Method And Requirement Of Firebrick Masonry For Ebullizing Furnace

Ebullient furnace lining refractories are mainly composed of refractory bricks and amorphous refractories. The following is the construction method of firebrick.

The lining masonry of ebullient furnace is mainly divided into two parts: wall and vault

(1) Refractory brick masonry.

Before construction, the center line of the furnace is measured with the theodolite, the elevation of the foundation is re-measured, and the elevation of the first layer of bricks on the furnace shell is marked every 5 meters. The stratification line is drawn along the vertical direction as a reference for the masonry of the furnace bottom and furnace wall.

The brick joints of all brick masonry must be filled with adhesive (including the joints between the brick masonry and the steel shell and the joints between the brick layers) so that all brick joints are filled, leaving no gaps and holes. And check regularly whether the position of the masonry is accurate after masonry. For multi-layer brick masonry floors, the total thickness of the brick wall must be checked. The required thickness of mortar joints should be 2mm(tolerance ±1mm) as far as possible.

A waterproof layer is arranged between the calcium silicate board, thermal insulation brick and thermal insulation firebrick to prevent absorption of solidified water. Plaster bottom layer can be used to set waterproof layer.

Expansion joints should be reserved correctly. The ceramic fiber felt is pasted on one side of the brick masonry as an expansion joint to ensure the specified thickness of the expansion joint.

(2) firebrick spherical arch masonry.

The top of the boiler is in the form of a firebrick spherical dome. Before refractory construction, the diameter of the furnace steel shell supporting the dust collector must be checked clockwise. To check, divide the circumference into 12 equal parts and check the circumference with a rope. The length of the rope must equal the diameter. If there is a defect, the case manufacturer must be notified to repair the defect.

The mixing of refractory mud should be carried out in strict accordance with the provisions of the product manual.

1) arch foundation brick construction: According to the design requirements, the expansion joint under the tail frame ring is provided with ceramic fiber. At the position above the support ring and the arch seat brick ring, the pressure resistant silicon fiber board is bonded to the steel shell. To ensure good bonding, moisten the aluminum silicate fiberboard slightly. Then, lay the supporting brick of the arch foundation brick on the support. In the process of masonry, use a level to check the level alignment of the supporting ring, and then prefabricate the sealing ring of the furnace brick masonry according to the requirements of the drawing. However, a 2mm wide sliding joint with oil paper between the ring and the support ring must be considered.

Apply mortar to the surface of the supporting brick, place the arch base brick on the supporting brick, and beat it with a rubber mallet to secure it. The brick leans back slightly.

If the construction of the cylindrical brick masonry is not completed at the beginning of the construction of the vault, a relatively thick adhesive auxiliary material can be applied at the front end to make the arched foundation brick slightly inclined. Use a level to check the position of each brick. The inner edge of the brick shall be adjusted according to the corresponding inner diameter indicated on the drawing. Slight irregularity can be compensated by gluing auxiliary material joints. If there is a large deviation from the original size, the correct fireproof concrete can be used or the brick can be cut to the required size for repair. However, the thickness of the brick should be at least 70% of the original thickness. After the arch foundation brick is laid, it must be fixed to prevent tilt.

1- Flat steel body; 2- Concrete; 3- Firebrick; 4- arch foundation brick; 5- Supporting bricks; 6- Combine frame rings

2) Top brick construction: The irregular top brick ring is laid in the direction of the arch foundation brick, and the construction is strictly in accordance with the mix ratio of each circle of special-shaped brick marked on the drawing. The average thickness of the mortar joint must be 2mm, and special hardener must be added to the bonding auxiliary material of the masonry vault brick. When laying bricks in both directions, only after completing one circle can the next circle of bricks be laid on the hardened part of the binder. The bond attachment of the upper ring of the brick must be completely hardened when laying. If checked with a tool, the tool tip should not be inserted into the joint of the bonding material.

Only 4 circles of bricks can be laid per day, and irregular circles of unfinished bricks on the vault must be completed within the same working day.

3) Crown measurement: Check the spacing of 12 positions and the diameter of 4 positions outside each complete crown brick circle. Check the measurement results according to the values shown in the drawing.

Because the vault at the final dome is affected by gravity and may be slightly lower than the value indicated on the drawing, it is necessary to consider that the brick slightly exceeds the elevation position and cannot be less than the indicated spacing or diameter.

4) Arch closure: After the last circle of bricks is laid, use formwork to pour the refractory concrete top block in the center of the arch. Secure the formwork to the vault with fixed wire, then pour the top stop block from the top. After the concrete has hardened, the formwork is removed and the vaulted brick masonry is laid from the upper part.

If it is a dome with a central vent, the construction of the brick masonry will continue after the last ring of bricks is closed.

 

 

 

 

 

 

 

 

 

JIYGO REFRACTORY & ABRASIVE LIMITED