Changxing Refractory,Refractory Brick,Castable,Ladle Nozzle,Calcium Silicate,Silicon Carbide: Advantages of covering agent
Changxing Refractory,Refractory Brick,Castable,Ladle Nozzle,Calcium Silicate,Silicon Carbide: Advantages of covering agent: covering agent 1, Insulation covering agent is made of low thermal conductivity material composition, such as: expanded perlite, expand...
2.In addition to the low thermal conductivity material, by adding a certain percentage of the heating material, and under the heat of the metal liquid, the oxidant provides oxygen to oxidize the reducing agent and prolong the solidification time of the metal liquid in the riser.
3.In the case of different insulation covering agent, the mouth shrinks into a "dish-shaped flat or hemispherical bottom, which is shaped like a U-shaped throat.
(1) Clay refractory brick, clay brick A12O3 content is generally between 30% -50%, the price is low. Mainly used for ladle permanent layer and ladle bottom.
(2) high alumina brick. Brick A12O3 content of 50% -80%, mainly for the working layer ladle.
(3) wax stone brick. The refractory supplier brick is characterized by high SiO2 content. Generally more than 80%, anti-erosion than the clay brick and the integrity of the good, and not hanging residue. Commonly used in the ladle wall and package at the end.
(4) Zircon brick. The brick is mainly used for ladle slag line parts. Brick ZrO2 content is generally between 60% -65%.
(5) Magnesia carbon bricks. The brick is mainly used for ladle slag line parts, especially for multi-furnace continuous casting occasions. Brick MgO content is generally about 76%, carbon content of 15% -20%. It is characterized by small erosion of slag, erosion resistance, good resistance to spalling.
(6) aluminum-magnesium castables. The castable is mainly used for the steel body, and is characterized in that, under the action of molten steel, MgO and A12O3 in the castable react with each other to form aluminum oval spinel, thereby improving the thermal shock resistance of the lining.
(7) aluminum-magnesium carbon brick. This brick is developed on the basis of aluminum-magnesium castable ladle lining, long service life.
(8) Do not burn brick. At present, the materials used in ladle firing bricks can be made into corresponding unburned brick. Its characteristics are relatively simple production process, the price is lower. Brick itself has a certain mechanical strength and erosion resistance, easy construction masonry.
If the ladle itself is also used for refining, you can also choose MgO-Cr2O3-A10O3 series and magnesia carbon brick refractory, are: magnesia-chrome brick, magnesia-chrome-aluminum brick, dolomite brick.
In the content of ink material used for ladle lining brick, it is best to apply a layer of anti-oxidation coating on its surface to prevent burning in the package, the lining surface oxidation loose, affecting its service life.
The word "current" can be read in months or even weeks as the computer industry in the electronics industry changes. When it comes to the development and application of refractories in the glass industry, it can easily be read as five or ten years. Based on this notion of time, we will recall that there has been a change in the discussion of the "current" area (more conservatively) in the latter area.
There are three major driving forces behind the development of refractory materials. The first glass manufacturer typically needs to improve glass quality in order to maintain it at least. The second glass kiln economy required a longer kiln operation cycle and a third pure oxygen combustion system with impact. These three requirements usually determine the choice of improved refractories when repairing the kiln. These impetuses have also prompted the glass manufacturer to use the furnace with improved fire-resistant products for maintenance and repair, as well as the introduction of new technologies for a wide range of maintenance runs.
Melting-cast alumina bricks have been melting pool top this part of the establishment of its application, the main melting high-quality glass pure oxygen combustion furnace was applied. Prior to the advent of pure oxygen combustion technology, only beta alumina bricks were used to melt pool superstructure and no melt cast alumina bricks were used on top of the melting pool. Today, both β-alumina and α-β alumina melt-cast products are used to produce color TV (screen cone), float glass and borosilicate glass pure oxygen combustion furnace some or all of the roof. Melt-cast AZS bricks can typically be used at 1600 ° C or 1650 ° C (depending on the glazing), while furnace tops with fused alumina are successfully operated at 1700 ° C. This gives glass manufacturers greater flexibility when creating refractory glass.
For many years, melt-cast AZS roofs have successfully undergone a cooling and reheating test to enable them to use multiple operating cycles. There is now a bit of experience in the successful implementation of top cooling and reheating of fused-alumina roofing, demonstrating an economically viable life when they use two or more cycles of operation. The results of fused alumina furnace roof observation (thermal observation and shutdown) show that these materials are both chemically and mechanically stable. This was the earliest observation of this type of masonry study since there was neither a fused alumina reference nor the empirical basis of its roof application.
High-chromium refractory products used to be mainly used to enhance the glass furnace, and a small amount used in insulation glass pool furnace. High chrome bricks are increasingly being used by some soda lime glass furnaces. Its main use has not only been limited to all or part of the flow hole, but also for the end wall and to a limited extent for the filler brick. For high chrome brick components, they are potentially dangerously colored, so that high-chromium products are often not compatible with very "white" glass. In the initial period this product was mainly used for colored glass, but high chromium products have also been successfully used in transparent container glass furnaces. The use of high-chromium glass furnaces depends largely on the design of the liquid hole, the cooling of the liquid hole, the daily production of the furnace, and the operation of the furnace. A glass manufacturer may use high-chrome bricks for the entire cover plus the melting tank end wall. High Chromite brickwork liquid caves offer the potential to increase kiln life because this material provides at least twice as much resistance to most glass as molten AZS bricks. However, some design parameters differ from those of fused AZS bricks and need to be discussed with the supplier.
Due to the different kiln body structure and thermal engineering process, intermittent kiln produces 5 times more flue gas than continuous kiln production. In general, the higher the gas temperature, the greater the proportion of heat loss. If the gas temperature is 1093 ℃, the heat loss reaches 55%; when the gas temperature is 1427 ℃, the heat loss reaches 70%. For the firing of refractory hot gas intermittent inverted kiln, according to the relevant experimental data show that: flue gas away from the kiln away from the heat about the furnace total heat expenditure of 35% to 40% in the absence of any heat recovery In the case of the measure, the heat balance calculation results, the thermal efficiency is only 10% ~ 15%. This is a big heat loss. Therefore, the use of flue gas heat is a very important energy recovery.
Set the heat exchanger in the flue is an important means of waste heat recovery. The hot air obtained after the heat exchange can be directly sent to the burner for combustion air, or the hot air can be diluted to the drying medium of the product embryo drying kiln or used to make the thermal efficiency of the kiln reach 30% or higher.
When the firing system uses a heat exchanger to preheat the air and use this hot air to make the combustion-supporting combustion air, the thermal efficiency of the kiln can be improved, the fuel consumption can be reduced, and the energy-saving effect can be achieved. And in the organization of high temperature combustion flame temperature can increase, increase heating efficiency, shorten the heating time (firing cycle). And because the hot air volume expansion, resulting in the burner orifice flow rate increases, accelerating the kiln gas circulation, contribute to the kiln temperature uniformity. The data show that: when the preheated air temperature reaches 220 ~ 250 ℃, can reduce fuel consumption by 6% to 8%. At the same time different combustion temperature, the impact on the flame temperature is very large. Even when the gas is not preheated, the combustion temperature of the gas increases significantly as the preheating temperature of the combustion air increases. This not only can solve the problem of low firing temperature, but also plays an important role in saving energy and reducing consumption.
In intermittent kiln production, because the fuel is changed with the heating stage, the amount of flue gas generated by the fuel also changes. In the event of a large fire, since the amount of fuel per unit time increases, the flue gas and temperature also inevitably increase. Preheat air combustion just to meet the requirements of combustion. Metal pipe heat exchangers are commonly used in production. Due to the limitations of high temperature oxidation and mechanical properties, the maximum service temperature is generally limited to below 500 ° C because of their low life (about 0.5 years). Metal pipe aluminum treatment, its service life is only about a year. The use of heat-resistant stainless steel or heat-resistant cast iron, the maximum temperature is generally limited to below 900 ℃. However, due to its high price, the use of units unbearable. 1. Because the fuel is the producer gas, the chimney bricks will not block. Life can be more than 10 years. Designed to ensure that the heat transfer efficiency, heat transfer area as large as possible (such as a group of 4 × 200m3 Square inverted hearth heat exchange area of ??about 230m2), although the volume is large, but the site conditions permit a one-time investment in the province, the flue System resistance is generally about 147 ~ 196Pa, chimney can be selected according to the height (usually about 50m).
The use of heat exchanger temperature is a very important factor in heat recovery. If the flue gas temperature is 1315 ℃, the use of thermal efficiency of 60% ceramic heat exchanger can save about 48% of fuel, if the use of thermal efficiency of 60% metal heat exchanger, you must first add cold air flue gas temperature dropped to 815 ℃ below, so that only 24% of fuel savings. Table 1 shows the effect of blending cold air on fuel economy.
In order to play the respective advantages of ceramic and metal heat exchangers, the two are used in tandem, known as a hybrid heat exchanger. First high-temperature flue gas into the ceramic heat exchanger, flue gas temperature dropped to below 815 ℃, and then into the metal heat exchanger. The flow of cold air is first into the metal heat exchanger, the heated air and then into the ceramic heat exchanger for further heating, the final preheated air temperature up to 1093 ℃.
|blast furnace refractory|
The main production of anhydrous stemming ingredients ratio (%): Brown Iron Jade 15-24, 6-15 silicon carbide, coke 20, lime 12-16, tar 18-20. The gun mud compressive strength of 20Mpa, open the mouth opening in the blast furnace refractory openings easy, and anti-erosion performance is better.
The key component of lime mud is too large, will cause mud shrinkage is too large, resulting in cracks, too small, affect the mud plasticity, in the amount of stemming on the basis of 12%, and gradually found in the burn line changes Is +0.3%, the best performance, high plasticity at the moment, when there is good micro-expansion at high temperature tapping, no cracks, effective from the no swelling, cracks caused by channeling iron, , The risk of burned stave in severe cases.
Key components of low, medium temperature sintering agent added in a large amount, will have an impact on the stability of the iron, sintering agent added to the stemming at low temperature to generate low-melt, so anti-erosion ability of stemming deteriorated, splashing spatter . Found that when the ratio of 2.5%, when dealing with the iron mouth, than the water cannons save 25min time, and does not affect the trenches processing, tapping, the iron flow stability.
The above anhydrous mud in the domestic water heaters No. 1 and No. 2 blast furnace used, compared with the same period of water mud, blast furnace technical indicators are as follows: Tiekou pass rate increased by 2%, the punctuality rate rose 6.6%, iron content Poor pass rate rose 8%, iron mouth tapping wind rate decreased 96%, increase once a day tapping, blast furnace operation safety factor has also been improved. The development and application of this anhydrous stem mud has been extremely successful, contributing to the steady and high yield of refractories for blast furnaces.
How to Choose Refractory Bricks Used for Different Parts of Blast Furnace
|blast furnace refractory lining material|
The damaged performance of high temperature to fire brick:
(1)Erosion. When the edge air develops excessively, but the factory uses poor quality refractory material which has lower refractoriness under load, if the high temperature is over than allowable temperature, the fire lining brick will be eroded.
(3)Thermal shock. Thermal shock is a phenomenon when the fire brick meet the unsteady thermal stress and then become damaged.Cracks will occur in the refractory bricks and eventually broken.
2.Mechanical erosion and abrasion
4.One of the important factors of firebrick refractory sale lining damage is unreasonable design, construct and furnace structure. Poor quality refractory and furance construction create the condition for the first kind of destructive factors.
Changxing Refractory,Refractory Brick,Castable,Ladle Nozzle,Calcium Silicate,Silicon Carbide: Advantages of covering agent
Changxing Refractory,Refractory Brick,Castable,Ladle Nozzle,Calcium Silicate,Silicon Carbide: Advantages of covering agent : covering agent ...
covering agent 1, Insulation covering agent is made of low thermal conductivity material composition, such as: expanded perlite, expand...
20th Century 50--70 years, China's steel plants mainly used aluminosilicate refractory materials , including clay, alumina brick and ...
blast furnace refractory lining material 1.Temperature. The damaged performance of high temperature to fire brick: (1)Erosion. When t...