A demagnetization device and demagnetization method for electronic grade chemical NMP

Abstract

The invention relates to a demagnetization device and a demagnetization method for electronic-grade chemical NMP. The demagnetization device comprises a liquid tank, an electric demagnetization component, a waste liquid tank and a delivery pump. The liquid tank and the electric demagnetization component are demagnetized by a delivery pump and a pipeline. The waste liquid tank and the electric demagnetization component are connected by a pipeline for removing magnetic substances after demagnetization. The demagnetization method comprises: (1) demagnetization: in a power-on state, the material is demagnetized by a magnetic medium net and then flows back into the liquid tank for continuous circulation; (2) back-blowing: in a power-on state, the material stops entering, and the nitrogen pressure pushes the material remaining at the bottom of the electric demagnetization cavity into the liquid tank; (3) flushing: in a power-off state, the material stops entering, and NMP enters the cavity to flush the magnetic substances attached to the magnetic medium net under pressure; (4) slag discharge: in a power-off state, the material stops entering, and the nitrogen discharges the magnetic substances after flushing into the waste liquid tank. The invention can improve the purity of NMP to meet the requirements of electronic grade of NMP.

Description

Technical Field

[0001] The invention belongs to the technical field of NMP demagnetization, and in particular relates to an electronic-grade chemical NMP demagnetization device and a demagnetization method. Background Art

[0002] NMP solution is an excellent advanced solvent, a polar solvent with strong selectivity and good stability. It is an excellent cleaning agent for high-precision electronics, circuit boards, and lithium batteries. It is widely used in the refining of advanced lubricants, the synthesis of polymers, insulating materials, pesticides, pigments, and cleaning agents. As an important chemical raw material, NMP is also a commonly used cleaning agent solvent in the production process of lithium batteries. In the production process of lithium batteries, NMP is often used as a cleaning agent solvent when making lithium battery positive and negative electrode materials and lithium battery diaphragms. NMP solution cannot contain metal substances. During the production process, the NMP aqueous solution needs to be demagnetized.

[0003] In the traditional NMP chemical demagnetization process, a pipeline permanent magnetic iron remover is usually installed before filling, connected by a metal pipe. The magnetic field strength is 8000-12000GS, and the demagnetization ability is weak. Because the magnetic material adheres to the magnetic rod, it needs to be manually disassembled and cleaned regularly. Often, incomplete manual cleaning will cause some magnetic material to remain, posing a quality risk. In addition, for high-purity chemicals, the trace requirements for magnetic materials are generally increased from ppm to ppb level, and the size of metal particles is reduced from 1μm to 0.05μm. Therefore, if the battery grade is increased from 99.9% to the electronic grade 99.99%, it is necessary to optimize and innovate the system to achieve high-quality and high-purity chemical reagent production. Summary of the invention

[0004] In order to solve the problems in the prior art, the present invention provides an electronic-grade chemical NMP demagnetization device to improve the purity of NMP to meet the requirements of NMP electronic grade.

[0005] The present invention solves the technical problem by adopting the following technical solutions:

[0006] The present invention aims to provide an electronic grade chemical NMP demagnetization device, comprising a liquid tank, an electric demagnetization component, a waste liquid tank and a delivery pump. The liquid tank and the electric demagnetization component are demagnetized by a delivery pump and a pipeline circulation, and the waste liquid tank and the electric demagnetization component are connected by a pipeline to remove magnetic substances after demagnetization by the electric demagnetization component.

[0007] Furthermore, the electromagnetism removal component includes an electromagnetism removal cavity and a magnetic medium net and an electromagnetic coil connected in the electromagnetism removal cavity.

[0008] Furthermore, an NMP cleaning port and a nitrogen port are provided on the top of the electromagnetism removal chamber.

[0009] Furthermore, a cooling element is provided in the electromagnetism removing cavity, and the cooling element has an internal oil circuit and an external water circuit.

[0010] Furthermore, the magnetic medium material contains one or more elements such as Fe, Ni, Cr, Co, etc.

[0011] Furthermore, the liquid tank is provided with a feed port and a return port, the delivery pump is connected to the feed port and the bottom of the electromagnetism removal component through a set feed pipe, and the top of the electromagnetism removal component is connected to the return port through a set reflux pipe.

[0012] Furthermore, a four-way transfer interface is provided at the bottom of the electromagnetism demagnetization chamber, a reflux pipe 2 is provided between the four-way transfer interface and the reflux pipe 1, a slag discharge pipe is provided between the four-way transfer interface and the waste liquid tank, and the four interfaces of the four-way transfer interface are respectively connected to the bottom of the electromagnetism demagnetization chamber, the feed pipe, the reflux pipe 2 and the slag discharge pipe.

[0013] Furthermore, the magnetic flux density of the electromagnetism demagnetization assembly is 2.0-3.5T, the magnetic field strength is 12000-30000Gs, the output is 1-50T / H, and the pressure is 0.01-1.0Mpa.

[0014] Furthermore, the liquid tank, the electromagnetism removal chamber and the pipeline in contact with the material are all made of corrosion-resistant and pressure-resistant non-metallic materials.

[0015] A method for demagnetizing electronic grade chemical NMP comprises the following steps:

[0016] (1) Demagnetization: When the power is on, the NMP in the liquid tank is transported to the electromagnetization chamber through the delivery pump. After the material is demagnetized by the magnetic medium, it flows back to the liquid tank and circulates continuously;

[0017] (2) Blowback: When the power is on, the material stops entering, and nitrogen enters the electromagnetism removal chamber through the nitrogen port with a pressure of 0.5MPa. The nitrogen pressure pushes the material remaining at the bottom of the electromagnetism removal chamber to the liquid tank, reducing the material residue in the equipment;

[0018] (3) Flushing: When the power is off, the material stops entering, and NMP enters the chamber through the NMP cleaning port pipe to flush the magnetic material attached to the magnetic medium net under pressure;

[0019] (4) Slag discharge: When the power is off, the material stops entering, and nitrogen is used to discharge the flushed magnetic material into the waste liquid tank through the nitrogen port.

[0020] Compared with the prior art, the beneficial technical effects of the present invention are:

[0021] 1. The present invention adopts electromagnetic demagnetization instead of permanent magnet. The electromagnetic magnetic field is evenly distributed and has a high gradient, which avoids the problem of permanent magnet magnetic attenuation leading to a decrease in demagnetization ability. The magnetic field intensity is higher, the demagnetization ability is stronger, and the effect is better, so as to achieve the purification of high-quality chemicals and upgrade the chemical NMP from battery grade (99.9%) to electronic grade (99.99%).

[0022] 2. The device of the present invention does not require manual cleaning, avoids residual magnetic materials, can realize continuous and automated demagnetization, improves productivity, and avoids operators in the cleaning and disassembly process, reduces material loss, reduces safety hazards, and achieves safe production.

[0023] 3. The entire device of the present invention is made of non-metallic material to avoid the introduction of metal and improve quality control capabilities; the device is equipped with an internal oil circulation and a water-cooled external circulation system to increase the life of the equipment.

[0024] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above contents of the present invention and its objectives, features and advantages more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention is a schematic diagram of an electronic grade chemical NMP demagnetization device.

[0026] Figure 2 It is a schematic structural diagram of the electric demagnetization component of the present invention.

[0027] 1-liquid tank, 11-feeding port, 12-discharging port, 13-feeding port, 14-returning port, 2-electromagnetic demagnetization component, 21-electromagnetic demagnetization chamber, 22-NMP cleaning port, 23-nitrogen port, 24-cooling part, 25-equipment base, 26-electromagnetic coil, 27-chamber top cover, 28-magnetic medium net, 29-inner cylinder, 3-waste liquid tank, 31-slag discharge pipe, 32-drain pipe, 4-delivery pump, 5-feeding pipe, 6-reflux pipe one, 7-four-way adapter, 8-reflux pipe two. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following embodiments are only exemplary illustrations and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope of protection that the present invention is intended to protect.

[0029] In addition, unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0030] An electronic-grade chemical NMP demagnetization device comprises a liquid tank 1, an electric demagnetization component 2, a waste liquid tank 3 and a delivery pump 4. The liquid tank 1 comprises a feed port 11 and a discharge port 12. The feed port 11 is used to input non-demagnetized NMP material into the liquid tank 1, and the discharge port 12 is used to output the demagnetized NMP from the liquid tank 1. The liquid tank 1 is also provided with a feed port 13 and a return port 14. The feed port 13 is connected to the inlet of the delivery pump 4 through a feed pipe 5, and the outlet of the delivery pump 4 is connected to the electric demagnetization component 2 through the feed pipe 5. The electric demagnetization component 2 is connected to the return port 14 through a return pipe 6. The NMP in the liquid tank 1 is transported to the electric demagnetization component 2 for demagnetization by the delivery pump 4, and then flows back to the liquid tank 1, so as to obtain the electronic-grade chemical NMP through cyclic demagnetization. It should be understood that control valves are provided on each pipeline to control the flow of the medium in the pipeline.

[0031] The electromagnetism removal assembly 2 includes an electromagnetism removal chamber 21, an NMP cleaning port 22, a nitrogen port 23, a cooling member 24, an equipment base 25, an adapter, a chamber top cover 27 and a magnetic medium net 28. The chamber top cover 27 covers the top of the electromagnetism removal chamber 21. The top of the electromagnetism removal chamber 21 is provided with an NMP cleaning port 22 and a nitrogen port 23. The electromagnetism removal chamber 21 is provided with an inner cylinder 29, and a magnetic medium net 28 is provided in the inner cylinder 29. An electromagnetic coil 26 and a cooling member 24 are provided outside the inner cylinder 29. The magnetic medium net 28 is used to remove magnetic impurities contained in NMP. Preferably, the magnetic medium net The mesh body 28 is in the shape of a mesh cake, and the cooling member 24 is used to cool the electromagnetic coil 26. A transfer port is provided at the bottom of the electromagnetism demagnetization cavity 21, and the entire electromagnetism demagnetization cavity 21 is supported and fixed by a base provided at the bottom. During demagnetization, NMP enters the inner cylinder 29 from the transfer port at the bottom of the electromagnetism demagnetization cavity 21, and the magnetic medium mesh 28 is made magnetically conductive under the action of the energized electromagnetic coil 26. When NMP passes through the magnetic medium mesh 28, the magnetic impurities in the NMP are captured by the magnetic medium mesh 28, and the demagnetized NMP returns to the liquid tank 1 from the reflux pipe 6 at the top of the electromagnetism demagnetization cavity 21.

[0032] The magnetic medium net 28 is a man-made composite material with special electromagnetic properties. It is composed of a series of microstructures or unit cells. The size of these microstructures is much smaller than the wavelength of electromagnetic waves. They can be arranged and stacked to form a two-dimensional or three-dimensional structure with specific properties. The unique design and control of the magnetic medium net 28 enables it to exhibit extraordinary magnetic response. The unit cells of the magnetic medium net 28 are usually composed of conductive materials, insulating materials or magnetic materials to achieve the desired electromagnetic response. The unique design and microstructure of the magnetic medium net 28 enable it to have a significant impact on the magnetic field component of electromagnetic waves. By adjusting the size, shape and arrangement of the unit cells, the magnetic medium net 28 can exhibit abnormal magnetic responses, such as negative magnetic permeability, negative magnetic susceptibility and negative refraction.

[0033] The material of the magnetic medium network 28 contains one or more elements such as Fe, Ni, Cr, and Co.

[0034] The electromagnetic coil 26 of the electromagnetism removal component 2 is provided with an oil circuit internal circulation and a water cooling external circulation system.

[0035] The whole electric demagnetization component 2 has a power of 5-200KW, a magnetic flux density of 2.0-3.5T, a magnetic field strength of 12000-30000Gs, an output of 1-50T / H, and a pressure of 0.01-1.0Mpa. It can be used for high-purity chemicals such as electronic-grade chemicals NMP, including semiconductors, liquid cleaning agents for chips, and high-purity chemical reagents for demagnetization.

[0036] The adapter is a four-way adapter 7, and a return pipe 2 8 is provided between the four-way adapter 7 and the return pipe 1 6, and a slag discharge pipe 31 is provided between the four-way adapter 7 and the waste liquid tank 3, that is, the four interfaces of the four-way adapter 7 are respectively connected to the bottom of the electromagnetism demagnetization cavity 21, the feed pipe 5, the return pipe 2 8 and the slag discharge pipe 31. When backblowing, the material remaining in the electromagnetism demagnetization cavity 21 is pushed to the liquid tank 1 through the return pipe 2 8, and when discharging slag, the magnetic material after washing is discharged into the waste liquid tank 3 through the slag discharge pipe 31.

[0037] The waste liquid tank 3 is provided with a waste liquid inlet connected to the slag discharge pipe 31, and a sewage valve and a sewage pipe 32 are arranged at the bottom of the waste liquid tank 3 for discharging waste materials.

[0038] Preferably, the liquid tank 1, the electromagnetism removal chamber 21 and the parts of each pipeline in contact with the material are made of non-metallic materials, including corrosion-resistant and pressure-resistant non-metallic materials such as PTFE, PP, and HDPE. The delivery pump 4 is a non-metallic delivery pump 4, such as a diaphragm pump, etc., made of PP material.

[0039] The principle of demagnetization of the present invention is:

[0040] When a current is generated in a closed circuit, the conductor passing through it has a magnetic field. This magnetic field generated by the current is called the current magnetic field. The strength of the magnetic field of the current is related to the magnitude of the current. Under certain conditions, the greater the current, the greater the magnetic field of the current. The way in which the electromagnetism removal component 2 generates a magnetic field is that when power is turned on, the coil in the electromagnetism removal cavity 21 generates a high-flux magnetic field. When the material enters the electromagnetism removal cavity 21 and passes through the magnetic medium net 28, the magnetic material in the material will be adsorbed by the magnetic medium net 28; when the power is turned off, the electromagnetism removal component 2 no longer generates a magnetic field, and the magnetic medium net 28 no longer has magnetic adsorption capacity. Therefore, this device uses the electromagnetic effect to remove magnetic materials from materials.

[0041] This device has 4 demagnetization operation modes, including demagnetization, back blowing, flushing, and slag discharge. The operation modes are as follows:

[0042] (1) Demagnetization: When the power is on, the NMP in the liquid tank 1 is transported to the electromagnetization chamber 21 by the delivery pump 4. After the material is demagnetized by the magnetic medium 28, it flows back to the liquid tank 1 and circulates continuously.

[0043] (2) Blowback: When the power is on, the material stops entering, and nitrogen enters the electromagnetism removal chamber 21 through the nitrogen port 23 with a pressure of 0.5 MPa. The nitrogen pressure pushes the material remaining at the bottom of the electromagnetism removal chamber 21 to the liquid tank 1, thereby reducing the material residue in the equipment.

[0044] (3) Flushing: When the power is off, the material stops entering, and NMP enters the cavity through the NMP cleaning port 22 to flush the magnetic material attached to the magnetic medium net 28 under pressure.

[0045] (4) Slag discharge: When the power is off, the material stops entering, and nitrogen is discharged into the waste liquid tank 3 through the nitrogen port 23 to flush the magnetic material.

[0046] The above operation mode is adjusted according to the production situation of the material. It can be set fully automatically or adjusted in sections manually. This cycle is repeated to achieve high-quality demagnetization control of electronic-grade chemical NMP.

[0047] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0048] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. An electronic grade chemical NMP demagnetization device, characterized in that, The invention comprises a liquid tank (1), an electric demagnetization component (2), a waste liquid tank (3) and a delivery pump (4); the liquid tank (1) and the electric demagnetization component (2) are demagnetized by a delivery pump (4) and a pipeline; the waste liquid tank (3) and the electric demagnetization component (2) are connected by a pipeline to remove magnetic substances after demagnetization by the electric demagnetization component (2); The electromagnetism removal component (2) comprises an electromagnetism removal cavity (21) and a magnetic medium net (28) and an electromagnetic coil (26) connected in the electromagnetism removal cavity (21); The top of the electromagnetism removal chamber (21) is provided with an NMP cleaning port (22) and a nitrogen port (23); The liquid tank (1) is provided with a material delivery port (13) and a material return port (14); the delivery pump (4) is connected to the material delivery port (13) and the bottom of the electromagnetism removal component (2) via a material delivery pipeline (5); the top of the electromagnetism removal component (2) is connected to the material return port (14) via a return pipeline (6); A four-way transfer interface (7) is provided at the bottom of the electromagnetism removal chamber (21); a return pipe (8) is provided between the four-way transfer interface (7) and the return pipe (6); a slag discharge pipe (31) is provided between the four-way transfer interface (7) and the waste liquid tank (3); and the four interfaces of the four-way transfer interface (7) are respectively connected to the bottom of the electromagnetism removal chamber (21), the feed pipe (5), the return pipe (8) and the slag discharge pipe (31); The magnetic flux density of the demagnetization component (2) is 2.0-3.5T, the magnetic field strength is 12000-30000Gs, the output is 1-50T / H, and the pressure is 0.01-1.0Mpa; The demagnetization method includes the following steps: (1) Demagnetization: When the power is on, the NMP in the liquid tank (1) is transported to the electromagnetization demagnetization chamber (21) through the delivery pump (4). The material is demagnetized by the magnetic medium (28) and then flows back to the liquid tank (1), and the cycle continues. (2) Blowback: When the power is on, the material stops entering, and nitrogen enters the electromagnetism removal chamber (21) through the nitrogen port (23) with a pressure of 0.5 MPa. The nitrogen pressure pushes the material remaining at the bottom of the electromagnetism removal chamber (21) to the liquid tank (1), thereby reducing the material residue in the equipment; (3) Flushing: When the power is off, the material stops entering, and NMP enters the chamber through the NMP cleaning port (22) pipeline to flush the magnetic material attached to the magnetic medium net (28) under pressure; (4) Slag discharge: When the power is off, the material stops entering, and nitrogen is discharged into the waste liquid tank (3) through the nitrogen port (23) to flush the magnetic material.

2. An electronic grade chemical NMP demagnetization device as claimed in claim 1, characterized in that: A cooling element (24) is also provided in the electromagnetism removal cavity (21), and the cooling element (24) has an internal oil circuit and an external water circuit.

3. An electronic grade chemical NMP demagnetization device as claimed in claim 1, characterized in that: The material of the magnetic medium network (28) contains one or more elements of Fe, Ni, Cr and Co.

4. An electronic grade chemical NMP demagnetization device as claimed in claim 1, characterized in that: The liquid tank (1), the electromagnetism removal chamber (21) and the pipeline in contact with the material are all made of corrosion-resistant and pressure-resistant non-metallic materials.

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