External-direct-flow and internal-spiral-flow type efficient blowing oxygen lance nozzle

Abstract

The utility model belongs to the technical field of ferrous metallurgy, and particularly relates to an outer-direct-flow and inner-spiral-flow type efficient blowing oxygen lance nozzle. The outer straight-flow type spray pipe and the inner spiral-flow type spray pipe are arranged at the bottom of the spray head, and parameter requirements of the spray pipes are set. According to the arrangement scheme of the outer direct-flow type spray holes of the outer direct-flow and inner spiral-flow type high-efficiency blowing oxygen lance spray head, the interaction among jet streams is weakened, the contact area of jet flow and a molten pool is increased, the generation rate of liquid drops acted by the jet flow and the molten pool is obviously improved, the slagging effect is obvious, and the service life of the spray head is prolonged. The same steel grade is smelted on the premise of ensuring the same molten iron pretreatment component, the same scrap steel adding amount and the same slag adding amount in the converter steelmaking process, and the slagging time is shorter than that of a traditional oxygen lance nozzle.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the steel metallurgy technical field, concretely relates to a high -efficient oxygen lance spray head of outside direct current inside whirl -type blow smelting. TECHNICAL BACKGROUND

[0002] The performance, structure and corresponding blow smelting process of oxygen lance are closely related to the converter steelmaking effect, especially in top-blown oxygen converter steelmaking, the oxygen lance plays a leading role, which determines a series of important process factors such as the contact area of oxygen jet and converter bath, jet penetration depth, bath stirring effect, bath temperature rising rate and oxidation degree of various elements, therefore, plays a crucial role in slagging, splashing, impurity removal, end point control and various economic and technical indicators.

[0003] Therefore, in order to further improve the oxygen supply intensity, shorten the blowing time, and avoid the occurrence of out-of-furnace splashing, the utility model provides a high -efficient oxygen lance spray head of outside direct current inside whirl -type blow smelting. CONTENT OF UTILITY MODEL

[0004] In view of the above-mentioned technical problems, the utility model provides a high -efficient oxygen lance spray head of outside direct current inside whirl -type blow smelting. The spray head can effectively shorten the blowing time, reduce the in-furnace splashing of molten steel, and has good slagging effect.

[0005] In order to achieve the above-mentioned purpose, the technical scheme provided by the utility model is as follows.

[0006] A high -efficient oxygen lance spray head of outside direct current inside whirl -type blow smelting, including first pipe body 1;First pipe body 1 outside the second pipe body 4 of being equipped with, and first pipe body 1 with the second pipe body 4 between leaving first ring gap;The center of the bottom of second pipe body 4 is provided with through-hole 6;Second pipe body 4 outside the third pipe body 5 of being equipped with, and second pipe body 4 with the third pipe body 5 between leaving second ring gap;First pipe body 1, second pipe body 4 and third pipe body 5 are all cylindrical pipe body;

[0007] The bottom of third pipe body 5 is provided with outside direct current type spray pipe 2, and outside direct current type spray pipe 2 passes through the bottom wall of third pipe body 5, second pipe body 4 and first pipe body 1, and is communicated with the inside of first pipe body 1, and outside direct current type spray pipe 2 is multiple;

[0008] The bottom of third pipe body 5 is provided with inside whirl -type spray pipe 3, and inside whirl -type spray pipe 3 is arranged between every two adjacent outside direct current type spray pipe 2, and inside whirl -type spray pipe 3 passes through the bottom wall of third pipe body 5, second pipe body 4 and first pipe body 1, and is communicated with the inside of first pipe body 1, and inside whirl -type spray pipe 3 is multiple;

[0009] The distance between the axis of outside direct current type spray pipe 2 and the axis of spray head is L2, and the distance between the axis of inside whirl -type spray pipe 3 and the axis of spray head is L1, and L2 is greater than L1.

[0010] Further, the outer straight-flow nozzle 2 and the inner rotating-flow nozzle 3 adopt Laval nozzles.

[0011] Further, the ratio of the throat diameter d 2t of the outer straight-flow nozzle 2 to the throat diameter d 1t of the inner rotating-flow nozzle 3 is d 2t / d 1t =1.0~1.5.

[0012] Further, the ratio of the outlet diameter d 2e of the outer straight-flow nozzle 2 to the outlet diameter d 1e of the inner rotating-flow nozzle 3 is d 2e / d 1e =1.0~1.5.

[0013] Further, the angle between the central axis of the outer straight-flow nozzle 2 and the central axis of the lance is a2, the angle between the central axis of the inner rotating-flow nozzle 3 and the central axis of the lance is a1, and a2-a1=3°~5°.

[0014] Further, the rotation angle of the inner rotating-flow nozzle 3 is b1=8°~12°.

[0015] Further, L2 / L1=1.10~1.30.

[0016] Further, the total number of the nozzles of the lance is 6, of which 3 are the outer straight-flow nozzles 2 and 3 are the inner rotating-flow nozzles 3, and the lance is suitable for a 200~300-ton converter.

[0017] Compared with the prior art, the beneficial effects of the present application are as follows.

[0018] 1. Compared with the conventional lance of the same converter capacity, the arrangement of the outer straight-flow nozzle holes of the outer straight-flow inner rotating-flow high-efficiency blowing and refining lance of the present application weakens the interaction between the jet streams, increases the contact area between the jet and the molten pool, significantly improves the droplet generation rate of the jet and the molten pool, and significantly improves the slag melting effect. Under the premise of ensuring the same pretreatment composition of the molten iron, the same amount of scrap steel and the same amount of slag addition in the converter steelmaking process, the same steel grade is smelted, and the slag melting time of the conventional lance is shortened by 10-20s.

[0019] 2. In addition to increasing the generation of molten metal droplets and better process control, using the high-efficiency blowing and refining lance in the steelmaking process can also bring other benefits. The service life of the lance is prolonged: the arrangement of the outer straight-flow nozzle holes and the inner rotating-flow nozzle holes staggered provides more water-cooled space for fluid flow, and under the same smelting conditions, the smelting furnace number of the lance of the present application is increased by 30~50 times compared with the conventional lance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a front sectional view of the external direct current and internal swirl high-efficiency blowing oxygen lance nozzle of the utility model.

[0021] Figure 2 This is a three-dimensional cross-sectional view of the external direct current and internal swirl high-efficiency blowing oxygen lance nozzle of the utility model.

[0022] Figure 3 This is a top view of the nozzle of the external direct current and internal swirl high-efficiency blowing oxygen lance of the utility model.

[0023] Figure 4 This is a bottom view of the nozzle of the external direct current and internal swirl high-efficiency blowing oxygen lance of the utility model.

[0024] Label: 1. First tube body; 2. External straight-flow nozzle; 3. Internal swirl nozzle; 4. Second tube body; 5. Third tube body; 6. Through hole. DETAILED DESCRIPTION

[0025] The following embodiments of the technical solution of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only examples and cannot be used to limit the scope of protection of the present invention.

[0026] like Figures 1-4 As shown, the embodiment of the present invention provides an external direct current inner swirl type high-efficiency blowing oxygen lance nozzle, comprising a first tube body 1; a second tube body 4 is sleeved on the outside of the first tube body 1, and a first annular gap is left between the first tube body 1 and the second tube body 4; a through hole 6 is opened in the center of the bottom of the second tube body 4; a third tube body 5 is sleeved on the outside of the second tube body 4, and a second annular gap is left between the second tube body 4 and the third tube body 5; the first tube body 1, the second tube body 4 and the third tube body 5 are all cylindrical tubes; an external direct current nozzle 2 is provided at the bottom of the third tube body 5, and the external direct current nozzle 2 passes through the third tube body 5. The second tube body 4 and the bottom wall of the first tube body 1 are connected to the interior of the first tube body 1, and there are multiple external straight-flow nozzles 2; an internal swirl nozzle 3 is provided at the bottom of the third tube body 5, and the internal swirl nozzle 3 is provided between every two adjacent external straight-flow nozzles 2. The internal swirl nozzle 3 passes through the third tube body 5, the second tube body 4 and the bottom wall of the first tube body 1, and is connected to the interior of the first tube body 1. There are multiple internal swirl nozzles 3; the distance between the axis of the external straight-flow nozzle 2 and the axis of the nozzle is L2, and the distance between the axis of the internal swirl nozzle 3 and the axis of the nozzle is L1, and L2 is greater than L1.

[0027] This embodiment uses a group of external direct-flow nozzle holes and a group of internal swirl nozzle holes to replace the traditional oxygen lance nozzle holes. The external direct-flow nozzle holes are arranged on the periphery of the nozzle end face with a relatively large center distance. During the blowing process, the external direct-flow nozzle holes avoid the rapid fusion of the jet streams and ensure the independence of each stream in the jet direction, thereby increasing the contact area between the jet streams and the molten pool. Moreover, the jet intensity of the dispersed streams is relatively weak, which to a large extent prevents splashing from being too high and ejected from the furnace mouth. Compared with the external direct-flow nozzle holes, the internal swirl nozzle holes are arranged on the inner side of the nozzle end face with a relatively small center distance. The internal swirl nozzle holes can enable the jet streams to stir the converter molten pool in a swirl manner, thereby ensuring the stirring intensity of the molten pool during the blowing process.

[0028] In one embodiment, the throat diameter d of the outer straight nozzle 2 is 2t The throat diameter d of the inner swirl nozzle 3 1t The ratio is (46.4 / 37.6)d 2t / d 1t =1.2; the outlet diameter d of the external straight-flow nozzle 2 2e The outlet diameter d of the inner swirl nozzle 3 1e The ratio is (61.2 / 50.3)d 2e / d 1e =1.2. This preferred diameter ratio enables the reactants to be mixed quickly and evenly, thereby significantly improving the kinetic conditions of various chemical reactions during the steelmaking process, such as oxidation, desulfurization, and dephosphorization, and accelerating the reaction rate, thereby shortening the time required to reach the blowing endpoint.

[0029] In one embodiment, the central axis of the outer straight-flow nozzle 2 forms an angle α2 with the central axis of the nozzle head, while the central axis of the inner swirl nozzle 3 forms an angle α1 with the central axis of the nozzle head. (16° - 12° (α2 - α1) = 4°); the rotation angle of the inner swirl nozzle 3 is β1 = 8°. This preferred angle ratio allows the oxygen in the inner swirl to generate a strong swirling airflow within the molten pool, forming a vortex and causing intense movement of the molten steel and slag within the pool. The outer straight-flow oxygen jet penetrates deeply into the bottom of the molten pool, further enhancing the stirring effect. This combined stirring method can rapidly homogenize the composition and temperature within the molten pool.

[0030] In one embodiment, (115 / 100) L2 / L1 = 1.15. This preferred distance ratio allows the rotational force generated by the internal swirling oxygen flow to promote better mixing of the slag and molten steel, improving the slag's fluidity. The external direct oxygen jet helps blow the slag toward the edge of the molten pool, expanding the reaction interface between the slag and molten steel, and accelerating the melting and reaction of the slag.

[0031] During blowing, oxygen enters the first pipe body 1 of the lance from the oxygen branch pipe, and then enters the outer straight-flow nozzle 2 and the inner rotational-flow nozzle 3, and the oxygen is sprayed from the outer straight-flow nozzle 2 and the inner rotational-flow nozzle 3 to form supersonic jets; cold water enters the second ring gap through the through hole 6 from the first ring gap.

[0032] To verify the obvious effect of the oxygen lance nozzle of the utility model compared with the traditional oxygen lance nozzle, comparative experiments of the new type of outer straight-flow inner rotational-flow oxygen lance nozzle and the traditional oxygen lance nozzle under the same smelting conditions are carried out, and the specific sizes of the two oxygen lance nozzles are shown in Table 1.

[0033] Table 1 Geometric parameters of the traditional oxygen lance nozzle and the new type of oxygen lance nozzle for 260t converter.

[0034]

[0035] During the experiment, the produced steel grade is plain carbon plate, the molten iron quantity is 260t, the scrap steel quantity is 30-40t, the total pipe oxygen pressure is 1.3MPa, the working oxygen pressure is 1.05MPa, the oxygen supply flow is 56000Nm 3 / h, the blowing lance position is changed at 2.5m-3.0m, the process lance position is changed at 2.5m-2.7m, and the carbon pulling lance position is changed at 2.0m-2.4m.

[0036] To ensure the accuracy of the experiment, the pretreated molten iron composition used in the experiment is shown in Table 2, and the difference of each furnace and the average value is not large. The blowing effect of the representative 5 consecutive furnaces is recorded and compared and analyzed.

[0037] Table 2 Analysis of key smelting indexes.

[0038]

[0039] By comparing the indexes in Table 2, it is found that the advantages of the outer straight-flow inner rotational-flow high-efficiency blowing oxygen lance nozzle are reflected in that the blowing time is shortened by 35 seconds, the oxygen supply intensity is increased by 0.40 m 3 / t min, and the splashing rate is reduced by 0.54%. This is mainly due to that the oxygen in the inner rotational-flow part generates strong rotational airflow in the molten pool to form a vortex, so that the molten steel and slag in the molten pool move violently. The outer straight-flow oxygen jet further strengthens the stirring effect. This combined stirring mode can make the composition and temperature in the molten pool rapidly and uniformly. In the steelmaking process, when the slagging material or alloy material is added, the strong stirring can make them quickly disperse in the molten pool and accelerate the diffusion speed of the reaction substances.

[0040] Compared with the current oxygen lance nozzle, the high-efficiency blowing oxygen lance nozzle can effectively shorten the blowing time, which fully shows that the main oxygen jet flow adopts the way of blowing gas cyclone blowing, can effectively improve the blowing stirring condition, and enhance the stirring intensity of the molten pool.

Claims

1. A high-efficiency external-DC internal-cyclone type blow converting oxygen lance nozzle, characterized in that, Including first pipe body (1), the first pipe body (1) outside is equipped with second pipe body (4), and the first pipe body (1) and the second pipe body (4) between leave first ring gap, the bottom of the second pipe body (4) is equipped with through-hole (6) in the center, the second pipe body (4) outside is equipped with third pipe body (5), and the second pipe body (4) and the third pipe body (5) between leave second ring gap, the first pipe body (1), the second pipe body (4) and the third pipe body (5) are all cylindrical pipe body, The bottom of the third pipe body (5) is provided with outer straight-flow nozzle (2), the outer straight-flow nozzle (2) passes through the bottom wall of the third pipe body (5), the second pipe body (4) and the first pipe body (1), and is communicated with the inside of the first pipe body (1), the outer straight-flow nozzle (2) is multiple, The bottom of the third pipe body (5) is provided with inner rotating-flow nozzle (3), the inner rotating-flow nozzle (3) is arranged between every two adjacent outer straight-flow nozzle (2), the inner rotating-flow nozzle (3) passes through the bottom wall of the third pipe body (5), the second pipe body (4) and the first pipe body (1), and is communicated with the inside of the first pipe body (1), the inner rotating-flow nozzle (3) is multiple, The distance between the axis of the outer straight-flow nozzle (2) and the nozzle axis is L2, the distance between the axis of the inner rotating-flow nozzle (3) and the nozzle axis is L1, L2 is greater than L1.

2. The outer-DC inner-cyclone high-efficiency blowing oxygen lance nozzle according to claim 1, characterized in that, The throat diameter d of the outer straight jet nozzle (2) 2t The throat diameter d of the inner rotating jet nozzle (3) 1t The ratio d 2t / d 1t = 1.0 ~ 1.

5.

3. The outer-DC inner-cyclone high-efficiency blowing oxygen lance nozzle according to claim 1, characterized in that, The ratio of the exit diameter d 2e of the outer straight jet nozzle (2) to the exit diameter d 1e of the inner rotating jet nozzle (3) is d 2e / d 1e = 1.0 to 1.

5.

4. The outer-DC inner-cyclone high-efficiency blowing oxygen lance nozzle according to claim 1, characterized in that, The angle between the central axis of the outer straight-flow nozzle (2) and the central axis of the nozzle is α2, the angle between the central axis of the inner rotating-flow nozzle (3) and the central axis of the nozzle is α1, α2-α1 = 3°~5°.

5. The outer-DC inner-cyclone high-efficiency blowing oxygen lance nozzle according to claim 1, characterized in that, The rotation angle of the inner rotating-flow nozzle (3) is β1= 8°~12°.

6. The outer-DC inner-cyclone high-efficiency blowing oxygen lance nozzle according to claim 1, characterized in that, L2 / L1=1.10~1.

30.

7. The outer-DC inner-cyclone high-efficiency blowing oxygen lance nozzle according to claim 1, characterized in that, The total number of the nozzle of the oxygen lance nozzle is 6, wherein the 3 outer straight-flow nozzles (2), 3 inner rotating-flow nozzles (3).

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