Silicon slurry continuous heating evaporation equipment

Abstract

The utility model discloses equipment for continuously heating and evaporating silicon slurry. The equipment comprises a shell, a cone, an end socket and a slurry stirrer, the whole material is Q345 and Q235; the shell is fixedly connected with the cone, the coil is wound on the outer sides of the shell and the cone, current passing through the coil is adjusted through the control cabinet, electric energy is converted into heat energy according to the electromagnetic induction principle, and materials in the equipment are evenly heated. A heat preservation layer is arranged on the outer side of the coil and is made of aluminum silicate, aerogel, ceramic fibers and the like. The equipment system is high in heating efficiency, traditional heat conduction oil jackets or half-pipe heating is replaced by electromagnetic heating, and the heating speed and the energy utilization rate are increased.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of silicon slurry continuous heating evaporative equipment, belong to organic silicon production technical field. BACKGROUND

[0002] Organic silicon material is macromolecular material with organic and inorganic structure simultaneously, and it is excellent in temperature resistance, weather resistance, electrical performance, physiological inertia and surface performance. Organic silicon material system takes metal silicon and methanol as starting point, first synthesizes chloromethane from methanol and hydrochloric acid, synthesizes organosilicon chlorosilane monomer from chloromethane and metal silicon, then hydrolyzes monomer to obtain siloxane base raw material represented by D4, and base polymer such as 110 raw rubber or 107 glue, and then various terminal downstream products are prepared. Organic silicon downstream industry mainly includes silicone rubber, silicone oil, silicone resin and functional silane, which are collectively referred to as four major categories of organic silicon materials.

[0003] Organic silicon monomer reaction is the reaction of silicon powder and chloromethane under the action of catalyst (such as copper powder, etc.) in a fluidized bed reactor at 280-300℃ and 0.2MPa. The methyl chlorosilane generated by the reaction is a mixture, mainly including monomethyltrichlorosilane, dimethyldichlorosilane, trimethylmonochlorosilane, etc., and also produces some by-products, such as high-boiling substances, silicon tetrachloride, and monomer containing hydrogen. The synthesis gas coming out of the fluidized bed contains organic silicon monomer, unreacted chloromethane and unreacted silicon powder, which is separated from most of the silicon powder by a cyclone separator, and a small amount of fine silicon powder is taken to a washing tower for dust removal by monomer spraying wet method. The solid-liquid mixture discharged from the bottom of the washing tower is generally referred to as silicon slurry in the industry. Silicon slurry mainly contains some high-boiling organic silicon compounds, such as disilane, disiloxane and silane, etc. The chemical structure of these components is relatively complex and has certain reactivity, which can be recycled. Silicon slurry contains suspended silicon powder and various metal impurities such as copper and tin introduced during production. The presence of these metal impurities not only increases the difficulty of waste slurry treatment, but also may cause potential pollution risk to the environment. If it is randomly piled up or improperly treated, the organic components in the organic silicon waste slurry may volatilize into the air, causing air pollution; harmful substances such as heavy metals in it may seep into the soil and groundwater, causing long-term pollution to the soil and water sources, affecting the ecological environment and human health. For example, contaminated soil may inhibit the growth of vegetation and reduce the yield and quality of crops; contaminated water sources may not meet the demand for production and living water. Waste slurry exposed to air is easy to burn, which poses a fire hazard. During storage and transportation, if leakage, spilling or other situations occur, safety accidents may be caused. Therefore, it is necessary to recover the effective components in the silicon slurry to reduce its treatment amount.

