APMG Plastics’ long-lasting extract system designs have been keeping industrial plants’ air clean and pollutant-free for almost eighty years. Recently an SOS was received from a client whose APMG extract system was made and fitted back in the 1980s and only now needed attention. Our team provided a full refurbishment, redesigning and replacing the components that had reached the end of their working lives.

An extract system from the 80s

In 1989 APMG designed, manufactured and commissioned a complete fume removal system for an electrode coating plant in the north west of England.

The system handled chemical fumes from the plant’s activities and needed to be efficient, effective, dependable and appropriate for the application. Using its team’s experience in design, thermo plastics fabrication and fan applications APMG delivered a system that has functioned safely and reliably for thirty years.

The system was designed to ensure that noxious fumes are expelled from the 1.7 metre diameter stack at a velocity of at least 10 metres per second.

Six plastic forward curved centrifugal fans were installed serving several process lines. The discharge of these process fans was collected into one main header duct. A bleed damper at one end and a large dilution backward curved fan at the other end ensured that a constant air velocity through the discharge stack was maintained depending on which process fans were operating at any one time.

Time for a refurb

 In 2019, after 30 years of continuous operation, the system showed signs of deterioration. The client requested that APMG Plastics undertake some remedial works to the large dilution fan and, after conducting a full survey of the system, a schedule of works was agreed.

The original Durafan BC1600 backward curved impeller was manufactured from glass fibre. Standard polypropylene constructed impellers were not – and still aren’t – capable of handling the tip speed of over 10,000 feet per minute this fan requires.

A new impeller, mild steel shaft and bearings assembly were needed. In the late 1990’s APMG had discontinued the backward curved range of fan units with glass fibre impellers. APMG Plastic’s design engineers created a like-for-like impeller constructed from mild steel. It was overlaid in a chemical resistant Polyglass VEF coating to protect it from any hazardous materials within the airstream.

A new PVC fan case with a GRP coating was manufactured in the APMG Plastics fabrications department.  Given its overall size of around 3.5 metres wide, 1.2 metres deep and 2.9 metres high this was made by skilled fabricators in three sections and assembled on site. Bespoke inlet and outlet flexible connections were fabricated to precisely accommodate the fan casing.

The motor and drive system were fully replaced. The fan pedestal was refurbished and repainted and fitted with anti-vibration mounts to stabilise the fan. A replacement grille section for the bleed end of the duct was manufactured and fitted into a new grille housing made from plastic reinforced GRP.

APMG Plastics’ experienced installation team attended site to fit and replace all the elements of the system that needed upgrading.

An extract system for the future

‘Our client couldn’t be more delighted,’ says Peter Royse, Plastics Division Manager.

‘The original APMG system was fully maintained and withstood decades of operation. It has kept the air clear of pollutants and safeguarded the company’s personnel from chemical fumes throughout that time. The newly refurbished system incorporates modern technology and is ready to serve for another 30 years.’

To discuss your extract system application contact the APMG Plastics team.