Poly 2-vinylpyridine evaporation crystallization device and method

Abstract

The present invention relates to the field of separation, and in particular to a poly (2-vinyl pyridine) evaporation crystallization device and method. The device comprises a reactor, wherein an evaporation crystallization component for performing evaporation crystallization treatment on the poly (2-vinyl pyridine) is arranged in the reactor. The device achieves an evaporation crystallization extraction effect on an organic phase in the poly (2-vinyl pyridine) reactor residue through cooperation between the reactor, a pretreatment device and a separator, prepares a high-value picolinic acid product, avoids waste while improving economic benefits, and achieves carbon emission reduction while ensuring economic benefits, in line with the concept of green and sustainable development.

Description

Technical Field

[0001] The present invention relates to the field of separation, and in particular to a poly 2-vinyl pyridine evaporation crystallization device and method. Background Art

[0002] The preparation of 2-vinylpyridine typically involves heating and distilling a 2-vinylpyridine mother liquor under alkaline conditions to obtain a separated and purified 2-vinylpyridine product. This reaction inevitably produces an alkaline polymer residue at the bottom of the evaporator. The main components of the organic phase of this residue are complex macromolecular pyridine derivatives (mostly poly-2-vinylpyridine polymers and by-products), similar to asphaltene. These asphaltene-like products have high calorific value, are highly toxic, corrosive, and have a complex composition. With no clear end use, they can only be disposed of as hazardous waste, presenting a technical challenge that urgently needs to be addressed in the preparation of 2-vinylpyridine products.

[0003] If kettle residue is reutilized as a resource, not only can hazardous waste be reduced, disposal costs reduced, and the cost of the main product lowered, but the recovered potassium salts and pyridine derivatives can also be used as by-products to generate additional benefits. This ensures economic benefits while also reducing carbon emissions, in line with the concept of green and sustainable development.

[0004] Therefore, based on the above-stated viewpoint, there is still room for optimization in the existing methods for treating still-residue poly-2-vinylpyridine. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a poly 2-vinyl pyridine evaporation crystallization device, including a reactor, wherein an evaporation crystallization component for evaporating and crystallizing poly-vinyl pyridine is provided in the reactor, and the evaporation crystallization component includes:

[0006] The dividing ring plate is located in the reactor to separate the reactor into an evaporation chamber and a crystallization chamber.

[0007] The storage cylinder is arranged on the upper side of the reactor and is communicated with the reactor. A pre-processor is arranged between the storage cylinder and the reactor.

[0008] The connecting ring sleeve is located in the reactor and on the upper side of the separating ring plate. A separator is provided between the connecting ring sleeve and the separating ring plate.

[0009] Preferably, the pre-processor comprises two annular air pipes spaced apart and located in the storage cylinder, a plurality of air guide pipes are uniformly connected to the two annular air pipes in a circumferential direction, and the plurality of air guide pipes extend downward and penetrate into the evaporation chamber.

[0010] Preferably, the connecting ring sleeve is evenly connected to connecting conduits passing through the reactor in the circumferential direction, all the connecting conduits are commonly connected to a connecting ring pipe, and the connecting ring pipe is circumferentially connected to a plurality of sinking air pipes.

[0011] Preferably, a plurality of communication ports are provided on the lower side of the storage cylinder, and the communication ports are correspondingly connected to closed blocks.

[0012] Preferably, the diameter of the communication port is distributed in a stepped manner, and the closing block has an extension rod extending downwardly from the communication port, and the lower side of the extension rod is connected to a mounting frame that is limitedly penetrated on the reactor.

[0013] Preferably, the side of all the mounting frames passing through the reactor is jointly supported against the outer edge of the storage cylinder.

[0014] Preferably, the separator includes a driving rotating rod passing through the separation ring plate, and the upper limit of the driving rotating rod is connected to a stirring frame located in the evaporation chamber.

[0015] Preferably, a plurality of discharge ports are evenly opened on the circumferential direction of the connecting ring sleeve, and a filter plate is mutually limitedly connected between the driving rotating rod and the connecting ring sleeve.

