阅读说明：本技术 双流化床生产无水氟化铝系统及方法 (System and method for producing anhydrous aluminum fluoride by double fluidized beds ) 是由 李长明 许新芳 刘正锋 于 2020-05-28 设计创作，主要内容包括：一种双流化床生产无水氟化铝系统,包括一级气流反应器、主流化床、副流化床,所述一级气流反应器底部的固相出口与主流化床的顶部的固相入口连接,所述一级气流反应器的气相出口与副流化床底部的气相入口连接,所述副流化床侧部的固相出口与一级气流反应器顶部的固相入口连接,主流化床产生的尾气进入副流化床后,在加热湿态氢氧化铝的同时,自身温度降低,提高热能利用率,由于尾气温度降低,尾气中的有效组分更容易被吸收,吸收装置就可以变得更简单,达标排放更容易,还降低了能耗,本发明还提供了一种双流化床生产无水氟化铝方法。(The invention discloses a system for producing anhydrous aluminum fluoride by using double fluidized beds, which comprises a primary airflow reactor, a main fluidized bed and an auxiliary fluidized bed, wherein a solid phase outlet at the bottom of the primary airflow reactor is connected with a solid phase inlet at the top of the main fluidized bed, a gas phase outlet of the primary airflow reactor is connected with a gas phase inlet at the bottom of the auxiliary fluidized bed, a solid phase outlet at the side part of the auxiliary fluidized bed is connected with a solid phase inlet at the top of the primary airflow reactor, and after tail gas generated by the main fluidized bed enters the auxiliary fluidized bed, the temperature of the tail gas is reduced while wet aluminum hydroxide is heated, so that the heat energy utilization rate is improved.)

1. A double fluidized bed production anhydrous aluminium fluoride system which characterized in that: the fluidized bed comprises a primary gas flow reactor, a main fluidized bed and a secondary fluidized bed, wherein a solid phase outlet at the bottom of the primary gas flow reactor is connected with a solid phase inlet at the top of the main fluidized bed, a gas phase outlet of the primary gas flow reactor is connected with a gas phase inlet at the bottom of the secondary fluidized bed, and a solid phase outlet at the side part of the secondary fluidized bed is connected with a solid phase inlet at the top of the primary gas flow reactor.

2. The dual fluidized bed anhydrous aluminum fluoride production system of claim 1, wherein: the system for producing the anhydrous aluminum fluoride by the double fluidized beds further comprises a secondary gas flow reactor, a gas phase inlet on the side part of the secondary gas flow reactor is connected with a gas phase outlet of the primary gas flow reactor, a solid phase outlet on the bottom part of the secondary gas flow reactor is connected with a solid phase backflow inlet on the side part of the main fluidized bed, and a gas phase outlet on the top part of the secondary gas flow reactor is connected with a gas phase inlet on the bottom part of the auxiliary fluidized bed.

3. The dual fluidized bed anhydrous aluminum fluoride production system of claim 2, wherein: the system for producing the anhydrous aluminum fluoride by the double fluidized beds further comprises a third-stage gas flow reactor, wherein a gas-phase inlet on the side part of the third-stage gas flow reactor is connected with a gas-phase outlet on the top part of the second-stage gas flow reactor, a solid-phase outlet on the bottom part of the third-stage gas flow reactor is connected with a solid-phase backflow inlet on the side part of the main fluidized bed, and a gas-phase outlet on the top part of the third-stage gas flow reactor is connected with a gas.

4. The dual fluidized bed anhydrous aluminum fluoride production system of claim 3, wherein: the structure of the main fluidized bed is the same as that of the auxiliary fluidized bed, the main fluidized bed comprises a tank body and a bottom bed arranged in the tank body, the tank body is divided into a relatively independent bottom cavity and a reaction cavity by the bottom bed, the reaction cavity is positioned above the bottom cavity, a hood is arranged on the bottom bed, an inlet of the hood is communicated with the bottom cavity, and an outlet of the hood is communicated with the reaction cavity.

