RU2045568C1 - Method of producing charcoal and apparatus for performing the same - Google Patents

Abstract

FIELD: forestry and timber procession industry. SUBSTANCE: apparatus for producing charcoal, being in the form of a steel vertical retort, provided by several mutually joined chambers, is mounted with an inclination by 40-50 degrees relative to horizontal surface of the ground. The apparatus has three five chamber-sections, separated one from another by apertural gates, providing upon their successive raising displacement of wood into each next chamber-section, being heated successively at different temperature intervals and being discharged periodically. EFFECT: enhanced efficiency. 3 cl, 3 dwg

Description

 The invention relates to forestry and the wood processing industry.

 Widely known are devices and methods for producing charcoal. The devices used are chamber, retort, and shaft type heating furnaces. In this case, only retort and shaft type devices are considered (the latter as the most productive).

 A retort type shaft furnace is known, which consists of three chambers: drying, carbonization and pyrolysis. All three chambers are located vertically with an offset relative to each other by the size of the diameter, as a result of which the installation has a ladder-like appearance. Connections between chambers in the form of leaks, through which material is unloaded from the previous chamber and loaded into the next one. The carbonization chamber is heated through the walls of the retort, the time of the carbonization process (without drying and pyrolysis) is 47 hours. A shaft furnace of this type has a low productivity, bulky design and gives an increased yield of coal fines formed during unloading of the retort.

 The Swedish gas company’s circulation shaft furnace consists of three separate chambers located one below the other: drying, carbonization and cooling of coal. Material is reloaded through hatches. Drying time is 5-9 hours, the same amount of time the coal cools down, as a result of which the installation has a low productivity. Charcoal is largely destroyed by overload from chamber to chamber.

 The oven of the Lambiot system is loaded with pre-dried wood. Pre-drying is carried out in seven tunnel-type chambers. The internal dimensions of each chamber: length 23 m, width 1.7 m, height 1.95 m. Firewood comes to the drying chambers on trolleys. In total, seven trolleys in operation are 70 trolleys. Drying time is 24 hours. The oven itself of the Lambiot system has the following dimensions: diameter 2.8 m, height of the cylindrical part 15 m, loading area located at an altitude of 25.5 m from the ground. In the middle part of the furnace, a cone facing downward with a hole is fixed, the role of which is to uniformly distribute the coolant gas over the retort section. The residence time of wood and coal in the furnace is 12-19 hours. Installation of a continuous Lambiot, i.e. It has a continuous release of finished charcoal, which leads to a systematic collapse of the upstream material in the furnace and, accordingly, to excessive destruction of the finished charcoal in the lower part of the retort. In addition, the continuous release of charcoal in the lower part of the retort makes it almost impossible to control the quality of the obtained charcoal according to the degree of burnout (carbon content, calorie content, etc.).

 An analogue of the invention is a vertical continuously operating retort, which is a vertical steel cylinder with an inner diameter of 2.7 m and a height of 15 m. The retort is made of separate cages connected to each other on flange bolted joints. At the bottom and top, the retort is equipped with lock chambers through which charcoal is unloaded and timber is loaded. The lower airlock is equipped with three gates, and the upper airlock for loading wood is not finally structurally designed. The designs used had serious drawbacks: they required frequent repairs, did not provide the necessary density, and often failed due to clogging of the sealing devices with wood chips, bark, sawdust, etc.

 The coolant is introduced in the middle part of the retort into an annular space formed by the retort wall and a steel truncated cone attached to the retort walls with a narrow hole down. Purpose of the cone: uniform distribution of the coolant over the furnace section; improvement of heat transfer between the heat carrier and wood; taking on a partial vertical load of the overlying column of material in order to reduce the grinding of downstream charcoal.

 It should be noted that the above technical results can be achieved in other, more rational ways.

The essence of the invention lies in the fact that the steel retort (width 1.0-1.4 m, height 6-10 m, depending on the number of sections) is installed at an angle of 40-60 ^about the horizontal surface of the earth, equipped with 3-5 camera sections , separated from each other by perforated vertical hoists with gates, providing for successive lifting movement of wood into each subsequent chamber. By the length of time the wood stays in all the chamber sections, the required quality of charcoal is achieved depending on the properties of the source wood.

In the production process of charcoal, which includes heating the timber-sections in the cells to 400-600 ^C and unloading timber, heating the wood cells produce 3-5-sections successively in different temperature ranges, and unloading is performed periodically.

 The relatively small dimensions of the furnace facilitate its maintenance. For example, in the case of operation of a 3-4-section furnace (length height is 6-8 m) when using the terrain (installing the furnace on a hill or mountain), the use of expensive loading devices can be excluded, since in this case the retort loading hatch will be located at a height of 1.2-1.8 m from the surface of the earth.

 Perforated gates divide the retort into 3-5 sections (drying, carbonization and pyrolysis), which allows, by adjusting the temperature regime in sections, to obtain charcoal of a given quality; the heat carrier gas is evenly distributed over the retort’s cross section due to the holes evenly distributed over the gate area, and they also assume, which is very important, the entire load of the overlying material, and only 1 / 3-1 / 5 falls on each gate (depending on the number sections in the retort) of the load, as a result of which the grinding of charcoal under the influence of an overlying column of material is almost completely eliminated.

 Figure 1 presents a General view of the installation, section, where 1 retort; 2 camera sections of a retort; 3 supports; 4 insulating masonry made of refractory bricks; 5 lifting hole gates; 6 cables for lifting gates; 7 blocks; 8 tub for loading wood chocks in a retort; 9 cable for lifting tubs; 10 block tubs; 11 guides for the movement of the bucket; 12 firebox; 13 furnace cover for loading solid fuel; 14 charcoal suppression chamber; 15 extinguishing chamber body; 16 conveyor for supplying charcoal to the warehouse; 17 grates of the furnace; 18 chamber for collecting ash from the furnace; 19 cover for unloading ash; 20 gates for loading the charcoal extinguishing chamber; 21 chimney openings; in Fig.2 a section aa in Fig.1, where 22 is a gate for the release of charcoal from the quenching chamber; 23 cable for lifting the gate of the quenching chamber; 24 winch for lifting a hole gate; figure 3 diagram of the boot device (bucket).

PRI me R. The device for producing charcoal is a steel retort 1, consisting of 3 chamber sections 2. The retort is installed obliquely at an angle of 40-60 ^about to the horizontal surface of the earth on the supports 3, which are a welded structure of I-beams or channels. The lower part of the retort (to the midline) is lined with refractory brick along the entire length to reduce heat loss to the environment. The upper part of the retort along the entire length can be covered with any removable lightweight thermal insulation, for example, sheets of iron rolled along the diameter of the retort with a thickness of 0.5-1.5 mm with riveted asbestos sheets.

 The camera sections 2 are separated by lifting hole gates 5, which are raised and lowered by means of winches due to cables 6 thrown through blocks 7. The manual drive of the winches can be replaced by an electric one. Similar gates are installed at the upper and lower ends of the retort, but with the difference that the gate at the upper end of the retort has no holes.

 The loading device consists of a cylindrical vessel-tub 8, moving in the vertical direction with a winch and a cable 9, thrown over the block 10 tubs. On the bucket 8, blocks 10 are welded from two sides eccentrically with respect to its axis, through which the hoisting cables are thrown 9. A furnace 12 with a lid 13 for supplying solid fuel and a chamber for collecting ash 18, as well as a wood quenching chamber, is attached to the lower end of the retort 1 coal 14. The gate 22 (figure 3) is used to release charcoal from the quenching chamber to the conveyor 16.

The method of producing charcoal in the above installation is as follows. Tub 8 is filled with wood chocks and with the help of a cable 9 a winch rises to the upper position. Due to the eccentric position of the blocks 10 in a tub 8 at its upper position, the open upper end of the vanes 5 of the retort is inverted (turn on of ^about 130-140 standard position), resulting in lumps of wood fall into the upper chamber section. After which the cable 9 is released, the bucket under its own weight takes the usual vertical position and lowers to the lower position. The loading gate of the upper chamber section is lowered. Subsequently, wood chocks from the upper chamber section during the alternate raising and lowering of the perforated gates 5 and under the action of their own gravity along the cylindrical generatrix of the retort.

 After drying in the upper chamber section, wood chocks are transferred to the middle chamber section as described above, after which a new batch of wood is loaded into the upper chamber section. Therefore, at the same time, a new batch of wood is dried in the upper chamber section and carbonization of the previous load in the middle section. After the drying process is completed, the corresponding movements are made in the upper chamber-section: the charred wood in the middle chamber-section, when lifting the gate 5, located between the middle and lower chamber-sections, moves to the lower chamber-section. Dried wood from the upper chamber moves to the middle when lifting the gate 5 located between them.

Thus, the moment comes when all the chamber sections are loaded with wood, and in the upper one there is a drying process, in the middle chamber there is a carbonization process, in the lower pyrolysis of wood to produce charcoal at a temperature of 450-550 ^о С (depending on the required quality of the final product by carbon content, calorific value, etc.).

 As the finished charcoal is unloaded from the lower chamber to the quenching chamber, the wood moves from each upstream chamber to the next chamber and the upper chamber section is loaded.

 Wood heating is carried out in the described case with flue gases entering the retort after burning fuel in the furnace 12. Firewood, coal, gas, liquid fuel can be used as fuel. Solid fuel is introduced into the furnace when the lid 13 is lifted, from where the ash spills into the chamber 18 and is removed when the lid 19 is opened.

 If gaseous or liquid fuel is used, a special nozzle for supplying fuel must be installed in the furnace.

 Flue gases from the furnace 12 enter the retort, the passage through which uniformly in cross-section is ensured by holes (perforated gates) evenly located on the surface of the gates. Solid (not perforated) is only the gate at the upper end of the loading retort. After passing the retort under the influence of the draft of the chimney, flue gases through holes 21 and chimneys enter the chimney.

 The finished charcoal is discharged from the lower chamber section into the extinguishing chamber 14, where water is injected through the built-in nozzle to extinguish and cool the charcoal, after which the final product, when opening the gate 22, enters the extinguishing chamber onto the conveyor 16.

Sequential gradual heating in separate chambers-sections of wood portions with a volume of 1.5-2 m ³ allows you to get charcoal with the desired quality characteristics depending on the properties of the feedstock, the duration and temperature of heating and not to grind the charcoal formed in the lower chamber with an upstream mass wood.

The drying process limits the whole process, since it is longer in time than the direct pyrolysis of dry wood. By calculation it found that at ambient temperature, 180-200 ^C. chocks wood drying process is 4-6 hours. Therefore, the residence time in the drying timber (top) and secondary chambers must be a total of 4-6 hours, or in each of these chambers for 2-3 hours. Therefore, the same time is wood in the pyrolysis (lower) chamber. Every 2-3 hours, thus, the release of the finished batch of charcoal from the lower chamber. Ultimately, the time spent by wood in each chamber, and first of all in the drying chamber, depends on the temperature of the flue gases, which, in turn, depends on the type of fuel used.

 An increase in the retort of the number of chamber sections to 4-5 reduces the residence time of wood in the drying chambers to 30-60 minutes each.

Claims (2)

1. A device for producing charcoal, made in the form of a steel vertical retort, equipped with several interconnected chambers, characterized in that the retort is installed at an angle of 40 60 ^o to the horizontal surface of the earth, equipped with 3 5 chamber sections, separated from each other by holes vertical lifting gates, providing for successive lifting movement of wood in each subsequent chamber. 2. A method of producing charcoal, including heating wood in chambers of sections up to 400 600 ^o C and unloading wood, characterized in that the wood is heated in 3 5 chamber chambers in series at different temperature intervals, and unloading is carried out periodically.