提高熱風爐風溫的有效技術措施

1. 提高熱風爐理論燃燒溫度。 這是獲得高風溫的關鍵。目前可采取的主要措施有: (1) 富化高爐煤氣,提高煤氣熱值。可采用摻燒焦爐煤氣來使煤氣熱值得到提高,通常來說,焦爐煤氣每增加 1%,混合煤氣低熱值增加 125～138KJ / m3,熱風溫度可提高15℃左右。 (2) 提高煤氣和助燃空氣的預熱溫度,即提高空、煤氣帶入的物理顯熱。預熱空煤氣比富化煤氣提高發熱值的方法更為理想。目前已有的預熱爐技術和熱風爐自預熱技術等就是以此為出發點用不同方式來預熱助燃空氣,可提高熱風爐溫度。 (3) 采用富氧燃燒,即減少生成的煙氣量。富氧燃燒是對普通助燃空氣富氧後進行燃燒,是一項高效節能的燃燒技術,同等條件下可有效降低過剩空氣系數,減少煙氣量,提高理論燃燒溫度,增產節焦效益明顯。但是,富氧流量不能無限增大,否則煙氣量過少不能滿足格子磚蓄熱量要求,會得不償失。1. improve the theoretical combustion temperature of hot blast stove. This is the key to obtaining high wind temperature. At present, the main measures can be taken as follows: (1) enrich the blast furnace gas and raise the calorific valu彩色沥清地坪e of the gas. Coke oven gas can be mixed to increase the heat of gas. Generally speaking, for every 1% increase in coke oven gas, the low calorific value of mixed gas can be increased by 125-138KJ/m3, and the hot air temperature can be increased by about 15 C. (2) improve the preheating temperature of gas and combustion air, that is, the physical sensible heat brought by high altitude and gas. The method of preheating the air gas is more ideal than that of enriching the gas to increase the calorific value. At present, the existing preheating furnace technology and hot stove self-preheating technology are based on this to preheat combustion-supporting air in different ways, which can improve the temperature of hot stove. (3) oxygen enriched combustion is used to reduce the amount of smoke generated. Oxygen-enriched combustion is a high-efficiency and energy-saving combustion technology which combusts ordinary combustion-supporting air after enriching oxygen. Under the same conditions, it can effectively reduce excess air coefficient, reduce flue gas, increase theoretical combustion temperature, increase production and save coke. However, the oxygen-enriched flow rate can not be increased indefinitely, otherwise too little flue gas can not meet the heat storage requirements of lattice bricks, it will be gratuitous.2. 采用內襯合理、低應力、定向膨脹的熱風管道系統。2. a hot air piping system with reasonable lining, low stress and directional expansion is adopted.這對高溫長壽熱風爐十分重要。熱風管道為高爐送風,長期受到周期性變化的高溫影響,容易發生管道燒紅、漏風甚至變形受損,嚴重影響送風的溫度和穩定性。為此,在結構設計時應合理佈置管道拉桿和波紋補償器,以減小應力對管道產生的影響: 一般需要在熱風支管上以及主管上支管的兩側設置補償器,主管端部根據需要另設補償器; 設置導向和固定支座等措施使管道受到有限制的定向膨脹等；同時要保證這些設施不影響管道上閥門的安裝和檢修等工作。管道工作層一般選用耐熱溫度高、蠕變率低、抗熱震性能好的低蠕變高鋁質,在關鍵部位如熱風管口、三岔口等應當采用組合磚砌築結構,同時也要重視管道的隔熱保溫,保證整體內襯工作的穩定性和氣密性。This is very important for high temperature and long life hot stove. Hot air pipeline is the blast furnace air supply, which is affected by periodic high temperature for a long time. It is prone to red burning, air leakage and even deformation damage, which seriously affects the temperature and stability of the air supply. Therefore, in structural design, the tie rods and corrugated compensators should be reasonably arranged in order to reduce the influence of stress on the pipeline. Generally, compensators should be installed on the hot air branch pipe and on印花地坪 both sides of the upper branch pipe of the main pipe, and compensators should be installed at the end of the main pipe according to the need. Measures such as setting guidance and fixed support should be taken to make the pipeline subject to limited orientation. At the same time, ensure that these facilities do not affect the installation and maintenance of valves on pipelines. Pipeline working layers are generally made of low creep and high aluminium with high heat resistance, low creep rate and good thermal shock resistance. Composite brick masonry structure should be adopted in key parts such as hot air pipe outlet and three forks. At the same time, attention should be paid to heat insulation of pipeline to ensure the stability and air tightness of the whole lining.3. 采用頂燃式熱風爐結構。3. adopt top combustion type hot blast stove structure.頂燃式熱風爐鋼殼結構均勻對稱，同內燃式熱風爐相比，在相同熱風爐容量條件下，蓄熱面積可增加25%～30%; 爐內氣流分佈均勻、傳熱對稱、均勻性好、熱效率高，因而熱風溫度高; 同時也較好的避免瞭外燃式熱風爐占地面積大、投資費用高的缺點。實踐證明，頂燃式熱風爐以較低的拱頂溫度便可實現高風溫，耐火材料工作條件得到明顯改善，可同時做到高風溫和長壽命。The steel shell structure of top-fired hot stove is uniform and symmetrical. Compared with internal combustion hot stove, under the same capacity of hot stove, the heat storage area can be increased by 25%-30%. The air distribution in the furnace is uniform, the heat transfer is symmetrical, the uniformity is good, and the heat efficiency is high, so the hot air temperature is high. At the same time, the external-fired hot stove occupies a large area. The disadvantages of high investment cost. Practice has proved that the top-fired hot blast stove can achieve high air temperature with lower vault temperature, and the working conditions of refractories have been significantly improved. It can achieve high air temperature and long service life at the same time.