[0016] Preferably, a sliding float is sleeved on the outer side of the driving rotating rod, and a connecting sleeve sleeved on the driving rotating rod is commonly connected between the sliding float and the filter plate, and the connecting sleeve is passed through the separating ring plate.

[0017] In addition, the present invention also provides a poly 2-vinyl pyridine evaporation crystallization method, comprising the following steps:

[0018] S1: The dehydrated and evaporated alkaline kettle residue from the vinyl pyridine production line is mixed with deionized water for dilution. The diluted organic phase mixture is pre-passed into a storage cylinder for temporary storage, and nitric acid solution is injected into the evaporation chamber in the reactor to wait for reaction.

[0019] S2: The nitric acid solution in the reactor is heated and the gas in the evaporation chamber is extracted through a pre-processor to form a micro-vacuum environment to avoid explosion. The hot air flow during the extraction process is driven through the storage cylinder to preheat the organic phase mixed liquid in the storage cylinder.

[0020] S3: The preheated organic phase mixed liquid is injected into the evaporation chamber to undergo an oxidation reaction with the nitric acid solution. During the reaction, the temperature in the reactor rises, the nitric acid solution evaporates, and is discharged through a connecting conduit and condensed to recover the nitric acid solution. The reaction crystallization of the nitric acid solution and the organic phase mixed liquid is accelerated by mechanical induction, and centrifugal force is used to separate the precipitated picolinic acid nitrate crystals from the reaction liquid.

[0021] S4: The crystals precipitated and separated in the evaporation chamber are introduced into the crystallization chamber, and an alkaline aqueous phase is injected into the crystallization chamber to further separate and purify the organic phase crystals and the neutralization reaction liquid. The neutralized liquid is then evaporated and crystallized twice in the crystallization chamber to obtain granular potassium nitrate. Finally, the mother liquor in the crystallization chamber is evaporated to dryness, and the obtained solid mixture is rinsed with anhydrous ethanol. The solid is dried to obtain a powdered potassium nitrate product, and the ethanol solution is evaporated and crystallized to obtain a picolinic acid product.

[0022] In summary, this application includes at least one of the following beneficial technical effects:

[0023] 1. The present invention achieves the evaporation, crystallization and extraction effect of the organic phase in the poly (2-vinyl pyridine) kettle residue through the cooperation between the reactor, the pretreatment device and the separator, and prepares a high-value picolinic acid product, thereby avoiding waste and improving economic benefits. While ensuring economic benefits, it also achieves carbon emission reduction in line with the concept of green and sustainable development.

[0024] 2. The present invention achieves vacuum extraction in the reactor and preheating of the organic phase mixture and nitric acid solution through the mutual cooperation between the pretreatment device and the separator, thereby avoiding safety risks and increasing the efficiency of evaporation and separation of the residual organic phase in the reactor.

[0025] 3. The present invention achieves the goal of promoting the precipitation of crystals from the reaction liquid in the evaporation chamber by the mutual cooperation between the driving shaft, the stirring frame and the filter plate, while applying a certain centrifugal force to separate the precipitated crystals from the evaporation chamber, thereby effectively improving the efficiency of evaporation and crystallization separation of the reaction liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below with reference to the accompanying drawings and examples.

[0027] Figure 1 It is a structural schematic diagram of the present invention.

[0028] Figure 2 It is a structural schematic diagram of the evaporation crystallization component of the present invention.

[0029] Figure 3 It is a structural diagram of the preprocessor of the present invention.

[0030] Figure 4 It is a structural schematic diagram of the annular trachea of ​​the present invention.

[0031] Figure 5 This invention Figure 4 A magnified view of center.

[0032] Figure 6 It is a structural schematic diagram of the separator of the present invention.

[0033] Figure 7It is a structural schematic diagram of the filter plate of the present invention.

[0034] Figure 8 This invention Figure 7 Magnified view of B.

