WO2016013293A1

WO2016013293A1 - Method for producing modified coal and device for producing modified coal

Info

Publication number: WO2016013293A1
Application number: PCT/JP2015/065461
Authority: WO
Inventors: 小菅　克志; 淳志小林; 白水　渡
Original assignee: 新日鉄住金エンジニアリング株式会社; Nsプラント設計株式会社
Priority date: 2014-07-23
Filing date: 2015-05-28
Publication date: 2016-01-28
Also published as: AU2015293497B2; AU2015293497A1; JP6322509B2; CN106661476B; CN106661476A; JP2016023280A

Abstract

A method for producing modified coal, said method comprising: a first drying step (S11) for heating air taken from the outside, fluidizing high-water content coal using the heated air to give a fluidized coal bed, and evaporating moisture from the high-water content coal in the fluidized coal bed to give primarily dried coal; a second drying step (S12) for indirectly heating the primarily dried coal, further evaporating moisture from the primarily dried coal to give dried cool and, at the same time, recovering first steam evaporated from the primarily dried coal; a dry distillation step (S20) for dry distilling the dried coal to give modified coal and, at the same time, recovering, as exhaust gas, combustion exhaust gas that remains after supplying dry distillation heat required for dry distillation of the dried coal to thereby generate second steam; and a cooling step (S30) for cooling the modified coal. In the first drying step, the air is indirectly heated by the first steam. In the second drying step, the primarily dried coal is indirectly heated using the second steam.

Description

Modified coal production method and modified coal production apparatus

The present invention relates to a method for producing modified coal for producing modified coal from high-moisture coal, and an apparatus for producing modified coal.
This application claims priority based on Japanese Patent Application No. 2014-150073 for which it applied to Japan on July 23, 2014, and uses the content here.

In recent years, coal with high water content such as lignite and bituminous coal (high moisture coal) is dried and dry-distilled, etc., and the fuel ratio is adjusted from 2 to 4, which is equivalent to low volatile steam coal. A method for producing reformed coal to be a good fuel is being studied. In addition, the fuel ratio said here means the weight ratio of the fixed carbon part with bad combustibility with respect to the volatile matter with good combustibility in coal. The reformed coal having a fuel ratio of 2 to 4 is used by being burned for power generation at a power plant, for example.
In the method for producing modified coal from this type of high moisture coal, drying of the high moisture coal is important, and the following methods are known as the drying method.

For example, Patent Document 1 describes a method of providing a preheating device for preheating high moisture coal to improve fluidization of the high moisture coal in the dryer.
Patent Document 2 discloses that steam discharged from a drying apparatus is compressed and used for drying high-moisture coal, and steam drain from the drying apparatus is used for preheating drying.
In addition to these, a WTA method described in Non-Patent Document 1 is known as a similar drying method.

JP 2013-178026 A JP 2013-178028 A

Brown coal, which is representative of high-moisture coal, has the property of being easily ignited (spontaneous ignition) when the water content decreases.
Therefore, for example, when high-moisture coal is indirectly heated with steam to dry high-moisture coal containing 50 to 60% of water by mass to an extent containing 10% of water by mass, drying operation As a countermeasure against ignition, a method of drying the inside of a dryer in a water vapor atmosphere without oxygen is being put into practical use.

However, in order to indirectly heat and dry high moisture coal, a large amount of steam for heating is required. For this reason, if high moisture coal is not dried using cheap water vapor | steam, the drying cost of high moisture coal will become high, and there exists a problem that the manufacturing cost of reformed coal will also become high correspondingly.

Therefore, as a method for securing a large amount of steam for heating, for example, by compressing the steam evaporated during drying of the high moisture coal, and using this compressed steam for drying the high moisture coal, it is necessary to dry the high moisture coal. A method for reducing the amount of water vapor from the outside has been developed.
However, in order to compress water vapor, an expensive compressor and enormous electric power for compression are required. Therefore, the steam for drying the high moisture coal obtained by this conventional method is not inexpensive.

The present invention has been made in view of such problems, and can dry high-moisture coal without igniting it, obtain water vapor for drying high-moisture coal at low cost, and high An object of the present invention is to provide a modified coal production method and a modified coal production apparatus capable of reducing the amount of water vapor for drying the moisture coal.

A method for producing a modified coal according to one aspect of the present invention is a method for producing a modified coal from a high-moisture coal that is a coal containing at least 45% of water in a mass ratio. Heating the taken-in air, fluidizing the high moisture coal with the heated air to form a coal fluidized bed, and evaporating moisture from the high moisture coal in the coal fluidized bed to form primary dry coal A step of indirectly heating the primary dry coal, further evaporating water from the primary dry coal to obtain dry coal, and recovering the first water vapor evaporated from the primary dry coal; A dry distillation step of generating second steam by dry distillation of the dry coal to obtain the modified coal, and exhaust heat recovery of the combustion exhaust gas after supplying the dry distillation heat necessary for the dry distillation of the dry coal; The reforming A cooling step for cooling the charcoal, wherein in the first drying step, the air is indirectly heated with the first water vapor, and in the second drying step, the primary drying is performed using the second water vapor. It is characterized by indirectly heating coal.

An apparatus for producing modified coal according to one aspect of the present invention is an apparatus for producing modified coal that produces modified coal from high-moisture coal, which is coal containing 45% or more of water by mass ratio. A drying unit that evaporates water from moisture coal to form dry coal, a dry distillation unit that carbonizes the dry coal to form reformed coal, and a cooling unit that cools the modified coal, and the drying unit Heating the air taken in from the outside, fluidizing the high moisture coal with the heated air to form a coal fluidized bed, evaporating moisture from the high moisture coal in the coal fluidized bed and primary dry coal A first drying unit that indirectly heats the primary dry coal, further evaporates water from the primary dry coal to form the dry coal, and collects the first water vapor evaporated from the primary dry coal A second drying section, and The distilling section generates the second steam by exhaust heat recovery of the combustion exhaust gas after carbonizing the dry coal and supplying the carbonization heat necessary for the dry distillation of the dry coal, the first drying section, The air is indirectly heated with the first water vapor, and the second drying section indirectly heats the primary dry coal with the second water vapor.

In the first drying step, it is more preferable to indirectly heat the coal fluidized bed with the first steam.

More preferably, the first drying section indirectly heats the coal fluidized bed with the first steam.

The amount of moisture that evaporates from the primary dry coal in the second drying step after the high moisture coal becomes the primary dry coal with respect to the amount of moisture that evaporates from the high moisture coal in the first drying step. Is more preferably doubled.

In the first drying step, it is more preferable to indirectly heat the air with the second water vapor.

According to the modified coal production method and modified coal production apparatus of the present invention, high moisture coal can be dried without igniting, and steam for drying the high moisture coal can be obtained at low cost. The amount of water vapor for drying the high moisture coal can also be reduced.

It is a block diagram of the manufacturing apparatus of the modified coal of 1st Embodiment of this invention. It is a block diagram of the carbonization equipment of the manufacturing apparatus shown in FIG. It is a flowchart which shows the manufacturing method of the modified coal of 1st Embodiment. It is an operation diagram which shows drying operation of a 1st drying process based on the low temperature humidity chart with respect to air and water. It is a block diagram of the manufacturing apparatus of the modified coal of 2nd Embodiment of this invention.

(First embodiment)
Hereinafter, a first embodiment of a modified coal production apparatus (hereinafter also abbreviated as “production apparatus”) according to the present invention will be described with reference to FIGS. 1 to 4.

As shown in FIG. 1, the manufacturing apparatus 1 according to the present embodiment includes a drying facility (drying unit) 10 that evaporates moisture from a high-moisture coal M1 to dry coal M3, and dry coal from which moisture has evaporated in the drying facility 10. A dry distillation facility (dry distillation section) 30 that carbonizes M3 into reformed coal M4 and a cooling facility (cooling section) 40 that cools the modified coal M4 obtained by the dry distillation facility 30 are provided.

In addition, the high moisture coal M1 said here means the coal which contains a water | moisture content 45% or more by mass ratio. Reference numerals M3 and M4 and reference numeral M2 to be described later do not mean pipes and conveyors, but mean dry coal, modified coal, and primary dry coal supplied by these pipes and conveyors.

The drying facility 10 includes a first drying facility (first drying unit) 11 and a second drying facility (second drying unit) 12.

The first drying equipment 11 heats the air M5 taken from the outside, fluidizes the high-moisture coal M1 with the heated air M5 to form a coal fluidized bed M6, thereby performing a drying operation, and high moisture Coal M1 is designated as primary dry coal M2.
The second drying facility 12 indirectly heats the primary dry coal M2 treated in the first drying facility 11 with a carbonization process steam (hereinafter referred to as second steam), which will be described later, to further remove moisture from the primary dry coal M2. Evaporate to dry coal M3.

The first drying equipment 11 includes an air fan 15 that takes in air M5 from the outside, an air preheater 16 that heats the air M5 taken in by the air fan 15, and air heating that further heats the air M5 heated by the air preheater 16. And an air fluidized bed dryer (hereinafter referred to as a dryer) 18 to which air M5 heated by the air heater 17 is supplied.

