Porous screening device for rice grains

Abstract

The invention relates to the technical field of rice grain screening, in particular to a porous screening device for rice grains, which comprises an adjustable screening component set, an outer rack component set is arranged outside the adjustable screening component set, the outer rack component set is used for fixing the adjustable screening component set, the adjustable screening component set comprises an upper screening plate, and screening holes are formed in the upper screening plate. The distance between the upper sieve plate and the lower sieve plate can be accurately controlled, so that the extending length of the conical column is adjusted, the opening size of the sieve holes is adjustable, the adjusting operation is simple, the adjusting efficiency is ensured, and the practicability is very high; blockage cleaning of the screen holes in the screen plate is automatically completed, manual complicated blocked screen hole cleaning work is not needed, and the usability of the whole screening device is improved.

Description

Technical Field

[0001] The invention relates to the technical field of rice grain screening, in particular to a porous screening device for rice grains. Background Art

[0002] A rice grain sifter is a device used to sift and sort rice or other grains. It is often used in rice processing to remove impurities, broken rice, stones and other unwanted materials to ensure the quality of the final product. The working principle of the sifter is usually to vibrate so that larger particles remain on the screen, while smaller particles will pass through the screen and be separated.

[0003] In the vibration screening of the prior art, grains with a size similar to that of the sieve holes are easily stuck in the sieve holes during the screening vibration, forming blockages, resulting in reduced screening efficiency. Currently, the blockages are manually pounded out of the sieve holes. For a large number of sieve holes on the sieve, this maintenance method is inefficient, time-consuming and labor-intensive, and increases the equipment downtime for maintenance. When screening rice and grain materials of different sizes, the existing screening device needs to replace the sieve plate with a suitable sieve hole size to ensure the accuracy of the screening. However, the replacement work requires the disassembly of the sieve plate and the main frame of the screening machine, and the replacement takes a long time. In addition, in order to meet different screening grain needs, it is necessary to reserve sieve plates of various sizes, which increases unnecessary usage costs. Summary of the invention

[0004] In order to overcome the above-mentioned technical problems, the purpose of the present invention is to provide a porous screening device for rice grains, so as to solve the problem that in the vibration screening of the prior art proposed in the above-mentioned background technology, grains with a size similar to the sieve holes are easily stuck in the sieve holes during the screening vibration and form blockages, resulting in reduced screening efficiency. At present, the blockages are manually pounded out of the sieve holes. For a large number of sieve holes on the screen, this maintenance method is inefficient, time-consuming and labor-intensive, and increases the problem of equipment downtime maintenance time.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a porous screening device for rice grains, comprising: an adjustable screening component group, the adjustable screening component group is used to screen rice grains, an outer frame component group is arranged outside the adjustable screening component group, and the outer frame component group is used to fix the adjustable screening component group, the adjustable screening component group comprises an upper sieve plate, the upper sieve plate is provided with sieve holes, the bottom of the upper sieve plate is provided with a lower sieve plate and a conical column, the side of the upper sieve plate is provided with a side long plate, one side of the side long plate is provided with a back plate member, the other side of the side long plate is provided with a front plate mouth, the bottom of the front plate mouth is provided with a lower frame shell, the lower frame shell is connected to a short corrugated plate, an upper plate is connected between the front plate mouth and the back plate member, A threaded rod and a guide rod are provided inside the upper plate, and a lower plate is provided at the bottom of the upper plate; the outer frame component group includes a frame plate, the bottom of the frame plate is connected to a bottom plate, a bottom collecting bucket and a long corrugated plate are provided inside the frame plate, a vibration isolation spring is provided at the bottom of the bottom plate, a frame base is provided at one end of the vibration isolation spring, and a vibration motor is connected to the bottom of the bottom plate; an adjustable feeding component group is provided on one side of the adjustable screening component group, the adjustable feeding component group is used to guide the feeding of rice grains, the adjustable feeding component group includes a feeding trough, a convex plate is connected to the side of the feeding trough, the convex plate is connected to a fixed shaft, the fixed shaft is connected to a limiting sleeve through a threaded connection, and a guide mouth is provided on the side of the limiting sleeve.

