Pigment dosing in paper production
- APEX10 hose pump replaces PC model
- Stator and rotor wear now eliminated
- Excessive downtime and maintenance a thing of the past
Paper mill installs APEX hose pumps for abrasive pigment dosing
BillerudKorsnäs has replaced a progressive cavity (PC) pump with APEX10 hose 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.
“We put the pigment into the stock preparation end of the paper machine to introduce a colour shade to certain grades,” explains the Engineering Manager. “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. 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 as 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.
“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.”
Lime slurry dosing and high solids, lead-based slurry transfer
- Tough process conditions with flows up to 2500 litre/hour
- Hose replacement not expected before 14 months running is complete
Bredel APEX35 hose pumps improve quality and reduce maintenance costs
The New Braunfels, Texas plant of the Canyon Regional Water Authority is keen on sourcing an alternative to its progressive cavity (PC) pump to increase the accuracy of pH control. The potable water plant currently controls pH by dosing lime slurry using a PC pump, which runs for approximately 12-16 hours a day at a rate of 900 litre/hour.
Reliable, consistent flow
Watson-Marlow has supplied a Bredel APEX35 hose pump to the New Braunfels CRWA plant so that engineers can see the benefits of using a hose pump to handle the lime slurry. First of all, insufficient flow consistency of the PC pump is prone to causing fluctuations in the pH control, which means variations in water quality. Installation of the APEX35 hose pump with its stable and consistent flow means that these problems have already been eliminated.
Another huge practical advantage of this new hose pump at the site is reduction in maintenance. The abrasive nature of the lime slurry means that maintenance is required on the PC pump every three months and takes up to five hours to complete. Furthermore, this often requires expensive consumables such as stators, rotors or linings. In contrast, the APEX35 pump has required no maintenance in its first six months of operation at CRWA, and when maintenance is finally required, it will take no more than 30 minutes, with the only consumable part being a single hose element.
The outstanding success of the CRWA APEX pump trial was replicated at the plant of Addenda Corporation, which is in the process of comparing its existing hose pump to a new Bredel APEX35. Here the task involves the accurate transfer of a very abrasive, high solids, lead-based slurry between process stages. The existing hose pump and the APEX35 are being run under exactly the same process conditions, with flow at approximately 2500 litre/hour.
The company’s existing pump requires hose replacement every 8-9 months; a very acceptable and cost effective uptime period. The APEX35 pumps' hose replacement significantly is not expected before 14 months running is complete. This is thanks largely to the APEX design, which is optimised for medium pressure applications and long lasting hose elements, and increase it pump uptime arrives as a consequence of selecting the right pump for the application.
Advantages to customers handling abrasives
When handling abrasive substances, a major advantage of APEX hose pumps is that they have no costly wearing components like seals, valves, membranes, stators, rotors or glands to maintain. Self-priming, dry running, and with no internal valves, hose pump technology also helps users improve their processes by eliminating troublesome ancillary items like anti-siphon valves, back-pressure valves, degassing valves or run-dry protection. Consequently, APEX hose pumps are perfectly suited for transfer and metering abrasive, corrosive, viscous, shear-sensitive, gaseous, crystallising fluids, or even fluids with a combination of these properties.
Designed for longevity
Another important factor in being able to reduce maintenance costs at Addenda is that the APEX35 requires 18% less hose compressions for the same volume transferred by the existing hose pump (which needs around 1500 strokes for each 1000 litres). What’s more, the direct coupled technology and self-supporting rotor on the APEX35 help maximise gearbox and bearing life to further add to the package of savings for the plant.
Abrasive brine causes progressive cavity pump problems
- Progressive cavity pump stator or rotor replaced every month. APEX35 still running after 6 months
- Minimum 4 hours pc pump repair time v 20 minutes APEX35 hose installation
New Bredel APEX35 hose pump cuts maintenance costs at ‘energy from waste’ plant
The trial of a new APEX35 hose pump from Watson-Marlow Fluid Technology Group at EEW Saarbrücken GmbH, a producer of energy from waste, has indicated the significant potential savings in pump maintenance costs. Not only is the APEX35 pump able to run without clogging, for a much longer period when pumping abrasive brine at EEW, but downtime and the cost of replacement parts is reduced greatly.
EEW Saarbrücken GmbH, MHKW Pirmasens operates a waste-heat power plant in Pirmasens, Germany. Each year the facility recycles around 180,000 tons of waste, generating around 75,000 MWh of electricity (enough for 20,000 households) as well as 25,000 MWh of district heating (enough for 2000 households). These figures also allow some 52 million litres of heating oil to be saved in energy production every year.
Among the site’s operations is the separation of crystalline sodium chloride from its highly concentrated solution in the process water before disposal. Here, a special centrifuge is used as a thickener to separate the solution from the abrasive salt slurry (density 2.16 kg/l), which is called brine or ‘solebrei’.
EEW has been using a progressive cavity pump to feed the centrifuge (flooded suction, 1 bar back pressure), for approximately 1.5 hours every 3-4 hours in a 24/7 operation. However, the abrasive nature of the brine demanded the repair of the pc pump stator or rotor every month, along with occasional replacement of the linings. Furthermore, not only would it take a minimum of four hours to perform the repairs (using expensive replacement consumables), but the pump would also have to be removed from the process line.
Dissatisfied with the situation, plant engineers at EEW requested a trial of the new Bredel APEX35 hose pump. This model was selected because it was thought to offer the greatest potential maintenance savings in this abrasive handling, intermittent duty application. The results were nothing short of impressive.
During the first six months of the trial, the APEX35 required no maintenance whatsoever. Additionally, as the only wear part in APEX pumps is the hose, this could be replaced quickly (20 minutes) and easily without removing it from the process line. Considering that a replacement stator alone for the progressive cavity pump is thought to cost around €1500, the projected payback period for the APEX35 hose pump is extremely short. In addition, there is the saving in inventory as only the hose will need to be kept in stock.
Abrasive core wash slurry transfer
- AOD pump needed two weekly maintenance v APEX35 ten weeks uptime
- APEX35 maintenance less than 50% of the time to return AOD pump to operating condition
A new APEX35 hose pump from Watson-Marlow Fluid Technology Group is proving that it can deliver significantly reduced maintenance requirements at the world’s largest manufacturer of freight carriage components, Amsted Rail. Put to the test in a process-critical abrasive slurry transfer operation, the trial has demonstrated that in comparison with existing air operated diaphragm pumps, the Bredel APEX35 can extend the time between scheduled maintenance intervals dramatically at this important producer of rail side frames and bolsters.
Scott Schuette, Amsted Rail’s Engineering Manager had worked with Bredel hose pumps in the past at Elementis Pigments, and brought his confidence in the technology to Amsted Rail.
New pump offers cost savings
Kurt Krummrich, Industrial Sales Manager at Watson-Marlow Pumps Group explains, “Amsted Rail has used air-operated diaphragm [AOD] pumps in this particular process for many years. Scott's willingness to try something new, coupled with our discussion that maintenance cost savings could be achieved by installing the new APEX35, got our foot in the door.”
Perfectly suited to abrasive handling
When handling abrasive substances such as the core wash slurry, a major advantage of APEX hose pumps is that they have no costly wearing components like seals, valves, membranes, stators, rotors or glands to maintain. The pumps are also self-priming and dry running.
Significantly reduced maintenance costs
The Bredel APEX35 hose pump replaced an AOD pump on one of the dip tanks, running with flooded suction and virtually no pressure. While the AOD pumps need to be maintained every two weeks, the APEX35 hose pump ran continuously for ten weeks before any maintenance was carried out.In addition to the significantly longer uptime periods, when maintenance of the APEX pump is required, additional savings are apparent as it takes less than 50% of the time needed to reinstate the AOD pump to operating condition, with only a single replacement part required – the precision machined hose element.
Energy cost savings
Although the AOD pumps have been in use for many years, Mr Schuette's aims for the future are to choose pumps that not only reduce maintenance and downtime, but also that do not require compressed air for their operation.
The benefits of the APEX pumps' increased uptime and process continuity at Amsted Rail are clear, and the company can look forward to substantial savings in labour and parts, with a greatly decreased cost of ownership.