Preventive measures for spring fracture of quartz sand vibrating screen
(professional solution)
1. Precise selection and matching
1. Precise stiffness calculation
Based on the model of the vibrating screen, processing capacity (quartz sand
density is approximately 1.6 t/m³), and excitation force, accurately calculate
the required spring stiffness. Avoid excessive amplitude due to insufficient
stiffness or resonance caused by excessive stiffness.
2. Material upgrade
High-strength alloy spring steel such as 60Si2MnA is selected, and the
surface undergoes shot peening to enhance fatigue life. In humid environments,
stainless steel is preferred for corrosion resistance.
3. Structural optimization
Large-tonnage screening machines (>10t) utilize composite springs (steel
springs + rubber) to buffer impact forces and reduce the risk of metal
fatigue.
II. Scientific installation and debugging
1. Basic level calibration
Before installation, use a level gauge to check the flatness of the
foundation, ensuring an error of ≤2mm/m². Uneven contact surfaces of spring
supports can lead to localized stress concentration.
2. Pre-compression control
When installing the spring, apply a preload of 10%-15% of the rated load
(refer to the equipment manual) to avoid amplitude loss of control during
no-load operation.
3. Group stiffness matching
The stiffness deviation of all springs in the same screening machine should
be ≤5%. When replacing, the entire set must be replaced, and it is prohibited to
mix products from different batches.
III. Key points of operation and maintenance
1. Load monitoring
The fluctuation of quartz sand feeding quantity should be controlled within
±15% of the rated value, as overload operation will cause a sudden increase in
spring stress. It is recommended to install a weighing sensor-linked feeder.
2. Temperature management
When the continuous operating ambient temperature exceeds 60℃, the
load-bearing capacity of the spring decreases by more than 20%. In
high-temperature conditions, it is necessary to add a heat dissipation device or
choose a heat-resistant spring.
3. Dust-proof seal
Intrusion of quartz sand dust into the coil spring gaps can accelerate wear.
Consider installing a silicone dust cover or using compressed air to clean the
spring gaps weekly.
4. Regular testing
Inspect each shift for cracks in the spring (with a focus on the 1.5 coils at
the end), and measure the change in free height monthly. If the height decreases
by 3%, replacement is required.
IV. Response to special working conditions
1. High-frequency vibrating screen (>1500rpm)
Use a small pitch spring with a wire diameter of ≥14mm to avoid harmonic
resonance caused by high-frequency vibration.
2. Corrosive environment
If the quartz sand contains salt or acidic substances, it is necessary to use
SUS316 stainless steel springs with a Teflon coating.
3. Low temperature in winter (<-10℃)
As the brittleness of the spring increases, it is necessary to preheat the
equipment to room temperature before feeding. It is preferable to use 50CrVA
material, which has better low-temperature toughness.
V. Demonstration of Improvement for Failure Cases
The issue of 6 sets of springs being damaged monthly in a quartz sand
factory
Original configuration: Ordinary carbon steel spring (stiffness 160N/mm)
Improvement plan:
"- Replace with shot-peened 60Si2MnA spring (stiffness 185N/mm)"
"- Add a spring dust cover"
"- Install a fluctuation suppressor on the feeding system"
Result: The lifespan of the spring has been extended from 15 days to 8
months
Implementation suggestions:
Establish the "Vibration Screen Spring Inspection Checklist" to record the
compression amount, surface condition, and environmental parameters for each
inspection. Collaborate with suppliers to conduct spring fatigue life testing
(recommended to be ≥5 million cycles) to ensure it matches the actual working
conditions. Through systematic management, the spring failure rate can be
reduced by over 70%, significantly enhancing the continuous operation capability
of the quartz sand production line.