The main body of the filter is composed of a shell, a filter plate, a cover lifting structure, an automatic slag removal device, etc. the filter plate is composed of multi-layer stainless steel filter materials, which is installed on the central liquid collecting pipe, which is very convenient for disassembly and cleaning. During filtration, the filtrate containing filter aid enters the filter through the conveying system to form a stable filter cake on the filter screen (the filter cake layer can provide countless fine channels), and then the filtrate is actually filtered through the micropores of the filter cake layer.