Toward more flexible production with low-load combustion

Valmet’s new concept for low-load combustion (also called partial bed operation) in CFB boilers improves production flexibility and emissions control as well as provides an efficient tool for production optimization, among others. To date, this operation mode has been available for bubbling fluidized bed (BFB) boilers only. The solution is applicable to both new CFB boilers and existing ones as a retrofit.

Improved production flexibility

Production optimization

Better emissions control

Financial benefits

Optimizing CFB boilers with partial bed operation

In the low-load combustion solution, the furnace bottom is divided into separately controllable windboxes, allowing fluidization closure in some areas. By reducing the fluidization area, it’s possible to minimize the primary airflow while maintaining sufficient fluidization and pressure drop. Having less primary air increases bed temperatures and improves the control of NOx, unreacted NH3 and CO emissions.

Automation is designed to mitigate the risk of agglomeration and back-sifting in partial bed operation mode. For example, the primary air fan minimum load can set a limit for reducing the boiler’s minimum load. It’s possible to achieve an even lower minimum load with dedicated design of combustion air and recirculating gas ducting.

Leading the way toward carbon neutrality

Apr 24, 2024

Since the start-up of the Naistenlahti 3 plant, Tampereen Energia has more than halved CO2 emissions from its total energy production. The new plant is also unique since it pilots partial bed combustion, which is now available for the CFB boilers to boost flexibility in their production structure.

Valmet CFB Boiler

Jul 16, 2015

Valmet CFB Boiler is an advanced circulating fluidized bed (CFB) boiler developed by Valmet. It combines high-efficiency combustion of various solid fuels with low emissions, even when burning fuels with completely different calorific values at the same time.

Our expertise is at your service

Our focus is to bring your performance forward. Our expertise in sustainable energy production is at your disposal. Get in touch with our specialists through your local Valmet office, or the link below.