Air Jet Sieving Machine

What is the Air Jet Sieving Machine?

A single-sieve analyzer where a rotating slit nozzle beneath the sieve pulls fine powder through the mesh by airflow and a vacuum. It is designed for cohesive, fine powders from roughly 20 to 500 µm that blind ordinary shakers, and is widely used for cement, toners and pharmaceutical granules.

Overview

The air jet machine clamps one sieve at a time under a transparent lid. A vacuum cleaner creates underpressure of about 4 to 4.5 kPa while a nozzle rotates below the mesh at about 20 to 30 rpm, blowing air through a slot that sweeps the sieve surface. The air jet lifts and disperses the powder, and air flows through the apertures, carrying fine particles into a cyclone or filter. Sequential sieving with each mesh yields a size distribution with good reproducibility and is faster for fine material than shaker methods. Sample load is typically 10 to 100 g per sieve. Test time is often 2 to 5 minutes per sieve and is determined by constant-mass checks. Surface static and humidity can affect results, so antistatic conditions and dry powders are recommended.

How does it work?

A sieve analyzer agitates a stack of test sieves, arranged with the coarsest aperture on top, so that particles either pass through an aperture or are retained on it. The agitation may be vertical throw from an electromagnetic drive, horizontal circular motion combined with tapping, air jets that clear the mesh from below, or ultrasonic vibration for fine sieves. Particles pass when their smallest projected dimension is smaller than the aperture and their orientation allows. After a set time, each sieve and the receiver pan are weighed, and mass percentages are calculated as individual and cumulative retained or passing fractions. Sieve sizes and tolerances are defined in ISO 3310 and ASTM E11, and procedures in ISO 2591-1. Amplitude, time, sample mass and sieve condition govern repeatability and end-point.

What are the key features?

• Rotating slit nozzle cleans the mesh throughout the test
• Adjustable vacuum monitored by digital or analog gauge
• Single-sieve operation for 200 mm sieves with transparent lid
• Cyclone or filter to recover passing fine fraction
• Programmable test time with automatic shut-off
• Suitable for sieves from 20 µm to 500 µm

What are the technical specifications?

A typical air jet sieving machine configuration offers sieve diameter of 200 mm, aperture range of 20–500 µm, vacuum of 2–6 kPa adjustable, nozzle speed of ≈ 20–30 rpm, sample load of 10–100 g per sieve and timer of 0–99 min. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Air Jet Sieving Machine is used in cement and lime fineness, pharmaceutical granules and powders, toner, pigment and ceramic powders, metal powder fine fractions and food powders such as sugar and starch. Across the wider Sieve Analyzers class, laboratories also deploy it for aggregate and sand grading in construction, soil and sediment particle size and mining and mineral processing.

Which standards and certifications apply?

Relevant standards and methods include ISO 3310-1, ISO 3310-2, ASTM E11, ISO 2591-1, ASTM C136, ASTM D422, ASTM B214 and GB/T 6003.1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Do not overload sieves; typical loads are a single layer of particles or 100 to 200 g on a 200 mm sieve, depending on aperture. Determine the test duration by checking that less than 0.1 percent of the sample mass passes per minute. Inspect sieves for damage, clean them with brushes or ultrasonic baths, and never use sharp tools on fine meshes. Periodically check sieve aperture conformity with certified reference materials or calibration sieves and optical measurement according to ISO 3310. Place the machine on a level, rigid bench, and use dust extraction for fine powders. Record humidity, since moisture causes agglomeration. Keep a maintenance schedule for drives and clamps.

How do I select the right Air Jet Sieving Machine?

Choose the air jet machine for fine, cohesive, hygroscopic or electrostatic powders under about 500 µm where shakers blind the mesh. Specify sieve apertures, sample quantity, vacuum source, cyclone or filter needs, and standard such as ISO 8130-1 or ASTM B214. It is slower for full distributions because sieves are run individually.

How does it compare with other Sieve Analyzers variants?

Select the mechanism from the material. Free-flowing granules and aggregates above about 100 µm suit electromagnetic or tapping shakers. Fine, cohesive powders between roughly 20 and 150 µm need air jet or ultrasonic assistance to prevent blinding. Materials that agglomerate or contain soluble fines need wet sieving. Consider the sieve diameter (200, 300 or 400 mm), maximum stack height, load capacity and programmable amplitude and time. Verify compatibility with the standard you follow, such as ASTM C136 for aggregates, ASTM D422 or ISO 17892-4 for soils, or ISO 2591-1. Noise, dust enclosure, digital amplitude control and whether results are recorded electronically also matter. Compare with laser diffraction or image analysis only after noting that sieve and optical sizes differ.