CN108722870B

CN108722870B - Screening machine and screening equipment

Info

Publication number: CN108722870B
Application number: CN201810345884.2A
Authority: CN
Inventors: 刘占鑫
Original assignee: Zhangye Academy Of Agricultural Sciences
Current assignee: Zhangye Academy Of Agricultural Sciences
Priority date: 2018-04-17
Filing date: 2018-04-17
Publication date: 2021-01-15
Anticipated expiration: 2038-04-17
Also published as: CN108722870A

Abstract

The invention provides a screening machine and screening equipment, and relates to the technical field of screening devices. The screening machine comprises a constant-speed feeding device, a seed screening device, an impurity screening device and a support frame; the uniform-speed feeding device is connected with the seed screening device, and a discharge port of the uniform-speed feeding device corresponds to a feeding port of the seed screening device; the impurity screening device is sleeved outside the seed screening device; the support frame includes first support and second support, and impurity screening plant connects on first support, and the outside at first support is established to the second support cover, connects through the connecting rod between first support and the second support. The problems that the seed raw materials are screened by adopting the fine screening equipment driven by the motor, the equipment investment cost is high, the screened seeds can not meet the requirements, and the occupied area is large are solved. The constant-speed feeding device is used for feeding the seeds at a constant speed by the seed screening device, screening the seeds by the seed screening device, and screening impurities by the impurity screening device, and has the advantages of small occupied area and convenience in installation.

Description

Screening machine and screening equipment

Technical Field

The invention relates to the technical field of screening devices, in particular to a screening machine and screening equipment.

Background

In the agricultural field, after the seeds of crops are collected, the seeds need to be processed and treated to be put on the market for sale. Seed material often contains some impurities, such as: rough grass, shrubber, etc., which need to be distinguished from seeds during processing and treatment in order to screen seeds of good quality.

Among the above-mentioned prior art, when screening seed raw materials, main artifical screening, people use the sieve to carry out first screening back to the impurity in the seed raw materials, need many times inspection, just can select high-quality seed, adopt the mode of artifical screening, can be accurate select out impurity, the seed quality after the screening is very good, but, the mode of adopting artifical screening need consume a large amount of operating time.

Therefore, people adopt the fine selection equipment driven by the motor to screen the seed raw materials, and although the screening time is prolonged by adopting the mode, the investment cost of the equipment is high, the later maintenance cost is high, the power consumption of the equipment is high, the occupied area is large, and the operation is laborious; and the screened seeds contain more small particle impurities, so that the seeds cannot be accurately screened.

Disclosure of Invention

The invention aims to provide a screening machine to solve the technical problems that in the prior art, a screening device driven by a motor is adopted to screen seed raw materials, the investment cost of the device is high, the screened seeds cannot meet the requirements, and the occupied area is large.

The invention also provides screening equipment to solve the technical problems of high equipment investment cost and poor screened seed effect in the prior art.

The invention provides a screening machine which comprises a constant-speed feeding device, a seed screening device, an impurity screening device and a supporting frame, wherein the seed screening device is arranged on the constant-speed feeding device;

the uniform-speed feeding device is connected with the seed screening device, a discharge port of the uniform-speed feeding device corresponds to a feeding port of the seed screening device, so that seed raw materials in the uniform-speed feeding device can uniformly enter the seed screening device, and seeds in the seed raw materials are screened by the seed screening device;

the impurity screening device is sleeved outside the seed screening device, after the seed screening device screens seeds, impurities in the seed raw materials are guided to the impurity screening device, and the impurities in the seed raw materials are screened by the impurity screening device;

the support frame includes first support and second support, impurity screening plant connects on the first support, the second support cover is established the outside of first support, first support with connect through the connecting rod between the second support.

Further, the uniform-speed feeding device comprises a hopper and a fan;

the hopper is provided with a discharge port, and the discharge port is used for guiding the seed raw materials in the hopper to the seed screening device;

the number of the discharge ports is multiple, and the discharge ports are all arranged on the hopper;

be equipped with the air intake on the hopper, the fan is connected air intake department, the fan can blow the seed raw materials in the hopper makes the seed raw materials be in even in the hopper along a plurality of the discharge gate diffusion.

Further, the uniform-speed feeding device also comprises a first spiral sheet;

the first spiral piece is connected in the hopper, and the plurality of discharge ports are arranged on the first spiral piece;

the first spiral piece is provided with a first guide groove, and the first guide groove can guide seed raw materials to enter the discharge hole.

Further, the seed screening device comprises a second spiral sheet, a supporting shaft and a first discharging part;

the number of the second spiral pieces is multiple, the second spiral pieces are sequentially sleeved from top to bottom, and the second spiral pieces are sequentially sleeved on the supporting shaft from top to bottom;

the first discharging part is connected to a discharging opening of the second spiral sheet at the lower part.

Furthermore, the diameters of the second spiral pieces are sequentially increased from top to bottom.

Further, a second guide groove is formed on the upper surface of the second spiral piece, and the second guide groove can guide the seeds to flow downwards along the support shaft.

Furthermore, a step is arranged at the discharge port of the second spiral sheet at the lower part, the steps are multilayer, and the first discharge part is connected with a filter plate;

the filter with the step corresponds the setting.

Further, the impurity screening device comprises a third spiral sheet and a second discharging part;

the number of the third spiral pieces is multiple, and each third spiral piece is sequentially sleeved on each second spiral piece from top to bottom;

the second discharging part is connected to the discharging opening of the third spiral piece at the lower part.

Furthermore, the diameters of the plurality of third spiral pieces are sequentially increased from top to bottom.

The invention also provides screening equipment which comprises a mounting rack and a plurality of screening machines;

the mounting frame is provided with a plurality of mounting seats, and each screening machine is connected to each mounting seat;

the lower part of the mounting rack is connected with rollers.

According to the screening machine provided by the invention, the uniform speed feeding device is connected with the seed screening device, the uniform speed feeding device can uniformly feed materials to the seed screening device, and a discharge hole of the uniform speed feeding device corresponds to a feeding hole of the seed screening device, so that seed raw materials in the uniform speed feeding device can uniformly enter the seed screening device to be fed; the seed screening device can screen out seeds in the seed raw materials; the impurity screening device is sleeved outside the seed screening device, the impurity screening device can screen out impurities in the seed raw materials, and after the impurities are screened, the seeds are screened through the seed screening device, so that the purpose of screening the seeds and the impurities simultaneously is achieved, the seeds can be accurately screened, and high-quality seeds are screened out; impurity screening plant connects on the first support, utilize first support is right impurity screening plant fixes, the second support cover is established the outside of first support, utilizes the second support is right the position of first support is fixed, and first support with connect through the connecting rod between the second support, make fixed more firm between two supports, adopt the structure of support frame, area is little, makes the sieve separator can shift position as required at any time. The constant-speed feeding device can feed the seeds into the seed screening device at a constant speed, screens the seeds by using the seed screening device, and screens impurities by using the impurity screening device, so that the seeds and the impurities are quickly separated, and the aim of quickly separating is fulfilled.

The invention also provides screening equipment, wherein the mounting frame is connected with the plurality of screening machines, the screening machines can accurately and quickly screen the seed raw materials, the quality of the screened seeds is good, the whole screening equipment occupies a small area, and the screening work efficiency of the whole equipment is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic structural diagram of a screening machine according to an embodiment of the present invention;

FIG. 2 is an enlarged view of portion A of FIG. 1;

FIG. 3 is an enlarged view of portion B of FIG. 1;

FIG. 4 is an enlarged view of portion C of FIG. 1;

FIG. 5 is a front view of a screening machine provided in accordance with an embodiment of the present invention;

fig. 6 is a top view of a screening machine according to an embodiment of the present invention.

Icon: 100-uniform feeding device; 200-a seed screening device; 300-impurity screening device; 400-a support frame; 101-a hopper; 102-a fan; 103-a discharge hole; 104-an air inlet; 105-a first helical flight; 106-a first guide slot; 201-a second spiral sheet; 202-supporting shaft; 203-a first discharge part; 204-a second guide slot; 205-step; 206-a filter plate; 301-a third flight; 302-a second discharge; 401-a first scaffold; 402-a second support; 403-connecting rod.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Fig. 1 is a schematic structural diagram of a screening machine according to an embodiment of the present invention.

As shown in fig. 1, the screening machine provided by the present invention comprises a uniform feeding device 100, a seed screening device 200, an impurity screening device 300 and a supporting frame 400;

the uniform-speed feeding device 100 is connected with the seed screening device 200, and a discharge port of the uniform-speed feeding device 100 corresponds to a feed port of the seed screening device 200, so that seed raw materials in the uniform-speed feeding device 100 can uniformly enter the seed screening device 200, and seeds in the seed raw materials are screened by the seed screening device 200;

the impurity screening device 300 is sleeved outside the seed screening device 200, after the seed screening device 200 screens seeds, impurities in the seed raw material are guided to the impurity screening device 300, and the impurities in the seed raw material are screened by the impurity screening device 300;

the supporting frame 400 comprises a first support 401 and a second support 402, the impurity screening device 300 is connected to the first support 401, the second support 402 is sleeved outside the first support 401, and the first support 401 and the second support 402 are connected through a connecting rod 403.

In fig. 1, the constant velocity feeding device 100 is disposed at the uppermost position, the upper end of the constant velocity feeding device 100 is a feeding port, and the lower end of the constant velocity feeding device 100 is a discharging port.

The seed screening device 200 is arranged at the lower part of the uniform speed feeding device 100, and the discharge hole of the uniform speed feeding device 100 just corresponds to the feeding hole at the upper end of the seed screening device 200, so that the uniform speed feeding device 100 can feed the seed screening device 200, and the seed screening device 200 is used for screening seeds in seed raw materials.

Impurity screening plant 300 cover is established in the outside of seed screening plant 200, the size of impurity screening plant 300 is greater than the size of seed screening plant 200, the seed is under the effect of self gravity, along the quick downstream of inside seed screening plant 200, accomplish the screening process to the seed, and the weight ratio of impurity is lighter, can be along the slow downstream of the impurity screening plant 300 in the outside, accomplish the screening process to impurity, utilize the action of gravity of seed self, accomplish the process of screening impurity, compare in prior art, the electric energy has been saved.

Impurity screening plant 300 is connected in first support 401's inside, utilizes first support 401 to fix impurity screening plant 300, and first support 401 adopts the square iron pole of three vertical settings, and three square iron poles are the triangle-shaped and connect in impurity screening plant 300's outside, support impurity screening plant 300, set up the supporting legs at the lower extreme of three square iron poles to support impurity screening plant 300.

The second bracket 402 is sleeved outside the first bracket 401, and the second bracket 402 adopts a square bracket structure; the second support adopts four vertically arranged square iron rods, the four square iron rods are connected into a square shape and connected to the outside of the first support 401, and the position of the first support 401 is fixed by the second support 402.

In order to make the firm in connection of second support 402, adopt square iron set to connect between adjacent square pole, the quantity of square iron set is for a plurality of that from top to bottom set up, utilizes a plurality of square iron set to make second support 402 more firm.

The first support 401 and the second support 402 are connected through a connecting rod 403, the connecting rod 403 is a square iron rod, the inner side end of the square iron rod is welded on the first support 401, the outer side end of the square iron rod is welded on the second support 402, and the first support 401 and the second support 402 are connected and fixed through the connecting rod 403.

A plurality of connecting rods 403 are arranged between the first bracket 401 and the second bracket 402 from top to bottom, and the connection between the two brackets is more firm by the plurality of connecting rods 403.

According to the invention, the support frame 400 is connected to the outer part of the impurity screening device 300, and the position of the impurity screening device 300 is fixed by using the support frame 400, so that the impurity screening device occupies a small area and is convenient to move.

Fig. 2 is an enlarged view of a portion a in fig. 1.

As shown in fig. 2, further, the constant speed feeding device 100 includes a hopper 101 and a fan 102;

a discharge port 103 is formed in the hopper 101, and the discharge port 103 is used for guiding the seed raw materials in the hopper 101 out to the seed screening device 200;

the number of the discharge ports 103 is multiple, and the discharge ports 103 are all arranged on the hopper 101;

the hopper 101 is provided with an air inlet 104, the fan 102 is connected to the air inlet 104, and the fan 102 can blow the raw materials in the hopper 101, so that the raw materials are uniformly diffused along the plurality of discharge holes 103 in the hopper 101.

In fig. 2, the hopper 101 is formed in an inverted cone shape, and a discharge port 103 is provided in a lower side wall of the hopper 101 so that the seed material can leak out along the discharge port 103.

Fig. 3 is an enlarged view of a portion B in fig. 1.

In fig. 3, the discharge port 103 is a square through hole formed on the side wall of the lower part of the hopper 101, the seed material leaks downwards along the square through hole, the two sides of the outer wall of the square through hole are respectively connected with a first turned edge and a second turned edge which are turned inwards, a cover body is inserted into the square through hole, and the two sides of the cover body can be cut into along the two turned edges to seal the opening of the square through hole; the upper end of the cover body is provided with a third turning edge which is turned outwards and is convenient for being held by hands of people, so that the cover body is opened upwards, or the cover body is covered downwards at the square through hole to seal the square through hole; the position that the lid closed square through-hole has decided the flow that the seed raw materials flowed out, utilizes the lid to adjust the size of the mouth that closes, controls the flow of seed raw materials.

In order to allow the seed material to flow rapidly, a plurality of discharge ports 103 are provided at a lower side wall position of the hopper 101, so that the seed material can flow uniformly to the outside along the plurality of discharge ports 103.

In fig. 2, an air inlet 104 is formed in a side wall of the hopper 101, the air inlet 104 is a through hole formed in the side wall of the hopper 101, and the fan 102 is connected to the air inlet, so that when the fan 102 operates, the generated air can be blown into the hopper 101 along the air inlet 104 to blow the seed material in the hopper 101, so that the seed material is uniformly diffused along the inner wall of the hopper 101, and the seed material is diffused along the direction of the plurality of discharge ports 103, so that the seed material is uniformly diffused to the seed sieving device 200.

The fan 102 can adjust the constant-speed blowing to feed the seed raw materials at a constant speed; the blower 102 may be adjusted to blow quickly when the amount of the seed material is large, or adjusted to blow slowly when the amount of the seed material is small, according to the actual use requirement.

Further, the uniform-speed feeding device 100 further comprises a first spiral sheet 105;

the first spiral piece 105 is connected in the hopper 101, and the discharge ports 103 are all arranged on the first spiral piece 105;

the first spiral piece 105 is provided with a first guide groove 106, and the first guide groove 106 can guide the seed raw material to enter the discharge hole 103.

In fig. 2, a first spiral piece 105 is welded on the inner wall of the hopper 101, so that the seed raw material can move along the inner wall of the first spiral piece 105 under the blowing of the fan 102 to orient the flow direction of the seeds; the plurality of discharge ports 103 are disposed on the first spiral piece 105, and when the seed material moves along the inner wall of the first spiral piece 105, the seed material can gradually leak out to the seed sieving device 200 along the plurality of discharge ports 103.

In one embodiment of the present invention, a first guide groove 106 is formed on an inner wall of the first spiral piece 105, and the first guide groove 106 may be a protrusion so that the seed material can move along the protrusion to guide the seed material to the discharge hole 103.

In another embodiment of the present invention, the first guiding groove 106 may be an inwardly recessed groove so that the seed material can move along the recessed groove to guide the seed material to the discharging hole 103.

In one embodiment of the present invention, in order to better guide the discharge of the seed material, a plurality of first guide grooves 106 may be provided on the inner wall of the first spiral piece 105, and the seed material can be uniformly guided to the plurality of discharge holes 103 by the plurality of first guide grooves 106.

Fig. 4 is an enlarged view of a portion C in fig. 1.

Further, the seed sieving device 200 comprises a second spiral sheet 201, a supporting shaft 202 and a first discharging part 203;

the number of the second spiral pieces 201 is multiple, the second spiral pieces 201 are sequentially sleeved from top to bottom, and the second spiral pieces 201 are sequentially sleeved on the supporting shaft 202 from top to bottom;

the first discharging part 203 is connected to the discharging port of the lower second spiral sheet 201.

In fig. 1 and 3, the number of the second flights 201 is plural, and the plural second flights 201 are sequentially sleeved from top to bottom along the support shaft 202, so that the seed material can rotate around the support shaft 202 as a rotation center along the plural second flights 201, and through the multiple rotation screening, the first discharging part 203 is connected to the outlet of the second flight 201 at the lowest part, that is, the left position in fig. 1, and seeds with better quality fall out along the first discharging part 203 at the lower part for collection.

The support shaft 202 is a vertically arranged cylindrical rod.

Further, the diameters of the second spiral pieces 201 are sequentially increased from top to bottom.

The diameter of a plurality of second flights 201 increases gradually, can make the seed raw materials that second flight 201 on upper portion sieved in-process that drops down, centrifugal force crescent gradually to can outwards carry the impurity in the seed raw materials, make impurity along impurity screening plant 300 motion, thereby make the quality that the seed was sieved better.

Further, a second guide groove 204 is formed on the upper surface of the second spiral piece 201, and the second guide groove 204 can guide the seeds to flow downward along the support shaft 202.

In fig. 3, a second guide groove 204 is formed on the inner wall of the second spiral piece 201, the second guide groove 204 is a protrusion formed on the inner wall of the second spiral piece 201, and the second guide groove 204 can guide the seeds to move downward in the vertical direction under the action of their own gravity, so that the impurities move along the second guide groove 204 to the impurity screening device 300.

Further, a step 205 is arranged at a discharge port of the second spiral sheet 201 at the lower part, the step 205 is multi-layer, and a filter plate 206 is connected at the first discharge part 203;

the filter plate 206 is disposed corresponding to the step 205.

In fig. 4, a discharge port of the second spiral piece 201 is provided with a step 205, the step 205 has multiple layers, and the lengths of the ends of the multiple layers of steps 205 are gradually increased from top to bottom, so that seeds can drop down layer by layer along the multiple layers of steps 205, and the seeds drop according to a certain sequence.

In one embodiment of the present invention, the end of the step 205 is connected to a filter plate 206, the filter plate 206 is made of steel plate, the filter plate 206 is provided with a plurality of through holes, the diameter of the through holes is slightly larger than the diameter of the seeds, and the filter plate 206 is used to filter impurities larger than the seeds in the seed material, so that the seeds with qualified size pass through the filter plate 206.

After the seed passes through the screening of second flight 201, most impurity has been strained, and the seed of minority has the impurity of great granule, utilizes filter 206 can be quick to filter out these impurity of great granule, avoids artifical secondary screening, and the impurity of smaller size can also block the lower part at filter 206.

First ejection of compact portion 203 has bottom plate and two curb plates, and bottom plate and two curb plates form the structure of a material way, set up the recess respectively at the inner wall of two curb plates, and the both sides difference block of filter 206 is connected in the recess, fixes filter 206.

In an embodiment of the present invention, a plurality of grooves may be formed in the inner walls of the two side plates of the first discharging portion 203, so that when the first filter 206 has a large amount of impurities, the second filter 206 may be inserted into the lower portion of the first filter 206, and then the first filter 206 may be taken out, and the second filter 206 is used for filtering, so that the filter 206 can be quickly replaced, thereby improving the filtering efficiency of the impurities.

Further, the impurity screening device 300 comprises a third spiral plate 301 and a second discharging part 302;

the number of the third spiral pieces 301 is multiple, and each third spiral piece 301 is sequentially sleeved on each second spiral piece 201 from top to bottom;

the second discharging part 302 is connected to the discharging port of the lower third spiral plate 301.

In fig. 1, 5 and 6, the diameter of the third spiral piece 301 is larger than that of the second spiral piece 201, the second spiral piece 201 is sleeved in the third spiral piece 301, seeds are screened along the second spiral piece 201 by rotating under the action of self gravity, the impurities are light, and are screened along the third spiral piece 301 by rotating after being thrown out by the side edge of the second spiral piece 201.

The plurality of third spiral pieces 301 are sequentially sleeved on the plurality of second spiral pieces 201 from top to bottom, so that the effect of screening the seed raw materials is good.

In an embodiment of the present invention, since the diameter of the third spiral sheet 301 is larger than that of the second spiral sheet 201, three second spiral sheets 201 can be accommodated in each third spiral sheet 301, so that after the seeds are sequentially screened in the three second spiral sheets 201, the screened impurities can enter the third spiral sheet 301, and the screening is more thorough.

At the discharge port of the lowermost third flight 301, i.e., at the lower right position in fig. 1, a second discharge portion 302 is provided to lead out the impurities along the right side.

The second discharging portion 302 includes a bottom plate and two side plates, which form a material channel structure and prevent impurities from falling out.

The outlet of the second discharging part 302 is higher than the outlet of the first discharging part 203, so that the impurities are lighter in weight, and the impurities in the second discharging part 302 can be conveniently led out.

Further, the diameters of the third spiral pieces 301 are sequentially increased from top to bottom.

In an embodiment of the present invention, the diameters of the plurality of second spiral pieces 201 are sequentially increased from top to bottom, the diameter of the third spiral piece 301 needs to correspond to the structure of the second spiral piece 201, and the diameters of the plurality of third spiral pieces 301 are sequentially increased from top to bottom, so that after the second spiral pieces 201 with the sequentially increased diameters are screened, the impurities are screened along the plurality of third spiral pieces 301.

the lower part of the mounting rack is connected with rollers.

Connect a plurality of sieve separators on the mounting bracket, a plurality of sieve separators sieve the seed raw materials simultaneously, have improved the efficiency of screening to the electric energy has been practiced thrift. The lower part of the mounting frame is connected with the roller, so that the screening equipment can be moved to any required position according to the use requirement, the movement is convenient, and the occupied space is saved.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A screening machine is characterized by comprising a uniform-speed feeding device (100), a seed screening device (200), an impurity screening device (300) and a supporting frame (400);

the uniform-speed feeding device (100) is connected with the seed screening device (200), a discharge hole of the uniform-speed feeding device (100) corresponds to a feeding hole of the seed screening device (200), so that seed raw materials in the uniform-speed feeding device (100) can uniformly enter the seed screening device (200), and seeds in the seed raw materials are screened by the seed screening device (200);

the impurity screening device (300) is sleeved outside the seed screening device (200), after the seed screening device (200) screens seeds, impurities in the seed raw materials are guided to the impurity screening device (300), and the impurities in the seed raw materials are screened by the impurity screening device (300);

the supporting frame (400) comprises a first bracket (401) and a second bracket (402), the impurity screening device (300) is connected to the first bracket (401), the second bracket (402) is sleeved outside the first bracket (401), and the first bracket (401) and the second bracket (402) are connected through a connecting rod (403);

the uniform-speed feeding device (100) comprises a hopper (101) and a fan (102);

a discharge port (103) is formed in the hopper (101), and the discharge port (103) is used for guiding the seed raw materials in the hopper (101) out to the seed screening device (200);

the number of the discharge ports (103) is multiple, and the discharge ports (103) are all arranged on the hopper (101);

the improved seed feeder is characterized in that an air inlet (104) is formed in the hopper (101), the fan (102) is connected to the air inlet (104), the fan (102) can blow seed raw materials in the hopper (101), and the seed raw materials are uniformly diffused along the plurality of discharge holes (103) in the hopper (101).

2. The screening machine according to claim 1, wherein the constant velocity feed device (100) further comprises a first flight (105);

the first spiral piece (105) is connected in the hopper (101), and the discharge holes (103) are all arranged on the first spiral piece (105);

the first spiral piece (105) is provided with a first guide groove (106), and the first guide groove (106) can guide seed raw materials to enter the discharge hole (103).

3. A screening machine according to claim 2, characterized in that said seed screening device (200) comprises a second spiral (201), a supporting shaft (202) and a first outfeed portion (203);

the number of the second spiral pieces (201) is multiple, the second spiral pieces (201) are sequentially sleeved from top to bottom, and the second spiral pieces (201) are sequentially sleeved on the supporting shaft (202) from top to bottom;

the first discharging part (203) is connected to a discharging opening of the second spiral sheet (201) at the lower part.

4. A screening machine according to claim 3, wherein the diameter of a plurality of said second flights (201) increases in order from top to bottom.

5. A screening machine according to claim 3, wherein the second flights (201) have second guide slots (204) formed thereon, the second guide slots (204) being adapted to guide seeds flowing down along the support shaft (202).

6. A screening machine according to claim 3, characterized in that the discharge opening of the lower second flight (201) is provided with steps (205), said steps (205) are multi-layered, and a filter plate (206) is connected to the first discharge portion (203);

the filter plate (206) is arranged corresponding to the step (205).

7. A screening machine according to claim 3, characterized in that said impurity screening device (300) comprises a third spiral flight (301) and a second outfeed portion (302);

the number of the third spiral pieces (301) is multiple, and each third spiral piece (301) is sequentially sleeved on each second spiral piece (201) from top to bottom;

the second discharging part (302) is connected to a discharging port of the lower third spiral sheet (301).

8. A screening machine according to claim 7, wherein the diameter of a plurality of said third flights (301) increases in order from top to bottom.

9. A screening apparatus comprising a mounting frame and a plurality of screening machines according to any one of claims 1 to 8;

the lower part of the mounting rack is connected with rollers.