Fertilizer screening device and screening method
By setting up an airflow grading mechanism at the third outlet of the fertilizer screening device and combining vibration screening, the problem that smaller particles and powder in the particle fertilizer are not completely screened out is solved, and the particle size uniformity and fluidity are achieved. promote.
Patent Information
- Application Number
- CN202411322226.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-23
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2044-09-23
AI Technical Summary
The existing granular fertilizer screening device cannot effectively remove smaller particles and powder from granular fertilizers, resulting in incomplete screening, affecting the uniformity and fluidity of the particle size.
Design a fertilizer screening device including a frame, a drive mechanism and a screening mechanism, and by providing an airflow grading mechanism at the third outlet, the fertilizer and powder with smaller particles are reflowed to the secondary screen by using airflow purge. Repeated screening, combined with a vibrating screening mechanism and air hood, improve screening efficiency and effect.
It effectively reduces the content of powder and small particles in the granular fertilizer, improves the uniformity and fluidity of the particle size, and improves the screening efficiency and discharge efficiency.
Smart Images
Figure CN118831824B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of solid particle separation, and in particular to a fertilizer screening device and a screening method. Background Art
[0002] The production process of granular fertilizer is as follows: raw material pretreatment, granulation, drying, screening and packaging. During the drying process, the particles may be agglomerated or uneven. The screening process is to remove the larger particles, smaller particles and agglomerated particles from the dried material to ensure that the particle size of the material after screening is uniform and has good fluidity.
[0003] At present, common screening devices include vibrating screens, reciprocating screens, etc., which can be designed as a single-stage screen or a multi-stage screen according to needs. The screening of granular fertilizers requires the removal of larger and smaller particles, and a two-stage screen is usually used. Using the existing two-stage screen to screen granular fertilizers will result in the granular fertilizers still containing a large number of smaller particles and powder, resulting in incomplete screening. Summary of the invention
[0004] The object of the present invention is to provide a fertilizer screening device and a screening method to solve the problem that the existing screening device causes the obtained granular fertilizer to contain more small particles and powder.
[0005] The present invention is achieved through the following technical solutions:
[0006] A fertilizer screening device comprises a frame, a driving mechanism and a screening mechanism, wherein the driving mechanism is used to drive the screening mechanism to make reciprocating motion on the frame, and the screening mechanism comprises a screening housing, wherein a primary screen and a secondary screen are sequentially arranged in the screening housing from top to bottom; a first material guide member for guiding out materials intercepted by the primary screen is arranged on the screening housing; a third material guide member for guiding out materials intercepted by the secondary screen is arranged on the screening housing; and a second material guide member for guiding out materials passing through the secondary screen is arranged at the bottom of the screening housing;
[0007] The side wall of the screening shell is provided with a third outlet matched with the third material guide member, and the fertilizer screening device also includes an airflow grading mechanism; the airflow grading mechanism includes a guide plate; the guide plate is arranged at the third outlet, and there is a spacing between the two ends of the guide plate in the width direction and the two side walls of the third outlet respectively; an airflow buffer chamber is formed inside the guide plate; the airflow buffer chamber is connected to the air supply mechanism, and a plurality of through holes are provided on the material-facing wall of the airflow buffer chamber, and an airflow is blown toward the discharge end of the secondary screen through the plurality of through holes, and the airflow is used to blow fertilizers and powders with smaller particles onto the secondary screen for reflux screening.
[0008] The fertilizer with smaller particles in the present invention specifically refers to the granular fertilizer that can pass through the secondary screen.
[0009] The screening of granular fertilizer is to screen out the larger particles, smaller particles and agglomerated particles in the dried material to ensure that the particle size uniformity and fluidity of the material after screening are good. That is, the screening of granular fertilizer needs to go through two screenings. The first screening is to screen out the fertilizer with larger particles and agglomerated particles, and the second screening is to screen out the smaller particles and powder in the material. There are the following principles for the screening of solids: if the density of coarse particles is small and the density of fine particles is large, it is easy to screen; on the contrary, if the density of coarse particles is large and the density of fine particles is small, screening is relatively difficult. Most of the granular fertilizers are still medium-sized materials, that is, the materials that need to be packaged are finally retained, while the fertilizers with larger particles, agglomerated fertilizers and fertilizers with smaller particles account for a relatively small proportion, that is, in granular fertilizers During the first screening, the density of coarse particles in the screened material is small, and the density of fine particles is large, so it is easy to screen. During the second screening, the density of coarse particles is large, and the density of fine particles is small, which makes screening difficult. Some fertilizers and powders with smaller particles have not been screened and fall on the bottom of the screening shell through the secondary screen, and enter the discharge end of the secondary screen with other granular fertilizers, and are exported by the third guide member through the third outlet, especially the powder. Since the powder has a certain adhesion, it can adhere to the granular fertilizer. The larger the specific surface area of the granular fertilizer, the stronger the ability to adhere to the powder, which leads to the exported granular fertilizer containing more smaller particles and powder, especially more powder. Therefore, the focus and difficulty of the present invention is to remove the powder in the granular fertilizer obtained after the secondary screening.
