In the field of chemical water treatment, rubber plays a vital role as an anti-corrosion material. Rubbers that have been heated and vulcanized not only have excellent heat resistance, mechanical strength, but also excellent corrosion resistance. These properties make rubber an indispensable lining material in water treatment equipment.
Rubber has a wide range of applications, and we can choose different types of rubber according to the use temperature of the equipment and the characteristics of the medium. In general, ebonite-lined equipment is suitable for long-term operating temperatures between 0°C and 65°C, while linings with a combination of soft rubber, semi-hard rubber and hard and soft rubber are suitable for a wider temperature range, from -25°C to 75°C. It is worth mentioning that factors such as the temperature of rubber use, the concentration of contact medium and other factors will have an impact on its service life. Excessive temperature will accelerate the aging of rubber, destroy its adhesion to metal, and cause it to fall off; Too low a temperature will cause the rubber to lose its elasticity, and due to the difference in the expansion coefficient between the rubber and the metal, it may lead to stress concentration, which can then tear the rubber layer.
In the selection of rubber, hard rubber has good adhesion to metal, good corrosion resistance and aging resistance, but temperature resistance, impact resistance and elasticity are slightly poor. Soft rubber excels in these areas, but its corrosion resistance and adhesion to metal are relatively weak. The properties of semi-hard rubber fall somewhere in between, providing flexible options for different applications. For example, for equipment such as ion exchangers, acid storage tanks, etc., we usually choose hard rubber as the bottom lining; For decarburizers, decarburizers or equipment with a low concentration of corrosive media, a layer of semi-hard rubber or hard rubber can be selected. Pipes are usually lined with a layer of hard rubber to enhance their corrosion resistance.
However, simply choosing the right type of rubber is not enough to guarantee the quality and performance of the lining. Before the construction of the rubber lining, the matrix metal structure process of the rubber lining equipment should be carefully inspected to ensure that it meets the requirements of the rubber lining. The base of the water treatment equipment is mostly made of carbon steel, and sometimes cast iron. These matrix materials must be free of defects such as sand holes and shrinkage holes, and the weld should be smooth and smooth, without porosity, welding nodules, welding slag and other defects, so as not to puncture the rubber. There should be no convex and concave places greater than 3mm on the surface of the steel shell, and where there are edges and corners, there should be a circular arc transition, and its r> 5mm. Some are at right angles, the corners should be filled in before the lining, and the arc transition should be formed after filling with small rubber.
In addition, before the construction of the rubber lining, all the welding, opening, pressure test and other mechanical processing work of the equipment should be completed. This is because these tasks may cause problems such as stress concentration, uneven welds, etc., which can affect the quality of the rubber lining and damage the rubber liner. If these tasks are carried out after the rubber lining is completed, it may cause problems such as cracking and falling off of the rubber layer, which will seriously affect the service life and performance of the equipment.
In summary, selecting the right rubber type and ensuring the process quality of the matrix metal structure is the key to ensuring the performance of rubber linings in chemical water treatment equipment. Only by being meticulous and rigorous in these two aspects can we ensure the long-term stable operation and service life of the equipment.