At the heart of industrial operations lies a problem that keeps engineers up at night: corrosion. The thought of equipment slowly deteriorating, with its once-smooth surfaces riddled with rust, can be enough to make someone’s blood curdle.
That’s where chemical cleaning from B&W Energy Services comes in.
Depending on your project’s unique requirements, chemical cleaning can look a few different ways, and B&W is here to break it down.
A Chemical Cleaning Overview
No matter which chemical cleaning method you employ, chemical cleaning typically uses chemical solutions to remove oil, grease, mineral deposits and other contaminants from the interior of systems. The chemicals involved in the chemical cleaning process vary depending on the piping system’s material and the type of buildup. For rust and scale buildup removal, acid-based cleaners are most commonly used. Alkaline cleaners are highly effective in removing oil and grease.
Pre-Operational Cleaning vs. Post-Operational Cleaning
Most forms of chemical cleaning fall into one of two categories: pre-operational cleaning and post-operational cleaning. Pre-operational cleaning is performed following construction activities to prepare equipment and facilities for operation by removing any materials that could interfere with performance. Post-operational cleaning may be performed for a variety of reasons, including an observable reduced heat transfer or flow rate following production, increased access for more thorough inspection or to address safety concerns. Some of the most commonly performed chemical cleaning procedures include degreasing only, boiler boil-outs and acid-based chemical cleaning.
What Is Degreasing?
Degreasing removes excess oil, grease, lubricants and other foreign matter from piping, process equipment and steam-generating equipment. Although there are various degreasing methods, the process typically involves an external heat source and temporary circulation pumps.
Which Degreasing Method Should You Use?
The appropriate degreasing method for your project depends on the kind of equipment you’re cleaning and the material it’s made of. Several degreasing techniques include forced circulation and natural circulation like in a boiler boil-out. Degreasing is commonly applied to amine systems, critical oxygen gas systems and some steam-generating equipment.
What Is A Boiler Boil-Out?
Following the manufacturing process, newly installed boilers are often slick with oil, grease and organic material from the boiler’s internal components. If these coatings aren’t removed, they may reduce the boiler’s heat transfer rate and cause tubes to overheat and burst. Due to the risks that contaminants pose to equipment, conducting a boil-out is essential to thoroughly cleanse a boiler.
To decontaminate a boiler, B&W injects a chemical cleaner with a high pH directly into the boiler water to thoroughly degrease and passivate internal surfaces. The heat accelerates the boiler chemical cleaning process as the solution recirculates and dissolves any grease or oil within the boiler’s internal systems. While a boiler boil-out can technically be classified as a degreasing process, degreasing is typically a standalone process using external pumps and equipment. Boiler boil-outs commonly apply to smaller package boilers, HRSGs or other lower-pressure steam-generating equipment. B&W typically performs this on college campuses or other CHP-type projects.
Boiler Boil-Out in Action
B&W is grateful to have had the opportunity to contribute to several Combined Heat and Power (CHP) upgrade projects on large university campuses in Connecticut and Minnesota. Both projects included new gas-fired boiler installations aimed at improving central utility plant power and heating reliability while reducing emissions. We supported boil-out and steam blows at the facilities to help with start-up.
What is Acid-Based Chemical Cleaning?
Acid-based chemical cleaning is commonly applied to high-pressure steam-generating equipment and critical piping systems to remove corrosion, scale and other materials from the interior of systems. It is commonly combined with a degreasing process in a single volume fill to reduce the amount of waste effluent generated during cleaning.
The most common pre-operational chemical cleaning method uses a citric acid-based chemical blend for new equipment to remove mill scale, rust, preservatives and other materials from its surfaces. Once cleaning is complete, an oxidizing agent is used to passivate the metal surfaces to provide protection against further corrosion until the system is put into service. Additional preservation methods, such as introducing nitrogen to the system, may be used if equipment startup is delayed.
Acid-Based Chemical Cleaning in Action
B&W is grateful to have provided specialized chemical cleaning services for the Great Plains Power Station in Canada’s Saskatchewan province. The 360-megawatt natural gas plant will provide reliable power for approximately 360,000 homes in Saskatchewan while supporting renewable power generation and coal retirements. B&W performed full chemical cleaning on a triple-pressure HRSG for Burns & McDonnell, the project’s EPC contractor. We’re thankful we were granted the opportunity to deliver chemical cleaning services for this project.
Whether we’re conducting a boiler boil-out or the chemical cleaning of piping systems, B&W is committed to ensuring the longevity and efficiency of critical equipment for our clients. Need to break down rust and scale buildup? Banish oil and grease residue? With B&W’s chemical cleaning services on your side, you can rest assured that your project is in highly experienced hands.