A crystallization device and crystallization method for producing bismuth oxide

Abstract

The present invention relates to the field of crystallization technology, and specifically to a crystallization device and a crystallization method for producing bismuth oxide, wherein the crystallization device for producing bismuth oxide comprises a cylinder, a crystallization screening assembly is arranged in the cylinder, the crystallization screening assembly comprises a screening cylinder and an upper end cover and a lower end cover arranged at both ends of the screening cylinder, the screening cylinder comprises at least three straight cylinders coaxially sleeved together, and fluid channels for solution to flow in the up and down directions are formed between the outermost straight cylinder and the inner wall of the cylinder, between two adjacent straight cylinders, and inside the innermost straight cylinder, respectively, and an upper connecting groove for connecting the upper ends of two adjacent fluid channels is arranged on the upper end cover, and a lower connecting groove for connecting the lower ends of two adjacent fluid channels is arranged on the lower end cover, so that the upper connecting groove, the lower connecting groove and each fluid channel form a curved S-shaped flow channel, and a screening net is arranged between each two adjacent straight cylinders. The present invention can screen crystal particles multiple times at the same time, improve screening efficiency, and reduce production costs.

Description

Technical Field

[0001] The present invention relates to the field of crystallization technology, and in particular to a crystallization device and a crystallization method for producing bismuth oxide. Background Art

[0002] Bismuth oxide can be divided into industrial grade and electronic grade, among which electronic grade bismuth oxide has higher purity requirements, requiring a purity of more than 99.5%. At present, most bismuth oxide manufacturers use wet nitric acid systems to produce bismuth oxide. The process of the wet process is: refined bismuth → melting → water quenching → nitric acid dissolution → solution concentration and crystallization → crystallization calcination → bismuth oxide; during the solution concentration and crystallization process, the bismuth oxide crystal particles crystallized from the solution need to be filtered and screened. However, during the crystallization process, the size of the crystal particles is uneven, and as time changes, small crystal particles will gradually become larger. In this way, it is impossible to fully screen the crystal particles through only one filtration and screening, and the subsequent screening process of the crystals is cumbersome, which increases production costs. Summary of the invention

[0003] In order to overcome the shortcomings of the prior art, the present invention proposes a crystallization device and a crystallization method for producing bismuth oxide, so as to solve the technical problem that the crystallization device for producing bismuth oxide in the prior art cannot fully filter and screen the crystals, thereby increasing the production cost.

[0004] A crystallization device and a crystallization method for producing bismuth oxide of the present invention adopt the following technical scheme:

[0005] A crystallization device for producing bismuth oxide, comprising a cylinder whose axis extends in the up-down direction, a liquid inlet for introducing a solution into the cylinder is opened on the side wall of the cylinder, a crystallization screening assembly is arranged in the cylinder, the crystallization screening assembly comprises a screening cylinder whose axis extends in the up-down direction, and an upper end cover and a lower end cover respectively arranged at the upper and lower ends of the screening cylinder, the screening cylinder comprises at least three straight cylinders coaxially sleeved together, fluid channels for the solution to flow in the up-down direction are respectively formed between the straight cylinder located in the outermost layer and the inner wall of the cylinder, between two adjacent straight cylinders and inside the straight cylinder located in the innermost layer, an upper connecting groove for connecting the upper ends of two adjacent fluid channels is provided on the upper end cover, and a lower connecting groove for connecting the lower ends of two adjacent fluid channels is provided on the lower end cover, so that the upper connecting groove, the lower connecting groove and each fluid channel form an S-shaped flow channel, a screening net is provided between each two adjacent straight cylinders, and each of the screening nets is used to intercept crystal particles of a set diameter size in the S-shaped flow channel.

[0006] Furthermore, a liquid outlet hole is opened in the center of the lower end cover, and a four-way pipe is connected to the bottom of the cylinder, and the four-way pipe includes a liquid inlet pipe, a liquid outlet pipe and two reflux pipes. The liquid inlet pipe is connected to the bottom of the cylinder and communicated with the liquid outlet hole, so as to allow the solution in the cylinder to enter the four-way pipe. The ends of the two reflux pipes away from the liquid inlet pipe are respectively connected to the side walls of the cylinder and communicated with the S-shaped flow channels in the cylinder, so that the solution discharged from the cylinder can return to the screening cylinder through the liquid inlet pipe and the two reflux pipes for screening. The liquid outlet pipe is used to discharge the solution in the cylinder to the outside after the screening is completed.

[0007] Furthermore, two independent S-shaped flow channels are formed in the screening cylinder, the upper end cover and the lower end cover, and the two S-shaped flow channels are respectively located on the radial sides of the screening cylinder, and two liquid inlets are respectively opened on the side walls of the cylinder, one end of the two S-shaped flow channels is respectively connected with the two liquid inlets, and the other end is connected with the liquid outlet, and the flow directions of the two S-shaped flow channels are opposite, the screening cylinder is fixedly arranged in the cylinder, and the upper end cover and the lower end cover are rotatably arranged in the cylinder, and the upper end cover and the lower end cover are fixedly connected by a connecting rod extending in the up and down directions so that the upper end cover and the lower end cover rotate synchronously, and the top end of the cylinder is provided with a rotating drive mechanism for driving the upper end cover and the lower end cover to rotate a set angle, and when the upper end cover and the lower end cover rotate in the same direction by a set angle, the flow direction of the solution in the two S-shaped flow channels is switched.

