If a few decades ago, the only heating option for many was coal and firewood, today there is gas. Nevertheless, this natural fuel is sometimes not possible to fail. Say, in some places in the private sector and holiday villages there is no gas main. In order not to resort to heating with coal, the owners build pyrolysis furnaces with their own hands. Let's see what kind of equipment it is and what are its key features.
How does the boiler work and what is pyrolysis
Do not confuse this equipment with a conventional solid fuel boiler. Units, although they can use the same fuel, such as coal, briquettes and firewood, but the principle of their work is noticeably different.
In our case, we are dealing with the so-called dry distillation. The combustion process proceeds at a temperature of 200 to 800 degrees with a reduced amount of oxygen in the combustion chamber. As a result, dry wood decomposes into solid residue and wood coke, and the most important element is pyrolysis gas. The latter is mixed with oxygen and serves as a kind of activator of the combustion process. It is worth noting that today do-it-yourself pyrolysis furnaces are made quite often. This is due to their simple design and relatively easy assembly. By the way, the smoke that is formed during the combustion process does not contain harmful impurities. This can be achieved through the interaction of pyrolysis gas with carbon.
Top Camera Location
This design looks more advantageous against the background of the lower location of the camera. However, it is worth noting that such pyrolysis furnaces have appeared relatively recently. With their own hands they were designed by craftsmen, after which they were already sold in a professional performance. Today, although they are in some demand, they have not yet received their due popularity. As for the merits, they are obvious. Such equipment operates on natural traction and is completely non-volatile. In addition, the inverted design adds some zest. The principle of operation of such a furnace is based on the fact that pyrolysis gas rises from the main chamber located in the lower part of the furnace to the upper chamber, where it is mixed with oxygen. Thin air enters through the bottom opening in the furnace body , which in combination with oxygen provides an oxidation reaction. Actually, the combustion of fuel is carried out in the lower chamber, then the coolant is heated. It is interesting that this type of pyrolysis furnace, made with your own hands, with proper execution can work on one portion of fuel for up to 12-14 hours.
A little bit about the device
You must understand that the pyrolysis furnace consists of two combustion chambers. Both are needed to maintain combustion. One of the chambers into which the fuel is loaded must be tightly closed to prevent the ingress of oxygen. Do not forget about this when designing the product. As a result, pyrolysis gas is formed, which rises into the afterburner, where it is mixed with secondary air. At the same time, combustion efficiency increases, as does heat transfer. The upper and lower chambers are separated by grates. One of the features of the process is overhead ventilation. In addition, the organization of forced traction is important. This will significantly reduce aerodynamic drag.
Do-it-yourself pyrolysis furnace : about safety
If you are going to design your own heating equipment, you should understand that there are strict requirements for the quality of the air-fuel mixture and the safety of the furnace itself. For this simple reason, you will need at least a minimum of experience with drawings and possession of any type of welding equipment. For accurate operation, you will need to use electronics, and for high quality of the product body - alloy steel. The electronic component is needed to control the pyrolysis process. If this is not taken into account, then your pyrolysis furnace by and large will turn into the most ordinary potbelly stove. Well, now let's move on to the main stage, consider how to make equipment with your own hands. With the proper skill and equipment, this will not be difficult.
Materials and Tools
Before the pyrolysis furnace with your own hands will be designed, you need to acquire a set of tools, without which work is impossible, as well as material. First of all, you will need a welding machine and an electric drill. Also among the necessary tools should be present and angle grinder (angle grinder ). In priority, it should be under a circle with a diameter of 125 mm, if this is not possible, then the 230 mm option is suitable. You will also need sheet metal. Its thickness should be at least 4 mm and not more than 7.5 mm. In any case, the internal parts must be made of steel with a thickness of at least 4 mm. In this case, the material for the housing may be less than 3 mm thick. In addition, you will need to take a few packs of electrodes and about 10-15 pieces of refractory brick for lining. Cutting and grinding wheels 230 and 125 mm, respectively, should be at hand. For the organization of electronics do not need so much. A fan and a temperature sensor will be enough. Grates are used to separate the chambers. Do not forget to purchase two doors.
Do-it-yourself pyrolysis furnace: instructions and technology
Work begins with calculations. If you do not have an engineering mindset, then you can turn to specialists for help. Typically, the prices of such services are small. The scheme itself looks something like this:
- Welding work. Here you have to make a steel case and chambers (combustion and afterburning).
- Lining of the inside of fireclay (refractory) bricks.
- Making holes for supplying oxygen supply systems to the combustion chambers.
- Preparation of the combustion chamber window and door installation.
- Installing a water shirt.
- Mounting the fan in the exhaust pipe.
With this scheme, a pyrolysis furnace is made with your own hands. Drawings in this case may or may not be present. The first option is preferable, since the accuracy of the work and the operational characteristics of the product will be better.
Start of work
It must be understood that the basis of any boiler is a firebox and a combustion chamber. The temperature there is quite serious, usually about 500-1000 degrees Celsius, so you need to use a special metal. If there is none, any other will do, but then it is better to make the walls double. Wall cutting must be done using angle grinders according to the dimensions indicated on the drawings. Dimensions must be transferred as accurately as possible, for this use a ruler and other measuring tools. After that, stiffeners are created from the profiled pipe . As you can see, for now, a do-it-yourself pyrolysis furnace, drawings for which should be at your fingertips, is very simple. The main thing here is to comply with the technology.
Making important parts
Any self-made brick pyrolysis furnaces imply a door for the combustion chamber and an ash compartment. They need to be done. To begin with, holes are drilled in the front wall, which are made according to the size of the door. In order for the work to be performed as accurately as possible, it is recommended to mark with a sharp object and only then proceed to cutting.
Next you need to prepare a water tank. The tank must be made of stainless steel. It is imperative to weld a container that will not leak. If in doubt, it is best to consult a specialist. Do-it-yourself mini pyrolysis furnace is made in the same way as its large prototype. In any case, it is a complex of pipes that forms a flow path with high heat transfer between them.
How to assemble the structure?
To reduce the complexity, it is recommended to assemble directly at the place of work. Take care of this in advance so as not to carry heavy loads. Before proceeding, the foundation is laid, then the inner walls are placed around the perimeter, and the ash compartment is mounted on the bottom. The inner walls are joined by welding. In principle, the housing is ready, now it is time to weld the combustion chambers, heat exchanger and grid-irons along the guides. The stiffeners are vertically welded, and then the external walls are mounted. Our pyrolysis furnace is already practically done with our own hands. The scheme implies the presence of sand between the inner and outer walls. It is needed for heat storage and protection against overheating.
Finish the construction
After the sand is filled, sealed doors are mounted, a water circuit is connected. Today, many say that it is not practical to make a pyrolysis boiler, the power of which will be less than 15 kW. In principle, the metalwork is completed. And a simple do-it-yourself pyrolysis furnace is practically made. All that remains is to do some work with the brick. What is a refractory mortar made for? By the way, there are a huge number of cooking recipes, which one to choose, it's up to you. You need to know that chamotte brick is suitable for lining the firebox . True, in this case, you do not need to rely on the product to work for more than one season. As you can see, do-it-yourself pyrolysis furnaces are not manufactured very quickly and not as easy as we would like, but it is quite possible to do this.
The final stage of work
And the final touches. First, you need to make a heat exchanger from fireclay bricks. It should be divided into two cameras. Then in the free position is the installation of grates. You need to understand that when heated, they expand and fill the gap left. At the very end, doors are inserted, valves and levers are adjusted. It is necessary to properly adapt the fan, which is necessary to overcome aerodynamic drag. For example, a do-it-yourself camping pyrolysis furnace is made in approximately the same way. But its design implies significantly smaller dimensions and weight due to the absence of a lining and thick steel. Nevertheless, in nature such equipment works quite efficiently.