Capacities | High Pressure Inspirator
TABLE 3. FACTORS FOR RICH OPERATION AND FOR OTHER GASES % air gas spud area thru capacity and mixture Btu/ft 3 sp gr ft 3 air/ft 3 Inspirator factor press. factor 800 0.54 5.8 100 0.68 1.36 90 0.56 1.65 80 0.47 2.00 70 0.38 2.44 1000 0.6 10.0 90 0.83 1.21 80 0.67 1.50 70 0.53 1.90 1200 0.7 11.7 100 1.25 0.85 90 1.03 1.02 80 0.83 1.28 70 0.66 1.60 gas specifications
Example: Non-standard selection. Inspirator to supply 80% air for 300 cfh of 20 psi 1000 Btu/ft 3 gas.
standard drill is #44 with 0.00581 sq. in. area. Therefore, specify a 3070-4 Inspirator with #44 spud drill. To find actual mixture pressure, multiply 1.64 × 1.50 = 2.46"w.c. Propane and butane does not inspirate as much air in a 3070 mixer as high pressure natural gas. To use propane, butane, or low-pressure gases in an open-air torch, see Bulletin 4696 “Gas- Compressed Air Torches”
In Table 1, read a 0.67 capacity factor and a 1.50 spud and mixture pressure factor. The required 300 cfh capacity × 0.67 = 201 cfh equivalent capacity. In the left half of Table 1, look down the 20 psi gas pressure column until you find a gas flow near 201 cfh. 192 cfh corresponds to a 3070-4 50 tentative inspirator size and drill designation and 1.64"w.c. tentative mixture pressure. The last number means #50 spud drill, which has 0.00385 sq. in. area (from any drill size table). Multiply this by the spud area factor, 0.00385 × 1.50 = 0.00578 sq. in. The next larger
TABLE 4. COMBUSTION AIR CAPACITIES, CFH FOR NORTH AMERICAN PREMIX BURNERS (sold separately see Bulletin 4682) For nozzle capacity in Btu/h HHV, assuming 100% air through the nozzle, multiply figures below by 100. Nozzle can be run rich at air rates below, using secondary air to complete combustion of the exess fuels.
Burner Air Flow scfh
Burner Air Flow scfh
Mixture Pressure in inches of water
Burner
Burner
Mixture Pressure in inches of water
Size
1
2
3
4
Size
1
2
3
4
-0-A -0-B -0-C -1-A -1-B -2-A -2-B -2-C -2-D -3-A -3-B -4-A -4-B -4-C
200 250 280 350 440 560 650
280 350 400 490 620 790 920 1100 1240
340 430 490 600 760 960 1120 1340 1510
390 500 570
-5-A -5-B -6-A -6-B -6-C -7-A -7-B -7-C -8-A -8-B -8-C -8-D
2450 2900 3200 3850 4250 4750 6000 7050 10500 13000 18000
3450
4220
4900 5800 6400 7700 8500
4100 5000
4510
5500
700 880 1120 1300 1560 1760 1960 2400 3000 3800 4100
5450 6600
6000
7300
6700 8500
9500
8450 10300 12000
780 880 980 1200 1500 1900 2050
9950 12100
14100
14800 18200 21000 18400 22500 26000 25500 31200 36000
1380
1690
1690 2060
21500 30200 37200 43000
2120
2580
-9-D
37700 53000 65000 75500
2680 3280
2890
3530
4651-01 4651-0
130 250
183 350
225 433
260 500
Bulletin 3070 Page 4
Made with FlippingBook flipbook maker