High-purity instant potassium sulfate screening device and method

Abstract

The invention relates to the technical field of chemical raw material production, in particular to a high-purity instant potassium sulfate screening device and method.The high-purity instant potassium sulfate screening device comprises a first screening drum, a second screening drum and a material guiding assembly, the rotating directions of the first screening drum and the second screening drum are opposite, and the two ends of the first screening drum are communicated; the material guide assembly extends into the first screen drum and is located above the second screen drum, an extrusion space used for crushing potassium sulfate cakes is reserved between the bottom of the second screen drum and the bottom of an inner cavity of the first screen drum, an impurity containing cavity is formed in the inner cavity of the second screen drum, and an elastic turning plate opened through extrusion is arranged on the side wall of the second screen drum. Three crushing procedures can be carried out on material cakes, the crushing efficiency is improved, and it is guaranteed that the particle size distribution of materials is uniform; the second screen drum can collect impurities, the situation that blocking is caused by extrusion of hard impurities when cakes are rolled between the two screen drums is avoided, the protruding pieces can uninterruptedly dredge the first screen holes in the process, and the procedure of shutdown cleaning is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical raw material production, and in particular to a high-purity instant potassium sulfate screening device and method. Background Art

[0002] Potassium sulfate, a high-quality, chlorine-free potash fertilizer and an important chemical raw material, is widely used in the cultivation of chlorine-sensitive cash crops (such as tobacco, fruits, and vegetables), as well as in industries such as medicine and glass. The core value of instant potassium sulfate lies in its rapid and complete dissolution in water, facilitating modern precision irrigation and foliar spraying. Achieving excellent solubility requires not only high chemical purity but also, more crucially, an ideal physical form: uniform crystal particle size, no agglomerates, no oversized particles, and a powder with good flowability and a high specific surface area. Screening, as a core physical separation process for controlling the final particle size distribution and removing oversized particles and agglomerates, is crucial to ensuring the quality of instant potassium sulfate.

[0003] Existing screening is required in the production of instant potassium sulfate. Firstly, it ensures uniform particle size distribution to ensure efficient dissolution; secondly, it removes impurities such as stone particles from the potassium sulfate to ensure high product purity. Potassium sulfate crystals are prone to forming tiny lumps or soft aggregates during production, drying, and transportation. Traditional screening equipment is insufficient to break up these micro-agglomerates caused by electrostatic forces, surface tension, or residual moisture. Because the size of potassium sulfate crystal agglomerates is larger than that of impurities, which in turn are larger than the potassium sulfate crystals, in practice, sieve apertures that are only wide enough for potassium sulfate crystals to pass through can result in material loss from agglomerated potassium sulfate crystals and low screening efficiency. If a crushing assembly is included in the screening device, it can easily cause hard impurities such as stone particles to become stuck in the crushing assembly. Furthermore, high-purity potassium sulfate crystals are easily clogged by unqualified fine powder or micro-agglomerates when passing through the sieve apertures, especially when handling materials with slightly high water content or strong electrostatic adsorption. Frequent shutdowns for manual cleaning or screen replacement not only significantly reduce production efficiency, but also increase labor costs and downtime losses. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a high-purity instant potassium sulfate screening device and method.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A high-purity instant potassium sulfate screening device comprises a first sieve drum for screening potassium sulfate crystal particles and a material guide assembly, wherein both ends of the first sieve drum are connected, and a material guide pipe of the material guide assembly extends into the upper end of the inner cavity of the first sieve drum; a second sieve drum is further provided in the first sieve drum, rotating in the opposite direction to the first sieve drum; the second sieve drum is located below the material guide pipe; an extrusion space for breaking potassium sulfate agglomerates is reserved between the bottom of the second sieve drum and the bottom of the inner cavity of the first sieve drum; an impurity accommodating chamber is provided in the inner cavity of the second sieve drum; and an elastic flap that is squeezed open is provided on the side wall of the second sieve drum.

[0006] Furthermore, a mounting bracket is fixedly provided at one end of the first sieve drum, and a rotating shaft driven by an external power device is provided on the mounting bracket. The end of the rotating shaft facing the inner cavity of the first sieve drum is connected to the second sieve drum via a transmission assembly. The mounting bracket has a cross structure, and the rotating shaft passes through the center of the mounting bracket and is fixedly connected to the mounting bracket. When the external power device drives the rotating shaft, the rotating shaft drives the entire first sieve drum to rotate, realizing the process of rotating and screening the material. The transmission assembly can realize the synchronous counter-rotation of the first and second sieve drums driven by a single power device, reducing additional power consumption.

[0007] Furthermore, the device further comprises a first support frame for supporting the first screen drum, the first support frame being provided with a positioning hole for the rotation shaft to pass through, and the first support frame being fixedly mounted on the support base. The first support frame is used to support the installation of the first screen drum, and two limit assemblies are provided on the rotation shaft, the two limit assemblies being located at the front and rear ends of the first support frame, respectively, to ensure that the rotation shaft does not shift laterally or tilt during rotation.

[0008] Furthermore, a rotating wheel is provided at the end of the rotating shaft away from the first sieve drum. A drive motor is provided on the support base, and the rotating wheel is connected to the drive motor via a rotating belt. The operation of the drive motor drives the rotating belt, which in turn drives the synchronous rotation of the rotating wheel. The rotation of the rotating wheel, in turn, drives the rotation of the first sieve drum via the rotating shaft. Simultaneously, a cooperating transmission assembly drives the second sieve drum to rotate in the opposite direction, thereby achieving the functions of screening, breaking up lumps, and collecting impurities.

[0009] Further, the transmission assembly comprises a positioning plate, a synchronous wheel, a first transmission wheel, a second transmission wheel and a driven shaft, the rotating shaft penetrates through the positioning plate and is connected with the synchronous wheel, the driven shaft is located below the synchronous wheel, the first transmission wheel and the second transmission wheel are respectively located on the two sides of the synchronous wheel, the driven shaft, the first transmission wheel and the second transmission wheel are connected through a transmission belt, the driven shaft, the first transmission wheel and the second transmission wheel are all arranged on the inner side of the transmission belt, and the synchronous wheel is arranged on the outer side of the transmission belt. The rotating shaft is fixedly connected with the shaft core of the synchronous wheel, when the driving motor works, the rotating shaft rotates to drive the synchronous wheel to rotate, the synchronous wheel is aligned with the driven shaft in the vertical direction, the first transmission wheel and the second transmission wheel are respectively arranged on the two sides of the synchronous wheel, the driven shaft is connected with the first transmission wheel and the second transmission wheel through the transmission belt, and the rotation direction of the driven shaft is consistent with the rotation direction of the first transmission wheel and the second transmission wheel. Since the synchronous wheel is arranged on the outer side of the transmission belt, the rotation direction of the synchronous wheel is opposite to the rotation direction of the driven shaft.

[0010] Further, a plurality of strip-shaped grooves penetrating the inner cavity are arranged on the side wall of the second screen cylinder at equal intervals, the long side of the strip-shaped groove is parallel to the axis of the second screen cylinder, and the elastic flap is covered on the strip-shaped groove through the torsion spring. The width of the strip-shaped groove is larger than the size of the conventional impurity particle, and in the extrusion space, the relative rotation of the first screen cylinder and the second screen cylinder can crush and decompose the caked potassium sulfate particles, the decomposed qualified particles fall out of the first screen hole, and the impurities with a larger volume cannot pass through the first screen hole of the first screen cylinder and are pushed to the inner cavity of the second screen cylinder to make the adjacent elastic flap turn over to the inner cavity of the second screen cylinder. At this time, the impurities are pushed into the inner cavity of the second screen cylinder, and after losing the extrusion force, the elastic flap restores the elastic deformation to continue to close the strip-shaped groove.

[0011] Further, a plurality of protruding pieces capable of being extruded and retracted are arranged on the elastic flap, a plurality of first screen holes are uniformly distributed on the first screen cylinder, the distribution interval of the protruding pieces corresponds to the distribution interval of the first screen holes, and the cross-sectional size of the protruding pieces is matched with the size of the first screen hole. In the extrusion space, when the protruding piece touches the hard impurities, the elastic component arranged inside the protruding piece is compressed to avoid the situation that the protruding piece is stuck during rotation. The size of the protruding piece is slightly larger than the size of the first screen hole, the bottom of the second screen cylinder is tangent to the inner cavity bottom of the first screen cylinder directly below the second screen cylinder, a plurality of transversely arranged protruding pieces are embedded in the first screen holes in the same row on the first screen cylinder, and the first screen holes blocked can be periodically dredged.

