CN111438059A

CN111438059A - Screening equipment and fish screening method

Info

Publication number: CN111438059A
Application number: CN202010278476.7A
Authority: CN
Inventors: 刘特元; 刘斌斌; 余洗清
Original assignee: Huawen Food Co ltd
Current assignee: Jinzi Food Group Co ltd
Priority date: 2020-04-10
Filing date: 2020-04-10
Publication date: 2020-07-24
Anticipated expiration: 2040-04-10
Also published as: CN111438059B

Abstract

The invention relates to screening equipment and a fish screening method. The feed inlet of the first rotary screen is connected with the oversize material outlet of the vibrating screen; the stepped screening device is connected with an oversize material outlet of the first drum screen and comprises a multistage climbing belt, a first magnetic adsorption piece and an air screen mechanism; each grade of climbing belt is sequentially arranged in a first direction, and each climbing belt comprises a first end and a second end which is inclined upwards relative to the first end; in the conveying direction of the multi-stage climbing belts along the first direction, any two adjacent stages of climbing belts are sequentially a first climbing belt and a second climbing belt, and the first end of the second climbing belt is positioned below the second end of the first climbing belt; the first magnetic adsorption piece is arranged at the second end of any first climbing belt; the air screen mechanism comprises a first air pipe, the first air pipe is provided with a first air outlet section, and the first air outlet section is arranged on the upper surface of the first end of the second climbing belt. The screening quality and efficiency can be improved by adopting the screening equipment.

Description

Screening equipment and fish screening method

Technical Field

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

Background

The screening equipment is widely and practically mechanical equipment in production processes such as fish embryo processing procedures and the like, and is used for sorting and screening materials. For example, fish embryo screening generally adopts a vibrating screen to screen fish meal and fish slag in an up-and-down vibrating mode, and then adopts an artificial screening mode to perform final screening. The process and process for screening the fish embryos by adopting the mode of combining the vibrating screen and the manual screening are too simple and single, the content of the screened impurities is higher, and the screening efficiency is low.

Disclosure of Invention

Based on this, it is necessary to provide a screening apparatus and a fish screening method capable of improving screening quality and efficiency.

A screening apparatus comprising:

vibrating screen;

the feed inlet of the first rotary screen is connected with the oversize material outlet of the vibrating screen; and

the stepped screening device is connected with a screen oversize material outlet of the first rotary screen; the stepped screening device comprises a multistage climbing belt, a first magnetic adsorption piece and an air screen mechanism; each grade of climbing belt is sequentially arranged in a first direction, and each climbing belt comprises a first end and a second end which is inclined upwards relative to the first end; in the conveying direction of the multi-stage climbing belts along the first direction, any two adjacent stages of climbing belts are a first climbing belt and a second climbing belt in sequence, and the first end of the second climbing belt is positioned below the second end of the first climbing belt; the first magnetic adsorption piece is arranged at the second end of any first climbing belt; the air screen mechanism comprises a first air pipe, the first air pipe is provided with a first air outlet section, and the first air outlet section is arranged on the upper surface of the first end of the second climbing belt.

In some of these embodiments, the screening apparatus further comprises a second trommel having a screen aperture smaller than that of the first trommel;

the feed inlet of the second rotary screen is connected with the screen lower discharge port of the first rotary screen, and the screen upper discharge port of the second rotary screen is connected with the stepped screening device.

In some embodiments, the screening apparatus further includes a third drum screen, the third drum screen sequentially includes a first screen area and a second screen area along the axial conveying direction of the drum, the screen apertures of the first screen area and the second screen area are both smaller than the screen aperture of the second drum screen, and the screen aperture of the first screen area is smaller than the screen aperture of the second screen area;

and the feed inlet of the third rotary screen is connected with the screen underflow discharge outlet of the second rotary screen.

In some embodiments, the screening apparatus further comprises a color selector, a feed inlet of the color selector is connected with an oversize material discharge outlet of the third drum screen, and a discharge outlet of the color selector is connected with the stepped screening device.

In some embodiments, the screening apparatus further comprises a horizontal oscillating screen, wherein the horizontal oscillating screen comprises a large-aperture screen layer and a small-aperture screen layer stacked below the large-aperture screen layer;

the feed inlet of the horizontal swinging screen is connected with the undersize discharge outlet of the second screen mesh area in the third drum screen, the feed inlet of the horizontal swinging screen is communicated with the oversize space of the large-aperture screen mesh layer, and the oversize discharge outlet of the horizontal swinging screen corresponding to the large-aperture screen mesh layer is connected with the stepped screening device.

