Long-burning furnaces are a logical development of classical furnaces used for heating residential and technical premises. The appearance of such devices is associated with the desire to increase the heat transfer from one quantity of firewood (to increase the efficiency of the furnace) and to extend the operating time on one load.
The main fuel for such stoves is firewood. Alternatively, compressed briquettes containing woodworking waste or sawdust can be used. Coal and its varieties are used less often, since they contribute to the accelerated burning of the material of metal walls.
Design
There are many factory modifications of furnaces that differ in cost and functionality. A number of them are designed for heating and cooking. Consider the simplest options for equipment at home, garage or cottage, which you can order a welder or do it yourself.
The principle of burning in classic long-acting stoves is based on the advancement of the flame in the laying of firewood from top to bottom. An example is the burning of a match - if the sulfur head is at the top during arson, the flame will slowly “creep” down until it reaches the fingers.
Upward movement of the flame leads to almost instantaneous combustion of the match. In this case, heat generation is significantly reduced, since the substances released during the decomposition of the tree do not have time to burn out and give heat. When slowly interacting with atmospheric oxygen, it manages to react with a greater amount of released gases, which makes such a process energetically justified.
The simplest design, which has a really long work cycle, got its name from the name of the developer - “Bubafonya”. There are various modifications to its layout, which you can prepare yourself.
This furnace is a thick-walled metal cylinder, the lower part of which has a welded flat bottom. A circular hole is cut in the upper side of the cylinder, to which a pipe for flue gas removal is welded. From above, the cylinder is closed by a removable cap having a cut hole in the middle. A pipe is inserted into it, acting as a blower.
A disk with a diameter slightly smaller than the internal dimensions of the barrel is welded to the bottom of the pipe. It serves as a kind of piston that goes down as the firewood burns. To improve the contact of the bookmark with the incoming air, metal strips having an arbitrary shape are welded to the bottom of the disc.
Flue gases in such a furnace go around a metal disk and exit through a side pipe. The latter is connected to a high pipe (more than 3 m), necessary for the complete removal of combustion products and to prevent their entry into the room through the remaining slots.
The advantages of this design include:
- the lowest consumption of firewood among similar designs;
- long burning time (up to 8 hours);
- the practical absence of ash in the combustion products. Cleaning such an oven with constant use is sufficient once a week.
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Disadvantages of the Bubafon furnace:
- weak heating of the chimney leading to the formation of condensate;
- the inability to heat a completely large room;
- the need to control the combustion process in order to avoid burning into the room.
In difficult weather conditions, such a stove will be a real gift for heating a barn, garage or cottage trailer. With it, you do not need to constantly run outside for firewood or keep them right in the room.
More familiar to our opinion, the fireplace stove is not new, but it has all the signs of a long burning stove. The peculiarity of its design is the presence of a special protrusion before the start of the chimney, twisting down the spiral of flue gases and directing them back into the combustion zone.
Together with the special design of the chimney, which has bends along its length, only a limited amount of combustion gases is removed from the fireplace. The speed of their exit is additionally regulated by shifting a special shutter - view.
The advantages of the English fireplace stove are associated with its properties such as:
- the consumption of less air for the combustion of one amount of firewood. This increases the heat transfer, as it prevents the heating of excess air mass;
- repeated contact of air mixed with flue gases increases the degree of conversion of fumes and burns it to carbon dioxide;
- reduced exhaust gas increases the duration of combustion and increases the interval between the laying of firewood;
- with the correct design of the fireplace it is not necessary to constantly monitor the correctness of its operation. After entering the mode, it will function as fuel is added.
Try to minimize the use of fuel other than firewood and fuel briquettes. For coal, it is better to use specially designed furnaces.
How to make?
Lay out an English fireplace with long burning do it yourself, but this requires the knowledge of a bricklayer and stove maker.
The stages of the construction of the fireplace include:
- careful layout of the room, excluding the presence of combustible materials near the furnace;
- provision of a stock of building materials. The laying of the furnace is undesirable to be interrupted, otherwise you can get a structure that is prone to cracking;
- preparation of the base (foundation) for the furnace;
- masonry and installation of plug-in elements.
Before work, it is advisable to study the subject literature in order to get a truly high-quality and efficient heating system.
To assemble the Bubafony furnace with your own hands, you need welding, a grinder, a file for deburring, a hammer and pliers for bending the edges of the metal. The ideal material for the preparation of the furnace frame is a metal cylinder with a thickness of 4-5 mm.
For practical purposes, you can use a large gas cylinder, a thick-walled barrel or a piece of pipe. Depending on the available material, the dimensions of the elements to be joined will vary.
The steps for assembling the furnace are as follows:
- we give the initial workpiece an even cylindrical shape having an even bottom and neck;
- weld to the resulting workpiece a flat bottom;
- we make a cover for the furnace, the edges of which will be slightly bent inward - this will fix its position. In the middle of the cover we make a hole that will be slightly larger than the diameter of the duct pipe;
- in the upper part of the body we cut a hole for the chimney and weld the outlet pipe. It will be further fixed to the main chimney;
- preparing the movable part. To do this, we weld a flat disk to the duct, which is slightly smaller than the internal diameter of the furnace. We fix guides from below to the disk that will allow air to be freely supplied to the wood.
After all the manipulations, the oven is ready. Now you need to install it in place, attach it to the chimney and make a test run with a small load of dry firewood. The dimensions and appearance of the Bubafonya furnace can be seen in the figures. We also recommend watching a video in which Alexey will talk about the process of creating a stove from a gas cylinder:
Precautions
All long-burning furnaces, with the exception of automated factory equipment, require constant monitoring. To a lesser extent, this applies to English fireplaces, which have been tested by time. To reduce the risk of furnaces made of metal, you should pay attention to the following nuances:
- between the heated surface and the walls you need to put a reflector that will prevent fire and direct heat to the useful heating of the room;
- if the furnace works for a very long time, and the temperature of the pipeline is low, then condensate will accumulate in it. Do not forget to drain it to prevent the chimney from breaking;
- control indoor air if using homemade structures. The room may be filled with smoke due to violation of the traction regime, as well as as a result of burning metal surfaces.
Periodically inspect the furnace for through burns of metal. Promotional brochures guaranteeing the performance of a cast-iron stove for 50 years are openly lying - long-term use, high temperature and aggressiveness of flue gases reduce the life time by several times.
Long-burning furnaces are widely used for heating small buildings, repair shops and farms. A variety of materials can be used as fuel, including wood recyclables. A long work cycle allows you to minimize the frequency of fuel replacement and increase the energy efficiency, reducing the cost of purchasing energy.