[0006] Preferably: the adjustable screening component groups are provided in two groups, and the two groups of adjustable screening component groups are distributed up and down in the outer frame component group, the conical columns are provided in plurality, and the plurality of conical columns are evenly distributed on the lower screen plate, the conical columns are connected to the lower screen plate, the upper screen plate is provided with sieve holes at positions corresponding to the plurality of conical columns, the conical columns can pass through the sieve holes, and the top surface diameter of the conical columns is smaller than the bottom surface diameter.

[0007] Preferably: there are two side long plates, the back plate part is connected between the two side long plates, the front plate mouth is connected between the two side long plates, the two sides of the upper sieve plate are connected to the side long plates, and the other two sides of the upper sieve plate are respectively connected to the front plate mouth and the back plate part, the lower frame shell is provided with a through groove corresponding to the lower sieve plate, and the lower frame shell is connected to the lower sieve plate through the through groove, there are two short corrugated plates, and the two short corrugated plates are distributed on both sides of the lower sieve plate, one of the short corrugated plates is connected between the front plate mouth and the lower frame shell, and the other short corrugated plate is connected between the back plate part and the lower frame shell, the upper plate is connected between the back plate part and the front plate mouth, and the lower plate is connected to the lower frame shell, one end of the threaded rod is connected to the lower plate through a rotating shaft, the threaded rod is connected to the upper plate through a thread, one end of the guide rod is connected to the lower plate, and the guide rod is in sliding contact with the upper plate through a through hole.

[0008] Preferably: the bottom of the bottom plate is in contact with the bottom collecting bucket, two long corrugated plates are provided, the two long corrugated plates are symmetrically distributed on both sides of the adjustable screening component group, the long corrugated plates are connected between two lower frame shells, the vibration isolation spring is connected between the bottom collecting bucket and the frame base, and the frame base is used to contact the ground.

[0009] Preferably, the vibration motor is connected to the bottom of the bottom collecting bucket, and the outside of the vibration motor is connected to a power supply battery.

[0010] Preferably: there are three adjustable feeding component groups, and the three adjustable feeding component groups are respectively installed on the sides of the bottom collecting bucket and the two front plate mouths, and there are two convex plates and fixed axes, and the two convex plates and fixed axes are symmetrically distributed on both sides of the feeding trough.

[0011] Preferably, the side of the material discharge chute is provided with an opening, and the convex plate is connected to the bottom of the material discharge chute.

[0012] Preferably, the guide nozzle is in rotational contact with the fixed axis through the through hole, and the guide nozzle is clamped between the limiting sleeve and the convex plate.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. The threaded rod in the adjustable screening component group is adjusted to accurately control the distance between the upper screen plate and the lower screen plate, thereby adjusting the extension length of the conical column. This design makes the opening size of the screen hole adjustable, the adjustment operation is simple, and it can screen grains of various sizes while ensuring the adjustment efficiency, which is very practical;

[0015] 2. After the screening is completed, the upper and lower sieve plates fit perfectly together, so that the conical column can completely pass through the sieve holes and push out the blocked grains to achieve the purpose of cleaning the sieve holes. This design does not require manual cleaning of the blocked sieve holes in actual use, which reduces labor costs and improves the efficiency of cleaning the sieve holes;

[0016] 3. The design of the adjustable unloading component group allows adjustment according to different collection container heights, which improves the unloading flexibility and applicability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 It is a structural schematic diagram of the overall bottom of the present invention;

[0019] Figure 3 It is a structural schematic diagram of the adjustable screening component group of the present invention;

[0020] Figure 4 It is a structural schematic diagram of the bottom part of the adjustable screening component group of the present invention;

[0021] Figure 5 It is a schematic structural diagram of a cross-section of an adjustable screening component assembly of the present invention;

[0022] Figure 6 It is a schematic diagram of the exploded structure of the adjustable screening component assembly of the present invention;

[0023] Figure 7 It is a structural schematic diagram of the upper sieve plate and the lower sieve plate of the present invention;

[0024] Figure 8 It is a structural schematic diagram of a partial cross-section of the upper sieve plate and the lower sieve plate of the present invention;

[0025] Fig. 9 For the present invention Figure 8 The structural diagram at A in the middle;

