What is the flat-oven coking technology?

“The \"open hearth\" was likely a type of heating furnace that preceded the tubular heating furnace; later, it was mainly used for steel production. Nowadays, open hearths are being phased out in steel manufacturing in favor of the converter method for steel production.

Based on the clues provided by Bai Ding, a search was conducted and the following results were obtained for sharing: Open-hearth furnace Composition: An open-hearth furnace consists of a melting chamber, furnace head, rising channel, slag chamber, regenerative chamber, reversing valve, flue, chimney, etc. The melting chamber is the central part of the open-hearth furnace; it has a charging door at the front and a steel outlet at the bottom at the rear. Purpose: Open-hearth steelmaking is a method in which raw materials such as pig iron and scrap steel are melted and refined into molten steel using an open-hearth furnace, with gas or heavy oil as fuel, under direct heating by the burning flame. 　　History: Open-hearth steelmaking has been the primary method of steel production worldwide since 1864, when the Frenchman P. Martin successfully produced molten steel using a flame furnace with a regenerative chamber and scrap steel as well as pig iron. It remained the dominant method until 1960, after which it was gradually replaced by oxygen converters and electric arc furnaces for steel production. 　　Characteristics of open-hearth steelmaking: ① Heat is supplied from the outside. Due to the large size of the basic oxygen furnace, the long melting time, as well as the significant heat loss through the furnace walls and the heat carried away by the hot exhaust gases, it is necessary to supply fuel from the outside and use preheated air to burn the fuel in order to maintain the heat required for steel production. 　　②Oxidizing atmosphere. The combustion gases (furnace gas) in the open-hearth furnace chamber contain O2, CO2, H2O, etc., which have an oxidizing effect on the molten pool, keeping the slag highly oxidizing at all times. Oxygen supply solely through furnace gas is slow; adding iron ore or blowing oxygen can accelerate the reaction process. 　　③The role of slag is important. Slag lies between the furnace gas and the molten steel; it serves as a medium for heat and oxygen transfer from the furnace gas to the molten pool. It also plays an important role in removing impurities such as sulfur and phosphorus, preventing the molten steel from becoming over-oxidized, and stopping the molten steel from absorbing gases like hydrogen and nitrogen. Therefore, an appropriate amount of slag and slag layer thickness should be maintained in the furnace; to obtain good quality slag, the molten iron in the pool must have an appropriate carbon content.