01. Construction of castables for flue lining
The construction of castables for the flue lining can be carried out after the installation is in place, or the lining can be constructed first and then installed. The temperature of the flue is not high, but the flue gas, dust and acid corrosion are great. In particular, the heat exchanger needs to be flushed with water, which has a great impact on the construction and use of the lining material.
During the lining construction of the flue, a 3mm gap should be left between each cast body to set expansion joints. The construction of castables is to apply sealing material to the adjacent position of one piece of castable before pouring the next piece.
02. Before installation
It would be better if the lining is constructed after the installation is complete. Large-diameter flue linings are easy to construct with castables. However, if the large-diameter pipes are heavy and the lining construction is carried out before installation, the weight of the pipes will be doubled, the installation risk will be high, and the components will be difficult to weld. The lining is suitable for construction after installation.
The picture shows the construction of flue lining refractory castables before installation. It is suitable for the construction of castables for small diameter flue linings because of its light weight. Pre-installation construction also reduces the difficulty of high-altitude operations. Pouring is performed on the ground, resulting in low labor intensity and high construction efficiency. The disadvantage is that the lining construction cannot be carried out continuously and the expansion joints are not easy to handle.
03. The first thing to pay attention to during construction is safety.
The first thing to pay attention to is safety, then the way the anchors are welded and poured. For large-diameter flues, the anchor nails are first welded and then the anchors are painted, and then the construction is carried out in separate halves. After the two halves within 180° are constructed first, the pipe is turned 180°, and then three and four halves are constructed. During flap construction, if there is an insulation layer, the insulation castable for the insulation layer should be constructed first, and then the working layer of wear-resistant castable should be constructed.
In addition, if there are two types of construction of the pipeline lining, it must be constructed in four separate sections. However, construction of the next section can only be carried out after 12 hours of completion of each section. The lower half of the construction is poured first, and then the flue is placed on the ground. Flip and pour the other half.
04.Construction of lining on the ground
If the lining is constructed on the ground, the pipe opening must be corrected and measures to prevent deformation must be taken. Prevent the pipe mouth from deforming due to heavy or light weight when the pipeline is turned over during construction. No construction will be carried out on locations that are prone to deformation during construction, and lining construction will be carried out on the demolished locations after construction of other locations is completed.
Pipe elbows, expansion joints, and valves must be constructed in sections, and expansion joints must be reserved in horizontal and vertical pipe sections. Parts that are not high can be poured using a diagonal mold, vibrated and compacted, and the excess parts can be cut off along the tangent line. If the space is small and the construction joints are high, the castables are constructed using flat joints, and 3mm high-temperature resistant ceramic fiber felt is sandwiched in the joints, and then assembled and welded.