## What Is Reverse Osmosis and How Does It Work?
### The Concept of Osmosis
To grasp reverse osmosis, let’s first understand osmosis. Osmosis is a naturally occurring process where water molecules move from an area of low concentration (less contaminated water) to an area of high concentration (more contaminated water) through a semipermeable membrane. This membrane allows only water molecules to pass while blocking larger molecules and ions. The goal of osmosis is to reach equilibrium, where the concentration of substances on both sides of the membrane is equal.
### Reverse Osmosis: The Opposite Process
Reverse osmosis (RO) flips this natural process. By applying pressure to the contaminated water side, water molecules are forced through the semipermeable membrane from the high concentration side to the low concentration side. This process removes contaminants, resulting in purified water.
## What Is an RO Water System?
An RO water system is an engineered solution designed to purify water by removing undesirable substances. At Daly Middle East, our RO systems, known as watermakers, are primarily used for desalination, transforming brackish or seawater into freshwater suitable for various uses.
### Who Benefits from an RO Watermaker?
Our clients, including offshore rigs, ships, and marine facilities, rely on RO systems to generate freshwater on-site, avoiding the high costs and logistical challenges of transporting water from land. These systems are crucial for small, self-contained communities in remote locations, providing a reliable source of freshwater.
## How Does an RO Water System Work?
### Feed Water Supply
The system begins by tapping into the existing seawater ring main, supplying the feed water. If the main cannot sustain the required pressure, a booster pump may be installed.
### Pre-Filtration
Feed water is passed through a pre-filter skid to remove suspended solids, such as drill cuttings, ensuring that only filtered seawater enters the reverse osmosis units.
### Reverse Osmosis Process
A high-pressure pump forces the pre-filtered seawater through semipermeable membranes. These membranes allow water molecules to pass while rejecting contaminants like ions and hydrocarbons. If the seawater has been chlorinated, it first goes through a dechlorination unit.
### Permeate Water Treatment
The resulting freshwater, or permeate water, goes through a remineralisation column. This step stabilizes the pH level to prevent corrosion in metal pipes and storage tanks and improves the water’s flavor by adding necessary minerals. Our systems achieve approximately a 40% recovery rate, meaning 40% of the feed water is converted into freshwater, with the remaining concentrated water disposed of according to regulations.
## Custom-Built RO Systems
For clients with specific needs, Daly Middle East offers custom-engineered RO systems with higher recovery rates. These systems are tailored to the operational specifications, including salinity levels, required water volume, available feed water, and electrical supply.
### Daly RO45 and Daly RO82 Specifications
Our standard units, the Daly RO45 and Daly RO82, are designed for optimal performance in the Arabian Gulf. These units deliver between 45m³ to 82m³ of freshwater per day from seawater with salinity levels up to 42,000ppm. Key specifications include:
– **Output**: 45m³ – 82m³ freshwater/day
– **Dimensions**: 1350mm (width) x 2000mm (length) x 1812mm (height)
– **Frame Type**: Skid Mounted, Carbon Steel Epoxy Coated
– **Electrical Panel**: Schneider Type
– **Piping and Fittings**: PVC for low-pressure, 316 SS for high-pressure
– **Electrical Requirements**: 480VAC, 60Hz, 3 Phase
### Pre-Filter Skid Specifications
– **Skid Type**: Dual Cartridge Filter Assemblies
– **Frame Type**: Skid Mounted, Carbon Steel Epoxy Coated
– **Optional Booster Pump**: Available based on sea water ring main pressure
– **Electrical Panel**: Schneider Type with Start/Stop buttons, indicators, and main isolator
## Conclusion
Reverse osmosis is a vital water treatment process, especially for offshore and remote locations where freshwater is scarce. Daly Middle East offers both standard and custom-built RO systems to meet diverse needs, ensuring a reliable supply of high-quality freshwater.
For more information or to discuss your specific requirements, contact Daly Middle East. Our experts are ready to provide solutions tailored to your operational needs.