Refractory castables, as key materials for high temperature industrial equipment, have a direct impact on the performance and service life of the equipment due to their construction quality and workmanship. Especially in winter, due to the low ambient temperature, it brings extra challenges to the construction of refractory castables. Therefore, it is crucial to master the construction method of winter refractory castables.
The general standard for winter construction is that when the outdoor average daily temperature is steadily lower than 5℃ for three consecutive days, the construction of refractory castables should adopt the winter construction standard. Before construction, the temperature of the working environment should be measured, including the temperature of the air outside the shed should not be less than 5 ℃, the temperature around the workplace and the lining, the temperature of the material in the shed after heating, fire-resistant burnt material out of the tank, into the mold and the maintenance of the temperature, etc., should be set up to measure the temperature of the staff, should be measured every 4 hours 1 time and make a good record.
The materials delivered to the construction site should have quality certificate, valid inspection report and product instruction manual, and indicate the name of manufacturer, product name, brand name, weight, production date and expiration date. Materials should be checked before construction, and when in doubt, they should be sent to the nationally recognized laboratory for physical and chemical index test.
Before the construction in winter, the coarse and fine aggregate and powder used for the preparation of refractory castables should be sufficiently prepared and stored in the warehouse with a cover on the top and a mat on the bottom, and should be kept dry. The materials should be arranged according to specifications and varieties, and should be labeled. Aluminate cement should be preferred for the preparation of refractory castables. Clean water should be used when mixing the refractory castables.
Before the construction of refractory castables, special winter construction program should be prepared and technical briefing should be carried out. After the acceptance of the previous process, the construction of the next process can be carried out.
The construction personnel shall have special training for winter construction. Warming hut and material heating facilities should be set up in time, and there should be a person in charge of maintenance. The mixing apparatus should be set near the pouring place. Counting M apparatus, temperature measuring equipment should be used after being tested and qualified.
Before construction, simulated construction should be carried out under the same conditions to verify the winter construction measures.
In winter construction, the refractory castables suitable for low-temperature environment should be selected. This kind of castable usually has good frost resistance and low temperature fluidity, and can keep good working performance under low temperature. In addition, the castables should be preheated before construction to improve its fluidity and facilitate construction operation.
Layered pouring: It is recommended to use layered pouring method during winter construction. Through layered pouring, the pouring speed and thickness can be better controlled to avoid defects such as cold joints and hollowing.
Vibrating and compacting: During the pouring process, the refractory castables should be vibrated and compacted with vibrators. Vibrating can improve the compactness and uniformity of the castables, and enhance its mechanical properties and durability.
Temperature control: During the construction process, the ambient temperature and the temperature of the castables should be closely monitored. If necessary, heating measures can be taken, such as using electric blankets, hot air guns and other tools to heat the castables to ensure that their construction temperature meets the requirements.
After the pouring is completed, insulation measures should be taken in time for maintenance. Insulation materials can be used to cover the pouring surface and maintain appropriate temperature and humidity to promote the hardening and strength development of the castables. During the maintenance period, external impact and vibration should be avoided so as not to affect the performance of the castables.
When constructing refractory castables in winter, the influence of low-temperature environment on the castables should be fully considered, and corresponding measures should be taken to ensure the construction quality and safety. By choosing the refractory castables suitable for winter construction, controlling the construction temperature, adopting appropriate construction methods and maintenance measures, the construction effect and performance of refractory castables can be effectively improved. At the same time, the construction process should follow the relevant norms and standards to ensure the construction quality and safety.
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