Case Studies

Waste Recycling Business Saves £20k a Year in Progressive Cavity Pump Repair Costs

Arthurs Waste Management is a recycling business that processes skip waste including mixed aggregate from building and construction sites.

Like many companies in the waste industry, they had been supplied with a traditional progressive cavity pump as their main workhorse for the thickener underflow, moving slurry to a holding tank. As is also typical in this application, the slurry often contains abrasive particles such as grit and sharp stone chippings.

Progressive cavity pumps are very good for smooth heavy-bodied pastes; they produce a high pressure and a consistent flow rate, but they can be difficult and expensive to repair.

Due to the inconsistencies and sharp aggregates often found in slurries from construction sites, municipal waste, food factory effluent and ‘green-bin’ waste processing, the inside of pump parts can wear down very quickly. Although special alloys can delay this wear, it makes a replacement stator (which is naturally large on a progressive cavity screw pump), expensive to purchase.

Another disadvantage of using progressive cavity pumps with abrasive fluids – as for some other positive displacement type pumps too – is that their operation relies on tight tolerances between the moving parts to function as they should.

For Arthurs’ recycling facility, the overall result of these pumps’ limitations was rapidly declining efficiency and increasing running costs. As soon as the stator edges and cavity lining begins to wear down, the result is reduced performance and energy wastage, leading all too soon to pump failure.

The failings of the progressive cavity pump meant that the company was being hit by repair bills of £6 - £7k every three or four months. This, along with the downtime of two to three days’ production whilst the pump was repaired was a serious drag on the company’s resources, making targets difficult to meet.

The site manager approached Atlantic Pumps for advice who studied the application and the nature of the slurries handled. Taking the site needs into account and armed with experience gained in working with other recycling facilities, an LSM peristaltic-type pump was recommended as the best fit for purpose.

The LSM range of pumps are ideally suited to thick paste-like abrasive slurry applications as a trouble-free alternative to Progressive Cavity Screw pumps. They have pressure, speed and flow characteristics similar to progressive cavity pumps without such strict tolerance requirements and fewer opportunities for blockages.

LSM pumps, in addition to being very robust, have many other advantages, including:

  • The abrasion-resistant, flexible rubber pipe is the only part of the pump that comes into contact with the media being pumped.
  • The pump can safely run dry, without burning or overheating as dry-running progressive cavity pumps are prone to do.
  • With less chance of blockages, the pump can also be run backwards or forwards to clear the pipeline.
  • Their output can be controlled consistently by the rotation speed.
  • Very few wearing parts. These are also generally quick and low-cost to change.
  • This type of pump is seal-free, eliminating the cost of mechanical seals and time-consuming gland packing.

The LSM pump that Atlantic installed in this recycling facility had a smaller, more efficient motor than the progressive cavity pump it replaced, saving energy costs and reducing the site’s environmental impact.

As forecasted, the LSM paid for itself within a year from the repair and maintenance savings alone. Their smart move from the all-to-often specified progressive pump to an LSM pump enabled Arthurs Waste Management to make considerable efficiency gains, reduced operating costs ongoing and increased the site’s capacity.

As an update (Dec 2022) two years after installation, they’ve gone from spending £20k a year on expensive repair and parts replacements to not having had a single call-out or breakdown.

Andy Smith, Managing Director of Atlantic Pumps explains, “We’re passionate about helping recycling facilities like Arthurs reduce their costs and environmental impact. Our experienced and specialist pump engineers, along with our technical consultants are committed to finding the best solution for our clients”.

If you have a progressive cavity pump that is giving you occasional trouble, check out our Progressive Cavity Pumps Troubleshooter for possible reasons.

If you’re wondering which pump is best-for-purpose, whether for slurry, dirty-water or aggregate-laden slurry, ask an Atlantic Pumps consultant for free advice today.

The Ultimate Guide To Quarry Sustainability