Working Principle of Temperature and Pressure Monitoring Equipment for the Pyrolysis Section of an Oil Sludge Pyrolysis Refinery

Working Principle of Temperature and Pressure Monitoring Equipment for the Pyrolysis Section of an Oil Sludge Pyrolysis Refinery (Simplified Version)

The temperature and pressure monitoring equipment forms a closed-loop system of collection-transmission-processing-alarm-interlocking, adapted to the high-temperature, oil-gas and high-dust working conditions of the pyrolysis furnace. The core working principles of each device are as follows:

I. Temperature Monitoring Equipment

High-temperature resistant thermocouple: Based on the Seebeck effect, two different metals form a closed loop. The temperature difference between the furnace temperature measurement end and the constant temperature reference end generates a thermoelectric potential, which increases with the temperature difference. The potential is converted to output real-time temperature values for contact temperature measurement.

Infrared temperature sensor: Utilizing the infrared thermal radiation effect, it receives infrared rays radiated by objects in the furnace and calculates the temperature based on the fixed relationship between radiation energy and temperature. This non-contact method makes up for the blind spots of thermocouple temperature measurement.

Temperature transmitter: Amplifies and filters the weak analog signals from thermocouples/sensors, converts them into 4-20mA/RS485 standard signals, and transmits them to the central control system with anti-interference performance to ensure accurate and stable data transmission.

II. Pressure Monitoring Equipment

Pressure transmitter: Relying on the piezoresistive effect, the furnace pressure acts on the semiconductor chip to change its resistivity and resistance, which is converted into a voltage signal. The signal is then amplified and calibrated to output a standard signal for monitoring the slight positive/negative pressure inside the furnace.

Differential pressure transmitter: Detects the pressure difference at the furnace inlet/outlet, flue and other parts, judges material blockage and flue dust accumulation through pressure difference changes, and indirectly warns of abnormal furnace pressure.

Vacuum/shock-resistant pressure gauge: The internal elastic element deforms under pressure to drive the pointer to deflect and display the real-time on-site pressure, serving as a backup for remote monitoring. The shock-resistant type is adapted to furnace vibration conditions.

III. Supporting Equipment for Data Integration and Alarm

PLC/DCS central control system: Receives all standard temperature and pressure signals, displays real-time data and dynamic curves, and triggers an audible and visual alarm immediately when parameters exceed the preset safety threshold.

Temperature and pressure interlock alarm device: Interlocks with the central control system; while issuing an alarm, it triggers interlocking actions of the feeding, heating and pressure relief systems, automatically cutting off feeding, stopping heating and opening pressure relief devices for rapid disposal of abnormalities.

Data recorder: Automatically stores historical temperature and pressure data, supports abnormal marking and trend analysis, and is used for accident traceability, process optimization and safe production archiving.