Combustion Catalog | Fives North American

Product Overview | Flame-Jet ™

4545 Flame-Jet Burners are nozzle mixing, sealed-in gas burn- ers of large capacity for use on installations ranging from low temperature air heaters and ovens to high temperature forging furnaces. They produce a penetrating jet of hot gases with high forward velocity. Flame-Jet burners operate dependably at air/ gas ratios (listed in Table 2) ranging from excess air to excess fuel (with sufficient air for near-complete combustion in the furnace, supplied adjacent to the burners). Design Features. The burners are made of relatively few, large parts that minimize maintenance problems. The internal flow passages are designed to give quiet operation. Air flows from a central orifice that is surrounded by an annular gas orifice. The result is a single jet flame of high forward velocity, causing heat to penetrate deeply into the furnace. Because Flame-Jet burners are nozzle-mix, there is no possibility of flashback. The burner turndown is high, provided the control system is good enough to maintain correct air/gas ratio at very low firing rates. Flame-Jet burners are suitable where control of furnace atmo- sphere is important and air infiltration is not desirable. The burn- ers are tightly sealed, with threaded connections for the observa- tion port, pilot, and flame rod adapter; the cast iron mounting plate is large enough to make a tight seal with the furnace wall; and the burner can be operated rich, lean, or on correct air/gas ratio, even against some backpressure in the combustion cham- ber. A complete burner includes mounting plate, tile, and observation port, but dœs not include pilot tip or flame rod adapter which are optional extras. If no pilot or flame monitoring device is ordered with the burner, the openings for these devices are plugged and should be kept closed when not used. Burner Operation. Flame-Jet burners, whether operating on natural or coke gas, require very little gas pressure at the burner, although higher gas pressures are an advantage for air/gas ratio control. The minimum required supply pressure for the gas is de- termined primarily by the pressure drop through the gas piping and accessories.

when using an interrupted pilot. Use a UV detector with the 4545- 9. Do not use a flame rod. A pilot flame just large enough to satisfy a flame rod will not light the -9 flame. When using flame supervision devices, 6 osi minimum pilot air pressure and low fire lighting are recommended. Ultraviolet detecting devices can be used with air/gas ratios within the range shown in Table 2. Ground Rods. The main flame is not normally grounded, and thus requires ground rods to complete a circuit through a flame rod. Ground rods are not required with ultraviolet flame detectors. When using a flame rod, one ground rod is required with a 4545-6 or -7 Burner, and four rods with a -8-A or -8-B. The appropriate ground rods (7 ½ " long) are furnished at no extra cost when ordered with a burner. Burner tiles are a dense castable that is good for 3200°F in the tile or about 2800°F furnace temperature. When the burner is shut off, continue air flow to protect the nozzle from furnace radiation. The cast tile has an expanded metal liner with welded mounting hooks. This unit is bolted to the heavy duty mounting plate. Bonding cement seals the joint. The uniform thickness of the cylindrical burner tiles greatly reduces the likelihood of thermal cracking. Jacketed Tiles. 4545 Burners are available with metal support jackets around the tile for applications where the tile is not supported by furnace refractory. Jackets are available in three different metals and have maximum temperature rating for each. They must be protected with sufficient insulation so as not to exceed rated temperature. Maximum temperature rating for jacket metals depends upon frequency of heat-up/cool-down cycles. As an example, batch annealing furnaces that are heated and cooled every day should use the "intermittent exposure" ratings. Continuous annealing furnaces that remain at the same temperature for months at a time, can use the higher "continuous" rating.

Continuous Intermittent

Designation Jacket metal max. temp.

exposure

4545- -LC 4545- -L4 4545- -L9

carbon steel 304 stainless 309 stainless

700°F 1600°F 1900°F

700°F 1500°F 1800°F

Flame-Jet burners may be lighted in hot or cold furnaces, at rich or lean air/gas ratios, by a North American 4011-12 Pilot Set.

Flame Supervision. The stability of Flame-Jet burners permits any size to be operated with an interrupted pilot, which is strong- ly recommended. Either a flame rod or an ultraviolet detector can be used with -6 through -8-B sizes to monitor main flame

Bulletin 4545 Page 2

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