System and method for continuous post-treatment of AMPS slurry

Abstract

The invention discloses a system and method for continuous post-treatment of AMPS slurry, the system comprises a rotary filter press, a material crushing conveyor and a paddle dryer, the rotary filter press comprises a filtering area, a washing area, a pre-drying area and a discharging area, the discharging area is communicated with the material crushing conveyor, the material crushing conveyor is communicated with the material crushing conveyor, and the paddle dryer is communicated with the pre-drying area. The material crushing conveyor is communicated with the paddle dryer, and rake teeth and a spiral are arranged in the powder crushing conveyor. Compared with the prior art, the AMPS slurry post-treatment process has the advantages that the AMPS slurry post-treatment process is shortened, the treatment energy is high, the operation is simple, the washing efficiency is high, the product purity is high, the rotary filter press and the drying machine which are used are small in occupied area, low in energy consumption, high in heat efficiency, high in continuous treatment capacity and high in automation degree, and the production cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of production of 2-acrylamide-2-methylpropanesulfonic acid (AMPS) slurry, and in particular to a method and system for post-processing 2-acrylamide-2-methylpropanesulfonic acid (AMPS) slurry. Background Art

[0002] 2-Acrylamido-2-methylpropanesulfonic acid (hereinafter referred to as AMPS) has a variety of excellent properties due to its special molecular structure. It is widely used in many fields such as oil field exploitation, chemicals, sewage treatment, and biomaterials, and has huge market potential. The post-treatment of AMPS slurry is related to product purity and production investment and operating costs.

[0003] At present, the post-processing of AMPS slurry is mainly carried out through centrifuge filtration and scraper film evaporator drying. Due to the presence of corrosive liquids in the material, the sealing ring is easily damaged, and the intermittent operation will inevitably cause the leakage of highly toxic material acrylonitrile gas, which poses a huge hidden danger to the life safety of operators and the environment and has high energy consumption. The drying equipment used is usually a scraper film evaporator, whose working principle is that the wet product delivered through the inlet nozzle is captured by the high-speed rotating rotor blades and applied to the heating wall for drying, which not only has high energy consumption and occupies a large area, but also has high investment. Summary of the invention

[0004] The purpose of the present invention is to provide a system and method for continuous post-processing of AMPS slurry, so as to improve the degree of continuous operation of AMPS slurry post-processing, reduce system energy consumption, and be used for producing high-quality AMPS.

[0005] To achieve the above-mentioned purpose, the present invention provides a system for continuous post-processing of AMPS slurry, which includes: a rotary filter press, a material crushing conveyor, and a dryer. The rotary filter press includes a filtration area, a washing area, a pre-drying area, and a unloading area. The unloading area is connected to the material crushing conveyor, and the material crushing conveyor is connected to the dryer. The powder crushing conveyor is provided with rake teeth and a spiral.

[0006] In one embodiment, the washing zone includes a primary washing zone and a secondary washing zone; and the rotary filter press is a fully enclosed rotary filter press.

[0007] In one embodiment, a drying gas-liquid separation tank and a filter cloth washing liquid tank are further provided, wherein the drying gas-liquid separation tank is connected to the outlet of the pre-drying zone; the filter cloth washing liquid tank is connected to the rotary filter press, and the outlet of the filter cloth washing liquid tank is connected to the inlet of the washing zone, and washing liquid is provided in the washing zone, and the washing liquid is 1 to 1.2 times the mass of the filter cake.

[0008] In one embodiment, it also includes a cooler, a mixer, a silo, a first bag dust collector, and a circulating air cooler. The material outlet of the dryer is connected to the cooler. The cooler is provided with a honeycomb jacket and two wedge-shaped shafts. Circulating cooling water is passed through the two wedge-shaped shafts and the honeycomb jacket. The mixer is connected to the discharge port of the cooler. The discharge port of the mixer is connected to the feed port of the silo. The first bag dust collector is connected to the top of the silo. The first bag dust collector is connected to the circulating air cooler. The circulating air cooler is in turn connected to the mixer.

