Continuous desolventizing and washing process and system for energetic material solid particles
By using a continuous desolution washing process of polar solvents and water in the desolution tower and the water washing tower, safety hazards and low product purity in traditional processes are solved, and a more efficient and safer desolution and washing effect is achieved.
Patent Information
- Application Number
- CN202411491818.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-24
- Publication Date
- 2025-03-07
AI Technical Summary
The traditional batch washing process poses safety risks when dealing with energy-containing materials, and it is difficult to effectively remove unseparated solvent impurities, resulting in a decrease in product purity.
The continuous desolution washing process is adopted, and the temperature and stirring speed are controlled by using polar solvents and water in the desolution tower and the water washing tower respectively to achieve safe, continuous desolution and washing of energy-containing materials.
This process improves the safety and purity of the product, reduces the loss of by-products, and achieves more efficient desolution and washing effects.
Smart Images
Figure CN119569574A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of energetic material processing, and in particular to a continuous desolventizing and washing process for energetic material solid particles and a system thereof. Background Art
[0002] Energetic materials have a high impact sensitivity. In the traditional intermittent washing and refining process, there are many online materials. There are certain risks of vibration, friction, impact, etc. during the process of pouring, centrifugation or filtration, and transportation. In particular, the general energetic materials are large molecular nitro compounds. During the washing process, it is necessary to remove the unseparated solvents and other light components brought by the reaction process. In the traditional washing kettle, the linear speed of the agitator tip is relatively high, which will aggravate the impact of the energetic materials and thus cause danger.
[0003] 2,4-Dinitroanisole is an important fine chemical and organic intermediate. It is not only an effective insecticide, but also a raw material for synthesizing dyes, medicines and pesticides. It is used as an insecticide in medicine and a dye intermediate in industry to produce red agent RC. It is widely used in the chemical industry.
[0004] At present, the existing domestic industrial production of 2,4-dinitroanisole desolventizing and washing adopts a batch process. The methanol solution of 2,4-dinitroanisole generated by the etherification reaction is evaporated and desolventized in a reactor at a temperature of 65 degrees. Impurities are divided into two categories, one is soluble in solvents such as methanol but insoluble in water, and the second is impurities such as salts and sodium phenolate that are soluble in water. The traditional process contains suspended solids. By evaporating the solvent, methanol is evaporated and recovered, but the first type of impurities dissolved in methanol are still in the solid product. Also, due to the concentration during the solvent evaporation process, this part of the impurities is insoluble in water and difficult to remove during water washing, resulting in reduced product purity. If the methanol solution of 2,4-dinitroanisole is directly filtered, first, methanol has a large solubility in 2,4-dinitroanisole, and the product loss is large. If the temperature is lowered, the solubility of the by-product in the organic solvent is reduced, and it will still be carried in the crude product, affecting the product purity. Summary of the invention
[0005] The purpose of the present invention is to provide a continuous desolventizing and washing process for energetic material solid particles.
[0006] The invention also discloses a system for continuous desolventizing and washing process of energetic material solid particles. The innovation of the present invention is to utilize the influence of the polarity change of the mixed solvent on the solubility and the density concentration gradient and other measures to continuously desolventize, wash and purify the energetic material, so as to achieve the purpose of safety and convenience.
[0007] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is: A continuous desolventizing and washing process for energetic material solid particles comprises the following steps: continuously feeding 2,4-dinitroanisole methanol suspension with a concentration of 15-30% and a desolventizing agent into a desolventizing tower for countercurrent desolventizing, the desolventizing agent is fed below the 2,4-dinitroanisole methanol suspension, the mass ratio of the desolventizing agent to the 2,4-dinitroanisole methanol suspension is 0.5-2, the temperature during desolventizing is controlled at 30-40°C, stirring is performed during desolventizing at a speed of 5-20 rpm, crude 2,4-dinitroanisole precipitated by desolventizing is discharged from the bottom of the desolventizing tower, and the methanol desolventizing agent is continuously discharged from the upper part of the desolventizing tower.
[0008] Furthermore, the crude 2,4-dinitroanisole is discharged from the bottom of the desolventizing tower and then washed with water at 50-80° C. to obtain 2,4-dinitroanisole.
[0009] Furthermore, during water washing, water and crude 2,4-dinitroanisole are continuously fed into a water washing tower, the mass ratio of water to crude 2,4-dinitroanisole feed is 3-6:1, and stirring is performed while washing, and the stirring speed is 50-200 rpm. The 2,4-dinitroanisole after water washing is discharged from the bottom of the water washing tower, and washing water is continuously discharged from the upper part of the water washing tower.