[0004] The process of reducing the amount of silicon slurry mainly re-evaporates to recover monomer and high-boiling substances in the silicon slurry. The traditional evaporation equipment is a vertical evaporation kettle, the outer wall of which is welded with a jacket or a half pipe, and the inner part is connected with a heat conducting oil to provide heat for the material in the kettle. The built-in stirring prevents the silicon powder from depositing and facilitates the heat transfer of the outer wall. The heating equipment and the heating form utilize the principle of heat conduction to heat, and need a system of a heat oil pump, a heat oil tank, heat oil heating, a circulating pipeline and the like. The preheating of the heat conducting oil needs time, and the temperature is transmitted to the kettle wall, and then the kettle wall is transmitted to the medium, so the heat transfer is slow, the heat loss and energy consumption are large, the temperature control is lagged, and the heat exchange area per unit volume is limited, which is not conducive to the expansion of the device scale. SUMMARY

[0005] In view of the technical problems of low heat transfer efficiency and large energy consumption of the continuous heating and evaporation of the silicon slurry, the utility model develops a kind of equipment for the continuous evaporation of silicon slurry.

[0006] A kind of equipment for the continuous heating and evaporation of silicon slurry, including shell, cone, head, slurry agitator;Overall material is Q345, Q235;Shell is fixedly connected with cone, shell and cone outside are wound with coil, current through coil is adjusted by control cabinet, utilize electromagnetic induction principle to convert electric energy into heat energy, realize the uniform heating of the material in the equipment. Coil outside is provided with heat preservation layer, and the material is silicon acid aluminum, aerogel, ceramic fiber and the like.

[0007] The upper part of the shell is provided with the head, and the slurry agitator is arranged at the center of the head.

[0008] The number of slurry blades of the slurry agitator is 2 or 3, and the slurry agitator is deep into the center of the cone.

[0009] The height-diameter ratio of the shell is 2-4, and the cone angle of the cone part is 60-90 degrees.

[0010] The control cabinet is interlocked with the temperature and liquid level instruments inserted into the cylinder body, and the current is adjusted to control the temperature and liquid level. The temperature of the silicon slurry is controlled at 180-280 DEG C. The heating substance is a black brown liquid containing silicon powder, copper powder, methyl chlorosilane monomer, methyl chlorosilane high-boiling substance and having a solid content of 5%-60% and a certain fluidity.

[0011] The utility model utilizes electromagnetic induction principle to convert electric energy into heat energy, realizes the uniform heating of the silicon slurry, and overcomes the problems of complex silicon slurry evaporation equipment system, low internal heat exchange efficiency, poor heat exchange effect with the increase of production capacity in the prior art. The equipment is simple and saves investment. The temperature control is accurate, the heating speed is fast, and the problem of temperature control lag in the original technology is overcome. The energy saving is more than 30% than indirect heating. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1The utility model silicon slurry continuous heating evaporation equipment, wherein, 1, shell 2, cone 3, head 4, stirring 5, coil 6, control cabinet 7, heat preservation layer.

[0013] Figure 2 Prior art silicon slurry evaporation equipment system, 1' evaporation kettle 1-1' heat conducting oil half pipe 1-2' evaporation kettle stirring 2' heat conducting oil outlet pipe network 3' heat conducting oil import pipe network 4' heat conducting oil circulating pump 5' heat conducting oil heating system. DETAILED DESCRIPTION

[0014] Example 1

[0015] As Figure 1 Silicon slurry continuous heating evaporation equipment shown, including shell 1, cone 2, head 3, slurry stirrer 4;Shell 1 and cone 2 fixed connection, shell 1 and cone 2 outside winding coil 5, through the control cabinet 6 adjust the current through the coil 5;Coil 5 outside is provided with heat preservation layer 7.

[0016] The upper portion of shell 1 is provided with head 3, and the central position of head 3 is provided with slurry stirrer 4.

[0017] The number of slurry stirrer 4 paddle is 2 or 3, and the slurry stirrer 4 is deeply inserted into the center of cone 2.

[0018] The height-diameter ratio of shell 1 is 2-4, and the taper angle of the cone part is 60-90 degrees.