[0035] In the figure, 1, reactor; 100, evaporation chamber; 101, crystallization chamber; 2, evaporation crystallization assembly; 20, separation ring plate; 200, opening; 21, storage cylinder; 22, pre-processor; 220, annular air pipe; 221, air guide pipe; 222, connecting duct; 223, connecting ring pipe; 224, sinking air pipe; 225, connecting port; 226, closing block; 227, extension connecting rod; 228, mounting frame; 229, tightening spring; 23, connecting ring sleeve; 230, discharge port; 24, separator; 240, driving rod; 241, stirring frame; 242, filter plate; 243, sliding float; 244, connecting sleeve; 245, filling pipe; 25, limiting guide rod; 250, stop hole. DETAILED DESCRIPTION

[0036] The following is combined with Figure 1 To the attached Figure 8 The embodiments of the present invention are described in detail.

[0037] The embodiments of the present application disclose a poly (2-vinyl pyridine) evaporation and crystallization apparatus and method. The present application is primarily used in the process of treating still residue produced during the preparation of 2-vinyl pyridine. Technically, the organic phase (poly (2-vinyl pyridine polymer)) in the still residue is subjected to evaporation and crystallization treatment, thereby achieving resource recovery and utilization of the still residue. In particular, during the evaporation and crystallization of poly (2-vinyl pyridine), the efficiency of evaporation and crystallization of the poly (2-vinyl pyridine polymer) is effectively increased by pre-treating the organic phase mixture and nitric acid solution. Furthermore, the present application also promotes the precipitation of crystals from the reaction liquid in the evaporation chamber by cooperating with each other, including a driving shaft, a stirring frame, and a filter plate, while applying a certain centrifugal force to separate the precipitated crystals from the evaporation chamber, thereby effectively improving the efficiency of evaporation and crystallization of the reaction liquid.

[0038] Example 1: Reference Figure 1 As shown, a poly (2-vinyl pyridine) evaporation crystallization device includes a reactor 1, a built-in heating element (not shown in the figure) in the reactor 1 to provide the temperature environment required during the treatment process, and an evaporation crystallization component 2 for evaporation crystallization of poly (2-vinyl pyridine) is provided in the reactor 1.

[0039] During use, the dehydrated and evaporated alkaline still residue from the vinyl pyridine production line is mixed with deionized water, and the high-concentration potassium hydroxide in the still residue dissolves in water to form an alkaline solution. The organic phase (pyridine derivative) in the still residue is insoluble in the alkali, forming a liquid-liquid two-phase, which is naturally separated. The organic phase has a low density and floats on the upper layer. The organic phase (mainly a poly-2-vinyl pyridine polymer) and the alkaline solution aqueous phase (potassium hydroxide) are respectively obtained through liquid-liquid separation. The diluted organic phase mixture and nitric acid solution are respectively injected into the reactor 1 for mixing and oxidation reaction. The organic phase mixture is evaporated and crystallized by the evaporation crystallization component 2 to obtain an evaporated, concentrated and crystallized product, which is then filtered and dried to obtain a picolinic acid product, thereby realizing the evaporation and crystallization treatment of the poly-2-vinyl pyridine mixture and the resource recovery and utilization of the still residue.

[0040] Reference Figures 1 to 3 As shown, the evaporation crystallization component 2 for evaporation crystallization of poly 2-vinyl pyridine is shown; specifically, the evaporation crystallization component 2 includes:

[0041] The separation ring plate 20 is limitedly located in the reactor 1 to separate the reactor 1 into an evaporation chamber 100 and a crystallization chamber 101 in the upper and lower parts.

[0042] The storage cylinder 21 is disposed on the upper side of the reactor 1 and is in communication with the reactor 1 . A pre-processor 22 is disposed between the storage cylinder 21 and the reactor 1 .

[0043] The connecting ring sleeve 23 is located in the reactor 1 and on the upper side of the separating ring plate 20 . A separator 24 is provided between the connecting ring sleeve 23 and the separating ring plate 20 .

