What are the methods in industrial cleaning? For example, a small amount of a certain substance can be added. The corrosion inhibitor is corrosive, which can greatly reduce the corrosion rate of metal. This substance is called corrosion inhibitor. This method of maintaining the metal is called corrosion inhibitor protection. Classification of corrosion inhibitors: The mechanism of action is divided into anode, cathode and mixed type. The characteristics of the maintenance membrane are: oxidation type, adsorption type, precipitation type. Other classifications: ① Organic and inorganic corrosion inhibitors ② Liquid phase, gas phase, solid phase corrosion inhibitors ③ Steel, copper, aluminum corrosion inhibitors ④ Acidic, alkaline, neutral corrosion inhibitors.
Its positive and negative ions will be surrounded by water dipoles, such as water containing dissolved salts. They are also arranged in the water dipole group in a positive and negative order. They cannot move on their own, so they cannot approach the wall of the tube, and then deposit on the wall of the tube to form scale. Classification of cleaning methods: physical cleaning method; chemical cleaning method; electronic cleaning method (electronic descaling, antiscaling); electrostatic cleaning method (static antiscaling, descaling) without changing the cleaning method of dirt components. That is, the method that does not change the original chemical molecular composition. Mechanical cleaning method: cleaner and scraper cleaning method, drilling pipe cleaning method, shot peening method. Water cleaning method: Low-pressure hydraulic cleaning (the pressure of low-pressure cleaning is 196-686 kPa, and the physical cleaning method is to apply external force to remove various kinds of pollution with the aid of hand tools and machinery. About 2-7 kgf / cm2, equal to 0.2 -0.7Mpa high pressure hydraulic cleaning: The pressure of high pressure cleaning is 4900 kPa, about 50 kgf / cm2, which is equal to 5Mpa. This method is also called high pressure water jet method and high pressure cleaner.
It prevents scale and descaling. When water passes through a high-frequency electric field, the principle of scale prevention and descaling by electronic cleaning is to change the molecular structure of water by using a high-frequency electric field. Its molecular physical structure has changed. The original associated macromolecules were broken into single water molecules. The positive and negative ions of the salt in the water were surrounded by a single water molecule. The speed of movement was reduced, the number of effective collisions was reduced, and the electrostatic attraction was reduced. Heated wall type pipe surface structure, to achieve the purpose of anti-scaling. At the same time, due to the increase of the dipole moment of the water molecules, the positive and negative ions of the salt (the increase of the absorption capacity of the scale molecules increases the scale on the heating surface or the pipe wall). It is soft and easy to fall off, and the effect of descaling occurs.
The purpose of antiscaling and descaling is also achieved by changing the state of water molecules, but the latter uses the effect of electrostatic fields. Electrostatic antiscaling and descaling are the same as electronic descaling. Not electronic. The mechanism is that water molecules have polarity (also known as dipoles). When water dipoles pass through an electrostatic field, each water dipole will be continuously arranged in a positive and negative order. If the water contains dissolved salts, the positive and negative ions will be surrounded by the water dipoles, and they will be arranged in the water dipole group in the positive and negative order. They cannot move on their own, so they cannot be near the wall of the tube. And then deposited on the wall of the tube (apparatus) to form scale. At the same time, the oxygen released from the water can cause a very thin oxide layer on the pipe wall, which can prevent the pipe (apparatus) wall from corrosion.
Such as acid scale washing, alkaline washing and so on. In order to prevent the substrate from being corroded in the chemical cleaning or to control the corrosion rate within the allowable range, the chemical cleaning method: the use of chemical agents to contaminate the surface or cover layer (such as scale layer) with a chemical reaction with it to be removed. Normally, an appropriate amount of corrosion inhibitor and additives for activation, penetration and wetting are added to the chemical cleaning solution. Methods: Soaking method, circulation method, running cleaning method are also called non-stop chemical cleaning method.
Gives steel high corrosion resistance. In addition, the characteristics of main metal materials: a general term for alloy steels resistant to corrosion by acids, alkalis, salts, and the like. Among them are mainly alloy steels containing chromium. After chromium was added. Adding nickel, molybdenum, titanium, manganese, nitrogen and other elements to chromium steel can improve its corrosion resistance and process performance. The chromium content of stainless steel is generally not less than 12%. There are two types of chromium stainless steel (containing 12% or more chromium) and nickel-chrome stainless steel (containing 12% chromium and 8% nickel). Carbon alloy, which contains manganese, silicon, and a small amount of phosphorus and sulfur, is brittle and hard without ductility. Carbon steel is also called carbon steel, and its carbon content can be divided into low carbon according to the carbon content. Steel, medium carbon steel or high carbon steel. Copper alloy. Copper is a non-ferrous metal with good ductility. It is soft, conductive and thermally conductive. Copper and other metals can form many very good alloys, such as bronze (containing copper 80% tin 15% zinc 5% brass (containing copper 60-90% zinc 40-10% is easy to process, many mechanical parts are aluminum alloys made of brass. Aluminum is a light metal with good ductility. Aluminum in The air is easily oxidized, and a dense oxide film is formed on the surface, which can perform its own maintenance. Aluminum and many metals can form alloys with small specific gravity and high strength, which is widely used in various industries.