MAC Air Classifier for Precision Fine Particle Separation
For manufacturers processing fine powders and dry bulk materials, controlling particle size distribution is essential for maintaining product quality and process efficiency. The Prater MAC Air Classifier is a forced-vortex classification system designed to deliver exceptionally precise particle separation across a wide range of feed variations. By combining adjustable centrifugal force with controlled airflow, the system separates particles based on size and density to produce uniform, high-quality material streams.
The MAC Air Classifier is capable of separating particles within a typical range of approximately 3 to 150 microns, making it well-suited for applications that require ultra-fine classification and narrow particle size distributions. The machine can operate either as a stand-alone classification system with feeder, fan, and collection equipment or as part of a closed-circuit grinding system integrated with milling equipment.
Its heavy-duty construction, precision rotor design, and adjustable secondary air stream allow operators to fine-tune the cut point and capture near-size particles efficiently, helping manufacturers achieve consistent material specifications across industries such as food processing, chemicals, minerals, and advanced materials manufacturing.
KEY FEATURES AND BENEFITS
HD construction in carbon or stainless steel
Constant diameter, precision fit rotor for excellent sharpness of cut
Precise on-stream control of cut point simply by varying rotor speed
Adjustable secondary air system for greater capture of near-size particles
Low system resistance for less power consumption
Optional ceramic, tungsten, polyurethane, or rubber lining for abrasive service
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Theory of Operation
Prater MAC Air Classifiers utilize adjustable centrifugal force to separate particles in a pneumatic circuit. As product is conveyed thru the primary air inlet, individual particles are subjected to aerodynamic drag by the pneumatic air. This drag force varies with the size and density of the individual particles. As particles spiral toward the classifier rotor, one of two things occur:
drag force of smaller, more aerodynamic particles exceeds the centrifugal force exerted by the rotor, and particles pass through the machine as fines; or
centrifugal force overcomes the drag force, causing larger, less aerodynamic particles to accelerate away from the rotor, where a cyclonic chamber collects the coarse particles and discharges them through a rotary airlock fitted to the bottom of the machine.
Cut-point is determined when the forces are equal, in which case particles have a 50/50 chance of passing as fines. Cut-point is variable and can be controlled by adjusting the rotor speed. A secondary air inlet introduces a controllable amount of air that moves upward into the classification zone, increasing agglomerated and near-size particles' residence time. This air helps to increase collection efficiency of the desirable product.
Frequently Asked Questions
What is the Prater MAC Air Classifier used for? The MAC Air Classifier is designed to separate dry bulk materials by particle size and density using centrifugal force and airflow. It is commonly used to produce narrow particle size distributions for fine powders and industrial bulk solids processing.
What particle size range can the MAC Air Classifier separate? The MAC Air Classifier typically separates particles in the range of approximately 3 to 150 microns, depending on material characteristics and operating parameters.
How does the MAC Air Classifier work? Material enters the classification chamber where airflow and centrifugal force act on each particle. Finer particles are carried through the classifier as product fines, while larger particles are rejected and discharged through a collection chamber.
Can the MAC Air Classifier be integrated into existing processing systems? Yes. The system can operate as a stand-alone classifier or be integrated into closed-circuit grinding systems with milling equipment to continuously remove correctly sized particles while recirculating oversized material.
What materials can be processed in a MAC Air Classifier? The MAC Air Classifier processes a wide range of dry bulk materials including chemicals, minerals, food ingredients, graphite, carbon, calcium compounds, and other powders requiring precise particle separation.
Here is a sample of materials that have been used in our air classifier equipment (keep in mind that there are more dry free-flowing materials that can be easily processed in our air classifier that are not be listed below):
