Pyrolysis furnaces by one's own hands: device, principle of operation and assembly diagram

If several decades ago the only option for heating was coal and firewood for many, today there is gas. Nevertheless, this natural fuel is sometimes not possible to bring. For example, in some places in the private sector and holiday villages there is no gas main. In order not to resort to coal heating, the owners build pyrolysis furnaces with their own hands. Let's see what kind of equipment it is and what its key features are.

How does the boiler work and what is pyrolysis?

Do not confuse this equipment with a conventional solid fuel boiler. Aggregates, though they can use similar fuel, such as coal, briquettes and firewood, but the principle of their work is significantly different.

In our case, we are dealing with a so-called dry distillation. The combustion process takes place at a temperature of 200 to 800 degrees with a reduced amount of oxygen in the combustion chamber. As a result, the dry tree decomposes into a 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 pyrolysis furnaces are made with their own hands quite often. This is due to their simple construction and relatively easy assembly. By the way, the smoke that forms during combustion, does not contain harmful impurities. This can be achieved through the interaction of pyrolysis gas with carbon.

Top camera location

This design looks more profitable against the background of the lower location of the camera. However, it should be noted that such pyrolysis furnaces have appeared relatively recently. Their own hands were designed by folk craftsmen, after which they were sold already in professional execution. Today, though they are enjoying some demand, they have not received the proper popularity yet. 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 flavor. The principle of operation of such an oven 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 mixes with oxygen. Through the lower opening in the furnace body comes rarefied air, which in conjunction with oxygen provides an oxidation reaction. Actually 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 their own hands, with competent performance can work on one portion of fuel up to 12-14 hours.

About the device

It is necessary to understand that the pyrolysis furnace consists of two combustion chambers. Both are needed to maintain combustion. One of the chambers into which fuel is loaded must be tightly closed to prevent oxygen from entering. Do not forget this when designing the product. As a result, pyrolysis gas is formed, which rises to the combustion chamber where it mixes with secondary air. At the same time, the combustion efficiency increases, as does the heat transfer. The upper and lower chambers are separated by grates. One of the features of the technological process is the upper ventilation. In addition, the organization of forced draft is important. This will significantly reduce the aerodynamic drag.

Pyrolysis oven with your hands: about safety

If you are going to design the heating equipment on your own, you should understand that strict requirements are imposed on the quality of the air-fuel mixture and the safety of the furnace itself. For this simple reason, you will need at least minimal experience with drawings and ownership of any type of welding equipment. For precise work, you will need to use electronics, and for high quality of the case - alloy steel. The electronic component is needed to control the pyrolysis process. If this is not taken into account, then your pyrolysis furnace will by and large become a very ordinary burger. Well, now let's move on to the main stage, we'll see how to make the equipment yourself. If you have the proper skill and equipment, this will not be very difficult.

Materials and Tools

Before the pyrolysis oven itself is constructed, it is necessary 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 (USM). In the priority it should be under a circle with a diameter of 125 mm, if this is not possible, then the option is 230 mm. 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 can 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 bricks for lining. At hand should be cutting and grinding wheels 230 and 125 mm, respectively. To organize electronics, not much is needed. A fan and a temperature sensor will suffice. The grates are used to separate the chambers. Do not forget to buy two doors.

Pyrolysis oven with own hands: instruction and technology

Work begins with calculations. If you do not have an engineering mindset, you can contact the specialists for help. Usually the prices for such services are small. The circuit itself looks like this:

• Welding works. Here you have to make a steel hull and chambers (combustion and afterburning).
• Lining of the inside of fireclay (refractory) bricks.
• Execution of holes for supplying oxygen supply systems to the combustion chambers.
• Preparation of the combustion chamber window and door installation.
• Installation of water jacket.
• Mounting the fan in the discharge pipe.

According to this scheme, a pyrolysis oven is made by oneself. Drawings in this case can either be present or not. The first option is more preferable, as the accuracy of the work and the performance characteristics of the product will be better.

Commencement of work

It is necessary to understand that the basis of any boiler is a furnace 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. The cutting of the walls must be carried out with the help of a grinder 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. Afterwards, stiffeners are created from the profiled tube . As you can see, so far the pyrolysis oven with your own hands, the drawings for which should be at your fingertips, is very simple. The main thing here is to observe technology.

Making important knots

Any brick pyrolysis furnace, made by hand, means the presence of a door for the combustion chamber and the ash compartment. They need to be done. To start, holes are drilled in the front wall, which are made according to the size of the door. To work as accurately as possible, it is recommended to mark up with a sharp object and then start cutting.

Next you need to prepare a water tank. The tank must be made of stainless steel. It is extremely important to weld a container that will not leak. If in doubt, then it's best to consult a specialist. Mini pyrolysis oven with its own hands is manufactured in the same way as its large prototype. In any case, this is a complex of pipes, which forms a flow path between them with a large heat transfer.

How to assemble the structure?

To reduce labor input, it is recommended to perform assembly on site. Take care of this in advance so as not to carry weights. Before proceeding, the foundation is laid, then the inner walls are put along the perimeter, and the ash compartment is mounted on the bottom. The inner walls are connected by welding. In principle, the body is ready, now it's time to weld the combustion chambers, heat exchanger and grate guides. The stiffeners are welded vertically , and then the outer walls are mounted. Already practically made our pyrolysis oven with our own hands. The scheme implies the presence of sand between the inner and outer walls. It is necessary for the accumulation of heat and protection against overheating.

Finish the construction

After the sand is filled, sealed doors are mounted, the circuit is connected with water. Today, many people say that it is inadvisable to produce a pyrolysis boiler with a capacity of less than 15 kW. In principle, the metalwork is completed. And a simple pyrolysis oven with their own hands is practically made. All that is left is to do some work with the brick. For what a refractory solution is made. By the way, the recipes for cooking there is a huge amount, which one to choose, it's up to you. It is necessary to know that fireclay bricks are suitable for the furnace lining . However, in this case, you do not need to rely on the work of the product for more than one season. As you can see, pyrolysis furnaces are not manufactured very quickly and not as easily as we would like, but it is quite possible to do this.

The final stage of work

And the finishing touches. First, you need to make a heat exchanger made of fireclay bricks. It should be divided into two chambers. Then, the grate is installed in the free position. It should be understood that when heated they expand and fill the gap left. At the very end, the doors are inserted, the latches and levers are adjusted. It is necessary to properly adjust the fan, which is necessary to overcome the aerodynamic drag. For example, a pyrolysis stove with your own hands is made about the same. But its design implies much smaller dimensions and weight due to the absence of lining and thick steel. Nevertheless, in nature such equipment works quite efficiently.