[0009] In one embodiment, the dryer is a paddle dryer and is provided with a honeycomb jacket. The top of the dryer is also connected to a second bag dust collector, and the second bag dust collector is connected to a primary cooler, a secondary cooler and an induced draft fan in sequence. Circulating cooling water is passed through the primary cooler and circulating chilled water is passed through the secondary cooler.

[0010] The present invention also provides a method for continuous post-processing of AMPS slurry, which comprises: AMPS acrylonitrile slurry is input into the filtering zone of a rotary filter press, and solids in the AMPS acrylonitrile slurry form filter cakes on the filter cloth in the filtering zone; the filter cakes are respectively washed, dried, and discharged in the washing zone, pre-drying zone, and unloading zone of the rotary filter press, and the filter cakes are discharged to a powder crushing conveyor, and the filter cakes are uniformly conveyed to a dryer under the action of rake teeth and spirals of the powder crushing conveyor, and the acrylonitrile in the filter cakes is evaporated in the dryer to form qualified products.

[0011] In one embodiment, the washing area includes a primary washing area and a secondary washing area. The filter cake formed in the filtration area enters the primary washing area of ​​the rotary filter press as the rotary filter press rotates, and the filter cake is washed for the first time in the primary washing area with a primary washing liquid; the filter cake washed for the first time enters the secondary washing area of ​​the rotary filter press as the rotary filter press rotates, and the filter cake is washed for the second time in the secondary washing area with a secondary washing liquid; the washed filter cake enters the drying area of ​​the rotary filter press for drying; the dried filter cake enters the unloading area as the rotary filter press rotates, and under the combined action of the unloading scraper, gravity and unloading back-blowing air, the filter cake is separated from the rotary pressure filter and enters the material crushing conveyor;

[0012] The primary washing liquid in the primary washing zone is fresh acrylonitrile solvent, or filter cloth washing liquid from a filter cloth washing liquid tank; the secondary washing liquid in the secondary washing zone is fresh acrylonitrile solvent;

[0013] The mother liquor separated by filtration in the filtration zone, the primary washing filtrate produced in the first washing process, and the secondary washing filtrate produced in the second washing process are respectively recovered and recycled;

[0014] The drying zone uses nitrogen to dry the filter cake, and the tail gas and washing liquid generated during the drying process enter the drying gas-liquid separation tank, the nitrogen and the acrylonitrile solvent are separated into gas and liquid in the drying gas-liquid separation tank, the separated tail gas enters the subsequent system, and the separated solvent is recovered and recycled.

[0015] In one embodiment, after the filter cake leaves the rotary pressure filter and enters the material crushing conveyor, the filter cloth is cleaned by using filter cloth flushing liquid and filter cloth back-blowing air;

[0016] In one embodiment, the devices at both ends of the rotary filter press are provided with an air outlet and a liquid discharge outlet for airtightly discharging the leaked acrylonitrile solvent into a liquid leakage tank.

[0017] In one embodiment, the AMPS powder after being dried by the dryer is further subjected to subsequent processing, and the subsequent processing includes: the AMPS powder is cooled in the cooler, and the material is transported to the silo under the action of the circulating air nitrogen of the mixer, and the transported nitrogen is filtered through the first bag dust collector and the filter and then returned to the mixer for recycling.

[0018] The acrylonitrile solvent vapor, nitrogen and a small amount of dust evaporated by the dryer during the drying process are dedusted by the second bag filter and then enter the primary cooler, where they are preliminarily cooled by circulating cooling water, and the acrylonitrile solvent generated by cooling enters the solvent storage tank. The tail gas after the preliminarily cooling enters the secondary cooler and is further cooled by chilled water, and the acrylonitrile solvent generated by cooling enters the solvent storage tank. The dry tail gas after further cooling is discharged into the subsequent system under the action of the induced draft fan, and the recovered acrylonitrile solvent enters the solvent storage tank.

[0019] Compared with the prior art, the present invention has at least the following advantages:

[0020] 1. The rotary filter press used in the present invention is an integrated device integrating filtration, washing, drying and unloading, which replaces the intermittently operated centrifuge. The equipment is excellent in airtightness, there is no risk of leakage of hazardous materials such as acrylonitrile, and the equipment occupies a small area.

[0021] 2. The current production process of AMPS inevitably produces sulfonic acid and amide by-products. The present invention uses a rotary filter press for continuous filtration, washing and drying, which shortens the process flow, and has a simple operation process, high washing efficiency and high product purity.

[0022] 3. The material crushing conveyor can evenly transport the material to the downstream dryer under the action of rake teeth and spiral, and can also isolate the rotary filter press used for filtering, washing and pre-drying, so that the acrylonitrile vapor generated by the dryer will not be connected in series with the upstream system, and will not affect the continuous operation of the process.

[0023] 4. The dryer and cooler used in the present invention are both paddle-type, and heat is exchanged with hot materials through the wall. The special honeycomb jacket design ensures that the cooling medium or heating medium has no short circuit or dead zone, and the flow rate is high. The equipment has the characteristics of high heat transfer rate, etc. Compared with the scraper film evaporator commonly used for drying slurry materials, it has the advantages of low speed, large processing capacity, low investment cost, low energy consumption, etc.

[0024] 5. The present invention allows the cooled AMPS powder to be immediately fed into a mixer and transported to a silo via gas for continuous operation.

[0025] 6. The present invention can continuously process AMPS slurry, realize full automatic control, and is simple to operate manually. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the process flow of the continuous post-treatment of AMPS slurry according to the present invention.

[0027] Among them, the figure markings are: 1-rotary filter press; 2-drying gas-liquid separation tank; 3-filter cloth washing liquid tank; 4-filter cloth washing liquid delivery pump; 5-material crushing conveyor; 6-second bag dust collector; 7-first cooler; 8-second cooler; 9-induced draft fan; 10-dryer; 11-cooler; 12-discharge valve; 13-mixer; 14-first bag dust collector; 15-silo; 16-filter; 17-Roots blower; 18-circulating air cooler. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments to further understand the purpose, solution and effect of the present invention, but it is not intended to limit the scope of protection of the claims attached to the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] Figure 1 The process flow diagram of the continuous post-treatment of AMPS slurry of the present invention is shown in FIG. The system for the continuous post-treatment of AMPS slurry comprises: a rotary filter press 1 , a material crushing conveyor 5 , and a dryer 10 .

[0030] The rotary filter press 1 includes a filtering area, a washing area, a pre-drying area, and a discharging area. The rotary filter press 1 can be, for example, a fully enclosed rotary filter press. AMPS acrylonitrile slurry is input into the filtering area of ​​the rotary filter press 1, and the solids in the AMPS acrylonitrile slurry form filter cakes on the filter cloth in the filtering area; the filter cakes are washed, dried, and discharged in the washing area, pre-drying area, and discharging area of ​​the rotary filter press 1, respectively. The washing area includes a primary washing area and a secondary washing area. The primary washing liquid in the primary washing area is a fresh acrylonitrile solvent, or a filter cloth washing liquid from the filter cloth washing liquid tank 3; the secondary washing liquid in the secondary washing area is a fresh acrylonitrile solvent. The filter cake formed in the filtering area enters the primary washing area of ​​the rotary filter press 1 as the rotary filter press 1 rotates, and the filter cake is washed for the first time in the primary washing area with the primary washing liquid; the filter cake washed for the first time enters the secondary washing area of ​​the rotary filter press 1 as the rotary filter press 1 rotates, and the filter cake is washed for the second time in the secondary washing area with the secondary washing liquid. The washed filter cake enters the drying area of ​​the rotary filter press 1 for drying; the drying area uses nitrogen to dry the filter cake, and the tail gas and washing liquid generated during the drying process enter the drying gas-liquid separation tank 2, and the nitrogen and acrylonitrile solvent are separated into gas and liquid in the drying gas-liquid separation tank 2, and the separated tail gas enters the subsequent system, and the separated solvent is recovered and recycled.

[0031] The equipment at both ends of the rotary filter press 1 is provided with an exhaust port and a drain port, which are used to discharge the leaked acrylonitrile solvent into the leakage tank in a closed manner, so as to ensure the safety of the system and prevent the acrylonitrile solvent from leaking into the environment.

[0032] The dried filter cake enters the discharge area as the rotary filter press 1 rotates. After passing through the discharge area, the filter cake is separated from the rotary pressure filter 1 by the combined action of the discharge scraper, gravity and discharge back-blowing air. After entering the material crushing conveyor 5, the filter cloth is cleaned by filter cloth washing liquid and filter cloth back-blowing air to achieve the purpose of self-cleaning. At this time, the equipment completes a cycle.

[0033] The material crushing conveyor 5 is connected to the dryer 10. The powder crushing conveyor 5 is provided with rake teeth and spirals. Under the special rake tooth structure and spiral action of the crusher, the material can not only evenly convey the AMPS filter cake to the dryer 10, but also separate the dryer 10 from the unloading area of ​​the rotary filter press 1, and no drying steam will flow into the rotary filter press 1.

[0034] The filter cake is evenly conveyed to the dryer 10 by the rake teeth and spiral of the powder crushing conveyor 5. The dryer 10 is a paddle dryer and is provided with a honeycomb jacket. The dryer 10 has a self-cleaning ability and an adjustable overflow structure. The dryer 10 has a honeycomb jacket design, so that the cooling medium or the heating medium has no short circuit or dead zone, the flow rate is high, and the equipment has the characteristics of high heat transfer rate. The acrylonitrile in the filter cake is evaporated and a qualified product is formed. The temperature of the AMPS powder discharged from the dryer 10 is about 85°C, so the AMPS powder dried by the dryer 10 is also subjected to subsequent treatment.

[0035] The material outlet of the dryer 10 is connected to the cooler 11. The cooler 11 is provided with a honeycomb jacket and two wedge-shaped shafts. Circulating cooling water is passed through the two wedge-shaped shafts and the honeycomb jacket. The honeycomb jacket design of the cooler 11 ensures that the cooling medium or the heating medium has no short circuit or dead zone, the flow rate is high, and the equipment has the characteristics of high heat transfer rate. The AMPS powder dried by the dryer 10 first enters the cooler 11, and the cooler 11 has an adjustable overflow structure. The AMPS powder is indirectly heat-exchanged with the two wedge-shaped shafts of the cooler 11 and the circulating cooling water in the jacket. The cooled AMPS powder moves toward the outlet of the cooler 11 under the action of the two wedge-shaped shafts of the cooler 11 and gravity. In this process, the AMPS powder is continuously cooled. The temperature of the cooled AMPS powder is about 60°C, and it is discharged into the discharge valve 12 with an air lock function over the overflow weir at the outlet of the cooler 11.

[0036] The mixer 13 is connected to the discharge port of the cooler 11, the discharge port of the mixer 13 is connected to the feed port of the silo 15, the first bag filter 14 is connected to the top of the silo 15, the first bag filter 14 is connected to the circulating air cooler 18, and the circulating air cooler 18 is connected to the mixer 13. After passing through the discharge valve 12, the AMPS powder enters the mixer 13, and under the action of the circulating air nitrogen, the material is transported to the silo 15 to wait for packaging. After the transported nitrogen is filtered by the first bag filter 14 and the filter 16, it enters the circulating air cooler 18 for cooling under the action of the Roots blower 17, and the cooled circulating nitrogen enters the mixer 13, realizing the closed circulation and energy-saving transportation of nitrogen.

[0037] The top of the dryer 10 is also connected to the second bag filter 6, which is connected to the primary cooler 7, the secondary cooler 8 and the induced draft fan 9 in sequence. Circulating cooling water is introduced into the primary cooler 7, and circulating refrigerated water is introduced into the secondary cooler 8. The acrylonitrile solvent vapor, nitrogen and a small amount of dust evaporated in the drying process of the dryer 10 are dedusted by the second bag filter 6 and then enter the primary cooler 7. The primary cooler 7 is preliminarily cooled by circulating cooling water, and the acrylonitrile solvent generated by cooling enters the solvent storage tank. The tail gas after preliminarily cooling enters the secondary cooler 8 and is further cooled by circulating refrigerated water. The acrylonitrile solvent generated by cooling enters the solvent storage tank. The dry tail gas after further cooling is discharged into the subsequent system under the action of the induced draft fan 9, and the recovered acrylonitrile solvent enters the solvent storage tank.

[0038] The system for continuous post-treatment of AMPS slurry of the present invention is further provided with a drying gas-liquid separation tank 2 and a filter cloth washing liquid tank 3 .

[0039] The dry gas-liquid separation tank 2 is in communication with the drying area of ​​the rotary filter press 1. The dry gas-liquid separation tank 2 is used to collect tail gas and washing liquid generated in the drying area of ​​the rotary filter press 1 during the drying process.

[0040] The filter cloth washing liquid tank 3 is connected with the rotary filter press 1, and the outlet of the filter cloth washing liquid tank 3 is connected with the inlet of the primary washing zone. The washing liquid is provided in the washing zone, and the washing liquid is 1 to 1.2 times of the mass of the filter cake. After the filter cake passes through the unloading zone, it is separated from the rotary pressure filter 1 under the joint action of the unloading scraper, gravity and unloading back-blowing air. The filter cloth washing liquid and the filter cloth back-blowing air are used to clean the filter cloth to achieve the purpose of self-cleaning. At this time, the equipment completes a cycle; the filter cloth washing liquid tank 3 is used to collect the washed filter cloth washing liquid. The filter cloth washing liquid in the filter cloth washing liquid tank 3 can be transported to the primary washing zone of the rotary filter press 1 through the filter cloth washing liquid delivery pump 4 as a primary washing liquid for recycling, and used for the first washing of the filter cake, or mixed with fresh acrylonitrile solvent for the first washing of the filter cake in the primary washing zone.

[0041] In the system for continuous post-treatment of AMPS slurry of the present invention, the mother liquor separated by filtration in the filtration zone, the primary washing filtrate generated in the first washing process, and the secondary washing filtrate generated in the second washing process are respectively recovered and recycled.

[0042] The present invention also provides a method for continuous post-processing of AMPS slurry, which comprises: AMPS acrylonitrile slurry is input into the filtering zone of a rotary filter press 1, and solids in the AMPS acrylonitrile slurry form filter cakes on the filter cloth in the filtering zone; the filter cakes are respectively washed, dried, and discharged in the washing zone, pre-drying zone, and unloading zone of the rotary filter press 1, and the filter cakes are discharged to a powder crushing conveyor 5, and the filter cakes are uniformly conveyed to a dryer 10 under the action of rake teeth and spirals of the powder crushing conveyor 5, and the acrylonitrile in the filter cakes is evaporated in the dryer 10 to form qualified products.

[0043] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the claims of the present invention.

Claims

1. A system for continuous post-processing of AMPS slurry, characterized in that: include: A rotary filter press, a material crushing conveyor and a dryer. The rotary filter press includes a filtering area, a washing area, a pre-drying area and a discharging area. The discharging area is connected to the material crushing conveyor, the material crushing conveyor is connected to the dryer, and the powder crushing conveyor is provided with rake teeth and a spiral.

2. The system according to claim 1, characterized in that The washing area includes a primary washing area and a secondary washing area; the rotary filter press is a fully enclosed rotary filter press.

3. The system according to claim 1, characterized in that A drying gas-liquid separation tank and a filter cloth washing liquid tank are also provided. The drying gas-liquid separation tank is connected to the outlet of the pre-drying zone; the filter cloth washing liquid tank is connected to the rotary filter press, and the outlet of the filter cloth washing liquid tank is connected to the inlet of the washing zone. Washing liquid is provided in the washing zone, and the washing liquid is 1 to 1.2 times the mass of the filter cake.

4. The system according to claim 1, characterized in that It also includes a cooler, a mixer, a silo, a first bag dust collector, and a circulating air cooler. The material outlet of the dryer is connected to the cooler. The cooler is provided with a honeycomb jacket and two wedge-shaped shafts. Circulating cooling water is passed through the two wedge-shaped shafts and the honeycomb jacket. The mixer is connected to the discharge port of the cooler. The discharge port of the mixer is connected to the feed port of the silo. The first bag dust collector is connected to the top of the silo. The first bag dust collector is connected to the circulating air cooler. The circulating air cooler is in turn connected to the mixer.

5. The system according to claim 1, characterized in that The dryer is a paddle dryer and is provided with a honeycomb jacket. The top of the dryer is also connected to a second bag dust collector, and the second bag dust collector is connected to a primary cooler, a secondary cooler and an induced draft fan in sequence. Circulating cooling water is introduced into the primary cooler and circulating chilled water is introduced into the secondary cooler.

6. A method for continuous post-treatment of AMPS slurry, characterized in that: include: AMPS acrylonitrile slurry is input into the filtration zone of the rotary filter press, and the solid in the AMPS acrylonitrile slurry forms a filter cake on the filter cloth in the filtration zone; the filter cake is washed, dried, and discharged in the washing zone, pre-drying zone, and unloading zone of the rotary filter press, and the filter cake is discharged to the powder crushing conveyor, and the filter cake is evenly conveyed to the dryer under the action of the rake teeth and spiral of the powder crushing conveyor, and the acrylonitrile in the filter cake is evaporated in the dryer to form a qualified product.

7. The method according to claim 1, characterized in that The washing zone includes a primary washing zone and a secondary washing zone. The filter cake formed in the filtration zone enters the primary washing zone of the rotary filter press as the rotary filter press rotates. The filter cake is washed for the first time in the primary washing zone by a primary washing liquid. The filter cake after the first washing enters the secondary washing area of ​​the rotary filter press as the rotary filter press rotates, and the filter cake is washed for the second time in the secondary washing area with the secondary washing liquid; The washed filter cake enters the drying area of ​​the rotary filter press for drying; the dried filter cake enters the unloading area as the rotary filter press rotates, and under the combined action of the unloading scraper, gravity and unloading back-blowing air, the filter cake leaves the rotary pressure filter and enters the material crushing conveyor; The primary washing liquid in the primary washing zone is fresh acrylonitrile solvent, or filter cloth washing liquid from a filter cloth washing liquid tank; The secondary washing liquid in the secondary washing zone is fresh acrylonitrile solvent; The mother liquor separated by filtration in the filtration zone, the primary washing filtrate produced in the first washing process, and the secondary washing filtrate produced in the second washing process are respectively recovered and recycled; The drying zone uses nitrogen to dry the filter cake, and the tail gas and washing liquid generated during the drying process enter the drying gas-liquid separation tank, the nitrogen and the acrylonitrile solvent are separated into gas and liquid in the drying gas-liquid separation tank, the separated tail gas enters the subsequent system, and the separated solvent is recovered and recycled.

8. The method according to claim 1, characterized in that After the filter cake leaves the rotary pressure filter and enters the material crushing conveyor, the filter cloth is cleaned by filter cloth washing liquid and filter cloth back-blowing air; The equipment at both ends of the rotary filter press is provided with an exhaust port and a liquid discharge port, which are used to discharge the leaked acrylonitrile solvent into the liquid leakage tank in a sealed manner.

9. The method according to claim 1, characterized in that: The AMPS powder dried by the dryer is also subjected to subsequent treatment, which includes: the AMPS powder is cooled in the cooler, and the material is transported to the silo under the action of the circulating air nitrogen of the mixer, and the transported nitrogen is filtered by the first bag dust collector and the filter and then returned to the mixer for recycling.

10. The method according to claim 1, characterized in that The acrylonitrile solvent vapor, nitrogen and a small amount of dust evaporated by the dryer during the drying process are dedusted by the second bag filter and then enter the primary cooler, where they are preliminarily cooled by circulating cooling water, and the acrylonitrile solvent generated by cooling enters the solvent storage tank. The tail gas after the preliminarily cooling enters the secondary cooler and is further cooled by chilled water, and the acrylonitrile solvent generated by cooling enters the solvent storage tank. The dry tail gas after further cooling is discharged into the subsequent system under the action of the induced draft fan, and the recovered acrylonitrile solvent enters the solvent storage tank.

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