A UK cement production facility has improved its maintenance operations and safety levels by installing new equipment from NOV Mono.
Hanson Cement has achieved these improvements by adding a duty/standby Mono Munchpump package to the sewage handling operations at its Padeswood plant in Mold, North Wales.
The plant had originally been using submersible pumps for sewage transfer duties, but these had become inefficient. 'Any maintenance work involved an engineer going down into a confined space,' explains Hanson's engineering manager, Paul Cowell. 'We wanted to make maintenance and cleaning operations safer, easier and more effective.'
Mono designed and installed an aboveground Munchpump package that includes two EZstrip progressing cavity pumps and two SB Munchers, in a duty/standby arrangement, transferring the sewage at 25m3/h to the main sewerage system. The Munchers macerate any solids within the flow to a small particle size, therefore protecting the pumps from any large solids, which could cause blockages.
Each shaft of the Munchers is fitted with a series of interleaving cutters that allow liquid to pass through, trapping the solids and macerating with their high torque cutting action. Low operating and cutter tip speeds dramatically reduce mechanical wear and also offers reduced noise levels when compared to high speed macerators.
Combining a Mono progressing cavity pump with a Mono Muncher allows the use of small bore pipework, typically 50mm, which is a more cost effective solution to the traditional 100mm rising main sewer and offers the further advantage of eliminating the risks of solids settling and septicity. As the equipment is surface mounted and installed in a clean, dry environment, access for maintenance is more user friendly than submersible pumps, with no need to lift equipment out of dirty sumps and one-man accessibility.
Munchpumps can consume less than 50% of the energy of a comparable submersible pump.
The positive displacement action of the EZstrip progressing cavity pumps allows the speed to be set independent of pressure, allowing slow speed operation of the unit. This contributes significantly towards low wear rates, reduced energy consumption, extended component life and greater reliability of the overall pump package. The pumps also feature Mono's unique EZstrip design which allows maintenance, cleaning and de-ragging operations to be carried out in situ, without the need to remove the pumps or disconnect any associated pipework. This can reduce a typical day-long maintenance operation down to just 30 minutes.
'The Mono Munchpump package has certainly made a valuable contribution to the high levels of performance we expect at the Padeswood plant,' concludes Paul Cowell. 'It continues to operate well and has proved to be a considerable improvement over our previous system.'