Water recovery & ZLD
SILEX™
Silica and scaling control ahead of evaporation and reuse loops.
A deep-bed upflow sand filter that cleans its own bed continuously: no backwash cycle, so it never stops filtering.
The SILEX sand filter's effectiveness lies in the fact that no shutdowns are necessary for backwash cycles. The inlet is at the bottom of the filter; as the feed flows upward through the sand bed, solids are retained in the filter sand and the filtrate exits over a weir at the top. The sand sinks into an airlift pipe at the center of the filter, which transports it up to the sand washer, where solids are separated. Clean sand falls back onto the bed, creating a continuous internal sand circulation.
How it works
The process
The Silex filter is a deep-bed upflow filter with continuous bed cleaning, so no shutdown is needed for a backwash cycle. Feed enters at the bottom and flows up through the sand bed, where the solids are retained; the filtrate leaves over a weir at the top. The sand sinks and enters an airlift pipe at the centre of the filter, which carries the sand-and-solids mix up to the sand washer. There the solids are separated off and the clean sand falls back onto the bed, creating a continuous internal sand circulation. The modular design means any throughput can be matched, and the filter comes as either a free-standing stainless steel tank or a concrete basin.
Specifications
| Filter type | Deep-bed upflow with continuous bed cleaning |
| Backwash | None: no shutdown for backwash |
| Versions | Free-standing stainless steel tank, or concrete basin |
| Main material | EN 1.4301 / EN 1.4404 / EN 1.4571 |
| Max allowed temperature | 60 °C |
| Sand washer | Glass-fibre reinforced composite |
| Rubber couplings | EPDM |
| Head loss pipe | PVC |
| Internals | Water distributor, sand distributor, sand washer, guide tube, airlift pump |
| Sizing | Modular: from 2.86 m² filter area per unit |
Key advantages
- Filters continuously: no backwash shutdowns
- No separate backwash sequence to run, and no backwash water to pump
- Modular, so any throughput can be matched
- Available in stainless steel or concrete construction
- Built to meet the tightening effluent limits on municipal and industrial plants
- Simple internals with no moving parts in the bed
Gallery
Where it is applied
- Polishing municipal effluent to tighter limits
- Polishing industrial effluent
- Solids removal ahead of reuse or membranes
Reference plants
The largest 6 of 7 plants delivered with SILEX, 1996–2025.
| Plant | Location | Capacity | Year | Process |
|---|---|---|---|---|
| BAMO Technology Hungary | Ács, Hungary | 48,000 m³/day | 2024 | Physico-chemical · DAF · filtration |
| EVE Power Hungary Kft | Debrecen, Hungary | 245 m³/day | 2025 | Physico-chemical · lamella sep · MBR · DAF · UF |
| Eve Power Hungary Kft. | Debrecen, Hungary | 245 m³/day | 2023 | lamella sep · DAF · MBR · Physico-chemical · UF |
| SEMCORP Hungary Kft. | Debrecen, Hungary | 26 m³/day | 2024 | MBR · Physico-chemical · UF |
| Halms Hungary Kft. | Debrecen, Hungary | 5 m³/day | 2025 | AC filter · RO |
| POLIFARBE Kft | Bócsa, Hungary | 2 m³/day | 2001 | Physico-chemical · filtration |
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