VEGA VEGASON 71 - D - Manual (Page 27)

VEGASON 71 - D 27
7 Output results
7.6.2 Trapezoidal weir (Cipolletti)
With sharp weir edge (Cipolletti)
3 - 4 x h
max
≥
2 x h
max
Explanation:
Q
max
= max. flow in m 3 /h
B = weir width (bottom) in mm or m
K = weir specific factor
h
max
= max. weir height in mm or m
k = thickness of the weir in mm
B
45
°
k
≈
3 mm
Selection of the actual flow (Q)
Flow schedule for usual trapezoidal weir
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
300 2011 116,8 150 29,5 60
450 3014 354,4 240 44,3 60
600 4011 760,4 330 58,9 60
800 5353 1457,0 420 78,7 60
1000 6688 2581,0 530 93,3 60
1500 10043 6523,0 750 147,6 60
2000 13381 14397,0 1050 196,7 60
3000 20082 36893,0 1500 295,1 60
If a trapezoidal weir 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
= 36893 m 3 /h
- Mode 0 - 82 , flow = 3689
- Mode 0 - 83 , multiplier = 1
- 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 =
0,6 m
K = 4011 (derived from B)
h = 0,27 m
Calculation example
Q =
4011• 0,27 1,5 = 562,73 m 3 /h
Programming acc. to calculation example
Q
max
= 562,73 m 3 /h
- Mode 0 - 82 , flow = 0563
- Mode 0 - 83 , multiplier = 0
- Mode 0 - 84 , time unit = 3 (h)
Weir
K (Factor)
k
≈
3 mm
1 /
4
h
max
h max
2 - 3 x h
max
or