The trial of an APEX35 hose pump from Watson-Marlow Fluid Technology Group at EEW Saarbrücken, a German producer of energy from waste, has indicated significant potential savings in pump maintenance costs.
It found that the pump was able to run without clogging for a much longer period when pumping abrasive brine, with downtime and the cost of replacement parts reduced.
EEW operates a waste heat power plant in Pirmasens. Each year the facility recycles around 180,000 tonnes of waste, generating electricity and district heating.
Among the site’s operations is the separation of crystalline sodium chloride from its highly concentrated solution in the process water before disposal. A special centrifuge is used as a thickener to separate the solution from the abrasive salt slurry, called brine or solebrei.
EEW had been using a progressive cavity pump to feed the centrifuge for around 90 minutes every three to four hours in a 24/7 operation. But the abrasive nature of the brine demanded the repair of the pump stator or rotor every month, along with occasional replacement of the linings.
This would take a minimum of four hours to perform and the pump would have to be removed from the process line.
During the first six months of the trial, the APEX35 required no maintenance. Because the only wear part is the hose, this can be replaced easily in 20 minutes without removing it from the process line, and compares favourably with stator replacement.