Radiation tubes are commonly used in industrial applications that require isolation of workpieces from the combustion environment. The working principle of the W-shaped radiation tube heating device is that fuel burns in a sealed radiation tube, heating the surface of the radiation tube and mainly transferring heat to the heated workpiece in the form of thermal radiation.
Because the combustion products do not come into contact with the workpiece, the combustion atmosphere will not cause oxidation or combustion of the workpiece. The atmosphere and heating temperature inside the furnace are easy to control and adjust, suitable for high-quality heating requirements of cold-rolled strip steel and other products. Although radiation tubes have many advantages, they still have some defects, such as uneven surface temperature, high NOx emissions, and short service life. The high-temperature flue gas in the radiation tube transfers heat to the radiation tube through convection and radiation. The radiation tube works continuously for a long time in harsh environments of 850-1080. Under the combined action of alternating thermal stress and self weight, the radiation tube is prone to bending fatigue damage and creep deformation damage, leading to radiation tube failure. The failure of radiation tubes due to stress damage is still a concern in the industry.
What are the characteristics of gas radiation tubes?
Characteristics of gas radiation tube: Due to the fact that combustion exhaust gas is not introduced into the furnace, the atmosphere inside the furnace is easy to control and regulate; The temperature distribution inside the furnace can be controlled according to the configuration of the radiation tube to achieve uniform heating; Due to the fast heating and cooling speed and wide adjustment range, more complex temperature control and heating programming can be achieved; According to the furnace type and purpose, the form of the radiation tube can be freely selected (such as straight tube, sleeve tube, U-shaped tube, etc.); Easy to install waste heat recovery devices and improve thermal efficiency, radiation tubes can be used in the following situations: controlled atmosphere heat treatment furnaces; Uniform temperature distribution inside the heating furnace; Avoid direct contact between the heat treatment furnace and wastewater and exhaust gas; In situations where air exchange and radiation heat exchange are significant; As a heat source for liquid heating and salt bath furnaces.
Types of gas radiation tubes: Gas radiation tubes include straight tube type, sleeve type The structure of U-shaped, W-shaped, O-shaped, P-type, and trident straight radiation tubes is simple. The burner is installed at one end of the straight tube, and the gas is burned in the pipeline. The combustion exhaust gas is discharged from the other end of the pipeline. This type of pipeline has poor surface temperature distribution and low thermal efficiency. When the furnace is blocked or closed, heat loss is caused by natural ventilation. In high-temperature applications, ceramic radiation tubes can be used. If two straight radiation tubes are used in pairs, a waste heat recovery device is installed at the outlet of one tube to preheat the air required for the combustion of the other radiation tube. This can not only improve the surface temperature distribution of the radiation tube, but also improve thermal efficiency. However, installation and disassembly are not convenient. The telescopic radiation tube is made of The telescopic structure composed of inner and outer pipes ensures uniform temperature distribution on the surface of the pipeline, high thermal efficiency, and easy disassembly and assembly.