Engineering Around Constraints: ISF Delivers End-to-End Milling Upgrade for Long-Standing Client

At the end of 2024, ISF was approached by one of its long-standing customers, a national poultry feed mill based in Buckinghamshire, and tasked with delivering a complex site-wide upgrade. Having worked with the client for over 35 years, this was another successful collaboration that highlighted ISF’s engineering expertise and commitment to delivering lasting results.

The project was split into two carefully planned phases to minimise production downtime and was completed earlier this year. It provided the ideal opportunity to showcase ISF’s ability to overcome technical challenges, maximise throughput, and deliver high-value engineering within strict timeframes.

Phase One: A Cool Solution to a Hot Problem

The initial brief centred around a key item of process equipment: the pellet cooler. This single-deck unit, essential for cooling freshly pressed feed pellets prior to dispatch, was due for replacement, ideally with a more efficient double-deck version. The aim was to reduce batch changeover times and increase hourly throughput.

However, the mill’s location within a former aircraft hangar, just two storeys high, posed a significant obstacle. A conventional double-deck cooler would not physically fit within the building’s height constraints.

ISF’s engineering team carried out a full site survey before designing a bespoke under-hopper system to work within the available headroom. Using in-house 3D modelling tools, the team developed a shallow-profile discharge hopper with a 1.5-metre-wide chain and flight conveyor. This, combined with shortened support legs, reduced the overall cooler height by 500mm, enabling installation within the restricted vertical space.

Two teams of three engineers completed the installation within a tightly scheduled three-day shutdown. To ensure full compatibility with downstream equipment, the new, wider conveyor was calibrated to run at a slower speed to maintain consistent flow rates. ISF’s team also remained onsite during electrical commissioning to ensure a smooth restart.

As a result of the upgrade, throughput increased from 12 to 16 tonnes per hour, and batch changeover times were significantly reduced, with the upper deck now able to hold product while the lower deck discharges.

Phase Two: Breathing New Life into an Ageing System

With the new cooler operational, attention turned to other parts of the line. This included replacing outdated and inefficient equipment such as the press, conditioner, crumbler, and sieve, all critical to maintaining consistent pellet quality.

The conditioner, a key component that injects steam and molasses into the meal before pelleting, was of particular importance. Once formed, the pellets pass through the new cooler, into the crumbler, then the sieve, which removes dust prior to fat coating and storage.

The customer sourced the specialist process equipment, while ISF designed and fabricated all the necessary supporting steelwork at its York facility. ISF engineers then removed the old press and conditioner and installed the new equipment using a 300-tonne crane provided by Baldwins. During the works, the industrial fan was also replaced as a preventative measure to avoid future disruption.

This phase was delivered over two separate two-day shutdowns to minimise operational impact. ISF supported the client throughout, from shutdown planning and layout design to fabrication and installation of all new support structures.

Proven Impact, Engineered to Last

Following completion of both phases, throughput rose to around 20 tonnes per hour, a 60% uplift in productivity. The plant is now equipped with modern, efficient, and reliable systems designed to support long-term production demands.

This project highlights ISF’s practical, customer-focused engineering approach. Instead of asking whether a solution is possible, the team focuses on how to make it work. Whether dealing with space restrictions or time pressure, ISF consistently delivers by combining in-house design and fabrication with a collaborative ethos built on long-term client partnerships.

To discuss your next mechanical or plant upgrade, contact the ISF team:
www.isfyork.com/contact