[0010] Furthermore, during water washing, water and crude 2,4-dinitroanisole are washed in countercurrent, and water is fed below the crude 2,4-dinitroanisole. Countercurrent washing has a better washing effect.
[0011] Furthermore, the desolventizing agent is a polar solvent that does not dissolve 2,4-dinitroanisole; the polar solvent is ethanol, acetone, butanol or water.
[0012] Furthermore, the 2,4-dinitroanisole is discharged, heated and melted, and then separated into layers, and the lower layer is taken to obtain the purified 2,4-dinitroanisole, which is further purified to obtain the purified 2,4-dinitroanisole.
[0013] A system for continuous desolventizing and washing process of energetic material solid particles comprises a desolventizing tower, wherein a material inlet No. 1 and a desolventizing inlet are provided on the wall of the desolventizing tower, and the desolventizing inlet is located below the material inlet No. 1; a coolant circulation channel No. 1 is provided on the wall of the desolventizing tower; a liquid discharge port No. 1 is provided on the top of the desolventizing tower and a material discharge port No. 1 is provided on the bottom; and a stirrer No. 1 is also provided in the desolventizing tower.
[0014] Furthermore, the No. 1 discharge port of the desolventizing tower is connected to the water washing tower through the No. 1 pipeline, the No. 2 material feed port and the water inlet are arranged on the wall of the water washing tower, the No. 1 pipeline is connected to the No. 2 material feed port of the water washing tower, the No. 2 cooling liquid circulation channel is arranged on the wall of the water washing tower, the No. 2 liquid discharge port is arranged on the top of the water washing tower, the No. 2 discharge port is arranged on the bottom, and the No. 2 agitator is also arranged in the water washing tower. The 2,4-dinitroanisole after desolventizing is washed to remove the impurities dissolved in water.
[0015] Furthermore, valves are provided at the No. 1 discharge port and the No. 2 discharge port; the bottom of the desolventizing tower and the water washing tower is a conical structure, and the No. 1 agitator and the No. 2 agitator both include a stirring shaft and a conical frame stirring head at the bottom of the stirring shaft that matches the conical structure at the bottom of the desolventizing tower and the water washing tower, and the conical frame stirring head is a hollow structure; the No. 1 agitator and the No. 2 agitator are also provided with more than one group of stirring blades, and a baffle is also provided below each group of stirring blades in the water washing tower, and the baffle is fixedly arranged on the wall of the water washing tower, and more than one through hole is provided on the baffle; the through holes on the upper and lower baffles are staggered, and the angle between the stirring blades in the water washing tower and the horizontal plane is 60~80°. The conical frame stirring head can reduce the dead angle of stirring, and the setting of the baffle can extend the washing time.
[0016] Furthermore, the inner walls of the desolventizing tower and the water washing tower are provided with a non-stick layer, and the non-stick layer is made of fluorine lining, PEEK, PE or PP material; the height-to-diameter ratio of the desolventizing tower is 8-15:1, and the height-to-diameter ratio of the water washing tower is 3-6:1. The non-stick layer is provided to reduce the adhesion of 2,4-dinitroanisole to the wall after crystallization. The size and residence time of the crystals are strictly controlled by setting the height-to-diameter ratio.
[0017] The beneficial effects of the present invention are: 1. The polar solvent in the present invention changes the solvent polarity of the original reaction system, reduces the solubility of the energetic material, and adjusts the temperature and stirring speed so that the crystallization speed and particle size of 2,4-dinitroanisole are strictly controlled.
[0018] 2. According to the Stokes formula, the falling speed of particles is inversely proportional to the density and viscosity, and is proportional to the square of the particle size diameter. In the design of the desolventizing tower, the height-to-diameter ratio of the tower is comprehensively considered in the present invention, and the crystal size and residence time are strictly controlled. The solvent removed from the upper part of the desolventizing tower does not contain particles, and the crystal particle size at the lower part is suitable, which is conducive to the transportation of suspended matter.
[0019] 2. The solubility of 2,4-dinitroanisole in a mixed solution of polar solvent and methanol increases with increasing temperature. At the same temperature, the solubility of 2,4-dinitroanisole in the mixed solution decreases with decreasing methanol content. When the methanol content in the mixed solution reaches 50%, the solubility of 2,4-dinitroanisole in the mixed solution is the lowest; below 50°C, 2,4-dinitroanisole is almost insoluble in the mixed solution; this solubility characteristic of 2,4-dinitroanisole is used in the desolventizing and water washing process to reduce the solubility of the product in methanol, thereby improving the product yield.
[0020] 3. The present invention utilizes the change in polarity of solvents of different concentrations to change the solubility of the product in the solvent, and then adjusts the speed of crystallization and the particle size through temperature and stirring speed. The liquid holding time is adjusted through valve control so that the crystals reach a controlled size, which is conducive to precipitation and sinking, so that the precipitated particles are discharged from the lower part of the desolventizing tower, and the stirring speed and the addition ratio of the polar solvent are controlled to form a concentration gradient of the solvent, reduce backmixing, and the solvent is extracted from the upper part to achieve continuous desolventizing. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 It is a schematic diagram of the structure of the present invention.
[0022] Figure 2 Schematic diagram of the structure of the desolventizing and water washing tower wall.
[0023] Figure 3 Schematic diagram of the structure of the baffle.
[0024] Figure 4 This is the layout diagram of the stirring blades. DETAILED DESCRIPTION
[0025] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings.
[0026] Example 1: Figure 1 , 2As shown in Figures 3 and 4, a system for continuous desolventizing and washing process of energetic material solid particles comprises a desolventizing tower 1. A material inlet 1.1 and a desolventizing inlet 1.2 are provided on the wall of the desolventizing tower 1. The desolventizing tower 1 inlet 1.2 is located below the material inlet 1.1. A coolant circulation channel 1.3 is provided on the wall of the desolventizing tower 1. The structure can be realized by setting the wall into a double-layer hollow structure. A liquid discharge port 1.4 is provided on the top of the desolventizing tower 1 and a material discharge port 1.5 is provided on the bottom. A stirrer 1.6 is also provided in the desolventizing tower. The No. 1 discharge port 1.5 of the desolventizing tower 1 is connected to the water washing tower 3 through the No. 1 pipeline 2. The No. 2 material feed port 3.1 and the water inlet 3.2 are provided on the wall of the water washing tower 3. The No. 1 pipeline 2 is connected to the No. 2 material feed port 3.1 of the water washing tower. The No. 2 coolant circulation channel 3.3 is provided on the wall of the water washing tower 3, which can be achieved by setting the wall into a double-layer hollow structure. The No. 2 liquid discharge port 3.4 is provided on the top of the water washing tower and the No. 2 discharge port 3.5 is provided on the bottom. The No. 2 agitator 3.6 is also provided in the water washing tower 3. A valve 4 is provided at both the No. 1 discharge port 1.5 and the No. 2 discharge port 3.5; the bottom of the desolventizing tower 1 and the water washing tower 3 is a conical structure, and the No. 1 agitator 1.6 and the No. 2 agitator 3.6 both include a stirring shaft 3.61 and a conical frame stirring head 3.62 located at the bottom of the stirring shaft 5 and matching the conical structure of the bottom of the desolventizing tower 1 and the water washing tower 3, and the conical frame stirring head 3.62 is a hollow structure; the No. 1 agitator 1.6 and the No. 2 agitator 3.6 are also provided with more than one group of stirring blades 3.63, and a baffle 3.64 is also provided below each group of stirring blades 3.63 in the water washing tower 3, and the baffle 3.64 is fixedly arranged on the wall of the water washing tower 3, and more than one through hole 3.641 is provided on the baffle 3.64; the through holes 3.641 on the upper and lower baffles 3.64 are staggered, and the angle between the stirring blades 3.63 in the water washing tower 3 and the horizontal plane is 60~80°.
[0027] A delivery pump 5 for conveying materials is provided at the front end of the desolventizing tower 1, on the No. 1 pipeline 2, and at the rear end of the water washing tower 3. The inner walls of the desolventizing tower 1 and the water washing tower 3 are provided with a non-stick layer, which is made of fluorine lining, PEEK, PE or PP material; the height-to-diameter ratio of the desolventizing tower 1 is 8~15:1, and the height-to-diameter ratio of the water washing tower 3 is 3~6:1.
[0028] Embodiment 2: A continuous desolventizing and washing process for energetic material solid particles, comprising the following steps: 15% concentration of 2,4-dinitroanisole methanol suspension and desolventizing agent are continuously fed into desolventizing tower 1 for countercurrent desolventizing, the desolventizing agent is a polar solvent that does not dissolve 2,4-dinitroanisole; the polar solvent is ethanol. The desolventizing agent is fed below the 2,4-dinitroanisole methanol suspension, the mass ratio of the desolventizing agent to the 2,4-dinitroanisole methanol suspension is 0.5, the temperature during desolventizing is controlled at 30°C, the desolventizing agent is stirred while stirring, the stirring speed is 5 rpm, the crude 2,4-dinitroanisole precipitated by desolventizing is discharged from the bottom of desolventizing tower 1, and the methanol desolventizing agent is continuously discharged from the upper part of desolventizing tower 1.