[0008] Furthermore, the straight cylinders are arranged at intervals of four, the upper end cover and the lower end cover are both circular structures, the outer diameters of the upper end cover and the lower end cover are larger than the outer diameter of the outermost straight cylinder, the upper ends of the four straight cylinders are butted against the lower side of the upper end cover, and the lower ends are butted against the upper side of the lower end cover, the lower side of the upper end cover is provided with an upper partition extending along the diameter of the upper end cover, the upper partition divides the upper end cover into a first semicircle and a second semicircle, the first semicircle is provided with a semicircular first upper connecting groove and a second upper connecting groove, the first upper connecting groove is located on the periphery of the second upper connecting groove; the second semicircle is provided with a semicircular third upper connecting groove and a fourth upper connecting groove, the fourth upper connecting groove is located on the periphery of the third upper connecting groove, the The first upper communicating groove, the second upper communicating groove, the third upper communicating groove and the fourth upper communicating groove are separated by the upper partition plate, and the first upper communicating groove and the fourth upper communicating groove are cross-distributed in the radial direction of the upper end cover, the second upper communicating groove and the third upper communicating groove are cross-distributed in the radial direction of the upper end cover, the first upper communicating groove connects the fluid passage between the outermost straight cylinder and the cylinder body, and between the outermost straight cylinder and its adjacent straight cylinder, the second upper communicating groove connects the fluid passage between the middle two layers of straight cylinders, and between the innermost straight cylinder and its adjacent straight cylinder, the third upper communicating groove connects the fluid passage inside the innermost straight cylinder, and between the innermost straight cylinder and its adjacent straight cylinder, the fourth upper communicating groove connects the fluid passage between the middle two layers of straight cylinders The fluid passage between the outermost straight cylinder and its adjacent straight cylinder; the upper side of the lower end cover is provided with a lower baffle extending along the diameter of the lower end cover, the lower baffle corresponds to and is parallel to the upper baffle, the lower baffle divides the lower end cover into a third semicircle and a fourth semicircle, the third semicircle corresponds to the first semicircle up and down, the fourth semicircle corresponds to the second semicircle up and down, the third semicircle is provided with a semicircular first lower connecting groove and a second lower connecting groove, the first lower connecting groove is located on the periphery of the second lower connecting groove, the fourth semicircle is provided with a semicircular third lower connecting groove and a fourth lower connecting groove, the fourth lower connecting groove is located on the periphery of the third lower connecting groove, the first lower connecting groove, the second lower connecting groove and the third lower connecting groove are provided , and the fourth lower communicating grooves are separated by the lower partition plate, and the first lower communicating groove and the fourth lower communicating groove are cross-distributed in the radial direction of the lower end cover, the third lower communicating groove and the second lower communicating groove are cross-distributed in the radial direction of the lower end cover, the first lower communicating groove is connected to the fluid passages between the outermost layer of the straight tube and its adjacent straight tube, and between the two middle layers of the straight tube, the second communicating groove is connected to the fluid passages in the innermost layer of the straight tube, and between the innermost layer of the straight tube and its adjacent straight tube, the third communicating groove is connected to the fluid passages between the innermost layer of the straight tube and its adjacent straight tube, and between the two middle layers of the straight tube, and the fourth communicating groove is connected to the fluid passages between the outermost layer of the straight tube and the cylinder body, and between the outermost layer of the straight tube and its adjacent straight tube;The innermost straight cylinder of the screening cylinder is symmetrically provided with middle partitions on both sides in the radial direction, and the middle partitions extend radially outward from the innermost straight cylinder to the outermost straight cylinder. In the initial state, the middle partition corresponds to the upper partition and the lower partition up and down and are in the same plane. Two S-shaped flow channels are respectively located on both sides of the middle partition. When the upper end cover and the lower end cover rotate 180° in the forward direction or 180° in the reverse direction, the S-shaped flow channels located on both sides of the middle partition switch flow directions. ;

[0009] Furthermore, the screening net is a conical ring arranged coaxially with each straight cylinder, the axis of the screening net extends in the up-down direction, and the outer side surface is an inclined surface inclined upward from the inside to the outside in the radial direction, the upper end of the screening net is a large-diameter end, and the lower end is a small-diameter end, the upper and lower ends of the screening net are respectively connected to the inner walls of the two adjacent layers of straight cylinders, and an annular blanking trough extending along the circumference of the straight cylinder is provided at the position where each straight cylinder is connected to the lower end of the screening net, and a blanking channel extending in the up-down direction is provided at the lower end of the straight cylinder, the upper end of the blanking channel is connected to the blanking trough, a conveying channel is provided in the lower end cover, the lower end of the blanking channel is connected to one end of the conveying channel, and the other end of the conveying channel is connected to the outside of the cylinder, so that the crystal particles screened by the screening net are conveyed to the outside of the cylinder; the upper end of each screening net The connecting spring piece is movably connected to the inner wall of the straight cylinder, and the connecting spring piece is a flexible part that can be elastically deformed. The upper end of the screening net can overcome the force of the connecting spring piece and move upward to form a crystal channel for crystal particles to pass through between the upper end of the screening net and the inner wall of the straight cylinder. When the solution impacts the screening net from top to bottom, the upper end of the screening net is tightly fitted with the inner wall of the straight cylinder, and the crystal particles that meet the size requirements in the solution will be intercepted above the upper side of the screening net and enter the blanking channel. When the solution impacts the screening net from bottom to top, the upper end of the screening net is subjected to the upward force of the solution, and then overcomes the action of the connecting spring piece and moves upward, forming a crystal channel between the inner wall of the straight cylinder and the upper end of the screening net, so that the crystal particles that originally could not pass through the screening net pass through the screening net from the crystal channel to reach the space above the screening net.

[0010] Furthermore, the material blanking channel is an annular channel extending along the circumference of the straight cylinder, and the third semicircle and the fourth semicircle are respectively provided with blocking bars for blocking the lower end of the material blanking channel, the blocking bars on the third semicircle and the fourth semicircle are both semicircular ring-shaped, and the blocking bars on the third semicircle and the blocking bars on the fourth semicircle are staggered in the radial direction, and the third semicircle and the fourth semicircle are respectively provided with semicircular ring-shaped material receiving troughs, the material receiving troughs are connected with the upper end of the conveying channel, and the conveying channel is connected with the material blanking channel through the material receiving troughs, the material receiving troughs on the third semicircle and the material receiving troughs on the fourth semicircle are staggered in the radial direction, the material receiving troughs on the third semicircle correspond one-to-one with the blocking bars on the fourth semicircle and are connected to form a circle, and the material receiving troughs on the fourth semicircle correspond one-to-one with the blocking bars on the third semicircle and are connected to form a circle, and when the upper end cover and the lower end cover are rotated 180° relative to the screening drum, each blocking bar and the material receiving trough alternately cooperate with the parts of the material blanking channel located on both sides of the middle partition.

[0011] Furthermore, damping blocks are respectively provided in the third lower connecting groove and the fourth lower connecting groove, and the damping blocks are spaced apart along the extension direction of the semi-annular third lower connecting groove and the fourth lower connecting groove, and the damping blocks are used to reduce the flow area of ​​the S-shaped flow channel at the lower end position of the screening cylinder so that the flow velocity of the solution at the lower end position of the screening cylinder is higher than the flow velocity at other positions.

[0012] Furthermore, the damping block has a portion extending upward into the straight cylinder, the upper end of the damping block is close to the lower end of the screening net, the upper end of the middle partition is flush with the upper end of the screening cylinder, the lower end of the middle partition is higher than the upper end of the damping block, and the upper end of the lower partition is provided with a plurality of vertical plates at intervals along the extension direction of the lower partition, each of the vertical plates is respectively inserted between two adjacent straight cylinders, the upper end of each vertical plate is respectively connected to the lower end of the middle partition, and the two sides of each vertical plate are respectively fitted with the inner walls of the two adjacent straight cylinders, so that each vertical plate and the middle partition separate the interior of the screening cylinder into two isolated parts.