5. The dual fluidized bed anhydrous aluminum fluoride production system of claim 4, wherein: the solid phase outlet at the bottom of the primary gas flow reactor is communicated with the reaction cavity of the main fluidized bed, the solid phase inlet at the top of the primary gas flow reactor is communicated with the reaction cavity of the secondary fluidized bed, the gas phase outlet at the top of the tertiary gas flow reactor is communicated with the bottom cavity of the secondary fluidized bed, the solid phase outlet at the bottom of the tertiary gas flow reactor is communicated with the reaction cavity of the main fluidized bed, and the solid phase outlet at the bottom of the secondary gas flow reactor is communicated with the reaction cavity of the main fluidized bed.

6. A method for producing anhydrous aluminum fluoride by a double fluidized bed is characterized by comprising the following steps: the method is realized by adopting the double fluidized bed production anhydrous aluminum fluoride system of claim 1;

charging wet aluminum hydroxide into a reaction chamber of the secondary fluidized bed;

tail gas generated by the main fluidized bed enters the auxiliary fluidized bed through the primary airflow reactor, and wet aluminum hydroxide in a reaction cavity of the auxiliary fluidized bed forms a fluidized state under the action of the tail gas generated by the main fluidized bed and is dried;

the dried aluminum hydroxide flows downwards from the secondary fluidized bed into the primary gas flow reactor and is preheated by reversely contacting with the ascending tail gas generated by the main fluidized bed;

the aluminum hydroxide preheated by the primary gas flow reactor enters a reaction cavity of the main fluidized bed, and forms a fluidized state under the action of hydrogen fluoride gas in the reaction cavity of the main fluidized bed to react with hydrogen fluoride to produce aluminum fluoride and tail gas.

7. The dual fluidized bed process for producing anhydrous aluminum fluoride of claim 6, wherein: and controlling the temperature of the tail gas entering the reaction cavity of the secondary fluidized bed to be 300-400 ℃.

8. The dual fluidized bed process for producing anhydrous aluminum fluoride of claim 7, wherein: the temperature of the off-gas entering the reaction chamber of the secondary fluidized bed was controlled at 320 ℃.

9. The dual fluidized bed process for producing anhydrous aluminum fluoride of claim 6, wherein: in a reaction cavity of the main fluidized bed, the reaction temperature of the aluminum hydroxide and the hydrogen fluoride is controlled to be 480-520 ℃.

10. The dual fluidized bed process for producing anhydrous aluminum fluoride of claim 6, wherein: the tail gas generated by the main fluidized bed contains hydrogen fluoride gas.

Technical Field

The invention relates to the technical field of anhydrous aluminum fluoride production, in particular to a system and a method for producing anhydrous aluminum fluoride by using a double fluidized bed.

Background

The fluorine industry has become one of the sub-industries which have the most rapid development, technical prospects and development advantages of the chemical industry in China, and is known as the gold enterprise. With the progress of technology, the application range of fluorine chemical products is expanded to wider, deeper and higher fields, the competition among industries is continuously strengthened, the control and energy consumption among industries are particularly important, and the fluorine chemical products can stand in the same industry only by continuously optimizing the process, reducing the cost, reasonably and efficiently utilizing energy and improving the yield of fluorine production.

The existing anhydrous aluminum fluoride process adopts a single fluidized bed, drying transformation and reaction of aluminum hydroxide are completed in the fluidized bed to produce anhydrous aluminum fluoride, and water generated by the reaction and unreacted hydrogen fluoride gas are treated by a subsequent tail gas treatment system and then discharged after reaching the standard. However, the use of a single fluidized bed has the following disadvantages:

(1) the energy consumption is high: the anhydrous aluminum fluoride produced by fluidized bed reaction has high requirement on the temperature of a reaction system, the reaction of aluminum oxide and hydrofluoric acid is exothermic reaction, the dehydration of aluminum hydroxide is endothermic reaction, but the reaction and the dehydration of aluminum hydroxide are completed in a fluidized bed at the same time, the temperature in the fluidized bed can not be effectively controlled, a large amount of heat energy is lost after being absorbed by a washing system along with tail gas, the heat energy can not be fully utilized, and meanwhile, the heat energy is continuously supplemented into the fluidized bed to maintain the internal temperature of the fluidized bed, so that the waste of the heat energy is caused.

(2) The utilization rate of fluorine resources is low: the temperature of tail gas at the outlet of the single fluidized bed is about 320 ℃, the tail gas carries hydrogen fluoride gas which does not react with alumina, the part of gas enters a washing system, cooling treatment and spray adsorption are carried out on the gas by cooling equipment, hydrofluoric acid water recovered by adsorption is treated, the subsequent treatment cost is increased, and waste of fluorine resources is also caused.

Therefore, how to increase the reaction temperature inside the fluidized bed, reduce the hydrogen fluoride content and the tail gas temperature in the anhydrous aluminum fluoride tail gas, increase the yield of anhydrous aluminum fluoride and reduce the energy consumption is undoubtedly a problem to be solved urgently for anhydrous aluminum fluoride production enterprises.

Disclosure of Invention

In view of the above, it is necessary to provide a system for producing anhydrous aluminum fluoride by dual fluidized beds.

It is also necessary to provide a method for producing anhydrous aluminum fluoride by using the double fluidized beds.

The system for producing the anhydrous aluminum fluoride by the double fluidized beds comprises a primary gas flow reactor, a main fluidized bed and a secondary fluidized bed, wherein a solid phase outlet at the bottom of the primary gas flow reactor is connected with a solid phase inlet at the top of the main fluidized bed, a gas phase outlet of the primary gas flow reactor is connected with a gas phase inlet at the bottom of the secondary fluidized bed, and a solid phase outlet at the side part of the secondary fluidized bed is connected with a solid phase inlet at the top of the primary gas flow reactor.

Preferably, the system for producing anhydrous aluminum fluoride by using double fluidized beds further comprises a secondary gas flow reactor, a gas phase inlet at the side part of the secondary gas flow reactor is connected with a gas phase outlet of the primary gas flow reactor, a solid phase outlet at the bottom part of the secondary gas flow reactor is connected with a solid phase reflux inlet at the side part of the main fluidized bed, and a gas phase outlet at the top part of the secondary gas flow reactor is connected with a gas phase inlet at the bottom part of the secondary fluidized bed.

Preferably, the system for producing anhydrous aluminum fluoride by using double fluidized beds further comprises a third-stage gas flow reactor, a gas-phase inlet at the side part of the third-stage gas flow reactor is connected with a gas-phase outlet at the top part of the second-stage gas flow reactor, a solid-phase outlet at the bottom part of the third-stage gas flow reactor is connected with a solid-phase reflux inlet at the side part of the main fluidized bed, and a gas-phase outlet at the top part of the third-stage gas flow reactor is connected with a gas-phase inlet.

Preferably, the main fluidized bed and the secondary fluidized bed have the same structure, the main fluidized bed comprises a tank body and a bottom bed arranged in the tank body, the tank body is divided into a bottom cavity and a reaction cavity which are relatively independent by the bottom bed, the reaction cavity is positioned above the bottom cavity, a hood is arranged on the bottom bed, an inlet of the hood is communicated with the bottom cavity, and an outlet of the hood is communicated with the reaction cavity.

Preferably, a solid phase outlet at the bottom of the primary gas flow reactor is communicated with the reaction chamber of the main fluidized bed, a solid phase inlet at the top of the primary gas flow reactor is communicated with the reaction chamber of the secondary fluidized bed, a gas phase outlet at the top of the tertiary gas flow reactor is communicated with the bottom chamber of the secondary fluidized bed, a solid phase outlet at the bottom of the tertiary gas flow reactor is communicated with the reaction chamber of the main fluidized bed, and a solid phase outlet at the bottom of the secondary gas flow reactor is communicated with the reaction chamber of the main fluidized bed.

A method for producing anhydrous aluminum fluoride by a double fluidized bed is realized by adopting a system for producing anhydrous aluminum fluoride by the double fluidized bed;

charging wet aluminum hydroxide into a reaction chamber of the secondary fluidized bed;

tail gas generated by the main fluidized bed enters the auxiliary fluidized bed through the primary airflow reactor, and wet aluminum hydroxide in a reaction cavity of the auxiliary fluidized bed forms a fluidized state under the action of the tail gas generated by the main fluidized bed and is dried;

the dried aluminum hydroxide flows downwards from the secondary fluidized bed into the primary gas flow reactor and is preheated by reversely contacting with the ascending tail gas generated by the main fluidized bed;

the aluminum hydroxide preheated by the primary gas flow reactor enters a reaction cavity of the main fluidized bed, and forms a fluidized state under the action of hydrogen fluoride gas in the reaction cavity of the main fluidized bed to react with hydrogen fluoride to produce aluminum fluoride and tail gas.

