The material of the filler is divided into three categories: ceramic, metal and plastic.
(1) Ceramic filler
Ceramic fillers have good corrosion resistance and heat resistance. Ceramic fillers are cheap and have good surface wetting properties. They are brittle and fragile. It is commonly used in processes such as gas absorption, gas washing, and liquid extraction.
(2) Plastic filler
The material of plastic filler mainly includes polypropylene (PP), polyethylene (PE) and polyvinyl chloride (PVC), etc. Generally, polypropylene is used in China. The plastic filler has good corrosion resistance and can withstand the corrosion of general inorganic acids, alkalis and organic solvents. It has good temperature resistance and can be used at temperatures below 100°C for a long time.
Plastic filler is light in weight, low in price, has good toughness, impact resistance, is not fragile, and can be made into a thin-walled structure. It has large flux and reduced pressure, and is mostly used in devices such as absorption, desorption, extraction, and dust removal.
The disadvantage of plastic fillers is poor surface wetting performance, but the surface wetting performance can be improved by proper surface treatment.
(3) Metal filler
The metal filler can be made of a variety of materials, and corrosion is the main consideration when choosing.
Carbon steel fillers are low in cost and have good surface wetting properties. For non-corrosive or low-corrosive systems, priority should be given to their use.
Stainless steel packing has strong corrosion resistance, and generally can withstand the corrosion of common substances other than Cl-, but its cost is higher, and its surface wettability is poor. In some special occasions (such as vacuum precision under very low spray density) Distillation process), the surface needs to be treated to achieve good results.
Fillers made of titanium, special alloy steel and other materials are expensive, and are generally only used in certain highly corrosive materials.
Generally speaking, metal fillers can be made into thin-walled structures, which have large flux, low gas resistance, and high impact resistance. They can be used under high temperature, high pressure, and high impact strength, and have the widest range of applications.