Product Overview | Rasert™
THE 4748 RASERT ™ ADVANTAGE:
The 4748 RASERT has a number of advantages over conventional SERT's. Since the flame is in direct contact with the inside surface of the radiant tube, heat is transferred to the furnace more efficiently. The flame propagates outside the combustion tube rather than inside, resulting in less thermal stress on the combustion tube. RASERT is a patented design (#6,321,743) of the Gas Technology Institute (GTI) developed in collaboration with North American. BURNER CAPACITY The 4748-650 is available in one size. The minimum radiant tube inside diameter for this burner is noted in Table 1 below. Air capacities will be higher when starting the burner in a cold environment. Air flow will decrease as flue gases and tube temperatures increase. See page 3 for a detailed graph showing flue gas oxygen levels vs. radiant tube temperature. Furnace temperatures may cause slight variations in burner capacity. Page 4 has further information on radiant tube sizing.
REVERSE ANNULUS COMBUSTION Th e 4748 is a unique low NOx, high efficiency single ended radiant tube burner. Unlike conventional SERT burners, combustion occurs in the annulus formed between the outer radiant tube and the inner flue tube. Combustion gases then turn 180° to reverse through the inner flue tube to the integral high efficiency heat exchanger having a return gas flow path to conventional SERT burners; hence the name Reverse Annulus Single Ended Radiant Tube burner, or "RASERT." — Low NOx, CO and CO 2 emissions achieved by efficient staged combustion, and integral flue gas recirculation — Compatible with many existing control systems including simple cross-connected regulator systems — Built-in air/fuel metering and gas limiting orifice valve mean easier installation and commissioning — Direct spark ignition
Table 1
Radiant Tube
Air Capacity (scfh at 1650 F furnace temperature) with burner air supply pressure of
Burner
inside diameter
designation
1 osi
4 osi
9 osi
16 osi
inches
4748-650
425
850
1300
1750
6.50 - 7.38
SECONDARY AIR
FLUE OUTLET
FUEL IN
Bulletin 4748 Page 2
COMBUSTION AIR IN
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