[0026] Fig.10 It is a schematic structural diagram of the lower screen plate and the conical column part of the present invention;

[0027] Fig.11 For the present invention Fig.10 The structural diagram at B in the middle;

[0028] Fig.12 It is a structural schematic diagram of the outer frame component assembly part of the present invention;

[0029] Fig.13 It is a structural schematic diagram of the bottom part of the outer frame component assembly of the present invention;

[0030] Fig.14 It is a structural schematic diagram of the bottom collecting bucket part of the present invention;

[0031] Fig.15 It is a structural schematic diagram of the adjustable blanking component assembly of the present invention;

[0032] Fig.16 It is a structural schematic diagram of the front part of the adjustable blanking component assembly of the present invention;

[0033] Fig.17 It is a schematic diagram of the structure at C in the back panel of the present invention.

[0034] In the figure: 01, adjustable screening component group; 11, upper screen plate; 12, screen hole; 13, lower screen plate; 14, conical column; 15, side long plate; 16, back plate; 17, front plate mouth; 18, lower frame shell; 19, short corrugated plate; 110, upper plate; 111, lower plate; 112, threaded rod; 113, guide rod; 02, outer frame component group; 21, frame plate; 22, bottom plate; 23, bottom collecting bucket; 24, long corrugated plate; 25, vibration isolation spring; 26, frame base; 27, vibration motor; 03, adjustable unloading component group; 31, unloading chute; 32, convex plate; 33, fixed axis; 34, limit sleeve; 35, guide mouth. DETAILED DESCRIPTION

[0035] 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 creative work are within the scope of protection of the present invention.

[0036] See also Figure 1-17 An embodiment of the present invention is a porous screening device for rice grains, comprising: an adjustable screening component group 01, the adjustable screening component group 01 is used to screen rice grains, an outer frame component group 02 is arranged outside the adjustable screening component group 01, and the outer frame component group 02 is used to fix the adjustable screening component group 01, the adjustable screening component group 01 comprises an upper sieve plate 11, the upper sieve plate 11 is provided with sieve holes 12, the bottom of the upper sieve plate 11 is provided with a lower sieve plate 13 and a conical column 14, the side of the upper sieve plate 11 is provided with a side long plate 15, one side of the side long plate 15 is provided with a back plate 16, the other side of the side long plate 15 is provided with a front plate mouth 17, the bottom of the front plate mouth 17 is provided with a lower frame shell 18, the lower frame shell 18 is connected to a short corrugated plate 19, an upper plate 110 is connected between the front plate mouth 17 and the back plate 16, and the interior of the upper plate 110 A threaded rod 112 and a guide rod 113 are provided, and a lower plate 111 is provided at the bottom of the upper plate 110; the outer frame component group 02 includes a frame plate 21, the bottom of the frame plate 21 is connected to a bottom plate 22, the interior of the frame plate 21 is provided with a bottom collecting bucket 23 and a long corrugated plate 24, the bottom of the bottom plate 22 is provided with a vibration isolation spring 25, one end of the vibration isolation spring 25 is provided with a frame base 26, and the bottom of the bottom plate 22 is connected to a vibration motor 27; an adjustable feeding component group 03 is provided on one side of the adjustable screening component group 01, and the adjustable feeding component group 03 is used to guide the feeding of rice grains, and the adjustable feeding component group 03 includes a feeding trough 31, and the side of the feeding trough 31 is connected to a convex plate 32, and the convex plate 32 is connected to a fixed shaft 33, and the fixed shaft 33 is connected to a limiting sleeve 34 through a threaded connection, and the side of the limiting sleeve 34 is provided with a guide mouth 35.

[0037] There are two groups of adjustable screening component groups 01, and the two groups of adjustable screening component groups 01 are distributed up and down in the outer frame component group 02. There are multiple conical columns 14, and the multiple conical columns 14 are evenly distributed on the lower screen plate 13. The conical columns 14 are connected to the lower screen plate 13. The upper screen plate 11 is provided with sieve holes 12 at positions corresponding to the multiple conical columns 14. The conical columns 14 can pass through the sieve holes 12, and the top surface diameter of the conical columns 14 is smaller than the bottom surface diameter.

