Development of deliquoring method enhanced by electric and acoustic force fields

The method developed uses acoustic and electric force fields to enhance filtration by increasing filtration capacity and by reducing production costs and energy consumption.In both laboratory and pilot-scale filtration the application of an electric field increases the cake capacity of a vacuum disc filter significantly.When constant DC electric field was applied across the ceramic capillary filter (CERAMEC, TM), about 3.5 fold cace capacity values (with electric field: 250 kg D.S./m2h, without: 70 kg D.S./m2h) were recorded during the filtration of titanium dioxide suspension using a laboratory-scale filter.Using continuously operating pilot-scale filter, the values with and without electric field at its best were 60 kg D.S./m2h and 10 kg D.S./m2h respectively.When ultrasonic field was used during cake drying it was possible to obtain rapid dewatering effect, up to 6% decrease in the cake moisture content, from 25 wt-% to 18 wt-%, when using the laboratory-scale filter.In continuously operating pilot-scale filter the decrease in cake moisture content was about 3%, from 24 to 21 wt-%.This research has revealed thet the use of ultrasound is an effective way to increase the dewatering efficiency of the cake filtration processes.The most important advantages of this process are obtained in the filtration of suspensions with very fine particles, where conventional systems are inefficient.