RU75657U1 - REPORTS FOR CONTINUOUS THERMAL PROCESSING OF MILLED WOOD RAW MATERIALS - Google Patents

Abstract

The utility model relates to the field of thermal processing of crushed wood and can be used in devices for the continuous thermal processing of crushed wood raw materials. The technical task of the utility model is the creation of a transportable retort for wood pyrolysis, which has a high specific productivity due to the intensification of heat and mass transfer, reducing the size of the pyrolysis apparatus and metal consumption. The retort includes a reactor 1, a unit for loading 2 crushed wood into a reactor 1, a site 3 for pyrolysis of raw materials, a furnace 4, and a unit 5 for collecting gas and vapor. The reactor vessel 1 is installed horizontally, contains a horizontal channel 6 of constant cross section, which is equipped with a knot 7 for pressing the crushed wood raw material mounted at its beginning with the formation of dense but gas-permeable layers in the form of monoliths of wood particles, which simultaneously serve as filters for the coolant and gas-vapor, the node 5 for the selection of combined cycle gases of pyrolysis and waste coolant is located in the middle of the channel 6 and is made in the form of a collector with horizontal slots 8, and a horizontal channel 6 ends with the furnace device 4. The chopped wood continuously enters through the loading unit 2 into the reactor 1. At the beginning of the horizontal channel 6, with the help of the screw 9 of the unit 7, the chopped wood is pressed to form dense but gas-permeable layers in the form of monoliths from wood particles, which simultaneously serve as filters for coolant and combined cycle gases. The pyrolysis steam gas formed during thermal decomposition exits the retort through the collector of unit 5. A countercurrent feed of raw materials feeds the gas coolant from the furnace device 4. The heat carrier is formed from flue gases and non-condensable pyrolysis gases. The coal formed as a result of pyrolysis is pushed from the retort by the screw 10 into the coal receiver 11. 2 p. Fs, 1 nez. P.

Description

The utility model relates to the field of thermal processing of crushed wood and can be used in devices for the continuous thermal processing of crushed wood raw materials.

Known methods of thermal processing of crushed wood in retorts and gas generators of mine type. A disadvantage of the known methods is that the process of thermal processing proceeds with a low relative velocity of the gas coolant, because with an increase in it, there is a mechanical ablation of wood particles from the retort along with volatile vapor-gas thermolysis products; moreover, coal generation is not provided for in gas generating units as a commercial product.

A known method for the production of charcoal and installation for the production of charcoal (RU N 2166527, СВВ 53/02, publ. 02.01.2000). Installation in the form of a retort is a cylindrical chamber mounted vertically, with the transition in the lower part into a cone. Conditionally, the height retort can be divided into three parts: the upper one, intended for drying wood, the middle (expanded), where the pyrolysis and calcination of coal takes place, the lower one - the coal cooling zone. In the interval between the upper and middle zones there is a combustion device where hot gas of pyrolysis, taken from the bottom of the middle part of the retort (pyrolysis zone), as well as combustion air of combined-cycle gases, is supplied by gas blowing. In the upper part of the retort is equipped with a device for loading wood, in the bottom - a device for unloading coal.

A disadvantage of the known retort is the location of the combustion device between the pyrolysis zone and the wood drying zone. Partially burnt

Combined gas from the furnace device is fed into a retort on a layer of wood heated up to 100 ° C, which excludes continued combustion and leads to the extinction of the torch. The temperature in the pyrolysis zone of the retort therefore does not exceed 500 ° C, which reduces the productivity of the installation, does not allow to obtain high-quality coal due to insufficient calcination, and excludes the possibility of processing wood with a humidity above 35%.

A known apparatus, which is a mechanized furnace, consisting of a loading device, a shaft, a device for the selection of coal and a furnace device with burners, which allows to obtain charcoal product of improved quality with a lower content of volatile substances. (AS USSR No. 346327, MKI C10V 3/00, publ. 07.28.1972 - prototype).

However, this apparatus also has significant disadvantages inherent in apparatuses with internal heating and a moving layer under the action of its own mass, because this limits the linear velocity of the gas coolant and the pyrolysis steam and gas in the mine, due to the entrainment of particles of the processed raw materials into the condensation system. In turn, a forced decrease in the linear velocity of the coolant in the shaft of the apparatus sharply reduces the specific productivity of the apparatus due to the low values of the coefficients of heat transfer between the coolant and the raw materials in the apparatus.

The technical task of the utility model is the creation of a transportable retort for wood pyrolysis, which has a high specific productivity due to the intensification of heat and mass transfer, reducing the size of the pyrolysis apparatus and metal consumption.

The problem is achieved in that in a retort for continuous thermal processing of crushed wood raw materials by pyrolysis with countercurrent flow of gas heat carrier to the processed wood, including a reactor, a unit for loading crushed wood into a reactor, a site for pyrolysis of raw materials, a furnace device and a unit

selection of combined-cycle gases, - the reactor vessel is installed horizontally, contains a horizontal channel of constant cross-section, which is equipped with a prepress assembly of chopped wood raw materials mounted at its beginning with the formation of dense but gas-permeable layers in the form of wood particle monoliths, which simultaneously serve as filters for the coolant and gas-vapor, this site selection of combined cycle gases of pyrolysis and waste coolant is located in the middle of the channel and is made in the form of a collector with horizontal slots, and the horizon The main channel ends with a furnace device, while the moving parts of the retort are located in the zones of the lowest temperatures.

