CN202155160U - Conical dual-rotor continuous mixing unit - Google Patents

Abstract

The conical double-rotor continuous mixing unit of the utility model is mainly composed of a mixing part and a discharging part, and can adopt a single-stage or double-stage form. The mixing part is mainly composed of feeding device, barrel, conical rotor, heating and cooling device and transmission device. The two rotors used for mixing are conical, and the center line is at a certain angle when installed. The outer diameter profile of each mixing rotor is tapered from large to small, and has a feeding section and a mixing section. The feeding section adopts a screw conveying structure; viewed from the cone surface perpendicular to the outer contour of the rotor, the structure of the mixing section is cam-shaped, S Typical rotor features such as shaped or square rotor types. When the single-stage form is adopted, the end of the rotor adopts a spiral structure to build pressure to convey the material to the machine head; when the two-stage form is adopted, the compounded material enters the next-stage screw extruder through the valve to establish pressure to convey the material to the machine head. Both forms use the machine head suitable for the cavity for granulation or molding. In order to further increase the pressure, a melt pump can also be connected in front of the machine head. The two rotors can be at the same speed or at different speeds, and multiple shearing, stretching and kneading zones are formed during operation, and the material exchange between the rotors is more frequent, which effectively improves the masticating, melting and dispersing performance of the equipment, and shortens the processing time. time, increased production. The mixing unit can be used for mixing and granulation in the processing of rubber, paint, propellant, explosive, pulp, plastic, food, pharmaceutical, feed, etc.

Description

Conical double rotor continuous mixing unit

technical field

The invention relates to a conical double-rotor continuous mixing unit, which can be used in the mixing and granulation process of rubber, paint, propellant, explosive, paper pulp, plastic, food, pharmacy, feed and the like. the

Background technique

Mixing is a key process link that determines the performance of polymer products, especially for high viscoelastic materials such as rubber. The uniformity and stability of material mixing is the key to ensure the quality of polymer products. The realization of uniform mixing mainly depends on mixing technical equipment, including open mixer, internal mixer, double-rotor continuous mixer and screw extruder. Industrially, screw extruders are mainly used for plasticizing plastics, food and thermoplastic elastomers, while the other three are mainly used for mixing complex materials such as rubber, coatings, explosives and propellants. Open mills and internal mixers are batch mixing equipment, which are not only inefficient, but also difficult to achieve the same mixing quality of different batches of materials. the

The double-rotor continuous mixer combines the excellent mixing characteristics of the internal mixer, and also operates continuously, and is widely used in industrial mass production. It is mainly composed of barrel, rotor, unloading device and other parts. The mixing chamber on the barrel is two interconnected holes with a circular cross section, and the materials are sheared, pulverized, kneaded and mixed by the rotor in the mixing chamber. The non-meshing counter-rotating rotor is mainly composed of feeding section, mixing section and discharging section. The feeding section of the rotor is like two non-meshing twin-screws. Driven by the threads of the feeding section of the rotor, the material fed from the feeding port reaches the mixing section. The helix angles on the surface of the mixing section of the rotor are different and the threads are staggered, where the materials are melted, mixed and plasticized. The unloading device can control the opening of the unloading door to achieve the purpose of controlling the residence time of materials in the mixing chamber. the

If we learn from the characteristics of the conical twin-screw extruder, the outer diameter constant rotor in the ordinary twin-rotor continuous mixer is changed into a conical structure with a large tail diameter and a small front diameter, and the barrel also adopts a suitable conical structure, then A new continuous mixer can be formed. The diameter of the tail of the rotor increases, which increases the bearing capacity of the screw, increases the feeding amount, and improves the output; the volume of the feeding section is large, and it is easy to add a large volume of bulk powder; the diameter of the rotor in the discharge section is small, and the shear and The frictional heat is also small, which is suitable for mixing some special materials. the

