The filter element is made of glass fiber filter material and thickened frame. It can be installed in the oil circuit of the hydraulic system. It is used for solid particles and colloidal substances in the oil to keep the oil clean and prolong the service life of the hydraulic system. . The principle of the infrared flame detector for the normal operation of the hydraulic system: There are a large amount of visible light and infrared rays above 0.9m in the flame. The light of these wavelengths is not easily absorbed by coal dust, water vapor and other combustion products, so it is suitable for detecting pulverized coal flames. , Heavy oil flame and suitable for fuel combustion with large inert gas content. Infrared flame detection detects the presence of flame by detecting the infrared intensity and flame frequency radiated by the burning flame. The probe uses lead sulfide phototube or silicon photodiode. Because the furnace is completely burned and the fire zone flame flicker frequency usually does not exceed 2HZ, so through the filter circuit, infrared flame detection can distinguish between the burner flame and the background flame.