SU994560A1 - Tuyere device of blast furnace - Google Patents

Description

(54) BURGER TYPE OF DOMAIN FURNACE The invention relates to ferrous metallurgy, namely, equipment for blast furnaces for blowing. Known tuyere instruments of blast furnace pedeals for supplying a mixture of blown fuel with fuel and containing a blowing nozzle adjacent to the tuyere are known. inside the space of which fuel supply pipe is introduced 1 Known constructions of tuyere. devices do not create the technologically required homogeneity of the mixture, which adversely affects the distribution of reducing gases over the cross section of the blast furnace and is the cause of black carbon occurrence, a sharply worsening drainage of liquid smelting products in the near-furman space, which in turn leads to premature lance burning and , as a result, to the planned stopping of furnaces, as well as .. to reduce the intensity of melting. To improve the mixing of the fuel-water mixture, to increase the degree of its homogeneity in the inner space of the tuyere, inserts made of water-cooled or from some heat-resistant material are installed. The closest to the invention in technical essence and the achieved result is a blast furnace blast furnace device containing a blast nozzle, a lance with a fuel inlet pipe and a shaped heat-resistant multi-nozzle insert located in the internal space of the device 2. The disadvantage of such a constructive solution is the low degree of mixing of blast components with the fuel to the combustion mixture in the local areas of the tuyere, uneven temperature level after mixing, which ultimately worsens g with the heat of reaction of the fuel and homogeneity of the hearth gas and leads to an increase in coke consumption and to a decrease in the resistance of the tuyeres. The aim of the invention is to reduce the consumption of coke and improve the homogeneity of the furnace gas. The goal is achieved by the fact that in a known tuyere apparatus containing a blowing nozzle, a lance for feeds blow into the furnace with a fuel inlet nozzle and a shaped heat-resistant multi-nozzle insert located in the inside of the device, the insert is installed Bq the inner space of the tuyere to form two expanding nozzles critical the smaller section of which is located between the outlet end of the blowing nozzle and the outlet of the fuel-feeding pipe, and the critical section of the larger nozzle is located at a distance -6 diameters of the fuel supply pipe from the smaller critical section; the nozzles blow along the stream. Such an implementation and installation of the insert allow two stage mixing within the inner space of the tuyere to blow with fuel, to stabilize the mixed flow and to supply the fuel to the working space of the furnace with a high degree of mixing in the form of a powerful high-speed jet and a circular cross section. to increase the uniformity and distance of the discharge stream. FIG. 1 shows a tuyere device, a longitudinal section; in fig. cross section. A-A in FIG. The device contains a blowing nozzle 1 adjacent to the lance 2 by means of a detachable connection with a ball sharpening over the surface of the abutment. The tuyere 2 is made in the form of a water-cooled body 3 of conical shape, through which the fuel inlet pipe with the outlet 5 is passed into the inner space 6 of the tuyere, in which the profiled insert 7 is installed. The insert 7. is made in the form of two irregular shapes (asymmetric cones 8 and 9 connected by common surfaces 10 between each other, with grooves 11 and 12 on the lateral surface of the cones 8 and 9, which form with the inner wall 13 of the housing 3 two expanding nozzles and 15 with the input strip 16 and 17, respectively, and with critical sections and 18 and T9, respectively. The upper dilating nozzle 1 is made with a smaller flow area, the lower nozzle 15 with a larger flow area, and the ratio of the upper critical section to the lower one is within 0.5-0.8. The largest cross-sectional area of the insert 7 must be within 13-15% of the cross section of space 6. Critical section 18 should be located between the outlet end of the blowing nozzle 1 and the outlet 5 of nozzle 4, and critical section 19 should be located at a distance of k-6 diameters pipe k from critical section 18 in the direction of the blast flow. The insert 7 can be made independently water-cooled or connected by pipes with a water-cooled body. som 3. The insert 7 may also be made of a heat-resistant or refractory material, such as silicon carbide, etc., pressed or cast. It is also possible to perform an insert 7 with cooling in the center and an outer lining or fire-resistant coating (dusting. The opening angle of the expanding nozzles is selected from the conditions of continuity of flows and practically amounts to 6-8 ° for the upper nozzle and 10 for the lower nozzle. during the collision of the streams, the active interaction between each other, the presence of a stabilization area after the collision. The device operates as follows: the high-temperature blast is supplied through the nozzle 1 to the tuyere 2, and the fuel (natural, coke and other) The second gas flows through the pipe 4 and the outlet 5 into the space 6. At the meeting, the top of the cone 8 from the insert 7 blows: the stream is distributed into two unequal parts: kO% blow enters through the inlet part 16 to the critical section 18, and the rest is blown enters through the inlet part 17 to the critical section 19B of the critical section 18, the speed of the upper part increases, the blast flow increases, the ejecting effect increases, suction (trapping) and crushing of the fuel jet, active interaction with the fuel, averaging comp onentov between themselves in the expanding part 14. Simultaneously with the passage of H1 1 of the lower part of the blast flow through the critical section 19, its velocity increases, after which the lower stream collides with the upper angle of attack equal to the angle of the cone 9 which contributes to the better incorporation of oxidative components into the previously mixed reductive oxidation coyponents. The mixing process proceeds vigorously since the quantities of movement of the coy- donated flows are commensurate. After mixing the bottom, the lower and the lower flows, the uniform flow merged together continues to move within the space of 6 lance and expire into the furnace with high kinetic energy. Thus, in the proposed device, the quality of mixing is achieved by a two-stage mixing of blowing with fuel, the absence of a stagnant zone behind the insert, a section of stabilization between the insert and the output end of the tuyere. The location of the critical section of the smaller nozzle in the area between the outlet end of the blowing nozzle and the outlet of the fuel inlet nozzle allows to form a high-speed flow to blow before meeting with the fuel, to increase its ejecting effect, to increase the interaction of the flow with the fuel. The location of the critical section of the larger nozzle at the t-S distance of the fuel supply pipe diameters along the flow contributes to optimal mixing conditions of the upper flow blowing with fuel and high-speed form. lower flow allows the lower flow to be introduced into the secondary mixing with sufficient uniformity of the upper flow. A decrease in the specified distance less than the diameters leads to a premature meeting of the flows going to the secondary mixing. impairs the uniformity of distribution of reducing components in the blast stream. Increasing this distance by more than 6 diameters leads to the elimination of the stabilization area behind the insert and to the disturbance of the total flow after the collision, to a decrease in the range and removal of the mixing process beyond the limits of the tuyere. The above BepiXMero ratio of the critical section to the lower one is within 0.5-0.8 cnoco6cTByet OBJFMmization of the distribution of the blast flow going to the primary and primary mixing. Decrease of the indicated ratio of the value of 0.5 to a value. Worsening the primary mixing of the blast and fuel flow reduces the overall homogeneity after the secondary mixing. Increasing this ratio by more than 0.8 leads to ignition and local overheating in the upper part of the tuyere. The table lists the results of comparative tests of the proposed technical solution in comparison with the known.

Known solution No 0.5 2.8 13.9 EOS

1.2 1.4 l, 2 27.3 1.170

- Proposed

Krivorozhstal 2.9 .3.2 3.1 0.1 1.8 1000 Novolipetsk 5.0 11.3 8.0 3.3 1.0 1100

5.0 O, O

5.5 11.5

Claims (1)

Claim A blast furnace tuyere device containing a blast nozzle, a blast feed lance into a furnace with a fuel supply pipe, and a shaped heat-resistant insert located 994560 8 in the internal space of the device, characterized in that, in order to reduce coke consumption due to an increase in the degree of fuel reaction and uniformity of the furnace gas, the insert is installed inside the lance with the formation of two expanding nozzles, the critical section of the smaller of which is located between the outlet end of the blast nozzle and the outlet the hole of the fuel supply pipe, and the critical section of the larger nozzle is at a distance of 4-6 diameters of this pipe · from the critical section of the smaller nozzle along the flow of the blast.