Contents of the invention

Different from the traditional double-rotor mixing machine, the continuous mixing machine of the present invention adopts two conical rotors arranged at a certain angle to form a conical double-rotor mixing structure, as shown in Figure 1. The conical double-rotor continuous mixing unit is mainly composed of a mixing part and a discharge part, which can be in a single-stage or double-stage form; the mixing part is mainly composed of a feeding device, a barrel, a conical rotor, a heating and cooling device and a transmission. device composition. The outer diameter profile of each mixing rotor is tapered from large to small, and has a feeding section and a mixing section. The feeding section adopts a screw conveying structure; viewed from the cone surface perpendicular to the outer contour of the rotor, the structure of the mixing section is cam-shaped, S Rotor characteristics of shaped or square rotor type. the

Further, for continuous mixing, the mixed material must be transported to the machine head for granulation or molding, that is, a discharge part is required in addition to the mixing part. In this way, the conical double-rotor continuous mixing unit is composed of a mixing part and a discharging part. The complete unit formed for this purpose can be either single-stage or double-stage. the

The single-stage conical double-rotor continuous mixer is that the rotor is composed of a non-meshing screw feeding section, a mixing rotor section and a screw discharging section in turn. The material is continuously added and mixed, and is forced to be discharged to the machine head through the conveying section for granulation. Or forming, the cavity structure of the head depends on the shape of the exported product. In order to increase the outlet discharge pressure, a gear pump can also be connected in front of the machine head. the

The two-stage conical double-rotor continuous mixing unit is shown in Figure 1, which mainly consists of a mixing part and a discharging part. In the first stage, the non-intermeshing screw feeding section and the mixing rotor section are manufactured as a whole, and the materials are continuously fed and mixed, and discharged to the second stage through the discharge valve with adjustable opening at the end. The opening of the valve controls the discharge rate and creates a second-order fullness, builds up pressure, and changes the mixing intensity in the mixing section. The second stage can be a screw extruder, which adopts a screw structure suitable for adding molten materials, and is conveyed to the machine head by the screw for granulation or molding. The cavity structure of the machine head depends on the shape of the exported product. In order to increase the outlet discharge pressure, a gear pump can also be connected in front of the machine head. the

When the conical double-rotor kneader is running, the material is added at the feeding port and conveyed to the kneading rotor section through the screw, and the effective rotor structure is fully utilized for repeated mixing and plasticizing. The mixing section of the rotor of the present invention is conical, the diameter of the section close to the feeding is large, and the diameter of the section close to the discharge is small. Correspondingly, the barrel containing the rotor is also formed by the combination of three cones. In addition to the periodic changes in the circumferential and axial structures of the traditional rotor, the diameter of the conical rotor changes from large to small, which will generate axial compression and kneading and enhance the The axial conveying effect promotes the movement of the mixed material downstream. Therefore, it can significantly improve the mixing effect and increase the output, and has the effect of energy saving and emission reduction. the

At the same time, the diameter of the tail of the conical rotor is increased, the feeding amount is increased, and the output is also increased; the bearing capacity of the rotor is increased, the service life of the gears and bearings is long, and it is conducive to the arrangement of thrust bearings and gears; the volume close to the feeding section is large and easy Adding a larger volume of bulk density powder is also conducive to heat conduction, and it is easier to heat or cool the material; the volume close to the discharge section is small, the peripheral speed is small, the shear generated is low, and the frictional heat is also small. The risk of damage is small; as the outer diameter of the rotor gradually decreases, the material is gradually compressed, so that the screw groove is filled with the material faster, ensuring continuous and smooth mixing of the material; under the same production capacity, the back pressure can be lower. In this way, this type of mixer can also be used for heat-sensitive materials such as powders and PVC. the

Description of drawings

Figure 1 is a schematic diagram of the structure of the conical double-rotor continuous mixing unit

1-motor, 2-reduction and distribution box, 3-barrel, 4-feeding device, 5-heating device, 6-conical rotor,

