Because W2N sheets are manufactured from pure cellulose incorporating carefully chosen wet strength resins within the cellulose matrix, the sheet has a high wet strength and is very durable. This allows the sheet to be used time and time again, so minimising costs.
The pore size distribution of the sheet is carefully controlled so that there is even build up of the filter cake on the sheet. This ensures that filter capacity is maximised and that there is minimum risk of bleed through of even the finest of fines, whilst minimising the pressure drop through the filter.
W2N sheets are very tolerant of pressure transients during the filtration cycle because the formulation used in their manufacture, coupled with the manufacturing process produces an extremely durable yet flexible sheet.
Typically for this application, 0.5% or even more of kieselguhr is added to the syrup as a filter aid and prior to batch filtration, 500 grammes per square metre of filter plate area is applied as a pre-coat in treated water. Sugar syrup filtration flow rates vary according to conditions, e.g., viscosity and sugar quality etc. High quality, relatively dilute sugar syrup made be filtered at 950 litres per square metre per hour. On the other hand, flow rates as low as 300 litres per square metre per hour may be possible with high concentrations of syrup containing activated carbon and kieselguhr.
Carlson XE20H or XE50H sheets are normally used for polishing when no decolourisation is needed.
For more specific information click on the links below:
