Title of Invention

ENERGY EFFICIENT CONCENTRATION PROCESS OF SUGARCANE JUICE IN SUGAR MANUFACTURE

Abstract An energy efficient process for concentration of sugarcane juice in sugar manufacture comprising: expansion of steam in the turbine of the heat pump, concentration of sugarcane juice in a heat pump based steam turbine driven Freeze Concentration System (FCS) heating concentrated juice from FCS with vapors from a heat transfer vessel, further concentration of juice in single or plurality of heat transfer vessels, utilizing expanded steam obtained from the steam turbine for heating juice in the heat transfer vessel, recycling heating effect of clear juice to raw juice and sulphured juice, heating separated water from FCS by steam and supplying it for utilities such as imbibition, filter cake washing and milk of lime, steam supply to vacuum pan.
Full Text FORM - 2
THE PATENTS ACT, 1970
COMPLETE SPECIFICATION
(SECTION -10)
AN ENERGY EFFICIENT CONCENTRATION PROCESS OF SUGARCANE JUICE IN SUGAR MANUFACTURE
Dr.MILIND VISHWANATH RANE
4B,ANJANEYA CO-OPERATIVE HOUSING SOCIETY,IN FRONT OF
HIRANANDANI FOUNDATION SCHOOL,HIRANANDANI
GARDEN,POWAI.MUMBAI-400 076
SIDDHARTH KANTILAL JABADE
FLAT 3A.PRASHANTA, 50/51 TULSHIBAGWALE COLONY,SAHAKARNAGAR NO.2 ,PUNE- 411009
TUSHARCHANDRA S. INGALE
FLAT 3,SARITA APARTMENT,NEW ERA SOCIETY,MARKET YARD AREA,BIBWEWADIPOWAI, PUNE- 411037
An Indian National
The following specification particularly describes the invention and the manner in which it is to be performed.
GRANTED
15-12-2004

FIELD OF INVENTION
The present invention relates to an Energy Efficient Concentration process of Sugarcane Juice in Sugar Manufacture using judicious combination of Freeze Concentration System (FCS) with turbine driven Heat Pump (HP) and heat transfer vessel wherein the juice is heated by steam from the turbine to operate the process at temperatures as low as possible. Further, heat of the clarified juice is recycled to heat raw juice and sulphured.
BACKGROUND OF THE INVENTION
In the concentration process, water is separated from the sugarcane juice by heating it in a multi-effect evaporator where high temperatures are used causing inversion of • sugar resulting in low yields.
In multi-effect evaporator a change in vapor pressure on the shell side of the evaporator causes changes in juice concentration in the intermediate stages. If down stream effect cannot use the entire vapour developed by preceding effect, the pressure in the preceding effect builds up and evaporation slows down. Multiple-effect evaporator using falling-film type heat transfer vessel requires additional power consumption for recirculation of solution and due to much longer tubes of around 10 meters, there is additional burden in maintenance and operation of the equipment.
The aim is to achieve energy efficiency and to operate concentration process at temperatures as low as possible to avoid inversion problem.


Sugar factories follow different types of evaporator configurations like Quadruple, Quiptuple, Vapor Cell and Quadruple, Double Effect Vapor Cell and Quadruple etc
However, in related technologies for concentration of solutions, attempts have been made to design systems and processes for removal of solvents.
US patent 6,309,513 discloses an apparatus for desalination of seawater by evaporation in a multi-stack array of vertical tube bundles, with waste heat. It is based on a new path of steam flow by using large stacked tube bundles. However, this system has to work under vacuum as it is utilizing the steam which is otherwise going to condenser and is not effectively used. It is single stage and typically applicable for very large volumes of the order of 50,000 gallons per day. However, sugarcane juice cannot be completely concentrated in a single stage as this will result in increased retention time of juice in the evaporator resulting in inversion.
US patent 6, 497,912 discloses system and method of controlling the brix of a concentrated juice product discharged from an evaporator. A predictive model is used to control brix in a final concentrated product by controlling one of steam or juice flowing to the evaporator. However, when used in mult-effect evaporator with vapour bleeding, the process requires adjustment of several interdependent parameters. This enhances the complexity of the process controls and makes the process techno economically unattractive.
The desired features of sugarcane juice concentration process are:
a. Energy efficiency: Consumption of the heat source (steam consumption) as
low as possible per unit sugarcane crushed
b. Process temperature as low as possible to avoid sugar inversion and scaling
problems
c. Recycling of heat in the sugarcane juice (solution)
d. Reduced maintenance of the heat transfer parts
e. Minimum process controls

f. Use of minimum evaporator vessels
a. Low retention time of solution in evaporator
b. Low initial and operating cost
SUMMARY OF THE INVENTION
The main object of the invention is to provide energy efficient process for concentration of sugarcane juice in sugar manufacture
Another object of the invention is to provide appropriate combination of steam turbine driven FCS with heat transfer vessel
Another object of the invention is to achieve process temperature as low as possible in heat transfer vessel to avoid problems of sugar inversion
Yet another object of the invention is to utilize heat in the low pressure steam which other wise is rejected to the condenser cooling water
Another object of the invention is to provide energy efficiency in terms of reduced steam consumption, lower process temperature and minimum loss of sugar due to inversion
Yet another object of the invention is to recycle the heat in the clear juice to the raw juice and sulphured juice.
A
M
Another object of the invention is to provide a system with minimum use of the heat transfer vessels
Yet another object of the invention is to achieve as low retention time of the solution as possible in heat transfer vessel to avoid problems of sugar inversion

Thus in accordancei with this invention the process of concentration of sugarcane juice involves:
a. Concentrating the juice (from 15 to 45 Brix) in FCS
b. Heating concentrated juice from FCS with vapor from a heat transfer vessel
c. Further concentration of juice (from 45 to 60 Brix) in the heat transfer vessel
d. Utilizing expanded steam which is at low temperature obtained from a steam
turbine for heating juice in the heat transfer vessel
e. Recycling heating effect of clear juice to raw juice and sulphured juice
f. Heating separated water from FCS by steam and supplying it for utilities such
as imbibition, filter cake washing and milk of lime
It may be noted that the compressor of the HP is driven by the steam turbine
DETAILED DESCRIPTION OF THE INVENTION
The features and advantages of this invention will become apparent in the following detailed description and the preferred embodiments with reference to the accompanying drawings. For purpose of the description contained herein, the definitions of the following terms are relevant (Hugot, 1986):
a. Raw Juice: This is the sugarcane juice coming from mills
b. Clarification: Treatment of sugarcane for removing suspended and dissolved
impurities.
c. Clear juice:The juice obtained after separation of precipitated impurities.
d. Syrup: Concentrated clear juice
e. Brix: Dissolved solids in sugar bearing liquid indicated as Bx
f. Pan: Apparatus in which syrup or molasses are boiled so as to obtain sugar
crystals of the desired size.
g. Sulphured juice: Part of the clarification process in which juice is reacted with
sulphur dioxide, this process is carried out in two stages
Appropriate combination of FCS and heat transfer vessel to achieve energy efficiency is selected based on the following:

a/Conventional systems such as Quadruple, Quiptuple, Vapor Cell and Quadruple, Double Effect Vapor Cell and Quadruple have steam consumption on cane in the range of 46 to 51 % with process temperatre of 115°C A detailed analysis of the combination of FCS and heat transfer vessels have been considered and the steam consumption and process temperatures were evaluated. It is surprisingly been found that if is possible to achieve minimum steam consumption (39%) and low process temperature (of 55°C as compared to 115°C in conventional systems) by a judicious combination of steam turbine driven FCS and a heat transfer vessel. Table 1 presents different combinations of FCS with heat transfer vessel, and steam consumption, process temperature and additional steam required for syrup heating for each combination. It may be noted that only option 5 in Table 1 achieves the best results with 39% stem consumption on cane, 55°C operating temperature and requirement of no additional steam for syrup heating.