[0013] Furthermore, a through hole is opened in the center of the upper end cover, and internal teeth are provided on the inner wall of the through hole. A driving motor is installed on the upper end of the cylinder body, and the output shaft of the driving motor extends in the up and down directions. The lower end of the output shaft is connected to a driving gear, and the driving gear is meshed with the internal teeth to drive the upper end cover to rotate.

[0014] A crystallization method for producing bismuth oxide adopts the above-mentioned crystallization device for producing bismuth oxide. The steps of the method for producing bismuth oxide include: passing a solution into a cylinder through a liquid inlet and into an S-shaped flow channel, and a plurality of screening nets in the S-shaped flow channel screen the crystal particles in the solution.

[0015] The beneficial effects of the present invention are as follows: a crystallization device and a crystallization method for producing bismuth oxide of the present invention, wherein the crystallization device is provided with a crystallization screening component in a cylinder, wherein the screening cylinder of the crystallization screening component is formed by coaxially nesting multiple layers of straight cylinders, and upper end covers and lower end covers are provided at the upper and lower ends of the multiple straight cylinders, so that a curved S-shaped flow channel is formed in the screening cylinder, and a screening net is provided in each of two adjacent layers of straight cylinders to screen the solution multiple times, and the solution can be screened repeatedly multiple times at the same time, thereby improving the screening efficiency of the crystal particles and reducing the production cost at the same time.

[0016] In addition, the present invention rotates the upper end cover and the lower end cover relative to the screening cylinder, and switches the flow direction of the two S-shaped flow channels by rotating the upper end cover and the lower end cover. On the one hand, different screening net parts can be switched for screening, and on the other hand, the screening net can be backwashed. At the same time, a plurality of damping blocks are arranged on the lower end cover, which can prevent the crystal particles from sinking and staying on the lower end cover when passing through the position of the lower end cover. The upper end of the damping block extends to the lower side of the screening net, so that when the crystal particles enter the upper part of the screening net from the bottom of the screening net through the crystal channel, the solution flow rate above the screening net will decrease, so that the relatively large crystal particles will fall onto the screening net and enter the drop chute. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work. Those skilled in the art should understand that these drawings are not necessarily drawn to scale.

[0018] Figure 1 This is a schematic diagram of the appearance of an embodiment of a crystallization device for producing bismuth oxide according to the present invention;

[0019] Figure 2 It is a cross-sectional schematic diagram of an embodiment of a crystallization device for producing bismuth oxide according to the present invention;

[0020] Figure 3 It is a three-dimensional schematic diagram of an upper end cover and a lower end cover in one embodiment of a crystallization device for producing bismuth oxide of the present invention;

[0021] Figure 4 for Figure 3 A magnified view of the local area A in FIG.

[0022] Figure 5 It is a cross-sectional schematic diagram of an upper end cover and a lower end cover in one embodiment of a crystallization device for producing bismuth oxide of the present invention;

[0023] Figure 6It is a cross-sectional schematic diagram of a screening cylinder in one embodiment of a crystallization device for producing bismuth oxide of the present invention;

[0024] Figure 7 Another cross-sectional schematic diagram of an embodiment of a crystallization device for producing bismuth oxide according to the present invention;

[0025] Figure 8 for Figure 7 A magnified schematic diagram of the part B in the middle;

[0026] Fig. 9 for Figure 7 A magnified schematic diagram of the local C in the middle;

[0027] Fig.10 It is a three-dimensional schematic diagram of an upper end cover in one embodiment of a crystallization device for producing bismuth oxide of the present invention;

[0028] Fig.11 The present invention is a three-dimensional schematic diagram of a lower end cover in one embodiment of a crystallization device for producing bismuth oxide.

[0029] In the figure: 100, cylinder; 110, leg; 120, reflux pipe; 130, liquid inlet pipe; 150, material receiving box; 200, rotary drive mechanism; 210, drive gear; 300, liquid inlet; 400, four-way pipe; 500, damping block; 510, upper end cover; 511, perforation; 512, first upper connecting groove; 513, second upper connecting groove; 514, third upper connecting groove; 515, fourth upper connecting groove; 520 , connecting rod; 530, lower end cover; 531, first damping block, 532, second damping block; 533, third damping block; 534, blocking strip; 535, lower partition; 536, material receiving trough; 538, conveying channel; 540, vertical plate; 550, upper partition; 600, screening cylinder; 610, straight cylinder; 611, material dropping channel; 612, material dropping trough; 620, middle partition; 630, screening net; 640, connecting spring piece. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] An embodiment of a crystallization device and a crystallization method for producing bismuth oxide of the present invention is as follows: Figures 1 to 11As shown, the crystallization device for producing bismuth oxide comprises a cylinder 100 with an axis extending in the up-down direction, a leg 110 is provided at the bottom of the cylinder 100, and a liquid inlet 300 for introducing a solution into the cylinder 100 is provided on the side wall of the cylinder 100. A crystallization screening assembly is provided in the cylinder 100, and the crystallization screening assembly comprises a screening cylinder 600 with an axis extending in the up-down direction, and an upper end cover 510 and a lower end cover 530 respectively provided at the upper and lower ends of the screening cylinder 600. The screening cylinder 600 includes at least three straight cylinders 610 coaxially sleeved together. In this embodiment, four straight cylinders 610 are arranged at intervals. Fluid channels for the solution to flow in the up and down directions are formed between the outermost straight cylinder 610 and the inner wall of the cylinder body 100, between two adjacent straight cylinders 610, and inside the innermost straight cylinder 610. The upper end cover 510 is provided with an upper connecting groove for connecting the upper ends of the two adjacent fluid channels, and the lower end cover 530 is provided with a connecting groove for connecting the two adjacent fluid channels. The lower connecting groove at the lower end makes the upper connecting groove, the lower connecting groove and each fluid channel form an S-shaped flow channel. A screening net 630 is provided between each adjacent two straight cylinders 610. Each screening net 630 is used to intercept crystalline particles of a set diameter in the S-shaped flow channel. When the solution enters the S-shaped flow channel, multiple screening nets 630 repeatedly screen the crystalline particles in the solution. In this way, crystal particles that meet the size can be screened out during the process of the solution passing through the S-shaped flow channel, thereby improving the screening efficiency and reducing the production cost.

[0032] In this embodiment, a liquid outlet hole is provided at the center of the lower end cover 530, and a four-way pipe 400 is connected to the bottom of the cylinder 100. The four-way pipe 400 includes a liquid inlet pipe 130, a liquid outlet pipe and two return pipes 120. The liquid inlet pipe 130 is connected to the bottom of the cylinder 100 and communicated with the liquid outlet hole, so as to allow the solution in the cylinder 100 to enter the four-way pipe 400. The ends of the two return pipes 120 away from the liquid inlet pipe 130 are respectively connected to the side wall of the cylinder 100 and communicated with the S-shaped flow channel in the cylinder 100, so that the solution discharged from the cylinder 100 can be returned to the screening cylinder 600 through the liquid inlet pipe 130 and the two return pipes 120 for re-screening, so that the crystal particles in the solution can be screened out more fully. In order to ensure the circulation of the solution in the cylinder 100, a circulation pump is provided in the liquid inlet pipe 130, and the circulation pump is used to transport the solution to the outside of the cylinder 100. The liquid outlet pipe is used to discharge the solution in the cylinder 100 after the screening is completed.

[0033] In this embodiment, two independent S-shaped flow channels are formed in the screening cylinder 600, the upper end cover 510 and the lower end cover 530. The two S-shaped flow channels are respectively located on the radial sides of the screening cylinder 600. Figure 2As shown in , the two S-shaped flow channels are respectively the first flow channel located on the left and the second flow channel located on the right. Two liquid inlets 300 are respectively provided on the side walls of the cylinder 100, one end of the two S-shaped flow channels is respectively connected with the two liquid inlets 300 in a one-to-one correspondence, and the other end is connected with the liquid outlet. The flow directions of the two S-shaped flow channels are opposite, the screening cylinder 600 is fixedly arranged in the cylinder 100, the upper end cover 510 and the lower end cover 530 are rotatably arranged in the cylinder 100, and the upper end cover 510 and the lower end cover 530 are fixedly connected by a connecting rod 520 extending in the up-down direction, so that the upper end cover 510 and the lower end cover 530 rotate synchronously. The top of the cylinder 100 is provided with a rotating drive mechanism 200 for driving the upper end cover 510 and the lower end cover 530 to reciprocate at a set angle. When the upper end cover 510 and the lower end cover 530 rotate at a set angle, the flow direction of the solutions in the two S-shaped flow channels is switched, that is, the flow direction of the solutions in the two S-shaped flow channels is opposite to the original flow direction.

[0034] In this embodiment, four straight cylinders 610 are arranged at intervals, and four upper connecting grooves and four lower connecting grooves are respectively provided. The upper end cover 510 and the lower end cover 530 are both circular structures, and the outer diameters of the upper end cover 510 and the lower end cover 530 are both larger than the outer diameter of the outermost straight cylinder 610. The upper ends of the four straight cylinders 610 are butted against the lower side of the upper end cover 510, and the lower ends are butted against the upper side of the lower end cover 530. The lower side of the upper end cover 510 is provided with an upper partition 550 extending along the diameter of the upper end cover 510, and the upper partition 550 divides the upper end cover 510 into a first semicircle and a second semicircle, and the first semicircle is provided with a semicircular first upper connecting groove 512 and a second upper connecting groove 513, and the first upper connecting groove 512 is located at the periphery of the second upper connecting groove 513. The second semicircle is provided with a semicircular third upper communicating groove 514 and a fourth upper communicating groove 515, the fourth upper communicating groove 515 is located at the periphery of the third upper communicating groove 514, the first upper communicating groove 512, the second upper communicating groove 513 and the third upper communicating groove 514 and the fourth upper communicating groove 515 are separated by the upper partition plate 550, and the first upper communicating groove 512 and the fourth upper communicating groove 515 are cross-distributed in the radial direction of the upper end cover 510, the second upper communicating groove 513 and the third upper communicating groove 514 are cross-distributed in the radial direction of the upper end cover 510, and the first upper communicating groove 512 is connected to the fourth upper communicating groove 515. The fluid passages between the outermost straight cylinder 610 and the cylinder body 100, and between the outermost straight cylinder 610 and its adjacent straight cylinder 610; the second upper connecting groove 513 connects the fluid passages between the middle two layers of straight cylinders 610, and between the innermost straight cylinder 610 and its adjacent straight cylinder 610; the third upper connecting groove 514 connects the fluid passages inside the innermost straight cylinder 610, and between the innermost straight cylinder 610 and its adjacent straight cylinder 610; the fourth upper connecting groove 515 connects the fluid passages between the middle two layers of straight cylinders 610, and between the outermost straight cylinder 610 and its adjacent straight cylinder 610.

[0035] The upper side of the lower end cover 530 is provided with a lower partition 535 extending along the diameter of the lower end cover 530, and the lower partition 535 corresponds to and is parallel to the upper partition 550 in the upper and lower directions. The lower partition 535 divides the lower end cover 530 into a third semicircle and a fourth semicircle, and the third semicircle corresponds to the first semicircle in the upper and lower directions, and the fourth semicircle corresponds to the second semicircle in the upper and lower directions. The third semicircle is provided with a semicircular first lower connecting groove and a second lower connecting groove, and the first lower connecting groove is located at the periphery of the second lower connecting groove. The fourth semicircle is provided with a semicircular third lower connecting groove and a fourth lower connecting groove, and the fourth lower connecting groove is located at the periphery of the third lower connecting groove. The first lower connecting groove, the second lower connecting groove, the third lower connecting groove and the fourth lower connecting groove are separated by the lower partition 535, and the first The lower connecting groove and the fourth lower connecting groove are cross-distributed in the radial direction of the lower end cover 530, and the third lower connecting groove and the second lower connecting groove are cross-distributed in the radial direction of the lower end cover 530. The first lower connecting groove connects the fluid passages between the outermost straight cylinder 610 and its adjacent straight cylinder 610, and between the two middle straight cylinders 610. The second connecting groove connects the fluid passages in the innermost straight cylinder 610, and between the innermost straight cylinder 610 and its adjacent straight cylinder 610. The third connecting groove connects the fluid passages between the innermost straight cylinder 610 and its adjacent straight cylinder 610, and between the two middle straight cylinders 610. The fourth connecting groove connects the fluid passages between the outermost straight cylinder 610 and the cylinder body 100, and between the outermost straight cylinder 610 and its adjacent straight cylinder 610.

[0036] At the same time, the innermost straight cylinder 610 of the screening cylinder 600 is symmetrically provided with a middle partition 620 on both sides of the radial direction, and the middle partition 620 extends radially outward from the innermost straight cylinder 610 to the outermost straight cylinder 610. In the initial state, the middle partition 620 corresponds to the upper partition 550 and the lower partition 535 up and down and is in the same plane. The two S-shaped flow channels are respectively located on both sides of the middle partition 620. The middle partition 620 divides the screening cylinder 600 into two radially symmetrical parts. When the upper end cover 510 and the lower end cover 530 are moved in the positive direction, the middle partition 620 is moved in the positive direction. When rotating 180° or 180° in the opposite direction, the relative positions of the upper end cover 510 and the lower end cover 530 and the screening drum 600 change, that is, the positions of the first semicircle and the second semicircle in the circumferential direction of the screening drum 600 are swapped, and at the same time, the positions of the third semicircle and the fourth semicircle in the circumferential direction are swapped, so that the S-shaped flow channel on both sides of the middle partition 620 switches the flow direction, that is, the flow direction in the S-shaped flow channel on both sides of the middle partition 620 is opposite to the original flow direction, so that the screening net 630 located in the S-shaped flow channel can be flushed in the reverse direction.

[0037] In this embodiment, the screening net 630 is a conical ring shape coaxially arranged with each straight cylinder 610, the axis of the screening net 630 extends in the up-down direction, and the outer side surface of the screening net 630 is an inclined surface inclined upward from the inside to the outside along the radial direction, the upper end of the screening net 630 is a large diameter end, and the lower end is a small diameter end, and the upper and lower ends of the screening net 630 are respectively connected to the inner walls of the two adjacent layers of straight cylinders 610. An annular material drop groove 612 extending along the circumference of the straight cylinder 610 is provided at the position where each straight cylinder 610 is connected to the lower end of the screening net 630, and a material drop channel 611 extending along the up-down direction is provided at the lower end of the straight cylinder 610, and the upper end of the material drop channel 611 is connected to the material drop groove 612, and a conveying channel 538 is provided in the lower end cover 530, and the lower end of the material drop channel 611 is connected to one end of the conveying channel 538, and the other end of the conveying channel 538 is connected to the outside of the cylinder 100, so that the crystal particles screened by the screening net 630 are transported to the outside of the cylinder 100. In addition, a material receiving box 150 is connected to the lower end of the cylinder 100 for receiving the crystal particles discharged from the cylinder 100.

[0038] In this embodiment, the upper end of each screening net 630 is movably connected to the inner wall of the straight cylinder 610 through a connecting spring piece 640. The connecting spring piece 640 is a flexible member capable of elastic deformation. The upper end of the screening net 630 can overcome the force of the connecting spring piece 640 and move upward to form a crystal channel for crystal particles to pass between the upper end of the screening net 630 and the inner wall of the straight cylinder 610. The upper end of the connecting spring piece 640 is attached to the inner wall of the straight cylinder 610, and the lower end is attached to the inner side surface of the screening net 630. In the initial state, the connecting spring piece 640 makes the upper end of the screening net 630 fit closely to the inner wall of the straight cylinder 610. When the solution impacts the screening net 630 from top to bottom, the crystal particles in the solution that meet the size requirements will be intercepted above the upper side surface of the screening net 630 and enter the drop channel 611. When the solution impacts the screening mesh 630 from bottom to top, the upper end of the screening mesh 630 is subjected to the upward force of the solution, thereby overcoming the action of the connecting spring piece 640 and moving upward, forming a crystal channel between the inner wall of the straight cylinder 610 and the upper end of the screening mesh 630, so that the crystal particles that originally could not pass through the screening mesh 630 can pass through the screening mesh 630 from the crystal channel and reach the space above the screening mesh 630.

[0039] During the screening process, each screening mesh 630 does not participate in the screening of crystal particles at the same time as a whole. Only half of each screening mesh 630 can screen the crystal particles at a time. That is to say, only the part of the inner side of the screening mesh 630 that is opposite to the flow direction of the solution can intercept the crystal particles and reach the outside of the cylinder 100 through the drop channel 611 and the conveying channel 538, while the part of the inner side of the screening mesh 630 that is in the same direction as the solution flow direction cannot intercept the crystals. When the solution in the S-shaped flow channel switches its flow direction, the other half of each screening mesh 630 will participate in the screening of the crystal particles.

[0040] In this embodiment, the blanking channel 611 is an annular channel extending along the circumference of the straight cylinder 610, and the third semicircle and the fourth semicircle are respectively provided with four blocking bars 534 for blocking the lower end of the blanking channel 611. The blocking bars 534 on the third semicircle and the fourth semicircle are both semicircular, and the blocking bars 534 on the third semicircle and the blocking bars 534 on the fourth semicircle are staggered in the radial direction. The third semicircle and the fourth semicircle are respectively provided with semicircular receiving grooves 536, and the receiving grooves 536 are connected to the upper end of the conveying channel 538. The conveying channel 538 is connected to the conveying channel 538 through the receiving grooves. The groove 536 is connected to the material receiving channel 611, and the material receiving groove 536 on the third semicircle and the material receiving groove 536 on the fourth semicircle are staggered in the radial direction. The material receiving groove 536 on the third semicircle corresponds one-to-one with the blocking strip 534 on the fourth semicircle and is connected to form a circle. The material receiving groove 536 on the fourth semicircle corresponds one-to-one with the blocking strip 534 on the third semicircle and is connected to form a circle. When the upper end cover 510 and the lower end cover 530 are rotated 180° relative to the screening drum 600, each blocking strip 534 and the material receiving groove 536 are alternately matched with the parts of the material receiving channel 611 located on both sides of the middle partition 620.

[0041] Damping blocks 500 are respectively provided in the third lower connecting groove and the fourth lower connecting groove. The damping blocks 500 are spaced apart along the extension direction of the semi-annular third lower connecting groove and the fourth lower connecting groove. The damping blocks 500 are used to reduce the flow area of ​​the S-shaped flow channel at the lower end of the screening cylinder 600 so that the flow velocity of the solution at the lower end of the screening cylinder 600 is higher than the flow velocity at other positions.

[0042] In this embodiment, the damping block 500 has a portion extending upward into the straight cylinder 610, the upper end of the damping block 500 is close to the lower end of the screening mesh 630, the upper end of the damping block 500 is located below the lower end of the screening mesh 630, the upper end of the middle partition 620 is flush with the upper end of the screening cylinder 600, the lower end of the middle partition 620 is located on the lower side of the screening mesh 630 and is higher than the upper end of the damping block 500, the upper end of the lower partition 535 is provided with a plurality of vertical plates 540 at intervals along the extension direction of the lower partition 535, each of the vertical plates 540 is respectively inserted between two adjacent straight cylinders 610, the upper end of each vertical plate 540 is respectively connected to the lower end of the middle partition 620, and the two sides of each vertical plate 540 are respectively fitted with the inner walls of the two adjacent straight cylinders 610, so that each vertical plate 540 and the middle partition 620 separate the interior of the screening cylinder 600 into two isolated parts.

[0043] When the solution in the S-shaped flow channel passes through the four lower connecting grooves of the lower end cover 530 respectively, the crystal particles are easy to sink and stay at this position because the position is a turning position. By setting the damping block 500 in the lower connecting groove of the lower end cover 530, the flow rate of the solution at the position of the lower end cover 530 can be increased, so that the solution can take away the crystal particles. In addition, when the solution carries the crystal particles and moves upward from the bottom of the screening net 630, for the crystal particles that meet the size, due to the large size of the crystal particles, they cannot pass through the screening net 630 upward, and can only pass through the crystal channel on the periphery. When the crystal particles enter the top of the screening net 630, the solution flow rate is slowed down relative to the position where the damping block 500 is set. At this time, the crystal particles that meet the size will be easier to fall above the screening net 630, and then discharged from the outside of the cylinder 100.

[0044] In addition, the damping blocks 500 in the present invention are provided with three groups, namely the first damping block 531, the second damping block 532 and the third damping block 533. The three groups of damping blocks 500 are respectively arranged in the first lower connecting groove, the third lower connecting groove and the fourth lower connecting groove, and are evenly spaced and distributed along the circumference of the corresponding lower connecting grooves. Since the second lower connecting groove is directly connected to the liquid outlet hole located at the center of the lower end cover 530, there is no need to set the damping block 500.

[0045] In this embodiment, a through hole 511 is opened at the center of the upper end cover 510, and internal teeth are provided on the inner wall of the through hole 511. A driving motor is installed at the upper end of the cylinder 100, and the output shaft of the driving motor extends in the up and down directions. The lower end of the output shaft is connected to a driving gear 210, and the driving gear 210 is engaged with the internal teeth to drive the upper end cover 510 to rotate.

[0046] The present invention provides a method for producing bismuth oxide using the above-mentioned crystallization device for producing bismuth oxide. When working, the liquid outlet pipe of the four-way pipe 400 is first closed, and then the solution is respectively introduced into the cylinder 100 through the two liquid inlets 300, and then the solution respectively enters the two S-shaped flow channels. After being screened by the screening nets 630 in the two S-shaped flow channels, the solution flows into the four-way pipe 400 from the bottom of the cylinder 100, and then returns to the cylinder 100 through the reflux pipes 120 on both sides, and re-enters the two S-shaped flow channels for screening. Figure 2As shown in the figure, the flow paths of the solutions entering the two S-shaped flow channels are: the flow path in the first flow channel is: the fluid channel between the cylinder 100 and the outermost straight cylinder 610, the first upper connecting groove 512, the fluid channel between the outermost straight cylinder 610 and its adjacent straight cylinder 610, the first lower connecting groove, the fluid channel between the middle two straight cylinders 610, the second upper connecting groove 513, the fluid channel between the innermost straight cylinder 610 and its adjacent straight cylinder 610, the second lower connecting groove, the liquid outlet, and the four-way pipe 400. In this flow path, the solution first flows upward from the outside of the screening cylinder 600 into the upper end of the screening cylinder 600, then flows downward from the upper end, and finally flows out from the lower end of the screening cylinder 600. The flow path in the second flow channel is: the fluid channel between the cylinder 100 and the outermost straight cylinder 610, the fourth lower connecting groove, the fluid channel between the outermost straight cylinder 610 and its adjacent straight cylinder 610, the fourth upper connecting groove 515, the fluid channel between the middle two straight cylinders 610, the third lower connecting groove, the fluid channel between the innermost straight cylinder 610 and its adjacent straight cylinder 610, the third upper connecting groove 514, the innermost straight cylinder 610, the liquid outlet, and the four-way pipe 400. In this flow path, the solution first flows downward from the outside of the screening cylinder 600 into the lower end of the screening cylinder 600, then flows upward from the lower end, and finally passes through the innermost straight cylinder 610 from top to bottom and flows downward from the lower end of the innermost straight cylinder 610 into the four-way pipe 400. When the solutions in the two S-shaped channels pass through the sieve mesh 630 from top to bottom, the crystal particles of the appropriate size will be intercepted on the upper side of the sieve mesh 630, and enter the material channel 611 through the material channel 612, and then enter the material receiving channel 536 and the conveying channel 538 set on the lower end cover 530 from the lower end of the straight cylinder 610, and are discharged into the material receiving box 150 outside the cylinder body 100 through the conveying channel 538. When the solution passes through the sieve mesh 630 from bottom to top, a crystal channel will be opened between the upper end of the sieve mesh 630 and the inner wall of the straight cylinder 610 to allow the crystal particles that cannot pass through the sieve mesh 630 to pass through. Due to the damping block 500 set on the lower connecting groove, the crystal particles can be prevented from sinking and staying on the lower end cover 530 when passing through the position of the lower end cover 530. At the same time, the upper end of the damping block 500 extends to the lower side of the screening mesh 630. In this way, when the crystal particles pass through the crystal channel from the bottom of the screening mesh 630 into the top of the screening mesh 630, the solution flow rate above the screening mesh 630 will decrease, thereby causing relatively large crystal particles to fall onto the screening mesh 630 and enter the drop chute 612.

[0047] After the solution is repeatedly circulated and screened for a period of time, the drive motor is started, and the drive motor drives the upper end cover 510 and the lower end cover 530 to rotate 180 degrees in the positive direction synchronously. When the upper end cover 510 and the lower end cover 530 are rotated into place, the circumferential positions of the first upper connecting groove 512, the second upper connecting groove 513 and the third upper connecting groove 514 and the fourth upper connecting groove 515 are swapped, that is, the first upper connecting groove 512 and the second upper connecting groove 513 are switched from the original position located above the left side of the screening cylinder 600 to the position located above the right side of the screening cylinder 600, and correspondingly, the third upper connecting groove 514 and the fourth upper connecting groove 515 are switched from the position away from the position located above the right side of the screening cylinder 600 to the position located above the left side of the screening cylinder 600. In the same way, the positions of the first lower connecting groove, the second lower connecting groove and the third lower connecting groove and the fourth connecting groove on the lower end cover 530 are synchronously swapped in the circumferential direction of the lower end cover 530. This will switch the curved flow direction of the left and right S-shaped channels, that is, the flow direction of the solution in the first channel will be opposite to the original flow direction, and the flow direction of the solution in the second channel will also be opposite to the original flow direction. In this way, on the one hand, different parts of the screening net 630 can be switched for screening, and on the other hand, the screening net 630 can be reverse flushed.

[0048] When the solution is repeatedly circulated and screened for multiple times, the screening is completed, and the liquid outlet pipe is opened to discharge the solution in the cylinder 100.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A crystallization device for producing bismuth oxide, comprising a cylinder (100) whose axis extends in the vertical direction, and a liquid inlet (300) for introducing a solution into the cylinder (100) is provided on the side wall of the cylinder (100), characterized in that: The cylinder (100) is provided with a crystal screening assembly, which includes a screening cylinder (600) whose axis extends in the up-down direction, and an upper end cover (510) and a lower end cover (530) respectively provided at the upper and lower ends of the screening cylinder (600). The screening cylinder (600) includes at least three straight cylinders (610) coaxially sleeved together, and fluid channels for the solution to flow in the up-down direction are formed between the outermost straight cylinder (610) and the inner wall of the cylinder (100), between two adjacent straight cylinders (610), and inside the innermost straight cylinder (610). An upper connecting groove for connecting the upper ends of two adjacent fluid channels is provided on the upper end cover (510), and a lower connecting groove for connecting the lower ends of two adjacent fluid channels is provided on the lower end cover (530), so that the upper connecting groove, the lower connecting groove and each fluid channel form a curved S-shaped flow channel. A screening net (630) is provided between each two adjacent straight cylinders (610). Each of the The screening nets (630) are respectively used to intercept crystal particles of a set diameter in the S-shaped flow channel; a liquid outlet hole is opened at the center of the lower end cover (530); the bottom of the cylinder (100) is connected to a four-way pipe (400); the four-way pipe (400) includes a liquid inlet pipe (130), a liquid outlet pipe and two return pipes (120); the liquid inlet pipe (130) is connected to the bottom of the cylinder (100) and communicates with the liquid outlet hole, so as to allow the cylinder (100) to flow freely. 0) enters the four-way pipe (400), and one end of the two return pipes (120) away from the liquid inlet pipe (130) is respectively connected to the side wall of the cylinder (100) and communicates with the S-shaped flow channel in the cylinder (100), so that the solution discharged from the cylinder (100) returns to the screening cylinder (600) through the liquid inlet pipe (130) and the two return pipes (120) for screening, and the liquid outlet pipe is used to discharge the solution in the cylinder (100) to the outside after the screening is completed;Two independent S-shaped flow channels are formed in the screening cylinder (600), the upper end cover (510) and the lower end cover (530). The two S-shaped flow channels are respectively located on two radial sides of the screening cylinder (600). Two liquid inlets (300) are respectively provided on the side walls of the cylinder body (100). One end of the two S-shaped flow channels is respectively connected to the two liquid inlets (300), and the other end is connected to the liquid outlet. The flow directions of the two S-shaped flow channels are opposite. The screening cylinder (600) is fixedly arranged in the cylinder body (100). The upper end cover (510) and the lower end cover (530) are respectively connected to the liquid outlet. 530) is rotatably arranged in the cylinder (100), the upper end cover (510) and the lower end cover (530) are fixedly connected by a connecting rod (520) extending in the up-down direction, so that the upper end cover (510) and the lower end cover (530) rotate synchronously, and the top end of the cylinder (100) is provided with a rotation driving mechanism (200) for driving the upper end cover (510) and the lower end cover (530) to rotate at a set angle, and when the upper end cover (510) and the lower end cover (530) rotate in the same direction at a set angle, the flow direction of the solutions in the two S-shaped flow channels is switched. ; 2. The crystallization device for producing bismuth oxide according to claim 1, characterized in that: Four straight cylinders (610) are arranged at intervals. The upper end cover (510) and the lower end cover (530) are both circular structures. The outer diameters of the upper end cover (510) and the lower end cover (530) are both larger than the outer diameter of the outermost straight cylinder (610). The upper ends of the four straight cylinders (610) are butted against the lower side of the upper end cover (510), and the lower ends are butted against the upper side of the lower end cover (530). The lower side of the upper end cover (510) is provided with an upper baffle (550) extending along the diameter of the upper end cover (510). The upper baffle (550) connects the upper end cover (510) is divided into a first semicircle and a second semicircle, the first semicircle is provided with a semicircular ring-shaped first upper connecting groove (512) and a second upper connecting groove (513), the first upper connecting groove (512) is located on the periphery of the second upper connecting groove (513); the second semicircle is provided with a semicircular ring-shaped third upper connecting groove (514) and a fourth upper connecting groove (515), the fourth upper connecting groove (515) is located on the periphery of the third upper connecting groove (514), the first upper connecting groove (512), the second upper connecting groove (513) and the third upper connecting groove The first upper connecting groove (512) and the fourth upper connecting groove (515) are separated by the upper partition plate (550), and the first upper connecting groove (512) and the fourth upper connecting groove (515) are cross-distributed in the radial direction of the upper end cover (510), and the second upper connecting groove (513) and the third upper connecting groove (514) are cross-distributed in the radial direction of the upper end cover (510), and the first upper connecting groove (512) connects the outermost straight tube (610) and the cylinder body (100), and the outermost straight tube (610) and its adjacent straight tube (610). The second upper connecting groove (513) connects the fluid passages between the middle two layers of straight tubes (610) and between the innermost layer of straight tubes (610) and its adjacent straight tubes (610); the third upper connecting groove (514) connects the fluid passages inside the innermost layer of straight tubes (610) and between the innermost layer of straight tubes (610) and its adjacent straight tubes (610); the fourth upper connecting groove (515) connects the fluid passages between the middle two layers of straight tubes (610) and between the outermost layer of straight tubes (610) and its adjacent straight tubes (610);A lower baffle (535) extending along the diameter of the lower end cover (530) is provided on the upper side of the lower end cover (530); the lower baffle (535) corresponds to and is parallel to the upper baffle (550) in the upper and lower directions; the lower baffle (535) divides the lower end cover (530) into a third semicircle and a fourth semicircle; the third semicircle corresponds to the first semicircle in the upper and lower directions; the fourth semicircle corresponds to the second semicircle in the upper and lower directions; the third semicircle is provided with a semicircular first lower connecting groove and a second lower connecting groove; the first lower connecting groove is located on the periphery of the second lower connecting groove; the fourth semicircle is provided with a semicircular third lower connecting groove; The first lower communicating groove and the fourth lower communicating groove are arranged on the periphery of the third lower communicating groove. The first lower communicating groove, the second lower communicating groove, the third lower communicating groove and the fourth lower communicating groove are separated by the lower partition plate (535). The first lower communicating groove and the fourth lower communicating groove are cross-distributed in the radial direction of the lower end cover (530). The third lower communicating groove and the second lower communicating groove are cross-distributed in the radial direction of the lower end cover (530). The first lower communicating groove is connected to the fluid channel between the outermost straight tube (610) and its adjacent straight tube (610), and between the two middle straight tubes (610). The second connecting groove connects the fluid passages in the innermost straight cylinder (610) and between the innermost straight cylinder (610) and its adjacent straight cylinder (610); the third connecting groove connects the fluid passages between the innermost straight cylinder (610) and its adjacent straight cylinder (610) and between the two middle straight cylinders (610); the fourth connecting groove connects the fluid passages between the outermost straight cylinder (610) and the cylinder body (100) and between the outermost straight cylinder (610) and its adjacent straight cylinder (610); the radial direction of the innermost straight cylinder (610) of the screening cylinder (600) is connected to the fluid passages in the innermost straight cylinder (610) and the innermost straight cylinder (610) of the screening cylinder (600); A middle partition (620) is symmetrically arranged, and the middle partition (620) extends radially outward from the innermost straight tube (610) to the outermost straight tube (610). In an initial state, the middle partition (620) corresponds to the upper partition (550) and the lower partition (535) in the upper and lower directions and is located in the same plane. Two S-shaped flow channels are respectively located on both sides of the middle partition (620). When the upper end cover (510) and the lower end cover (530) rotate 180° in the forward direction or 180° in the reverse direction, the S-shaped flow channels located on both sides of the middle partition (620) switch flow directions. ; 3. The crystallization device for producing bismuth oxide according to claim 2, characterized in that: The screening net (630) is a conical ring arranged coaxially with each straight cylinder (610); the axis of the screening net (630) extends in the up-down direction, and the outer side surface is an inclined surface that inclines upward from the inside to the outside in the radial direction; the upper end of the screening net (630) is a large-diameter end, and the lower end is a small-diameter end; the upper and lower ends of the screening net (630) are respectively connected to the inner walls of two adjacent layers of straight cylinders (610); and an annular material drop groove (610) extending along the circumference of the straight cylinder (610) is provided at the position where each straight cylinder (610) is connected to the lower end of the screening net (630). 2), and a material dropping channel (611) extending in the up-down direction is provided at the lower end of the straight cylinder (610), the upper end of the material dropping channel (611) is communicated with the material dropping trough (612), a conveying channel (538) is provided in the lower end cover (530), the lower end of the material dropping channel (611) is communicated with one end of the conveying channel (538), and the other end of the conveying channel (538) is communicated with the outside of the cylinder (100), so that the crystal particles screened by the screening net (630) are transported to the outside of the cylinder (100); each screening net (63 The upper end of the sieve net (630) is movably connected to the inner wall of the straight tube (610) through a connecting spring piece (640), and the connecting spring piece (640) is a flexible member capable of elastic deformation. The upper end of the sieve net (630) can overcome the force of the connecting spring piece (640) and move upward to form a crystal channel for crystal particles to pass through between the upper end of the sieve net (630) and the inner wall of the straight tube (610). When the solution impacts the sieve net (630) from top to bottom, the upper end of the sieve net (630) is tightly fitted with the inner wall of the straight tube (610), and the solution conforming to the large Crystal particles with small requirements will be intercepted above the upper side of the screening net (630) and enter the material drop channel (611). When the solution impacts the screening net (630) from bottom to top, the upper end of the screening net (630) is subjected to the upward force of the solution, thereby overcoming the action of the connecting spring sheet (640) and moving upward, forming a crystal channel between the inner wall of the straight cylinder (610) and the upper end of the screening net (630), so that crystal particles that originally could not pass through the screening net (630) pass through the screening net (630) from the crystal channel and reach the space above the screening net (630).

4. The crystallization device for producing bismuth oxide according to claim 3, characterized in that: The material-dropping channel (611) is an annular channel extending along the circumference of the straight cylinder (610); the third semicircle and the fourth semicircle are respectively provided with blocking bars (534) for blocking the lower end of the material-dropping channel (611); the blocking bars (534) on the third semicircle and the fourth semicircle are both semicircular in shape, and the blocking bars (534) on the third semicircle and the blocking bars (534) on the fourth semicircle are staggered in radial direction; the third semicircle and the fourth semicircle are respectively provided with semicircular material receiving grooves (536); the material receiving grooves (536) are communicated with the upper end of the conveying channel (538); the conveying channel (538) is connected to the material-dropping channel (611) through the material receiving grooves (536); The material channel (611) is connected, the material receiving grooves (536) on the third semicircle and the material receiving grooves (536) on the fourth semicircle are staggered in the radial direction, the material receiving grooves (536) on the third semicircle correspond one-to-one with the blocking bars (534) on the fourth semicircle and are connected to form a circle, and the material receiving grooves (536) on the fourth semicircle correspond one-to-one with the blocking bars (534) on the third semicircle and are connected to form a circle, and when the upper end cover (510) and the lower end cover (530) are rotated 180 degrees relative to the screening drum (600), the blocking bars (534) and the material receiving grooves (536) are alternately matched with the parts of the material dropping channel (611) located on both sides of the middle partition (620).

5. The crystallization device for producing bismuth oxide according to claim 4, characterized in that: Damping blocks (500) are respectively arranged in the third lower connecting groove and the fourth lower connecting groove. The damping blocks (500) are spaced apart along the extension direction of the semi-annular third lower connecting groove and the fourth lower connecting groove. The damping blocks (500) are used to reduce the flow area of ​​the S-shaped flow channel at the lower end of the screening cylinder (600), so that the flow velocity of the solution at the lower end of the screening cylinder (600) is higher than the flow velocity at other positions.

6. The crystallization device for producing bismuth oxide according to claim 5, characterized in that: The damping block (500) has a portion extending upward into the straight cylinder (610), the upper end of the damping block (500) is located below the lower end of the screening net (630), the upper end of the middle partition (620) is flush with the upper end of the screening cylinder (600), the lower end of the middle partition (620) is higher than the upper end of the damping block (500), and the upper end of the lower partition (535) is provided with a plurality of vertical plates (540) at intervals along the extension direction of the lower partition (535), each of the vertical plates (540) is respectively inserted between two adjacent straight cylinders (610), the upper end of each vertical plate (540) is respectively connected to the lower end of the middle partition (620), and the two sides of each vertical plate (540) are respectively fitted with the inner walls of the two adjacent straight cylinders (610), so that each vertical plate (540) and the middle partition (620) separate the interior of the screening cylinder (600) into two isolated parts.

7. The crystallization device for producing bismuth oxide according to claim 6, characterized in that: A through hole (511) is provided at the center of the upper end cover (510), and internal teeth are provided on the inner wall of the through hole (511). A driving motor is installed at the upper end of the cylinder (100), and the output shaft of the driving motor extends in the up-down direction. The lower end of the output shaft is connected to a driving gear (210), and the driving gear (210) meshes with the internal teeth to drive the upper end cover (510) to rotate.

8. A crystallization method for producing bismuth oxide, characterized in that: The crystallization device for producing bismuth oxide according to any one of claims 1 to 7 is used, and the steps of the crystallization method for producing bismuth oxide include: passing the solution into the cylinder through the liquid inlet and into the S-shaped flow channel, and the multiple screening nets in the S-shaped flow channel screen the crystal particles in the solution.

Images