For seawater reverse osmosis systems, the high pressure of the discharged concentrated water, if recycled, can greatly reduce the energy consumption of the system and reduce operating costs.
The two main types of energy recovery technology currently in use are turbine and pressure based.
01 Turbine energy reclaimers
The Turbine Energy Recycler is an integral turbine pump, similar to a reversing single stage centrifugal pump.
The unit is connected in series with a high pressure pump on the inlet side of the reverse osmosis, transferring the pressure of the concentrated reverse osmosis water to the entire inlet water, with an energy recovery efficiency of around 60-80%, which reduces the head of the high pressure pump.
02 Pressure Energy Reclaimer
The Pressure Exchanger Energy Reclaimer, abbreviated as PX, uses an ingenious design to convert energy using the principle of positive displacement, transferring the pressure of the concentrated reverse osmosis water to an equal amount of feed water.
This means that the raw water is divided in two ways after the security filter, one way to the energy recovery device and one way to the high pressure pump.
The device is connected in parallel with the high-pressure pump and is able to reduce the flow of the high-pressure pump, with an energy recovery efficiency of more than 95%.
As the PX high pressure outlet water goes to the high pressure pump outlet, a booster pump needs to be set to overcome the loss of pressure drop and resistance losses.