[0010] The material-facing wall of the present invention specifically refers to the side wall of the guide plate that contacts the material when the material at the discharge end of the secondary screen moves downward. The present invention can control the flow rate of the airflow purged from the through hole so that the airflow purged from the through hole can purge the fertilizer and powder with smaller particles and smaller weight onto the secondary screen, while the granular fertilizer with relatively larger gravity continues to move downward and is guided out of the screening shell.
[0011] The present invention provides an airflow grading mechanism at the third outlet of the fertilizer screening device, and the airflow grading mechanism includes a guide plate. On the one hand, the guide plate can block the material entering the discharge end of the secondary screen to prevent the material from directly entering the third guide member through the third outlet for discharge; on the other hand, a plurality of through holes are provided on the material-facing wall of the guide plate, and an airflow is blown toward the discharge end of the secondary screen through the plurality of through holes. The airflow is used to blow fertilizers and powders with smaller particles onto the secondary screen for reflux screening, while granular fertilizers with relatively large gravity directly move downward through the gap between the guide plate and the third outlet to the third guide member to be discharged from the fertilizer screening device. Part of the powder and small-granular fertilizers in the material blown back to the secondary screen for the first time still fail to pass through the secondary screen, and continue to fall to the third outlet, be blown again by the airflow, and return to the secondary screen for further screening. The content of powder and small-granular fertilizers in the granular fertilizers obtained for packaging can be effectively reduced through repeated reflux screening.
[0012] Preferably, the airflow led out from the through hole is a dry hot airflow, which can not only purge the material but also has a drying effect, thereby improving the separation efficiency of the powder and granular fertilizer by purge.
[0013] In a preferred embodiment, the airflow classification mechanism further includes an air intake main pipe, a second connecting rod and an air intake branch pipe;
[0014] The guide plate is a semicircular plate, and the outer arc surface of the semicircular plate serves as the material-facing surface; the airflow buffer cavity is a semicircular cavity body matched with the semicircular plate;
[0015] The air intake main pipe is arranged on the inner side of the guide plate, and the air intake main pipe is connected to the guide plate through a plurality of air intake branch pipes. The air intake main pipe, the air intake branch pipes and the air flow buffer cavity form an air flow passage. The plurality of air intake branch pipes are evenly arranged in the circumferential direction of the guide plate, and a plurality of through holes are evenly arranged in the circumferential direction of the incoming material wall.
[0016] One end of the second connecting rod is connected to the outer wall of the guide plate, and the other end is used for detachable connection with the side wall of the third outlet.
[0017] The present invention makes the guide plate a semicircular arc plate, which not only enables the guide plate to block the material at the discharge end of the secondary screen, but also the outer arc surface of the semicircular arc plate has a diversion effect on the material, and can quickly discharge the product granular fertilizer with relatively large particles. On the one hand, it can improve the discharge efficiency, and on the other hand, it can avoid the accumulation of product granular fertilizer at the discharge end of the secondary screen, which affects the blowing effect of the airflow on small granular fertilizer and powder.
[0018] If the airflow is introduced directly into the semicircular cavity through an air inlet pipe, the airflow may not be mixed quickly in the airflow buffer cavity, that is, the airflow velocities derived from several through holes are different. There may be a local excessive airflow velocity and a local excessive airflow velocity. A high airflow velocity may cause relatively large fertilizer particles to be blown back to the secondary screen. A low airflow velocity may cause powder and small fertilizer particles to be mixed into the product granular fertilizer.
