5.1 General Process Design |
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5.1.1 The design of a converter steelmaking shop shall determine the nominal capacity and quantity of converters and the arrangement of secondary refining unit according to product mix.
5.1.2 In a converter steelmaking shop,2 or 3 rather than>4 converters should be arranged.No standby converters are arranged.In a shop with more than 3 converters,the converters should be arranged by groups.
5.1.3 The nominal capacity of furnace shall be the average tapping in the campaign life and the maximum tapping shall be 1.05 1.1 times of the nominal capacity.The furnace should be operated in staged and quantitative method.
5.1.4 The annual capacity of blowing furnace shall be calculated with the following formula:
Where Q ———Annual qualified liquid steel production per blowing furnace(t/a);
G ———Average tapping per heat in campaign life of furnace(t/h);
T ———Average tap-to-tap time per heat(min/heat);
N ———Annual effective operating time of furnace(d/a);
n 1 ———Annual furnace repair time(d/a);
n 2 ———Annual scheduled routine maintenance time(d/a);
n 3 ———Annual shop maintenance time(d/a);
n 4 ———Annual operation time loss(d/a).
5.1.5 The composition of a converter steelmaking shop should be in accordance with the following provisions:
1 The main production system should include main shop building,hot metal pretreatment station,scrap proportioning shop,slag shop,fume cleaning facility,gas recovery facility and wasteheat steam recovery facility;
2 The auxiliary production system should include ferroalloy storage and transport facility,bulk material storage and transport facility,quick analysis room,compressed air station,shop power distribution substation,water treatment facility,dedusting facility and domestic and welfare facilities;
3 In the design,the shop composition may be determined according to such actual conditions as production capacity and material supply.
5.1.6 If there are such usable alloying elements as niobium,vanadium and titanium contained in hot metal,they shall be recovered with proper smelting process.
5.1.7 The operation of a new converter should be controlled by a dynamic close-loop control system with real-time signal feedback of sublance measurement system and(or)continuous furnace gas analysis system.
5.1.8 The measuring instruments shall be equipped for process steps of converter and operating parameters of power media and all measured data shall be input to basic automation system.A quick analysis system shall be adopted for sampling of operation and the data shall be transmitted to process computer system.
5.1.9 The gases,fuel and cooling water with piping used for converter operation shall be in accordance with the following provisions:
1 The capacity for supply of oxygen,argon,nitrogen,steam,compressed air and fuel shall be arranged according to the working system specified in the design and calculated based on the consumption per ton steel and the hourly productivity of converter shop.
2 The capacity of gas storage tank shall meet the peak demand of shop.Moreover,the capacity shall be adaptable to consumption fluctuation and shall also meet at least the demand for a heat in case the gas supply gets in failure.
3 If the construction of shop is executed by phases,the main media pipeline should be built based on the final production scale.However,for the related utility,the general layout may be made reservation for space of expansion,or the shop building may be made reservation for condition of additional unit,depending on the actual condition.
5.1.10 The main techno-economic indices of a new converter steelmaking shop should be determined according to Table 5.1.10.
Table 5.1.10 Main techno-economic indices of a new converter steelmaking shop
Notes:1 The indices of consumption are referred to the consumption per ton qualified liquid steel.
2 The consumption of ferroalloy is based on the production of common carbon steel and low alloy steel.
3 The consumption of active lime is based on the process with hot metal desulfurization.
4 The consumption of oxygen includes the scattered consumption of oxygen for the shop.
5 The consumption of furnace lining is based on the process with slag splashing operation and the campaign life of furnace is 5000heats 15000heats .
6 The calorific value of converter gas is 6.69×10 6 J/Nm 3 .
7 The data mentioned above is based on the conventional converter operation mode.