One small change in boiler feed level control, one massive change for the better

To improve steam quality, Grundfos offered a solution and replaced the fixed-speed CR pumps for boiler feed with Grundfos iSOLUTIONS CRIE pumps with integrated variable speed drives. They also removed the modulating valve from the boiler. The CRE pump controls the level in the steam boilers, going up and down in speed depending on demand. At the same time, the Grundfos pumps use built-in functions in the drive – i.e. limit-exceed and signal relay output – to control a bypass valve to secure flow through the economiser when the burner is running but the boiler is not calling for water. All control is handled by the drive at exactly the right time to have a safe and efficient boiler operation and reduce complexity.

The outcome was very impressive. The boiler’s improved performance not only resulted in better steam quality but also achieved significant energy savings. Grant’s are estimating about 40% energy savings on that one pump alone, that equates to about GBP5,000 a year. There are all these impacts, plus the guarantee of having a reliable system.