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Show Table-5 Outline specification of CISC bur ro GNC GNC GNC GNC GNC GNC GNC 10 16 25 40 63 100 160 Maximum combustion xlO1* (Kcal/h) 100 160 250 400 630 1000 1600 Differential wind pressure between wind box and furnace (mmAq) 160 180 220 250 270 280 280 GNE burner For low NOx boilers with city gas, XB burner and others have been developed and employed already for many boilers. NOx suppression principle of most of these low NOx burners is basically the gas injection type exhaust gas self recirculation combustion using the pressure of medium pressure city gas (AP=1,500 to 3,000mmAq). On the other hand, the requirement for low NOx has been expanded from comparatively larger sized boilers in the past to medium or small sized boilers. Accordingly, the supply of city gas to boilers from low pressure lines as shown in Table-6 has been increasing besides the medium pressure. Table-6 Low pressure supply city gas City gas High calorific Standard value pressure 6C 4,500KmJl/Nm3 lOOmmAq max200mm Aqmin 50mmAq 13A ll,000Kml>/Nm3 200mmAq max250mm 'Aqmin. lOOmmAq This is an air injection type low NOx gas burner intended for low pressure supply under the1 situation. As the principle, this is the combination of the air injection type exhaust gas self recirculation mechanism of GNC burner and the gas suction type primary combustion mechanism(Venturi Fig -35 Structual drawing of GNE burner Combustion /exhaust gas <3 - 28 - |