Centrifugal machine for producing 2-chloro-4-fluorobenzoic acid

Abstract

The invention relates to the technical field of centrifugal machines, and discloses a centrifugal machine for producing 2-chloro-4-fluorobenzoic acid, which comprises a centrifugal machine body, a feeding hole is formed in the upper part of the centrifugal machine body, a rotary drum is arranged in the centrifugal machine body, a separation mechanism and an air cylinder are respectively arranged above the centrifugal machine body, and a scraper component is connected below the air cylinder; by constructing a double-stroke progressive scraping scheme, the problem that a traditional fixed scraper is difficult to consider scraping efficiency and cleanliness at the same time is thoroughly solved, under driving of a main-stage stroke of an air cylinder, the scraper makes contact with the inner wall of a rotary drum firstly, most of loose material layers are rapidly removed, and it is avoided that separation efficiency is affected by excessive accumulation of crystals, and after the main-stage stroke is completed, separation efficiency is greatly improved. When the rotary drum rotates, the air cylinder enters the secondary stroke, the control cylinder set drives the driving scraper set to further expand to the limiting position, at the moment, the position covering unit of the driven scraper set automatically fills the gap between the adjacent scraping arm units under the linkage effect of the driving scraper set, a complete annular scraping face is formed, and stubborn materials remaining on the inner wall of the rotary drum are deeply cleared away.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of centrifuges, in particular to a centrifuge for 2-chloro-4-fluorobenzoic acid production. BACKGROUND

[0002] 2-chloro-4-fluorobenzoic acid is an important organic synthesis intermediate and is widely used in the fields of fine chemical industry such as medicine and pesticide. The molecule structure of 2-chloro-4-fluorobenzoic acid contains chlorine and fluorine atoms, which endows special chemical properties and is often used for constructing active molecules containing fluorine and chlorine functional groups. In the production process, the reaction generates solid phase crystallization products and liquid phase mixtures. Because the 2-chloro-4-fluorobenzoic acid crystalline particles are small and easy to agglomerate, and are difficult to separate from the mother liquor, the centrifuge can realize the solid-liquid separation quickly by means of centrifugal force, so that the solid phase crystallization is enriched on the inner wall of the drum, and the liquid phase is efficiently discharged, which not only guarantees the product purity, but also recycles the mother liquor, avoids material waste and pollution, and is the key equipment for realizing the solid-liquid separation, improving the production efficiency and product quality in the production of the product.

[0003] Although the centrifuge is used for solid-liquid separation, the scraper design of the prior art has obvious defects, which seriously restricts the separation efficiency and product quality. In production, 2-chloro-4-fluorobenzoic acid crystallization continuously generates with the reaction, and the small crystalline particles just precipitated will gradually adhere to the surface of the drum. Because the existing scraper is fixed in structure and cannot be adjusted, if it is initially set to closely fit the surface of the drum, a small amount of newly generated solid phase will be immediately scraped off by the scraper as soon as the drum captures it, which will prevent the crystallization from fully growing and enriching, not only increasing the difficulty of subsequent crystallization purification, but also causing the solid phase to repeatedly circulate in the centrifuge due to frequent scraping, thereby reducing the overall efficiency of the separation process. In order to avoid the newly generated solid phase from being scraped off too early, a gap is intentionally left between the scraper and the surface of the drum.

[0004] With the progress of production, the solid phase adhered to the surface of the drum continuously accumulates, especially the characteristics of 2-chloro-4-fluorobenzoic acid which is easy to agglomerate, which will form a dense and thick adhesion layer of solid phase. The scraper with a reserved gap cannot reach the deep layer of the inner wall of the drum, and cannot effectively clean the stubborn residues. These residual solid phases will pollute the subsequent batch of materials, affect the product purity, and increase the load of the drum rotation, thereby increasing the energy consumption and fault risk of the equipment.

[0005] Meanwhile, in the production of 2-chloro-4-fluorobenzoic acid, the reaction system is complex, and the mother liquor may contain unreacted raw materials, by-products and the like, which may adhere to the drum together with the crystals. The existing fixed scraper is difficult to adapt to different adhesion states of the mixture. When there are many impurities in the mother liquor, a complex adhesion structure is formed between the solid phase, the liquid phase and the impurities. When the fixed scraper is scraped, it is easy to cause incomplete scraping or to scrape too much liquid phase, which not only causes product loss, but also makes it difficult to recover the mother liquor, and cannot efficiently realize resource recycling. Moreover, because the scraper cannot be adjusted, it is difficult to flexibly adjust the scraping force and the fitting degree in the face of different batches of 2-chloro-4-fluorobenzoic acid crystal forms and particle size changes (such as changes in crystal particle size and agglomeration degree caused by fluctuations in reaction conditions), it is difficult to stably ensure the solid-liquid separation effect, and long-term use will also cause unreasonable contact between the scraper and the drum, aggravate the wear of the inner wall of the drum, shorten the service life of the equipment, and increase the cost of equipment maintenance and replacement of enterprises, which becomes a key bottleneck restricting the large-scale and high-quality production of 2-chloro-4-fluorobenzoic acid.

[0006] Therefore, the present application provides a centrifuge for producing 2-chloro-4-fluorobenzoic acid. SUMMARY

[0007] The present application aims to provide a centrifuge for producing 2-chloro-4-fluorobenzoic acid to solve the problems raised in the background art.

[0008] To achieve the above-mentioned purpose, the present application provides the following technical solution: a centrifuge for producing 2-chloro-4-fluorobenzoic acid, comprising a centrifuge body, a feed inlet is arranged above the centrifuge body, a drum is installed inside, a separation mechanism and a cylinder are further arranged above the centrifuge body, and a scraper assembly is connected below the cylinder; the scraper assembly is composed of a control cylinder group, a driving scraper group and a driven scraper group; the top of the control cylinder group is in transmission connection with the telescopic end of the cylinder, and the bottom is in transmission connection with the driving scraper group; the driving scraper group comprises at least two scraper arm units which are distributed radially symmetrically along the drum; the driven scraper group comprises a plurality of supplemental units which are movably arranged between adjacent scraper arm units and form a dynamic reconstruction structure of the scraping surface with the driving scraper group; after the centrifugation is completed, the centrifuge realizes progressive scraping through two-stage travel control of the cylinder: first, the primary travel is executed, the driving scraper group is driven by the control cylinder group to make the scraper arm units of the driving scraper group contact the inner wall of the drum, and most of the loose material layer is removed through movement; then, the secondary travel is executed, the control cylinder group drives the driving scraper group to further expand to the limit working position, and at the same time, the supplemental units of the driven scraper group automatically fill the gaps between adjacent scraper arm units through the movement of the driving scraper group, and the blind area annular scraping surface is reconstructed, so that the remaining stubborn material on the inner wall of the drum is completely scraped off; the linkage structure design of the driving scraper group and the driven scraper group ensures the timing switching precision of the two scraping states, and the supplemental units form overlapping cooperation with the adjacent scraper arm units in the working state, so that the scraping blind area is effectively eliminated.

[0009] Preferably, the control cylinder set comprises a center cylinder, a driving shaft and a driving gear, the center cylinder is fixedly connected to the fixed end surface of the cylinder, the driving shaft is slidingly connected to the inside of the center cylinder, and the driving shaft is fixedly connected to the telescopic end of the cylinder, and the driving gear is rotationally connected to the middle part of the inner cavity of the center cylinder.

[0010] Preferably, the driving scraper set comprises two racks movably connected to the inside of the center cylinder, both of the racks are engaged with the driving gear, and both of the racks are mirror-symmetrically arranged, and one of the racks is fixedly connected to the driving shaft, when the driving shaft moves, it pushes the corresponding rack to move synchronously, under the engagement of the driving gear, it drives the other rack to move reversely, and the outside of each rack is provided with a plurality of driving plates.

[0011] Preferably, the driven scraper set comprises a plurality of driven plates, one driven plate is arranged between every two driving plates, the outside of each driven plate is provided with a bearing plate, and the bottom of each bearing plate is rotationally connected with two lateral strips, and the lateral strips are movably arranged on the driving plates.

[0012] Preferably, the surface of the center cylinder is provided with two sliding grooves I, and the sliding grooves I correspond to the racks, and are used for guiding and limiting the movement of the racks.

[0013] Preferably, the driving scraper set further comprises two sliding rings movably connected to the surface of the center cylinder, the sliding rings correspond to the racks, and the parts of the sliding rings and the racks exposed outside the center cylinder are fixedly connected, the surface of each sliding ring is fixedly connected with a number of fixed piles corresponding to the number of driving plates, the surface of each fixed pile is rotationally connected with a supporting strip, the surface of each supporting strip is rotationally connected with an ear plate, and the top of each ear plate is fixedly connected with a driving plate.

[0014] Preferably, the sliding ring is provided with a sliding groove II matched with the rack, which can ensure the sliding connection of the two and provide a guiding space for the movement of the rack.

[0015] Preferably, the two sides of the ear plate are provided with side holes, the driven scraper set further comprises a number of driven bases corresponding to the number of driven plates, the driven bases are fixedly connected to the surface of the bearing plate, a plurality of springs are fixedly connected in the driven bases, the other ends of the springs are fixedly connected to the surface of the driven plate, and the driven plate and the driven base are in a sliding fit.

[0016] Preferably, the lateral strips are hingedly connected with the driving plates through the side holes on the two sides of the ear plate, forming a synchronous linkage structure, and ensuring the consistency of the trajectories of the driven plates and the driving plates.

[0017] Preferably, the driven plate is synchronously stretched and contracted by the lateral strip when the driving plate moves; when the driving plate reaches the maximum stroke, the driven plate completely fills the gap between adjacent driving plates to form a continuous scraping surface; when the driving plate returns, the driven plate is compressed by the spring and retracts into the driven base.

[0018] Preferably, the pressure sensors are arranged on the inner wall of the rotating drum in a circumferential direction, and the scraping contact pressure data is collected in real time and transmitted to the PLC controller, so that the displacement compensation amount of the two-stage stroke of the air cylinder is automatically corrected to realize dynamic adaptation of the scraping force to the material adhesion characteristics.

[0019] Compared with the prior art, the present application has the following advantages: 1. By constructing a progressive scraping scheme with double strokes, the problem that the traditional fixed scraper cannot balance the scraping efficiency and cleanliness is solved. Under the driving of the main stage stroke of the air cylinder, the scraper first contacts the inner wall of the rotating drum, quickly removes most of the loose material layer, avoids excessive accumulation of crystals affecting the separation efficiency, and after the main stage stroke is completed, the air cylinder enters the secondary stroke, the control cylinder group drives the driven scraper group to further expand to the limit position, at this time, the complementary unit of the driven scraper group automatically fills the gap between the adjacent scraper arm units under the linkage action of the driven scraper group, forming a complete annular scraping surface, and the stubborn material remaining on the inner wall of the rotating drum is deeply cleaned. This double-stroke progressive scraping mode avoids the problem that the traditional scraper removes the crystals that are not fully enriched too early, and can implement the scraping in stages and strategically after the completion of the centrifugal operation, according to the material layer with different thickness and adhesion strength, which significantly improves the thoroughness of solid-liquid separation.

[0020] 2. The center cylinder, driving shaft and driving gear inside the control cylinder group build a stable and precise transmission system. The center cylinder provides a mounting base for the driving shaft and the driving gear. The driving shaft directly transmits the power of the air cylinder, and the driving gear makes the two mirror-symmetric racks move in opposite directions by meshing with the racks. Compared with the traditional scraper power transmission, the transmission structure ensures the synchronous and opposite movement of the scraper arm units, provides stable power for the scraping operation, and makes the scraping process more orderly in the production of 2-chloro-4-fluorobenzoic acid, avoids incomplete scraping or damage to the rotating drum caused by uneven power, ensures stable separation operation, and improves production continuity.

[0021] 3. The rack and drive plate design of the active scraper assembly further optimizes the separation effect. Two racks mesh with the drive gear; one moves with the drive shaft while the other moves in the opposite direction, coordinating the scraper unit's operation. The drive plate outside the racks directly contacts the inner wall of the drum. Driven by the racks, it can gently clean the loose layer first, and then thoroughly process stubborn residues according to the material separation process. Traditional fixed scrapers tend to scrape too early or not clean thoroughly. This design is adapted to the dynamic process of 2-chloro-4-fluorobenzoic acid crystal formation and adhesion, allowing crystals to grow and accumulate fully, reducing the difficulty of subsequent purification, improving separation efficiency and product purity, reducing the circulation of solid phase within the equipment, and ensuring efficient production.