[0019] The present invention provides an air intake main pipe, which supplies air to the semicircular cavity through a plurality of evenly arranged air intake branches, so that the air flow in the semicircular cavity can be uniform, and the flow rates of the air flows derived from the plurality of through holes are almost the same, thereby ensuring the blowing effect of the plurality of through holes on small-particle fertilizers and powders.
[0020] In a preferred embodiment, the direction of the central axis of the through hole is the same as the moving direction of the material on the secondary screen, that is, the direction of the airflow blown out of the through hole is opposite to the material falling from the discharge end of the secondary screen, which is conducive to improving the blowing effect of the airflow on small particle powder and powder.
[0021] In a preferred embodiment, guide plates are provided on both sides of the discharge end of the secondary screen; a discharge channel is formed between the guide plate and the outer wall of the guide plate, and the discharge channel can be swept by the airflow led out of the through hole. The guide plates can block the materials at both ends of the discharge end of the secondary screen, so as to prevent the materials from entering the fertilizer screening device before being swept by the airflow, thereby making the obtained product fertilizer still contain more lower granular fertilizer and powder.
[0022] Since the discharge channel formed between the guide plate and the guide plate can be swept by the airflow led out from the through hole, it is ensured that all materials at the discharge end of the secondary screen are swept by the airflow, and the problem of the product fertilizer still containing a large amount of lower granular fertilizer and powder due to the material not being swept by the airflow can be avoided.
[0023] In a preferred embodiment, both ends of the semicircular arc plate are placed on the third material guide member, the highest point of the semicircular arc plate protrusion is placed on the secondary screen, and the radial length of the semicircular arc plate placed on the secondary screen is less than or equal to the radial length of the semicircular arc plate placed on the third material guide member;
[0024] One end of the guide plate close to the semicircular plate intersects with the tangent line of the end of the semicircular plate.
[0025] The semicircular arc plate and guide plate arranged above can ensure that all materials are discharged from the discharge channel and ensure that all materials are swept by the air flow before being discharged.
[0026] In a preferred embodiment, the secondary screen includes an upper screen, a transition plate and a lower screening mechanism from top to bottom. The lower screening mechanism is vibrated by a vibration motor. The fertilizer and powder with smaller particles at the discharge end of the secondary screen are blown by the airflow classification mechanism to the lower screening mechanism for reflux screening.
[0027] That is, the lower screening mechanism of the present invention not only performs reciprocating motion as a whole to achieve screening, but also performs vibration screening locally, which can improve the screening effect of the lower screening mechanism. The lower screening mechanism cooperates with the airflow grading mechanism, and can quickly screen the material blown to the discharge end of the secondary screen and drop it to the bottom of the screening shell, avoiding multiple reciprocating backflows of small-particle fertilizers and powders, thereby improving the screening efficiency.
[0028] In a preferred embodiment, the lower screening mechanism comprises a lower screening mesh, an elastic frame and a fourth fixing member;
[0029] The lower screen is arranged in an elastic frame, and the elastic frame is used to connect with the transition plate and the inner wall of the screening shell;
[0030] The fourth fixing member is arranged on the lower end surface of the lower screen, and the third fixing member is arranged below the lower screen in the screening shell, and the third fixing member and the fourth fixing member are connected by a spring.
[0031] The elastic frame can be made of plastic and has elasticity to adapt to the vibration screening of the lower screen.
[0032] In a preferred embodiment, an exhaust hood is arranged above the discharge end of the secondary screen in the screening shell, and the exhaust hood is connected to the waste bin outside the screening shell through an exhaust pipe. The exhaust hood is used to guide the powder at the discharge end of the secondary screen out of the screening shell by adsorption.
[0033] By controlling the air flow speed in the exhaust hood, it is possible to extract the powder with a smaller weight without affecting the granular fertilizer.
[0034] Since the most difficult part of the fertilizer to screen is the powder, the powder will separate from the granular fertilizer during the airflow blowing process. Part of the powder will fall to the bottom of the screening shell through the secondary screen, and the other part can be guided out of the screening shell through the exhaust hood, thereby improving the screening effect of the reflux screening.
[0035] In a preferred embodiment, a first positioning column is provided on the frame, a second positioning column is provided on the outer wall of the screening shell, and the first positioning column and the second positioning column are movably connected via a first connecting rod.