[0012] Furthermore, a plurality of second sieve holes of equal size to the first sieve holes are provided between any two of the strip-shaped grooves, and the plurality of second sieve holes are evenly spaced along the long axis of the second sieve drum. Because the aperture of the second sieve holes is larger than the size of the crystal particles but smaller than the size of impurities, the second sieve holes can cause any qualified crystal particles that accidentally enter the second sieve drum to fall out or be ejected by centrifugal force, while retaining the impurities in the second sieve drum.

[0013] Furthermore, the material guide assembly includes a material guide unit and a material guide pipe. The bottom end of the material guide pipe is provided with an opening, the length of which is the same as the length of the second screen drum. The material guide unit draws material into the material guide pipe. The slit-type opening forces the material to form a thin layer and evenly distribute it above the second screen drum, ensuring uniform distribution and crushing of the material and reducing the possibility of reduced screening efficiency due to uneven distribution.

[0014] Furthermore, annular panels are provided on the outer periphery of both ends of the first screen drum. During the rotation of the first screen drum, the annular panels can prevent materials from falling out of both sides of the first screen drum, thereby ensuring the normal screening process of the materials.

[0015] Furthermore, the support base is provided with a collection trough notch located directly below the first sieve drum. Below this notch is a collection device for collecting qualified potassium sulfate crystal particles. After each operation cycle, the second sieve drum is removed and its contents cleaned to ensure the proper functioning of subsequent screening processes.

[0016] Furthermore, a second support frame is provided on the support base, and the second support frame is connected to one end of the second screen drum via a rotating shaft. The second support frame and the first support frame are arranged relative to the first screen drum. Since the first screen drum is provided with a mounting frame at one end facing the first support frame, and the mounting frame rotates with the rotation of the first screen drum, the second support frame is arranged at the other end of the first screen drum to ensure the normal installation of the second screen drum.

[0017] A method for using a high-purity instant potassium sulfate screening device, characterized in that it comprises the following steps: S1: Feeding and preliminary crushing: Start the drive motor, and drive the rotating shaft to rotate through the rotating belt, so that the first screen drum rotates forward while the second screen drum rotates reversely. The potassium sulfate material to be screened is introduced into the first screen drum through the material guide pipe. Under the action of gravity, the material hits the side wall of the second screen drum to achieve preliminary crushing of agglomerates; S2: Impurity separation and secondary crushing of agglomerates. Qualified crystal particles and crushed small particles are screened out by the first screen drum and collected in the gap of the aggregate trough. Unbroken agglomerates move with the material to the extrusion space and are crushed by the shear force generated by the inner wall of the first screen drum and the outer wall of the second screen drum. Hard impurities cannot be crushed and are pressed into the impurity holding chamber. S3: Fine screening and dynamic dredging, the protruding piece further impacts and breaks the remaining micro-agglomerates, and when the protruding piece impacts hard impurities in the extrusion space, elastic contraction occurs, which can avoid extrusion jamming; S4: The protruding piece periodically inserts into the first screen hole when the second screen cylinder rotates, forcibly ejects the blockage, realizes continuous self-cleaning, and the qualified potassium sulfate crystals after screening are output through the gap of the collecting tank, and the impurities are stored in the second screen cylinder, so that the high-efficiency screening and crushing cycle operation can be realized by continuously feeding.