[0022] 4. The driven scraper assembly, including the driven plate, support plate, and side strips, is key to eliminating scraping blind spots. The driven plate is positioned in the gap between the drive plate and the drive plate, the support plate provides the mounting base, and the side strips connect the two to create a linkage. When the drive plate moves, the side strips drive the driven plate to move synchronously, filling the gaps. Addressing the issue of 2-chloro-4-fluorobenzoic acid easily agglomerating to form a dense layer, traditional fixed scrapers cannot handle gap residue. In this design, the driven plate, pushed by a spring, can precisely fill the gaps, forming a continuous annular scraping surface. This structure thoroughly cleans the residue on the inner wall of the drum, preventing material contamination of subsequent batches, ensuring stable product quality, and solving the purity and energy consumption problems caused by gap residue in traditional scrapers.

[0023] 5. The active scraper assembly, including the slip ring, fixed stack, support bar, and ear plate, improves the motion coordination of the scraper unit. The slip ring moves with the rack, and the fixed stack, support bar, and ear plate form a linkage mechanism, converting the slip ring motion into the lifting force of the drive plate. Traditional scraper motion is prone to jamming and uneven force distribution. This design makes the expansion of the drive plate more stable and controllable. In the production of 2-chloro-4-fluorobenzoic acid, this coordinated motion ensures that the drive plate is subjected to uniform force, avoiding damage to the drum due to excessive local force, extending the service life of the equipment, and making the scraping action smoother, improving the scraping effect, ensuring the high efficiency and stability of solid-liquid separation, and reducing equipment maintenance costs.

[0024] 6. The pressure sensor on the inner wall of the drum works in conjunction with the PLC controller to build an intelligent control mechanism. The pressure sensor collects scraping pressure data in real time, transmits it to the PLC, and automatically corrects the cylinder stroke compensation. Traditional scrapers cannot adapt to the adhesion characteristics of different batches of materials. This design can dynamically adjust the scraping force according to the differences in the crystal morphology and humidity of 2-chloro-4-fluorobenzoic acid. This intelligent control not only ensures efficient removal of the solid phase, but also avoids damage to the drum due to excessive scraping force. It achieves a dual improvement in equipment stability and material separation cleanliness, helping to promote the large-scale, high-quality production of 2-chloro-4-fluorobenzoic acid and breaking through the production bottleneck caused by the lack of intelligent adaptation in traditional equipment. Attached Figure Description

[0025] Figure 1 This is a frontal perspective three-dimensional schematic diagram of the main structure of the present invention; Figure 2 is a partial top view schematic diagram of the main structure of the present application; Figure 3 is a sectional view schematic diagram of the main structure of the present application; Figure 4 is a schematic diagram of the scraper assembly of the present application; Figure 5 is a sectional view schematic diagram of the scraper assembly of the present application; Figure 6 is a sectional view schematic diagram of the central cylinder of the present application; Figure 7 is a bottom view schematic diagram of the scraper assembly of the present application; Figure 8 is a schematic diagram of the driving scraper group of the present application; Figure 9 is a schematic diagram of the driven scraper group of the present application.

[0026] In the figure: 1, centrifuge body; 2, feed inlet; 3, rotary drum; 4, separation mechanism; 5, air cylinder; 61, control cylinder group; 611, central cylinder; 6111, sliding slot one; 612, driving shaft; 613, driving gear; 62, driving scraper group; 621, rack; 622, sliding ring; 6221, sliding slot two; 623, fixed stack; 624, support strip; 625, ear plate; 6251, side hole; 626, driving plate; 63, driven scraper group; 631, lateral strip; 632, bearing plate; 633, driven base; 634, spring; 635, driven plate. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0028] It should be noted that the rotary drum 3 only provides the function of separating raw materials by centrifugal force generated by rotation, and the separation mechanism 4 only provides the function of uniformly dispersing raw materials. The working principle and specific structure of the above structure are both prior art, and therefore, in view of the universality of the above structure, the specific principle will not be described in detail.

