Industrial Powder Process Safety: Magnetic Detection and Capture for Quality Assurance

Context

In the powder processing industry, the presence of metal contaminants poses a major risk. These particles can originate from machine wear, raw materials or human activity. Their presence can lead to non-conformities, defective equipment and health risks for consumers or operators.

To guarantee the safety of processes and the quality of end products, manufacturers use detection and magnetic collection systems. These solutions make it possible to effectively remove ferrous particles and prevent contamination.

This article discusses the technologies available on the market and their integration into production lines.

 

1. Why secure a powder process with magnetic devices?

1.1. The risks of metal contamination in the manufacturing industry

Metal particles in industrial processes can have various causes:

• Equipment wear: wear on conveyor belts, mills and other machines that come into contact with powders.
• Contaminated raw materials: metal contaminants in batches from suppliers.
• Human intervention: loose parts, tools or accidental fragments.

The consequences can be serious:

• Impairment of the quality of the end product.
• Risk of rejection of batches and non-compliance with standards (HACCP, ISO 22000, ATEX).
• Damage to production equipment.
  
   

1.2. The advantages of magnetic systems for industrial safety

The use of magnetic collection systems offers several advantages:

• Effective removal of ferrous contaminants at various stages of the process.
• Protection of equipment by preventing abrasive particles from entering sensitive machinery.
• Improved compliance with applicable legal requirements.
• Reduced maintenance costs and production downtime thanks to efficient monitoring and filtration.
   

1.3. Which sectors use magnetic separation?

Magnetic separation is a cross-cutting technology suitable for various industrial sectors:

• Agri-food : prevention of contamination in flour, sugar and spices.
• Chemicals and pharmaceuticals: protection of sensitive mixtures and chemical products.
• Construction and recycling: removal of metal contaminants in aggregates and recycled materials.
  
   

2. Magnetic detection and capture: what devices are on the market?

2.1. Filtration magnets in production lines

Filtration magnets are essential devices for capturing ferrous particles in powder flows. Different types of magnets are available:

• Static magnetic bars: integrated into chutes or conduits, they trap fine metallic particles. They can represent a flow restriction for certain cohesive powders with average flowability. A simple and inexpensive solution.
• Dynamic magnetic bars: rotating magnetic bars are preferred for high flow rates on powders that are more complicated in terms of flow (milk powder, cocoa, etc.). Equipped with a gear motor, this bar cage rotates, keeping the powder in motion to break any potential bridges. This solution is more expensive but often more efficient than static bars. It is a good compromise between simple bars and detectors with ejectors. The device is often installed just before the packaging lines (Flowmatic, Palsack, PalDrum…)
• Magnetic grids: used in sieving, they ensure effective quality control.
• Magnetic plates: suitable for conveyors, they capture metallic contaminants as the product passes.

The strength of these systems is measured in Gauss. The industrial standard is set between 6,000 and 10,000 Gauss.

 

2.2. Industrial metal detectors

Unlike magnets that capture ferrous particles, metal detectors identify the presence of metallic contaminants, including non-ferrous ones (aluminum, copper, brass):

• Electromagnetic induction detectors: capable of identifying all types of metals, they are often placed before critical process steps.
• Conveyor belt systems: allow for rapid detection and automatic rejection of contaminated products.
• Specific detectors for sensitive equipment: integrated into grinders, mixers, or bagging machines.

These devices are typically complemented by an ejection system to remove the detected particles.

Calibration of these devices is necessary upon commissioning. Calibration balls are then passed through the detector to adjust its sensitivity (aluminum, bronze, copper, tin). This calibration must be performed regularly to avoid detection discrepancies.

Automatic calibration modules can be fitted to detectors to perform this check regularly.

 

2.3. High-performance magnetic separators

Some equipment goes beyond simple capture and ensures efficient sorting of contaminants:

• Cascade magnetic separators: used for large volumes, they eliminate metals in several stages.
• Vibrating screens with integrated magnets: combine filtration and magnetic separation for a double level of security.
• Eddy current separators: specifically designed for non-ferrous contaminants.

3. Integrating magnetic solutions into an industrial process

3.1. When to integrate a magnetic capture device?

The effectiveness of a magnetic system depends heavily on its positioning in the production line. It can be placed at various strategic locations:

• At the start of the line: control of raw materials before processing. Capture devices are preferred: magnetic grids at silo outlets, Big Bag, bag, or drum emptying stations. Magnetic bars are also installed inline on pneumatic transfer pipes.
• Before sensitive equipment: protection of grinders, mixers, and bagging machines.
• At the end of production: guarantee of final quality before packaging the conditioned containers. Detection tunnels are preferred, especially for small containers (boxes, bags, drums). Metal particle detectors are planned upstream of Big Bag or octabin fillers. Ejectors can be included to avoid stopping production.

3.2. Automation and real-time monitoring

Evolution in technology now allows for the integration of connected magnetic detection and capture systems:

• Smart sensors: provide real-time alerts on the presence of contaminants.
• Predictive maintenance: reduction of interventions through automated diagnostics.
• Continuous monitoring: prevents the accumulation of contaminants and optimizes yield.

3.3. Use cases and feedback

The integration of magnetic solutions has allowed many companies to improve their productivity and compliance. Examples:

• Food industry: reduction of contamination thanks to filtration magnets.
• Pharmaceutical sector: installation of magnetic detectors to guarantee homogeneous mixtures free of contaminants. Detection devices are also planned on end-of-line packaging lines to discard non-compliant batches.
• Recycling and Construction: use of high-performance magnetic separators to sort materials.

4. FAQ: Answers to frequently asked questions

4.1. What is the difference between a magnet and a metal detector?

Magnets only capture ferrous particles, while metal detectors identify all types of metals, including non-ferrous ones.

Magnets must be cleaned regularly to remove particles and maintain their efficiency. Detectors do not capture particles. Ejectors must be coupled to allow for the removal of detected metallic particles. This inevitably leads to product loss since "batches" of product are evacuated.

4.2. What maintenance is required for a magnetic capture system?

Regular cleaning of magnets is essential to maintain their effectiveness and avoid contaminant buildup.

Several features can be provided to simplify cleaning. Bars are inserted into sleeves. Removing the sleeves allows the captured particles to be "released" effortlessly.

Easyclean systems are preferred on high-speed lines requiring just-in-time operation.

4.3. Can several detection and capture technologies be combined?

Yes, combining magnets, detectors, and magnetic separators optimizes process safety.

4.4. Do magnetic systems work in ATEX environments?

Yes, most devices (capture and detection) are ATEX certified for use in explosive atmospheres.

4.5. How to choose the best solution for my industry?

Analysis of product type, flow rate, and regulatory requirements helps select the most suitable solution.

The cost of the system must also be considered in light of the possible consequences.
 

Conclusion:

Integrating magnetic solutions into industrial processes guarantees the safety of products and equipment.

It is important to clearly distinguish between capture and detection to adapt the device according to your needs and objectives.

👉 Do you have a project? To permanently secure your powder processes and guarantee an optimal level of quality and compliance, contact our teams to discuss your project and benefit from a magnetic detection and capture solution perfectly adapted to your needs.