Coal-burning furnaces for the production of charcoal. Self-incineration oven

Charcoal is one of the most ancient types of fuel. It is used not only for cooking and heating the house. It is used in the chemical and metallurgical industries, in livestock and construction, medicine and pharmacology. Today, most of the charcoal is produced in small enterprises. The production of charcoal and its sale is a lucrative business in the areas where forests grow, and it can be organized even on your own countryside site.

The process of carbonation

As wood raw materials are used not only firewood of different types of wood, but also waste woodworking or furniture production: knots, hemp, sawdust. Peat is used in marshy areas.

Wood in the process of charring goes through three stages: preliminary drying, thermal decomposition and cooling.

The initial drying and heating of the raw material in the chamber is due to the heat supplied from the outside. The own process of heat generation (chemical exothermic reaction) begins when the temperature of the wood reaches 280 ° C. Further heat supply is no longer needed.

Finished coal after burning is cooled to a temperature at which it is impossible to spontaneously burn coal, that is below 40 ° C.

During the first day in the mixture of flue gases and char products, there are still a lot of water vapor that are released during the drying process. Then the mixture becomes drier and can be used as additional fuel in the same furnace or, more effectively, in a nearby standing.

Equipment for burning coal

For the production of charcoal, coal-burning furnaces of various capacities are used. It turns out that such coal in the process of pyrolysis, that is, wood is burned without access to oxygen.

Coal-burning furnaces for the production of charcoal are produced stationary and mobile.

Stationary equipment is used by large enough manufacturers for the continuous process of pyrolysis of large volumes of wood.

Large stoves are much more productive than mobile ones, they can use several types of fuel, but they are subject to high environmental safety requirements.

Mobile ovens are inefficient, small in size, and are used either in places where there is raw material, for example, in logging areas, or where the final product is needed, for example, at construction sites.

In mobile furnaces fuel is the same waste of wood, of which coal is produced.

If the furnace operates on waste, the benefits are double, and coal is produced without additional fuel costs, and waste is recycled, which still would have to be disposed of, spending time and money on this. This type of production of charcoal is the cheapest.

Continuous combustion equipment

A separate group consists of coal-burning furnaces in which flue gases from combustible fuel enter the chamber, pass through wood, attach to them vapors and gases, which are products of drying and charring of wood raw materials, and come out. In them, the process of pyrolysis passes most evenly, since the wood directly contacts the coolant supplied from below. But pyrolysis chemicals contain a large concentration of chemical compounds, which are the products of decomposition of wood, so you need to install additional equipment for the useful use or burning of pyrolysis by-products.

This is how the continuously operating vertical retorts work, in the chamber of which the wood is dried at the top, pyrolysis passes in the middle layer, calcination of coal and its cooling - at the very bottom.

Continuous operation of the furnace and coal combustion with removable containers or retorts. The principle of operation of such facilities is that each subsequent batch of raw material is heated to the required temperature due to the exothermic reaction in the previous one.

In this process, the formation of coal occurs in each retort independently of the others, and the furnace, in which the pyrolysis gases are discharged, is located separately from the replacement chambers.

Retorts and chambers for pyrolysis are made of metal with thermal insulation.

Carbon burning equipment

The simplest construction of a coal burning furnace is a conventional two-liter metal barrel into which wood is laid and set on fire. Additional heat is not supplied, and gas masks are discharged through a special small hole. Production of low-quality coal, with output less than fifteen percent, dirty, but practically cost-free.

There are now designs of coal-burning furnaces in which the walls of the chamber are heated by the coolant, from which the heat is transferred to the firewood in it. This, as a rule, charcoal kilns of the periodic cycle, where at a certain time intervals there is a whole process of burning coal: wood is loaded, re-routed, the finished coal is unloaded, the wood is again loaded, and so on.

In mixed-action machines, the loading of timber and the discharge of finished coal is periodically performed, but some part of the wood is always in the process of pyrolysis.

Furnaces can also be made of metal or bricks.

Three-chamber char combustion

The steam-gas mixture, which is removed from the pyrolysis chamber, condenses upon cooling. Pyrolysis liquid (liquid) and non-condensable gases, since they are not widely used, are used as additional fuel in the combustion chamber. The withdrawal of by-products for afterburning is provided by the design of the furnace. The effect of this design is not only in fuel economy, but also in protecting the environment.

Three-chamber coal-burning furnaces provide a continuous cycle of coal production. In each chamber, one of the stages of the cycle passes separately, and the initial drying of the raw material occurs due to the heat that is obtained by burning pyrolysis gases. In addition to saving fuel, such furnaces have many other advantages. Since the loading of wood and the unloading of the finished coal occur at different times, the operating personnel are loaded more evenly. The cost of a three-chamber furnace is lower than a single-chamber furnace of the same volume, and the efficiency and service life are higher due to load sharing.

Such equipment is designed for long-term operation in large plants, and if it is equipped with a gas-generating boiler, then sawdust and shavings can be used as fuel.

Single-chamber char combustion

Charcoal in small quantities (up to 8 tons per month) can be produced in a single-chamber furnace. The full production cycle depends on the model of the device and can take 1-3 days.

Such an oven can be used in private households, in public catering establishments, for the purpose of recycling waste products and substandard products in small woodworking enterprises.

The principle of production in them and large-scale industrial furnaces is no different. Single chamber furnaces are usually smaller in size, they are loaded with less raw materials, but they take up less space, they are easy to transport if necessary.

For a long time abroad there has been a production of coal-burning stoves for domestic use. Dishes on the grill or barbecue are cooked on environmentally friendly charcoal.

Characteristics and design of a coal burning furnace

Manufacturers of coal-burning furnaces, both foreign and domestic, as the first characteristic indicate the working volume of one chamber and the total number of chambers in the furnace. Then it is usually indicated the volume of firewood with the given sizes and humidity, which can be loaded into the furnace at a time. This indicator is important for observing the next parameter - the duration in hours of the main working cycle.

To determine the efficiency of a particular model, two parameters are set for one type of wood - the estimated number of firewood loaded into the pyrolysis chamber and the output of coal from them.

The last ones indicate the overall dimensions of the furnace and its mass. If the device is not supposed to be transported, this data may not play a special role, but during transportation it can become decisive.

As a rule, a household single-chamber furnace is a metal barrel with a small slope or a metal barrel mounted on a support with a furnace built-in at the bottom.

The furnace itself, the furnace body, the pipe box and the hatch door are made of steel with a thickness of at least 3 mm, and the outer skin is 1 mm thick.

Double-sided welds, which connect the shells of the case, are strengthened by shrouds, which are made of a pipe of rectangular cross-section, impart rigidity to the structure and additional strength, if the container suddenly increases pressure.

To reduce heat loss between the body of the chamber and the outer skin, a thermal insulation material is laid. This measure increases the efficiency of the furnace. The walls of the furnace from inside are laid out with fire-resistant bricks.

Devices for afterburning of charring products can be supplied separately.

Self-incineration oven

The barrel on the stand is the simplest design, but for greater efficiency and fire safety the barrel needs to be installed on a nonflammable substrate or buried in a pit.

From brick or metal, you can independently manufacture carbon burning kilns. A drawing can be found on the Internet, as, however, and a fairly detailed description. However, it should be understood that the quality of the homemade oven and the final product is much lower, and there will be no large volumes of coal.

In the summer cottage you can make a coal pit, or you can build a coal burning furnace from barrels. To do this, you need to excavate a hole of this diameter so that a barrel can fit into it, which you still need to brick, in the bottom of the barrel, cut a hole about 100 mm in diameter and put it in the pit with a hole down.

Then it is necessary to lay a barrel with bricks, slots at the top to close with some fireproof material, and with mineral wool to insulate the upper bottom. That's all, you can get your coal for the fireplace and barbecue.

The design of the two barrels is more effective and reliable. The container, which is half the size of the volume, is put into a large container, filled with firewood and covered tightly with a lid, and small-fraction waste of wood is poured into the space between the walls and ignited, then the big barrel is also closed with a lid in which the pipe is inserted. But both of these furnaces are suitable for use only outdoors and far enough away from them.