Maize miller reaps the benefit of gravity metal detectors

Adhering to the strictest food safety standards, Corson Grain Products is one of the largest maize milling operations in Australia. At its remote Queensland site, the company recently installed a Fortress Technology gravity Stealth metal detector with configuration and service support provided by local food safety partner Diverseco. Impressed with the performance and reliability of the gravity system located at the Warwick mill, the miller ordered two additional Stealth metal detectors for its Gisborne mill.

Located in the agricultural heartland of South East Queensland, quality control for Corson Grain Products is dependent on the performance of its equipment. “It is a four-hour road trip from Brisbane to Warwick, so inspection reliability is extremely important to maintain machine uptime and prevent production disruptions,” said Diverseco Inspection Product Manager Simon Collins.

“In addition to being a rural location, there are many operational challenges in milling environments. Among them high vibrations and electromagnetic interference, which can cause false readings and product waste if detectors are not of the highest quality or correctly positioned and calibrated properly.”

Addressing these factors is especially important for the family-owned business, which has operated under a ‘nothing added, nothing wasted’ philosophy.

Zero waste food safety commitment

Ensuring adherence to the most robust food safety certification requirements, including HACCP, BRCGS, HALAL, PIF, GMO-free statements and MPI Approval, the Fortress Technology Stealth Gravity metal detector supports this zero-waste policy.

“The system delivers exceptional metal detection performance, effectively preventing contamination and minimising unnecessary product waste. This commitment aligns with Corson Grain’s dedication to robust food safety practices and zero waste policies,” said Tim Briggs, Production Manager at Corson Grain Products in Queensland.

The long-term reliability of Fortress Technology equipment played a key role in the upgrade decision. A Fortress Phantom metal detector, which had operated in the New Zealand plant for over 20 years, was relocated to the Queensland site and assessed following transit. While the unit had delivered decades of dependable performance, the team determined that investing in a next-generation system would better support future operational goals.

According to Briggs, the Stealth metal detector proved itself the moment it was installed. Equipped with noise immunity and digital filters, the latest model delivers good sensitivity and food safety assurance.

The Queensland team particularly appreciates the detector’s accuracy in identifying contaminants, its user-friendly operation and the straightforward installation process.

Transitioning to hourly automatic testing

Several months after the installation, the Queensland site activated the Fortress Technology Halo Automatic Testing feature with the help of Diverseco. This feature has strengthened and future-proofed the miller’s inspection program, ensuring that it remains adaptable to the evolving compliance and verification standards within the industry.

Currently, the team validates machine performance by dropping ferrous, non-ferrous and stainless steel test balls through the metal detector aperture every hour. This regular testing procedure confirms that the reject mechanism is functioning correctly and ensures compliance with machine performance validation requirements.

Optimising the vertical footprint

Positioned under one of five maize storage silos on a mezzanine floor, milled maize flour trickles through the metal detector aperture. “This is a relatively slow-flowing application, inspecting approximately two tonnes of GMO-free maize flour per hour. The bulk bag filling station is located directly underneath the mezzanine floor,” Collins said.

Briggs confirmed that the milling of high-quality maize is a precise process to ensure the right texture and nutritional value is maintained. “Our milling process is guided by strict food safety standards and comprehensive inspection testing to ensure the finest products are distributed to customers throughout Asia–Pacific,” Briggs said.

“Maize is brought into the mill from the silo storage where it is weighed, pre-cleaned and transferred to the conditioning bin to soften the skin. From there it moves into the degerminator which skins and breaks the kernels for optimum milling. It then moves through an array of metal rollers, plates and sifters. That’s why we are so meticulous in our choice of metal detection equipment and localised support.”

Corson Grain Products had to adapt the reject configuration. The reject pipe was extended to direct rejected product through the flooring to a separate collection bin on the ground floor.

“By utilising vertical space, the mezzanine ‘inspection’ floor doubles the usable area, separating the milling and dispensing process from the ground-level packaging site, while allowing for the integrated, gravity-fed removal of reject materials through the floor,” Briggs said.

For ease of programming and calibration, the metal detector control panel is located on the lower floor beside the milling sacks.

Satisfied with the performance and reliability of the Queensland metal detector, Corson Grain subsequently acquired additional Fortress Technology systems for its Warwick facility and New Zealand site.

Images: Supplied