CN213943872U

CN213943872U - Material screening device and rice sieve

Info

Publication number: CN213943872U
Application number: CN202022693249.9U
Authority: CN
Inventors: 朱建武; 蒋江; 雷艳清
Original assignee: Hunan Chenzhou Grain & Oil Machinery Co ltd
Current assignee: Hunan Chenzhou Grain & Oil Machinery Co ltd
Priority date: 2020-11-19
Filing date: 2020-11-19
Publication date: 2021-08-13
Anticipated expiration: 2030-11-19

Abstract

The utility model discloses a material screening plant and rice sieve, have the framework of material transmission mouth and locate the screening mechanism in the framework including the top, screening mechanism is used for screening the material according to the particle diameter of material, and the framework includes that the side has the open-ended frame, locates the preceding door plant of open-ended and the back door plant that is used for the gland frame on the lateral wall of frame relatively, and on screening mechanism located the frame, preceding door plant detachably located the preceding lateral wall of frame on, back door plant detachably located the back lateral wall of frame on. The utility model discloses a material screening plant, screening mechanism wash and change the convenience.

Description

Material screening device and rice sieve

Technical Field

The utility model relates to a mechanical equipment technical field especially relates to a material screening plant. The utility model discloses still relate to a rice sieve.

Background

The principle of screening and grading the white rice aims at different sizes and sizes of the rice, and the rice is effectively graded by utilizing a plurality of layers of sieve plates with corresponding sizes. The sieve body is generally provided with 4-6 layers of sieve plates, materials flow on the sieve plates, materials smaller than the sieve mesh size pass through the sieve plates to reach the lower layer of sieve plates, and materials larger than the sieve mesh size are left on the sieve plates and collected, so that effective classification is achieved.

The sieve plate of the existing rice sieve is of a drawer type structure, and the sieve plate is connected with the frame body in a sealing manner through a sealing sleeve. When the screen plate is cleaned, the screen plate is usually required to be pulled out of the frame body and then the surface of the screen plate is cleaned, so that the screen plate is easy to loosen, the sealing performance with the frame body is poor, and the screen plate is difficult to clean and replace.

The homogeneity of material on the sifter has a big influence to the sorting effect of white rice sieve, and current white rice sieve generally adopts defeated material mouthful material directly to get into first layer sieve, and the material does not have at sifter lateral distribution evenly just to get into the sifter, and the material forms near feed position easily and piles up, causes first layer sieve to block up easily and influences the screening effect to screening time is long, screening efficiency is low.

SUMMERY OF THE UTILITY MODEL

The utility model provides a material screening plant to solve the technical problem that current screening mechanism is difficult to wash and change.

In order to achieve the above object, the utility model adopts the following technical scheme:

the utility model provides a material screening plant, has the framework of material transmission mouth and locates the screening mechanism in the framework including the top, and screening mechanism is used for screening the material according to the particle diameter of material, and the framework includes that the side has open-ended frame, locates the preceding door plant and the back door plant that are used for the open-ended of gland frame on the lateral wall of frame relatively, and screening mechanism locates on the frame, and preceding door plant detachably locates on the preceding lateral wall of frame, and back door plant detachably locates on the back lateral wall of frame.

Furthermore, the screening mechanism comprises a pre-screening sieve, a special-rice sieve, a common-rice sieve and a broken-rice sieve which are sequentially arranged at intervals from top to bottom, the material screening device further comprises a material dripping plate which is obliquely arranged between the material conveying port and the pre-screening sieve and used for uniformly distributing materials input from the material conveying port and then guiding the materials to the feeding side of the pre-screening sieve, the output side of the material dripping plate is obliquely downwards arranged along the direction from the rear side to the front side of the frame, and a first material guide plate used for guiding screen underflow screened by the pre-screening sieve to the feeding side of the special-rice sieve is arranged between the special-rice sieve and the pre-screening sieve.

Furthermore, the special-meter sieve is formed by laying two special-meter sieve layers with the same sieve pore diameter along the vertical interval, the first material guide plate is arranged between the upper special-meter sieve layer and the preselection sieve, the second material guide plate used for guiding undersize formed by screening the upper special-meter sieve layer is arranged between the upper special-meter sieve layer and the lower special-meter sieve layer, and the undersize on the upper special-meter sieve layer and the undersize on the lower special-meter sieve layer are respectively guided to the common-meter sieve.

Further, preceding door plant is used for preventing that screening mechanism during operation material from the front side spill of framework, is equipped with first material guiding groove and second material guiding groove on the preceding door plant, first material guiding groove is used for leading first material guide board and upper level special meter sieve layer intercommunication and then make the material on the first material guide board lead to on the upper level special meter sieve layer along first material guiding groove, second material guiding groove is used for leading first material guide board and lower floor special meter sieve layer intercommunication and then make the material on the first material guide board lead to on the special meter sieve layer of lower floor along second material guiding groove.

Furthermore, the number of the first material guide grooves is multiple, the multiple first material guide grooves are arranged at intervals along the length direction of the front door plate, the second material guide grooves are arranged between every two adjacent first material guide grooves, and the sum total value of the groove widths of all the second material guide grooves is equal to the sum total value of the groove widths of all the first material guide grooves.

Further, a third material guide plate for guiding undersize of the lower-layer special-meter sieve layer to the feeding side of the common rice sieve is arranged between the lower-layer special-meter sieve layer and the common rice sieve, and the output side of the third material guide plate is obliquely arranged downwards.

Furthermore, be equipped with the output frame board that has the transport cavity on the lateral wall adjacent with preceding door plant in the framework, the input port of output frame board communicates with the output side of second material guide board and the output side of third material guide board respectively, and the output port of output frame board communicates to on general rice sieve, and then inputs the undersize thing that the screening of upper specially rice sieve layer formed and the undersize thing that the screening of lower floor specially rice sieve layer formed to general rice sieve simultaneously through output frame board to carry out the screening next time.

Further, general rice sieve includes first meter sieve layer and the second meter sieve layer of following vertical interval and laying, and the downside on first meter sieve layer is located on the second meter sieve layer is in order to carry out further screening to the undersize thing that first meter sieve layer screened and formed, and the undersize thing on upper strata special meter sieve layer and the undersize thing on lower floor special meter sieve layer are leading-in respectively to first meter sieve layer on.

Further, screening mechanism still includes the collection flitch that is used for leading the undersize thing that the screening of millet sieve formed and exports of locating the downside of millet sieve, and the output side of collection flitch sets up to the decline.

The utility model also provides a rice sieve, including foretell material screening plant with be used for driving material screening plant and make the horizontal rotary motion of material screening plant and then carry out the drive arrangement that sieves to the material on the material screening plant.

The utility model discloses following beneficial effect has:

the utility model discloses a material screening plant, through on locating the frame with screening mechanism, preceding door plant detachably locates the front side of frame and compresses tightly screening mechanism, the rear side of frame is located to back door plant detachably and extrudes screening mechanism, when the leakproofness of screening mechanism installation is screened or inspection screening mechanism installation is cleared up to needs, only need to open preceding door plant and/or back door plant and wash or inspect screening mechanism from the outside of frame, need not to repeat many times to pull out screening mechanism in order to clear up, avoid screening mechanism atress deformation influence screening mechanism and the leakproofness of framework connection when pulling out the washing.

In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be described in further detail with reference to the drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. In the drawings:

FIG. 1 is a schematic structural view of a material screening device according to a preferred embodiment of the present invention;

figure 2 is an exploded view of a material screening device according to a preferred embodiment of the present invention;

FIG. 3 is a schematic view of the construction of the front door panel of FIG. 2;

FIG. 4 is a partial schematic perspective view of a material screening device according to a preferred embodiment of the present invention;

figure 5 is a process flow diagram of a material screen in accordance with a preferred embodiment of the present invention in operation.

Illustration of the drawings:

100. a material screening device; 10. a frame body; 20. a screening mechanism; 21. pre-screening; 22. a specially-sized sieve; 23. a common rice sieve; 24. crushing and screening rice; 25. a first material guide plate; 26. a second material guide plate; 27. a third material guide plate; 28. a material collecting plate; 30. a material dripping plate; 40. a front door panel; 41. a first material guiding groove; 42. a second material guiding groove; 50. and outputting the frame plate.

