Designing a fired heater in accordance with API (American Petroleum Institute) standards involves several steps and considerations. While this article provides a general overview, it's important to note that designing a fired heater is a complex process that requires specialized knowledge and expertise.
It's always recommended to consult relevant codes, standards, and experienced professionals for a comprehensive design.
1. Determine Design Basis:
- Understand the process requirements, including the type of fluid being heated, desired outlet temperature, and flow rates.
- Identify the fuel type and its properties (e.g., natural gas, fuel oil, etc.).
- Determine the required heat duty and efficiency of the fired heater.
2. Select Appropriate API Standards:
- Identify the relevant API standards that apply to your specific fired heater design. Some important API standards for fired heaters include:
- API Std 560: Standard for Fired Heaters for General Refinery Service
- API Std 530: Calculation of Heater Tube Thickness in Petroleum Refineries
- API Std 573: Inspection of Fired Boilers and Heaters
- API Std 537: Flare Details for General Refinery and Petrochemical Service
3. Heater Configuration and Sizing:
- Select the appropriate fired heater configuration based on the process requirements and API guidelines (e.g., box-type, cylindrical, etc.).
- Determine the heater size, including the number and arrangement of tubes, and consider factors such as tube spacing, layout, and accessibility for maintenance.
4. Combustion System Design:
- Design the combustion system, including burners, fuel supply, and combustion air supply.
- Follow API guidelines for burner selection, flame shape, stability, and emissions control.
- Consider safety aspects, such as flame detection, ignition systems, and control measures.
5. Heat Transfer Surface Design:
- Determine the type of heat transfer surfaces (tubes, coils, etc.) based on the process requirements.
- Perform thermal design calculations to ensure proper heat transfer and consider fouling, corrosion, and erosion factors.
- Determine tube sizes, materials, and wall thickness based on API Std 530 and other applicable standards.
6. Mechanical Design:
- Design the fired heater structure, including the support system, refractory lining, expansion joints, and ducting.
- Consider factors such as thermal expansion, wind loads, seismic loads, and other environmental conditions.
- Ensure compliance with relevant API standards and applicable mechanical codes.
7. Instrumentation and Controls:
- Specify instrumentation and control systems for safe and efficient operation.
- Include temperature, pressure, and flow measurement devices, safety interlocks, and automatic control systems.
- Follow API guidelines for instrument locations, safety shutdown systems, and emergency response.
8. Documentation and Compliance:
- Prepare detailed engineering drawings, specifications, and documentation.
- Ensure compliance with API standards, local regulations, and industry best practices.
- Conduct inspections, testing, and certification as per API Std 573 and other applicable standards.
Remember, the information provided here is a general overview, and designing a fired heater requires specialized engineering knowledge and adherence to specific API standards. Always consult relevant codes, standards, and experienced professionals for a comprehensive and compliant design.
