High alumina brick lining can be divided into four categories according to the size and refinement of brick joints. Type and size of brick joint: class I ≤ 0.5mm; Class II ≤ 1mm; Class III ≤ 2mm; Grade IV ≤ 3mm. The mortar joint of the brick joint shall be filled with fireproof slurry, and the upper and lower brick joints shall be staggered.
The preparation of refractory slurry for masonry shall follow the following principles.
2.1 before masonry, various refractory slurries shall be pre tested and pre paved to determine the bonding time, initial setting time, consistency and water consumption of different slurries.
2.2 different instruments shall be used to prepare different slurries and cleaned in time.
2.3 different slurries shall be mixed with clean water. The water volume shall be weighed accurately, mixed evenly and used at any time. The prepared hydraulic and pneumatic mud shall not be used with water, and the initial setting mud shall not be used.
2.4 when preparing phosphate bound mud, the specified material retention time shall be ensured. The prepared mud shall not be diluted with water. Due to the corrosivity of the slurry, it shall not be in direct contact with the metal shell.
Before the construction of brick lining, the site shall be comprehensively inspected and cleaned.
Before the construction of brick lining, the setting out shall be done well, and the size and elevation of each part of masonry shall be checked according to the design drawings.
The basic requirements for bricklaying are: the bricks shall be closely pasted, the brick joints shall be smooth and straight, the circle shall be accurate, the bricks shall be locked firmly without dislocation, sagging and void, and the masonry shall be flat and vertical. High alumina bricks shall be laid in staggered joints, the slurry in the brick joints shall be full, the surface shall be pointed, the brick joints shall be horizontal and vertical, the arc surface shall be smooth, and the masonry shall be dense.
According to the design scheme, the layout of different high alumina brick varieties is carried out. When building brick lining, the fullness of fireproof mud shall be greater than 95%. The joint of face brick shall be pointed with raw slurry, but the excess slurry on the brick lining surface shall be removed in time.
Flexible tools such as wood hammer, rubber hammer or hard plastic hammer shall be used for bricklaying. Steel hammer shall not be used. Bricks shall not be cut on the masonry. After the slurry is dry and hard, the masonry shall not be knocked or corrected.
Bricks of different materials and types shall be strictly separated, and bricks of the same quality, type and length shall be selected.
The thickness of dry joint steel plate is generally 1-1.2mm, which is required to be flat without crimping, distortion and burr. The width of each plate shall be about 10mm less than the width of the brick. During masonry, the steel plate shall not exceed the brick edge, and there shall be no steel plate ringing and bridging. Only one steel plate is allowed for each weld. Narrow steel plates for adjustment shall be used as little as possible. Cardboard for expansion joints shall be placed according to the design.
When locking bricks, flat bricks shall be used for locking and finishing, and the adjacent brick roads shall be staggered by 1-2 bricks. It is forbidden to lock the brick with castable alone, but the last lock brick can be fixed with castable.
The following common problems shall be avoided when laying refractory and thermal insulation lining.
11.1 dislocation: unevenness between layers and blocks.
11.2 inclination: that is, the horizontal direction is uneven.
11.3 uneven mortar joint: the width of mortar joint is different, which can be adjusted by proper brick selection.
11.4 climbing: that is, the wall is regular and uneven, which shall be controlled within 1mm.
11.5 separation: the brick ring in the arc masonry is not concentric with the shell.
11.6 double joint: that is, the upper and lower mortar joints overlap, and only one mortar joint is allowed between the two layers.
11.7 through joint: it is not allowed to overlap the mortar joints of internal and external horizontal layers, or even expose the shell.
11.8 opening: in arc masonry, the mortar joint is small inside and large outside.
11.9 gap: that is, the mortar between the layer, brick and shell is not full and is not allowed to appear in the lining of fixed equipment.
11.10 rough joint: the brick joint is not plastered and the wall is not clean.
11.11 serpentine bending: that is, longitudinal, circumferential or transverse joints are not straight lines, but wavy bending.
11.12 masonry bulge: due to equipment deformation, the equipment surface shall be leveled during masonry. During the construction of double-layer lining, the insulation layer can be used for leveling.
11.13 mud mixing: do not misuse mud.
The refractory and thermal insulation composite lining of masonry equipment shall be built in layers and sections, and mixed layer and mortar masonry are strictly prohibited. Masonry insulation lining shall also be filled with mortar and joints. In case of holes and riveted weldments, bricks or plates shall be processed, and the joints shall be filled with mud. It is strictly prohibited to pave at will, leave room everywhere, and do not use mud. In the insulation layer, high alumina bricks shall be used to build the bricks under the anchor, behind the arch foot brick, around the hole and the contact expansion.
Expansion joints must be reserved for high alumina brick lining according to the design. The expansion joint width shall not have negative tolerance. There should be no hard debris left in the joint. The joints shall be filled with fire-resistant fibers to avoid the phenomenon that the outside is full and the inside is empty. Generally, expansion joints cannot be set in the insulation layer.
The lining of important and complex parts shall be prefabricated first. Castable lining can be used for lining with complex structure and large amount of brick processing.
The exposed metal parts left in the brick lining, including brick supporting plate and brick retaining plate, shall be sealed with special-shaped bricks, castables or refractory fibers, and shall not be directly exposed to the high-temperature kiln gas in use.
Anchor bricks are masonry structural bricks, which shall be reserved according to the design regulations. Anchor bricks with cracks shall not be used around hanging holes. The metal hook shall be placed flat and hung firmly. The lifting hole and hook shall not be stuck, and the gap can be filled with refractory fiber.
When paving capping bricks, joint bricks and bent bricks, if the original bricks can not meet the capping requirements, the brick cutter shall be used for finishing processing, and manual processing of bricks is not allowed. Size of processed brick: the top brick shall not be less than 70% of the original brick; Flat joint brick and bent brick shall not be less than 1 / 2 of the original brick. It must be locked with the original brick. It is strictly prohibited to process brick working face. The processing surface of the brick shall not face the furnace, working face or expansion joint.
