Conventional radiant tube burner common form a parallel flow burners and swirl burners, both the room temperature or preheat to 200 ℃ ~ 200 ℃ air mixed with fuel gas diffusion combustion.This can produce local high temperature burning, burning the peak of temperature is higher, radiant tube along the length direction, large temperature difference of the radiation tube surface caused by local high temperature calcination and oxidation corrosion;If after combustion air is preheated, burning formation of NOx emission concentration will increase significantly.Waste heat recovery device is the important part to improve the thermal efficiency of the radiation tube heating device.Early use of radiant tube heating device, because there is no set of flue gas waste heat recovery unit, exhaust heat loss is bigger, its thermal efficiency is less than 50%.People later in order to improve thermal efficiency of radiant tube heating device, set in the exhaust end of the radiant tube waste heat recovery unit, recycling exhaust heat to preheating combustion-supporting air, as shown in figure 1.But because of the waste heat recovery unit USES a common wall between structure, heat recovery effect is not very ideal, air preheating temperature is only 200 ~ 300 ℃, flue gas waste heat recovery is only 30%.The thermal efficiency of conventional gas radiant tube heating device is difficult to break through 75%.