The online particle size analyzer is the core equipment for real-time quality
monitoring of quartz sand production lines, responsible for dynamically
detecting the particle size distribution of sand particles (with a required
detection error of ≤± 2%), and providing data support for adjusting the crushing
and sand making processes. If there is a large detection error (exceeding ± 5%)
and fast data drift (deviation exceeding 3% within 1 hour), it will lead to
production parameter adjustment errors and fluctuations in finished product
quality. Based on practical experience, summarize the three-step troubleshooting
method to quickly restore accurate detection.
Step 1: Calibrate the detection system and optical components - the core
components determine the data accuracy
Optical component contamination and improper parameter settings are the main
causes of large errors.
Abnormal laser transmitter or receiver: laser power attenuation (below 70% of
rated value), weak signal for fine particle detection; The receiver lens is
coated with fine quartz sand powder (thickness exceeding 0.1mm), causing
distortion in light refraction. Use a laser power meter to detect and replace
the attenuation transmitter; Wipe the lens with anhydrous ethanol and install a
dust protection cover (with air blowing function, air pressure 0.3MPa) to avoid
dust pollution.
Poor adaptability of detection parameters: the diameter and detection
distance of the light spot do not match the quartz sand particle size (such as
detecting 0.1-5mm sand particles, with a light spot diameter of only 2mm), and
large particles obstruct the light; The sampling frequency is too low (<10
times/second), resulting in insufficient data representativeness. Adjust the
spot diameter to 5-8mm and the detection distance to 80-100mm, matching the
mainstream quartz sand particle size range; Increase the sampling frequency to
15-20 times per second, take the average output, and reduce the impact of
instantaneous fluctuations.
Step 2: Optimize the sample pretreatment and circulation system - sample
representativeness anti drift
Abnormal sample preparation and transportation can lead to data drift and
errors.
Insufficient sample concentration or uniformity: concentration below 5%,
insufficient particles in the detection area, and scattered data; Concentration
exceeding 15%, particles obstructing each other, misjudging particle size; The
sample was not sufficiently dispersed, and fine particles agglomerated (particle
size exceeding twice the actual size). Adjust the sample concentration to 8%
-12% through a variable frequency pump, and install an ultrasonic disperser
(power 500W, frequency 20kHz) in the sampling tube to remove agglomerated
particles; Install a stirring device (with a speed of 300r/min) to ensure even
distribution of samples in the detection tank.
Flow pool blockage or pipeline sedimentation: fine powder (thickness
exceeding 0.5mm) adheres to the inner wall of the flow pool, changing the
detection light path; The horizontal section of the pipeline is too long
(>1m), causing particle settling and resulting in sample stratification.
Rinse the circulation pool weekly with a high-pressure water gun (0.4MPa) and
soak it in a specialized cleaning agent to remove stubborn adhesives; Tilt the
pipeline at 10 ° for installation, shorten the horizontal section to within
0.5m, and install a vibrator (frequency 15Hz) to prevent particle settling.
Step 3: Improve the calibration mechanism and adapt to the environment -
reduce deviations from external factors
Lack of calibration and environmental interference can exacerbate detection
issues.
Long calibration cycle or improper reference materials: Failure to calibrate
for more than 3 months, accumulation of instrument system errors; The selected
standard particle size has a large deviation from the actual detection range
(such as using coarse sand standard material for detecting fine sand), and the
calibration is invalid. Calibrate once a month with quartz sand standard samples
(particle size 0.1-5mm, deviation ≤± 0.1mm), and correct the detection curve
through software; Perform specialized calibration immediately after each change
in material particle size range.
Environmental temperature and humidity or electromagnetic interference:
temperature fluctuations exceeding ± 5 ℃ (standard working temperature 20-25 ℃),
thermal expansion and contraction of optical components affecting accuracy;
Nearby high-power devices (such as frequency converters and motors) generate
electromagnetic interference, resulting in abnormal data transmission. Install
air conditioning and dehumidifier to control the ambient temperature at 22 ± 2 ℃
and humidity at 50% -60%; Install a shielding layer on the instrument signal
line and keep it away from electromagnetic interference sources (distance ≥ 3m)
to ensure stable data transmission.
Daily maintenance should pay attention to: checking the laser power, cleaning
the lens and circulation pool every day; Weekly calibration of sampling
frequency and sample concentration; Monthly monitoring of the operation status
of dispersers and mixing devices, and verification of the accuracy of standard
samples. By implementing the above measures, the detection error can be reduced
to within ± 1.5%, and the data drift can be controlled within ≤ 1% per hour,
providing reliable data support for precise control of the quartz sand
production line. If there are still problems, it is recommended to contact the
manufacturer to test the stability of the optical system and optimize the
detection algorithm for specific particle size ranges.