Waste Management Case Study: Viridor, Rochester Plastic Recycling Facility

“Proof is in the pudding and Expel worked. I am really impressed”.

Mark Gibson – Maintenance Supervisor – Viridor.

About the customer

Viridor is the largest UK-owned recycling, renewable energy and waste management company.

Viridor announced that all its recyclable plastic waste will be reprocessed in the UK from 2020 as part of the company’s recycling investment programme. Viridor’s full range of services includes recycling and waste advice and auditing; advanced materials recycling; glass and plastics reprocessing; composting; mechanical and biological treatment; anaerobic digestion; waste to energy; transport; collection; landfill disposal; and habitat restoration and management.

Project Background

The Rochester Plastic Recycling Facilities site run approximately 16 optical sorting machines. These machines are critical to the site as they are used for a variety of reasons including the separation of non-recyclable plastics or plastics which are not PET. Compressed air is vital to the functionality of optical sorters and the performance of these machines can be drastically hindered if liquid water, oil emulsion fluids and/or solid particulates enter the compressed air lines; a problem known all too well to Maintenance Supervisor, Mark Gibbon. When the optical sorting machines were exposed to these contaminants the mac valves would get damaged and need replacing. This would impede the overall efficiency of the site.

Furthermore, Viridor as a company are very keen to make their sites as sustainable as possible and are always looking for ways to reduce environmental impact where possible.

After learning about the Expel compressed air filter, Maintenance Supervisor Mark Gibbon was quick to realise how Expel could boost the productivity of the site and reduce the environmental impact of compressed air usage.

air compressor water traps

Why did Rochester PRF Site choose Expel?

The site had both refrigerant dryers and conventional compressed air filters installed as an attempt to solve the problem of moisture and solid particulates in compressed air lines. However, these solutions were not getting rid of the problem which was exemplified through the large numbers of mac valves which were being damaged by moisture and were in need of constant replacement.

After installing Expel, its effectiveness was noticed very quickly as the maintenance team found they were no longer having to replace moisture damaged mac valves. So why has Expel succeeded where other solutions have failed? – The answer is simple. Expel has a unique patent protected design which allows it to continually remove 99.999% of all liquid water, oil emulsion fluids and solid particulates down to 1 micron from compressed air lines. In contrast, traditional compressed air filters contain disposable internal elements that become less and less effective the more they are used and unlike Expel, can never guarantee that these harmful contaminants will not reach critical machinery like optical sorting machines.

Refrigerant dryers were also proving problematic for this site because when the compressed air leaves the dryer it has to travel a long distance before it reaches the optical sorting machines, and the compressed air is exposed to temperature changes which would fall below the dryer dewpoint. Expel can still operate in very low temperatures, making it a far more reliable solution for the site.

These outstanding results did not go unnoticed by Mark Gibson’s team and have since attracted from other sites. For example, Maintenance Supervisor Andrzej Slimak from the Crayford Material Recycling Facility site was so impressed with these results that he asked us to visit his sites as a matter of urgency to eradicate the problem of moisture from compressed air lines as soon as possible. This site has since ordered units, and we are very excited to hear about the results in due course!

air compressor water traps

"Two months since installing Expel and I’ve not had to change one mac valve"

Mark Gibson – Maintenance Supervisor – Viridor.


Reduced Downtime

Reduced Maintenance

Increased Sustainability

Reduced Costs


[contact-form-7 id="6806" title="Contact form 1"]

Translate »
Follow by Email