[0038] Two side long plates 15 are provided, a back plate 16 is connected between the two side long plates 15, a front plate mouth 17 is connected between the two side long plates 15, two sides of the upper sieve plate 11 are connected to the side long plates 15, and the other two sides of the upper sieve plate 11 are respectively connected to the front plate mouth 17 and the back plate 16, a lower frame shell 18 is provided with a through groove corresponding to the lower sieve plate 13, and the lower frame shell 18 is connected to the lower sieve plate 13 through the through groove, and two short corrugated plates 19 are provided, and the two short corrugated plates 19 are distributed on both sides of the lower sieve plate 13, and one short corrugated plate 19 is connected between the front plate mouth 17 and the lower frame shell 18, another short corrugated plate 19 is connected between the back plate part 16 and the lower frame shell 18, the upper plate 110 is connected between the back plate part 16 and the front plate mouth 17, the lower plate 111 is connected to the lower frame shell 18, one end of the threaded rod 112 is connected to the lower plate 111 through a rotating shaft, the threaded rod 112 is connected to the upper plate 110 through a thread, one end of the guide rod 113 is connected to the lower plate 111, and the guide rod 113 is in sliding contact with the upper plate 110 through a through hole.

[0039] The bottom of the bottom plate 22 is in contact with the bottom collecting bucket 23. Two long corrugated plates 24 are provided. The two long corrugated plates 24 are symmetrically distributed on both sides of the adjustable screening component group 01. The long corrugated plates 24 are connected between the two lower frame shells 18. The vibration isolation spring 25 is connected between the bottom collecting bucket 23 and the frame base 26. The frame base 26 is used to contact the ground. The connection between the lower screen plate 13 and the through groove of the lower frame shell 18 is specifically as follows: the short sides on the left and right sides of the lower screen plate 13 are as follows: Fig.10 The position shown is connected to the lower frame shell 18 through a through groove, and the long sides on the upper and lower sides of the lower screen plate 13 are not connected to the through groove of the lower frame shell 18, and the two long sides and the through groove of the lower frame shell 18 are three centimeters apart. When grains fall on the lower screen plate 13, they will fall to the bottom from the space between the long sides on both sides of the lower screen plate 13 and the through groove of the lower frame shell 18 due to vibration.

[0040] The vibration motor 27 is connected to the bottom of the bottom collecting bucket 23, and the outside of the vibration motor 27 is connected to a power supply battery.

[0041] There are three adjustable feeding component groups 03, and the three adjustable feeding component groups 03 are respectively installed on the sides of the bottom collecting bucket 23 and the two front plate mouths 17, there are two convex plates 32 and fixed shafts 33, and the two convex plates 32 and fixed shafts 33 are symmetrically distributed on both sides of the feeding trough 31.

[0042] An opening is provided on the side of the material discharge chute 31 , and a convex plate 32 is connected to the bottom of the material discharge chute 31 .

[0043] The guide nozzle 35 is in rotational contact with the fixed shaft 33 through the through hole, and the guide nozzle 35 is clamped between the limiting sleeve 34 and the convex plate 32 .

[0044] Working principle: When using the device to screen rice grains, first adjust the two groups of adjustable screening component groups 01 according to the screening needs of the grains. When adjusting, you only need to control the threaded rod 112 in the adjustable screening component group 01 to rotate. The rotation of the threaded rod 112 will drive the upper plate 110 to move up and down on the upper plate 110 through the thread, and then drive the upper screen plate 11 to move. Through this movement, the length of the conical column 14 extending out of the screen hole 12 can be adjusted. When the distance between the upper screen plate 11 and the lower screen plate 13 is small, the length of the conical column 14 extending out of the screen hole 12 is The conical column 14 is a cone-shaped structure, and will block most of the space of the sieve hole 12. Large grains of grain cannot pass through the sieve hole 12 and fall onto the lower sieve plate 13. When the distance between the upper sieve plate 11 and the lower sieve plate 13 is large, the conical column 14 extends out of the sieve hole 12 less, and the conical column 14 will block a small part of the space of the sieve hole 12. At this time, large grains of grain can pass through the sieve hole 12 and fall onto the lower sieve plate 13, and then can fall down through the two sides of the lower sieve plate 13. After adjusting the distance between the upper sieve plate 11 and the lower sieve plate 13 in the adjustable screening component group 01 on both sides;

[0045] Pour the rice grains that need to be screened onto the top layer of adjustable screening component group 01. With the start of the front plate mouth 17, the two layers of adjustable screening component group 01, the adjustable feeding component group 03 and the upper part of the outer frame component group 02 will vibrate. The vibration will make the rice grains screened in the adjustable screening component groups 01 on both sides. The large grains in the uppermost adjustable screening component group 01 will not be able to pass through the sieve hole 12, but will only move to the position of the front plate mouth 17 with the vibration, and enter from the side opening of the feeding trough 31 in the adjustable feeding component group 03 with the vibration, and be discharged into the external collection sack or other collection structure along the feeding trough 31 and the guide mouth 35. At this time, the screened rice grains are of the largest volume, and the remaining grains will pass through The rice grains pass through the sieve holes 12 and fall onto the lower sieve plate 13, and then fall into the second layer of adjustable screening component group 01 below from the long sides of the lower sieve plate 13 and the through grooves of the lower frame shell 18. At this time, the rice grains are screened by the second layer of adjustable screening component group 01. The medium-sized grains cannot pass through the sieve holes 12 of the second layer, and then move along the upper sieve plate 11 to the front plate mouth 17 and are discharged to the external collection device through the adjustable unloading component group 03. The remaining rice grains pass through the sieve holes 12 and enter the lower sieve plate 13, and then continue to fall. At this time, the rice grains are small-volume grains or impurities, and fall into the bottom collecting bucket 23, and are discharged to the external collection container through the adjustable unloading component group 03 installed on the side of the bottom collecting bucket 23.

[0046] After the overall screening is completed, the upper sieve plate 11 in the two adjustable screening component groups 01 is completely fitted with the lower sieve plate 13. At this time, the conical column 14 will completely pass through the sieve hole 12. The diameter of the bottom surface of the conical column 14 is the same as the diameter of the sieve hole 12. The conical column 14 can push out the rice grains that may be blocked in the sieve hole 12, thereby achieving the purpose of clearing the blockage in the sieve hole 12.

[0047] The vibration isolation spring 25 is used to reduce the vibration transmitted to the frame base 26 by the vibration motor 27 to ensure the stability of the placement of the entire device. The limit sleeve 34 in the adjustable feeding component group 03 is rotated so that the limit sleeve 34 does not contact the guide nozzle 35. The angle of the guide nozzle 35 can be adjusted. After adjusting to a suitable angle, the limit sleeve 34 is reversed to make it fit on the side of the guide nozzle 35. The position of the guide nozzle 35 is fixed by friction contact. This design can adapt to collection containers, collection mechanisms, etc. at different heights, so that the screened rice grains can be fed into them.

[0048] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A porous screening device for rice grains, characterized in that: include: An adjustable screening component group (01) is used for screening rice grains. An external frame component group (02) is arranged outside the adjustable screening component group (01). The external frame component group (02) is used to fix the adjustable screening component group (01). The adjustable screening component group (01) comprises an upper screen plate (11). The upper screen plate (11) is provided with screen holes (12). A lower screen plate (13) and a conical column (14) are arranged at the bottom of the upper screen plate (11). The side of the upper screen plate (11) is provided with a side length A plate (15), a back plate (16) is arranged on one side of the side long plate (15), a front plate mouth (17) is arranged on the other side of the side long plate (15), a lower frame shell (18) is arranged at the bottom of the front plate mouth (17), a short corrugated plate (19) is connected to the lower frame shell (18), an upper plate (110) is connected between the front plate mouth (17) and the back plate (16), a threaded rod (112) and a guide rod (113) are arranged inside the upper plate (110), and a lower plate (111) is arranged at the bottom of the upper plate (110); The outer frame component group (02) comprises a frame plate (21), the bottom of the frame plate (21) is connected to a bottom plate (22), a bottom collecting bucket (23) and a long corrugated plate (24) are arranged inside the frame plate (21), a vibration isolation spring (25) is arranged at the bottom of the bottom plate (22), one end of the vibration isolation spring (25) is provided with a frame base (26), and the bottom of the bottom plate (22) is connected to a vibration motor (27); An adjustable feeding component group (03) is provided on one side of the adjustable screening component group (01), and the adjustable feeding component group (03) is used to guide the feeding of rice grains, and the adjustable feeding component group (03) comprises a feeding trough (31), a convex plate (32) is connected to the side of the feeding trough (31), the convex plate (32) is connected to a fixed shaft (33), the fixed shaft (33) is connected to a limiting sleeve (34) through a threaded connection, and a guide nozzle (35) is provided on the side of the limiting sleeve (34).

2. A porous screening device for rice grains according to claim 1, characterized in that: The adjustable screening component groups (01) are provided in two groups, and the two groups of adjustable screening component groups (01) are distributed in the upper and lower parts of the outer frame component group (02); a plurality of conical columns (14) are provided, and the plurality of conical columns (14) are evenly distributed on the lower screen plate (13); the conical columns (14) and the lower screen plate (13) are connected; the upper screen plate (11) is provided with screen holes (12) at positions corresponding to the plurality of conical columns (14); the conical columns (14) can pass through the screen holes (12); and the top surface diameter of the conical columns (14) is smaller than the bottom surface diameter.

3. A porous screening device for rice grains according to claim 1, characterized in that: The side long plates (15) are provided with two, the back plate member (16) is connected between the two side long plates (15), the front plate mouth (17) is connected between the two side long plates (15), the two sides of the upper sieve plate (11) are connected to the side long plates (15), the other two sides of the upper sieve plate (11) are respectively connected to the front plate mouth (17) and the back plate member (16), the lower frame shell (18) is provided with a through groove corresponding to the lower sieve plate (13), and the lower frame shell (18) is connected to the lower sieve plate (13) through the through groove, the short corrugated plates (19) are provided with two, and the two short corrugated plates (19) are distributed on both sides of the lower sieve plate (13), one of the short corrugated plates (19) 19) is connected between the front plate mouth (17) and the lower frame shell (18), another short corrugated plate (19) is connected between the back plate part (16) and the lower frame shell (18), the upper plate (110) is connected between the back plate part (16) and the front plate mouth (17), the lower plate (111) is connected to the lower frame shell (18), one end of the threaded rod (112) is connected to the lower plate (111) through a rotating shaft, the threaded rod (112) is connected to the upper plate (110) through a thread, one end of the guide rod (113) is connected to the lower plate (111), and the guide rod (113) is in sliding contact with the upper plate (110) through a through hole.

4. A porous screening device for rice grains according to claim 1, characterized in that: The bottom of the bottom plate (22) contacts the bottom collecting bucket (23), two long corrugated plates (24) are provided, and the two long corrugated plates (24) are symmetrically distributed on both sides of the adjustable screening component group (01), the long corrugated plates (24) are connected between the two lower frame shells (18), the vibration isolation spring (25) is connected between the bottom collecting bucket (23) and the frame base (26), and the frame base (26) is used to contact the ground.

5. A porous screening device for rice grains according to claim 1, characterized in that: The vibration motor (27) is connected to the bottom of the bottom collecting bucket (23), and the outside of the vibration motor (27) is connected to a power supply battery.

6. A porous screening device for rice grains according to claim 1, characterized in that: There are three adjustable material discharge component groups (03), and the three adjustable material discharge component groups (03) are respectively installed on the sides of the bottom collecting bucket (23) and the two front plate nozzles (17); there are two convex plates (32) and fixed shafts (33), and the two convex plates (32) and fixed shafts (33) are symmetrically distributed on both sides of the material discharge trough (31).

7. A porous screening device for rice grains according to claim 1, characterized in that: The side of the material discharge chute (31) is provided with an opening, and the convex plate (32) is connected to the bottom of the material discharge chute (31).

8. A porous screening device for rice grains according to claim 1, characterized in that: The guide nozzle (35) is in rotational contact with the fixed shaft (33) through the through hole, and the guide nozzle (35) is clamped between the limiting sleeve (34) and the convex plate (32).

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