Cheresources.com spray tower Page 4
105
Total amount heat in plant
Q
plant
= Q
Fin
+Q
la
+Q
s
Q
plant
=
10886370
Btu/h
106
107
B
C
D
E
F
G
H
I
J
108
HEAT UTILISATION
109
Heat for water evaporation
Q
ev
= m
ev
· [h
2
(H
2
O) - h
1
(H
2
O)]
Q
ev
=
5721585.434
Btu/h
110
Heat from dried material
Q
dm
= m
dm
· cp
dm
· T
dm
Q
dm
=
294461.5557
Btu/h
111
Heat on exit
112
Q
out
= Qa
out
+Q(N
2
)
out
+Q(CO
2
)
out
+Q
LA
+(m
f
· 1.035 · h
2
w)
Q
out
=
3105253.055
Btu/h
113
Furance losses
Q
FL
= Q
Fin
- Q
Fout
Q
FL
=
1367147.23
Btu/h
114
Tower losses
Q
TL
= Q
plant
- (Qev+Qop+Qout+Q
FL
)
Q
TL
=
397922.7287
Btu/h
115
116
HEAT BALANCE IN %
Btu/h
%
117
Furance losses
Q
FL
=
1367147.23
12.55833882
118
Heat losses in powder
Q
dm
=
294461.5557
2.704864483
119
Heat in exit air (heat on exit )
Q
out
=
3105253.055
28.5242285
120
Heat for water evaporation
Q
ev
=
5721585.434
52.55733024
121
Tower losses
Q
TL
=
397922.7287
3.655237959
122
10886370
100
123
124
TOTAL AMOUNT OF EXIT AIR ON EXIT TEMPERATURE (m
out)
125
lb
ft
3
/h
126
Air
39904.79065 649961.2491
127
Water
6199.598205 347983.6133
128
CO
2
1669.03477 2336.648678
129
N
2
5559.871452 312075.7335
130
TOTAL (m
out
)
53333.29507 1312357.245
131
132
PROCESS OPTIMISATION WITH EXIT AIR RECIRCULATION
133
134
Recirculation range (0 - 70%)
RR =
60
%
135
Air humidity on 20 °C
X =
0.01488
lb/lb
136
Amount of air leaving tower
m
out
=
41900.03018
lb
137
138
Recirculation rate
139
m
rec
= m
out
· (%RR/100)
m
rec
=
25140.01811
lb
140
141
Amount of air leaving plant
142
m(air)
lp
= m
out
- m
rec
m(air)
lp
=
16760.01207
lb
143
Amount of fresh air
144
m
fa
= m
ha
- m
rec
- m(air)
comb.
m
fa
=
5143.940926
lb
145
Amount of air blend
146
m(air)
bl
= m
rec
+ m
fa
m(air)
bl
=
30283.95903
lb
147
Temperature of blended air
148
T(air)
bl
= [(m
rec
· T
out
)+(m
fa
· T
fa
)]/(m
rec
+ m
fa
)
T(air)
bl
=
202.483174
°F
149
Amount of hot entering air
150
m
eha
= m
rec
+ m
fa
+ m(air
comb.
)
m
eha
=
39904.79065
lb
151
Heat of blended air
152
Q(air)
bl
= [m(air)
bl
* cp(air)bl * T(air)
bl
] - (m
fa
* h
3
a)
Q(air)
bl
=
1419862.187
Btu/lb
153
Total amount of heat required
154
Q
tot
= (Q
1
+ Q
2
) - Q(air)
bl
Q
tot
=
8330942.57
Btu/lb
155
156
Amount of fuel (recirculation)
157
mf
rc
= Q
tot
/ NCVF
mf
rec =
470.334282
lb
158
159
Fuel savings (%)
160
FS = [100 - (mf
rc
/ m
f
)] · 100
FS =
12.3601471
%
