3. Infrared Thermal Imaging System

Infrared thermal imager uses infrared detector and optical imaging objective lens to accept the infrared radiation energy distribution pattern of the target to reflect on the photosensitive element of infrared detector, so as to obtain infrared thermal image. Different colors on the thermal image represent different temperatures of the object to be measured. The non-contact temperature measurement method of the infrared thermal imager can measure the real time temperature without affecting the work of the roller and take cooling measures at any time. The principle of infrared thermal camera: All objects with temperatures above absolute zero (-273℃) in nature emit infrared rays (or thermal radiation), which are widespread in nature. The atmosphere and clouds absorb visible and near-infrared light, but are transparent to 3-5 microns and 8-14 microns. Therefore, these two bands are called "atmospheric Windows" of infrared. With these two Windows, we can get a clear view of what is ahead on a completely dark night or in a thick cloud of smoke. Using infrared thermal imaging technology to observe the situation in the blast furnace can effectively solve the furnace no visible light, high dust, high humidity environment clearly display the situation. Based on the technology base, Yoseen Infrared has been developed specially for the optimal letter technology co., LTD specially used for burden surface monitoring of infrared thermal imaging system, the system is a kind of installed on the blast furnace top, through the hole to real-time continuous monitoring of furnace production situation, on the control of indoor monitor can within the furnace on the distribution of the material surface, material layer combustion situation in real time observation, real-time and accurate for the blast furnace operators make more correct and scientific judgment and decision-making, improve the production efficiency.

Schematic diagram of infrared monitoring system for furnace charge surface

The whole system is composed of special infrared thermal imager, protective cover and transmission protection device, network wire transmission system, background display system and software.

3.1 special infrared thermal imager, according to the requirements of high burden surface observation we special produce the small aperture pinhole camera, through the thermal imager in blast furnace roof opening into the hole on the condition of the furnace monitoring, large field of view Angle of pinhole lens can not only ensure the scope of the observation can also reduce the risk of material churning the lens damage.

Special infrared thermal imager for blast furnace

3.2 Protective cover and transmission protection device

3.2.1 The pure air cooling technology of the protective cover adopts forced air cooling, which is simple to use, easy to maintain and not subject to regional restrictions. The cooling technology is used to ensure the normal operation of the system as a part of the air source for the blowing lens. According to the scientific design of airflow distribution, the rotating air curtain is formed in front of the lens, which increases the intensity of the air curtain and the area of blowing, and effectively prevents the dust and lens objects in the furnace

3.2.2 The overall structure of the transmission protection device is made of special high-temperature resistant stainless steel material, so it has high strength of high-temperature resistance and corrosion resistance. Based on the original technology, it adopts mold design, which makes the device beautiful in appearance, compact and light. The transmission part adopts high-precision metal guide rail transmission, and adopts self-locking motor as the power, the movement is flexible, which overcomes the traditional screw nut structure is easy to deformation stuck, the whole system structure is simple, compact, delicate, light weight. It can be used for both electric and manual operation to make the device reach in and exit smoothly and reliably. Manual push and pull the probe cover or press the push button on site, exit button and operator in the control room can both conduct remote control on the entry and exit of the thermal imager. When the compressed air pressure is lower than the set value ≤ 0.1mpa, or when the internal temperature of the thermal imager is higher than the set value ≥55℃, or when power is cut off (UPS power is required), the thermal imager can automatically exit the furnace, and the observation hole will automatically close and send an alarm signal. Temperature control adopts digital display, and the upper and lower limits of temperature control can be set in advance to realize over-temperature alarm.

3.3 The thermal imager of the network cable transmission system has a standard network interface, which can be transmitted through the network cable or optical fiber according to the site environment. The screen of the front-end thermal imager can be connected to the back-end computer software for staff to observe and record.

In the process of regional temperature analysis, the local temperature can be displayed by adding a temperature measuring object. The temperature measuring objects that can be added include point temperature measuring object, line temperature measuring object and polygon temperature measuring object.

After adding the temperature measuring object, the characteristic temperature of the temperature measuring object will be displayed, such as the highest temperature, the lowest temperature, the average temperature, etc., which is convenient for local analysis.

3.4.2 Unique DDE detail enhancement algorithm Aiming at the high temperature and high dust environment in the blast furnace, in order to solve the problem of clear image, for the monitoring system software of the blast furnace infrared thermal imager, we adopt a unique DDE detail enhancement algorithm, which can remove the influence of dust and flame and see the material surface clearly and intuitively.

4. Summarize

Wuhan Yoseen Infrared Technology Co., Ltd. has developed this monitoring system of infrared thermal imager for the image of furnace charge surface through years of accumulation and combined with complex working conditions on site. Through the temperature measurement of infrared thermal imager imaging characteristic solved inside the blast furnace sealed environment effectively through visible light observation problem, at the same time, using small aperture pinhole camera solve the problem of the blast furnace roof installation space is limited, at the same time through the air-cooled refund bore shield and automatic protection device to ensure thermal imager front working environment temperature, when the temperature anomalies in a timely manner will pop-up equipment, ensure the safety of the equipment. The unique DDE detail enhancement algorithm eliminates the influence of smoke and flame in the furnace, making the imaging picture sharpness of the furnace charge surface to a higher level, which has been recognized and praised by customers in the industry, providing great help for improving the iron making technology and efficiency.