CN218946331U

CN218946331U - Energy-saving steel ladle lining structure

Info

Publication number: CN218946331U
Application number: CN202222481844.5U
Authority: CN
Inventors: 田守信; 申娟娟; 张继国; 贺恒星; 田守民
Original assignee: YANGGU XINMIN REFRACTORY MATERIALS CO Ltd; SHANDONG KEXIN NEW MATERIALS CO Ltd
Current assignee: YANGGU XINMIN REFRACTORY MATERIALS CO Ltd; SHANDONG KEXIN NEW MATERIALS CO Ltd
Priority date: 2022-09-20
Filing date: 2022-09-20
Publication date: 2023-05-02
Anticipated expiration: 2032-09-20

Abstract

The utility model discloses an energy-saving steel ladle lining structure which comprises a heat preservation layer, a safety layer and a working layer; the working layer consists of a slag line working layer and a molten pool working layer; the safety layer is made of high-performance refractory materials such as high-performance magnesia carbon bricks. Plays a vital role in the safety of the ladle in the running process; the heat preservation layer is composed of a heat insulation film and a heat preservation block. The heat insulation film is adhered to the inner surface of the ladle shell, the thickness of the heat insulation film is less than 0.2mm, and the heat insulation film plays an important role in heat reflection. The heat-insulating block consists of a nano-micron light heat-insulating block and a nano-plate embedded in the nano-micron light heat-insulating block. The nano-micron light heat-insulating block plays a role in heat insulation and protection of the nano-plate and also plays a role in resisting molten steel leakage. The ladle structure remarkably reduces heat transfer, and plays an important role in ladle molten steel temperature and molten steel temperature drop prevention. Through scientific masonry, each part fully plays a role, ensures the safe operation and heat dissipation of the ladle to be reduced to an extremely low degree, and obviously saves energy and reduces production cost.

Description

Energy-saving steel ladle lining structure

Technical Field

The utility model belongs to the field of energy conservation of metallurgical kilns, and particularly relates to an energy-saving steel ladle lining structure.

Background

When the temperature of molten steel is too high in the continuous casting process, the molten steel is easy to oxidize secondarily, inclusions are increased, meanwhile, a series of problems such as bulging, steel leakage, developed columnar crystals, center segregation, serious shrinkage cavity and the like of a casting blank in the casting process are easy to occur, and both the theory and practice of high-efficiency continuous casting show that the realization of low-temperature casting is one of important means for improving the drawing speed and the quality of the casting blank. Therefore, continuous casting is required to cast high-grade steel types such as bearings, gears, cords, petroleum billets, automobile plates and the like, low superheat degree casting is required to be realized for improving the quality of casting billets, and production accidents of low-temperature casting molten steel temperature drop and tundish nozzle sticking are also required to be solved. In order to achieve the aim, the smaller the fluctuation range of the molten steel temperature in the continuous casting process is, the better the fluctuation range is, the temperature of each furnace is required to be controlled within 10 ℃, and the temperatures of each furnace are basically consistent, so that the used ladle is covered and insulated and baked during the blank period, and the sufficient molten steel filling time from the continuous casting to the continuous casting is required to achieve the heat saturation of the ladle, the selection and the masonry method of the ladle lining refractory have great influence on the heat insulation performance of the ladle, the ladle lining refractory is expected to have sufficient strength, and the working layer is required to have good heat insulation and heat preservation effects besides the good high-temperature and corrosion resistance performance.

For ladle lining heat preservation, a layer of silicon-calcium plate or fiber felt and the like is used for heat preservation in a steel shell, and then a layer of permanent layer of castable is poured. The layer of castable is typically aluminum-magnesium or high aluminum. And then masonry the working layer. The magnesia carbon bricks with high heat conductivity coefficient are commonly used in the working layer. Its carbon content is as high as 14% or more, so its thermal conductivity is as high as 15 w/(m k). The ladle masonry mode leads to higher ladle shell temperature, and the steel shell temperature generally reaches more than 300 ℃. Some reached approximately 400 ℃. Thus, a large amount of heat is emitted, and the energy consumption is increased and the environment is deteriorated, resulting in an increase in cost.

In recent years, a nano heat insulating plate is presented, and the heat conductivity coefficient of the material is very low and is about 20% of that of a common heat insulating material. Plays an important role in energy saving. The method is applied to ladle heat preservation, and can reduce the temperature of the ladle shell to below 300 ℃ and reach 260-300 ℃. However, the nanomaterial has a heat insulating effect by forming closed nanopores, and the active sintering of the nanomaterial results in a low use temperature range, typically 1100 ℃ or less. For such high temperatures of the ladle, it is evident that the actual working environment temperature is higher than its sintering temperature. The material is easy to sinter, so that the heat conductivity coefficient is increased, the shrinkage is large, and the service life is greatly shortened. Therefore, not only the heat preservation performance is reduced, but also the steel lining structure is damaged, so that the hidden danger of safety accidents is caused.

The Chinese patent document with the authority of publication number CN101386067B discloses a steel ladle lining and a masonry process thereof, wherein a layer of light mullite brick is added between a nanometer heat insulation plate and a permanent layer casting material, so that the working environment temperature of the heat insulation layer can be reduced from above 1350 ℃ to within 1100 ℃. However, the mullite brick in the patent has a brick joint, and steel leakage is easy to occur after long-term use. In addition, the patent adopts heavy aluminum-magnesium casting material as a permanent layer, and the heat preservation performance is obviously improved compared with that of the traditional ladle lining, the temperature of the steel shell is reduced from 300 ℃ to 260 ℃, but the temperature is still very high, and the heat loss is serious.

Disclosure of Invention

In order to solve the problems, the ladle lining structure and the masonry method can reduce the temperature drop of molten steel in a ladle, realize energy conservation and low superheat degree casting of a tundish and ensure smooth production.

In order to solve the technical problems, the utility model provides the following technical scheme:

an energy-saving steel ladle lining structure sequentially comprises a heat insulation layer, a safety layer and a working layer from a steel ladle shell to the inside, wherein the working layer consists of a slag line working layer and a molten pool working layer, the heat insulation layer consists of a heat insulation film and a heat insulation block, the heat insulation film is adhered to the inner surface of the steel ladle shell, the heat insulation block consists of a nano-micron material block and a nano-heat insulation plate, a groove is formed in one surface, close to the heat insulation film, of the nano-micron material block, and the nano-heat insulation plate is inlaid in the groove.

The preferable scheme is as follows: the thickness of the heat insulation film is smaller than 0.2mm, and the heat insulation film is made of any one of aluminum foil, tin paper, galvanized paper, stainless steel paper, magnesium aluminum alloy paper, titanium foil, silver-plated paper and copper paper.

The preferable scheme is as follows: the thickness of the safety layer is 20-150 mm, and the two surfaces parallel to the steel ladle shell are coated with reflective heat insulation coating, wherein the thickness of the safety layer is less than 1mm.

The preferable scheme is as follows: the thickness of the slag line working layer is 100-250 mm, and the thickness of the molten pool working layer is 100-200 mm.

The preferable scheme is as follows: the thickness of the heat preservation block is larger than or equal to 20mm, the depth of the groove is 5-50 mm, and the depth of the groove is consistent with the thickness of the nanometer heat insulation plate.

Compared with the prior art, the utility model has the following beneficial effects:

1. the working layer adopts a heat-insulating magnesia carbon brick, and the heat conductivity coefficient of the heat-insulating magnesia carbon brick is less than 5 w/(mk); the temperature of the back surface of the working layer can be reduced to 1400 ℃ at 1500 ℃. Thus, the method is very beneficial to energy conservation and prolonging the service life of the high-strength light nano-micron castable and the nano-thermal insulation board;

2. the safety layer on the back of the working layer adopts high-performance bricks such as magnesia carbon bricks, corundum spinel bricks and the like, which are very corrosion-resistant refractory materials, and the safety layer forms an integral pot like the extremely high-performance refractory materials, thereby providing safety guarantee for preventing steel drilling and steel leakage. Meanwhile, as the heat-insulating paint is coated on the two sides, the heat-insulating paint plays a good role in reducing heat loss;

3. the back of the safety layer is a heat preservation block, and a high temperature area is made of nano-micron materials in the heat preservation block, and the heat preservation block can be formed by mechanical pressing or casting. It plays an important role in protecting the nano-plate and further reducing heat dissipation; the nano-plate is protected by nano-micron material in the protection Wen Kuaicao, so that the pressure and hot surface temperature are prevented from exceeding the standard, and the nano-plate works under the safe condition. Thus greatly prolonging the service life of the nano plate. The service life of the nano plate is only 1-2 months when the nano plate is used on a steel ladle, and the service life of the nano plate with the structure exceeds one year, so that the service life of the nano plate is completely synchronous with that of a permanent layer or a safety layer;

4. compared with the heat insulation coating, the heat insulation film adopted on the inner surface of the steel shell has the following advantages: the heat reflection coefficient is higher, so that the energy-saving effect is better and the construction is more convenient;

5. the composite structure is adopted to build the lining, so that the heat preservation performance is very good; even under the condition of ladle capacity expansion, the temperature of the ladle shell can be reduced by more than 100 ℃; the energy consumption of the refining ladle is reduced by 7.5 kwh/ton of steel and the superheat degree of pouring steel in the tundish is reduced; the quality of the steel billet is obviously improved, the cost is reduced, and the energy is saved and the environment is protected; in the continuous casting process, the temperature fluctuation of the molten steel of the tundish is controlled within 10 ℃, so that conditions are created for continuous casting of special steel, and the internal quality waste of billets can be reduced.

Drawings

FIG. 1 is a schematic diagram of the structure of an energy-saving ladle liner of the utility model;

FIG. 2 is a diagram of the internal structure of the thermal insulation block of the present utility model;

wherein 1 is a steel cladding, 2 is a heat insulation film, 3 is a heat insulation block, 4 is a safety layer, 5 is a working layer, 31 is a nanometer heat insulation plate, and 32 is a nanometer micrometer block.

Detailed Description

In order that the manner in which the above recited features, objects and advantages of the present utility model are obtained will become readily apparent, a more particular description of the utility model will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Based on the examples in the embodiments, those skilled in the art can obtain other examples without making any inventive effort, which fall within the scope of the utility model. The experimental methods in the following examples are conventional methods unless otherwise specified, and materials, reagents, etc. used in the following examples are commercially available unless otherwise specified.

Example 1

As shown in fig. 1, the energy-saving steel ladle lining comprises a heat insulation film, a heat preservation layer, a safety layer and a working layer, wherein the working layer consists of a slag line working layer and a molten pool working layer, the thickness of the slag line working layer is formed by MT-14A magnesia carbon bricks with the thickness of 200mm, and the thickness of the molten pool working layer is formed by aluminum magnesia carbon bricks with the thickness of 180 mm. The heat insulation coefficient of the brick is less than 5 w/(mk), and the back temperature of the working layer can be reduced from 1500 ℃ to 1400 ℃, which is beneficial to saving energy and improving the service life of the high-strength light nano-micron material and the nano heat insulation board.

The safety layer is made of high-strength magnesia carbon bricks with carbon content of 5, and the bricks are anti-corrosion refractory materials, so that safety guarantee is provided for preventing steel drilling and steel leakage. And the double sides of the safety layer are also coated with heat insulation paint, which plays a good role in reducing heat loss. The thickness of the security layer was 60mm.

The heat preservation layer is made of 10mm nano plates and heat preservation blocks, wherein the heat preservation blocks are specifically alumina nano-micro blocks, and the nano plates are arranged in grooves of the alumina nano-micro blocks. The area fraction of the nano plate to the heat insulation block is 80%, and the thickness of the heat insulation layer is 50mm. The heat insulating film was aluminum paper with a thickness of 15. Mu.m.

The method for building the ladle lining comprises the following steps:

(1) Cleaning slag, rust and dust deposit in the cladding, attaching double-sided adhesive tape, and then attaching aluminum paper to the inner surface of the ladle shell, wherein the thickness of the aluminum paper is 15 mu m, and the reflectivity is 95%.

(2) The insulating blocks are built layer by layer from the lower part of the wrapping wall, the insulating blocks need to be squeezed tightly, and fireclay can be used. But no fireclay is used near the surface of the heat insulation film, the layers are built by staggered joint, and when the joint is more than 1/3, bricks are cut and built. When the ratio is less than 1/3, the high-strength heat-insulating fireclay is used for filling. A gap must not be left.

(3) And a safe layer is built by layers from the lower direction of the wall. High-temperature high-strength fireclay is used between the high-strength magnesia carbon bricks with the carbon content of 5 percent, a wood hammer is used for beating, compaction and sealing, fireclay is not used on the back and the front of the bricks, and fireclay is used between layers. The bricks between the layers are laid with certain staggered joints. The built safety layer becomes a high-durability whole after baking, and plays an important role in safety.

(4) The slag line working layer is built by MT-14A heat insulation magnesia carbon bricks, and the molten pool working layer with the thickness of 180mm is built by aluminum magnesia carbon bricks. And the layers of bricks are built in staggered layers.

(5) After the working layer is built, the opening of the bag is sealed by plastic castable, and then the bag is naturally dried for 24 hours.

(6) Then baking with small fire, baking with medium fire and large fire for more than 8 hours after water is removed, and baking temperature before on-line use is not lower than 1000 ℃. The performance index of the refractory material is shown in Table 1

Table 1 refractory performance

Product name	High-strength light micro-nano block	Nano plate	Magnesia carbon brick	Aluminium magnesia carbon brick	High-performance magnesia carbon brick
						Region of action	Thermal insulation block	Thermal insulation block	Slag line	Molten pool	Security layer
MgO/%≧	2		78	8	80
						F.C/%≧			14	9	4
Al ₂ O ₃ /%≧	85	60	2	70	5
						SiO ₂ /%≧		20
Compressive strength/MPa ∈	5	0.2	35	40	45
						Bulk Density/g.cm ^-3 ≧	1.6	0.3	3.00	2.95	3.05
Apparent porosity/% -less than or equal to			3	4	4
						Thermal conductivity/w. (mk) ^-1	0.3	0.025	6	5	1.5

The construction is carried out on a 120t ladle according to the method described in the embodiment 1, the ladle is put into operation, the temperature of the steel shell is 210 ℃ (slag line) and 205 ℃ (ladle wall), compared with the prior ladle shell temperature of 350 ℃, the temperature is reduced by more than 140 ℃, the tapping temperature is reduced by 16 ℃, and the cost and the energy consumption are remarkably reduced.

Example 2

The basic structure of the energy-saving steel ladle lining can still refer to figure 1, but the thickness of the heat insulation block is reduced to 40mm, the thickness of the inner nano plate is still 10mm, and the thickness of the safety layer is changed to 40mm.

Construction was performed as described in example 2 on a 120t ladle, and after the ladle was put into operation, the ladle temperature was stabilized at 240 ℃ (slag line) and 235 ℃ (bath). Compared with the prior structural steel ladle shell with a 20mm fiber board heat insulation layer and a 100mm high-aluminum casting material permanent layer, the temperature of the structural steel ladle shell is reduced by as much as 110 ℃ at 350 ℃. In particular, the weight of the steel ladle is reduced by 7 tons, and the safety of driving and transportation is improved. On the other hand, the steel holding capacity can be improved by about 1.2 tons, the yield can be increased by 1 percent, and the steelmaking efficiency is improved.

Example 3

The basic structure of the energy-saving ladle lining can still be referred to in fig. 1, but the energy-saving ladle lining is different from the embodiment 1: the heat insulating film is silver plated on the surface of a steel plate, and the thickness of the heat insulating film is 20 mu m. The thickness of the heat preservation block is 100mm, the thickness of the nano plate in the heat preservation block is 20mm, the nano-micron material part is 80mm, and the thickness of the whole heat preservation block is 100mm. The safety layer is 50mm thick.

Construction was performed as described in example 3 on a 90 ton LF-VD ladle, the ladle was put into operation and the steel shell temperature was stabilized at 180 ℃ (slag line) and 175 ℃ (bath). The temperature of the ladle shell is reduced by nearly 50 percent compared with the prior ladle shell. In particular, the prior use of 10mm nano-plates is changed to cause the temperature instability of the ladle. When the 10mm nano plate is adopted in the past, the temperature of the ladle shell is increased from 260 ℃ to 340 ℃ or higher after one or two ladle passes. The temperature of the ladle shell with the structure is 160-190 ℃ and is stable for more than one year, and the ladle shell is synchronous with the safety layer. This significantly reduces costs and saves energy, bringing great stability to the production planning schedule.

The embodiments of the present utility model have been described in detail with reference to the drawings, but the present utility model is not limited thereto, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present utility model.

Claims

1. The utility model provides an energy-saving ladle lining structure, inwards is heat preservation, safe layer and working layer from the ladle shell in proper order, the working layer constitute by slag line working layer and molten pool working layer, its characterized in that, the heat preservation comprises thermal-insulated membrane and heat preservation piece, wherein, thermal-insulated membrane adhesion is at the ladle shell internal surface, the heat preservation piece comprises nanometer material piece and nanometer heat insulating board, the one side that is close to the thermal-insulated membrane of nanometer material piece is provided with the recess, nanometer heat insulating board inlays in the recess.

2. The energy-saving steel ladle lining structure according to claim 1, wherein: the thickness of the heat insulation film is smaller than 0.2mm, and the heat insulation film is made of any one of aluminum foil, tin paper, galvanized paper, stainless steel paper, magnesium aluminum alloy paper, titanium foil, silver-plated paper and copper paper.

3. The energy-saving steel ladle lining structure according to claim 2, wherein: the thickness of the safety layer is 20-150 mm, and the two surfaces parallel to the steel ladle shell are coated with reflective heat insulation coating, wherein the thickness of the safety layer is less than 1mm.

4. An energy-efficient ladle lining structure according to claim 3, wherein: the thickness of the slag line working layer is 100-250 mm, and the thickness of the molten pool working layer is 100-200 mm.

5. The energy-saving steel ladle lining structure according to claim 1, wherein: the thickness of the heat preservation block is larger than or equal to 20mm, the depth of the groove is 5-50 mm, and the depth of the groove is consistent with the thickness of the nanometer heat insulation plate.