阅读说明：本技术 一种流化浮选分离回收农田残膜的方法及装置 (Method and device for recovering farmland residual films through fluidized flotation separation ) 是由 胡灿 李洁 贺小伟 王旭峰 郭文松 王龙 陈墨 赵鹏飞 于 2020-07-13 设计创作，主要内容包括：本发明涉及农田残膜回收再利用技术领域,具体涉及一种流化浮选分离回收农田残膜的方法及装置。该装置包括依次设置的流化制备池、流化浮选池和残膜收集池,所述流化制备池为流化浮选池提供流化溶液,所述流化浮选池的顶部转动设置有浮选网板,浮选网板带动残膜向残膜收集池收集,残膜收集池的底部设有残膜过滤网。回收方法包括步骤1：残膜粉碎与田间杂物筛选；步骤2：流化浮选,2.1流化溶液的制备,2.2残膜流化浮选；步骤3：残膜冲洗与收集；步骤4：烘干处理,即得到回收残膜。本发明对回收后的农田残膜与残茬、土块等田间杂物进行流化浮选分离,再清洗干燥,得到干净可再回收利用的碎膜,达到了农田残膜干净可回收再利用的目标。(The invention relates to the technical field of farmland residual film recycling, in particular to a method and a device for recycling farmland residual films through fluidized flotation separation. The device is including the fluidization preparation pond, fluidization flotation cell and incomplete membrane collecting pit that set gradually, fluidization preparation pond provides the fluidization solution for fluidization flotation cell, the top in fluidization flotation cell is rotated and is provided with the flotation otter board, and the flotation otter board drives incomplete membrane and collects to incomplete membrane collecting pit, and the bottom in incomplete membrane collecting pit is equipped with the incomplete membrane filter screen. The recovery method comprises the following steps of 1: crushing residual films and screening field sundries; step 2: fluidized flotation, 2.1 preparation of a fluidized solution, and 2.2 residual film fluidized flotation; and step 3: washing and collecting residual films; and 4, step 4: and drying to obtain the recovered residual film. The invention carries out fluidized flotation separation on the recovered farmland residual films and field sundries such as stubble, clods and the like, and then cleans and dries the farmland residual films to obtain clean recyclable broken films, thereby achieving the aim of clean and recyclable farmland residual films.)

1. The utility model provides a device of incomplete membrane in farmland is retrieved in fluidization flotation separation, a serial communication port, including fluidization preparation pond (1), fluidization flotation cell (4) and incomplete membrane collecting pit (6) that set gradually, fluidization preparation pond (1) provides fluidization solution for fluidization flotation cell (4), the top rotation of fluidization flotation cell (4) is provided with flotation otter board (2), and flotation otter board (2) drive incomplete membrane is collected incomplete membrane to incomplete membrane collecting pit (6), and the bottom of incomplete membrane collecting pit (6) is equipped with incomplete membrane filter screen (5).

2. The device for separating and recovering farmland residual films by fluidized flotation according to claim 1, characterized in that a water pump (10) is arranged at the bottom of the fluidized preparation tank (1), and a water outlet of a water pipe (11) connected with the water pump (10) is arranged above the fluidized flotation tank (4).

3. The device for separating and recovering farmland residual films by fluidized flotation according to claim 1, characterized in that a stirring paddle is further arranged in the fluidized preparation tank (1) for stirring the fluidized solution.

4. A fluidized flotation separation farmland residual film recycling device according to claim 1, characterized in that the height of the fluidized flotation tank (4) is higher than that of the residual film collecting tank (6).

5. The method for recovering the residual farmland films by using the device for separating and recovering the residual farmland films by fluidized flotation as claimed in claim 1, which is characterized by comprising the following steps:

step 1: smashing residual films and screening field sundries: crushing the recovered residual film, and then carrying out primary screening to remove part of field impurities;

step 2: fluidized flotation:

2.1 preparation of the fluidized solution: preparing a fluidized solution in a fluidized preparation tank (1);

2.2 residual film fluidized flotation: pressurizing the fluidized solution for 2 minutes, then introducing the pressurized fluidized solution into a fluidized flotation tank (4), adding 1/2 of which the amount is equal to the capacity of the fluidized flotation tank (4), and then adding the residual membrane to be separated into the fluidized flotation tank (4) to form a fluidized mixture, so that the capacity of the fluidized flotation tank (4) reaches 3/4; continuously adding a fluidized solution into the fluidized flotation tank (4), turning over the flotation screen plate (2), and driving the surface residual film to flow into the residual film collecting tank (6) by the flotation screen plate (2) to finish fluidized separation;

and step 3: washing and collecting residual membranes: washing and collecting the residual film collected by the residual film collecting tank (6);

and 4, step 4: drying treatment: and (4) taking out the residual film obtained in the step (3), naturally drying the residual film, and then drying the residual film by hot air to obtain the recovered residual film.

6. The method of claim 5, wherein the size of the residual film after pulverization in step 1 is about 4 to 7cm²。

7. The method according to claim 5, wherein the fluidizing solution is a sodium chloride solution, and the ratio of pure water to sodium chloride is 10: 1, specifically, adding purified water into a preparation pool, adding sodium chloride according to a mass ratio, and uniformly stirring at 120r/min for 20min to prepare a sodium chloride solution.

8. The method according to claim 5, wherein step 4 is specifically: taking out the residual membrane in the collection tank, naturally drying for 1 hour, then adopting a hot air drying mode, setting the drying temperature to be 40 ℃, horizontally spreading the residual membrane in the collection tank for 180 degrees, and stopping after the drying time is 30 minutes and the residual membrane is recovered.

9. The method according to claim 5, wherein the mesh size of the residual film filtering net (5) is in a linear relationship with the size of the crushed residual film and the recovery amount of the residual film, and the linear relationship is calculated according to the formula (1):

in the formula (1), z_lMesh size in mm; x is the number of₁The recovery amount of the primary residual film is kg; m is_nIs the average residual film fragment size in mm; b is the test fitting coefficient and takes the value of 2.7542.

10. The method of claim 9, wherein the primary residual film recovery amount is not more than 200 kg.

Technical Field

The invention relates to the technical field of farmland residual film recycling, in particular to a method and a device for recycling farmland residual films through fluidized flotation separation.

Background

The residual film pollution belongs to agricultural non-point source pollution, and at present, the pollution of the residual film of the farmland is increasingly serious. Mechanized recovery is the most important way to solve the pollution of the residual film of the farmland. However, the comprehensive treatment of the residual film pollution mainly focuses on the popularization and application of mechanical film collecting operation and degradable films, and a clear solution for resource recycling of the recovered residual films cannot be provided, so that the recovered residual films are accumulated in a field in large quantity, and part of farmers adopt field landfill and incineration modes to cause serious secondary pollution. The difficulty and the enthusiasm of the recovered residual film are further increased by the problem of difficult treatment of the recovered residual film, and the residual film can be changed into valuable things only by solving the problem of processing and recycling of the recovered residual film, so that the residual film is really recycled. The residual film after mechanical recovery is seriously damaged and is mixed with more field impurities such as field clods, sand and stones, crop stubble and the like to form a residual film mixture, the physical characteristics of the residual film mixture are difficult to accurately measure, the cost of processing the residual film mixture into plastic particles is higher, and the separation technology is difficult to achieve; in addition, the residual film mixture is intensively combusted to generate electricity, so that the heat efficiency is low, a large amount of field impurities are difficult to be refined into the granular fuel required by electricity generation, and the recycling value is low, so that the residual film mixture is effectively separated, the residual film can be processed and reused, and the problem of secondary pollution of the residual film can be thoroughly solved. Although there have been descriptions in the prior art regarding methods for separating residual films from agricultural fields, for example: (Chinese invention patent CN2015101

35802.8 residual film separating and cleaning device) mainly adopts a screening method to separate residual films, but cannot separate the residual films from other field sundries.

Disclosure of Invention

The invention provides a method and a device for separating and recovering farmland residual films by fluidized flotation, aiming at the problems that farmland residual films are difficult to separate, more field sundries such as field clods, sand and stones, crop residual stubbles and the like are mixed in the recovered residual films, the residual films are difficult to separate from the field sundries, and the residual films are recovered and reused.

In order to solve the problems, the invention adopts the following technical scheme:

the invention provides a device for separating and recovering farmland residual films by fluidized flotation, which comprises a fluidized preparation tank, a fluidized flotation tank and a residual film collecting tank which are sequentially arranged, wherein the fluidized preparation tank provides a fluidized solution for the fluidized flotation tank, a flotation screen plate is rotatably arranged at the top of the fluidized flotation tank and drives the residual films to be collected to the residual film collecting tank, and a residual film filtering screen is arranged at the bottom of the residual film collecting tank.

Preferably, a water pump is arranged at the bottom of the fluidization preparation tank, and a water outlet of a water pipe connected with the water pump is arranged above the fluidization flotation tank.

Preferably, the fluidization preparation tank is further provided with a stirring paddle for stirring the fluidization solution.

Preferably, the height of the fluidized flotation tank is higher than that of the residual membrane collecting tank.

The invention also provides a method for recovering farmland residual films by utilizing the device for recovering farmland residual films through fluidized flotation separation, which comprises the following steps:

step 1: smashing residual films and screening field sundries: crushing the recovered residual film, and then carrying out primary screening to remove part of field impurities;

step 2: fluidized flotation:

2.1 preparation of the fluidized solution: preparing a fluidized solution in a fluidized preparation tank (1);

2.2 residual film fluidized flotation: pressurizing the fluidized solution for 2 minutes, then introducing the pressurized fluidized solution into a fluidized flotation tank (4), adding 1/2 of which the amount is equal to the capacity of the fluidized flotation tank (4), and then adding the residual membrane to be separated into the fluidized flotation tank (4) to form a fluidized mixture, so that the capacity of the fluidized flotation tank (4) reaches 3/4; continuously adding a fluidized solution into the fluidized flotation tank (4), turning over the flotation screen plate (2), and driving the surface residual film to flow into the residual film collecting tank (6) by the flotation screen plate (2) to finish fluidized separation;

and step 3: washing and collecting residual membranes: washing and collecting the residual film collected by the residual film collecting tank (6);

and 4, step 4: drying treatment: and (4) taking out the residual film obtained in the step (3), naturally drying the residual film, and then drying the residual film by hot air to obtain the recovered residual film.

Preferably, the size of the residual film after crushing in the step 1 is about 4-7 cm²。

Preferably, the fluidizing solution is a sodium chloride solution, and the ratio of pure water to sodium chloride is 10: 1, specifically, adding purified water into a preparation pool, adding sodium chloride according to a mass ratio, and uniformly stirring at 120r/min for 20min to prepare a sodium chloride solution.

As a preferred scheme, step 4 specifically comprises: taking out the residual membrane in the collection tank, naturally drying for 1 hour, then adopting a hot air drying mode, setting the drying temperature to be 40 ℃, horizontally spreading the residual membrane in the collection tank for 180 degrees, and stopping after the drying time is 30 minutes and the residual membrane is recovered.

Preferably, the mesh size of the residual film filter screen, the size of the crushed residual film and the recovery amount of the residual film are in a linear relation, and the linear relation is calculated according to a formula (1):

in the formula (1), z_lMesh size in mm; x is the number of₁The recovery amount of the primary residual film is kg; m is_nIs the average residual film fragment size in mm; b is the test fitting coefficient and takes the value of 2.7542.

Preferably, the recovery amount of the primary residual film is not more than 200 kg.

The technical scheme of the invention has the following beneficial effects:

1. the invention carries out fluidized flotation separation on the recovered farmland residual films and field sundries such as stubble, clods and the like, and then cleans and dries the farmland residual films to obtain clean recyclable broken films, thereby achieving the aim of clean and recyclable farmland residual films.

2. The device for separating and recovering the residual films of the farmland by fluidized flotation comprises a fluidized preparation pool, a fluidized flotation pool and a residual film collecting pool which are sequentially arranged, wherein the fluidized preparation pool is used for preparing a fluidized solution and supplying the fluidized solution to the fluidized flotation pool, and the fluidized flotation pool can collect the residual films to the residual film collecting pool through a flotation screen plate which is rotatably arranged above the fluidized preparation pool.

3. The method comprises the steps of firstly pressurizing the fluidized solution in the fluidized preparation pool for 2 minutes, then introducing the pressurized fluidized solution into the fluidized flotation pool, stopping the addition of the pressurized fluidized solution after the capacity of the fluidized flotation pool is 1/2, keeping the fluidized solution in a fluidized state, and then quickly adding the residual film stubble to be separated into the fluidized flotation pool to enable the capacity of the fluidized flotation pool to reach 3/4 to form a fluidized mixture, wherein the fluidized solution can generate updraft to drive fragments of micro plastics and the like with lower density in the mixture to float to the surface layer of the fluidized flotation pool, so that the step realizes the fluidized flotation of the residual film.

Drawings

FIG. 1 is a schematic structural diagram of a device for separating and recovering farmland residual films by fluidized flotation.

FIG. 2 is a schematic structural diagram of a fluidized preparation tank for separating and recovering farmland residual films by fluidized flotation.

In the figure, 1-fluidization preparation tank, 2-flotation screen plate, 3-rotating shaft, 4-fluidization flotation tank, 5-residual membrane filter screen, 6-residual membrane collecting tank, 7-water outlet, 8-water inlet, 9-clapboard, 10-water pump, 11-water pipe, 12-mounting hole, 13-stirring shaft and 14-stirring blade.

Detailed Description

The invention is further described with reference to the accompanying drawings and specific examples, which are not intended to be limiting in any way.