The Sydney University solar desalination pilot plant design

Following an extensive feasibility study, a solar distillation pilot plant using Sydney University evacuated tubular collectors was designed. In this paper, the major design decisions regarding plant and fluid circulation are discussed.     

Operational experience of 2 × 11,500m3d MSF seawater desalination plant

This paper outlines the operational experience with 2 × 11,500 m³ p.d. Multi Stage Flash desalination plants which were introduced to Bahrain in 1976. It attempts to place in perspective the problems which this technology presented, as it was new to Bahrain. The particular difficulties which resulted from use of bare carbon steel are identified. The corrective measures which were taken to minimise the rate of corrosion are stated. The paper concludes that careful specifications of materials for such plants is essential, and that the necessary expertise must be available at start up to achieve stable operation and to minimise down time.     

Review of desalination plant operating experiences

Recent operating experience reports of water desalting plants reveal that quite a few of these water desalting plants operate substantially differently from what they were designed to. The reports also show that their desalted water costs are substantially greater than was contemplated in the initial economic planning of the system.Reported problems for these conditions include the total spectrum of plant operation criteria. Some plants are plagued with a greater number of shutdowns and plant maintenance needs, thus yielding a lower than expected onstream availability factor. Other plants through aging are no longer able to maintain their design capacities, and also require higher energy consumption than during the initial operation period. In summary, most desalting plants have not been able to produce either the amount of pure water at their expected cost, or operate satisfactorily over the full expected life of the system.The paper will evaluate some of the causes of these reported problems and will recommend possible remedies.     

Designing of an electrodialysis desalination plant

The design and operation of an electrodialysis desalination process are based on a set of fixed and variable parameters such as stack construction, feed and product concentration, membrane properties, flow velocities, current density, recovery rates, etc. These parameters are interrelated and may be rather different for different applications. For an efficient operation of an electrodialysis desalination plant, the process has to be optimized in terms of overall costs considering component properties and operating parameters. In this study the design and optimization of an electrodialysis plant to be used for brackish water desalination has been treated. The required equations were derived or, as in the case of the limiting current density, were experimentally determined. As an example, an electrodialysis plant with a sheet-flow stack construction and given feed solution composition was designed and optimized in terms of overall costs and the sensitivities of the different parameters are analyzed.     

Seawater desalination and reverse osmosis plant design

Plant site, water intake, pretreatment, choice of materials of construction, design alternatives and energy recovery are important variables to be considered in the design of seawater desalination plants employing “permasep” B-10 reverse osmosis modules. Techniques are outlined to permit custom design of seawater desalination plants which offer reliable long term performance as well as competitive economics.     

Computer code for optimizing MSF desalination plant

Egypt faces the prospect of population growth pressing on available agricultural land resources. A very large areas of coastal desert could be helpful in population density redistribution and of great economical interest, with the installation of a suitable water supply.Of the many desalination processes, the Multi-Stage Flash (MSF) desalination process is still the most developed and reliable technology for large scale conversion of sea water to fresh water.In this paper, a computer code was developed for optimizing a large scale MSF plant. This code can calculate the optimum design for the plant, and the minimum cost of product fresh water, as a function of both design and operating variables.Sample results obtained using this code for the Egyptian conditions are presented. The effect of energy and material costs, the chemical treatment type, and the feed water salinity on the optimum performance ratio and the minimum fresh water cost are drawn.     

The formation and properties of Al/Mg scales on Al heat- exchange surfaces in desalination plant

Three types of scales containing Al and Mg have been shown to form during the corrosion of Al in seawater in the pH range 6.3–8.5. The type most frequently occurring has a structure similar to that of the natural mineral hydrotalcite. It can be formed from the Al(OH)₃ produced by the corrosion of Al and Mg²⁺ ions present above pH 6.3. The Al:Mg ratio in this compound increases with pH, resulting in a form of buffering action. In the presence of these scales anodic breakdown of the corrosion film takes place at a potential 100–200 mV more anodic than in their absence. The structures, mechanisms of formation, and effects of these scales in the operation of distillation plants with Al surfaces are discussed, as well as their effects on the operation and interpretation of laboratory corrosion tests.     

Combined Yanbu and Media power and desalination plant

This paper describes and explains the major design orientations taking into account S.W.C.C.'s standards and experience, concerning ratio water/power efficiency, thermodynamic characteristics, margins of capacity, number of units, type of evaporators, flexibility and reliability of operation with some informations regarding sea water treatment materials, corrosion control, mineralization of product water.

Some informations regarding the erection and manufacturing of plant equipments are also given.     

Eight-year operational experience with a 13,400 M3/d reverse osmosis desalination plant at Kashima works of Sumitomo metals

Recently, the reverse osmosis has been applied widely to industrial water purification and accepted commercially. A large number of RO systems are now in operation all over the world. Sumitomo Metals adopted the first 3,000 m³/d (800,000 gpd) reverse osmosis system as pretreatment for ion exchange equipment in 1971, which was expanded to a combined capacity of 13,400 m³/d (3.54 mgpd). Since its start up of operation, various operational problems have been experienced at Kashima and cured to establish a stablized modes of operation.This paper presents a comprehensive review of the operation, maintenance, steps taken for trouble-shooting, and performance data of the world's largest reverse osmosis desalination plant operating now in Kashima Steel Works of Sumitomo Metals, Japan.