Introduction to refractory spray coating construction methods

Gunmetal is the most common repair material. Gunmetal is widely used because it can be constructed at any temperature, including normal and high temperatures, and the operation is also very simple. The construction methods of gunning repair projects can be divided into dry, semi-dry, and wet methods according to the transportation method of raw materials.

Refractory spray coating construction method

1. Dry hair is a method of transporting powder without moisture content and adding moisture to the nozzle position. The semi-dry method is a method of transporting powder containing part of the moisture and placing it at the nozzle position plus the remaining moisture. The wet method is a method of transporting drilling mud with added water. At present, dry hair is a commonly used construction method in various factories. An automatic spray repair equipment was developed because the temperature of the dry hair repair surface is related to the addition of moisture.
2. Wet gunning is not only used in the construction of repair materials but also in the construction of damaged inner villages. The high-speed cyclone of the spray paint equipment is sprayed into a common location and adsorbed on the working surface, which is called spraying. There are many different methods of spraying, and there are several types of the most common ones.
3. There are flame spraying and plasma spraying methods, but they are rarely used in refractory insulation materials. The slag spraying method is based on the instructions for using a high-pressure oxygen gun to spray on the furnace. This type is not common.
4. The dry spraying method is the most common method. The spray paint is compressed by air and transferred to the nozzle through the pipeline to meet the water. The material and water in the nozzle are mixed and sprayed onto the working lining. However, when spraying on the lining, the part will have a lower rebound force. Perhaps, the lower the rebound force ratio, the higher. When spraying, it is not good to use too much or too little energy. The spray gun should be moved up, down, left, and right to ensure the spray coating. Thick and well-proportioned.
5. The thickness of each spray of dry spraying method should not be too thick. If it is too thick, it will easily fall off. Normally it cannot exceed 50mm. In the wet test spraying method, the refractory castable with good fluidity is pumped to the nozzle through the pipeline and is sprayed to the working surface by the high-pressure cyclone in the nozzle. There are 4 processes in total: Mixing, Underwater Concrete, Spurting and Condensation. This method is mostly used for repair. Often used to create lining directly. Linings for ladles and furnaces can be manufactured immediately. The characteristics of the wet trial spraying method are that it is easy to use, does not require a template, is low-cost, and is fast. However, the adhesion rate of the wet test spray method is very important. If there is more water in the material, the initial setting will be longer, and no flow or slippage will occur, otherwise, separation will occur. If the adhesion is not good, it is likely to be caused by uneven spraying or excessive spraying. Perhaps, uneven materials are bad and can easily lead to cracking and lamination.