The high-moisture coal M1 is supplied to the dryer 18 at a constant predetermined weight per hour. The dryer 18 is connected to an exhaust air dust collector (hereinafter referred to as a dust collector) 19 for recovering coal fines and the like accompanying the exhaust air.

A heating pipe (heating pipe) 22 that is connected (communication) to one end of a second steam supply pipe (hereinafter referred to as supply pipe) 21 through which the second steam flows is disposed in the second drying facility 12. .
The other end of the supply pipe 21 is connected to the dry distillation facility 30. The end of the heating pipe 22 on the side not connected to the supply pipe 21 is collected in a pipe (not shown) in which steam condensate is arranged at substantially atmospheric pressure, and is returned as steam condensate as necessary. .

The second drying facility 12 is connected to the dryer 18 of the first drying facility 11. The primary dry coal M2 supplied into the second drying facility 12 from the dryer 18 is indirectly heated by contacting the outer surface of the heating pipe 22 installed in the second drying facility 12, and the primary dry coal is obtained. It is dried by evaporating the water in M2. The pipe 23 branches from the supply pipe 21 and is connected to the air heater 17.
In order to heat the air M 5 taken from the outside by the air heater 17, water vapor (second water vapor described later) is supplied to the air heater 17 through the pipe 23.

One end of a first water vapor supply pipe (hereinafter referred to as a supply pipe) 24 through which indirect heating and drying process water vapor (hereinafter referred to as a first water vapor) flows is connected to the second drying facility 12 via a dust collector 25. ing.
The other end of the supply pipe 24 extends to the air preheater 16 and is connected to the air preheater 16. As a result, the first water vapor is supplied from the second drying equipment 12 to the air preheater 16 via the supply pipe 24. The air M5 taken from the outside is indirectly heated by the first water vapor in the air preheater 16.

As shown in FIG. 2, the carbonization facility 30 includes, for example, a known external heat type rotary kiln 31, a secondary combustion device 32 connected to the rotary kiln 31, a steam generation device 33 connected to the secondary combustion device 32, A dust removing device 34 connected to the steam generating device 33, a suction fan 35 connected to the dust removing device 34, and an exhaust gas treatment device 36 connected to the suction fan 35 are included.

The rotary kiln 31 is connected to the second drying facility 12 of the drying facility 10. The inside of the rotary kiln 31 is set in an environment of, for example, several hundred degrees C. in which oxygen does not exist, and dry coal M3 supplied from the second drying equipment 12 is dry-distilled to obtain reformed coal M4. The reformed coal M4 is supplied to the cooling facility 40.
The secondary combustion device 32, the steam generation device 33, the dust removal device 34, the suction fan 35, and the exhaust gas treatment device 36 will be described later.

The cooling facility 40 cools the reformed coal M4 carbonized in the carbonization facility 30 to a temperature at which it does not ignite by contact oxidation with air, for example, several tens of degrees centigrade.

Next, a method for manufacturing the modified coal M4 of the present embodiment (hereinafter also abbreviated as “manufacturing method”) using the manufacturing apparatus 1 configured as described above will be described.

FIG. 3 is a flowchart showing the manufacturing method of this embodiment.
This production method includes a drying step S10 in which moisture is evaporated from the high-moisture coal M1 to obtain dry coal M3, a dry distillation step S20 in which dry coal M3 is subjected to dry distillation after the drying step S10 to obtain reformed coal M4, And a cooling step S30 for cooling the modified coal M4 after the step S20.

In the drying step S10, the air-fluidized bed drying step (hereinafter referred to as the first drying step) S11 that dries the high-moisture coal M1 to the primary dry coal M2, and the primary dry coal M2 is further dried to obtain the dry coal M3. An indirect heating drying step (hereinafter referred to as a second drying step) S12.

The first drying step S11 heats the air M5 taken from outside, fluidizes the high moisture coal M1 with the heated air M5 to form a coal fluidized bed M6, and evaporates moisture from the high moisture coal M1 during the flow. Dry to obtain primary dry coal M2.
In the second drying step S12, after the first drying step S11, water is further evaporated from the primary dry coal M2 to obtain dry coal M3.

In the first drying step S11, air M5 is taken in from the outside by the air fan 15. As will be described later, the first water vapor is supplied from the second drying equipment 12 to the dust collector 25 through the supply pipe 24 and is further supplied from the dust collector 25 to the air preheater 16 through the supply pipe 24. Thereby, the taken-in air M5 is indirectly heated by the first steam by contacting the outer surface of the supply pipe 24 in the air preheater 16.

The air M5 heated by the air preheater 16 is further supplied to the air heater 17. As will be described later, the second water vapor is supplied from the dry distillation equipment 30 to the air heater 17 through the pipe 23. Thereby, the taken-in air M5 is indirectly heated with the second steam by contacting the outer surface of the pipe 23 in the air heater 17.
That is, the air M5 heated by the air preheater 16 is further indirectly heated by the air heater 17.

In addition, the 1st water vapor | steam and the 2nd water vapor | steam respectively used by the air preheater 16 and the air heater 17 are discharged | emitted outside as steam condensate, or are returned as steam condensate as needed.

In the present embodiment, the air M5 is indirectly heated by contacting the outer surface of the supply pipe 24 in the air preheater 16 and the outer surface of the pipe 23 in the air heater 17. Take the case as an example.
However, the configuration for indirectly heating the air M5 is not limited to the

supply pipes

24 and 23. For example, an indirect heat exchanger such as a multi-tube type (shell-and-tube type) or a plate type is appropriately used. It can be selected and used.
The same applies to the heating tube 22 of the second drying facility 12 and the heating tube 52 of the dryer 18 described later.

The air M5 heated by the air heater 17 is supplied to the dryer 18. The temperature of the air M5 when it is supplied to the dryer 18 may be a temperature that does not reach the ignition temperature even when the high moisture coal M1 generates heat by oxidation, and is preferably 120 ° C. or less, for example, from the viewpoint of preventing ignition.

High moisture coal M1 is supplied to the dryer 18. The average particle diameter of the high moisture coal M1 is, for example, 3 mm. In this example, the high moisture coal M1 before performing the first drying step S11 supplied to the dryer 18 contains, for example, 60% by mass of moisture, and the remaining 40% is composed of volatile matter and fixed carbon. Each is composed of about 20% and some ash.

The high moisture coal M1 supplied to the dryer 18 is fluidized by the air M5 supplied to the dryer 18 to become a coal fluidized bed M6. The high moisture coal M1 in the coal fluidized bed M6 is heated by the heated air M5, whereby the moisture evaporates from the high moisture coal M1. Thus, the high moisture coal M1 which comprises the coal fluidized bed M6 turns into primary dry coal M2 because a water | moisture content evaporates from the high moisture coal M1.

In addition, the air M5 supplied to the dryer 18 is humidified with the evaporated water from the high moisture coal M1. The air M5 that has been humidified in the dryer 18 becomes exhausted air accompanied by fine coal powder and the like, is discharged from the dryer 18, and is supplied to the dust collector 19. The exhaust air is separated into exhaust air and fine coal powder by the dust collector 19. The fine coal powder or the like separated by the dust collector 19 is collected, and is granulated as necessary, and returned to the primary dry coal M2. On the other hand, the exhaust air (air) from which the coal fine powder and the like are separated is discharged from the dust collector 19 to the outside.

The temperature inside the coal fluidized bed M6 of the dryer 18 is desirably a temperature at which the high moisture coal M1 does not generate oxidation heat due to oxygen in the air M5, and is preferably 60 ° C. or less, for example. That is, it is preferable that the dryer 18 performs drying until the moisture content of the primary dry coal M2 reaches the limit moisture content. For example, as an example, it is preferable to perform a drying operation in a range until the water content is reduced to 20% by weight, that is, in a constant rate drying speed region.
Even when the primary dry coal M2 is dried to a moisture content lower than the limit moisture content, the high temperature coal M1 can be dried by setting the internal temperature of the coal fluidized bed M6 to a relatively low temperature of 60 ° C. or less. preferable.

When the drying operation of the coal fluidized bed M6 in the dryer 18 is finished, the first drying step S11 is finished, the process proceeds to the second drying step S12, and the primary drying coal M2 processed by the dryer 18 is used as the second drying equipment. 12 is supplied.

In the second drying step S 12, the primary dry coal M 2 is indirectly heated by the second steam supplied through the supply pipe 21 through the heating pipe 22 in the second drying facility 12. In the second drying facility 12, the primary dry coal M 2 is indirectly heated by contacting the outer surface of the heating pipe 22.
As described above, the primary dry coal M2 is heated by the heating pipe 22 arranged in the second drying facility 12, and thereby moisture is evaporated from the primary dry coal M2.

In the drying step S10, drying is performed until the high moisture coal M1 becomes the dry coal M3.
At this time, the amount of water evaporated until the primary dry coal M2 becomes the dry coal M3 in the second drying step S12 is the total amount of the first water vapor obtained from the water evaporated in the second drying step S12, and the first drying step. It is preferable from the viewpoint of thermal efficiency to set so that the total amount of steam required for drying from the high moisture coal M1 to the primary dry coal M2 in step S11 is balanced (equal).

The primary drying after the fixed amount of high moisture coal M1 becomes the primary dry coal M2 in the first drying step S11 with respect to the amount of moisture evaporated in the first drying step S11 from the fixed amount of high moisture coal M1. It is preferable that the amount of water evaporated from the coal M2 in the second drying step S12 is twice.
That is, for example, in the case where the high moisture coal M1 having a moisture content of 60% by weight in the drying step S10 is dried until the dry coal M3 has a moisture content of 10% by weight, the first drying step S11. It is preferable to dry the high moisture coal M1 having a moisture content of 60% by weight to obtain a primary dry coal M2 having a moisture content of 50% by weight.

Further, the temperature of the air M5 when supplied to the dryer 18 is, for example, 120 ° C. or less, the temperature inside the dryer 18 is, for example, 60 ° C. or less, and the primary dry coal M2 at the end of the first drying step S11. By setting the water content of the water to 50% by weight, the high-moisture coal M1 can be dried without being ignited even in an atmosphere of air M5 in the first drying step S11.

The second water vapor supplied to the heating pipe 22 installed in the second drying facility 12 through the supply pipe 21 is condensed in the heating pipe 22 and discharged as vapor condensed water.
The first water vapor, which is water evaporated from the primary dry coal M2, is collected and supplied to the dust collector 25 through the supply pipe 24. Thereby, even if, for example, coal fine powder or the like is accompanied with the first water vapor, the first water vapor and the coal fine powder or the like can be separated in the dust collector 25. The separated first water vapor is supplied from the dust collector 25 to the air preheater 16 through the supply pipe 24. That is, as shown in FIG. 3, the first water vapor obtained in the second drying step S12 is used in the first drying step S11.

A part of the first steam supplied from the dust collector 25 to the air preheater 16 through the supply pipe 24 is branched from the supply pipe 24 and supplied to the second drying facility 12, for example. Thereby, in the 2nd drying process 12, primary dry coal M2 can be dried under the atmosphere of water vapor like usual.
In addition, when supplying a part of 1st water vapor | steam to the 2nd drying equipment 12, you may raise flow volume using ventilation means, such as a fan which is not shown in figure. Thereby, indirect heating can be performed while fluidizing the primary dry coal M2 in the second drying equipment 12.
The fine coal powder or the like separated by the dust collector 25 may be returned to the dry coal M3 supplied from the second drying facility 12 to the dry distillation facility 30, for example, after increasing the particle size as necessary.

When the drying process of the primary dry coal M2 in the second drying facility 12 is completed and the dry coal M3 is manufactured, the dry coal M3 manufactured in the second drying facility 12 is supplied to the dry distillation facility 30.
Thereby, 2nd drying process S12 is complete | finished and it transfers to dry distillation process S20.

In the carbonization step S20, the dry coal M3 is carbonized as described above in the carbonization facility 30. In this dry distillation operation, gas and tar components are generated by thermally decomposing volatile components of the dry coal M3 in the rotary kiln 31 shown in FIG.
The gas and tar generated inside the rotary kiln 31 are discharged from the inside of the rotary kiln 31 to the outside, and are combusted together with the air supplied to heat the rotary kiln 31 outside. Thereby, calorie | heat amount (dry distillation heat) required for dry distillation of dry coal M3 can be obtained. This dry distillation heat is supplied to the rotary kiln 31.

The gas and tar remaining without being burned in the rotary kiln 31 are supplied from the rotary kiln 31 to the secondary combustion device 32. By burning the gas and tar content more completely in the secondary combustion device 32, a high-temperature combustion exhaust gas can be obtained.
In the steam generation apparatus 33, the second steam can be obtained by recovering exhaust heat using the combustion exhaust gas.

The second water vapor may be a low-pressure water vapor having a relatively low pressure (for example, 0.4 MPaG (megapascal gauge) or more). The combustion exhaust gas is sucked by the suction fan 35 through the dust removing process by the dust removing device 34. Further, the combustion exhaust gas is exhausted from the dry distillation equipment 30 through exhaust gas treatment such as desulfurization by the exhaust gas treatment device 36.

As shown in FIG. 1, the second water vapor is supplied to the second drying facility 12 through the supply pipe 21 and the heating pipe 22. That is, as shown in FIG. 3, the second water vapor obtained in the dry distillation step S20 is used in the second drying step S12.
A part of the second water vapor flowing through the supply pipe 21 is supplied to the air heater 17 through the pipe 23 shown in FIG.

When the production of the modified coal M4 in the dry distillation facility 30 is finished, the modified coal M4 produced in the dry distillation facility 30 is supplied to the cooling facility 40. Thereby, dry distillation process S20 is complete | finished and it transfers to cooling process S30.
In addition, it is preferable that it is 400 degreeC or more and 650 degrees C or less, for example, as for the temperature of the modified coal M4 when dry distillation process S20 is complete | finished with respect to fuel ratio 2-4, and it is 450 degrees C or more and 600 degrees C or less. More preferred.

