In order to ensure the long-term and trouble-free lifetime of the seawater reverse osmosis (SWRO) process and its enabling technology, it is essential to utilize the most advanced and reliable materials of construction. One of the more advanced and unique materials currently in use in SWRO desalination applications is high purity (>99%) aluminum oxide (alumina) ceramics. Due to its hardness, self-lubricating properties, high compressive strength and chemical resistance, alumina ceramics create an ideal fluid bearing for the rigors of seawater applications, which perform in conditions that combine corrosive and potentially two-phase (solid/fluid) environments.
High purity alumina ceramics developed and manufactured by Energy Recovery are particularly unique because of the innovative design of the company’s PX devices and the intense conditions of SWRO plants in which they operate. When in use, the ceramicbased devices are supported by a seawater fluid bearing while rotating and being pressurecycled millions of times per year. The durability of ceramics in high pressure, corrosive seawater environments is fundamental to the success of these devices and is quantified and categorized throughout this paper. The enhancement of ERI material science and technological improvements has shown to improve the overall durability of the product and significantly reduce sound levels to below 81 decibels.
Technical data shows that at peak rates, Energy Recovery ceramics inside the PX device wear at less than 3 microns per year (.003 inches over 25 years). The findings identify wear and prove that ERI alumina ceramics can last longer than 25 years in a seawater desalination reverse osmosis plant.
More than 15,000 PX units have been installed world-wide. Some units have been in operation for as long as 12 years. With zero failure as a result of PX technology designed ceramics, research indicates that PX devices will continue operating well into the future.