[0036] Based on the screening method of the fertilizer screening device, the dried granular fertilizer is injected into the screening shell, the granular fertilizer is first screened on the primary screen, and the granular fertilizer intercepted by the primary screen is discharged through the first material guide; the granular fertilizer after the primary screening falls on the secondary screen for secondary screening, and the granular fertilizer falling after the secondary screen screening is discharged through the second material guide; the granular fertilizer intercepted by the secondary screen is swept by the airflow discharged by the airflow classification mechanism at the third outlet onto the secondary screen for reflux screening, so that the small granular fertilizer (granular fertilizer that can pass through the secondary screen) and powder mixed in the granular fertilizer intercepted by the secondary screen are screened again and fall to the bottom of the screening shell, and are finally discharged by the second material guide.
[0037] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0038] 1. The present invention provides an airflow classification mechanism at the third outlet of the fertilizer screening device, and blows airflow to the discharge end of the secondary screen through a plurality of through holes. The airflow is used to blow fertilizers with smaller particles and powders onto the secondary screen for reflux screening. Repeated reflux screening can effectively reduce the content of powders and small-particle fertilizers in the granular fertilizers obtained for packaging.
[0039] 2. The present invention can not only realize uniform air supply and improve the blowing effect of airflow on small-particle fertilizers and powders by reasonably designing the structure of the airflow classification mechanism, but also avoid the accumulation of product granular fertilizers at the discharge end of the secondary screen, which affects the blowing effect of airflow on small-particle fertilizers and powders, and has the advantage of high discharge efficiency.
[0040] 3. The present invention improves the secondary screen, which includes an upper screen, a transition plate and a lower screening mechanism from top to bottom. The lower screening mechanism is vibrated by a vibration motor. The lower screening mechanism of the present invention cooperates with the airflow classification mechanism, which can quickly screen the material blown to the discharge end of the secondary screen and drop it to the bottom of the screening shell, avoiding multiple reciprocating backflows of small-particle fertilizers and powders, and improving the screening efficiency.
[0041] 4. The present invention provides an exhaust hood which cooperates with the airflow classification mechanism. A part of the powder material blown to the discharge end of the secondary screen by the airflow classification mechanism falls to the bottom of the screening shell through the secondary screen, and the other part can be guided out of the screening shell through the exhaust hood, thereby improving the screening effect of the reflux screening. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:
[0043] Figure 1 It is a structural schematic diagram of the fertilizer screening device of the present invention;
[0044] Figure 2 is a cross-sectional view of the screening mechanism of the present invention;
[0045] Figure 3 It is a schematic diagram of the cooperation between the secondary screen and the airflow classification mechanism in Example 1 of the present invention;
[0046] Figure 4 Schematic diagram of the cooperation between the secondary screen and the airflow classification mechanism in Example 2 of the present invention Figure 1 ;
[0047] Figure 5 Schematic diagram of the cooperation between the secondary screen and the airflow classification mechanism in Example 2 of the present invention Figure 2 ;
[0048] Figure 6 It is a structural schematic diagram of the airflow classification mechanism of the present invention;
[0049] Figure 7 for Figure 6 A partial enlarged view of point A in the middle.
[0050] Marks and corresponding parts names in the attached drawings:
[0051] 1-frame; 2-screening mechanism; 3-airflow classification mechanism; 4-guide plate; 5-exhaust hood; 6-exhaust pipe; 7-first connecting rod; 8-spring; 11-first positioning column; 21-screening shell; 22-first screen; 23-secondary screen; 24-first material guide; 25-second material guide; 26-third material guide; 27-second positioning column; 31-intake main pipe; 32-guide plate; 33-second connecting rod; 34-airflow buffer chamber; 35-intake branch pipe; 211-third outlet; 212-first outlet; 213-first fixing member; 214-second fixing member; 215-third fixing member; 221-blocking plate; 231-upper screen; 232-transition plate; 233-lower screening mechanism; 321-through hole; 2331-lower screen; 2332-elastic frame; 2333-fourth fixing member. DETAILED DESCRIPTION
[0052] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the embodiments. The schematic implementation mode of the present invention and its description are only used to explain the present invention and are not intended to limit the present invention. The embodiments described below are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.
[0053] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to those of ordinary skill in the art that these specific details do not have to be employed to practice the present invention. In other embodiments, in order to avoid confusing the present invention, known structures, materials or methods are not specifically described. The materials, instruments and reagents used in the following examples, unless otherwise specified, can be obtained from commercial sources. The technical means used in the examples, unless otherwise specified, are conventional means well known to those skilled in the art.
