FORM 2
THE PATENT ACT, 1971
(39 OF 1970)
AND
THE PATENT RULES, 2003
COMPLETE SPECIFICATION (See Section 10; Rule 13)
TITLE OF THE INVENTION:
FUEL PELLET BASED COMPACT COOK STOVE AND A METHOD OF OPERATING THE STOVE
APPLICANT:
1.
Name: Abellon CleanEnergy Limited
Nationality: Indian
Address: 10th Floor, Sangeeta Complex, Mr. Parimal Railway Crossing,
Ellisbridge, Ahmedabad-380 006, Gujarat India
Telephone No: 079- 66309332 Fax: +91-79-66309334
2.
Name: Dhara Equipments
Nationality: Indian
Address: 908/1, C Estate. Phase - IV,
Naroda,, Ahmedabad - 382 330. Gujarat (INDIA)
Telephone No: 079- 22842475
Ahmedabad - 380054, Gujarat, INDIA
The following Specification describes the invention

TITLE: Fuel Pellet based Compact Cook Stove and A Method of Operating the Stove
FIELD OF INVENTION:
The present invention is relates to a fuel pellet based compact cook stove and a method of operating the Stove. The present invention provides the compact cook stove, which is easy to move and operated on variety of fuel pellets as source of combustion material and the method of operating the same to achieve high efficiency of fuel use and decrease the undesirable emissions.
BACKGROUND OF INVENTION:
Fuel pellets are made specifically for energy generation. Fuel pellets are made from variety of
biomass like; wood residue, agricultural residue, muncipal solid waste, coal powder, etc. Fuel
pellets are manufactured in several types and grades as fuels for thermal power plants,
commercial and domestic applications like cooking and heating. Pellets are produced by
pelletiziation technology at high pressure so they are extremely dense and can be produced
with a low moisture content below 10% that allows them to burn with a better combustion
efficiency.
A pellet stove is a stove that burns fuel pellets, which are manufactured from compressed
biomass material to create a source of heat for residential, commercial and industrial spaces.
By feeding fuel into a burn-pot areaby either continuos or batch mode, they create a flame
that requires little to no physical adjustments.
Utilization of biomass for heat generation is not a new concept. It has been done since ancient
times when people discovered that a fire in their cave could not only provide light but also
heat. With the advent of fuel pellet stoves, burning wood/agriresidue/other biomass for heat
and light becomes easier and cheaper.
Pellet stoves are smaller and more efficient than the traditional biomass burning stove. There
have been many attempts to design more efficient pellets consuming cooking stove. The

challenge for those seeking to design a cooking stove to replace conventional stove is to provide a stove that not only burns the pellets efficiently/ but also reducing the fuel consumption and hazardous emissions, it is also easy, compact, movable and cheap to manufacture, use and maintain. There are many disclosures of biomass stoves of various designs. Some are designed as camping stoves, some as space heating devices and some are more directed to the specific needs of those communities that rely on a biomass stove as their primary means for cooking.
There have been many attempts to design efficient biomass based cook stove, US Patent 5,842,463 discloses a portable wood burning camp stove comprising a combustion chamber with a lower grate for supporting the fuel and an outer wall around the combustion chamber such that an annular space is formed between the combustion chamber and the outer wall. In operation primary combustion air is drawn into the bottom of the combustion chamber and secondary air is drawn into the bottom of the annular space, passes up the outside of the combustion chamber and the heated secondary combustion air is introduced into the top of the combustion chamber. The primary and secondary air flows are dependent on natural convection and are not controlled.
According to the patent US 5,123,360, the innovation consists in an optimization of air circulation by splitting the supply stream for different uses: combustion air feeding, depressurizarion of the combustion chamber, heat exchange (heat the inlet air and cool the exterior of the devices), preventing back flue gas in auger feed. However the main function of this innovation is air heating. As a result, cooking efficiency and diversity in types of cooking are reduced.
US Patent 6,520,173 discloses a portable solid-fuel camp stove comprising a combustion chamber having a suspension screen for supporting the fuel. Primary combustion air flows into the combustion chamber from below the suspension screen. Extra oxygen can be

supplied to aid in the ignition and acceleration of the rate of combustion of the fuel by the user blowing air by mouth through a hose connected to an opening in the combustion chamber wall, above the suspension screen.
US Patent 4,730,597 addresses a biomass stove which is essentially a free convection driven combustion system with secondary air being introduced through holes of varying sizes at multiple levels on the removable fuel basket. The distribution of holes is dependent on the nature of the fuel. One of the key features claimed is the introduction of reflector plates below the grate to reduce the heat loss from the stove bottom.
IN229283 addresses a fuel efficient biomass stove and a method of operating the stove to achieve a high efficiency of fuel use and relatively low undesirable emissions. The fuel efficient biomass based stove applicable for heating water and the like.
US Patent 5,429,110, the innovation is mainly concentrating on heat insulation issues. While establishing a cold and a hot compartment separated by a double layer wall where air flow is circulating, they ensure stability at the required temperature in the pellet storage and electrical components. However the heat transfer between the cooked stuff and the superheated air is not optimized, and the exhaust goes through the cooking dish before spreading in the kitchen.
Among most of the prior art, yet integration of the ergonomic, fuel choice, safety, small scale operation, environmental protection and health aspect has not been deeply focused upon in biomass fuel pellets based cooking stove design. Present invention relates to compact cook-stove by taking care and overcome of all limiting factor as mention above.
In the present invention, air is supplied using a fan below the fuel burner cell, at a fixed level close to the top of the stove, bottom of burner cell and the center of the stove. This results in gasification of the fuel pellets and subsequent combustion of the evolved gases with

additional air from the little upper level of the center thus providing better and complete combustion.
SUMMARY OF THE PRESENT INVENTION:
The present invention relates to a stove incorporating, small domestic compact fuel pellet based stove, a combustion shell without refractory, well ergonomic to support complete combustion of fuel pellets, accelerated air supply, noise less operation, compact structure, vessel holding structure and wide base. The present stove is compact, total weight of 8 to 9 kg, fuel holding capacity of fire pot/combustion chamber is 400 -500 g, inner diameter of top portion of stove is 8.0 -8.5 cm, outer diameter at top 11 -12 cm, outer diameter at bottom 22 -25 cm, fuel bed height 14-15 cm, stove height 34-36 cm and ratio of fuel bed to the diameter of the combustion chamber is between 1.64 to 1.76.
The invention further described specific metal burner cell (burner area) with ergonomic of the burner cell and IBR pipe as outer shell to increase the durability, easy combustion, and minimize repairing cost of the stove. The present invention also provide design/arrangement of stove component to reduce heat loss and provide better radiation heat zone for more gasification which resultant in to increase heat capacity, efficiency, sustainable energy output and complete combustion.
The main aspect of invention is ergonomic of compact stove operate on fuel pellet and useful in routine small cooking at domestic level. The stove fire pot/combustion chamber is with no refractory and made up of metal materiel. It is cylindrical in shape with secondary hole of 5 mm at top and primary holes at bottom and on central beam of 5 mm. Outer shell of cooking ' stove is made up of IBR pipe, bottom diameter is of 22-25 cm with wide air inlet duct and electric fan, top of stove is of 11-12 cm with vessel stand. Fuel holding capacity of combustion chamber is of 400-500 g, primary air supply and secondary air supply is propelled through air duct with electric fan. Primary air enter through primary air holes at bottom of combustion

chamber, secondary air travel through passage between inner shell and outer shell, get preheated and enter in to combustion chamber from secondary holes and enhance combustion of volatile gases generate due to fuel gasification. Due to enhanced primary air and preheated secondary air complete combustion of fuel takes place, resulting in to clean and environment friendly stove operation. Secondary air passes through secondary air passage, which hinder heat transfer to outer shell and keep outer layer cool to ambient temperature which facilitate users friendly working environment. Fuel pellet burn completely and generated ash is collected at bottom of stove. Outer shell has handle for stove handling/positioning. The present stove is small, compact and specifically made for domestic cooking of all types like; frying, boiling, steaming, baking, roasting etc,
A BRIEF DESCRIPTION OF THE DRAWING:

Number Element Figure
1 Vessel stand Fig. 1
2 Burner area Combustion chamber Fig 1
3
Fig 1
4 Outer shell Fig 1
5 Air duct Fig 1
6 7 Fan
Ash collection chamber
Air zone
Stove base Fig Fig 1 1
8 9
Fig Fig 1

1
10 Handle Fig 1
11 Combustion zone Fig 1
12 Lid
Secondary holes
Inner shell Fig 2
13
Fig 3
14
t- Fl"9 3
15 Secondary air passage Fig Fig Fig 3
16 Central beam
Bottom of combustion chamber
3
17

3
18 Primary air holes Fig 3
19 Primary air inlet Fig 3
FIG. 1 a schematic front view is of present stove/ indicated by the arrows, to show various structure.
FIG. 2 is a schematic top cum front view of present stove of FIG. 1 according to the present invention.
FIG. 3 is a longitudinal section view through the stove of FIG. 1, showing various of its parts, their configuration and relationship
In accordance with a preferred embodiment of the invention as shown in the top perspective view in FIG. 1, a pellet cook stove includes an vessel stand 1, stove burner area 2, Combustion chamber 3 is cylindrical shape, outer shell 4 made up of IBR pipe with strong handle 10, to provide primary and secondary air it has provision of air duct 5 with electric fan 6. Stove has large base 9 with ash collection chamber 7 with wide air zone 8. FIG. 2, is top cum front view

of stove showing all most all parts as mention in Fig. 1, in addition lid 12 on combustion chamber 3. The FIG. 3, is longitudinal section view of cook stove clearly shows burner area 2, combustion chamber 3, outer shell 4, combustion zone 11, air duct 5, electric fan 6, ash collection chamber 7, air zone 8, stove base 9, handle 10, lid 12, secondary holes 13, inner shell 14, secondary air passage 15, central beam 16, bottom of combustion chamber 17, primary air holes 18 for entry of primary air to bottom of combustion chamber 3, primary air inlet 19.
DETAILED DESCRIPTION OF THE INVENTION:
The present invention is related to compact, efficient cook stove with small combustion chamber of fuel holding capacity of 400 to 500 gram, stove canopy is cylindrical shape with large base to provide strong foundation and appropriate vessel stand suitable for all types of cooking vessel use in domestic cooking like; frying, boiling, steaming, backing, roasting etc. Stove is small, compact, suitable for all types of domestic cooking, propelled by enhanced air through electric fan, smoke & noise less operation, complete combustion, large ash collection zone, leak proof outer body and suitable for all types of fuel pellets made from virgin and processed biomass. Total weight of stove is between 8 to 9 kg and height is 34 -36cm.
In accordance with a preferred embodiment of the invention cook stove in compact and cylindrical shape made up of IBR pipe with wide vessel stand 1 and base 9. The stove structure contain overall leak proof outer body with suitable color coating preferably metallic silver, ash collection chamber 7 with diameter 22-25 cm is just below the air zone 8 chamber with long outer shell 4 having inner shell 14 which act as combustion chamber 3. Outer shell 4 is welded with three metal pieces to form vessel stand 1 suitable for all types of cooking vessel use at domestic level. Outer shell 4 has one handle 10 for positioning of stove and also for handling of stove during cooking operation. Total stove height is 34-36 cm, outer diameter at top is 11-12 cm, outer diameter at bottom is 22- 25 cm with provision of air duct 5 with electric fan 6, fuel bed height in combustion chamber 3 is 14 -15 cm. Inner shell 14, contain

total 27-30 secondary holes 13 of 5 mm size at a fixed level close to the top and total 18-22 holes of 5mm size at a little upper level of the center of the stove on central beam 16. In total the present invented stove comprising of vessel stand 1, stove burner area 2, Combustion chamber 3, outer shell 4, air duct 5, electric fan 6, ash collection chamber 7, stove base 9, handle 10, lid 12, inner shell 14 and central beam 16. The ergonomic of all component resulting in to compact cook stove applicable for all domestic cooking.
The combustion chamber 3 is cylindrical shape with heavy metal ring on top fit to outer shell 4 with metal lid 12. The combustion chamber 3 is covered with strong outer layer 4 made up of IBR pipe. Cavity between outer shell 4 and inner shell 14 is act as area for secondary air passage 15. Secondary air propelled by electric fan 6 from air duct 5 is enter in to combustion chamber 3 and enhance complete combustion of volatile gases generated by burning of fuel pellet. The combustion chamber 3 is refractory less and receiving primary air from primary air inlet 19 through primary air holes 19 on bottom of combustion chamber 3 and central beam 16. While secondary air enter in to combustion chamber through secondary holes 13 through secondary air passage 15. The combustion chamber 3 is designed to operate on variety of fuel pellets made out of processed or virgin biomass. The ratio of height and diameter of combustion chamber 3 along with distribution of primary air through primary air holes 18 and secondary air through secondary air holes 13 contribute complete combustion of volatile gas generated out of fuel pellets gasification and provide smoke less cooking operation. The combustion chamber 3 is design to fill up 400 -500 kg of fuel pellets with bulk density 600 - 700 kg/m3, height of fuel bed in combustion chamber is of 14 -15 cm.
The combustion chamber 3 is cylindrical shape with central beam 16. Combination chamber 3 has perforated bottom which act as primary air inlet 19. Central bean 16 also has primary holes from which primary air enter in to combustion chamber 3. Top of combustion chamber 3 has series of secondary 13 holes of 5 mm size. Primary and secondary air is propelled by

electric fan 6 through air duct 5. Air enter in to air zone 8 through air duct 5, primary air directly enter in to combustion chamber from bottom while secondary air passing from secondary air passage 15 between outer shell 4 and inner shell 14. while passing through secondary air passage 15, its get preheated and preheated air enter in to combustion chamber 3 from secondary air holes 13, which enhance the complete combustion of volatile gas generated by gasification of fuel pellets and enhance the efficiency of stove.
The said compact cooking stove is operate on biomass fuel pellets, feeding of fuel is manually as per the holding capacity of combustion chamber 3, fuel pellets feeding start from bottom of inner shell 14 and continue up to 1 cm below from the secondary air holes 13. Maximum 400 -500 gram of fuel pellet can fill up in inner shell, after feeding complete fuel pellets the height of fuel bed is 14 -15 cm. The ratio of the height of the fuel bed (14 -15 cm) to the diameter of the combustion chamber (8.5 cm) is between 1.64 to 1.76. An electrical cord with adapter is provided to connect the stove fan 6 to the mains 220 V, single phase supply. The 220V supply is stepped down to 24V through a 24V step down adapter. The output of the transformer is given to high speed electric fan 6, adapter has a regulator switch to control voltage frequency to adjust at low, medium or high and thus controlling fan 6 speed and subsequently combustion of biomass fuel and stove flam.
Operation of the present invention: The combustion chamber 3 is filled with commercial fuel pellets up to 14 cm height from bottom. Ignition is facilitated by spraying small amount of liquid fuel like kerosene (approx 3 - 5 ml) on the surface of the fuel pellet. The fuel pellet is started to ignite within 4-5 minutes of time. Start supply of air to combustion chamber 3 by connecting adapter to 220 volt power supply. For initial time (~ lmin) keep adapter on low stage so fuel pellets get heated properly and start burning, after that speed of fan 6 can set to medium or high as per cooking requirement. Through primary air inlet 19 and primary air holes 13 primary air enter into combustion chamber and bring volatile gas upward. Primary

air- also pass through holes on central beam 16 which also helps in maintain air fuel ratio which leads to proper combustion. Secondary air pass through secondary air passage 15 and enter in to combustion chamber 3 through secondary holes 13 by controlling speed of electric fans 6 operator can control actually primary and secondary air which maintain require air into combustion chamber 3 which leads to fast and complete combustion which nullify blacking of vessels. Once the fuel pellets has started to burn, the hot volatile gases start to come from the surface. The secondary air supply from the secondary air holes 13 on combustion chamber 3 and primary air from primary air holes 18 helps to burn all volatile gases and produce bright flam. The cooking stove operate at constant temperature without noise and smoke production according to the fuel capacity, the heat obtained and speed of fuel combustion can be adjusted by managing air supply through fans 6. The cooking stove operation can be closed when all fuel pellets convert into ash. To start the new operation, fill up combustion chamber 3 with fresh fuel pellet and start stove as describe above. After subsequent operation generated ash is collected at ash collection chamber 7, combustion chamber 3 is removed manually and by inverting stove with help of handle 10 on outer shell 4. All types of cooking like; frying, baking, steaming, roasting and boiling are performed on stove at domestic level.

CLAIM:
1. An efficient compact cooking stove comprising,
a. a compact stove design for domestic cooking
b. a compact stove design for solid biomass pellet as fuel source
c. cylindrical combustion zone, air circulation zone and ash collection zone
d. combustion chamber without refractory within the combustion zone
e. a strong cylindrical structure with wide base and vessel stand
f. an integrated air circulation zone for primary and secondary air distribution
g. a fan to propelled enhance air
h. a compact design integrating occupational safety with complete fuel combustion, smokeless, noiseless, regulated air supply easy to operate, easy to handle, compatible for all types of fuel pellets made from processed or virgin biomass.
2. The compact stove as claimed in claim 1, broadly consist vessel stand, outer shell, inner
shell with metal lid, handle, air circulation zone, air inlet with electric fan, ash collection zone, base and electric cord with adapter, total weight 8 -9 kg and height 34 -36 cm.
3. The compact stove as claimed in claim 1, where in inner diameter of stove at top is 8.0 -8.5
cm, outer diameter at top is 11 -12 cm and outer diameter at bottom 22-25 cm.
4. The combustion chamber as claimed in claim 1, is without refractory, cylindrical in shape,
closed bottom with perforated plate and central beam with 18-22 hole of 5 mm size and 27-30 holes of 5 mm in series at a fixed level close to top.
5. The combustion chamber as claimed in claim 1, is accommodate 400-500 grams of fuel
pellet with bulk density of 600 - 700 kg/m3 and height of fuel bed in combustion chamber is of 14 -15 cm, ratio of fuel bed to the diameter of the combustion chamber is between 1.64 to 1.76.
6. The air circulation system as claimed in claim 1, where in source of air is electric fan and
primary air enter in to combustion chamber through bottom and central beam and secondary air through secondary holes of 5 mm size on top of the combustion chamber, so enhance complete combustion of volatile gas from fuel pellet gasification.
7. The fan as claimed in claim 1, is electrically operated for blowing inlet air to air zone and
controlled speed through nob on inbuilt adapter at high medium and low stage.
8. The fuel source for stove design as claimed in claim 1, is compressed fuel pellets made
from all types of processed or virgin biomass from wood, wood reside, forest left over,

grasses, saw dust, agricultural residue and any process industry waste.
9. The compact cook stove operate by fuel pellet as claimed in claim 1, is easy transportable,
durable and suitable for all types of domestic cooking like; frying, baking, steaming, roasting, boiling with noise less and smoke less operation.
10. A compact efficient solid biofuel operated pellet stove as herein described with reference
to foregoing drawings.