[0029] The crude 2,4-dinitroanisole is discharged from the bottom of the desolventizing tower 1 and then washed with water at 50°C to obtain 2,4-dinitroanisole. During the washing, water and crude 2,4-dinitroanisole are continuously fed into the washing tower 3, and the mass ratio of water to crude 2,4-dinitroanisole is 3:1. The washing is performed while stirring at a speed of 50 rpm. The washed 2,4-dinitroanisole is discharged from the bottom of the washing tower 3, and the washing water is continuously discharged from the upper part of the washing tower 3.
[0030] During the water washing, water and crude 2,4-dinitroanisole are washed in countercurrent, and water is fed below the crude 2,4-dinitroanisole. After the 2,4-dinitroanisole is discharged, it is heated and melted, and then separated into layers, and the lower layer is taken to obtain refined 2,4-dinitroanisole.
[0031] Embodiment 3: A continuous desolventizing and washing process for energetic material solid particles, comprising the following steps: 22% concentration of 2,4-dinitroanisole methanol suspension and desolventizing agent are continuously fed into desolventizing tower 1 for countercurrent desolventizing, the desolventizing agent is a polar solvent that does not dissolve 2,4-dinitroanisole; the polar solvent is acetone. The desolventizing agent is fed below the 2,4-dinitroanisole methanol suspension, the mass ratio of the desolventizing agent to the 2,4-dinitroanisole methanol suspension is 1, the temperature during desolventizing is controlled at 35°C, the desolventizing agent is stirred while stirring, the stirring speed is 15 rpm, the crude 2,4-dinitroanisole precipitated by desolventizing is discharged from the bottom of desolventizing tower 1, and the methanol desolventizing agent is continuously discharged from the upper part of desolventizing tower 1.
[0032] The crude 2,4-dinitroanisole is discharged from the bottom of the desolventizing tower 1 and then washed with water at 70°C to obtain 2,4-dinitroanisole. During the washing, water and crude 2,4-dinitroanisole are continuously fed into the washing tower 3, and the mass ratio of water to crude 2,4-dinitroanisole is 4:1. The washing is performed while stirring at a stirring speed of 100 rpm. The washed 2,4-dinitroanisole is discharged from the bottom of the washing tower 3, and the washing water is continuously discharged from the upper part of the washing tower 3.
[0033] During the water washing, water and crude 2,4-dinitroanisole are washed in countercurrent, and water is fed below the crude 2,4-dinitroanisole. After the 2,4-dinitroanisole is discharged, it is heated and melted, and then separated into layers, and the lower layer is taken to obtain refined 2,4-dinitroanisole.
[0034] Embodiment 4: A continuous desolventizing and washing process for energetic material solid particles, comprising the following steps: 2,4-dinitroanisole methanol suspension with a concentration of 30% and a desolventizing agent are continuously fed into a desolventizing tower 1 for countercurrent desolventizing, wherein the desolventizing agent is a polar solvent that does not dissolve 2,4-dinitroanisole; the polar solvent is butanol. The desolventizing agent is fed below the 2,4-dinitroanisole methanol suspension, and the mass ratio of the desolventizing agent to the 2,4-dinitroanisole methanol suspension is 2. The temperature during desolventizing is controlled at 30-40°C, and the desolventizing agent is stirred at a stirring speed of 20 rpm. The crude 2,4-dinitroanisole precipitated by desolventizing is discharged from the bottom of the desolventizing tower 1, and the methanol desolventizing agent is continuously discharged from the upper part of the desolventizing tower 1.
[0035] The crude 2,4-dinitroanisole is discharged from the bottom of the desolventizing tower 1 and then washed with water at 80°C to obtain 2,4-dinitroanisole. During the washing, water and crude 2,4-dinitroanisole are continuously fed into the washing tower 3, and the mass ratio of water to crude 2,4-dinitroanisole is 6:1. The washing is carried out while stirring at a stirring speed of 200 rpm. The washed 2,4-dinitroanisole is discharged from the bottom of the washing tower 3, and the washing water is continuously discharged from the upper part of the washing tower 3.
[0036] During the water washing, water and crude 2,4-dinitroanisole are washed in countercurrent, and water is fed below the crude 2,4-dinitroanisole. After the 2,4-dinitroanisole is discharged, it is heated and melted, and then separated into layers, and the lower layer is taken to obtain refined 2,4-dinitroanisole.
[0037] Example 5: Referring to Example 4, the polar solvent was replaced by water.
[0038] The described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
Claims
1. A continuous desolventizing and washing process for energetic material solid particles, characterized in that: The following steps are involved: A 2,4-dinitroanisole methanol suspension with a concentration of 15-30% and a desolventizing agent are continuously fed into a desolventizing tower for countercurrent desolventizing. The desolventizing agent is fed below the 2,4-dinitroanisole methanol suspension. The mass ratio of the desolventizing agent to the 2,4-dinitroanisole methanol suspension is 0.5-2. The temperature during desolventizing is controlled at 30-40°C. The desolventizing agent is stirred at a speed of 5-20 rpm. The crude 2,4-dinitroanisole precipitated by desolventizing is discharged from the bottom of the desolventizing tower, and the methanol desolventizing agent is continuously discharged from the upper part of the desolventizing tower.
2. The continuous desolventizing and washing process of energetic material solid particles according to claim 1, characterized in that: The crude 2,4-dinitroanisole is discharged from the bottom of the desolventizing tower and then washed with water at 50-80° C. to obtain 2,4-dinitroanisole.
3. The continuous desolventizing and washing process for energetic material solid particles according to claim 2, characterized in that: During water washing, water and crude 2,4-dinitroanisole are continuously fed into the water washing tower, the mass ratio of water to crude 2,4-dinitroanisole is 3-6:1, and stirring is performed while washing, and the stirring speed is 50-200 rpm. The 2,4-dinitroanisole after water washing is discharged from the bottom of the water washing tower, and the washing water is continuously discharged from the upper part of the water washing tower.
4. The continuous desolventizing and washing process for energetic material solid particles according to claim 3, characterized in that: During the water washing, water and crude 2,4-dinitroanisole are washed in countercurrent, and the water is fed below the crude 2,4-dinitroanisole.
5. The continuous desolventizing and washing process of energetic material solid particles according to claim 1, characterized in that: The desolventizing agent is a polar solvent that does not dissolve 2,4-dinitroanisole; the polar solvent is ethanol, acetone, butanol or water.
6. The continuous desolventizing and washing process for energetic material solid particles according to claims 2 to 4, characterized in that: The 2,4-dinitroanisole is discharged, heated and melted, and then separated into layers, and the lower layer is taken to obtain purified 2,4-dinitroanisole.
7. A system for the continuous desolventizing and washing process of energetic material solid particles according to claims 1 to 5, characterized in that: It includes a desolventizing tower, wherein a material inlet No. 1 and a desolventizing inlet are arranged on the wall of the desolventizing tower, the desolventizing inlet is located below the material inlet No. 1, a cooling liquid circulation channel is arranged on the wall of the desolventizing tower, a liquid discharge port No. 1 is arranged on the top of the desolventizing tower, and a material discharge port No. 1 is arranged on the bottom, and a stirrer No. 1 is also arranged in the desolventizing tower.
8. The system for continuous desolventizing and washing process of energetic material solid particles according to claim 7, characterized in that: The No. 1 discharge port of the desolventizing tower is connected to the water washing tower through the No. 1 pipeline. The wall of the water washing tower is provided with a No. 2 material feed port and a water inlet. The No. 1 pipeline is connected to the No. 2 material feed port of the water washing tower. The wall of the water washing tower is provided with a No. 2 coolant circulation channel. The top of the water washing tower is provided with a No. 2 liquid discharge port, the bottom is provided with a No. 2 discharge port, and the water washing tower is also provided with a No. 2 agitator.
9. The system for continuous desolventizing and washing process of energetic material solid particles according to claim 8, characterized in that: Valves are provided at the No. 1 discharge port and the No. 2 discharge port; the bottom of the desolventizing tower and the water washing tower is a conical structure, and the No. 1 agitator and the No. 2 agitator both include a stirring shaft and a conical frame stirring head located at the bottom of the stirring shaft and matching the conical structure of the bottom of the desolventizing tower and the water washing tower, and the conical frame stirring head is a hollow structure; the No. 1 agitator and the No. 2 agitator are also provided with more than one group of stirring blades, and a baffle is also provided under each group of stirring blades in the water washing tower, and the baffle is fixedly arranged on the wall of the water washing tower, and more than one through hole is provided on the baffle; the through holes on the upper and lower baffles are staggered, and the angle between the stirring blades in the water washing tower and the horizontal plane is 60~80°.
10. The system for continuous desolventizing and washing process of energetic material solid particles according to claim 9, characterized in that: The inner walls of the desolventizing tower and the water washing tower are provided with a non-stick layer, and the non-stick layer is made of fluorine lining, PEEK, PE or PP material; the height-to-diameter ratio of the desolventizing tower is 8-15:1, and the height-to-diameter ratio of the water washing tower is 3-6:1.