Gravity Fall Metal Detectors

Gravity fall metal detector systems are suitable for the inspection of any free-flowing powder or granular products such as flour, milk powder, dried fruits, and peanuts.

The product flows through the production line and free-falls under gravity through a small metal detector aperture, achieving high sensitivity. If metal is detected, a fully automatic, high-speed reject device diverts the contaminated product, isolating it from the main product flow. Other names you might find which refer to the very same machine are freefall metal detector or gravity-fed metal detector.

Throat or VFFS metal detectors are similar to gravity-fall systems in that they inspect free-falling product under gravity, but throat metal detectors do not have an integrated reject system. Instead, they are fully integrated with a multi-head weigher and bagmaker, and either send a signal to the bagmaker to make a double bag, or simply stop the line so contaminated product can be removed from the production line.

Gravity fall metal detection systems are designed specifically for the inspection of free-falling powders and granular products in non-pressurized applications, incorporating different reject devices depending on the inspected application. Y-Valve Gravity Fall systems are suitable for the inspection of powders and granular products. The Y-Valve's quick release and captive reject mechanism simplifies cleaning procedures, ideal when product changeovers are frequent and when regular cleaning between production batches is required.

Sealtite Gravity Fall systems feature an innovative design to provide a dust-tight seal. This virtually eliminates the escape of uncontaminated products into the reject channel, reducing product waste. Sealtite technology is ideal for inspection of high-value, dusty products in explosive environments and applications where insertion space is limited.

Open Diverter Gravity Fall systems provide a cost-effective solution for non-dusty products and can be upgraded to Sealtite standards retrospectively if required. This system is best for non-dusty granular products where insertion space is limited.

METTLER TOLEDO Safeline's Profile technology allows manufacturers to reduce the frequency of routine performance monitoring tests through Reduced Test (RT) Mode. RT Mode enables the metal detector to operate at a higher level of sensitivity than required, monitoring the metal detector's performance to a level of certainty that the frequency of routine performance monitoring can be significantly reduced (subject to quarantine periods). Automatic Test System (ATS) greatly boosts productivity and worker safety on the production line by eliminating the need to test at height for most routine performance monitoring tests. ATS decreases the time required to conduct performance monitoring tests by >80% (from 3-5 minutes per line, to under 45 seconds per line). ATS is the only method that can consistently confirm worst-case sensitivity performance, delivering enhanced compliance and greater brand protection.

In some cases, depending on the testing protocol undertaken by your business, Reduced Test Mode and ATS can lead to significant uptime advantages, improved overall equipment effectiveness (OEE), and cost savings – all highly desirable attributes in today’s demanding production environments.

Related Content:

• Reduced Test Frequency Benefits
• ATS Datasheet

If operating in a potentially explosive atmosphere, certain Gravity Fall metal detection systems can be supplied to comply with ATEX / IECEx / Hazloc regulations. Please discuss your requirements with your local sales representative.

METTLER TOLEDO Safeline Profile Gravity Fall metal detectors can contribute to safer working practices in food manufacturing environments.

By reducing the frequency of metal detector testing using new Reduced Test Mode technology, there is a corresponding reduction in the number of "ladder climbs" required by an operator to conduct the test, either to drop the sample through the aperture or to access the HMI to run the test routines. Emulation, another feature available on our Profile metal detectors, allows the metal detector HMI to be controlled from a variety of networked devices such as a tablet or mobile phone. This again reduces the need to work at height if the HMI is installed in an awkward location, as is the case in many dry product inspection applications.

ATS virtually eliminates the need to work at height to conduct most routine performance monitoring tests, and removes the requirement for line operators to reach across installed equipment to drop the test samples through the aperture of the metal detector.