Working Principle and Common Faults of Cyclone Airlock

# Working Principle and Common Faults of Cyclone Airlock Cyclone airlock (also known as rotary air lock, rotary feeder) is usually matched with cyclone separator. Its functions are **air locking, sealing and uniform discharging**, preventing air leakage under negative pressure and air outflow under positive pressure. ## 1. Working Principle ### 1.1 Cyclone Separator (Upper Part) Dust-laden gas enters the cylinder tangentially at a high speed of 15–25 m/s: - External swirling flow: spirals downward along the cylinder wall; - Centrifugal force throws dust to the wall, and dust falls into the hopper along the wall; - After the air flow reaches the bottom of the cone, it reverses to form an internal upward swirling flow, and clean air is discharged from the central exhaust pipe. ### 1.2 Cyclone Airlock (Air Lock Component under Hopper) Structure: Shell + impeller (blades) + rotating shaft + sealing part + transmission device. Working Process: 1. The impeller rotates to store dust falling from the hopper in separate compartments; 2. When the impeller rotates to the lower position, dust is discharged by gravity; 3. The gap between blades and shell is extremely small (≤ 0.5 mm). Blades always seal the upper and lower cavities to block direct airflow, realizing **discharging without air leakage and air locking without material blockage**. In one sentence: The cyclone separates dust by centrifugal force; the cyclone airlock realizes air locking and discharging through rotating compartment sealing. ## 2. Common Faults, Causes and Solutions ### 2.1 Air Leakage (Most Common, Sharply Reduces Dust Removal Efficiency) **Phenomenon**: Strong air suction, dust emission at discharge outlet; obvious drop of dust removal efficiency. **Causes**: - Impeller wear leading to excessive gap; - Aging of gaskets and flange seals; - Wear or perforation of shell (especially cone and discharge section); - Improper rotating speed causing unstable material seal. **Solutions**: - Repair or replace the impeller if the gap exceeds 0.5 mm; - Replace gaskets and fasten bolts; - Weld and repair worn or perforated parts; - Adjust rotating speed to maintain a thin material layer for air sealing inside the impeller. ### 2.2 Impeller Stuck / Unable to Rotate **Phenomenon**: Motor overload, abnormal noise, tripping; impeller cannot be rotated manually. **Causes**: - Foreign matter (bulky materials, welding slag, iron wire) stuck inside; - Damp and agglomerated materials adhering to blades and shell; - Bearing damage due to lack of lubrication or corrosion; - Deformed impeller or bent rotating shaft. **Solutions**: - Stop equipment to clear foreign matter and sticky materials; - Replace bearings and replenish lubricating grease; - Correct or replace deformed impeller and bent shaft. ### 2.3 No Discharge / Poor Discharge **Phenomenon**: Material accumulation in hopper, low or no discharge. **Causes**: - Excessively high system negative pressure sucking materials; - Serious air leakage caused by large impeller gap, airflow carries away materials; - Excessively high rotating speed throws materials back to the hopper by centrifugal force; - Viscous, damp and fine materials with poor fluidity and bridging phenomenon. **Solutions**: - Adjust fan damper to reduce system negative pressure; - Repair impeller gap and enhance sealing performance; - Reduce rotating speed; - Install vibrator / air cannon on hopper to break material bridging; adopt heat preservation to prevent condensation if necessary. ### 2.4 Vibration, Abnormal Noise and Shaking **Phenomenon**: Severe shaking, loud noise, loose flange and anchor bolts. **Causes**: - Uneven installation and loose anchor bolts; - Unbalanced impeller caused by uneven wear or sticky material eccentricity; - Worn bearings and misaligned coupling; - Resonance with connected pipelines. **Solutions**: - Level the equipment and fasten anchor bolts; - Clean sticky materials and correct impeller dynamic balance; - Replace bearings and align the coupling; - Install flexible connectors and damping supports for pipelines. ### 2.5 Overheated Bearings / Short Service Life **Causes**: - Insufficient or deteriorated lubricating grease; - Dust enters bearings due to poor shaft end sealing; - Excessive axial and radial force, misalignment installation. **Solutions**: - Regularly replenish high-quality lubricating grease; - Optimize shaft end sealing structure to prevent dust ingress; - Correct installation alignment to reduce extra stress on bearings. ## 3. Quick Judgment Tips - **Air leakage**: Strong air at discharge outlet + low efficiency → Check gap, gaskets and wear parts; - **Stuck impeller**: No rotation + abnormal noise + overload → Clear foreign matter, check bearings and sticky materials; - **Poor discharge**: Hopper full + little output → Reduce negative pressure, lower speed, break material bridging; - **Severe vibration**: Shaking + noise + loose bolts → Level installation, fasten bolts, correct impeller balance.