FORM 2
THE PATENTS ACT, 197Q
(39 OF 1970)
AND
THE PATENT RULE, 2001
COMPLETE SPECIFICATION
(SEE SECTION 10 AND RULE 13)
"AN IMPROVED PROCESS OF SUGARCANE JUICE EVAPORATION AND TREATMENT OF RECOVERED WATER FOR DRINKING PURPOSES"
TRANSPARENT ENERGY SYSTEMS PRIVATE LIMITED AN INDIAN NATIONAL "PUSHPA HEIGHTS", 1ST FLOOR, BIBWEWADI CORNER, PUNE-SATARA ROAD, PUNE-411 037, MAHARASHTRA, INDIA.
THE FOLLOWING SPECIFICATION DESCRIBES THE NATURE OF THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF INVENTION:-
The present invention relates to an improved process of sugarcane juice evaporation and treatment of recovered water for drinking purposes. More particularly, the process in the present invention recovers water for value added utilization such as distilled water for premium applications and/or packaged drinking / mineral water.
PRIOR ART:-
The sugarcane crop is harvested mechanically or by hand, chopped into lengths and conveyed to the processing plant. Here it is either milled and the juice is extracted with water or the sugar is extracted by diffusion. The juice is then clarified with lime and heated to kill enzymes. The resulting thin syrup is concentrated in a series of evaporators (multi-effect evaporators) after which further water is removed by evaporation in vacuum containers. The resulting supersaturated solution is seeded with sugar crystals. The sugar crystallizes out and it is separated from the fluid and dried. Molasses is a by-product of the process and the fiber from the stems, known as bagasse, is combusted in high pressure steam boiler of captive cogeneration plant in sugar mil!. High pressure steam generated in the boiler drives backpressure steam turbine to generate power. The exhaust steam from backpressure turbine is used to run multi effect evaporators for sugarcane juice boiling. The crystals of raw sugar have a sticky brown coating and can either be used as they are or can be bleached by sulphur dioxide or treated in a carbonation process to produce a white product.
The sugarcane juice evaporation is the most energy intensive process in sugar making. The energy efficiency of sugarcane juice evaporation can be improved by high efficiency energy conserving multistage sugarcane juice evaporators with thermo-compressor (Patent Application Number 367/MUM/2005) and a Super-Efficient Seven Stage Sugar Cane Juice Evaporator with Thermo Compressor (1668/MUM/2006).

LIMITATIONS OF PRIOR ART:-
1. The water evaporated in juice boiling is contaminated with juice droplets therefore; it is either used for irrigation or as make up water in cooling towers of captive cogeneration power plant of the sugar mill.
PRESENT SCENARIO AND NEED FOR INVENTION:-
Sugarcane is a water intensive crop. Sugarcane is grown as cash-crop even in many water scarce regions in India. Water constitutes 72% of the mass of sugarcane; which is evaporated while sugar making. Substantial of the sugarcane growing areas are water scarce. Therefore, there is need to recover this water as premium value added by product sellable in the vicinity of the plant.
OBJECT OF THE PRESENT INVENTION:-
Object of present invention aims at an improved process of sugarcane juice evaporation and treatment of recovered water for drinking purposes. More particularly, the process in the present invention recovers water for value added utilization such as distilled water for premium applications and/or packaged drinking / mineral water.
It is also the object of the present invention to eliminate the draw backs of the prior art.
STATEMENT OF INVENTION:-
Accordingly the invention provides an improved process of sugarcane juice evaporation and treatment of recovered water for drinking purposes comprises steps:
a. In an integrated sugarcane processing first crushing of sugarcane in a milling
section;
b. Separating and sending the bagasse to cogeneration plant for steam
generation ;
c. extracts sugarcane juice and supplying for heating and evaporation;

d. heating and evaporating of juice of step(c ) in multi stage evaporates by the
steam of backpressure turbine exhaust supplied by the cogeneration plant to
separate water vapour from sugar syrup ;
e. Condensing the said water vapour of step (d) in a condenser;
f. to produce sugar (4) and byproduct molasses from the syrup of step (d);
g. Distilling Treating the condensed / distilled water of step (e) in distillation plant
or/and packaged drikingdrinking water plant for obtaining drinking water or
treating the condensed water of step (e) in demineralization plant for
obtaining/battery water.
DESCRIPTION OF FIGURES:-
Fig. 1. Schematic diagram showing typical modern sugar mill with seven stage
evaporators recovering distilled condensate water from sugarcane juice
Fig. 2. Schematic diagram showing details of traditional sugar mill recovering condensate
water of inferior quality
Fig. 3. Schematic diagram showing details of integrated scheme of sugar mill with sugar
processing tine and treatment line for TecoveTed distilled water to make it suitable for other
value added uses such as packaged drinking water or distilled water.
Fig.4. Schematic diagram showing details of a typical stage of multistage evaporator
including two stage vapor liquid separation process.
DETAILED DESCRIPTION OF THE INVENTION:-
As described in the figure 1, in the present invention, the sugarcane is crushed in milling section (1) and the sugarcane juice is collected in raw juice tank (2) and bagasse is sent to cogeneration plant (14) wherein high pressure steam is generated to drive backpressure turbine to generate electricity. The exhaust steam (3) from cogeneration plant is supplied to multistage evaporators (9) for juice evaporation. The sugarcane juice is then passed through series of steam heated pre heaters (6), (7), (8). The steam (20) supplied to these pre heaters comes from corresponding stage of multistage evaporators as shown in figure 1. Process of sulphitation (4) is carried out after preheating juice through preheaters (6). The sulphited juice is then further heated through preheaters (7). The hot sulphited juice is then clarified (5). The clarified juice is further heated in

preheaters (8). It is then fed to multistage evaporators (9) for juice boiling. The vaporsof residual quantity (21) from last stage are condensed in air cooled condenser (10) equipped with axial fan (12) to blow air on fined tubes through which the steam flows. To meet the fluctuating loads a dump condenser (11) is provided to condense excess steam. Steam is extracted from intermediate stage of multistage evaporator for supplying to vacuum pans (16) where in the concentrated juice collected in concentrate tank (15) is evaporated further to saturation levels such as to crystalize the sugar. The crystalized sugar (19) is filtered out in centrifuge / filter (17) and the molasses (18) is separated for disposal. The water evaporated and condensed in multistage evaporators and air cooled condenser is collected in condensate tank (13). The said recovered water can be processed for value added application such as packaged drinking / mineral water and/or distilled water for automobile battery refill.
As shown in figure 2, the traditional sugarmill comprises of a milling section (1) wherein sugarcane is crushed to extract sugarcane juice which collected in raw juice collection tank (2). The raw juice is heated in raw juice heater (3). Then sulphitation (4) of juice is carried out. Sulphited juice is heated further in sulphited juice heaters (5). The sulphited juice is then clarified in clarifier (6). The clarified juice is then heated further in clarified juice heaters (7). The heaters (3), (5) and (7) are all steam driven heaters for which steam supplied is backpressure turbine exhaust steam (11) supplied by cogeneration plant (14). The hot clarified juice is concentrated in evaporator section (8). The cogeneration plant supplies backpressure turbine exhaust steam (11) to drive evaporation section. The concentrated juice is collected in concentrate juice tank (9). The concentrated juice is further evaporated n vacuum pans (15) to saturation concentrations at which the sugar crystallizes out. The crystallized sugar (17) is separated in filter / centrifuge (16). The molasses (18) separated is sent for disposal. The water evaporated in multistage evaporators is condensed in water cooled spray condensers (10) equipped with cooling towers (12). The condensate water is collected in condensate tank (13).
The figure 3 shows the scheme of the present invention related to integrated sugarcane processing comprising of milling section (1) which separates bagasse (6) and extracts sugarcane juice (2) which could be processed in sugarmill (3) which could be as shown in figure 1 or figure 2 to produce sugar (4) and byproduct molasses (5). The Bagasse (6) is supplied to cogeneration plant (7) which produces high pressure steam to drive

backpressure steam turbine to generate electricity (13). The exhaust steam (8) from cogeneration plant is supplied to multistage evaporators in sugrmill as explained in figure 1 and 2 for sugarcane juice evaporation. The equivalent amount of condensate (9) is returned by sugarmill to cogeneration plant. As per the present invention, the condensate water (10) recovered by sugarmill is treated further in distilled water plant (11) and/or packaged drinking water plant (12) to obtain respective value added product.The condensed water (10) shall be treated as described above to make it sellable as packaged drinking water as per IS14543 in form of 1 liter bottles or 200 ml_ pouches. Thesecould be sold at local hotels with minimum distribution cost. It is also possible to generate battery water salable at local petrol filling stations for automobiles.Thus, substantial of the sugarcane growing areas being water scarce, this recovered water becomes a premium value added by product of the sugarcane processing plant.
As shown in figure 4, the sugarcane juice evaporation is carried out in energy efficient multistage evaporators each stage of which is equipped with efficient two stage vapor liquid separators to separate droplets from evaporated water vapors. Each stage of the said multistage evaporator consists of a juice a falling film heat exchanger as shown in figure 4 having juice inlet pipe (1), shell (4), a juice distribution plate (2), vertical tubes (3), primary flash chamber (13), secondary cyclone separator (10), juice recirculation pump (7) and juice recirculation pipe line (9). The steam is supplied to shell of the falling film heat exchanger wherein the heat is transferred from steam to juice falling in form of a film through the inside of tubes. The vapor from the juice at boiling point temperature is separated bytwo stage vapor liquid separation process involving primary flash chamber (13) consisting of vapor space (5) and settling chamber(6) and secondary cyclone separator (10). The vapors separated in primary flash chamber are conveyed to secondary cyclone separator by duct (9). The droplets separated by secondary cyclone separator are returned to primary flash chamber through pipe (12) at bottom of secondary cyclone separator. The droplet free water vapors are conveyed to shell of next stage by duct (11). The vapors are condensed in various stages of multistage evaporators in the same cascading manner.
Variations Possible
1. Can be used for sugar making from various sources apart from sugarcane such as Sap collected from palm trees such as palmyra-palm (Borassusflabellifer L),

coconut palm (Cocosriucifera L), wild date-palm (Phoenix sylvestris L.), Sugar beet(Beta vulgaris) and sago palm (Caryotaurens L.)
2. The most optimum configuration of following options can be chosen to achieve best
steam economy while designing the Multistage Evaporator for juice concentration -
a. Number of stages
b. Type of heat exchanger design such as falling film evaporator, rising film
evaporator, forced circulation evaporator etc.
c. Forward feed or backward feed configuration
d. With or without thermo-compression depending on the motive steam
pressure and quantity
e. Cascade of preheaters depending on chosen configuration to improve
steam economy
f. Air Cooled Condenser or Water Cooled Condenser for condensation of the
steam evaporated in last stage remaining in excess after recovery in
preheaters.
3. The required quantity of steam is tapped from appropriate stage of evaporator and
it is supplied to preheater to achieve improved steam economy. The number and
operating conditions of preheaters are chosen depending on the chosen
configuration. For example, for forward feed arrangement, steam from each stage
is partly utilized for preheating purpose and the remaining is supplied to the
subsequent stage. In case of backward feed arrangement, steam from the last
stage only is utilized for preheating purpose and the rest is condensed in
condenser.
4. The recovered water can be treated to make it salable as packaged drinking water as per IS14543
5. The recovered water can be treated to make it salable as battery water for automobiles
ADVANTAGES OF THE PRESENT INVENTION:-
1. Saves bagasse
2. Recovers water of premium quality
3. Substantially improves economics of sugar mill by creating water as additional source of revenue.

WE CLAIM:-
1. An improved process of sugarcane juice evaporation and treatment of recovered
water for drinking purposes comprises steps:
a. In an integrated sugarcane processing first crushing of sugarcane in a
milling section;
b. Separating and sending the bagasse to cogeneration plant for steam
generation ;
c. extracts sugarcane juice and supplying for heating and evaporation;
d. heating and evaporating of juice of step(c ) in multi stage evaporates by the
steam of backpressure turbine exhaust supplied by the cogeneration plant
to separate water vapour from sugar syrup ;
e. Condensing the said water vapour of step (d) in a condenser;
f. to produce sugar (4) and byproduct molasses from the syrup of step (d);
g. Treating the condensed / distilled water of step (e) in packaged drinking
water plant for obtaining drinking water or treating the condensed water of
step (e) in demineralization plant for obtaining battery water.Distilling the
condensed water of step (e) in distillation plant or/and packaged driking
water plant for obtaining drinking/battery water.
2. A process as claimed in claim 1 wherein the said water of step (g) obtained from packaged drinking water plant is of as per IS 14543 in form of 1 liter bottles or 200 ml pouches or similar.
3. A process as claimed in claim 1 wherein the said water of step (g) obtained from distill waterDemineralization plant is of battery water grade.
4. An process as claimed in claim 1 wherein the said Multistage evaporators with each stage equipped with a two stage vapor liquid separators to separate droplets from evaporated water vapors Each stage consists of a juice a falling film heat exchanger having juice inlet pipe (1), shell (4), a juice distribution plate (2), vertical tubes (3), primary flash chamber (13), secondary cyclone separator (10), juice recirculation pump (7) and juice recirculation pipe line (9); The steam is supplied to shell of the falling film heat exchanger wherein the heat is transferred from steam

to juice falling in form of a film through the inside of tubes; The vapor from the juice at boiling point temperature is separated by two stage vapor liquid separation process involving primary flash chamber (13) consisting of vapor space (5) and settling chamber(6) and secondary cyclone separator (10); The vapors separated in primary flash chamber are conveyed to secondary cyclone separator by duct (9);The droplets separated by secondary cyclone separator are returned to primary flash chamber through pipe (12) at bottom of secondary cyclone separator; The droplet free water vapors / steam are conveyed to shell of next stage by duct (11); The vapors are condensed in various stages of multistage evaporators in the same cascading manner;