Analysis of Machining Processes for Biomass Boiler Shell Manufacturing

The biomass boiler shell, as a core component bearing high-temperature and high-pressure conditions, directly affects the boilers energy efficiency and safety. The following analyzes key technical points from the perspective of machining processes to help the industry optimize production processes.​

I. Precision Blanking and Forming Process​
High-precision cutting of Q245R boiler steel, 316L stainless steel, and other plates is performed using laser cutting or CNC plasma cutting, controlling dimensional deviations ≤±0.5mm to ensure subsequent splicing accuracy. Circular arc / right-angle bending is completed by CNC bending machines, and stiffeners, observation holes, and other structures are processed with mold stamping to improve shell rigidity and functionality.​

II. Welding Process and Sealing Guarantee​
The shell is spliced using fully automatic argon arc welding or submerged arc welding. For thick plates (≥10mm), multi-layer and multi-pass welding is implemented, preheating to 150-200℃ before welding, and RT X-ray inspection is performed after welding to ensure that the weld has no pores or cracks. The airtightness test pressure is 1.5 times the working pressure to eliminate the risk of flue gas leakage.​

III. Precision Machining and Surface Treatment​
Key parts such as flange sealing surfaces and nozzle bevels are precision machined by CNC lathes / milling machines, with surface roughness controlled below Ra1.6μm to ensure component assembly accuracy. Finally, sandblasting and rust removal + high-temperature resistant coating (such as aluminum-silicon coating) are performed, with temperature resistance up to 600℃ or more, significantly improving the shells corrosion resistance and oxidation resistance.​

IV. Core Points of Quality Control​

• Dimensional Accuracy: Key hole spacing (deviation ≤±0.3mm) and roundness error (≤0.1% D) are detected using a coordinate measuring machine;​

• Mechanical Properties: Tensile / bending tests are performed on samples, and the weld strength must be ≥85% of the base material;​

• Reliability Testing: High-temperature pressure-bearing tests are performed simulating biomass combustion conditions to verify the long-term operational stability of the shell.​

Biomass boiler shell manufacturing needs to take into account high-temperature resistance, corrosion resistance, and structural strength. Through CNC and automated machining processes, production efficiency and product quality can be effectively improved, providing a solid guarantee for the efficient operation of clean energy equipment.