Mixing device for plastic powder flame retardant production

Abstract

The utility model discloses a kind of mixing devices for plastic powder flame retardant production, it is related to plastic powder flame retardant production technical field, including mixing cylinder, mixing cavity and cooling cavity are opened in the mixing cylinder, rotatable stirring shaft is arranged in the mixing cavity, a plurality of stirring rods are fixedly connected on the stirring shaft, the cooling cavity is isolated to the mixing cavity and is equipped, baffle is fixedly connected in the cooling cavity, the baffle is separated to form spiral cooling channel in cooling cavity, cooling liquid that can circulate flows is filled in the cooling channel, the device improves the characteristics of the thermal stability of plastic powder flame retardant mixing.

Description

TECHNICAL FIELD

[0001] The utility model relates to plastic powder flame retardant production technical field, specifically is a kind of mixing device for plastic powder flame retardant production. BACKGROUND

[0002] Plastic powder flame retardant is a kind of chemical substance added to plastic to improve its flame retardant performance, which inhibits or delays the combustion process of plastic through different mechanisms. The production mixing process of plastic powder flame retardant is to mix different raw materials or additives according to specific proportion and sequence to obtain flame retardant products with specific performance.

[0003] The current powder mixing equipment has significant defects when handling nano additives, flame retardants and other heat-sensitive materials: high-speed stirring can easily cause local overheating, leading to agglomeration of nano materials or decomposition of flame retardants; conventional equipment cannot isolate air, and there are safety hazards in the process of mixing flammable powder.

[0004] Therefore, it is necessary to design a mixing device for plastic powder flame retardant production to improve the thermal stability of plastic powder flame retardant mixing. INVENTION CONTENTS

[0005] The utility model aims at the existing technical defects, provides a kind of mixing device for plastic powder flame retardant production to solve the problems raised in the above background.

[0006] To solve the above technical problems, the utility model provides the following technical scheme: a kind of mixing device for plastic powder flame retardant production, including mixing cylinder, mixing cavity and cooling cavity are opened in the mixing cylinder, rotatable stirring shaft is arranged in the mixing cavity, a plurality of stirring rods are fixedly connected on the stirring shaft, the cooling cavity is isolated to mixing cavity and is equipped, the cooling cavity is fixedly connected with the partition, the partition is separated to form spiral cooling channel in the cooling cavity, the cooling channel is filled with circulating cooling liquid.

[0007] The utility model further illustrates that the top of the mixing cylinder is provided with a flange for sealing the top of the mixing cavity, a main feed inlet for injecting base powder into the mixing cavity and a secondary feed inlet for injecting main flame retardant into the mixing cavity are formed on the flange, and a sprayer for spraying atomized nano additives into the mixing cavity is also provided on the flange. A discharge port is formed on the lower side of the mixing cylinder.

[0008] The utility model further illustrates that a plurality of stirring rods are linearly and uniformly distributed along the axis direction of the stirring shaft in groups of three, the stirring rods in the same group are uniformly distributed in a circle around the central axis of the stirring shaft, and the length of the stirring rods in the lower conical cavity in the mixing cavity decreases from top to bottom.

[0009] The utility model further illustrates that the discharge port is located the positive center of the conical bottom of the mixing cavity, and a discharge valve is arranged at the discharge port.

[0010] The utility model further illustrates that the driving motor is fixedly connected with the sleeve which is rotatably connected with the discharge port through the bearing and is arranged at the lower end of the stirring shaft, and the connecting rod is fixedly connected with the inner wall of the discharge port and is arranged on the upper side of the discharge valve.

[0011] The utility model further illustrates that the flange is additionally provided with a vacuum interface, and the vacuum interface is connected with a nitrogen generator and a vacuum pump through a three-way valve pipeline.

[0012] The utility model further illustrates that the temperature sensors are embedded in the inner wall of the mixing cavity and are evenly arranged on the inner wall of the mixing cavity from top to bottom.

[0013] The utility model further illustrates that the upper end of the cooling channel is connected with a heat exchanger through a pipeline, the output end of the heat exchanger is connected with a refrigerating machine through a pipeline, and the output end of the refrigerating machine is connected to the lower end of the cooling channel through a pipeline.

[0014] Compared with the prior art, the utility model has the beneficial effects that: the utility model realizes dynamic temperature control by setting temperature sensors and a spiral cooling channel to heat-exchange and cool the mixing cavity, so that overheating of the material during mixing is avoided.

