All components will age, wear, and even lose their performance under chemical, mechanical and thermal action. Therefore, when choosing filler materials, the performance and price of the materials must be taken into account, and appropriate materials should be selected.)Chemical ceramics require not only good chemical corrosion resistance, but also impermeability, high mechanical strength, thermal stability and excellent temperature resistance.
ptfe film adhesive tapes plastic material (polyethylene, polyvinyl chloride, chlorinated polyvinyl chloride, polyvinylidene fluoride, polypropylene, polytetrafluoroethylene, etc. It has poor corrosion resistance to phosphoric acid and is not resistant to alkali, especially concentrated lye. When the tensile strength is large, the allowable thermal deformation stress is large, so the thermal stability and temperature resistance of the material are better. The third consideration is not to pollute or affect product quality. Materials with excellent corrosion resistance, heat resistance and mechanical properties can have a long lifespan, but they are very expensive. Secondly, consider that it is durable and not deformed at operating temperature.
When the elastic modulus is small, the deformation stress is small for the same amount of deformation. When the thermal conductivity is large, the temperature difference of each part after the ceramic part is heated is small. The linear expansion coefficient is small, the deformation amount when the temperature changes is small. Therefore, according to different requirements, three chemical ceramics such as acid-resistant ceramics, acid-resistant and temperature-resistant ceramics and industrial ceramics can be produced.
Regarding the thermal stability and rapid temperature resistance of ceramics, the thermal conductivity, linear expansion coefficient, elastic modulus and tensile strength of ceramics should also be considered.Ceramic materials (lightweight ceramics, heavy ceramics, acid-resistant ceramics, alkali-resistant ceramics, etc.Tower packing and internals are usually made of metal, plastic and ceramics. Because the large amount of silicon dioxide (SiO2) contained in the ceramics and the lye are easy to generate silicate. On the basis of meeting the above three requirements, an economical and reasonable material is selected through analysis and comparison.
The choice of materials is mainly considered in terms of performance and price. However, it is difficult to meet these requirements at the same time. When selecting materials, the first consideration is the ability to withstand the corrosion of the separation medium. In addition to hydrofluoric acid and silicofluoric acid, chemical ceramics can withstand almost all concentrations of inorganic acids, salts and organic media. Because ceramics are used as fillers, unlike chemical equipment, their allowable operating temperature is much higher than when used as equipment, and the maximum operating temperature can reach 1200-1600°C
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