In the cooling step S30, the modified coal M4 produced by the dry distillation equipment 30 is cooled to about several tens of degrees Celsius by a known cooling method.
Through the above steps, a modified coal M4 corresponding to low volatile steam coal having a fuel ratio of 2 to 4 can be produced.

(Example)
Here, an embodiment of the present invention will be described in more detail with specific examples. However, the present invention is not limited to the following examples.
FIG. 4 is a low temperature humidity chart for air and water. The horizontal axis of FIG. 4 represents air temperature (dry bulb temperature), and the vertical axis represents air humidity (absolute humidity, kg-water vapor / kg-dryair). Moreover, the curve which goes to the right in FIG. 4 represents the relative humidity.
The dryer 18 will be described on the premise of a drying operation before the moisture content of the primary dry coal M2 reaches the limit moisture content. In air fluidized bed drying, the amount of water evaporated from coal is equal to the amount of water taken out of the system by air. Therefore, the amount of moisture taken out by air is shown using a low temperature humidity chart.

If the temperature of the outside air is 25 ° C., this air is in the state of point A if the relative humidity (relative humidity) is 100%. When the air in the state of point A is heated to, for example, 70 ° C., the temperature rises while the amount of water vapor contained in the air remains constant, and the air enters the state of point B1.

When the air in the state of point B1 is supplied to the dryer 18 of the drying facility 10, the air is adiabatically cooled while fluidizing the high-moisture coal and moves along the adiabatic cooling line (straight-downward straight line in FIG. 4). Thus, the point C1 is about 35 ° C. and the relative humidity is 95%. That is, the air at the outlet of the dryer 18 is in the state of point C1.
When the air state changes from the point B1 to the point C1, the water content of 0.014 (kg-water vapor / kg-dryair) corresponding to the length L1 of the vertical axis between the point B1 and the point C1 is increased to a high water content. It can be removed from coal by evaporation (water can be taken into the air).
In addition, although the case where the relative humidity is 95% due to adiabatic cooling is described here, it is not limited to 95%. The relative humidity is affected, for example, by the operating conditions of the dryer.

When the air in the state of point A is heated to, for example, 120 ° C., the air is in the state of point B2. When the air in the state of point B2 is supplied to the dryer 18, the air is adiabatically cooled to about 42 ° C. and a relative humidity of 95% to be in the state of point C2.
When the air condition changes from point B2 to point C2, 0.031 (kg-water vapor / kg-dryair) of water corresponding to the length L2 of the vertical axis between point B2 and point C2 is evaporated. Can do.

In addition, since the possibility that high moisture coal will ignite becomes high in practice, it is difficult to heat the air to the following temperature, but an example will be described for reference.
When the air in the state of point A is heated to, for example, 220 ° C., which is outside the range described in FIG. 4, and the air in this state is supplied to the dryer 18, the air is adiabatically cooled and the relative humidity is 95%. It will be in the state of C3. In this case, 0.058 (kg-water vapor / kg-dryair) of water corresponding to the length L3 can be evaporated.

As described above, according to the modified coal manufacturing apparatus 1 and the manufacturing method of the present embodiment, the drying step S10 includes the first drying step S11 and the second drying step S12.
Then, the first steam generated in the second drying step S12 is used to indirectly heat the air taken from the outside in the first drying step S11, and the second steam produced by exhaust heat recovery in the dry distillation step S20 is used. In the second drying step S12, the primary dry coal M2 is indirectly heated.

Thus, the inexpensive second water vapor produced by waste heat recovery in the carbonization step S20 can be used for the second drying step S12. Moreover, in drying process S10, in order to utilize the 1st water vapor | steam generate | occur | produced in 2nd drying process S12 for the drying heat source in 1st drying process S11, high moisture coal M1 is used for 1st drying process S11 and 2nd drying process S12. It can be dried in two steps.

In the present embodiment, the first water vapor generated in the second drying step S12 is used for internal circulation. For this reason, the amount of steam used for internal circulation can be reduced, and the amount of water vapor required to dry the high-moisture coal M1 can be reduced by 30 compared to the conventional manufacturing methods described in

Patent Documents

1 and 2, for example. % Can be reduced.
Thus, enormous electric power is not required for drying the high moisture coal M1, and the amount of water vapor for drying the high moisture coal M1 can be reduced.
Furthermore, since the temperature inside the dryer 18 is relatively low at 60 ° C. or lower, the high moisture coal M1 can be dried without igniting.

The amount of water evaporated in the second drying step S12 is doubled from the amount of water evaporated in the first drying step S11 from the fixed amount of high moisture coal M1. Thereby, the total amount of the first steam obtained in the second drying step S12 is equal to the total amount of steam required for drying in the first drying step S11, and the thermal efficiency in this manufacturing method can be increased.

In the first drying step S11, the temperature of the air M5 can be more reliably increased by indirectly heating the air M5 taken from the outside with the second water vapor.
In the drying step S10, the air M5 taken from the outside is supplied to the dryer 18, but an inert gas such as nitrogen may be used instead of the air M5.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. However, in the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, the description thereof is omitted, and only different points will be described.

As shown in FIG. 5, the manufacturing apparatus 2 of the present embodiment is connected to the connection pipe 51 connected to the supply pipe 24 and the connection pipe 51 in addition to the components of the manufacturing apparatus 1 of the first embodiment. And a heating pipe (heating pipe) 52 disposed in the dryer 18.

For example, the heating pipe 52 is disposed so as to be horizontal to a portion where the coal fluidized bed M6 is formed (the surface of the coal fluidized bed M6). The coal fluidized bed M 6 in the dryer 18 contacts the outer surface of the heating pipe 52. The first water vapor passing through the supply pipe 24 is supplied to the heating pipe 52 through the connection pipe 51. Thereby, the coal fluidized bed M6 is indirectly heated by the first steam by contacting the outer surface of the heating pipe 52.
Note that one end of the heating pipe 52 is connected to the connection pipe 51. The first steam becomes steam condensed water via the other end of the heating pipe 52 and is discharged to the outside.

The manufacturing method of this embodiment using the manufacturing apparatus 2 configured as described above will be described.
In the first drying step S 11, the first water vapor that has flowed from the second drying facility 12 to the supply pipe 24 further flows into the connection pipe 51 and the heating pipe 52. Thereby, the coal fluidized bed M6 can be indirectly heated with the first steam through the heating pipe 52.
As a result, the high-moisture coal M1 is indirectly heated not only by the air M5 taken from outside and heated, but also by the first water vapor.

(Example)
Here, an embodiment of the present invention will be described in more detail with specific examples. However, the present invention is not limited to the following examples.

In FIG. 4, when the air in the state of point A is heated to, for example, 120 ° C., the air is in the state of point B2. When the coal fluidized bed M6 is heated by the heating pipe 52 provided in the dryer 18, the heating heat quantity ratio between the heat quantity by the heated air and the heat quantity by indirect heating using the heating pipe 52 becomes 1: 1 ( When heating is performed so that the length L3 in FIG. 4 is twice the length L2, the air in the state of point B2 is in the state of point C3 described above.
For this reason, any heat source having a temperature higher than the wet bulb temperature of 49 ° C., which is the temperature at the intersection of the line passing through the point C3 and parallel to the vertical axis, and the horizontal axis can be used in place of the first water vapor.

Thus, when the heating heat quantity ratio of the heat quantity by the heated air and the heat quantity by the indirect heating using the heating pipe 52 is 1: 1, the production apparatus 2 can be used even with the first steam at about 110 ° C. The effect of evaporating the moisture of 0.058 (kg-water vapor / kg-dryair), which is the same as the preheating of the outside air from 120 ° C. to 220 ° C., is obtained.

The effect corresponding to the amount of heat when the fluidized bed M6 is indirectly heated by the heating pipe 52 is that the air is heated by the amount of heat corresponding to the amount of heat that heats the fluidized bed M6 from 120 ° C. Equivalent drying effect.
Further, the heating calorie ratio between the amount of heat by the heated air and the amount of heat by indirect heating using the heating tube 52 may be other than 1: 1.

As described above, according to the modified coal manufacturing apparatus 2 and the manufacturing method of the present embodiment, the high-moisture coal M1 is dried without igniting, and the water vapor for drying the high-moisture coal M1 is inexpensive. Waste heat recovery steam (second steam) can be used. In addition, the amount of water vapor can be reduced.

Furthermore, in the first drying step S 11, the coal fluidized bed M 6 is indirectly heated with the first steam through the heating pipe 52. Therefore, by indirectly heating not only with the air M5 but also with the first water vapor, more water can be evaporated from the high-moisture coal M1 while maintaining the temperature inside the dryer 18 at a relatively low temperature. it can.
Thus, by providing the heating tube 52, the air volume required for drying can be reduced, and the manufacturing apparatus 2 can be reduced in size.

As mentioned above, although 1st Embodiment and 2nd Embodiment of this invention were explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The structure of the range which does not deviate from the summary of this invention Changes, combinations, deletions, etc. are also included. Furthermore, each of the configurations shown in each embodiment can be used in appropriate combination.

For example, in the first embodiment and the second embodiment, in order to further increase the temperature of the air M5 when supplied to the dryer 18, the air M5 is heated with water vapor obtained outside the manufacturing apparatus. Also good. On the other hand, when the temperature of the air M5 supplied to the dryer 18 is sufficiently high, the air M5 may not be heated with the second steam.

In the first embodiment and the second embodiment, moisture is evaporated from the high moisture coal M1 to primary dry coal M2, and water is further evaporated from the primary dry coal M2 to dry coal M3. When grasping the dryness of the equipment (water evaporation), for example, directly measuring the moisture content of each of the primary dry coal M2 and dry coal M3, the drying temperature in each dry equipment, What is necessary is just to estimate a drying condition based on the residence time etc. which were calculated | required from the differential pressure | voltage of the layer. However, it is not limited to these methods.

In addition, when there is surplus second water vapor in the manufacturing apparatus, the second water vapor may flow through the heating pipe 52.
The manufacturing apparatus may not include the air heater 17. In this case, the temperature of the drying air M5 is, for example, a maximum of 100 ° C., preferably 70 to 90 ° C.

ADVANTAGE OF THE INVENTION According to this invention, while drying high moisture coal, it can obtain the water vapor | steam for drying high moisture coal cheaply, and also the quantity of the water vapor | steam for drying high moisture coal is also reduced. be able to. Therefore, it has industrial applicability.

1, 2 ... Production equipment (Production equipment for modified coal)
10 ... Drying equipment (drying section)
11 ... First drying equipment (first drying section)
12 ... Second drying equipment (second drying section)
30 ... Carbonization equipment (carbonization section)
40 ... Cooling equipment (cooling section)
DESCRIPTION OF SYMBOLS 51 ... Connection piping M1 ... High moisture coal M2 ... Primary dry coal M3 ... Dry coal M4 ... Modified coal M5 ... Air M6 ... Coal fluidized bed S10 ... Drying process S11 ... First drying process (air fluidized bed drying process)
S12 ... Second drying step (indirect heating drying step)
S20 ... dry distillation process S30 ... cooling process

Claims

A method for producing modified coal, which produces modified coal from high-moisture coal that contains 45% or more of water by mass,
Heating air taken from outside, fluidizing the high moisture coal with the heated air to form a coal fluidized bed, and evaporating moisture from the high moisture coal in the coal fluidized bed to form primary dry coal A drying process;
A second drying step of indirectly heating the primary dry coal, further evaporating moisture from the primary dry coal to dry coal, and recovering the first water vapor evaporated from the primary dry coal;
A dry distillation step of generating second steam by carbonizing the dry coal to form the modified coal, and recovering exhaust heat from the combustion exhaust gas after supplying the dry distillation heat necessary for the dry distillation of the dry coal;
A cooling step for cooling the modified coal,
In the first drying step, the air is indirectly heated with the first water vapor,
In the second drying step, the primary dry coal is indirectly heated using the second water vapor.
The method for producing reformed coal according to claim 1, wherein, in the first drying step, the coal fluidized bed is indirectly heated with the first steam.
The amount of moisture that evaporates from the primary dry coal in the second drying step after the high moisture coal becomes the primary dry coal with respect to the amount of moisture that evaporates from the high moisture coal in the first drying step. The method for producing reformed coal according to claim 1 or 2, wherein is 2 times.
The method for producing modified coal according to claim 1, wherein in the first drying step, the air is indirectly heated with the second steam.
An apparatus for producing modified coal that produces modified coal from high-moisture coal that contains 45% or more of water by mass,
A drying unit that evaporates moisture from the high moisture coal to dry coal;
A carbonization section for carbonizing the dry coal into the modified coal;
A cooling unit for cooling the modified coal,
The drying unit
Heating air taken from outside, fluidizing the high moisture coal with the heated air to form a coal fluidized bed, and evaporating moisture from the high moisture coal in the coal fluidized bed to form primary dry coal One drying section,
Indirectly heating the primary dry coal to further evaporate water from the primary dry coal to form the dry coal, and a second drying unit for recovering the first water vapor evaporated from the primary dry coal; Have
The dry distillation section generates the second water vapor by dry distillation of the dry coal and exhaust heat recovery of the combustion exhaust gas after supplying the dry distillation heat necessary for the dry distillation of the dry coal,
The first drying unit indirectly heats the air with the first water vapor,
The said 2nd drying part is a manufacturing apparatus of the modified coal which heats the said primary dry coal indirectly using 2nd water vapor | steam.
The modified coal production apparatus according to claim 5, wherein the first drying unit indirectly heats the coal fluidized bed with the first steam.