I. Equipment composition

The hot blast furnace system uses natural gas, blast furnace gas, diesel, light and heavy oil and other fuels. The overall engineering design is based on the principle of safety and reliability, fully meeting the process requirements of hot air.

II. Key Points of Design

1) Equipped with an integrated or split standard burner, using air and gas (oil) external mixing and local internal mixing cyclone gas nozzles to mix the gas and air well, so that the gas in the mixed gas reaches the ignition concentration of the combustion environment, and the temperature of the mixed gas in the environment rises to the ignition temperature.

2) The temperature field of the hot blast furnace combustion area is stable, so that the flame is stable and the combustion is safe, ensuring that the gas does not flame out during the combustion process.

3) During the design, the hot blast furnace structure is scientifically and reasonably arranged, tangential (or longitudinal) air intake, rotating combustion in the furnace body, increasing the gas combustion time, and making the gas (oil) fully burned. Ensure sufficient heating capacity.

4) Preheating hot blast furnace, the preheating air temperature reaches 170℃--200℃ or higher, which is a safer, more economical and energy-saving enhanced combustion method.

5) A flame stabilizer is set at the burner outlet to make the flame stable, without flame failure or interruption.

6) The hot air furnace adopts a fully automatic ignition control system. The ignition device adopts high-energy automatic pulse electric spark ignition. A nozzle uses a double flame detector to detect the entire ignition process to ensure the safety and reliability of ignition and prevent system safety problems caused by damage to a single device. The system is interlocked with explosion-proof valves and automatic gas source cut-off valves to achieve a double insurance and double safety ignition control system.

7) The entire system can be equipped with a PLC fully automatic control cabinet to automatically control the real-time uninterrupted loop operation of the gas (oil) volume and air supply volume. The various technical parameters of the hot air furnace operation are automatically controlled according to the designed self-control requirements and a certain communication method, and are interlocked with the drying system.

III. Technical Description

This gas (oil) hot air furnace is mainly composed of a steel structure frame furnace body, a combustion system, and a temperature control ventilation device. Refractory materials (or inner zirconium ceramic fiberboard) are cast inside the furnace body, and insulation materials are wrapped outside, and then steel plates are wrapped, and reinforced with steel sections. The inner wall of this structure is heat-resistant and wear-resistant, the furnace body has a large heat storage capacity, good insulation effect, and is conducive to stable combustion. The burner and hot air furnace have flameout protection, automatic ignition control, and interlocking control of automatic adjustment of hot air output temperature.

1) This system adopts gas (oil) combustion and gas ignition mode, and both adopt large and small fire automatic conversion and electronic pulsation automatic ignition device, flame detection safety automatic control, and interlocking automatic control with explosion-proof valves and automatic gas source cut-off valves to achieve a double insurance and double safety ignition control system.

2) All set key valves use professional manufacturer valves, and all motors use explosion-proof motors.

3) The secondary fan adopts variable frequency speed regulation to meet different gas (oil) and air volume ratios and hot air output temperature of the hot air furnace.

4) The hot air furnace has its own control system, including the control of all the hot air furnace main equipment and peripheral drying equipment. The system should have two modes: on-site control and centralized control, and can achieve disturbance-free switching between the two modes.