Cyclonic filtration

Cyclonic filtration is a technique used to filter particles from an air, gas, or liquid stream without the initial use of filters. Cyclonic separation relies on rotating effects and gravity to disperse powder mixtures, especially those in the lower μm size range. The process creates a high-frequency gyrating airflow within a cylindrical or conical container, referred to as a cyclone. Air moves in a helical pattern, starting at the top of the cyclone and ending at the bottom. It then exits through the center of the cyclone in a straight stream.

How Cyclonic Filtration Works

Larger particles (in the upper μm size range) have too much inertia to follow the tight curve of the stream. These particles hit the cyclone’s outer wall and fall to the bottom, where they can be removed. In conical cyclone systems, the flow moves towards the container’s contracted area. As the rotating stream reduces in size, it effectively separates the larger and smaller particles. The cyclone’s geometry and flow frequency determine its cut point. Particles larger than the cut point are removed more efficiently. Research in cyclone technology has led to improved designs, helping industries meet stricter air quality standards for particle emissions.

Applications of Cyclonic Filtration

Cyclone technology is widely used across many industries. It helps in the recovery of materials and acts as a collector to reduce atmospheric pollution, complying with particle emission regulations. Cyclone systems efficiently recover active pharmaceutical ingredients, chemicals, and food powders, especially after drying processes like fluid bed and spray drying. These cyclone collectors are essential in production processes, enabling direct powder capture without the need for filters.

How We Can Help with Cyclone Technology Development

Designing an optimal cyclone requires consideration of various factors. Flow disturbances or deviations from the intended flow pattern can significantly reduce efficiency.

For instance, it is crucial that air enters tangentially at the top of the cyclone. Avoid constricting baffles or lids at the outlet, as these can interfere with airflow. The cut size of particles and their shape also play important roles in the cyclone’s effectiveness. Additionally, the strength and hardness of powder particles are crucial to prevent the formation of fines.

Cyclone Systems for Powder Recovery in Various Industries

Cyclone technology is applied in many sectors, including:

  • Pharmaceuticals
  • Chemicals
  • Food and feed ingredients
  • Nanoparticles
  • Mineral processing
  • Catalysts
  • Milling and drying processes