阅读说明：本技术 高填充双转子混炼螺杆 (High-filling double-rotor mixing screw ) 是由 汤善国 李立辉 汤瑜 于 2021-09-23 设计创作，主要内容包括：本发明公开了一种高填充双转子混炼螺杆,包括成对的一号螺杆与二号螺杆,一号螺杆在混炼段设第一异形螺旋与第二异形螺纹,二号螺杆在混炼段设第三异形螺旋与第四异形螺纹,第一、第二、第三及第四异形螺纹均由两段旋向相反的螺棱在混炼段的中部相交而成,并分别形成第一、第二、第三及第四螺棱交汇点。本发明将一对螺杆形成的四个螺棱交汇点沿着物料流向布置在轴向的不同位置,将螺棱交汇点进行分散设置,即扩大了各螺棱交汇点之间的区域,在该较大的区域范围内形成混炼的主要区域。在保证较好的捏合、熔融、混合、塑化效果的前提下,实现了缓解物料的堆积和停滞、利于散热的目的。(The invention discloses a high-filling double-rotor mixing screw, which comprises a first screw and a second screw which are paired, wherein the first screw is provided with a first special-shaped screw and a second special-shaped screw in a mixing section, the second screw is provided with a third special-shaped screw and a fourth special-shaped screw in the mixing section, the first, second, third and fourth special-shaped screws are formed by intersecting two sections of screw edges with opposite rotation directions in the middle of the mixing section, and a first screw edge intersection point, a second screw edge intersection point, a third screw edge intersection point and a fourth screw edge intersection point are respectively formed. The invention arranges four screw ridge junction points formed by a pair of screws at different axial positions along the material flow direction, and dispersedly arranges the screw ridge junction points, namely, enlarges the area between the screw ridge junction points and forms a main mixing area in the larger area range. On the premise of ensuring better effects of kneading, melting, mixing and plasticizing, the aims of relieving accumulation and stagnation of materials and facilitating heat dissipation are fulfilled.)

1. A high-filling double-rotor mixing screw comprises a first screw (1) and a second screw (2) which are arranged in pair, wherein the first screw (1) and the second screw (2) are sequentially divided into a feeding section (A), a mixing section (B) and a discharging section (C) along the material flow direction, a first special-shaped spiral (101) and a second special-shaped thread (102) are arranged on the first screw (1) in the mixing section (B), a third special-shaped spiral (201) and a fourth special-shaped thread (202) are arranged on the second screw (2) in the mixing section (B), the first special-shaped spiral (101), the second special-shaped thread (102), the third special-shaped spiral (201) and the fourth special-shaped thread (202) are formed by intersecting two sections of spiral edges with opposite rotation directions in the middle of the mixing section (B), and form a first spiral edge intersection point (103), a second spiral edge intersection point (104) and a fourth spiral edge intersection point (202) respectively, A third ridge intersection (203) and a fourth ridge intersection (204), characterized in that,

the axial positions of the first spiral edge junction point (103), the third spiral edge junction point (203), the second spiral edge junction point (104) and the fourth spiral edge junction point (204) are sequentially arranged along the material flow direction.

2. The highly filled dual rotor mixing screw of claim 1, wherein the distance of the first flight convergence (103) from the exit end of the mixing section (B) is less than 2/5 of the total length of the mixing section (B).

3. The highly filled, dual rotor mixing screw of claim 2, wherein the distance of said fourth flight convergence (204) from the exit end of said mixing section (B) is greater than 1/4 for the total length of said mixing section (B).

4. A highly filled dual rotor mixing screw according to claim 3, characterised in that the distance of the third flight junction (203), the second flight junction (104) from the exit end of the mixing section (B) is equal to 1/3 for the total length of the mixing section (B).

5. The highly filled dual rotor mixing screw of claim 1, wherein notches are provided at the second flight junction (104) and the third flight junction (104).

6. The highly filled, dual rotor mixing screw of claim 1, wherein the phase angle between screw No. one (1) and screw No. two (2) is 115 °.

Technical Field

The invention relates to the technical field of high polymer processing machinery and screws, in particular to a high-filling double-rotor mixing screw.

