boiling house efficiency

BOILING HOUSE BOILING HOUSE EFFICIENCY EFFICIENCY

1

by

MUHAMMAD IQBAL QURESHI

DGM (Production)

Boiling House Efficiency Boiling House Efficiency

Boiling House Efficiency can be measured Boiling House Efficiency can be measured and expressed by the crystallize-able and expressed by the crystallize-able sucrose recovered in sugar % crystallize-sucrose recovered in sugar % crystallize-able sucrose available in Mixed Juice.able sucrose available in Mixed Juice.

This is based on the practical finding that This is based on the practical finding that for every part of non-sucrose present in for every part of non-sucrose present in the mixed juice, a certain corresponding the mixed juice, a certain corresponding amount of sucrose will be retained in the amount of sucrose will be retained in the molasses when properly exhausted.molasses when properly exhausted.

Boiling House Efficiency Boiling House Efficiency (Cont.)(Cont.)

The non-crystallize-able sucrose in The non-crystallize-able sucrose in mixed juice will vary according to the mixed juice will vary according to the purity of mixed juice, as juices of lower purity of mixed juice, as juices of lower purity (provided such low purities are not purity (provided such low purities are not due to cane deterioration) are usually due to cane deterioration) are usually associated with a higher reducing sugar associated with a higher reducing sugar ash ratio, which as we know helps to ash ratio, which as we know helps to achieve better exhaustion as salts have achieve better exhaustion as salts have more affinity for reducing sugars than for more affinity for reducing sugars than for sucrose.sucrose.

It has also been found that after It has also been found that after drought, when the reducing sugars drought, when the reducing sugars ash ratio is exceptionally high through ash ratio is exceptionally high through cane deterioration such juice would cane deterioration such juice would not respond as stated.not respond as stated.


Viscosity retards the rate of Viscosity retards the rate of crystallization tremendously and As the crystallization tremendously and As the boiling house of any sugar mills is boiling house of any sugar mills is bound by limitation of pans and bound by limitation of pans and crystallizers capacities such crystallizers capacities such deteriorated and viscous juice will lead deteriorated and viscous juice will lead to a poor boiling house performance, to a poor boiling house performance, however high may be the reducing however high may be the reducing sugar to ash ratio.sugar to ash ratio.


Obviously, unusual high losses in the Obviously, unusual high losses in the filter cake or in the undetermined filter cake or in the undetermined losses through entrainment or losses through entrainment or inversion, also lead to poor boiling inversion, also lead to poor boiling house performance excessive house performance excessive destruction of reducing sugar during destruction of reducing sugar during clarification by a too high pH will also clarification by a too high pH will also lead to poor boiling house lead to poor boiling house performance. performance.


It is therefore very much clear that if we It is therefore very much clear that if we are talking about the boiling house are talking about the boiling house efficiency we should start from cane, efficiency we should start from cane, because problem of viscosity does not because problem of viscosity does not start in the factory itself but it start much start in the factory itself but it start much earlier. We cane see by checking earlier. We cane see by checking following factors. These factor must be following factors. These factor must be controlled.controlled.

1.1. Does the cane contain white tops?Does the cane contain white tops?2.2. Does the cane contain a lot of impurities such Does the cane contain a lot of impurities such

as soil and other foreign matters?as soil and other foreign matters?


3.3. If the field was burned before harvesting, how If the field was burned before harvesting, how long has the cane remained in the field, before long has the cane remained in the field, before being transported to factory ?being transported to factory ?

4.4. Has the stock been renewed daily i.e. cane Has the stock been renewed daily i.e. cane stock in factory yard must be cleared?stock in factory yard must be cleared?

5.5. Is Mill sanitation a common practice i.e. Is Mill sanitation a common practice i.e. application of hot water jets and biocides.application of hot water jets and biocides.

6.6. Is the waiting tanks under juice tank is very Is the waiting tanks under juice tank is very large preferably made conical bottom with less large preferably made conical bottom with less retention time? At Matiari we eliminate the tank retention time? At Matiari we eliminate the tank with help of our juice stabilization system.with help of our juice stabilization system.


7.7. Is the clarification of juice carried out without Is the clarification of juice carried out without using excessive lime? This year lime using excessive lime? This year lime consumption is less as compare to previous consumption is less as compare to previous years.years.

8.8. Clarification process is well known to eliminate Clarification process is well known to eliminate impurities from Juice i.e. ash not eliminated in impurities from Juice i.e. ash not eliminated in Clarification. They will find their way into the Clarification. They will find their way into the final molasses where over and above their final molasses where over and above their weight, they are going to maintain more sugar weight, they are going to maintain more sugar in solution. Ash increase purity of mother liquor. in solution. Ash increase purity of mother liquor.


8.8. PH meter must be very reliable and proper pH PH meter must be very reliable and proper pH control preferable auto-pH control correctly applied.control preferable auto-pH control correctly applied.

9.9. What is the purity of low grade Massecuite. Purity of What is the purity of low grade Massecuite. Purity of C-Massecuite should neither be too high, because C-Massecuite should neither be too high, because sufficient drop in purity will not be obtained; nor too sufficient drop in purity will not be obtained; nor too low because viscosity of Massecuite necessarily be low because viscosity of Massecuite necessarily be very high and difficulty of molasses separation in the very high and difficulty of molasses separation in the centrifugals; optimum purity of C-Massecuite for any centrifugals; optimum purity of C-Massecuite for any particular sugar factory could be obtained by plotting particular sugar factory could be obtained by plotting the C-Massecuite versus final Molasses purity for the C-Massecuite versus final Molasses purity for past seasons.past seasons.


10.10. The purity of C-Sugar should not be very low The purity of C-Sugar should not be very low because too much molasses and impurities are because too much molasses and impurities are re-circulated and crystallization is rendered re-circulated and crystallization is rendered very difficult because of increasing viscosity of very difficult because of increasing viscosity of mother liquor, recycling impurities increases mother liquor, recycling impurities increases volume of C-Massecuite.volume of C-Massecuite.

11.11. Temperature of Massecuite at time of curing Temperature of Massecuite at time of curing should not be higher then 52 should not be higher then 52 00C, which is C, which is considered the near optimum temperature considered the near optimum temperature when curing very heavy density Massecuite. If when curing very heavy density Massecuite. If temperature will exceeds saturation temperature will exceeds saturation temperature crystals start dissolving.temperature crystals start dissolving.


12.12. Crystal size Crystal size

Size of crystal in C-Massecuite Size of crystal in C-Massecuite should be around 0.25 – 0.30 mm. should be around 0.25 – 0.30 mm. However if viscosity of Massecuite is However if viscosity of Massecuite is not too high, smaller grain will give not too high, smaller grain will give better exhaustion of molasses due to better exhaustion of molasses due to greater surface area of crystal, best greater surface area of crystal, best way to achieve required crystal size way to achieve required crystal size is by true seeding using slurry. Slurry is by true seeding using slurry. Slurry should be uniform and even.should be uniform and even.


13.13. Massecuite should contain crystals of the Massecuite should contain crystals of the same size and free from any false grain. same size and free from any false grain. False grain blocks the passage of False grain blocks the passage of molasses and more water will have to be molasses and more water will have to be used in centrifugal in order to produce C-used in centrifugal in order to produce C-Sugar of required purity. When false grain Sugar of required purity. When false grain passes through the screens, they passes through the screens, they contributes to increase in the purity of contributes to increase in the purity of final molasses. Same size crystals make final molasses. Same size crystals make curing more easy at centrifugals.curing more easy at centrifugals.


14.14. Massecuite should be free from Massecuite should be free from Bagasse. It prevents molasses from Bagasse. It prevents molasses from getting out of the centrifugal getting out of the centrifugal screens. we have covered our tanks.screens. we have covered our tanks.

15.15. Centrifugal screen should be Centrifugal screen should be examined regularly and damaged examined regularly and damaged screen should be replaced at once.screen should be replaced at once.


IMPURITIES DEVELOPED AND IMPURITIES DEVELOPED AND PROCESSINGPROCESSING

As reducing sugars are destroyed or sucrose As reducing sugars are destroyed or sucrose is inverted due to high temperature we must is inverted due to high temperature we must pay careful attention.pay careful attention. Minimum retention time. As at Matiari Sugar Mills Minimum retention time. As at Matiari Sugar Mills

Ltd we used juice flow Stabilization system Ltd we used juice flow Stabilization system including flow meter and auto level control including flow meter and auto level control eliminating the screen juice tank at Mill house and eliminating the screen juice tank at Mill house and weighing scale at process house weighing scale at process house

Control of Exhaust and live steam temperature at Control of Exhaust and live steam temperature at Evaporator and pan by auto de-supper heating Evaporator and pan by auto de-supper heating system.system.

IMPURITIES DEVELOPED AND IMPURITIES DEVELOPED AND PROCESSINGPROCESSING

Ensured that barometric condensers are Ensured that barometric condensers are working well i.e. Vacuum obtained is working well i.e. Vacuum obtained is sufficiently high to obtain a maximum sufficiently high to obtain a maximum boiling temp: of 65boiling temp: of 65ooC. It is well known that C. It is well known that froth fermentation, Maillard Reaction b/w RS froth fermentation, Maillard Reaction b/w RS And lactic acid accelerated at high And lactic acid accelerated at high temperature ,in which COtemperature ,in which CO22 gas liberates. gas liberates.

Impurities introduced in the factory with Impurities introduced in the factory with lime and water, good quality lime is used lime and water, good quality lime is used with maximum CaO% i.e. more than 90% . with maximum CaO% i.e. more than 90% . Use of condensate for imbibitions, MOL and Use of condensate for imbibitions, MOL and polyelectrolyte preparation.polyelectrolyte preparation.

TECHNIQUESTECHNIQUES

Pans must have good circulation and sufficient Pans must have good circulation and sufficient capacity, we have used pan circulators in batch pans.capacity, we have used pan circulators in batch pans.

Appropriate cooling time must be given to Appropriate cooling time must be given to Massecuite before curing, especially “B” and “c” Massecuite before curing, especially “B” and “c” Massecuite.Massecuite.

Massecuite should be gravitate through crystallizers, Massecuite should be gravitate through crystallizers, Massecuite heaters and centrifugal.Massecuite heaters and centrifugal.

No dilution in Massecuite done.No dilution in Massecuite done.

Good pan work resulting Massecuite with required Good pan work resulting Massecuite with required crystal content high Brix as well as, well formed crystal content high Brix as well as, well formed crystals without false grain.crystals without false grain.

The Continuous PanThe Continuous Pan The Continuous Pan has been increasing The Continuous Pan has been increasing

interest of technologist because of rapid interest of technologist because of rapid increase in manufacturing cost. increase in manufacturing cost. Economic saving is expected by an Economic saving is expected by an increase in throughput, by the reduction increase in throughput, by the reduction of downtime associated with batch of downtime associated with batch pans, when stopping and starting and by pans, when stopping and starting and by an improve steam consumption on the an improve steam consumption on the pan floor, provided sufficient heating pan floor, provided sufficient heating surface area is available at evaporators surface area is available at evaporators to boil the pan with later stage vapors.to boil the pan with later stage vapors.

The Continuous PanThe Continuous Pan

The Continuous Pan now provided fully automated The Continuous Pan now provided fully automated and continuous operations to cater for all and continuous operations to cater for all Massecuite.Massecuite.

Owing to the use of effectively selected control Owing to the use of effectively selected control instruments, it will boil consistent quality “B” and instruments, it will boil consistent quality “B” and “C” Massecuite regularly.“C” Massecuite regularly.

With application of Radio Frequency PROBES “A” With application of Radio Frequency PROBES “A” Massecuite can be boiled without “False grain” to Massecuite can be boiled without “False grain” to give good quality “A” sugar of lower colour index.give good quality “A” sugar of lower colour index.

Better steam economy can be achieved from the Better steam economy can be achieved from the use of continuous pan, operated on 2use of continuous pan, operated on 2ndnd or 3 or 3rdrd vapor. vapor.

B.B. Microprocessor/Digital control is Microprocessor/Digital control is taking over the technical control taking over the technical control and monitoring of process operation and monitoring of process operation including pan boiling to dominate including pan boiling to dominate human errors and guard against human errors and guard against deficiencies, and time lags inherent deficiencies, and time lags inherent in operation based controls.in operation based controls.

STRATEGYSTRATEGY

Strategy for improvement in Strategy for improvement in performanceperformance

Increase in supply of improved cane Increase in supply of improved cane varietyvariety

Good cane preparation for utilization of Good cane preparation for utilization of Auto-cane preparation & feeding systemAuto-cane preparation & feeding system

The philosophy of control The philosophy of control is to ensure is to ensure constant and regular feeding of cane to constant and regular feeding of cane to cane cutter (if installed), Fibrizer of Mills cane cutter (if installed), Fibrizer of Mills and at the same time to avoid “chokes” . and at the same time to avoid “chokes” . Mills setting of a tandem is carried out for Mills setting of a tandem is carried out for a planned daily cane crushinga planned daily cane crushing

Strategy for improvement in Strategy for improvement in performanceperformance

For maximum extraction from the For maximum extraction from the Mill house a regular and Uniform Mill house a regular and Uniform cane feeding is required. To ensure cane feeding is required. To ensure uniform cane feeding, PLC uniform cane feeding, PLC (programmable logic controller) is (programmable logic controller) is installed, so that the speed of installed, so that the speed of carriers can be automatically carriers can be automatically controlled. The PLC system helps in controlled. The PLC system helps in avoiding chokes.avoiding chokes.

STEPS TAKEN FOR STEPS TAKEN FOR IMPROVEMENTIMPROVEMENT

Uniform Juice flow by flow meter and Uniform Juice flow by flow meter and level control at Mill House Juice tank. level control at Mill House Juice tank. Therefore avoiding waiting tankTherefore avoiding waiting tank

Use of pH meter and Auto-control Use of pH meter and Auto-control system by the end of seasonsystem by the end of season

Use of 30 Mesh screen at MOL hopper Use of 30 Mesh screen at MOL hopper and regular cleaning of MOL tanksand regular cleaning of MOL tanks

Temperature of mud at vacuum filter is Temperature of mud at vacuum filter is kept 80 kept 80 00C. Mud tank and allied pipes C. Mud tank and allied pipes lagged lagged

Level of feed trough is controlled no Level of feed trough is controlled no overflow is allowed to mud tank.overflow is allowed to mud tank.

Purity of cloudy and clear filtrate is checked Purity of cloudy and clear filtrate is checked at regular basis because 1 degree drop in at regular basis because 1 degree drop in filtrate purity from clear juice equivalent to a filtrate purity from clear juice equivalent to a loss of 0.1% in BHRloss of 0.1% in BHR

Use of VFD and level transmitter at Use of VFD and level transmitter at Massecuite pump to save the power as well Massecuite pump to save the power as well as crystal breaking by overflow of as crystal breaking by overflow of Massecuite from pugmil bottle stopped, Massecuite from pugmil bottle stopped, because of level transmitter send signal to because of level transmitter send signal to VFD.VFD.

STEPS TAKEN FOR STEPS TAKEN FOR IMPROVEMENTIMPROVEMENT

Modern ResearchModern Research

Modern Research shows that use of lime saccharate for clarification is better than milk of lime

In line Mixing is possible. Reaction takes only 45 sec to complete

Results Of The Fine Tuning Jobs Results Of The Fine Tuning Jobs of Boiling Houseof Boiling House

Improved Juice Clarification as Improved Juice Clarification as compare to last years, due to proper compare to last years, due to proper juice heating and mud removal from juice heating and mud removal from Juice Clarifier as well as maintaining Juice Clarifier as well as maintaining Filter Cake temperature at 80Filter Cake temperature at 8000CC

Storage Tanks are covered to Storage Tanks are covered to prevent mixing of bagacilloprevent mixing of bagacillo

Fine Tuning Jobs of Boiling Fine Tuning Jobs of Boiling HouseHouse

Muddy juice circulation stopped from Muddy juice circulation stopped from vacuum filter mud trayvacuum filter mud tray

New screen provided to vacuum filter New screen provided to vacuum filter #2#2

Bagacillo screen area increasedBagacillo screen area increased Purity drop of Clarified Juice to Purity drop of Clarified Juice to

Filtrate is reduced from Filtrate is reduced from 1.1 to 0.421.1 to 0.42


07 Nos. VFD installed at Process House07 Nos. VFD installed at Process House for Massecuite and Magma Pumps.for Massecuite and Magma Pumps.

A-Massecuite, 02 Nos.A-Massecuite, 02 Nos. B-Massecuite, 01 No.B-Massecuite, 01 No. C-Grain, 02 Nos.C-Grain, 02 Nos. C-Massecuite, 01 No.C-Massecuite, 01 No. C-Magma, 01 No.C-Magma, 01 No.

Benefits of VFD Benefits of VFD Avoided recirculation and re-pumping of Avoided recirculation and re-pumping of

massecuite causing grinding of Crystals hence massecuite causing grinding of Crystals hence controlling the Massecuite level as well as controlling the Massecuite level as well as power saving.power saving.


Continuous operation of C-Conti Pan Continuous operation of C-Conti Pan Control of purity drop between Massecuite Control of purity drop between Massecuite

and Molasses especially in “C” to Final and Molasses especially in “C” to Final Molasses this year remain 20Molasses this year remain 2000 as compare as compare to 17to 1700 and 18 and 1800 for last two seasons. for last two seasons.

Proper cleaning of centrifugal backing Proper cleaning of centrifugal backing screen screen

Proper control of C- Massecuite cooling Proper control of C- Massecuite cooling and re-heatingand re-heating

Use of condensate water for sugar drying Use of condensate water for sugar drying in radiators in place of steam.in radiators in place of steam.

Performance comparisonPerformance comparison

25.4826.0427.65NS TO Pol Ratio

3.853.924.1N S % Primary Juice

17.1318.6220.19Purity Drop from “C” mass: to F M

1.21.090.42Purity Drop Clarified Juice to Filtrate

Season 2011-12

Season 2010-11Season 2009-

10

Cane M T 442261.637 441928.1 412513.1

Clarification Effect 10.87 9.52 10.08

Molasses percent Cane 4.61 4.56 4.5

Sugar loss in mol 1.41 1.43 1.42

Non-Sugar Removed 10.50 9.06 9.71

Lime Consumption % Cane 0.1124 0.1547 0.1291

BH R87.03

86.91 86.80

RBHR92.14

91.75 91.80

Red. Boiling House Recovery

90.690.8

9191.291.491.691.8

9292.292.4

2004-2005

2005-2006

2006-2007

2007-2008

2008-2009

2009-2010

2010-2011

2011-2012

Boiling House Recovery

82.5

83

83.5

84

84.5

85

85.5

86

86.5

87

87.5

2004-2005

2005-2006

2006-2007

2007-2008

2008-2009

2009-2010

2010-2011

2011-2012

Boiling HouseRecovery

Primary NS Sugar Pol Ratio

0

5

10

15

20

25

30

35

40

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 101 106 111 116 121 126 131

Primary Non SugarPol Ratio 2009-10



NS Removal %

0

2

4

6

8

10

12

14

16

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 101 106 111 116 121 126 131

2009-10 2010-11 2011-12

Molasses % Cane

0

1

2

3

4

5

6

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 101 106 111 116 121 126 131

2009-10 2010-11 2011-12

Loss in Final Molasses % Cane

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 101 106 111 116 121 126 131

2009-10 2010-11 2011-12

Loss in V.F % Cane

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 101 106 111 116 121 126 131

2009-10 2010-11 2011-12