One of the leading oleochemicals manufacturers in India was using a 45 kW centrifugal pump for boiler feed application, which was set on continuous operation. The feed water to the boiler was regulated through a feed valve controlled by level sensors inside the boiler and a bypass line.
The excess feed water was bypassed through a bypass line to the de-aerator resulting in low system efficiency consuming high energy for this application. Also, the use of a feed valve required periodic maintenance and higher pump capacity to compensate for pressure drop across this feed valve.
The Solution
Grundfos standard CRN pump with fixed speed and a CRNE – SF model consuming total energy of 16.5 kW, was the ideal solution for the process automation and control requirement of this boiler feed application. Level transmitter signal (4-20mA) is directly given to the CRNE pump and set to constant level operating mode, thereby eliminating the need for a feed valve and a bypass line. The Grundfos CRNE pump is controlled directly based on the boiler steam consumption so that there is no bypass of the feed water or energy wastage in the process.
The Outcome
With Grundfos iSOLUTIONS, system complexity is reduced to an absolute minimum. The boiler feed pumps are sized to match the steam production, resulting in increased system efficiency. Steam quality is also improved due to the constant water level maintained in the boiler drum. The iSOLUTIONS for this boiler feed application has resulted in an overall reduction in the boiler maintenance as well.
