FORM-2
THE PATENT ACT. 1970
(39 OF 1970)
&
THE PATENT RULES. 2003
COMPLETE SPECIFICATION
[SECTION 10; RULE 13]
"NATURAL AIR DRAFT BIOMASS COOKING AND HEATING STOVE"
GREENWAY GRAMEEN INFRA PVT. LTD.,
301, CHAWLA COMPLEX, SECTOR NO. 15, CBD BELAPUR, NAVIMUMBAI400614

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT HAS TO BE PERFORMED:
PROBLEM/BACKGROUND
Cooking is still a major health hazard leading to accidents & deaths especially in villages & small towns due to the unavailability of clean cooking fuel such as LPG cylinder.
Villagers normally have been using Kerosene, Wood or other biomass material such as kitchen or farm waste for cooking. But the problem is the release of Carbon Monoxide (CO) gas fumes due to incomplete combustion leading to respiratory disorders and deaths and is also a major source of indoor pollution.
Forced Draft Gas Stove uses biomass material / pellets have become popular of late but due to the moving parts maintenance cost is higher as also there is a possibility of a breakdown.
Also biomass pellets increase the cost of the fuel for the user thus increasing the overall cost of operation.
Top Lit Up Draft (TLUD) stoves have also become prevalent but due to the increased height of the stove; cooking becomes more cumbersome as also there is a need to feed fuel from top of the stove.
OBJECT OF THE INVENTION
This invention relates to creating differential air pressure in the combustion chamber of a cooking &. heating stove thus maintaining an optimal air fuel ratio for better combustion leading to less generation of fumes; especially Carbon Monoxide (CO) gas which leads to better cooking condition and general health of the women of the house hold involved in cooking.

Also due to the use of natural air draft / pressure there is no need to use forced air draft which requires a fan and motor leading to lower maintenance and hence lower cost of ownership of the cooking & heating stove.
FIELD OF INVENTION
This invention relates to a cooking and heating stove which creates differential air pressure without the use of forced draft due to it's conical structure leading to secondary air flow in the combustion chamber which generates heat; used for both cooking and heating purposes.
ABSTRACT
Conventional type of stoves & methods used for cooking mainly in villages & small towns such as 3 stone cooking, Rocket stove etc, have been popular but each of them have it's own shortcomings as also availability of conventional fuels used such as Kerosene & Wood is increasingly becoming a challenge with rising costs.
Biomass Stoves which use either readily available fuel such as wood sticks, farm waste etc. or biomass pellets are gaining popularity.
Forced Draft Biomass Stove uses a Fan and has a motor attached to it which leads to maintenance issues especially in rural areas where availability of skilled manpower is limited as also increasing the cost of ownership.
The said invention, Natural Air Draft Biomass Stove meant for cooking and heating does not require a fan and motor thus avoiding maintenance issues and lowering cost of ownership as also provides improved thermal efficiency and CO/CO2 ratio.

DESCRIPTION
Cooking is an important and inevitable need of any household. Traditionally Kerosene and Wood have been used as the primary cooking fuel but availability of the same has been a challenge as also thermal efficiency of the Stove using Kerosene & Wood is low leading to more wastage of fuel and slower heating or cooking.
Traditional cooking methods such as 3 stone cooking, rocket stove cooking as also use of conventional fuels such as Kerosene & Wood had been popular but have drawbacks such as slower cooking, heat losses, high emissions, low thermal efficiency, fatigue factor and safety hazards. Biomass Stove offers promise due to the ability to use kitchen & farm waste which is found aplenty in rural areas; the primary users of such stoves.
The challenge is in finding biomass waste with high calorific value and a stove which can be designed to use biomass in it's natural form i.e. unprocessed and burns well in the stove.
Forced Air Draft Biomass Stoves has been available in the market but they require a fan for inducing air flow which increases costs and leads to potential maintenance issues. Also replacing or repairing a fan can pose to be a problem in rural areas which has lack of trained manpower.
The said invention, Natural Air Draft Biomass Heating & Cooking Stove has been designed in a manner that it does not require a fan and works on the principle of creating differential air pressure sufficient enough to maintain the air-fuel ratio in an optimal range in the combustion chamber of the stove as described in the enclosed drawings as part no. 1.
Biomass can be easily fed to the stove from the top (typically smaller pieces) as described in the enclosed drawings as part no. 7 or the bottom akin to a traditional biomass chulha

(stove). Even long uneven sticks & other forms of biomass fuel can be placed on the grate as described in the enclosed drawings as part no. 2 and thereafter inserted into the stove.
Also the biomass fuel may be simply pushed into the stove as also placed on top of the grate thus eliminating any risk of fire or touching the stove's heated parts.
Thus one of the major draw back in a regular Biomass Stove has been addressed i.e. cutting wood twigs, bamboo shoots etc. to a particular size before inserting it in the stove.
This along with the better thermal efficiency of about 32% leading to lower fuel wastage and CO/CO2 ratio of 0.0265 leading to lower emission of stock gases are favourable to the end users.
This will improve the health of women who spend at least 2-3 hours cooking every day as also solve her and the household problem of having to source lower amount of biomass fuel thus saving time and drudgery in the act of collecting biomass fuel.

We will now describe the various parts and functioning of the invention, Natural Air Draft Biomass Cooking & Heating Stove which are illustrated in the enclosed drawings: -
1. Combustion Chamber: The chamber in which fire takes place
2. Opening: This is used for inserting biomass fuel
3. Barrel: Outer covering for the combustion chamber and the cone
4. Reducer: A conical structure; acts as an insulator and also directs the hot air into the combustion chamber via secondary holes

5. Perforations for secondary air: Provides air for secondary combustion; converts unburnt carbon and carbon monoxide to carbon dioxide
6. Grate: Support for fuel; provides a passage for primary air from beneath the wood pieces; sufficient amount of oxygen/air gets enveloped around the wood pieces required for better combustion
7. Top Lid: Top cover for stove which has pot supports attached; acts as a seal for air to avoid any leakage of air to the surroundings (air should pass from the cone into the combustion chamber and not to the surroundings directly)

8. Bottom Lid: Provides a base for the combustion chamber and the cone; serves as an inlet for secondary air
9. Pot Support: Support for utensils
10. Leg: Support on which stove rests; maintains a predetermined gap between the base of the
stove and the surface on which the stove is kept to assist in the provision of required air for
secondary combustion

11. Handle: Bakelite made handles keep the temperatures low so that it can be touched while cooking
12. Inlet for secondary air: provides air for secondary combustion

I/We claim:
1. A front feeding heating and cooking stove which uses biomass fuel such as wood
sticks, agriculture & kitchen waste etc. and creates differential air pressure leading to
natural air draft primarily due to the conical structure (as detailed in drawing sheet no.
II below as item no. 4) and aided by the presence of perforations (as detailed in
drawing sheet no. I & II below as item no. 5) leading to secondary air flow in an L
shaped combustion chamber (as detailed in drawing sheet no. I & II below as item no.
1) which is used primarily for cooking & heating.
2. An L shaped combustion chamber (as detailed in drawing sheet no. I & II below as
item no. 1) used in the cooking and heating stove has a cylindrical vertical part fixed
to a parabolic horizontal structure.
3. The parabolic horizontal structure which is part of the combustion chamber as explained in claim no. 2 is protruding out for better air flow management and easy feeding of biomass fuel such as long, uneven wooden sticks in unprocessed form.
4. The above mentioned stove as mentioned in claim nos. 1 & 2 can also be used as a Room Heater for indoor heating purposes.
5. The above mentioned stove as mentioned in claim nos. 1 & 2 can have a grill at the top of the stove for safe and easy cooking.