AZS Bricks

Fused cast bricks casting types :

General casting PT: Due to volume shrinkage from liquid-solid transform and rapid solidification of a casting ,normal cast blocks have their cavity located under the filling scar. The feasible limits of cavity can be evaluated and indicated by the volume-weight testing of blocks in-situ according to the technical specifications.

Tilt casting QX:  In this method, the casting cavity is located towards the lower back face of a block; the feasible limits of cavity can be evaluated and indicated by the volume-weight testing of blocks in-situ according to the technical specifications. Meanwhile, blocks which height less than 900mm are not suitable to be manufactured by this process.

Reinforced casting ZWS: In this developed process, reduced cavity is located towards the bottom of a casting; a little part of the cavity will be remained at the end of the block after the header cutting. Block evaluation in-situ begins from the determination for the feasible size and deepness of cavity remainder at first and then to the volume-weight testing of blocks according to the technical specifications.

Void-free casting WS:  In the process, additional liquid from the header fills sufficiently into a casting; the header is then cut off leaving a block free of casting cavities. Block evaluation in-situ includes the acceptance or rejection for somewhat trace of cavity remainder which perhaps appeared and the volume-weight testing of blocks according to technical specifications.

Advantages:

High Refractoriness: Fused cast AZS bricks and products have a high refractoriness, meaning they can withstand extremely high temperatures without melting or deforming. This makes them ideal for use in furnaces, kilns, and other high-temperature environments.

Chemical Resistance: Fused cast AZS bricks and products are resistant to a wide range of chemicals, including acids, alkalis, and molten salts. This makes them suitable for use in applications where they will be exposed to harsh chemicals.

Thermal Shock Resistance: Fused cast AZS bricks and products have excellent thermal shock resistance, meaning they can withstand rapid changes in temperature without cracking or spalling. This makes them ideal for use in applications where the temperature fluctuates frequently.

Corrosion Resistance: Fused cast AZS bricks and products are resistant to corrosion from molten glass, slag, and other corrosive materials. This makes them suitable for use in glass furnaces, metallurgical furnaces, and other applications where they will be exposed to corrosive environments.

Application:

Glass Furnaces: Fused cast AZS bricks and products are the most commonly used refractory material in glass furnaces. They are used to line the melting tanks, regenerators, and other components of glass furnaces.

Metallurgical Furnaces: Fused cast AZS bricks and products are also used in metallurgical furnaces, such as steel melting furnaces and copper smelting furnaces. They are used to line the melting furnaces, refining furnaces, and other components of metallurgical furnaces.

Power Plants: Fused cast AZS bricks and products are used in power plants to line the boilers and other components that are exposed to high temperatures.

Incinerators: Fused cast AZS bricks and products can be used in incinerators to line the combustion chambers and protect them from the high temperatures and corrosive gases.

Other Applications: Fused cast AZS bricks and products are also used in a variety of other applications, such as cement kilns, petrochemical plants, and waste treatment facilities.

The following problems should be paid attention to in the use of fused AZS bricks:

① Irregular changes in thermal expansion. The expansion curve of the fused AZS brick is abnormal in the vicinity of 1000℃. The internal Zr02 crystal undergoes a reversible crystal transformation and has a large volume change. Therefore, bricks containing ZrO2 should not be used at temperatures around 1000℃. Parts of sharp fluctuations. When baking the kiln, the temperature change should not be too large at 900～1150℃, generally not more than 15℃/h, and a steady temperature rise is required. Some parts should be protected from cold wind and other bricks should be used to prevent explosion.

② Shrinkage. During casting, shrinkage holes often appear at the nozzle, where there are many pores in the brick body, and the density is poor. Therefore, when building the glass melting pool wall, the shrinkage holes are all directed toward the inner direction of the kiln. If the sprue faces outwards, when the brick body erodes very thinly, it will cause glass leakage accident. When used in the upper flame space of the kiln, the service life is very long, and there will be no problem of running glass. Therefore, the sprue is used outward to extend the service life.

③ Eutectic. When fused AZS bricks and clay bricks are in contact with masonry, eutectic will occur at a high temperature of 1300℃. Therefore, when choosing refractory materials, avoid contacting two refractory materials with serious eutectic phenomenon, such as silica bricks. The bottom of the fused AZS brick is most vulnerable to corrosion by the fused AZS brick.