CN113996522A

CN113996522A - Selective filtering precleaner

Info

Publication number: CN113996522A
Application number: CN202111250705.5A
Authority: CN
Inventors: 狄胜; 车琴; 黄涛; 杨志诚
Original assignee: Goldlong Machinery And Engineering Co ltd
Current assignee: Goldlong Machinery And Engineering Co ltd
Priority date: 2021-10-26
Filing date: 2021-10-26
Publication date: 2022-02-01
Anticipated expiration: 2041-10-26
Also published as: CN113996522B

Abstract

The utility model relates to a filterable preliminary cleaning sieve of selectivity belongs to feed processing's field, and it includes the organism, the organism internal rotation is connected with a sieve section of thick bamboo, be equipped with the inlet pipe on the organism, the bottom of the body is equipped with row's hopper, the intercommunication has the preliminary cleaning pipeline and lets the position the pipeline on the inlet pipe, let the position pipeline and sieve section of thick bamboo inside intercommunication, let the position pipeline with arrange the hopper intercommunication, just be located on the inlet pipe and be equipped with reversing mechanism between the preliminary cleaning pipeline and the position the pipeline, reversing mechanism is used for switching on the inlet pipe and the preliminary cleaning pipeline or inlet pipe and lets the position the pipeline. This application makes the material selectively get into a sieve section of thick bamboo and just clears or directly get into to arrange the hopper and in order carrying out subsequent manufacturing procedure according to the different situations of material, has the effect that reduces the equipment degree of wear that the unnecessary use of just clearing sieve leads to.

Description

Selective filtering precleaner

Technical Field

The application relates to the field of feed processing equipment, in particular to a selective filtration precleaner.

Background

The feed is a general term for the food of animals raised by human beings, and the raw materials of the feed comprise soybean, corn, fish meal, additives and the like. In the production and processing of feed, the precleaner is the equipment that is used for carrying out prefiltration to the feed ingredient, and the drum precleaner is one of the kind of the precleaner that commonly uses.

Be provided with a sieve section of thick bamboo in the drum precleaner, seted up a large amount of sieve meshes on the sieve section of thick bamboo, the material gets into a sieve section of thick bamboo, and a sieve section of thick bamboo rolls in order to carry out impurity separation to the material, and the material that the size is less than the sieve mesh is just stayed a sieve section of thick bamboo outside being separated out a sieve section of thick bamboo, and the material that leaves a sieve section of thick bamboo will carry out subsequent further edulcoration etc. and handle.

For a large-scale feed production and processing assembly line with higher standardization, a primary cleaning sieve is often used as equipment of a first procedure, namely, raw materials enter the primary cleaning sieve to start to enter an integral processing procedure; the primary cleaning sieve carries out primary impurity removal on the raw material, and the raw material is separated from the primary cleaning sieve and then is continuously subjected to each subsequent treatment procedure on the production line.

With respect to the related art in the above, the inventors consider that there are the following drawbacks: if the raw materials have already been carried out preliminary filtration edulcoration before getting into the assembly line, then the first process that it experienced after getting into the assembly line will produce obvious effect hardly, and increased the inside degree of wear of precleaner.

Disclosure of Invention

To ameliorate the above problems, the present application provides a selective filtration scalping screen.

The application provides a selective filtration's precleaner adopts following technical scheme:

the utility model provides a selective filtration's precleaner, includes the organism, the organism internal rotation is connected with a sieve section of thick bamboo, be equipped with the inlet pipe on the organism, the bottom of the body is equipped with row's hopper, the intercommunication has precleaner pipeline and the pipeline of stepping down on the inlet pipe, the pipeline of stepping down communicates with the inside of a sieve section of thick bamboo, the pipeline of stepping down is fought the intercommunication with arranging, just be located precleaner pipeline on the inlet pipe and be equipped with reversing mechanism between the pipeline of stepping down, reversing mechanism is used for switching on the inlet pipe and precleaner pipeline or inlet pipe and the pipeline of stepping down.

Through adopting above-mentioned technical scheme, reversing mechanism control inlet pipe and just clear pipeline or stepping down switching on and sealing of pipeline, according to the different situation of material, selectively make the material get into a sieve section of thick bamboo and carry out just clear or directly get into to arrange the hopper in order to carry out subsequent manufacturing procedure, reduced the equipment degree of wear that the unnecessary use of just cleaning sieve leads to.

Preferably, state reversing mechanism and include switching-over cylinder, connecting rod, installation axle and switching-over board, the switching-over cylinder is articulated with the inlet pipe, the connecting rod is articulated with the piston rod of switching-over cylinder, installation axle and connecting rod fixed connection, the installation axle rotates with the inlet pipe to be connected, the installation axle is located the inlet pipe and is located just clear pipeline and let between the pipeline, the edge and the installation axle fixed connection of switching-over board, the rotation plane of switching-over cylinder is parallel with the rotation plane of installation axle.

By adopting the technical scheme, the telescopic piston rod of the reversing cylinder controls the rotation of the reversing plate through the connecting rod and the mounting shaft, the reversing plate directly controls the communicated route in the pipeline in the reversing way, and the purpose of reversing and guiding materials is realized.

Preferably, be equipped with the butt groove on the inlet pipe inner wall, be equipped with the butt pad on the cell wall in butt groove, the one side and the butt pad laminating of installation axle are kept away from to the switching-over board.

By adopting the technical scheme, after the edge of the reversing plate is attached to the butt gasket, the sealing property between the edge of the reversing plate and the inner wall of the feeding pipe is improved, and meanwhile, the butt gasket plays a certain role in buffering and protecting the reversing plate in the process of impacting the reversing plate by materials.

Preferably, the screen drum comprises a filtering part and an impurity discharging part which are communicated with each other, one end of the primary cleaning pipeline, which is far away from the feeding pipe, is positioned in the filtering part, a filtering hole for feeding raw materials to pass through is formed in the drum wall of the filtering part, and the discharging hopper is positioned below the filtering part; the trash discharging device is characterized in that trash discharging holes are formed in the cylinder wall of the trash discharging portion and used for allowing impurities to pass through, pushing spiral plates are fixedly connected to the inner wall of the filtering portion, and trash discharging pipes are arranged on the machine body and below the trash discharging portion.

Through adopting above-mentioned technical scheme, the feed ingredient granule in the material is less, and its accessible filters the hole and directly gets into row's hopper, and the great debris of volume move to arranging the miscellaneous hole under the promotion of the propelling movement spiral plate that is rotating to finally leave sieve section of thick bamboo and organism through arranging miscellaneous hole, realize the preliminary clearance of material from this.

Preferably, a cleaning mechanism is arranged in the machine body and comprises a sweeping drum brush, the sweeping drum brush comprises bristles, and the end portions of the bristles are in contact with the outer wall of the filtering portion.

Through adopting above-mentioned technical scheme, at a sieve section of thick bamboo pivoted in-process, the friction takes place for brush hair tip and a sieve section of thick bamboo outer wall, and the material of part card in filter hole department receives the touching of brush hair and is pushed back to a sieve section of thick bamboo, has reduced the material on a sieve section of thick bamboo wall and has remained, and impurity such as the flock that mix with in the material, iron wire have certain probability to be struck off by the brush hair, has improved the efficiency and the effect of preliminary clearance.

Preferably, sweep a section of thick bamboo brush and still include the installation piece, the one end fixed connection that a sieve section of thick bamboo was kept away from to installation piece and brush hair, clean the mechanism and still include the installation shell, the installation shell passes through the bolt with the installation piece and can dismantle the connection.

Preferably, clean the mechanism and still include control assembly, control assembly is used for controlling the installation shell and removes, control assembly includes the control guide rail, the length direction of control guide rail is parallel with the axis of a sieve section of thick bamboo, the installation shell slides with the control guide rail and is connected.

Through adopting above-mentioned technical scheme, control assembly control is carried and is swept a section of thick bamboo brush and remove along control guide rail, has formed along the ascending relative friction trend of a sieve section of thick bamboo axial between brush hair and the sieve section of thick bamboo this moment, and the frictional force direction between brush hair tip and the sieve section of thick bamboo becomes various promptly, and the material on the sieve section of thick bamboo wall is touched and takes place to translocate by the brush hair more to improve and clean the effect.

Preferably, the control assembly still includes control gear and control lever, the control gear rotates with the organism to be connected, coaxial fixedly connected with transmission gear portion on the outer wall of a sieve section of thick bamboo, control gear meshes with transmission gear portion, the one end of control lever is articulated with control gear's edge, the other end and the installation shell of control lever are articulated, control gear's rotation plane is parallel with the length direction of control guide rail.

Through adopting above-mentioned technical scheme, control gear and control lever, installation shell have formed one set of slider-crank mechanism, and when a sieve section of thick bamboo pivoted, transmission gear portion on the sieve section of thick bamboo passes through the sawtooth meshing and drives control gear and rotate, for control assembly provides power, under slider-crank mechanism's drive, sweeps a section of thick bamboo brush along control guide rail reciprocating motion.

Preferably, the machine body is provided with an observation window, and the sweeping drum brush is positioned between the observation window and the screen drum.

Through adopting above-mentioned technical scheme, operator's accessible observation window observes the inside sieve section of thick bamboo of organism, cleans the behavior of mechanism.

Preferably, the top of the machine body is provided with a dust exhaust pipeline, and a filter element is arranged in the dust exhaust pipeline.

Through adopting above-mentioned technical scheme, the material will produce the raise dust in the rolling in-process of a sieve section of thick bamboo, and the raise dust gets into the dust exhaust pipeline, and part feed ingredient will be intercepted by the filter core in the raise dust, the reuse of being convenient for to the utilization ratio of raw materials has been improved.

In summary, the present application includes at least one of the following beneficial technical effects:

1. through the arrangement of the reversing mechanism, the piston rod of the reversing cylinder stretches out and draws back to control the reversing plate to rotate through the connecting rod and the mounting shaft, the reversing plate selectively seals the primary cleaning pipeline or the abdicating pipeline, for materials which do not need to be subjected to primary filtering, the reversing plate rotates until the primary cleaning pipeline is sealed, and at the moment, the materials entering from the feeding pipe directly flow to the discharging hopper through the abdicating pipeline, so that the materials enter the next processing procedure, and unnecessary machine loss of the primary cleaning sieve is reduced;

2. through the arrangement of the cleaning mechanism, the bristles are in contact with the filtering part of the screen drum, the surface of the screen drum is rubbed with the end parts of the bristles in the rotating process of the screen drum, the bristles push the materials clamped at the filtering hole back into the screen drum, and meanwhile, the bristles can also scrape strip-shaped impurities remained on the filtering part from the screen drum, so that a certain impurity removing effect is achieved;

3. through control assembly's setting, the rotation of a sieve section of thick bamboo drives control gear through transmission gear portion and rotates in turn, and control gear and control lever, installation shell have formed one set of slider-crank mechanism, and the slider in the model is for carrying the installation shell of sweeping a section of thick bamboo brush, and installation guide rail reciprocating motion will be followed to the installation shell to make sweeping a section of thick bamboo brush have along sieve section of thick bamboo ascending trend of movement, increased the variety of the relative friction direction on brush hair and sieve section of thick bamboo surface, promoted and cleaned the effect.

Drawings

FIG. 1 is a schematic structural diagram of a scalping screen for selective filtration in an embodiment of the present application.

Fig. 2 is a schematic diagram for embodying the internal structure of the scalping screen in the embodiment of the present application.

Fig. 3 is a schematic structural diagram for embodying the working principle of the reversing mechanism in the embodiment of the present application.

Fig. 4 is a partially enlarged view of a portion a in fig. 2.

Fig. 5 is a schematic structural diagram for embodying the recovery mechanism in the embodiment of the present application.

Description of reference numerals: 1. a body; 11. a discharge hopper; 12. a drive motor; 13. a trash removal pipe; 14. an observation window; 15. a feed pipe; 151. a butt joint groove; 152. abutting the pad; 16. preliminarily cleaning the pipeline; 17. a abdication pipeline; 2. a reversing mechanism; 21. a reversing cylinder; 22. a connecting rod; 23. installing a shaft; 24. a reversing plate; 3. a screen cylinder; 31. a filtering part; 311. a filtration pore; 32. a trash removal part; 321. impurity removal holes; 33. pushing the spiral plate; 34. a transmission gear portion; 4. a cleaning mechanism; 41. a cylinder sweeping brush; 411. mounting blocks; 412. brushing; 42. mounting a shell; 43. a control component; 431. a control gear; 432. a control lever; 433. controlling the guide rail; 5. a recovery mechanism; 51. a dust exhaust pipeline; 52. a pattern plate; 53. a filter element; 54. and a blowback pipe.

Detailed Description

The present application is described in further detail below with reference to figures 1-5.

The embodiment of the application discloses selective filtration's precleaner, as shown in fig. 1 and 2, including organism 1, be provided with in the organism 1 and be used for carrying out the sieve section of thick bamboo 3 of prefilter edulcoration processing to the material, be provided with the inlet pipe 15 that is used for adding the material in sieve section of thick bamboo 3 on the organism 1, the organism 1 bottom is provided with the row's hopper 11 that is used for discharging the raw materials after filtering, is provided with on the organism 1 and is used for driving sieve section of thick bamboo 3 pivoted driving motor 12. The drum precleaner, which is the device for the material to enter the first pass of the process line, provides the option of whether the material in the feed pipe 15 enters the screen drum 3.

As shown in fig. 2 and 3, the axis of the screen drum 3 is parallel to the horizontal direction, one end of the feeding pipe 15 is located at the highest position of the machine body 1, the end is a feeding end, and the other end is a discharging end; be fixed with on the organism 1 and just clear pipeline 16 and let a way pipeline 17, be three way type intercommunication and reciprocal anchorage between the discharge end of the one end of just clear pipeline 16, the one end of the pipeline 17 of letting a way and inlet pipe 15, the one end that the inlet pipe 15 was kept away from to just clear pipeline 16 is located a sieve section of thick bamboo 3, let a way pipeline 17 keep away from the one end of inlet pipe 15 extend to the lateral wall department of arranging hopper 11 and communicate with it. The reversing mechanism 2 is arranged in the feeding pipe 15 and is positioned at the position where the feeding pipe is communicated with the primary cleaning pipeline 16 and the abdicating pipeline 17, and the reversing mechanism 2 is used for controlling selective conduction or selective plugging of the feeding pipe 15 and the primary cleaning pipeline 16 or the abdicating pipeline 17.

As shown in fig. 2 and 3, the reversing mechanism 2 includes a reversing cylinder 21, a connecting rod 22, a mounting shaft 23 and a reversing plate 24, the reversing cylinder 21 and the connecting rod 22 are both located outside the feeding pipe 15, the reversing cylinder 21 is hinged to the feeding pipe 15, one end of the connecting rod 22 is hinged to the end of the piston rod of the reversing cylinder 21, the mounting shaft 23 is rotatably connected to the feeding pipe 15, one end of the mounting shaft 23 is located outside the feeding pipe 15, the other end of the connecting rod 22 is hinged to one end of the mounting shaft 23 located outside the feeding pipe 15, and the rotation planes of the reversing cylinder 21, the connecting rod 22 and the mounting shaft 23 are vertical planes and parallel to each other. The plate surface of the reversing plate 24 is rectangular, one side edge of the reversing plate 24 is fixedly connected with the part, located inside the feeding pipe 15, of the mounting shaft 23, the plate surface of the reversing plate 24 is perpendicular to the rotating plane of the mounting shaft 23, the size of the plate surface of the reversing plate 24 is the same as that of the section of the primary cleaning pipeline 16, and the plate surface of the reversing plate 24 is larger than that of the section of the abdicating pipeline 17. At this time, when the piston rod of the reversing cylinder 21 extends, the connecting rod 22 rotates to drive the mounting shaft 23 to rotate, and the reversing plate 24 rotates together with the mounting shaft 23; when the surface of the reversing plate 24 is parallel to the vertical plane, the passage between the feeding pipe 15 and the primary cleaning pipeline 16 is blocked, and the feeding pipe 15 is communicated with the abdicating pipeline 17.

As shown in fig. 3, a contact groove 151 is formed on the inner wall of the feeding pipe 15, the inner wall of the feeding pipe 15 where the contact groove 151 is located is opposite to the primary cleaning pipe 16, the length direction of the contact groove 151 is the same as the length direction of the mounting shaft 23, and a contact pad 152 made of rubber is attached to the bottom of the contact groove 151. The reversing plate 24 rotates to enable the edge of one side, far away from the mounting shaft 23, of the reversing plate 24 to abut against the abutting pad 152, at the moment, the reversing plate 24 seals a passage between the feeding pipe 15 and the abdicating pipeline 17, and materials falling from the feeding pipe 15 are guided into the primary cleaning pipeline 16 by the reversing plate 24 and enter the screen drum 3 through the primary cleaning pipeline 16.

As shown in fig. 2, the screen cylinder 3 is divided into two parts in the axial direction: the filtering part 31 and the impurity removing part 32 are coaxially and fixedly connected, the driving motor 12 is positioned at a position close to the impurity removing part 32, and an output shaft of the driving motor 12 is coaxially and fixedly connected with the end face of the impurity removing part 32; the filter part 31 is located at a side relatively close to the feeding pipe 15, the opening of the primary cleaning pipe 16 is located in the range of the filter part 31, and the discharge hopper 11 is located right below the filter part 31. The wall of the filtering portion 31 is provided with a plurality of filtering holes 311, the size of the orifice of each filtering hole 311 is small, raw material substances required to be extracted in the material supply pass through and fall into the discharging hopper 11, meanwhile, the inner wall of the filtering portion 31 is fixedly welded with the pushing spiral plate 33, and in the rotating process of the screen drum 3, the pushing spiral plate 33 synchronously rotates and pushes large-particle impurities in the filtering portion 31 to the impurity discharging portion 32. Arrange and offer the great row's miscellaneous hole 321 of size on the miscellaneous portion 32, the below fixed mounting who just is located row miscellaneous portion 32 on organism 1 has row miscellaneous pipe 13, and the impurity of big granule leaves sieve section of thick bamboo 3 and gets into row miscellaneous pipe 13 through arranging miscellaneous hole 321 to leave organism 1, realize preliminary edulcoration operation.

As shown in fig. 2 and 4, a cleaning mechanism 4 is disposed in the machine body 1, the cleaning mechanism 4 is used for cleaning the outer wall of the filtering portion 31 of the screen drum 3, the cleaning mechanism 4 includes a control component 43, an installation shell 42 and a drum cleaning brush 41, the drum cleaning brush 41 includes an installation block 411 and bristles 412, in this embodiment, the installation block 411 is a square wood block, the bristles 412 are made of steel wire, and the bristles 412 are fixed on one side of the installation block 411. The control assembly 43 comprises a control guide rail 433, the control guide rail 433 is welded inside the machine body 1, the length direction of the control guide rail 433 is parallel to the axis of the screen drum 3, and the mounting shell 42 is connected with the control guide rail 433 in a sliding manner, that is, the sliding direction of the mounting shell 42 is consistent with the length direction of the control guide rail 433; one side of the mounting shell 42 facing the screen drum 3 is in an opening shape, the opening is used for placing the mounting block 411, and after the mounting block 411 is placed in the mounting shell 42, the mounting shell 42 is penetrated by bolts and screwed into the mounting block 411, so that the mounting and fixing of the sweeping drum brush 41 are realized. Sweep a section of thick bamboo brush 41 and be fixed in back in the installation shell 42, the tip that installation piece 411 was kept away from to brush hair 412 and the outer wall contact of filter part 31, at a sieve section of thick bamboo 3 pivoted in-process, brush hair 412 tip and the friction of taking place of sieve section of thick bamboo 3 outer wall, partly block receive brush hair 412's touching and pushed back in sieve section of thick bamboo 3 in the material of crossing filter hole 311 department, reduced the material residue on the wall of sieve section of thick bamboo 3 section of thick bamboo, and there is certain probability in the material such as the dander, iron wire to be scraped by brush hair 412.

As shown in fig. 4, the control assembly 43 can make the mounting block 411 carrying the sweeping drum brush 41 reciprocate along the control guide rail 433, the outer wall of the impurity discharging part 32 of the screen drum 3 is integrally formed with a transmission gear part 34, the transmission gear part 34 is coaxial with the screen drum 3, the control assembly 43 further comprises a control gear 431 and a control rod 432, the control gear 431 is rotatably connected with the machine body 1, the control gear 431 is meshed with the transmission gear part 34, and both are bevel gears, that is, the rotation plane of the control gear 431 is perpendicular to the rotation plane of the screen drum 3. One end of the control rod 432 is hinged to the end face of the control gear 431 and is close to the edge of the control gear 431, the other end of the control rod 432 is hinged to the mounting shell 42, at this time, the control gear 431, the control rod 432, the control guide rail 433 and the mounting shell 42 are established to form a set of crank slider mechanism, when the control gear 431 rotates, the control rod 432 is repeatedly pushed and pulled by the control gear 431, that is, the control gear 431 repeatedly pushes and pulls the mounting shell 42 through the control rod 432, so that the mounting shell 42 reciprocates along the axial direction of the screen cylinder 3, the sweeping cylinder brush 41 and the filtering part 31 have a relative friction trend along the axial direction of the screen cylinder 3, and therefore the success rate of scraping impurities on the screen cylinder 3 by the brush bristles 412 is improved.

As shown in fig. 1, 2 and 4, an observation window 14 is opened on the machine body 1 and located near the cleaning mechanism 4, and a sweeping drum brush 41 is located between the observation window 14 and the drum wall of the screen drum 3, so that an operator can observe the working conditions of the cleaning mechanism 4 and the screen drum 3 conveniently.

As shown in fig. 1 and 5, in the rotation process of the screen drum 3, the material rolls in the screen drum 3 to generate the raise dust, and the raise dust contains a part of feed raw materials, so the recycling mechanism 5 is arranged on the machine body 1, the recycling mechanism 5 comprises a dust exhaust pipeline 51, the dust exhaust pipeline 51 is arranged above the machine body 1, a flower plate 52 is arranged in the dust exhaust pipeline 51, a filter element 53 made of a filter cartridge is arranged on the flower plate 52, and most material particles in the raise dust can be intercepted by the filter element 53. A blowback pipe 54 is fixedly communicated with one side of the dust exhaust pipe 51, which is positioned on the faceplate 52 and is far away from the machine body 1, and the orifice of the blowback pipe 54 extends into the dust exhaust pipe 51 and faces the filter cartridge; the operation principle of the recovery mechanism 5 is the same as that of the filter cartridge dust collector, and the detailed description thereof is omitted.

The implementation principle of the selective filtering precleaner is as follows:

to the fodder material that needs to carry out prefiltration, control reversing mechanism 2 makes reversing plate 24 overturn, inlet pipe 15 and the pipeline 16 intercommunication of just clearing, and the material gets into a sieve section of thick bamboo 3, and a sieve section of thick bamboo 3 rotates, and the material that needs to be utilized gets into row hopper 11 through filtering hole 311 in filter part 31 department, then gets into the next process of assembly line, and bulky impurity is pushed to row miscellaneous portion 32 and falls into row miscellaneous pipe 13. If the materials do not need to be preliminarily purified, the reversing mechanism 2 is controlled to overturn the reversing plate 24, the feeding pipe 15 is communicated with the abdicating pipeline 17, and the materials leave the feeding pipe 15 and then directly enter the discharging hopper 11 and enter the next procedure.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. The utility model provides a filterable precleaner of selectivity, includes organism (1), organism (1) internal rotation is connected with a sieve section of thick bamboo (3), be equipped with inlet pipe (15) on organism (1), organism (1) bottom is equipped with row's hopper (11), its characterized in that: the feed pipe (15) are communicated with a primary cleaning pipeline (16) and an abdicating pipeline (17), the abdicating pipeline (17) is communicated with the inside of the screen drum (3), the abdicating pipeline (17) is communicated with the discharge hopper (11), the feed pipe (15) is provided with a reversing mechanism (2) which is positioned between the primary cleaning pipeline (16) and the abdicating pipeline (17), and the reversing mechanism (2) is used for conducting the feed pipe (15) and the primary cleaning pipeline (16) or the feed pipe (15) and the abdicating pipeline (17).

2. A selective filtration precleaner according to claim 1, wherein: reversing mechanism (2) are including switching-over cylinder (21), connecting rod (22), installation axle (23) and reversing plate (24), switching-over cylinder (21) are articulated with inlet pipe (15), connecting rod (22) are articulated with the piston rod of switching-over cylinder (21), installation axle (23) and connecting rod (22) fixed connection, installation axle (23) rotate with inlet pipe (15) and are connected, installation axle (23) are located inlet pipe (15) and are located between first clear pipeline (16) and abdication pipeline (17), the edge and the installation axle (23) fixed connection of reversing plate (24), the rotation plane of switching-over cylinder (21) is parallel with the rotation plane of installation axle (23).

3. A selective filtration precleaner as claimed in claim 2, wherein: be equipped with butt joint groove (151) on inlet pipe (15) inner wall, be equipped with butt joint pad (152) on the cell wall in butt joint groove (151), one side and the laminating of butt joint pad (152) that installation axle (23) were kept away from in switching-over board (24).

4. A selective filtration precleaner according to claim 1, wherein: the screen drum (3) comprises a filtering part (31) and an impurity discharging part (32) which are communicated with each other, one end of the primary cleaning pipeline (16) far away from the feeding pipe (15) is positioned in the filtering part (31), a filtering hole (311) for feeding raw materials to pass through is formed in the drum wall of the filtering part (31), and the discharging hopper (11) is positioned below the filtering part (31);

arrange miscellaneous hole (321) on arranging the section of thick bamboo wall of miscellaneous portion (32) department, arrange miscellaneous hole (321) and supply impurity to pass through, fixedly connected with propelling movement spiral plate (33) on filtering part (31) inner wall, it is equipped with row miscellaneous pipe (13) just to be located to arrange miscellaneous portion (32) below on organism (1).

5. A selective filtration precleaner according to claim 4, wherein: be equipped with in organism (1) and clean mechanism (4), clean mechanism (4) including sweeping a section of thick bamboo brush (41), sweep a section of thick bamboo brush (41) including brush hair (412), the tip of brush hair (412) and the outer wall contact of filter house (31).

6. A selective filter scalping screen as claimed in claim 5, wherein: sweep a section of thick bamboo brush (41) and still include installation piece (411), the one end fixed connection of sieve section of thick bamboo (3) is kept away from with brush hair (412) to installation piece (411), clean mechanism (4) and still include installation shell (42), installation shell (42) and installation piece (411) pass through the bolt and can dismantle the connection.

7. A selective filtration precleaner according to claim 6, wherein: clean mechanism (4) and still include control assembly (43), control assembly (43) are used for controlling installation shell (42) and move, control assembly (43) are including control guide rail (433), the length direction of control guide rail (433) is parallel with the axis of a sieve section of thick bamboo (3), installation shell (42) and control guide rail (433) slide and are connected.

8. A selective filtration precleaner according to claim 7, wherein: the control assembly (43) further comprises a control gear (431) and a control rod (432), the control gear (431) is rotatably connected with the machine body (1), a transmission gear part (34) is coaxially and fixedly connected to the outer wall of the screen drum (3), the control gear (431) is meshed with the transmission gear part (34), one end of the control rod (432) is hinged to the edge of the control gear (431), the other end of the control rod (432) is hinged to the mounting shell (42), and the rotating plane of the control gear (431) is parallel to the length direction of the control guide rail (433).

9. A selective filter scalping screen as claimed in claim 5, wherein: an observation window (14) is formed in the machine body (1), and the drum sweeping brush (41) is located between the observation window (14) and the screen drum (3).

10. A selective filtration precleaner according to claim 1, wherein: dust exhaust pipeline (51) is seted up at organism (1) top, be equipped with filter core (53) in dust exhaust pipeline (51).