[0019] The equipment for the continuous heating evaporation of silicon slurry adopts Q345R material for the pressure part, the evaporation kettle cylinder and the head are spirally wound with electromagnetic induction lines, the double-layer heat preservation of aerogel felt is adopted, the heat preservation layer is thin, and the installation is simple and convenient. Single-layer slurry stirrer, three slurry blades are installed in the cone part, only the flow of silicon powder needs to be maintained, and the deposition of silicon powder is prevented. The digital control cabinet is adopted, the current and the temperature in the kettle are interlocked, the power and the frequency of the power supply are remotely controlled through the on-site PLC or DCS, and the heating temperature and the time are accurately controlled. If the temperature is too high or the equipment is abnormal, the control system can automatically cut off the power supply and alarm.

[0020] The same silicon slurry feeding and control requirements as in example 2 are evaporated, the alternating current is passed into the coil, the high-frequency alternating eddy current is formed in the kettle body, a large amount of heat energy can be generated in the kettle body within 10 minutes, and the heating effect required by the process is achieved. The heat conversion efficiency of the present application can be up to 95% or more, and at least 18% of energy can be saved compared with the traditional silicon slurry evaporation equipment.

[0021] Example 2

[0022] As Figure 2As shown, a workshop now has a set of silicon slurry evaporation equipment, including evaporation kettle, heat transfer oil circulating pump, heat transfer oil electric heater, heat transfer oil circulating pipeline, heat transfer oil circulating pipeline is provided with manual valve, automatic control valve, flow meter, thermometer, etc. The evaporation kettle is welded with a half pipe outside, and the circulating heat transfer oil is heated to evaporate the high-boiling organic silicon chlorosilane in the kettle. Double-layer slurry stirring is arranged inside to speed up heat transfer and prevent silicon slurry from depositing and clogging the equipment.

[0023] The silicon slurry with a solid content of about 10% is once put into the kettle at 4 tons. When starting the heat transfer oil system for heating for the first time, the heat transfer oil circulating pump is started to circulate cold oil, the electric heater is powered on to start heating the heat transfer oil, the temperature of the heat transfer oil rises to 270°C, and the power of the electric heater is adjusted to maintain the temperature of the heat transfer oil entering the evaporation kettle stable. The silicon slurry starts to evaporate continuously, and the silicon slurry is intermittently put in at 1.7 tons / hour. When the solid content of the silicon slurry in the kettle is greater than 50% or the temperature is higher than 230°C, the feeding is stopped, and the silicon slurry is discharged. The flow rate of the heat transfer oil is 100 m³ / h, and the outlet temperature is 250°C. The heat transfer oil system of the system needs 2 hours to run and heat up to the process temperature. The electric energy is converted into heat energy of the heat transfer oil. The heat transfer oil pipeline system dissipates heat, and the heat transfer oil conducts heat through the kettle wall to the silicon slurry on the wall side, and then to the silicon slurry inside. The heat transfer is slow, and the heat loss is large. The power of the electric heater is 1600 kW, and the actual effective heat exchange is 1300 kW.

Claims

1. A continuous heating and evaporation equipment for silicon slurry, characterized in that, Includes shell (1), cone (2), end cap (3), and paddle mixer (4); The shell (1) is fixedly connected to the cone (2). The outer sides of the shell (1) and the cone (2) are wound with coils (5). The upper part of the shell (1) is provided with a head (3). A paddle stirrer (4) is provided at the center of the head (3). The evaporator cylinder and the head are spirally wound with electromagnetic induction wire. The current passing through the coil (5) is adjusted by the control cabinet (6). The outer side of the coil (5) is provided with a heat insulation layer (7). The control cabinet (6) is interlocked with the temperature and liquid level instruments inserted into the cylinder. The current is adjusted to control the temperature and liquid level. The paddle stirrer (4) has 2 or 3 blades. The paddle stirrer (4) extends into the center of the cone (2). The height-to-diameter ratio of the shell (1) is 2 to 4. The cone angle of the cone part is 60 to 90 degrees.

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