Industry application of vertical long shaft semi submersible turbine pump solution in seawater desalination field

The application scenarios of seawater desalination are extensive, covering multiple fields such as water supply, industry, and ecological governance. The vertical long axis semi submersible turbine pump mainly undertakes two core applications: raw seawater extraction and system support.
1. Core application scenarios of seawater desalination
Municipal water supply field
It is the largest application direction of seawater desalination, providing drinking water for coastal cities and remote islands with scarce freshwater resources. For example, large-scale seawater desalination projects in the Middle East, North Africa, and coastal areas such as Qingdao in Shandong, Zhoushan in Zhejiang, and Liuheng Island in Zhejiang can produce tens of thousands of tons of desalinated water per day, which can serve as an important supplement to municipal water supply; In dry years or when water sources are suddenly polluted, it can also be used as an emergency drought resistant and backup water source to start water supply.
Industrial water use field
It is the fastest-growing application direction of seawater desalination. Coastal thermal power plants, nuclear power plants, etc. require a large amount of fresh water as circulating cooling supplement water, boiler feedwater, and equipment flushing water. Seawater desalination pumps can provide high-quality desalinated water for such power plants; At the same time, it can also provide independent desalinated water sources for small scenes such as seaside villa areas.
Special Scene
Can provide fresh water for ocean ships and offshore platforms (such as Indonesian offshore oil fields) to meet the living and production needs of offshore operators; It can also provide water for resorts, offshore platforms and other places.
2. Solution for vertical long axis semi submersible turbine pump in seawater desalination scenarios
Extraction and transportation of raw seawater
The core requirements for seawater intake are high flow stable water supply, resistance to seawater corrosion, and adaptability to tidal water level fluctuations; As the front-end core equipment of seawater desalination system, it is responsible for extracting raw seawater from nearshore, offshore or water intake pump stations, and transporting it to subsequent pretreatment and desalination processes. This type of corrosion-resistant vertical long shaft semi submersible turbine pump is suitable for high flow (500-5000m ³/h) and medium low head (20-80m) working conditions. The core components are mostly made of duplex stainless steel or super duplex steel materials to resist seawater corrosion; Some pump models can be equipped with anti attachment devices to prevent marine organisms from affecting the operational efficiency of the pump; For the scenario of seawater freezing in winter, a heater can also be equipped to ensure normal water intake.
Pre treatment and transportation of seawater desalination
In the seawater desalination pretreatment stage, as the core water supply equipment, a corrosion-resistant vertical long shaft semi submersible turbine pump is used. The overcurrent components of the pump are made of super duplex steel material, which can resist the corrosion and wear of salt and impurities in seawater; Paired with an external cooling and lubrication system, it ensures stable operation of the equipment under high load conditions, provides stable and sufficient seawater raw materials for subsequent desalination processes, and improves the efficiency of the entire seawater desalination system.
Concentrated saltwater discharge from reverse osmosis system
Pressurize the original seawater through a high-pressure pump and pass it through a reverse osmosis membrane module; Under pressure, water molecules pass through the reverse osmosis membrane, while impurities such as salt, minerals, and microorganisms in seawater are trapped on one side of the membrane, forming concentrated saltwater. The salinity is usually about twice or even higher than that of the original seawater, and it has strong corrosiveness; In addition to salt content, concentrated salt water may also contain impurities such as heavy metals, organic matter, and microorganisms that must be discharged to ensure the continuous, efficient, and stable operation of the reverse osmosis system. The high flow, high head, corrosion-resistant, high chromium duplex steel vertical long shaft semi submersible turbine pump is one of the key equipment in the concentrated salt water discharge process, responsible for lifting concentrated salt water from the concentrated salt water tank to the discharge outlet or treatment area. A variable frequency speed regulating vertical long shaft pump is used to adjust the working point through variable frequency according to the flux attenuation of the reverse osmosis membrane, ensuring stable system production capacity and recovery rate; Simultaneously selecting pump types with high efficiency and wide coverage areas to reduce system energy consumption and enhance the economic viability of seawater desalination projects.
Optimization of pump shaft cooling and lubrication
The vertical long shaft semi submersible turbine pump used in the seawater desalination water intake pump project requires real-time cooling and lubrication of the pump shaft with water during operation to prevent wear of the pump shaft and shaft sleeve. The conventional solution is to use production fire water for lubrication during startup, and switch to seawater self lubrication from the pump outlet during normal operation. However, due to the high impurities in seawater, the filter needs to be cleaned frequently. The optimization plan can use the clean seawater filtered by the seawater chlorination system as a lubricating water source, which not only avoids impurities blocking the filter, but also extends the maintenance cycle of the pump shaft and shaft sleeve from once a year to once every 3 years, reducing maintenance costs and labor intensity of employees.
Adaptation and transformation for special working conditions
For working conditions such as high sand content, seawater corrosion, and high temperature, the vertical long shaft semi submersible turbine pump can be retrofitted for environmental adaptation: wear-resistant lining plates can be installed in working conditions with high sand content; Select super duplex steel impellers in seawater conditions; When transporting high-temperature media, a water-cooled bearing box is configured to extend the service life of the pump and ensure stable operation of the system.
Overall targeted solution
Large flow adaptation process scale: The modular impeller design can meet the range of single pump flow from 80 to 13600m ³/h, adapting to different needs from small-scale desalination stations of thousands of tons to large-scale desalination projects of 100000 tons. Multiple pumps in parallel can meet the water intake requirements of large-scale projects of millions of tons.
Anti clogging and anti fouling design: The pump inlet is equipped with a large aperture self-cleaning filter screen to block large marine impurities, combined with an anti marine biological device to avoid algae and shellfish from adhering and blocking the flow channel, ensuring continuous operation and reducing manual cleaning frequency.
Low energy optimized hydraulic design: The vertical long shaft semi submersible turbine pump uses hydraulic software to optimize the impeller flow channel, reduce inlet resistance, and improve delivery efficiency. Compared with traditional submersible pumps, it can reduce operating energy consumption by 8% -12% and lower the overall water production cost of seawater desalination.