1. Application Background
In multiple production industries such as building materials, metallurgy, chemical engineering, and environmental protection, rotary kiln equipment is widely used for processing solid materials. Through the rotation of the kiln body, it promotes material mixing, calcination, and contact reactions. Rotary kilns are mainly applied in calcining cement clinker (cement kilns), pelletizing mineral powder and sand (chemical kilns), sludge treatment (hazardous waste kilns), and calcining activated lime (lime kilns).
2. Operational Pain Points of Rotary Kilns
As a key thermal equipment in the production of building materials and environmental protection such as cement, metallurgy, and lime, the rotary kiln is known as the “heart” of the entire plant. During operation, if a “red kiln” occurs due to the detachment or thinning of refractory bricks, the kiln must be shut down for maintenance. Therefore, daily temperature monitoring is particularly important.
1) Ring Formation Inside the Kiln
Changes in temperature and the composition of raw materials and fuels are prone to causing ring formation inside the kiln. If the process is not adjusted in a timely manner, it will lead to poor ventilation inside the kiln, affecting product quality and output.
2) Thinning and Detachment of Refractory Bricks
With the increasing service life of the rotary kiln, the inner lining will thin or even detach under continuous high-temperature erosion and friction from clinker, resulting in partial exposure of the kiln shell and forming a “red kiln”. This often leads to unplanned kiln shutdowns for maintenance, which is a key factor affecting the high quality, high output, low consumption, and annual operation rate of cement kilns.
3) Erosion and Detachment of Refractory Bricks
Gradual erosion and detachment of internal refractory materials, if not detected in a timely manner, will cause the steel plate to be directly exposed to high-temperature environments, resulting in softening or even ablation. In severe cases, it threatens production safety and may cause unplanned kiln shutdowns or safety accidents.
3. Application Value of the Rotary Kiln Thermal Imaging Monitoring Solution
The temperature detection of the rotary kiln shell has evolved from manual detection with temperature guns to automatic detection with infrared shell scanners. Currently, with the maturity of infrared thermal imaging technology, more and more users are adopting rotary shell thermal imaging monitoring systems developed based on thermal imaging technology, which can monitor the kiln surface in real time more intuitively and clearly.
1) Ensuring Production Safety
Timely detect abnormal high-temperature points to avoid kiln shell damage, fires, and other safety accidents caused by local overheating.
2) Extending Equipment Service Life
Reasonably arrange maintenance plans to avoid excessive wear and unnecessary damage to equipment, thereby extending its service life.
3) Improving Management Efficiency
Real-time transmission of temperature data, through intuitive thermal imaging images and temperature change curves, assists process personnel in remote monitoring and centralized management, improving the scientificity of decision-making.
4) Reducing Maintenance Costs
Discover potential problems in advance and conduct targeted maintenance, avoiding large-scale maintenance and component replacement caused by sudden equipment failures, and reducing unnecessary maintenance time and costs.
5) Enhancing Production Efficiency
Avoid production interruptions caused by equipment failures and ensure continuous and stable production.
4. Thermal Imaging Online Monitoring System – Rotary Kiln Shell
The thermal imaging shell temperature monitoring and early warning system can present the real dynamic kiln operating conditions. The image is composed of temperature data, with each pixel corresponding to a temperature value, displaying the kiln shell temperature status in real time. The system can intuitively show the thickness of the kiln skin inside the kiln, the development trend of ring formation, and whether the refractory bricks are detached or thinned. Through the high-temperature alarm function, it can timely detect abnormal high-temperature points, assist process personnel in adjusting parameters, and ensure the safe and stable operation of the kiln system.
1) Installation Plan
The length of the kiln body is approximately 18-90m and the diameter is 4.5~5.5m. Installation position is about 35~40m away from the rotary kiln. Adopt Raythink’s infrared thermal camera to generate 1200×600 pixel infrared video images.
2) Solution Advantages
① Clear images and high temperature measurement accuracy.
② 24/7 uninterrupted detection, data visualization, and support for historical data tracking.
③ Non-contact temperature measurement, good stability, and long service life.
④ Easy installation and low cost.
5. Professional Analysis Software Functions
1) Historical Data Playback
Supports image capture at intervals of at least 30 seconds, with a recording time of no less than 12 months, and can be played back in video format.
2) Alarm Information Management
Supports high-temperature alarms, all alarm records are retrievable, and queries can be made by time, alarm type, alarm level, and other fields.
3) Refractory Life Management
Supports visual display of refractory materials, facilitating the grasp of refractory configuration and service cycle of the rotary kiln and assisting in process management.
4) File Management
Supports alarm statistics by team and generates daily, monthly, and annual production reports; supports refractory life file management and historical data query, facilitating process optimization and equipment operation and maintenance.
5) Kiln Size Marking
Realize the one-to-one correspondence between the meter position of the kiln length and the meter position of the temperature curve drawing in the upper and lower layout.
6) Visual Information Management
Automatically generate temperature curves for clear display of defect locations; support zoned temperature measurement monitoring and alarm setting.
6. System Hardware Configuration
| Number | Name | Quantity | Remarks |
| 1 | Rotary Kiln Shell Temperature Infrared Thermal Imaging Temperature Measurement Front-end Device | 1 set | Thermal imaging detector resolution: 1200×600 [super-pixel algorithm up to 2400×1200], one optical fiber interface, two gigabit waterproof network interfaces, waterproof aviation power interface, and self-starting cooling fan. |
| 2 | Rotary Kiln Shell Temperature Early Warning Comprehensive Analysis Software | 1 set | Real-time temperature measurement, analysis curve (one-to-one correspondence with the meter position of the kiln in the upper and lower layout), high-temperature automatic tracking, refractory file, historical playback, etc. |
| 3 | Terminal Receiving Unit (Computer) | 1 unit | 16G or more memory, 1T SSD hard disk, Intel Core i5 or higher processor, 1G or more independent graphics card, standard HDMI interface, 27-inch or larger ultra-wide monitor, Windows 10 Professional operating system. |
| 4 | Auxiliary Materials | 1 batch | Stainless steel control box [including installed switching power supply, maintenance guide rail socket, terminal block], optical fiber, bracket, network cable (standard configuration). |
7. System Parameters – Rotary Kiln Shell Monitoring
- System Name: Rotary Kiln Shell Temperature Infrared Thermal Imaging Monitoring and Early Warning System
- Detector Type: VOx uncooled infrared focal plane detector
- Infrared Detector Resolution: 1200×600 (super-pixel 2400×1200)
- Thermal Sensitivity: <40mK
- Image Frequency: 25Hz (synchronization of image and temperature data frame rate)
- Waveband: 7.5~14μm
- Pixel Pitch: 12μm
- Temperature Measurement Range: -20℃~650℃
- Temperature Measurement Accuracy: ±2℃ or ±2% of the reading
- Network Interface: Equipped with both optical fiber and gigabit Ethernet interfaces
8. Application Industries
- Cement Industry: Cement kilns (calcining cement clinker)
- Steel Industry: Pelletizing kilns (pelletizing mineral powder and sand)
- Hazardous Waste Industry: Hazardous waste kilns (sludge treatment)
- Building Materials Industry: Lime kilns (calcining activated lime)
