Pre-engineered commercial / industrial Reverse Osmosis Systems
CWC is Africa's most experienced manufacturer of pre-engineered and custom built reverse osmosis systems for the treatment of residential, commercial and industrial water supplies.
What is Reverse Osmosis (RO)?
All water contains Total Dissolved Solids (TDS). TDS is the measurement by weight of the dissolved materials in a given volume of water. If a material will completely dissolve and is not visible in the water, it is part of the TDS of the water.
Reverse Osmosis helps to lower the TDS content of water, by passing it through a semi-permeable membrane with a pore size of less than 0.0005 microns in diameter. The purified (permeate) water produced by a Reverse Osmosis system is amongst the purest form of treated water available.
Reverse Osmosis can be effectively used for the reduction of Total Dissolved Solids in groundwater, surface water and sea water applications.
How Reverse Osmosis Works
Reverse Osmosis is a membrane process that acts as a molecular filter to remove over 99% of all dissolved minerals. Water passes through the membrane while the dissolved and particulate matter is left behind.
As pressure is applied to the concentrated solution, the flow is reversed and water is passed through the membrane from the concentrated side to the dilute side.
Water molecules penetrate the thin layer of the membrane and diffuse through it molecule by molecule. Dissolved salt ions would also diffuse through this layer, except that the solubility of the salt ions in the feed is much less than that of the water. This results in water passing through the membrane more rapidly than salts, causing separation.
The driving force of the reverse osmosis process is driven by both the feed water pressure and the concentration differentials across the membrane surface. For water, the pressure effect is the most important, and for the dissolved ions in the water, the concentration difference is the most important. Therefore, increases in pressure increase the amount of treated water without causing a corresponding increase in waste flow.
The RO process removes most of the dissolved mineral salts, almost all of the particulate matter and most of the dissolved organic compounds.
Reverse Osmosis Applications
- Drinking Water-Reduces scaling; improves taste and clarity. Removes excess dissolved salts and bacteria.
- Food & Beverage-Superior taste and increased cost savings.
- Ice Production-Reduces scaling; improves taste and clarity.
- Restaurants-Improves steamer operation.
- Humidification-Reduces scaling and dusting.
- Grocery Stores-Prevents scaling in vegetable misters.
- Pretreatment-For use in deionization systems.
- Boilers-Improves energy efficiency.
- Vehicle Wash-Provides spot-free rinses.
- Water Jet Cutting-Improves operating efficiency; extends orifice life.
Contaminants Removed By Reverse Osmosis
Reverse Osmosis systems remove substantial amounts of most dissolved minerals (such as salts, metals and other minerals).
Most bacteria and other microbiological contaminants are also removed due to their size in relation to the size of a membrane pore.
Any particulate matter remaining after pre-treatment will also be removed, although RO is not recommended as a filtration process.
The following commonly found minerals are actively reduced by Reverse Osmosis:
| Cations | Anions |
|---|---|
| Calcium | Carbonate |
| Magnesium | Bicarbonate |
| Sodium | Sulphates |
| Potassium | Chlorides |
| Ammonium | Flouride |
| Barium | Nitrates |
| Strontium | Boron |
| Silica |
Reverse Osmosis Specifications
CWC manufactures a broad range of Reverse Osmosis systems for almost any application. Specifications below are for our pre-engineered equipment range. For information on larger Reverse Osmosis systems supplied by CWC, visit our custom Reverse Osmosis systems section. For information on our Seawater Desalinators, visit our Seawater Reverse Osmosis section.
| Model | Pure water flow* | Approximate recovery |
|---|---|---|
| A-146 | 750 lpd | 50% |
| A-246 | 1500 lpd | 50% |
| A-346 | 2250 lpd | 50% |
| A-265 | 3360 lpd | 60% |
| A-365 | 5000 lpd | 60% |
| A-280 | 10000 lpd | 75% |
| A-380 | 15000 lpd | 75% |
| A-480 | 20000 lpd | 75% |
| A-680 | 30000 lpd | 75% |
| A-880 | 40000 lpd | 75% |
| A-1080 | 50000 lpd | 75% |
| A-1280 | 60000 lpd | 75% |
*Approximate initial capacity based on properly pretreated feed water of 500 ppm TDS as NaCI, 25°C, Silt Density Index below 3, and 10 bar applied pressure supplying water to atmosphere. Productivity will vary depending on the feed water conditions.
reverse osmosis System technical parameters:
| Inlet Pressure | 200-400 kPa |
| Operating Pressure | 600-1200 kPa |
| Power | 220VAC or 380 V 3-phase |
| Operating Temperature | 1-38°C |
| Maximum Turbidity | 1 NTU |
| pH range | 3-11 |
| Maximum feed chlorine | 0 ppm |
| Maximum feed TDS | 1000 ppm |
| Maximum iron in feed | 0.1 ppm |
a-series reverse osmosis - Standard Features
- Low pressure switch - protects the pump during low pressure operation.
- Connection for liquid level controls - allows for simple integration and operation.
- Electrical control panel - all controls housed in an IP55 steel enclosure.
- Free standing frame - durable, compact epoxy coated steel frame. No mounting necessary.
- TDS indicator - monitor the purity of the treated water.
- Rotameters - allows for accurate flow measurement and system control.
- Recycle valve - reduce waste and increase system recoveries.
- Pre-filter - 1-micron cartridge filter for particulate matter removal.
- RO feed pump - multistage centrifugal feed pump.
- RO membranes - Hydranautics membrane elements.
- Pressure gauges - allows for accurate measurement of system performance.
reverse osmosis pre-treatment
On all pre-engineered RO systems, CWC offers a pre-treatment plant as an option. The pre-treatment plant is mounted on a separate free-standing frame, and consists of the following components:
- Multimedia filter - removes suspended solids and turbidity.
- Activated carbon filter - removes chlorine, tastes, odours and organic colour.
- Water softener - reduces feed water hardness to protect RO membranes from fouling.
- System feed pump.
In addition to the pre-treatment system, CWC can add the following pre-treatment and post treatment items to all reverse osmosis systems in the pre-engineered equipment range:
- UV sterilizer.
- Ozone generator.
- Chlorine dosing system.
- Anti-scalant dosing system.
- pH control system.
- Ultrafiltration pre-treatment unit for high turbidity feed water supplies.
- Cleaning in place system.
Reverse Osmosis Design Considerations
In order to accurately size a reverse osmosis system for commercial or industrial applications, we will need to know the following:
- The amount of water you expect to use per 24-hour period.
- Your peak water demand.
- Operating hours per day.
- Your water pressure.
- The quality of your water - see our water analysis section for more information.
- What you plan to use the purified water for.
- Your site layout.
Your local approved CWC distributor can help you calculate your purified water needs, and can arrange for a professional water analysis to be taken. For more information about CWC's reverse osmosis systems and how the RO process can help you in your home or business, contact CWC today.