Detailed Description

The embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways, which are defined and covered below.

FIG. 1 is a schematic structural view of a material screening device according to a preferred embodiment of the present invention; figure 2 is an exploded view of a material screening device according to a preferred embodiment of the present invention; FIG. 3 is a schematic view of the construction of the front door panel of FIG. 2; FIG. 4 is a partial schematic perspective view of a material screening device according to a preferred embodiment of the present invention; figure 5 is a process flow diagram of a material screen in accordance with a preferred embodiment of the present invention in operation.

As shown in fig. 1 and 2, the material sieving apparatus 100 of the present embodiment includes a frame 10 having a material feeding port at a top thereof and a sieving mechanism 20 disposed in the frame 10, wherein the sieving mechanism 20 is configured to sieve the material according to a particle size of the material, the frame 10 includes a frame having an opening at a side thereof, a front door panel 40 and a rear door panel oppositely disposed on a side wall of the frame for covering the opening of the frame, the sieving mechanism 20 is disposed on the frame, the front door panel 40 is detachably disposed on a front side wall of the frame, and the rear door panel is detachably disposed on a rear side wall of the frame. The utility model discloses a material screening plant 100, on locating the frame through screening mechanism 20, preceding door plant 20 detachably locates the front side of frame and compresses tightly screening mechanism, the rear side of frame is located to back door plant detachably and extrudes screening mechanism 20, when the leakproofness of screening mechanism or inspection screening mechanism 20 installation is cleared up to needs, only need to open preceding door plant and/or back door plant and wash or inspect screening mechanism 20 from the outside of frame, need not to repeat many times and pull out screening mechanism 20 in order to clear up, avoid screening mechanism 20 atress deformation influence screening mechanism 20 and the leakproofness of framework connection when pulling out the washing.

It can be understood that, in this embodiment, the screening mechanism is located in the draw-in groove of the inside wall of frame, and the front side and the rear side of frame have the opening respectively, and preceding door plant adopts the hinge vertical hinged door to locate on the preceding lateral wall of frame, and the back door plant is the hanging door of bolt locking on the rear side wall of frame, and preceding door plant and back door plant compress tightly the screening mechanism simultaneously from the front side and the rear side of screening mechanism after closing, make screening mechanism and frame sealing connection.

Further, the screening mechanism 20 comprises a preselection screen 21, a special-meter screen 22, a common-meter screen 23 and a broken-rice screen 24 which are sequentially arranged from top to bottom at intervals, the material screening device further comprises a material dripping plate 30 which is obliquely arranged between the material conveying port and the preselection screen 21 and used for uniformly distributing materials input from the material conveying port and then guiding the materials to the feeding side of the preselection screen 21, the output side of the material dripping plate 30 is obliquely downwards arranged along the rear side of the frame towards the front side, and a first material guide plate 25 used for guiding undersize materials screened by the preselection screen 21 to the feeding side of the special-meter screen 22 is arranged between the special-meter screen 22 and the preselection screen 21. Specifically, the utility model discloses a material screening plant 100, including framework 10, screening mechanism 20 and trickling board 30. The screening mechanism 20 vibrates along with the frame 10 to make the materials flow on the screening mechanism 20, so as to screen and collect the materials with different particle sizes on the screening mechanism 20, thereby achieving the effective classification of the materials. Screening mechanism 20 includes along vertical preselection sieve 21, the special rice sieve 22, general rice sieve 23 and the broken rice sieve 24 of interval arrangement from last to down in proper order, is used for sieving the chaff group in the material through preselection sieve 21, is favorable to preventing that the chaff group in the material directly gets into the sieve layer in the small aperture of screening mechanism 20 lower part, avoids the sieve in-layer pile and the jam in the small aperture of material screening mechanism 20 lower part. The material dripping plate 30 is arranged between the material conveying opening and the pre-selection screen 21, the material input from the material conveying opening is received through the feeding side of the material dripping plate 30, the output side of the material dripping plate 30 is arranged in a downward inclined mode, the material dripping plate 30 does planar rotary motion along with the frame body 10 and is evenly distributed on the material dripping plate 30 in the process of moving from the feeding side of the material dripping plate 30 to the discharging side of the material dripping plate 30, and the material after being evenly distributed in the transverse direction is output to the feeding side of the pre-selection screen 21 from the discharging side of the material dripping plate 30 so that the material can evenly enter the screen surface of the pre-selection screen 21, therefore, the material is prevented from being accumulated near the feeding position of the pre-selection screen 21, and rapid screening of the material is facilitated.

It is understood that in this embodiment, the material sieving device 100 has a three-dimensional square structure. Specifically, the material sieving device 100 is a square structure, the material is sieved in the material sieving device 100, and oversize products on different sieve layers flow into different material collecting pipelines from the discharging side of the sieving mechanism 20. Each screen body can be a single-layer plate or a plurality of single-layer plates which are arranged and combined at intervals along the vertical direction. Optionally, the material is rice kernels.

Undersize of the pre-screening sieve 21 is discharged from the bran dough hopper, undersize enters the next-layer of the special-rice sieve 22, oversize of the special-rice sieve 22 is discharged to the special-rice bucket to be collected, undersize of the special-rice sieve 22 enters the next-layer of the common-rice sieve 23, oversize of the common-rice sieve 23 is discharged to the common-rice bucket to be collected, undersize of the common-rice sieve 23 enters the next-layer of the broken-rice sieve 24 to be further screened, so that broken rice is collected through the broken-rice bucket, and rice grains screened by the rice drying sieve are collected. So as to complete the multi-layer screening of the materials.

Optionally, the pre-screen 21 is removably positioned within the frame 10. Specifically, since the northern client front polishing machine is easy to process to form bran clusters, the client requires to screen the bran clusters, and the northern client generally is round-grained japonica rice with large yield, a layer of pre-screening sieve 21 is provided for screening the bran clusters; because southern burnishing machine processing is difficult for forming the bran group, can not need to remove bran group sifter, nevertheless southern is long grain type long-grained long-shaped rice, and output is little relatively, for improving the utility model discloses a material screening plant's commonality, in 21 detachably locates framework 10 of pre-selection sieve.

Further, the special-meter sieve 22 is composed of two special-meter sieve layers with the same sieve pore diameter, which are arranged at intervals along the vertical direction, a first material guide plate 25 is arranged between the upper special-meter sieve layer and the preselection sieve 21, a second material guide plate 26 for guiding undersize formed by sieving the upper special-meter sieve layer is arranged between the upper special-meter sieve layer and the lower special-meter sieve layer, and undersize on the upper special-meter sieve layer and undersize on the lower special-meter sieve layer are respectively guided to the common-meter sieve 23. The two-layer parallel feeding mode is adopted, so that the screening efficiency of the material screening device is favorably enhanced, and the screening yield of the material screening device is increased.

Further, please refer to fig. 3 and 5, the front door panel 40 is used for preventing the materials from splashing from the front side of the frame body when the screening mechanism 20 works, the front door panel is provided with a first material guiding groove 41 and a second material guiding groove 42, the first material guiding groove 41 is used for communicating the first material guiding plate 25 with the upper special-meter sieve layer so as to guide the materials on the first material guiding plate 25 to the upper special-meter sieve layer along the first material guiding groove 41, and the second material guiding groove 42 is used for communicating the first material guiding plate 25 with the lower special-meter sieve layer so as to guide the materials on the first material guiding plate 25 to the lower special-meter sieve layer along the second material guiding groove 42. It will be appreciated that the side wall of the frame 10 adjacent the feed side of the pre-screening screen 21 is provided with a front door 40 for enclosing the opening to prevent material from spilling out of the opening when the screening mechanism 20 is in operation. Through the parallelly connected screening subassembly structure that the micron sieve 22 adopted two layers of micron sieve layer to constitute, can realize not increasing sifting surface length and width, under the minimum condition of altitude variation, make the handling capacity of white rice classifying screen increase at double, can satisfy the requirement that equipment is upsized, and, when door plant 40 is used for compressing tightly the screening mechanism 20 of locating in framework 10 before setting up, set up first material guiding groove 41 and second material guiding groove 42 on the lateral wall of door plant 40 in the front, be convenient for distribute the material on trickling flitch 30 to two-layer micron sieve layer simultaneously, be favorable to the increase of output, the work efficiency of screening mechanism 20 has been guaranteed. Optionally, in this embodiment, the front door panel 40 has a double-layer panel structure, the bottom surface of the first material guiding groove 41 is arranged in a vertically downward inclined manner, the lower slope surface of the first material guiding groove 41 is arranged flush with the surface of the upper super-micrometer sieve layer, and the material automatically slides onto the upper super-micrometer sieve layer after entering the first material guiding groove 41 from the material dripping plate 30; the bottom surface of the second material guide groove 42 is arranged along the vertical downward inclination, the downward slope surface of the second material guide groove 42 is arranged flush with the surface of the lower-layer special-meter sieve layer, and the materials automatically slide onto the lower-layer special-meter sieve layer after entering the second material guide groove 42 from the material dripping plate 30. The material distributing mode of the two parallel-connected special meter sieve layers adopts the mutually independent guide mode to respectively guide in the materials uniformly distributed by the material flowing plate 30, so that the mutual interference during the material feeding is avoided.

Specifically, an input port of the first material guide groove 41 is communicated with an output side of the first material guide plate 25, and an output port of the first material guide groove 41 is communicated with an input side of the upper-layer super sieve layer; the input port of second material guide groove 42 communicates with the output side of first material guide plate 25, and the delivery outlet of first material guide groove 41 communicates to the input side of lower floor's special meter sieve layer, and then conveys the material of first material guide plate 25 simultaneously to upper special meter sieve layer and lower floor's special meter sieve layer through first material guide groove 41 and second material guide groove 42 and screens.

Preferably, in order to facilitate the observation of the screening mechanism 20 from the outside of the frame 10 and the maintenance when the screen layer of the screening mechanism 20 is clogged, one side of the front door panel 40 is hinged to the side wall of the frame 10, and the other side of the front door panel 40 is connected to the side wall of the frame 10 in a snap-fit manner.

Further, the number of the first material guide grooves 41 is plural, the plural first material guide grooves 41 are arranged at intervals along the length direction of the front door panel 40, the second material guide grooves 42 are arranged between two adjacent first material guide grooves 41, and the sum total of the groove widths of all the second material guide grooves 42 is equal to the sum total of the groove widths of all the first material guide grooves 41. The sum total value of the groove widths of the first material guide groove 41 and the second material guide groove 42 is controlled to be the same, so that the amount of materials entering the first material guide groove 41 and the second material guide groove 42 is the same, the feeding of the upper layer of the specially-sized sieve layer and the feeding of the lower layer of the specially-sized sieve layer are the same, the parallel connection of two layers of materials is guaranteed to be uniformly distributed and controlled to be in the same thickness, and the material screening device 100 achieves the best screening effect and improves the screening yield.

Further, referring to fig. 4 and 5, a third material guide plate 27 for guiding undersize of the lower layer of the super-sieve layer to the feeding side of the ordinary rice sieve 23 is disposed between the lower layer of the super-sieve layer and the ordinary rice sieve 23, the output side of the third material guide plate 27 is disposed obliquely downward, an output frame plate 50 having a conveying cavity is disposed on the side wall of the frame 10 adjacent to the front door plate 40, the input ports of the output frame plate 50 are respectively communicated with the output side of the second material guide plate 26 and the output side of the third material guide plate 27, the output port of the output frame plate 50 is communicated to the ordinary rice sieve 23, and further, the undersize formed by the screening of the upper layer of the super-sieve layer and the undersize formed by the screening of the lower layer of the super-sieve layer are simultaneously input to the ordinary rice sieve 23 through the output frame plate 50 for the next screening. And undersize materials on the upper layer of the special-meter sieve layer are prevented from entering the lower layer of the special-meter sieve layer again for repeated screening, and the screening yield is further improved. It will be appreciated that the conveying cavities of the output frame 50 include a material guiding cavity disposed obliquely downwards in the direction of the feed side of the screening means 20 towards the discharge side, a vertically disposed guiding cavity, and a material discharging cavity disposed obliquely upwards in the direction of the feed side of the screening means 20 towards the discharge side.

Further, general rice sieve 23 includes first meter sieve layer and the second meter sieve layer of following vertical interval and laying, and the undersize thing that the downside on first meter sieve layer was located in the second meter sieve layer in order to carry out further screening to the undersize thing that first meter sieve layer screening formed, and the undersize thing on upper specially meter sieve layer and the undersize thing on lower floor specially meter sieve layer are leading-in respectively to first meter sieve layer on.

It can be understood that, in this embodiment, the first meter sieve layer is a whole meter sieve layer, and for convenience of packing, the top meter sieve layer forms the whole meter after being sieved, the bottom meter sieve layer forms the whole meter after being sieved, and the whole meter sieve layer forms the whole meter after being sieved, are collected by the same collecting hopper. Specifically, oversize materials of the upper-layer special-meter sieve layer, the lower-layer special-meter sieve layer and the first-meter sieve layer are whole meters and are collected through a collecting hopper, oversize materials of the second-meter sieve layer are ordinary meters, oversize materials of the broken-meter sieve layer are large broken meters, and undersize materials are broken meters.

Further, the crushed rice screening mechanism 20 further includes an aggregate plate 28 provided on a lower side of the crushed rice screen 24 for guiding and discharging undersize formed by screening of the crushed rice screen 24, and an output side of the aggregate plate 28 is disposed to be inclined downward.

The utility model discloses a during material screening plant 100 during operation, material screening plant 100 is plane rotary motion under actuating mechanism's drive, the material gets into the input side of trickling flitch 30 through defeated material mouth, the material is at the in-process that moves to the output side of trickling flitch 30 from the input side of trickling flitch 30, because trickling flitch 30 is plane rotary motion along framework 10 and makes the material follow horizontal evenly distributed on trickling flitch 30, evenly distributed is at the discharge side of trickling flitch 30 on the material of trickling flitch 30 along transversely getting into screening mechanism 20 and carrying out the multilayer screening uniformly.

It can be understood that the screening mechanism 20 of the present invention includes six screening layers, and when the screening is performed in the screening mechanism 20, the pre-selection screen layer on the first layer is used for screening bran dough, oversize materials are discharged from a bran dough hopper, undersize materials flow into a first material guide groove 41 and a second material guide groove 42 of a front door plate 40 through a bottom flowing plate, materials uniformly enter a special meter sieve layer on the upper layer of a second sieve layer and a special meter sieve layer on the lower layer of a third sieve layer through a front door plate 40, undersize materials of the second sieve layer and the third sieve layer simultaneously enter a first meter sieve layer on the fourth sieve layer, the oversize materials and oversize materials of the fourth sieve layer flow into a whole meter hopper together, undersize materials of the fourth sieve layer flow onto a second meter sieve layer on the fifth sieve layer, oversize materials of the fifth sieve layer flow out of a common meter hopper, undersize materials enter a sixth sieve layer, oversize materials of the sixth sieve layer enter a large broken meter hopper, and undersize materials enter a small broken meter hopper; because the southern bran dough is less and the bran dough does not need to be sieved, one layer of sieve layer can be changed into a sieve plate with the diameter of phi 5-6, the bran dough opening is changed into a whole rice opening, and the rest sieve layers are unchanged, so that the yield is greatly increased, and the requirement of customers in the southern area on large yield can be met.

The utility model also provides a rice sieve, including foretell material screening plant 100 with be used for driving the 100 horizontal rotary motion of material screening plant with the drive arrangement who sieves the rice in the material screening plant 100.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A material screening device comprises a frame body (10) with a material conveying opening at the top and a screening mechanism (20) arranged in the frame body (10), wherein the screening mechanism (20) is used for screening materials according to the particle sizes of the materials,

the frame body (10) comprises a frame with an opening on the side surface, a front door plate (40) and a rear door plate which are oppositely arranged on the side wall of the frame and used for pressing the opening of the frame, the screening mechanism (20) is arranged on the frame,

the front door panel (40) is detachably arranged on the front side wall of the frame, and the rear door panel is detachably arranged on the rear side wall of the frame.

2. A material screening apparatus according to claim 1,

the screening mechanism (20) comprises a pre-screening sieve (21), a special rice sieve (22), a common rice sieve (23) and a broken rice sieve (24) which are sequentially arranged at intervals from top to bottom,

the material screening device also comprises a material dripping plate (30) which is obliquely arranged between the material conveying port and the pre-screening sieve (21) and is used for uniformly distributing the materials input from the material conveying port and then guiding the materials to the feeding side of the pre-screening sieve (21), the output side of the material dripping plate (30) is obliquely and downwards arranged along the rear side of the frame towards the front side,

a first material guide plate (25) used for guiding undersize materials screened by the pre-screening sieve (21) to the feeding side of the special sieve (22) is arranged between the special sieve (22) and the pre-screening sieve (21).

3. A material screening apparatus according to claim 2,

the special-meter sieve (22) is composed of two special-meter sieve layers with the same sieve pore diameter which are arranged at intervals along the vertical direction, the first material guide plate (25) is arranged between the upper special-meter sieve layer and the pre-selection sieve (21), the second material guide plate (26) for guiding undersize materials formed by screening the upper special-meter sieve layer is arranged between the upper special-meter sieve layer and the lower special-meter sieve layer,

undersize of the upper layer of the special rice sieve layer and undersize of the lower layer of the special rice sieve layer are respectively led onto the common rice sieve (23).

4. A material screening apparatus according to claim 3,

the front door plate (40) is used for preventing materials from splashing out of the front side of the frame body when the screening mechanism (20) works, a first material guide groove (41) and a second material guide groove (42) are arranged on the front door plate,

the first material guiding groove (41) is used for communicating the first material guiding plate (25) with the upper-layer special-meter sieve layer so as to lead the material on the first material guiding plate (25) to the upper-layer special-meter sieve layer along the first material guiding groove (41),

the second material guide groove (42) is used for communicating the first material guide plate (25) with the lower layer and enabling the materials on the first material guide plate (25) to be guided to the lower layer along the second material guide groove (42) on the special meter sieve layer.

5. A material screening apparatus according to claim 4,

the number of the first material guide grooves (41) is multiple, the first material guide grooves (41) are distributed at intervals along the length direction of the front door panel (40), the second material guide groove (42) is arranged between every two adjacent first material guide grooves (41),

the sum of the groove widths of all the second material guiding grooves (42) is equal to the sum of the groove widths of all the first material guiding grooves (41).

6. A material screening apparatus according to claim 5,

a third material guide plate (27) used for guiding undersize of the lower-layer special-rice sieve layer to the feeding side of the general rice sieve (23) is arranged between the lower-layer special-rice sieve layer and the general rice sieve (23), and the output side of the third material guide plate (27) is obliquely arranged downwards.

7. A material screening apparatus according to claim 6,

an output frame plate (50) with a conveying cavity is arranged on the side wall, adjacent to the front door plate (40), of the frame body (10), the input port of the output frame plate (50) is communicated with the output side of the second material guide plate (26) and the output side of the third material guide plate (27) respectively, the output port of the output frame plate (50) is communicated to the common rice sieve (23), and then undersize formed by screening of the upper special rice sieve layer and undersize formed by screening of the lower special rice sieve layer are simultaneously input to the common rice sieve (23) through the output frame plate (50) so as to carry out next screening.

8. A material screening apparatus according to claim 3,

the common rice sieve (23) comprises a first rice sieve layer and a second rice sieve layer which are arranged at intervals along the vertical direction, the second rice sieve layer is arranged at the lower side of the first rice sieve layer so as to further sieve undersize materials formed by sieving the first rice sieve layer,

and undersize of the upper layer of the specially-sized sieve layer and undersize of the lower layer of the specially-sized sieve layer are respectively guided to the first meter sieve layer.

9. A material screening apparatus according to claim 3,

the screening mechanism (20) further comprises a material collecting plate (28) which is arranged on the lower side of the rice crushing sieve (24) and used for guiding and outputting undersize materials formed by screening the rice crushing sieve (24), and the output side of the material collecting plate (28) is obliquely arranged downwards.

10. A rice sieve, which is characterized in that,

the material screening device comprises the material screening device as claimed in any one of claims 1 to 9, and a driving device for driving the material screening device to enable the material screening device to horizontally rotate to screen materials on the material screening device.