VEGA VEGASON 71 - D - Manual (Page 26)

VEGASON 71 - D 26
B
7 Output results
7.6.1 Khafagi-Venturi flume
with rectangular cross-section and flat bottom
Selection of the actual flow (Q)
Flow schedule for usual Venturi flumes
B K Q
max
h
max
Q
min
h
min
in mm (Factor) in m 3 /h in mm in m 3 /h in mm
45 605 80 260 4,8 40
120 838 124 280 9,3 50
160 1106 210 330 16,2 60
200 1383 363 410 25,6 70
240 1654 532 470 37,4 80
320 2178 864 540 58,8 90
640 4280 3776 920 383 200
If a Venturi flume acc. to above value is used, the value for
Q
max
can be taken out of the respective column and can be
used for programming of mode
0 - 82
…
0 - 84
.
Programming acc. to selection Q
max
= 864 m 3 /h
- Mode
0 - 82
, flow = 0864
- Mode 0 - 83 , multiplier = 0
- Mode 0 - 84 , time unit = 3 (h)
Calculation of the actual flow value (Q)
The following formula can be used for calculation of the
actual flow for liquid levels < h
max
… > h
min
.
Q = K • h 1,5
Q in m 3 /h
B in m
h in m
Assumed values for a calculation example
B = 0,16 m
K = 1106 (derived from B)
h = 0,25 m
Calculation example
Q =
1106 • 0,25 1,5 = 138,2 m 3 /h
Programming acc. to calculation example
Q
max
= 138,2 m 3 /h
- Mode
0 - 82
, flow = 0138
- Mode 0 - 83 , multiplier = 0
- Mode 0 - 84 , time unit = 3 (h)
90 °
h
max
Sensor
3 - 4 x h
max
Sensor
Explanation:
Q
max
= max. flow in m 3 /h
B = flume width in mm or m
K = flume specific factor
h
max
= max. damming height in mm or m
K (factor)