James Cropper Paper Manufacturer in Cumbria
JAMES CROPPER has been manufacturing speciality paper at its mill near Kendal in Cumbria for around 150 years. The mill makes a wide variety of speciality papers and technical fibres for use in products such as insulation and fire retardant materials.
Until fairly recently, the company used two 55kW pumps to supply medium pressure water to various processes in the mill. The rate of delivery from each pump was controlled by a valve positioned downstream of the pump. This arrangement meant that the pumps were running constantly, irrespective of the level of demand for water. In addition, the valves placed a significant restriction on the flow of water through the pipes, even when fully open. James Cropper’s personnel realised that variable speed drives could provide a more efficient alternative and called in Northumberland-based Quantum Controls Ltd to supply and commission a new drive-based control system.
The system has boosted efficiency at the mill in three ways.
First, the new drives vary the speed of the pump motors automatically to match the changing demand for water.
Second, the drives have allowed the old control valves to be removed, eliminating the previous flow restrictions. The company can now pump more water and meet its maximum demand using just one pump. The spare pump, fitted with its own variable speed drive, is now kept on standby to provide back-up in emergencies.
Third, the new system allows Cropper to reduce the standby pressure in its water system when there is no demand from the mill. Because it is now easier to control the pump output on demand, the standby pressure can be lowered.
The drives-based system is thus providing James Cropper with the same service as its previous installation, but uses much less energy. The project is saving the company around £20,000 a year in energy costs, and has paid for itself within a year, as well as reducing the number of pumps needed under normal circumstances from two to one.