We make a long burning pot with our own hands - instruction

Solid fuel boilers have a serious drawback - the need to constantly load the next portion of fuel: wood, coal, briquettes or pellets. Because of this feature, they are not even considered as a variant of a boiler for a private house. This problem can be solved by manufacturing a long-burning boiler operating on virtually any kind of solid fuel, including incinerated waste.

The principle of the operation of the boiler

The principle of operation of the boiler of long-term combustion is based on the property of solid fuel, for example, firewood, with a high heat emission for several hours, while combustion of fuel is more complete and the amount of waste is significantly reduced. It is possible to achieve the smoldering of firewood instead of active burning due to the boiler arrangement.

A long-burning boiler is a roomy furnace with a limited combustion zone and adjustable air intake. Loading of a large batch of fuel is carried out once every 12-16 hours, and by limiting the supply of oxygen in the boiler, slow decay occurs at high temperatures. Smoke gases are discharged through a pipe, which, passing through the heat exchanger, heats the water for the heating system. Thus, the loading of the boiler can be carried out only 1-2 times per day, while the heating system will function in a practically continuous mode.

Boiler arrangement

Boiler of long burning, made by hand, it is most convenient to weld from a pipe with a diameter of 300 mm, with a metal thickness of at least 3-4 mm, otherwise the high temperature will quickly lead to burnout of the boiler walls. The height of the pipe can be from 800 to 1000 mm, the volume of a one-time fuel loading depends on it. Conditionally, the boiler can be divided into three zones:

• fuel loading zone, its height can vary as the firewood burns down;
• zone of combustion and generation, where there is a slow decay of fuel;
• is the zone of complete combustion where the ash burns and flue gas is burnt.

The device that limits the combustion zone, and therefore the operating time of the boiler without fuel charging, is called the air distributor. It is a circle of metal 4-6 mm thick with a hole in the center, through which air is supplied through the telescopic tube into the combustion zone. The diameter of the distributor should be slightly less than the diameter of the boiler to ensure its unimpeded movement. The height of the combustion zone, which receives evenly distributed air, is regulated by the impeller and the width of its blades. Usually the height of the air distributor does not exceed 5 cm, otherwise the fuel will burn out quickly enough.

The pipe through which air enters is either telescopic or solid. The diameter of the pipe is about 60 mm, and the hole in the distributor should have a diameter of no more than 20 mm, so as not to oversaturate the combustion chamber with oxygen. Air enters the pipe either directly from the atmosphere, or, for more efficient and stable combustion, from the air heating chamber located in the upper part of the boiler. The air supply to the chamber is regulated by an air damper in the upper part of the boiler.

Flue gas discharge is carried out through a chimney welded to the side wall of the boiler in the upper part. The pipe should be horizontal for 40-50 cm, so as not to create unnecessary traction.

From the bottom it is necessary to execute the door to remove ash, ash and other combustion products. In a long-burning boiler, solid fuel burns out more completely than in a conventional furnace, so ash removal will have to be done less frequently.

Heating of the heating medium for the domestic hot water heating system can be carried out in two ways:

1. Carry out an external tank, inside which the chimney passes. Hot smoke heats the heating medium for the heating system.
2. The water heat exchanger tube is passed through the combustion chamber of the boiler and the water in the tank is heated by the coil connected to this pipe.

The first method is much easier to perform when it comes to a small house. The second method is more effective, but it is more difficult to perform such a boiler construction.

Technology for the implementation of a long-life burning boiler

Materials needed:

• Metal pipe with diameter from 300 mm, metal thickness not less than 3 mm;
• Sheet metal 4 mm;
• Metal pipe with a diameter of 60 mm for air supply, diameter 100 mm - for flue gas discharge;
• Welding machine, Bulgarian.

A long-burning boiler must be installed on a flat horizontal surface, sometimes it is necessary to make a formwork under a boiler made of concrete.

1. The pipe for the boiler is cut to the selected length - from 800 to 1000 mm. If the length is longer, it will be difficult to load firewood. The edges are leveled. Weld the bottom of sheet metal, and if necessary, and legs from the channel.
2. An air distributor is made: a circle made of metal is made 20 mm smaller than the inner diameter of the pipe, a hole with a diameter of no more than 20 mm is drilled in its center. To the bottom of the combustion distributor, an impeller with blades of sheet metal is welded, the width of the blades is not more than 50 mm. In the upper part a 60 mm pipe is welded to the regulator, so that the hole is in its center. The height of the pipe must not be less than the height of the boiler itself. In the upper part, the tube is equipped with a shutter, which regulates the supply of oxygen.
   

   Air distributor for the long burning boiler

3. In the lower part of the boiler, a door is made to remove the ash: a concave rectangle is cut using a bolgar, welded to it with hinges and a locking handle and used as a door.
4. In the upper part of the boiler a 100 mm chimney is welded. The pipe should be practically horizontal for at least 40 cm, after which it is passed through a heat exchanger, a heating system in the form of a tank.
   

   Welding of a chimney to a heating boiler

Make a cover with a hole for the distributor pipe. The cover must fit snugly against the combustion chamber, otherwise smoke will escape from under it.

Fuel loading and boiler operation

Unlike a conventional furnace, in which it is necessary to supply air to the entire volume of fuel, oxygen must be supplied very limited in a long-burning boiler. In addition, the amount of fuel loaded directly depends on the burning time of the boiler. Therefore, the fuel in the boiler of prolonged combustion is loaded as tightly as possible, trying not to leave gaps. In this case, you can use not only firewood, but also peat, coal, combustible household waste, sawdust - in a word, everything that can smolder.

The fuel is loaded as follows:

1. Remove the cover from the boiler;
2. Remove air regulator;
3. Tightly load the boiler up to the level of the chimney;
4. The upper part of the fuel is sprayed with a liquid for ignition;
5. Install the regulator and cover;
6. Open the air flap at the top of the air pipe to the maximum;
7. They throw inside it a burning beam and wait for the beginning of the smoldering of fuel, after which the shutter is covered.

The smoke emerging from the chimney indicates the beginning of sustainable combustion. As the fuel burns out, the air feed pipe will fall with the regulator, it will be possible to determine the degree of combustion of firewood.

Video - long burning boiler with own hands

For the manufacture of a long combustion boiler with a more complicated design with front loading of the combustion chamber, you can use the drawing:

A long burning boiler can be useful not only for heating the house, but also for seasonal heating of the greenhouse,workshop or crib. With proper installation and use it is safe, economical, can work on almost any fuel, including household waste. The boiler does not require constant monitoring, it is sufficiently experienced to find out the frequency of loading. It should be noted that the duration of combustion depends not only on the volume of the boiler, but also on the type of fuel.