Calculation of Evacuation Times
The entire volume that has to be evacuated is required to calculate the efficiency of the vacuum system.
VG = V1 + V2 + V3 + V4 + V5 + ...
VG = Volume to be evacuated [m3]
V1 = Volume of suction cups [m3]
V2 = Volume of mounting elements [m3]
V3 = Volume of vacuum hoses [m3]
V4 = Volume of distributor [m3]
V5 = Volume of prefilter (if necessary) [m3]
V6 = Volume of solenoid valve (if necessary) [m3]
...
Example:
VG = 6 x 35 cm3 + 6 x 9.5 cm3 + 6 x 43 cm3 + 1 x 38.5 cm3
VG = 564 cm3 = 0.000564 m3
Calculation of evacuation time t [h]
t = (VG x In (Pa/Pe) x 1,3)/V
VG = Volume to be evacuated [m3]
In = Natural logarithm
Pa = Absolute start pressure [1,013 mbar]
Pe = Absolute final pressure [mbar]
V = Suction rate of vacuum generator [m3/h]
Example:
t = (0.000564 m3 x In (1,013 mbar / *400 mbar) x 1.3) / 6.95 m3
t = 0,0000980 h = 0,35 sec
*60% = 400 mbar absolute