Refractory material for petrochemical furnace

Chemical and petroleum industry is an important field of application of refractory materials. Due to the thermal furnace more complex operating condition. Therefore, the need for various types ofrefractory materials was selected to fit their specific application conditions. Here, select some of the more prominent examples of special applications for some simple instructions.

(1) Refractory materials for carbon black fuel furnace. In order to improve the production efficiency and the reaction degree, the reaction temperature must be increased in order to improve the production efficiency and the reaction temperature. Again. To produce hard carbon black, but also the need to improve the reaction temperature. In particular, the production of long-life, rolling wear small tires need more hard carbon black, the reaction temperature to reach 2000 ~ 2100 DEG C, which requires more refractory material and adapt.

(2) Slag gasification device. It is well known that the gas industry is widely used in refractories. The operating temperature and pressure of the refractory material used in the gasification equipment areextremely harsh, and the operation temperature and pressure are high: the slag belongs to the acid slag which has very strong corrosion resistance. At the same time, there is a highly corrosive gas. Refractory materials used for high resistance to acid slag corrosion can be used to obtain high life.

(3) The oil cracking unit: the operating conditions in the catalytic cracking unit are the most demanding operating conditions, including high temperature and high pressure. The refractory material used in the catalytic cracking unit is required to have high wear resistance and low thermal conductivity so that the two contradictory properties.

New building materials-Basic refractory

Alkaline refractory materials mainly refers to the oxidation of magnesium, calcium oxide as the main component of the refractory, the alkaline slag has a strong anti – erosion ability. Including magnesia brick, magnesia brick, magnesia chrome brick, dolomite brick (see magnesia brick).

Commonly used is brick. Containing magnesium oxide 80% ~ 85% of magnesia brick, on the basic slag and iron slag has good resistance, refractoriness than clay brick and brick. Mainly used in open hearth furnace, oxygen converter, electric furnace, non-ferrous metal smelting equipment and high temperature equipment.

Characteristics of basic refractory materials

Inorganic non metallic materials with fire resistance higher than 1580. Refractoriness refractory cone specimen under no load, resistance to high temperature and not softening melting down Celsius temperature. Refractory materials and high temperature technology, which originated in the middle of the Bronze Age. In the Eastern Han Dynasty has made China kiln firing porcelain material and with fireclay refractory sager. At the beginning of twentieth Century, the refractory materials were developed in the direction of high purity, high density and ultra high temperature, and there was no need to burn, and the energy consumption is small. Modern, with the atomic energy technology, space technology, new energy technology development, with high temperature resistance, corrosion resistance, thermal shock resistant, resistant refractory material erosion comprehensive excellent performance has been applied.

Refractory material in steel making system

The steelmaking system includes a converter, electric furnace, furnace, ladle, ladle and tundish. Ladle and tundish is an important auxiliary equipment of the steel making furnace, and also the most important equipment for the use of refractory materials.

In the converter and electric furnace, the general use of refractory spray paint repair, the method is manual cast refractory materials, wet, dry or flame spraying and slag splashing furnace, etc…

In the electric furnace, the dry vibration material of the refractory material, the pre cast or cast in place or the furnace cover: triangle area and other parts are better use effect.

In the converter, the widespread adoption of slag splashing furnace maintenance technique and the service life of furnace can reach more than 10000 times; outside furnace refining furnace are more, the RH process and the method of DH degassing device insertion tube lining of the body, generally with high aluminum refractory  material is poured into a whole, the service life is 20-80 times.

Damage reason of refractory

According to the specific conditions of various furnaces and thermal equipment, proper selection and application of refractory material is very necessary. It is to improve the service life of the kiln and thermo technical equipment, reduce maintenance time, reducing the consumption of refractory material and energy, improve furnace production and guarantee the quality of the products and reduce the cost of production plays an important role.

As is known to all, there will be some damage reasons for different kinds of kilns or thermal equipment under different working conditions. Even in different parts of the same furnace or thermal equipment. There are many factors that affect the damage of refractory materials:

(1) The use of the temperature is too high, exceeding the limit temperature of the refractory;

(2) The temperature changes in temperature, refractory material damage in blast crisis;

(3) The refractories by slag furnace, mechanical shock or friction and wear serious the damage;

(4) The refractory material is damaged by the high temperature physical and chemical erosion and penetration of the molten metal, slag and furnace gas;

(5) The thermal stress and the weight of the heat generated by the heat of the refractory material cause damage to the stress concentration and the volume effect.

The above factors are not isolated, only to find out the main influencing factors in order to correct selection of refractory materials.

Insulation materials used in power plant

Thermal insulation refractory material in the electric power industry especially thermal power plants, such as coal-fired power plants occupies an important position. It has energy saving, reduce heat loss, to meet the requirements of the power plant production process, ensure theequipment, production and personal safety, improve the environment, improve the economic benefit, is an important part of the construction of power plants. So the power plant is commonly used in the refractory material is light heat insulation brick. According to the present and future development, electric power industry of insulating refractory material demand quantity big, more varieties, high quality requirements, which the fiber insulation refractoriness demand maximum, followed by hard material, and is lightweight materials and thermal insulation coating.

One, according to the various parts of the heat preservation refractory materials of the insulation requirements of choice

(1) The medium temperature of the equipment and the pipeline at 350~600 is chosen to use calcium silicate products, aluminum silicate composite insulation;

(2) with rock, mineral wool products such as insulation equipment and piping medium temperature less than 350 DEG c;

(3) The valve, elbow and other special-shaped pieces of light insulation material or heat preservation coating insulation;

(4) The use of ordinary aluminum silicate fiber rope insulation is less than 38mm;

(5) The low temperature equipment and piping in the wet environment are chosen for the insulation of the hydrophobic insulation material

High alumina refractory brick for hot blast furnace

Hot air furnace is insulation and withstand high temperature load, so to determine the various parts of the furnace lining refractory brick material and thickness of, should according to the requirements of masonry bearing temperature, load and heat insulation and flue gas of masonry of physical and chemical action condition and decide.

The has good resistance to creep and corrosion resistance, domestic use of high aluminum brick containing Al2O3 with greater than 65% is adopted abroad of SiO2 94~96% siliceous refractory brick is with or containing Al2O3 72%~76% mullite refractory brick using high temperature zone of the upper 30% to 40% of the height of hot air furnace lining refractory bricks. According to the experiment, under the condition of 0.2MPa, 1550 and 50h, the former is 0%~0.5%, the latter is 0.1%~0.3%, and so the creep resistance is good. The brick arch with the thermal shock resistance is better, so as to avoid peeling and cracking. For the middle and lower part of the refractory brick should be considered to the compressive strength, the general use of clay brick and high alumina brick. Selection of heat insulation material should pay special attention to the work of the hot surface temperature should not be higher than the allowable temperature. Insulation wall and the upper part of the vault generally use diatomite refractory brick or lightweight clay brick.

Refractory materials for aluminium melting furnace

The main equipment for thermal melting aluminum has calcinations sintering furnace, melting furnace and electrolytic cell. The rotary kiln firing with a lining of high aluminum brick masonry are commonly used, other parts available clay brick as a liner, insulation layer close to the furnace shell at laying a layer of refractory fiber felts and masonry a layer of light brick or light weight castable refractory pouring.

The most common aluminum smelting equipment is a reflective furnace. The lining of the molten aluminum contact. In general, the Al2O3 content is 80% ~ 85% of the high aluminum brick masonry, melting high purity aluminum metal, are advised to the mullite brick and corundum mullite brick. Some factories in hearth slope and scrap aluminum material, easy erosion and wear parts, the use of silicon nitride bonded silicon carbide brick masonry. Flow aluminum groove and an opening of the aluminum and other parts, aluminum melt erosion heavier, the general use of self bonding or silicon nitride combined silicon carbide brick masonry, and also useful zircon brick lining. The effect of the refractory fiber cone is better than that of the aluminum outlet. The lining does not contact the molten aluminum, using clay brick, fireclay refractory castable refractory material such as plastic or masonry. In order to speed up the melting speed and save energy, light brick, light refractory and refractory fiber products are widely used in the present work.

Aluminum smelting induction crucible furnace is more commonly used equipment, its lining generally use Al2O3 content is 70% ~ 80% of high alumina castable refractory ramming material production, but also useful for just corundum brick concrete lining of.

Aluminum molten liquid from the furnace outlet, the flow of aluminum trough. The slot liner generally adopts silicon carbide brick, useful also fused silica foam perform. Such as the use of precast block for tank lining, the surface should be coated fused silica or as protective layer with high alumina cement electric fused silica foam refractory castable.