Modified polypropylene foamed bead reaction kettle

Abstract

The invention relates to reaction equipment, and concretely relates to a modified polypropylene foamed bead reaction kettle. The reaction kettle comprises a reaction kettle body, a variable frequencymotor is arranged above the reaction kettle body, the variable frequency motor is connected with a speed reducer, the speed reducer is connected with an outer permanent magnet, an inner permanent magnet is arranged in the outer permanent magnet, and a first sealing cavity is formed between the outer permanent magnet and the inner permanent magnet; a stirring shaft positioned at the longitudinal central axis of the reaction kettle body is arranged in the reaction kettle body; a shaft cooling water jacket is arranged on the outer surface of the stirring shaft; the shaft cooling water jacket is connected with a shaft cooling water inlet and a shaft cooling water outlet; the stirring shaft is connected through a shaft coupling which is arranged in an upper kettle body, is positioned above an upper kettle body flange and is movably connected to the stirring shaft; and the stirring shaft is connected with a bearing, and a bearing cooling water jacket is arranged on the outer surface of the bearing. According to the reaction kettle, reliable sealing performance can be guaranteed, so that accurate temperature and pressure control can be carried out, and good foaming performance is achieved.

Description

technical field [0001] The invention relates to a reaction device, in particular to a modified polypropylene foamed bead reaction kettle. Background technique [0002] Reactors are widely used in coatings, medicine, building materials, chemicals, pigments, resins, food, scientific research and other industries. The equipment can be made of carbon steel, stainless steel and other materials according to the process requirements of the user's products, and heating and cooling devices can be set to meet different requirements. process and production needs; the heating forms include jacket electric heating and coil heating. The equipment has reasonable structural design, advanced technology, durability, and has the characteristics of simple operation and convenient use. High chemical equipment. The reaction kettle used in the supercritical carbon dioxide autoclave pressure foaming process also needs to be stirred during the heating and pressing process to ensure the uniform di...

AI Technical Summary

Problems solved by technology

[0005] 1. Since the foaming temperature is 2-4 degrees near the melting point, too high or too low will affect the particle forming effect. Accurate temperature control is very important for foaming. The existing technology often overheats in the control, resulting in particle foaming bubble failure

[0006] 2. Pressure is the main factor determining the foaming ratio of particles. Pressure fluctuations during the reaction process will cause uneven foaming and uneven density of particles;

[0007] 3. The known internal and external bearings of the foaming reactor are prone to air leakage due to the high working pressure. In order to prevent leakage, mechanical, nitrogen or hydraulic seals are required, but this problem still cannot be completely solved;

[0008] 4. The temperature of the lower bearing close to the stirring paddle in the reactor is high, and the working life is low, which can only be used for about two months;

[0009] 5. In order to make the material disperse evenly, the material is usually stirred and dispersed in water. Due to the existence of water, the reactor is easy to rust

Usually the kettle body made of stainless steel will make the equipment expensive;

[0010] 6. During the production process of the reactor, a variety of materials need to be added through multiple equipment interfaces. Since the reactor is in a high-temperature and high-pressure environment when it is working, the inlet and outlet interface valves are prone to leakage;

[0011] 7. If the stirring speed is too fast or too slow, it will affect the dissolution rate and crystallization performance of the foaming agent in the polypropylene particles;

[0012] 8. In the production process, once the stirring stops or the temperature is overheated, the particles in the kettle will stick together and the materials will be scrapped; seriously, the materials will not be discharged, and the polypropylene particles will form a sticky whole in the kettle, resulting in a major economic loss

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