As an important amorphous refractory material, refractory plastic has been widely used in many industrial fields, especially in the construction of high-temperature furnaces, due to its excellent plasticity and refractory properties. This article will introduce the construction technology of refractory plastic and related precautions in detail to help construction personnel better master and apply this material.
Refractory plastic is mainly composed of granular and powdered refractory raw materials, plastic clay, binder and plasticizer. Before construction, comprehensive preparation work is required. First, the steel structure, baseline and holes of the furnace are fully inspected to ensure that they meet the design requirements. At the same time, prepare the required construction machinery and tools, including air compressors, pneumatic tamping machines, tamping hammers, templates and various finishing tools. Refractory plastic blanks should be stored in a cool and dry warehouse to prevent them from losing plasticity due to water evaporation.
During the construction process, tamping is one of the key steps. Refractory plastic needs to be constructed by tamping. When tamping, it is necessary to ensure that the blanks are tightly laid, only one layer is laid at a time, and a pneumatic tamping machine is used for tamping. During the ramming process, the hammer head should move along the length of the furnace wall, and each ramming should be overlapped by about 1/4 to ensure that the entire blank surface is rammed 2 to 3 times. When encountering anchor bricks, the furnace wall plastic should be rammed to the upper surface of the anchor brick, and part of the material should be dug out to place the die. When the placement size is reached, the die is removed and the anchor brick is installed to ensure that the two are tightly combined to prevent fire and furnace wall collapse.
The treatment of the working surface of the refractory plastic lining is equally important. After the construction is completed, the surface needs to be trimmed, stripped, pierced with vent holes, and expansion joints are cut. Surface trimming mainly involves cutting off excess parts to make it meet the design size. Stripping treatment uses a wire brush to expose the internal pores on the surface to facilitate moisture removal. The vent hole is set by piercing the hole perpendicular to the working surface with a breathable needle. The depth is about 1/3 of the lining thickness, and the hole spacing is 150 to 250 mm to buffer the rapid expansion of the lining and prevent cracks or peeling. In addition, expansion joints are set up according to design requirements, and refractory fibers are filled in the joints to ensure that the surrounding area is compacted.
During construction, some key issues need to be noted. First, the construction of refractory plastics should be carried out continuously to avoid long-term interruptions. If it must be interrupted, the compacted plastics should be covered with plastic sheets to prevent dehydration. When the ambient temperature is below 10°C, anti-cold measures should be taken to ensure the quality of construction. In addition, during the construction process, close cooperation should be carried out with various types of work to ensure the rationality of the construction sequence and process.
Finally, quality inspection and acceptance are required after the construction is completed. The inspection content includes whether the construction meets the design requirements, whether the structure is complete, whether the material quality is qualified, whether the ramming is dense, and whether the surface treatment is standardized. Only through strict inspection and acceptance can the construction of refractory plastics achieve the expected effect and ensure the safe operation and long-term stability of high-temperature furnaces and kilns.
In summary, the construction technology of refractory plastics involves multiple links, from construction preparation to ramming construction, to lining working surface treatment and quality inspection, and each step needs to be carried out strictly in accordance with technical specifications. Through scientific and reasonable construction methods and rigorous quality control, the excellent performance of refractory plastics can be fully utilized to provide reliable fire-resistant protection for various industrial fields.