High wind temperature is one of the main skills to strengthen the training of the blast furnace and decrease the burning ratio. It has great significance for the manufacturers to reduce the environmental pollution. Now, the world's leading iron and steel enterprises in the hot air temperature is usually above 1300 degrees celsius. In recent years, China's key steel enterprises in the level of wind temperature rise year by year, in 2009 reached 1158, but most companies are still below 1150, compared with the world's leading level of greater distance, demand to adopt measures to increase the level of wind temperature.
1 the theoretical burning temperature of hot blast stove.
This is the key to obtain high wind temperature. Now the main way to adopt the hot air stove is: (1) the rich blast furnace gas, and the progress of the gas calorific value. Can choose to burn coke oven gas to make the gas calorific value of progress, generally speaking, coke oven gas every 1%, mixed gas low heat value added 125 ~ m3 / 138KJ, hot air temperature can be improved about 15. (2) the progress of preheating temperature of gas and combustion air, namely air, gas into the physical progress of sensible heat. The way of preheating the air to the gas is more ideal than the rich gas. Now the preheating furnace and the hot air stove self preheating skills and so on is the starting point for the starting point to use a different way to preheat the air, can improve the hot air stove temperature. (3) the use of oxygen enriched combustion, that is to cut the amount of gas generated. Oxygen enriched combustion is of ordinary combustion air oxygen enriched burning, is a high efficiency energy saving burning skills and under conditions of equality can be useful to decrease excess air coefficient, flue gas reduction amount, improve theoretical combustion temperature, production increasing and coke saving benefit significantly. However, the oxygen enriched flow can not be infinite, or the flue gas quantity is too small can not satisfy the requirements of the grid brick heat storage, will get lost.
2, the reasonable lining selection of hot air duct system should be low force, directional swell.
The high temperature hot blast furnace longevity is very important. Hot air pipe for blast furnace air supply, for a long time by periodic change of the high temperature influence, prone to pipeline burning red, air leakage and deformation damage, seriously affect the supply air temperature and stability. Therefore, in the design and construction should be reasonable arrangement of the pipe rod and corrugated compensator, in order to reduce the influence of stress on pipeline: usually demand in blast branch and executive branch on both sides of the setting compensator, head end according to demand another compensator; is provided with a guide and a fixed support and other ways to keep pipelines was constrained directional swell etc.; together to ensure that the equipment does not affect the pipeline valve installation and maintenance operations. Pipeline operation layer usually choose high temperature resistance, creep rate low, good thermal shock resistance of low creep high alumina, in the key parts such as hot air nozzle, three fork should be selected combination of brick masonry structure together to focus on pipeline insulation, ensure all lining operation stability and hermeticity.
3 the construction of the top burning hot blast stove.
Top combustion type hot air furnace steel shell structural homogeneity symmetry, with internal combustion type hot air furnace compared under the same hot air furnace capacity conditions, storage area can add 25% ~ 30%; gas flow in the furnace to distribute uniform and symmetrical heat transfer, good uniformity, high thermal efficiency, the hot air temperature is high; together better avoid external combustion type hot air furnace covers an area and high investment cost of defects. Practice has proved that the top combustion type hot air furnace to lower the temperature of the dome can complete the high blast temperature and operation condition in refractory material has been significantly improved, do high wind gentle macrobian life together.