[0018] Compared with the prior art, the present application has the following beneficial effects: 1. The present application sets the second screen cylinder in the first screen cylinder, and the first screen cylinder and the second screen cylinder rotate in opposite directions, so that the agglomerated particles falling from the material guide pipe to the second screen cylinder are impacted by gravity and preliminarily broken, and the shear force is formed in the extrusion space below the second screen cylinder to break the agglomerates for the second time, and the protruding piece can break the agglomerates for the third time when the second screen cylinder rotates, so as to realize the effect of high-efficiency breaking of agglomerates. 2. The present application sets the impurity accommodating cavity and the elastic flap in the second screen cylinder, and the hard impurities such as stones are locked in the impurity accommodating cavity after entering the cavity through the elastic flap, and the movable elastic flap can avoid the hard impurities from being jammed in the extrusion space. 3. The present application sets the protruding piece and the matching structure thereof and the first screen hole, and under the reverse rotation mechanism of the first screen cylinder and the second screen cylinder, the effect of dynamically dredging the first screen hole is achieved, which can reduce the steps of frequent shutdown for manual cleaning or replacement of the screen, greatly improve the production efficiency, and reduce the labor cost and downtime loss. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a three-dimensional structure schematic diagram of the present application; Figure 2 is a plane perspective structure schematic diagram of the present application; Figure 3 is a split structure schematic diagram of the second screen cylinder; Figure 4 is an explosion schematic diagram of the rotating shaft and the transmission assembly; Figure 5 is a structure schematic diagram of the transmission assembly; Figure identification: 1-first screen drum, 2-second screen drum, 3-material guide pipe, 4-elastic flap, 5-mounting frame, 6-rotating shaft, 7-first support frame, 8-positioning hole, 9-support base, 10-rotating wheel, 11-drive motor, 12-rotating belt, 13-positioning plate, 14-synchronizing wheel, 15-first transmission wheel, 16-second transmission wheel, 17-driven shaft, 18-transmission belt, 19-protrusion, 20-first sieve hole, 21-second sieve hole, 22-annular enclosure, 23-aggregate trough gap, 24-second support frame. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0021] Example 1, as Figure 1-Figure 5 As shown, the present invention discloses a high-purity instant potassium sulfate screening device, comprising a first sieve drum 1 for screening potassium sulfate crystal particles and a material guiding assembly, wherein both ends of the first sieve drum 1 are connected, and a material guiding pipe 3 of the material guiding assembly extends into the upper end of the inner cavity of the first sieve drum 1, and a second sieve drum 2 with a rotation direction opposite to that of the first sieve drum 1 is further provided in the first sieve drum 1, and the second sieve drum 2 is located below the material guiding pipe 3, and an extrusion space for breaking potassium sulfate agglomerates is reserved at the bottom of the second sieve drum 2 and the bottom of the inner cavity of the first sieve drum 1, the inner cavity of the second sieve drum 2 is provided with an impurity containing cavity, and the side wall of the second sieve drum 2 is provided with an elastic flap 4 that is squeezed open.

[0022] A mounting bracket 5 is fixedly provided at one end of the first screen drum 1. A rotating shaft 6 driven by an external power device is provided on the mounting bracket 5. The rotating shaft 6 is connected to the second screen drum 2 at one end facing the inner cavity of the first screen drum 1 through a transmission assembly. Specifically, the mounting bracket 5 is a cross structure. The rotating shaft 6 passes through the center of the mounting bracket 5 and is fixedly connected to the mounting bracket 5. When the external power device drives the rotating shaft 6, the rotating shaft 6 drives the entire first screen drum 1 to rotate, realizing the process of rotating and screening materials. The transmission assembly can realize the synchronous reverse rotation of the first screen drum 1 and the second screen drum 2 driven by a single power device, and can also reduce additional power consumption and avoid spatial interference problems.

[0023] The first support frame 7 is further provided with a positioning hole 8 for the rotation shaft 6 to pass through, and the first support frame 7 is fixedly mounted on a support base 9. Specifically, the first support frame 7 is used to support the installation of the first screen drum 1. Two limit assemblies are provided on the rotation shaft 6, and the two limit assemblies are respectively located at the front end and the rear end of the first support frame 7 to ensure that the rotation shaft 6 does not cause lateral displacement or tilting during rotation.

[0024] A rotating wheel 10 is provided at the end of the rotating shaft 6 away from the first screen drum 1. A drive motor 11 is provided on the support base 9. The rotating wheel 10 is connected to the drive motor 11 via a rotating belt 12. Specifically, the operation of the drive motor 11 drives the rotation of the rotating belt 12, which in turn drives the synchronous rotation of the rotating wheel 10. The rotation of the rotating wheel 10 then drives the rotation of the first screen drum 1 through the rotating shaft 6. At the same time, through the mutually cooperating transmission components, the second screen drum 2 is driven to rotate in the opposite direction, achieving the functions of screening, breaking lumps, and collecting impurities. Preferably, a spherical roller bearing is embedded in the positioning hole 8 of the first support frame 7, so that the rotating shaft 6 only transmits torque, and the radial load is borne by the bearing. An outer spherical bearing with a seat is used at the rotating shaft connection of the second support frame 24 to form a second support point. The rotating shaft 6 only bears torsional loads, eliminating bending stress. A bearing seat can be added to the rotating shaft 6 to withstand radial and axial loads. This reduces the load on the rotating shaft 6 and ensures long-term stable operation.

[0025] The transmission assembly comprises a positioning plate 13, a synchronous wheel 14, a first transmission wheel 15, a second transmission wheel 16 and a driven shaft 17, the rotating shaft 6 is connected with the synchronous wheel 14 through the positioning plate 13, the driven shaft 17 is below the synchronous wheel 14, the first transmission wheel 15 and the second transmission wheel 16 are respectively on the two sides of the synchronous wheel 14, the driven shaft 17, the first transmission wheel 15 and the second transmission wheel 16 are drivingly connected through a transmission belt 18, the driven shaft 17, the first transmission wheel 15 and the second transmission wheel 16 are all arranged on the inner side of the transmission belt 18, and the synchronous wheel 14 is arranged on the outer side of the transmission belt 18. Specifically, the rotating shaft 6 is fixedly connected with the shaft core of the synchronous wheel 14, when the driving motor 11 works, the rotating shaft 6 rotates to drive the synchronous wheel 14 to rotate, the synchronous wheel 14 is vertically aligned with the driven shaft 17, the first transmission wheel 15 and the second transmission wheel 16 are respectively arranged on the two sides of the synchronous wheel 14, the driven shaft 17 is drivingly connected with the first transmission wheel 15 and the second transmission wheel 16 through the transmission belt 18, and the rotating direction of the driven shaft 17 is consistent with the rotating direction of the first transmission wheel 15 and the second transmission wheel 16. Since the synchronous wheel 14 is arranged on the outer side of the transmission belt 18, the rotating direction of the synchronous wheel 14 is opposite to the rotating direction of the driven shaft 17. As described above, when the driving motor 11 works, the synchronous wheel 14 rotates in the same direction as the output shaft of the driving motor 11, and the driven shaft 17 rotates in the opposite direction of the output shaft of the driving motor 11. Preferably, the positioning plate 13 is provided with circular holes for the synchronous wheel 14, the first transmission wheel 15, the second transmission wheel 16 and the driven shaft 17 to pass through, and the first transmission wheel 15, the second transmission wheel 16 and the driven shaft 17 are respectively rotatably arranged on the positioning plate 13. Since the synchronous wheel 14 is fixed by the rotating shaft 6 and cannot be displaced, and the driven shaft 17 is fixedly connected with one end of the second screen cylinder 2, the relative position of the second screen cylinder 2 fixes the driven shaft 17 and prevents it from being displaced. Even if the positioning plate 13 is not fixed by any object, since the upper and lower circular holes thereof are position-limited, the positioning plate 13 can ensure the relative fixation and stability of its position. The positioning plate 13 is used to fix the relative positions of the first transmission wheel 15 and the second transmission wheel 16, so that the transmission belt 18 can stably drive the stable rotation of each wheel body.

[0026] The side wall of the second screen cylinder 2 is provided with a plurality of strip-shaped slots penetrating the inner cavity at equal intervals, the long side of the strip-shaped slot is parallel to the axis of the second screen cylinder 2, and the elastic flap 4 is covered on the strip-shaped slot by a torsion spring. Specifically, the width of the strip-shaped slot is larger than the size of the conventional impurity particles (such as stone particles and particulate impurities), and in the extrusion space, the relative rotation of the first screen cylinder 1 and the second screen cylinder 2 can crush and decompose the caked potassium sulfate particles, and the decomposed qualified particles fall out of the first screen hole 20, while the larger impurities cannot pass through the first screen hole 20 of the first screen cylinder 1 and will push the adjacent elastic flap 4 to flip towards the inner cavity of the second screen cylinder 2 under the relative extrusion of the first screen cylinder 1 and the second screen cylinder 2, at this time the impurities will be pushed into the inner cavity of the second screen cylinder 2, and after losing the extrusion force, the elastic flap 4 restores the elastic deformation to continue to close the strip-shaped slot.

