Combustion Catalog | Fives North American

Sizing Tables | 4950 Flame Grid

Table 3. Grid air capacities

Figure 1. Minimum oxygen content in fume stream.

Air flow at 0.5"w.c. (1.25 mbar) pressure drop *

18

Flame Grid designation 4950-0812 4950-1212 4950-1412 4950-2012 4950-1424 4950-2024 4950-2624 4950-3624 4950-2648 4950-3648 4950-5248 4950-7248

Shutter wide open

Shutter at min. setting

scfm (Nm 3 /h)

scfm (Nm 3 /h)

16

710 (19.0) 1060 (28.3) 1240 (33.1) 1800 (48.1) 2500 (67) 3550 (95) 4600 (123) 6400 (171) 9200 (246) 12 700 (339) 18 400 (492) 25 400 (679)

440 (11.8) 660 (17.6) 770 (20.6) 1100 (29.4) 1500 (40) 2200 (59) 2850 (76) 3900 (104) 5700 (152) 7900 (211) 11 400 (305) 15 800 (422)

NOTE: Curve is based on 1400°F burner outlet temperature and natural gas fuel. For other conditions consult factory.

14

12

100

300 (149)

500

700 (371)

900

1100 (593)

(122)

(260)

(482)

Fume inlet temperature, F

√   new table x (3550 scfm = 7100 scfm √ 2.0 0.5 Table 4. Natural gas capacities

Table 1. Effects of inlet temperature

New Air Flow =

x (Flow from table)

Inlet

Grid air capacity correction factors 60 °F (16 °C) basis

Gross input heating air to 1400 °F (760 °C) Btu/h/scfm (kW/Nm 3 /h)

temperature

°F (°C)

Example: Air flow in scfm for 4950-2024 with shutters wide open @ 2.0"

60 (16)

1.00

1810 (0.851) 1640 (0.771) 1510 (0.710) 1390 (0.653) 1260 (0.592) 1130 (0.531) 1000 (0.470) 870 (0.409) 730 (0.343) 590 (0.277) 440 (0.207) 290 (0.136)

200 (93) 300 (149) 400 (204) 500 (260) 600 (316) 700 (371) 800 (427) 900 (482) 1000 (538) 1100 (593) 1200 (649)

1.13

1.21 1.29 1.36 1.43 1.49 1.56 1.62 1.68 1.73 1.79

Gas flow capacity range with standard #46 drill 0.081 Ø (2.06 mm) Nm 3 /h Min*/Max

scfm Min*/Max

Flame Grid designation  4950-0812 4950-1212 4950-1412 4950-2012 4950-1424 4950-2024 4950-2624 4950-3624 4950-2648 4950-3648 4950-5248 4950-7248

@ 1.0

@ 3.0 psi  2500 3600 4350 6100 8600 12 200 15 800 21 700 31 600 43 300 63 200 86 600

@ 2.5

@ 200

"w.c. 

mbar 

mbar 

270 390 480 670

7.2

64.7 93.4

10.4 12.8 17.9 25.1 35.8 46.2 63.5 92.6 127 185 253

Table 2. Pressure drop correction factors

115

160 225 321 414 570 831

Pressure

Air Factor based on 0.5"w.c. #

Pressure

Air Factor based on 0.5"w.c. #

drop

drop

940 1340 1730 2380 3470 4760 6940 9500

"w.c. (mbar)

"w.c. (mbar)

0.2 (0.50) 0.3 (0.75) 0.4 (1.00) 0.5 (1.25) 0.6 (1.50) 0.7 (1.75) 0.8 (2.00)

1.59 1.28 1.12 1.00 0.92 0.85 0.79

0.9 (2.25) 1.0 (2.50) 1.2 (3.00) 1.4 (3.50) 1.6 (4.00) 1.8 (4.50) 2.0 (5.00)

0.75 0.71 0.65 0.60 0.56 0.53 0.50

1140 1662 2275

Bulletin 4950 Page 4

* See "Fluid Flow" chapter in North American COMBUSTION HANDBOOK for explanation of correction procedure.

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