Fourteen rules that refractory castable construction must fo
Fourteen rules that refractory castable construction must follow
Refractory castable lining
1) The construction site should be cleaned and cleaned.
3) Refractory castables and refractory bricks or thermal insulation products shall be blocked by water-absorbing methods when they are touched. Foam boards and plastic sheets may be used for barrier construction and removed after construction.
1) The support is strong to disassemble and facilitate the seam to leak
3) Reserve wood planks for expansion joints should be fixed to avoid shifting when vibrating
5) When the poured pouring material does not reach 1.2MPa, it should not be installed on it.
7) The load-bearing formwork should be removed when the castable arrives at 70% strength. The non-bearing formwork should be removed when the pouring material strength can ensure that the lining appearance and corners are not damaged due to demoulding.
1.3 The lining construction joints shall be determined before the construction of the refractory castables. The construction shall be carried out in succession. The thickness of refractory linings of the same type shall be formed at one time, and the layered construction shall be forbidden. If it is suspended for any reason, it shall be treated according to the construction joints and comply with the following rules:
2) Construction joint interface type:
b When the lining thickness δ>50mm, a stepped joint should be made (see the figure below)
4) The joint surface of the hydraulic refractory castable should be fully wetted during casting or spraying. The joining surface of the gas-hard thermosetting refractory castable should be evenly coated with the binder solution, and the loosened joints and the remaining refractory castable should be removed.
1.4 The dimension of the voids and the orientation and structure of the expansion joints of all pouring linings shall conform to the planning rules and be filled with data according to the planning rules. When the plan has no rules for the gap size of the expansion joints, the uniform value of the large expansion joints per meter of long lining, The following data can be used in clay and high-alumina casting guesses:
2 phosphate castable 6～8mm
4 Portland cement refractory castable 5～8mm
1.6 When the lining thickness of heat-insulating and refractory castables is ≤50mm, manual tamping can be done by hand using the method of painting by hand. The surface of the lining after pouring should be flat and compact and not be calendered.
1.8 When the casting mold for refractory castables is poured, it shall be vibrated. The mechanical vibration shall meet the following rules:
2) The height of the pouring layer using the puncturing vibrator should not be greater than 300mm The vibrating rod should be pierced into the base layer Castable 50mm The moving interval should not be greater than the vibrating rod's effect radius and the oscillation time should not be too long to make the internal bubbles overflow The slurry can no longer sink
1.9 Semi-wet mechanical spraying of refractory castables, suitable for insulating refractory castables, lightweight refractory castables, dense refractory castables, but alumina hollow sphere refractory castables shall not be applied by semi-wet mechanical spraying and shall comply with the following rule:
a Water pressure not less than 0.6MPa
c Operating environment should have ventilation equipment
2) The spraying should be sprayed once in a row and sprayed to the planned thickness. If the lining is thicker and needs to be layered, the secondary layer should be sprayed before the initial setting of the front layer spray coating and the rebound material attached to the support or pipeline. Should be promptly eradicated.
4) Spray thickness should be checked in time. If the thick part is flattened, no thick part can be sprayed in time, and the sprayed surface must not be calendered. The rebound material should not be used.
6) When the appearance of large lines of expansion should be cut in time after spraying.
1) Wet maintenance After the castable is hardened, keep the surface of the lining covered to meet the wet conditions, and the natural maintenance relative humidity of 35% to 75% is appropriate.
3) During the maintenance of the CA-50 aluminate cement refractory castables, the weather conditions should be used to determine whether to adopt the method of lowering the surface lining temperature. Strengthen pre-maintenance, natural condition maintenance after at least 1d.
5) During the maintenance of castables, no external force and sensation shall be allowed.
1.12 The surface of refractory lining refractory lining should not have the disadvantages of shedding, cracks, holes, etc. When there are no special requirements for planning, there should be fine mesh cracks and a few pores.
1.14 When repairing refractory lining lining defects, the defects affecting the lining structural function shall be studied and dealt with by relevant units such as planning, supervision and construction, and shall comply with the following rules:
2) The repair material maintenance method should be common with the original lining.
3) The repair site should be carefully filled with hydraulic refractory castables, joints should be fully wetted, and the joints of the gas hard thermo-resistant refractory castables should be evenly coated with the binder solution.