DESC:Field of invention
The present invention relates to sugar cane molasses or vinasse treatment systems and more particularly to an advanced sugar cane molasses or vinasse treatment system utilizing multiple effect evaporation and spray drying technique.

Background of the invention
India is known as one of the largest countries producing ethanol from molasses. Spent Wash is a liquid effluent and In India average spent wash generation is about 8-15Liters / Liter of alcohol produced. The spent wash is the bio-product used for treatment of distillery spent wash or Vinasse. It is a dark brown color liquid with an unpleasant odor.
There are various types of spent wash treatment systems available in art that independently perform the task of separating, collecting and retaining the contaminants/residue of the spent wash. In addition, development in the spent wash treatment systems has grown beyond imagination. In general, various types of spent wash treatment systems are available in the art and each of them has its own advantages and limitations.
However, treatment of spent wash is big challenge for distillery plants. Spent wash contain very hazardous product, which cannot release into water directly as it causes water pollution and air pollution. It requires comprehensive treatment to meet prescribed standards for effluent disposal. It is acidic effluent rich acidic and characterized by high BOD and COD. Currently available spent wash treatment systems demand high energy consumption for operation. Moreover, the currently known spent wash treatment systems are incompetent to prevent emissions and require high capital investments. Conventionally, existing systems demand high skilled staff for operation, maintenance and cleaning thereof. In particular, the spent wash treatment systems are complex in nature and involve additional components that lead to increase the overall cost of the spent wash treatment system.
Accordingly, there exists a need of an advanced spent wash treatment system that overcomes all the drawbacks of the prior art.
Objects of the invention
An object of the present invention is to provide an advanced spent wash treatment system that is economical and easy to operate.
Another object of the present invention is to provide an advanced spent wash treatment system which is capable of efficient disposal of waste water with low energy consumption.
Another object of the present invention is to provide an advanced spent wash treatment system without incineration of spent wash which gives potash with 5% of moisture.
Yet another object of the present invention is to provide an advanced spent wash treatment system which gives solid by- product or Potash after treatment is purely organic, non- hazardeous and eco-friendly.
Summary of the Invention
The present invention provides an advanced spent wash system that includes a first section, a second section, a third section and fourth section. The first section is a hot air generator system which is connected to the third section through ducting. The third section is a spray drying system wherein drying takes place. The second section is a feed system connected to the third section through a feed pipe. The third section is connected to the fourth section which is a collection system that collects byproducts of the process.
The first section includes a bunker, a fan, a combustion furnace, a primary settler, a secondary settler and a temperature controller unit. The bunker is a fuel bunker that provides fuel to the combustion furnace through a spreader. The fan is configured to blow air to the combustion furnace. The temperature controller unit is configured to maintain temperature of the combustion furnace at about 240 0C.
The second section includes a feed tank, a water funnel, a feed pump, a VFD flow controller and a temperature controller. The feed tank is provided with a steam jacket for increasing temperature and heating of the feed being maintained at 60 0C.
The third section includes a spray dryer chamber, an atomizer, a cyclone separator, a first and second rotary air lock valve and a variable frequency drive (VFD). The spray drying chamber is maintained under vacuum. The spray drying chamber receives hot air at 240 0C through an inlet thereof. The spray dryer chamber receives the feed slurry at 60 0C through the atomizer thereby contacting with the hot air at 240 0C thereby forming a mist such that hot air facilitates drying of the feed. The cyclone separator receives a mixture of hot air and fine product particles for separation of solid particles therefrom. The VFD is configured to control the speed of atomizer. The third section includes a wet scrubbing unit for scrubbing of dry powder particles escaped from the cyclone separator in a closed loop manner.
The fourth section has a conveying duct that pneumatically conveys dried spent wash powder collected through the first motorized rotary air lock valve of the spray dryer chamber and the second motorized rotary air lock valve of the cyclone separator. The dried spent wash powder separates from conveying air through a second cyclone separator. The fourth section includes a bag filter that arrests fine solid particles carried with conveying air. The fourth section operates under vacuum through an induced draft (ID) fan.
Brief description of the drawings
FIG. 1 shows block diagram for an advanced spent wash treatment system constructed in accordance with the present invention; and
FIG. 2 is a process flow diagram for the advanced spent wash treatment system of FIG.1.
Detailed Description of the invention
The foregoing objects of the present invention are accomplished, and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.
Accordingly, the present invention provides an advanced an advanced spent wash treatment system that is economical and utilizes very less energy consumption. The present invention also provides the advanced spent wash system that has very low maintenance, as it uses a less number of components to avoid complexity. The advanced spent wash system has very low maintenance and which is substantially easy to operate and clean.
Referring to FIG. 1, one preferred embodiment of an advanced spent wash/ Vinasse treatment system (1000) is shown. The advanced an advanced spent wash/ Vinasse include a first section (10), a second section (20), a third section (30) and fourth section (40). The first section (10) is a hot air generator system which is connected to the third section (30) through ducting. The third section (30) is a spray drying system wherein drying takes place. The second section (20) is a feed system connected to the third section (30) through a feed pipe. The third section (30) is connected to the fourth section (40) which is a collection system that collects byproducts of the process.
Referring to FIG. 1 and 2, the first section (10) is a hot air generator system that is designed to generate heat and it includes a bunker (100), a fan (110), a combustion furnace (120), a primary settler (130), a secondary settler (140) and a temperature controller unit (150). In an embodiment, the bunker (100) is a coal bunker that provides coal, wood chips and other fuel in the combustion furnace (120) through a spreader (125). In another embodiment, the bunker (100) is a bagasse feeder that provides bagasse and other fuel to the fluidized bed combustion furnace (120) which burns in the combustion furnace (120). The spreader (125) is a pneumatic spreader in this one embodiment however other types of spreader systems may be utilized in other alternative embodiments of the present invention. The fan (110) is a forced draft fan that is configured to blow the air to the combustion furnace (120) to increase the combustion which enters at atmospheric temperature of 30 0C through inlet pipe and heated at 240 0C before being channelized to the third section (30) which is a spray drying system. The temperature controller unit (150) is configured thereon to maintain temperature at 240 0C such that the ambient air at 300C is discharged if the temperature rises above 240 0C and the fan (110) blows and increase the combustion if temperature decreases below 240 0C. In one preferred embodiment, the first section (10) is designed such that it advantageously utilizes an exhaust boiler flue gas at 1400C along line 155 as a process air instead of ambient air at 300C thereby saving more than 50 % of heat energy required for process air. Accordingly, in this embodiment the system (1000) requires ?T of 100 0C to achieve the required temperature of 240 0C when the inlet temperature is at 140 0C in comparison to requirement of ?T of 210 0C to achieve the required temperature of 240 0C when the inlet temperature is at ambient temperature of 30 0C. In an embodiment, the temperature control unit (150) is operated manually however it is understood that the temperature control unit (150) may be operated automatically in other alternative embodiments of the present invention. The temperature controller unit (150) is configured to maintain the temperature at 240 0C at all the time during operation of the combustion furnace (120). The first section (10) is a hot air generator system that channelizes hot air at 240 0C to the third section (30) which is a spray drying section.
The second section (20) is a feed system that includes a feed tank (160), a water funnel (170), a feed pump (180), a VFD flow controller (190), a temperature controller (200). A bio methanated spent wash is allowed to flow to feed tank (160) through a feed pipe connected thereto. The feed tank (160) is provided with a steam jacket wherein the steam is allowed to enter to said jacket of the feed tank (160) to increase the temperature of the feed contained in the feed tank (160). The water funnel (170) is provided to feed water into the third section (30) only on the occasion of startup and shutdown of the third section (30) however the circulation of feed water through water funnel (170) is totally cut off during actual operation of the system (1000). The feed pump (180) is designed such that feed control is maintained by air outlet temperature such that if the outlet temperature increases then the feed flow is increased or alternatively if the outlet temperature decreased then accordingly the feed flow is decreased. In one preferred embodiment of the present invention, the set point of outlet air temperature is kept at 110 0C and the amount of feed to next section (30) which is a spray drying section varies by automatically varying speed of the feed pump (180) thereby varying frequency through VFD. Accordingly, the second section (20) is a feed system wherein the feed pump (180) is controlled through the VFD flow controller (190) such that flow control of the feed is maintained by air outlet temperature of the cyclone separator (210) of the third section (30) such that if the outlet temperature increases above 110 0C then flow of the feed is increased and if the outlet temperature decreases below 110 0C then the feed flow is decreased.
In the context of present invention, the feed slurry is channelized to third section (30) which is a spray drying section that includes a spray dryer chamber (210), an atomizer (220), a first cyclone separator (230), a rotary Air Lock Valve (240) and a variable frequency drive (VFD) (250). The spray drying chamber (210) is maintained under vacuum of -10 mm to -20 mm of water column (wc) using ID fan (308) which is a system driver of the process that facilitates passage of hot air through the entire system and hot air at 240 0C enters through an inlet thereof via an ID fan 208. The feed slurry enters to spray dryer chamber (210) through the atomizer (220) which comes in contact with the hot air maintained at 240 0C thereby forming a mist wherein hot air facilitates drying of the feed. A first motorized rotary air lock valve (240) is configured at the bottom to dispense dried spent wash powder from bottom of the spray dryer chamber (210) after drying thereof. The mixture of hot air and fine suspended by product particles is channelized to the first cyclone separator (230) for further separation of solid particles therefrom and the dried spent wash powder is collected through a second motorized rotary air lock valve (240). The VFD (250) is configured to the atomizer (220) to control the speed of atomizer. In this embodiment atomizer (220) operates in the range of 6000 rpm to 9000 rpm. However, it is understood that atomizers of other capacities may be used in other alternative embodiments of the present invention. The wet scrubbing unit (310) allows any dry powder escaping from the cyclone separation to enter the scrubbing unit (310) through an ID fan 308 and allowed to be washed with water spray in a close loop system and allowed to be collected in the bottom tank wherein the air/vapor is exhausted which has particle size below than 50 ppm which is as per standard of government set for air pollution. Hence, there is no air pollution and the water is recycled for further process.
The dried spent wash powder collected through the first motorized rotary air lock valve (240) at the bottom of the spray dryer chamber (210) and the second motorized rotary air lock valve (240) at the bottom of the cyclone separator (230) is conveyed to fourth section (40) through a pneumatic conveying system. This system consists of a conveying ducting (245) that conveys the dried spent wash powder and dried spent wash powder separates from the conveying air through a second cyclone separator (255). This section includes a bag filter (260), an air filter (270) and a packaging section (280). The bag filter (260) arrests the fine particles carried with conveying air and escaped from the cyclone separator (255). The fourth section (40) also includes a third air lock rotary valve, a fourth air lock rotary valve and a fifth air lock rotary valve (240) that are used to discharge product thereby avoiding contact with the atmospheric air entering from outside atmosphere in to the system (1000). A solenoid valve (290) is configured for giving pressurized pulsing of air and a centrifugal blower (300) is configured to exhaust the conveying air. The centrifugal blower (300) is driven by a TEFC motor through V belt and pulleys. The centrifugal blower (300) is statically and dynamically balanced. The centrifugal blower (300) is provided with anti-vibration pads, air flow control damper for regulating flow of air. In addition, compressed air passes through bag filter (260) at 6 kg/cm2 for cleaning purposes.
EXAMPLE- 1
For feed (spent wash) of 1900 kg/hr capacity which has
• water to solid ratio in proportion to 55% : 45%
• Q is 11,00,000 kcal/hr
• Inlet air Temperature 240 0C
• Outlet air temperature 110 0C
• Output product has 5% moisture
For the treatment of feed of (spent wash) of 1900 kg/hr capacity having water solid ratio in proportion of 55% : 45%, Q of 11,00,000 kcal/hr is required. Inlet temperature is maintained at 240 0C and the outlet air temperature is maintained at 110 0C. The output product which is obtained at the end contains following parameters.
Sr. No. Parameter Unit Value
1 pH (5% solution) - 07.43
2 Electric Conductivity (5% solution) mmhos/cm 13.82
3 Moisture 0% 04.06
4 Silica (on Dry basis) % 01.14
5 Organic Carbon (on Dry basis) % 32.10
6 C/N - 11.16
7 Total Nitrogen (on Dry basis) % 02.88
8 Phosperous % 02.52
9 Potassium % 21.50
10 Calcium % 02.92
11 Magnesium % 02.42
12 Sulphur % 02.40
13 Iron % 00.21
14 Manganese ppm 72.60
15 Zinc ppm 22.12
16 Copper ppm 10.33
17 Boron ppm 61.30
18 Molybdenum % <0.01
19 Aluminum % 00.16
20 Fluoride ppm 29.53

Advantages of the present invention-
1. The advanced spent wash treatment system produces the Potash which maintains all nutrients value.
2. The advanced spent wash treatment system maintains low temperature for drying to avoid losses of vitamins, nutrients.
3. The advanced spent wash treatment system reduces air pollution.
4. The advanced spent wash treatment system produces product (Potash) that is environment friendly, and non-hazardous to the environment.
5. The advanced spent wash treatment system produces the product (Potash) that is non-phototoxic to crops.
The foregoing description of specific members of the present invention has been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching.
The members were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others, skilled in the art to best utilize the present invention and various members with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the scope of the present invention.

,CLAIMS:We Claim:
1) An advanced spent wash treatment system comprising:
a first section (10) having a bunker (100), a fan (110), a combustion furnace (120), a primary settler (130), a secondary settler (140) and a temperature controller unit (150), the bunker (100) providing fuel to the combustion furnace (120) through a spreader (125), the fan (110) configured to blow air to the combustion furnace (120), the temperature controller unit (150) is configured to maintain temperature of the combustion furnace (120) at about 240 0C;
a second section (20) having a feed tank (160), a water funnel (170), a feed pump (180), a VFD flow controller (190) and a temperature controller (200), the feed tank (160) provided with a steam jacket for increasing temperature and heating the feed being maintained at 60 0C;
a third section (30) having a spray dryer chamber (210), an atomizer (220), a first cyclone separator (230), a first and second rotary air lock valve (240) and a variable frequency drive (VFD) (250), the spray drying chamber (210) being maintained under vacuum, the spray drying chamber (210) receiving hot air at 240 0C through an inlet thereof, the spray dryer chamber (210) receiving the feed slurry at 60 0C through the atomizer (220) thereby contacting the hot air at 240 0C thereby forming a mist such that hot air facilitating drying of the feed, the first cyclone separator (230) receiving a mixture of hot air and fine product particles for separation of solid particles therefrom, the VFD (250) is configured to control the speed of atomizer (220), the third section (30) having a wet scrubber (310) scrubbing unit (310) for scrubbing of dry powder particles escaping from the cyclone separator (230) in a closed loop manner; and
a fourth section (40) having a conveying duct (245) pneumatically conveying dried spent wash powder collected through the first motorized rotary air lock valve (240) of the spray dryer chamber (210) and the second motorized rotary air lock valve (240) of the cyclone separator (230), the dried spent wash powder separating from conveying air through a second cyclone separator (255), the fourth section (40) having a bag filter (260) arresting fine solid particles carried with conveying air, the fourth section (40) operating under vacuum through an induced draft (ID) fan, wherein
the first section (10) is a hot air generator section wherein an exhaust boiler flue gas is entered at 140 0C and heated up to 240 0C such that heat energy requirement is reduced to ?T of 100 0C from ?T of 210 0C thereby saving heat energy more than 50 %;
the second section (20) is a feed system wherein the feed pump (180) is controlled through the VFD flow controller (190) such that flow control of the feed is maintained by air outlet temperature of the cyclone separator (210) of the third section (30) such that if the outlet temperature increases above 110 0C then flow of the feed is increased and if the outlet temperature decreases below 110 0C then the feed flow is decreased; and
the spray drying chamber (210) is maintained under vacuum such that the air inlet temperature is maintained at 240 0C and air outlet temperature is maintained at 110 0C for effective drying of the feed.

2) The advanced spent wash system as claimed in claim 1, wherein the fan (110) is a forced draft fan that is configured to blow the air to the combustion furnace (120) to increase the combustion such that air enters at an atmospheric temperature of 30 0C and heated to a temperature of 240 0C before being channelized to the third section (30).

3) The advanced spent wash system as claimed in claim 1, wherein the bunker (100) is a fuel bunker that provides coal, wood chips and other fuel to the combustion furnace (120).

4) The advanced spent wash system as claimed in claim 1, wherein the bunker (100) is a bagasse feeder that provides bagasse and other fuel to the fluidized bed combustion furnace (120).

5) The advanced spent wash system as claimed in claim 1, wherein the water funnel (170) is provided to feed water into the system (1000) only on the occasion of startup and shutdown of the system (1000)

6) The advanced spent wash system as claimed in claim 1, wherein the feed entering to section (30) varies by automatically varying speed of the feed pump (180) thereby varying frequency thereof.

7) The advanced spent wash system as claimed in claim 1, wherein the first motorized rotary air lock valve (240) is configured at a bottom of the spray dryer chamber (210) to dispense dried spent wash powder therefrom.

8) The advanced spent wash system as claimed in claim 1, wherein the second motorized rotary air lock valve (240) is configured at a bottom of the cyclone separator (230) to dispense the dried spent wash powder therefrom.

9) The advanced spent wash system as claimed in claim 1, wherein the atomizer (220) has a speed ranging from 6000 to 9000 rpm.

10) The advanced spent wash system as claimed in claim 1, wherein the scrubber facilitates collection of products having particle size less than 50 ppm.