[0044] Reference Figures 2 to 4As shown, before the organic phase mixture and nitric acid are respectively injected into the reactor 1 for reaction, due to the strong oxidizing property of nitric acid itself, a large amount of heat and gas will be released during the reaction with the organic phase mixture. The oxygen in the air is a combustion aid that can accelerate the oxidation reaction. When there is air in the reactor 1, the oxygen will react with the nitric acid and organic matter to generate more oxidation products and heat, making the reaction more intense and increasing the risk of deflagration. Therefore, in order to avoid the problem of deflagration, a pre-processor 22 for extracting excess gas in the reactor 1 is provided. Specifically, the pre-processor 22 includes two annular air pipes 220 limited in the storage cylinder 21, and a plurality of air guide pipes 221 are uniformly connected to the two annular air pipes 220 in a circumferential direction. The plurality of air guide pipes 221 extend downward into the evaporation chamber 100 to extract excess gas from the reactor 1 in the initial stage, so that the nitric acid and organic phase mixture react under a slight vacuum condition, effectively avoiding the occurrence of explosion problems. In order to provide the negative pressure suction required for extracting the gas, an air pump limited in the storage cylinder 21 is also connected to the upper side of one of the annular air pipes 220 (not shown in the figure).

[0045] Furthermore, since the oxidation reaction of nitric acid and the organic phase mixture usually requires certain heating conditions, in the initial state, the nitric acid solution is first injected into the connecting ring sleeve 23 in the evaporation chamber 100 for preheating treatment, and at the same time, the heated gas in the evaporation chamber 100 is extracted through the air pump, two annular air pipes 220 and a plurality of air guide pipes 221. Since heat is always transferred from a high-heat area to a low-heat area, after the heated gas is extracted through the air guide pipes 221 and the annular air pipes 220, its heat is transferred to the organic phase mixture in the storage cylinder 21, forming a preheating effect on the organic phase mixture in the storage cylinder 21, thereby improving the efficiency of subsequent oxidation reactions and evaporation crystallization.

[0046] Reference Figure 2 and Figure 3As shown, the preheated organic phase solution is injected into the evaporation chamber 100 to undergo an oxygenation reaction with the nitric acid solution. After the reaction is completed, the internal temperature of the reactor 1 is increased by the heating element to form a distillation effect on the oxidation synthesis reaction liquid, and the unreacted nitric acid in the reaction liquid is evaporated. At this time, in order to guide the nitric acid vapor to be discharged for condensation, a connecting conduit 222 that passes through the reactor 1 is evenly connected circumferentially on the connecting ring sleeve 23. The connecting conduit 222 is preferably made of a heat-insulating material to prevent the high temperature in the reactor 1 from being transferred to the connecting conduit 222. All the connecting conduits 222 are connected to a connecting ring pipe 223 at one end passing through the outside of the reactor 1. A number of downpipes 224 are connected circumferentially on the connecting ring pipe 223. The connecting ring pipe 223 and the downpipe 224 are preferably made of a heat-conducting material to increase the rate of heat exchange between the connecting ring pipe 223 and the downpipe 224 and the outside world, thereby improving the condensation effect of the nitric acid vapor.

[0047] Furthermore, after the nitric acid vapor is discharged outward through a plurality of connecting conduits 222 and introduced into the connecting ring pipe 223, the high heat of the nitric acid vapor is exchanged with the outside air through the connecting ring pipe 223, causing the high-temperature nitric acid vapor to condense and then fall into a plurality of descending air pipes 224 to accumulate and reform into a nitric acid solution.

[0048] It should be noted that during the oxidation synthesis reaction of nitric acid and organic phase solution, as the reaction proceeds, a portion of nitrogen oxide tail gas (such as nitric oxide, nitrogen dioxide, etc.) will gradually be generated during the reaction process, and will also be introduced into the connecting ring pipe 223 and the downdraft pipe 224 through several connecting conduits 222. At this time, the nitrogen oxide tail gas is absorbed by the nitric acid solution in the downdraft pipe 224 so that the nitric acid solution can be recycled later.

[0049] At the same time, during the entire treatment process, it is necessary to always maintain a slightly negative pressure state in the reactor 1.

[0050] Reference Figures 3 to 5 As shown, in the initial state, since it is necessary to draw a vacuum inside the reactor 1, in order to control the organic phase mixed liquid in the storage cylinder 21 to fall into the reactor 1 and contact with the nitric acid solution, and at the same time to preheat the organic phase solution, a plurality of connecting ports 225 are provided on the lower side of the storage cylinder 21 to communicate with the evaporation chamber 100, so as to introduce the organic phase mixed liquid in the storage cylinder 21 into the evaporation chamber 100, and a closed block 226 is connected to the connecting port 225 to control the falling of the organic phase solution in the storage cylinder 21, so as to avoid the organic phase solution from contacting the nitric acid solution in the evaporation chamber 100 in advance, which may easily cause the problem of explosion.

[0051] Reference Figures 3 to 5As shown, the diameter of the communication port 225 is set to be stepped and reduced to limit the downward movement of the sealing blocking block 226, thereby forming a sealing effect on the storage cylinder 21. The sealing blocking block 226 extends downward corresponding to the communication port 225 with an extension connecting rod 227. The lower side of the extension connecting rod 227 is connected with a mounting frame 228 which is limitedly penetrated through the reaction kettle 1. An abutting spring 229 is sleeved on the extension connecting rod 227 and is located between the mounting frame 228 and the storage cylinder 21.

[0052] In the initial state, the pressure inside the reaction kettle 1 is the same as that of the outside world. The abutting spring 229 is in a compressed and abutting state to provide a tendency for the storage cylinder 21 to always slide upward, so that the sealing blocking block 226 closely abuts at the communication port 225, forming an initial sealing effect on the storage cylinder 21, so as to avoid the problem that the organic phase mixture liquid falls into the evaporation chamber 100 after being injected into the storage cylinder 21.

[0053] During use, after evacuating the inside of the reaction kettle 1, the pressure inside the reaction kettle 1 decreases and forms a pressure difference with the outside atmospheric pressure. The outside pressure difference drives the whole storage cylinder 21 to move downward, forming a relative position sliding with the sealing blocking block 226, so that the sealing blocking block 226 is separated from the communication port 225, and at the same time drives the connected abutting spring 229 to be further compressed, so as to facilitate the preheated organic phase mixture liquid in the storage cylinder 21 to fall into the reaction kettle 1.

[0054] It should be noted that although the reaction kettle 1 is heated and the temperature is increased while evacuating the inside of the reaction kettle 1, since high temperature will cause the nitric acid solution to pyrolyze in advance, the rising efficiency of the pressure inside the reaction kettle 1 caused by heating in the initial state is less than the efficiency of reducing the pressure inside the reaction kettle 1 by vacuum pumping. That is, the pressure inside the reaction kettle 1 is always less than the outside atmospheric pressure in the vacuum pumping state.

[0055] Refer to Figure 3 and Figure 4 As shown, since it is necessary to drive the storage cylinder to slide in the vertical direction, the mounting frame 228 is arranged in a "C" - shaped structure. Its vertical section is limitedly connected to the reaction kettle 1, and one of the horizontal sections on its lower side is connected to the extension connecting rod 227. All the upper - side horizontal sections of the mounting frame 228 jointly abut against the outer edge of the storage cylinder 21 to ensure the stability of the storage cylinder 21 when sliding in the vertical direction.

[0056] Refer to Figure 6 and Figure 7As shown, the separator 24 includes a driving rod 240 that penetrates the separating ring plate 20. The upper limit of the driving rod 240 is connected to a stirring frame 241 located within the evaporation chamber 100. During use, the driving rod 240 is driven to rotate using existing motor drive technology. The rotation of the driving rod 240 drives the stirring frame 241 to rotate synchronously, so that the stirring frame 241 drives the oxidation synthesis reaction liquid (nitric acid solution and organic phase mixture) within the evaporation chamber 100 to rotate and shift. During the initial reaction of the nitric acid solution and organic phase mixture within the evaporation chamber 100, the rotation of the stirring frame 241 accelerates the reaction crystallization (picolinic acid nitrate crystallization) of the nitric acid solution and organic phase mixture. During the middle and late stages of the oxygenation reaction, the rotation of the stirring frame 241 applies centrifugal force to the reaction liquid, thereby promoting the separation of precipitated crystals from the reaction liquid.

[0057] In order to discharge the filtrate after the crystals are discharged, a drain pipe is provided on the connecting sleeve and the reactor 1 , and the drain pipe is in a normally closed state.

[0058] Further, refer to Figure 2 、 Figure 6 and Figure 7 As shown, the connecting ring 23 is provided with a plurality of discharge ports 230 uniformly distributed along its circumference. A filter plate 242 is positioned between the driving rod 240 and the connecting ring 23 to filter crystals precipitated from the reaction solution. The separating ring 20 also has an opening 200 formed therein to allow the precipitated crystals to fall into the crystallization chamber 101. Initially, the filter plate 242 is attached to the separating ring 20 (i.e., at the bottom of the evaporation chamber 100).

[0059] During use, when it is necessary to drive the crystals in the evaporation chamber 100 to separate from the reaction liquid, the filter plate 242 is driven to move upward. In the process of the filter plate 242 moving up to a position flush with the discharge port 230, the crystals mixed in the reaction liquid in the evaporation chamber 100 will be gradually driven to move upward. At this time, the centrifugal force applied by the rotation of the stirring frame 241 is used so that the precipitated crystals are separated from the filter plate 242 and discharged from the evaporation chamber 100 through the discharge port 230, thereby completing the effect of driving the crystals to separate from the reaction liquid. At this time, the filtrate after the crystals are discharged can be discharged through the drain pipe.

[0060] Furthermore, refer to Figure 6 and Figure 7As shown, in order to further process the crystals (picolinate nitrate crystals) precipitated from the oxidation synthesis reaction in the evaporation chamber 100, it is necessary to introduce the alkaline aqueous phase after the initial liquid-liquid separation into the crystallization chamber 101 for a neutralization reaction. At the same time, in order to drive the filter plate 242 upward to complete the effect of driving the crystals precipitated in the evaporation chamber 100 to separate from the reaction liquid, a sliding float 243 is provided on the outer sliding sleeve of the driving rotating rod 240. The sliding float 243 and the filter plate 242 are commonly connected with a connecting sleeve 244 sleeved on the driving rotating rod 240. The connecting sleeve 244 is slidably penetrated on the separating ring plate 20 and is connected to a filling pipe 245 passing through the reactor 1 in the crystallization chamber 101. The filling pipe 245 is preferably arranged on the lower side of the sliding float 243.

[0061] During use, after the crystals are precipitated and separated in the evaporation chamber 100, the alkaline aqueous phase after initial separation is injected into the crystallization chamber 101. As the alkaline aqueous phase is injected, the sliding float 243 also floats upward. The upward movement of the sliding float 243 drives the connecting sleeve 244 and the filter plate 242 to move upward synchronously, so as to achieve the effect of driving the crystals in the evaporation chamber 100 to separate from the reaction liquid.

[0062] The crystals (picolinate nitrate crystals) in evaporation chamber 100 fall into crystallization chamber 101, where they undergo a neutralization reaction with the aqueous alkali solution. Nitric acid solution is then injected into crystallization chamber 101 to neutralize the aqueous alkali solution, producing a neutralized solution (primarily picolinic acid and potassium nitrate). This neutralized solution is then heated to evaporate and concentrate, producing granular potassium nitrate. Finally, the granular potassium nitrate is washed with anhydrous ethanol, filtered to obtain refined granular potassium nitrate, and dried to obtain the granular potassium nitrate product, completing the resource recovery of the organic phase (poly-2-vinylpyridine polymer) in the still residue.

[0063] As an optional embodiment, a stirring frame 241 located on the lower side of the sliding float 243 can be limited on the driving rod 240 to promote the precipitation effect of crystals in the crystallization chamber 101. At the same time, in the initial state, the sliding float 243 is spaced apart from the bottom of the reactor 1, so that the sliding float 243 can respond to the floating in time, so as to synchronously drive the connecting sleeve 244 and the filter plate 242 to move upward, thereby promoting the separation of the precipitated crystals and the reaction liquid in the evaporation chamber 100.

[0064] Example 2: Reference Figure 7 and Figure 8 As shown, based on Example 1, to improve the efficiency of crystallization discharge from the evaporation chamber 100, at least one limiting guide rod 25 is provided on the lower side of the separating ring plate 20, and a stop hole 250 is provided on the sliding floating plate 243 to correspond to the limiting guide rod 25. In the initial state, the limiting guide rod 25 and the stop hole 250 are spaced apart, and the height of the stirring frame 241 in the evaporation chamber 100 is preferably relatively flush with the discharge port 230.

[0065] When in use, after the alkali liquid aqueous phase is injected into the crystallization chamber 101, the sliding float 243 that floats with the alkali liquid aqueous phase synchronously drives the connecting sleeve 244 and the filter hole plate 242 to move upward synchronously, so that the stop hole 250 on the sliding float 243 and the limiting guide rod 25 on the separating ring plate 20 form a relative position sliding effect. After the filter hole plate 242 moves up and fits the lower side of the stirring frame 241 in the evaporation chamber 100, the limiting guide rod 25 is correspondingly inserted into the stop hole 250 to limit the connecting sleeve 244, the sliding float 243 and the filter hole plate 242 from sliding upward. The rotation of the orifice plate 242 prevents the rotation of the driving rod 240 from driving the filter orifice plate 242 to rotate, and the rotation of the driving rod 240 will synchronously drive the stirring frame 241 to rotate, so that the stirring frame 241 in the evaporation chamber 100 rotates and slides relative to the filter orifice plate 242, so that the rotating stirring frame 241 can exert a certain centrifugal force on the crystals on the filter orifice plate 242 while scraping and pushing the crystals on the filter orifice plate 242, so as to achieve the effect of promoting the efficient discharge of crystals from the evaporation chamber 100.

[0066] In addition, the present invention also provides a poly 2-vinyl pyridine evaporation crystallization method, comprising the following steps:

[0067] S1: The dehydrated and evaporated alkaline kettle residue from the vinyl pyridine production line is mixed with deionized water for dilution. The diluted organic phase mixture is pre-passed into the storage cylinder 21 for temporary storage, and nitric acid solution is injected into the evaporation chamber 100 in the reactor 1 for reaction.

[0068] S2: The nitric acid solution in the reactor 1 is heated and the gas in the evaporation chamber 100 is extracted through the pre-processor 22 to form a micro-vacuum environment to avoid explosion, and the hot air flow during the extraction process is driven through the storage cylinder 21 to preheat the organic phase mixed liquid in the storage cylinder 21.

[0069] S3: The preheated organic phase mixture is injected into the evaporation chamber 100 to undergo an oxidation reaction with the nitric acid solution. During the reaction, the temperature in the reactor 1 increases, the nitric acid solution evaporates, and is discharged through the connecting conduit 222 and condensed to recover the nitric acid solution. The reaction crystallization of the nitric acid solution and the organic phase mixture is accelerated by mechanical induction, and the centrifugal force is used to separate the precipitated picolinic acid nitrate crystals from the reaction solution.

[0070] S4: The crystals precipitated and separated in the evaporation chamber 100 are introduced into the crystallization chamber 101, and an alkaline aqueous phase is injected into the crystallization chamber 101 to further separate and purify the organic phase crystals and the neutralization reaction liquid. The neutralized liquid is then evaporated and crystallized twice in the crystallization chamber 101 to obtain granular potassium nitrate. Finally, the mother liquor in the crystallization chamber 101 is evaporated to dryness, and the obtained solid mixture is rinsed with anhydrous ethanol. The solid is dried to obtain a powdered potassium nitrate product, and the ethanol solution is evaporated and crystallized to obtain a picolinic acid product.

[0071] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as exemplary and non-restrictive.

[0072] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A poly (2-vinyl pyridine) evaporation crystallization device, comprising a reaction kettle (1), characterized in that: The reactor (1) is provided with an evaporation crystallization component (2) for performing evaporation crystallization treatment on poly-2-vinylpyridine. The evaporation crystallization component (2) comprises: A separating ring plate (20) is located within the reactor (1) to separate the reactor (1) into an evaporation chamber (100) and a crystallization chamber (101) at the top and bottom; A storage cylinder (21) is provided on the upper side of the reactor (1) and is connected to the reactor (1), and a pre-processor (22) is provided between the storage cylinder (21) and the reactor (1); A connecting ring sleeve (23) is located within the reactor (1) and on the upper side of the separating ring plate (20), and a separator (24) is provided between the connecting ring sleeve (23) and the separating ring plate (20); The pre-processor (22) comprises two annular air pipes (220) spaced apart and located within the storage cylinder (21); a plurality of air guide pipes (221) are uniformly connected to each other in the circumferential direction between the two annular air pipes (220); and the plurality of air guide pipes (221) extend downward and penetrate into the evaporation chamber (100); The storage cylinder (21) is provided with a plurality of communication openings (225) on the lower side, and the communication openings (225) are connected to corresponding closing blocks (226); The caliber of the communication port (225) is distributed in a stepped manner, and the closing block (226) is provided with an extension connecting rod (227) extending downwardly from the communication port (225), and the lower side of the extension connecting rod (227) is connected to a mounting frame (228) that is limitedly penetrated on the reactor (1); The separator (24) includes a driving rotating rod (240) passing through the separation ring plate (20), and the upper limit of the driving rotating rod (240) is connected to a stirring frame (241) located in the evaporation chamber (100); The connecting ring sleeve (23) is evenly provided with a plurality of discharge ports (230) on the circumferential direction, and a filter plate (242) is connected between the driving rod (240) and the connecting ring sleeve (23) in a mutually limiting manner. The driving rotating rod (240) is sleeved with a sliding floating plate (243) on its outer side. The sliding floating plate (243) and the filter plate (242) are connected to each other by a connecting sliding sleeve (244) sleeved on the driving rotating rod (240). The connecting sliding sleeve (244) is passed through the separating ring plate (20).

2. A poly 2-vinylpyridine evaporation crystallization device according to claim 1, characterized in that: The connecting ring sleeve (23) is evenly connected to connecting conduits (222) passing through the reactor (1) in the circumferential direction. All the connecting conduits (222) are commonly connected to a connecting ring pipe (223). The connecting ring pipe (223) is connected to a plurality of sinking air pipes (224) in the circumferential direction.

3. A poly 2-vinylpyridine evaporation crystallization device according to claim 1, characterized in that: All the mounting frames (228) pass through one side of the reactor (1) and are supported against the outer edge of the storage cylinder (21).

4. A poly (2-vinyl pyridine) evaporation crystallization method, using a poly (2-vinyl pyridine) evaporation crystallization device according to any one of claims 1 to 3, characterized in that: The crystallization method comprises the following steps: S1: The dehydrated and evaporated alkaline kettle residue from the vinyl pyridine production line is mixed with deionized water for dilution, the diluted organic phase mixture is pre-passed into a storage cylinder (21) for temporary storage, and a nitric acid solution is injected into the evaporation chamber (100) in the reactor (1) for reaction; S2: heating the nitric acid solution in the reactor (1) and extracting the gas in the evaporation chamber (100) through the pre-processor (22) to form a micro-vacuum environment to avoid explosion, and driving the hot air flow in the extraction process to pass through the storage cylinder (21) to preheat the organic phase mixed liquid in the storage cylinder (21); S3: The preheated organic phase mixture is injected into the evaporation chamber (100) and undergoes oxidation reaction with the nitric acid solution. During the reaction, The temperature in the reactor (1) increases, the nitric acid solution evaporates, is discharged through the connecting conduit (222) and condensed, the nitric acid solution is recovered, the reaction crystallization of the nitric acid solution and the organic phase mixture is accelerated by mechanical induction, and the precipitated picolinic acid nitrate crystals are separated from the reaction solution by centrifugal force; S4: The crystals separated and precipitated in the evaporation chamber (100) are introduced into the crystallization chamber (101), and an alkaline aqueous phase is injected into the crystallization chamber (101) to further separate and purify the organic phase crystals and the neutralization reaction liquid. The neutralization liquid is then evaporated and crystallized twice in the crystallization chamber (101) to obtain granular potassium nitrate. Finally, the mother liquor in the crystallization chamber (101) is evaporated to dryness, and the obtained solid mixture is rinsed with anhydrous ethanol. The solid is dried to obtain a powdered potassium nitrate product, and the ethanol solution is evaporated and crystallized to obtain a picolinic acid product.

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