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New Apex35 pump trial indicates lower maintenance costs

Watson-Marlow Fluid Technology Group (W-M) announced that a trial of its new Apex35 Bredel hose pump at German energy-from-waste producer EEW Saarbrücken's plant has indicated the pump's potential to cut maintenance costs.

The company reports its Apex35 pump was able to run without clogging for a long period while pumping abrasive brine and that the downtime and cost of replacement parts was reduced.

EEW Saarbrücken's waste-heat power plant in Pirmasens,Germany, recycles approximately 180,000 tonnes of waste per annum, generating around 75,000 MWh of electricity (enough for 20,000 households and 25,000 MWh of heating (2,000 households).

One of the plant's functions is the separation of crystalline sodium chloride from a highly concentrated solution in the process water before disposal.

In this process, a centrifuge acts as a thickener to separate the solution from the abrasive salt slurry (2.16 kg/l density), 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, but the abrasive brine required the pc pump stator or rotor to be repaired every month, along with occasional replacement of the linings.

The repair process would take a minimum of four and require the use of expensive replacement consumables and the pump would also have to be removed from the process line.

The Apex35 was called for trial by EEW, and W-M reports the pump required no maintenance during its first six months of operation.
The only wear part in the Apex pump is the hose, which according to W-M and EEW could be replaced in 20 minutes without removing the pump itself.

A replacement stator alone for the progressive cavity pump is thought to cost around €1500, so Watson-Marlow report an 'extremely' short payback period for the Apex35 hose pump.

The Apex35 has no wearing components, such as seals, valves, membranes, stators, rotors, or glands, which makes the pumps suitable for handling difficult abrasive, viscous, corrosive, gaseous, or crystallising fluids.