Pressure Sand Filter

Description

The Pressure Sand Filter/Multigrade Sand Filter is a depth filter that employs a predetermined percentage of coarse and fine material. This setup creates a filter bed with big enough pore sizes to hold both large and small suspended particles. This filter has a far greater specific flow rate than traditional filters, and it is the most often used method for removing turbidity from water. The Pressure Sand Filter is made up of several layers of sand of various sizes and specific gravity. These filters are made to remove turbidity and suspended particles from feed water with the least amount of pressure drop possible. These Filters are custom designed to suit the process requirement.

A pressure sand filter is made up of a vertical or horizontal pressure vessel with a set of frontal pipe work and valves, graded silica quartz sand supported by layers of graded under bed consisting of pebbles and gravels, a top distributor to distribute the incoming water uniformly throughout the cross section of the filter, and an under drain system to uniformly collect the filtered water.

Operation

The suspended matter, which is treated with a coagulant such as alum or poly electrolyte, is kept on the sand surface and between the sand grains immediately below the surface while raw water passes down through the filter bed. Over time, the loss of head increases steadily, and the flow decreases if the pressure drop over the filter becomes excessive.

The filter is subsequently removed from service, and the filter media is cleaned using flow reversal, often known as backwash. The backwash procedure is occasionally preceded by air scouring via agitation through the under drain system to assist in cleaning the bed. The air scouring agitates the sand with a scrubbing action, which loosens the intercepted particles. The filter is now ready to be put back into service.

Features & Benefits

Higher specific flow rate than traditional down flow filters, which saves space and money
Very little maintenance required.
Backwash water usage is reduced.
In most cases, raw water can be used for backwash.
The user-friendly and simple-to-operate multiport valve is operated by a single lever.
Plastic piping do not require Maintenance and are corrosive resistance.
Options for manual and automatic operation.
Custom sizes and configurations are available.
Ideal for pre-treatment.
Higher Specific velocity.

Applications

Treatment of waste water
Production of drinking water
Filtration in swimming pools
Pre filtration for membrane systems
Filtration of gray or surface water
Swimming pool water

Operation