Introduction to Conservation Design

Abstract: During the half century of development from a laboratory discovery to plants capable of producing up to half a million tons of desalinated seawater per day, Reverse Osmosis (RO) technology has undergone rapid transition. This transition process has caused signification transformation and consolidation in membrane chemistry, module design, and RO plant configuration and operation. From the early days, when cellulose acetate membranes were used in hollow fiber module configuration, technology has transitioned to thin film composite polyamide flat-sheet membranes in a spiral wound configuration. Early elements – about 4-inches in diameter during the early 70s – displayed flow rates approaching 250 L/h and sodium chloride rejection of about 98.5 percent. One of today’s 16-inch diameter elements is capable of delivering 15-30 times more permeate (4000-8000 L/h) with 5 to 8 times less salt passage (hence a rejection rate of 99.7 percent or higher). This paper focuses on the transition process in RO module configuration, and how it helped to achieve these performance improvements. An introduction is provided to the two main module configurations present in the early days, hollow fiber and spiral wound and the convergence to spiral wound designs is described as well. The development and current state of the art of the spiral wound element is then reviewed in more detail, focusing on membrane properties (briefly), membrane sheet placement (sheet length and quantity), the changes in materials used (e.g. feed and permeate spacers), element size (most notably diameter), element connection systems (interconnectors versus interlocking systems). The paper concludes with some future perspectives, describing areas for further improvement.

Introduction: This manual provides guidance and criteria for the design of small water supply, treatment, and distribution systems. For the purpose of this manual, small water systems shall be those having average daily design flow rates of 380 000 liters per day (l/d) (100 000 gallons per day (gpd)) or less. However, the use of the term small is arbitrary, there being no consensus in the water supply literature with respect to its meaning. Regulations regarding the acceptability of a water source, degree of treatment required, and the monitoring requirements are not based on flow rates, but rather on a water system classification relating to the number of people served and for what period of time. Figure 1-1 provides a flowchart for system classification. Refer to Chapter 3, paragraph 3-4b for the appropriate nomenclature.

PROCESS ENGINEERING AND THE ROLE OF PROCESS ENGINEER   Process design is the design of processes for desired physical and or chemical transformation of materials. Process design is central to chemical engineering and it can be considered to be the summit of chemical engineering, bringing together all of the components of that field. Process Engineering involves the design of unit operations & equipment design. Role of Process Engineer: Chemical engineers (or process engineers) are responsible for developing new industrial processes and designing new process plants and equipment or modifying existing ones. The processes that they come up with are used to create products ranging from oil and gas, chemicals, petrochemicals, and specialty chemicals to food and drink. It is a vocation wherein the process engineer is supposed to perform any one or all of the activities mentioned below to provide documentation for a safe, reliable, and profitable design  Design new equipment/unit/plant as per good and internationally accepted engineering practices (Greenfield)  Rate or checks the adequacy of existing equipment/unit/plant for changed operating conditions (e.g. pressure, temperature, flow, etc.) as per good and internationally accepted engineering practices (Brownfield) 

Introduction: Founded in 1981, Purolite is a leading manufacturer of ion exchange, catalyst, adsorbent and specialty resins. With global headquarters in the United States, Purolite is the only company that focuses 100% of its resources on the development and production of resin technology. Responding to the needs of our customers, Purolite has built the largest technical sales force in the industry, the widest variety of products and five strategically located Research and Development groups. Our ISO 9001 certified manufacturing facilities in the U.S.A, Romania and China combined with more than 40 sales offices in 30 countries ensure complete worldwide coverage.