What are the common faults of dust removal and cleaning machines

Dust removal and cleaning machines are key equipment used in fields such as agriculture, grain processing, and feed production to remove impurities (such as dust, straw, stones, metals, etc.) from materials and to grade and screen them. Its common faults can be classified into four major categories: mechanical faults, electrical faults, airway faults and improper operation and maintenance. The following is a detailed analysis:

I. Mechanical failure

The screen is clogged or damaged

Reason

Excessive moisture of materials: Damp materials (such as freshly harvested grains) tend to adhere to the screen, causing blockages.

Improper screen hole size: The screen mesh holes are too small, preventing large particle impurities from passing through. Or the pore size is too large, allowing fine impurities to leak through.

Improper installation of the screen: The screen is not tensioned or fixed firmly, becomes loose and deformed during operation, and is damaged by friction with the frame.

Excessive impurity content in the material: Too many impurities exceed the processing capacity of the screen, accelerating wear.

Symptoms: Decreased screening efficiency, increased impurities at the discharge port, and local damage to the screen mesh causing material leakage.

Solution

Pre-treat the materials (such as drying or sun-drying) to reduce humidity.

Select a screen with an appropriate aperture based on the material characteristics (for example, a 1.5-3mm round hole screen is used for grain cleaning).

Retighten the screen and secure it firmly. Regularly inspect and replace the worn screen.

Add a pre-cleaning process (such as air separation or magnetic separation) to reduce the impurities entering the screen.

Fan failure

Reason

Impeller wear: Long-term inhalation of dust or hard impurities can cause the impeller to become unbalanced or perforated.

Bearing damage: Insufficient lubrication or dust intrusion can cause the bearing to get stuck or overheat.

Belt looseness: The drive belt of the fan ages or has insufficient tension, resulting in a decrease in rotational speed.

Air duct blockage: Dust or foreign objects accumulate and block the air duct, reducing the air volume.

Symptoms: Weakened wind force, poor dust removal effect, abnormal noise or intensified vibration of the fan.

Solution

Regularly clean the dust accumulated on the impeller and replace the worn impeller.

Regularly lubricate the bearings (such as adding lithium-based grease every three months) and install dust covers.

Adjust the tension of the belt and replace the aged belt.

Clear the debris in the air duct to keep it unobstructed.

Failure of transmission components

Reason

Chain/belt breakage: Excessive tension, sudden load changes or aging can cause breakage.

Gear wear: Poor lubrication or impurity intrusion leads to pitting or tooth breakage on the tooth surface.

Coupling damage: Poor alignment or overload causes the elastic element of the coupling to break.

Symptoms: Equipment shutdown, abnormal noise from transmission, and excessive vibration.

Solution

Adjust the tension of the chain/belt to the specified range (such as 1%-2% chain sag).

Change the lubricating oil regularly and clean the impurities in the gearbox.

Recalibrate the coupling alignment and replace the damaged elastic element.

Ii. Electrical Faults

The motor overheats or burns out

Reason

Overload operation: The screen is clogged or the air volume of the fan is insufficient, causing the motor load to increase.

Unstable voltage: The grid voltage fluctuates by more than ±10%, causing excessive motor current.

Poor heat dissipation: The motor cooling fan is damaged or the ambient temperature is too high.

Insulation aging: Long-term operation of the motor leads to a decline in the insulation performance of the windings.

Symptoms: The motor housing is hot to the touch, smoking, has an unpleasant smell, and even trips and stops.

Solution

Clean the screen and air ducts to ensure the normal operation load of the equipment.

Install a voltage stabilizer or voltage compensation device.

Repair the cooling fan and improve the ventilation conditions.

Regularly test the insulation resistance of the motor (it should be ≥0.5MΩ), and rewind the windings if necessary.

Control circuit fault

Reason

Sensor failure: Faults in wind pressure sensors, material level sensors, etc. lead to control failure.

Contactor/relay adhesion: Contact erosion or arc causes inability to break normally.

Circuit aging: Vibration causes the terminal blocks to loosen or the insulation to break, resulting in a short circuit.

Symptoms: The equipment cannot be started, the automatic control fails, and the circuit breaker trips frequently.

Solution

Calibrate the sensors regularly and replace the failed components.

Clean the contactor contacts and replace the adhered relay.

Tighten the terminal blocks and wrap the insulation layer of the damaged circuit.

Inverter failure

Reason

Incorrect parameter Settings: too short acceleration/deceleration time, improper overload protection threshold.

Poor heat dissipation: Dust accumulation inside the frequency converter or fan failure causes overheating.

Harmonic interference: Grid harmonics can cause false alarms or damage to frequency converters.

Manifestations: The frequency converter reports fault codes (such as OC overcurrent, OH overheating), and the output voltage is unstable.

Solution

Reset the inverter parameters (such as acceleration time of 5 to 10 seconds) according to the motor parameters.

Clean the heat sink of the frequency converter and replace the faulty fan.

Install reactors or filters to suppress harmonics.

Iii. Airway Failure (for Pneumatic Cleaning Models)

Insufficient air volume

Reason

The fan speed has decreased: due to loose belt, motor failure or insufficient voltage.

Air duct leakage: Poor sealing or damage at the connection points of the pipes.

Dust collector blockage: Excessive dust accumulation in the bag filter leads to increased resistance.

Symptoms: Insufficient suspension of materials and poor separation effect of light impurities.

Solution

Inspect the fan drive system and restore the rated speed.

Seal the air duct interfaces and repair damaged pipes.

Regularly clean or replace the filter bags of the dust collector (such as vibrating the dust collector every shift).

Unstable air pressure

Reason

Air compressor failure: Insufficient air supply due to damaged air valves and worn piston rings.

Gas storage tank leakage: The safety valve and drain valve are not closed tightly or the tank body is corroded and leaks gas.

Pneumatic component failures: Solenoid valve jamming, cylinder sealing ring aging.

Symptoms: The pneumatic valve operates slowly and the screen vibrates abnormally.

Solution

Repair or replace the air valves and piston rings of the air compressor.

Check the sealing of the gas storage tank and repair any leaks.

Clean the solenoid valve and replace the cylinder sealing ring.

Four. Faults caused by improper operation and maintenance

The operation parameters were set incorrectly

Reason

Improper air volume/air pressure: Excessive air volume causes the material to be blown away, while insufficient air volume makes it impossible to separate impurities.

Incorrect vibration frequency of the screen: A frequency that is too high accelerates the wear of the screen, while a frequency that is too low reduces the screening efficiency.

Manifestations: The quality of the output material does not meet the standards, and the energy consumption of the equipment increases.

Solution

Adjust the air volume according to the characteristics of the materials (for example, the air velocity for wheat cleaning is 3-5m/s).

The vibration frequency of the screen (usually 50-100Hz) is adjusted through a frequency converter or an eccentric block.

Insufficient maintenance

Reason

Failure to clean regularly: Dust accumulation leads to poor heat dissipation of the equipment and accelerated wear of components.

Lack of lubrication: Lubricating oil is not added to bearings, chains and other parts on time.

Vulnerable parts have not been replaced: Screens, belts, filter bags, etc. have been used beyond their service life.

Manifestations: Increased failure rate and shortened service life.

Solution

Formulate a maintenance plan (such as daily cleaning, weekly lubrication, and monthly replacement of vulnerable parts).

Establish equipment files to record maintenance history and replacement cycles.

The feeding of materials is uneven

Reason

Feeder malfunction: Unstable speed of the screw conveyor or blockage of the hopper.

Poor material fluidity: Excessive moisture content or caking leads to poor discharging.

Symptoms: Uneven load on the screen mesh and accelerated local wear.

Solution

Inspect and repair the transmission system of the feeder to ensure uniform feeding.

Pre-treat materials (such as crushing lumps and reducing humidity).

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