[0054] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0055] Embodiment 1:
[0056] like Figure 1-Figure 3 , Figure 6-Figure 7As shown, a fertilizer screening device comprises a frame 1, a driving mechanism and a screening mechanism 2, the driving mechanism is used to drive the screening mechanism 2 to reciprocate on the frame 1, specifically, a first positioning column 11 is arranged on the frame, and a second positioning column 27 is arranged on the outer wall of a screening shell 21, the first positioning column 11 and the second positioning column 27 are movably connected by a first connecting rod 7, and the movable connection can realize the reciprocating motion of the screening mechanism 2, the screening mechanism 2 is tilted, and the high end of the screening mechanism 2 realizes the reciprocating motion of the screening mechanism 2 in its tilted direction through an eccentric wheel and a motor, the granular fertilizer to be screened is injected from the high end of the screening mechanism 2, and screening is realized during the reciprocating motion, that is, the fertilizer screening device of this embodiment is a reciprocating screening device, and the structural mixing principle of the reciprocating screening device adopts the existing technology. The screening mechanism 2 includes a screening shell 21, the top of which is an open end for injecting granular fertilizer into the screening shell 21, and a primary screen 22 and a secondary screen 23 are sequentially arranged in the screening shell 21 from top to bottom, and the primary screen 22 and the secondary screen 23 are both arranged obliquely; a first material guide 24 for guiding out the material retained by the primary screen 22 is arranged on the screening shell 21, specifically, a baffle plate 221 is arranged at the lower end of the primary screen 22, and the baffle plate 221 is arranged horizontally, and a first fixing member 213 for fixing the baffle plate 221 is arranged on the inner wall of the screening shell 21, and the first fixing member 213 can be a fixing plate arranged horizontally, and the baffle plate 221 and the first fixing member 213 can be connected by bolts, and the screening shell 21 is perpendicular to the reciprocating motion direction. A first outlet 212 is arranged on the side wall of the screening housing 21; and a first material guide 24 matching with the first outlet 212 is arranged on the outer wall of the screening housing 21. The large-particle fertilizer intercepted by the primary screen 22 falls to the baffle plate 221, and is guided to the first receiving part through the first material guide 24 after being guided out from the first outlet 212. The first material guide 24 can be a U-shaped plate arranged in an inclined manner, and the first receiving part can be a receiving bucket. The screening housing 21 is provided with a third material guide 26 for guiding out the materials intercepted by the secondary screen 23; specifically, a third outlet 211 is arranged on the bottom side wall of the screening housing 21, and a third material guide 26 matching with the third outlet 211 is arranged on the bottom outer wall of the screening housing 21. The third material guide 26 can be a U-shaped plate arranged in an inclined manner. A second material guide 25 for guiding out the materials passing through the secondary screen 23 is arranged at the bottom of the screening housing 21; the second material guide 25 can be a material guide pipe.
[0057] The fertilizer screening device further includes an airflow classification mechanism 3; the airflow classification mechanism 3 includes a guide plate 32; the guide plate 32 is arranged at the third outlet 211, and there is a spacing between the two ends of the guide plate 32 in the width direction and the two side walls of the third outlet 211, and the width direction of the guide plate 32 specifically refers to Figure 3The guide plate 32 is in the horizontal direction shown; an airflow buffer chamber 34 is formed inside; the airflow buffer chamber 34 is connected to the air supply mechanism, and a plurality of through holes 321 are provided on the material-facing wall of the airflow buffer chamber 34, and an airflow is blown to the discharge end of the secondary screen 23 through the plurality of through holes 321, and the airflow is used to blow the fertilizer and powder with smaller particles onto the secondary screen 23 for reflux screening. Preferably, the airflow derived from the through holes 321 is a dry hot airflow, which can not only blow the material, but also has a drying effect, thereby improving the separation efficiency of the powder and the granular fertilizer through blowing.
[0058] In this embodiment, an air flow is blown toward the discharge end of the secondary screen 23 through a plurality of through holes 321. The air flow is used to blow fertilizers with smaller particles and powders onto the secondary screen 23 for reflux screening. Repeated reflux screening can effectively reduce the content of powders and small-particle fertilizers in the obtained product granular fertilizer.
