- Fire clay brick / high alumina brick furnace bottom is generally composed of several layers of vertical brick lining, and each layer can be built into a cross or a straight shape. The center lines of the upper and lower phases are at an included angle of 30 °, and the center line of the uppermost furnace bottom brick is at an included angle of 30 ° ~ 60 ° with the center line of the tap hole.
- There are usually two kinds of masonry methods for the cruciform at the center of the furnace bottom:
(1) Setting out and masonry shall be carried out according to the cross center line marked on the cooling wall. Four guide square timbers with flat surface and at right angles to each other shall be placed along the line, and the center points shall be staggered to avoid through joints. The center point of the center line of the upper brick shall be positioned at a distance of half the brick thickness of the center point of the lower brick.
(2) Locate the central brick according to the cross center line of the furnace bottom, mark the vertical line of the central brick surface that coincides with the cross line of the furnace bottom, then stagger half of the thickness of the brick column, draw a cross line, and place 4 guide square timbers along the line, which is the guide surface for masonry.
- Note that the square timber is not only the masonry guide surface, but also has the function of support. Therefore, its support surface and bottom surface need to be planed and formed at right angles to each other.
- Square timber shall be placed along the line, and its perpendicularity shall be checked with a level ruler, and the allowable error shall be within 0.1mm. When laying the bottom of each layer of bricks, accurately check whether the cross line is at a 90 ° right angle. Check and ensure that the guide square timber is accurate and consistent with the cross line without deviation, so as not to affect the masonry quality.
- The central cross line of the furnace bottom is the key to the masonry of the whole layer of furnace bottom. After laying the bottom, check the brick joint and verticality of clay / high alumina brick. After confirming that it is qualified, stick to the first row of bricks and start building bricks at two corners in turn. After 3 ~ 4 rows of bricks are laid, that is, the masonry has certain stability, the guide square timber can be removed, and then the four corners can be built synchronously.
- The clay brick / high alumina brick furnace bottom shall be built with phosphate refractory slurry. The thickness of the construction expansion joint shall be reserved in strict accordance with the construction requirements, and the refractory slurry in the brick joint must be dense and full. The viscosity of the refractory slurry shall be strictly controlled according to the amount of water added in the construction instructions.
- Specific bricklaying process of clay brick / high alumina brick: pre lay dry pendulum first, and start formal bricklaying after passing the joint inspection; Clean the construction surface, first lay a layer of refractory slurry, and then brush, dip and knead the slurry in turn. Phosphate refractory slurry flows quickly. During operation, hold the lower end of the brick with one hand and the lower part of the intersection edge between the large surface and the side of the brick with the other hand. Knead up and down for 4 ~ 5 times and quickly find the brick position.
- The key points of laying furnace bottom clay brick / high alumina brick are: stable adhesion, low reliance, short pulling and re kneading.
Stable dipping: take out the clay brick / high alumina brick after fully dipping it with phosphate refractory slurry.
Low: when clay brick / high alumina brick is stained with slurry and ready to be in place, it should be lowered as low as possible. To prevent the refractory slurry from falling out of the brick joint and affecting the compactness and fullness of the brick joint slurry.
Short pull: when kneading, the distance of pulling up and down should be short, generally 30 ~ 40mm.
Re kneading: the kneading action should be heavy and tight.
After the clay brick / high alumina brick is in place, align it with a wooden hammer, tap it gently and move it slowly to avoid the sinking and loosening of the refractory slurry.
- Check and adjust the verticality of refractory bricks for many times during masonry to ensure that the vertical error does not exceed 2mm.
- After each row of bricks is laid, the verticality of bricks, the flatness of the upper surface of refractory bricks, the thickness of reserved expansion joint and the relative elevation difference of each point of brick lining shall be checked again, so as to facilitate the construction and masonry of the next row of clay bricks / high alumina bricks.
- a 100 ~ 150mm expansion joint shall be reserved between the furnace bottom masonry and the cooling wall or carbon block protection wall, and shall be densely filled with carbon tamping materials. For the parts with the width less than 1 / 2 of the brick at the edge, the processed brick is generally not used, and the carbon tamping material is also used for filling.