Recommendations
SALUTAR anaerobic filterParshall flumeSharp-edged inletVelocity gradient to Parshall meterDynamic viscosity of atmospheric airSpecification for blowers

Parshall flume selection (Life Saneamento)

Input data

Flow

Output data

Minimum Parshall size

k minimum

n minimum

Velocity gradient of the minimum size

Intermediary Parshall size

k intermediary

n intermediary

Velocity gradient of the intermediary size

Maximum Parshall size

k maximum

n maximum

Velocity gradient of the maximum size

Description

Given the flow, selects the Parshall size. In some cases, it indicates up to three possibilities. It shows the values for k and n of the equation 𝑄=𝑘⋅𝐻𝑛 𝑄=𝑘⋅𝐻^𝑛, for each case (metric units), as well as the corresponding velocity gradient.

Parshall Life SaneamentoParshall Life Saneamento

Parshall dimensions table

W (in or ft)
W (cm)
A
B
C
D
E
F
G
K
N
1”
2.5
36.3
35.6
9.3
16.8
22.9
7.6
20.3
1.9
2.9
2”
5,0
27,6
40,6
13,5
21,4
25,4
11,4
25,4
2,2
4,3
3”
7.6
46.6
45.7
17.8
25.9
38.1
15.2
30.5
2.5
5.7
6”
15.2
62.1
61
39.4
40.3
45.7
30.5
61
7.6
11.4
9”
22.9
88
86.4
38.1
57.5
61
30.5
45.7
7.6
11.4
1’
30.5
137.1
134.4
61
84.5
76.2
61
91.5
7.6
22.9
1,5’
45.7
144.8
142
76.2
102.6
91.5
61
91.5
7.6
22.9
2’
61
152.3
149.3
91.5
120.7
91.5
61
91.5
7.6
22.9
3’
91.5
167.5
164.2
122
157.2
91.5
61
91.5
7.6
22.9
4’
122
182.8
179.2
152.5
193.8
91.5
61
91.5
7.6
22.9
5’
152.5
198
194.1
183
230.3
91.5
61
91.5
7.6
22.9
6’
183
213.3
209
213.5
266.7
91.5
61
91.5
7.6
22.9
7’
213.5
228.6
224
244
303
91.5
61
91.5
7.6
22.9
8’
244
244
239
274,5
340
91.5
61
91.5
7.6
22.9
10’
305
274.5
260.8
366
475.9
122
91.5
183
15.3
34.3

Source: AZEVEDO NETTO, J. M. de; FERNANDEZ Y FERNANDEZ, Miguel. Manual de hidráulica, 9.ed. São Paulo: Blucher, 2015.


Note:

  1. The value of velocity gradient must be verified through hydraulic calculations. It was obtained using the following expression::
G=1000⋅𝑄0.7𝑊1.2G = 1000⋅ \frac{𝑄^{0.7}}{𝑊^{1.2}}
  1. Smaller Parshall flumes (W = 1" and W = 2") are not considered in this calculation, because they are not commonly used in potable water treatment plants.

Source: (Vianna, Marcos R. Hidráulica aplicada às estações de tratamento de água. 6. ed. Belo Horizonte: Bloom, 2019);

Get to Know Life Saneamento

Discover the innovative solutions from Life Saneamento in water and sewage treatment plants made of FRP (Fiber Reinforced Polyester) and Stainless Steel. Learn more at https://www.lifesaneamento.com.br/

References

  • Parlatore, A. C. Mistura e floculação. In: CETESB. Técnica de abastecimento e tratamento de água. Vol. II. São Paulo:CETESB, 1974.