Belt filter press is an efficient solid-liquid separation device which is based on chemical flocculation contact filtration and mechanical extrusion. It has the advantage of simple technological process, high automatic level, continuous operation, easy operation and so on.
Working principle: The flocculated sludge will first get into the gravity dewatering zone; most of the free water will be filtered by the filter belt under gravity. During the running of filter belt, the sludge will enter into wedge zone which composed of two filter belts. The sludge will slowly be pressed by two filter belts, then it is gradually thickened, decreased activity and transit to press area. In the press area, the sludge is pressed by incremental squeezing force and shearing force as the two filter belts are replaced by the upper and lower displacement. The majority of free water and interstitial water remain in sludge will be filtered and the sludge becomes flake filter cake. The upper and lower filter belts are separated by the discharge roller, and the filter cake will be scraped by scraper, and finally completed the solid-liquid separation. The upper and lower filter belts are reused for the next cycle after washing.
In actual engineering, the main specifications to decide the performance of beltfilter press are: ①filtering capacity ②cake moisture ③amount of chemical dosage ④power cost ⑤washing water consumption ⑥belt tension, etc. Among which the filter capacity is the primary index to evaluate its general function. There are many factors to affect belt filter press, but mainly reflect in gravity dewatering zone, squeezing zone, and filter belt speed, filter belt tension, roller diameter, filter belt selection, dosing, etc. And these factors are also the integrated performance of the design and manufacture of the belt filter press.