[0027] A plurality of extrudable protrusions 19 are arranged on the elastic flap 4, a plurality of first screen holes 20 are uniformly distributed on the first screen cylinder 1, the distribution interval of the protrusions 19 corresponds to the distribution interval of the first screen holes 20, and the cross-sectional size of the protrusions 19 is adapted to the size of the first screen holes 20. Specifically, in the extrusion space, when the protrusions 19 touch the hard impurities, the elastic components arranged inside the protrusions 19 are compressed to avoid the situation of being stuck during rotation. In the continuous operation of the first screen cylinder 1, the potassium sulfate crystals are easy to form small clumps or soft agglomerates, and the surface tension or residual moisture makes them easy to block the first screen hole 20. The size of the protrusions 19 is slightly larger than the size of the first screen hole 20, and under the second screen cylinder 2, the bottom of the second screen cylinder 2 is tangent to the inner cavity bottom of the first screen cylinder 1, and the plurality of transversely arranged protrusions 19 are embedded in the same row of first screen holes 20 on the first screen cylinder 1, which can periodically dredge the blocked first screen holes 20.

[0028] A plurality of second screen holes 21 equal in size to the first screen hole 20 are arranged between any two strip-shaped slots, and a plurality of second screen holes 21 are arranged at equal intervals along the long axis of the second screen cylinder 2. Specifically, when the material falls onto the second screen cylinder 2, the caked potassium sulfate crystals will be broken, and the required crystal particles may also enter the second screen cylinder 2 due to gravity impact. Or in the process of impurities being extruded into the second screen cylinder 2, the required crystal particles are mixed into the second screen cylinder 2. At this time, since the aperture of the second screen hole 21 is larger than the size of the crystal particles and smaller than the size of the impurities, the second screen hole 21 can drop the required crystal particles or throw them out by centrifugal force, while retaining the impurities in the second screen cylinder 2.

[0029] The material guide assembly includes a material guide unit and a material guide pipe 3. The bottom end of the material guide pipe 3 is provided with an opening, the length of which is the same as the length of the second screen drum 2. Specifically, the material guide unit draws material into the material guide pipe 3. The slit-type opening forces the material to form a thin layer and evenly distribute it above the second screen drum 2, ensuring uniform distribution and crushing of the material and reducing the reduction in screening efficiency caused by uneven distribution.

[0030] Annular panels 22 are further provided on the outer periphery of both ends of the first screen drum 1. Specifically, during the rotation of the first screen drum 1, the annular panels 22 can ensure that the material does not fall out of the two sides of the first screen drum 1, thereby ensuring the normal screening process of the material.

[0031] The support base 9 is provided with a collection trough notch 23, located directly below the first sieve drum 1. Specifically, a collection device is provided below the collection trough notch 23 to collect qualified potassium sulfate crystal particles. After each operation cycle, the second sieve drum 2 is removed and its impurities are cleaned to ensure the normal operation of subsequent screening processes.

[0032] A second support frame 24 is further provided on the support base 9, and the second support frame 24 is connected to one end of the second screen drum 2 via a rotating shaft. Specifically, the second support frame 24 and the first support frame 7 are arranged relative to the first screen drum 1. Since the first screen drum 1 is provided with a mounting frame 5 at one end facing the first support frame 7, and the mounting frame 5 rotates with the rotation of the first screen drum 1, in order to ensure the normal installation of the second screen drum 2, the second support frame 24 is arranged at the other end of the first screen drum 1.

[0033] Example 2: Based on Example 1, this example proposes a method for using a high-purity instant potassium sulfate screening device, comprising the following steps: S1: Start the drive motor 11, and drive the rotating shaft 6 to rotate through the rotating belt 12, so that the first screen drum 1 rotates forward while the second screen drum 2 rotates reversely. The potassium sulfate material to be screened is introduced into the first screen drum 1 through the material guide pipe 3. Under the action of gravity, the material hits the side wall of the second screen drum 2 to achieve gravity crushing of the agglomerates.

[0034] S2: The size of the crystal particles with qualified particle size is less than 0.5mm, and the aperture of the first sieve hole 20 is 0.5mm. The qualified crystal particles and the crushed small particles are screened out by the first sieve drum 1 to the aggregate trough gap 23 and collected, and the unbroken agglomerates move with the material to the extrusion space. The extrusion space gap is 2.5mm, and the size of conventional stone particles, gravel, metal debris, hard agglomerates and other impurities is greater than 2.5mm. The shear force generated by the inner wall of the first sieve drum 1 and the outer wall of the second sieve drum 2 is squeezed and crushed. Hard impurities and some potassium sulfate crystals with high water content or moisture agglomerates form hard agglomerates similar to stone after long-term compaction or repeated dry-wet cycles. Because they cannot be crushed, they are pushed into the impurity holding chamber. Among them, the elastic flap 4 is arranged inside the strip groove, which ensures that the elastic flap 4 can only flip one-way toward the inner cavity of the second sieve drum 2 to prevent impurities from being thrown out during the rotation of the second sieve drum 2.

