Uploaded by Sandra Helena Westrupp Medeiros

# Linha-q

```Condensador
Refluxo
1
Equa&ccedil;&atilde;o da Linha de Opera&ccedil;&atilde;o
da Se&ccedil;&atilde;o de Retifica&ccedil;&atilde;o, LOR:
Tambor
de
Refluxo
๐ฒ๐ = ๐ฑ๐ + ๐ฑ ๐ ๐
n
Vn+1
yn+1
Ln
xn
D, xD
1
๐ณเดค ๐+๐
xm+1
Vapor
Equa&ccedil;&atilde;o da Linha de Opera&ccedil;&atilde;o
da Se&ccedil;&atilde;o de Esgotamento, LOE:
เดฅ๐
๐ฝ
ym
m
เดฅ = ๐ฑ๐าง − ๐ฑ ๐ ๐
๐ฒ๐
2
1
L&iacute;quido
Refervedor
B, xB
Base (Res&iacute;duo)
2
Realizar a subtra&ccedil;&atilde;o entre as equa&ccedil;&otilde;es LOR – LOE:
เดฅ = ๐ฑ ๐ − ๐าง + ๐ฑ ๐ ๐ + ๐ฑ๐ ๐
๐ฒ ๐−๐
L
V
F, zF
๐าง
เดฅ
๐
Eq. 1
Visando eliminar a vaz&atilde;o de vapor da Eq. 1
para deixa-la em fun&ccedil;&atilde;o da vaz&atilde;o de l&iacute;quido,
faz-se o balan&ccedil;o material no est&aacute;gio de
alimenta&ccedil;&atilde;o da coluna:
๐๐ญ ๐ = ๐๐ซ ๐ + ๐ฑ๐ ๐
Eq. 2
Substituindo a Eq. 2 na Eq. 1 e dividindo-se
เดฅ
๐−๐
๐ − ๐าง
๐ฒ
=๐ฑ
+ ๐ณ๐
๐ญ
๐ญ
Eq. 3
โช Sabendo-se que q &eacute; a fra&ccedil;&atilde;o de l&iacute;quido na alimenta&ccedil;&atilde;o, ou seja, o
fluxo de l&iacute;quido na alimenta&ccedil;&atilde;o corresponde a qF e o fluxo de vapor
a (1 – q)F, tem-se:
เดฅ = ๐−๐ช ๐
๐−๐
๐ − ๐าง = −๐ช๐
เดฅ
๐ฝ−๐ฝ
๐−๐=
๐ญ
Eq. 4
เดฅ
๐ณ−๐ณ
๐=
๐ญ
Eq. 5
โช Portanto, substituindo-se as Eq. 4 e 5 na Eq. 3, chega-se &agrave; Equa&ccedil;&atilde;o 6
que representa a linha de opera&ccedil;&atilde;o da alimenta&ccedil;&atilde;o, linha-q:
๐
๐๐ญ
๐=
๐−
๐−๐
๐−๐
Eq. 6
4
5
F → L&iacute;quido no Ponto de Bolha
L
V
L
F
เดฅ
๐ฝ= ๐ฝ
F
เดฅ
๐ณ
เดฅ
๐ฝ
L −L
q=
F
เดฅ
๐ณ=๐ญ+๐ณ
เดฅ
๐ฝ
๐ญ+๐ณ−๐ณ
๐=
=1
๐ญ
6
F → Vapor no Ponto de Orvalho
L
V
F
L
เดฅ
๐ฝ=๐ญ+๐ฝ
เดฅ
๐ณ=๐ณ
เดฅ
๐ฝ
F
เดฅ
๐ณ
เดฅ
๐ฝ
L −L
q=
F
๐ณ−๐ณ
๐=
=0
๐ญ
7
L
V
เดฅ
๐ฝ&lt;๐ฝ
L
F
F
เดฅ
๐ณ
เดฅ
๐ฝ
L −L
q=
F
Tb: temperatura do ponto de bolha
TF: temperatura da alimenta&ccedil;&atilde;o
๏ฌ: calor latente de vaporiza&ccedil;&atilde;o
เดฅ
๐ณ&gt;๐ญ+๐ณ
เดฅ
๐ฝ
๐ฏ๐ฝ − ๐ฏ๐ญ
๐=
๐ฏ๐ฝ − ๐ฏ๐ณ
q = 1+
c pL (Tb − TF )
๏ฌ
8
F → Vapor Superaquecido
L
V
เดฅ
๐ฝ&gt;๐ญ+๐ฝ
L
F
F
เดฅ
๐ณ
เดฅ
๐ฝ
L −L
q=
F
เดฅ
๐ณ&lt;๐ญ+๐ณ
๐ฏ๐ฝ − ๐ฏ๐ญ
๐=
๐ฏ๐ฝ − ๐ฏ๐ณ
q=−
Td: temperatura do ponto de orvalho
เดฅ
๐ฝ
c pV (TF − Td )
๏ฌ
9
L
V
L
เดฅ
๐ฝ = ๐ฝ๐ญ + ๐ฝ
F
F
เดฅ
๐ณ
เดฅ
๐ฝ
L −L
q=
F
เดฅ
๐ณ = ๐ณ๐ญ + ๐ณ
เดฅ
๐ฝ
๐ณ๐ญ + ๐ณ − ๐ณ ๐ณ๐ญ
๐=
=
๐ญ
๐ญ
10
A condi&ccedil;&atilde;o da alimenta&ccedil;&atilde;o pode, agora, ser descrita pela linha q:
q&gt;1
linha q /
• L&iacute;quido no ponto de bolha
q=1
linha q |
0&lt;q&lt;1
linha q \
• Vapor no ponto de orvalho
q=0
linha q โ
• Vapor Superaquecido
q&lt;0
linha q /
11
Efeito da condi&ccedil;&atilde;o t&eacute;rmica da alimenta&ccedil;&atilde;o sobre a inclina&ccedil;&atilde;o da linha-q
Curva de Equil&iacute;brio
q=1
q&gt;1
L
0&lt;q&lt;1
L+V
L*
๐ช=
V
q=0
L&iacute;quido
แ −๐
๐
๐
L&iacute;quido + Vapor