SUPERHEATING OF AN EXPORT GAS USED IN A REDUCTION PROCESS, IN ORDER TO BALANCE OUT AMOUNT FLUCTUATIONS, AND DEVICE

摘要

The method comprises cooling a first partial amount of a recycling gas in a cooler (5) to form a cold recycling gas, supplying the cold recycling gas to an export gas (2) in a pressure-controller and/or amount-controlled manner to balance out amount fluctuations of the export gas, supplying a second partial amount of the recycling gas to the export gas as hot recycling gas having a higher temperature than the cold recycling gas, and introducing an export gas mixture (8) comprising the cold recycling gas and the hot recycling gas into a reduction process (1). The method comprises cooling a first partial amount of a recycling gas in a cooler (5) to form a cold recycling gas, supplying the cold recycling gas to an export gas (2) in a pressure-controller and/or amount-controlled manner to balance out amount fluctuations of the export gas, supplying a second partial amount of the recycling gas to the export gas as hot recycling gas having a higher temperature than the cold recycling gas, and introducing an export gas mixture (8) comprising the cold recycling gas and the hot recycling gas into a reduction process (1). The temperature of the export gas mixture is higher than the temperature of the export gas. The temperature of the export gas or rather the export gas mixture is set such that the temperature is higher than the dew point or dew point temperature of the export gas mixture. The cold recycling gas has the same temperature as the export gas. The method further comprises introducing reduction gas obtained from the export-gas mixture into a reduction unit for reduction of metal oxides, removing the reduction gas as a top gas from the reduction unit after a partial reduction of the metal oxides and production of the reduction gas, compressing the export-gas mixture in a compressor for a process gas, cooling the process gas using a cooler, removing carbon dioxide and/or water in the process gas using a removing device to obtain the reduction gas, and heating the reduction gas using a heater. The hot recycling gas has a temperature of 150[deg] C. The export gas includes a crucible gas from a steel mill, from a plant for production of pig iron, from a coal gasification plant and/or from a coking plant, is subjected to a device for dust removal and/or gas cleaning before the reduction process, and is supplied to the hot recycling gas and the cold recycling gas before the dust removal and/or gas purification step. The temperature of the export gas mixture is higher than 15[deg] C of the temperature of the export gas before the supplying to the hot recycling gas and the cold recycling gas, and is controlled to a certain value. An independent claim is included for a device for balancing out amount fluctuations.