Advantages of Strong Convection Full Hydrogen Bright Bell Annealing Furnace

1. Product introduction:
Strong convection bell annealing furnaces are used for bright annealing of cold rolled strips. The strong convection hood type annealing furnace is composed of a solid annealing furnace table and the supply medium input/output pipes below it, a protective cover, an electric heating cover and a cooling cover with a spray device. There is a protective gas valve station under the annealing furnace table. The coils to be annealed are stacked on the hearth, with special forms of intermediate convection plates placed between the coils. When the coil is annealed, high-purity hydrogen and nitrogen are used as protective gases. Fasten the protective cover and the heating cover with the heating cover equipment over the coil to be annealed. After the annealing, the heating mantle is hoisted to an annealing-ready furnace table with a crane. Fasten the cooling cover on the outside of the protective cover for cooling. Then, under suitable temperature conditions, start the spray cooling device. After cooling, close the spray cooling device and lift the cooling cover and protective cover. Unload the coil from the hearth, ready for the next annealing.
The strong convection full hydrogen bright bell furnace, as the name suggests, is that the protective gas used for heat treatment is all hydrogen (H2). In the traditional old-fashioned bell-type furnace, HNX (hydrogen-nitrogen mixture) is used as the protective gas for annealing, mainly nitrogen, while in the strong convection full-hydrogen bright bell-type furnace, the medium for heat conduction is 100 % hydrogen. Hydrogen has the smallest atomic weight and is an extremely active gas, especially in the high temperature state of heating, the flow speed is abnormally fast; the heat conduction speed of hydrogen is 7 times that of nitrogen, and it can conduct heat directly from the radial direction of the steel coil; hydrogen Its density is also very small, only 1/14 of that of nitrogen; therefore, it can significantly reduce the power consumption of the furnace circulating fan and reduce the noise of the equipment. In addition, hydrogen also has the ability to effectively convert hydrogenation residues into water vapor at high temperature, which is of great significance for improving the annealing quality of cold-rolled sheets. Hydrogen is obtained in the strong convection bright bell furnace produced by our company. A very good security application.

2. Product Features:
1. The configuration ratio of the furnace table and the heating hood is reduced. The traditional HNX bell furnace is generally 2:1, that is, 2 furnace tables are equipped with 1 heating hood. Due to the extremely short cooling time of the full hydrogen furnace, the furnace hood ratio is reduced to 1. :6:1, reducing the floor space and saving investment, especially for large furnace groups.

2. High output, which can increase the output by 30-40%. Since the full hydrogen furnace uses 100% hydrogen as the protective gas, it adopts corrugated inner cover, large gas flow and high-speed burner, gas/water combined cooling method and strong convection, etc. The reason is that the output is greatly improved. The hourly output of the furnace table can generally reach 1.7-1.8t/h for deep-drawing EDDQ, and the hourly annealing capacity of CQ material gas can reach 5.3t/h, and the heating capacity can reach 152KWh/ton. steel.
There is no oxidation phenomenon. Due to the reliable sealing of two PPm levels (one percent), sufficient purging time, and advanced control methods, the annealed steel coil will not have oxidation color.

3. Avoid sticking. Because the steel coil is treated for a short time in the furnace, in the heating and cooling process, the temperature difference between the upper steel coil and the lower steel coil in the furnace, the outside and inside of the steel coil is very small, and the temperature is very uniform , local overheating and sticking will not occur.

4. The full hydrogen furnace can cool the steel coil to a flat temperature. In addition to greatly reducing the cooling time, it can also avoid the risk of rust spots and damage to the strip edge during the transfer of the steel coil to the cooling table. Satisfactory mechanical properties and surface finish can be obtained. The products annealed in the full hydrogen furnace can fully meet all the requirements of the DIN standard, such as high plasticity and high compression ratio (r), high work hardening index (n) and satisfactory mechanical properties.

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