أخبار الشركة عن Kegu Engineering Notes #12

In many high-temperature kiln systems, operators naturally assume that:

The highest risk occurs during full-load production.

After all, during operation:

• Temperature is highest
• Mechanical load is continuous
• Materials are under constant stress

However, field observations in Pressureless Sintered Silicon Carbide Roller systems often show the opposite:

Many failures actually occur during shutdown and cooling.

During stable operation:

• Temperature distribution becomes relatively uniform
• Thermal expansion reaches equilibrium
• Structural stress can partially stabilize

But during shutdown:

• Outer surfaces cool first
• Internal regions remain hot
• Thermal gradients rapidly reverse

This creates:

• Tensile stress at the surface
• Differential contraction
• Severe local stress concentration

Related reading:

• Why Thermal Shock Is Often Misdiagnosed
• Understanding Thermal Stress in Spring-Supported SiC Rollers

In brittle ceramic systems, tensile stress is far more dangerous than compressive stress.

During cooling:

• Supports begin constraining contraction
• Contact stress increases
• Existing microcracks propagate rapidly

Typical failure locations:

• Roller ends
• Contact zones
• Support interfaces

This is why many Pressureless Sintered Silicon Carbide Roller failures appear:

• After production stops
• During overnight cooling
• Or during emergency shutdown

Most failures are NOT caused by:

• Insufficient bending strength
• Material defects
• Poor straightness

Instead, they are caused by:

System-level thermal stress evolution.

Critical factors include:

• Cooling rate
• Support rigidity
• Contact stress
• Thermal expansion mismatch

Related articles:

• Why Straightness Does Not Guarantee Reliability

Compared with rigid wheel support systems:

Spring-supported structures can:

• Absorb thermal displacement
• Reduce contact stress peaks
• Improve thermal expansion compensation

This helps reduce:

• Edge cracking
• Spiral wear
• Sudden brittle fracture

Recommended reading:

• Wheel Support vs Spring Support: Which One Actually Extends Roller Life?
• Why Spring Support Reduces Thermal Stress in SiC Rollers

To reduce shutdown-related failure:

✔ Control cooling rate
✔ Avoid sudden temperature drops
✔ Reduce support constraint
✔ Inspect contact zones regularly
✔ Improve stress distribution in kiln design

Recommended products:

• Pressureless Sintered Silicon Carbide Roller
• SSiC Beam

In high-temperature kiln systems:

Cooling can be more dangerous than operation itself.

For brittle ceramic materials like SSiC:

The real failure trigger is often:

• Thermal gradient reversal
• Constraint-induced tensile stress
• Progressive crack propagation during shutdown

Understanding this mechanism is critical for improving:

• Roller service life
• Kiln stability
• Production reliability

As lithium battery cathode material production continues moving toward:

• Higher throughput
• Longer kiln operation cycles
• Larger roller spans

More kiln manufacturers are reevaluating traditional rigid support structures.

According to discussions at recent industry exhibitions in Shenzhen, several equipment manufacturers are now prioritizing:

• Spring-supported roller systems
• Thermal stress management
• Roller lifetime optimization

The reason is increasingly clear:

Roller reliability is becoming a process stability issue — not simply a material issue.

In high-throughput LFP and NCM production lines:

Even minor roller deformation or cracking can lead to:

• Temperature inconsistency
• Powder transport instability
• Increased defect rate

This trend is driving growing demand for:

• High-density Pressureless Sintered Silicon Carbide Roller systems
• Thermal-stress-optimized support structures
• Long-life kiln components for continuous production environments

A European kiln equipment manufacturer experienced repeated roller-end cracking in a continuous high-temperature sintering line.

• Frequent roller replacement
• Edge chipping near support zones
• Sudden fractures during shutdown cycles

Initial diagnosis focused on:

• Material strength
• Roller straightness

However, system analysis later showed the real issue was:

Excessive contact stress caused by rigid wheel support structures.

The customer upgraded to:

• Spring-supported roller structures
• Optimized preload distribution
• High-density Pressureless Sintered Silicon Carbide Roller components

After optimization:

• Roller failure rate reduced by 70%
• Shutdown-related cracking decreased significantly
• Roller lifetime increased from 4 months to over 12 months

The project confirmed an important principle:

In high-temperature kiln systems, support structure design often matters more than material strength alone.