阅读说明：本技术 多级分沙装置及分沙方法 (Multi-stage sand separating device and sand separating method ) 是由 陈明建 刘三豆 陈明群 于 2021-01-29 设计创作，主要内容包括：本发明涉及建筑施工技术领域,公开了一种多级分沙装置及分沙方法,该多级分沙装置包括筛料机构、旋流分沙机构以及输料系统；筛料机构用于对大颗粒泥沙和中颗粒泥沙进行筛选；旋流分沙机构包括至少一个旋流器,旋流器用于筛选出泥浆中的小颗粒泥沙；输料系统包括第一输送管道、设置在第一输送管道上的第一阀门、第二输送管道以及设置在第二输送管道上的第二阀门。本申请提供的一种多级分沙装置,通过设置筛料机构以及旋流分沙机构,当使用上述多级分沙装置对多种不同大小的泥沙进行分离筛选时,能够分离出大颗粒泥沙、中颗粒泥沙以及小颗粒泥沙,实现了对多种不同尺寸的泥沙进行分离筛选,大大提高了泥沙的筛选效率。(The invention relates to the technical field of building construction, and discloses a multi-stage sand separating device and a sand separating method, wherein the multi-stage sand separating device comprises a screening mechanism, a rotational flow sand separating mechanism and a material conveying system; the screening mechanism is used for screening large-particle sediment and medium-particle sediment; the cyclone sand separating mechanism comprises at least one cyclone, and the cyclone is used for screening out small-particle sediment in the slurry; the material conveying system comprises a first conveying pipeline, a first valve arranged on the first conveying pipeline, a second conveying pipeline and a second valve arranged on the second conveying pipeline. The application provides a pair of multistage husky device of dividing divides husky mechanism through setting up sieve material mechanism and whirl, when using above-mentioned multistage husky device of dividing to separate the screening to the not silt of multiple equidimension, can separate out large granule silt, well granule silt and tiny particle silt, has realized separating the screening to the silt of multiple not unidimensional, has improved the screening efficiency of silt greatly.)

1. A multi-stage sand separating device, comprising:

the screening mechanism is used for screening large-particle sediment and medium-particle sediment, and comprises a screening table and a screen structure, wherein the screening table is provided with a net-shaped end face for screening the large-particle sediment, an inner cavity with a downward opening is formed below the net-shaped end face, the screening table is provided with a feeding channel communicated with the cavity, the feeding channel is used for directly feeding the sediment into the cavity, the screen structure is arranged below the net-shaped end face and the feeding channel, and the screen structure is used for screening the medium-particle sediment;

the rotational flow sand separating mechanism comprises at least one cyclone, and the cyclone is used for screening out small-particle sediment in slurry; and

the feeding system comprises a first conveying pipeline, a first valve, a second conveying pipeline and a second valve, wherein the first valve and the second valve are arranged on the first conveying pipeline, the second valve is arranged on the second conveying pipeline, the first conveying pipeline passes through the feeding channel and is communicated with the cavity, and the second conveying pipeline is communicated with the cyclone.

2. The multi-stage sand separating device according to claim 1, wherein the screen structure extends obliquely upward in a horizontal direction; and/or the screen structure is resilient so that silt filtered through the screen structure can bounce off the surface of the screen structure.

3. The multi-stage sand separating device according to claim 2, wherein the screen structure comprises a first screen layer, a plurality of elastic members and a second screen layer, the plurality of elastic members are arranged between the first screen layer and the second screen layer, and one end of each elastic member is connected with the first screen layer, and the other end of each elastic member is connected with the second screen layer.

4. The multi-stage sand separating device according to claim 1, wherein the screening mechanism further comprises a recovery tank disposed below the screen structure; the screen cloth bench is provided with a shunt door, and after the shunt door is opened, the cavity above the screen cloth structure is communicated with the recovery box, so that silt above the screen cloth structure can directly pass through the shunt door to enter the recovery box.

5. The multi-stage sand separating device according to any one of claims 1 to 4, wherein the screening mechanism further comprises a filter screen disposed in the cavity between the feed channel and the screen structure, the filter screen being adapted to filter sand and sand directly entering the cavity from the feed channel.

6. The multi-stage sand separating device according to claim 1, wherein the cyclone sand separating mechanism further comprises a pressure dividing box, the cyclone has an input hole for inputting the mud to be separated, a first output hole for outputting the silt and a part of the fluid, and a second output hole for outputting another part of the fluid; the cyclone is communicated with the pressure dividing box through the second output hole, the pressure dividing box is used for bearing fluid output from the second output hole, and the pressure dividing box is communicated with the outside through a pipeline.

7. The multi-stage sand separating device of claim 6 wherein the swirler includes a separating end and a converging end, the input aperture and the second output aperture being disposed on the separating end, the first output aperture being disposed on the converging end.

8. The multi-stage sand separating device according to claim 7, wherein a separating cavity and a closing cavity are arranged inside the cyclone, the separating cavity is communicated with the closing cavity, the separating cavity is positioned at the separating end, and the closing cavity is positioned at the closing end; the separation cavity is communicated with the outside through the input hole, the separation cavity is communicated with the partial pressure box through the second output hole, and the mouth receiving cavity is communicated with the outside through the first output hole.

9. The multi-stage sand separating device of claim 8 wherein the inner diameter of the mouth collector cavity is tapered in a direction from the separating cavity to the first output aperture.

10. A multi-stage sand separating method, which is characterized in that the multi-stage sand separating device of any one of claims 1 to 9 is used for separating and screening sand sediment with different sizes, and the multi-stage sand separating method comprises the following steps:

dropping mud to be screened from the net-shaped end surface of the screening platform, so that silt with the size smaller than the net holes of the net-shaped end surface can fall into the cavity of the screening platform from the net holes, so that large-particle silt with the size larger than the net holes of the net-shaped end surface can be screened, and silt falling into the cavity can fall onto the net-shaped structure, so that medium-particle silt with the size larger than the net holes of the screen structure can be screened;

the mud to be screened is thrown into the cavity from the feeding channel through the first conveying pipeline, the mud falls on the screen structure, the screen structure can separate and screen the mud, and silt with the size smaller than that of the mesh holes of the screen structure can fall below the screen structure from the mesh holes so as to screen medium-particle silt with the size larger than that of the mesh holes of the screen structure;

and the second conveying pipeline conveys the slurry to be screened into the cyclone, and the cyclone can separate the small-particle sediment from the slurry.

Technical Field

The invention relates to the technical field of building construction, in particular to a multi-stage sand separating device and a sand separating method.

Background

A fluid cyclone is a common type of separation and fractionation equipment. The basic principle of the cyclone is to separate two-phase or multi-phase mixtures with certain density difference, such as liquid-liquid, liquid-solid, liquid-gas, etc., under the action of centrifugal force. The mixed liquid tangentially enters into the cyclone under certain pressure to produce high speed rotating flow field inside the cylindrical cavity. The components with high density in the mixture simultaneously move downwards along the axial direction under the action of the cyclone field, move outwards along the radial direction, move downwards along the wall of the cone section when reaching the cone section, and are discharged from the bottom flow port, so that an outer vortex flow field is formed; the component with low density moves towards the central axis direction, and forms an inner vortex moving upwards in the axis center and then is discharged from the overflow port, thus achieving the aim of separating two phases.

The sand separator is also called a vibrating screen, and is a machine specially designed for screening stones in a stone yard. The sand separating machine has wide application range, almost relates to the aspects of life, and needs various types of vibrating screens during processing and manufacturing. The vibrating screen is mainly used in the industries of mines, coal, smelting, building materials, refractory materials, light industry, chemical industry, medicines, foods and the like.

Among the prior art, the sand separator that has silt and select separately function need change the screen cloth in different apertures when separating the screening to the silt of multiple not unidimensional, and the installation of screen cloth is dismantled very troublesome to screening efficiency has been influenced greatly. The cyclone is applied to the sand separator, so that the sand of various sizes can be classified and screened.

Disclosure of Invention

The invention aims to provide a multi-stage sand separating device and a multi-stage sand separating method, and aims to solve the problem that in the prior art, when an existing sand separating machine is used for separating and screening various kinds of sediment with different sizes, the screening efficiency is low.

The present invention is achieved in that, in a first aspect, the present invention provides a multistage sand separating device comprising:

the screening mechanism is used for screening large-particle sediment and medium-particle sediment, and comprises a screening table and a screen structure, wherein the screening table is provided with a net-shaped end face for screening the large-particle sediment, an inner cavity with a downward opening is formed below the net-shaped end face, the screening table is provided with a feeding channel communicated with the cavity, the feeding channel is used for directly feeding the sediment into the cavity, the screen structure is arranged below the net-shaped end face and the feeding channel, and the screen structure is used for screening the medium-particle sediment;

the rotational flow sand separating mechanism comprises at least one cyclone, and the cyclone is used for screening out small-particle sediment in slurry; and

the feeding system comprises a first conveying pipeline, a first valve, a second conveying pipeline and a second valve, wherein the first valve and the second valve are arranged on the first conveying pipeline, the second valve is arranged on the second conveying pipeline, the first conveying pipeline passes through the feeding channel and is communicated with the cavity, and the second conveying pipeline is communicated with the cyclone.

Further, the screen structure extends upwards obliquely along the horizontal direction; and/or the screen structure is resilient so that silt filtered through the screen structure can bounce off the surface of the screen structure.

Further, the screen structure comprises a first screen layer, a plurality of elastic pieces and a second screen layer, the elastic pieces are arranged between the first screen layer and the second screen layer, one end of each elastic piece is connected with the first screen layer, and the other end of each elastic piece is connected with the second screen layer.

Further, the screening mechanism further comprises a recovery box, and the recovery box is arranged below the screen structure; the screen cloth bench is provided with a shunt door, and after the shunt door is opened, the cavity above the screen cloth structure is communicated with the recovery box, so that silt above the screen cloth structure can directly pass through the shunt door to enter the recovery box.

Further, sieve material mechanism still includes the filter sieve, the filter sieve sets up in the cavity, and be located feedstock channel with between the screen cloth structure, the filter sieve is used for the follow feedstock channel directly gets into silt in the cavity filters.

Furthermore, the rotational flow sand separating mechanism also comprises a pressure dividing box, and the cyclone is provided with an input hole for inputting the mud to be separated, a first output hole for outputting the silt and one part of the fluid and a second output hole for outputting the other part of the fluid; the cyclone is communicated with the pressure dividing box through the second output hole, the pressure dividing box is used for bearing fluid output from the second output hole, and the pressure dividing box is communicated with the outside through a pipeline.

Further, the swirler includes a separation end and a closing end, the input hole and the second output hole are disposed on the separation end, and the first output hole is disposed on the closing end.

Furthermore, a separation cavity and a closing cavity are arranged in the cyclone, the separation cavity is communicated with the closing cavity, the separation cavity is positioned at the separation end, and the closing cavity is positioned at the closing end; the separation cavity is communicated with the outside through the input hole, the separation cavity is communicated with the partial pressure box through the second output hole, and the mouth receiving cavity is communicated with the outside through the first output hole.

Further, the inner diameter of the contracting cavity is gradually reduced along the direction from the separating cavity to the first output hole.

Compared with the prior art, the invention mainly has the following beneficial effects:

according to the multi-stage sand separation device, the screening mechanism and the rotational flow sand separation mechanism are arranged, so that when the multi-stage sand separation device is used for separating and screening various kinds of sediment with different sizes, large-particle sediment, medium-particle sediment and small-particle sediment can be separated, the separation and screening of various kinds of sediment with different sizes are realized, and the screening efficiency of the sediment is greatly improved; simultaneously, mud to be screened can be input to the upper part of the screen structure from the first conveying pipeline, and silt with the size larger than the diameter of the mesh of the screen structure and silt with the size smaller than the diameter of the mesh of the screen structure are separated; in addition, the mud to be screened can be directly input into the cyclone through the second conveying pipeline, and the silt in the mud can be separated; the screening function of this multistage sand separating device is more comprehensive, and the usage is more extensive for the screening mode of multiple difference.

In a second aspect, the present invention further provides a multistage sand separation method, in which any one of the above multistage sand separation devices is used to separate and screen silt of different sizes, and the multistage sand separation method includes:

dropping mud to be screened from the net-shaped end surface of the screening platform, so that silt with the size smaller than the net holes of the net-shaped end surface can fall into the cavity of the screening platform from the net holes, so that large-particle silt with the size larger than the net holes of the net-shaped end surface can be screened, and silt falling into the cavity can fall onto the net-shaped structure, so that medium-particle silt with the size larger than the net holes of the screen structure can be screened;

the mud to be screened is thrown into the cavity from the feeding channel through the first conveying pipeline, the mud falls on the screen structure, the screen structure can separate and screen the mud, and silt with the size smaller than that of the mesh holes of the screen structure can fall below the screen structure from the mesh holes so as to screen medium-particle silt with the size larger than that of the mesh holes of the screen structure;

and the second conveying pipeline conveys the slurry to be screened into the cyclone, and the cyclone can separate the small-particle sediment from the slurry.

Compared with the prior art, the multistage sand separating method provided by the invention has the advantages that various different screening modes can be selected according to different sizes of the sediment to be screened, so that the screening function of the multistage sand separating device is more comprehensive, and the application is more extensive.

Drawings

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

Fig. 1 is a schematic structural diagram of a multi-stage sand separating device provided by an embodiment of the invention;

FIG. 2 is a schematic structural diagram of a material sieving mechanism in a multi-stage sand separating device according to an embodiment of the present invention;

fig. 3 is a schematic cross-sectional structure diagram of a material sieving mechanism in a multi-stage sand separating device according to an embodiment of the invention;

fig. 4 is a schematic structural diagram of a screen structure in a multi-stage sand separating device provided by an embodiment of the invention;

fig. 5 is a schematic structural diagram of a cyclone sand separating mechanism in a multi-stage sand separating device according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a cyclone in a multi-stage sand separating device according to an embodiment of the present invention.

Reference numerals: 1-material sieving mechanism, 2-cyclone sand separating mechanism, 3-material conveying system, 11-material sieving table, 12-screen mesh structure, 13-filter sieve, 21-cyclone, 22-pressure separating box, 31-first conveying pipeline, 32-second conveying pipeline, 111-mesh end surface, 112-cavity, 113-feeding channel, 114-material receiving groove, 121-first screen mesh layer, 122-elastic part, 123-second screen mesh layer, 211-first output hole, 212-separating end, 213-closing end and 214-annular raised strip.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The same or similar reference numerals in the drawings of the present embodiment correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. based on the orientation or positional relationship shown in the drawings, it is only for convenience of describing the present invention and simplifying the description, but it is not intended to indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and are not to be construed as limiting the present patent, and the specific meaning of the terms may be understood by those skilled in the art according to specific circumstances.

The following describes the implementation of the present invention in detail with reference to specific embodiments.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a multi-stage sand separating device according to the present invention, and referring to fig. 2-5, the multi-stage sand separating device according to the present embodiment includes a material sieving mechanism 1, a cyclone sand separating mechanism 2, and a material conveying system 3; the screening mechanism 1 is used for screening large-particle sediment and medium-particle sediment, the screening mechanism 1 comprises a screening table 11 and a screen structure 12, the screening table 11 is provided with a net-shaped end face 111 for screening the large-particle sediment, an inner cavity 112 with a downward opening is formed below the net-shaped end face 111, the screening table 11 is provided with a feeding channel 113 communicated with the cavity 112, the feeding channel 113 is used for directly feeding the sediment into the cavity 112, the screen structure 12 is arranged below the net-shaped end face 111 and the feeding channel 113, and the screen structure 12 is used for screening the medium-particle sediment;

the cyclone sand separating mechanism 2 comprises at least one cyclone 21, and the cyclone 21 is used for screening out small-particle sediment in the slurry;

the feeding system 3 comprises a first conveying pipeline 31, a first valve arranged on the first conveying pipeline 31, a second conveying pipeline 32 and a second valve arranged on the second conveying pipeline 32, wherein the first conveying pipeline 31 is communicated with the cavity 112 through a feeding channel 113, and the second conveying pipeline 32 is communicated with the cyclone 21.

Wherein, the granularity of large granule silt, well granule silt and tiny particle silt reduces in proper order, and the granularity of large granule silt is greater than the mesh diameter of netted terminal surface 111, and the granularity of well granule silt is between the mesh diameter of netted terminal surface 111 and the mesh diameter of screen structure 12, and the granularity of tiny particle silt is less than the mesh diameter of screen structure 12.

The aperture size of the mesh on the mesh end surface 111 is changed according to the requirement, so that large-particle silt with different sizes can be screened out; the aperture size of the mesh of the screen structure 12 is changed according to the requirement, and medium-particle sediment with different sizes can be screened out; the cyclone sand separating mechanism 2 can separate out small-particle silt in the slurry screened by the screening mechanism 1, and certainly, the cyclone sand separating machine can also separate out the silt in the slurry not screened by the screening mechanism 1.

According to the multi-stage sand separation device, the screening mechanism 1 and the rotational flow sand separation mechanism 2 are arranged, so that when the multi-stage sand separation device is used for separating and screening various kinds of silt with different sizes, large-particle silt, medium-particle silt and small-particle silt can be separated, the separation and screening of various kinds of silt with different sizes are realized, and the screening efficiency of the silt is greatly improved; simultaneously, mud to be screened can be input above the screen structure 12 from the first conveying pipeline 31, and silt with the size larger than the diameter of the meshes of the screen structure 12 and silt with the size smaller than the diameter of the meshes of the screen structure 12 are separated; in addition, the mud to be screened can be directly input into the cyclone 21 through the second conveying pipeline 32, and the silt in the mud can be separated; the screening function of this multistage sand separating device is more comprehensive, and the usage is more extensive for the screening mode of multiple difference.

Of course, the multi-stage sand separating device can be used not only for screening silt, but also for a plurality of fields such as mineral separation, material classification and the like, and the invention is not limited to this.

In this embodiment, the mesh diameter of the mesh end face 111 is larger than the mesh diameter of the screen structure 12.

Referring to fig. 2-4, as an embodiment of the present invention, the screen structure 12 extends obliquely upward along the horizontal direction; and/or the screen structure 12 is resilient so that sediment filtered through the screen structure 12 can be knocked off the surface of the screen structure 12. Therefore, silt left above the screen structure 12 after being screened by the screen structure 12 can automatically slide down along the inclined plane of the screen structure 12, and the silt is prevented from remaining on the screen structure 12, so that meshes of the screen structure 12 are blocked; moreover, silt falling from the cavity 112 onto the screen structure 12 and having a size larger than the mesh of the screen structure 12 can be flicked off by the screen structure 12, thereby more effectively preventing silt from depositing on the screen structure 12.

Referring to fig. 4, in the present embodiment, the screen structure 12 includes a first screen layer 121, a plurality of elastic members 122 and a second screen layer 123, the plurality of elastic members 122 are disposed between the first screen layer 121 and the second screen layer 123, and one end of each elastic member 122 is connected to the first screen layer 121, and the other end is connected to the second screen layer 123.

Preferably, the elastic member 122 includes a spring. Of course, the elastic member 122 may have other specific elastic structures.

Referring to fig. 2 and 3, as an embodiment of the present invention, the net-shaped end surface 111 extends obliquely upward in a horizontal direction. In this way, silt left above the net-shaped end face 111 after being screened by the net-shaped end face 111 can automatically slide down along the inclined net-shaped end face 111, and the silt is prevented from remaining on the net-shaped end face 111, so that meshes of the net-shaped end face 111 are blocked.

Preferably, a material receiving groove 114 is arranged at the bottom of the net-shaped end surface 111 along the extending direction of the net-shaped end surface 111. The material collecting groove 114 can collect silt which automatically slides down along the inclined net-shaped end surface 111, so that workers can carry the silt conveniently.

Referring to fig. 3, as an embodiment of the present invention, the material sieving mechanism 1 further includes a filter sieve 13; a filter sieve 13 is arranged in the cavity 112 between the feed channel 113 and the screen structure 12, the filter sieve 13 being arranged to filter silt thrown directly into the cavity 112 from the feed channel 113. The filter sieve 13 can play a role in filtering sundries. For example, when the multistage sand separation device is used for separating silt in mud, impurities contained in the mud can be filtered by the filter sieve 13, and workers only need to clean the filter sieve 13 regularly or irregularly.

As an embodiment of the present invention, the material sieving mechanism 1 further includes a recycling bin disposed below the screen structure 12; be provided with the reposition of redundant personnel door on sieve material platform 11, after the reposition of redundant personnel door was opened, be located the cavity 112 and the collection box intercommunication of screen cloth structure 12 top to silt that is located screen cloth structure 12 top can directly get into in the collection box through the reposition of redundant personnel door. When the screen structure 12 performs a normal separation and screening work on the sediment, the recovery tank can recover the remaining mixture (such as water, sediment, etc.) falling from the meshes of the screen structure 12; when the screen structure 12 is blocked, the excessive silt is deposited above the screen structure 12, and the silt deposited above the screen structure 12 can be discharged into the recovery tank by opening the shunt door. The siltation can effectually be prevented to the top of screen cloth structure 12 in the design of reposition of redundant personnel door for multistage sand separating device has better practicality.

Preferably, the recovery tank communicates with the second conveying duct 32 through a duct; thus, the slurry screened by the screening mechanism 1 can be conveyed to the cyclone 21 by the conveying system 3 through the second conveying pipe, so that the cyclone 21 screens out small-particle silt in the slurry.

Wherein, according to the kind and the size variation of silt, can change different collection boxes or place different charging boxes in the collection box.

Referring to fig. 5, in the present embodiment, the cyclone sand separating mechanism 2 further includes a pressure-dividing box 22, and the cyclone 21 has an input hole for inputting the slurry to be separated, a first output hole 211 for outputting the silt and a part of the fluid, and a second output hole for outputting another part of the fluid; the cyclone 21 is communicated with the partial pressure tank 22 through a second output hole, the partial pressure tank 22 is used for carrying the fluid output from the second output hole, and the partial pressure tank 22 is communicated with the outside through a pipeline so as to discharge the fluid in the partial pressure tank 22.

Specifically, referring to fig. 6, the cyclone 21 includes a separating end 212 and a converging end 213, the input hole and the second output hole are disposed on the separating end 212, and the first output hole 211 is disposed on the converging end 213.

Specifically, a separation cavity and a closing cavity are arranged inside the cyclone 21, the separation cavity is communicated with the closing cavity, the separation cavity is located at the separation end 212, and the closing cavity is located at the closing end 213; the separation chamber is communicated with the outside through the input hole, the separation chamber is communicated with the partial pressure box 22 through the second output hole, and the closing-up chamber is communicated with the outside through the first output hole 211. Mud enters the separation cavity from the input hole and can be separated in the separation cavity, separated sediment and a part of fluid enter the closing-in cavity and are discharged from the first output hole 211, and the other part of the fluid is discharged from the second output hole.

Specifically, the inner diameter of the mouth-receiving chamber is gradually reduced in the direction from the separation chamber to the first output hole 211. That is to say, the inlet port of closing up the oral cavity is big, and the outlet port is little, because the abrupt change of closing up intracavity aperture for silt and some fluid of separating can spout fast under pressure, prevent that silt from producing the siltation in the position of first delivery port 211. Set the output of silt to the structure of binding off simultaneously, also can prevent that silt from taking place the splash, be not convenient for collect the transportation pipeline in.

Preferably, the cyclone 21 is provided with an annular rib 214 on the outer wall thereof, which facilitates the mounting and handling of the cyclone 21. For example, when it is desired to connect the external pipe to the terminating end 213, the external pipe may be fixed and sleeved on the annular protrusion strip 214, so that the silt and a portion of the fluid output from the first output hole 211 enter the external pipe.

The invention also provides a multistage sand separation method, which is used for separating and screening the sediment with different sizes by adopting any one of the multistage sand separation devices, and comprises the following steps:

mud to be screened is thrown down from the net-shaped end surface 111 of the screening platform 11, silt with the size smaller than the net hole of the net-shaped end surface 111 falls into the cavity 112 of the screening platform 11 from the net hole so as to screen large-particle silt with the size larger than the net hole of the net-shaped end surface 111, and the silt falling into the cavity 112 falls onto the net-shaped structure so as to screen medium-particle silt with the size larger than the net hole of the screen structure 12;

mud to be screened is thrown into the cavity 112 from the feeding channel 113 through the first conveying pipeline 31, the mud falls on the screen structure 12, the screen structure 12 can separate and screen the mud, and silt with the size smaller than the meshes of the screen structure 12 falls below the screen structure 12 from the meshes so as to screen medium-particle silt with the size larger than the meshes of the screen structure 12;

the slurry to be screened is conveyed via a second conveying pipe 32 into a cyclone 21, which cyclone 21 is able to separate small-particle silt from the slurry.

Referring to fig. 1, the slurry can be respectively input into the cavity 112 and the cyclone 21 by respectively controlling the opening and closing of the first valve and the second valve, so as to realize the separation and screening of different kinds of silt.

According to the multistage sand separation method, multiple different screening modes can be selected according to different sizes of the sediment to be screened, so that the multistage sand separation device is more comprehensive in screening function and wider in application.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.