In the field of industrial production, converters are key thermal equipment, and the integrity of the refractory materials on their inner walls directly affects production efficiency, product quality, and safe production. However, long-term exposure to high temperatures, material erosion, chemical attack, and other factors easily cause problems such as spalling, wear, and cracks in the converter's refractory lining. If not repaired in a timely manner, this will not only shorten the service life of the converter but also may lead to serious consequences such as production interruptions and increased energy consumption. As an efficient converter maintenance equipment, the semi-dry refractory hot gunning machine, with its unique gunning method and excellent performance parameters, has become a core equipment for solving the repair problems of converter refractory linings, providing an important guarantee for the stable operation of industrial production.

The performance advantages of the semi-dry refractory hot gunning machine are first reflected in its core parameters that accurately match industrial needs. Each parameter is carefully designed to ensure the equipment can operate stably under different working conditions.

In terms of the hopper volume, the 0.8 cubic meter design is a key choice that balances practicality and flexibility. This volume can not only meet the material demand for a single gunning operation of medium and large converters, reducing operation interruptions caused by frequent material feeding and improving overall construction efficiency, but also avoid increasing the overall weight and floor space of the equipment due to an overly large hopper. It facilitates the movement and deployment of the equipment in the workshop, especially suitable for scenarios with limited space or requiring multi-station operations. Whether for the local repair of cement rotary kilns, iron and steel blast furnace hot stoves, or glass melting furnaces, the 0.8 cubic meter hopper can provide continuous and stable raw material supply for gunning operations.

The gunning material conveying power is set to an adjustable range of 60-100 kg/min, which is a core advantage of the equipment to adapt to different repair needs. In actual operations, gunning requirements vary significantly: when dealing with small-area, high-precision local repairs of the converter lining, the conveying power can be reduced to approximately 60 kg/min. By precisely controlling the amount of gunning material, material waste is avoided, while ensuring the flatness and compactness of the repaired area. When handling large-area spalling or emergency repair tasks, the conveying power can be increased to 100 kg/min to quickly cover the damaged area, shorten the converter shutdown maintenance time, and minimize production losses. This adjustability enables the equipment to flexibly meet the diverse repair needs of converters in different industries such as cement, iron and steel, non-ferrous metals, and glass.

The pipeline operation range reaches 12,000 mm (12 meters), which greatly expands the equipment's operation space. Converters have complex structures, and some damaged areas may be located deep inside the equipment or in positions that are difficult to access directly. The 12-meter pipeline length can easily cover these remote areas. There is no need to frequently move the main body of the equipment; gunning operations can be completed only by adjusting the pipeline direction. This parameter not only reduces the work intensity of operators but also minimizes the interference of equipment movement on the surrounding environment of the converter. At the same time, it avoids the problem of reduced gunning precision that may be caused by frequent equipment displacement, ensuring high-quality gunning can be achieved at any key part of the converter.

The semi-dry gunning method is a core feature that distinguishes this equipment from dry and wet gunning machines. Its unique working principle determines the equipment's comprehensive advantages in efficiency, quality, and environmental friendliness.

The working process of semi-dry gunning can be divided into three key stages: First, the gunning material (dry refractory powder) undergoes pre-mixing treatment in the hopper to ensure the material is uniform and free of agglomeration. Then, the refractory powder is conveyed to the gun head at a certain speed using compressed air. At the gun head, an appropriate amount of water (or a special binder solution) is sprayed into the powder through a special atomization device, forming a thin wet layer on the surface of the powder while keeping the overall structure loose (the moisture content is usually controlled between 5% and 10%). Finally, the wet powder is sprayed at a high speed (usually up to 30-50 m/s) onto the damaged refractory lining surface of the converter by the thrust of compressed air. Through the impact and extrusion between the powder particles and the evaporation and solidification of moisture, a dense and firm refractory repair layer is formed.

The advantages of this gunning method are remarkable: Compared with dry gunning, the semi-dry method adds an appropriate amount of water, which significantly reduces the amount of dust generated during the gunning process. This not only improves the working environment and protects the health of operators but also reduces powder waste. At the same time, the addition of water enables the refractory powder to bond better after spraying, resulting in a repair layer with higher compactness, stronger erosion resistance, and longer service life of the repaired area. Compared with wet gunning, the semi-dry gunning material has a lower moisture content, so the repair layer dries faster after gunning. The converter can be reheated and put into production without a long waiting period for drying, significantly shortening the maintenance cycle. In addition, wet gunning materials are prone to problems such as flowing and cracking due to their high moisture content, while semi-dry gunning materials are in a loose and wet state, which has good formability after spraying and allows precise control of the thickness of the repair layer. It is especially suitable for repairing converter parts that require high flatness.

With its excellent performance parameters and semi-dry gunning technology, this equipment has been widely used in converter maintenance in multiple industrial fields and has become an important equipment to ensure stable production in various industries.

In the cement industry, the cement rotary kiln is a core production equipment. The linings of its burning zone and transition zone are long-term exposed to high temperatures (above 1400°C), material erosion, and chemical attack, which easily cause problems such as brick spalling and wear. The semi-dry refractory hot gunning machine can repair the damaged lining quickly with a conveying power of 60-100 kg/min through a 12-meter-long pipeline that extends deep into the kiln when the rotary kiln is shut down briefly (or shut down with residual temperature). The repair layer formed by gunning is closely bonded to the original lining and has excellent high-temperature resistance, which can effectively extend the operation cycle of the rotary kiln, reduce unplanned shutdowns caused by lining damage, and ensure the continuous and stable cement production.

In the iron and steel industry, the maintenance of refractory linings of equipment such as blast furnace hot stoves, converters, and ladles is crucial. Taking the blast furnace hot stove as an example, its lining is long-term scoured by high-temperature hot air (1200-1300°C), which easily causes cracks and spalling. If not repaired in time, it will lead to a decrease in hot air temperature and affect the blast furnace smelting efficiency. This gunning machine can perform precise gunning on key parts of the hot stove such as the dome and combustion chamber. The 0.8 cubic meter hopper can meet the material demand for a single local repair of the hot stove. The repair layer formed by semi-dry gunning has strong thermal shock resistance, which can effectively resist the impact of hot air temperature fluctuations and ensure the stable operation of the hot stove.

In the glass industry, parts such as the tank wall, breast wall, and small furnace of the glass melting furnace are long-term in contact with high-temperature glass liquid and corrosive gases. Lining damage will lead to serious problems such as glass liquid leakage and product quality decline. Due to the extremely high shutdown cost of the glass melting furnace, higher requirements are placed on maintenance efficiency and quality. The semi-dry refractory hot gunning machine can operate without shutting down the melting furnace (or in a slightly hot state). The low-dust semi-dry gunning will not pollute the glass liquid, and the 12-meter pipeline can cover the key areas inside the melting furnace to repair the damaged lining quickly, minimizing production losses.

In addition, in industries such as non-ferrous metal smelting (e.g., aluminum electrolytic cells, copper converters) and chemical engineering (e.g., calcium carbide furnaces, rotary kilns), this equipment has also become an ideal choice for converter maintenance due to its flexible parameter adjustment, wide operation range, and high-quality gunning effect.

To give full play to the performance advantages of the semi-dry refractory hot gunning machine, standardized operating procedures and regular equipment maintenance are crucial. This not only ensures the safety and efficiency of gunning operations but also extends the service life of the equipment and reduces operating costs.

In terms of operating procedures, the following steps must be strictly followed: Before operation, check the integrity and tightness of various components of the equipment (hopper, conveying pipeline, gun, air compressor) to ensure no leakage or damage. At the same time, adjust the conveying power (60-100 kg/min) according to the gunning requirements, and determine the water addition amount at the gun head based on the characteristics of the refractory powder to ensure the powder is evenly wetted. During operation, the operator should control the distance (usually 0.8-1.5 meters) and angle (as perpendicular to the gunning surface as possible) between the gun and the gunning surface, and move the gun at a uniform speed to avoid excessive thickness or thinness of local gunning. At the same time, closely monitor the material level in the hopper and replenish the powder in a timely manner to prevent the occurrence of layers in the gunning layer due to material interruption. After operation, clean the residual powder in the hopper in a timely manner, and purge the conveying pipeline and gun with compressed air to avoid powder agglomeration and blockage. At the same time, turn off the air compressor and equipment power, and complete the operation records (such as gunning location, gunning amount, equipment operating parameters, etc.).

In terms of equipment maintenance, focus should be placed on the following key points: Regularly check the mixing device of the hopper to ensure the mixing blades are free of wear and deformation, and the powder is mixed evenly. Regularly inspect the inner wall of the conveying pipeline; if severe wear is found (such as thinning of the pipeline or the appearance of holes), replace it in a timely manner to avoid a decrease in conveying power caused by pipeline leakage. Regularly clean the atomization device at the gun head to prevent nozzle blockage by scale or powder residues, which may affect water addition control and gunning effect. In addition, regularly lubricate and maintain power components such as the air compressor and motor to ensure their smooth operation and reduce the occurrence of faults.

With the continuous improvement of requirements for production efficiency, environmental protection, and intelligence level in the industrial field, the semi-dry refractory hot gunning machine is also continuously upgraded towards intelligence and green development, and will further meet the development needs of the industry in the future.

In terms of intelligent upgrades, more intelligent control technologies will be introduced into the equipment in the future: Sensors will be installed to monitor parameters such as the conveying speed of gunning material, the water addition amount of the gun, and the thickness of the gunning layer in real time, and the data will be transmitted to the central control system. The system can automatically adjust the operating state of the equipment according to preset parameters to realize "one-click gunning" and reduce human operation errors. At the same time, combined with the operation data of the converter (such as temperature, pressure, and lining wear condition), AI algorithms can be used to predict the lining damage trend and plan gunning schemes in advance to realize "predictive maintenance" and further reduce the converter shutdown time. In addition, the application of remote control technology will allow operators to complete gunning tasks through a remote control console without working in close proximity to the site, greatly improving operational safety, especially suitable for high-temperature and high-risk converter environments.

In terms of green upgrades, optimization will be carried out from two aspects: materials and energy consumption. On the one hand, more environmentally friendly refractory gunning materials (such as low-heavy-metal and recyclable powder) will be developed. Combined with the low-dust advantage of semi-dry gunning, environmental pollution will be further reduced. On the other hand, more efficient power systems (such as energy-saving motors and variable-frequency air compressors) will be adopted to reduce the energy consumption of equipment operation. At the same time, by optimizing the pipeline design, material loss during powder conveying will be reduced, material utilization rate will be improved, and "energy conservation and consumption reduction" will be realized.

As a core equipment for industrial converter maintenance, the semi-dry refractory hot gunning machine has the advantages of 0.8 cubic meter hopper volume, adjustable conveying power of 60-100 kg/min, 12-meter pipeline operation range, and unique semi-dry gunning technology, which together constitute the equipment's performance advantages of high efficiency, flexibility, and high quality. In the future, with the continuous integration of intelligent and green technologies, this equipment will play an important role in more industrial fields, provide stronger support for the long-life and high-efficiency operation of industrial converters, and promote the development of industrial production in a more sustainable and efficient direction.