Background

A twin-rotor continuous mixer is a novel continuous internal mixer (CN 201950743U, CN 102241085B) developed and manufactured by Farre1 company in the middle of sixties on the basis of a Banbury mixer which is a brand name product of the Farre1 company. The machine mainly comprises a charging barrel, a rotor and a discharging device. The mixing cavity on the charging barrel is a through cavity with an infinite cross section; the charging barrel is also provided with a cooling water hole and an electric heater, so that the materials can be heated and cooled according to the process requirement. The materials are sheared, crushed, kneaded and mixed by the double rotors in the mixing cavity. The discharging device consists of a discharging door and an adjusting device. Through adjusting the adjusting device of unloading, can control the degree of opening of unloading the door, reach the degree of fullness in mixing chamber of control material, and then the purpose of the mixing intensity that the control material experienced. The machine is convenient to maintain, so that the machine is attracted by people. Especially in the large petrochemical industry, is widely used for mixing synthetic polymer materials.

The rotors of a typical double-rotor continuous mixer are a pair of profiled screws, which can be divided into a charging section, a mixing section and a discharging section according to their functions. Wherein, the feeding section is like two non-meshed twin screws, and the materials fed from the feeding port reach the mixing section under the pushing of the screw threads of the mixing section of the rotor. The mixing section is like a pair of internal mixer rotors, and the surface of the mixing section is provided with two pairs of threads with opposite rotating directions and unequal helical angles, and the materials are extruded and crushed, thereby being kneaded, melted, mixed and plasticized. The cross section of the discharging section is generally elliptical or cylindrical or is a threaded section, and materials after mixing are mainly discharged out of the mixing cavity of the charging barrel through a discharging opening.

Typically, the compounding section of each screw rotor has two large lead profile spirals each consisting of two oppositely handed flights intersecting at the middle of the compounding section and forming flight intersections, each pair of screw rotors having four flight intersections. The front screw edge of the screw edge junction conveys the material forward, while the rear screw edge of the screw edge junction pushes the material in the feeding direction. In the mixing process, under the effect of positive and negative spiral arris, the material can take place to pile up and the stagnation at spiral arris intersection point, because four spiral arris intersection point positions are concentrated relatively, consequently form a detention zone, this detention zone can influence the volume exchange and the heat transfer of material to lead to the high temperature of material, take place the degradation even.

Disclosure of Invention

In order to overcome the defects of material accumulation, detention and even degradation of the existing double-rotor mixing screw in the material mixing process, the invention provides a high-filling double-rotor mixing screw.

The technical scheme adopted by the invention is as follows: a high-filling double-rotor mixing screw comprises a first screw and a second screw which are arranged in pairs, wherein the first screw and the second screw are sequentially divided into a feeding section, a mixing section and a discharging section along the material flow direction, the first screw is provided with a first special-shaped screw and a second special-shaped screw in the mixing section, the second screw is provided with a third special-shaped screw and a fourth special-shaped screw in the mixing section, and the first special-shaped screw, the second special-shaped screw, the third special-shaped screw and the fourth special-shaped screw are formed by intersecting two sections of screw ridges with opposite rotation directions in the middle of the mixing section and respectively form a first screw ridge intersection point, a second screw ridge intersection point, a third screw ridge intersection point and a fourth screw ridge intersection point; the axial positions of the first spiral edge junction, the third spiral edge junction, the second spiral edge junction and the fourth spiral edge junction are sequentially arranged along the material flow direction.

Preferably, the distance between the intersection of the first flight and the outlet end of the mixing section is less than 2/5 of the total length of the mixing section.

Preferably, the distance between the intersection of the fourth flight and the outlet end of the compounding section is greater than 1/4 of the total length of the compounding section.

Preferably, the distance between the third flight intersection and the second flight intersection and the outlet end of the mixing section is equal to 1/3 of the total length of the mixing section.

Preferably, a notch is arranged at the intersection point of the second spiral edge and the third spiral edge.

Preferably, the phase angle between the screw rod I and the screw rod II is 115 degrees.

The invention has the beneficial effects that: the invention arranges four screw ridge junction points formed by a pair of screw rotors at different positions in the screw axial direction along the material flow direction, and dispersedly arranges the screw ridge junction points, namely, the area between the screw ridge junction points is enlarged, and a main mixing area is formed in the larger area range. Therefore, the invention realizes the purposes of relieving the accumulation and stagnation of materials and facilitating heat dissipation on the premise of ensuring better kneading, melting, mixing and plasticizing effects.

Drawings

FIG. 1 is a schematic diagram of an embodiment of the present invention.

FIG. 2 is a schematic axial view of the intersection of the ridges in an embodiment of the present invention.

FIG. 3 is a diagram showing the specific location of the flight convergence point in the mixing section in an embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view of the phase angle between the screw I and the screw II according to an embodiment of the present invention.

A first screw 1, a first special-shaped spiral 101, a second special-shaped thread 102, a first spiral ridge junction 103 and a second spiral ridge junction 104;

a second screw 2, a third deformed screw 201, a fourth deformed screw 202, a third screw edge junction 203 and a fourth screw edge junction 204;

a charging section A, a mixing section B and a discharging section C.

Detailed Description

The present invention will be explained in detail below with reference to the accompanying drawings.

In the embodiment, as shown in fig. 1 and 2: a high-filling double-rotor mixing screw comprises a first screw 1 and a second screw 2 which are arranged in pair, wherein the first screw 1 and the second screw 2 are sequentially divided into a feeding section A, a mixing section B and a discharging section C along the material flow direction, the first screw 1 is provided with a first special-shaped screw 101 and a second special-shaped screw 102 in the mixing section B, the second screw 2 is provided with a third special-shaped screw 201 and a fourth special-shaped screw 202 in the mixing section B, and the first special-shaped screw 101, the second special-shaped screw 102, the third special-shaped screw 201 and the fourth special-shaped screw 202 are formed by intersecting two sections of screw ridges with opposite rotation directions in the middle of the mixing section B and respectively form a first screw ridge junction 103, a second screw ridge junction 104, a third screw ridge junction 203 and a fourth screw ridge junction 204; the axial positions of the first spiral edge junction 103, the third spiral edge junction 203, the second spiral edge junction 104 and the fourth spiral edge junction 204 are sequentially arranged along the material flow direction. In the embodiment, four screw ridge junction points formed by a pair of screw rotors are arranged at different positions in the axial direction of the screw along the material flow direction, and the screw ridge junction points are arranged in a dispersing way, namely, the area between the screw ridge junction points is enlarged, and a main mixing area is formed in the larger area range. On the premise of ensuring better effects of kneading, melting, mixing and plasticizing, the aims of relieving accumulation and stagnation of materials and facilitating heat dissipation are fulfilled.

In the example, as shown in fig. 3: the distance between the first spiral rib junction point 103 and the outlet end of the mixing section B is less than the total length of the mixing section B of 2/5; the distance between the fourth screw ridge junction point 204 and the outlet end of the mixing section B is larger than the total length of the mixing section B of 1/4; the distance between the third flight junction 203, the second flight junction 104 and the exit end of mixing section B is equal to the total length of mixing section B at 1/3. In this embodiment, the total length of the kneading section B is H, and the distance between the intersection point of each flight and the outlet end of the kneading section B is H. The change of the position of the intersection point of the screw edges of the large-lead special-shaped screw can change the flow field in the mixing cavity, and further has different degrees of influence on the shearing rate, the average speed, the viscosity and the pressure of the material. It is generally believed that the forward flight of the profiled spiral needs to be long enough for the material to build up sufficient velocity and pressure; in order to provide sufficient counter pressure to produce a high shearing speed of the material, the longer the counter helix of the profiled spiral, the better. Through a large number of experiments, it is found that the best overall performance is obtained when the intersection point of the spiral edges is in the range 1/4 < H/H < 2/5, in particular H/H = 1/3. Therefore, considering the mixing effect, the first rib junction 103 may be disposed at H/H =2/5, the third rib junction 203 and the second rib junction 104 may be disposed near H/H =1/3, and the fourth rib junction 204 may be disposed at H/H =1/4, so as to maximize the main mixing area, thereby alleviating the accumulation and stagnation of materials and facilitating heat dissipation.

In the embodiment, the second ridge junction 104 and the third ridge junction 104 are provided with notches. The breach that these two places set up in mixing process, can alleviate piling up and the stagnation of material on the one hand, and on the other hand does benefit to the material and on the horizontal ascending flow to improve mixing effect.

In the example, as shown in fig. 4: the phase angle between screw 1 and screw 2 was 115 °. The transverse flow of materials between the first screw 1 and the second screw 2 is generally considered to be closely related to the phase angle between the first screw and the second screw, and data show that the transverse flow of the materials between the two screws reaches the maximum at the phase angle of 118-122 degrees under the premise of keeping other conditions unchanged. Therefore, the phase angle between the first screw 1 and the second screw 2 is set to be slightly lower than the limit range, so that the whole mixing performance is improved, and the stable, adjustable and controllable performance of the device can be ensured.

It should be understood that the above-described embodiments of the present invention are merely examples for illustrating the present invention, and are not intended to limit the embodiments of the present invention. Obvious variations or modifications of the present invention are possible within the spirit of the present invention.