Industrial and commercial boilers handle a lot of water, and do a lot of work. That’s why operating them requires particular attention to industrial water treatment. Because what you put into your boiler in terms of water will tell you what you get out of it in terms of life and efficiency.
WHY IT MATTERS
While every boiler should have proper water treatment, it’s especially important in large-production, large-horsepower boilers for several reasons.
- Cost: Big boilers come with big price tags. If you’re investing that much money in clean, reliable, efficient steam, you’re going to want to get the biggest return for your investment for the longest amount of time. Nothing else will pay you back as much in terms of efficiency and longevity as smart industrial water treatment.
- Energy Use: Proper water treatment prevents the formation of performance-robbing corrosion and scale, both of which will cost you money every month in terms of wasted fuel dollars.
- Down Time: If you’re running a commercial boiler, that means every minute of downtime means lost production and reduced profitability. Investing up-front in proper industrial water treatment will pay off down the road in terms of reliable, consistent production.
- Environmental Compliance: Depending on where your business is located, your commercial boiler may have to comply with environmental regulations concerning the quality of the water with which it operates.
TAKE A SAMPLE
If you want to maintain your industrial water quality, the first thing to do is establish a baseline. Industrial water treatment isn’t a one-size-fits-all process. Figuring out what procedures you need to follow starts with knowing what you’re dealing with. Proper analysis of the incoming water supply can tell you the hardness, relative cleanliness, pH levels, chemical contents, and other specifics that will determine what equipment, chemicals, and procedures you need to implement to treat your water.
But this isn’t a one-time activity. It’s important to perform regular water quality analysis on your incoming water supply, and on the water in your pressure vessel. Even slight variations in the incoming supply can have noticeable – and lasting – effects on your boiler’s health and output.
PRETREATMENT
Depending on the number of dissolved solids and the relative purity of your incoming water, your industrial water treatment process may need to start with either filtration, sedimentation (settling of dissolved materials over time), or chemical additives. This will reduce the number of impurities and corrosion-causing compounds that will eventually make their way into the pressure vessel.
SOFTENING
The hardness of your water supply has to do with the quantity of minerals dissolved in it. The harder the water, the more minerals it contains. Water is “softened” by removing those minerals. There are two main ways that water can be softened. The first method is by chemical precipitation, which is the addition of chemicals that cause all of the dissolved solids to clump together into larger and larger particles until gravity causes them to fall out of suspension.
The second method is known as “ion exchange”. Inside an ion-exchange water softener, thousands of resin beads are soaked in salt water, causing them to become covered in sodium ions. As the hard water passes through the resin medium, the sodium ions react with the calcium, iron, and magnesium to pull them out of suspension and attach them to the resin. They are later rinsed off as waste water when the softener replenishes the salt water, a process known as “regeneration”.
There are other dissolved solids in your water that softening doesn’t remove. Over time, though, these solids will clump together and settle on the bottom of the pressure vessel where they can be removed by simply performing regular blowdowns.
pH CONTROL
Depending on the quality of your water, you will probably need to do some sort of adjustment to the pH level in your water. Ideally, the pH level should be maintained at 9 to prevent the formation of corrosion and scale. Caustics are added to increase alkalinity in the pressure vessel, while amines are added to prevent acidic corrosion in the steam system.
CHEMICAL ADDITIVES
Most industrial water treatment processes require the addition of another round of chemicals to keep the water at the proper quality for boiler operation. These chemicals are usually added to the feedwater just before it enters the boiler pressure vessel, and are used to further fine-tune pH levels, lower the level of corrosion-causing oxygen, and help inhibit other types of corrosion.
Specifically,
Sodium sulfite is added to remove excess oxygen
Phosphates and polymers are added for sludge conditioning and suspension
To make sure you’re maintaining your water at the correct parameters, be sure to check out the recommended ABMA & ASME boiler water limits on this chart.
If you have any questions about your water quality, or if you’d like to have a professional evaluate and fine-tune your water quality for longer boiler life and greater efficiency, WARE is standing by to help. We also offer classes at our Boiler University online and in-person to help boiler operators perform proper water analysis and get the most out of their industrial water treatment equipment. Whatever we can do to help, just let us know.