Rotary Gunning Machine: An Efficient Solution in the Field of Industrial Kiln Maintenance
In industrial production, kilns serve as core thermal equipment, and the integrity of the refractory materials on their inner walls directly impacts production efficiency and safety. Long-term high-temperature operations easily cause damage such as spalling and erosion on the inner walls of kilns. Traditional manual repair methods are not only inefficient but also pose safety hazards. As an efficient automated maintenance device, the rotary gunning machine, with its precise, fast, and durable repair capabilities, has become a core piece of equipment for kiln maintenance in industries such as metallurgy, building materials, and chemical engineering.
I. Working Principle: The Precise Repair Logic Driven by Rotational Power
The core working principle of the rotary gunning machine is based on a coordinated mechanism of "mechanical rotational pressure + material atomization and spraying", achieving efficient repair through three key processes:
Material Conveying and Mixing
First, the equipment automatically mixes refractory powder, binder, and water in a preset ratio to form a uniform paste-like gunning material. Compared with manual mixing, mechanical proportioning can control the material uniformity error within ±2%, ensuring stable refractory performance of the repair layer.
Rotational Pressure Spraying
The mixed gunning material is delivered to the rotating spray head by a high-pressure pump. The spray head rotates at high speed, and under the action of centrifugal force, the material is atomized into fine particles and sprayed onto the damaged surface of the kiln.
Dense Adhesion and Forming
When the high-speed sprayed material particles hit the inner wall of the kiln, they form a dense accumulation layer. Combined with the curing effect of the binder, this effectively prevents the repair layer from falling off.
II. Core Structure and Technical Features: Balancing Efficiency and Durability
(I) Key Components
The structural design of the rotary gunning machine centers on three core requirements: "stable conveying, precise control, and safe durability", and mainly includes five core systems:
Material Supply System: Composed of a storage bin, screw conveyor, and metering pump, it enables continuous material supply and precise proportioning, and is compatible with various refractory materials such as fire clay bricks and high-alumina bricks.
Rotary Spraying System: Its core consists of a variable-frequency speed-regulating motor and a wear-resistant alloy spray head. The motor can adjust the rotation speed according to repair needs, and the spray head reduces the cost of frequent replacement.
Hydraulic Control System: It drives the lifting and rotation of the spray head arm through hydraulic cylinders, meeting the full-section repair needs of small and medium-sized kilns with a positioning accuracy error of ≤5mm.
(II) Core Technical Advantages
Compared with traditional manual repair and fixed gunning machines, the rotary gunning machine has significant advantages:
High Efficiency and Energy Saving: A single device can complete 15-25 square meters of repair work per hour, with an efficiency 8-10 times that of manual work. At the same time, precise spraying reduces material waste, and the material utilization rate can reach more than 90% (compared to only 60% for traditional manual work).
Safety and Reliability: Operators complete the work through remote control without entering the high-temperature area inside the kiln (the temperature of the kiln inner wall often reaches above 1000°C), completely avoiding safety risks such as scalding and oxygen deficiency.
High Repair Quality: The repair layer formed by rotational atomization has high density (bulk density ≥2.3g/cm³) and strong erosion resistance, which can extend the service life of the kiln by 3-6 months and reduce the number of shutdowns for maintenance.
Strong Adaptability: It supports a variety of refractory materials (monolithic refractories, plastic refractories, etc.) and can be adapted to different kiln types (rotary kilns, shaft kilns, tunnel kilns) by replacing the spray head, meeting maintenance needs in multiple scenarios.
III. Application Scenarios: Covering Kiln Maintenance Needs in Multiple Industries
With its flexible and efficient characteristics, the rotary gunning machine has been widely used in the following industrial fields:
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Metallurgical Industry: Repair of inner linings of blast furnaces and converters
In iron and steel production, the hearth of blast furnaces and the lining of converters are long-term subjected to molten iron scouring and high-temperature erosion, which easily leads to local spalling. The rotary gunning machine can quickly repair damaged areas during the blast furnace blowdown period (usually only 8-12 hours). Using high-alumina gunning materials, the repair layer can withstand temperatures above 1700°C, ensuring the continuous and stable operation of the blast furnace. Data from an iron and steel enterprise shows that after using this equipment, the service life of the blast furnace inner lining has been extended from 18 months to 24 months, reducing annual maintenance costs by approximately 1.2 million yuan.
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Building Materials Industry: Repair of refractory bricks in cement rotary kilns
The cement rotary kiln is a core equipment in cement production, and the refractory bricks in its burning zone (temperature 1450-1600°C) wear out the fastest. Traditional manual repair requires the kiln to be shut down for 3-5 days, while the rotary gunning machine can realize "online hot repair" without completely shutting down the kiln. It only needs to reduce the kiln speed to operate, and the single repair time is shortened to 4-6 hours, which can reduce the production loss caused by kiln shutdown by approximately 5,000 tons of cement per year.
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Chemical Industry: Maintenance of calcium carbide furnaces and glass kilns
In calcium carbide production, the furnace wall of calcium carbide furnaces is eroded by high-temperature molten materials, which easily forms cavities; the checkerwork of the regenerator in glass kilns also often has blockages and damages. The rotary gunning machine can achieve precise repair for these complex structures by adjusting the spray head angle (0-90°). Using corrosion-resistant refractory materials, it effectively improves the operational stability of the equipment and reduces safety hazards in chemical production.
IV. Development Trends: Upgrades in Intelligence and Large-Scale Design
With the improvement of industrial automation and the demand for green production, the rotary gunning machine is developing in the following directions:
Large-Scale Adaptation: For large rotary kilns and ultra-high-temperature kilns, develop equipment with a larger operating radius and higher temperature resistance (spray head temperature resistance of 1200°C) to meet the maintenance needs of large industrial kilns.
Green Improvement: Optimize the design of the dust removal system, adopt low-noise fans (noise ≤75dB), and at the same time develop environmentally friendly binders to reduce volatile organic compound (VOCs) emissions, in line with the green production requirements under the "dual carbon" goal.
Conclusion
As an "efficient guardian" for industrial kiln maintenance, the rotary gunning machine solves the pain points of low efficiency, high risk, and poor quality of traditional repair methods through technological innovation, and provides key support for the continuous production and cost control of industries such as metallurgy, building materials, and chemical engineering. With the continuous breakthroughs in intelligent, large-scale, and green technologies, its application scenarios in the industrial field will be further expanded, injecting stronger impetus into the long-term operation of industrial equipment.
