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As the critical first stage in the water purification process, clarifiers remove large quantities of suspended and organic matter from your supply water. There are three main types of clarifiers: Coagulators, Cold-Lime Softeners, and Lamella Clarifiers. The difference in quality between the raw, untreated water and your post-clarification water determines the chemical storage and feed equipment needed for disinfection, coagulation, pH adjustment, coagulation enhancement and floc (waste sludge) formation. When do you need it? Coagulator Clarifiers are used to treat surface water with high suspended solids levels. Coagulants are introduced into the clarifier, agglomerating suspended materials and absorbing some of your process water’s alkalinity. Coagulated materials are then flushed out of the system as sludge. This prevents a build-up of suspended solids at the filtration stage, reducing filter maintenance and chemical use at later stages. Cold-Lime Softening Clarifiers are used when the surface water is “hard”, or has a high lime and mineral content, and high suspended solids levels. Lamella Clarifiers are small, low-flow-rate coagulator clarifiers. Coagulants are introduced and the water is flocculated before allowing agglomerated materials to settle to the bottom of the clarifier. Agglomerated materials are then flushed out of the system. Clarifiers are normally followed by gravity filters.
Filters are standard pretreatment systems in the water treatment process, effectively removing a large percentage of suspended solids from your process water by straining it through various media. Esli offers a complete range of high-quality filter systems that minimize maintenance and maximize the performance of water demineralization systems. When do you need it? Filters are required in virtually every water treatment process, removing suspended particulate matter from your intake water (municipal or natural source). The type of filter you employ is determined by factors such as flow rate, the quality of water you require and the properties of your intake water. Gravity Filters are simple systems, typically employed downstream of clarifiers, that allow gravity to force water through a filter bed of sand and anthracite. This process does a thorough job of removing particulate matter at low flow rates. Pressure Filters are designed to remove specific contaminants from pressurized process water using specialized filter beds. Specialized pressure filters are often used in conjunction with one another, as determined by the quality of your intake water and your downstream equipment requirements.
• Multi-Media
Filters use layers of different
media to remove suspended solids
from supply water. Cartridge Filters use standard, interchangeable filter elements to remove suspended solids from system water, and are employed to protect RO and other water treatment systems downstream.
There are two basic categories of demineralization systems: roughing demineralizers and polishing demineralizers. The roughing demineralization stage does a thorough job purifying your raw process water, removing the bulk of mineral contamination and bringing your water quality close to your desired purity. Polishing demineralizers put the final touch on your process water, achieving the exact water quality you need. Roughing Demineralizers consist of either a Cation/Anion or reverse osmosis (RO) system. Cation /Anion systems use any combination of specialized ion exchange units to achieve the water purity determined by your process requirements. RO systems use membrane technology to provide a continuous process with reduced chemical consumption. Polishing Demineralizers are specialized systems that are used after the roughing stage to reduce any residual minerals and ionic content. In some applications, such as low-pressure boilers, polishing is not required.
*
Typically an RO System is a stand-alone
unit, capable of achieving near
polished water quality when a double
pass system is used. However, in
certain cases RO is followed by an
ion exchange unit in the roughing or
polishing stage to achieve extreme
water purity.
*E-Cell™
produces higher quality water than
mixed beds at comparatively lower
operating costs with average TDS
(Total Dissolved Solids) levels. Reverse osmosis (RO) is a membrane process designed primarily for the removal of TDS (Total Dissolved Solids). RO also removes TOC’s (Total Organic Carbon) and colloidal materials. RO supplements ion exchange in applications where there is a wide variation in process water quality. RO can replace both primary Cation and Anion systems, with benefits that include continuous operation and reduced regeneration chemical consumption. RO units are composed of pressurized housings containing high-purity membranes. Where single-pass reverse osmosis cannot achieve an acceptable water quality, double-pass systems can be used. When do you need it? Use RO for continuous operation to reduce regeneration chemical usage and when the raw water is high in TDS. RO systems also remove more TOC’s (Total Organic Carbon) than conventional deionization systems. Using the latest in gel and macroreticular resin technology, Esli ion exchange systems set new standards in performance, water consistency, resin efficiency and system robustness. As process water passes through a bed of ion exchange resin, these resins attract and absorb ionic contaminants: Cation resins absorb positively charged ions and Anion resins absorb negatively charged ions. This absorption can occur in separate Cation and Anion Exchange stages, or with mixed resins in a single stage. When do you need it? Co-Current Regeneration Systems are self-contained pressure vessels containing Cation or Anion resins. They are primarily used for applications that require low to medium water quality, such as boiler water. They can be operated as working ion exchangers or as polishers downstream of counter current systems. Split-flow Counter Current Regeneration Systems produce water of higher quality using a regeneration process where regenerant chemical flows in opposing directions through the resin bed. This both cleans and reconditions the resin bed, returning it to a highly regenerated state. Depending on your application, the unit may be loaded with a single bed of softener, strong acid Cation or strong base Anion resins. Counter Current Layered Bed Systems are single vessels with a mix of weak and strong Cation resins or weak and strong Anion resins. Layered bed systems provide higher chemical efficiency without extra vessels. Amberpack™ Packed Bed Systems are suited for applications that demand higher water purity, higher flow rates, reduced chemicals, reduced waste and a more compact design. The types of resins used and the configuration of the vessel are site specific and based on water chemistry. Sandwich Amberpack™ Packed Bed Systems combine two chambers into a single vessel that contains either separate Cation and Anion resins or weak and strong resins. This is especially useful when floor space is limited. Mixed Bed Systems deliver superior quality water in high-pressure feed water applications. Cation and Anion resins are intimately mixed in the bed, effectively removing all types of ion contamination. Mixed beds are often the final demineralization stage in the water treatment process, and can also be used for high-purity condensate polishing applications. Cation Polishers are used to remove most of the remaining Sodium ions, typically polishing process water from two-bed demineralizers. When used in conjunction with packed bed demineralizers, Cation polishers produce close to mixed-bed water quality. E-Cell™ systems are a revolutionary approach to electrodeionization (EDI) that replaces conventional mixed-bed technology to offer a host of dramatic benefits. No regeneration chemicals are needed; no hazardous waste stream is produced; operation is continuous with consistent and predictable water quality, and facility requirements are substantially reduced. E-Cell™ is the only EDI system with a modular design that is robust enough to handle the flow rate demands of industrial applications. It has the ability to benefit virtually every pure water application in every sector of industry. It's safe, easy and economical to use; it substantially reduces the chemical infrastructure needed; water quality is consistently in excess of 16 MOhm.cm, and it can help you meet your environmental goals. How it works? E-Cell™ removes ions from process water using conventional ion exchange resins, but with a key difference. Applying an electrical current across the bed forces the continual migration of contaminant ions from the feed water into the concentrate stream, purifying the water and effectively eliminating the downtime, costs and chemicals of the conventional regeneration process. In processes where boiler water is recycled after use, such as in the power generation industry, a condensate polishing system is used to remove ionic contamination, trace hardness, Silica and other corrosive agents. There are three basic types of condensate polishing systems: Mixed Bed External Regen, Mixed Bed In-situ Regen and Cation Polishers (Sodium and Amine cycles). The key difference between these systems is the regeneration method used – external regeneration produces a more highly polished condensate quality because it reduces cross contamination of the resin beds. And because chemicals are not introduced directly into the system, there is no chance of their entering the process stream. ConeSep™ External Regen Systems are comprised of three separate vessels that enable you to operate with flexible resin volumes and to regenerate resins externally, virtually eliminating any chance of cross contamination. ConeSep™ systems also provide extremely reliable operation.
1st
Vessel: Separation and Anion
regeneration. Mixed Bed In-situ Regen Condensate Polishers perform all operations inside a single vessel. Adding inert resin to the condensate polisher bed can reduce cross contamination in in-situ regenerated systems.
Amine and Sodium Cycle Condensate
Polishers are essentially co-current
ion exchange systems with a resin
bed that removes
Degasification systems remove both naturally occurring gases and gases that are byproducts of various stages of water treatment, reducing the load on your ion exchange systems. Using these simple and cost-effective systems can dramatically reduce the frequency of resin regeneration cycles. And they are virtually maintenance free. Forced Draft Decarbonators consist of an atmospheric tank filled with plastic packing on top of a clearwell. Process water is sprayed from the top onto the packing, thinly spreading the water and releasing trapped carbon dioxide. The released gas is then blown out a vent in the top of the tank by a low pressure fan, and the process water flows down into a clearwell at the bottom of the unit and out to the next stage of treatment. When do i need it? Forced draft decarbonators remove gas, principally Carbon Dioxide, from process water, and are typically placed between Cation and Anion ion exchange units, or either before or after an RO unit. If your process water has a high level of Carbon Dioxide, not using a decarbonator can result in the need for increased Anion resin regeneration and the associated downtime and chemical costs. Carbon Dioxide is a byproduct of Cation exchange and of the various acids used to control pH levels in process water. Waste neutralization systems even out the pH levels of wastewater by mixing high and low pH waste streams, or by adding acids or caustics when required. Wastewater includes the backwash and spent regenerants from ion exchange regeneration and other process waste streams. Although regulations for pH levels vary from location to location, most counties and municipalities regulate the pH of discharge water to between 6.0 and 9.0. Wastewater is mixed in the waste neutralization tank. If the pH is below 6.0 caustic is added, if above 9.0 acid is added. |
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