background image

(5)栅槽与出水渠道连接处的渐窄部分长度

1

2

0.38

2

L

L

m

=

=

(6)过栅水头损失(h

1

因 栅 条 边 为 矩 形 截 面 , 取

k=3 , 则 

m

g

v

k

kh

h

103

.

0

60

sin

81

.

9

2

9

.

0

)

02

.

0

01

.

0

(

42

.

2

3

sin

2

2

3

4

2

0

1

=

°

×

×

×

×

=

=

=

α

ε

其中 =

ε β(s/e)

4/3

     h

0

:计算水头损失

     k:系数,格栅受污物堵塞后,水头损失增加倍数,取 k=3

     ε:阻力系数,与栅条断面形状有关,当为矩形断面时 =2.42

β

(7)栅后槽总高度(H)

            取栅前渠道超高

h

2

=0.3m , 则 栅 前 槽 总 高 度

H

1

=h+h

2

=0.47+0.3=0.77m

      栅后槽总高度 H=h+h

1

+h

2

=0.47+0.103+0.3=0.87

(8)格栅总长度 L=L

1

+L

2

+0.5+1.0+0.77/tanα

=0.77+0.38+0.5+1.0+0.77/tan60°

=3.09m

(9)每日栅渣量

3

1 1

86400

1.25

/

100

z

Q w

w

m d

k

=

=

>0.2m

3

/d

      所以宜采用机械格栅清渣

(10)计算草图如下: