1) cast iron pipe type hot air stove, can not withstand the high temperature and high pressure, the supply of the wind temperature is very low, has been eliminated.
2) internal combustion type hot blast stove although through improved refractory materials, such as aluminum alloy well type hot blast stove measures can provide more than 1000 DEG C, the temperature of blast furnace, but due to the hot blast stove is by the combustion chamber model well type annealing furnace and heat storage chambers, the middle wall separate and partition in the combustion and the process of air supply produced temperature fluctuations, especially in the lower temperature, in a variety of should be under the action of force, easy to crack, off brick, burn through or even collapse. At the same time, using the hot-air furnace metal burner enable direct flame impingement partition, and caused resonance in the combustion chamber, more drama the lining damage. Transformation of internal combustion type hot air furnace although in the partition wall in the lower temperature difference between the larger areas inside and outside the ring built a layer of insulating brick and ceramic burner for alternative metal burner, overcome the partition burn through problem, reduce the damage, but did not cancel partition, fundamentally solve off brick.
3) the advantages of the external combustion type hot blast stove is to cancel the partition wall, and the combustion chamber aluminum alloy box type hot air stove and the heat storage chamber are completely separated, and the storage room of the lattice brick column stability is good. The disadvantages are: large investment, large land area, the need to increase steel and refractory brick. The connecting section of the combustion chamber and the storage chamber, the complex of the brick type, and the difficulty of the masonry, and become the weak link in the structure.
4) top combustion type hot air furnace has the advantages of: and external combustion type as, the abolition of the partition, fundamentally eliminate the fatal weakness of internal combustion type, and in the capacity of hot air furnace is the same, the storage area increased by 25% - 30%. The short flame burner is used directly in the top of the combustion, high temperature and high temperature, reduce the heat loss, is conducive to the improvement of the vault temperature. The furnace has simple structure, good structure strength, little brick type, easy to masonry. (4) improved the working conditions of the refractory materials, area of heavy load of the lower part of the low temperature; upper temperature high load is small. The area is small, compared with the external combustion type, can save about 20% of steel and refractories. But to make the top burning type hot air stove work smoothly also need to solve the following problems: 1. To ensure that the gas in the vault of the limited space to complete combustion, and ensure the uniform distribution of air flow. The vault shall be set up in the place of the burner, and shall be subjected to a strong temperature fluctuation. Therefore, this part of the need to use high temperature resistant and heat resistance and heat resistance of the refractory material. The hot air outlet at the top, the hot air pipe to extend to the height of the furnace roof, need to set up the corresponding pipe support and expansion ring. Because of the hot air valve, valve valve burning at the top, must be at the top of a hoisting equipment, in order to repair and replacement.
5) the ball type hot blast stove is only used for small blast furnace below 100m3, which is similar to the top of the hot blast stove, it is not only a lattice brick, but a high alumina ball directly into the hot air stove. It requires the gas containing dust or clean for a large amount of work.