An overview,
Filter medium is the heart of the filter press work. Filter medium with pressure filter and the filtering mechanism of the slurry matches, directly affect the normal use of pressure filter and the work efficiency. Therefore, selecting suitable filter medium is the core of filter press used technology. While the filter medium manufacturers for the production of the performance of the filter medium and the selection method provides a large number of technical information, but the choice of filter press filter medium used will depend on material filter process long-term experience and experiment to determine. The selection of filter medium has accumulated rich experience and a large number of experimental data, a solid liquid separation of users can provide better selection service.
Second, suitable for plate and frame filter filter medium for the pause
Plate and frame filter filter medium for filter cloth commonly pause, also have choose cardboard or filter paper (MianBing filter and plate and frame type filter oil machine) do the filter medium. Suitable for filter press filter cloth according to the material, synthetic fiber as more; According to the structure points to woven fabric and fiber felt, paper, filter paper mainly. For fabric and nonwoven filter cloth has a large number of various literature introduction, each manufacturer of filter cloth has detailed instructions. Here focuses on a kind of suitable for filter press filter cloth "high temperature to finalize the design (calender) filter cloth". After high temperature to finalize the design (calender) treatment of filter cloth, yarn between the hole shape by is bell shaped into a bell shape. Undifferentiated filter filter cloth when the filter solids (tiny particles) easily trapped inside the bell mouth blocking filter channel, cannot form a good bridge pore, affect the filtering effect. Filter cake and filter cloth bonding. Influence of the filter cake off and filter cloth washed to regenerate. After high temperature to finalize the design of the filter cloth, smooth surface, stable structure of aperture, out of shape not easily; Bell mouth formed funnel-shaped, solid particles are not card wall; Can form good bridging filter layer; Higher filtration precision, filter cake off easy, filter cloth, cleaning, and improve the sealing between the filter plate, reduce the capillary leakage between the filter plate, more adapt to the operation of the automatic filter press. High temperature to finalize the design technology of surface treatment effect is better. Also only monofilament filter cloth to keep the structure stability of the deformation after processing, but monofilament filter cloth impact and tensile strength are far less multifilament filter cloth is high, very easy to broken. Therefore, filter cloth manufacturers produced a discuss silk cloth, overcome the shortcoming of monofilament filter cloth. Do intercept with monofilament filter cloth layer, using multifilament filter cloth for support layer. In this processing technology in the production of filter cloth, very adapt to the use of filter press for the filter cloth.
Third, plate and frame filter press the matching principle and method of filter cloth
(1) according to the chemical and physical properties of the material, choose the material of filter cloth. All the filter cloth suppliers as soon as possible to provide detailed technical data, can be reference to choose.
(2) according to the requirement of the filter precision selecting filter cloth permeability (intercept larger size). Can provide reference to filter cloth supplier of the larger intercept primary technical parameters of particle size, etc. Filter cloth although initial filtration precision of filter press played an important role, but it's also the higher the initial filtration precision, the better, to consider the filtering precision can meet the requirements of low. Because of the pressure filter in the filter after period of time to form a filter, filter cloth of the intercept effect is very small, really fine filtering effect "filter", forming a good filter layer is the key to the filter press used technology.
(3) the stripping performance of filter cake. When selecting filter cloth paying special attention to the filter cake stripping performance. Filter cloth surface smooth level off, the filter cake off quickly and thoroughly to filter operation time is short, high efficiency. Filter cake adhesion on the filter cloth is not easy to peel, will extend the time of the operation of the pressure filter, reduce the work efficiency. Such as to change the filter cloth, the time will be longer. Now in general use box pressure filter, filter cloth change is more troublesome. Choice than long filament and staple fiber monofilament filter cloth filter cloth discharge cake performance is better, choose satin weave discharge cake performance is better than flat fabric filter cloth.
(4) the regeneration performance of the filter cloth. When selecting filter cloth notice also choose the filter cloth regeneration performance. Regeneration performance good filter cloth can be directly on the filter machine to washing of filter cloth, in cloth. Replacement of the filter cloth by simple processing (dry, water, etc.) to restore the filtration efficiency more than 80%.
(5) the material of filtration experiment. The use of filter press technology is a kind of experiment technology. In the filter cloth after preliminary selection of raw materials (don't change the material properties and process conditions) filtering experiment is very important. For small sample experiment material filtering. Inspects the filtration rate of filter cloth and retaining effect, moisture content of filter cake, cake, regeneration properties