[0015] The vacuum interface is connected with the nitrogen generator to replace the air in the mixing cavity, so that the risk of oxidation and combustion of the combustible powder is eliminated. DRAWINGS

[0016] The drawings are used to provide a further understanding of the utility model and constitute a part of the specification, are used to explain the utility model together with embodiments of the utility model, and do not constitute a limitation on the utility model. Fig. 1 It is the overall structure schematic diagram of the utility model; Fig. 2 It is the mixing barrel side sectional structure schematic diagram of the utility model; In the figure: 1, mixing barrel; 2, support frame; 3, mixing cavity; 4, flange; 5, main feed inlet; 6, auxiliary feed inlet; 7, injector; 8, stirring shaft; 9, stirring rod; 10, discharge port; 11, driving motor; 12, vacuum interface; 13, cooling cavity; 14, partition; 15, cooling channel; 16, sleeve; 17, connecting rod. DETAILED DESCRIPTION

[0017] The utility model discloses technical scheme further non-restrictive detailed description of the following combined with preferred embodiment and its drawings. Obviously, the described embodiment is only a part of the embodiment of the utility model, and is not all the embodiment. Based on the embodiment in the utility model, all other embodiments obtained by the ordinary skill in the art without making creative labor belong to the range of protection of the utility model.

[0018] Please refer to Figs. 1-2 The utility model provides technical scheme: a kind of mixing device for plastic powder flame retardant production, including mixing cylinder 1, support frame 2 is fixedly connected in mixing cylinder 1 outer side, the upper part of mixing cylinder 1 is cylindrical, the lower part of mixing cylinder 1 is conical, mixing cavity 3 is set up in mixing cylinder 1, flange 4 is installed at the top of mixing cylinder 1, and the top of mixing cavity 3 is sealed by flange 4.

[0019] Main feed port 5, vice feed port 6 are set up on flange 4, main feed port 5 is used to inject base powder into mixing cavity 3, and vice feed port 6 is used to inject main flame retardant into mixing cavity 3;Ejector 7 is additionally provided on flange 4, and ejector 7 is used to spray atomized nano adjuvant or surface modifier into mixing cavity 3.

[0020] Rotatable stirring shaft 8 is arranged in mixing cavity 3, and a plurality of stirring rods 9 are fixedly connected on stirring shaft 8, the stirring rods 9 are linearly and uniformly distributed along the axis direction of stirring shaft 8 in groups of three, and the stirring rods 9 in the same group are uniformly distributed in a circle with the central axis of stirring shaft 8 as the center.

[0021] Among them, the length of the stirring rod 9 located in the lower conical cavity in the mixing cavity 3 decreases from top to bottom, so as to fit the lower conical cavity of the mixing cavity 3.

[0022] Discharge port 10 is formed in the lower side of mixing cylinder 1, and the discharge port 10 is located at the center of the conical bottom of mixing cavity 3, and a discharge valve is arranged at the discharge port 10, the discharge valve is a control valve for controlling the opening and closing of the discharge port 10.

[0023] Stirring shaft 8 is vertically arranged, driving motor 11 is fixedly connected to the upper end of stirring shaft 8 and penetrates flange 4, the lower end of stirring shaft 8 extends into discharge port 10 and is rotatably connected with sleeve 16 through bearing, the outer circumference of sleeve 16 is fixedly connected with connecting rod 17, connecting rod 17 is fixedly connected with the inner wall of discharge port 10, and connecting rod 17 is located above the discharge valve.

[0024] Vacuum interface 12 is additionally provided on flange 4, nitrogen generator and vacuum pump are connected with vacuum interface 12 through three-way valve pipeline.

[0025] The cooling cavity 13 is arranged on the mixing barrel 1, the cooling cavity 13 is arranged on the mixing cavity 3, the spiral-shaped partition plate 14 is fixedly connected in the cooling cavity 13, the cooling cavity 13 is divided into the spiral-shaped cooling channel 15 by the spiral-shaped partition plate 14, and the cooling channel 15 is filled with cooling liquid, so that the material in the mixing cavity 3 is cooled.

[0026] The temperature sensors are embedded in the inner wall of the mixing cavity 3, the temperature sensors are uniformly arranged on the inner wall of the mixing cavity 3 from top to bottom, and the temperature sensors are used for detecting the temperature of the material at different depths in the mixing cavity 3.

[0027] The upper end of the cooling channel 15 is connected with a heat exchanger through a pipeline, the output end of the heat exchanger is connected with a refrigerating machine through a pipeline, and the output end of the refrigerating machine is connected to the lower end of the cooling channel 15 through a pipeline.

[0028] In the embodiment, nitrogen is injected into the mixing cavity 3 by the nitrogen generator, air in the mixing cavity 3 is replaced and filled, then base powder is added into the mixing cavity 3 through the main feeding port 5, and then the driving motor 11 is started to drive the stirring shaft 8 to stir.

[0029] In the stirring process, the cooling temperature and flow rate of the cooling liquid in the cooling channel 15 are detected and controlled by the temperature sensors, so that the temperature of the base powder in the mixing cavity 3 is ensured to be less than or equal to 40 DEG C.

[0030] Then, the main flame retardant is sequentially added into the mixing cavity 3 through the auxiliary feeding port 6, and the nano additive or surface modifier is sprayed into the mixing cavity 3 through the injector 7, so that the base powder is mixed with the main flame retardant and the nano additive / surface modifier.

[0031] When the material in the mixing cavity 3 is uniformly mixed by the stirring shaft 8 and the stirring rod 9, the stirring is stopped, then the vacuum pump is started, and the vacuum degree in the mixing cavity 3 reaches 10-50 mbar, so that the air in the powder is extracted and the compactness of the powder is improved.

[0032] Then, nitrogen is filled into the mixing cavity 3 again, and pressure relief is performed, after the pressure relief is completed, the discharge valve is opened, and the powder in the mixing cavity 3 is removed from the discharge port 10, and the mixing is completed.

[0033] In the description of the utility model, it should be understood that the orientation or position relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model, and does not indicate or imply that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, therefore it cannot be understood as a limitation on the utility model.

[0034] It should be pointed out finally that: the above examples are only used to illustrate the technical solutions of the utility model, and not limit it. Although the utility model has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement to part of the technical features, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the utility model.

Claims

1. A mixing device for producing flame retardant in plastic powder, characterized in that: The device includes a mixing cylinder (1), which has a mixing chamber (3) and a cooling chamber (13). The mixing chamber (3) is equipped with a rotatable stirring shaft (8), and several stirring rods (9) are fixedly connected to the stirring shaft (8). The cooling chamber (13) isolates the mixing chamber (3). A partition (14) is fixedly connected to the cooling chamber (13). The partition (14) divides the cooling chamber (13) into a spiral cooling channel (15), which is filled with a circulating coolant.

2. The mixing device for producing flame retardant in plastic powder according to claim 1, characterized in that: The mixing cylinder (1) is equipped with a flange (4) to seal the top of the mixing chamber (3). The flange (4) has a main feed port (5) for injecting base powder into the mixing chamber (3) and a secondary feed port (6) for injecting main flame retardant into the mixing chamber (3). The flange (4) is also equipped with an injector (7) for spraying atomized nano-additives into the mixing chamber (3). The mixing cylinder (1) has an outlet (10) on its lower side.

3. The mixing device for producing flame retardant in plastic powder according to claim 2, characterized in that: Several stirring rods (9) are linearly and evenly distributed in groups of three along the axis of the stirring shaft (8). The stirring rods (9) in the same group are evenly distributed in a circle with the central axis of the stirring shaft (8) as the center. The length of the stirring rods (9) located in the lower conical cavity of the mixing chamber (3) decreases from top to bottom.

4. A mixing device for producing a plastic powder flame retardant according to claim 3, characterized in that: The discharge port (10) is located at the center of the conical bottom of the mixing chamber (3), and a discharge valve is provided at the discharge port (10).

5. A mixing device for producing a plastic powder flame retardant according to claim 4, characterized in that: The upper end of the stirring shaft (8) is fixedly connected to the drive motor (11) through the flange (4), and the lower end of the stirring shaft (8) extends into the discharge port (10) and is rotatably connected to the sleeve (16) through the bearing. The outer circumference of the sleeve (16) is fixedly connected to the connecting rod (17), and the connecting rod (17) is fixedly connected to the inner wall of the discharge port (10). The connecting rod (17) is located on the upper side of the discharge valve.

6. A mixing device for producing a plastic powder flame retardant according to claim 5, characterized in that: A vacuum port (12) is provided on the flange (4), and the vacuum port (12) is connected to a nitrogen generator and a vacuum pump through a three-way valve pipe.

7. A mixing device for producing a plastic powder flame retardant according to claim 6, characterized in that: The mixing chamber (3) is equipped with several temperature sensors embedded in its inner wall. The temperature sensors are evenly spaced from top to bottom along the inner wall of the mixing chamber (3).

8. A mixing device for producing a plastic powder flame retardant according to claim 7, characterized in that: The upper end of the cooling channel (15) is connected to a heat exchanger via a pipe, and the output end of the heat exchanger is connected to a refrigerator via a pipe. The output end of the refrigerator is connected to the lower port of the cooling channel (15) via a pipe.

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