The Value of Good Boiler Blowdown Control

A Critical Component of the Boiler Water Treatment Program

In a steam boiler system, blowdown involves removing a portion of the concentrated boiler water and replacing it with feedwater, which is a mixture of condensate and makeup water.

Good blowdown control is a critical component of the boiler water treatment program.  Boiler blowdown is heated, treated feedwater that is sent to the drain instead of converted into steam. Blowdown is used to control the dissolved and suspended solids level in a boiler within the range necessary to minimize scale deposits and carryover.  Too much blowdown increases fuel, water, and treatment requirements.  Too little blowdown can cause scale deposits and wet steam (carryover).

There are two types of boiler blowdown.

  • Surface Blowdown:  A continuous or intermittent process designed to remove the dissolved solids that concentrate near the liquid’s surface using a graduated needle valve or motorized valve actuated by a boiler blowdown controller.
  • Bottom Blowdown:  A manual procedure to remove accumulated sediment and sludge from the bottom of the boiler (e.g., mud drum).  This procedure is typically performed for a few seconds once every shift or, in smaller boilers, once a day.

The blowdown rate is expressed as a percentage of feedwater flow rate, and determined by the feedwater “cycles of concentration” that are maintained in the boiler.  The feedwater cycles reflect the extent impurities in the feedwater concentrate in the boiler water.

The higher the feedwater cycles, the more the feedwater impurities have been concentrated in the boiler water and the lower the blowdown rate.   As in cooling tower systems, the cycles of concentration is usually estimated by measuring the relative levels of a soluble impurity in the boiler water and feedwater.

Blowdown is Necessary to Keep Boilers Running Efficiently

Boiler blowdown rates typically range from 2% to 10% of the feedwater flow rate, but can be much higher if the condensate return is low or the makeup water quality is poor. The optimum blowdown rate for a particular boiler system is determined by various factors including:

  • Boiler design
  • Makeup water quality
  • Operating conditions
  • Feed/control equipment
  • Treatment product selection
  • Degree of onsite monitoring

Chem-Aqua Can Help You Determine Your Optimal Boiler Blowdown Rate

Blowdown is necessary to remove impurities in your boiler water system and keep it running efficiently. In order to ensure safe, reliable, and cost-effective steam production, it is essential to optimize your boiler’s blowdown rate. Chem-Aqua is a resourcefully green leader in boiler water treatment solutions.

A customized water treatment program from Chem-Aqua can help you determine the optimal blowdown rate to maximize energy efficiency and to protect your boiler system from the harmful effects of corrosion, scale, and carryover.

Read more at chemaqua.com

Follow us on social media for the latest updates in B2B!

Image

Latest

influencer partnerships
Moving Beyond Social Media Buzz: How Authentic Content & Long-Term Influencer Partnerships Can Drive Hotel ROI
July 30, 2025

Influencer marketing is rapidly changing, and many hotels are still figuring out how to tap into its full potential. As travelers demand more authentic and relatable content, the pressure is on for hotels to adapt their marketing strategies. But with skepticism around the true ROI of influencer partnerships, it’s more important than ever for brands…

Read More
workforce
Building a Future-Ready Workforce: With Traditional Training Models Failing, It’s Time for Employers and Educators to Build Solutions Together
July 30, 2025

In an era where the average job tenure in the U.S. hovers under four years and industries are evolving faster than academic curricula can keep up, the need for a new approach to workforce development has never been more urgent. Companies like Amazon and McDonald’s are responding by investing in “education as a benefit”…

Read More
belief
Learning Out Loud with Belief, Courage, and the Power of Yes
July 30, 2025

In a world where workplace disengagement is on the rise, with global employee engagement falling to just 21% in 2024, leaders and teams are increasingly seeking meaning, connection, and growth in their work. Amid this shift, professionals are asking deeper questions about purpose and fulfillment, both individually and collectively. That’s exactly where Paul Plamondon’s…

Read More
professional advancement
The Measured Mindset: How Mentorship, Curiosity, and Listening Drive Professional Advancement and Growth
July 29, 2025

Not every path into analytics starts with code and spreadsheets. For some, it begins with curiosity, adaptability, mentorship, and a willingness to learn something entirely new. That’s the case for Mayank Malviya, whose journey from a humanities education in India to a career in U.S.-based market research reveals how initiative and mentorship can accelerate…

Read More