[0035] S3: The protruding member 19 further impacts and crushes the remaining micro-agglomerates. At the same time, when the protruding member 19 impacts hard impurities in the extrusion space, it elastically contracts to avoid extrusion jamming.

[0036] S4: The protrusion 19 is periodically inserted into the first sieve hole 20 as the second sieve drum 2 rotates, forcibly ejecting the blockage and achieving continuous self-cleaning. The qualified potassium sulfate crystals after screening are output through the gap 23 of the aggregate trough, and the impurities are collected in the second sieve drum 2. After the operation cycle is completed, the second sieve drum 2 is taken out and the impurities inside it are cleaned and removed to facilitate subsequent operations.

[0037] Example 3: Based on Example 2, this example performs laser particle size analysis on potassium sulfate crystals to analyze the particle size distribution of potassium sulfate after screening.

[0038] Potassium sulfate raw material with a 25% agglomeration rate (maximum agglomerate size 8 mm) and a 3% stone impurity content was used. The speed of the first sieve drum 1 was set at 35 rpm, the speed of the second sieve drum 2 was set at 40 rpm, and the extrusion clearance was set at 2.5 mm. After one hour of continuous operation, three batches of samples (500 g each) were collected from the gap 23 of the aggregate trough.

[0039] The experimental results show that the proportion of 0.5mm particles dropped from 18.7% to 0.2%, proving that gravity impact, shear extrusion and crushing by the protrusion 19 can effectively eliminate lumps. In addition, the remaining 0.2% is micro-fibrous impurities (non-potassium sulfate lumps) that have not been screened out. The target particle size range of 0.10-0.50mm accounts for 98.5% (the industry's instant potash fertilizer requirement is ≥95%), which meets production standards. Fine powder less than 0.10mm accounts for only 1.3% (12.8% in the raw material), thanks to the second sieve hole 21 intercepting fine powder, and there is no grinding effect in the extrusion space, which avoids excessive crushing of crystals. When the agglomerated particles are greatly reduced or eliminated, the dissolution time of the target particle size particles is 15±3 seconds, which is 20 times higher than the raw material dissolution efficiency.

[0040] In summary, the present application controls the particle size distribution, so that 98.5% of the product is concentrated in the 0.10-0.50mm optimum fast-dissolving interval, while achieving trace impurity mixing and zero screen clogging.

[0041] Of course, the present application can have other various implementations, and those skilled in the art can make various corresponding changes and modifications to the present application without departing from the spirit and essence of the present application, but these corresponding changes and modifications should all belong to the protection scope of the claims attached to the present application.

Claims

1. A high-purity instant potassium sulfate screening device, comprising a first sieve drum (1) for screening potassium sulfate crystal particles and a material guide assembly, wherein both ends of the first sieve drum (1) are connected, and a material guide pipe (3) of the material guide assembly extends into the upper end of the inner cavity of the first sieve drum (1), characterized in that: A second sieve drum (2) is further provided in the first sieve drum (1) and rotates in the opposite direction to the first sieve drum (1). The second sieve drum (2) is located below the material guide tube (3). An extrusion space for crushing potassium sulfate agglomerates is reserved between the bottom of the second sieve drum (2) and the bottom of the inner cavity of the first sieve drum (1). An impurity accommodating chamber is provided in the inner cavity of the second sieve drum (2). An elastic flap (4) that is opened by squeezing is provided on the side wall of the second sieve drum (2). A protrusion (19) that can be squeezed and retracted is provided on the elastic flap (4).

2. A high-purity instant potassium sulfate screening device according to claim 1, characterized in that: A mounting frame (5) is fixedly provided at one end of the first sieve drum (1), and a rotating shaft (6) driven by an external power device is provided on the mounting frame (5). One end of the rotating shaft (6) facing the inner cavity of the first sieve drum (1) is connected to the second sieve drum (2) through a transmission assembly.

3. A high-purity instant potassium sulfate screening device according to claim 2, characterized in that: It also includes a first support frame (7) for supporting the first screen drum (1), wherein the first support frame (7) is provided with a positioning hole (8) for the rotating shaft (6) to pass through, and the first support frame (7) is fixedly mounted on the support base (9).

