The Refractory Anchor is a non-metal or metal component installed on the furnace shell or steel structure supporting the furnace lining and is embedded in the lining body for anchoring and connection. It is an important part of modern unshaped refractory linings and a key technical measure to improve the service life of linings. Especially it is used as the skeleton structure of refractory castable lining.
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| RS High-Quality Refractory Anchor Bricks |
Classification of Refractory Anchors
Anchors are divided into two categories: metal anchors and non-metal anchors, including supports, thrusts, and anchor nails. Hanging bricks are also refractory anchoring bricks(http://www.aluminabricks.com/refractory-bric/anchor-brick/). The technical requirements for anchoring bricks are high strength and good thermal stability. Therefore, three-level clinker is generally used as the raw material and fired at high temperatures. For example, the chemical composition of high alumina anchor bricks in a factory is mainly A1203≥50% and Si02≥46%. Refractoriness is 1750℃, strength is 3.8MPa, 1200℃ linear expansion coefficient is 5.8X10-6K-1, 1450℃ returning linear change +0.1%, load softening starting temperature is 1430℃.
There are various shapes and connection methods of anchor bricks, and their sizes are also different. The most commonly used anchor bricks are 330, 380, 440, and 500mm in length, and the thickness is generally about 100mm. Mainly used for refractory castable lining. The shape without holes is generally used in the refractory plastic lining.
Metal anchors are generally made of ordinary steel, heat-resistant steel is the best, but it increases the cost of thermal equipment. Metal supports and thrusts are generally made of heat-resistant cast steel.
Metal anchors are easily oxidized at high temperatures, so they should be buried in the lining. The distance between the hot end and the working surface of the lining body and the thickness of the dependent body need to be determined according to the operating temperature, generally 20-200mm.
Metal anchors are generally welded to the furnace shell and have various shapes. The most commonly used ones are Y, V, and L shapes. There are also several shapes of support and thrust. The former is used in higher furnace walls and the latter is used in furnace roofs with steep slopes.
The installation holes or necks of the anchor bricks shall not have cracks and the dimensions shall be accurate. The welding between the metal anchor and the furnace shell should be fully welded, and there should be no false welding or missing places, and the size should be accurate. The ceramic anchors and metal anchors of the refractory fiber lining also have various shapes and sizes, and their function is mainly to fix the refractory fiber lining.
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| Masonry of Refractory Anchor Bricks |
How to Build Refractory Anchor Bricks
The anchor brick is a special type of refractory brick that adopts the hanging form to support the structure of the furnace roof and furnace wall. It can also be called hanging bricks and anchors. The anchor bricks are used to prevent the leakage of reactive gas and hot gas in the furnace from damaging the metal hangers and causing the furnace roof to collapse.
Industrial kiln and flue walls are composed of the inner lining, heat insulation layer, and outer wall layer. The refractory bricks for the lining and the fired bricks for the outer wall need to be connected with anchor bricks. The anchor has high tensile and flexural strength, especially the stress generated at the groove is blocked at the rib and cannot be transmitted. Therefore, it is not easy to break when the anchor brick is used in this structure.
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| Hanging Anchor Bricks |
Precautions for refractory anchoring brick masonry
1. When laying bricks, apply mortar carefully from both sides to prevent gas from leaking from the stovetop.
2. The hanging part of the anchor brick should not be damaged.
3. Ensure the size of the joints, accurately determine the position when laying on the top, and let the hanging metal parts play a private role.
4. Expansion joints should be properly left between the furnace body and the anchor bricks.
5. Air hardening mud should be used for laying anchor bricks.
6. The arrangement of anchoring bricks should be determined according to the range and frequency of temperature changes and the size of the direct wall area. Usually, 6 anchor bricks are used per square.
7. When the masonry is close to the anchor brick position, the lower row of bricks should be made in advance to determine the accurate position of the anchor brick. Use a wire brush to thoroughly clean the welding parts of the metal shell, and use welding rods that are compatible with the welding parts to firmly weld the anchor pipe.
8. After the anchoring brick is built, insert the anchoring hook. Fill the airstrike with refractory fiber felt and plug it tightly to form a certain degree of protection for the anchors.
9. The thickness of the anchorage hook has certain requirements. Not too thin, too thin will burn slowly and cause early damage to the lining. The heat-resistant steel material of the anchoring hook must be selected according to the national standard heat-resistant steel to meet the demand.
Learn more about the refractory anchors, please contact us by email: info@aluminabricks.com.
