4. DESCRIPTION:
FIELD OF INVENTION
This invention relates to a Naga King Chilli dryer that is used to dry Naga King
Chillies in whole form. This dryer requires no human intervention to the chillies
during the drying process and is thus safe for the operator to dry such high heat
content chillies. The dryer is suitable for high volume drying of Naga King
Chilies by heated air obtained from indirect heating.
BACKGROUND OF THE INVENTION
Amongst Chillies, the-Naga King Chilli variety grows extensively in the plain and
hilly regions of North-East part of India. The Naga King Chilli has been declared
as the hottest chilli in the world by the Chilli Peeper Institute, New Mexico state
University. Naga King Chilli has nearly 1,001,300 Scoville heat Unit (SHU)
whereas the red Savina habanero Chilli (once upon a time considered, to be the
hottest chilli) from Mexico has nearly 5,80,000 SHU. Naga King Chilli in ripe
state is very tender and highly perishable and has moisture content is in the range
of 80% to 85% by wt. The shape of Naga King Chilli is conical inside hollow
with base diameter between 20 to 30 mm and length between 50-80 mm with
wavy surface. Naga King Chilli is also known as Bhut Jolokia (in Assamese) and
Raja Mircha (in Hindi). The Naga King Chilli has also been registered as a
Geographical Indication (GI) No. 109 by the GI Registry.
Drying of fresh Naga King Chillies is done to preserve the chillies for storage
and hence its export. For drying, it is necessary to reduce the moisture content of
the chillies below 10% to stop bacteria growth and facilitate longer storage period.
This is a major activity in the Naga King Chilli industry. There are two harvesting
seasons for Naga King Chilli- summer harvesting from May to August in plain
regions and winter harvesting from September to December in hilly regions.
There are three methods in practice for drying freshly harvested ripe Naga King
Chillies-
a) Sun Drying; This is a traditional method. Here, fresh ripe Naga King Chillies
are spread evenly on bamboo mats or concrete floor or G.I. net trays under

scorching heat of the sun for 7 to 10 days for drying. This method is in
practice in summer harvesting season. Sun drying is an outdoor activity. So,
cloudy weather may increase the drying time and labour involvement.
Besides, accumulation of dirt is another factor. Moreover, the colour fades
and below 10% moisture level drying is hardly achieved. This leads to
bacterial growth when stored. Sundried Naga King Chillies have less demand
in consumer market due to low quality from the above mentioned facts.
Again, regular handling of Naga King Chillies during sun drying is very
cumbersome job due to high heat value & high pungency.
b) Smoke Drying: This is another traditional method. Here, fresh-ripe Naga
King Chillies are spread evenly on wire mesh trays and fire is lit below the
trays using wood or bamboo roots. Trays are kept at a sufficient height so that
fire cannot reach fhe bottom of the trays but the smoke does. Fresh chillies are
exposed to the hot air and smoke with intermittent handling. It normally takes
72-84 hours to reach sufficient drying for storage. This method is in practice
in hilly regions during winter harvesting. The drawbacks of this method are-
even drying is hardly achieved, the red colour blackens with carbon
deposition, they cannot be stored for a long time, there is less market demand,
damages to the whole form of chillies usually take place during drying and
Aflatoxin may grow in storage from moulds.
c) Machine Drying: The commercially available conventional batch dryers use
single truck or double trucks and trays, inside an insulated housing using
parallel hot air flow over the static bed of Naga King Chillies, using 8-18 kw
electric load for heating air along with the blower, in a closed circuit hot air
recirculating system. It takes 18-24 hrs. to obtain below 10% moisture content
of the chillies. However, the machine dryers have many drawbacks-
i. In case of power failure, running the dryer in secondary power sources- i.e.
mostly diesel based electric generators, makes the cost of production high.
ii. Minimum one time intermittent handling of half dry Naga King Chillies is
required for even drying. Heat loss takes place while opening the cabinet
door or trays for intermittent handling of chillies. Again, handling of half

dry Naga King Chillies is a very tedious job due its very high and pungent
vapour and is also time consuming and labour intensive.
iii. As the Naga King Chilli is very bulky in nature, the conventional dryers
always run in under capacity utilization than the design capacity that
hampers quantity of production.
iv. Reference may be made to the patent no US-3362081, "Cabinet Dryer and
Method" wherein upright hose dryer has a chamber with perforated bottom
and top walls and a re-circulated dust structure in a sidewall having an
impeller to draw moisture laden air through said top wall, expel part of such
air and re-circuTate The reminder of the air through the bottom wall,. Fresh
air is added to the1 re-circulated air and the mixture is heated. But here, the
air and rate of drying is very slow and under capacity utilization for drying
fresh ripe Naga King Chillies is whole form.
v. Another reference thay be made to patent no. IN 10868 "Cabinet Dryer for
Ginger and Turmeric" wherein hot air from the bottom heating chamber
moves up through the perforation in the trays and also through the channels
in a zigzag way and interacts with the sliced ginger or turmeric (freshly
harvested) to be dried, before it leaves the dryer. An exhaust fan is mounted
at the top of the chamber sucks moisture laden air out from the chamber.
But here, the materials of the bottom trays dry earlier than the top trays
because upcoming hot air losses heat and gradually reaches near saturation
and so uniform drying is not possible. If the trays are loaded with more
slices, the perforation through the trays is restricted and the hot air passing
through the channels increases drying time as well as leads to uneven
drying.
But in this dedicated Naga King Chilli Dryer, the chillies are dried to <10%
moisture content with indirectly heated air from both the top and the bottom
through airflow provided by a single Draft Fan in a closed cabinet. It requires no
physical handling of the chillies during drying and also can be used in remote
plain or hilly regions where there is just single phase or no electricity.

OBJECT OF THE INVENTION
The principal object of the invention is to provide a Naga King Chilli dryer for
drying of Naga King Chillies to <10% moisture content with indirect heating.
Another object of the present invention is to provide a Naga King Chilli dryer that
requires no handling of Naga King Chillies during the drying process.
Another object of the present invention is to provide a Naga King Chilli dryer
which can run on domestic single phase power supply or a generator with peak
load of 500watts only.
SUMMARY OF THE INVENTION:
The invention is a Naga King Chilli (i.e. Capsicum chinense) dryer that can
efficiently dry the chillies to <10% moisture content requiring only 500Watts of
single phase electricity and solid fuel like firewood, coal, coke, agri-waste etc. It
comprises of three compartments- Furnace Compartment(40), Blower
Compartment(41) and Drying Compartment(42) in an insulated Cabinet(l). The
Furnace Compartment(40) comprises of a Furnace(44) where fuel is burnt to
produce heat; a Heat Exchanger(lO) which takes in hot exhaust from the
Furnace(44) and transmits the heat to the air around and a Chimney(3) which
takes out hot flue gases from the Heat Exchanger(lO). The Blower
Compartment(41) comprises of a Draft Fan Assembly(66) having a Draft fan(18)
that blows air from the Furnace Compartment(40) towards the Drying
Compartment and vice-versa. The single Draft Fan(18) can be placed in both
horizontal and vertical positions to create horizontal and vertical air flow
respectively. The Drying Compartment(42) comprises of a Tray Chamber(26)
where Trays(28) loaded with the chillies are kept; an Upper Duct(31) which
connects the upper area of the Tray Chamber(26) to the Furnace Compartment(40)
and a Lower Duct(29) which connects the lower area of the Tray Chamber(26) to
the Blower Compartment(41). To dry the chillies placed in the Tray Chamber(26),
fuel is burnt in the Furnace(44) and the hot air produced passes to the Heat
Exchanger(10). The Draft Fan(18) is operated and the circulated air gets heated up
by the Heat Exchanged 10) that then passes through the Tray Chamber(26) from

the bottom to the top by operating the Draft Fan(18) in the horizontal
configuration and from the top to the bottom by operating the Draft Fan(18) in the
vertical configuration, alternately. During this process, fresh air is continuously
drawn in and hot humid air is continuously allowed to flow out. Also, motor of
the Draft Fan(18) is continuously supplied with outside air to keep it cool during
operation within higher temperatures on the inside. When the temperature in the
upper portion of the Tray Chamber(26) is achieved to be same with that of the
lower portion i.e. at 60± 2°C, the chillies have been dried successfully. In this way
the invention can dry the chillies in both upward and downward circulation
through them without any intermittent handling of them during the whole drying
process. The drying rate is also high because of large area of chilli surface is
exposed and in contact with hot air and also short distance of travel of hot air for
internal moisture.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 shows the front view of the Naga King Chilli Dryer.
Figure 2 shows the Frame(43) on which the Naga King Chilli Dryer is
constructed.
Figure 3 shows a cutout of a side of the Cabinet(l) of the Naga King Chilli Dryer.
Figure 4 shows the Furttace(44) of the Furnace Section(40) of the Naga King
Chilli Dryer.
Figure 5 shows the Draft Fan Assembly(66).
Figure 6 shows the Heat Exchanger(10).
Figure 7 shows the Pressure Baffle(21).
Figure 8 shows a Tray(28) held by Tray holder (27).
Figure 9 shows the airflow inside the Cabinet(l) when the Draft Fan(18) is
operated in the vertical position.
Figure 10 shows the airflow inside the Cabinet(l) when the Draft fan(18) is
operated in the horizontal position.

DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING DRAWINGS:
The present invention is a Naga King Chilli Dryer that is used to dry Naga King
Chillies i.e. Capsicum chinense, also known as 'Bhut Jolokid' in Assam and 'Raja
Mirchd"in the rest of India. Such chillies have very high heat content and are
therefore dangerous to dry properly in state-of-the-art dryers.
The Naga King Chilli Dryer comprises of an insulated Cabinet(l) having
three Compartments,inside-,Furnace Compartment(40), Blower Compartment(41)
and Drying Compartment(,42.) respectively. There is also a Chimney(3) that is
mounted on the top of the Cabinet(l) and a Chimney(3 3) mounted to the side of
theCabinet(1).
The Cabinet(1) is.built on a Frame(43) made of mild steel angles which in
turn is covered by an Outer Cover(2) i.e. a 1mm thick mild steel sheet, and an
Inner Cover(65) i.e. a 1mm thick polished aluminium sheet in the Drying
Compartment(42) and 1mm thick mild steel sheet in both the Blower
Compartment(41) and Furnace Compartment(40) respectively. The said
aluminium sheet helps to reflect and thus retain heat in the Drying
Compartment(42) for efficiency. Also, the space between the Inner Cover(65) and
the Outer Cover(2) is filled up with a Heat Insulating Material(4), typically
glasswool. There are also, Wheels(6) mounted to the bottom of the dryer at the
Frame(43) which facilitates movement of the dryer.
The Furnace Compartment(40) comprises of a Furnace(44), a Heat
Exchanger(10), an Air Deflector(63) and an Fresh Air Inlet(8).
The Furnace(44) is made of 8mm thick mild steel sheet and is mounted to
the Frame(43). It is octahedron in shape that is based on a hexagon of sides
400mm-350mm-175mm-100mm- 175mm-350mm respectively as a vertical slice
and where the side of 100mm forms the base. The Furnace(44) is 1000mm in
length, 400mm in width and 440mm in height and comprises of a cast iron
Grate(64) inside and a circular Flue(45) of diameter 125 mm emerging from the
top surface of the Sidewall(4,6).of the said furnace. The Flue(45) emerges from the

Sidewall(46) so that carbon deposits(soot) produced stick less in it. The Flue(45)
connects to the Heat Exchanger(lO) above. One Face(47) of the Furnace(44) is
open to the outside for loading fuel to burn inside, cleaning of ashes and entry of
air for combustion. The Furnace (44) can burn firewood, coke, coal or agri-waste
to produce heat for the dryer.
The Heat Exchanger (10) is a set of two rows of identical mild steel
Pipes(54) where one row is arranged on top of the other with a gap of 50mm in
between them. They are held on a Heat Exchanger Frame (56) which in turn is
mounted to the Frame(43) Each row comprises of five pipes arranged parallel to
each other with a uniform'gap of 50mm in-between: Every pipe measures 600mm
in length, having 2mm wall thickness and 125mm in internal diameter. Now, the
first pipe of the bottom row connects to the Flue(45) below at one end and the
other end connects to the nearby end of the adjacent pipe in the same row through
Connectors(55). Similarly, the other end of the adjacent pipe connects to the
nearby end of the next adjacent pipe in the same row and so on. The free end of
the fifth pipe in that row connects to the nearby end of the pipe in the top row,
above. The other end of the pipe in the top row connects to the nearby end of the
adjacent pipe in the top row and so on. Finally, the free end of the fifth pipe in the
top row connects to the Chimney (3) above at the Inlet(62) through the Outlet(59).
The Connectors(55) that link the pipes are pipe return bends, also made of mild
steel of same thickness and internal diameter as that of the pipes. The Heat
Exchanger(lO) receives hot flue gases from the Furnace(44) below that in turn
travels more than 6000mm distance through the pipes to effectively release heat in
a single pass to the flowing air surrounding it. The Heat Exchanged 10) is used to
heat both fresh air and recirculated air on the inside of the dryer during the drying
process, indirectly buf in a compact space.
The Chimney(3)' is a long mild steel tube of internal diameter 200mm and
wall thickness 2mm, that is mounted on the top of the Cabinet(l). The Inlet(62) of
the Chimney(3) is connected to the Outlet(59) of the Heat Exchanger (10). The
Chimney (3) receives ahd: then directs the hot flue gases from the Heat Exchanger
(10) to the outside of the Cabinet (1), to the atmosphere.

The Air Deflector(63) is a curved mild steel sheet that is placed at the
corner above the Heat Exchanger (10). The Air Deflector(63) deflects air flowing
from the Heat Exchanger(10) towards the Upper Duct(31) and vice versa. The Air
Deflector(63) prevents flowing of air to the said corner and provides a smooth
flow of the air between the Heat Exchanger (10) and the Upper Duct(31).
The Fresh Air Inlet(8) is an insulated rectangular door which when
opened, allows air outside the Cabinet(l) to flow into the Furnace
Compartment(40) directly.
The main advantage of this novel Furnace Compartment(40) is that the
furnace arid heat exchariger are placed inside the cabinet' on the path of airflow
which allows for maximum retention of heat as compared to the placement of
furnace on the outside with heat loss. Another advantage is the compactness of the
components and the bilt-in form.
The Blower Compartment (41) comprises of a Draft Fan Assembly(66), a
Fresh Air Inlet(7) and a Pressure Baffle (21).
The Draft Fan Assembly(66) comprises of a squared Frame (14) made of
mild steel angles thatis. mounted to the Frame(43). The Frame (14) is covered by
a Fan Cover(13) which is a rectangular sheet of mild steel with a hole in its central
portion of diameter larger by 2cm than that of the sweep of the blades of the Draft
fan(18). The Frame(14) also has Mounts(49) attached to it that are mild steel
extensions from the said frame on the inside, each having a hole at which the
mounting rods of the Draft Fan (18) are mounted. There are Baffles(20) that are
mild steel sheets being attached to the Frame (14) on two opposite sides. The
Baffles(20) create a ducting effect to the airflow of the Draft Fan(18). The Frame
(14) also has Rods(50), each emerging from a respective corner of the Frame (14)
and then being attached to a Shaft (15) by their respective ends. The Shaft (15) is
a hollow mild steel pipe that is held by Bearings(51) which in turn are mounted on
the Frame(43). On one side of the Shaft (15), there is a Lever (19) attached to it
after the Bearings(51) and it stays on the outside of the Cabinet(l). The Shaft (15)
rotates on the Bearings ('5l) with the Lever (19) and hence the Draft fan(18) rotates

Draft Fan(18) in the horizontal and vertical position. Now, the Shaft (15) has a
half scoop cutout in the middle in which a mild steel cylindrical Container(52)
having a perforated bottom is mounted. The Container(52) contains the body of
the Motor(53) of the Draft Fan(18) inside it and has a minimum gap of 12mm
between the outer surface of the body of the said motor and the inside surface of
the said container, all around. To contain the body of the Motor(53) on the
Container(52), at first the maximum cylindrical diameter of the same is
determined. Then adding the clearance of 12mm, the Container(52) is made. After
that, the half scoop cutout is made in the shaft so that the Container(52) is
container in it and then any leaks therein are sealed. Also, the power cables of the
Motor(53) of the Draft Fan (18) are drawn out through a perforation in the bottom
of the Container (52) and then through the inside of the Shaft (15) to the outside.
On the other hand; the Pressure Baffle (21) is a rectangular Frame(56)
made from mild steel flats on which two mild steel Sheet(58) are attached from
both the sides of the Frame (56). The top member of the Frame(56) is mounted to
the Frame(43) wit Hinges (57) and a portion of the said top member extends
further to form a Lever (22). The Lever(22) stays on the outside of the Cabinet(l).
The Pressure Baffle(21) can be rotated about the Hinges(57) using the Lever (22)
and it either rests on the Baffle(20) when the Draft Fan(18) is in the horizontal
position or on the Fan°C6ver (13) when the Draft Fan (18) is in the vertical
position.
The Fresh Air Inlet(7) is an insulated door which when opened, allows
outside air to flow into the Blower Compartment(41) directly.
Now, the Blower Compartment (41) can provide airflow in either
vertically or horizontally. For horizontal airflow, the Pressure Baffle (21) is
rotated up by operating the Lever (22) and then the Lever (19) is operated to bring
the Draft Fan (18) to a horizontal position. Next, the Pressure Baffle (21) is
rotated back which now rests on the Baffle(20). Operating the Draft Fan (18) in
this configuration enables it to suck in air from the Furnace Compartment(40) on
the top and blow it towards the Drying Compartment(42) at the Lower Duct(29).
Alternately, for vertical airflow, the Pressure Baffle (21) is rotated up by operating

the Lever (22) and then the Lever (19) is operated to bring the Draft Fan (18) to a
vertical position. Next, the Pressure Baffle (21) is rotated back which now rests on
the Fan Cover (13). Operating the Draft Fan (18) in this configuration enables it to
suck in air from the bottom i.e. from the Lower Duct(29) and blow towards the
Furnace Compartment(40). However, during these two configurations, the Draft
Fan(18) also sucks in fresh air from the outside through the Shaft (15), which then
flows through the perforated base of the Container(52), touching the Motor(53) of
the Draft Fan(18) and to the inside. This is an important feature of the Dryer
where the motor of the Draft Fan (18) is always kept cool with the fresh air being
continuously drawn from the outside even in the presence of hot air in the Blower
Compartment (41). This feature enables the proper working of the dryer with an
industrial grade draft fan.
The Drying Compartment (42) comprises of a Tray Chamber(26),
Trays(28), Upper Duct(31), Upper Duct Exhaust Door(32), Lower Duct(29),
Lower Duct Exhaust Door(30) and Vertical Outlet(33).
The Tray Chamber(26) is a region inside the Drying Compartment(42)
covered by an insulated Loading Door(5) on the cabinet(l). Through the Door(5),
Naga King Chillies kept on Trays(28) are loaded for drying. The Tray
Chamber(26) is divided into two equal parts and in each area there are three pairs
of Tray Holders(27). Each pair of Tray Holders(27) holds one Tray(28) and thus a
total of six Trays(28) can be used in the Tray Chamber(26). The Tray Holders(27)
are mild steel flats welded to the Frame(43). Each Tray(28) has a Frame(60) made
from stainless steel angles and the bottom of the Trays(28) is a Grill (36) made
from stainless steel wires. Above the Grill(36), a food grade stainless steel 304
wire Mesh(61) of size 30 holes per square inch is fixed. The Sides(35) of the
Tray(28) are made of food grade wood. The height of each of the Trays(28) is
100mm.
The Upper Duct(31) is the long area above the Tray Chamber (26) where
air flows from the Furnace Compartment(40) into the Trays(28) or air flows from
the Trays(28) towards the Furnace Compartment(40).

The Lower Duct (29) is the long area below the Tray Chamber (26) where
air flows from the Blower Compartment(41) into the Trays(28) or air flows from
the Trays(28) towards the Blower Compartment(41).
The Upper Duct Exhaust Door(32) is an insulated door in the Upper Duct
(31) which when opened, allows air present in the Upper Duct(31) to escape to the
Chimney(33) through it. Also, The Lower Duct Exhaust Door(30) is an insulated
door in the Lower Duct (29) which when opened, allows air to escape to the
Chimney(33).
The Chimney(33) is a long pipe mounted at the outer surface of the Drying
Compartment (42) into which the Upper Duct Exhaust Door(32) and the Lower
Duct Exhaust Door(30) opens. The Chimney(33) receives humid air from the
Upper Duct(31) or Lower Duct (29) and releases it to the outside of the Cabinet(l)
to the atmosphere.
The operation of the Naga King Chilli dryer is very simple. At first, Naga King
Chillies are placed on the Trays(28) evenly up to its height. Next, the Loading
Door(5) of the Drying Compartment(42) is opened and the Trays(28) are loaded
into the Tray Chamber(26). The Loading Door(5) is closed firmly. After that, fuel
(firewood, coke, coal, agri-waste etc.) is loaded and ignited in the Furnace(44) and
the Fresh Air Inlet(7) is closed and Fresh Air Inlet(8) is opened but the Lower
Duct Exhaust Door(30) and the Upper Duct Exhaust Door(32) are kept closed.
When the fuel is burning, the Pressure Baffle (21) is lifted up by operating the
Lever (22) and then the Lever (19) is operated to bring the Draft Fan (18) to a
horizontal position. Next, the Pressure Baffle (21) is put down which now rests on
the Baffle(20). In this Horizontal configuration, the Draft Fan(18) sucks in air
from the top i.e. heated air from the Heat Exchanger(10) and the Furnace(44), and
blows it to the Drying Compartment(42) through the Lower Duct(29) which then
enters the Tray Chamber(26) where the hot air passes through the Trays(28)
thereby drying the chillies placed there. The air coming out through the Trays(28)
above passes through the Upper Duct(31) and then back to the Heat
Exchanger(10).

After 30 minutes of the initial fuel ignition, the Draft Fan(18) is switched
on and the Lower Duct Exhaust Door(30) is kept closed but the Upper Duct
Exhaust Door(32) is now opened. Now, heated air circulates as per configuration
stated as above but now the temperature in the Lower Duct(29) shall be
maintained at 60± 2° C, that can be monitored by using a thermometer placed
there and the readings displayed outside or by other means. To maintain the said
temperature in the Lower Duct(29), either burning of fuel in the Furnace(44) is
controlled and/or the Fresh Air Inlet(7) is opened, which lowers the temperature.
After 90 minutes of the above operation, the Draft Fan(18) is switched off.
The Pressure Baffle (21) is lifted up by operating the Lever (22) and then the
Lever (19) is operated to bring the Draft Fan (18) to a vertical position. Next, the
Pressure Baffle (21) is put down which now rests on the Fan Cover (13).
Operating the Draft Fan (18) in this Vertical configuration enables it to suck in air
from the bottom i.e. from the Lower Duct(29) and blow towards the Furnace
Compartment(40). Also, the Fresh Air Inlet(8) is now closed but the Fresh Air
Inlet(7) is opened and the Lower Duct Exhaust Door(30) is opened and the Upper
Duct Exhaust Door(32) is closed. The Draft Fan(18) is now switched on. In this
configuration, the dryer is allowed to run maintaining a temperature of 60± 2°C at
the Upper Duct(31) that can be monitored by using a thermometer placed there
and the readings displayed outside or by other means. To maintain the said
temperature in the Upper Duct(31), either burning of fuel in the Furnace(44) is
controlled and/or the Fresh Air Inlet(8) is opened, which lowers the temperature.
The dryer is run for 60 minutes in this Vertical configuration.
After 60 minutes, the dryer is again put in Horizontal Configuration as
stated above and their run for 60 minutes. The dryer is now run in Vertical and
Horizontal configurations alternately for 60 minutes each until the temperature at
both the Upper Duct(31) and the Lower Duct(29) is the same i.e. 60± 2°C. When
such a situation is achieved, the fuel in the Furnace(44) is removed but the Draft
Fan(18) is allowed to fun for 20 minutes in whichever configuration it was in.
After 20 minutes, the Draft Fan(18) is switched off and the Loading Door(5) is
opened. The Trays(28) are removed which now contain dried chillies.

The key of efficient drying of the Naga King Chillies by this invention is
that indirectly heated air passes through the stationary permeable bed of Naga
King Chillies in both upward and downward circulation through them without any
intermittent handling of them during the whole drying process. This dries them
evenly to <10% moisture content. This drying is achieved by a single air cooled
Draft Fan(18) that provides both vertical and horizontal flow of heated air inside.
Also, during the drying process, fresh outside air is continuously drawn in and
hot-humid air from the inside exists continuously without using any exhaust fan.
The drying rate is also high because of large area of chilli surface is exposed and
in contact with hot air and also short distance of travel for internal moisture-rich
air produced from the bed of chillies. But the striking advantage of this invention
is that fresh outside air enters the dryer continuously automatically due to pressure
at the back of the draft fan remaining below the atmospheric pressure and the
advantageous position of the fresh air inlets and hollow shaft with perforated
container. The maximum pressure drop that can be taken through the bed of
chillies without developing leak or air by passing is roughly below 40 mm of
water. Hence, uniform drying of chillies with retention of aroma, color, pungency
and other ingredients are obtained.

5. CLAIMS:
IClaim-
1. A Naga King Chilli Dryer comprising:
a Cabinet(l) having a Frame(43) wherein a heat resistant Inner Cover(65)
and Outer Cover(2) are attached to the said Frame from the inside and
outside respectively characterized in that the space between the said covers
is filled up with a Heat Insulating Material(4);
a Chimney(3) mounted on the top of the Cabinet(l), the Inlet(62). of which
being connected to the Outlet(59) of the Heat Exchanger (10) characterized
in that the flue gases flowing out from the Heat Exchanger (10) is directed
to the outside of the Cabinet(l) by the Chimney(3); and
a Chimney(33) mounted to the side of the Cabinet(l) into which the Upper
Duct Exhaust Door(32) and the Lower Duct Exhaust Door(30) opens.
2. A Naga King Chilli Dryer as claimed in claim 1 wherein the Cabinet(l)
comprises:
a Furnace Compartment(40) comprising:
a Furnace(44) capable of burning solid fuel to produce hot flue
gases,
a Heat Exchanger(10) capable of receiving hot flue gases produced
in the Furnace(44),
an Air Defiector(63), and
a Fresh Air Inlet(8) that allows air outside the Cabinet(l) to flow into
the Furnace Compartment(40) directly when opened;
a Blower Compartment(41) comprising:
a Draft Fan Assembly(66) capable of circulating air inside the
Cabinet(1),
a Fresh Air Inlet(7) that allows outside air to flow into the Blower
Compartment(41) directly when opened, and

a Pressure Baffle (21) that channels the inside flowing air between
the Drying Compartment(42) and the Furnace Compartment(40)
through the Blower Compartment(41); and
a Drying Compartment(42) comprising:
a Tray Chamber(26) wherein Trays(28) containing Naga King
Chillies are loaded for drying,
an Upper Duct(31) that connects the top surface of the Tray
Chamber(26) to the Furnace Compartment(40),
a Lower Duct(29) that connects the bottom surface of the Tray
Chamber(26) to the Blower Compartment(41),
an Upper Duct Exhaust Door(32) that allows air in the Upper
Duct(31) to escape to the Vertical Outlet(33) when opened,
a Lower Duct Exhaust Door(30) that allows air in the Lower
Duct(29) to escape to the Vertical Outlet(33) when opened, and
a Chimney (33) wherein both the Upper Duct Exhaust Door(32) and
the Lower Duct Exhaust Door(30) opens into.
3. A Naga King Chilli Dryer as claimed in claim 2 wherein the Furnace(44)
is octahedron in shape based on a hexagon of sides 400mm-350mm-
175mm-100mm-175mm-350mm respectively as a vertical slice wherein
the side of 100mm forms the base; said furnace is made of 8mm thick mild
steel sheet and is 1000mm in length, 400mm in maximum width and
440mm in maximum height and comprises of a cast iron Grate(64) inside
and a circular Flue(45) of diameter 125 mm emerging from the top surface
of the Sidewall(46) which in turn connects to the Heat Exchanger(lO)
above.
4. A Naga King Chilli Dryer as claimed in claim 2 wherein the Heat
Exchanger(10) is a set of two rows of five identical mild steel Pipes(54)
arranged horizontally, one on top of the other wherein each pipe is
mounted to the Heat Exchanger Frame(56) and measures 600mm in
length, 2mm in wall thickness and 125mm in internal diameter and are

arranged parallel to the adjacent pipe(s) with a uniform gap of 50mm in
between characterized in that the first pipe of the bottom row connects to
the Flue(45) below at one end and the other end connects to the nearby end
of the adjacent pipe in the same row through Connectors(55) and the other
end of the adjacent pipe connects to the nearby end of the next adjacent
pipe in the same row and so on and the free end of the fifth pipe in that
row connects to the nearby end of the pipe in the top row, above and the
other end of the pipe in the top row connects to the nearby end of the
adjacent pipe in the top row and so on and the free end of the fifth pipe in
the top row connects to the Chimney (3) above at the Inlet(62) through the
Outlet(59); said Connectors(55) are pipe return bends made of mild steel
with identical wall thickness and internal diameter as that of the pipes(54).
5. A Naga King Chilli Dryer as claimed in claim 2 wherein the Air
Deflector(63) is a curved mild steel sheet placed at the corner of the
Cabinet(l) above the Heat Exchanger (10) that deflects air flowing from
the Heat Exchanger (10) towards the Upper Duct(31) and vice versa.
6. A Naga King Chilli Dryer as claimed in claim 2 wherein the Draft Fan
Assembly(66) comprises of a squared Frame (14) covered by a Fan
Cover(13) having a hole in its central portion, and having fan Mounts(49)
at which a Draft Fan (18) is mounted, and having Baffles(20) made of
mild steel sheets on two opposite sides, and having Rods(50) emerge from
the corners wherein the said rods are attached to a hollow Shaft(15) that in
turn is held by Bearings(51) being attached to the Frame(43) wherein the
said shaft also has a Lever(19) attached to it characterized in that the said
shaft having the said fan attached to it, can be rotated about the axis of the
said shaft by using the Lever(19).
7. A Naga King Chilli Dryer as claimed in claim 6 wherein the Shaft(15) has
a half scoop cutout in the middle in which a cylindrical Container (52)
having a perforated base is mounted that in turn contains the body of the
Motor(53) of the Draft Fan (18) inside leaving a minimum gap of 12mm

between the outer surface of the body of the said motor and the inside
surface of the said container, all around.
8. A Naga King Chilli Dryer as claimed in claim 2 wherein the Pressure
Baffle (21) is a rectangular Frame(56) on which two mild steel Sheet(58)
are attached from both the sides wherein the top member of the Frame(56)
is mounted to the Frame(43) with Hinges(57) and a portion of the said top
member extends further to form a Lever(22) characterized in that the
Pressure baffle can be rotated about the said hinges by using the Lever
(22).
9. A Naga King Chilli Dryer as claimed in claim 2 wherein the Tray
Chamber(26) is a region in the Drying Compartment(42) inside the
Cabinet(1) comprising of perforated bottom Trays(28) held on Tray
Holders(27) that in turn are attached to the Frame(43) wherein the said
chamber is covered by an insulated Loading Door(5) on the Cabinet(1)
characterized in that the Naga King Chillies are kept on the said Trays(28)
for drying.