SU1010135A1 - Method for controlling fuel flows in tuyers of blast furnace - Google Patents

Description

1.1 The invention relates to black melliturgy, in particular to the domain production, and can be used to control the fuel consumption; by the tuyeres of the blast furnace. The supply of fuel to the blast furnace without regard to the distribution of fuel and blowing through the tuyeres is accompanied by significant fluctuations in costs. Deviations in consumption of blowing tuyeres reach 50–150; from, the average value of tl 3 3 fuel, for example, natural gas 0-188 23. Uneven distribution disturbs the ratio of topliner and oxidizer, which leads to fluctuations in the temperatures of the tuyere foci and, as a result, the amount of charge vanishing in cross section blast furnace. Known methods for controlling fuel consumption for blast furnace tuyeres are carried out in accordance with the flow rate measured by a calibrated device, such as a Venturi tube. The disadvantages of these methods are low resistance due to high temperatures and the erosive effect of the flow to blow and after the measuring device. The latter requires an artificial extension of the tuyere air duct, which is difficult to implement under the conditions of the blast furnace. The closest to the invention to the technical nature is a method for controlling fuel consumption for blast furnace tufts, including measuring total blowing costs and fuel consumption, fuel consumption for tuyeres and changing fuel consumption for each tuyere Z. To determine fuel consumption for each tuyere, measure The first pressure of the flow is blown at the measuring sites of the tuyere devices and determine the fuel consumption for each tuyere from the dependence (l With J: 1 JJ where is the fuel consumption for the j th tuyere, the reduced coefficient of resistance j-ro of the tuyereted boron equipment; LR; - pressure drop over the measuring section / tuyere device; Pa; Vy- - total fuel consumption for the blast furnace. their change due to normal wear and tear, which complicates control over the distribution of blowing and impairs the regulation of fuel consumption through the blast furnace tuyeres. The aim of the invention is to increase the efficiency of use. The goal is achieved by the fact that according to the method, which includes measuring total costs of blowing and fuel, fuel consumption for tuyeres and measuring fuel consumption for each tuyere, the amount of water supplied to each tuyere and its difference are measured: this lance, and the amount of fuel supplied through this lance change in proportion to this indicator based on the dependence (1 p - fuel consumption per jth lance, 11 total fuel consumption per blast furnace, - coolant consumption per j-io tuyere, t / h ;. D-tj is the temperature difference between the cooler at the jth tuyere, ° C. Additional measurements of the amount of water supplied to each tuyere and the temperature difference of the water accurately determine the fuel consumption determined from (2); fuel consumption for blast furnace tuyeres due to the accuracy and reliability of measurement of the dependent quantities of the quantity of supplied water. For each tuyere and water temperature difference, the thermal load on the tuyere: hearth and moving materials. As shown by measurements made on the blast furnace ff 9 of the Krivorozhstal plant, the main amount310

the heat comes from the hot blowing and the tuyere hearth, due to the fact that the lining of the lance of the tuyere is 10-12% of the area of the lance's internal glass, and the value of the specific heat flux is one order and does not depend on the flow to blow, the lance is determined by the flow rate to blow. Within the range of changes in the velocity-flow to blow in the lumens, we observe a linear relationship between the flow rate and the value of the heat transfer coefficient from the flow to blow

oL 70, it + 2.17W, (3) where cL is the heat transfer coefficient from

flow blowing, W / mk; W- flow rate blowing, nm / s. Therefore, the relative distribution

A blast furnace characterizes the relative distribution of blowing through it, and hence the fuel consumption for each tuyere proportional to the magnitude of the thermal loads.

In order to exclude a constant heat pool from the tuyere zone, which will increase the accuracy of fuel consumption control, the amount and temperature difference of the supplied cooler is measured on the cooled flange of the tuyere nozzle or on a specially built heat meter.

At a 5,000 m furnace of the Krivorozhstal metallurgical plant, which has 36 tuyeres, the amount and temperature difference of the supplied chiller was measured, the values of which

Table continuation

7. 10101

Determine natural gas consumption

on the 1st tj) ypMyVf-f 0.032 X 50000 1600 m3 / h,

where 50,000 is the total consumption of natural gas per kiln, m- / h.s

The consumption of natural gas for the second and other lances is calculated in a similar way, the calculation results are listed in the table).

With the help of throttle valves on the natural gas paths, the consumption of natural gas for each tuyere is set, proportional to the flow rate to blow.

The lack of regulation of the distribution of fuel among the tuyeres according to is with the amount of blowing leads to the topic; that the fuel (natural gas, fuel oil and other) comes in violation of the stoichiometric ratios. As a result, on the tuyeres, on which the consumption of jo blow less than the tehiometric, part

358

the fuel does not burn and it decomposes with the release of soot, and this contributes to the blockage of the hearth.

The proposed method of controlling the fuel consumption allows the liquidation of the heat of combustion of the fuel to be eliminated due to a violation of the stoichiometric ratios of the fuel to the blast.

The proposed method allows to ensure a uniform temperature distribution of the tuyere foci and, as a result, a uniform discharge of the charge over the cross section of the blast furnace. This results in coke saving.

For a blast furnace that smelts 3 million tons of pig iron per year, the expected economic effect from the use of the invention will be about 780.0 thousand rubles. in year.

Claims (1)

METHOD FOR REGULATING FUEL CONSUMPTION BY. BURNING FURNACE FUMS, including measurement of total blast and fuel consumption, lance fuel consumption and fuel consumption measurement for each lance, differing in that, in order to increase fuel efficiency, they additionally measure the amount of water supplied per lance and its difference temperatures at the inlet and outlet of this lance, and the amount of fuel supplied through this lance is changed proportionally to this indicator based on the dependence of where the fuel consumption per 1st lance, m ³ / h; .. total fuel consumption for a blast furnace, m ³ / h; cooler consumption on j-th Furmu, t / h; temperature difference of the cooler at the jth lance, ° C. SU.,., 101013 sL> 1 .10101 is