(1) Technical scope of application

(1) Technical scope of application

It is mainly used in the steelmaking industry, food and other industries to replace its old baking furnaces with high-efficiency baking furnaces.

(2) Technical principles (transformation content)

① Technical introduction of efficient baking furnace

Baking furnace, including furnace body, charging device, combustion system, etc. The hearth of the furnace body is cylindrical and the lower part is a tilted constriction. There is a sector valve at the outlet of the constriction to control the discharge. An annular main combustion chamber is arranged in the middle and lower part of the furnace. Two main burners are symmetrically arranged on the periphery of the combustion chamber along the tangential direction. The combustion products rotate in a circular manner along the furnace body in the combustion chamber. A circle of downwardly sloping nozzles is arranged on the furnace shell, and rotating combustion products are sprayed into the furnace from the nozzles to mix with the alloy in the furnace to bake the alloy in the furnace. Since the nozzle is tilted downward, the alloy in the furnace will not block the nozzle. There is an auxiliary combustion chamber in the lower part of the furnace with an auxiliary burner inside. The auxiliary combustion chamber is arranged outside the furnace shell along the tangent line, and combustion gas is injected into the furnace along the tangent line. In the early stage of baking or when high output is required, the auxiliary burner is put into work to heat the alloy. In the middle and late stages of baking, the auxiliary burner stops working, and the secondary air duct supplies air into the furnace to cool the alloy that has been baked and dried. The hot air preheated by the alloy, together with the high-temperature flue gas sprayed out from the combustion chamber, bakes the alloy in the middle and upper part of the furnace. Because the burners are evenly distributed around the furnace body, the heat distribution is uniform, the baking speed is fast, the thermal efficiency is high, and the alloy is dehydrated uniformly.

② Principle of power saving

According to the existing factory layout, the steel structure of the baking furnace was adaptively transformed, and the original baking furnace was improved into a narrow-mouth oven and a baking furnace with additional front-burner. Before the renovation, the baking furnace was heated by hot air, which required a large amount of hot air, resulting in a large exhaust volume, high gas consumption, and a slow heating rate of the baking furnace. After the transformation, a burner in front of the furnace was added, which improved the thermal efficiency and reduced the exhaust volume. The narrow-mouth oven improved the uniformity of strip heating.

(3) Application cases

The energy-saving renovation project of the after-combustion system of the C209 color coating unit of the Cold Rolling Plant of Baoshan Iron and Steel Co., Ltd.

(1) Implementation content and cycle: replace the original baking furnace with a high-efficiency baking furnace, and replace the original incinerator system with a regenerative thermal incinerator.

(2) Energy conservation and emission reduction effect and investment payback period: The energy conservation amount of this project is 7718 tons of standard coal, and the investment amount of this project is 41.4534 million yuan. The annual economic benefits are not given. Its payback period cannot be calculated.

(4) Potential for replication and promotion, energy-saving potential (payback period)

This technology is not widely used, and the technology is not very mature. It is impossible to see its input-output ratio, and it is impossible to judge whether the technical transformation method is effective in saving energy. Therefore, the report does not recommend the use of this technology.