Overview
Industrial kilns play a crucial role in the production of various materials by providing controlled heating environments necessary for achieving desired material properties and product characteristics.
Industrial kilns are large refractory-lined rotating drums or high-temperature ovens or furnaces which are commonly used in industries such as cement, ceramics, metallurgy, and chemical processing for tasks like drying, baking, calcining, sintering, and annealing.
What is Kiln
It can be said that kilns are indispensable tools which is required where controlled heating is required. These are slightly inclined at a horizontal axis. During the process, the mixture of raw materials is formed and then mixed with another material which is used as a binder.
This mixture was then fed into the pellet kiln in which the mixture will be heated to a high temperature to form pellets, which are then used in further processes.
These kilns come in various configurations depending on the specific requirements of the materials being processed and the desired outcomes.
Refractory Lining of Kiln
The refractory lining of an industrial kiln is the most important component designed to withstand the high temperatures as well as the corrosive nature of the inside material. The lining acts as a protection wall to the structural integrity of kiln, prevent contamination of material and ensures the longer life of kiln.
In summary, kiln refractory linings are carefully engineered to provide thermal insulation, resist high temperatures and to prevent erosive effects of the material being processed in the kiln.
Depletion of Refractory Lining
The depletion of refractory lining of kiln is a common issue that can occur over time due to various reasons. Some common reasons are: High temperatures, chemical attack, mechanical wear, lack of maintenance, poor installation etc.
These refractories have limited lives, as the lining starts degrading over time and there are greater chances of accidents. The maintenance and re-lining of these refractories has a significant contribution to the cost of the production. Apart from the economic impact of a breakdown, there is a high risk of personnel injuries and loss of life.
To minimise the depletion of refractory linings, it is very essential to ensure proper installation and to conduct continuous monitoring with timely repairs and maintenance.
The most effective method to overcome this situation is by tracking the temperature pattern of the external surface of the kilns using thermography. This thermal detail can be used to provide a scheme for re-lining the damaged area of the refractory and also increases the utilization of refractories
Pyrosens’s Solution
Pyrosens’s Kiln Monitoring System with ThermCAM-series integrated with InfraVIEW software provides a precise and reliable temperature measurement solution to enhance plant safety and helps in organizing maintenance schedules in metallurgical plants as it provides continuous thermal monitoring as well as a large panel area for temperature measurement.
ThermCAM-Series thermal cameras are a non-contact temperature measuring instrument that can measure the temperature from -20°C to 120°C/100°C to 1000°C (other temperature ranges are also available). It can detect the spectral range of 8-14 μm and has an accuracy of ±2% of reading in °C or °K.
The camera system captures thermal images of the kiln by calculating the temperature at the kiln’s surface. An increase in temperature at the outer shell and accelerated rate of increase in temperature gives a clear indication of refractory damage, alarming to set a schedule for refractory relining.
To acquire more precise information and temperature of a particular region, user can also create different types of RoIs in various shapes and sizes for further analysis and reports.
Alarms and indicators can be installed to generate signals if in case kiln’s surface temperature goes above the maximum mentioned temperature which is user predefined. By this operator can check the requirement of a schedule for refractory relining. These alert signals can also be received over email and SMS as required by the user.
Software Configuration
InfraVIEW is a windows-based software which is particularly dedicated for industrial thermal imaging applications. The InfraVIEW software provides easy and quick framework for the documentation of the recorded raw data which has been continuously captured through thermal camera.
InfraVIEW software provides high-speed real time data acquisition through which one can easily record, view analyse and store the captured thermal videos/ images as well as the temperature data. It also allows captured temperature data to be integrated to I/O modules or can be connected to PLC via OPC/UA server.
Salient features of InfraVIEW Software
- Real-time display of thermal images.
- Includes 9 different color palates, according to user application.
- Multiple types of ROI including point, line, and area with min./max./avg. temperature display.
- Histogram and trend chart of ROI can be generated for data analysis.
- Temperature Display on Mouse Over.
- Alarm generation for entire or ROI based on minimum, maximum or average temperature.
- Data export to text or Microsoft Excel (includes thermal image, ROI table summary/data, image data).
Thermal Camera Connections
Advantages of the system
- Automatic and non-contact temperature measurement system, which increases personnel safety.
- Improve kiln safety.
- Increases refractory life span.
- Prevents refractory failure.
- Allows timely relining of refractory.
- Easy interface and flexible according to operation needs.
