Nutsche Filter comprises of a cylindrical shell with a welded dished end at the top and either a flanged and bolted dished end or a welded dished end / flat welded end at the bottom depending on process / customer’s requirements. The vessel is divided into two compartments by means of a perforated plate, provided with suitable filter cloth or porous tiles. An agitator of unique design is provided inside the vessel. This agitator can perform multifarious activities by manipulating its movements of vertical and rotational directions simultaneously, by means of push buttons switches/PLC. The filter is capable of operating under either pressure or vacuum or a combination of both.
Slurry is fed into the top compartment from where filtrate passes into the lower chamber en route to receiver.
Solids are deposited on the filtering media in the top compartment and take the shape of cake of a uniform thickness. The agitator pushes the solid content in the slurry upwards by keeping it under suspension till maximum possible filtrate passes through the filter bed. This reduces time and increases productivity. It then seals the cracks in the cake, which develops after most of the filtrate has passed through, by smoothening the top surface of the cake. It also squeezes out some of the moisture in the cake by slightly pressing the cake uniformly with the specially designed agitator.
After the initial solvent/mother liquor has been separated, sometimes it is necessary to wash the cake. The Agitator has been designed in such a way that after adding wash liquor on the cake, the entire cake can be re-slurried and agitated, so that all the particles forming the cake can be exposed to wash liquor and be thoroughly washed. This improves quality of the finished products.
After washing and removal of wash liquor, the cake can be discharged through a quick opening side discharge door, by rotating and lowering agitator in the discharge direction. No manual handling is required.
ADVANTAGES OF AGITATED NUTSCHE FILTERS
- The filter works as a completely closed system, eliminating any possibility of atmospheric pollution from toxic fumes / obnoxious smell generated from the slurry.
- Very high solvent recovery is possible.
- Explosion or fire hazard on account of spillage is eliminated.
- Manpower saving. All operations can be handled by a single unskilled person with little training.
- Very effective washing of cake due to re-slurrying resulting in thorough particulate washing and reduces number of washes, and volume of wash liquor.
- Possibility of doing reaction, filtration, washing and distillation in the same equipment. In some cases drying operation can also be carried out in the same equipment. Heat transfer surface can be provided by means of a jacket or limpet coils on the vessel walls. Indirect heating can be provided on the filter base and agitator.
- Available in special construction for sterile applications with high standards of particulate purity.
Materials of Construction include the following:
- Carbon Steel
- Stainless Steel
- Nickel / Nickel Alloys
- Super Stainless Steels
- Special alloys like Hastelloy C , Inconel etc.
Sizing, selection of configuration, M.O.C’s, methodology of filtration etc. are based on material characteristics. Suitable linings of FRP / FRV, Rubber, Acid-resistant bricks and tiles or corrosion resistant fluorocarbons can be offered.
- Pressure-cum-Vacuum filter
- Bottom detachable arrangement for ease of cleaning / cloth fixing
- Electro-mechanical drive and hydraulic shaft lift
- Hydrauclic lift and drive
- Hydraulic discharge valve
- GMP Models for clean room applications
- Filter-cum-Dryers for drying of wet cakes
- Different stirrer designs based on physical characteristics of materials
Working Capacity (Ltrs.)
Filtering area (sq. m.)
Motor H.P. Rotary
Internal dia. (mm)
Over height (mm)