阅读说明：本技术 一种多级流化床串联的一氧化二氯连续生产系统及生产方法 (Multistage fluidized bed series-connected continuous production system and production method for dichlorine monoxide ) 是由 韩向阳 罗秋生 张长香 罗昭 唐能敏 羊学友 于 2018-06-19 设计创作，主要内容包括：本发明公开了一种多级流化床串联的一氧化二氯连续生产系统及生产方法,包括多级串联的流化床,所述流化床按照由高到低的依次设置,且每一级流化床均连接有旋风分离器,所述流化床内设置有搅拌桨,搅拌桨上设置有导流片,通过搅拌桨的搅拌和反应气的配合实现固体物料的流态化,且通过搅拌桨及导流片的作用使反应气形成螺旋上升的气流,从而降低设备的能耗,同时避免固体物料板结；本发明的固体物料从上至下流动,而反应气从下至上运动,从而大大提高固体物料与反应气的接触时间,提高物料的转化率机产品的产率；本发明具有物料转化率高,动力消耗低、固体物料不易板结等优点。(The invention discloses a continuous production system and a production method for dichlorine monoxide connected in series with multistage fluidized beds, wherein the continuous production system comprises the multistage fluidized beds connected in series, the fluidized beds are sequentially arranged from high to low, each stage of fluidized bed is connected with a cyclone separator, a stirring paddle is arranged in the fluidized bed, a flow deflector is arranged on the stirring paddle, fluidization of solid materials is realized through the stirring of the stirring paddle and the cooperation of reaction gas, and the reaction gas forms spirally rising gas flow through the actions of the stirring paddle and the flow deflector, so that the energy consumption of equipment is reduced, and the solid materials are prevented from being hardened; the solid material flows from top to bottom, and the reaction gas moves from bottom to top, so that the contact time of the solid material and the reaction gas is greatly prolonged, and the yield of the conversion rate of the material and the product is improved; the invention has the advantages of high material conversion rate, low power consumption, difficult hardening of solid materials and the like.)

1. A multistage fluidized bed tandem continuous production system for dichlorine monoxide is characterized in that: the fluidized bed comprises multiple fluidized beds (1) which are sequentially connected in series from high to low, and a discharge hole of the fluidized bed (1) at a high position in the adjacent two-stage fluidized bed (1) is higher than a feed hole of the fluidized bed (1) at a low position; the fluidized beds (1) at all levels are connected with cyclone separators (2), the discharge holes of the cyclone separators (2) are connected with the material return holes of the fluidized beds (1) at the current level, and the exhaust holes of the cyclone separators (2) are connected with the air inlet of the fluidized bed (1) at the previous level; the fluidized bed (1) at the highest position is connected with a feeding tank (3), and the fluidized bed (1) at the lowest position is connected with an air compressor (4) and a chlorine storage tank (5); the outer surface of the fluidized bed (1) is also provided with a half-pipe cooler (6), and the half-pipe cooler (6) is connected with a chilled water unit (7); still be provided with stirring rake (8) in fluidized bed (1) at each level, the both sides of stirring rake (8) are provided with water conservancy diversion piece (9).

2. A continuous production system of dichlorine monoxide with multi-stage fluidized bed series according to claim 1, wherein: the flow deflector (9) is obliquely arranged towards the direction deviating from the axis of the fluidized bed (1), and the oblique angle is 5-10 degrees.

3. A continuous production system of dichlorine monoxide with multi-stage fluidized bed series according to claim 1, wherein: an interstage cooler (10) is further arranged at an exhaust port of the cyclone separator (2), an inlet cooler (11) is further arranged at an air inlet of the fluidized bed (1) positioned at the bottom, and the interstage cooler (10) and the inlet cooler (11) are both connected with the chilled water unit (7).

4. A continuous production system of dichlorine monoxide with multi-stage fluidized bed series according to claim 1, wherein: control valves (12) used for controlling material discharge are arranged between the fluidized beds (1) at all levels and between the cyclone separators (2) and the fluidized beds (1), and the control valves (12) are butterfly valves, knife-shaped valves or plunger valves.