Preferably, the temperature of the tail gas entering the reaction cavity of the secondary fluidized bed is controlled to be 300-400 ℃.

Preferably, the temperature of the off-gas entering the reaction chamber of the secondary fluidized bed is controlled at 320 ℃.

Preferably, the reaction temperature of the aluminum hydroxide and the hydrogen fluoride is controlled to be 480-520 ℃ in the reaction chamber of the main fluidized bed.

Preferably, the off-gas generated from the main fluidized bed contains hydrogen fluoride gas.

The invention has the beneficial effects that:

(1) the wet aluminum hydroxide directly enters the secondary fluidized bed without additionally building drying equipment; surface water and crystal water of aluminium hydroxide are got rid of through the reaction heat that utilizes aluminium fluoride, play energy saving and consumption reduction's effect, fluidized bed equipment characteristic has decided aluminium hydroxide and is in fluidized state, and aluminium hydroxide water content is even, avoids getting into that local water content is too high or lead to its inside reaction temperature unstable after low aluminium hydroxide gets into the mainstream fluidized bed excessively.

(2) After directly entering the secondary fluidized bed, the wet aluminum hydroxide is not contacted with high-temperature air flow (the temperature is about 550-650 ℃) but contacted with medium-temperature air flow (the temperature is about 320 ℃), so that the cracking phenomenon of the aluminum hydroxide is avoided, the superfine aluminum hydroxide micropowder is generated, the quality and the yield of the aluminum fluoride product are improved, and the granularity and the fluidity of the product are better.

(3) After the tail gas that the mainstream fluidized bed produced gets into the side fluidized bed, when heating wet aluminium hydroxide, self temperature reduces, improves heat utilization rate, because the tail gas temperature reduces, the active ingredient in the tail gas is absorbed more easily, and absorbing device just can become simpler, and discharge up to standard is easier, has still reduced the energy consumption.

(4) After entering the secondary fluidized bed, the tail gas generated by the main fluidized bed reacts with the aluminum hydroxide while heating the wet aluminum hydroxide, so that the aluminum hydroxide is transformed, the reaction activity is improved, the content of unreacted hydrogen fluoride in the tail gas is reduced, and the reaction rate of the hydrogen fluoride is improved.

(5) By adopting the mode of combining the main fluidized bed and the auxiliary fluidized bed, the dehydration of the aluminum hydroxide and the reaction of the aluminum hydroxide and the hydrogen fluoride are respectively and independently carried out without mutual influence, the stable control of respective temperature is easily realized, the internal reaction temperature of the main fluidized bed can be independently improved, the reaction efficiency is improved, the temperature of the auxiliary fluidized bed is independently reduced, and the generation of the ultra-fine aluminum hydroxide micro powder is reduced.

(6) Most of the heat of the tail gas is absorbed by the aluminum hydroxide in the secondary fluidized bed, and the heat released by the aluminum hydroxide and the hydrogen fluoride in the main fluidized bed is added, so that the heat does not need to be supplemented from the outside during the operation of the whole system, and the energy consumption is reduced.

(7) After the aluminum hydroxide dried by the secondary fluidized bed enters the primary gas flow reactor, the aluminum hydroxide flows from top to bottom in the primary gas flow reactor, the tail gas generated by the main fluidized bed flows from bottom to top in the primary gas flow reactor, the aluminum hydroxide and the tail gas flow in opposite directions, the tail gas is cooled, the aluminum hydroxide is heated to a transition temperature, the aluminum hydroxide is stably transited from the secondary fluidized bed with lower temperature to the main fluidized bed with higher temperature, and the aluminum hydroxide can be prevented from bursting due to temperature shock to generate superfine aluminum hydroxide micro powder.

(8) The wet aluminum hydroxide is dried by adopting the auxiliary fluidized bed, the concentration of hydrogen fluoride in the tail gas for drying the aluminum hydroxide is much smaller than that of the hydrogen fluoride in the main fluidized bed, the dried aluminum hydroxide is in a high-expansion state in the auxiliary fluidized bed, the mobility is good, the aluminum hydroxide can be fully contacted with the low-content hydrogen fluoride in the tail gas, and compared with the existing disc type drying equipment, the cooling effect on the tail gas and the absorption effect on the hydrogen fluoride in the tail gas are better.

Drawings

FIG. 1 is a schematic structural diagram of the system for producing anhydrous aluminum fluoride by using the double fluidized beds.

In the figure: a first-stage gas flow reactor 10, a main fluidized bed 20, a secondary fluidized bed 30, a second-stage first-stage gas flow reactor 40 and a third-stage first-stage gas flow reactor 50.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

Referring to fig. 1, the present invention provides a dual fluidized bed system for producing anhydrous aluminum fluoride, which includes a primary gas flow reactor 10, a main fluidized bed 20, and a secondary fluidized bed 30, wherein a solid phase outlet at the bottom of the primary gas flow reactor 10 is connected to a solid phase inlet at the top of the main fluidized bed 20, a gas phase outlet of the primary gas flow reactor 10 is connected to a gas phase inlet at the bottom of the secondary fluidized bed 30, and a solid phase outlet at the side of the secondary fluidized bed 30 is connected to a solid phase inlet at the top of the primary gas flow reactor 10.

Tests show that in the drying process, the temperature is unstable, so that the moisture removal cannot meet the requirements, a single fluidized bed is adopted, the drying process of the aluminum hydroxide and the reaction of the aluminum hydroxide and the hydrogen fluoride are carried out simultaneously, the drying process of the aluminum hydroxide is an endothermic reaction, the reaction of the aluminum hydroxide and the hydrogen fluoride is an exothermic reaction, so that the temperature in the fluidized bed is not constant, the drying of the aluminum hydroxide is influenced, the reaction of the aluminum hydroxide and the hydrogen fluoride is influenced, the final yield of the aluminum fluoride is influenced, and the loss of the hydrogen fluoride in tail gas is increased.

The method adopts a single fluidized bed, the drying temperature of the aluminum hydroxide and the reaction temperature of the aluminum hydroxide and the hydrogen fluoride are contradictory, the temperature is too low, the reaction kinetics of the aluminum hydroxide and the hydrogen fluoride are insufficient, the particle size of the wet aluminum hydroxide is crushed to be too fine under the condition of high temperature, the reaction of the aluminum hydroxide and the hydrogen fluoride is influenced, the final yield of the aluminum fluoride is influenced, and the loss of the hydrogen fluoride in tail gas is increased.

The invention has the beneficial effects that:

(1) the wet aluminum hydroxide directly enters the secondary fluidized bed 30 without additionally building drying equipment; surface water and crystal water of aluminium hydroxide are got rid of through the reaction heat that utilizes aluminium fluoride, play energy saving and consumption reduction's effect, fluidized bed equipment characteristic has decided aluminium hydroxide and is in fluidized state, and aluminium hydroxide water content is even, avoids getting into that local water content is too high or lead to its inside reaction temperature unstable after low aluminium hydroxide gets into mainstream fluidized bed 20.

(2) After directly entering the secondary fluidized bed 30, the wet aluminum hydroxide is not contacted with high-temperature air flow (the temperature is about 550-650 ℃) but contacted with medium-temperature air flow (the temperature is about 320 ℃), so that the cracking phenomenon of the aluminum hydroxide is avoided and the generation of superfine aluminum hydroxide micropowder is avoided, the quality and the yield of aluminum fluoride products are improved, and the granularity and the fluidity of the products are better.

(3) After the tail gas that the mainstream fluidized bed 20 produced gets into side fluidized bed 30, when heating wet aluminium hydroxide, self temperature reduces, improves heat utilization rate, because the tail gas temperature reduces, the active ingredient in the tail gas is absorbed more easily, and absorbing device just can become simpler, and it is easier to reach standard and discharge, has still reduced the energy consumption.

(4) After entering the secondary fluidized bed 30, the tail gas generated by the main fluidized bed 20 reacts with the aluminum hydroxide while heating the wet aluminum hydroxide, so that the aluminum hydroxide is transformed, the reaction activity is improved, the content of unreacted hydrogen fluoride in the tail gas is reduced, and the reaction rate of the hydrogen fluoride is improved.

(5) By adopting the mode of combining the main fluidized bed 20 and the auxiliary fluidized bed 30, the dehydration of the aluminum hydroxide and the reaction of the aluminum hydroxide and the hydrogen fluoride are respectively and independently carried out without mutual influence, the respective temperature is easily and stably controlled, the reaction temperature in the main fluidized bed 20 can be independently increased, the reaction efficiency is improved, the temperature of the auxiliary fluidized bed 30 is independently reduced, and the generation of the ultra-fine aluminum hydroxide micro powder is reduced.

(6) The heat of the tail gas is mostly absorbed by the aluminum hydroxide in the secondary fluidized bed 30, and the heat released by the aluminum hydroxide and the hydrogen fluoride in the main fluidized bed 20 is added, so that the whole system does not need to supplement heat from the outside during operation, and the energy consumption is reduced.

(7) After the aluminum hydroxide dried by the secondary fluidized bed 30 enters the primary gas flow reactor 10, the aluminum hydroxide flows from top to bottom in the primary gas flow reactor 10, the tail gas generated by the main fluidized bed 20 flows from bottom to top through the primary gas flow reactor 10, the aluminum hydroxide and the tail gas flow in the reverse direction, the tail gas is cooled, the aluminum hydroxide is heated to a transition temperature, the aluminum hydroxide is stably transited from the secondary fluidized bed 30 with lower temperature to the main fluidized bed 20 with higher temperature, and the aluminum hydroxide can be prevented from bursting due to temperature shock to generate superfine aluminum hydroxide micro powder.

(8) The wet aluminum hydroxide is dried by the auxiliary fluidized bed 30, the concentration of hydrogen fluoride in the tail gas for drying the aluminum hydroxide is much smaller than that of the hydrogen fluoride in the main fluidized bed 20, and the dried aluminum hydroxide is in a high expansion state in the auxiliary fluidized bed 30, has good fluidity, can be fully contacted with the low-content hydrogen fluoride in the tail gas, and has better cooling effect on the tail gas and better absorption effect on the hydrogen fluoride in the tail gas compared with the existing disc type drying equipment.

Referring to fig. 1, further, the dual fluidized bed anhydrous aluminum fluoride production system further comprises a secondary gas flow reactor 40, a gas phase inlet on the side of the secondary gas flow reactor 40 is connected with a gas phase outlet of the primary gas flow reactor 10, a solid phase outlet on the bottom of the secondary gas flow reactor 40 is connected with a solid phase reflux inlet on the side of the main fluidized bed 20, and a gas phase outlet on the top of the secondary gas flow reactor 40 is connected with a gas phase inlet on the bottom of the secondary fluidized bed 30.

Referring to fig. 1, further, the dual fluidized bed anhydrous aluminum fluoride production system further includes a third-stage gas flow reactor 50, a gas phase inlet at the side of the third-stage gas flow reactor 50 is connected with a gas phase outlet at the top of the second-stage gas flow reactor 40, a solid phase outlet at the bottom of the third-stage gas flow reactor 50 is connected with a solid phase reflux inlet at the side of the main fluidized bed 20, and a gas phase outlet at the top of the third-stage gas flow reactor 50 is connected with a gas phase inlet at the bottom of the secondary fluidized bed 30.

Referring to fig. 1, further, the main fluidized bed 20 and the secondary fluidized bed 30 have the same structure, the main fluidized bed 20 includes a tank body and a bottom bed arranged in the tank body, the bottom bed divides the tank body into a bottom cavity and a reaction cavity which are relatively independent, the reaction cavity is arranged above the bottom cavity, a hood is arranged on the bottom bed, an inlet of the hood is communicated with the bottom cavity, and an outlet of the hood is communicated with the reaction cavity.

The main fluidized bed 20 or the sub-fluidized bed 30 is preferably constructed in the same manner as in "intermediate cyclone recycle fluidizing device" of utility model having grant publication No. CN 208661080U.

Referring to fig. 1, further, a solid phase outlet at the bottom of the primary gas flow reactor 10 is communicated with the reaction chamber of the main fluidized bed 20, a solid phase inlet at the top of the primary gas flow reactor 10 is communicated with the reaction chamber of the secondary fluidized bed 30, a gas phase outlet at the top of the tertiary gas flow reactor 50 is communicated with the bottom chamber of the secondary fluidized bed 30, a solid phase outlet at the bottom of the tertiary gas flow reactor 50 is communicated with the reaction chamber of the main fluidized bed 20, and a solid phase outlet at the bottom of the secondary gas flow reactor 40 is communicated with the reaction chamber of the main fluidized bed 20.

Referring to fig. 1, an embodiment of the present invention further provides a method for producing anhydrous aluminum fluoride by using a dual fluidized bed, which is implemented by using a system for producing anhydrous aluminum fluoride by using a dual fluidized bed;

charging wet aluminum hydroxide into the reaction chamber of the secondary fluidized bed 30;

tail gas generated by the main fluidized bed 20 enters the secondary fluidized bed 30 through the primary gas flow reactor 10, and wet aluminum hydroxide in a reaction cavity of the secondary fluidized bed 30 forms a fluidized state under the action of the tail gas generated by the main fluidized bed 20 and is dried;

the dried aluminum hydroxide flows downwards from the secondary fluidized bed 30 into the primary gas flow reactor 10 and is preheated by being in reverse contact with the ascending tail gas generated by the main fluidized bed 20;

the aluminum hydroxide preheated by the primary gas flow reactor 10 enters the reaction chamber of the main fluidized bed 20, and forms a fluidized state under the action of the hydrogen fluoride gas in the reaction chamber of the main fluidized bed 20 to react with the hydrogen fluoride to produce aluminum fluoride and tail gas.

Further, the temperature of the tail gas entering the reaction cavity of the secondary fluidized bed 30 is controlled to be 300-400 ℃.

Further, the temperature of the off-gas entering the reaction chamber of the secondary fluidized bed 30 was controlled at 320 ℃.

Further, in the reaction chamber of the main fluidized bed 20, the reaction temperature of the aluminum hydroxide and the hydrogen fluoride is controlled to be 480-520 ℃.

Further, the tail gas generated in the main fluidized bed 20 contains hydrogen fluoride gas.

In a specific embodiment, a plurality of first guide plates and a plurality of second guide plates are arranged in the reaction cavity of the secondary fluidized bed 30 from top to bottom, the first guide plates and the second guide plates are arranged in a staggered manner in the vertical direction, one end of each first guide plate is in contact with the left side wall of the reaction cavity of the secondary fluidized bed 30, the other end of each first guide plate extends downwards at a certain angle, one end of each second guide plate is in contact with the right side wall of the reaction cavity of the secondary fluidized bed 30, the other end of each second guide plate extends downwards at a certain angle, and the plurality of first guide plates and the plurality of second guide plates form a zigzag flow channel in the reaction cavity of the secondary fluidized bed 30. Through holes are preferably densely distributed on the first guide plate and the second guide plate.

Above-mentioned side fluidized bed 30's inner structure, can guarantee hydrogen fluoride gas and aluminium hydroxide fully contact, and can guarantee aluminium hydroxide homodisperse, good mobility has, especially aluminium hydroxide humidity after the drying is even, can prevent to lead to the fact the temperature in the fluidized bed invariable because of aluminium hydroxide local humidity is too high or low excessively, the flow direction and the developments behind hydrogen fluoride gas entering side fluidized bed 30, after guaranteeing to contact the aluminium hydroxide material, hydrogen fluoride gas flow dead angle can not appear and arouse local too high, local hardening can not appear, the corruption that causes equipment can not appear ponding more.

The steps in the method of the embodiment of the invention can be sequentially adjusted, combined and deleted according to actual needs.

The modules or units in the device of the embodiment of the invention can be combined, divided and deleted according to actual needs.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.