Application of water treatment technology in enameled wire production
The quality of the enameled wire depends on the main raw materials and technology of copper and lacquer. Technological equipment has also attracted enough attention, but in the production process, water, an indispensable auxiliary material, is often overlooked. Mainly because of the understanding of the role of water in the production process and the lack of knowledge of water quality itself.
1 Water and water quality
Water is used as industrial raw materials or as process water and production process water, and its quality directly affects product quality and yield. Therefore, the preparation of pure water has become a subject of industrial production.
In the process of natural circulation and social circulation, water will always be mixed with a variety of impurities. There is no real pure water in nature. It always exists in a certain solution or turbid state. She contains various impurities. This impurity is divided into five categories.
1. Electrolyte: It refers to the substance which exists in the ionic state in water. Including soluble inorganic, organic, and charged colloid ions, etc., it has conductivity, so the relative conductivity of such impurities can be reflected by measuring the conductivity or resistivity of water.
2. Organic matter: It refers to natural or synthetic organic matter. Such as organic acids, organic metal compounds and so on.
3, particulate matter: including sediment, dust, organic matter. Microorganisms and colloidal particles.
4. Bacteria and microorganisms: Bacteria and microorganisms in water include plankton and algae.
5. Dissolved gas: It includes N2, CL2, H2S, CO, CO2, CH4 and so on.
The commonly used water is surface water and groundwater. They all contain the above impurities and dissolved matters. Even tap water cannot be used directly in the production of enameled wire because tap water contains chlorine (bleach, chlorine gas). It is a strong oxidant and has a direct oxidative and corrosive effect on metals. . In water treatment, we use activated carbon filters to remove them.
Second, the impact of water quality on enameled wire production
There are many uses for enameled wire production water, which also have different requirements on water quality. According to the use of water quality requirements can be divided into: annealing furnace water sealing water, equipment cooling water, lubricant preparation water.
1. Influence on the quality of enameled wire.
In the production process of enameled wire, if the particles in the water remain on the copper wire, the oxidation surface of the copper wire will be uneven, resulting in pinholes; the pollution of ionic impurities will increase the surface charge density of the copper wire, causing the electrochemical performance of the oxide layer to decline. Affects its parameters. During the drawing process, these impurities can be absorbed into the copper wire and can diffuse into the inside of the copper wire, affecting the smoothness of the surface of the copper wire, causing defects such as uneven local resistance and easy breakdown. It also affects the paint effect due to oil or organic substances in the water. , Poor adhesion of the paint film, producing pores, and reducing its insulation parameters. In particular, the pollution of CL will produce deliquescent effect, which will cause dark spots in high humidity climates. This is the reason for the dark spots of enameled wires. Furthermore, the paint film is perforated and the moisture further penetrates, which causes the quality parameters of the enameled wires to decrease. It is also the cause of the voltage drop.
2. Impact on mechanical parts.
We know that in the process of mechanical equipment transmission, in order to ensure that the equipment runs at high speed and continuous operation under metal friction conditions, the equipment must be cooled. If the cooling water contains a large amount of impurities, it will occur: equipment pollution, corrosion, scaling, salt formation, pipeline accumulation of sludge, scale deposition and blockage. The cooling effect of the equipment is reduced. The facilities are damaged quickly, the maintenance pressure is increased, and the mechanical life is reduced. Both the production efficiency and economic benefits will be greatly affected.
The blockage of the annealing tube of the annealing furnace encountered during the production of the enameled wire and the surface dirt of the invading guide wheel are all related to the deposition of calcium and magnesium ions in hard water.
3, the effect on drawing lubricant
The impurities in the water, especially the hardness components, will chemically react with the alkaline lubricant, which will consume a large amount of lubricant, reducing its effect, reducing its effect, and accelerating deterioration. Therefore, many manufacturers use pure water in the preparation of lubricating fluid, the effect is much better.
In short, the washing liquid of the product is involved, and the water quality of the cooling water (direct contact with the product) must be strictly controlled. The smaller the wire diameter, the higher the requirement. Roughly controlled in the following areas:
(1) Enameled wire, copper wire annealing water sealing water: meets the standard of primary distilled water, electrical conductivity <10 / CM, no CL detection, no hardness.
(2) Mechanical cooling water: demineralized water standard.
(3) Lubricant: Standard for demineralized water.
Third, water quality treatment methods
At present, in the enameled wire industry, three processing methods are generally used.
1. Membrane separation technology
That is, the reverse osmosis method, which is the currently popular membrane separation technology in the world, is used for water quality treatment. The desalination rate is about 98%. It is distinct from the traditional electrodialysis and ion exchange technology in that it saves a lot of acid and alkali. However, the quality of the incoming water is relatively strict. If the quality of the incoming water is too poor and the effluent does not meet the standard, secondary treatment is required.
Raw water-sand filter-activated carbon filter-softener-precision filter-reverse osmosis machine.
(2) Electrodialysis-ion exchange technology
Its process is to add pre-salting equipment electrodialysis before ion exchange (anode bed-anion bed-mixed bed). First 80% of the salt was removed by electrodialysis, and the remaining 20% was removed by an ion exchange process. This process has high water quality. It can reach below 0.5 / CM, and is stable and not affected by water temperature, but the disadvantages are also obvious, which is mainly a large consumption of acid and alkali, which affects environmental protection.
Raw water-precision filter-electrodialysis-water tank-positive bed-overcast bed-mixed bed
(3) Softened water technology
This process is the simplest and only requires water to pass through the sodium ion exchanger. Meet demineralized water standards. Fouling sodium salts can be reduced in the cooling system. However, the effluent quality of this process is the worst and CL cannot be removed.
Raw water-precision filter-softener.
The water treatment process equipment is not complicated, and the operation is convenient. However, its industry is relatively biased and it is an auxiliary equipment for the industry. Generally, people don't pay enough attention to it. They do random management and have many part-time management. So not many good companies are used.
Product quality is the lifeline of an enterprise. All factors that affect product quality should be taken seriously, or they will suffer unpredictable losses and consequences. Such examples are endless in our enameled wire production industry, which is why water quality treatment is widely valued today.
Test the water in the cooling water tank twice a week with silver nitrate. If the water turns white, replace the water in the sink. Not only use deionized water, but also regularly change the isolation water in the water tank. Replace the water regularly with new water every day to ensure that the water in the isolation water tank does not contain excessive impurities.