5. The method for producing dichlorine monoxide of a multistage fluidized bed-series continuous production system for dichlorine monoxide according to any one of claims 1 to 4, wherein: the method specifically comprises the following steps:

A. a feeding stage: introducing a small amount of compressed air into the fluidized bed, adding sodium carbonate powder into the fluidized bed through a material storage tank positioned at the top, opening a butterfly valve between each stage of fluidized bed to uniformly distribute the sodium carbonate with each stage of fluidized bed through gravity, and simultaneously starting a stirring paddle to fluidize the sodium carbonate in each stage of fluidized bed;

B. an initial reaction stage: introducing mixed gas containing chlorine into the fluidized bed at the lowest position to react the mixed gas with the sodium carbonate in a fluidized state; after the mixed gas reacted in the lowest-stage fluidized bed is separated by the cyclone separator, the gas enters the upper-stage fluidized bed to continuously react with fluidized sodium carbonate, and the solid particles obtained by separation return to the fluidized bed; simultaneously opening an inlet cooler and an interstage cooler for cooling;

C. a continuous production stage: when the exhaust port of the cyclone separator connected with the highest fluidized bed detects the dichlorine monoxide, the chlorine content of the mixed gas is gradually increased; when the temperature in the lowest stage fluidized bed is reduced or is close to the temperature of the raw material mixed gas, partial sodium chloride is discharged through a butterfly valve at the bottom, and the corresponding sodium carbonate is supplemented into the highest stage fluidized bed according to the corresponding molar ratio.

6. A process for the production of dichloro-monoxide as claimed in claim 4, wherein: the compressed air flow rate of the feeding stage is 0.1-0.9 m/s.

7. A process for the production of dichloro-monoxide as claimed in claim 4, wherein: the chlorine content of the mixed gas in the initial reaction stage is 4%, and the chlorine content of the mixed gas in the continuous production stage is 3% -15%, preferably 4% -9%; the reaction temperature in each fluidized bed of the initial reaction stage and the continuous production stage is-5-10 ℃.

8. A process for the production of dichloro-monoxide as claimed in claim 4, wherein: the pressure in each stage of the fluidization length in the initial reaction stage and the continuous production stage is 0.01-0.1 MPa; the rotating speed of the stirring paddle in each stage of the fluidized bed in the initial reaction stage and the continuous production stage is 60-120 rpm/min.

9. A process for the production of dichloro-monoxide as claimed in claim 4, wherein: the adding amount of sodium carbonate in each stage of fluidized bed occupies 7-15% of the volume of the fluidized bed; the bulk density of the sodium carbonate is 0.732g/ml-0.850 g/ml; the water content of the sodium carbonate is 5-10%.

Technical Field

The invention relates to the technical field of chemical production, in particular to a continuous production system and a continuous production method for dichlorine monoxide with a series of multistage fluidized beds.

Background

Dichlorine monoxide of the formula Cl₂O, which is a brown yellow gas at normal temperature and normal pressure and is the acid anhydride of hypochlorous acid; can be dissolved in carbon tetrachloride for storage, is commonly used for strong oxidants and chlorinating agents, and is commonly used for the production of chlorinated isocyanuric acid in industry; in the prior art, chlorine is often reacted with moist sodium carbonate, and the principle is that a mixed gas of chlorine and air is made to pass through a solid sodium carbonate powder layer to generate a mixed gas of dichlorine monoxide, air and carbon dioxide.

Chinese patent publication No. CN106946225A, 7/14/2017, discloses a fluidized bed apparatus and a method for producing dichlorine monoxide, the fluidized bed apparatus comprising: the fluidized bed reactor comprises a gas inlet, a solid inlet, a product outlet, a distribution plate and a finger-shaped pipe; a cyclone separator having an inlet connected to the product outlet of the fluidized bed reactor. The method for producing the dichlorine monoxide by adopting the fluidized bed device comprises the following steps: a reaction stage: introducing the mixed gas containing chlorine into a fluidized bed reactor, and allowing the mixed gas containing chlorine to pass through the hydrated sodium carbonate in a fluidized state for reaction to obtain a gas product carrying solids; a separation stage: solids in the solids-laden gaseous product from the fluidized-bed reactor are separated off by means of a cyclone to give a gas containing dichlorine monoxide. The fluidized bed device of the invention is adopted to produce the dichlorine monoxide, water and organic solvent are avoided being used through gas-solid reaction, water resources are saved, environmental pollution is avoided, no waste water is generated, and the fluidized bed device is green, environment-friendly and energy-saving.

Although the fluidized bed device disclosed in the patent can improve the conversion rate of sodium carbonate, continuous industrial production is realized, the defect that a large amount of water and organic solvent are needed in the traditional process is overcome, and the purposes of environmental protection, energy conservation, economy and continuous production are achieved; however, such production devices still have disadvantages, the main drawbacks of which are: 1. the reaction residence time is short, and the one-way reaction efficiency is low; 2. the byproduct sodium chloride and a large amount of unreacted sodium carbonate need to be discharged from the top of the bed together with reaction gas, and return to the fluidized bed for circular reaction after two-stage cyclone separation, so that a large amount of power is consumed; 3. because the gas velocity of the fluidized bed is certain, sodium carbonate solid containing a small amount of water or generated sodium chloride and unreacted sodium carbonate are wrapped to inevitably form large-particle solid, the solid is larger than the buoyancy of ascending gas and inevitably falls to the bottom of the fluidized bed, partial solid residue accumulated at the bottom of the fluidized bed or agglomeration inevitably causes uneven gas flow distribution, so that the periodic reaction effect of the fluidized bed is easily poor, the total conversion rate of sodium carbonate is poor, and the tube array of the fluidized bed is easy to wear, thereby endangering the production safety; 4. since sodium carbonate contains a small amount of water, sodium chloride has some deliquescence, and thus the mixture thereof may adhere to the surfaces of the tubes or equipment, causing caking, especially when the machine is frequently started and stopped, and being more prone to clogging.

Disclosure of Invention

Aiming at the defects that a distribution plate and a finger-shaped hole are easy to block and need to be overhauled frequently, the reaction time is short, the material conversion rate is low, the power consumption is high, the material is easy to harden, the product yield is low and the like in the prior art, the invention provides the continuous production system of the dichlorine monoxide with the multistage fluidized beds connected in series, the conversion rate of sodium carbonate and the yield of chlorine can be effectively improved by adopting the system, and meanwhile, the system has the advantages of automatic separation of solid raw materials, difficulty in hardening, low power consumption and the like.

The invention realizes the aim through the following technical scheme:

a multistage fluidized bed tandem continuous production system for dichlorine monoxide is characterized in that: the fluidized bed comprises a plurality of fluidized beds which are sequentially connected in series from high to low, and a discharge hole of a fluidized bed at a high position in two adjacent fluidized beds is higher than a feed hole of a fluidized bed at a low position; the fluidized beds at all levels are connected with cyclone separators, the discharge port of each cyclone separator is connected with the material return port of the fluidized bed at the level, and the exhaust port of each cyclone separator is connected with the air inlet of the fluidized bed at the upper level; the fluidized bed at the highest position is connected with a feeding tank, and the fluidized bed at the lowest position is connected with an air compressor and a chlorine storage tank; the outer surface of the fluidized bed is also provided with a half-pipe cooler, and the half-pipe cooler is connected with a chilled water unit; still be provided with the stirring rake in the fluidized bed at each level, the both sides of stirring rake are provided with the water conservancy diversion piece.

The flow deflector is obliquely arranged in a direction deviating from the axis of the fluidized bed, and the oblique angle is 5-10 degrees.

An interstage cooler is further arranged at an exhaust port of the cyclone separator, an inlet cooler is further arranged at the air inlet of the fluidized bed positioned at the bottom, and the interstage cooler and the inlet cooler are both connected with a water chiller.

Control valves for controlling material discharge are arranged between the cyclone separators and the fluidized beds among the fluidized beds at all levels, and the control valves are butterfly valves, knife-shaped valves or plunger valves.

Correspondingly, the invention also discloses a method for producing the dichlorine monoxide by using a dichlorine monoxide production system with a series of multistage fluidized beds, which is characterized by comprising the following steps:

A. a feeding stage: introducing a small amount of compressed air into the fluidized bed, adding sodium carbonate powder into the fluidized bed through a material storage tank positioned at the top, opening a butterfly valve between each stage of fluidized bed to uniformly distribute the sodium carbonate in each stage of fluidized bed through gravity, and simultaneously starting a stirring paddle to fluidize the sodium carbonate in each stage of fluidized bed;

B. an initial reaction stage: introducing mixed gas containing chlorine into the fluidized bed at the lowest position to react the mixed gas with the sodium carbonate in a fluidized state; after the mixed gas reacted in the lowest-stage fluidized bed is separated by the cyclone separator, the gas enters the upper-stage fluidized bed to continuously react with fluidized sodium carbonate, and the solid particles obtained by separation return to the fluidized bed; simultaneously opening an inlet cooler and an interstage cooler for cooling;

C. a continuous production stage: when the exhaust port of the cyclone separator connected with the highest fluidized bed detects the dichlorine monoxide, the chlorine content of the mixed gas is gradually increased; when the temperature in the lowest stage fluidized bed is reduced or is close to the temperature of the raw material mixed gas, discharging partial sodium chloride through a control valve at the bottom, and supplementing corresponding sodium carbonate into the highest stage fluidized bed according to a corresponding molar ratio; meanwhile, solid materials are transferred downwards step by step from the fluidized bed at the highest position through the control valve, continuous feeding and continuous discharging are realized, and continuous and stable operation of the whole system is further realized.

The compressed air flow rate of the feeding stage is 0.1-0.9 m/s, and the preferable flow rate is 0.3-0.6 m/s.

The chlorine content of the mixed gas in the initial reaction stage is 1% -4%, and the chlorine content of the mixed gas in the continuous production stage is 3% -15%, preferably 4% -9%; the reaction temperature in each fluidized bed of the initial reaction stage and the continuous production stage is-5-10 ℃, and the preferable temperature is 3-8 ℃.

The pressure in each fluidized bed of the initial reaction stage and the continuous production stage is 0.01Mpa-0.1Mpa, preferably 0.02 Mpa-0.05 Mpa; the rotating speed of the stirring paddle in each stage of the fluidized bed in the initial reaction stage and the continuous production stage is 60-120 rpm/min.

The adding amount of sodium carbonate in each stage of fluidized bed occupies 7-15% of the volume of the fluidized bed; the bulk density of the sodium carbonate is 0.732g/ml-0.850 g/ml; the water content of the sodium carbonate is 5-10%, and the preferable water content of the sodium carbonate is 6-7%.

Compared with the prior art, the invention has the following beneficial effects:

1. the fluidized bed adopted by the dichloro monoxide production system is internally provided with the stirring paddle, and fluidization is formed in a mode of combining the stirring paddle and the airflow, so that the overhigh requirements on the flow rate and the flow velocity of the reaction gas and the distribution plate are reduced, the power consumption is reduced on one hand, the material loss or the reduction of the reaction efficiency caused by the sudden change of the flow rate of the gas is avoided, and the reaction is more stable; on the other hand, the requirement of the reaction on the particle size of the material is reduced, the application range of the material is expanded, the production cost is reduced, and the requirement on the precision of the airflow distributor due to the change of the production load is reduced; simultaneously the stirring rake can effectively aggravate the collision between solid phase materials such as sodium carbonate at the in-process of stirring, prevents that sodium carbonate and reaction from generating the sodium chloride caking and on being attached to the pipeline of equipment to improve the protection effect to equipment, prolong the life of equipment, still avoided simultaneously because of the material reaction scheduling problem that large granule material deposit arouses in the fluidized bed bottom inadequately, improved the conversion rate of material.

2. The guide vanes are arranged on two sides of the stirring paddle, the guide vanes are inclined by 5-10 degrees in the direction deviating from the axis of the fluidized bed, and the guide vanes can effectively prevent reaction gas flow from forming vortex on the surface of the stirring paddle, so that the effect of spiral gas flow formed by the reaction gas under the action of the stirring paddle is improved, the energy consumption is further reduced, and the continuity and the stability of system production are ensured.

3. The invention adopts a mode of multistage series fluidized bed reactors to generate the dichlorine monoxide, the solid material enters from the fluidized bed at the highest layer, and the gas enters from the fluidized bed at the lowest layer, thereby realizing the reverse contact reaction of the powder and the gas, prolonging the contact time of the solid material and the reaction gas, and improving the reaction quality; compared with the traditional fluidized bed, the invention realizes the natural separation of gas-phase materials and solid-phase materials, reduces the load of a cyclone separator and the fluidized bed, and simultaneously can improve the concentration of chlorine gas introduced into the fluidized bed, thereby greatly improving the conversion rate of sodium carbonate.

4. The invention adopts a multi-stage series connection mode to generate the dichlorine monoxide, solid phase raw materials enter from the top and are discharged from the bottom, and gas phase raw materials enter from the bottom and are discharged from the top, so that the solid phase materials in a fluidized bed at the top are mainly sodium carbonate, the middle stages are a mixture of the sodium carbonate and sodium chloride, the fluidized bed at the lowest position is mainly sodium chloride, and the solid materials such as the sodium carbonate and the like move from top to bottom under the action of gravity and are finally discharged; the inverted matching relationship between the concentration of the sodium carbonate and the concentration of the chlorine ensures that the sodium carbonate which is not reacted in the previous stage can continuously contact and react with the chlorine in the fluidized bed in the next stage and fully react, thereby greatly prolonging the contact time and reaction efficiency of the sodium carbonate and the chlorine and improving the conversion rate of the sodium carbonate and the chlorine; meanwhile, the invention can control the discharge time and discharge amount of materials through the control valve at the bottom of each stage of fluidized bed, thereby controlling the effective residence time of the sodium carbonate in the fluidized bed, changing the problems of short residence time and low single-pass conversion rate caused by the reaction time determined by the air velocity of the traditional fluidized bed, realizing optimized production and being beneficial to improving the conversion rate of the sodium carbonate and the yield of the dichlorine monoxide.

5. On one hand, the fluidized bed at each stage is connected with the cyclone separator, so that solid particles at the outlet of each stage can be recovered and returned to the bottom of the reactor at the same stage for reaction, and the conversion rate of solid materials is improved; on the other hand, the solid particles are prevented from hardening in the cooler when passing through the cooler, so that the cooler is blocked to influence the passing of air flow, the service life of the equipment is prolonged, the continuous operation of the equipment is ensured, and the reaction efficiency is improved.

6. The invention is provided with the inlet cooler and the interstage cooler, and can effectively remove reaction heat, thereby controlling the temperature of the reaction gas in the fluidized bed and between the fluidized beds at different levels, ensuring the temperature of the reaction gas to be always in the optimal reaction state, avoiding the decomposition of the dichlorine monoxide caused by high temperature, and improving the yield of the dichlorine monoxide and the conversion rate of sodium carbonate.

Drawings

FIG. 1 is a schematic view of a production system of the present invention;

reference numerals: 1. fluidized bed, 2, cyclone separator, 3, feed tank, 4, air compressor, 5, chlorine storage jar, 6, half-pipe cooling tube, 7, refrigerated water unit, 8, stirring rake, 9, water conservancy diversion piece, 10, interstage cooler, 11, entry cooler, 12, control valve, 13, driving motor.

Detailed Description

The invention will be further illustrated by the following specific examples: