75 Tonne/Day Reverse Osmosis Water Treatment System – Stainless Frame

The Reverse Osmosis Water Treatment System brings together on a single frame the membranes, pump, protection and measuring equipment needed for high-volume daily production.

The Reverse Osmosis Water Treatment System suits sites that use around 75 m³ of treated water a day and whose feed water TDS is up to 2,000 ppm.

Food & Beverage ProductionBoiler Feed WaterTextiles & Dye HousesHotels & Large FacilitiesProcess Water LinesSites Using Well WaterGreenhouses & Soilless GrowingIndustrial Cleaning & Washing

The Reverse Osmosis Water Treatment System is based on a membrane separation process that drives water under high pressure through semi-permeable membranes. As the US Environmental Protection Agency (EPA) also points out in its overview of treatment technologies, pre-treatment is often needed to keep the membrane from fouling and clogging; water that does not pass through the membrane is separated off as concentrate.

1. 1

   It Passes the Cartridge Filter

   Water coming from the sand, carbon and softening stages passes through the 5 micron cartridge filter at the unit’s inlet; fine particles are held back before they reach the membranes.

2. 2

   The Pressure Is Checked

   The low-pressure switch watches the inlet line; the feed water pressure should be within 2–5 bar. The high-pressure switch, in turn, monitors the pressure at the pump outlet.

3. 3

   High-Pressure Pump

   The vertical-shaft stainless pump raises the water to a working pressure of 9–12 bar and delivers it to the 15-membrane array; a regulating valve at the pump outlet balances the flow.

4. 4

   Separation at the Membrane

   Water molecules pass through the semi-permeable membrane to form the product water (permeate); dissolved salts and inorganic substances stay on the feed side of the membrane.

5. 5

   Product Water and Concentrate Separate

   The product water passes the flow meter and conductivity meter and goes into the tank; the concentrate stream is sent to drain through the reject line regulating valve. The autoflush valve flushes the membranes automatically.

When choosing the Reverse Osmosis Water Treatment System, the daily water requirement, the raw water analysis, pre-treatment and the installation infrastructure should be assessed together.

The performance of the Reverse Osmosis Water Treatment System depends on regular monitoring of the pre-treatment, the cartridge filter and the membranes.

• The 5 micron cartridge filter should be checked regularly and replaced when it is dirty or when the pressure difference between the inlet and outlet sides of the filter rises markedly.
• Flow meter, pressure gauge and conductivity readings should be logged regularly; a fall in product flow or a rise in conductivity can point to membrane fouling.
• Fouled membranes are cleaned by chemical cleaning (CIP); a membrane cleaning unit can be added to the system as an option.
• Maintenance of the pre-treatment stages should not be neglected; TFC membranes are sensitive to chlorine, so the carbon stage must be renewed on time once it is saturated.
• The TDS, iron, silica, temperature and pressure of the feed water should be monitored to keep them within the stated limits.
• If antiscalant dosing is installed, the level in the chemical tank should be checked regularly; the drain line for concentrate and flushing water must always be kept clear.