CN216337769U

CN216337769U - Double-angle multi-flow multi-hole oxygen lance nozzle

Info

Publication number: CN216337769U
Application number: CN202120977923.8U
Authority: CN
Inventors: 杨振海; 潘宇
Original assignee: Suzhou Dongda Hansen Metallurgical Industry Co ltd
Current assignee: Suzhou Dongda Hansen Metallurgical Industry Co ltd
Priority date: 2021-05-10
Filing date: 2021-05-10
Publication date: 2022-04-19
Anticipated expiration: 2031-05-10

Abstract

The utility model belongs to the technical field of converter steelmaking, and particularly relates to a double-angle multi-flow multi-hole oxygen lance nozzle which is suitable for a converter top blowing oxygen lance with the diameter of more than 273 mm. The dual-angle flow adjustable multi-hole oxygen lance nozzle can enable high-pressure oxygen to form a plurality of supersonic oxygen jets which are different in angle, different in flow and arranged in a crossed manner in a converter, so that the impact area of the oxygen on a molten pool is enlarged, the stirring effect and the slag steel reaction rate are enhanced, the blowing performance of the converter oxygen lance is improved, the phenomena of splashing, slag overflow and the like are reduced, the slag melting is accelerated, and the smelting time is shortened.

Description

Double-angle multi-flow multi-hole oxygen lance nozzle

Technical Field

The utility model belongs to the technical field of converter steelmaking, and particularly relates to a double-angle multi-flow multi-hole oxygen lance nozzle.

Background

At present, converter steelmaking becomes a main means for steelmaking at home and abroad, an oxygen lance is key equipment in the converter steelmaking process, and an oxygen lance nozzle is an important part of the oxygen lance. The oxygen lance nozzle has the function of converting high-pressure high-purity oxygen in an oxygen pipeline into supersonic oxygen jet flow through a Laval type nozzle. The interaction of the oxygen jet stream with the bath is primarily dependent on the velocity magnitude and distribution of the jet as it reaches the surface of the bath. In the aspect of thermodynamics, oxygen reacts violently with elements in steel after entering molten steel, is subjected to desiliconization in the early stage and decarburization in the later stage, releases a large amount of heat, improves the temperature of the molten steel, and can realize dephosphorization and desulfurization by controlling the redox atmosphere of a converter; in the aspect of dynamics, the oxygen jet pushes the molten steel to move violently, the slag and the molten steel are fully stirred and uniformly mixed, the slag steel reaction interface is enlarged, the mass transfer coefficient of elements is improved, and the purpose of smelting is achieved.

However, in the blowing process, the nozzle of the oxygen lance is close to a high-temperature molten pool, the working environment is very severe, the heat radiation of a high-temperature region with the fire point of about 2500 ℃ is borne, the oxygen lance also suffers from the violent scouring of molten steel, steel slag and high-temperature gas and the corrosion of gas in the steel making process, and the differences in the steel making process, raw materials and the like, so that the unfavorable phenomena of lance burning, slag splashing, slag overflow, component segregation and the like exist in the steel making production process, and the problems of slag adhesion, burning loss, water leakage and the like also occur on the oxygen lance. These problems all affect the production rhythm of the processes of steel making, subsequent refining, continuous casting and the like, and reduce the quality and the yield of molten steel. Therefore, the converter oxygen lance and the operation process thereof are extremely important in the steelmaking process, and the proper oxygen lance nozzle is also the key.

SUMMERY OF THE UTILITY MODEL

Aiming at the technical problems, the utility model provides a double-angle multi-flow multi-hole oxygen lance nozzle, and the distribution of oxygen jet flow and the flow field in a molten pool are optimized through the reasonable design of the number of Laval type nozzles, the area of the nozzles and the included angle between the nozzles and the center line of an oxygen lance. The dual-angle multi-flow multi-hole oxygen lance nozzle can adopt different structural designs according to different furnace types and different technical requirements, and is simple to operate and good in performance in the converter blowing process. Compared with the common oxygen lance nozzle, the multi-hole oxygen lance nozzle provided by the utility model has three main effects: firstly, when the converter is operated at a low lance position, the converter can quickly melt slag, the splashing is weakened, and the dephosphorization effect is good; secondly, the problems of slag adhesion, burning loss, water leakage and the like can be effectively reduced, the service life of the oxygen lance is prolonged, the blowing performance is excellent, the blowing time is shortened, and the consumption of iron and steel materials is reduced.

The specific technical scheme of the utility model is as follows:

the utility model provides a double-angle multi-flow multi-hole oxygen lance nozzle and a preparation method thereof, the oxygen lance nozzle is suitable for a converter top-blown oxygen lance with the diameter of more than 273mm, the multi-hole oxygen lance nozzle is provided with two groups of nozzles, the two groups of nozzles are the same in number and are arranged in a staggered manner in a ring shape, and all the nozzles are Laval type nozzles; two groups of nozzles are respectively called A group and B group, and the two groups of nozzles are arranged according to one of the following four schemes:

large flow at a small included angle, and small flow at a large included angle: the included angle between the group A nozzles and the center line of the oxygen lance is smaller than that of the group B nozzles, and the throat area and the outlet area of the group A nozzles are larger than those of the group B nozzles;

small included angle and small flow, large included angle and large flow: the included angle between the group A nozzles and the center line of the oxygen lance is smaller than that of the group B nozzles, and the throat area and the outlet area of the group A nozzles are smaller than those of the group B nozzles;

③ same included angle, different oxygen flow: the included angle between the group A nozzles and the center line of the oxygen lance is the same as that between the group B nozzles, and the throat area and the outlet area of the group A nozzles are smaller than those of the group B nozzles;

fourthly, different included angles and the same oxygen flow: the throat area and the outlet area of the group A nozzles and the group B nozzles are the same, and the included angle between the group A nozzles and the center line of the oxygen lance is smaller than that between the group A nozzles and the center line of the oxygen lance.

Preferably, in the first setting, the included angle between the group A nozzles and the central line of the oxygen lance is 10-15 degrees, and the included angle between the group B nozzles and the central line of the oxygen lance is 15-20 degrees; in the second setting, the included angle between the group A nozzles and the central line of the oxygen lance is 10-15 degrees, and the included angle between the group B nozzles and the central line of the oxygen lance is 15-20 degrees; in the third setting, the included angles between the nozzles of the group A and the nozzles of the group B and the center line of the oxygen lance are 12-16 degrees; in the fourth arrangement, the included angle between the group A nozzles and the central line of the oxygen lance is 10-15 degrees, and the included angle between the group B nozzles and the central line of the oxygen lance is 15-20 degrees.

Preferably, in the first setting, the throat area and the outlet area of the group A nozzles are 1-1.5 times of those of the group B nozzles; in the second or third arrangement, the throat area and outlet area of the nozzles in the group B are 1-1.5 times of those of the nozzles in the group A. That is, in each setting, if the apertures of the nozzles are different, the nozzles are set according to the condition that the throat and outlet areas of the larger nozzle are 1-1.5 times (more than 1 time and less than or equal to 1.5 times) of the smaller nozzle, and after the nozzles are set, the oxygen flow of the smaller group of nozzles is also smaller and accounts for about 40% -50% of the total flow; the other group of nozzles has larger oxygen flow, which accounts for about 50 to 60 percent of the total flow.

The included angle between the nozzle of the multi-hole oxygen lance nozzle and the center line of the oxygen lance refers to the included angle between the center line of the nozzle and the center line of the oxygen lance, and the center line of the oxygen lance is also the center line of the inner pipe, the middle pipe and the outer pipe of the oxygen lance. Different included angles are adopted within 10-20 degrees according to different converter volume ratios and furnace conditions.

It is further desired that the number of laval type nozzles of the multi-hole lance nozzle head is determined by the nominal volume of the converter, and may be 4, 6, 8 or 10, and that all the nozzles are equally divided into two groups in a staggered arrangement as described above.

The multi-hole oxygen lance nozzle comprises a crown, nozzles, an oxygen disc, a water guide plate, an outer pipe, a middle pipe and an inner pipe besides the two groups of nozzles; the inner tube end is connected with the oxygen disc, the middle tube end is connected with the water guide plate, the outer tube end is connected with the head crown, one end of each nozzle is communicated with the oxygen disc and the inner tube, and the other end of each nozzle is arranged on the head crown and is communicated with the outside.

Preferably, the nozzle is connected with the oxygen disk and the head crown by brazing, the inner pipe is connected with the oxygen disk and the outer pipe is connected with the head crown by argon arc welding, the middle pipe is connected with the water guide plate by threads, and the water guide plate is fixed on the head crown by welding. The head crown, the nozzle, the water guide plate and the oxygen plate are made of red copper.

The preparation method of the porous oxygen lance nozzle comprises the following steps: various parameters of the porous spray head are designed, then the head crown, the nozzle, the oxygen disc and the water guide plate are forged by using a die, the red copper material is adopted, and the processing precision of each part is strictly controlled; assembling all parts, welding the water guide plate on the head crown, mounting the nozzle on the head crown by brazing, and mounting the oxygen disc on the nozzle by brazing; finally, the inner pipe and the oxygen plate and the outer pipe and the crown are welded together through argon arc welding, the middle pipe is connected with the water guide plate through threads, and the assembly of the spray head is completed completely; and the oxygen lance can be delivered after passing the water pressure and X-ray inspection.

The utility model has the beneficial effects that: by adjusting the number of nozzles of the multi-hole oxygen lance nozzle, the throat and outlet area of the nozzles (the utility model adopts a Laval type nozzle, the middle part of the nozzle is provided with a narrow throat, and the flow of the nozzle can be set by setting the throat area and the outlet area of the narrow throat) and the included angle between the nozzles and the center line of the oxygen lance, the oxygen can form a plurality of supersonic oxygen jets with different included angles, different flows and cross arrangement in the converter, the possibility of converging the supersonic oxygen jets in the converter is greatly reduced, the impact area of the oxygen on a molten pool is enlarged, the distribution of the oxygen in the molten pool is more uniform, the stirring effect and the slag steel reaction speed are improved, the dead zone is reduced, and the converting performance of the converter oxygen lance is improved. Different design ideas in the utility model are suitable for different converter volume ratios and converter conditions. Of the two groups of nozzles with different included angles and flow rates, the nozzle group with a large included angle can be decarburized and heated, so that slag overflow splashing caused in the blowing process is inhibited, and a certain CO secondary combustion effect is achieved; the other group of nozzles with small included angles can also perform decarburization and temperature rise, enhance stirring and improve dephosphorization effect; when a large-flow oxygen stream reaches the surface of a molten pool, the oxygen stream has a higher speed, the molten pool can be impacted out of a deep pit, strong stirring is carried out, an emulsion layer of slag, bubbles and metal droplets can form a foam slag layer in the furnace, when the foam slag layer reaches a certain height, the phenomenon of slag overflow at a furnace mouth is easy to occur, at the moment, the small-flow oxygen stream can inhibit the situation, the slag overflow at the furnace mouth is reduced, and the secondary combustion can be carried out on floating CO to increase the temperature in the furnace. Two oxygen jets with different flow rates can also improve the FeO content in the slag, accelerate slag melting and improve the dephosphorization effect. In a word, the utility model improves the blowing performance and the service life of the oxygen lance, inhibits the phenomena of splashing, slag overflow and the like, accelerates the slagging speed, shortens the blowing time, reduces the consumption of steel materials and reduces the erosion of molten steel to the converter lining.

Drawings

FIG. 1 is a simplified schematic diagram of a dual angle dual flow 6 hole lance tip in example 1. In the figure, 1 is a crown, 2 is a nozzle, 3 is an oxygen disk, 4 is a water guide plate, 5 is an outer pipe, 6 is a middle pipe and 7 is an inner pipe.

FIG. 2 is a schematic diagram of the dual angle dual flow 6 hole lance tip nozzle arrangement on the crown of the lance tip in example 1.

Detailed Description

The application of the present invention will be further explained by way of examples with reference to the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the utility model, and not restrictive of the full scope of the utility model. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the utility model encompassed by the appended claims.

The utility model provides a double-angle multi-flow multi-hole oxygen lance nozzle, wherein the specific structure of a double-angle double-flow 6-hole oxygen lance nozzle is shown in figure 1, the arrangement of 6 nozzles of the nozzle is shown in figure 2, and the nozzles are circular in the embodiment, so that the area of the nozzle can be directly reflected by the diameters of the throat and the outlet of a laval nozzle. The multi-hole oxygen lance nozzle comprises a crown 1, nozzles 2, an oxygen disc 3, a water guide plate 4, an outer pipe 5, a middle pipe 6 and an inner pipe 7, wherein the end of the inner pipe 7 is connected with the oxygen disc 3, the end of the middle pipe 6 is connected with the water guide plate 4, the end of the outer pipe 5 is connected with the crown 1, one end of each nozzle 2 is communicated with the oxygen disc and the inner pipe, and the other end of each nozzle is arranged on the crown and is communicated with the outside. The 6 nozzles are divided into two groups, each group of 3 nozzles are arranged in a mutually staggered mode in an annular mode, and the outlet diameter and the throat diameter of the two groups of nozzles are different as shown in figure 2 (only the outlet diameter is shown in figure 2). FIG. 1 shows one of each set of nozzles, the angle of the centerline of the two sets of nozzles to the centerline of the lance, i.e., the centerline of the inner tube, the middle tube, and the outer tube, is 12 and 16, respectively. As can be understood by those skilled in the art, only one of the four arrangements of the present application is shown in FIGS. 1 and 2, and the angles and the diameters of the two sets of nozzles have other three arrangements, and the difference is mainly embodied in that the angles and the diameters of the nozzles are different, and the adjustment is carried out on the basis of the oxygen lance nozzle shown in FIG. 1.

The specific preparation process of the oxygen lance nozzle in the embodiment is as follows:

designing various parameters of an oxygen lance nozzle according to the furnace volume ratio and the furnace condition of a converter, wherein the parameters mainly comprise the number of nozzles, the diameter of a nozzle throat, the diameter of an outlet, included angles (the included angles of the nozzles in the embodiment refer to the included angles of the center line of the nozzles and the center line of the oxygen lance) and the like, and designing the size parameters of each part of the nozzle;

secondly, forging and pressing the parts of the crown 1, the nozzle 2, the oxygen disc 3 and the water guide plate 4 by using a die, wherein the parts are made of red copper, and the processing precision of each part is strictly controlled;

sequentially assembling all parts, welding the water guide plate 4 to the head crown 1, then installing the nozzle 2 on the head crown 1 by brazing, installing the oxygen disk 3 on the nozzle 2 by brazing, finally respectively welding the inner tube 7 and the oxygen disk 3 as well as the outer tube and the head crown 1 together by argon arc welding, and connecting the middle tube 6 and the water guide plate 4 together by threads;

fourthly, after the spray head is completely assembled, the whole oxygen lance is subjected to water pressure and X-ray inspection, and the oxygen lance can leave the factory after being qualified.

Example 1

Double-angle double-flow 6-hole oxygen lance nozzle

In 2017, a 180t converter of a certain steel plant in 7 Yue lake, North Ozhou has a serious furnace mouth expansion phenomenon, about 30 minutes of time is wasted by each team to treat slag accumulated at the furnace mouth, and the production rhythm of the steel plant is seriously influenced. After the designer of the company communicates with the on-site technician of the steel mill, the decision is made to use the dual-angle dual-flow 6-hole oxygen lance nozzle, the structure of which is shown in figures 1 and 2. Design Mach number 2.0, design oxygen pressure 0.81Mpa, design oxygen flow 30000Nm³The included angle of three nozzles is 12 degrees, the diameter of the throat is 37.8mm, the diameter of the outlet is 49.1mm, and the oxygen flow accounts for 55 percent of the total flow; the included angle of the other three nozzles is 18 degrees, the diameter of the throat is 34.2mm, the diameter of the outlet is 44.4mm, and the oxygen flow accounts for 45 percent of the total flow.

Through production tests, the blowing effect is excellent, and the four-hole oxygen lance nozzle used before is completely replaced. Compared with the prior four-hole spray head, the six-hole double-angle double-flow spray head has the following advantages: firstly, smelting is stable, splashing is small, and the steel material of the same steel grade is reduced from 1065.3kg/t to 1057.67 kg/t; the consumption of the alloy of the same steel grade is reduced from 22.31kg/t to 21.32 kg/t; ③ the oxygen supply time of the direct continuous casting steel grade is reduced to 14.08min from 15.49min before, and the oxygen supply time of the refined steel grade is reduced to 15.23min from 17.18min before; the slagging effect is good, the qualification rate of the primary converter pouring temperature is less than or equal to 1660 ℃ and P is less than or equal to 0.040 percent is 96.6 percent, and the converter pouring qualification rate is improved by 3.2 percent compared with the former 93.4 percent.

Example 2

Double-angle double-flow 4-hole oxygen lance nozzle

A120 t converter of a steel plant of Guangdong Shaoyuan, Guangdong, 5 months in 2018 has a bottleneck in the process of improving the capacity, the oxygen pressure and the flow are increased for improving the capacity, so that the one-pouring success rate of the converter is greatly reduced, 4-hole double-flow double-angle oxygen lance nozzles are designed and produced by the company, the Mach number is designed to be 2.03, the oxygen pressure is designed to be 0.85Mpa, and the oxygen flow is designed to be 28800Nm³The included angle of the two nozzles is 11.5 degrees, the diameter of the throat is 35.8mm, the diameter of the outlet is 47.1mm, and the oxygen flow accounts for 55 percent of the total flow; the included angle of the other two nozzles is 13.2 degrees, the diameter of the throat is 32.4mm, the diameter of the outlet is 42.6mm, and the oxygen flow accounts for 45 percent of the total flow.

After a period of production practice, the converter-first pouring success rate is improved to 95% from 87%; the hit rate of the end point C is improved to 93 percent from the previous 83 percent; the hit rate of the end point P is improved to 96 percent from the previous 89 percent; the hit rate of the end point temperature is improved from the previous 80% to 92%; the average blowing time of the converter is reduced from 14min12s of each previous steel to 12min47s of the current steel, and the smelting time of each steel is shortened by 1min25 s; the consumption of the steel material is reduced from the previous 1059kg/t to the current 1051 kg/t.

Example 3

Double-angle single-flow 6-hole oxygen lance nozzle

150t converter of a certain steel plant of Suzhou, Jiangsu province in 9 months in 2018 for improving the capacity and improving the oxygen of the top-blown oxygen lanceThe flow rate and the slag overflow phenomenon of the converter due to serious splashing occur, and the consumption of iron and steel materials is greatly increased. In order to solve the problem, the company designs and produces a double-angle single-flow 6-hole oxygen lance nozzle for the same, and designs Mach number to be 2.00, oxygen pressure to be 0.81Mpa and oxygen flow to be 35000Nm³The included angle of three nozzles is 11 degrees, the diameter of the throat is 38.54mm, the diameter of the outlet is 50.07mm, and the oxygen flow accounts for 50 percent of the total flow; the included angle of the other three nozzles is 15 degrees, the diameter of the throat is 38.54mm, the diameter of the outlet is 50.07mm, and the oxygen flow accounts for 50 percent of the total flow.

After a period of production practice, the average smelting period of the converter is reduced from 31min23s to 28min47 s; the splashing slag overflow rate is reduced to 3.1 percent from the former 12 percent; the consumption of the steel material is reduced from 1062kg/t to 1053kg/t at present.

Example 4

Single-angle double-flow 6-hole oxygen lance nozzle

180t converters in a certain steel plant, Jiangsu Jiangyin 10 months in 2019 have serious standard exceeding of the content of a terminal component P of the converters due to large fluctuation of raw and auxiliary material components and unstable molten iron scrap steel, and the final slag of the converters is over-diluted and the furnace condition is extremely poor due to the fact that a large amount of slag melting agents are added for controlling the terminal component. The company designs and produces a single-angle double-flow 6-hole oxygen lance nozzle, wherein the Mach number is 2.02, the oxygen pressure is 0.83Mpa, and the oxygen flow is 33000Nm³The included angles of the nozzles are 13 degrees, the throat diameters of the three large-flow nozzles are 38.8mm, the outlet diameters of the three large-flow nozzles are 50.8mm, the oxygen flow accounts for 55 percent of the total flow, and stirring, decarburization and temperature rise can be increased; the throat diameter of the other three small-flow nozzles is 35.1mm, the outlet diameter is 46mm, and the oxygen flow accounts for 45% of the total flow, so that the three small-flow nozzles are responsible for slagging and enhancing the dephosphorization effect.

After a period of production practice, the single-angle double-flow 6-hole oxygen lance nozzle and the constant-lance variable-pressure operation mode thereof are recognized by field technicians and operators consistently, splashing and slag overflow caused by frequent lifting of the oxygen lance are avoided, and the splashing and slag overflow rate is reduced to 3% from the previous 11%; the alkalinity of the converter final slag is increased to 3.26 from the previous 2.78, and the qualified rate of the converter end point P is increased to 96% from the previous 86%; the consumption of the steel material is reduced from 1065kg/t to 1052 kg/t.

Claims

1. A double-angle multi-flow multi-hole oxygen lance nozzle is characterized in that the multi-hole oxygen lance nozzle is provided with two groups of nozzles, the two groups of nozzles are the same in number and are arranged in a staggered manner, and all the nozzles are Laval type nozzles; the two groups of nozzles are respectively called A group and B group, the included angle between the A group of nozzles and the center line of the oxygen lance is smaller than or equal to that between the B group of nozzles, the throat area and the outlet area of the A group of nozzles are larger than or equal to those of the B group of nozzles, but the included angle between the A group of nozzles and the center line of the oxygen lance, the throat area and the outlet area of the nozzles cannot be the same as those of the B group of nozzles at the same time.

2. The dual angle multi-flow multi-hole lance tip of claim 1 wherein two sets of nozzles are arranged according to one of four schemes:

large flow at a small included angle, and small flow at a large included angle: the included angle between the group A nozzles and the center line of the oxygen lance is smaller than that between the group A nozzles and the center line of the oxygen lance, the throat area and the outlet area of the group A nozzles are larger than those of the group B nozzles, the included angle between the group A nozzles and the center line of the oxygen lance is 10-15 degrees, and the included angle between the group B nozzles and the center line of the oxygen lance is 15-20 degrees;

small included angle and small flow, large included angle and large flow: the included angle between the group A nozzles and the center line of the oxygen lance is smaller than that between the group A nozzles and the center line of the oxygen lance, the throat area and the outlet area of the group A nozzles are smaller than those of the group B nozzles, the included angle between the group A nozzles and the center line of the oxygen lance is 10-15 degrees, and the included angle between the group B nozzles and the center line of the oxygen lance is 15-20 degrees;

③ same included angle, different oxygen flow: the included angle between the group A nozzles and the center line of the oxygen lance is the same as that between the group B nozzles, the throat area and the outlet area of the group A nozzles are smaller than those of the group B nozzles, and the included angles between the group A nozzles and the group B nozzles and the center line of the oxygen lance are 12-16 degrees;

fourthly, different included angles and the same oxygen flow: the throat area and the outlet area of the group A nozzles and the group B nozzles are the same, the included angle between the group A nozzles and the center line of the oxygen lance is smaller than that between the group B nozzles, the included angle between the group A nozzles and the center line of the oxygen lance is 10-15 degrees, and the included angle between the group B nozzles and the center line of the oxygen lance is 15-20 degrees.

3. The dual-angle multi-flow multi-hole oxygen lance nozzle as claimed in claim 2, wherein in the first setting, the throat area and the outlet area of the group A nozzles are 1-1.5 times of those of the group B nozzles; in the second or third arrangement, the throat area and outlet area of the nozzles in the group B are 1-1.5 times of those of the nozzles in the group A.

4. The dual angle multi-flow multihole oxygen lance tip as claimed in claim 1, wherein the total number of nozzles is 4, 6, 8 or 10.

5. The dual angle multi-flow multi-hole oxygen lance nozzle of claim 1 further comprising a crown, an oxygen tray, a water deflector, an outer tube, a middle tube and an inner tube; the inner tube end is connected with the oxygen disc, the middle tube end is connected with the water guide plate, the outer tube end is connected with the head crown, one end of each nozzle is communicated with the oxygen disc and the inner tube, and the other end of each nozzle is arranged on the head crown and is communicated with the outside.

6. The dual angle multi-flow multi-hole oxygen lance nozzle of claim 5 wherein the crown, nozzle, water deflector and oxygen tray are made of red copper.

7. The dual-angle multi-flow multi-hole oxygen lance nozzle as claimed in claim 5, wherein the nozzle is connected with the oxygen tray and the crown by brazing, the inner tube is connected with the oxygen tray and the outer tube is connected with the crown by argon arc welding, the middle tube is connected with the water guide plate by screw thread, and the water guide plate is fixed on the crown by welding.