Gas generator - apparatus for the production of gas from coal, firewood, wood waste and other materials. The generated fuel can replace the traditional hydrocarbon fuel - natural gas for home heating and gasoline for the car.
The main idea of using such a unit is saving on fuel costs. The constant increase in the cost of gasoline, propane and methane makes domestic craftsmen look for alternative ways to produce fuel.
To make a gas generator with your own hands, you need to understand its structure and principle of operation.
We will explain how the conversion of solid fuel into a combustible gas takes place, we will designate the design features of the unit and give examples of self-assembly of simple devices. For better assimilation of information, we have supplemented the article with visual diagrams, photographs and video clips.
The content of the article:
Gas generator: device and principle of operation
- Fuel options for generating plant
- What happens inside the gas generator
- Features of work of various converters
- Advantages and disadvantages of gas generators
- Work units homemade unit
Manufacturing technology of the gas generator
- Option # 1: An example of the construction of the device on the corner
- Option # 2: Gas generator from two hundred liter barrels
- Option # 3: Homemade model for ICE
- Nuances of the work and operation of gas generators
- Conclusions and useful video on the topic
Gas generator: device and principle of operation
The gas generator is a device that converts liquid or solid fuel into a gaseous state for further combustion in order to generate heat.
Fuel options for generating plant
The fuel-powered or mining units have a more complex structure than models using different types of coal or firewood.
Therefore, it is the solid-fuel gas generators that are most often found - a blessing, the fuel for them is affordable and cheap.
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The gas supplied by homemade gas generators will serve as fuel for gas boilers and stoves.
Gas generators will provide fuel for vehicles. In priority cargo transport units
Especially high economic effect is the use of gas as a fuel for agricultural machinery.
Gas from a homemade unit can ensure the operation of gas appliances used in the suburban area.
Gas supply to the boiler for home heating
Gas production for vehicles
Production of gas for agricultural equipment
Gas lights and heaters
As a solid fuel in a gas generator use:
- wood, lignite and coal;
- wood pellets from wood waste;
- straw, sawdust and firewood;
- peat briquettes, coke;
- husk sunflower seeds.
Particularly thrifty owners themselves harvested sawdust briquettes.
Gas generation is possible from all these types of fuel. The release of energy depends on calorific value of different types of fuel.
Moreover, the heat from the combustion of raw materials in the gas generator is obtained more than from the use of solid fuel in boilers. If the efficiency of the usual wood boiler varies between 60–70%, then for the gas-generating complex the indicator reaches 95%.
But here it is necessary to take into account one nuance. The boiler burns fuel to heat the water, and the gas generator only produces fuel. Without a heater, stove or engine, the sense from a homemade gas generator will be zero.
The resulting gas should immediately be used - accumulating it in any container is economically unprofitable. To do this, you will have to install additional equipment, depending on the power supply.
In Soviet times, gas generators were used even for the operation of trucks, the produced gas is enough for the operation of an internal combustion engine.
What happens inside the gas generator
The basis of the gas generator is the pyrolysis of solid fuel that occurs at high temperatures and low oxygen content in the furnace. Several chemical reactions take place at the same time inside the gas generating device.
The scheme of an industrial gas generator is a rather complicated installation with many separate devices, each of which has its own operation (+)
Technologically, the process of generation of combustible gas is divided into three successive stages:
- Thermal decomposition of fuel. The process takes place under conditions of oxygen deficiency, which is fed to the reactor only one third of that required for normal combustion.
- Purification of the produced gas. In a cyclone (dry swirl filter) the gas cloud is filtered from volatile ash particles.
- Cooling. The resulting gas mixture is cooled and subjected to additional purification from impurities.
In fact, in the unit as such of the gas generator, it is the first process that takes place - pyrolysis. All the rest is the preparation of the gas mixture for further combustion.
The pyrolysis chamber of an improvised gas generator is divided into a solid fuel bunker (1), a firebox (2) and an ashpit (3)
At the outlet of the gas generating plant, a combustible mixture of carbon monoxide, hydrogen, methane and other hydrocarbons is obtained.
Also, depending on the fuel used in the pyrolysis, water in the form of steam, oxygen, carbon dioxide and nitrogen are added to them in varying amounts. According to the principle described, they function and pyrolysis heating boilersdemonstrating high efficiency.
Features of work of various converters
Gas generators for the device and technology of internal processes are:
They differ in points of air supply and the output of the generated gas.
Direct process flows when the air mass is pumped out from below and the output of the combustible mixture at the top of the structure.
Reversed option implies the supply of oxygen directly to the oxidation zone. However, it is the hottest in the gas generating device.
It is quite difficult to make an injection into it independently, therefore this principle of operation is applied only in industrial installations.
In the direct gas-generating process, a large amount of tar and moisture is formed at the outlet, which is too complex do-it-yourself implementations, while the horizontal one has reduced performance, but an extremely simple design (+)
AT horizontal gas generator the outlet with gas is located directly above the grate in the zone of combining oxidation and reduction reactions. This design is the simplest in independent execution.
Advantages and disadvantages of gas generators
It will cost a factory-made domestic gas generator 1.5–2 times more expensive than a conventional solid fuel boiler. Is it worth spending on this "miracle technique"?
Among the advantages of using gas generators are:
- full burnout, loaded into the furnace, and the minimum amount of ash;
- relatively high efficiency when working together with ICE either gas boiler;
- wide range of solid fuels;
- ease of operation and no need to continuously monitor the operation of the unit;
- time interval between rebootsfireboxes - up to a day on the wood and up to a week on the corner;
- possibility of using undiluted wood - wet raw materials can be used only in some models of gas generators;
- environmental friendliness of the device - this device does not have an exhaust pipe, all the generated gas flows in a direct stream into the combustion chamber of the engine or boiler.
When using wet wood, the generator will work, but gas production will be reduced by 20–25%. The drop in productivity is due to the evaporation of natural moisture from wood.
This leads to a decrease in temperature in the furnace, which slows down the process of pyrolysis. It is best to thoroughly dry the logs before loading into the pyrolysis chamber. Industrial devices are fully automated, the fuel supply to them is produced by a screw from a nearby container.
A self-made gas generator is not happy with this autonomy, but it is also quite simple to use. It is necessary only from time to time to load it with fuel to the eyeballs.
Operating temperatures in the gas generator reach values of 1200–1500 ° C, its body must be made of materials withstanding such loads
There are fewer flaws in the gas generator, but they are:
- weak gas volume controllability - when the temperature in the furnace decreases, the pyrolysis stops and instead of the combustible gas mixture, a mixture of resins is formed at the outlet;
- cumbersome installation - even a homemade gas generator of average power of 10–15 kW occupies a rather large space;
- duration of kindling - before the reactor produces the first gas will take 20-30 minutes.
After “warming up” the generator stably produces a certain amount of gas mixture, which must be burned or thrown into the air. To make this unit with your own hands will require strong gas cylinders or thick steel, and this is a lot of money. But all this pays off the efficiency of the generator and the cheapness of the original fuel.
Some models of gas generators are equipped with an air blowing fan, while others are not. The first option allows you to increase the capacity of the installation, but it binds its power supply. If you need a small generator for cooking food in nature, then you can do with a compact unit without an air blower.
Most of the self-made gas-generating installations work through natural thrust.
The 2.4 kW portable gas generator that runs on wood makes it easy to prepare lunch outside the city far from civilization (+)
To heat a private house will need more powerful and volatile device. However, in this case, it is worthwhile to take care of a backup electric generator, so that overnight in case of an accident on the network, you will not be left without power supply or without heating.
Work units homemade unit
To figure out how you can make a solid gas generator with your own hands, you must clearly represent its structure. Each element has its own purpose, even the absence of one of them is unacceptable.
Inside the case of a self-made gas generator should be present:
- a solid fuel tank at the top of the unit;
- pyrolysis chamber, where the process of smoldering;
- air distribution device with check valve;
- grate with ash;
- discharge pipe for the produced gas;
- cleaning filters.
In a home-made generator, a sufficiently high temperature is formed on the wood, therefore, stringent requirements are imposed on each of its elements. For the case, durable sheet steel is used, and all the parts inside are selected as heat-resistant as possible.
To ensure the tightness of the fuel loading hatch in the closed state, the lid will need a gasket. The cheapest material for this is asbestos. However, it is not harmless to human health, it is better to find in the store special heat-resistant pads based on silicones or silicates.
The gases generated in the combustion chamber are first mixed with air and cooled, and then cleaned in a filter made of expanded clay or sawdust (+)
The body can be either cylindrical or rectangular. Often, to simplify the work takes a couple of cylinders for natural gas or iron barrels. One of the grates at the bottom of the firebox is welded “tightly”, and the second one is built in so that it can be moved. It is necessary to clean them from slag and ash.
The air distribution unit is located outside the enclosure. It provides the necessary amounts of oxygen to the furnace, but due to the non-return valve it does not release combustible gases from it.
Manufacturing technology of the gas generator
Independently make the gas-generating installation in several ways. The choice here depends on the availability of materials and the further use of the produced gas.
Option # 1: An example of the construction of the device on the corner
Consider an example of making useful homemade metal bucket with a lid. At first we will prepare the unit which will process gas received from installation in the electric power.
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In order for equipment generating electricity to run on gas, its fuel system needs to be reworked.
Instead of the dismantled air filter, a plate is installed with a tee fixed on it. A ball valve and an air filter are attached to it.
To avoid gas leaks from the system, plastic pipes should be replaced with metal after testing.
The exhaust pipe is made so that the exhaust is partially fed into the furnace. A gas supply pipe is connected to the second tee nozzle.
Alteration of the fuel system of the electric generator
Modernization of the air filter unit
Replacement of plastic pipes with metal analogues
Improving the exhaust pipe device
After preparing the consumer for the upcoming operation, it is possible to start building the gas generator directly.
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Step 1: For the device entering the generator, three sheets of metal were cut out of a bucket. One of them was bent according to the shape of the bucket.
Step 2: For fastening the plate in its corners, bolt holes are drilled. At the bottom, about 5 cm from the bottom of the bucket, drill a hole under the inlet tube
Step 3: Holes are drilled in the bucket, complementary to the plate holes. To do this, the plate is applied to the bucket and mark their position.
Step 4: An inlet tube is inserted into the wall of the bucket reinforced with a plate through the hole
Step 5: The position of the incoming tube is fixed by welding outside and inside the bucket.
Step 6: For the reliability of the place of contact of the plate with the bucket, the points of fastenings and the pipe entry area are processed with silicone sealant
Step 7: The gas inlet is constructed in the same way. True, instead of one plate, two counterparts are mounted. To the outer welded pipe
Step 8: A plate with a gas outlet coming out, as a counter internal to it, is mounted on a high-temperature sealant and fixed with bolts
Metal plate to strengthen the entrance
Drilling holes in the metal plate
Drilling holes in the billet gas generator
Installing the entrance tube in the wall of the bucket
Fastening the incoming tube welding machine
Processing with silicone sealant
Specific installation pipe in the lid of the bucket
Strengthening the outlet pipe at the top of the gas generator
A nozzle that removes gas from the installation must be provided with a filter, since in the process of combustion, coal emits a lot of fine mist and dust.
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Step 9: In the filter device used an empty can of paint and a piece of foam rubber
Step 10: Holes are cut in the bottom and in the lid of the tin can
Step 11: Foam rubber cut to the tank cavity is laid
Step 12: The filter constructed in the manner described above is installed in front of the outlet pipe inside the gas generator tank
Materials for the manufacture of the filter
Formation of holes in the can
Inside the banks fit foam rubber
Installing the filter for the produced gas
Having completed the process of building a homemade gas generator, you need to check it for operability.
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Testing the work of a homemade gas generator is best carried out in the open air
Stone or charcoal is laid in the gas generator furnace, after which the system is ignited
In addition to the functionality and performance of the system, you should check all the connections, if necessary, you need to modify problem areas with a gas analyzer
To stop the combustion process, plugs installed at the inlet are useful. They will stop the flow of air into the unit.
Connection to the generator
Fuel loading into the furnace
Leak test with gas analyzer
Installing the plug on the inlet
Option # 2: Gas generator from two hundred liter barrels
For a barrel homemade gas generator will require a pair of tanks in 200 liters. One of them is inserted into the other two thirds.
The space formed below will be used as a combustion chamber, and the upper part will be ideal for a firewood or pellet bunker.
Inside the body of the barrel will be smoldering with the generation of gas, and outside the cylinder from the old fire extinguisher in the cleaning filter it will be cleaned of non-combustible impurities
On the side, at the level of the pyrolysis section, the pipe with a section of 50 mm is welded for air injection, and closer to the lid, the exhaust pipe is welded. In the bottom of the inner barrel cut out the hole for the flow of fuel into the combustion chamber, and attached to the bottom of the outer door blowing.
It remains only to make the filters cleaning the gas mixture before transferring it to the boiler. To do this, you will need used fire extinguishers or pipe sections of similar size.
On top of them tightly closed, and the bottom of the conical welded nozzle, at the end of which there is a fitting for the removal of ash. Then a side pipe is cut in to supply the gas mixture for cleaning, and a tap for already filtered gas into the cover.
The initial purification of gas from particles of soot and ash occurs due to centrifugal forces in the outer filter for coarse cleaning (+)
Further, in order to lower the temperature of the combustible gas, a cooling radiator is made of several pipes with a diameter of 10 cm. Between themselves they are connected by small nozzles.
For the final purification of gas install another filter with expanded clay, small metal washers or sawdust inside. It is permissible to use the latter material only on condition that the incoming gas has already cooled, otherwise it may lead to a fire.
From the gas cylinder will make a “stove”. Instructions for creating a primitive furnace are given in this article.
Option # 3: Homemade model for ICE
For a car or motorcycle, a homemade gas generator is made in a similar pattern. Only here it is necessary to reduce the size of the installation to a minimum. To carry a heavy machine with it is expensive, and it looks not very aesthetic.
To make it easier for yourself, for the automotive version of the generator it is best to take the cylinders from under the gas. The main thing is to make sure before welding that there is already no hint of the presence in the propane tank, otherwise a small explosion may occur. To do this, unscrew the cylinder valve and fill the container to the eye with water.
To cool the combustible mixture at the exit of the installation, you can adapt a conventional heating radiator.
Initially, the automobile gas generator produces too hot gases. They must necessarily be cooled. Otherwise, when in contact with hot parts of the engine, they may spontaneously ignite. In addition, the heated gaseous fuel has a low density, because of which it will be simply problematic to burn it in the cylinders.
A self-made gas generator for a car can be mounted in the trunk or on a trailer.
The second method is preferable due to:
- ease of repair;
- opportunities to leave the gas generating unit in the garage;
- the presence of free space in the trunk;
- the possibility of using the installation for other needs than fuel supply in the internal combustion engine.
Do not be afraid of road bumps. When jumping on bumps solid fuel in the combustion chamber will be shaken, which will only contribute to its better mixing and burning.
Nuances of the work and operation of gas generators
It is important to remember that the gas produced by the installation is odorless and poisonous. If the welding of metal parts of the gas generator will be mistakes, then the trouble can not be avoided.
For the natural flow of air in the combustion chamber can be drilled around the circumference of the casing holes of 5 mm. All installation work and performance checks should be carried out in a well-ventilated workshop or on the street.
The kindling of a solid fuel gas generator does not differ from the ignition of a wood-burning stove. Firewood or another fuel variant is put inside, and then they are set on fire with a splinter.
After ignition, the valve is covered to limit the flow of oxygen into the combustion chamber. In order for the homemade gas generator to work properly, you must correctly adjust the output of the resulting gas mixture and the supply of oxygen.
Before starting to make a gas generator, it is necessary to make engineering calculations in which take into account the area of combustion and the type of fuel, as well as the required output power and the intended mode work.
Conclusions and useful video on the topic
How to use a charcoal gas generator as a fuel supplier for a small car:
A simple gas generator of propane cylinders:
The device of the wood gas generator:
The above methods are suitable for the independent production of an effective gas generator. But the models of this device, there are much more. Some of them are easier to make, others more difficult.
The main thing when assembling the unit is to pay maximum attention to the quality of welds, otherwise gas leaks and explosion may occur. If everything is done correctly, the gas generator will properly serve 10–15 years. And then the metal of the case will start to burn through, and you will have to do everything anew.
Do you have practical assembly skills or experience using a homemade gas generator? Please share your knowledge and ask questions about the topic of the article in the comments below.