What are the advantages of using refractory plastics on the top of heating furnaces?

The use of refractory plastics in heating furnace roofs represents an upgrade. Originally, furnace roofs used refractory bricks, which later evolved into refractory castables. Refractory plastics are the third generation of this upgrade.

Heating furnace roofs are subject to high temperatures and severe airflow erosion. Early refractory bricks were suspended from the roof, and later refractory castables were cast in the formwork. However, roofs suspended with refractory bricks lack airtightness and result in heat loss. Furthermore, refractory bricks are shaped and have uneven surfaces, which create airflow resistance and reduce heat utilization. In severe cases, localized brick fallout can occur.

While the conversion to refractory castables for heating furnace roofs overcomes some of the drawbacks of refractory bricks, they suffer from poor thermal shock resistance, which can cause large-scale collapse. Furthermore, refractory castable construction requires expansion joints in the formwork, resulting in gaps in the surface and less than ideal performance.

Using refractory plastic completely avoids the drawbacks of using refractory bricks or refractory castables. Plastic offers excellent thermal shock resistance and strong airtightness. Furthermore, it facilitates repair and maintenance work, a major advantage of using plastic.

Other advantages of using refractory plastic include resistance to rapid cooling and heating, as well as good spalling resistance. Refractory plastic is generally used most frequently for repairs.

It is crucial to carefully store refractory plastic before construction. If it hardens during use, it cannot be reused, as it has lost its plasticity and softens in contact with water. Shrinkage joints in plastic should be addressed after oven curing, and areas with significant shrinkage should be filled with plastic to ensure a complete seal.

In summary, the advantages of using refractory plastic include good thermal shock resistance, resistance to rapid cooling and heating, and good spalling resistance. For urgent repairs, it can be used directly as the oven temperature rises, without baking.

Reheating Furnace