FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)

1. '' Biomass Wood Gas Cook Stove’

2. (A) Alpha Renewable Energy Pvt. Ltd
(B) Indian Company
(C) B-7 Abhay Nagar, Gorwa,
Vadodara-390003,
Gujarat, India

The following specification particularly describes the invention and the manner in which it is to be performed.

Biomass Wood Gas Cook Stove
Field of the Invention
The invention relates to combustion of biomass materials, such as wood chips, in a furnace suitable for use as a heat source in residential or commercial dwellings

Background of the invention
Cooking with three stone fires is a common practice in Asia, Africa and other developing countries. Many governments have made efforts in improving Chula (a common name for the cook stove in India) but they are not always acceptable by the rural population because of numbers of reason. Although the urban population enjoys the luxury of cooking with Natural gas and electricity the rural population is far behind due to infrastructure and affordability of cooking with better fuels. As a general rule of developing countries more population leaves in rural area than urban area.

Current method of cooking is notoriously inefficient, slow, smoky, terrible health effects, waste wood and destroys the forest thus making wood collection much harder day by day for the users, at the same time increasing Co2 emission. Smoke from burning these fuels gives off a poisonous cocktail of particles and chemicals that bypass the body''s defenses and more than doubles the risk of respiratory illnesses such as bronchitis, pneumonia , breathlessness, chest pains, headaches, ear and eye problems, and giddiness are just some of the symptoms poor women and children suffer in their homes

This is double sided loss to the country and the world. As a country they are losing forest cover at the same time increasing Co2 in the air plus the health risk of rural population.

Many different designs of improved cook stoves or Chula exits but none of them are fully acceptable to the rural population in the developing countries. Each one has more than few draw back e.g.
(a) Stove too small or too large for living structure,
(b) Stove too slow to start. Many stove designs require user to blow on fire for initial combustion. This blowing is done by mouth or small piece of hallow pipe, the user are literality breathing smoke until fire gets started.
(c) Stove is not portable: It is destroyed during moving, or cannot be carried to temporary place of work. Staying in temporary accommodation for work is common in developing countries.
(d) Most Stove works with fuels like wood and coal. They don’t work with freely available biomass like twigs, corn cobs, cow dung etc. in the area.
(e) Stove too expensive to purchase and requires help from trained workers for installation which they cannot afford.
(f) This improved stoves or Chula are unable to efficient combustion the biomass in small scale, overall efficiency near only 23-30%. Heat from combustion of the biomass drives off volatiles from wood faster than they can be combusted. This puts lot of burden on women and children as they have to deal with indoor smoke every day while doing cooking.
(g) Animal dung is also widely used for cooking in rural areas. This dung is most polluting and produces less energy than other biomass but it is still used as cooking fuel because they cannot afford other fuels and they have to cook to eat. Most of the improved stoves or Chula don’t address this problem. Combustion and overall efficiencies of improved stove burning dung is generally very low. Fuel is eventually reduced to charcoal, which burns slowly under normal air draft – giving poor combustion performance.
(h) Some improved stoves (a vented mud stove) were designed for superior heat transfer to the cooking surface. While decreasing wood consumption, they still produce substantial pollution, as they suffered from decreased combustion efficiency

Object of the invention
In the present invention has developed a wood gas stove that will fit the budget of the rural population in developing countries, including the size needed for their cooking, in which operation cost is almost nil as the power can be drawn from multiple sources like solar, hand charger, or electricity out let. It works on the free fuel supply of the biomass; Wood gas stove also meets the requirements of their cooking practices. It is efficient, affordable, simple to use, long lasting, reduces the most harmful indoor air pollution and fit commercial infrastructure of each country. The present invention able to achieve all this with our updraft/downdraft wood gas stove which works on principles of wood gasification, a model of gasification used in big gasification system worldwide. Wood gas stove operates in two different gasification and combustion modes. In the “volatile burning” mode, the stove makes charcoal from biomass fuels. In the “charcoal burning mode” the charcoal is gasified to produce a CO flame.

BRIEF DESCRIPTION OF THE DRAWINGS
Fig.1 front view of the Biomass Wood gas Cook Stove off condition
Fig.2 front view of the Biomass Wood gas Cook Stove in on condition

DISCLOSURE OF THE INVENTION
The present invented improved wood gas stoves works on the principal of Gasification. By using a gasification solution for combustion of biomass heat transfer characteristics are improved greatly. The gasification / combustion process runs via two step process, whereby the biomass is gasified first with the resulting gas then combusted

All current wood cooking stoves require the user to blow on the fire with a small pipe for an extended period before the fire is ready for cooking. This can be especially taxing when trying to start a fire with damp wood during monsoon season. The present invented wood gas stove user does not have to do this, as fan (24) is supplying combustion air (16) & (17) in the correct amount to get the fire started. Full flame will be visible in less than 1 minute and effortless. In start up, wood gas gasifier is filled to nearly top with biomass. Fire is started on the top with dry leaves, grass or anything like waste paper. Once the tinder is lighted, the air flow is started on low speed. (11) The wood gas stove operates on two speeds that are low and high. (11) & (12) (See figure 1) Starting at slow speed provides just enough air to get combustion going. Once the fire is lighted, it is switch on to regular speed. This eliminates need to blow with mouth and breath all the Co2.It will run until the fuel is consumed. A clean yellow- blue gas flame just like Natural gas is produced as air then gasifies the charcoal to CO (23) which gives hotter temperature at the grate.

With-in 30 seconds to 1 minute, it is turned on to full power. Figure 2 explains the production of wood gases from the biomass the bottom air (16) acts as the carrier of all volatiles.(18) As the hot wood release volatiles the bottom air(16) carries them on the top through a bed of burning wood (20) & (21) which consumes volatiles. The gas then passes through the resulting charcoal and is reduced to a low energy fuel gas. The makeup air from the side of the wood gas stove (17) at the combustion zone (23) provides necessary oxygen for the conversion all the other gases into useful energy to the cooking pot. Essentially due to thermo-chemical processes such as pyrolysis, (20) combustion (23) and reduction taking place, gives wood gas stove high efficiency.

The makeup air(17) & (18) and combustion air is controlled so as wood gas stove biomass is burned with insufficient air (25) as in a gasifier, thus it makes producer gas containing primarily CO, H2, CO2, H2O and CH4. The charcoal then further reduces the CO2 and H2O combustion products back to CO and H2 fuel. Figure 2 to also explain wood gas stove operates on correct air/ fuel ration to produce maximum flame temperature. (23). This reduces the emissions from the close coupled gasifier burner and wood gas stove produces much far less emissions than any other cooking device in developing countries.

If longer cooking is required, more fuel can be added judiciously in an updraft mode in which charcoal combustion (21) supplies heat to pyrolysis the new fuel for gasification. Aluminum reflector panels (28) are used inside the stove to reflect infrared heat back to the fire – increasing efficiency and decreasing outside metal temperatures.

In wood gas stove inner can (27) hold the biomass where combustion takes place. This combustion is controlled by make-up air drawn from air inlet (15) by fan (24) and sent in different direction as needed from bottom and top.(16) & (17) This results in greater efficiency and more heat to the cooking pot. The outer can (26) holds Aluminum reflector panels (28) to reflect infrared heat back to the fire. This keeps outside can (28) cooler plus provides travel path for the combustion air to travel where needed.

Reduced inner can (27) provides control burn of biomass at the same time more direct energy to transfer to the cooking pot. It also arrests heat loss to the atmosphere. As all the volatiles are channel to the flaming burning zone (18) & (22) promotes increased efficiency and more heat from the biomass compare to any other system. The amount of heat needed for cooking can be obtain from 50 to 55% of biomass when compared with three stone fires in developing countries. This higher efficiency saves user time and cost of cooking. In the present invention wood gas stove is light enough and portable yet it is a well deign small gasifier which has the excellent heat transfer to the pot. It is large enough to cook a proper meal for a household of 4-6 persons. Based on the same principles we have bigger sizes for larger family.

This moveable unit requires no set up, just fill the wood and do the cooking as the present invented stove operates on clean combustion of wood with consistent heat output on gasification principles it has a blue flame and very little smoke in the beginning at the start of fire only. The complete combustion
also eliminates polluting byproducts.

Object of the invention
1. Converting biomass on a small scale using gasification principle to produce wood gas for cooking. The volatiles and Co2 which increases green house gas are trapped and converted to useful energy for cooking. The remaining Co2 are absorbed by the trees and vegetation thus promotes helping hand in cleaner air.
2. Controlling the output needed to cook by controlling combustion air. Thus making cooking more pleasure.
3. Converting agriculture waste of biomass like twigs, corn cobs, nut shell, etc into clean useful energy on small scale for cooking. This will reduce the burden on wood, which will promote healthy forests
4. Reducing the indoor smoke emissions, a major health hazards for women and children in developing countries.
5. Reducing the waste and increasing the efficiency from the biomass cooking which in turn saves tree. More saved trees mean more absorption of Co2 which in return gives better quality air.
6. Reducing the smoke emission when cooking with animal dung at the same time increasing the amount of heat to the cooking pot in shorter time.
7. A way of starting fire for cooking without blowing air from the mouth on the fuel. A common ways of starting fire for cooking in developing countries.
8. An efficient way of cooking using Agriculture biomass as fuels. A reduction in 50% fuel needed to do the cooking will save rural poor time and money.
9. Cooking time for the poor population in developing countries will be reduced as wood gas stove produces much hotter heat which can be controlled.
10. The design of inner and outer can eliminates the heat loss to atmosphere and directs majority of the heat to the cooking pot.
11. As all the volatiles and tar gets converted to energy, there will be very less blackening of cooking pot, thus making cooking pot easy to clean.

We Claims

1. Biomass Wood Gas Cook Stove is consists with fan (24) low and high speed air flow controller (11 & 12) , inner can (27), air inlet (15) and aluminum reflector panels (28);
wherein fan (24) is provided for supplying combustion air (16 & 17) in the correct amount to get the fire started;
wherein low and high speed air flow controller (11 & 12) are provides to control the air flow,
wherein inner can (27) hold the biomass where combustion takes place,
wherein air inlet (15) is provided to controlled the combustion takes place in inner can(27),
wherein aluminum reflector panels (28) is provided to reflect infrared heat back to the fire.

2. Biomass Wood Gas Cook Stove substantially herein described with reference to the foregoing description and the accompanying drawings.