Water treatment demineralization

The quahty of feed water required depends on boiler operating pressure, design, heat transfer rates, and steam use. Most boiler systems have sodium zeohte softened or demineralized makeup water. Feed-water hardness usually ranges from 0.01 to 2.0 ppm, but even water of this purity does not provide deposit-free operation. Therefore, good internal boiler water treatment programs are necessary. 

High Pressure Boiler Water Treatment. High pressure boilers usually have feed water composed of demineralized makeup water and a high percentage of condensate returns. Because of these conditions, high pressure boilers are prone to caustic and acid attack. Low pressure boilers that use dernineralized water and condensate as feed water are also susceptible to caustic and acid attack. 

Other paved areas Secondary water treatment—deionization, demineralization, pH and... 

Boiler water treatment Base exchange Dealkylization Demineralization Demin, water tank Demin, water pump Bulk acid and alkali storage Neutralizing... 

As part of the overall boiler plant operational management process, various items of water treatment equipment must be periodically checked, tested, back-washed, regenerated, or otherwise maintained. Such equipment may include filters, ion-exchange softeners and demineralizers, the RO plant, chemical feed tanks, and condensate polishers. 

Synthetic resins are extremely widely used, both pre-boiler and postboiler. Pre-boiler, they are employed for basic MU water treatment (e.g., softening) and various higher quality purification processes (e.g. dealkalization and demineralization). Post-boiler applications are for condensate polishing. 

Wastewater streams from the utility functions include boiler and cooling tower blowdowns and waste brine and sludge produced by demineralizing and other water treatment systems. The quantity and quality of the wastewater streams depend on the design of the systems and the water source. These streams usually contain high dissolved and suspended solids concentrations and treatment chemicals from the boiler and cooling tower. The blowdown streams also have elevated temperatures. 

Reverse osmosis is a process used by some plants to remove dissolved salts. The waste stream from this process consists of reverse osmosis brine. In water treatment schemes reported by the industry, reverse osmosis was always used in conjunction with demineralizers, and sometimes with clarification, filtration, and ion exchange softening. 

S.B. Applebaum, Demineralization by Ion Exchange Water Treatment Chemical Processing of Other Liquids, Academic, NY, ... 

An integrated water-treatment system designed to use different water sources and different treatment processes, including membrane processes, has been realized in Temeuzen (The Netherlands) [15]. Raw-water sources and treatments include seawater and integrated membrane system to produce demineralized water fresh water, and ion exchange to produce demineralized water effluent industrial wastewater-treatment plant (WWTP) and media filtration to produce cooling tower supply water. 

Water pipes, water demineralization, waste-water treatment plant, site drainage, and sewers ... 

J.M. Montgomery, Consulting Engineers, Inc. Ion exchange and demineralization. In Water Treatment Principles and Design John Wiley Sons New York, 1985. 

Examples of major ion-exchange applications are listed in Table 13.2-1, The fields of water treatment, effineal treat mam, and pollution control ate predominant and there heve been many recent advnaces. For example, the partial demineralization of brackish water using the Siimherm process has been developed in Australia and this is probably one of the most innovative developments in recent yarns. Important applications in the fields of medicine, pharmacology, chemical processing, catalysis, and analytical techniques are also mentioned. The remainder of this suction describes some important applications in detail. 

One of the most innovative industrial uses of reverse osmosis is at the Petromin Refinery in Riyadh, Saudi Arabia. The refinery takes an unusable municipal wastewater, secondary effluent from the Riyadh sewage treatment plant, and by using lime clarification, filtration, reverse osmosis and ion exchange demineralization, it converts that useless waste into the entire process water requirements for the refinery. Figure 4.16 is the process flow schematic for the refinery water treatment plant. 

In some instances, water produced by EDI with 10-18 megohm-cm resistivity can be used directly. Commonly, an EDI system is followed by a mixed-bed polishing filter in order to assure high purity. For customers EDI demineralization means lower water-treatment cost and less risk to downstream equipment and products [8,9]. 

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