Paper mill installs APEX hose pumps for abrasive pigment dosing
The Beetham, Cumbria plant of BillerudKorsnäs has replaced a progressive cavity (PC) pump with APEX10hose pump technology from Watson-Marlow Fluid Technology Group on an application dosing abrasive pigment in kraft paper manufacture. The move has solved the problem of stator and rotor wear on the PC pump that was leading to a drop in performance, downtime, and the need for regular maintenance.
At Beetham, kraft paper is produced in quantities of circa 34,000 tonnes a year across three shifts using 140 employees. In an application involving the dosing of pigment into paper stock, the plant was experiencing difficulty with its PC pump.
“We put the pigment into the stock preparation end of the paper machine to introduce a colour shade to certain grades,” explains Engineering Manager Tony Halhead. “We dose very low, precise volumes as the shade is critical. However, the abrasive nature of the pigment was causing the stators and rotors in our 1” PC pump to wear, leading to a drop in performance.”
As a result, the engineering team at Beetham would have to speed up the three-phase inverter in the control box to maintain flow rates at the required levels, causing even faster wearing. However, if the drop in performance went unnoticed, it could lead to a variation in shade and to rejected paper. On a long production run this could be very expensive.
“We were experiencing dips in performance on a regular basis so we decided to address the situation, particularly when also considering the downtime and maintenance issues,” says Mr Halhead. “Other Watson-Marlow pumps were being used on site successfully so we thought they would be a natural first port of call.”
Uptime and continuity
Watson-Marlow recommended the use of an APEX10 hose pump. APEX pumps are engineered for maximum uptime and process continuity. Through design attributes such as heat dissipation, precision machined hose elements and optimised hose compression, APEX pumps reduce hose element fatigue compared to other hose pumps and when a hose replacement is required, this is a quick task which can be carried out in-situ by maintenance staff. The benefit for APEX users such BillerudKorsnäs is reduced maintenance intervals, leading to decreased cost of ownership. Operating and inventory costs are also less, as a single hose element is all that needs to be replaced.
BillerudKorsnäs installed two APEX10 models in February 2014, one duty and one standby. The pumps are fixed to a mobile skid and piped with valves to speed changeover. Offering a 14 rpm, 0.18kW motor suitable for VSD control, the flow rate is 25-30 litre/hr when using a green pigment, and 10-15 litre/hr for a blue pigment. The pumps are flooded suction (600mm head into pump via 2.5 metres of 1/2' flexi hose). Discharge is via 18 metres of 1/2' flexi hose inclusive of an 8.5 metre lift into the paper stock tank.
“Since installation the APEX10 pumps have been running reliably in a 24/7 operation,” says Mr Halhead. “We are now considering the replacement of other PC pumps on site with APEX models.”
BillerudKorsnäs is a 4300-employee strong manufacturer of primary fibre-based packaging materials, working with over 1500 customers in over 100 countries. The company has eight production facilities, seven of which are in Scandinavia, and one in the UK, at Beetham. The specialty here is the manufacture of sterilised packaging paper for medical applications.