Even though more than 70% of the Earth's surface is covered by water, only 1% of it is drinkable. According to the UN, water scarcity is one of the main global challenges, today and into the future.
It is urgent to provide solutions to water scarcity, and reverse osmosis is considered one of the most effective solutions to address the challenge. The process, which turns seawater into freshwater, is simple and more efficient than other desalination methods.
Facts about water scarcity
- Worldwide consumption of drinking water doubles every 20 years.
- More than 1 billion people suffer from lack of freshwater.
- 300 million people in 150 countries rely wholly or partially on seawater desalination for their drinking water.
Reducing the energy cost of reverse osmosis
The process of pumping large amounts of seawater through desalination membranes is highly energy intensive.
In recent years, however, the increasing focus on climate change and energy efficiency has brought new pumping solutions to the forefront, particularly the use of positive displacement pumps with energy recovery devices and AC drives.
Over the past ten years, the number of SWRO plants using positive displacement pumps with energy recovery systems and AC drives has grown significantly. The systems have proven to outperform traditional centrifugal pumps on most operational parameters, returning efficiency rates of up to 92% and energy savings of up to 65%.
The increasing focus on climate change and energy efficiency has brought new pumping solutions to the forefront
The power of modularity
The trend towards modularity in medium and large size SWRO plants encourages the use of parallel-coupled trains of positive displacement pumps with energy recovery and AC drives.
The flexible set-up with multiple pumps running in parallel offers a number of advantages. For example, the capacity of the system can be adjusted continuously according to the need for water at any given time to save energy. If one of the pumps is out of order for maintenance, the remaining pumps automatically take over the full operations allowing production to continue 24/7/365.
In addition, the flow in a single pump can be adjusted without affecting the remaining pumps. This means that the AC drive can be sized for a single pump, while the rest of the pumps run directly online.
The simple configuration with parallel-coupled positive displacement pumps saves money on the AC drive and results in important energy savings during operation.
The number of SWRO plants using positive displacement pumps with energy recovery systems and AC drives has grown
Benefits of using several parallel-coupled pump trains
- High uptime and uninterrupted operation, even when one or more of the pumps are out for maintenance.
- One small, redundant pump is cheaper than one large redundant pump.
- Simple and energy efficient flow control.
These four core technologies from Danfoss work together to improve SWRO efficiency:
- APP pumps, designed for SWRO, offer the highest efficiency rates in the industry.
- iSave 3-en-1 energy recovery device is optimised for SWRO and results in substantial energy savings.
- VLT AQUA Drive FC 202 drives and controls all types of pumps and comes equipped with a cascade controller.
- DST P40I pressure sensor designed to meet the requirements of corrosive industrial environments.
Danfoss, your partner in pump solutions for SWRO
Danfoss is committed to supporting the desalination industry with energy efficient solutions for desalination. Based on decades of experience in developing components for critical applications like for instance axial pump technology, we use our extensive know-how of seawater reverse osmosis to lead the industry towards even better desalination methods.
Danfoss combines four core technologies to provide superior and cost-efficient desalination solutions: high pressure pumps, energy recovery devices, AC drives and pressure and fluid control sensors. These combine into highly efficient and lasting water purification solutions.
The simple configuration with parallel-coupled positive displacement pumps saves money on the AC drive and results in savings
Our product range for SWRO applications provides the following benefits:
- Efficiency rates of up to 92%.
- Energy savings of up to 65% compared to centrifugal pumps without energy recovery and AC drive.
- A single provider for pumps, energy recovery, drives and sensors.
- Minimal service, long service intervals and ultra-low maintenance costs.
- Simple and reliable operation.
- Small carbon footprint and light weight components.
Danfoss designs advanced technologies that enable us to build a better, smarter and more efficient future. In the world's growing cities, we enable the supply of fresh food and optimal comfort in our homes and offices, while meeting the need for energy-efficient infrastructure, connected systems and integrated renewable energy. Our solutions are used in areas such as refrigeration, air conditioning, heating, motor control and mobile machinery. Our innovative engineering dates back to 1933 and today Danfoss holds market-leading positions, employing 27,000 people and serving customers in more than 100 countries. We are privately held by the founding family.