APPLICATION

The SF/CF range, is a downflow, low pressure, granulated-bed filter which is extremely effective in liquid-solid separation at flow rates up to 30 M³ per hour sq. metre of filter area. Applications include removal of turbidity, and algae from potable water polishing and upgrading sewage works effluent and the treatment of process water. The standard range of filters extend, in capacity, from 2 to 75 M³/Hr or a single unit. Multiples are available to suit, either free standing or skid mounted, including ancillaries such as pumps, chemical dosing, and controls, to form a complete water purification package.

FILTRATION MEDIA

Each filter media is carefully selected and graded to suit duty and performance. Quartz sand? Anthracite, Activated Carbon, are among the commonest used, either singularly or in combination to maximize clarity at minimum pressure loss, simplifying back washing and maintenance sequence. In this way suspended solids removal capacity is secured within a very flexible and wide range up to 20 kg per sq. metre, filtration area.

CONSTRUCTION

The filter shell is normally of welded mild steel construction, with dished ends for the larger models, tested to 1.5 times maximum working pressure, and complete with access manhole, inlet/outlet flanges, drain point and air vent. The filtering media rests on a bed of suitably sized gravel which in turn is supported by a steel plate, through which specially designed thermoplastic nozzles ensure perfect distribution of flows throughout the whole filter bed area.

After testing, each unit receives an extensive course of corrosion protection treatment, including shot blasting to SA 2.5, priming, and epoxy resin coating The paint system for potable water filters is of an approved type, compatible with drinking water standards.

OPERATION

The SF/CF range is designed for simplicity of operation and maintenance. Components are readily accessible. Where pumps are included, they are interchangeable so that each can perform the duty of a feed or backwash unit, complete with a standby facility, to ensure continuous service

Filter cleaning is simply achieved by flow reversal - back washing Due to the carefully optimized bed design, resort to air scouring or other complex cleaning aids is obviated in the majority of applications, minimizing backwashing sequences and duration. This procedure can easily be carried out on a manual basis but automatic operation is optionally available as well. In this case the sequence is automatically initiated by the pressure loss monitor and/or a pre-set timer.