[0029] Please refer to Figures 1 to 9 , the present application provides an embodiment: The utility model provides a centrifuge for 2-chloro-4 fluorobenzoic acid production, including centrifuge body 1, be equipped with feed inlet 2 above centrifuge body 1, install drum 3 inside, top still be equipped with separating mechanism 4 and cylinder 5 respectively, and the scraper assembly is connected below cylinder 5, the scraper assembly is by control cylinder group 61, driving scraper group 62 and driven scraper group 63 constitute, control cylinder group 61 top and cylinder 5 telescopic end transmission connection, bottom and driving scraper group 62 transmission connection, driving scraper group 62 includes at least two radial symmetry distribution's scraper arm unit along drum 3, driven scraper group 63 includes a plurality of activity set up in the supplementary position unit between adjacent scraper arm unit, and with driving scraper group 62 constitute the scraping surface dynamic reconfiguration structure, and the centrifuge realizes progressive scraping through the two-stage travel control of cylinder 5 after centrifugal operation is completed: first, the main stage travel is executed, drives control cylinder group 61 to drive scraper group 62's scraper arm unit contact drum 3 inner wall, removes most loose material layer through movement, then, the secondary travel is executed, control cylinder group 61 drives driving scraper group 62 to further expand to the limit working position, and the supplementary position unit of driven scraper group 63 is automatically filled in the gap between adjacent scraper arm unit through the movement of driving scraper group 62, reconfigures the annular scraping surface without blind area, realizes the complete scraping of stubborn material remaining in the inner wall of drum 3, and the linkage structure design of driving scraper group 62 and driven scraper group 63 ensures the timing switching precision of two kinds of scraping state, and the supplementary position unit forms the overlapping cooperation with adjacent scraper arm unit under working condition, effectively eliminates the scraping blind area.

[0030] It needs explanation that the control cylinder group 61 includes the center cylinder 611, the driving shaft 612 and the driving gear 613, the center cylinder 611 is fixedly connected to the fixed end surface of the cylinder 5, the driving shaft 612 is slidingly connected to the inside of the center cylinder 611, and the driving shaft 612 is fixedly connected to the telescopic end of the cylinder 5, the driving gear 613 is rotatably connected to the middle part of the inner cavity of the center cylinder 611, the driving scraper group 62 includes two racks 621 which are movably connected to the inside of the center cylinder 611, the two racks 621 are engaged with the driving gear 613, and the two racks 621 are mirror-symmetrically arranged, and one of the two racks 621 is fixedly connected to the driving shaft 612, when the driving shaft 612 moves, the corresponding rack 621 is pushed to move synchronously, under the engagement of the driving gear 613, the other rack 621 is driven to move reversely, the outside of each rack 621 is provided with a plurality of driving plates 626, the driven scraper group 63 includes a plurality of driven plates 635, one driven plate 635 is arranged between every two driving plates 626, the outside of each driven plate 635 is provided with a bearing plate 632, the bottom of each bearing plate 632 is rotatably connected with two lateral strips 631, the lateral strips 631 are rotatably connected with the driving plates 626, when the driving plates 626 move, the driven plates 635 are driven to move synchronously, the surface of the center cylinder 611 is provided with two sliding grooves 6111 which correspond to the racks 621 and are used for guiding and limiting the movement of the racks 621, the driving scraper group 62 further includes two sliding rings 622 which are slidingly connected to the surface of the center cylinder 611, the sliding rings 622 correspond to the racks 621, and the parts of the sliding rings 622 which are exposed outside the center cylinder 611 are fixedly connected to the racks 621, the surface of each sliding ring 622 is fixedly connected with a number of fixing piles 623 which are matched with the number of the driving plates 626, the surface of each fixing pile 623 is rotatably connected with a support strip 624, the surface of the support strip 624 is rotatably connected with an ear plate 625, the top of the ear plate 625 is fixedly connected with the driving plate 626, the sliding ring 622 is provided with a sliding groove 6221 which is matched with the rack 621, and the sliding groove 6221 provides a guiding space for the movement of the rack 621 while ensuring the sliding connection between the sliding ring 622 and the rack 621, the two sides of the ear plate 625 are provided with side holes 6251, the driven scraper group 63 further includes a number of driven bases 633 which are matched with the number of the driven plates 635, the driven bases 633 are fixedly connected to the surface of the bearing plate 632, a plurality of springs 634 are fixedly connected in the driven bases 633, the other ends of the springs 634 are fixedly connected to the surface of the driven plate 635, and the driven plate 635 and the driven base 633 are in sliding fit, the lateral strips 631 are hingedly connected with the driving plates 626 through the side holes 6251 on the two sides of the ear plate 625, forming a synchronous linkage structure, ensuring the consistency of the trajectories of the driven plates 635 when the driven plates 635 move with the driving plates 626, and the driving plates 626 drive the driven plates 635 to synchronously stretch and contract through the lateral strips 631; when the driving plates 626 reach the maximum stroke, the driven plates 635 completely fill the gaps between the adjacent driving plates 626, forming a continuous scraping surface;When the driving plate 626 is retracted, the driven plate 635 is compressed by the compression spring 634 and retracted into the driven base 633. The inner wall of the rotating drum 3 is circumferentially spaced to arrange pressure sensors, which collect scraping contact pressure data in real time. After the data is transmitted to the PLC controller, the displacement compensation amount of the two-stage stroke of the air cylinder 5 is automatically corrected to realize dynamic adaptation of the scraping force to the material adhesion characteristics.

