Main factors affecting the operation effect of the box filter press

The filter press is a solid-liquid separation device. At present, the filter press dewatering is a method for the effective treatment of coal slurry water treatment, and the filter press is the necessary equipment for the closed cycle of washing water in the coal preparation plant. However, in practical applications, due to a variety of factors, the efficiency of the chamber filter press is often not ideal. The following describes the main factors affecting the operation of the box filter press

The working principle of the filter press:

Under the action of the hydraulic cylinder, the filter plate of the filter press moves along the main beam to form a closed filter chamber between adjacent filter plates. The coal slurry water is fed by the feed pump from the feed hole of the tail plate with a certain pressure. The pressure provided by the pump provides a pressure difference across the filter media for solid-liquid separation. The slime particles remain in the filter chamber, and the filtrate passes through the filter medium and is discharged from the water guide hole of the filter plate. After a period of time, the filtrate no longer flows out, and the filtration and dehydration process is completed; the feed is stopped, the filter plate is pulled apart in turn, and after the filter cake is detached, it is transported away by the transport equipment under the filter press, and the entire filter press cycle ends.

Main factors affecting the working condition of the filter press

The working condition of the filter press, the quality of the product and the working efficiency of the filter press are mainly integrated from the aspects of feed composition, physical properties, product moisture, cake formation, filtrate concentration and working efficiency (measured by filtration speed). Consider and measure.

Where: u is the filtration speed; ΔP is the filtration pressure; μ is the viscosity; L is the thickness of the filter cake; ε is the porosity; k1 is the Kozner constant; S0 is the specific surface area of ​​the particles.

According to the equation, it is not difficult to find that in the pressure filtration process, the filtration speed of the slurry is proportional to the filtration pressure, inversely proportional to the viscosity of the slurry, and as the pressure filtration progresses, the thickness of the filter cake increases, and the solids trapped in the filter chamber The porosity of the aggregate (which eventually develops into a filter cake) gradually decreases, and the filtration rate decreases. In addition, during the filtration process, the filtration rate is inversely proportional to the square of the specific surface area S0 of the particles. Therefore, to ensure efficient operation of the filter press, it is necessary to analyze from the above factors.

Feed pressure

In the actual production process, the filtration pressure is generally provided by the feed pump (there is also a very small proportion of the pump and air compressor combined feeding, which will not be discussed here), so the most important factor affecting the filtration speed is Feeding pressure of the feed pump. The feed pressure directly affects the working conditions of the filter press, and the separation effect of the filter press has a great relationship. In actual use, it is found that during the pressure filtration dehydration process, most of the water can be discharged by hydrostatically compressing the porosity of the small filter cake, but the hydrostatic pressure is not ideal by merely improving the hydrostatic pressure. The reason for the analysis may be as follows: As the pressure increases, the porosity of the filter cake gradually decreases, and the saturation of the filter cake pores gradually decreases. However, when the saturation of the filter cake approaches the residual saturation, the filter cake moisture is no longer basically Lower [ 2 ]. By analyzing the microstructure of the filter cake, it is known that the particles are arched at this time, and the moisture contained in this structure is not only difficult to discharge by the hydrostatic pressure provided by the conventional feed pump, but also causes equipment wear and failure.

Guangzhou Luyi Environmental Protection Equipment Co., Ltd.