Utilizing the right equipment and materials throughout your home or plant can help identify when maintenance is required; however, under-deposit corrosion and overheat damage do not follow a linear progression, so postponing it could cost utilities much more in terms of financial burdens than anticipated.
Table of Contents
Machines
Air-powered machines are now available that can help all sorts of boilers that remain in service for an extended period to stay clean with one pass of their nozzle. These powerful machines typically feature powerful motors and air compressors, and they are often used to remove light soot or heavy scale build-up on tubes up to 2.1/2″OD without needing an operator to hand passes brushes manually. They’re easy to operate while saving labor by eliminating this task altogether.
These units can also be utilized for so-called “online cleaning”, while boilers are in operation. Online cleaning on top of other methods seen here: putzmaus-america.com helps reduce fuel consumption and carbon dioxide emissions by clearing away ash build-up on boiler tubes that acts like an insulation layer. Power plant operation continues while tubes are cleared away, thus decreasing downtime and operational costs.
Chemical descaling of boilers provides an easy, faster, and less-invasive means of clearing away mineral-based deposits commonly referred to as scaling. A chemical descaler circulates through the tubes while dissolving deposits made up of rust, calcium, and limescale. There are different strength options depending on their thickness or length of presence in your boiler system.
Most retailers offer an expansive line of pneumatic and electric boiler cleaning machines, such as the PTC-75 featuring a 1Hp motor for maximum power when maintaining tubes. The variety of tools and flex shafts make this model suitable for tube sizes of all kinds.
Equipment
Maintaining equipment designed specifically to clean boilers is available, depending on the nature and location of deposits that require removal. Firetube deposits often necessitate mechanical brush cleaners with rotating brushes; while water side deposits typically need chemical scale removal solutions.
Most companies utilize high-pressure water jet equipment to clean boilers. This hydroblasting equipment uses pumps that can send up to 1,200 gallons per minute through its hoses – this enables the company to clean tubes and piping from a distance without having to shut down the boiler, while simultaneously minimizing risks that contaminants might fall onto equipment or personnel performing cleaning services.
Acid or chelant cleaning, also known as “chelanting,” uses mineral or organic acids to dissolve internal deposits. A common solvent for acid is 5% hydrochloric acid solution with inhibitor and complexors; other acids include phosphoric, sulfuric and sulfamic acids as well as organics such as ethylenediaminetetraacetic acid (EDTA).
One of the greatest challenges in boiler maintenance is estimating how much solvent will be necessary. Estimates rely on taking one sample of each boiler, but deposits do not remain evenly distributed throughout; making an exact estimation impossible. There are general rules of thumb which can help when making this prediction.
Storage and handling costs also play a substantial role. A typical boiler will generate three to four boiler volumes of chemical cleaning wastes which must be temporarily stored in frac tanks until they can be classified and properly disposed of.
Testing deposits in a boiler regularly to ascertain when cleaning should take place is vital in maintaining optimal functioning of its system and quickly addressing any potential issues such as incomplete combustion or impingements on flame. Testing can also detect issues like incomplete combustion and impingements on flame which require immediate attention.
Chemicals
When cleaning aboiler properly, certain chemicals are required. These include descalers, solvents and passivation products. Descalers work to dissolve mineral deposits like silica scale via chemical reaction with liquid cleaning agents such as methanol or acetone; solvents remove scale from tubes or surfaces such as surfaces; while passivation products serve to restore an effective protective layer after the cleaning process has completed.
When selecting a chemical cleaning solvent for your plant, it is important to carefully consider your unique requirements. As the deposit level varies across elevations and areas of steam side boilers, estimating how much cleaner are necessary cannot be accomplished through taking single tube samples or multiple samples taken from similar areas in a boiler.
After chemical cleaning is completed, its residual solution should be quickly and completely drained from the unit. Two full boiler volume rinses typically followed by a conductivity test to measure passivation should suffice; as part of its final rinse it is highly recommended to treat with passivation product to ensure metal surfaces are sufficiently protected from general corrosion following cleaning processes.
Safety
Safety should always come first when cleaning a boiler. One important measure to take when maintaining or servicing your boiler is making sure there are no obstructions on its combustion and air openings, to allow combustion byproducts to escape safely during heating cycles. It’s critical that all stack dampers remain open as this allows byproducts to escape safely instead of building up inside and causing irreparable damage to your boiler.
Safety should also include making sure there are no leaks on gas lines and water pumps, which could allow dangerous gasses into the atmosphere and pose health threats. Finally, all safety valves must be in working condition with fusible plugs installed as required for complete security.
Chemical cleaning is used to eliminate carbonate-based mineral deposits from the water side of boilers that inhibit water flow and heat transfer, known as “scale” – which you can learn about here. They can either be manually removed or dissolving them with chemicals to dissolve scale. Once completed, all excess chemicals must be drained off and clean water must be drained off in order to ensure there are no leftover toxins left behind.
Chemical use during cleaning processes may create toxic fumes that should be mitigated with respirators and protective clothing for maximum safety during cleaning processes. It should be remembered that acids used can corrode metal surfaces.