7-rotor cooling device, 8-motor, 9-reduction box, 10-barrel, 11-heating device, 12-screw,

13-machine head, 14-discharging valve, 15-connecting cylinder. the

Figure 2 is a schematic diagram of the arrangement structure of the conical double rotors

Detailed ways

This implementation case is a double-stage conical double-rotor continuous mixing unit. the

The conical double-rotor continuous mixing unit can be composed of a conical double-rotor continuous mixer connected with a screw extruder, as shown in Figure 1. The mixing part mainly includes: motor 1, deceleration and distribution box 2, barrel 3, feeding device 4, heating device 5, conical rotor 6, and rotor cooling device 7. The screw extrusion part includes: a motor 8, a reduction box 9, a barrel 10, a heating device 11, a screw 12, and a nose die 13. The mixing part and the screw extruding part are connected by a cylinder 15, in which a discharge valve 14 with an adjustable opening is provided. Motor 1, deceleration and distribution box 2 form the transmission device of the equipment. the

The mixing part uses two conical rotors, which are arranged at a certain angle when installed. The outer diameter profile of each mixing rotor is tapered from large to small, and has a feeding section and a mixing section. The feeding section adopts a screw conveying structure; viewed from the cone surface perpendicular to the outer contour of the rotor, the structure of the mixing section is cam-shaped, S Shaped or square rotor type and other rotor characteristics. the

The working principle of the continuous mixing unit is: the motor 1 drives the input shaft of the gearbox to rotate, and the torque and speed are distributed in the gearbox 2, and the two output shafts drive the two conical rotors 6 to rotate in the barrel. The two conical rotors 6 adjust the internal temperature by the end cooling system. The rotor has a non-meshing screw conveying section and a rotor-type mixing section, and is installed in the barrel 3, and the barrel adjusts the external temperature under the action of the heating device 5 . The material is fed into the barrel 3 through the feeding device 4, and conveyed to the mixing rotor section through the screw. The material is plasticized and mixed depending on the heat introduced from the barrel, the shearing, stretching and extrusion kneading of the rotor. The fully mixed material enters the screw extrusion part through the discharge valve 14 and the connecting cylinder 15, and is extruded through the head 13 under the action of the screw conveying to granulate or shape. In order to further increase the pressure, a melt pump can be connected in front of the machine head. the

The mixing sections of the two rotors are non-meshing, so they can be at the same speed or differential speed, and the rotation directions of the two rotors can be combined in different ways. For this reason, an integrated deceleration and distribution box can be used, or a separate deceleration box and distribution box can be used to realize the combination of rotor motion, and the requirement that the axis of the conical rotor is arranged at a cone angle needs to be considered. The rotor mixing section can make full use of various typical mixing rotor structures, such as the cam shape in Figure 2, the S shape in Figure 3, and the quadrilateral rotor type in Figure 4, etc. the

Because the rotor adopts the conical rotor, the axial extrusion and kneading effect is compounded on the traditional mixer, which more effectively improves the plasticizing, melting and dispersing performance of the equipment, shortens the processing time, and has the characteristics of energy saving and emission reduction. It can be used for mixing heat-sensitive materials such as powder and PVC. the

Claims (2)

1. The conical double-rotor continuous mixing unit is mainly composed of a mixing part and a discharge part, which can be in a single-stage or double-stage form; the mixing part is mainly composed of a feeding device, a barrel, a conical rotor, a heating and cooling device and a transmission device, characterized in that: the two rotors for mixing are conical and arranged at a certain angle. 2. The conical double-rotor continuous mixing unit according to claim 1, characterized in that: the outer diameter profile of each mixing rotor is tapered from large to small, has a feeding section and a mixing section, and the feeding section adopts a spiral Conveying structure; viewed from the cone surface perpendicular to the outer contour of the rotor, the structure of the mixing section presents the characteristics of a cam-shaped, S-shaped or square-shaped rotor. the

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