孔口與排氣量對照表
孔口與排氣量對照表
經過孔口之排氣，在 14.7psia ( 1 kg / cm 2 a ) 與 70 °F ( 21 °C )之大氣壓下每分鐘自由空氣之 M 3
Delivery via Aperture, Free air M 3 / min at 14.7 psia ( 1 kgf / cm 2 a ) and 70 °F ( 21 °C )
| 孔口前錶壓力
Gauge pressure before passing through |
孔口 直徑
Aperture diameter ( mm ) |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0.397 | 0.794 | 1.588 | 3.175 | 6.35 | 9.525 | 12.700 | 15.875 | 19.050 | 22.225 | 25.400 | ||
| kg / cm 2 | psi | 排氣每分鐘之自由空氣
Free air delivery I/min |
排氣每分鐘 M
3 之自由空氣
Free air delivery m 3 / min |
|||||||||
| 0.068 | 1 | 0.793 | 3.172 | 12.744 | 50.976 | 0.203 | 0.459 | 0.813 | 1.274 | 1.832 | 2.495 | 3.257 |
| 0.136 | 2 | 1.133 | 4.475 | 17.927 | 71.650 | 0.286 | 0.646 | 1.147 | 1.793 | 2.583 | 3.512 | 4.588 |
| 0.211 | 3 | 1.360 | 5.494 | 21.948 | 87.792 | 0.351 | 0.787 | 1.402 | 2.195 | 3.144 | 4.305 | 5.607 |
| 0.272 | 4 | 1.586 | 6.315 | 25.261 | 100.819 | 0.405 | 0.909 | 1.614 | 2.526 | 3.625 | 4.956 | 6.460 |
| 0.340 | 5 | 1.756 | 7.023 | 26.423 | 112.430 | 0.450 | 1.011 | 1.798 | 2.812 | 4.050 | 5.522 | 7.193 |
| 0.408 | 6 | 1.926 | 7.703 | 30.867 | 122.909 | 0.493 | 1.107 | 1.968 | 3.087 | 4.418 | 6.032 | 7.873 |
| 0.476 | 7 | 2.067 | 8.298 | 33.134 | 132.538 | 0.530 | 1.195 | 2.124 | 3.313 | 4.758 | 6.514 | 8.496 |
| 0.612 | 9 | 2.351 | 9.374 | 37.382 | 150.096 | 0.598 | 1.351 | 2.399 | 3.738 | 5.409 | 7.363 | 9.600 |
| 0.816 | 12 | 2.690 | 10.733 | 43.046 | 171.902 | 0.688 | 1.546 | 2.749 | 4.305 | 6.174 | 8.411 | 10.988 |
| 1.020 | 15 | 2.974 | 11.894 | 47.578 | 190.310 | 0.762 | 1.713 | 3.059 | 4.758 | 6.853 | 9.317 | 12.178 |
| 1.360 | 20 | 3.483 | 13.905 | 55.507 | 222.595 | 0.889 | 2.002 | 3.568 | 5.551 | 8.015 | 10.903 | 14.245 |
| 1.701 | 25 | 3.965 | 15.916 | 63.720 | 254.314 | 1.017 | 2.291 | 4.078 | 6.372 | 9.147 | 12.461 | 16.284 |
| 2.041 | 30 | 4.475 | 17.927 | 71.650 | 286.032 | 1.147 | 2.580 | 4.588 | 7.165 | 10.337 | 14.047 | 18.351 |
| 2.381 | 35 | 4.984 | 19.909 | 79.579 | 320.016 | 1.274 | 2.860 | 5.098 | 7.958 | 11.470 | 15.604 | 20.390 |
| 2.721 | 40 | 5.494 | 21.920 | 87.792 | 351.168 | 1.405 | 3.172 | 5.607 | 8.780 | 12.631 | 17.190 | 22.458 |
| 3.061 | 45 | 5.975 | 23.930 | 95.722 | 382.320 | 1.532 | 3.455 | 6.117 | 9.572 | 13.792 | 18.748 | 24.497 |
| 3.401 | 50 | 6.485 | 25.941 | 103.65 | 416.304 | 1.660 | 3.738 | 6.655 | 10.365 | 14.953 | 20.334 | 26.564 |
| 4.082 | 60 | 7.476 | 30.019 | 119.794 | 478.608 | 1.914 | 4.305 | 7.675 | 11.979 | 17.247 | 23.449 | 30.642 |
| 4.762 | 70 | 8.496 | 33.984 | 135.653 | 543.744 | 2.172 | 4.899 | 8.694 | 13.565 | 19.541 | 26.592 | 34.749 |
| 5.442 | 80 | 9.487 | 37.949 | 151.795 | 606.048 | 2.427 | 5.466 | 9.714 | 15.180 | 21.835 | 29.736 | 38.827 |
| 6.122 | 90 | 10.478 | 41.914 | 167.654 | 671.184 | 2.685 | 6.032 | 10.733 | 16.765 | 24.160 | 32.800 | 42.933 |
| 6.803 | 100 | 11.498 | 45.878 | 183.797 | 736.32 | 2.945 | 6.627 | 11.753 | 18.380 | 26.451 | 36.023 | 47.040 |
| 7.483 | 110 | 12.489 | 49.843 | 199.656 | 798.624 | 3.200 | 7.193 | 12.801 | 19.966 | 28.773 | 39.167 | 51.146 |
| 8.163 | 120 | 13.480 | 54.091 | 215.798 | 863.76 | 3.455 | 7.760 | 13.820 | 21.580 | 31.067 | 42.310 | 55.252 |
| 8.503 | 125 | 13.990 | 56.074 | 223.728 | 894.912 | 3.568 | 8.043 | 14.300 | 22.373 | 32.228 | 43.868 | 57.291 |
- 根據百分之百之流量係數，設若進口極圓時，則以 0.97 乘以值，設若為一銳緣孔口時，則乘數用 0.65。
- 此表僅能產生近似之結果，若欲作精確之測量，則請見 ASME 動力試驗規格流動容積速度之測量。
- 1 至 15psig 壓力值之計算，係使用標準絕熱公式。
- 超過 15psig 壓力值計算，係使用此近似之公式： w=0.5303acp./( √ T )。其中 w= 每秒排出之磅數，a= 孔口面積，平方吋，c= 流量係數，p= 上流總壓力，psia，T= 上流溫度，F 絕對。
- 上述情況值之計算係 c+1.0 , p= 錶壓 +14.7psia , T= 530F 絕對。
- 重量數改為容量時，則使用每立呎 0.0749 磅密度因素，此係用於 14.7psia 則此 70F 乾空氣之修正。
- 此公式不能用於 p ，少於兩倍大氣壓。
- On the basis of a 100% flow coefficient, suppose that the inlet is extremely round, then multiply the value by 0.97; if the aperture has knife edge, multiply them by 0.65.
- We can obtain only approximate results here. Fore accurate mcasurement, refer to measurement of flow volume speed in ASME Power Experiment Specifications.
- The standard thermal insulation formula is used in computation of pressure values between 1 and 15 psig.
- For the computation of pressure values over 15 psig, the following approximate formula is used : w= 0.5303acp./( √ T ),in which w= delivered pounds/sec, a= aperture area( in 2 ), c= flow coefficient, p= upstream gross pressure (psia), T= upstream temperature ( °F absolute).
- In the above cases of computation, c= 1.0, p= gauge pressure +14.7 psia, T= 530°F absolute.
- When weight is substituted by volume, the density factor of 0.0749 lb / ft3 is used instead, which is for 14.7 psia. So the 70°F is dry air correction.
- The formula is not applicable for p less than twice the atmospheric pressure.