The utility model has the following differences from the prototype:

- the reactor vessel is installed horizontally, contains a horizontal channel of constant cross section;

- the horizontal channel is equipped with a prepress assembly of the crushed wood raw material mounted at its beginning with the formation of dense, but gas-permeable layers in the form of monoliths of wood particles, which simultaneously serve as filters for the coolant and gas and vapor;

- the site for the selection of combined cycle gases of pyrolysis and waste coolant is located in the middle of the channel and is made in the form of a collector with horizontal slots;

- the horizontal channel ends with a furnace device;

- the moving parts of the retort are located in areas of the lowest temperatures.

This allows you to create a portable retort for wood pyrolysis, which has a high specific productivity, reducing the size of the pyrolysis apparatus and metal consumption.

In the patent information fund we reviewed, no similar technical solutions were found, nor were solutions with the indicated set of distinctive features.

The utility model is applicable and will be used in the industry in 2008.

In FIG. The retort diagram for continuous thermal processing of ground wood is shown.

The table shows the experimental data of the pyrolysis of chopped wood (birch chips) in the claimed retort.

A retort for continuous thermal processing of crushed wood raw materials by pyrolysis during countercurrent supply of gas coolant to the processed wood includes a reactor 1, a chopped wood loading unit 2 into a reactor 1, a raw material pyrolysis section 3, a furnace 4, and a steam and gas selection unit 5. The reactor vessel 1 is installed horizontally, contains a horizontal channel 6 of constant cross section, which is equipped with a knot 7 for pressing the crushed wood raw material mounted at its beginning with the formation of dense but gas-permeable layers in the form of monoliths of wood particles, which simultaneously serve as filters for the coolant and gas-vapor, the node 5 for the selection of combined cycle gases of pyrolysis and waste heat carrier is located in the middle of channel 6 and is made in the form of a collector with horizontal slots 8, and channel 6 ends flask device 4. Moving parts retort, namely, the screws 9 and 10, respectively prepressing unit 7 comminuted woody raw materials and for discharging from the retort the finished charcoal located in areas most low temperatures. For finished coal in the device has a receiver 11.

Retort works as follows.

The chopped wood is continuously fed through the loading unit 2 to the reactor 1. At the beginning of the horizontal channel 6, with the help of the screw 9 of the unit 7, the chopped wood is pressed to form dense but gas-permeable layers in the form of monoliths from wood particles, which simultaneously serve as filters for the coolant and gas-vapor. The pyrolysis steam gas formed during thermal decomposition exits the retort through the collector of unit 5. A countercurrent feed of raw materials feeds the gas coolant from the furnace device 4.

The coolant is formed from flue gases and non-condensable pyrolysis gases. The coal formed as a result of pyrolysis is pushed from the retort by the screw 10 into the coal receiver 11.

Execution of pressed layers and pyrolysis in continuously formed pressed layers eliminates mechanical entrainment of solid particles of raw materials and reduces the time of pyrolysis of crushed wood due to the intensification of heat and mass transfer processes by increasing the velocity of the gas carrier in the layer of pyrolyzable material above its critical value (fluidization rate ), as well as minimizing the time spent on steam and gas in the reaction zone, which provides the mind the elimination of secondary cracking reactions of liquid products in the gas phase. The claimed retort for wood pyrolysis is transportable, has a high specific productivity due to the intensification of heat and mass transfer, a decrease in the size of the pyrolysis apparatus and metal consumption.

Table Pyrolysis of birch wood \ chips \ in retort Performance indicators N experiments one 2 3 four 5 1. Productivity, retorts, kg / h 47, 6 51.6 60.6 57.2 48,4 2. The temperature regime of the retort, ° C: 2.1. Heat carrier, input 1100 1100 1100 950 950 2.2.Gas from a retort 120 125 120 96 115 3. The hydraulic mode of the retort, kPa: 3.1. Heat carrier, input 5.28 6, 66 9.31 110.7 12.45 3.2. Gas from the retort 0.17 0.2 0.63 0.7 0.73 3.3 layer resistance 5.11 6.46 8, 68 10.37 11.72 4. Gas flow rate, m3 / h 37.7 40.8 47.0 55.7 64.8 5. The time spent by the chips in the retort, s 75 70 60 76 75 6. The speed of steam and gas at the cross-section of the retort, m / s 2,56 2.79 3.20 4.09 4.26 7. The specific productivity of the retort, t / m3 h 15,2 16,4 19.3 15.0 15.3 8. Coal output from a.s.d.,% 20.9 21.3 21.6 29.6 28,4

Claims (2)

1. Retort for continuous thermal processing of crushed wood raw materials by pyrolysis during countercurrent supply of gas coolant to the processed wood, including a reactor, a unit for loading crushed wood into a reactor, a site for pyrolysis of raw materials, a furnace, and a steam and gas extraction unit, characterized in that the reactor vessel is installed horizontally , contains a horizontal channel of constant cross section, which is equipped with a prepress assembly of ground wood raw material mounted at its beginning to form by means of dense but gas-permeable layers in the form of monoliths from wood particles, which simultaneously serve as filters for the coolant and steam gases, while the site for the selection of pyrolysis steam and waste heat carriers is located in the middle of the channel and is made in the form of a collector with horizontal slots, and the horizontal channel ends with a furnace device. 2. Retort according to claim 1, characterized in that its moving parts are located in areas of the lowest temperatures.