Hitz Filter Press History and Theories of Filtration
Hitz Filter Press History
- ・1949 : Started Filter Press business for removal of impurity from colorant
- ・1971 : Developed Polypropylene plate
- ・1973 : Developed and released “Automatic Filter Press”
- ・1983 : Developed new filter plate type “MKⅡ” for efficient filtration
- ・1998 : Released “AUTOPAC” Filter Press as packaged lineup
- ・2004 : Released “ROLLFIT” Filter Press with drying function
- ・2006 : Released “U-TEC”. Filter Press with self-towing filter cloth
Theories of filtration
Slurry is supplied to chamber for filtration under 0.2 – 0.7MPa pressure (standard: 0.4MPa).
Cake layer is gradually created in the chamber. This layer can filtrate sub-micron particles which is smaller than filter cloth gap. Outcome filtrate volume becomes less as the pressure in the chamber increases due to resistance of cake layer accumulated in the chamber. Filtration ends when it comes to set time, pressure or discharge volume of filtrate.
Cake layer is compressed and squeezed by Diaphragm Sheet expanded with air (0.7MPa) or water (1.5 / 2.0MPa). After squeezing, cake layer is dehydrated and moisture is lesser. Also, remaining filtrate can be separated and collected.
Cake washing process
Washing agent is supplied to chamber to wash cake layer, causing Extract of ingredients and purify cakes
There are two method to wash cake.
1. Washing agent is supplied from slurry feeding inlets (Feed Washing Method).
2. Washing agent is supplied from outlet of filtrate and flow through cake layer to discharge
at other bottom corner (Back Washing Method).