| OCR Text |
Show Table 4. Specifications of applied boilers Boiler symbol Type Evaporation (MCR) Evaporating condition Furnace load (MCR) Draft form 1 - Burner unit construction Burner type Fuel A Flue and smoke tube boiler 2,500 kg/hr Saturation under 7 kg/cm^G 100x104 kcal/m3- hr Forced draft See Fig. 29. Pressure atomizing burner (60° hollow cone spray) Kerosene B Water-tube boiler 6,000 kg/h Saturation under 16 kg/cm2G 142x104 kcal/m3- hr Forced draft See Fig. 30. Steam atomizing burner (60° multi-hole divergent) A. B blended heavy oil Construction of the burner unit prior to modification was such that a strong turbulent flow is given to combustion air flow in order to complete combustion in an early stage by quickly mixing the fuel sprayed from the burner with combustion air. That is, in the flue and smoke tube boiler of Fig. 29p air for combustion supplied from the blower is divided into the primary air and secondary air after passing through the wind box. The primary air flows through the diffuse r provided at the burner tip, while the secondary air flows through the loop part surrounded by the diffuser and the swirl vane and through the swirl vane. The diffuser forms a low velocity region of air flow by means of radial swirl slits and air holes of about 5 m m diameter perforated on its conical surface and thus plays a role in maintaining the stability of the flame. Besides, the air which passes through the aforementioned loop part Fig. 29 • Construction of burner unit of flue and smoke tube boiler (boiler A) 11- 16 - |
