Ultrasonic cleaning machine is a key equipment for fine purification of
quartz sand. It uses ultrasonic cavitation effect to remove oil stains and mud
film on the surface of sand particles (with a requirement of impurity residue
rate ≤ 0.3% after cleaning), providing clean raw materials for high-end
application scenarios. If there is incomplete cleaning (residual impurity rate
exceeding 1%) and high sand particle damage rate (exceeding 5%), it will lead to
substandard purity of the finished product and increased loss of high-quality
sand. Based on practical experience, summarize the three-step troubleshooting
method to quickly restore efficient cleaning performance.
Step 1: Calibrate the ultrasound system and transducer - the core power
determines the cleaning effect
Abnormal ultrasound parameters and transducer status are the main reasons for
incomplete cleaning.
Inappropriate ultrasound frequency or power: frequency exceeding 80kHz, weak
cavitation effect, difficult to peel off stubborn mud film; Below 20kHz, the
impact force of cavitation bubbles is too strong, and sand particles are prone
to damage; The power is below 0.3W/cm ², and the cleaning intensity is
insufficient. Adjust the frequency to 40-60kHz (choose high frequency for fine
sand and low frequency for coarse sand), control the power within 0.5-0.8W/cm ²,
and accurately match it through a power regulator; Install frequency automatic
tracking function to avoid frequency drift during operation.
Aging or uneven installation of transducers: After more than one year of use,
the performance of piezoelectric ceramics deteriorates by more than 30%; The
installation spacing exceeds 15cm, and the ultrasonic field distribution is
uneven, resulting in cleaning dead corners. Replace the high-quality
piezoelectric ceramic transducer and install it in a "checkerboard arrangement"
with a spacing of 10-12cm to ensure full coverage of the ultrasonic field; Use
an ultrasonic power meter to ensure that the output power deviation of each
transducer is ≤ 5%.
Step 2: Optimize cleaning parameters and medium ratio - parameter adaptation
to prevent damage
Improper cleaning time, temperature, and medium concentration can exacerbate
cleaning problems.
Cleaning time too long or too short: over 30 minutes, sand particles collide
and damage each other; Less than 10 minutes, impurities have not been completely
removed. Adjust according to the degree of impurity attachment: 12-15 minutes
for mild pollution, 18-22 minutes for severe pollution, precisely controlled by
a timer; Adopting the "intermittent cleaning" mode (ultrasound for 3 minutes+1
minute stop) to reduce sand particle collision wear.
Abnormal cleaning temperature or medium concentration: When the temperature
is below 40 ℃, the ultrasonic cavitation efficiency decreases; Over 60 ℃, sand
particles are prone to cracking due to thermal expansion and contraction; The
concentration of the cleaning agent is less than 1%, indicating insufficient
cleaning ability; Exceeding 3%, residual chemicals are difficult to rinse.
Control the temperature at 45-55 ℃, use neutral quartz sand specific cleaning
agent, and adjust the concentration to 1.5-2%; After cleaning, rinse with pure
water for 3 times, each time for 2 minutes, to ensure that the residual drug is
≤ 0.05%.
Step 3: Adapt material status and cleaning fixtures - source protection to
reduce losses
Improper material pretreatment and tooling design can increase the risk of
damage and residue.
High moisture content or clumping of sand particles: If the moisture content
exceeds 10%, the sand particles will bond into clumps, and internal impurities
cannot be cleaned; The particle size of the agglomerates exceeds 20mm, making it
difficult for ultrasound to penetrate. Before cleaning, add a pre dispersion
process to reduce the moisture content to below 5%, and use a vibrating screen
to break up clumps; Install a stirring device (speed 30-50r/min) in the cleaning
tank to ensure even suspension of sand particles and avoid local
accumulation.
Improper material or loading capacity of the tooling: using metal tooling
doubles the rate of sand particle collision damage; The loading capacity exceeds
60% of the cleaning tank capacity, resulting in insufficient space for sand
particle movement and uneven cleaning. Replace the polyurethane soft tooling and
install partition grids (with a capacity of ≤ 5L per grid) to reduce friction
between sand particles; Control the loading capacity at 40-50% to ensure that
the sand particles fully contact the ultrasonic field and cleaning medium.
Daily maintenance should pay attention to: check the ultrasound power and
cleaning solution turbidity every day, and replace contaminated cleaning
solution in a timely manner; Calibrate the frequency and cleaning temperature of
the transducer weekly, and clean the sediment impurities at the bottom of the
tank; Monthly testing of the insulation performance of the transducer and
replacement of aging sealing rings. By implementing the above measures, the
residual impurity rate can be reduced to below 0.2%, and the sand damage rate
can be controlled within 2%, ensuring the high-end application needs of quartz
sand. If there are still problems, it is recommended to contact the manufacturer
to optimize the ultrasonic field distribution and match the cleaning parameters
for specific particle sizes of sand particles.