4. A high-purity instant potassium sulfate screening device according to claim 3, characterized in that: A rotating wheel (10) is provided at one end of the rotating shaft (6) away from the first screen drum (1), a driving motor (11) is provided on the supporting base (9), and the rotating wheel (10) is connected to the driving motor (11) via a rotating belt (12).

5. A high-purity instant potassium sulfate screening device according to claim 2, characterized in that: The transmission assembly comprises a positioning plate (13), a synchronous wheel (14), a first transmission wheel (15), a second transmission wheel (16) and a driven shaft (17); the rotating shaft (6) passes through the positioning plate (13) and is connected to the synchronous wheel (14); the driven shaft (17) is located below the synchronous wheel (14); the first transmission wheel (15) and the second transmission wheel (16) are respectively located on both sides of the synchronous wheel (14); the driven shaft (17), the first transmission wheel (15) and the second transmission wheel (16) are connected by a transmission belt (18); the driven shaft (17), the first transmission wheel (15) and the second transmission wheel (16) are all arranged on the inner side of the transmission belt (18); and the synchronous wheel (14) is arranged on the outer side of the transmission belt (18).

6. A high-purity instant potassium sulfate screening device according to claim 1, characterized in that: The side wall of the second screen drum (2) is provided with a plurality of strip grooves penetrating the inner cavity at equal intervals, the long sides of the strip grooves are parallel to the axis of the second screen drum (2), and the elastic flap (4) is rotated and covered on the strip grooves by a torsion spring.

7. A high-purity instant potassium sulfate screening device according to claim 6, characterized in that: The elastic flap (4) is provided with a plurality of extrudable and retractable protrusions (19), the first screen cylinder (1) is evenly distributed with a plurality of first screen holes (20), the distribution spacing of the protrusions (19) corresponds to the distribution spacing of the first screen holes (20), and the cross-sectional size of the protrusions (19) is adapted to the size of the first screen holes (20).

8. A high-purity instant potassium sulfate screening device according to claim 7, characterized in that: A plurality of second sieve holes (21) having the same size as the first sieve holes (20) are further provided between any two of the strip-shaped grooves. The plurality of second sieve holes (21) are arranged at equal intervals along the long axis of the second sieve drum (2).

9. A high-purity instant potassium sulfate screening device according to claim 1, characterized in that: The material guide assembly comprises a material guide unit and a material guide pipe (3); an opening is provided at the bottom of the end of the material guide pipe (3); and the length of the opening is the same as the length of the second screen drum (2).

10. A high-purity instant potassium sulfate screening device according to claim 1, characterized in that: Annular enclosure plates (22) are also provided on the outer periphery of both ends of the first screen drum (1).

11. A high-purity instant potassium sulfate screening device according to claim 3, characterized in that: A material collection trough notch (23) is provided on the support base (9), and the material collection trough notch (23) is located directly below the first screen drum (1).

12. A high-purity instant potassium sulfate screening device according to claim 11, characterized in that: A second support frame (24) is also provided on the support base (9), and the second support frame (24) is connected to one end of the second screen drum (2) via a rotating shaft.

13. A method for using the high-purity instant potassium sulfate screening device according to any one of claims 1 to 12, characterized in that: The following steps are involved: S1: feeding and preliminary crushing, start the equipment so that the first screen drum (1) rotates forward while the second screen drum (2) rotates reversely, and the potassium sulfate material to be screened is introduced into the interior of the first screen drum (1) through the material guide pipe (3). The material hits the side wall of the second screen drum (2) under the action of gravity, and the agglomerates are initially crushed; S2: impurity separation and secondary crushing of agglomerates. Qualified crystal particles and crushed small particles are screened out by the first sieve drum (1) and collected outside. Uncrushed agglomerates move with the material to the extrusion space and are crushed by the shear force generated by the inner wall of the first sieve drum (1) and the outer wall of the second sieve drum (2). Hard impurities cannot be crushed and are pressed into the impurity holding chamber. S3: fine screening and dynamic dredging, the protrusion (19) further impacts and crushes the remaining micro-agglomerates, and at the same time, when the protrusion (19) impacts hard impurities in the extrusion space, it undergoes elastic contraction; S4: The protrusion (19) periodically clears and cleans the first sieve drum (1) as the second sieve drum (2) rotates. Qualified potassium sulfate crystals after screening are screened out and collected by the first sieve drum (1), and impurities are collected in the second sieve drum (2).

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