Gas system of blast furnace mainly includes gas purification, TRT (blast furnace gas (waste heat) turbine power generator) and blast furnace gas discharge tower, etc.
Blast furnace gas purification adopts dry bag dust removal, that features high dedusting efficiency, no water consumption, low energy consumption and high automation. After the gravity/cyclone dust collector, the semi-clean furnace gas enters into the box from the air inlet of the lower end of the bag filter, the larger dust particles will naturally fall into the dust hopper by their own weight, the smaller particles will be dispersed in the gap between the filter bags of the filtration room and thus be blocked on the surface of the filter bags, and the filtered clean gas will be sent to the users by the pipeline network. The main equipments include dust collector box, filtration, pulse blowing, unloading, ash conveying, dry ash storage and transportation, and nitrogen gas supply system. The box of dust collector is welded as a whole, and the inlet and outlet air ducts, ash hopper and discharge pipe are integrated. The filtration system is mainly composed of filter bag, keel, flower plate components. The filter bag is the key element of the dust collector, which is made of filter cloth (filter material) after special treatment, and sewn into a barrel shape with unique sewing technology. The filter bag material is made of composite filter material, which is characterized by high temperature resistance, high strength and abrasion resistance. The filter bag mainly captures dust through sieving, inertia, diffusion, adhesion and electrostatic effects, and the dust removal efficiency can reach more than 99.99%.
The furnace gas after dust removal enters the TRT system, which converts the pressure and heat energy of the gas into electric energy. The gas comes out of the TRT and enters the net gas main through the water seal. The main equipments of TRT include main turbine, generator and power distribution, lubricating oil, hydraulic servo, valves, nitrogen sealing, water system, and instrumentation & control system.
Gas dispersing tower is used for the stable pressure dispersing of net gas and net gas main when the blast furnace is put into operation at the initial stage, big and medium repair, wind break and opening, and also can be used as the emergency accident dispersing under the condition that the temperature of the first half of the net gas of the dry dedusting bag system is over high or under low working condition. The dispersing tower generally adopts coke oven gas automatic ignition combustion discharging; the top of the tower should be higher than the height of nearby structures.
