Clarifier Cleaning
As the clarifier screens work to reduce suspended solids carry over, the filter cake of trapped solids will eventually reach a density sufficient to impair the flow. For efficient operation of the clarifier screens
it is vital that a regular cleaning regime is maintained.
The high open area and smooth surface of the mesh simplifies cleaning either manually with a hose pipe or by automated cleaning options using installed humus tank ancillary equipment.
Locker Clarifier Systems are designed for use in:
- Upward flow clarifiers
- Radial clarifiers
- End-flow tanks
- Pyramidal tanks.
Manual Backwashing
This is the usual method employed for horizontal end flow, pyramidal and small circular tanks. It is recommended that the water level is lowered and the screens thoroughly backwashed once per week. Where solids loadings are light this interval can be increased to every 2 weeks. A 45m2 tank can be hosed clean in around 20 minutes.
Where no suitable wash water supply exists on site, Locker can provide other humus tank ancillary equipment, such as a GRP boxed-out zone in the tank to provide a sump for use with a portable
pump cleaning kit. A 2 ins. pump delivering 600 l/min. max, 29 m maximum head is recommended.
If the site has a suitable electrical supply, a submersible pump cleaning kit with delivery hose and adjustable spray nozzle is available. The pump is suspended by a stainless steel chain into a suitable area of the tank.
Locker Auto-Cleaner
This humus tank ancillary equipment is employed on radial tanks and is mounted on the rotating half-bridge.
On the cleaning cycle the vacuum head is lowered below the water line to be close to the upper surface of the screens, the pump is activated and flocculated solids are sucked up through both layers of mesh and returned as a slurry to the central diffuser box.
The tank remains in operation during cleaning of humus tank ancillary equipment.
The image shows the clarifier screens installed as an annulus complete with a new inner baffle board. The existing scraper leg assembly is modified as necessary.
Spray Jet Backwash
Another type of humus tank ancillary equipment specifically designed for cleaning is a spray jet backwash.
An automated or semi-automated system of submersible pump and spray jets are mounted above the screens and available for all types of tanks; upward flow clarifiers, end-flow tanks and radial clarifiers.