[0059] In a preferred case, in order to improve the uniformity of the flow rate of the airflow derived from the plurality of through holes 321 on the airflow classification mechanism 3, the airflow classification mechanism 3 further includes an air intake main pipe 31, a second connecting rod 33 and an air intake branch pipe 35;
[0060] The guide plate 32 is a semicircular plate, and the outer arc surface of the semicircular plate serves as the material-facing surface; the airflow buffer cavity 34 is a semicircular cavity body matched with the semicircular plate;
[0061] The air intake main pipe 31 is arranged on the inner side of the guide plate 32, and the air intake main pipe 31 is connected to the guide plate 32 through a plurality of air intake branch pipes 35. The air intake main pipe 31, the air intake branch pipes 35 and the air flow buffer chamber 34 form an air flow passage. The plurality of air intake branch pipes 35 are evenly arranged in the circumferential direction of the guide plate 32, and a plurality of through holes 321 are evenly arranged in the circumferential direction of the incoming material wall. Specifically, as Figure 6 As shown, five intake branch pipes 35 are provided; two of them are arranged in the horizontal direction and are respectively connected to the two ends of the guide plate 32.
[0062] One end of the second connecting rod 33 is connected to the outer wall of the guide plate 32, and the other end is used to be detachably connected to the side wall of the third outlet 211; specifically, Figure 6 As shown, two second connecting rods 33 are symmetrically arranged on the outer wall of the guide plate 32, and a horizontally arranged slot can be arranged on the side wall of the third outlet 211, and a positioning spring is arranged at the bottom of the slot, so that the second connecting rod 33 can be detachably fixed in the slot through the positioning spring.
[0063] In a preferred case, the direction of the central axis of the through hole 321 is the same as the direction of material movement on the secondary screen 23. Specifically, Figure 6 As shown, the direction of the central axis of the through hole 321 is Figure 6In the vertical direction, the airflow purged from the through hole 321 flows upward and moves in the opposite direction to the granular fertilizer moving downward on the secondary screen 23, which can improve the purging effect of the airflow on the material.
[0064] In a preferred case, the secondary screen 23 is provided with guide plates 4 on both sides of its discharge end; a discharge channel is formed between the guide plates 4 and the outer wall of the guide plate 32, and the discharge channel can be swept by the airflow guided out of the through hole 321. Specifically, both ends of the semicircular plate are placed on the third guide member 26, the highest point of the semicircular plate protrusion is placed on the secondary screen 23, and the radial length of the semicircular plate placed on the secondary screen 23 is less than or equal to the radial length of the semicircular plate placed on the third guide member 26; the end of the guide plate 4 close to the semicircular plate intersects with the tangent of the end of the semicircular plate, such as Figure 3 As shown, the cross section of the guide plate 4 is a right triangle, that is, the shape of the guide plate 4 is a triangular prism with two adjacent faces perpendicular to each other, the two vertical faces of the triangular prism are respectively connected to the bottom inner wall and the other side wall of the screening shell, and the lower end of the inclined surface of the triangular prism is located at the end of the guide plate 32. Figure 3 As shown, the end of the guide plate 4 close to the semicircular plate intersects with the tangent of the end of the semicircular plate, and there is a gap between the lower end of the inclined surface of the triangular prism and the outer wall of the guide plate 32 located in the same horizontal direction; the inclined surface of the triangular prism guides the granular fertilizer, and guides the granular fertilizer at both ends of the discharge end of the secondary screen 23 in the width direction to the material channel that can be swept by the airflow, so as to prevent the granular fertilizer from directly entering the third guide member 26 before being swept by the airflow.
[0065] The screening process of this embodiment is:
[0066] The dried granular fertilizer is injected into the screening shell 21, and the granular fertilizer is first screened on the primary screen 22, and the large granular fertilizer intercepted by the primary screen 22 is discharged through the first guide member 24; the granular fertilizer after the primary screening falls on the secondary screen 23 for secondary screening, and the granular fertilizer screened and dropped by the secondary screen 23 is discharged through the second guide member 25; the granular fertilizer intercepted by the secondary screen 23 is swept by the airflow discharged by the airflow classification mechanism 3 at the third outlet 211 to the secondary screen 23 for reflux screening, so that the small granular fertilizer and powder mixed in the granular fertilizer intercepted by the secondary screen 23 are screened again and fall to the bottom of the screening shell 21, and finally discharged by the second guide member 25.
[0067] Embodiment 2:
[0068] like Figure 1-Figure 2 , Figure 4-Figure 7As shown, this embodiment is based on embodiment 1. This embodiment improves the secondary screen 23 on the basis of embodiment 1. Specifically, the secondary screen 23 includes an upper screen 231, a transition plate 232 and a lower screening mechanism 233 from top to bottom. The lower screening mechanism 233 is vibrated by a vibration motor. The fertilizer and powder with smaller particles at the discharge end of the secondary screen 23 are swept by the airflow classification mechanism 3 to the lower screening mechanism 233 for reflux screening; that is, the lower screening mechanism 233 of this embodiment is a vibrating screen; It is an existing technology to use a vibration motor to achieve vibration screening, that is, the lower screening mechanism 233 of this embodiment not only performs reciprocating motion as a whole to achieve screening, but also performs vibration screening locally, which can improve the screening effect of the lower screening mechanism 233. The lower screening mechanism 233 cooperates with the airflow classification mechanism 3, and can quickly screen the material blown to the discharge end of the secondary screen 23 and drop it to the bottom of the screening shell 21, avoiding multiple reciprocating backflows of small-particle fertilizers and powders, and improving the screening efficiency.
[0069] The specific structure of the lower screening mechanism 233 is as follows: it includes a lower screening mesh 2331, an elastic frame 2332 and a fourth fixing member 2333;
[0070] The lower screen 2331 is arranged in the elastic frame 2332, and the elastic frame 2332 is used to connect with the transition plate 232 and the inner wall of the screening housing 21, which can be bolted;
[0071] The fourth fixing member 2333 is arranged on the lower end surface of the lower screen 2331 . The third fixing member 215 is arranged below the lower screen 2331 in the screening housing 21 . The third fixing member 215 and the fourth fixing member 2333 are connected via a spring 8 .
[0072] Embodiment 3:
[0073] like Figure 2 As shown, this embodiment is based on Embodiment 1 or Embodiment 2. In order to better separate the powder in the granular fertilizer, an exhaust hood 5 is arranged above the discharge end of the secondary screen 23 in the screening shell 21. The exhaust hood 5 is connected to the waste bin outside the screening shell 21 through an exhaust pipe 6. The exhaust hood 5 is used to guide the powder at the discharge end of the secondary screen 23 out of the screening shell 21 by adsorption. This can be achieved by arranging a fan in the exhaust pipe 6, which is similar to a range hood.
[0074] In this embodiment, an exhaust hood 5 is provided to cooperate with the airflow classification mechanism 3. A part of the powder material blown to the discharge end of the secondary screen 23 by the airflow classification mechanism 3 falls to the bottom of the screening shell 21 through the secondary screen 23, and the other part can be guided out of the screening shell 21 through the exhaust hood 5, thereby improving the screening effect of the reflux screening.
[0075] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
[0076] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and the like cited in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of the relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.
Claims
1. A fertilizer screening device, comprising a frame (1), a driving mechanism and a screening mechanism (2), wherein the driving mechanism is used to drive the screening mechanism (2) to perform reciprocating motion on the frame (1), characterized in that: The screening mechanism (2) comprises a screening housing (21), wherein a primary screen (22) and a secondary screen (23) are arranged in sequence from top to bottom in the screening housing (21); a first material guide (24) for guiding out material retained by the primary screen (22) is arranged on the screening housing (21); a third material guide (26) for guiding out material retained by the secondary screen (23) is arranged on the screening housing (21); and a second material guide (25) for guiding out material passing through the secondary screen (23) is arranged at the bottom of the screening housing (21); The side wall of the screening housing (21) is provided with a third outlet (211) matched with the third material guide member (26); the fertilizer screening device further comprises an airflow classification mechanism (3); the airflow classification mechanism (3) comprises a guide plate (32); the guide plate (32) is provided at the third outlet (211), and a distance is provided between the two ends of the guide plate (32) in the width direction and the two side walls of the third outlet (211); an airflow buffer chamber (34) is formed inside the guide plate (32); the airflow buffer chamber (34) is connected to the air supply mechanism, and a plurality of through holes (321) are provided on the material-facing wall of the airflow buffer chamber (34), and an airflow is blown toward the discharge end of the secondary screen (23) through the plurality of through holes (321), and the airflow is used to blow the granular fertilizer and powdered material that can pass through the secondary screen (23) onto the secondary screen (23) for reflux screening; The airflow classification mechanism (3) further comprises an air intake main pipe (31), a second connecting rod (33) and an air intake branch pipe (35); The guide plate (32) is a semicircular plate, and the outer arc surface of the semicircular plate serves as a material-facing surface; the airflow buffer cavity (34) is a semicircular cavity body that matches the semicircular plate; The air intake main pipe (31) is arranged on the inner side of the guide plate (32), the air intake main pipe (31) is connected to the guide plate (32) via a plurality of air intake branch pipes (35), the air intake main pipe (31), the air intake branch pipes (35) and the air flow buffer chamber (34) form an air flow passage, the plurality of air intake branch pipes (35) are evenly arranged in the circumferential direction of the guide plate (32), and the plurality of through holes (321) are evenly arranged in the circumferential direction of the material receiving wall; One end of the second connecting rod (33) is connected to the outer wall of the guide plate (32), and the other end is used for detachably connecting to the side wall of the third outlet (211); The secondary screen (23) comprises, from top to bottom, an upper screen (231), a transition plate (232) and a lower screening mechanism (233); the lower screening mechanism (233) is vibrated by a vibration motor; granular fertilizer and powdered material that can pass through the secondary screen (23) at the discharge end of the secondary screen (23) are swept by the airflow classification mechanism (3) to the lower screening mechanism (233) for reflux screening; An exhaust hood (5) is arranged above the discharge end of the secondary screen (23) in the screening housing (21); the exhaust hood (5) is connected to a waste bin outside the screening housing (21) via an exhaust pipe (6); the exhaust hood (5) is used to guide powder at the discharge end of the secondary screen (23) out of the screening housing (21) by adsorption.
2. A fertilizer screening device according to claim 1, characterized in that: The direction of the central axis of the through hole (321) is the same as the direction of material movement on the secondary screen (23).
3. A fertilizer screening device according to claim 1, characterized in that: The secondary screen (23) is provided with guide plates (4) on both sides of its discharge end; a discharge channel is formed between the guide plates (4) and the outer wall of the guide plate (32), and the discharge channel can be swept by the airflow discharged from the through hole (321).
4. A fertilizer screening device according to claim 3, characterized in that: The two ends of the semicircular plate are placed on the third material guide member (26), the highest point of the semicircular plate protrusion is placed on the secondary screen (23), and the radial length of the semicircular plate placed on the secondary screen (23) is less than or equal to the radial length of the semicircular plate placed on the third material guide member (26); One end of the guide plate (4) close to the semicircular plate intersects with a tangent line of the end of the semicircular plate.
5. A fertilizer screening device according to claim 4, characterized in that: The lower screening mechanism (233) comprises a lower screening mesh (2331), an elastic frame (2332) and a fourth fixing member (2333); The lower screen (2331) is arranged in the elastic frame (2332), and the elastic frame (2332) is used to connect with the transition plate (232) and the inner wall of the screening housing (21); The fourth fixing member (2333) is arranged on the lower end surface of the lower screen (2331), and a third fixing member (215) is arranged below the lower screen (2331) in the screening housing (21), and the third fixing member (215) and the fourth fixing member (2333) are connected via a spring (8).
6. A fertilizer screening device according to any one of claims 1 to 5, characterized in that: The frame is provided with a first positioning column (11), the outer wall of the screening shell (21) is provided with a second positioning column (27), and the first positioning column (11) and the second positioning column (27) are movably connected via a first connecting rod (7).
7. A screening method for a fertilizer screening device according to any one of claims 1 to 6, characterized in that: The dried granular fertilizer is injected into the screening housing (21), and the granular fertilizer is first screened on the primary screen (22), and the granular fertilizer intercepted by the primary screen (22) is discharged through the first material guide (24); the granular fertilizer that has been screened once falls on the secondary screen (23) for secondary screening, and the granular fertilizer that falls after screening by the secondary screen (23) is discharged through the second material guide (25); the granular fertilizer intercepted by the secondary screen (23) is swept by the airflow discharged by the airflow classification mechanism (3) at the third outlet (211) onto the secondary screen (23) for reflux screening, so that the granular fertilizer and powder that can pass through the secondary screen (23) mixed in the granular fertilizer intercepted by the secondary screen (23) are screened again and fall to the bottom of the screening housing (21), and finally discharged by the second material guide (25).