Refractory Brick Structure
Preparation before construction
1. Do a good job of design and design, and clarify the design requirements and intentions of each part.
2. Do an effective connection between the design and installation and the kiln lining to ensure that the equipment installation and kiln lining construction are harmonious and the quality is optimal.
3. Check whether the materials, equipment, personnel quality and construction organization entering the construction are guaranteed.
4. Check if the kiln is clean, the welds and links are flat, and the brick block is perpendicular to the kiln axis.
Develop Practical and Feasible Scientific Construction Plans
The contents include the kiln lining project overview and work item list; comprehensive schedule and cross-operation plan, construction process and means, construction organization, safety technical measures, lining materials and construction tools, template supply plan and other related content .
Masonry Considerations
Refractory brick lining is reliably concentric with the kiln. It is required to make the brick lining as tight as possible, so that the top of the brick lining and the kiln cylinder should be fully adhered to each other, and as far as possible, the adjacent single brick wedge faces are completely in contact with each other, which can cause damage. Sexual stress is evenly dispersed, unable to cause local concentration
Lock fire brick lining, do not make the locking brick belt the weakest link in the kiln lining
Minimize the amount of steel plate, avoid the steel plate from squeezing and squeezing adjacent bricks after oxidation, causing cracking and spalling of refractory brick
In the preheater, decomposition furnace, kiln door cover and other different equipment, the brick lining needs to be as small as possible (1~1.5mm), the cement is full, to prevent the hot kiln gas from eroding the lining and the kiln shell through the brick joint, while lining The surface should be smooth and no steps should be formed to prevent the lining from accumulating in the movement and reduce the "alkaline corrosion" damage of the lining.
High alumina brick lining and the alkali-resistant brick lining are much smaller than the alkaline brick lining due to their thermal expansion property, resulting in less expansion stress, and it is not necessary to intentionally leave the brick joint, and the mud in the brick joint must be full.
Do not Use Steel Hammer
Refractory brick is a very brittle material. It can't withstand the impact of rigid tools. It must be operated with flexible tools such as raft, rubber raft or hard plastic enamel. Otherwise, it will be damaged during operation and even crack and break.
Brick lining for non-moving equipment by "Ding Ma"
Construction method
Arch method
On large kiln with a diameter of 4m or more, the arch method is commonly used.
Roof bracing
In the middle and small diameters within 4m in diameter, the roofing method is mainly used for masonry. In the kiln bricks with a diameter of 3.6m or more, it is necessary to make two kiln supports, which are called cross-shaped struts, and the kiln with a diameter of 3.6 meters or less One piece top support.
The construction difficulties of the preheating system lining are prominently displayed in the upper and lower cones, the cyclone part, the joint part, the curved part and the variable diameter part.
Construction of refractory castable
The construction of refractory castables is mainly composed of three links, namely mixing, pouring and curing.
Mixing
Forced mixer or mortar mixer must be used for mixing, and manual mixing is not available.
Equipment and tools, forced or mortar mixers, buckets, scales, vibrators, tools, trolleys
Mixing: First add the big bag material to the mixer, then add the small bag material, dry mix for 1-2 minutes, then add about 90% of the required water, stir for 2-3 minutes.
The remaining amount of water depends on the situation. When it is necessary to continue adding water, it can be discharged for 1-2 minutes after adding water.
Method for judging water content
In order to judge whether the moisture content of the stirring material is suitable, a simple "hand kneading" method can be used for the test. The stirring material is used to knead a compact pellet, and the pellet is polished by about 30 cm, and then hand-joined. Live, if the pellet is deformed and not spread, it means that the water content is just right. If the water content is just right, if the pellet is deformed and flows out of the hand gap, it means that the water content is too much. If the pellet is cracked and scattered, it means water content. Too little.
Mixing water consumption: According to the water consumption given in the manual of the batch, the water consumption is strictly controlled and accurately measured.
Precautions
The surface of the castable after vibrating should be kept natural, it should not be smeared with tools, and it is not allowed to smear on the surface.
The vibrating rod should be spared to ensure that the spare rod can be activated in time when the vibrating rod fails.
After the completion of construction, the construction body is prohibited from moving, vibrating or tapping within 24 hours, especially before the casting material is hardened. Otherwise, the casting body may cause cracks or even complete damage.
The castable should be continuously constructed. If it cannot be continuously constructed for various reasons, the construction joint can be left, and it is best to stay at the expansion joint. Otherwise, the construction joint is made into a pockmark, that is, the casting material is 10mm deep and 20mm wide. Cross groove, spacing around 100mm
Maintenance
Tools: polyethylene plastic film, straw bags, etc.
Ambient temperature requirements and control: The curing temperature of the castable body should be between 15 and 35 °C. It is better to exceed this temperature. Beyond this temperature range, polyethylene plastic film should be used to cover the surface of the construction body. Cover the wet grass bag and let the cast body dry naturally in the air for 1 day to bake.