(

Table 1: Summary Table

Process description of the sugarcane juice concentration using turbine driven FCS and a heat transfer vessel is as follows:
schematic of sugarcane juice concentration process is shown in Figure 1. Exhaust steam passes through conduit 1 to conduit 3 which is connected to turbine 4 and conduit 2 which supplies steam to pans. Turbine 4 is used to drive compressor of the Heat Pump of FCS wherein concentration of juice is carried out from 15 to 45 Brix. Steam after expansion in 4 passes through conduits 5 and 7 to heat transfer vessel 8 where further concentration of juice from 45 to 60 Brix is carried out. Vapours from 8 pass through conduit 9 to syrup heat exchanger 15. Raw juice passes through conduit 23 to heat exchanger 24 where it is heated by the clear juice passing through conduit 32. Thus the heat in the clear juice is recycled to raw juice. Raw juice passes through conduit 25 to sulphured juice heat exchanger 20 where it is further heated by the exhaust steam passing through conduit 19. Partially heated sulphured juice passes through conduit 26 to sulphured juice heat exchanger 27 where it is heated by clear juice passing through conduit 28. Thus heat in the clear juice is recycled to sulphured juice. Further heating of sulphured juice is carried out in the sulphured juice heat exchanger 17 where sulphured juice passing through 29 is heated by the exhaust steam passing through conduit 18. Sulphured juice passed through conduit 30 to clarifier 31, clear juice after clarification process passes through conduit 28 to 27. Clear juice passing through conduit 33 is passed to freeze concentration system 34 through conduit 37. Water separated in 34 passes through conduit 6 to heat exchanger 11 where it is heated by steam passing through conduit 14. This hot water is passed through conduit 12 utilities such as imbibition, filter cake washing, milk of lime. Syrup from freeze concentration system 34 passes through 35 is heated in heat exchanger 15 by the vapours form 8 passing through conduit 9. Syrup from 15 passes through conduit 36 to 8 for further concentration.
In another embodiment a ammonia turbine may be used to drive the compressor of the heat pump
In yet another embodiment the juice may be concentrated using plurality of heat transfer vessels
Example
A configuration of freeze concentration system with turbine driven heat pump which implements layer freezing process and evaporator vessel can be used for concentration of sugarcane juice from 15 to about 60 Brix. The factory under consideration is 2500 Ton Crushed per Day (TCD) capacity. Considering the concentration of juice from 15 to 45 Brix in the FCS and further in the

evaporator, power required to drive the turbine of the Heat Pump of FCS to separate water from the juice is about 575 kW. Considering the expansion of steam in the turbine from120°C to 60°C, stem required to produce 575 kW is 9.6 Tons Per Hour (TPH). The same steam after expansion in the turbine at 60°C can be used for heating syrup in the evaporator operating at 55°C to concentrate this syrup from 45 to 60 Brix. Direct steam at 120°C can be supplied to pans. Clear juice from the clarifier at about 95oC can be used to heat the raw juice and partially Sulphured Juice (SJ). Further heating of sulphured juice II and I is carried out by the direct steam at 120°C. The steam after heating SJ I and II is used to heat the separated water from FCS and syrup coming from FCS. Thus, total steam consumption of the concentration process of sugarcane along with raw juice, Sulphured juice and pan heating juice results in about 38 TPH i.e.38 percent on cane as compared to 53 TPH in case of most popular Vapor Cell and Quadruple configuration and 47 TPH in DEVC + Quad configuration.
It is evident form this invention that a judicious combination of appropriate devices such as steam turbine driven heat pump, syrup heat exchanger, sulphured juice heat exchanger and heat transfer vessel, it is possible to achieve an energy efficient concentration process of sugarcane juice in sugar manufacture operating at low process temperatures.

We claim
1. An energy efficient process for concentration of sugarcane juice in sugar manufacture comprising: expansion of steam in the turbine of the heat pump, concentration of sugarcane juice in a heat pump based steam turbine driven Freeze Concentration System (FCS) heating concentrated juice from FCS with vapors from a heat transfer vessel, further concentration of juice in single or plurality of heat transfer vessels, utilizing expanded steam obtained from the steam turbine for heating juice in the heat transfer vessel, recycling heating effect of clear juice to raw juice and sulphured juice, heating separated water from FCS by steam and supplying it for utilities such as imbibition, filter cake washing and milk of lime, steam supply to vacuum pan.
2. An energy efficient process for concentration of sugarcane juice in sugar manufacture as claimed in claim 1 wherein steam is expanded from 120 to 60°C in a steam turbine which drives heat pump of the freeze concentration system.
3. An energy efficient process for concentration of sugarcane juice in sugar manufacture as claimed in claim 1 wherein sugarcane juice is concentrated from 15 to 45 Brix in the heat pump based steam turbine driven freeze concentration system.
4. An energy efficient process for concentration of sugarcane juice in sugar manufacture as claimed in claim 1 wherein sugarcane juice is concentrated from 45 to 60 Brix in plurality or preferably single heat transfer vessel using expanded steam from the turbine.
5. An energy efficient process for concentration of sugarcane juice in sugar manufacture as claimed in claim 1 wherein separated water from freeze concentration system is heated to about 70 °C to 80°C using steam at about 105 °C to120°C.


An energy efficient process for concentration of sugarcane juice in sugar manufacture as claimed in claim 1wherein raw juice is heated to about 70°C using clear juice from the clarifier.
An energy efficient process for concentration of sugarcane juice in sugar manufacture as claimed in claim 1 sulphured juice is partially heated to about 90°C using clear juice from the clarifier.
An energy efficient process for concentration of sugarcane juice in sugar manufacture as claimed in claim 1 wherein sulphured juice is heated to about 103°C using steam at a temperature of about 105°C to 120°C.
An energy efficient process for concentration of sugarcane juice in sugar manufacture as claimed in claim 1 wherein sugarcane juice is clarified in a clarifier.
An energy efficient process for concentration of sugarcane juice in sugar manufacture as claimed in claim 1 wherein steam at about 105°C to 120°C is supplied to vacuum pans.
An energy efficient process for concentration of sugarcane juice in sugar manufacture as claimed in claim 1 wherein temperature of the juice in the heat transfer vessel is not more than 60°C.
An energy efficient process for concentration of sugarcane juice in sugar
manufacture as claimed in claim 1 wherein only single heat transfer vessel may
be used while further concentrating juice coming from the FCS. Dated 14/12/2004
Applicant Rane Milind Vishwanath

^

Documents:

598-mum-203-cancelled page(15-12-2004).pdf

598-mum-203-claim(granted)-(15-12-2004).pdf

598-mum-203-claims(granted)-(15-12-2004).doc

598-mum-203-correspondence(15-12-2004).pdf

598-mum-203-correspondence(ipo)-(17-8-2004).pdf

598-mum-203-drawing(8-6-2004).pdf

598-mum-203-form 1(10-6-2003).pdf

598-mum-203-form 19(16-7-2003).pdf

598-mum-203-form 2(granted)-(15-12-2004).doc

598-mum-203-form 2(granted)-(15-12-2004).pdf

598-mum-203-form 26(8-6-2004).pdf

598-mum-203-form 26(9-6-2003).pdf

598-mum-203-form 3(10-6-2003).pdf

598-mum-203-form 5(8-6-2004).pdf

abstract1.jpg


Patent Number 209956
Indian Patent Application Number 598/MUM/2003
PG Journal Number 40/2008
Publication Date 03-Oct-2008
Grant Date 12-Sep-2007
Date of Filing 10-Jun-2003
Name of Patentee RANE MILIND VISHWANATH
Applicant Address 4 B, ANJANEYA CO-OPERATIVE HOUSING SOCIETY, IN FRONT OF HIRANANDANI FOUNDATION SCHOO, HIRANANDANI GARDEN, POWAI, MUMBAI,
Inventors:
# Inventor's Name Inventor's Address
1 JABADE SIDDHARTH KANTILAL FLAT 3A, PRASHANTA, 50/51 TULSHIBAGWALE COLONY, SAHAKARNAGAR NO 2, PUNE-411009,
2 INGALE TUSHARCHANDRA S FLAT 3, SARITA APARTMENT, NEW ERA SOCIETY, MARKET YARD AREA, BIBWEWADI, PUNE-411037,
3 RANE MILIND VISHWANATH 4 B, ANJANEYA CO-OPERATIVE HOUSING SOCIETY, IN FRONT OF HIRANANDANI FOUNDATION SCHOO, HIRANANDANI GARDEN, POWAI, MUMBAI,
PCT International Classification Number C13J 1/86
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA