Dynamic Sand Filter
PRINCIPLE OF OPERATION
The feed water is fed into the filter at the base of the active sand bed through the distribution ring (D).
It then flows upward through the downward moving sand bed where the solids are filtered out. The clean filtrate exits the filter through the overflow weir (E). The continuous reject flow of washing water
is discharged through a separate outlet.
The dirty sand is continuously removed from the active sand bed (A) thanks to the action of the air-lift pump (C). This pump draws the contaminated sand from the bottom (B) of the filter body.
A mixture of sand, dirty particles and water is transported upward through the air-lift pipe into the washing chamber at the top of the filter.
| MAIN FEATURES AND BENEFITS
 - Absence of any mechanical moving parts
- Unique continuous back-wash system using counter current variable velocity washing
- Simple plant with no backwash water storage and backwash pumps.
- Higher suspended solids content in feed, high efficiency in removing fine solids
- Colloidal particles efficiently removed through simple in-line dosage of coagulants
- Coagulation, flocculation and filtration in one step thanks to the deep active bed.
- Very low pressure drop across the filter, gravity feed is possible in many instances
- Easy maintenance thanks to the internal sand air-lift system
| TYPICAL APPLICATIONS
 Pulp and Paper: Polishing of process waters for recycling
Oil Refining: Oil removal from waste waters
WWTP: Tertiary treatment; phosphorus removal
Iron and Steel: Oil and scale removal from cooling waters
Metal Finishing: Metal hydroxide removal from wastewaters
Water Supply: Potable water filtration, algae removal
General: Boiler feed water pre-treatment, cooling tower water clarification, membrane ultra-filtration and ozonization plant pre-treatment.
MATERIALS
All wetted parts are in stainless steel AISI 304L, Special construction materials available upon request.
MULTI-MODULE SYSTEM
Solution for installation in a concrete basin of several basic filter inserts.
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