft, and the screw reeling units on the two spindles separated by one spindle are parallel to each other.

[0035] This spiral-blade spreading and kneading self-cleaning device can be used in multi-axis horizontal reactors for reaction or devolatilization operations of high-viscosity materials.

[0036] The screw blade structure has six surfaces, including the outer curved surface of the screw blade, the inner curved surface of the screw blade, the short surface of the tail of the screw blade, the long surface of the tail of the screw blade, and two side surfaces of the screw blade. When running, the pointed corners face forward, and the junction of the short surface and the long surface of the tail is at the rear.

[0037] The thrust surface of the screw blade on the kneading and stirring shaft assembly has an angle θ with the axis of the mandrel, ranging from 5 to 20°, preferably 10 to 15°. The gap f between the outer curved surface of the screw blade and the mandrel is in the range of 1 ≤ f ≤ 20 mm, and the gap g between the side of the screw blade and the end face of the support of the mandrel is in the range of 1 ≤ g ≤ 20 mm.

[0038] Both the screw kneading unit and the mandrel are equipped with heat medium channels. The heat medium flows through the channels to heat the kneading stirring shaft assembly, thereby increasing the heat exchange efficiency of the material in contact with the kneading stirring shaft assembly.

[0039] The relationship between the outer diameter D of the kneading mixing shaft assembly and the outer diameter d of the mandrel is: D = i × d, where i is the depth ratio coefficient of the screw kneading mixing shaft assembly, and the design value range of i is 2-2.7. The outer diameter D of the kneading mixing shaft is determined based on the center distance L. The relationship between the center distance L and the outer diameter D of the kneading mixing shaft and the outer diameter d of the mandrel is: Center distance L = The length-to-diameter ratio of the kneading mixing shaft is l / D = 4:1-8:1, where l is the length of the kneading mixing shaft. The kneading mixing shaft assembly rotates in the same direction with differential speed. The speed ratio between the shafts is: 4:5 for dual shafts (corresponding to 4 and 5 screws per kneading unit for dual shafts, the same below), 4:5:4 for three shafts, and 4:5:4:5 for four shafts. The design range of the center distance L is 80-1100mm, and the rotational speed range of the kneading mixing shaft assembly is 2-100rpm.

[0040] The overall structure of each screw blade on the kneading and stirring shaft adopts a design similar to a simple harmonic wave. The length of each screw blade is determined by the lead S, which ranges from 2300 to 42000 mm. The angle θ between each screw blade and the axis ranges from 5 to 20°. The longer the lead S, the smaller the angle θ.

[0041] Figure 9 The diagram shows the diameter and clearance of the barrel and the screw blades of this invention (taking a horizontal triaxial reactor as an example), with barrel 108 and barrel jacket 109. In the diagram, e represents the clearance between the inner wall Φ of the barrel and the outer diameter D of the stirring shaft.

[0042] As attached Figure 10 As shown, the mandrel includes mandrel 1 201, mandrel 2 301 and mandrel 3 401 (taking a horizontal triaxial reactor as an example, the same below). The three mandrels are arranged in parallel, and several screw blade kneading units are equidistantly sleeved on each mandrel. Each screw blade kneading unit of mandrel 1 201 and mandrel 3 401 contains 4 screw blades, and each screw blade kneading unit of mandrel 2 301 contains 5 screw blades.

[0043] The mandrel support 207 on mandrel 1 201 includes mandrel 1 screw 202, mandrel 1 screw 203, mandrel 1 screw 3 204, mandrel 1 screw 4 205, and mandrel 1 screw 5 206 is coaxially adjacent to the mandrel support 207 on the mandrel support 1, with the mandrel 1 screw 2 203 positioned one position backward in the cross-section of the paper.

[0044] The mandrel 3 401 includes mandrel 3 screw 1 402 and mandrel 3 screw 2 403.

[0045] The mandrel support 308 on the mandrel 2 301 includes mandrel 2 screw 1 302, mandrel 2 screw 2 303, mandrel 2 screw 304, mandrel 2 screw 4 305, and mandrel 2 screw 5 306. The mandrel 2 screw 6 307 is coaxially adjacent to the mandrel support 308, and the mandrel 2 screw 2 303 is positioned one position backward in the cross-section of the paper.

[0046] The three axes correspond to a speed ratio of 4:5:4. Taking mandrel 1 201 and mandrel 2 301 as an example, the screw kneading units of two adjacent mandrels are staggered and rotate in the same direction. With this design, when the mandrel 1 screw 2 203 and its supporting component are in operation, they can pass smoothly between mandrel 2 screw 2 303 and mandrel 2 screw 6 307 without getting stuck.

[0047] 1. Overall technical parameters of the spiral-type spreading and kneading self-cleaning device

[0048] The kneading and stirring shafts are parallel 2-4 shafts.

[0049] The outer diameter d of the mandrel, and the outer diameter D of the kneading agitator shaft. The agitator shaft depth ratio coefficient i = The design value range for i is 2-2.7.

[0050] The center distance L between two adjacent kneading mixing shafts = The design range for the center distance L is 80-1100mm.

[0051] From the above center distance formula, we get the mandrel outer diameter d = The outer diameter of the mandrel is 43-733.

[0052] The outer diameter of the kneading mixing shaft is D = i·d. The minimum value of the outer diameter D is 2×43=86mm and the maximum value is 2.7×733≈1979mm. The range of the outer diameter D of the kneading mixing shaft is 86-1979mm.

[0053] The length-to-diameter ratio of the kneading mixing shaft is l / D = 4:1-8:1, where l is the length of the kneading mixing shaft.

[0054] 2. Structure and Self-Cleaning Instructions of the Spiral Blade Mixing Unit

[0055] As attached Figure 1 , 2 As shown in Figures 3, 4, 5, 6, 7, and 8, the screw blade includes a pointed tip and six surfaces: an outer curved surface 103, an inner curved surface 104, a long tail surface 105, a short tail surface 106, and two side surfaces 107. The pointed tip 102 faces the same direction as the rotation direction and is fixed to the support by mechanical connection or welding. (See attached figure) Figure 11 As shown, the overall structure of each screw blade on the kneading and mixing shaft adopts a design similar to a helical lead. Due to self-cleaning through meshing with adjacent screw blades on the bypass shaft, it breaks down into discontinuous individual screw blade structures. During rotation, it generates axial thrust, continuously and stably propelling the material along the axial direction. The length of each screw blade is determined by the lead S (i.e., the wave period, the distance a point on the screw blade moves along the axial direction when it completes one revolution along the wave and the axis), with a lead S range of 2300-42000 mm. (See attached image) Figure 11 As shown, taking mandrel 3401 as an example, the angle θ between each screw blade and the axis ranges from 5-20°. The larger the lead S, the smaller the angle θ. In actual production, the angle θ depends on the required material residence time; the larger the angle θ, the shorter the residence time.

[0056] For ultra-high viscosity and lumpy materials, the screw-blade mixing unit adopts a three-dimensional structural design with sharp corners and multiple curved surfaces. The three-dimensional design with sharp corners and curved surfaces facilitates the insertion and cutting of ultra-high viscosity or lumpy materials into the mixing unit, reducing the resistance of the material to the mixing unit.

[0057] 3. The self-cleaning and kneading functions of the spiral-type kneading self-cleaning device:

[0058] The kneading and self-cleaning functions of the screw blade mixing unit are mainly formed at the meshing points with adjacent screw blades. The multi-curved profile of the screw blades and the differential speed design of the mandrel enable mutual scraping between screw blades (including between the screw blade tip and the short tail surface, between the inner curved surface and the long tail surface), between the screw blade tip and the adjacent mandrel, between the screw blade side and the adjacent support, and between the outer curved surface of the screw blade and the inner wall of the barrel, thus forming a "self-cleaning" effect on the screw blade surface, support surface, shaft surface, and inner wall of the barrel.

[0059] The screw blades rotate in the same direction but at different speeds. At the meshing point, the pointed corners 102 and outer curved surfaces 103 of two adjacent screw blades on different axes rotate in opposite directions. The combined rotational speed enhances the effect of differential rotation, resulting in excellent stretching and film-forming effects on the material. Simultaneously, during the meshing process between the outer curved surface 103 of the mixing screw blade and the adjacent mandrel-201, as well as the meshing of the inner curved surface 104, the long tail surface 105, and the short tail surface 106 of the screw blade with adjacent screw blades, the screw blades shear and mix the material between them. This process is a "spreading and kneading" process, which improves the mass and heat transfer and interface renewal capabilities of the screw blade device, thereby increasing reaction or devolatilization efficiency.

[0060] The meshing is described as follows:

[0061] As attached Figure 10 As shown, the axial distance g between the second screw blade 303 and the first support member 207 of the spindle, and between the third screw blade 402 and the second support member 308 of the spindle, is very small. Taking the second screw blade 303 and the first support member 207 of the spindle as an example, during operation, the side of the second screw blade 303 can catch and sweep the residual material on the first support member 207 of the spindle, while the first support member 207 of the spindle can also catch and sweep the residual material on the side of the second screw blade 303 of the spindle, thus realizing the self-cleaning of the screw blade and the support member.

[0062] As attached Figure 12 As shown, during the rotation of the mandrel, when it reaches position one, it can be observed that due to the angle θ between the screw and the mandrel axis, the screw... Figure 12 Cross-sectional observation shows that there are not only three screw-kneading units. The screw and support facing inward will always be slightly ahead of the screw and support facing outward in the rotation direction. For example, on mandrel 1 201 and mandrel 2 301, screw 5 206 and screw 6 307 of mandrel 1 have almost completed the meshing process, while screw 2 203 of mandrel 1 and screw 2 303 of mandrel 2 facing outward are currently meshing.

[0063] Specific observation reveals that the first screw blade 202 and the second screw blade 203 on the first mandrel 201 mesh with the second screw blade 302 and the second screw blade 303 on the second mandrel 301, respectively. The meshing areas differ: the pointed corner of the first screw blade 202 meshes with the short tail face of the second screw blade 302, thus scraping away material from both surfaces; the inner curved surface of the second screw blade 203 meshes with the long tail face of the second screw blade 303, and the meshing surface is the same as that of the second screw blades 203 and 303, achieving a self-cleaning function between the screw blades; the second screw blade 303 and the third screw blade 402... The outer curved surfaces and sharp corners can scrape the surfaces of the first screw blade 201 and the second screw blade 301 of the mandrel, respectively, to achieve self-cleaning between the screw blades and the mandrel. In addition, the screw blades 202, 203, 204, and 205 of the first screw shaft 201 and the following screw blades, the screw blades 302, 304, 305, and 306 of the second screw shaft 301 and the following screw blades, and the remaining three groups of screw blades on the third screw shaft 401 except for the screw blade 402 and the following screw blades, the outer curved surfaces or sharp corners of these screw blades are scraping the inner wall of the barrel, to achieve self-cleaning between the screw blades and the inner wall of the barrel.

[0064] The advantages of the spiral-type spreading and kneading self-cleaning device for a multi-axis horizontal reactor according to the present invention are as follows:

[0065] 1. All-round efficient self-cleaning: When the screw-type spreading and kneading self-cleaning device is in operation, the outer curved surface of each screw can self-clean with the bypass shaft, and the two sides can self-clean with the two adjacent support members of the bypass shaft. The screws adjacent to the bypass shaft can also clean every surface of the screw except for the two sides of the screw. Therefore, this screw-type spreading and kneading self-cleaning device can achieve the largest self-cleaning area that can be achieved in the current self-cleaning kneading device, and minimize the accumulation of material in dead zones, avoiding problems such as thermal decomposition and uneven product polymerization caused by long-term material residence.

[0066] 2. Superior Mass Transfer Effect: In the direction of operation, the unique screw structure of the screw-type spreading and kneading self-cleaning device features a sharp angle at the front and an arc-shaped outer surface. During operation, the sharp angle allows for easier penetration and transfer of high-viscosity and high-melt-strength materials, enabling efficient mixing and cutting. It is suitable for materials with viscosity exceeding 300 Pa·s and those in a solid state, achieving high filling rates. Furthermore, at the same rotational speed, compared to other hook structures, the screw applies greater pressure to high-viscosity or high-melt-strength materials, exhibiting better film-forming properties. During devolatilization, it allows for the full exposure and release of volatile components in the material.

[0067] 3. Excellent heat transfer effect: The spindle and the screw kneading unit of the screw-type spreading and kneading self-cleaning device have heat medium flow channels inside, which can be heated by heat medium. It can provide heat to the material from all directions, with a large heat transfer area, more uniform heat transfer and more efficient heat transfer.

[0068] 4. Smooth operation: In the direction of rotation, the unique screw structure of the screw-type spreading and kneading self-cleaning device has sharp corners and smooth outer curved surfaces. When rotating, the sharp corners can more easily penetrate into high viscosity and high melt strength materials, reducing running resistance and reducing the resistance of high viscosity materials to the screw and the load on the main motor.

[0069] 5. Continuous Production: The screw blades on the spindle of the screw-type spreading and kneading self-cleaning device generate axial thrust during rotation because their thrust surfaces are at an angle to the axial direction, continuously and stably pushing the material along the axial direction. Therefore, the screw-type spreading and kneading self-cleaning device can operate continuously and stably for a long time.

[0070] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A spiral-type spreading and kneading self-cleaning device for a multi-shaft horizontal reactor, characterized in that: It includes 2-4 sets of kneading and stirring shaft assemblies. Each kneading and stirring shaft assembly consists of a screw kneading unit and a mandrel. There are 2-4 mandrels arranged in a straight line in the horizontal direction. The mandrels rotate in the same direction. Each mandrel has 5-20 screw kneading units equidistantly fixed along the axial direction. Each screw kneading unit consists of a support and screws distributed circumferentially around the edge of the support. Each screw includes a screw tip and 6 surfaces, namely the outer curved surface (103), the inner curved surface (104), the long surface (105) of the screw tail, the short surface (106) of the screw tail, and two side surfaces (107). The direction of the screw tip (102) is the same as the direction of rotation. During operation, the screw tip... Facing forward, the junction of the short and long surfaces of the screw tail is at the rear; the screw thrust surface and the spindle axis of the kneading stirring shaft assembly have an angle θ, ranging from 5-20°; the gap f between the outer curved surface of the screw and the spindle core ranges from 1≦f≦20mm; the gap g between the side of the screw and the end face of the spindle support ranges from 1≦g≦20mm; the relationship between the outer diameter D of the kneading stirring shaft assembly and the outer diameter d of the spindle is: D=i×d, where i is the depth ratio coefficient of the screw kneading stirring shaft assembly, with a design value range of 2-2.7; the outer diameter D of the kneading stirring shaft is determined based on the center distance L; the relationship between the center distance L and the outer diameter D of the kneading stirring shaft and the outer diameter d of the spindle is: center distance L= The kneading mixing shaft has a length-to-diameter ratio of l / D = 4:1-8:1, where l is the length of the kneading mixing shaft. The kneading mixing shaft assembly rotates in the same direction with differential speeds. The speed ratios between the shafts are: 4:5 for two shafts, 4:5:4 for three shafts, and 4:5:4:5 for four shafts. The center distance L is designed to be between 80-1100 mm. The kneading mixing shaft assembly rotates at speeds between 2-100 rpm. The length of each blade is determined by the lead S, which ranges from 2300-42000 mm. The angle θ between each blade and the axis is 5-20°. The longer the lead S, the smaller the angle θ.

2. The spiral-type spreading and kneading self-cleaning device for a multi-shaft horizontal reactor according to claim 1, characterized in that: The screw blades are distributed around the edge of the support member and are fixed to the top edge of the support member by mechanical connection or welding. Each screw blade kneading unit has 3-6 screw blades around the edge of the support member, with the pointed corners of the screw blades facing the same direction of rotation. The support members on each mandrel are arranged axially along the direction of the mandrel, and the support members on adjacent mandrels are arranged alternately.

3. The spiral-bladed spreading and kneading self-cleaning device for a multi-shaft horizontal reactor according to claim 1, characterized in that: Both the screw kneading unit and the mandrel are equipped with heat medium channels, through which heat medium is circulated to heat the kneading and stirring shaft assembly.

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