Layout for installtion of the heat recovery system on burner exhaust.

Burner exhaust
bypass from HRU

Bypass Preheated air to

damper burner @233°C
HRU

Burner
Burner exhaust
Flue gas inlet Damper
1832 kg/hr
@400°C

Specifications considered for design. Option 2 Operational Point

Specifications of the Hot exhaust
Sr No Hot Exhaust ( Flue gas) unit
1 Volume of the flue gas m³/hr 3500 2000
2 Temp. of the flue gas (Exchanger inlet) deg.c 400 400
3 Temp. of the flue gas (Exchanger outlet) deg.c 100 100
4 Temp.differance deg.c 300 300
4 Density of the flue gas at 175°C 0.52368945 0.5236895
5 Mass of the flue gas kg/hr 1832.91308 1047.3789
6 Possible energy recovery kcal/hr 137468.481 78553.418
7 Type of system air to air air to air
8 Eff. Of the heat recovery system 0.85 0.85
9 Energy recovery WRT eff. kcal/hr 116848.209 66770.405
Fresh Air to be preheated
1 Qty of the fresh air m³/hr 1800 1800
2 Density at 20 deg.c 1.16 1.16
3 Mass flow rate 2088 2088
4 Expected temp. increase over ambient deg.c 233.174107 133.24235
5 Ambient temp. deg.c 35 35
 To atmosphere

Ambient air @35°C

HRU

Damper Flue gas outlet

to chimney
@100°C
 Prepared by NYK
Op. Ex. Savings on gas consumption with the use of heat pipes by Apex Engineers Date 5/24/2023
Parameters
Output produced in calciner in kg per SCM of NG consumed from existing moly oxide plant data
✔ Average daily value for the year 22-23 8.32 kg product/scm Assumptions*
Data derived Daily Value for the same year with 95 % confidence 14.14 kg product/scm - No other operational impact on cost will be there upon installation of heat pipes
Data derived Daily Value for the same year with 99.7 % confidence 17.05 kg product/scm - Plant to operate for 330 days at 20 hrs per day.
- Volume of flue gas cosidered here is 2000 m3/hr (average) as opposed to 3500 m3/hr
New Calciner output 400 kg product/hr (peak) considered by Apex Engineers.

NG Consumption in volume
Average consumption rate 48.08 scm/hr

53600 kJ/kg
Calorific Value of Natural Gas
12921.9 kcal/kg

Density of NG 0.68 kg/scm

NG Consumption in mass
Average consumption rate 32.70 kg/hr

Symbols
Energy in E_in
Energy in flue gas E_fg
Balance energy used up by product and losses E_bal Calciner package without Heat Pipe

E_fg1
Calciner package without heat pipe
E_in1 422513.9 kcal/hr
E_fg1 78553.4 kcal/hr E_in1
E_bal1 343960.5 kcal/hr Calciner Block

E_bal1
E_bal and E_fg will be
same for both cases.
Product qty remains same
and losses will more or less
be same.

Calciner package with Heat Pipe

Calciner package with heat pipe Heat

E_fg2 Recovery
E_in2 355743.5 kcal/hr Unit
E_fg2 78553.4 kcal/hr
E_in2
E_bal2 343960.5 kcal/hr Calciner Block
Overall Heatpipe efficiency 85%
Heat recovered 66770.4 kcal/hr
E_bal2
27.5 kg/hr
Gas consumption with heat pipe
40.5 scm/hr
Heat recovered
32.7 kg/hr
Gas consumption without heat pipe
48.1 scm/hr

Net gas consumption reduced using heat pipe 7.6 scm/hr

Yearly reduction in NG consumption (330 days @ 20 hrs/day) 50152.5 scm
Cost of NG as on May 2023 48.13 Rs/scm
Annual savings on gas consumption 2413842 Rs.
Back
Days of MOLY OXIDE Moly Oxide
2022-2023 Output in Kg per gas consumed in SCM Count 220
1 2.476879774829 Skewness 3.09
2 5.22145783411938 Kurtosis 24.13
3 4.25003402749415 JB test statistic 5687.70
4 8.55675984027281 p-value (<0.05) 0
5 9.15689174779107 std deviation 2.91
6 7.35280038295753 average 8.32
7 7.24663677130045
8 10.3643332961177 68% 5.41
9 10.2796962643589 95% 2.50
10 6.63125704168629 99.70% -0.41
11 5.60134369751161
12 5.63126767806673 Output/SCM 8.32
13 4.73335186435263
14 4.31824903874623
15 3.17095791193756
16 9.10166683571637
17 8.66522246292318
18 6.59077291791528
19 11.171401212891
20 3.65447480416965
21 9.62314939434552
22 8.04927847181284
23 11.0409437890349
24 4.13625304136307
25 3.26926736441484
26 10.3054213999041
27 9.4034578329149
28 8.30574682203505
29 8.15627141877898
30 8.06477524660267
31 8.63365058880432
32 8.15875799798592
33 15.7463783330011
34 7.47512598526947
35 7.43261079986983
36 2.88520276302808
37 8.32104063296316
38 7.50161812297735
39 8.71077446282238
40 2.40158221887311
41 5.37612428454692
42 5.07409640465832
43 8.88547008547009
44 9.29571533845569
45 9.01266004375373
46 5.0936974296783
47 9.30338336657228
48 9.141949152542
49 9.09604121092424
50 8.41945800370341
51 8.58005645637668
52 7.20561169566344
53 8.42325478969325
54 7.99763033175459
55 8.12245620244238
56 6.80607173241342
57 4.45280139524648
58 8.62519602718362
59 8.88538557005319
60 9.27055886839543
61 8.75150945927828
62 9.16570791060855
63 3.46536368991917
64 8.71458212864238
65 30.8460634547605
66 9.72265923495425
67 9.27980776026636
68 8.6671664656595
69 9.20140081027231
70 8.42566943675003
71 9.66214995483288
72 6.48947951273616
73 4.68068368733408
74 3.69843987208928
75 2.7401880190546
76 6.65382335506857
77 4.36448876320866
78 10.0325584917084
79 1.47818259345236
80 4.44060562950948
81 5.28150037724972
82 6.10085009047201
83 8.96527534198417
84 8.64864864864999
85 8.6528939730227
86 2.83606500330589
87 6.24405328258896
 88 5.12728146013456
89 9.16916563767823
90 5.02012522361347
91 6.6093994036625
92 7.64886235275478
93 7.76919321021247
94 8.78559738134206
95 8.93063870605092
96 8.97159712325471
97 8.45350116094324
98 9.01739850869926
99 8.4894884697313
100 9.71076612757971
101 9.676613363793
102 27.74901635949
103 8.39462646647573
104 9.27108711397935
105 8.88510861031164
106 9.48294055575136
107 7.89931058455408
108 8.79804802150071
109 8.71762476310795
110 9.88152347725052
111 8.82419831703327
112 5.7291308237562
113 6.02189781021946
114 6.29515313909676
115 10.428587669104
116 9.14825456587137
117 10.3652517275418
118 9.80551914697724
119 8.95083159739465
120 9.63286590092288
121 9.29946166566907
122 9.36643835616532
123 6.70062414807308
124 8.07046036604428
125 8.58576472774614
126 5.94254230617899
127 7.43036054355901
128 8.86388844874062
129 10.0028559188921
130 10.3954129123532
131 9.34575810522271
132 6.35287870742545
133 7.42841167778397
134 4.17205095070974
135 3.98041635155067
136 8.43576687315494
137 9.99666777740658
138 8.44804233470954
139 10.211931797167
140 9.01073869183243
141 9.79038489054236
142 9.42660389291
143 10.0683338179705
144 9.62134188563674
145 9.2905345092296
146 8.97757234464963
147 10.5518180362017
148 10.3909264528196
149 11.6640572578825
150 4.90842135865867
151 10.2839093546862
152 9.75932190209564
153 9.90206746463499
154 9.82943867238718
155 10.2588793007663
156 6.82760125063628
157 10.4881062712403
158 7.0869747738801
159 11.1781597236682
160 11.1697449428299
161 8.57621265239977
162 12.1441959809961
163 3.04761904761905
164 6.42253521126761
165 8.18783865141415
166 9.20352812923373
167 8.23457915527108
168 8.67429404494109
169 8.37161196118294
170 8.63557312252964
171 8.54370732008763
172 9.14740983173026
173 10.5099996219421
174 8.64706623016891
175 8.64807962230497
176 7.67567567567568
177 8.215372794704
178 7.85630924254937
179 8.14180206794682
180 7.29442135751133
181 8.82352941176595
182 7.56227275193932
183 8.30477908025219
184 9.07031711640747
185 7.54481936846766
186 9.04142326075328
187 8.88210394837363
188 7.91879655323419
189 8.12854442344051
190 7.59793898748676
191 7.22082283795115
192 8.49198396793624
193 8.6119105601062
194 10.6454909977198
195 7.72475612971257
196 9.11747127963365
197 8.8837401212427
198 10.1896496303453
199 6.47641476761121
200 8.97778063603358
201 12.2392758756394
202 6.65303891041302
203 8.26484816692861
204 10.8010205688736
205 9.4176694307617
206 9.3106960950764
207 8.40226511310794
208 9.78268489309539
209 10.2015882712265
210 9.06006976669841
211 9.96760443307758
212 8.70791741583439
213 9.06351263771941
214 8.21008943707221
215 8.47941176470588
216 10.4680663308441
217 9.61846318036391
218 9.21018780550491
219 10.0820836075233
220 9.52520802741031
Moly Oxide
220
3.09
24.13
5687.70
0
2.91
8.32

11.23
14.14
17.05

kg/scm