COGENERATION ENHANCEMENT USING LOW
PRESSURE VAPOUR FOR CRYSTALLISATION
By: VIVEK VERMA
Copyright © 2016 Spray Engineering Devices Limited
…
TM
MISSION STATEMENT
Dedicated for Sustainable Environment Development
to Unlock Perpetual Food and Energy Resources.
Copyright © Spray Engineering Devices Limited
HIGHLIGHTS
Dhanalakshmi Srinivasan Sugars Pvt. Ltd. (DSSPL), Tamilnadu
• 3500 TCD Plant
• Current Steam Consumption 31-32% on cane
• Power export 100-105 kWh/Ton of cane
• Sugar Colour < 35 IU
• Modern boiling house with FFEs, DCH, SCP® for all Massecuite
• 2 roller 4-mill tandem plant
• 40% savings on power consumption by AC-VFD Motors
• Fully automated Sugar and Co-Generation units with DCS controls
…
TM
BOILING HOUSE CONFIGURATION
• Quintuple Evaporator Station with seven identical Tubular FFEs (1500 m2)
• Total HS = 10,500 m2 [9000 m2 - operation and 1500 m2 – in standby]
• Condensate Flash Vessel System
• DCH for Raw, Defecated and Clear Juice & Syrup heating
• Single Floating Evaporator for cleaning all effects
• Working temp. range: 125°C to 75°C
• All massecuite boiling through SCP® using 4th effect vapour
…
TM
OPERATING SCHEME AT DSSPL
…
TM
OPERATING PARAMETERS
Sr. No. Effects
Operating
Operating
Pressure (bar A) Temp. (0C)
Operating ∆T
1
1st Effect
1.8–1.9
118-120
6-80C
2
2nd Effect
1.3-1.4
110-112
8-90C
3
3rd Effect
0.9-1.0
98-102
7-100C
4
4th Effect
0.6-0.65
93-96
5-70C
5
5th Effect
0.35-0.40
75-78
12-150C
…
TM
BLEEDING ARRANGEMENT
Sr. No. Description
Configuration
Operating Temperature
1
MJ 1st Heating
Pan Vapour
54-57 0C
2
MJ 2nd Heating
5th Effect
74-77 0C
3
DJ 1st Heating
4th Effect
86-89 0C
4
DJ 2nd Heating
3rd Effect
96-99 0C
5
DJ 3rd Heating
2nd Effect
107-110 0C
6
CJ 1st Heating
2nd Effect
107-110 0C
7
All Pans (A, B, C & R)
4th Effect
93-96 0C
…
TM
CRYSTALLISATION & STEAM CONSUMPTION
• Evaporator bleeding for Pan Boiling directly effects the steam demand.
• Present design of pans prevent it to be operated with low pressure
vapour.
• SCP® is the solution for reducing steam demand.
• Shifting of vapour for pan boiling to later effects indirectly helps in
rising the liquor brix close to saturation alongwith direct steam saving.
• Crystallisation using later effect drives evaporator sizes identical ; only
the single evaporator is required as standby.
…
TM
EVAPORATION LOAD DISTRIBUTION
DSSPL, Tamilnadu
Conventional Plant
…
TM
EFFECT OF CRYSTALLISATION ON STEAM
60
56%
50
Steam Consumption
43%
37%
40
31%
30
28%
20
10
0
First Effect
Second
Effect
Third Effect Fourth Effect Fifth Effect
…
TM
CONVENTIONAL PAN
Steam 45% on
Cane - 120°C
40%
35%
10%
10%
5%
Condensate
VERTICAL CONTINUOUS VACUUM PAN(SCP®)
Steam 35% on
32%
Cane - 120°C
28%
Vapours
15%
20%
18%
2%
Condensate
CRYSTALLISATION SECTION
• 3 Nos. of Vertical Continuous Vacuum Pan (SCP®) for all Massecuite boiling.
• Capacity of SCP®A – 50 TPH, B – 20 TPH, C – 15 TPH, R1 – 25 TPH and R2 – 20
TPH.
• Molasses Conditioner for AH, BH, CL
• R1 molasses of direct contact heating type.
• 2 Nos. of Seed Crystallizer of 20T for A and B Seeds.
• 2 Nos. of Grain Crystallizer of 30T for B and C Grain.
• 5 Nos. of supply tanks of 2 for syrup & melt and 3 for molasses storage.
…
TM
COLOUR VALUE OF VARIOUS STREAMS
S. No.
Descriptions
Colour Value(IU)
S. No.
Descriptions
Colour Value (IU)
1.
Primary juice
26500
13.
Final Molasses
28400
2.
Mixed Juice
28540
14.
R1 Mol.
1023
3.
Clear juice
15458
15.
R2 Mol.
1437
4.
Syrup
15750
16.
Raw Melt
570
5.
“A” M/c
9200
17.
Clear Melt
342
6.
“B” M/c
15040
18.
B & C Melt
4550
7.
“C” M/c
20453
19.
C Seed
2400
8.
R1 M/c
950
20.
C fore Sugar
3715
9.
R2 M/c
1150
21.
C after Sugar
3180
10.
A Heavy
15304
22.
R1 Sugar
24
11.
B Heavy
22680
23.
R2 Sugar
41
12.
C Light
24540
24.
Blended
34
…
TM
COGEN EFFICIENCY COMPARISION
DSSPL, Tamilnadu
Conventional Plant
…
TM
COGENERATION
Particulars
Unit
SEASON WISE
2014-15
2013-14
2012-13
2011-12
2010-11
2009-10
Plant Crushing Rate
MT
3200
3000
2000
1600
2200
1900
Power Consumption
kWh/T
29.40
30.84
30.79
32.13
32.63
38.17
Sugar Colour
IU
33.93
MONTH WISE
Jan-2016
Feb-16
Mar-16
Apr-16
Power Generation
kWh/T
135.96
128.11
135.85
135.35
Power Consumption
kWh/T
32.5
29.81
31.86
30.14
Power Export
kWh/T
103.46
99.3
103.99
105.21
…
TM
PLANT VIEWS
…
TM
RESULTS
Sr. No.
Descriptions/Parameters
Value
1.
Crushing Capacity
3500 TCD
2.
Cane Crushed (MT)
5.0 Lakh
3.
Bagasse % Cane
27.5
4.
Fibre % Cane
13.10
5.
Steam Consumtion of the Plant
31-32% on cane
6.
Total Heating Surface Area of FFEs
10,500 m2
7.
A Masseciute (%) cane
29
8.
B Massecuite (%) cane
11
9.
C Massecuite (%) cane
8.5
10
Refined Sugar (R1) (%) cane
28
11.
Refined Sugar (R2) (%) cane
21
12.
Sugar Colour
< 35 IU
13.
Power Export
100-110 kWh/Tons
…
TM
CONCLUSION
Enhanced Power Generation (100 - 105 kWh/T)
by crystallization with 4th effect Falling Film Evaporator
using innovative approach and efficient technologies.
…
TM
THANK YOU
Copyright © 2016 Spray Engineering Devices Limited
…
TM