Application: Used in cement, chemical, and metallurgical industries—supporting coal mills, raw material mills (cement), cement mills, dryers, etc.;

Working Principle: YR Series Fuel Oil Hot Air Furnace (Patent No. 200420016992.9) consists of a fuel supply device, air supply device, combustion device, combustion chamber, and thermal control system. The combustion chamber wall of the all-steel hot air furnace is composed of multiple steel umbrella-shaped rings with different angles nested together, with a certain gap between each ring. The outer wall of the hot air furnace is a steel cylinder, forming an annular channel between the outer wall and the combustion chamber wall. Cold air is introduced through this annular channel and enters the furnace from the gaps between the umbrella rings to mix with high-temperature flue gas. The steel umbrella-shaped rings of the inner wall are made of different steels based on operating temperatures.

Main Performance and Features:

★ Rational Structure: The all-steel design of the hot air furnace offers low energy consumption, low wear, light weight, compact size, short installation time, cost savings, easy maintenance, and mobility;

★ Convenient Use: The all-steel structure has no refractory brick lining, requires no preheating when starting up, meets heating requirements immediately upon ignition, cools down quickly when shut down, and requires no emergency chimney;

★ Wide Adaptability: Capable of burning diesel, heavy oil, residual oil, etc.;

★ High Thermal Efficiency: High-efficiency atomizing fuel nozzle, multiple air distribution, excellent combustion effect, combustion efficiency ≥99%; Self-cooling insulation design, low outer wall temperature, thermal efficiency ≥98%;

★ Stable Heating: Adjustable heating temperature from 100–1200°C; Flexible load regulation of the hot air furnace, controllable via fully automatic or manual methods.

PLC Thermal Control:

The normal operation of the fuel oil hot air furnace is marked by the proper ratio of fuel oil volume to air blast volume, ensuring that the furnace temperature, flue gas outlet temperature, and exhaust gas temperature are controlled within a certain range to achieve the purpose of drying materials. Different process scenarios require different measurement and control parameters.

This PLC thermal control system features both manual and automatic control functions. The automatic functions include:

⑴. Automatic purging (pre-purge, post-purge), programmed ignition, and automatic flameout protection;

⑵. Over-temperature alarm and protection;

⑶. External fault alarm and protection;

⑷. Automatic adjustment of fuel oil volume and combustion air volume;

⑸. Centralized monitoring of process parameters such as temperature, pressure, valve position, and flow rate via touch screen, as well as control over the start/stop and switching of process equipment, monitoring the operational status of each process device;

⑹. Manual/automatic switching function.

According to the requirements of the central control DCS system, this PLC system can communicate with the central control DCS system via methods such as Ethernet, Profibus DP, Profinet, Modbus RTU, Modbus TCP, and point-to-point communication. This enables data exchange between the fuel oil furnace thermal PLC control system and the central control DCS system, allowing remote operation of the on-site hot air furnace equipment by the central control DCS system.

Electrical Flowchart:

Fuel Oil Hot Air Furnace Measurement and Control Process Parameters: