PRESSURE SAND FILTER

The Pressure Sand Filter/Multigrade Sand Filter is a depth filter that makes use of coarse and fine media mixed together in a fixed proportion. This arrangement produces a filter bed with adequate pore dimensions for retaining both large and small suspended particles. This filter performs at a substantially higher specific flow rate than conventional filters. Specific flow rates of 15 – 30 M/Hr. have been successfully obtained for treating water containing 50-25ppm suspended solids respectively to produce a filtrate with less than 5ppm. The Multigrade sand filter can handle feed water upto 25 NTU turbidity and the treated water from this range of filters will have <2 NTU.

Working Principle

In a Pressure Sand Filter, water is passed through multi layers of filter media consisting graded sand, pebbles and gravels layers. The contaminants in the water are captured in the media bed and filtered water passes into the discharge manifold at the bottom of the tanks. The next and last step is backwashing, a process of effectively removal of captured contaminants from the media bed. After back-washing the filter is rinsed with raw water and after the required quality of water is achieved the filter is put back into service.

Features & Advantages

• Higher specific flow rate than conventional down flow filters thereby saving on space and cost
• Very little maintenance required
• Lower backwash water requirement
• In most cases, raw water can be used for backwash
• Plastic piping do not require Maintenance and are corrosive resistance
• Single lever operated multiport valve makes it user friendly & easy to operate
• Manual/Automatic Operation Options
• Custom sizes and configurations
• Ideal for pre-treatment
• Higher Specific velocity
• Raw water can be used for backwashing the filter

Applications

• It is extensively used in side stream filtration of potable water treatment
• It is ideal for filtration of clarified water
• In addition it finds application in sea water filtration & filtration of chemical solutions. For these types of filtrations rubber lined or epoxy painted filters can be offered
• Pre treatment for Reverse Osmosis System
• Pre treatment for drinking water in housing societies, hotels and shopping malls
• Swimming Pool Filtration in Housing Societies & Hotels
• Pre treatment for Cooling towers and boiler feed