[0031] Specifically, after the equipment is started, the separation mechanism 4 operates first, and at the same time the rotating drum 3 rotates at high speed. The rotating drum 3 is the core carrier of centrifugal separation, and the centrifugal force field generated by its rotation provides the power basis for solid-liquid separation. At this time, the 2-chloro-4-fluorobenzoic acid production raw materials are put into the rotating drum 3 through the feed inlet 2, and the raw materials are uniformly distributed and contacted with the rotating drum 3 under the dispersion of the separation mechanism 4.

[0032] Based on the principle of centrifugal force, the solid phase material with larger density in the mixed raw materials moves to the inner wall of the rotating drum 3 and gradually adheres under the action of centrifugal force, while the liquid phase with smaller density gathers in the central area of the rotating drum 3 due to the difference in centrifugal force distribution, and finally flows into the special liquid phase collection part, completing the preliminary solid-liquid separation.

[0033] During the continuous rotation of the rotating drum 3, the driving plate 626 of the driving scraper group 62 is not in contact with the inner wall of the rotating drum 3 in the initial state, but as the separation process advances, the solid phase material adhered to the inner wall of the rotating drum 3 gradually thickens. At this time, the driving plate 626 can preliminarily scrape the thickened solid phase surface layer, to a certain extent, maintain the stability of the solid phase layer thickness of the inner wall of the rotating drum 3, and avoid affecting the separation efficiency due to excessive accumulation of solid phase. However, this stage is not a complete scraping operation, and mainly plays an auxiliary separation role.

[0034] When the centrifugal separation operation is completed, the key cleaning process of scraping is entered. At this time, the air cylinder 5 is started, the telescopic shaft of the air cylinder 5 is extended, and the driving shaft 612 of the control cylinder group 61 is lowered. Since the driving shaft 612 is fixedly connected with one of the two racks 621, the lowering of the driving shaft 612 directly drives the synchronous downward movement of the rack 621. Since the two racks 621 are both engaged with the driving gear 613, the other rack 621 will be raised in the opposite direction under the meshing transmission action of the driving gear 613, that is, the two racks 621 move in the opposite direction along the inner wall of the central cylinder 611.

[0035] With the movement of the rack 621, the slip ring 622 fixedly connected with the rack 621 also moves synchronously. The two slip rings 622 move towards each other along with the rack 621. During this process, the support bar 624 connected with the fixed stack 623 on the surface of the slip ring 622 is constrained by the movement of the slip ring 622 and rotates and swings towards the side closer to each other.

[0036] The rotation of the support bar 624 is converted into the jacking force of the driving plate 626 through the ear plate 625, and the driving plate 626 expands radially outward along the rotating drum 3 under the linkage of the ear plate 625.

[0037] When the ear plate 625 moves, the two side holes 6251 on both sides of the ear plate 625 pull the lateral strips 631. Since the two ends of the lateral strips 631 are respectively hinged to the ear plate 625 and the driving plate 626, and are affected by the expansion tendency of the driving plate 626, the hinged points of the two lateral strips 631 are synchronously lifted, thereby driving the position of the carrier plate 632 and the driven base 633 of the driven scraper group 63 to change. Under the linkage action, the driving plate 626 no longer blocks the driven plate 635, and the spring 634 in the driven base 633 is stretched elastically to push the driven plate 635 upward to accurately fill the gap between the adjacent driving plates 626.

[0038] Finally, the driving plate 626 and the driven plate 635 jointly form a continuous annular scraping surface. When the rotating drum 3 continuously rotates, the annular scraping surface closely adheres to the inner wall of the rotating drum 3 to comprehensively scrape the stubborn solid-phase materials adhered. Compared with a single scraper structure, the annular surface scraping mode can eliminate the scraping blind area, ensure that the solid phase in each area of the inner wall of the rotating drum 3 can be cleaned, and improve the cleaning thoroughness. The variable-diameter scraping logic that the driving plate 626 expands first and the driven plate 635 fills the gap later can adapt to the distribution characteristics of the solid-phase layer on the inner wall of the rotating drum 3, process the large-area loose materials first, and then clean the gap residues in detail, thereby avoiding the damage of the equipment caused by the hard contact between the scraper and the thick solid-phase layer, and improving the scraping efficiency.

[0039] After the scraping operation is completed, the extension shaft of the air cylinder 5 is reset, the driving shaft 612 is lifted, and the rack 621, the slip ring 622 and other components are moved in the reverse direction. The driving plate 626 falls back with the ear plate 625 and the supporting strip 624. At this time, since the driving plate 626 is an arc surface structure, the driving plate 626 exerts pressure on the driven plate 635 during the resetting process. The resetting forces of the arc surfaces of the two adjacent driving plates 626 form a resultant force, which forces the driven plate 635 to overcome the elastic force of the spring 634 and retract into the driven base 633. The spring 634 is compressed again. Thus, the components of the scraper assembly return to the initial position, and a complete working cycle of “centrifugal separation-scraping cleaning-component resetting” is completed.

[0040] During the entire working process, the pressure sensor arranged circumferentially on the inner wall of the rotating drum 3 collects the scraping contact pressure data in real time, which is transmitted to the PLC controller to automatically correct the displacement compensation amount of the two-stage stroke of the air cylinder 5. This intelligent control mechanism can dynamically adapt the scraping force according to the adhesion force differences caused by the adhesion characteristics such as the crystal form and humidity of different batches of 2-chloro-4-fluorobenzoic acid materials, thereby ensuring efficient scraping of the solid-phase materials and avoiding damage to the inner wall of the rotating drum 3 caused by excessive scraping force. The dual improvement of equipment operation stability and material separation cleanliness can help the efficient and stable development of the production process of 2-chloro-4-fluorobenzoic acid.

[0041] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other inventors can develop based on the same general inventive concepts embodied by the described embodiments. That is, although the present application is described in terms of particular embodiments and implementations, it is to be understood that the terminology used is for the purpose of descriptive clarity and that it should be taken in a descriptive sense and not a limiting sense.

[0042] While the embodiments of the application have been shown and described herein, it is to be understood that the application is not limited to these embodiments. Rather, many modifications, changes, substitutions, and alterations can be made to the embodiments without departing from the spirit and scope of the application as defined by the appended claims and their equivalents.

Claims

1. A centrifuge for the production of 2-chloro-4-fluorobenzoic acid, comprising a centrifuge body (1), wherein a feed inlet (2) is provided above the centrifuge body (1), a rotating drum (3) is installed inside, and a separation mechanism (4) and a cylinder (5) are respectively provided above the centrifuge body (1), and a scraper assembly is connected below the cylinder (5); characterized in that: The scraper assembly is composed of a control cylinder group (61), a driving scraper group (62) and a driven scraper group (63); the top of the control cylinder group (61) is in transmission connection with the telescopic end of the air cylinder (5), and the bottom is in transmission connection with the driving scraper group (62); the driving scraper group (62) comprises at least two scraper arm units symmetrically distributed along the radial direction of the rotating drum (3); the driven scraper group (63) comprises a plurality of compensation units movably arranged between adjacent scraper arm units and forms a dynamic reconstruction structure with the driving scraper group (62); after the centrifugal operation is completed, the centrifuge realizes progressive scraping through two-stage stroke control of the air cylinder (5): first, the primary stroke is executed, the control cylinder group (61) drives the scraper arm units of the driving scraper group (62) to contact the inner wall of the rotating drum (3), and most of the loose material layer is removed through movement; then, the secondary stroke is executed, the control cylinder group (61) drives the driving scraper group (62) to further expand to the limit working position, and at the same time, the compensation units of the driven scraper group (63) automatically fill the gaps between adjacent scraper arm units through the movement of the driving scraper group (62), reconstruct the blind area-free annular scraping surface, and realize complete scraping of the stubborn material remaining on the inner wall of the rotating drum (3); the linkage structure design of the driving scraper group (62) and the driven scraper group (63) ensures the timing switching precision of the two scraping states, and the compensation units form an overlapping cooperation with the adjacent scraper arm units in the working state, effectively eliminating the scraping blind area.

2. The centrifuge for producing 2-chloro-4-fluorobenzoic acid according to claim 1, characterized by: The control cylinder group (61) comprises a center cylinder (611), a driving shaft (612) and a driving gear (613), the center cylinder (611) is fixedly connected to the surface of the fixed end of the air cylinder (5), the driving shaft (612) is slidingly connected to the inside of the center cylinder (611), and the driving shaft (612) is fixedly connected to the telescopic end of the air cylinder (5), and the driving gear (613) is rotatably connected to the middle part of the inner cavity of the center cylinder (611).

3. The centrifuge for producing 2-chloro-4-fluorobenzoic acid according to claim 2, characterized by: The driving scraper group (62) comprises two tooth racks (621) movably connected to the inside of the center cylinder (611), both of the tooth racks (621) are in meshing relationship with the driving gear (613), and both of the tooth racks (621) are mirror-symmetrically arranged, and one of the tooth racks (621) is fixedly connected with the driving shaft (612); when the driving shaft (612) moves, it pushes the corresponding tooth rack (621) to move synchronously, and under the meshing relationship of the driving gear (613), it drives the other tooth rack (621) to move reversely; the outside of each tooth rack (621) is provided with a plurality of driving plates (626).

4. The centrifuge for producing 2-chloro-4-fluorobenzoic acid according to claim 3, characterized by: The driven scraper group (63) comprises a plurality of driven plates (635), one driven plate (635) is arranged between every two driving plates (626), the outside of each driven plate (635) is provided with a bearing plate (632), the bottom of each bearing plate (632) is rotatably connected with two lateral strips (631), and the lateral strips (631) are rotatably connected with the driving plates (626); when the driving plates (626) move, the driven plates (635) move synchronously.

5. The centrifuge for producing 2-chloro-4-fluorobenzoic acid according to claim 2, characterized by: The surface of the center cylinder (611) is provided with two sliding grooves (6111), the sliding grooves (6111) correspond to the rack (621) respectively, and are used for guiding and limiting the movement of the rack (621).

6. The centrifuge for producing 2-chloro-4-fluorobenzoic acid according to claim 3, characterized by: The active scraper group (62) further comprises two sliding rings (622) slidingly connected to the surface of the center cylinder (611), the sliding rings (622) correspond to the rack (621) respectively, and the sliding rings (622) and the rack (621) are fixedly connected with the parts exposed outside the center cylinder (611), the surface of the sliding ring (622) is fixedly connected with a number of fixed piles (623) corresponding to the number of the driving plates (626), the surface of the fixed pile (623) is rotatably connected with a support bar (624), the surface of the support bar (624) is rotatably connected with an ear plate (625), and the top of the ear plate (625) is fixedly connected with the driving plate (626).

7. The centrifuge for producing 2-chloro-4-fluorobenzoic acid according to claim 6, characterized by: The sliding ring (622) is provided with a sliding groove (6221) matched with the rack (621), which guarantees the sliding connection of the two and provides a guiding space for the movement of the rack (621).

8. The centrifuge for producing 2-chloro-4-fluorobenzoic acid according to claim 6, characterized by: The two sides of the ear plate (625) are provided with side holes (6251), the driven scraper group (63) further comprises a number of driven bases (633) corresponding to the number of the driven plates (635), the driven bases (633) are fixedly connected to the surface of the bearing plate (632), a plurality of springs (634) are fixedly connected in the driven base (633), the other end of the spring (634) is fixedly connected to the surface of the driven plate (635), and the driven plate (635) and the driven base (633) are in a sliding fit.

9. The centrifuge for producing 2-chloro-4-fluorobenzoic acid according to claim 4, characterized by: The lateral bar (631) is hinged to the driving plate (626) through the side holes (6251) on the two sides of the ear plate (625), forming a synchronous linkage structure, and ensuring the consistency of the trajectory of the driven plate (635) when the driven plate (635) moves with the driving plate (626).

10. The centrifuge for producing 2-chloro-4-fluorobenzoic acid according to claim 8, characterized by: When the driving plate (626) moves, the driven plate (635) is driven to expand and contract synchronously through the lateral bar (631); when the driving plate (626) reaches the maximum stroke, the driven plate (635) completely fills the gap between the adjacent driving plates (626), forming a continuous scraping surface; when the driving plate (626) returns, the driven plate (635) is compressed by the spring (634) and retracts into the driven base (633).

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