Waste heat recycling system for sintered hot ore and pellet cooling machine

Abstract

The invention discloses a waste heat recycling system for a sintered hot ore and pellet cooling machine. The waste heat recycling system comprises a high-temperature flue gas area, a medium-temperature flue gas area and a low-temperature flue gas area which are sequentially arranged in the cooling machine in the moving direction of sintered hot ores and pellets, the high-temperature flue gas area,the medium-temperature flue gas area and the low-temperature flue gas area are in communication with one another, grate beds for conveying the sintered hot ores and the pellets are correspondingly arranged in the high-temperature flue gas area, the medium-temperature flue gas area and the low-temperature flue gas area, and a high-temperature flue gas outlet, a medium-temperature flue gas outlet and a low-temperature flue gas outlet are formed in the upper portions of the grate beds correspondingly; and a first cooling air inlet, a second cooling air inlet and a third cooling air inlet which correspond to the high-temperature flue gas outlet, the medium-temperature flue gas outlet and the low-temperature flue gas outlet are formed in the lower portions of the grate beds correspondingly. According to the waste heat recycling system, smoke is utilized in a gradient mode by the double-pressure waste heat boiler, the exhaust temperature is reduced, meanwhile, the waste heat boiler adopts aregenerative mode, the first-section smoke temperature and the second-section smoke temperature of the novel cooling machine are increased, and the energy utilization rate is increased.

Description

technical field [0001] The invention relates to the technical field of ironmaking energy saving and emission reduction, in particular to a waste heat recovery and utilization system for sintering hot ore and pellet coolers. Background technique [0002] As an energy- and resource-intensive industry, the national iron and steel industry consumes about 16% of the country's total energy consumption, and the energy consumption per ton of steel is 20% higher than that of developed countries. Therefore, in the context of global energy conservation and emission reduction, it is of great significance to vigorously develop new technologies to promote low-energy steel production. [0003] At present, China has become a big iron and steel country. There are more than 500 iron and steel enterprises, including about 1,000 sets of raw material sintering machines and more than 600 sets of pellet sintering shaft furnaces. However, only 2 / 3 of the raw material sintering adopts the tradition...

AI Technical Summary

Problems solved by technology

Furthermore, the waste heat recovery of the belt cooler or the ring cooler adopts the sealing of the fixed fume hood and the mobile trolley to recover the high-temperature flue gas. Although there are many sealing methods in this recovery method, all the sealing methods cannot guarantee complete sealing, and the air leakage rate is in the 5%-30%, and the waste heat recovery only recovers the first stage and the second stage, a large amount of waste heat of flue gas below 250 ℃ is not used, and the efficiency of waste heat recovery is not high

The height of vertical cooling kiln equipment is high, and hot ore needs to be transported to the kiln roof by grate coolers and feed trucks. The heat loss during transportation is relatively large. Due to continuous loading of materials, the kiln roof cannot be fully sealed, and the kiln roof is slightly positive pressure, which is difficult to control accurately, or from Heat is blown out from the material inlet, or cold air is sucked in, resulting in a decrease in the temperature of the hot air

In addition, during heat recovery, the cooling air in the kiln passes through the low-temperature section and the high-temperature section in sequence, and the high-temperature air coming out is a mixed air with relatively low air temperature. The steam pressure of the boiler and steam turbine behind is low, and the power generation efficiency is not high.

It can be seen that the traditional cooler has inherent structural defects, which cause the sintering and pellet cooler to become the bottleneck of the sintering section under the conditions of air leakage and slow cooling and cooling speed

It limits the production capacity of the sintering section, wastes a lot of high-grade flue gas waste heat, and brings huge energy-saving and environmental protection pressure to steel companies

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