This paper gives a brief overview of the technology used to recover the energy from brine stream in large desalination plants, with a description of the modifications required if the recovery system with Pelton turbines is to be replaced by systems based on isobaric-chamber devices.

The paper points out that impulse turbine technology is well-established and readily acceptable to energy recovery systems for sea water reverse osmosis. The Pelton type impulse turbine has a very broad or “flat” efficiency characteristic curve.

These methods included various kinds of pressure exchangers, such as Francis type turbines, Pelton turbines, and hydraulic pressure boosters. Moreover, data from several actual plants were analyzed and evaluated, including simple batch and the simple batch with feed-and-bleed plants.

Pelton wheel is the preferred turbine for hydropower when the hydraulic head or the source of water at low flow rates. Regarding the flow rate and pressure of the RO system, the specifications of the Pelton Wheel are designed and calculated as tabulated in Table 1 .

In centrifugal energy recovery devices, the Pelton turbine is a common counterattack turbine, widely used in seawater desalination energy recovery systems. The efficiency of the Pelton turbine at 570m³/h and 3000 rpm is shown in Figure 12 .