Application of FGI frequency converter in filter machine
1.Overview
Filter is the use of porous filtration medium, to intercept the solid particles in the mixture of liquid and solid particles, and realize the solid and liquid separation equipment. Filter is widely used in chemical industry, petroleum, pharmaceutical, light industry, food, mineral processing and sand production, coal and water treatment and other industries. Separation of the container into upper and lower chambers is a simple filter. The suspension is added to the upper chamber, and the filter chamber enters the lower chamber through the filter medium under the pressure. The solid particles are trapped on the surface of the filter medium to form filter slag (or filter cake). In the process of filter filtration, the slag layer accumulated on the surface of the filter media is gradually thickened, and the resistance of the liquid through the slag layer increases, and the filtration speed decreases. When the filter chamber is filled with filter or the filter speed is too small, stop the filtration, remove the filter residue and regenerate the filter medium to complete a filtration cycle. The liquid passing through the filter layer and the filter medium must overcome the resistance, so there must be a pressure difference on both sides of the filter medium, which is the driving force to achieve the filtration. Increasing the pressure difference can accelerate the filtration, but the particles deformed after the pressure are easy to block the pores of the filtration medium when the pressure difference is large, and the filtration slows down instead.
2.Implementation plans
At present, the automatic filter press that has been successfully applied in the sand mining industry in China include LPP automatic filter press and domestic CFPP automatic filter press. CFPP-55 automatic filter press has a single filter board area of 2.56m2 and a single filter area of 56m2, which has been successfully applied in Sichuan metal mines and small and medium-sized mines in Xinjiang.
The application practice has proved that the CFPP-55 automatic filter press can effectively handle the viscosity and difficult to filter concentrate, and the moisture of the filter cake is significantly lower than that of the vacuum filter and the plate and frame filter press. However, when a sand and stone mining plant in Jilin province used this type of filter press for tailings dehydration, it was found that the automatic filter press has some phenomena such as incomplete filter sealing, rubber diaphragm and filter cloth consumption, small processing capacity and secondary increase of water, which finally led to the moisture of tailings unable to meet the process requirements. Therefore, it is decided to improve the phenomenon of the filter press by adding a frequency converter.
In order to solve the problem of the above high efficiency filter press in industrial applications, this project uses FGI FD300 frequency converter to realize the efficient dehydration process, filter plate sealing structure, vulnerable parts, etc., and implements the frequency conversion technical transformation of CFPP-55 automatic filter press by adding the frequency converter. After the transformation, the automatic filter press can continuously filter very thin and sticky materials such as phosphate tailings, and control the water within the range of process indexes.
3.Application advantage
(1) The application of frequency conversion technology slows down the instantaneous deformation of the rubber diaphragm;
(2) Because the rubber has good extension compensability, it can also solve the impact of residual filter residue on the sealing surface on the spray grouting, which can avoid the occurrence of spraying phenomenon to a large extent. This transformation has achieved good results, and also reduces the damage of the filter cloth at the sealing surface.
