Structure and working principle：
The rotary iron furnace is a metal melting furnace that uses natural gas as fuel and oxygen as combustion accelerant. It has been used in industrialized countries for about 50 years. The furnace consists of a furnace body, a rotating frame, a transmission mechanism, a fixed frame, a hydraulic system, a combustion control unit, a feeding part, a cooling water system, an exhaust gas purification system, etc. It is currently the most environmentally friendly melting furnace.
The theoretical temperature of natural gas burning in pure oxygen can reach about 3300°C, and the actual maximum temperature in the furnace can reach 2700~2750°C. The high temperature generated by the combustion of pure oxygen natural gas can melt all common metals.
The furnace body of the rotary furnace is installed on the rotating frame. Under the action of the hydraulic cylinder, the rotating frame can tilt the furnace body within a certain angle range to achieve process actions such as feeding, melting, and dumping out slag. At the same time, the furnace body can rotate around its axis under the action of the transmission mechanism; the rotational motion improves the heating efficiency of the furnace and is of great significance to the overheating of molten iron.
This furnace needs to add a certain amount of slag-forming agent when melting metal. The molten slag-forming agent and slag liquid have a protective effect on solid and liquid metals and can prevent metal oxidation.
The burning loss rate of silicon, manganese and other elements in the rotary iron furnace is equivalent to that of a coke-burning cupola. The content of carbon in the rotary furnace shows a downward trend, so a certain amount of carburizing agent (coke or graphite) needs to be added to the charge.
The process and production organization of the pure oxygen gas rotary furnace for melting cast iron are the same as those of the induction electric furnace. The flexibility is very high. After the metal charge is added into the furnace at one time, the drum-shaped furnace body slowly rotates around its horizontal axis, and the solid metal melts in the pure oxygen gas burner. It is melted into molten metal under the action of , and the molten iron is poured out before melting in the next heat.
Pure oxygen regenerative iron furnaces have been used in industrialized countries for about 50 years. In recent years, some iron foundries in my country have introduced this furnace to produce gray iron and ductile iron castings for export, and have achieved satisfactory results.
Superiority:
1) Each ton of iron emits 60 to 80m3 of carbon dioxide, and the carbon emissions are less than 40% of the coke-burning cupola, and the carbon emissions are less than 38% of the converted carbon emissions of coal-fired electricity used in electric furnaces; there is basically no nitrogen in the tail gas Oxides (NOx) and sulfur oxides (SO2) are currently environmentally friendly cast iron melting equipment.
2) Equipment investment is lower than that of electric furnaces. Compared with electric furnaces, the fixed production costs involved in "basic electricity charges" are avoided.
3) The rotary iron furnace is very adaptable and can produce various types of cast iron such as gray iron, ductile iron, vermicular iron, malleable iron (male steel), alloy cast iron, etc. It can also produce non-ferrous metals such as copper and aluminum alloys.
4) The furnace capacity is 3 to 30 tons, and the melting mode is the same as that of the electric furnace. One furnace melts in 60 to 80 minutes. The flexibility of the rotary furnace in terms of production organization is the same as that of the electric furnace and superior to the cupola furnace.
5) When producing ductile iron, the molten iron does not need desulfurization treatment, which can save the cost of desulfurization agents. This furnace is a new choice of cast iron melting equipment, and its characteristics are suitable for small and medium-sized iron foundries with small output and many varieties.