Wood gas generator with their own hands: how to make a wood gas generator on sawdust and wood

For thousands of years of history, mankind has learned how to produce oil and gas, invented electricity, uses the energy of wind and sun, but still burns wood in the furnaces. Firewood, sawdust, old wood, waste from the activities of woodworking enterprises - all this can be used if you make a wood burning gas generator with your own hands.

Many masters successfully use this device for home and even for the car. If you are interested in this topic, or have an idea to make a generator yourself, we will tell you how to put it into practice.

In our material we will discuss the principle of operation of a wood-based gas generator, the advantages and disadvantages of such a system, as well as how to assemble such a device independently.

The principle of operation of wood gas generators

The rapid burning of firewood in the open air mainly provides a certain amount of useful heat. But quite differently, wood behaves under the so-called pyrolysis burningi.e. when burning in the presence of a very small amount of oxygen.

In this situation, there is not so much burning, as the corruption of wood. A useful product of this process is not heat, but a combustible gas.

Gas generators were once actively used as a supplier of fuel for cars. And now you can occasionally meet cars that run on the gas they produce:

At slow burning of wood at the exit the mix turns out, containing the following products:

• methane (CH₄);
• hydrogen (H₂);
• carbon monoxide (also known as CO or carbon monoxide);
• various saturated carbohydrates;
• carbon dioxide (CO₂);
• oxygen (O₂);
• nitrogen (N);
• water vapor.

Only a part of these ingredients are combustible gases, all the rest is pollution or non-combustible ballast, which is better to get rid of. Therefore, it is necessary not only to burn the tree in a special installation, but also to clear the result, as well as to cool the resulting gas mixture.

In terms of industrial production, this process includes the following steps:

1. Solid fuel combustion in the presence of small (about 35% of the norm) amount of oxygen.
2. Primary Coarse Cleaningi.e. separation of volatile particles in a cyclone vortex filter.
3. Secondary coarse cleaningin which the gas is cleaned with a water filter, a so-called scrubber-cleaner is used.

Home-made devices for use at home look simpler and take up less space, but the principle of their work, as well as the design, are very similar. Before starting the manufacture of such a device, everything must be well thought out, as well as to draw up or find the design of the unit.

On the Internet there are many recommendations on how to make a home-made woody gas generator. Some of them are equipped with very real for the embodiment of the drawings.

Masters who have already managed to implement this fascinating process to some extent, note that a lot of time and effort may be needed. It may be necessary to perform more than one alteration and carry out a number of experiments in order to obtain an aggregate with acceptable characteristics.

Advantages and disadvantages of the system

Gas generators are extremely convenient to use. If the unit is made correctly, in compliance with all safety requirements, it is possible to load fuel into it very rarely. For example, it is possible to load firewood into the chamber only once a day, and if charcoal is used as a fuel, it will be enough once a week.

But this applies more to industrial devices. Course job homemade gas generator should be carefully monitored. The temperature of the hot gas can be very high, the risk of fire also increases significantly.

Wood is available material. Firewood, wood chips, and pressed sawdust, and any waste of the wood industry, and cellulose-containing materials. Dry and light charcoal is excellent as a fuel. If the size of the bunker allows, you can load firewood into it, even without splitting it, entirely.

The combustible gas obtained as a result of burning can be used to solve various problems: heating the house, car engine operation, even for generating electricity. But it is worth remembering about the "minuses" of this useful device.

To begin with, the industrial model of the gas generator, reliable, safe and convenient, is quite expensive. Not every home or dacha owner can afford such a unit. But the creation of a homemade gas generator, even from scrap materials can result in a tidy sum.

It is not always possible to use for it any available materials. All parts of the unit must be very strong and able to withstand high temperatures. Without fail, you will need a welding machine, as well as skills to work with it. Metal will have to cut and cook.

Counting on how much it would cost to create an improvised gas generator on sawdust, you should also consider consumables. It will take cast iron to create the grate, it is possible that for the manufacture of the lid, you will have to find or buy a special spring.

Heat resistant gaskets for manholes, for connecting individual elements of the device, etc. are also required. Before making a gas generator, you need to carefully calculate everything.

Another cost item for a gas generator is electricity, which is necessary to force air into the combustion chamber. If for some reason the electricity is turned off, the gas generator will not be able to work.

This situation is unacceptable, since a decrease in the combustion temperature can lead to contamination of the device with tar. As a result, you will have to stop the process, clean the gas generator, and then start it again.

Although it seems that the gas generator can be loaded with almost any kind of fuel, it should still be remembered that it should gradually, as it burns, descend down the bunker. Therefore, firewood for the generator should be prepared by cutting them into more or less identical elements.

Making a device by hand

First, you should decide for what purposes the gas generator will be manufactured: for the house or for the car. In the latter case, priority is given to low weight and compact size. The best material for a car gas generator is stainless steel, expensive, but durable and light. But for the home make a great device from scrap materials, which are easier to find and cost less.

Let us consider an example of the manufacture of a gas generator for fueling a motorcycle:

For the supply of a gaseous fuel to a gasoline engine, it should be cooled, cleaned and mixed with air in suitable proportions. To do this, the unit must be equipped with a fan for ignition, a cyclone, a filter, a mixer and a cooler.

It remains to supplement the self-made gas generator with devices that ensure normal operation, and solve problems with installing it on a motorcycle with a sidecar.

Of course, the closer the size and configuration of the homemade gas generator to the industrial model, the more efficient the device will work. It is difficult and not necessary to make an exact copy of a factory-made gas generator at home at home.

It is easier to copy a ready-made homemade unit, asking it from acquaintances, friends, or simply using the information on the Internet.

First, the main components of the gas generator are made, then they are assembled into a single device. To make such a device, you must prepare the following elements:

1. Body
2. Bunker for fuel.
3. Combustion chamber.
4. The neck of the combustion chamber.
5. Air distribution unit.
6. Filter node.
7. Pipe combustion chamber.
8. Grate, doors and other similar elements.

The body, which is sometimes called the filling chamber, can be either cylindrical or cubic. Therefore, the master has two options for its manufacture: use a suitable metal container, slightly modifying it, or make a body “from scratch” from a corner and sheet metal.

In the same way, a bunker for solid fuel, i.e. also made from sheet metal and a corner, is made. Later, the bunker is fixed inside the case, so its dimensions must be appropriate. However, sometimes it is easier to turn into the bunker part of the body of the gas generator. For this, part of the space is separated with metal plates.

A material suitable for the insides of a gas generator on wood - steel with a low carbon content. The case should be covered with a tight-fitting lid. Sealing is an important condition for proper operation of the generator, since it is in this way that a limited amount of oxygen is supplied.

The self-made gas generator is a rather heavy device, you should take care of its stability. For this purpose, strong legs are welded to the bottom of the case. Special attention should be paid to the lid through which the fuel is loaded.

Sometimes it is hard and it is not easy to lift it yourself. To solve the problem, you can use a special suspension spring.

For the combustion chamber will need a special heat-resistant steel, because it is here that the fuel is burning at very high temperatures. However, for these purposes you can successfully use an empty cylinder from domestic gas. Both new and used containers will do.

The metal neck of the combustion chamber, in which another important process is carried out — the cracking of the resins — should be separated from the rest of the elements by special heat-resistant gaskets. Asbestos is considered to be a suitable material for this, but it is better to use more modern and safe materials.

The air distribution unit is connected to the structure with the help of a socket, next to which a check valve is installed. The task of this element is to regulate the flow of air to the fuel and prevent leakage of the resulting combustible gas, for the sake of which the creation of a generator was started.

Between the air distribution box and the middle part of the combustion chamber there should be special calibration lance openings. After the combustion chamber put a filter system to clean the resulting gas mixture from contamination. The grate is designed to clean the combustion chamber.

It is usually made of cast iron. To facilitate the cleaning process, the middle part of the grate can be made movable or removable. The doors provide access to various departments of the gas generator and serve for loading firewood, cleaning the chamber combustion, etc. Of course, all such doors must be sealed and sealed with heat-resistant gaskets.

At the bottom is mounted pipe, through which the resulting gas mixture enters the filter unit, and then into the cooler. For the manufacture of a small cyclone filter, you can use the body of an old fire extinguisher or other metal container of suitable size and configuration.

It works in this way: polluted hot gas is injected into the upper part of the cyclone. Then in the round case, it begins to rotate. Under the action of centrifugal forces, particles of pollution move to the lower part of the device and leave it through the opening for unloading. The purified gas exits through another hole in the top of the filter.

At home, as a cooler, you can use a conventional radiator or make a special coil. Hot gas moves along such a long structure and gradually cools. If desired, you can arrange water cooling.

It is believed that a domestic gas generator is able to “digest” wood of any humidity, even 50%, which is typical of freshly chopped wood. In practice, it turns out that the higher the humidity of the fuel, the lower the efficiency of the gas generator. It is not recommended to load into the device fuel whose humidity exceeds 20%.

Correct the situation will allow a small modification of the device. An annular gas pipeline should be run from the combustion chamber nozzle, placing it in the space between the walls of the housing and the outer side of the loading chamber. As a result, part of the thermal energy will be transferred to the fuel, which will reduce its humidity. In addition, cooling will take less time, and the generator efficiency will increase.

Valuable information on gas generators

Sometimes the expectations of owners of private houses, who are thinking about purchasing or making a gas generator on their own, turn out to be too bright compared to the actual situation.

Argued that the efficiency of the gas generator, which is about 95%, significantly exceeds the efficiency of floor gas boilerwhich reaches 60-70%. These figures are generally correct, but it is not correct to compare them.

The first indicator reflects the efficiency of the production of combustible gas, and the second - the amount of heat obtained during the operation of the boiler. In both cases, wood burns, but the result of this process is qualitatively different. If further combustible gas obtained by pyrolysis of wood is used to heat a dwelling, such a comparison can be made.

It is also worth remembering that home-made gas generators, although they can work with high efficiency, are rarely as effective as industrial models. This point should be taken into account at the design stage of the unit and the calculation of the project cost and its expected efficiency.

If the need to create a gas generator is caused only by the desire to improve the heating system at home, you should pay attention to a similar device - pyrolysis boilerwhich works on very similar principles. Its main difference from the gas generator is that the resulting gas is immediately burned, and the resulting energy is used to heat the coolant in the heating system of the house.

In such a device, an additional combustion chamber is mounted, into which it is necessary to organize a separate air supply. If you need to heat the house with a gas generator, you will need more choose convector for heating. This will increase the cost of modernization or arrangement of heating. It is necessary to calculate whether the game is worth the candle?

An important point is the correct maintenance of the gas generator during its operation. Advertising claims that this is a universal device in which everything burns: from sawdust to freshly chopped wood. But advertising is silent about the fact that when loading wet raw materials, the amount of combustible gas produced can be reduced by 25% or more.

The optimum fuel for the gas generator, according to experts, is charcoal. When it burns, evaporation of moisture takes a minimal amount of energy, which allows to accelerate the processes of pyrolysis.

Vehicle owners can count on a gas generator not only for heating, but also for the operation of their vehicle. Indeed, in Europe a lot of motorists quite successfully adapted their transport to work on firewood. But most often it is a compact and durable device made of thin and durable stainless steel.

The cost of such units, even made independently, is not at all small. In the Russian realities, gas generators for cars are made of improvised means and installed on trucks.

The effect of their work is low, usually the presence of such an aggregate is accompanied by such phenomena as prolonged ignition, the need for continuous operation of the engine at high or medium speeds, which contributes to its speedy wear and tear.

An interesting option for using a gas generator in private households is the use of combustible gas for a home power station. Implement such a project using a diesel internal combustion engine.

Conclusions and useful video on the topic

This video demonstrates the process of working a homemade gas generator:

Here is an interesting experience in creating a homemade gas generator with the mistakes made:

This is a variant of a compact gas generator intended for installation on a vehicle:

Making a viable gas generator with your own hands is not so easy. Most often, such units are made for cars, but in homes they are quite effective. To a skillful master who is not afraid of difficulties and is ready for experiments, this task is quite capable.

If in the course of familiarization with the information you have any questions or have recommendations on the hand-assembled wood gas generator, please leave your comments below.