In the construction of industrial kilns, the construction of arches and vaults is very important. The refractory bricks used in this part are mainly arch angle bricks, lock bricks, hanging bricks, etc. according to their functions. Some kiln vaults also use refractory castables or ceramic fiber modules and other products. The construction specifications of refractory firebrick arches and vaults are as follows:
1. The materials used for the arch tire and its pillars should meet the support strength requirements.
2. The curvature of the arch tire should meet the design requirements and the tire surface should be flat. The arch tire should be supported correctly and firmly, and the arch and vault can be built only after passing the inspection.
3. Before building the vault, the arch foot beam and the frame column should be close together and should be inspected and qualified. Before building the vault with an adjustable frame, the frame and the tie rod should be adjusted and fixed, and should be inspected and qualified.
4. The surface of the arch foot should be flat and the angle should be correct. The arch foot shall not be leveled by thickening the brick joints. 5. Arch foot bricks should be built close to the arch foot beam. When there is masonry behind the arch foot bricks, the arch and vault can be built only after the masonry is completed. Insulating refractory bricks or diatomaceous earth bricks shall not be built behind the arch foot bricks. Refractories bricks of the same material as the vault can be built behind the arch foot bricks of the insulating brick vault. 6. Arches and vaults should be built with staggered joints. Arches and vaults built with staggered joints should be built along the longitudinal seam line, and the brick surface should be straight.
7. The processed bricks of the leveling layer on the upper part of the arch and vault can be replaced by refractory castables of the corresponding material. 8. Arches and vaults with different spans should be built in a ring. The brick ring surface of the ring arch and vault should be flat and perpendicular to the longitudinal center line.
9. Arches and vaults should be built symmetrically from the arch feet on both sides to the center at the same time. During masonry, the big and small heads of the arch bricks shall not be inverted.
10. The radial joints of the arch and vault should coincide with the radial direction. The inner surface of the arch and vault should be flat, and the misalignment should not exceed 3mm.
11. The lock bricks should be symmetrically and evenly distributed along the center line of the arch and vault. One lock brick should be driven into each ring of the arch and vault with a span of less than 3m, three lock bricks should be driven into each ring of the arch and vault with a span of 3m to 6m, and five lock bricks should be driven into each ring of the arch and vault with a span of more than 6m.
12. The depth of the lock refractory bricks built into the arch and vault should be 2/3 to 3/4 of the brick length, and the depth of the lock bricks in the same arch and vault should be consistent. The lock bricks symmetrical on both sides should be driven in evenly at the same time. A wooden hammer should be used to drive in the lock bricks, and a wooden block should be used when using an iron hammer.
13. Lock bricks should not be used with bricks less than 2/3 of the original brick thickness or bricks with long sides processed to make the large surface wedge-shaped.
14. The method of combining metal hooks and arch tires should be used to build spherical vaults. The spherical vault should be built ring by ring, and the door should be closed in time, and the gap should not exceed three rings. The door bricks should be evenly distributed, and the geometric dimensions of the masonry and the accuracy of the radial joints should be checked.
15. The hanging bricks should be pre-built, and should be selected and numbered, and can be processed if necessary. The hanging bricks of the hanging flat roof should be built from the middle to both sides. The inner surface of the hanging flat roof should be flat, and the misalignment should not exceed 3mm. When there is a gap between the upper edge of the earring of the hanging brick and the hanging beam, it should be tightened with a thin steel sheet. When building the hanging flat roof, expansion joints should be left at the contact between the side bricks and the furnace wall. The sloped furnace roof should be built from the turning point below to the two ends.
16. There should be no horizontal cracks at the main stress-bearing parts of the hanging bricks.
17. After the hanging refractory bricks on the furnace roof are built, the seams should be grouted on the furnace roof, and thermal insulation products should be laid at the specified positions.
18. After the hanging bricks with a hanger and nut structure are laid, the nuts of the hanger should be tightened. When tightening the nuts, the hanging bricks must not move upward, and the hooks should be close to the upper edge of the hanging brick holes.
19. The hanging arch should be built in a ring. The ring seams should be parallel to each other and should be perpendicular to the longitudinal center line of the furnace roof. When starting to build the hanging arch, you should first build a ring according to the design requirements, and then build in sequence based on this ring.
20. The hanging arch should be locked in rings, and the locking degree of each ring should be consistent. After the lock bricks are locked, the hanging long pins should be put in place immediately.
21. Before dismantling the arch tire with a span greater than 5m, a sign for measuring the sinking of the arch should be set; after the arch tire is removed, the sinking record should be kept.
22. The arch tire of the arch must be removed after all the lock bricks are tightened, the grooves at the arch foot are built, and the nuts of the skeleton tie rods are finally tightened.
