DIY pyrolysis boiler

Houses in regions remote from district heating are most often equipped with solid fuel boilers. Coal and firewood are used for their work. However, this design has a major drawback - the inconvenience of operation. Many people use electric heaters, but for heating they become very expensive. Nevertheless, now you can find a worthy alternative - a pyrolysis boiler with your own hands. A device of this class generates heat by burning wood or special briquettes. In addition, you can take advantage of woodworking waste. Let's take a closer look at the device of such equipment and the principles of its assembly.

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The device and principle of operation of the boiler

When organic substances are exposed to high temperatures, they decompose. This process is called pyrolysis. In order to prevent thermal decomposition from becoming ordinary combustion, the access of oxygen to the material that is involved in pyrolysis is limited.

The device in the pyrolysis chamber is the same as in the furnace of a conventional furnace:

• Through the loading window, solid fuel is placed on the grate, due to which air is supplied to the fuel.
• The fuel is ignited, and when it is all enveloped in flame, the access of fuel is significantly limited, which leads to a cessation of combustion.
• Only part of the fuel continues to burn. The heat generated in this case is sufficient for the rest of the fuel to decompose, releasing pyrolysis gas - a mixture of volatile organic substances.
• The gas is in the secondary chamber, in which sufficient air is supplied. Gas heated to a high temperature flashes from contact with oxygen. When it burns, a large amount of heat is released, which allows the main function of the boiler to be performed - to heat the coolant.

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Advantages of pyrolysis boilers:

• In boilers of this type, almost complete combustion of fuel occurs, so it does not need to be regularly cleaned of soot.
• Due to the fact that the fuel burns out completely, almost no harmful organic waste is emitted.
• Thanks to this, such boilers become not only more environmentally friendly, but also economical, since not only specialized fuel can be used as fuel, but also waste from various industries.
• Due to the more efficient use of fuel, one of its bookmarks is enough to work for twelve or more hours. At the same time, the direct burning boiler has enough bookmarks for four to five hours of operation. Thus, significant savings.

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Disadvantages of a gas boiler:

• The high cost of construction. Of course, it will pay off during operation, but the initial investment will be high.
• Care must be taken to monitor fuel moisture. If the humidity is above 20 percent, you will have to dry the fuel, otherwise the boiler will go out.
• The primary chamber may go out due to the low temperature of the coolant.
• Most models use forced draft using special air pumps that need to be connected to the mains.

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Making a pyrolysis boiler

You can make a pyrolysis boiler with your own hands, drawings and the principle of operation can be found on the Internet. Initially we prepare tools and materials. You should get:

• A set of drawings or a schematic diagram in which dimensions are indicated;
• Welding machine;
• Electrodes - two or three packs;
• Large and small angle grinders;
• Cutting circles;
• Grinding wheels;
• A pipe with a wall thickness of 3 mm, a diameter of 500 mm, a length of 1300 mm;
• A pipe with a wall thickness of 3 mm, a diameter of 450 mm, a length of 1500 mm;
• Pipe diameter 57 - 60 mm, length 1200 mm;
• Two rings with a diameter of 500 mm and a width of 25 mm;
• The sheet of metal from which the loading door and hatch for cleaning ash will be made;
• Two sets of hinges, handle, valve;
• Pieces of a channel or a corner from which legs and an impeller will be made;
• Asbestos cloth, which will be laid in the door;
• Asbestos cord, with which the firebox door and ash pan door will be sealed.

After all the preparations, you can begin to make a pyrolysis boiler of long burning with your own hands.

Making the boiler body:

• Pipes with a length of 1300 and 1500 mm are inserted one into one and connected using a ring.
• A circle with a diameter of 450 mm is cut out of a metal sheet and welded to the bottom of the inner pipe. As a result, a barrel with a diameter of 450 mm is obtained with a 25 mm wide welded around circuit.
• A rectangular hole is cut in the lower part of the barrel, the width of which is 150-160 mm, the height is 80-100 mm.
• Next, the ash pan hatch is welded in, a door is equipped with hinges and a latch.
• In the upper part of the “water jacket” a rectangular hole is cut through which fuel will be loaded.
• Next, the loading hatch is welded in, the door is equipped, hinges and a latch are hung.

Important! To reduce heat loss, the door is doubled, a double gasket is placed inside.

• An exhaust pipe is welded at the top, which will release the burnt gases into the chimney.
• In the upper and lower parts of the water jacket are welded pipes with a diameter of 40-45 mm, which are designed for the heating system.
• Threads are cut into the nozzles.

Important! It is necessary to thoroughly soap all the welds and pressure the boiler jacket with a pressure of more than 2 kg / cm2. All welds are thoroughly checked.

Air Dispenser Fabrication:

1. A circle with a diameter 20-30 mm smaller than the inside diameter of the boiler is cut out of a metal sheet.
2. A hole with a diameter of 57-60 mm is cut out in the center of the circle.
3. The air distribution pipe is inserted into the hole, everything is connected by a sealed seam.
4. Pieces of the channel or corner in the form of blades are welded onto the lower surface of the metal circle.
5. On the other hand, a loop is welded for raising and lowering the structure, the damper is adapted, with which the air supply to the combustion zone will be regulated.
6. A circle with a diameter of 500 mm is cut from a metal sheet, in the center of which a hole with a diameter of 70-80 mm is cut.
7. The air distributor is inserted into the boiler, the upper end of the pipe is threaded into the hole, the upper cover of the boiler is tightly welded.

The pyrolysis boiler, the drawing of which is very simple, is ready! Now it remains to test him.

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Pyrolysis boiler installation

When installing a heating system, it should be borne in mind that this type of boiler cannot be installed in a residential building. If you install the boiler yourself, follow the fire safety rules:

• The distance to the walls of the boiler room must be at least 300 mm;
• The foundation must be of non-combustible material;
• The ventilation system must be in good condition, since for the operation of the boiler an influx of fresh air is required;
• The chimney must be well insulated so that the roof of the boiler room does not catch fire.

Important! These rules do not differ from the rules intended for boilers of other types. Many homeowners are interested in how to convert a solid fuel boiler into a pyrolysis one.It is possible to do this, but experts recommend making the boiler “from scratch”.

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Thanks to the pyrolysis boiler, heating can become more profitable, since the fuel burns out almost completely. Another significant advantage is the long burning time, which means that you will not need to be afraid that the wood will burn out and the stove will go out. Reach comfortable conditions in your home with affordable means, then you will have more opportunities for relaxation!