Simulation Study on Coil of Biomass Carbonization Kettle

Area of Science:

• Materials Science
• Mechanical Engineering
• Chemical Engineering

Background:

• Coiling tubes in biomass carbonization kettles are prone to long-term operational damage and failure.
• Understanding the root causes of this failure is crucial for improving equipment longevity and efficiency.

Purpose of the Study:

• To investigate the causes of coiling tube damage in biomass carbonization kettles.
• To develop a numerical model for predicting stress and temperature distribution within the coiling tubes.
• To correlate simulation results with actual observed failure patterns.

Main Methods:

• A three-dimensional model of the carbonization kettle's coiling tube was created.
• Finite element analysis was used to simulate the temperature field under operational conditions.
• Tensile tests were performed on 20G steel specimens under simulated heat treatment conditions.
• A stress field model was developed by integrating material properties into the temperature field model.

Main Results:

• The temperature distribution within the coiling tube was found to be stable between 440-450 °C with a low relative error (0.78%) compared to actual measurements.
• Material properties (yield strength, elastic modulus) were determined for 20G steel under simulated conditions.
• Stress analysis indicated maximum compressive stress of 8.3 MPa at the second and fourth coil bends during initial equipment ventilation.
• These high-stress points correlate with observed partial failure locations in actual equipment.

Conclusions:

• The study successfully modeled the thermal and stress behavior of coiling tubes in biomass carbonization kettles.
• The simulation accurately predicts areas prone to failure, specifically at the bending points of the coil.
• Findings provide valuable insights for optimizing kettle design and material selection to prevent premature coiling tube failure.