In some embodiments, the third drum screen further comprises two undersize belt lines for receiving undersize material of the first screen area and undersize material of the second screen area, respectively, and conveying directions of the two undersize belt lines are opposite to each other.

In some of these embodiments, the first trommel, the second trommel, and/or the third trommel are double helical blade trommel screens.

In some embodiments, the stepped screening device further includes a second magnetic adsorption member, the second magnetic adsorption member is disposed on an upper surface of the first end of the second climbing belt, and the second magnetic adsorption member is closer to an end of the first end of the second climbing belt relative to the first air outlet section.

In some embodiments, the first magnetic attraction member and/or the second magnetic attraction member are both magnetic bars, and the first magnetic attraction member and/or the second magnetic attraction member are disposed perpendicular to the first direction.

In some embodiments, the air screen mechanism further includes a second air duct, the second air duct has a second air outlet section, the second air outlet section is disposed on the upper surface of the first end of the second climbing belt, and the second air outlet section is closer to the end of the second climbing belt than the first air outlet section.

In some embodiments, the air outlet holes of the first air outlet section and/or the second air outlet section are arranged towards the first end of the second climbing belt.

A fish screening method comprises the following steps:

carrying out vibration screening on the fish embryo material to be screened;

performing first roller screening on the screened materials subjected to the vibration screening; and

and (3) making the oversize material screened by the first roller pass through a multi-stage climbing belt and carrying out magnetic absorption and air separation impurity removal at the fault position of two adjacent stages of climbing belts.

In some of these embodiments, the method further comprises the steps of:

performing second roller screening on the undersize material screened by the first roller; the materials on the screen screened by the second roller pass through a multi-stage climbing belt and are subjected to magnetic absorption and air separation impurity removal at the fault position of two adjacent stages of climbing belts;

carrying out third roller screening on the undersize material screened by the second roller; performing color sorting on the screened material screened by the third roller; and the materials qualified by color selection pass through a multi-stage climbing belt and are subjected to magnetic absorption and air separation impurity removal at the fault of the adjacent two-stage climbing belt;

performing horizontal swinging screening on the undersize material screened by the third roller; and magnetically attracting the materials on the top layer screened by the horizontal pendulum through a multi-stage climbing belt and removing impurities by air separation at the fault position of two adjacent stages of climbing belts.

The screening equipment and the fish screening method firstly screen materials such as fish embryos in a vibration mode; then, carrying out first roller screening on the screened materials subjected to vibration screening; and then the materials on the screen screened by the first roller pass through a multi-stage climbing belt and are subjected to magnetic absorption and air separation impurity removal at the fault position of two adjacent stages of climbing belts. Compared with a screening mode combining a traditional vibrating screen and manual screening, the problem that metal impurities and light-weight impurities in materials such as fish embryos are not thoroughly removed is solved, the impurity content is effectively reduced, the quality of screened products is improved, the quality of the materials such as the fish embryos in subsequent processing is guaranteed, the experience of consumers is improved, the workload of manual screening is reduced, and the screening efficiency is improved.

Drawings

FIG. 1 is a schematic structural diagram of a screening apparatus according to an embodiment;

FIG. 2 is a schematic illustration of the construction of a shaker screen in the screening apparatus of FIG. 1;

FIG. 3 is a schematic view of a first trommel of the screening apparatus shown in FIG. 1;

FIG. 4 is a schematic view of the stepped screening device of the screening apparatus of FIG. 1;

FIG. 5 is a schematic view of the construction of the first and second ramp belts in the conveying direction of the material in the stepped screening apparatus shown in FIG. 4;

fig. 6 is a schematic structural view of an air screen mechanism in the stepped screening device shown in fig. 4.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

An embodiment of the invention provides screening equipment and a fish screening method. The fish screening method can be carried out by using the screening equipment.

The fish screening method will be described in detail with reference to the screening apparatus. It will be appreciated that the screening apparatus described above may be adapted for use in screening various materials as required. In a specific example, it can be used to screen fish embryos. Generally, the raw material of fish embryo contains fish head, fish meal and fish residue and metal impurities besides fish embryo.

Referring to fig. 1, an embodiment of the present invention provides a screening apparatus 10, in which the screening apparatus 10 includes a vibrating screen 100, a first drum screen 200, and a stepped screening device 700.

The vibrating screen 100 is used for vibrating screening of materials. Referring to fig. 2, in some embodiments, a shaker 100 includes a frame 110, a screen box, a vibratory screen 120, and a vibratory motor 130. The screen box is installed on the frame 110, the vibration screen 120 is disposed in the screen box, and the vibration motor 130 is connected to the vibration screen 120 for driving the vibration of the vibration screen 120. Further, the vibration screen 100 further includes a screen frame coupled with the vibration screen 120 for fixing the vibration screen 120. Further, the vibrating screen 100 further includes a damping spring 140, and the damping spring 140 is disposed between the frame 110 and the screen box for damping vibration.

The vibrating screen 100 utilizes the vibrating motor 130 as a vibration source, so that the fish embryos and other materials are thrown up on the screen of the vibrating screen 100, meanwhile, the fish embryos are driven to be conveyed forwards slowly in a linear motion, impurities or fish meal and the like with the size smaller than the mesh of the screen of the vibrating screen 100 can fall under the screen of the vibrating screen 100 through the screen of the vibrating screen 100, the oversize materials such as the fish embryos on the screen of the vibrating screen 100 are discharged from the oversize material discharge port, and the undersize materials are discharged from the undersize material discharge port of the vibrating screen 100.

Undersize materials are sometimes mixed with materials such as fish embryo and fish head except impurities, so that the undersize materials can be further screened as required, and material waste is avoided.

With continued reference to fig. 1, the inlet of the first trommel 200 is connected to the outlet of the oversize material of the vibrating screen 100. In this way, the oversize material of the vibrating screen 100 is conveyed to the first drum screen 200 through the undersize discharge port of the vibrating screen 100, and the first drum screen is performed.

In some of these embodiments, the screening apparatus 10 further includes a first trommel feed belt 810. Two ends of the first drum screen feeding belt 810 are respectively connected with a discharge port of oversize materials of the vibrating screen 100 and a feeding port of the first drum screen 200, and are used for conveying the oversize materials of the vibrating screen 100 to the first drum screen 200 for screening. It is understood that in some examples, the first trommel feed belt 810 may be omitted.

Further, in the example shown in fig. 1, the first trommel feed belt 810 is conveyed in the same direction as the first direction, and the feed inlet of the first trommel 200 is located at one end of the first trommel feed belt 810 adjacent to the stepped screening device 700.

Referring to fig. 3, in some embodiments, the first trommel 200 is a double helical blade trommel. Further, the first drum screen 200 includes a frame (not shown), a drum 210, and a driving motor (not shown). The cylinder is arranged on the frame, and the driving motor is used for driving the cylinder to overturn. The drum 210 has a screen and a double helical blade (not shown). The double-helical-blade drum screen has a better impurity removal effect than a single-helical-blade drum screen, the time for screening materials such as fish embryos in the drum screen is shortened by a half, and the meat quality of the fish embryos is effectively protected from being torn by high-strength screening.

Oversize material of the vibrating screen 100 falls into the first trommel 200 from the feed inlet of the first trommel 200, and through the overturning of the first trommel 200, the fish embryo is carried forward, rolled and overturned by the double helical blade. In the process, due to the rotation of the double spiral blades, the fish head and the fish embryo can be separated, and the separated fish head, the small fish embryo, the fish meal, the fish residue and the like can penetrate through the screen mesh of the first rotary screen 200 to form undersize materials.

Further, the first drum screen 200 comprises a first undersize belt line 220, undersize materials of the first drum screen 200 fall on the first undersize belt line 220, are carried out by the first undersize belt line 220 from an undersize discharge port, and then can selectively enter a feed port of the second drum screen 300. Oversize materials such as oversize fish embryos of the first drum screen 200 are sent to the stepped screening device 700 through the oversize material outlet for screening.

Further, the first drum screen 200 includes an undersize belt motor 230, and the undersize belt motor 230 is connected to the first undersize belt line 220 for driving the first undersize belt line 220 to operate.

Referring to fig. 1, the stepped screening device 700 is connected to the oversize material outlet of the first drum screen 200. Referring to fig. 4 and 5, the stepped screening apparatus 700 includes a multi-stage climbing belt 710, a first magnetic adsorbing member 721 and a wind screen mechanism 730. The climbing belts 710 at all levels are sequentially arranged in a first direction; the climbing belt 710 comprises a first end 701 and a second end 702 inclined upwards relative to the first end 701; in the conveying direction of the multistage climbing belts 710 along the first direction, any two adjacent stages of climbing belts 710 are a first climbing belt and a second climbing belt in sequence, and the first end 701 of the second climbing belt is located below the second end 702 of the first climbing belt.

The first magnetic attraction member 721 is disposed at the second end 702 of any of the first climbing belts.

Referring to fig. 5 and 6, the air sieving mechanism 730 includes a first air duct 731, the first air duct 731 has a first air outlet section 732, and the first air outlet section 732 is disposed on the upper surface of the first end 701 of the second climbing belt.

Further, the first end of the first climbing belt is connected with the oversize material outlet of the first drum screen 200. Therefore, materials on the screen, such as fish embryos on the screen of the first drum screen 200 and the like, sequentially enter other climbing belts at different levels from the first climbing belt to be screened by the stepped screening device 700.

The stepped screening device 700 is provided with a plurality of stages of climbing belts 710, and a first end 701 of a second climbing belt in any two adjacent stages of climbing belts 710 is positioned below a second end 702 of the first climbing belt, so that adjacent ends of any two adjacent stages of climbing belts 710 form a fault; the second end 702 of the first climbing belt with the higher fault position is provided with a first magnetic adsorption part 721, so that when materials such as fish embryos and the like on the first climbing belt are separated from the first climbing belt or are separated from the first climbing belt, the first magnetic adsorption part 721 can adsorb metal impurities mixed in the materials such as the fish embryos and the like; and the upper surface of the first end 701 of the second climbing belt with the fault at the lower position is provided with a first air outlet section 732, so that after metal impurities are removed from the materials such as fish embryos on the first climbing belt, in the process of falling to the second climbing belt, impurities lighter than normal materials such as normal fish embryos are blown out of the climbing belt 710 by the wind power provided by the air outlet section of the air pipe. Above-mentioned cascaded sieving mechanism 700 utilizes the fault ingenious and optimizes the position of first magnetic adsorption part 721 and first air-out section 732, has improved magnetism and has adsorbed and wind sieve efficiency, has got rid of metal impurity and light weight impurity in materials such as fish embryo effectively, has guaranteed the product quality after the screening, has improved screening efficiency.

The screening device 10 and the fish screening method firstly screen materials such as fish embryos in a vibration mode; then, carrying out first roller screening on the screened materials subjected to vibration screening; and then the materials on the screen screened by the first roller pass through a multi-stage climbing belt and are subjected to magnetic absorption and air separation impurity removal at the fault position of two adjacent stages of climbing belts. Compared with a screening mode combining traditional vibrating screen 100 and manual screening, the problem that metal impurities and light-weight impurities in materials such as fish embryos are not thoroughly removed is solved, the impurity content is effectively reduced, the quality of screened products is improved, the quality of the materials such as the fish embryos in subsequent processing is guaranteed, the experience of consumers is improved, the workload of manual screening is reduced, and the screening efficiency is improved.

With continued reference to fig. 1, in some embodiments, the screening apparatus 10 further includes a second trommel 300. The mesh size of the second trommel 300 is smaller than that of the first trommel 200. The feed inlet of the second drum screen 300 is connected with the screen outlet of the first drum screen 200, and the screen outlet of the second drum screen 300 is connected with the stepped screening device 700.

It is understood that the basic structure of the second trommel 300 may be substantially the same as the first trommel 200, except that the mesh size of the second trommel 300 is smaller than that of the first trommel 200. Thus, the second drum screen 300 performs the second drum screening on the undersize material screened by the first drum; the stepped screening device 700 is used for performing magnetic attraction and air separation impurity removal on the materials screened by the second roller through the multistage climbing belts and at the fault positions of the adjacent two stages of climbing belts. Further, the second trommel 300 may also be a double helical blade trommel.

Further, in some examples, the first trommel 200 is stacked with the second trommel 300, and the first trommel 200 is disposed above the second trommel 300, thereby reducing the footprint by half. The undersize material screened by the first drum screen 200 enters the second drum screen 300 below through the material channel to be screened continuously.

Further, the second drum screen 300 includes a second undersize belt line (not shown), and fish heads, small fish embryos, fish meal, fish residues, and the like separated again by the second drum screen 300 in the screening process may fall on the second undersize belt line through the screen, and are carried out of the second drum screen 300 by the second undersize belt line from an undersize discharge port, and then may selectively enter a feed port of the third drum screen 400. The oversize materials such as oversize fish embryos of the second drum sieve 300 are sent to the stepped sieving device 700 through the oversize material outlet for sieving.

Further, the screening apparatus 10 also includes a second trommel feed belt 820. Both ends of the second trommel feeding belt 820 are respectively connected with the second undersize belt line and the feeding port of the third trommel 400 (see below), and further the undersize material of the second trommel 300 is conveyed to the third trommel 400 through the second trommel feeding belt 820.

With continued reference to fig. 1, in some embodiments, the screening apparatus 10 further includes a third trommel 400. The third trommel 400 sequentially includes a first screen area and a second screen area along the axial conveying direction of the drum. The screen mesh apertures of the first screen area and the second screen area are smaller than the screen mesh aperture of the second drum screen 300, and the screen mesh aperture of the first screen area is smaller than the screen mesh aperture of the second screen area. The feed inlet of the third drum screen 400 is connected with the undersize discharge outlet of the second drum screen 300.

Further, the third trommel 400 is a double helical blade trommel.

Further, the third trommel 400 includes a third undersize belt line and/or a fourth undersize belt line. The third undersize belt line and the fourth undersize belt line are respectively used for receiving undersize materials in the first screen area and undersize materials in the second screen area.

Undersize material of the second rotary screen 300 enters the third rotary screen 400 from the feeding hole of the third rotary screen 400, and fish embryos are driven by the double helical blades to be conveyed forwards, rolled and turned over by turning over of the third rotary screen 400. In the process, due to the rotation effect of the double spiral blades, fish heads and fish embryos are separated, and the separated fish heads, small fish embryos, fish meal and fish residues and the like fall on a third undersize belt line of the front section through the first screen area of the front section and are taken out of the third rotary screen 400 by the third belt line; the fish head will fall on the fourth undersize belt line of the rear section through the second screen area of the rear section, be brought out of the third trommel 400 by the fourth belt line, and then selectively enter the horizontal pendulum sieve 600 (see below) for screening. Oversize material such as fish embryos on the second screen area may be fed through an oversize outlet to a color sorter 500 (see below) for screening.

Further, the conveying directions of the third undersize belt line and the fourth undersize belt line are deviated from each other. So the direction of delivery that the undersize material in first screen cloth district, the undersize material in second screen cloth district deviate from each other, and the material on the screen in second screen cloth district gets into look selection machine 500, and then reaches the effect that the screening result divide into three kinds of fish meal fish dregs, fish head, fish embryo.

With continued reference to fig. 1, in some embodiments, the screening apparatus 10 further includes a color sorter 500. The feed inlet of the color sorter 500 is connected with the discharge outlet of oversize products of the third rotary screen 400, and the discharge outlet of the color sorter 500 is connected with the stepped screening device 700. The color sorter 500 is used for screening oversize material from the third trommel 400; the stepped screening apparatus 700 is also used to screen the color sorter 500 for acceptable materials.

The undersize material screened by the second roller is subjected to third roller screening; then, carrying out color sorting and screening on the materials on the screen screened by the third roller; and then the qualified materials screened by the color sorting pass through a multi-stage climbing belt and are subjected to magnetic absorption and air separation impurity removal at the fault position of the adjacent two-stage climbing belt.

Further, the color sorter 500 includes a feeding system, an optical detection system, a signal processing system, a separation execution system, and a manual operation touch screen. The feeding system is used for feeding materials. The optical detection system is used for optically detecting the materials on the feeding system. The signal processing system is connected with the optical detection system and used for obtaining a processing result. And the separation execution system sorts the materials to a sorting area or a waste collection line according to the processing result. The sorting area is connected with the discharge port, and the qualified materials are discharged from the color sorter 500 through the discharge port. The off-spec material is collected on a waste collection line. The manual operation touch screen is connected with the feeding system, the optical detection system, the signal processing system and the separation execution system so as to input manual instructions.

Further, the feeding system also comprises a sensor, and the sensor is used for sensing the material passing through. The optical detection system is used for carrying out optical detection on the materials according to the intensity and color change of light before and after the materials pass through. The separation execution system can perform sorting work through the electromagnetic valve.

With continued reference to fig. 1, in one embodiment, the screening apparatus 10 further includes a pendulum screen 600. The horizontal swinging sieve 600 includes a large-aperture sieve layer and a small-aperture sieve layer stacked below the large-aperture sieve layer. The feed inlet of the horizontal swinging screen 600 is connected with the undersize discharge outlet of the fourth screen area in the third drum screen 400, and the feed inlet of the horizontal swinging screen 600 is communicated with the oversize space of the large-aperture screen layer. The oversize material outlet of the horizontal oscillating screen 600 corresponding to the large-aperture screen layer is connected with the stepped screening device 700.

It should be noted that the mesh size of the large-aperture mesh layer is larger than that of the small-aperture mesh layer, and the material passes through the large-aperture mesh layer and then the small-aperture mesh layer in the horizontal pendulum sieve 600. In addition, the mesh size of the large-aperture mesh layer is smaller than that of the second mesh zone in the third trommel 400.

The undersize material of the fourth screen area of the third trommel screen 400, which contains fish heads and fish meal, sometimes contains some fish embryos with smaller sizes, and the undersize material is screened again by the horizontal swing screen 600 to maximize the recovery of fish embryo raw materials.

Furthermore, the oversize material outlet corresponding to the large-aperture screen layer is a first layer of material outlet, the oversize material outlet corresponding to the small-aperture screen layer is a second layer of material outlet, and the undersize material outlet corresponding to the small-aperture screen layer is a third layer of material outlet. Specifically, the horizontal pendulum sieve 600 further comprises a bearing layer arranged on the small-aperture sieve layer; more specifically, the receiving layer is a stainless steel layer. So that the fish meal and fish residues can enter the third layer of discharge hole through the small-aperture screen layer and are screened out; the fish heads can be screened out through a discharge hole of the second layer of screen mesh; the fish embryo can be screened out through the discharge hole of the first layer screen mesh, thereby achieving the effect of 600 layered screening of the horizontal swing screen. Further, the fish embryos discharged from the outlet of the first screen can further enter the stepped screening device 700 for screening.

It is understood that the number of the horizontal pendulum screens 600 may be plural.

In a specific example, materials such as fish embryos and the like can be sequentially screened by a vibrating screen 100, a first drum screen 200, a second drum screen 300 and a third drum screen 400; the oversize material of the third drum screen 400 is sequentially screened by the color sorter 500 and the stepped screening device 700, and the undersize material of the third drum screen 400 is sequentially screened by the horizontal swing machine and the stepped screening device 700. In the specific example, the screening method of the material to be screened of the fish embryo comprises the following steps of S11-S15:

and step S11, performing vibration screening on the material to be screened of the fish embryo.

Step S12, performing first roller screening on the screened materials subjected to vibration screening; and making the materials on the screen screened by the first roller pass through a multi-stage climbing belt and perform magnetic absorption and air separation impurity removal at the fault position of two adjacent stages of climbing belts.

Step S13, performing second roller screening on the undersize material screened by the first roller; and making the oversize material screened by the second roller pass through a multi-stage climbing belt and perform magnetic absorption and air separation impurity removal at the fault position of two adjacent stages of climbing belts.

Step S14, carrying out third roller screening on the undersize materials screened by the second roller; performing color sorting on the oversize material screened by the third roller; and the materials which are qualified by color selection pass through a multi-stage climbing belt and are subjected to magnetic absorption and air separation impurity removal at the fault position of two adjacent stages of climbing belts.

Step S15, performing horizontal swing screening on the undersize materials screened by the third roller; and magnetically attracting, winnowing and removing impurities from the materials on the uppermost layer screened by the horizontal swing through the multistage climbing belts and at the fault positions of the two adjacent stages of climbing belts.

Through seven-fold screening, the impurity content in the fish embryo can be greatly reduced, and the quality of the fish embryo is greatly improved.

It is understood that in some embodiments, a manual screening step is also included after screening by stepped screening apparatus 700. The fish embryos are screened by the stepped screening device 700 and then sent to a manual screening workshop, the fish embryos on the operation table are screened manually in groups, the fish embryos with the sizes not within the specification range and other mixed trash fishes are mainly screened, and the screened qualified fish embryos are sent to a processing workshop for processing production. Through eight-fold screening, the impurity content in the fish embryo is further reduced, and the quality of the fish embryo is improved.

Further, in the stepped screening apparatus 700, the first direction is a linear direction, and the climbing belts 710 of each stage are sequentially disposed on a straight line.

In some of these embodiments, the number of the climbing bands 710 in the multi-stage climbing band 710 is three or more. The steps of the magnetic adsorption screening and the air screening are repeated for multiple times, so that the screening efficiency is further improved. It is understood that the number of the climbing bands 710 in the multi-stage climbing band 710 can be set according to specific needs. In the specific example shown in fig. 4, the number of the climbing belts 710 in the multistage climbing belt 710 is four, and other structures are similar. The quality of the fish embryo product after the three-time magnetic adsorption screening and the air screening is repeated is higher, and the fish embryo product can be subsequently manually screened again as required.

It is understood that the number of the climbing bands 710 in the multistage climbing band 710 may be two, as shown in fig. 5.

Furthermore, each climbing belt 710 further comprises a baffle 713, and the baffle 713 is arranged on the belt 711 and used for preventing materials such as fish embryos and the like on the belt 711 from sliding downwards; specifically, the number of the baffles 713 is plural, and the baffles are arranged in the conveying direction of the belt 711 in sequence at intervals.

It is understood that the "first climbing band" and the "second climbing band" described herein are relative to the adjacent two-stage climbing band 710; in any two adjacent stages of the climbing belts 710 in the conveying direction of the multistage climbing belt 710 in the first direction, "the first climbing belt" is located upstream, and "the second climbing belt" is located downstream. It is understood that in the conveying direction of the multi-stage climbing belts 710 along the first direction, other climbing belts 710 may be the "second climbing belt" except for the first climbing belt 710; in the conveying direction of the multistage climbing belt 710 in the first direction, the other climbing belts 710 except for the last climbing belt 710 may be the "first climbing belt".

It will be appreciated that in some embodiments, in the transport direction of multi-stage belts 710 along the first direction, first air conduit 731 is provided on each of the belts 710 except that the first air conduit 731 is not provided on the first belt 710. It is understood that in other embodiments, each climbing belt 710 can have a first air conduit 731 disposed thereon.

The first and second of the first and second climbing belts refer to the sequence of passing in the stepped screening device 700 in the conveying direction of the material. It will be appreciated that in one embodiment, the material to be screened in the stepped screening apparatus 700 is fed into the first ramp zone, then into the second ramp zone, and so on.

It is understood that, in some embodiments, in the conveying direction of the multi-stage climbing belts 710 along the first direction, the first magnetic adsorbing member 721 is disposed on all of the climbing belts 710 except the last climbing belt 710. It is understood that in other embodiments, the first magnetic absorption member 721 may be disposed on each of the climbing belts 710. It is understood that a plurality of first magnetic absorption members 721 may be disposed on one climbing belt 710, and in the specific example shown in fig. 4, the number of the first magnetic absorption members 721 is two, and the two first magnetic absorption members 721 are disposed perpendicular to the first direction.

In some embodiments, the stepped screening device 700 further comprises a second magnetic attraction member (not shown). The second magnetic adsorption member is disposed on the upper surface of the first end 701 of the second climbing belt, and the second magnetic adsorption member is closer to the end of the first end 701 of the second climbing belt than the first air outlet section 732. The metal impurities which are not adsorbed by the first magnetic adsorbing member 721 or have a lighter weight may be further mixed in the fish embryo and fall onto the second climbing belt, so that the metal impurities may be further adsorbed by the second magnetic adsorbing member, so as to recycle the metal impurities. In addition, the second magnetic adsorbing member is closer to the end of the first end 701 of the second climbing belt than the first air outlet section 732, and the second magnetic adsorbing member can blow the metal impurities which are not adsorbed or have lighter mass by the first magnetic adsorbing member 721 to the second magnetic adsorbing member by using the wind power provided by the first air outlet section 732, so that the second magnetic adsorbing member can complete the adsorption better.

In some embodiments, the first magnetic adsorbing member 721 and/or the second magnetic adsorbing member are both magnetic rods, and the first magnetic adsorbing member 721 and/or the second magnetic adsorbing member are disposed perpendicular to the first direction.

In some embodiments, the air screen mechanism 730 further comprises a second air duct (not shown). The second air duct has a second air outlet section, the second air outlet section is disposed on the upper surface of the first end 701 of the second climbing belt, and the second air outlet section is closer to the end of the second end 702 of the second climbing belt than the first air outlet section 732. Therefore, the second air outlet section of the second air pipe can carry out blowing type air separation on the materials such as fish embryos and the like spread on the second climbing belt so as to further remove the impurities with lighter weight.

With continued reference to fig. 5 and fig. 6, in some embodiments, the first air outlet section 732 and/or the second air outlet section are disposed perpendicular to the first direction.

In some embodiments, the air outlet 7321 of the first air outlet 732 and/or the second air outlet is disposed toward the first end 701 of the second climbing belt. The first end 701 of the second climbing belt is arranged obliquely downwards relative to the second end 702 of the second climbing belt, the air outlet 7321 is arranged towards the first end 701 of the second climbing belt, the conveying direction of materials such as fish embryos is obliquely upwards for a single climbing belt 710, and the materials with light weight can be also driven to move towards the first end 701 in the climbing process; therefore, the flowing directions of the materials such as the fish embryos and the impurities are opposite, and the materials and the impurities are further promoted to be effectively separated.

In some embodiments, the number of the air outlet holes 7321 on the first air outlet segment 732 and/or the second air outlet segment is multiple, and the air outlet holes 7321 are sequentially arranged along a direction perpendicular to the first direction.

In some of these embodiments, the air screen mechanism 730 further comprises a blower 733, the blower 733 being in communication with both the first and

second ductwork

731, 731. It will be appreciated that when the second ductwork is not present, the blower 733 is in communication with the first ductwork 731. In other examples, two blowers 733 may be used to communicate with the first and second ductwork 731, respectively.

Further, in this specific example, the fan 733 is provided on the climbing belt 710. A section of the first air duct 731 and/or the second air duct connected to the blower 733 is disposed parallel to a length direction of the climbing belt 710. Further, a section of the first air duct 731 connected to the first air outlet section 732 is disposed perpendicular to the first direction; furthermore, a section of the second air pipe connected with the second air outlet section is arranged perpendicular to the first direction.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A screening apparatus, comprising:

vibrating screen;

2. A screening apparatus according to claim 1, further comprising a second trommel having a smaller screen mesh size than the first trommel;

3. The screening apparatus according to claim 2, further comprising a third drum screen, wherein the third drum screen sequentially comprises a first screen area and a second screen area along the axial conveying direction of the drum, the screen apertures of the first screen area and the second screen area are smaller than the screen aperture of the second drum screen, and the screen aperture of the first screen area is smaller than the screen aperture of the second screen area;

4. The screening apparatus of claim 3, further comprising a color sorter, wherein a feed inlet of the color sorter is connected to a oversize product discharge outlet of the third trommel, and a discharge outlet of the color sorter is connected to the stepped screening device.

5. The screening apparatus of claim 4, further comprising a horizontal oscillating screen comprising a large-aperture screen layer and a small-aperture screen layer stacked below the large-aperture screen layer;

6. A screening apparatus according to claim 3, wherein the third trommel further comprises two undersize belt lines for receiving undersize material of the first screen area and undersize material of the second screen area respectively, the two undersize belt lines being conveyed in directions away from each other.

7. A screening apparatus according to claim 3, wherein the first trommel, the second trommel and/or the third trommel are double helical blade trommel screens.

8. The screening apparatus as claimed in any one of claims 1 to 7, wherein the stepped screening device further includes a second magnetic adsorbing member, the second magnetic adsorbing member is disposed on an upper surface of the first end of the second climbing belt, and the second magnetic adsorbing member is closer to an end of the first end of the second climbing belt than the first air outlet section.

9. The screening apparatus of claim 8, wherein the first and/or second magnetic attraction members are magnetic bars, and the first and/or second magnetic attraction members are disposed perpendicular to the first direction.

10. A fish screening method is characterized by comprising the following steps:

carrying out vibration screening on the fish embryo material to be screened;

11. The method of screening fish of claim 10, further comprising the steps of: