계산식

계산식

When inlet mass flow constant

Formula(1) : V = W x 22.4/Mw x (273+T)/273 x 760/P
Where) V : Exhaust Velocity of Vacuum Pump(㎥/hr)
T : Suction temperature(℃)
Mw : Moleculat Weight(Kg)
W : Suction Flow Rate(Kg/Hr)
P : Suction Pressure(Torr)
Example(1) Suction Temperature : 60℃
Suction Temperature : 15 Torr
Suction Flow rate : 10Kg/Hr(Air)
Then Vair = 10 × 22.4/29 × (273 + 60)/273 × 760/15= 478㎥/hr

When evacuation volume constant

Formula(2) : S=V/T x 2.3 log P1/P2
Where) S : Exhaust Velocity of Vacuum Pump(㎥/hr)
V : Equipment Volume (㎥)
T : Evacuation Time
P1 : Initial Pressure(torr)
P2 : Final Pressure(torr)
Example(1) Equipment Volume : 20㎥
Evacuation Time : 30 Min.
Final Pressure : 5 Torr
Then S = 20 /0.5 × 2.303Log 760/5 = 201 ㎥/hr