(1) when the filter press works, all the filter plates are pressed between the movable head plate and the fixed tail plate to form a sealed filter chamber between the adjacent filter plates, and the pulp is supplied by the feeding hole of the fixed tail plate. After all the filter chambers are filled with pulp, the pressure filtration process begins, and the pulp is separated by solid-liquid pressure with the feed pump. The solid particles are left in the filter chamber due to the obstruction of the filter cloth, and the filtrate is discharged through the drainage ditch on the filter plate through the filter cloth, and the dewatering process is completed when the filtrate is no longer flowing out. At this time, the feeding plate can be stopped and the head plate is returned to the original position, and the filter plate moving device will filter the plates successively. Filter cake fall off by self weight. So far, the pressure filtration process has been completed.
(2) the working principle of diaphragm filter press, the main difference between diaphragm filter press and ordinary box filter press is to add a layer of elastic film between filter plate and filter cloth. During the running process, when the feeding is finished, the high-pressure fluid medium can be injected between the filter plate and the diaphragm, and then the whole diaphragm will press up the filter cake so as to realize the further dewatering of the filter cake, namely press filtration.
(3) comparison of press filtration processes of two models
Usually, when the material with fine granularity and high viscosity is treated, the filtration resistance is large, and the constant pressure feeding filtration time required by ordinary filter plate filter press is longer. And diaphragm filter press, at this time can be properly cut off constant pressure feeding, converted to press filtration, with a very short press filter time to replace the ordinary filter press longer constant pressure feeding filtration time.
When the filter press has coarse particle size and no viscosity, the filter resistance is small, and the feed will be stopped in the short time without filtrate. Ordinary press next assignment is opened a head plate and a filter plate to start discharging cake off rate is very low, even can not block out most of the artificial poke, high moisture of filter cake, the cake unloading is very difficult, even after a cloth washing cycle can be carried out, resulting in big labor strength, discharging time long. Diaphragm filter press products at the end of feeding after entering a short press filtration process, the diaphragm up further dehydration filter cake compression; diaphragm compaction muster filter cake, in the discharge process, the filter cake can come off clean, so as to complete unloading process in a short time.