50 Tonne/Day Reverse Osmosis System

The 50 Tonne Reverse Osmosis System brings together on a single frame the components needed for steady production at high capacity.

The 50 Tonne Reverse Osmosis System suits sites that need around 50 m³ of low-conductivity water a day and whose feed water TDS does not exceed 2,000 ppm.

Factories & Production PlantsProcess Water LinesFood & Beverage ProductionBoiler & Steam SystemsHotels & AccommodationSites Using Brackish Well WaterGreenhouses & Agricultural IrrigationCar Wash & Rinse Water

Reverse osmosis is a membrane separation process that drives water through semi-permeable membranes at high pressure; the part that passes through the membrane is called product water (permeate), and the part that does not is called concentrate. The US Environmental Protection Agency’s (EPA) overview of treatment technologies also notes that pre-treatment is often needed to keep the membranes from fouling and clogging. The 50 Tonne Reverse Osmosis System carries out this process in five steps.

1. 1

   Cartridge Filter and Inlet Check

   Water arriving from the pre-treatment first passes through the 5 micron cartridge filter, which clears it of fine particles. A low-pressure switch monitors the inlet pressure; if the pressure is insufficient, the unit does not run.

2. 2

   High-Pressure Pump

   The stainless steel vertical-shaft pump raises the water to a working pressure of 9–12 bar and sends it to the membrane housings.

3. 3

   Separation at the Membranes

   The water passes through ten 4040 TFC membranes. As the water molecules pass through the membrane, dissolved salts and substances with larger molecules stay on the concentrate side.

4. 4

   Product Water and Concentrate

   Of the 83 m³ of feed water a day, 50 m³ is drawn off as product water and the rest goes to drain as concentrate. The flow meters show the two flows, and the conductivity meter shows the quality of the product water.

5. 5

   Delivery to a Tank or the Line

   The product water is delivered to a storage tank or to the line where it is used. The solenoid valves and the control panel with a mechanical board start and stop the unit automatically.

Before the 50 Tonne Reverse Osmosis System is chosen, the daily requirement, the raw water analysis, the pre-treatment and the installation conditions should be assessed together.

The 50 Tonne Reverse Osmosis System runs steadily when the pre-treatment and the monitoring figures are checked regularly.

• The cartridge filter should be checked regularly and replaced when the pressure difference between its inlet and outlet rises.
• The product water flow and conductivity should be recorded regularly; a fall in flow or a rise in conductivity can point to membrane fouling.
• When performance falls, the membranes should be cleaned chemically (CIP); a CIP system can be added to the unit as an option.
• On the pre-treatment side, keep track of the backwash of the sand and carbon units, the renewal of the carbon fill and the softener’s salt tank.
• The iron, silica, SDI and turbidity limits of the feed water should be maintained, and antiscalant dosed where there is a scaling risk.
• The regulating valves at the pump outlet and on the reject line are set for the 60% recovery rate; these settings should not be changed without technical knowledge.