Safety and Operation Precautions for Thermal Oil Boilers

I. Startup and Operation Precautions

1. Venting and Preheating:
   • During startup, thoroughly vent air, steam, and light components to ensure no impurities remain within the system.
   • Preheat the heating surface tubes and system piping to avoid localized overheating.
2. Valve Status:
   • Ensure auxiliary vent valves are closed during startup and operation to prevent severe consequences such as boiler failure or fire.
3. Temperature Control:
   • Strictly control the heating rate, typically below 40–50°C/h, to avoid overheating due to high thermal oil temperatures, reduced viscosity, and accelerated flow rates.

II. Safety Operation Precautions

1. Temperature and Pressure:
   • Strictly control the thermal oil's temperature and pressure within safe limits to prevent overheating and overpressure hazards.
   • Maintain circulation of the heat transfer fluid by not stopping the circulating pump during heating operations.
2. Emergency Shutdown:
   • In case of an emergency requiring an immediate shutdown, do not flood the furnace with water to prevent explosion.
3. Thermal Oil Selection:
   • Use suitable thermal oil and avoid using unqualified or mixed thermal oils to ensure quality and purity.
4. Safety Devices:
   • Ensure that safety devices for the thermal oil boiler and heating system are complete and functioning, such as over-temperature and over-pressure protection devices.
   • Regularly check and calibrate temperature, pressure, flow, and level gauges for accuracy.
5. Blowdown and Cleaning:
   • Regularly open the blowdown valve at the bottom of the expansion tank to drain condensate and other impurities.
   • Install filters at the inlet of the circulating pump and regularly clean them to remove debris and impurities.

III. Maintenance and Servicing Precautions

1. Regular Inspections:
   • Regularly inspect the boiler body, accessories, and piping systems for leaks, corrosion, or clogging.
   • Tighten connecting bolts regularly to maintain equipment integrity.
2. Cleaning and Blowdown:
   • Regularly clean the boiler interior to remove accumulated oil residue and deposits, ensuring thermal oil fluidity.
   • During cleaning, protect the boiler's heated surfaces from damage.
3. Combustion Adjustment:
   • Adjust combustion parameters based on fuel type and load changes to ensure stable and efficient combustion.
4. Lubrication and Tightening:
   • Regularly lubricate rotating parts to prevent wear.

IV. Other Precautions

1. Shutdown Procedures:
   • Gradually reduce temperature during shutdown. Stop the circulating pump only when the thermal oil temperature falls below 70°C.
   • Continue running the thermal oil circulating pump for some time after system shutdown to cool the heat carrier before draining the thermal oil back into the storage tank.
2. Professional Training:
   • Operators should receive professional training on the working principles, operation procedures, and safety knowledge of thermal oil boilers.
3. Safety Management System:
   • Establish and improve a safety management system for thermal oil boilers, clarifying responsibilities, workflows, and operating procedures to ensure safe operation.

Maintenance and Servicing Considerations for Thermal Oil Boilers:

1. Regular Inspections:
   • Conduct regular inspections of the boiler body, piping systems, valves, flanges, and connecting parts to ensure no leaks, corrosion, or cracks.
   • Check the integrity of the insulation layer to prevent heat loss and identify any damage or deterioration for prompt repair.
2. Cleaning and Descaling:
   • Regularly clean the boiler interior and piping systems to remove carbon deposits, oil sludge, and other impurities that can cause blockage and reduce heat transfer efficiency.
   • Use specialized cleaning agents and methods to avoid damaging the boiler.
3. Thermal Oil Management:
   • Monitor the quality and performance indicators of the thermal oil, such as viscosity, flashpoint, and acid number, to ensure they remain within acceptable ranges.
   • Timely replenish or replace the thermal oil, avoiding mixing different brands or types.
   • Perform regular dehydration treatments to remove moisture and volatile components from the thermal oil.
4. Burner Maintenance:
   • Regularly inspect the burner's nozzles, ignition electrodes, flame detectors, and other components to ensure they are clean, unblocked, and functioning correctly.
   • Adjust burner combustion parameters to suit varying fuel types and load demands.
5. Safety Accessory Checks:
   • Verify the accuracy and reliability of safety accessories like pressure gauges, thermometers, and safety valves through regular inspections and calibrations as required.
   • Ensure alarm systems and interlock protection mechanisms are functional to promptly alert and shut down fuel supply in emergencies.
6. Electrical System Maintenance:
   • Inspect electrical wiring, switches, motors, and other components for insulation integrity, signs of aging, or damage.
   • Clean electrical components to prevent dust accumulation and moisture ingress that could lead to short circuits or malfunctions.
7. Lubrication and Tightening:
   • Regularly lubricate rotating components to reduce wear and friction.
   • Tighten bolts and fasteners to prevent leaks and ensure structural integrity.
8. Shutdown Maintenance:
   • Implement proper preservation measures during extended shutdowns or seasonal breaks, such as draining the thermal oil, cleaning the boiler interior, and applying rust-preventive coatings.
   • Periodically check the boiler's condition during shutdowns to identify any abnormalities.
9. Training and Documentation:
   • Provide professional training to operators to enhance their skills and safety awareness.
   • Maintain a comprehensive maintenance and servicing record system, documenting the timing, content, identified issues, and resolution measures for each maintenance session to facilitate follow-up and analysis.