Systems for treating industrial water provide a range of filtration and separation requirements. They might be simple, single-unit processes that serve a number of applications or complicated, multiunit ones that can be rather complex. What is an industrial water treatment system, and how does it operate? may be your question if you’re new to the field of water treatment.
This article will concentrate on providing a high-level overview of the technologies that are frequently used and summarising how they function because industrial water treatment is a complex family of technologies and systems. This will help you better understand the best solutions for your facility.
Industrial Water Treatment System: What is it?
Water is treated by an industrial water treatment system to make it more suitable for a particular application, such as consumption, production, or even disposal. Nevertheless, though many of the technologies that make up these systems might be similar, each system will differ based on the demands of the institution. The following are some of the most common industrial water treatment systems:
- water treatment systems for boiler feed
- methods for treating water in cooling towers
Water Treatment Systems For Boiler Feed
In order to prevent boiler unit components and pipelines from being harmed by specific impurities contained in the boiler and/or makeup feeds, boiler feed water treatment systems are employed. Among these pollutants are dissolved solids, suspended solids, and organic material like iron, copper, silica, calcium, magnesium, aluminium, hardness, and dissolved gases. Boiler feed water, if not properly treated, can lead to scaling, corrosion, and fouling of the boiler and downstream machinery, which can result in expensive plant outages, high maintenance costs, increased fuel consumption, and boiler failure.
How does it work?
An efficient boiler feed water treatment system functions by filtering out dangerous contaminants before they reach the boiler and by regulating the water’s conductivity and acidity. Despite the fact that treatment trains differ, a typical system will include primary treatment and, depending on the boiler pressure, the amount of steam used, and the chemistry of the boiler feed and makeup water, it may also include polishing. Most often, a boiler feed water treatment system will perform any or all of the following procedures:
- Makeup water intake: As boilers are utilised, water is lost due to leaks, condensate return loss, and steam consumption. Makeup water has to be used in place of this water. Makeup water can be obtained from a raw water treatment plant or a treated city supply.
- Filtration: To remove silt, turbidity, and organic material from the stream, one or more filtration units are commonly used. Membrane filtering units may be a cost-effective way to stop fouling and excessive maintenance of downstream equipment when used as pretreatment and other equipment.
- Softening- It is frequently used to remove hardness, including bicarbonates, sulphates, chlorides, and nitrates, from boiler feed water. To do this, a softening resin is used, which is generally a strong acid cation resin with the ability to efficiently extract hardness ions from the stream.
- Dealkalization- Alkalinity can lead to corrosion in pipework, foaming, and carryover in boilers. Therefore, strong anion or weak acid followed by degasification are frequently used to treat boiler feed streams. These treatments serve to remove bicarbonate, sulphate, and nitrate ions, lowering pH.
- Nanofiltration and reverse osmosis (RO) (NF)- Although RO and NF are not always used to treat boiler feed water, they are effective in removing bacteria, salts, organic matter, silica, and hardness. Both RO and NF are membrane filtration processes, which use a semi-permeable membrane to trap pollutants that are too big to fit through their pores while allowing water molecules to pass through.
- Basic ion exchange- Deionizers may be used instead of membrane filtration for high pressure boilers or huge amounts of water. It often offers superior crops and water that is comparably higher in quality and resistivity.
- Degasification or deaeration- Any condensate that is returned to the system at this stage of the boiler feed water treatment procedure will mix with the treated makeup water and begin the deaeration or degasification process. When gases like oxygen and carbon dioxide bond to boiler equipment and pipes, they may be exceedingly corrosive, creating oxides and leading to rust. Therefore, reducing these gases to safe levels (almost 100%) might be crucial for the boiler system’s longevity and safety. In general, you may utilise a tray- or spray-type deaerator for degasification or oxygen scavengers. Deaeration devices exist in a variety of layouts depending on the manufacturer.
- Distribution- The water is supplied to the boiler where it is heated and utilised to produce steam after having been suitably cleansed in accordance with the boiler manufacturer’s recommendations and other industry-wide norms. The plant uses pure steam, loses the steam and condensate, and then pumps the condensate back into the process to mix with the makeup water that has already undergone pretreatment.
What Is the Process of Cooling Tower Water Treatment?
Filtration & Ultrafiltration
Cooling tower water treatment systems are efficient due to their adaptability. You may select a water treatment option that works in your system regardless of the design or construction of your water tower. You have a variety of options, all of which are influenced by elements such as the cooling method your tower uses (open circulation, once-through, closed-loop), the components it is constructed of, and the water quality in your location.
However tiny particles still get through the gaps, which is why ultrafiltration utilising a network of filters is crucial. These pollutants that pass through bigger pores are eventually caught in the process when many filters are utilised, each one becoming increasingly more restrictive. When pollutants are miniscule and at their last stages, you have choices such filters that contain a little electrical charge, which will draw the tiny particles and keep them in place. This guarantees that the water is pure and won’t clog your system.
Makeup Water Intake
Makeup water is used to replenish the water that the cooling tower loses to leaks, bleed, and evaporation. It may be obtained from a variety of resources, including surface water, well water, and municipal water. Depending on where the water comes from and how clean it already is, you’ll require water treatment at this point. If you do, the most typical water treatment in this area will alter the water’s hardness or softness and balance its pH to prevent system corrosion.
Water softening and Ion Exchange
Water hardness, or the presence of minerals in the water (and especially magnesium, calcium, and iron), can dramatically affect the lifespan and efficacy of your cooling tower. You can soften your water by inserting lime, or you can opt for a resin.
Chemical Addition
You can use chemicals to alter the characteristics of your water if necessary. Acidity is eliminated by corrosion inhibitors like bicarbonates, while biocides or algaecides stop biofilms and other types of organic development. Scale inhibitors like phosphoric acid are another option.
The Side-Stream Filter
There is a danger of contamination if your cooling tower utilises recirculated water because of drifts and leaks. Using side-stream filtration, which consists of a multimedia filtering device that can clean up to 10% of your water at a time, you can stop this water pollution.
Blowdown Operation
Reverse osmosis or other methods are used by certain cooling towers to reuse or recycle water. Even if the water has already been cleansed, this exposes it to additional pollutants. To get rid of the most frequent impurities that infiltrate the water during this procedure, demineralization treatment may be helpful in this situation.
Cleaning of Cooling Towers
Cleaning the system itself is one of the most neglected steps in cooling tower water treatment. Your system’s water may become polluted and/or susceptible to Legionella bacteria if suitable cooling tower cleaning services aren’t used. So, before starting the system, it is crucial to make sure the cooling tower is properly maintained and cleaned.
Halpin & Hayward is the industry leader in water treatment, and we would be pleased to help you choose the solution that will work best and last the longest for your cooling tower. Get in touch with us to set up a consultation so we can assess your water and offer suggestions for your tower system.