Working principle:

The combustion chamber is composed of a steel cylinder lined with castable, which is made of Q235. The combustion chamber is covered with a steel outer cylinder. The combustion torch is parallel to the axis of the combustion chamber, and the torch fully develops in the chamber to combust safely and stably. There is a high-speed injected secondary air around the furnace wall, which packages the combustion flame in the center of the furnace. The secondary air has a heat insulation and protection effect on the inner wall of the furnace, and controls the combustion temperature of the furnace at about 1000℃. The auxiliary air enters the furnace for the front end, then passes between the outer cylinder and the inner cylinder, and fully mixes with the high temperature flue gas produced by the combustion in the mixing room to produce the hot flue gas at the temperature required by the process. Through the cold air between the inner and outer cylinders, also cooling the inner cylinder and furnace insulation. The outer cylinder wall temperature is less than 60℃ at working. 

Main performance and features:

★ Reasonable Structure: hot air furnace full steel structure, low energy consumption, low wear, light weight, small size, short installation period, investment saving, simple maintenance, mobile etc.;

★ Easy to Use: no need to preheat before start, it can meet the heating requirements when switch-on, stop the furnace rapid cooling, without emergency chimney;

★ Wide Adaptability: combustible natural gas, coke oven gas, blast furnace gas, water gas, generating furnace coal gas, mixed gas and low calorific value gas;

★ High Thermal Efficiency: the combustion efficiency is higher than 99%; self-cooling and thermal insulation design, the furnace body outer wall temperature is low, and the thermal efficiency is more than 98%;

★ Heating Stability: heating temperature is 100-1200℃ adjustable; flexible load adjustment, can be controlled by fully automatic or manual way.

Composition:

combustion system (electric ignition device, flame detection device), gas valve system, air supply system, control system, etc. The combustion system mainly includes: burner, electric ignition device and flame detection device. The gas is fully burned by the burner in the burner flame cylinder and the combustion chamber, and the hot flue gas generated and the incoming cold air are mixed in the mixing chamber into the flue gas at the required temperature, providing a heat source for the rear sequence equipment. Electric ignition device: The electric ignition device includes the ignition electrode and the ignition gun. When the hot air furnace starts, light a small fire in the burner, and then ignite the main fire by a small fire. If the calorific value of the main gas is too low to ignite directly, the gas with high calorific value should be prepared for ignition; Flame detection device: the main function is to test whether the nod is successful and whether the furnace is stalled in the combustion process. Flame detection is the key equipment of the hot blast furnace safety monitoring system. 

The gas valve system is mainly composed of: electric regulating valve, pneumatic rapid cut-off valve, manual cut-off valve, ignition solenoid valve, pressure transmitter, high and low voltage switch, pressure gauge, release valve, gas leak detector, pipeline etc.

Gas is connected to the gas valve system from the main pipeline of the gas station. The electric regulating valve regulates the gas flow rate; once the furnace combustion abnormal, the pneumatic rapid cut-off valve will quickly cut off the gas, to ensure the safety of the furnace system ; close the hand cut-off valve and open the release valve if no use for a long time; The ignition solenoid valve controls the fire torch gas; the pressure transmitter measures the gas pressure and output it remotely; high and low voltage switches control ultra low voltage and ultra high voltage can not be put into work; the pressure gauge shows the gas pressure on the spot. Gas leakage detector is to check the site gas concentration of the valve system, exceeding the standard alarm. 

The air supply system is mainly composed of: combustion support fan, main air duct, air distribution fan, air distribution duct, combustion support air regulating valve, air distribution regulating valve.

The combustion supply fan provides the burner with the oxygen required for diesel combustion; the air volume is controlled by the combustion supply air regulating valve; the air supply fan provides the secondary air in the combustion chamber and the cooling air required for the mixing chamber. Air volume is controlled by the air regulating valve. 

Controlling system:

The system uses blast furnace gas / coke oven gas / natural gas as fuel, adopts automatic control and automatic ignition, and automatically adjusts the fuel volume, combustion supporting air volume and air distribution volume according to the change of load. Basic safety protection: the burner has safety protection from the ignition failure, high flue gas temperature, high gas pressure, low gas pressure, emergency stop and so on. The system adopts PLC control, which can communicate with the central control through the data bus to realize the central control and make manual intervention on site. 

Electrical flow chart:

Measurement and control process parameters of negative pressure heating system:

Photo of the scene:

Customer Evaluation: