JP7416654B2 - Modified coal manufacturing method and manufacturing equipment - Google Patents

Description

The present invention relates to a method and equipment for producing modified coal.

BACKGROUND ART Conventionally, as a method for producing reformed coal by carbonizing coal, a method described in Patent Document 1 below has been known. In this manufacturing method, thermal efficiency is increased by using carbonization gas as a heat source for carbonization.
By the way, in this type of method for producing reformed coal, the carbonization gas contains tar, which is a high boiling point component, so for example, this tar may adhere to the pipes and block them, causing problems in the carbonization equipment. There is a risk that the operating rate will decrease.
Therefore, in the manufacturing method described in Patent Document 1 listed below, adhesion of tar to piping and the like is suppressed by mixing low-temperature heating gas and waste heat gas with carbonization gas.

Japanese Patent Application Publication No. 2013-173831

However, in the conventional method for producing reformed coal, the structure of the carbonization apparatus for carbonizing the coal is complicated, and the operation becomes complicated.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to simplify the device configuration of a carbonization device in a reformed coal manufacturing facility and to facilitate operation.

In order to solve the above problems, the present invention proposes the following means.
[1] An inner cylinder that rotates around an axis; a heating chamber that covers the inner cylinder from the outside in the radial direction of the inner cylinder; An exhaust pipe that opens into a heating chamber; and a carbonization device having an exhaust pipe that opens into a heating chamber, and coal is supplied from an end located on the upstream side along the axial direction of the inner cylinder, and an end located on the downstream side along the axial direction. A reformed coal manufacturing facility in which reformed coal is discharged from a heating chamber, the equipment comprising: a temperature control unit that supplies oxygen-containing gas into a heating chamber to control the temperature within the heating chamber; and a flue that discharges the gas within the heating chamber. , wherein the flue is connected only to an end located on the upstream side of the heating chamber.
[2] The modified coal manufacturing equipment according to [1], wherein the temperature control unit maintains the temperature in the flue at 600°C or higher and controls the temperature in the heating chamber to be 600°C or higher.
[3] The temperature control unit controls the temperature in each control zone formed by dividing the heating chamber into a plurality of zones in the axial direction, and the flue is connected to the most upstream control zone among the plurality of control zones. The modified coal manufacturing equipment according to [1] or [2].
[4] The modified coal manufacturing equipment according to any one of [1] to [3], further comprising a stirring member that protrudes from the inner circumferential surface of the inner cylinder toward the axis and stirs the coal.
[5] The stirring member disposed in the downstream pyrolysis zone inside the inner cylinder has a larger inclination angle with respect to the axis than the stirring member disposed in the upstream moisture evaporation zone. Modified coal manufacturing equipment.
[6] The modified coal manufacturing equipment according to [5], wherein the stirring member disposed in the water evaporation zone has an inclination angle of 0 with respect to the axis.
[7] The reformed coal manufacturing equipment according to [5] or [6], wherein the stirring member is disposed in an axial direction within more than 90% of the heating region consisting of the water evaporation zone and the thermal decomposition zone.
[8] The modified coal manufacturing equipment according to any one of [4] to [7], wherein a gap is formed between the stirring member and the inner peripheral surface of the inner cylinder.
[9] The modified coal manufacturing equipment according to [8], wherein the size of the gap is 10% to 25% of the size of the stirring member in the radial direction of the inner cylinder.
[10] The reformed coal manufacturing equipment according to any one of [4] to [8], wherein the stirring member has a bent portion that is inclined with respect to the radial direction of the inner cylinder.
[11] The bent portion is formed on the axis side of the stirring member in a range of 30% or more and 70% or less of the height of the stirring member based on the inner peripheral surface of the inner cylinder,
The modified coal manufacturing equipment according to [10], wherein the angle of inclination of the bent portion with respect to the radial direction of the inner cylinder is 10° or more and 45° or less.
[12] An inner cylinder that rotates around an axis; a heating chamber that covers the inner cylinder from the outside in the radial direction of the inner cylinder; Using a carbonization apparatus having an exhaust pipe that opens into a heating chamber, coal is supplied from an end located on the upstream side along the axial direction of the inner cylinder, and the end located on the downstream side along the axial direction. A method for producing reformed coal in which reformed coal is discharged from the heating chamber, the method comprising: a temperature control step in which the temperature in the heating chamber is controlled by supplying oxygen-containing gas into the heating chamber; and a gas discharge step in which the gas in the heating chamber is discharged. , and in the gas discharge step, gas is discharged only from the end located on the upstream side in the heating chamber.
[13] The method for producing modified coal according to [12], wherein the temperature control step controls the temperature in the heating chamber to be 600° C. or higher.
[14] The temperature control step controls the temperature in each control zone formed by dividing the heating chamber into a plurality of zones in the axial direction,
The method for producing reformed coal according to [12] or [13], wherein the gas discharge step discharges gas from the most upstream control zone among the plurality of control zones.
[15] The method for producing modified coal according to any one of [12] to [14], wherein the coal is stirred using a stirring member that protrudes from the inner circumferential surface of the inner cylinder toward the axis.
[16] The modified coal according to [15], wherein the stirring member disposed in the pyrolysis zone on the downstream side at least inside the inner cylinder has an inclination angle with respect to the axis and stirs the coal so as to push it back to the upstream side. manufacturing method.
[17] The method for producing modified coal according to [15] or [16], wherein a gap is formed between the stirring member and the inner peripheral surface of the inner cylinder, and the coal stirred by the stirring member falls through the gap. .
[18] The stirring member has a bent portion that is inclined with respect to the radial direction of the inner cylinder, and the coal stirred by the stirring member falls from the bent portion, according to any one of [15] to [17]. A method for producing modified coal.

According to the above configuration, the device configuration of the carbonization device in the reformed coal production facility can be simplified and the operation can be facilitated while ensuring the availability of the carbonization device in the reformed coal production facility.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a modified coal production facility according to a first embodiment of the present invention. FIG. 2 is a schematic diagram of a carbonization apparatus that constitutes the reformed coal production facility shown in FIG. 1. FIG. FIG. 7 is an exploded inner view of an inner cylinder of a carbonization apparatus according to a second embodiment of the present invention. FIG. 4 is a cross-sectional view taken along line AA of the inner cylinder shown in FIG. 3 in a non-deployed state. FIG. 4 is a cross-sectional view taken along line BB of the inner cylinder shown in FIG. 3 in a non-deployed state. 4 is a front view of the stirring plate in the example shown in FIG. 3. FIG. 4 is a side view of the stirring plate in the example shown in FIG. 3. FIG. It is a sectional view of the inner cylinder of the carbonization apparatus concerning the modification of the 2nd embodiment of the present invention. It is a front view of the stirring plate by the modification of the 2nd embodiment of this invention. It is a side view of the stirring plate by the modification of the 2nd embodiment of this invention. It is a graph showing the relationship between the heating rate of coal, temperature, and volatile content in a verification test. It is a graph showing the measurement results of the overall heat transfer coefficient in the verification test. It is a graph showing the relationship between the size of the gap, the scattering rate, and the overall heat transfer coefficient in a verification test.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that, in this specification and the drawings, constituent elements having substantially the same functional configuration are designated by the same reference numerals and redundant explanation will be omitted.

(First embodiment)
Hereinafter, with reference to the drawings, a modified coal production facility according to a first embodiment of the present invention will be described.
As shown in FIG. 1, the reformed coal production facility 10 includes a drying device 11, a carbonization device 12, a cooling device 13, and an exhaust gas system 14. This production equipment 10 can be suitably used, for example, to reform low-grade coal with a high moisture content, such as lignite or sub-bituminous coal.

Drying device 11 dries coal. The drying device 11 dries the coal until, for example, the water content of the coal becomes 15% by weight or less, preferably 10% by weight or less. The carbonization device 12 carbonizes the dried coal. The carbonization device 12 carbonizes the coal until the temperature of the coal reaches, for example, 500°C or higher, specifically 550°C to 800°C, to convert it into reformed coal. The cooling device 13 cools the carbonized reformed coal. The cooling device 13 cools the coal until, for example, the temperature of the coal becomes 70°C or lower, preferably 60°C or lower.

The exhaust gas system 14 completely burns water vapor discharged from the carbonization device 12, carbonization gas that has been primarily burned through partial combustion (oxidation), and pulverized coal that is entrained in a small amount of the gas, and then releases it into the atmosphere as exhaust gas. The exhaust gas system 14 includes a secondary combustion device 15, a steam generator 16, a dust removal device 17, a suction fan 18, and an exhaust gas treatment device 19.

The secondary combustion device 15 performs secondary combustion of the primarily combusted carbonized gas to completely combust it. If NO _x is generated to the extent that it exceeds environmental standards at the stage of complete combustion, it is preferable to install a NO _x removal device in the latter stage.
The steam generator 16 generates steam by recovering waste heat from steam and completely combusted carbonized gas. The steam generator 16 supplies part or all of the recovered steam to the drying device 11 as a heat source for drying coal. The dust removal device 17 removes pulverized ash and the like accompanying the gas that has passed through the steam generator 16 . The suction fan 18 sucks the gas from the dust removal device 17 so that the pressure inside the heating chamber of the carbonization device 12 is constant, and sends it to the exhaust gas treatment device 19. The exhaust gas treatment device 19 refines the exhaust gas by removing SO _x and the like from the gas, and releases the exhaust gas into the atmosphere.

By the way, the carbonization apparatus 12 is a so-called external heating rotary kiln. As shown in FIG. 2, the carbonization apparatus 12 includes an inner cylinder 21, a heating chamber 22, and a temperature control section 23.

In the carbonization apparatus 12, coal passes through the interior of the inner cylinder 21 in the direction of the axis O of the inner cylinder 21. In the inner cylinder 21, a fixed amount of coal is supplied from the end located on the upstream side D1 along the axis O direction, and reformed coal is discharged from the end located on the downstream side D2. An upstream D1 end of the inner cylinder 21 is connected to the drying device 11, and a downstream D2 end of the inner cylinder 21 is connected to the cooling device 13.

The axis O of the inner cylinder 21 extends obliquely in the horizontal direction. Specifically, the axis O of the inner cylinder 21 has a gentle downward slope from the upstream side D1 to the downstream side D2 along the axis O direction. The inner cylinder 21 is formed to be rotatable around the axis O. The coal supplied from the upstream end D1 of the inner cylinder 21 is transmitted along the inner circumferential surface of the inner cylinder 21 because the inner cylinder 21 is inclined toward the downstream and rotates around the axis O. It gradually moves toward the downstream side D2 over a predetermined residence time.

The heating chamber 22 covers the inner tube 21 from the outside in the radial direction (hereinafter referred to as "radial direction") of the inner tube 21. The inner cylinder 21 is inserted into the heating chamber 22 in the direction of the axis O, and both ends of the inner cylinder 21 in the direction of the axis O protrude from the heating chamber 22 in the direction of the axis O.

Here, the inner cylinder 21 is provided with an exhaust pipe 24, and a so-called horned kiln is employed as the carbonization device 12.
A plurality of exhaust pipes 24 are arranged in the inner cylinder 21 in the direction of the axis O. The exhaust pipe 24 penetrates the inner tube 21 in the radial direction and opens into the heating chamber 22 . The exhaust pipe 24 is provided in the heating chamber portion 21 a of the inner cylinder 21 , which is a portion located within the heating chamber 22 . In the illustrated example, the exhaust pipe 24 is provided over the entire length of the heating chamber portion 21a in the direction of the axis O. A plurality of exhaust pipes 24 are arranged at equal intervals in the direction of the axis O. The exhaust pipe 24 discharges into the heating chamber 22 carbonized gas containing water vapor, which is a gas generated from coal inside the inner cylinder 21, and tar, which is a high boiling point component.

The temperature control unit 23 controls the temperature within the heating chamber 22 by supplying air into the heating chamber 22 . The temperature control unit 23 heats the inside of the heating chamber 22 by partially combusting (oxidizing) the carbonized gas containing tar as a high boiling point component discharged into the heating chamber 22 from the exhaust pipe 24 with air. Note that, similarly to air, it is also possible to supply an oxygen-containing gas different from air into the heating chamber 22. Here, the oxygen-containing gas means a gas that contains oxygen and can combust (oxidize) carbonized gas. As the oxygen-containing gas, in addition to air, for example, exhaust gas containing oxygen, oxygen-enriched air, etc. can be used. Furthermore, in this embodiment, the temperature control unit 23 is configured to be able to heat the inside of the heating chamber 22 using a heat source outside the heating chamber 22, that is, fuel gas. Moreover, natural gas, LPG gas, etc. can be used as the fuel gas, and is also used for preheating the system at startup.

The temperature control section 23 controls the temperature for each control zone Z1 to Z3. The control zones Z1 to Z3 are formed by dividing the inside of the heating chamber 22 into a plurality of zones in the direction of the axis O. In the illustrated example, the control zones Z1 to Z3 are divided into three, and from the upstream side D1 to the downstream side D2, the first control zone Z1, the second control zone Z2, and the third control zone Z3, in this order. It is sectioned.

The temperature control section 23 is equipped with a plurality of control systems 25 corresponding to the plurality of control zones Z1 to Z3, respectively. Each control system 25 includes at least an air supply section 26, a heating section 27, a temperature detection section 29, and a control main body section 30. In the illustrated example, in addition to the above, a steam supply section 28 is also provided in the control zones Z1 to Z3. Note that the air supply section 26 can also be referred to as an oxygen-containing gas supply section, including the case where an oxygen-containing gas other than air is supplied.

The air supply unit 26 supplies air into the heating chamber 22 . The air supply unit 26 includes a built-in air fan 31 that supplies air to the heating chamber 22 , a first pipe 32 that connects the built-in air fan 31 to the inside of the heating chamber 22 , and a first control unit installed in the first pipe 32 . A valve 33 is provided. The first pipe 32 is connected to the upper wall and lower wall portions of the heating chamber 22 so that the pipes on the upper wall side and the lower wall side are in opposite directions, and after the pipes on the upper wall and the lower wall are branched into multiple parts. has been done. Note that instead of the first control valve 33, a supply air amount control method in which the rotational speed of the motor of the driven air fan 31 is changed using an inverter can also be applied.

The heating unit 27 heats the inside of the heating chamber 22 using fuel gas (heat source) outside the heating chamber 22 . The heating unit 27 is interposed in a burner 34 that heats the heating chamber 22, a burner fan 36 that supplies air to the burner 34, a second pipe 37 that connects the burner fan 36 to the burner 34, and a second pipe 37. The third control valve 38 includes a second control valve 38 , a third pipe 39 that supplies fuel gas to the burner 34 , and a third control valve 40 interposed in the third pipe 39 . The burner 34 mixes air and fuel gas supplied from the supply section and burns the fuel gas. The burner 34 is provided on the lower wall portion of the heating chamber 22, and is provided in the same direction as the lower wall portion of the first pipe 32.

The steam supply unit 28 supplies steam into the heating chamber 22 to cool the inside of the heating chamber 22 . The steam supply unit 28 supplies steam at about 150° C. into the heating chamber 22, for example. The steam supply unit 28 includes a fourth pipe 41 that supplies steam into the heating chamber 22, and a fourth control valve 42 interposed in the fourth pipe 41. The fourth pipe 41 is connected to the lower wall of the heating chamber 22 in the same direction as the pipe installed on the lower wall of the first pipe 32.

The temperature detection unit 29 detects the temperature inside the heating chamber 22. The temperature detection section 29 can be configured by, for example, a temperature sensor.
The control main body section 30 controls the air supply section 26 , the heating section 27 , and the steam supply section 28 based on the detection result of the temperature detection section 29 . In the illustrated example, the control main body section 30 controls the air supply section 26, the heating section 27, and the steam supply section 28 by controlling the first to fourth control valves 33, 38, 40, and 42. The control main unit 30 is configured by a control device such as a PLC (Programmable Logic Controller), and may be implemented as a distributed control system (DCS).

Here, the heating chamber 22 is provided with a flue 43 for discharging gas from the heating chamber 22. The flue 43 is connected to the heating chamber 22 and connects the inside of the heating chamber 22 and the secondary combustion device 15. At this time, the flue 43 is connected only to the end of the heating chamber 22 located on the upstream side D1. Thereby, the gas in the heating chamber 22 is discharged only from the end portion of the heating chamber 22 located on the upstream side D1. The flue 43 is connected to the first control zone Z1 located at the most upstream side D1 among the plurality of control zones Z1 to Z3.

Next, the functions of the reformed coal manufacturing equipment 10 and the carbonization apparatus 12 will be explained.
The method for manufacturing modified coal using the modified coal manufacturing equipment 10 includes a drying step of drying coal, a carbonization step of carbonizing the dried coal, and a cooling step of cooling the carbonized coal. . The drying step is carried out by the drying device 11, the carbonization step is carried out by the carbonization device 12, and the cooling step is carried out by the cooling device 13.

In the carbonization step, first, a preheating step of preheating the heating chamber 22 is performed. At this time, the heating section 27 of the temperature control section 23 heats the inside of the heating chamber 22 .
Further, coal is supplied from the upstream end D1 of the inner cylinder 21, and reformed coal is discharged from the downstream end D2. At this time, when carbonized gas containing tar as a high boiling point component is generated from the coal passing through the inner cylinder 21, this carbonized gas is discharged from the inside of the inner cylinder 21 through the exhaust pipe 24 into the heating chamber 22.

Therefore, temperature control is performed in which air is supplied into the heating chamber 22 to control the temperature inside the heating chamber 22 (temperature control step). At this time, by partially burning (oxidizing) the carbonized gas in the heating chamber 22 with air, the temperature in the heating chamber 22 is increased, and the coal passing through the inner cylinder 21 is heated via the inner cylinder 21. be able to. Furthermore, the temperature within the heating chamber 22 can be raised to such an extent that tar does not adhere to the wall surface of the heating chamber 22 or the wall surface of the flue 43.

In this embodiment, when controlling the temperature of the heating chamber 22, the entire temperature inside the heating chamber 22 is controlled to be 600° C. or higher. At this time, the temperature control unit 23 controls the temperature of any of the plurality of control zones Z1 to Z3 to 600° C. or higher. The temperature control unit 23 controls the temperature inside the heating chamber 22 within a range in which the carbonization apparatus 12 can operate without increasing the temperature inside the heating chamber 22 excessively. Note that the temperature control section 23 can control the temperature of the heating chamber 22 by controlling only the amount of air supplied from the air supply section 26. Furthermore, the temperature control section 23 can also control the temperature of the heating chamber 22 by controlling not only the air supply section 26 but also the heating section 27 and the steam supply section 28 . Furthermore, the temperature control unit 23 may perform temperature control so that the temperature within the flue 43 is maintained at 600° C. or higher.

Here, the temperature in the heating chamber 22 can be changed as appropriate depending on, for example, the use of the reformed coal to be produced. The temperature in the heating chamber 22 can be set, for example, based on a reformed coal target temperature that is a target temperature of the reformed coal discharged from the inner cylinder 21. Specifically, the temperature in the heating chamber 22 can be set in a range 100° C. to 150° C. higher than the target temperature of the reformed coal. Note that it is not an essential condition that the temperature is in a range of 100° C. to 150° C. higher than the target temperature of the reformed coal, and any temperature higher than the target temperature of the reformed coal is applicable.

For example, by setting the target temperature of the reformed coal to 650°C to 850°C, the volatile matter (VM) of the coal can be set to 5 to 15% by mass, and the reformed coal can be made into anthracite-equivalent coal or semi-anthracite-equivalent coal. I can do it. Furthermore, for example, by setting the target temperature of the reformed coal to 550°C to 750°C, the volatile matter (VM) of the coal can be set to 10 to 30% by mass, and the reformed coal can be suitably used as coal equivalent to steam coal. .

By the way, when controlling the temperature of the heating chamber 22, the moisture in the coal evaporates at the stage when the coal supplied to the inner cylinder 21 from the end on the upstream side D1 is heated to about 150°C. As a result, in the part of the inner cylinder 21 located on the upstream side D1, the amount of heat required for heating the coal increases because the amount of heat required for evaporation of water is added, and in the part located on the downstream side D2, the amount of heat required for heating the coal increases. , the amount of heat required to heat the coal becomes smaller. Therefore, inside the inner cylinder 21, the temperature of the coal and the atmosphere is difficult to rise in the portion located on the upstream side D1. Further, in the portion located on the upstream side D1 of the inner cylinder 21, a large amount of water vapor is generated due to evaporation of water in the coal, and the amount of carbonized gas generated increases toward the downstream side D2. As a result, the amount of carbonized gas discharged from the exhaust pipe 24 into the heating chamber 22 is smaller on the upstream side D1 than on the downstream side D2. Therefore, also in the heating chamber 22, the temperature does not easily rise in the portion located on the upstream side D1 because the calorie of the atmospheric gas is low.

Therefore, in this embodiment, gas is discharged so that the gas is discharged only from the end located on the upstream side D1 in the heating chamber 22 (gas discharge step). That is, the gas in the heating chamber 22 is exhausted only from the flue 43 installed at the end located on the upstream side D1. As a result, the carbonized gas generated in large quantities in the portion located on the downstream side D2 within the heating chamber 22 passes through the portion located on the upstream side D1 within the heating chamber 22 in the process of being discharged from the heating chamber 22. At this time, by partially combusting (oxidizing) the carbonized gas by supplying air to the carbonized gas, the temperature of the portion located on the upstream side D1 in the heating chamber 22 can be reliably raised.

As explained above, according to the reformed coal production equipment 10, the carbonization apparatus 12, the reformed coal production method, and the carbonization method according to the present embodiment, the carbonization gas is partially combusted (oxidized) in the heating chamber 22. By doing so, the temperature inside the heating chamber 22 can be increased. Therefore, by increasing the temperature in the heating chamber 22 to such an extent that tar does not adhere to the wall surface of the heating chamber 22 or the wall surface of the flue 43, the operating rate of the carbonization device 12 in the reformed coal manufacturing facility 10 can be ensured. , the device configuration of the carbonization device 12 in the reformed coal manufacturing facility 10 can be simplified and the operation can be made easier.

Furthermore, since the temperature control unit 23 maintains the temperature inside the flue 43 at 600°C or higher and controls the temperature inside the heating chamber 22 to be 600°C or higher, the temperature on the wall surface of the heating chamber 22 and the flue 43 It is possible to reliably prevent tar from adhering to the wall surface. Thereby, the operating rate of the carbonization device 12 in the reformed coal manufacturing facility 10 can be ensured.

Furthermore, since the temperature control unit 23 controls the temperature for each of the control zones Z1 to Z3, the temperature inside the heating chamber 22 can be reliably raised to the extent that tar does not adhere to the wall surface of the heating chamber 22 or the wall surface of the flue 43. I can do it. For example, in the third control zone Z3 on the downstream side D2 where the temperature tends to rise among the plurality of control zones Z1 to Z3, excessive partial combustion (oxidation) of carbonized gas is suppressed and unburnt gas is transferred to the upstream side. In the first control zone Z1 on the upstream side D1 where the temperature does not easily rise, the carbonized gas containing unburned gas from the downstream side can be actively partially combusted (oxidized). Thereby, the operating rate of the carbonization device 12 in the reformed coal manufacturing facility 10 can be ensured.

Note that various changes can be made to this embodiment as exemplified below.

For example, in the example described above, the steam recovered by the steam generator 16 is supplied to the dryer 11 as a heat source, but the heat source may be supplied to the dryer 11 from a device different from the steam generator 16. Further, for example, in the above-described example, the temperature control section 23 controls the temperature in each of the control zones Z1 to Z3, but the temperature control section 23 may control the temperature inside the heating chamber 22 integrally. Furthermore, for example, although air is supplied into the heating chamber 22 in the above-mentioned example, an oxygen-containing gas different from air may be supplied into the heating chamber 22 similarly to the air. Here, the oxygen-containing gas means a gas that contains oxygen and can combust (oxidize) carbonized gas. As the oxygen-containing gas, in addition to air, for example, exhaust gas containing oxygen, oxygen-enriched air, etc. can be used. In addition, without departing from the spirit of the present invention, the components in the above-described example can be replaced with well-known components, and modifications may be combined as appropriate.

Next, first to third verification tests were conducted to verify the effects of the first embodiment described above. Note that in the following first to third verification tests, air as an oxygen-containing gas was supplied into the heating chamber 22.

(First verification test)
In the first verification test, the temperature inside the heating chamber 22 was verified based on the difference in the position of the flue 43 in the direction of the axis O. In the first verification test, two types of carbonization apparatuses 12 were used as Test Example A1 and Test Example B1. In both of these two carbonization apparatuses 12, the diameter of the inner cylinder 21 is 500 mm, the size of the heating chamber portion 21a of the inner cylinder 21 in the direction of the axis O is 3000 mm, and the inclination of the axis O of the inner cylinder 21 with respect to the horizontal direction is 3000 mm. The angle was 1.0 degrees, and the rotation speed of the inner cylinder 21 was 3.1 rpm. Further, the moisture content of the coal supplied to the inner cylinder 21 was set to 11.8% by weight, and the supply rate of the coal supplied to the inner cylinder 21 was set to 280 kg/h to 290 kg/h. Furthermore, the supply speed of the amount of air supplied from each control system 25 to each of the control zones Z1 to Z3 was set based on the temperature of the second control zone Z2. At this time, the supply speed of the air amount supplied to each control zone Z1 to Z3 was made equal, and the total air amount supply speed of the three zones was set to be 280 Nm ³ /h to 285 Nm ³ /h.

Here, the position of the flue 43 in the axis O direction was different between Test Example A1 and Test Example B1. In test example A1, the flue 43 was connected only to the control zone Z1 at the end of the upstream side D1 of the heating chamber 22, as in the above embodiment. In Test Example B1, the flue 43 was connected only to the control zone Z3 at the downstream end D2 of the heating chamber 22.
In this first verification test, the temperature of each of the first to third control zones Z3 and the discharged coal temperature, which is the temperature of the coal discharged from the inner cylinder 21, were measured. The results are shown in Table 1 below.

From this result, it was confirmed that in Test Example A1, the temperature within the heating chamber 22 was less likely to vary than in Test Example B1, and the temperature of the discharged coal was also increased.

(Second verification test)
In the second verification test, tar adhesion based on differences in temperature within the heating chamber 22 was verified. In the second verification test, two types of carbonization apparatuses 12 were used as Test Example A2 and Test Example B2. In both of these two carbonization apparatuses 12, the diameter of the inner cylinder 21 is 500 mm, the size of the heating chamber portion 21a of the inner cylinder 21 in the direction of the axis O is 3000 mm, and the inclination of the axis O of the inner cylinder 21 with respect to the horizontal direction is 3000 mm. The angle was 1.0 degrees, and the rotation speed of the inner cylinder 21 was 3.1 rpm. Further, the moisture content of the coal supplied to the inner cylinder 21 was set to 12.3% by weight, and the supply rate of the coal supplied to the inner cylinder 21 was set to 275 kg/h to 280 kg/h. Further, the flue 43 was connected only to the control zone Z1 at the upstream D1 end of the heating chamber 22.

In Test Example A2 and Test Example B2, in order to compare the influence of the operating temperature of the heating chamber 22 on tar adhesion, the target temperature of the second control zone Z2 was made different. In Test Example A2, the temperature of the second control zone Z2 was approximately 630°C, and in Test Example B2, the temperature of the second control zone Z2 was approximately 550°C. In Test Example A2 and Test Example B2, the supply rate of the amount of air supplied from each control system 25 to each of the control zones Z1 to Z3 was set based on the target temperature of each second control zone Z2. At this time, in each of Test Example A2 and Test Example B2, the supply speed of the amount of air supplied to each control zone Z1 to Z3 was made the same. Specifically, in Test Example A2, the total air supply rate for each control zone Z1 to Z3 was 215 Nm ³ /h, and in Test Example B2, the total air supply rate for each control zone Z1 to Z3 was 163 Nm 3 /h. ³ /h. The temperatures of each of the first to third control zones Z3 and the discharged coal temperature in this case are shown in Table 2 below.

In this second verification test, each of Test Example A2 and Test Example B2 was operated for 5 consecutive days, and the pressure loss between the inner cylinder 21 and the secondary combustion device 15 on the first day and the pressure loss on the fifth day were evaluated. The pressure loss between the inner cylinder 21 and the secondary combustion device 15 was measured. Here, the pressure loss from the inner cylinder 21 to the secondary combustion device 15 is measured by the gas pressure difference between the end of the inner cylinder 21 on the downstream side D2 and the end on the secondary combustion device 15 side. do.

In both Test Example A2 and Test Example B2, the pressure loss in the flue 43 immediately after the start of operation on the first day was 0.02 kPa. In Test Example A2, the pressure loss in the flue 43 on the fifth day was 0.03 kPa, whereas in Test Example B2, the pressure loss in the flue 43 on the fifth day was 1.45 kPa. .
From this result, it was confirmed that in Test Example A2, the pressure loss in the flue 43 was smaller than in Test Example B1, and tar adhesion was suppressed.

(Third verification test)
In the third verification test, differences in the volatile content of coal were verified by controlling the temperature in each control zone Z1 to Z3. In the third verification test, two types of carbonization apparatuses 12 were used as Test Example A3 and Test Example B3. In both of these two carbonization apparatuses 12, the diameter of the inner cylinder 21 is 500 mm, the size of the heating chamber portion 21a of the inner cylinder 21 in the direction of the axis O is 3000 mm, and the inclination of the axis O of the inner cylinder 21 with respect to the horizontal direction is 3000 mm. The angle was 1.0 degrees, and the rotation speed of the inner cylinder 21 was 3.1 rpm. Further, the moisture content of the coal supplied to the inner cylinder 21 was set to 12.1% by weight, and the supply rate of the coal supplied to the inner cylinder 21 was set to 220 kg/h to 225 kg/h. Further, the flue 43 was connected only to the control zone Z1 at the upstream D1 end of the heating chamber 22. Then, the supply speed of air supplied from each control system 25 to each of the control zones Z1 to Z3 was set based on the temperature of the discharged reformed coal. At this time, each control system 25 was controlled so that the temperature of the discharged coal was around 655°C.

In Test Example A3 and Test Example B3, the temperature distribution within the heating chamber 22 was made different.
That is, in Test Example A3, the temperature of the heating chamber 22 was controlled by the temperature control unit 23 so that the temperatures of each control zone Z1 to Z3 were approximately equal (see Table 3). At this time, in Test Example A3, the supply speed of the amount of air from each control system 25 was varied, and air was supplied to the first control zone Z1 at a rate of 120 Nm ³ /h, and to the second control zone Z2 at a rate of 70 Nm ³ /h. Air was supplied at a rate of 35 Nm ³ /h to the third control zone Z3.
On the other hand, in Test Example B3, the air supply speed from each control system 25 was made the same, and air was supplied to each control zone Z1 to Z3 at an air amount supply speed of 75 Nm ³ /h. As a result, the temperature of each control zone Z1 to Z3 varied as shown in Table 3.

In this third verification test, the volatile content of the reformed coal discharged from the inner cylinder 21 was measured for each of Test Example A3 and Test Example B3. In Test Example A3, the volatile content was 6.2% by weight, whereas in Test Example B3, the volatile content was 9.2% by weight.
From this result, it was confirmed that Test Example A3 had lower volatility than Test Example B3 and was carbonized effectively, even though the discharged coal temperature was the same as Test Example B3.

(Second embodiment)
Next, a second embodiment of the present invention will be described. In this embodiment as well, reformed coal is produced using production equipment that includes the same external heating rotary kiln carbonization apparatus as in the first embodiment. In this embodiment, a stirring member for stirring the coal in the inner cylinder of the carbonization apparatus is provided as described below. Regarding other points, it is possible to adopt the configuration of a general external heating rotary kiln without being limited to the example of the first embodiment described above. For example, in the heating chamber, the flue is not necessarily located at the upstream end. It does not have to be connected only to the section.

FIG. 3 is a developed view of the inner peripheral surface of the inner cylinder in the carbonization apparatus according to the second embodiment of the present invention. In the illustrated example, the inside of the inner cylinder 21 is divided into a feeding region 211 and a heating region 212 from the upstream side to the downstream side, and the heating region 212 is further divided into a moisture evaporation zone 212A and a pyrolysis zone 212B. Further, downstream of the pyrolysis zone 212B is an outlet region 213. In this embodiment, stirring plates 51 and 52 for stirring the coal protrude from the inner circumferential surface 21c of the inner cylinder 21 toward the axis O (see FIG. 2) in the water evaporation zone 212A and the thermal decomposition zone 212B, respectively. provided. The feed region 211 is provided with a feed lifter 211L for feeding coal into the heating region 212, and the exit region 213 is not provided with a stirring plate or a lifter.

The stirring plates 51 and 52 are arranged at predetermined intervals (in the illustrated example, at 45° intervals) in the circumferential direction of the inner cylinder 21, in addition to the exhaust pipes 24, which are arranged at 90° intervals in the circumferential direction of the inner cylinder 21. ). In the moisture evaporation zone 212A, each of the plurality of stirring plates 51 arranged in the circumferential direction extends parallel to the axis O. That is, the angle of inclination of the stirring plate 51 of the water evaporation zone 212A with respect to the axis O is 0. FIG. 4A is a cross-sectional view taken along the line AA in FIG. An example is shown in which they protrude from the center toward the axis O and are arranged at equal intervals in the circumferential direction of the inner cylinder 21. The stirring plate 51 is attached to the inner circumferential surface 21c via a bracket 53 at an end opposite to the axis O. The stirring plates 51 adjacent in the direction of the axis O are arranged offset from each other by 1/2 of the interval (22.5° in the illustrated example) in the circumferential direction of the inner cylinder 21. In this embodiment, the stirring plates 51 of the moisture evaporation zone 212A are arranged in, for example, four rows in the direction of the axis O.

On the other hand, in the pyrolysis zone 212B, a plurality of stirring plates 52 are arranged at the same circumferential intervals (45° intervals in the figure) and longitudinal intervals as the arrangement of the stirring plates 51 in the water evaporation zone 212A. . In the thermal decomposition zone 212B, each of the plurality of stirring plates 52 arranged in the circumferential direction has an inclination angle β (see FIG. 3) with respect to the axis O. The magnitude of the inclination angle β is, for example, about 4.3° to 4.5°. In the thermal decomposition zone 212B, since the stirring plate 52 has the inclination angle β, it is possible to stir the coal passing through the inner cylinder 21 when it is rotated in a predetermined direction so as to push it back to the upstream side. On the other hand, in the moisture evaporation zone 212A, the coal is sent to the pyrolysis zone 212B side by the stirring plate 51 having no inclination angle, so that the coal filling rate in the pyrolysis zone 212B becomes more uniform, and the residence time increases. can be set for a long time. FIG. 4B is a cross-sectional view taken along line BB in FIG. An example is shown in which not only the end surfaces but also the plate surfaces are visible because they protrude from the inner cylinder 21 toward the axis O, are arranged at equal intervals in the circumferential direction of the inner cylinder 21, and have an inclination angle β with respect to the axis O. There is. In this embodiment, the stirring plates 52 of the pyrolysis zone 212B are arranged in eight rows in the direction of the axis O, for example.

In addition, the stirring plate 52 in the pyrolysis zone 212B is attached to the inner peripheral surface 21c via a bracket 53, as shown in FIGS. 5A and 5B, and the stirring plate 52 is attached to the inner peripheral surface 21c of the inner cylinder 21. A gap 54 is formed therein. By forming such a gap 54, a part of the coal stirred by the stirring plate 52 when the inner cylinder 21 rotates can fall from the gap 54 along the inner circumferential surface 21c, and coal particles are Mixing of the coal inside the inner cylinder 21 can be promoted while preventing the coal from scattering toward the axis O side and being sucked into the exhaust pipe 24.

In this embodiment, the stirring plates 51 and 52 as described above are arranged in the direction of the axis O throughout the heating region 212 consisting of the water evaporation zone 212A and the thermal decomposition zone 212B. In order to uniformly stir and mix the coal while preventing scattering of the coal, it is preferable to install the stirring plates 51 and 52 in a range exceeding 90% of the heating area 212.

Next, with reference also to FIG. 1 described in the first embodiment, a method for producing reformed coal using the carbonization apparatus in this embodiment will be described. First, the inner tube 21 is rotated around the axis O by driving a drive section (not shown), and the inside of the heating chamber 22 is heated by the heating section 27 . When the inside of the inner cylinder 21 reaches a predetermined high temperature, coal is put into the inner cylinder 21 and carbonized by the high heat in the heating chamber 22.

When coal is introduced into the rotating inner cylinder 21, it is conveyed to the moisture evaporation zone 212A of the heating area 212 by the feed lifter 211L of the feed area 211, and the moisture contained in the coal is evaporated. In the water evaporation zone 212A, since the stirring plate 51 is arranged parallel to the axis O of the inner cylinder 21, the coal particles are conveyed along the inner circumferential surface 21c of the inner cylinder 21 while being stirred by the stirring plate 51. It is transported to the pyrolysis zone 212B.

In the thermal decomposition zone 212B, the stirring plate 52 is rotated by the rotation of the inner cylinder 21, and the coal is stirred and mixed inside the inner cylinder 21 by the stirring plate 52. At this time, some of the coal is lifted by the stirring plate 52, and other part of the coal is not lifted by the stirring plate 52, falls from the gap 54, and flows on the inner circumferential surface 21c. Since the entire coal on the stirring plate 52 does not fall toward the axis O side, the amount of scattering caused by stirring can be suppressed.

Here, as shown in FIG. 4B, the stirring plate 52 disposed in the pyrolysis zone 212B has a height ha (the dimension in the radial direction of the inner cylinder 21 based on the inner circumferential surface 21c). It is preferable to design it so that it is 60% to 90% of the coal filling height hm. If the coal filling height hm is too small relative to the height ha of the stirring plate 52, the stirring effect will be small, and if it is too large, the scattering of coal will increase. The amount of coal charged into the inner cylinder 21 may be adjusted so that the height ha of the stirring plate 52 falls within the above range with respect to the coal filling height hm. Further, as shown in FIG. 5A, from the intersection of the inner peripheral surface 21c and the extension surface of the stirring plate 52 (the position where the bracket 53 is joined to the inner peripheral surface 21c) to the end of the stirring plate 52 on the axis O side The height of the gap 54, that is, the distance from the intersection of the inner circumferential surface 21c and the extension surface of the stirring plate 52 to the end of the stirring plate 52 on the inner circumferential surface 21c side is defined as the height hb. In this case, the height hb of the gap 54 is preferably in the range of 10% to 25% of the height ha of the stirring plate 52, more preferably in the range of 10% to 20%.

In this way, in this embodiment, when coal is carbonized in the thermal decomposition zone 212B of the inner cylinder 21, the stirring by the stirring plate 52 can prevent the coal from coalescing and clumping. This reduces the temperature deviation of the coal deposited inside the inner cylinder 21, and the heat from the heating chamber 22 is efficiently transferred. Further, by providing the gap 54, scattering of coal during stirring can be suppressed, and particles of carbide, which is a non-volatile component, can be suppressed from being discharged from the exhaust pipe 24.

Further, as mentioned above, since the axis O of the inner cylinder 21 has a gentle downward slope, the coal moves toward the downstream side through the entire inner cylinder 21, but the stirring plate 52 of the pyrolysis zone 212B By having the inclination angle β, movement of the coal stirred by the stirring plate 52 to the downstream side is prevented to some extent, and a part of it is pushed back to the upstream side. On the other hand, in the moisture evaporation zone 212A, the coal is sent downstream by the stirring plate 51 having no inclination angle, so that the coal filling rate in the pyrolysis zone 212B becomes more uniform and the residence time becomes longer. For example, if the temperature in the pyrolysis zone 212B is set to 650° C. and a stirring plate having no inclination angle is provided in the pyrolysis zone 212B unlike this embodiment, the coal charged into the inner cylinder 21 will be transferred to the pyrolysis zone 212B. The residence time is, for example, about 50 minutes. With other conditions being the same, when the stirring plate 52 having the inclination angle β is provided in the pyrolysis zone 212B as in this embodiment, the time the coal stays in the pyrolysis zone 212B is extended by about 20% to 60%. This increases the heat receiving area of the coal by about 8%. That is, in the above example, the heat transfer efficiency to the coal in the carbonization apparatus is improved by about 8% due to the stirring plate 52 having the inclination angle β.

Note that this embodiment can be combined with the first embodiment described above, and various changes can be made as exemplified below. Further, the above-described configuration in which the stirring plate 52 is arranged with an inclination angle β and the configuration in which the gap 54 is provided between the stirring plate 52 and the inner circumferential surface 21c of the inner cylinder 21 each have separate effects. Therefore, only one of them may be adopted.

For example, in the above example, the stirring plate 51 in the moisture evaporation zone 212A is installed parallel to the axis O, but the stirring plate 51 in the moisture evaporation zone 212A may also be arranged at an angle of inclination to the axis O. In this case, it is preferable that the angle of inclination of the stirring plate 51 with respect to the axis O is set smaller than the angle of inclination β of the stirring plate 52.

Furthermore, the stirring plates 52 arranged in the circumferential direction of the inner cylinder 21 are preferably arranged at equal intervals, but may be arranged at irregular intervals. The number of stirring plates 52 can be set in a range of 4 to 12, more preferably 6 to 10, depending on the inner diameter of the inner cylinder 21. The number of stirring plates 52 installed in the circumferential direction of the inner circumferential surface 21c can be set as appropriate within a range that can improve the coal mixing and stirring effect, but if the number of installed stirring plates 52 is increased too much, coal particles will be scattered between the stirring plates 52. This is not preferable because the mixture becomes finely divided and the mixing ratio decreases.

Next, a modification of the second embodiment of the present invention will be described with reference to FIGS. 6, 7A, and 7B. In this modification, the stirring plate 52 is formed with a bent portion 52b that is inclined with respect to the radial direction of the inner cylinder 21. Specifically, as shown in FIG. 7A, from the intersection of the inner peripheral surface 21c and the extension surface of the stirring plate 52 (the position where the bracket 53 is joined to the inner peripheral surface 21c) to the axis O side of the stirring plate 52. The distance to the end is defined as height ha, and the height of the gap 54, that is, the distance from the intersection of the inner peripheral surface 21c and the extension surface of the stirring plate 52 to the end of the stirring plate 52 on the inner peripheral surface 21c side is defined as height. hb, and the distance from the inner circumferential surface 21c of the boundary between the bent portion 52b formed on the axis O side of the stirring plate 52 and other parts is the height hc, then the height hc is equal to the height ha. It is preferably in the range of 30% to 70%. In other words, the bent portion 52b is preferably formed in a range of 30% or more and 70% or less of the height of the stirring plate 52 on the axis O side of the stirring plate 52 based on the inner peripheral surface 21c of the inner cylinder 21. . Further, the inclination angle γ of the bent portion 52b with respect to the radial direction of the inner cylinder 21 is preferably 10° or more and 45° or less. In the above example, among the coal stirred by the stirring plate 52, the coal on the bent portion 52b falls first, so that, for example, the coal (inner cylinder) falls from the end of the stirring plate 52 where the bent portion is not formed. When the angle of the stirring plate 52 exceeds the horizontal due to the rotation of the stirring plate 21), the scattering of coal can be suppressed compared to the case where the coal falls all at once.

(Fourth verification test)
Next, the results of the verification test according to the second embodiment of the present invention will be explained. In the fourth verification test, as Test Example A4 and Test Example A5, a thermal decomposition test was conducted using lignite with a volatile content of about 50 wt% crushed to 5 mm or less and dried as raw coal. The graph of FIG. 8 shows the relationship between the heating temperature of raw coal and the VM value (volatile content) of the produced reformed coal. In Test Example A4, the heating rate of the coal was 7° C./min, and in Test Example A5, it was 25° C./min, each of which was maintained for 1 minute. When measuring the VM value in Test Examples A4 and A5 when the coal temperature was 550°C, 650°C, and 750°C, it was found that the VM value was higher in Test Example A4, which had a lower heating rate, than in Test Example A5. The result was that it was low. From this result, even if the final temperature of the coal is the same, the VM value of the coal can be reduced by setting the heating rate relatively low and maintaining the heating (residence) time in the pyrolysis zone for a long time. It can be seen that the volatilization of carbonized coal can be promoted.

(Fifth verification test)
In the fifth verification test, coal was carbonized using an externally heated rotary kiln with an inner cylinder inner diameter φ500 mm x heating length L = 3000 mm (length of the heating region including the water evaporation zone and the thermal decomposition zone). Four stirring plates were arranged in the circumferential direction of the inner peripheral surface of the inner cylinder over the entire length of the heating region, and the inclination angle of the stirring plates was 0.0° (Test Example B4), 4.0° (Test Example A6), 6 .0° (Test Example A7). In the experiment, the coal input amount was 280 kg/h, the rotation speed of the inner cylinder was 3.1 rpm, the downward slope angle of the inner cylinder was 1.0°, and the height of the stirring plate was ha = 90 mm, and Test Example B4 and Test Examples A6 and A7 were used. The actual residence time (min) and overall heat transfer coefficient (kcal/m ² h°C) were measured. The results are shown in Table 4.

From the test results shown in Table 4, in Test Examples A6 and A7 in which the stirring plate disposed in the heating area of the inner cylinder had an inclination angle, the actual retention time was longer than in Test Example B4 without an inclination angle. It was confirmed that the overall heat transfer coefficient increased.

(Sixth verification test)
In the sixth verification test, coal was carbonized using an externally heated rotary kiln in which the inner diameter of the inner cylinder was 500 mm, the heating length L was 3000 mm, and the downward slope angle of the inner cylinder was 1.0°. In Test Example B5, a stirring plate with no inclination angle to the axis was installed over the entire length of the heating area, and in Test Example A8, the stirring plate was installed at an angle of inclination of 600 mm from the upstream end of the inner cylinder in the heating area. A stirring plate without corners was installed, and thereafter a stirring plate with an inclination angle of 4° was installed. In Test Example A9, a stirring plate with no inclination angle was installed within a range of 600 mm from the upstream end of the inner cylinder in the heating region, and a stirring plate with an inclination angle of 6° was installed thereafter. In the experiment, the coal input amount was 280 kg/h, the rotation speed of the inner cylinder was 3.1 rpm, the height of the stirring plate was ha = 90 mm, the target temperature of the carbide at the downstream end of the inner cylinder was 640 ° C., and Test Example B5 For Test Examples A8 and A9, the actual residence time (min), overall heat transfer coefficient (kcal/m ² h°C), and coal volatile content (%) after carbonization were measured. The results are shown in Table 5.

From the test results shown in Table 5, in Test Examples A8 and A9, in which a stirring plate without an inclined angle was installed in the moisture evaporation zone and a stirring plate with an inclined angle in the pyrolysis zone, the heating area was tilted over the entire length of the heating area. Compared to the above test examples A6 and A7 in which a stirring plate with corners was installed, the actual retention time was slightly shorter mainly in the water evaporation zone. However, in the moisture evaporation zone, the moisture contained in the coal has not completely evaporated, so there is a large temperature difference between the inside and outside of the inner cylinder, so even if the residence time becomes longer, the overall heat transfer coefficient does not increase. Therefore, there was almost no difference in the overall heat transfer coefficient between Test Examples A6 and A7 and Test Examples A8 and A9, which had similar residence times in the thermal decomposition zone. Further, when the target temperature of the carbide at the downstream end of the inner cylinder was the same, modified coal with a lower volatile content was obtained in Test Examples A6 and A7, which had a longer actually measured residence time.

(Seventh verification test)
In the seventh verification test, coal was carbonized using an externally heated rotary kiln with an inner cylinder inner diameter of 500 mm, heating length L = 3000 mm, and an inner cylinder downward slope angle of 1.0°. A test was conducted on the measured value of the overall heat transfer coefficient inside the inner cylinder due to the difference in . Coal input amount: 190 kg/h to 280 kg/h, rotation speed of the inner cylinder: 2.2 rpm to 3.0 rpm, combustion temperature of the heating chamber: 790°C to 840°C, coal filling height hm inside the inner cylinder: 100 mm It was set in the range of ~140 mm. In Test Example B6, no stirring plate was provided, in Test Example A10, two stirring plates were arranged in the circumferential direction (180° intervals), and in Test Example A11, stirring plates were arranged in four pieces in the circumferential direction (90° intervals). However, in Test Example A12, eight stirring plates were arranged in the circumferential direction (at 45° intervals). The height ha of the stirring plate was 75 mm in all cases. For each test example, the arrangement length of the stirring plate was changed and coal was carbonized while changing the value K obtained by dividing the number of stirring plates in the circumferential direction x the total length of the stirring plate by the heating length L. The overall heat transfer coefficient U (kcal/m ² h°C) based on the area of the inner peripheral surface was measured.

FIG. 9 is a graph showing the measurement results of the overall heat transfer coefficient according to the seventh verification test. As shown in the graph, it was confirmed that by installing the stirring plate, and as the number of stirring plates in the circumferential direction and the total area increased, the overall heat transfer coefficient increased. This result shows that by installing stirring plates and increasing the number of plates in the circumferential direction and the total area, stirring and mixing of coal inside the inner cylinder is promoted.

(Eighth verification test)
In the eighth verification test, the difference in the scattering position of coal depending on the presence or absence of a bent part of the stirring plate in an externally heated rotary kiln with an inner cylinder inner diameter of 2700 mm and a heating length L = 3000 mm was calculated using DEM (Discrete Element Method). . The rotation speed of the inner cylinder was 2.7 rpm, and the filling height hm of the coal simulated particles inside the inner cylinder was 690 mm. Six stirring plates were arranged at 60° intervals in the circumferential direction in both Test Example B7 and Test Example A13. The stirring plate of Test Example B7 had a flat plate shape extending in the radial direction of the inner cylinder, and the stirring plate of Test Example A13 had a shape with a bent portion at the top of the stirring plate as shown in FIG. In both Test Example B7 and Test Example A13, no gap was formed between the stirring plate and the inner peripheral surface of the inner cylinder. In each of Test Example B7 and Test Example A13, the amount of scattering of coal particles stirred by the stirring plate during three rotations of the inner cylinder was calculated as a function of the distance from the central axis of the inner cylinder to the inner peripheral surface. did. The results are shown in Table 6.

From the results shown in Table 6, it can be seen that in Test Example A13, compared to Test Example B7, the range in which coal particles are scattered has moved from near the axis to near the inner peripheral surface. This result shows that by providing the stirring plate with a bent portion, it is possible to reduce the number of coal particles that are scattered near the axis of the inner cylinder and discharged from the exhaust pipe.

(Ninth verification test)
In the ninth verification test, coal was carbonized using an externally heated rotary kiln with an inner cylinder inner diameter φ500 mm and a heating length L = 3000 mm. The scattering situation was tested. In each example, the stirring plate has a height ha of 90 mm from the inner circumferential surface of the inner cylinder to the upper end, and has a bent portion at the upper part. The size of the gap between the stirring plate and the inner peripheral surface was 0 (no gap) in Test Example B8, 15 mm in Test Example A14, and 35 mm in height in Test Example B9. The moisture content of the coal charged into the inner cylinder was 12.50%, and the rotation speed of the inner cylinder was 3.1 rpm. In the test, a known yield function was used to calculate the predicted amount of reformed coal output after carbonization based on the input amount of coal and the temperature after heating. The difference between this predicted value and the measured value of the amount of reformed coal discharged from the inner cylinder is considered to be the amount of coal particles scattered inside the inner cylinder and discharged from the exhaust pipe, and the scattering rate is calculated. was calculated. The results are shown in Table 7.

The results shown in Table 7 show that the amount of coal scattering can be reduced by increasing the gap between the stirring plate and the inner peripheral surface of the inner cylinder. However, as shown in the verification test below, if the gap is too large, the heat transfer coefficient to the coal may decrease, so it is desirable to set the gap size within an appropriate range.

(10th verification test)
In the 10th verification test, coal was carbonized using an externally heated rotary kiln with an inner cylinder inner diameter of φ500 mm and a heating length L = 3000 mm. The overall heat transfer coefficient was actually measured in the case where there was no heat transfer coefficient. In each example, the height ha of the stirring plate from the inner peripheral surface of the inner cylinder to the upper end is 90 mm, and the size of the gap between the stirring plate and the inner peripheral surface is 0 (no gap) in Test Example B10. , 15 mm in Test Example A15, and 35 mm in Test Example B11. The rotation speed of the inner cylinder was 2.7 rpm, the amount of coal input was 280 kg/h, and the height hm of coal filling inside the inner cylinder was 150 mm. Table 8 shows the calculation results of the overall heat transfer coefficient in each example.

From the results shown in Table 8, the overall heat transfer coefficient increases in Test Example A15 with a gap size of 15 mm compared to Test Example B10 with no gap, but on the contrary, in Test Example B11 with a gap size of 35 mm. The overall heat transfer coefficient was lower than that of Test Example B10, which had no gaps. From this result, the efficiency of coal stirring can be improved by providing an appropriately sized gap between the stirring plate and the inner peripheral surface of the inner cylinder, but if the gap is too large, the efficiency of stirring will decrease. Recognize.

FIG. 10 is a graph showing the relationship between the size of the gap between the inner circumferential surface of the inner cylinder and the stirring plate, the scattering rate of coal, and the overall heat transfer coefficient for the results of the ninth and tenth verification tests described above. It is. As shown in the graph, the scattering rate of coal particles decreases as the gap becomes larger, while the heat transfer coefficient reaches its maximum when the gap is a predetermined value (15 mm in this example), and increases when the gap becomes too large. descend. For example, if the appropriate range in the graph is that the overall heat transfer coefficient exceeds 10 kcal/m ² h°C, then the gap size should be 9 mm to 23 mm, that is, 10% to 25% of the height ha of the stirring plate. is preferable, and a range of 10% to 20% of the height ha is more preferable.

Although preferred embodiments of the present invention have been described above in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person with ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea stated in the claims. It is understood that these also naturally fall within the technical scope of the present invention.

10... Manufacturing equipment, 11... Drying device, 12... Carbonization device, 13... Cooling device, 14... Exhaust gas system, 15... Secondary combustion device, 16... Steam generator, 17... Dust removal device, 18... Suction fan, 19... Exhaust gas treatment device, 21... Inner cylinder, 21a... Heating chamber portion, 21c... Inner peripheral surface, 211... Feeding area, 211L... Feeding lifter, 212... Heating area, 212A... Moisture evaporation zone, 212B... Pyrolysis zone, 213... Exit area, 22... Heating chamber, 23... Temperature control section, 24... Exhaust pipe, 25... Control system, 26... Air supply section, 27... Heating section, 28... Steam supply section, 29... Temperature detection section, 30... Control Main body, 31... Drive-in air fan, 32... First piping, 33... First control valve, 34... Burner, 36... Burner fan, 37... Second piping, 38... Second control valve, 39... Third piping, 40... Third control valve, 41... Fourth piping, 42... Fourth control valve, 43... Flue, 51... Stirring plate, 52... Stirring plate, 52b... Bending portion, 53... Bracket, 54... Gap, D1... Upstream side, D2...downstream side, O...axis, Z1...first control zone, Z2...second control zone, Z3...third control zone.

Claims (16)

an inner cylinder that rotates around its axis;
a heating chamber that covers the inner cylinder from the outside in the radial direction of the inner cylinder;
A carbonization device having a plurality of exhaust pipes arranged in the inner cylinder in the axial direction, penetrating the inner cylinder in the radial direction and opening into the heating chamber,
In the inner cylinder, coal is supplied from an end located on the upstream side along the axial direction, and modified coal is discharged from an end located on the downstream side along the axial direction. Equipment,
a temperature control unit that controls the temperature within the heating chamber by supplying oxygen-containing gas into the heating chamber;
Further comprising a flue for discharging gas in the heating chamber,
The temperature control unit controls the temperature for each control zone formed by dividing the heating chamber into a plurality of zones in the axial direction,
The flue is connected to the most upstream control zone among the plurality of control zones in the reformed coal production facility. The reformed coal manufacturing equipment according to claim 1, wherein the temperature control unit maintains a temperature in the flue at 600°C or higher and controls a temperature in the heating chamber to 600°C or higher. The modified coal manufacturing equipment according to claim 1 or 2 , further comprising a stirring member that protrudes from the inner circumferential surface of the inner cylinder toward the axis and stirs the coal. 3. The stirring member disposed in the downstream pyrolysis zone inside the inner cylinder has a larger inclination angle with respect to the axis than the stirring member disposed in the upstream moisture evaporation zone . Equipment for producing modified coal as described in . The modified coal manufacturing equipment according to claim 4 , wherein the stirring member disposed in the water evaporation zone has an inclination angle of 0 with respect to the axis. The reformed coal manufacturing equipment according to claim 4 or 5 , wherein the stirring member is arranged in a range exceeding 90% of a heating region consisting of the moisture evaporation zone and the thermal decomposition zone in the axial direction. . The reformed coal manufacturing equipment according to any one of claims 3 to 6 , wherein a gap is formed between the stirring member and the inner circumferential surface of the inner cylinder. The modified coal manufacturing equipment according to claim 7 , wherein the size of the gap is 10% to 25% of the dimension of the stirring member in the radial direction of the inner cylinder. The reformed coal manufacturing equipment according to any one of claims 3 to 7 , wherein the stirring member has a bent portion that is inclined with respect to the radial direction of the inner cylinder. The bent portion is formed on the axis side of the stirring member in a range of 30% or more and 70% or less of the height of the stirring member based on the inner circumferential surface of the inner cylinder,
The modified coal manufacturing equipment according to claim 9 , wherein the angle of inclination of the bent portion with respect to the radial direction of the inner cylinder is 10° or more and 45° or less. an inner cylinder that rotates around an axis; a heating chamber that covers the inner cylinder from the outside in the radial direction of the inner cylinder; and a plurality of heating chambers arranged in the axial direction in the inner cylinder, Using a carbonization apparatus having an exhaust pipe that penetrates and opens into the heating chamber, coal is supplied from an end located on the upstream side along the axial direction in the inner cylinder, and A method for producing modified coal, the method comprising discharging the modified coal from an end located on the downstream side,
a temperature control step of supplying oxygen-containing gas into the heating chamber to control the temperature inside the heating chamber;
a gas exhaust step of exhausting the gas in the heating chamber,
In the temperature control step, the temperature is controlled for each control zone formed by dividing the heating chamber into a plurality of zones in the axial direction,
In the method for producing reformed coal , the gas discharge step discharges gas from the most upstream control zone among the plurality of control zones . The method for producing modified coal according to claim 11 , wherein in the temperature control step, the temperature in the heating chamber is controlled to be 600°C or higher. The method for producing modified coal according to claim 11 or 12 , wherein the coal is stirred using a stirring member protruding from the inner circumferential surface of the inner cylinder toward the axis. 14. The stirring member disposed in the downstream pyrolysis zone at least inside the inner cylinder has an inclination angle with respect to the axis, and stirs the coal so as to push the coal back toward the upstream side. A method for producing modified coal. The production of modified coal according to claim 13 or 14 , wherein a gap is formed between the stirring member and the inner circumferential surface of the inner cylinder, and the coal stirred by the stirring member falls through the gap. Method. The stirring member has a bent portion inclined with respect to the radial direction of the inner cylinder, and the coal stirred by the stirring member falls from the bent portion, according to any one of claims 13 to 15 . The method for producing the modified coal described.

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