OCR Text |
Show quantity of blowing, (at 0.3 to 0.4 kg/10"Real, for example, the total effect of the furnace is reduced by 2 to 3%). This method is most effective for gas combustion. Fig-17 shows an example of steam addition and ejection of a city gas water tube boiler. As therein shown, the reduction effect almost proportional to the quantiy of ejection is obtained in the case of city gas if the ejection condition is selected properly. Fig. 18 Schematic drawing of XB burner Air v Combustion (j? exhaust gas Low NOx burner XB burner This is a self exhaust gas. t recirculation type low NOx burner, and as shown in Fig-18, fuel gas is ejected through the nozzle by the pressure of the city gas supply, and by the energy, combustion exhaust gas is re-circulated. Exhaust. gas re-circulation method is one of the most effective method in low NOx methods for boiler, but the flame is apt to become longer, as mentioned before. With XB burner, flame can be made shorter by multi-arrangement and application to various types of combustion chambers. Low extra air operation is also made possible. As the burner capacity, seven types are available from the rating of 80 x 10** Kcal/h to 1600 x 10* Kcal/h as shown in Table-4. 0 - 23 - |