Clearflow ZLD-BC 250

The stage that sits between a conventional RO plant and an evaporator. It takes concentrate that a standard train cannot push any further and pulls another 90 % of the water out of it, shrinking the thermal tail to a fraction of its usual size.

What it is designed to do

The Clearflow ZLD-BC 250 is a standard Clearflow configuration rated at 25 m³/h of permeate at 90 % system recovery, which is 600 m³ over a continuous day. The published envelope assumes 25 °C, a clean membrane and the design feed analysis; every project is re-projected against the water you actually have before a price is issued.

• Feed envelope — up to 22,000 mg/L TDS, SDI15 below 3, turbidity below 0.2 NTU
• Membrane hardware — 60 elements across 10 vessels, 2,232 m² of active area
• Energy — 3.85 kWh/m³ of product at design conditions, 135 kW installed motor load
• Delivery — 11.2 × 3.0 × 3.6 m, 15,200 kg dry, 22–26 weeks ex works

How the array is put together

The array is arranged as 2 stage, 6:4 taper with interstage boost, 6 elements per vessel. Element type is High-pressure 8040 element, 37.2 m² each; disc-tube option for high-fouling brine, running on high-pressure seawater polyamide run on a continuous antiscalant regime. Design flux is held at 11.2 LMH so the concentrate velocity through the last element stays inside the manufacturer envelope at design recovery — the single most reliable predictor of how long the membranes will last.

Operating conditions

Cleaning, control and materials

Four-stage CIP with acid and caustic circuits, 6,000 L. Control is by Industrial PLC with live saturation index supervision on the concentrate. The wetted specification is Super duplex 2507 throughout the high-pressure circuit. Pressurisation is by API 610 BB2 barrel pump with an interstage booster; hydraulic turbocharger providing interstage boost from the concentrate.