Title of Invention	AN IMPROVED DISTILLATION UNIT FOR PROCESSING AND HERBS FOR PRODUCING ESSENTIAL OILS AND ATTARS
Abstract	An improved distillation unit for processing flowers and herbs for producing essential oils and attars, characterized by a jacketed still having an length to diameter (L/D) ratio of 0.8-1.2, having a closable charge port in the top portion, a closable outlet at bottom and an opening at the top apex connected through a bend to a tapered gooseneck pipe, the tapered end of the said gooseneck pipe being connected to the inlet of a know shell and tube horizontal condenser, the outlet of the said condenser being connected to the inlet of a know vertical heat exchanger, the outlet of the said heat exchanger being connected through a pipe manifold provided with control valves to the top of two receiver vessels, one of the said receiver vessels being provided with an inlet pipe extending almost to the bottom and the other having an inlet pipe ending at the top

Title of Invention

AN IMPROVED DISTILLATION UNIT FOR PROCESSING AND HERBS FOR PRODUCING ESSENTIAL OILS AND ATTARS

Abstract

An improved distillation unit for processing flowers and herbs for producing essential oils and attars, characterized by a jacketed still having an length to diameter (L/D) ratio of 0.8-1.2, having a closable charge port in the top portion, a closable outlet at bottom and an opening at the top apex connected through a bend to a tapered gooseneck pipe, the tapered end of the said gooseneck pipe being connected to the inlet of a know shell and tube horizontal condenser, the outlet of the said condenser being connected to the inlet of a know vertical heat exchanger, the outlet of the said heat exchanger being connected through a pipe manifold provided with control valves to the top of two receiver vessels, one of the said receiver vessels being provided with an inlet pipe extending almost to the bottom and the other having an inlet pipe ending at the top

Full Text	This invention relates to "An Improved Distillation Unit For processing Flowers and Herbs for producing Essential Oils and Attars". Hssential oils and attars from (lowers and herbs such as Rose, Kcwda, Jasmine, Champa, Hina are traditionally produced in open fire heated copper stills. Kannauj, Agra, Ghajipur in UP, Keluapalli, Indrakshi, Tulu, Agraram in Ganjam district, Orissa and several other places in India are the places where the traditional 'Deg' method of distillation is extensively practiced even today for producing both essential oils and attars. Essentially, the technique is of water distillation. The main reason for adopting water distillation is because of the tendency of most of the floral materials to convert into glutinous mass under the action of steam, which prevents the volatile matter to come out. In the hitherto known distillation practice, the flowers and a requisite quantity of water are charged into a copper vessel ellipsoid in shape (Deg) provided with a cover or lid (snrpos)and connected to n heavily tinned receiver cum condenser (Bhnpkn) through a bamboo pipe (Chonga). Sealing is provided with clay and cotton and rags. The Bhapka is immersed in a pool of water and the still is heated using wood or cow dung cakes. The rate of distillation is controlled by the amount of iire and the condensation rate determined by the feel of touch by highly experienced workers. The distillate containing a major portion of water and a small quantity of oil are separated. The distillate water is either cohobated to recover more oil or is recycled into a subsequent batch. Attars are prepared in an analogous way by absorbing the vapours preferably in Sandalwood oil. Cheaper attars are prepared by absorbing the fragrance vapours in paraffin oil or dioctyl phthalate base. roblems ami drawbacks in the cxistiii}', method: 1. Due to complete closure ofllie system at the bcgiming itself,t hepressure inside the system increases considerably with heating resullin;; in leakages at several points and occasional blowing off of lid/chonga causing hazard besides loss of material. 2. Due to a relatively higher temperature and pressure of distillation, some of the essential oil components especially esters undergo hydrolysis while some terpene alcohols undergo molecular rearrangements producing an oil which is likely to be some what different in composition to the true essential oil. 3. The generated steam and oil vapours have to negotiate through a 10 mm dia opening of the bamboo uptake pipe suddenly from 350-400mm opening of the vessel. This causes considerable throttling in the vapour pipe and back pressure in the vessel resulting in rellux and condensation of higher boiling essential oil vapours into the still. 4. The rate of heating and hence the rate of distillation is difficult to control and is totally in the hands ofthe operator. 5. Due to direct heating ofthe Deg , at times there is localized overheating causing the plant material inside to get chaired imparting undesirable odour to the product. 6. Since essential oils/attars are known to react with copper, the bhapkas have to be heavily tinned every year before the distillation season starts. 7. Due to incomplete condensation and frequent change of receiver vessel during the course of distillation after temporarily cooling the 'Deg', considerable fragrance vapours escape resulting in loss of product and variability in yields. 8. The existing procedures/practices are not energy ellicient and consume a large quantity of lire wood/ fuel. 9. The existing procedures/practices are based mostly on experience and are rather an art than technology. In the hitherto known designs of essential oil distillation units the plant material is heated with water on a direct flame or the plant material is separated from the boiling water by means of a grid or it comes in direct contact with live steam. In all these methods, distillation is carried out relatively rapidly while dealing with herbaceous raw materials (0.3 - 2% Oil content). However, they are not particularly suitable for floral raw materials because the essence itself is present to a much smaller extent (0.01-0.1%) and the constituents also have relatively higher solubility in water. In yet other designs dealing with water-soluble floral oils, cohobation is carried out separately or cohobation columns are built-in the distillation unit itself to improve the recovery. However, these methods require prolonged distillation time needing reflux, which is known to cause alteration of the chemical constituents resulting in not true essential oils. The main object of the present invention is to provide an improved distillation unit for processing of flowers and herbs for producing essential oils and attars, which obviates the drawbacks on the hitherto known devices and methods as detailed above. Another object is to provide an improved distillation unit having a jacketed still with controlled temperature and pressure. Yet another object is to provide an improved distillation unit having a shell and tube condenser and a secondary heat exchanger. Still another object is to provide an improved distillation unit having two or more receivers to enable production of both essential oils and attars. In the present invention, the novelty resides in providing a device for production of both essential oils and attars. This has been made possible through the inventive step of heating of the plant material and water through jacket heating, wherein the jacketed cylindrical still has an length to diameter (L/D) ratio of 0.8-1.2, with water above its normal boiling point at the desired temperature. Due to this, not only the rate of heating and hence the rate of distillation is controlled, but the distilling vapor also is not allowed to undergo reflux. The plant material is subjected to heat treatment for the minimum amount of time possible. By recycling the distillation water into a subsequent batch, yields not only are improved by at least 20% but also the water soluble components are subjected to minimum heat exposure. The vapours generated from the above said jacketed still are passed through a condenser and heat exchanger through an inventive step of manifold and receiver vessels with suitable control valves. In the present invention, the distillation unit consists of a jacketed still which can be heated either with water in the jacket at 100-130°C obtained by direct heat on fire in a traditional or fuel efficient improved kiln using firewood or coal or gas. Alternatively steam generated from a boiler can be used for heating the still. Suitable metering and control devices are provided to the jacket and still to control temperature and pressure of the jacket fluid and the distillation rate. The vapour uptake pipe is a short and a gradually tapering gooseneck due to which throttling and backpressure do not occur and recoveries are improved. The vapours are first passed through a horizontal shell and tube condenser and the condensate through a second heat exchanger to cool the condensate further to ambient temperature. By venting out all the initial air present in the still through a vent in the receiver vessel, the distillation takes place at atmospheric pressure and at slightly lower than 100°C , thus causing much less deterioration of the product. As the jacket is always at a higher temperature it prevents reflux of the water and oil vapours. By controlling the temperature and pressure of the water in the jacket through control and metering devices, the rate of heat and hence of rate of distillation can be easily controlled. Since the heating of plant material is indirect through jacket water, the plant material is not overheated and the product is of a very good olfactory value devoid of burnt odours. All the parts of equipment which come in contact with either plant material or vapours or distillate are made of non-corrosive material such as AISI 304 stainless steel to obtain a product which is colourless to light yellow. The fuel consumption also is much less due to shorter distillation period. The still is provided with two openings: one for charging plant material and removal of spent material and the other for vapour uptake. The vapour uptake is permanently fitted with gooseneck and need not be disturbed excepting for maintenance. This avoids considerable labour in fixing them daily. Only the lid of the charging port needs to be opened and closed at the time of each batch of distillation making the entire operation simple and easy. By making suitable manipulation of the receiving vessel through a manifold the system can be used for producing both essential oils and attars from kewda or other floral raw materials. In Figl of the drawing accompanying this specification, a schematic of an embodiment of the improved distillation unit of the present invention is depicted. As shown in the accompanying drawing, the improved distillation unit consists of 1. A jacketed cylindrical still (1) made up of non-corrosive material such as AISI 304 S.S with an L/D ratio of 0.8 to 1.2 and provided with two openings at the top one for charging and removing plant material and other for mounting the vapour uptake pipe (4). The vessel is also provided with an outlet at the bottom (16) for removing water. The vessel is further provided with meters to measure pressure and temperature. 2. The jacket (2) is provided with inlet and outlet for introducing water/ steam and a water level indicator (17). Further metering devices for measuring temperature, pressure and an adjustable pressure safety valve to control temperature and pressure of the heating water/ steam are provided. The jacketed still can be mounted on a traditional or improved fuel-efficient brick kiln, which can burn firewood, coal or LPG. 3. The vapour uptake pipe (4) is a short pipe, which bends and tapers into a gooseneck (5) and is connected to a shell and tube horizontal condenser (8) for condensation of vapours through a union joint (7) and a ball valve (6). 4. The bottom end of the condenser is connected via a union joint (9) to another heat exchanger (10) for cooling the distillate to ambient temperature. 5. The heat exchanger (10) is connected through a manifold to two 10-40 liters capacity cylindrical receiver vessels (13 and 14) through a S.S. pipe (12) via another union joint (11). The S.S pipe in one of the receivers (13) reaches up to 10 cm from the bottom so that it can be used for collecting secondary distillate as well as for absorbing vapors in base oil such as sandalwood oil for attar making. The other vessel (14) is meant for collecting the primary distillate during the production of essential oil (rooh). The receiver vessels are provided with vent valves at the top for removing air from the system during distillation and level indicators (15) and bottom drain outlets. The charging port of the still is provided with a lid (3), which closes it through a neoprene gasket sealing and quick fastening screw and nut arrangement. Accordingly the present invention provides an improved distillation unit for processing flowers and herbs for producing essential oils and attars, characterized by a jacketed still(12) having an length to diameter (L/D) ratio of 0.8-1.2, having a closable charge port in the top portion, a closable outlet at bottom and an opening at the top apex connected through a bend to a tapered gooseneck pipe(5), the tapered end of the said gooseneck pipe(5) being connected to the inlet of a know shell and tube horizontal condenser(S), the outlet of the said condenser(S) being connected to the inlet of a known vertical heat exchanger(lO), the outlet of the said heat exchanger(lO) being connected through a pipe manifold provided with control valves to the top of two receiver vessels, one of the said receiver vessels being provided with an inlet pipe extending almost to the bottom and the other having an inlet pipe ending at the top. In an embodiment of the present invention, the jacketed still is provided with inlet and outlet for water/steam, water level indicator, and adjustable pressure safety valve, temperature and pressure indicators. In another embodiment of the present invention the receiver vessels are provided with vent valves at the top, liquid level indicators and bottom drain outlets. The novelty of the device of the present invention resides in being able to produce essential oils and attars as per requirement. An inventive step of the present invention lies with the indirect heating of the plant material either with hot water above its normal boiling point or with steam. By heating the jacket water in a close system with metering and safety devices, its pressure and temperature can be regulated and hence the rate of distillation. In case of recovery from flowers of essential oils, which are relatively more soluble in water, rate of distillation is a very important parameter and must be carefully regulated. The novel heating system comprising jacketed still having L/D ratio of 0.8-1.2 of the present invention makes it suitable for use with a conventional or modified kiln without use of a boiler as an option. A second inventive step is the provision of a separate port for charging and removing plant materials and is separated from the vapour uptake and connecting accessories. This makes the operation very simple suitable for working under field conditions. A third inventive step resides in the use of a secondary heat exchanger enabling the condensate to cool to ambient temperature and collecting through a manifold having control valves, the said manifold being connected to two receiver vessels so that the distillate can be collected in fractions as desired without discontinuing the distillation, which results in improved yields of the product. The novel distillation unit of the present invention allows for processing flowers and herbs for producing essential oils and attars by the means of heating of plant material with water/steam through controlled and indirect heating that enables distillation rate to be precisely controlled making it possible to obtain higher recoveries of fragrance material especially from flowers through simplified operation of the device suitable for work under field conditions. Further, the unit allows fractionation of the distillate through use of dual receivers and higher recoveries of essential oil due to better cooling by two heat exchangers, the horizontal condenser and vertical heat exchanger. The following examples are given by way of illustration of the practical use of the improved distillation unit of the present invention and should not be construed to limit the scope of the present invention. Example 1 50 Kg of Kewda (Pandanus fascicularls) flowers and 125 litres of good quality water are charged into the inner vessel of the still through the charging port and it is closed. The jacket is filled with about 160 litres of water and is heated quickly on a fuel efficient kiln with firewood or coal or LPG. In about an hour, the contents of the jacket reach a temperature of 100°C. When most of the air in the jacket is removed, it is closed and jacket water temperature is allowed to rise to about 112°C and maintained by controlling the rate of firing the kiln. By this time, the water along with fragrance from the still starts distilling slowly and attains a rate of about 6 litres per hour. When about 6 liters of first distillate are collected in the first vessel, the receiver is changed through the manifold and the second distillate is collected in the other receiver. About 10 liters of distillate are collected in the second vessel and yet a third distillate of about 20 litres is collected through fast distillation. After separating most of the bottom water layer from the first distillate by draining through bottom outlet, the oily and water layers are transferred to a glass separating funnel from which about 13 mL of the essential oil is collected. No essential oil is recoverable from the 2nd and 3rd distillates. Example 2 50 Kg of Kewda (Pandanus fascicularis) flowers and 100 litres of good quality water and the water distillate after separating the essential oil from the previous batch of operation are charged into the inner vessel of the still through the charging port and it is closed. The jacket is is heated quickly as in the previous batch and about 8 litres of first distillate is collected during the first hour. The receiver is changed through the manifold and 10 litres of the second distillate is collected in the other receiver again. A third distillate of about 20 litres also is collected through fast distillation. Processing of the first distillate as in the previous batch provides about 24 ml of essential oil. An equilibrium is established from the 3rd batch onwards and repetition of the process further provides 30 ml of the expensive essential oil depending on the quality of the flowers. This yield is in far excess of the yield obtained in the existing practice. Example3 In the case of production of attars: after collecting the first distillate as described in examples 1 and 2, the 2nd and 3rd distillates were allowed to be collected over 5 Kg of sandalwood oil till it was harmonized. After this initial processing, first distillate from 5000 fresh flowers was collected over the harmonized oil to get the 'Ek hazara' grade of attar. Kewda attars are graded based on the number of thousands of flowers used for absorbing the fragrance per kilogram of adsorbent oil. Example 4 In the case of production of attars: after collecting the first distillate as described in examples 1 and 2, the 2nd and 3rd distillates were allowed to be collected over 5 Kg of DOP (Dioctyl phthalate) oil till it was harmonized. After this initial processing, first distillate from 5000 fresh flowers was collected over the harmonized oil to get the 'Ek hazara' grade of attar. Kewda attars are graded based on the number of thousands of flowers used for absorbing the fragrance per kilogram of adsorbent oil. We Claim: 1. An improved distillation unit for processing flowers and herbs for producing essential oils and attars, characterized by a jacketed still(12) having an length to diameter (L/D) ratio of 0.8-1.2, having a closable charge port in the top portion, a closable outlet at bottom and an opening at the top apex connected through a bend to a tapered gooseneck pipe(5), the tapered end of the said gooseneck pipe(5) being connected to the inlet of a known shell and tube horizontal condenser(S), the outlet of the said condenser(S) being connected to the inlet of a know vertical heat exchanger(10), the outlet of the said heat exchanger(10) being connected through a pipe manifold provided with control valves to the top of two receiver vessels(13,14), one of the said receiver vessels being provided with an inlet pipe extending almost to the bottom and the other having an inlet pipe ending at the top. 2. An improved distillation unit as claimed in claim 1 wherein the jacketed still is provided with inlet and outlet for water/steam, water level indicator, adjustable pressure safety valve, temperature and pressure indicators. 3. An improved distillation unit as claimed in claims 1 wherein the receiver vessels are provided with vent valves at the top, liquid level indicators and bottom drain outlets. 4. An improved distillation unit for processing flowers and herbs for producing essential oils and attars, substantially as herein described with reference to the drawing accompanying this specification and examples.

Full Text

This invention relates to "An Improved Distillation Unit For processing Flowers and Herbs for producing Essential Oils and Attars".
Hssential oils and attars from (lowers and herbs such as Rose, Kcwda, Jasmine, Champa, Hina are traditionally produced in open fire heated copper stills. Kannauj, Agra, Ghajipur in UP, Keluapalli, Indrakshi, Tulu, Agraram in Ganjam district, Orissa and several other places in India are the places where the traditional 'Deg' method of distillation is extensively practiced even today for producing both essential oils and attars. Essentially, the technique is of water distillation. The main reason for adopting water distillation is because of the tendency of most of the floral materials to convert into glutinous mass under the action of steam, which prevents the volatile matter to come out.
In the hitherto known distillation practice, the flowers and a requisite quantity of water are charged into a copper vessel ellipsoid in shape (Deg) provided with a cover or lid (snrpos)and connected to n heavily tinned receiver cum condenser (Bhnpkn) through a bamboo pipe (Chonga). Sealing is provided with clay and cotton and rags. The Bhapka is immersed in a pool of water and the still is heated using wood or cow dung cakes. The rate of distillation is controlled by the amount of iire and the condensation rate determined by the feel of touch by highly experienced workers. The distillate containing a major portion of water and a small quantity of oil are separated. The distillate water is either cohobated to recover more oil or is recycled into a subsequent batch. Attars are prepared in an analogous way by absorbing the vapours preferably in Sandalwood oil. Cheaper attars are prepared by absorbing the fragrance vapours in paraffin oil or dioctyl phthalate base.
roblems ami drawbacks in the cxistiii}', method:
1. Due to complete closure ofllie system at the bcgiming itself,t hepressure inside the
system increases considerably with heating resullin;; in leakages at several points and
occasional blowing off of lid/chonga causing hazard besides loss of material.
2. Due to a relatively higher temperature and pressure of distillation, some of the
essential oil components especially esters undergo hydrolysis while some terpene
alcohols undergo molecular rearrangements producing an oil which is likely to be
some what different in composition to the true essential oil.
3. The generated steam and oil vapours have to negotiate through a 10 mm dia opening
of the bamboo uptake pipe suddenly from 350-400mm opening of the vessel. This
causes considerable throttling in the vapour pipe and back pressure in the vessel
resulting in rellux and condensation of higher boiling essential oil vapours into the
still.
4. The rate of heating and hence the rate of distillation is difficult to control and is
totally in the hands ofthe operator.
5. Due to direct heating ofthe Deg , at times there is localized overheating causing the
plant material inside to get chaired imparting undesirable odour to the product.
6. Since essential oils/attars are known to react with copper, the bhapkas have to be
heavily tinned every year before the distillation season starts.
7. Due to incomplete condensation and frequent change of receiver vessel during the
course of distillation after temporarily cooling the 'Deg', considerable fragrance
vapours escape resulting in loss of product and variability in yields.
8. The existing procedures/practices are not energy ellicient and consume a large
quantity of lire wood/ fuel.
9. The existing procedures/practices are based mostly on experience and are rather an art
than technology.
In the hitherto known designs of essential oil distillation units the plant material is heated with water on a direct flame or the plant material is separated from the boiling water by means of a grid or it comes in direct contact with live steam. In all these methods, distillation is carried out relatively rapidly while dealing with herbaceous raw materials (0.3 - 2% Oil content). However, they are not particularly suitable for floral raw materials because the essence itself is present to a much smaller extent (0.01-0.1%) and the constituents also have relatively higher solubility in water. In yet other designs dealing with water-soluble floral oils, cohobation is carried out separately or cohobation columns are built-in the distillation unit itself to improve the recovery. However, these methods require prolonged distillation time needing reflux, which is known to cause alteration of the chemical constituents resulting in not true essential oils.
The main object of the present invention is to provide an improved distillation unit for processing of flowers and herbs for producing essential oils and attars, which obviates the drawbacks on the hitherto known devices and methods as detailed above.
Another object is to provide an improved distillation unit having a jacketed still with controlled temperature and pressure.
Yet another object is to provide an improved distillation unit having a shell and tube condenser and a secondary heat exchanger.
Still another object is to provide an improved distillation unit having two or more receivers to enable production of both essential oils and attars.
In the present invention, the novelty resides in providing a device for production of both essential oils and attars. This has been made possible through the inventive step of heating of the plant material and water through jacket heating, wherein the jacketed cylindrical still has an length to diameter (L/D) ratio of 0.8-1.2, with water above its normal boiling point at the desired temperature. Due to this, not only the rate of heating and hence the rate of distillation is controlled, but the distilling vapor also is not allowed to undergo reflux. The plant material is subjected to heat treatment for the minimum amount of time possible. By recycling the distillation water into a subsequent batch, yields not only are improved by at least 20% but also the water soluble components are subjected to minimum heat exposure. The vapours generated from the above said jacketed still are passed through a condenser and heat exchanger through an inventive step of manifold and receiver vessels with suitable control valves.
In the present invention, the distillation unit consists of a jacketed still which can be heated either with water in the jacket at 100-130°C obtained by direct heat on fire in a traditional or fuel efficient improved kiln using firewood or coal or gas. Alternatively steam generated from a boiler can be used for heating the still. Suitable metering and control devices are provided to the jacket and still to control temperature and pressure of the jacket fluid and the distillation rate.
The vapour uptake pipe is a short and a gradually tapering gooseneck due to which throttling and backpressure do not occur and recoveries are improved.
The vapours are first passed through a horizontal shell and tube condenser and the condensate through a second heat exchanger to cool the condensate further to ambient temperature. By venting out all the initial air present in the still through a vent in the receiver vessel, the distillation takes place at atmospheric pressure and at slightly lower than 100°C , thus causing much less deterioration of the product. As the jacket is always at a higher temperature it prevents reflux of the water and oil vapours.
By controlling the temperature and pressure of the water in the jacket through control and metering devices, the rate of heat and hence of rate of distillation can be easily controlled. Since the heating of plant material is indirect through jacket water, the plant material is not overheated and the product is of a very good olfactory value devoid of burnt odours.
All the parts of equipment which come in contact with either plant material or vapours or distillate are made of non-corrosive material such as AISI 304 stainless steel to obtain a product which is colourless to light yellow. The fuel consumption also is much less due to shorter distillation period.
The still is provided with two openings: one for charging plant material and removal of spent material and the other for vapour uptake. The vapour uptake is permanently fitted with gooseneck and need not be disturbed excepting for maintenance. This avoids considerable labour in fixing them daily. Only the lid of the charging port needs to be opened and closed at the time of each batch of distillation making the entire operation simple and easy.
By making suitable manipulation of the receiving vessel through a manifold the system can be used for producing both essential oils and attars from kewda or other floral raw materials.
In Figl of the drawing accompanying this specification, a schematic of an embodiment of the improved distillation unit of the present invention is depicted.
As shown in the accompanying drawing, the improved distillation unit consists of 1. A jacketed cylindrical still (1) made up of non-corrosive material such as AISI 304 S.S with an L/D ratio of 0.8 to 1.2 and provided with two openings at the top one for charging and removing plant material and other for mounting the vapour uptake pipe (4). The vessel is also provided with an outlet at the bottom (16) for removing water. The vessel is further provided with meters to measure pressure and temperature. 2. The jacket (2) is provided with inlet and outlet for introducing water/ steam and a water level indicator (17). Further metering devices for measuring temperature, pressure and an adjustable pressure safety valve to control temperature and pressure of the heating water/ steam are provided. The jacketed still can be mounted on a traditional or improved fuel-efficient brick kiln, which can burn firewood, coal or LPG.
3. The vapour uptake pipe (4) is a short pipe, which bends and tapers into a gooseneck
(5) and is connected to a shell and tube horizontal condenser (8) for condensation of
vapours through a union joint (7) and a ball valve (6).
4. The bottom end of the condenser is connected via a union joint (9) to another heat
exchanger (10) for cooling the distillate to ambient temperature.
5. The heat exchanger (10) is connected through a manifold to two 10-40 liters capacity cylindrical receiver vessels (13 and 14) through a S.S. pipe (12) via another union joint (11). The S.S pipe in one of the receivers (13) reaches up to 10 cm from the bottom so that it can be used for collecting secondary distillate as well as for absorbing vapors in base oil such as sandalwood oil for attar making. The other vessel (14) is meant for collecting the primary distillate during the production of essential oil (rooh). The receiver vessels are provided with vent valves at the top for removing air from the system during distillation and level indicators (15) and bottom drain outlets.
The charging port of the still is provided with a lid (3), which closes it through a neoprene gasket sealing and quick fastening screw and nut arrangement.
Accordingly the present invention provides an improved distillation unit for processing flowers and herbs for producing essential oils and attars, characterized by a jacketed still(12) having an length to diameter (L/D) ratio of 0.8-1.2, having a closable charge port in the top portion, a closable outlet at bottom and an opening at the top apex connected through a bend to a tapered gooseneck pipe(5), the tapered end of the said gooseneck pipe(5) being connected to the inlet of a know shell and tube horizontal condenser(S), the outlet of the said condenser(S) being connected to the inlet of a known vertical heat exchanger(lO), the outlet of the said heat exchanger(lO) being connected through a pipe manifold provided with control valves to the top of two receiver vessels, one of the said receiver vessels being provided with an inlet pipe extending almost to the bottom and the other having an inlet pipe ending at the top.
In an embodiment of the present invention, the jacketed still is provided with inlet and outlet for water/steam, water level indicator, and adjustable pressure safety valve, temperature and pressure indicators.
In another embodiment of the present invention the receiver vessels are provided with vent valves at the top, liquid level indicators and bottom drain outlets.
The novelty of the device of the present invention resides in being able to produce essential oils and attars as per requirement. An inventive step of the present invention lies with the indirect heating of the plant material either with hot water above its normal boiling point or with steam. By heating the jacket water in a close system with metering and safety devices, its pressure and temperature can be regulated and hence the rate of distillation. In case of recovery from flowers of essential oils, which are relatively more soluble in water, rate of distillation is a very important parameter and must be carefully regulated. The novel heating system comprising jacketed still having L/D ratio of 0.8-1.2 of the present invention makes it suitable for use with a conventional or modified kiln without use of a boiler as an option.
A second inventive step is the provision of a separate port for charging and removing plant materials and is separated from the vapour uptake and connecting accessories. This makes the operation very simple suitable for working under field conditions.
A third inventive step resides in the use of a secondary heat exchanger enabling the condensate to cool to ambient temperature and collecting through a manifold having control valves, the said manifold being connected to two receiver vessels so that the
distillate can be collected in fractions as desired without discontinuing the distillation, which results in improved yields of the product.
The novel distillation unit of the present invention allows for processing flowers and herbs for producing essential oils and attars by the means of heating of plant material with water/steam through controlled and indirect heating that enables distillation rate to be precisely controlled making it possible to obtain higher recoveries of fragrance material especially from flowers through simplified operation of the device suitable for work under field conditions. Further, the unit allows fractionation of the distillate through use of dual receivers and higher recoveries of essential oil due to better cooling by two heat exchangers, the horizontal condenser and vertical heat exchanger.
The following examples are given by way of illustration of the practical use of the improved distillation unit of the present invention and should not be construed to limit the scope of the present invention.
Example 1
50 Kg of Kewda (Pandanus fascicularls) flowers and 125 litres of good quality water are charged into the inner vessel of the still through the charging port and it is closed. The jacket is filled with about 160 litres of water and is heated quickly on a fuel efficient kiln with firewood or coal or LPG. In about an hour, the contents of the jacket reach a temperature of 100°C. When most of the air in the jacket is removed, it is closed and jacket water temperature is allowed to rise to about 112°C and maintained by controlling the rate of firing the kiln. By this time, the water along with fragrance from the still starts distilling slowly and attains a rate of about 6 litres per hour. When about 6 liters of first distillate are collected in the first vessel, the receiver is changed through the
manifold and the second distillate is collected in the other receiver. About 10 liters of distillate are collected in the second vessel and yet a third distillate of about 20 litres is collected through fast distillation. After separating most of the bottom water layer from the first distillate by draining through bottom outlet, the oily and water layers are transferred to a glass separating funnel from which about 13 mL of the essential oil is collected. No essential oil is recoverable from the 2nd and 3rd distillates.
Example 2
50 Kg of Kewda (Pandanus fascicularis) flowers and 100 litres of good quality water and the water distillate after separating the essential oil from the previous batch of operation are charged into the inner vessel of the still through the charging port and it is closed. The jacket is is heated quickly as in the previous batch and about 8 litres of first distillate is collected during the first hour. The receiver is changed through the manifold and 10 litres of the second distillate is collected in the other receiver again. A third distillate of about 20 litres also is collected through fast distillation. Processing of the first distillate as in the previous batch provides about 24 ml of essential oil. An equilibrium is established from the 3rd batch onwards and repetition of the process further provides 30 ml of the expensive essential oil depending on the quality of the flowers. This yield is in far excess of the yield obtained in the existing practice.
Example3
In the case of production of attars: after collecting the first distillate as described in examples 1 and 2, the 2nd and 3rd distillates were allowed to be collected over 5 Kg of sandalwood oil till it was harmonized. After this initial processing, first distillate from 5000 fresh flowers was collected over the harmonized oil to get the 'Ek hazara' grade of
attar. Kewda attars are graded based on the number of thousands of flowers used for absorbing the fragrance per kilogram of adsorbent oil.
Example 4
In the case of production of attars: after collecting the first distillate as described in examples 1 and 2, the 2nd and 3rd distillates were allowed to be collected over 5 Kg of DOP (Dioctyl phthalate) oil till it was harmonized. After this initial processing, first distillate from 5000 fresh flowers was collected over the harmonized oil to get the 'Ek hazara' grade of attar. Kewda attars are graded based on the number of thousands of flowers used for absorbing the fragrance per kilogram of adsorbent oil.

We Claim:
1. An improved distillation unit for processing flowers and herbs for producing essential oils
and attars, characterized by a jacketed still(12) having an length to diameter (L/D) ratio of
0.8-1.2, having a closable charge port in the top portion, a closable outlet at bottom and an
opening at the top apex connected through a bend to a tapered gooseneck pipe(5), the
tapered end of the said gooseneck pipe(5) being connected to the inlet of a known shell and
tube horizontal condenser(S), the outlet of the said condenser(S) being connected to the inlet
of a know vertical heat exchanger(10), the outlet of the said heat exchanger(10) being
connected through a pipe manifold provided with control valves to the top of two receiver
vessels(13,14), one of the said receiver vessels being provided with an inlet pipe extending
almost to the bottom and the other having an inlet pipe ending at the top.
2. An improved distillation unit as claimed in claim 1 wherein the jacketed still is provided
with inlet and outlet for water/steam, water level indicator, adjustable pressure safety valve,
temperature and pressure indicators.
3. An improved distillation unit as claimed in claims 1 wherein the receiver vessels are
provided with vent valves at the top, liquid level indicators and bottom drain outlets.
4. An improved distillation unit for processing flowers and herbs for producing essential oils
and attars, substantially as herein described with reference to the drawing accompanying
this specification and examples.

Documents:

1087-del-2001-abstract.pdf

1087-del-2001-claims.pdf

1087-del-2001-correspondence-others.pdf

1087-del-2001-correspondence-po.pdf

1087-del-2001-description (complete).pdf

1087-del-2001-drawings.pdf

1087-del-2001-form-1.pdf

1087-del-2001-form-18.pdf

1087-del-2001-form-2.pdf

1087-del-2001-form-3.pdf

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Patent Number

220780

Indian Patent Application Number

1087/DEL/2001

PG Journal Number

30/2008

Publication Date

25-Jul-2008

Grant Date

05-Jun-2008

Date of Filing

30-Oct-2001

Name of Patentee

COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH

Applicant Address

Inventors:

#	Inventor's Name	Inventor's Address
1	PRATAP KUMAR DASH
2	HEM SHANKAR RAY
3	MADHAB RANJAN PANIGRAHI
4	JOSYULA SAMBA MURTY
5	SNEHASIS BEHERA
6	YERRAMILLI RAMACHANDRA RAO

PCT International Classification Number

C11B 1/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA