DE102005038135B3 - Charcoal kiln, for small-scale production, has shaft with grill at bottom, air inlets below grill producing fluidized bed of wood and water bath mounted directly under the grill cooling hot charcoal as it falls through - Google Patents

Abstract

Charcoal kiln, for small-scale production, has a shaft (2) with a grill (7) at the bottom, Air inlets (6) below the grill producing a fluidized bed of wood being treated. A water bath (9) is mounted directly under the grill which cools the hot charcoal (19) as it falls through. An independent claim is included for a method for producing charcoal using the kiln.

Description

The Invention relates to the production of charcoal and in particular a device for the continuous production of charcoal according to the generic term of claim 1 and a corresponding method with this Device feasible is.

devices for the continuous production of charcoal from above undried wood will be fed and from which at the bottom Charcoal is discharged (also referred to as moving bed devices), are known. They are usually used for the production of charcoal on an industrial scale used and are on the optimization of charcoal quality and the full Detoxification and, where appropriate, systemic use of the charcoal fumes in as economical as possible Directed way. These devices have a complicated Build up and are expensive accordingly.

For example, from the DE 29 53 663 A1 a device for environmentally friendly production of charcoal described in which the charcoal fumes are split over a return line in the device itself and burned without consumption of coal and then further burned outside the device in a separate chamber completely non-toxic gases, said chamber at the same time as a heat exchanger serves to heat air, which is passed into the combustion zone of the coal. The cooling of the charcoal takes place here in a cooling zone with cool gas.

In the EP 0 070 710 B1 describes a method and associated apparatus for obtaining a carbonaceous residue, which may be charcoal. There, the charcoal vapors are removed from the top of the apparatus, freed of particles and, where possible, condensed and the uncondensed portion returned to the apparatus in three streams at three different points to complete the process of drying and charring the material being treated to supply required heat. The process is not supplied with air or other source of oxygen. The feedstock is preferably pre-dried to a moisture content of 3-30%. The resulting charcoal is also cooled by means of gas, whereby the gas is heated at the same time.

Also in the process of EP 0 671 453 B1 flammable exhaust gases are withdrawn at the upper end of the device and partially fed to a combustion chamber. Some of the gases are stoichiometrically combusted there with air (the remainder are burned and vented with an excess of air) and mixed with the off-flue gas and introduced into the upper part of the apparatus where the wood (or biomass) is preheated. Another portion of a mixture of exhaust gas and stoichiometrically air-burned gas in the chamber 11 is optionally introduced into the apparatus at two points below the preheat zone and passed co-currently through the moving bed in the apparatus to optimize the conditions in the carbonization zone of the charcoal , The cooling of the charcoal takes place here by means of a cooling gas in a cooling zone.

The EP 1 473 351 A1 discloses a method for smokeless production of charcoal with a high temperature treatment and a device therefor. In this case, the gases which are formed during the charring of the wood are drawn off at the lower end of the device into a combustion chamber; this means that they flow in cocurrent with the moving bed through the device and used as a heat source. The system receives no additional energy. The charring in the charring zone and in the high temperature treatment zone located below the charring zone (temperature preferably 1200-1400 ° C) is controlled by a controlled air supply. The cooling of the charcoal is carried during transport to a Rüttelband in a guide chute, which has water-cooled walls.

in the Contrary to these elaborate methods and devices of the The prior art is the object of the present invention Provision of a device and a method necessary for the generation suitable for charcoal on a small scale are, as they are e.g. by a forest owner to use his beaten Trees especially from low quality and could be needed from the Schwachholzernte. she should not be big Require investment and with the least possible staff costs to operate.

These The object is achieved by the device of claim 1 and the method of claim 16 solved.

The inventive device has a shaft as a reactor in which the charring takes place on. This shaft preferably has continuous vertical walls. Be Floor plan is not limited (e.g., round, rectangular, oval), but is preferably square.

Also, the dimensions of the shaft are not particularly limited, but its height is preferably greater than its

The US 4 145 256 A describes a process for producing carbon with a particularly high carbon content from cellulosic material, such as agricultural waste products. Biomass is introduced from above into a vertical reaction chamber. The housing and the chamber is then heated by means of a heating rod until glowing coal is located in the lower area. The volatile constituents are released and burned in an overlying high-temperature combustion zone or can escape upwards. Above this zone, the temperature drops a little, so that the volatiles, such as tar, partially condense and so accumulate the carbon content of the charcoal.

Of the lower portion of the reaction chamber is sealed. The glowing coal fails a rust down in a limited space. There she is from sprayed with water at the bottom, to cool the coal below 85 degrees Celsius. The charcoal is preferred by so-called rust means in conjunction with interposed Grind plates. The air supply takes place above the grid. Furthermore, no water bath is shown.

Finally, that teaches JP 0 821 8077 A to produce charcoal in a reactor-like container and to discharge it into a spatially separate basin of water arranged next to it. In the middle of the reactor, a water-cooled grate is arranged. Two "pushers" designed as sliders are used to push the charcoal out of the reactor while being operated from the outside. The one slider is located above the grate and urges the charcoal partly through the grate and partly through an opening out of the container. The lower slide pushes the charcoal that has fallen through the grate out through the opening, where it falls into the water tank. Finally, air is supplied via an above the grate, arranged in the middle of the device blower.

diameter or the length one of his pages. In a square shaft, a ratio of side length to height of 1: 2 proven to 1: 3. For example, one side of the square plan can be 2 m long and the height 4 m or 5 m.

Of the Shaft can be made of any heat-resistant material. Advantageous he is made of steel.

Prefers there is an opening to escape wood fumes and gases in the upper part of the shaft.

On The shaft is preferably a lid that is adjustable open can be. In the continuous operation of the device according to the invention he is ordinary placed so that a narrow gap to escape the wood vapors and gases remains open without allowing air through the lid into the device penetrates, which he serves as the above-mentioned vent.

Also At the upper end of the shaft is any suitably designed charging device. It can be located inside the floor plan of the shaft next to the cover be arranged, but is preferably laterally to the shaft as aslant arranged downward chute. The shaft points at the Area, on which the chute is attached, an opening which through a closed on a hinge from above hanging door, as long as no wood is introduced into the device. The loading of the Feeding device can be done by means of a conveyor belt.

In the shaft wall can one or more show holes or control window for monitoring the operation of the device.

Something above the lower end of the shaft is the shaft of one Grating limited. This grating carries the moving bed made of wood and charcoal. Since the charcoal, which is directly above the Grate is located at a temperature of 500 to 600 ° C and at Approaching the device of up to 800 ° C, the grid is expediently made of a highly heat-resistant Special steel.

The Size of the openings hang in the grate depending on the size of the feed material. This may as a whole of course not through the openings fall in the rust. When using the device with sawed logs a length e.g. of at least 30 to 40 cm, the openings can be about 20 cm × 20 cm to 30 cm × 30 cm tall. The charcoal is falling only through the grate when it is almost completely charred is; At this stage she becomes friable. As a result, that wanders entire charcoal bed in the device down.

The Air supply to the device according to the invention is by preferably adjustable air supply means, which are useful in the Near the bottom of the shaft below the grate in the shaft wall are admitted, regulated, in general, so that a temperature of 500 to 600 ° C charcoal at the bottom of the shaft.

Just below the shaft is a Water tank whose water level is preferably directly adjacent to the lower end of the shaft. In this way, no air can get into the device at this point. Preferably located under the grate in the pool a transport device out of the pool, such as a conveyor belt. In this embodiment, the finished charcoal falls through the grate into the water and then onto the transport device in the water basin and is thereby cooled. It is then transported out of the water and dried in the air. The water in the pool is preferably a continuous flow of water through the pool.

The Device can be designed so that it is transportable.

Of the Operation of the device has two phases: the start-up phase and the stationary one Carbonization.

At the Approaching the device is about 3/4 with wood or other Biomass (collectively referred to collectively as wood). This does not have to be pre-dried. about the water basin and under the grate will be on one for this purpose attached plate a fire with a solid dried flammable Material ignited until the wood burns. At this stage, directly above the Grating temperatures up to 800 ° C arise. After a certain Time entertains the combustion above the grate itself, regulated by the air supply means, and the fire under the grate can be extinguished and the plate removed become.

If the wood or the charcoal bed is in steady state, runs the Charring without external energy supply, only with through the air supply means Regulated air supply, with the air in countercurrent to the wandering movement the bed flows upwards. The bed then has 3 zones: an upper drying zone in which the damp wood due to the rising warm vapors and gases is dried; a medium flame zone, in the wood vapors escape from the wood and partly from the air flowing through from below burn (the flames have the usual flame temperature of over 1000 ° C, but the temperature of the wood is below 600 ° C); and a lower glow zone, whose temperature is regulated to 500 to 600 ° C by means of the air supply means is and in the still remaining in the wood, not degraded to steam Non-carbon residues to be burnt; back remains essentially pure porous carbon, so the charcoal.

These Charcoal is, as mentioned above, friable and falls through the grate on the transport device in the pool, thereby she cooled becomes. It is then transported out of the water and dried, e.g. just in the air.

The Device becomes to the extent in which charcoal exits the device through the grate, preferably so charged with fresh undried wood that the Bay always about 3/4 filled is. These can be large Wooden parts act, e.g. sawed logs with a diameter of about 20 cm and a length of up to 1.5 m at a Device with a floor plan of about 2 m × 2 m.

In This process produces wood vapors and gases, some of which burn in the flame zone, but in part up in the device and through the gap, the lid leaves open, pour out of this. If necessary, a condensation device can be connected to the gap, in which the condensable part of the vapors is collected. she can if necessary subsequently be fractionally distilled.

The Pass time of the wood or charcoal can in a device of 2 m × 2 m × 4 m are less than 3 hours. This produces 0.5 to 1 tons of charcoal per hour. The device is needed only one operator. It is therefore ideal for the need for charring of wood on a small scale customized.

Short description of drawing

1 shows a partially broken, perspective oblique view of a preferred device according to the invention.

2 shows a side sectional view of the device of 1 ,

Now, an embodiment of the invention with reference to the 1 and 2 described.

A device 1 for the production of charcoal includes a vertical shaft 2 with square plan of steel with the dimensions 2 m × 2 m × 4 m height. The shaft 2 is at the top with a through a facility 13 adjustable to open lid 3 made of steel. In steady state operation of the device is the lid 3 opened a gap wide to allow the resulting vapors and gases to escape. On one side of the shaft 2 is an opening along the entire width of the page in its upper part 14 present to which a charging device 4 in the form of an obliquely downward slide connects. The opening 14 is down through one hanging door attached to a hinge (not shown) 5 , which can open to the interior of the shaft, closed when the device 1 not charged. For loading the device 1 with not dried tree trunks 15 (or other suitable biomass) is a conveyor belt 20 intended.

At a distance of a few centimeters from the bottom of the shaft 2 lies over the whole layout of the shaft 2 a grate 7 with openings 8th made of heat-resistant special steel. The openings 8th have dimensions of 20 cm × 20 cm.

In the side walls of the shaft 2 below the grate 7 are adjustable air supply means 6 admitted.

At the level of the wood or charcoal bed in the shaft 2 there is a lookout 12 to monitor the operation of the device 1 ,

Under the shaft 2 there is a pool of water 9 on one side of the shaft 2 goes beyond this. The water level 10 of the water basin 9 adjoins airtight to the lower end of the shaft 2 at. In the water basin 9 there is a conveyor belt 11 covering the whole area under the grate 7 takes and out of the water bath 9 out to a discharge point (not shown).

In the shaft 2 is the moving bed made of wood or charcoal, which is about 3/4 of the height of the shaft 2 occupies. It has three zones: an upper drying zone 16 in which the damp wood through the rising, at this point more than 300 ° C warm vapors and gases in the shaft 2 is dried. Then there is a middle flame zone 17 with a height of about 50 cm, escape in the wood vapors from the wood and partly at the bottom of the air supply means 6 burn incoming air. The flames have the usual flame temperature of over 1000 ° C, but the temperature of the wood is below 600 ° C. Finally, the moving bed has a third, lower Glimmzone 18 with a height of about 30-40 cm, their temperature by means of the air supply means 6 is regulated to 500 to 600 ° C and are burned in the still remaining in the wood, non-vapourised non-carbon residues, leaving substantially pure porous carbon, ie charcoal remains.

The finished, friable charcoal falls in the form of smaller pieces 19 through the grate 7 with cooling by the water in the water basin 9 on the conveyor belt 11 on which it is from the pool of water 9 is transported to a discharge point (not shown).

Claims (28)

Apparatus for the continuous production of charcoal in a moving bed of wood or other biomass ( 15 ) comprising: a) a delivery device ( 4 ) for wood or other biomass ( 15 ), b) a shaft ( 2 ), in which the moving bed of wood or other biomass ( 15 ) and an upper section ( 16 ) for drying, a middle section, a flame zone ( 17 ), for degassing and a lower section, a Glimmzone ( 18 ), to carbonize the wood or other biomass ( 15 ), so that charcoal ( 19 ) arises, c) one or more arranged in the lower region of the shaft air supply means ( 6 ), d) a grid arranged in the lower area of the shaft ( 7 ), on which the moving bed is supported and the charcoal ( 19 ) passes downwards, characterized in that the device further e) under the grid ( 7 ), directly adjacent to the shaft ( 2 ) a water basin ( 9 ) for catching and cooling the grate ( 7 ) passed charcoal ( 19 ), and f) the air supply means ( 6 ) below the grid ( 7 ) are arranged. Device according to Claim 1, in which a transport device ( 11 ) for transporting the charcoal ( 19 ) is present from the pool of water. Device according to one of claims 1 or 2, in which the transport device ( 11 ) is a conveyor belt that covers the entire surface under the grate ( 7 ) occupies. Device according to one of the preceding claims, wherein the water level ( 10 ) of the water basin ( 9 ) to the bottom of the shaft ( 2 ) and closes this airtight. Device according to one of the preceding claims, in which the water in the pool ( 9 ) is running water. Device according to one of the preceding claims, in which the shaft ( 2 ) has a square plan and continuous, substantially vertical walls. Device according to one of the preceding claims, in which the side lengths of the shaft ( 2 ) to whose height approximately in the ratio 1: 2 to 1: 3 stand. Device according to one of the preceding Claims in which the delivery device ( 4 ) for the wood or the other biomass ( 15 ) is closable. Device according to one of the preceding claims, in which in the upper region of the shaft ( 2 ) one or more openings ( 3 ) are present for the discharge of exhaust gases. Device according to one of the preceding claims, in which the air supply means ( 6 ) in the side walls of the shaft ( 2 ) under the grate ( 7 ) are arranged. Device according to one of the preceding claims, in which the air supply means ( 6 ) are adjustable in terms of the amount of air supplied. Device according to one of the preceding claims, in which one or more control windows ( 12 ) in one or more side walls of the shaft ( 2 ) available. Device according to one of the preceding claims, in which the openings ( 8th ) of the grate ( 7 ) are between about 20 cm × 20 cm and 30 cm × 30 cm in size. Device according to one of the preceding claims, in which an automatic conveying device for feeding wood or other biomass ( 15 ) is provided. Device according to one of the preceding claims, which is designed such that it is transportable. Process for the continuous production of charcoal in a moving bed of wood or other biomass ( 15 ), comprising the following steps: a) supplying the wood or the other biomass ( 15 ) to a shaft ( 2 ), in which the moving bed of wood or other biomass ( 15 ), to the extent that finished charcoal ( 19 ), b) drying the wood or other biomass ( 15 ) in an upper section ( 16 ) of the shaft ( 2 ), c) degassing the wood or other biomass ( 15 ) in a middle section ( 17 ) of the shaft ( 2 ), the flame zone ( 17 ), d) charring the wood or other biomass ( 15 ) in a lower section ( 18 ) of the shaft ( 2 ), the smoldering zone ( 18 ), so that hot charcoal ( 19 e) supplying air in the lower part of the shaft ( 2 f) passing the hot charcoal through a grid ( 7 ), characterized in that the method comprises the step g) catching and cooling the hot charcoal ( 19 ) in a water bath ( 9 ) under the grate ( 7 ) directly to the shaft ( 2 ), and h) supplying air in steps (e) below the grid ( 7 ) he follows. The method of claim 16, wherein the wood or other biomass ( 15 ) by means of a conveyor belt ( 20 ) is charged. Method according to one of claims 16 or 17, in which moist or dry wood ( 15 ) is placed in the device in the form of sawn logs up to about 20 cm thick and up to about 1.50 m long. A method according to any one of claims 16 to 18, wherein the supplied Air quantity is regulated. A method according to any one of claims 16 to 19, wherein air is supplied in such a way that a steady state and a temperature of about 500 ° C to 600 ° C in the Glimmzone ( 18 ) of the moving bed. A method according to any one of claims 16 to 20, wherein the during degassing escaping hot wood vapors and wood gases flow upwards in countercurrent to the migration of the bed. Process according to one of Claims 16 to 21, in which the hot wood vapors and wood gases escaping during the degassing are in the middle flame zone ( 17 ) of the moving bed partially burn. Method according to one of claims 16 to 22, wherein the drying of the wood or other biomass ( 15 ) takes place in the moving bed by heat together with hot wood vapors and wood gases escaping during degassing. Method according to one of claims 16 to 23, wherein the charcoal ( 19 ) with a conveyor belt ( 11 ) is transported out of the water bath. Method according to one of claims 16 to 24, wherein the charcoal ( 19 ) from the water bath ( 9 ) and then dried by air. A method according to any one of claims 16 to 25, wherein the average cycle time to finished charcoal ( 19 ) is between about 2.5 and 3.5 hours. A method according to any one of claims 16 to 26, wherein the average charcoal yield per hour approximately between 500 and 1000 kg. Method according to one of Claims 16 to 27, in which the shaft ( 2 ) always remains about 3/4 filled.