Our Blogs

Significant Energy Savings with VSDs in the Paper Production Process

ED_Pulp & Paper Blog 3

Process Water Pumps – Energy Drive Achieves +40% Energy Saving

Our client is saving over 40% in energy per year on their Process Water Pumps after an Energy Drive solution was installed at one of their plants.

The client site utilises five pumps to supply process water into the paper and pulp making processes across their plant. Each pump is powered by a 110kW motor, totaling 550kW at 525V. The system operates as an open water loop, recycling excess water back to the water storage dam.

Prior to implementing the Energy Drive solution, the site would maintain a pressure setpoint by manually controlling the number of pumps (typically 3 or 4) operating in conjunction with automated throttle valves, based on the plant requirements. The pumps would run at full speed and excess water would be fed back into the storage dam. This type of control is energy inefficient and induces high transient starting loads on the motors.

In 2013, Energy Drive installed five 110kW VFDs at 525V. Instead of the pump motors running full speed at a high-power demand and using throttle valves to maintain the pressure, the VFDs now vary the speed of all five pump motors to maintain the pressure setpoint during the various plant requirements allowing for increased system efficiency.

All Energy Drive installations are zero CapEx turnkey solutions with a contractual minimum net saving. The client has therefore benefitted from a total contract-to-date net saving of R5 203 977 from the first year, with zero capital outlay. Average power reduction was found to be 40.6%.

In addition to the energy saving benefits, the system has also extended the motors’ service intervals and reduced the electrical and mechanical strain on the motors.

Posted in

Energy Drive

Leave a Comment