High-pressure fan refers to a fan whose wind pressure is 30kPa~200KPa or compression ratio e=1.3~3 under design conditions. The current industry generally classifies gas ring vacuum pumps as high-pressure fans. High-pressure blower, also called high-pressure blower, is different from general centrifugal blower. When the impeller rotates, due to the centrifugal force, the wind vane causes the gas to move forward and outward, thereby forming a series of spiral motions. The air between the blades of the impeller rotates spirally and squeezes the gas outside the pump body (inhaled by the suction port) into the side groove. When it enters the side channel, the gas is compressed, and then returns to the blades of the impeller again. Speed ??up the rotation. When air passes through the impeller and the side grooves along a spiral track, each impeller blade increases the degree of compression and acceleration. As the rotation progresses, the kinetic energy of the gas increases, so that the pressure of the gas passing along the side channel further increases. When the air reaches the connection point between the side groove and the discharge flange, the gas is squeezed out of the blade and discharged from the pump body through the outlet muffler.
One of the biggest headaches for high-pressure fans used in industry is that high-pressure fans have been used in chemical raw materials for a long time, and the corrosion problems of high-pressure fans are encountered. Now I recommend four measures to prevent or slow down the corrosion of high-pressure fans.
1. It is very important to choose the right material of the high-pressure fan. Different materials and separation requirements require different models. After the model and main parameters are determined, the strength part materials are determined from the fundamentals based on the corrosion resistance of different materials in different environments, combining their physical and chemical properties, cost performance and many other factors. From the perspective of the material itself, the target material it targets is safe.
2. The mechanism design of the high-pressure fan. An excellent design can prolong the service life of the equipment and ensure the safety of the equipment. For the structural design, the design defects that are most likely to accelerate corrosion are the stress concentration tendency and the crevice environment. Sometimes despite the metal immersion in the solution, The corrosion rate is small; but the formation of crevices, due to changes in the chemical and electrochemical state of the internal solution, will cause severe crevice corrosion.
Three, the surface protection measures of the centrifuge
A basic idea to control corrosion is to isolate the corrosive environment. In the design of high-pressure fans, surface treatment methods are often used, such as flanges, galvanizing, chrome plating, chemical plating, etc. These methods are effective in many environments, but for rotating parts, one must pay attention to an important phenomenon: matrix The material and the coating are two kinds of materials with different linear expansion coefficients, which will produce different amounts of deformation when the rotating part is elastically deformed, which will cause a large number of micro-cracks; if the aforementioned phenomenon exists, it will accelerate the formation of corrosion. Therefore, the surface protection method of rotating parts should be used with caution.
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