Charcoal kiln "Continuous"

The charcoal kiln is designed for continuous charcoal production from hardwood and softwood. Production capacity of this kiln is 3400, 6000, 12000 tonnes/year of charcoal; the yield of charcoal when using hardwood species – not less than 170 kg/solid m3.


Description

The continuous furnace includes::

      1. Vertical shaft type kiln;
      2. Vertical twin wood dryer
      3. Recovery boiler, furnace for burning pyrolysis products
      4. *other equipment according to the pre-agreed specification.

The installation uses the following technical solutions:

      • The pyrolysis products of wood, which are burned in large volumes, provide the entire process with the heat of their own production. In the process of their combustion, flue gases with thermodynamic properties are formed, which in turn make it possible to pre-dry the wood, contribute to the decomposition of wood into gaseous, liquid substances and charcoal, and release thermodynamic steam for heating liquids for various purposes (technical and domestic).

      • Pyrolysis of wood solves the problem of processing liquid waste, various acids that can get into ground- or drainage-water and soil, so worstening the environmental situation.

      • An increase in the proportion of the final product of pyrolysis - charcoal - is achieved due to the automatic control of process parameters such as temperature, the presence of O2 (oxygen) and the gaseous substances used for heating.

      • Reduction of the amount of excess heat; the generation of thermodynamic steam occurs using a special residual heat boiler.

In order to get a final product yield of 170 kg / m3 and more, hardwood species should be used.

Raw materials

Good charcoal is produced under specific conditions. Raw materials should have the following characteristics: logs should be no more than 30 cm in length, their diameter should be 3-12 cm. Wood material must comply with established standards. It should not contain voids, putrefactive manifestations or rot.

Substandard wood can also be processed: but in this case, the annual productivity will decrease, while the yield of fines fraction will increase.

Technical description

Technical and commercial indicators

No.Name of parameterValue
1.Productivity of finished charcoal, tonnes/hour0,435 / 0,7 / 1,4
2.Wood consumption per 1 ton of charcoal, m36,3
3.Process water consumption per 1 ton of finished products, thousand m30,06

 

Technology Brief

To obtain gastronomic charcoal, it is necessary to comply with technological standards in its production: EN 1860, DIN 51749-N, AFNOR. The charcoal produced will have the following chemical composition:

  • Solid Carbon Content (Cfix) 78 – 88%
  • Volatiles 12 – 16%
  • Moisture content <6%
  • Ash content <4%

Fractions of charcoal, which reach a size of 20-60 mm and above and which meet these standards, are considered «commodity».

Logs, the length of which is not more than 30 cm, are placed in the hopper (9). Then, a special lifting device loads the material into the twin dryers (21 and 22) (vertical direct-flow). Loaded logs are fed through a distribution hopper and sealed chambers (loading).

The drying process is achieved by feeding the drying gas and wood to the top (direct-flow principle of operation). The maximum temperature is set at 230o C. This temperature is achieved by the addition of recirculating gas. Ordinary atmospheric air supply is also possible.

After drying, the wood falls into the retort chamber, equipped with a special double shutter, which is hermetically closed. Then the wood passes into the retort (1) (vertical part of kiln with continuous action).

While the wood goes down, there is a supply of the heat carrier gas moving up. The transfer of heat causes the pyrolysis processes necessary for the production of the final product, charcoal, to occur.

Technological production scheme of CK “Continuous”

Technological production scheme of CK “Continuous”

A gas injector increases the temperature to 500-600 oC, and injects heat-transfer gas to the middle of the retort. The supply temperature directly affects the type of charcoal obtained. After passing the retort, the heating gas along with the pyrolysis products is discharged in the upper part of the retort at a temperature of 1500 oC. The charcoal produced, constantly descending, passes through the heating gas inlet zone, after which it enters the cooling zone located at the bottom of the retort. Cooling occurs due to the supply of cold flue gases with a temperature of 30-40 oC in the lower part of the retort. Cooling gas is removed from the middle of the retort with a temperature of 350 degrees.

After cooling, the charcoal passes through the discharge chamber with a double tight shutter. With the help of an automatic device (conveyor), it enters the intermediate bunkers.

Only conditioned charcoal enters the hopper. The fine fraction is pre-screened. It, in turn, can be used in industry.

The heating gas that has already been exhausted and the pyrolysis products (resin, various acids, combustible gases) are discharged into the combustion chamber (3) through the upper part of the retort. Air is also pumped here with a fan. The supplied air is regulated based on the oxygen content in the combustion products, by a valve. The combustor is increased in volume to 50 m3, to permit complete disposal of combustible gaseous products. The temperature here can reach 1300 °C. During the process in the combustor, the combustion products are divided into three parts. Disposal of the first takes place in the boiler (4), in which steam is formed, providing primary cooling of the combustion products to 200-250 oC. The second portion is sent to the mixing chamber (6), to prepare the heating gas for its further supply to the retort. The third stream goes to the mixing chamber (5), where the lower temperature heat transfer gas for drying the raw materials is prepared.

Exhaust gases are discharged from the recovery boiler using a fan. These are also divided into 2 streams. The first goes to the mixing chamber of the dryer, the second to the mixing chamber of the retort. This is necessary to ensure the necessary gas temperature in both zones . The separation of gases into flows, and their regulation, is controlled by valves.

The heating and cooling gases in the retort are in a closed cycle. The spent heating gas from the dryer is discharged through a special chimney.

Why do customers choose us?

  • No emissions during operation
  • Compactness and mobility of equipment
  • High performance (up to 60 tons of charcoal per month)
  • Full mechanization and automation of the operational process
  • The use of modern materials - reliable design
  • The number of screenings does not exceed 1%
  • Quality and guarantees - confirmed by
    19 years of experience on the market
  • Mobile equipment

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