Application Of The Surface Texturing Technology In The Rotary Energy Recovery Device

Energy recovery devices, as an important unit of the reverse osmosis desalina t io n system, is used to recover the pressure energy of the high pressure brine and has significance in reducing the energy consumption of the desalination system. Rotary energy recovery device is one of the popular energy recovery devices, which owns the characteristics of high efficiency, good stability, flexible capability and small size, is a promising product.However, the rotary energy recovery device still has the problem of dramatica lly pressure change and the bad dynamical seal effect. This paper deals with the two problems by the application of the surface texturing technology.Firstly, the equal pressure grooves were textured on the surfaces of the end covers to prolong the pressure releasing process of the high pressure brine, which leaded the rotor to rotate in a more stable way. Under the condition of clearance of 0.05 mm, rotary speed of 500 rpm and pressure of 1.0-6.0 MPa, the experiments of device with and without equal pressure grooves were finished. The result il ustrates that, compared to the device without equal pressure grooves, the operating parameters of the device with equal pressure grooves was improved: under the pressure of 6 MPa, the turque was reduced from 27 N ? m to 22 N ? m, the efficiency is increased from 82% to 88%.Then, the spiral grooves were textured on the surfaces of the end covers to reduce the friction torque of the device under small clearance. Under the condition of clearance of 0.035 mm, rotary speed of 500 rpm and pressure of 1.0-6.0 MPa, the experiments of the device with and without spiral grooves were completed respectively. The data shows that, under the pressure of 6 MPa, compared to the device without spiral grooves, the torque of the device with spiral grooves was decreased from 13 N ? m to 7 N ? m, reduced by 46%, the efficiency is increased from 61% to 85%, which obviously proves the feasibility of the surface texturing technology. Under the contdition of clearance of 0.025 mm, pressure of 6 MPa and rotary speed of 500 rpm, the experiment of device with spiral grooves was also finished, the datas shows that the efficiency of the device was improved as the clearance was minimized, under the pressure of 6 MPa, the efficiency of the device with spiral grooves reached to 96.3% which can satisfy the requirement of the industry application wel.At the same time, the surface texturing technology can also be used by other fluid mechanical devices with similar structure and work conditions as the rotary energy recovery devices, to get better seal effect and prolong the work life of the seal.