KR100960793B1 - Upgrade method and apparatus of low rank coal - Google Patents

Abstract

PURPOSE: A method for making high quality coal with low-grade coal and an apparatus thereof are provided to improve quality of the low-grade coal having the moisture content more than 30% to power generation coal having moisture content less than 10%, a calorific value more than 6,500kcal/kg, which can prevent a spontaneous ignition of high-grade coal. CONSTITUTION: A method for making high quality coal with low-grade coal comprises the following steps: a step that a hot air of 100~130°C is injected into the low-grade coal of which granularity is 10~30mm and moisture content is more than 30% and dry primarily; a step of throwing in heavy oil ash powder 5~20 parts by weight having granularity less than 74μm to the low-grade coal 100 parts by weight and mixing; and the step of secondary drying a mixture in 120~150°C with microwaves as heating source. The apparatus for making high quality coal includes the following: a low-grade coal supply part; a heavy oil ash powder feeder: a hot air feed port; a porous plate(211) including an air supply nozzle(20) for first drying; a low-grade coal drying and stabilizing portion equipped with a low-grade coal stabilization device(21) for the second drying with microwave as a heating source; and a high-grade coal storage.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-grade coal,

In order to use low grade coal as fuel for a coal-fired power plant, the present invention high-grade low grade coal having a moisture content of 30% or more to high grade coal with a calorific value of less than 10% moisture and a calorific value of 6,500 kcal / kg or more and prevent spontaneous ignition of high grade coal And more particularly, to a method and apparatus for upgrading low-grade coal.

Generally, coal is divided into peat, brown coal, lignite, sub-bituminous coal, bituminous coal, and anthracite grades, , Volatile matter, high volatile bituminous coal, and anthracite are classified into semi-anthracite, anthracite, meta-anthracite and anthracite anthracite. Among these, Low Rank Coal (LRC) refers to brown coal and lignite bituminous coal, while bituminous coal and anthracite coal are classified as high rank coal (HRC).

Here, low grade and high grade do not mean the quality of coal but merely the difference in degree of carbonization. Generally, high-definition technology is defined as high grade coal (HRC: High Rank Coal) through dehydration, drying and stabilization using high water content ash (low grade).

Low-grade coal such as lignite is highly likely to spontaneously ignite due to the oxygen-functional group, which has a large number of pores and a large amount of lipid hydrocarbons and accumulates in the volatile matter due to accumulation of heat of adsorption by adsorption-desorption of moisture Use has been limited.

The moisture of low grade coal is divided into free water, interstitial water, surface water, and bound water. A large part of the low-grade coal water is the free water adhering to the surface of the low-grade coal, the water existing between the molecules of the low-grade coal and the molecules is the internal water, and the number of bonds is chemically bonded to the low-grade coal molecules. The free water and the surface water are dried at 100 ± 5 ° C, but the internal water and the combined water are destroyed and dried at about 400 ° C.

Therefore, in order to remove moisture from low-grade coal, it must be dried at a high temperature of 400 ° C or more, and thus it is disadvantageous in that it requires a lot of cost and energy for high-grade production. When the low-grade coal is dried at a high temperature as described above, the pores of the coal are mainly oxidized by oxygen oxidation reactors, hydroxyl groups (-OH), carboxyl groups (-COOH), carbonyl Group (Carbonyl group, -C = O) is generated. When they are exposed to air, they are oxidized by reacting with moisture and oxygen components, thereby raising the temperature inside the pores and causing spontaneous ignition. Therefore, it is essential to stabilize the coal through the drying process and to dry the coal with less than 10% water content in the pore by oil adsorption and molding (briquetting, pelletizing).

Accordingly, an object of the present invention is to provide a method for upgrading low-grade coal having a water content of 30% or more to a power generation coal having a calorific value of less than 10% and a calorific value of 6,500 kcal / kg or more and to prevent spontaneous ignition of high- Device.

In order to accomplish the above object, the present invention provides a method for producing a coal having a particle size of 10 to 30 mm and a moisture content of 30% or more by first introducing heated air at 100 to 130 ° C. into a low- And 5 to 20 parts by weight of the powder is added to 100 parts by weight of the lower coal and then the mixture is dried at a temperature of 120 to 150 ° C. using a microwave as a heat source.

The present invention also relates to a low-grade coal supply apparatus comprising a low-grade coal storage tank for storing low-grade coal, a low-grade coal rotary feeder for conveying the low-grade coal to the bottom by the stored low-grade coal, and a diaphragm; A heavy oil cake powder storage tank in which the heavy oil cake powder is stored, a heavy oil cake powder cake pulverizer for pulverizing the heavy oil cake powder to a particle size of 74 탆 or less, a heavy oil cake powder storage container for storing the pulverized heavy oil cake powder, A heavy oil powder feeder comprising a heavy oil cake powder bag filter for collecting the powder to be fed, a rotary valve for feeding the heavy oil cake powder downward and a heavy oil cake powder feed screw; A heating air supply unit including a blower, a heat exchanger for recovering heat of the dried and stabilized high-quality coal, and a heater for heating the heat exchanged air with air for drying; A low-grade coal inlet through which the coal fed through the low-grade coal feeder is injected, a heavy oil feed inlet through which the heavy oil powder fed through the heavy oil feeder is fed, and heated air fed through the heated air feeder A heated air inlet, a perforated plate having an air inlet at one side for heating the injected heated air through the low grade coal injected through the low grade coal inlet so as to primarily dry the low grade coal, the primary dried low grade coal and heavy oil A low-grade coal stabilizer for mixing the powders with a microwave as a heat source and performing secondary drying at 120 to 150 ° C, a steam suction unit for sucking the steam decomposed in the drying process of the low-grade coal, High-quality coal outlet, fine powder for discharging unburned heavy oil fine powder in matrix form A lower coal drying and stabilizing portion comprising a discharge portion; And a high-grade coal storage unit including a high-grade coal rotary feeder for feeding the high-grade coal discharged through the high-grade coal discharge port and a high-quality coal storage tank for storing the transferred high-quality coal. to provide.

The low-grade coal stabilization device includes a wave-type vibration plate for uniform mixing of the primary coal and the heavy oil powder introduced from the inlet of the heavy oil powder, and a low- A microwave supplier for microwave drying the mixture of the ash powder and a temperature sensor for measuring the temperature inside the mixture of the lower coal and the heavy oil ash powder.

The apparatus for upgrading the low grade coal may further comprise: a vapor phase powder collector for collecting powder in the dry steam sucked by the steam suction unit attached to the upper part of the low grade coal stabilization apparatus; a heavy oil powder recirculating the recovered powder A condenser for condensing the sucked vapor phase air, a gas-liquid separator for separating the gas in the condensed condensed water, a condensate reservoir for storing the condensate discharged from the gas-liquid separator, And a circulation pump for sending the condensed water to the cooling water.

Further, the upgrading device for the lower coal may further include an accessory part including a lower vibration spring device, a vibration supply device, and a vibration flow device support.

At this time, it is preferable that the oscillating flow plate is made of a material having a low permittivity permissible to transmit the supplied microwave.

The method and apparatus for upgrading low grade coal according to the present invention can make high grade of low grade coal having moisture content of 30% or more by using microwave drying and heavy oil fly ash for power generation coal having a heat value of less than 10% and calorific value of 6,500 kcal / kg or more In addition, it has a useful effect of preventing spontaneous combustion of high-grade coal.

Hereinafter, the present invention will be described in detail.

The method for upgrading a low grade coal according to the present invention is characterized in that the low grade coal having a particle size of 10 to 30 mm and a moisture content of 30% or more is firstly dried by injecting heated air at 100 to 130 ° C., 5 to 20 parts by weight of heavy oil powder is added to 100 parts by weight of the above-mentioned low-grade coal, and the mixture is dried at 120 to 150 ° C using microwave as a heat source.

Here, it is not necessary to limit the kind of low-grade coal, and it is possible to use it without restriction as long as the water content is 30% or more. In addition, the particle size of the low-grade coal is not necessarily limited, but low-grade coal having a particle size of 10 to 30 mm is used so that drying can be smoothly performed. If necessary, it may be pulverized before drying to have the above-mentioned particle size.

In order to remove the free water and the surface water adhering to the surface of the lower coal, the primary coal is heated to 100 ~ 130 ° C to perform the primary drying. The above primary drying is generally performed in the related art, and in the present invention, the heated air is injected to perform the primary drying.

Conventionally, in the process of upgrading low-grade coal, conventionally, drying is performed at 400 ° C or more to remove intrusive water such as pore water, coupled water in the capillary, internal retained water, etc. in the low-grade coal. In order to solve this problem, in the present invention, microwave is used as a heat source, and secondary drying is performed by mixing a hydrophobic heavy oil powder having a repulsive polarity but a high affinity with a carbon component. That is, 5 to 20 parts by weight of heavy oil powder having a particle size of 74 μm or less is added to the primary dried low-grade coal with respect to 100 parts by weight of low-grade coal, followed by secondary drying using a microwave as a heat source at 120 to 150 ° C. will be.

Here, the particle size of the heavy oil shavings powder is not necessarily limited, but it is preferable to use particles having a particle size of 74 탆 or less for effective drying. In consideration of the scattering during the working process, it is preferable to use a material having a particle size of 0.01 탆 or more.

If the amount of the heavy oil is less than 5 parts by weight based on 100 parts by weight of the low-grade coal, the temperature for the secondary drying is increased and the drying time is long. If the weight of the heavy oil is greater than 20 parts by weight, the amount of heat of the coal may be reduced.

As described above, the present invention applies a heat source application technique for moisture drying when a microwave heat source is applied instead of a direct or indirect heating method such as a heating furnace or an electric furnace, Which is a combustion byproduct of heavy oil ash, is added to increase the drying rate through hydrophobic action with binding water and to prevent spontaneous ignition by adsorption.

A microwave is a type of electromagnetic wave that is located between a far infrared ray and a radio wave (300 MHz to 300 GHz) in a spectrum. The most significant feature of microwaves is that they can heat up faster than conventional thermoelectric heating because they use the friction force by molecular rotation or rearrangement at the speed corresponding to the frequency of the electromagnetic wave. In addition, microwave energy has low energy that does not damage chemical bonds, so it does not deform or destroy the molecular structure. Due to such rapid temperature rise and chemical stability, microwave technology has already been applied in various chemical fields. In addition, the principle of microwave is that the material having a low permittivity (permeability) value has a property of transmitting microwave, while in the case of internal water such as water, which is a polar solvent having high permeability, And is evaporated as heat is released.

On the other hand, the heavy oil powder can be easily obtained as a combustion by-product of the heavy oil power plant. For example, in Pyungtaek Thermal Power Plant No. 1, Korea's Western Power Company, 3,134 tons / year is generated, and other heavy oil-fired power plants such as domestic Yeosu Thermal Power Plant are also generating large amounts. Therefore, it is possible to reinforce the fixed carbon component of low grade coal and to recycle heavy oil as designated waste when using heavy oil powder.

In the present invention, the difference in wettability between the carbon component and the hydrophilic binding water of the heavy oil having a hydrophobic property is used, that is, the repulsive force between the hydrophilic binding water and the carbon component of the hydrophobic lower coal, In order to increase the repulsion, a certain amount of heavy oil powder is used as the catalyst, which increases the hydrophobicity with the bonded water and increases the surface tension to accelerate the decomposition with the lower coal. At this time, Such as pore water and capillary tube water, to generate heat, thereby drying the combined water and the capillary coupling water at a temperature of 150 ° C or less, thereby spraying the water as steam and adsorbing the heavy oil powder to the pores, thereby preventing spontaneous ignition . In particular, the method according to the present invention as described above can be carried out at a temperature of from 400 to < RTI ID = 0.0 > A high-quality coal with a moisture content of 10% or less and a calorific value of 6,500 kcal / kg or more can be obtained by conducting it in about 25 minutes.

According to the present invention, there is provided an apparatus for effectively achieving the above-described method for upgrading low-grade coal. The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.

1 is an enlarged view of the main part of Fig. 1, Fig. 3 is an enlarged view of the perforated plate shown in Fig. 1, Fig. 4 is a cross- And Fig. 5 is an enlarged cross-sectional view of the oscillating flow plate shown in Fig.

As shown in FIGS. 1 to 5, the apparatus for upgrading low carbon according to the present invention includes a lower coal supply unit, a heavy oil feeder, a heating air supply unit, a lower coal drying and stabilizing unit, and a high-quality coal storage unit.

The low-grade coal supply unit includes a low-grade coal storage tank 1 for storing low-grade coal, a low-grade coal rotary feeder 2 for transporting the low-grade coal downwardly and a diaphragm 3.

Here, as described above, it is not necessary to limit the kind of the low-grade coal, and the low-grade coal can be used without restriction if it has a moisture content of 30% or more. In addition, the particle size of the low-grade coal is not necessarily limited, but low-grade coal having a particle size of 10 to 30 mm is used so that drying can be smoothly performed. If necessary, it may be pulverized before drying to have the above-mentioned particle size. The coal having such a particle size is conveyed to the lower coal inlet 17 by the rotary feeder 2 and the diaphragm 3.

The heavy oil powder feeder includes a heavy oil cake powder storage tank 4 for storing heavy oil cake powder, a heavy oil cake powder differentiator 5 for crushing the heavy oil cake powder to a particle size of 74 탆 or less, A heavy oil cake powder feed tank (6) for collecting powder scattered in the storage tank, a rotary valve (8) for feeding the heavy oil cake powder downward and a heavy oil cake powder feed screw (9).

The heavy oil shale powder uses combustion by-products of the heavy oil power plant, and the particle size of the heavy oil shatter powder is not necessarily limited, but it is preferable to use a material having a particle size of 74 탆 or less for effective drying.

The heating air supply unit includes a blower 10, a heat exchanger 13 for recovering the heat of the dried and stabilized high-grade coal, a heater 14 for heating the heat exchanged air with drying air ).

The heated air obtained by the heated air supply unit is used for primary drying or the like of low grade coal. At this time, as shown in the figure, the heated air supply unit includes a pressure gauge 11, a flow meter 12 for adjusting the air amount, a by-pass valve 15 used as circulation air, And a temperature measuring unit 16 for measuring the temperature of the fluid.

The low-grade coal drying and stabilizing unit includes a low-grade coal inlet 17 into which coal transferred through the low-grade coal supply unit is introduced, a heavy oil powder inlet 18 into which the heavy oil powder transferred through the heavy oil powder supply unit is introduced, A heated air inlet 19 for injecting the heated air fed through the heated air supply unit through a nozzle 212 formed at one side of the low-grade coal introduced through the low-grade coal inlet 17, A porous plate 211 equipped with an air inlet 20 at one side for primarily drying low grade coal, a primary plate 211 made of a mixture of the primary dried low grade coal and the heavy oil fly ash, A low-grade coal stabilizing device 21 for drying the low-grade coal, a steam suction unit 22 for sucking the steam decomposed in the drying process of the low-grade coal, A high quality coal discharge port 23, and a fine powder discharge unit 26 for discharging the heavy oil fine powder not adsorbed in a matrix form.

Here, the primary drying may be performed by injecting heated air at 100 to 130 ° C into the lower coal. In addition, the heavy oil powder having a particle size of 74 μm or less in the secondary drying is added in an amount of 5 to 20 parts by weight based on 100 parts by weight of the lower coal.

3, the size of the pores 211a is maintained at 1/5 to 1/10 of the particle size of the low grade coal particles, so that the low grade coal particles are mixed with the pores 211a It is desirable to prevent it from passing through.

The low-grade coal stabilizing device 21 is provided with a wave-type vibrating flow plate for uniform mixing of the primary dry low-grade coal and the heavy oil powder introduced from the heavy oil powder input port 18, And a temperature sensor 214 for measuring the temperature inside the mixture of the low-grade coal and the heavy oil shavings, and a temperature sensor 214 for measuring the temperature of the mixture of the low-grade coal and the heavy oil shavings .

Here, the microwave feeders 213a and 213b continuously irradiate the microwave until the temperature of the mixture of the low-grade coal and the heavy oil shavings becomes 120 to 150 ° C. When the temperature inside the mixture exceeds 150 ° C, . For this purpose, the microwave feeders 213a and 213b may be formed with a repetition structure of partly or entirely on / off.

In addition, as shown in FIG. 4, it is preferable that the microwave feeders 213a and 213b are disposed so as to cross each other without facing each other in order to prevent malfunctioning of the magnetron by inflow of microwaves and uniform irradiation. However, the arrangements of the microwave feeders 213a and 213b are not limited to those shown in the accompanying drawings, and the microwave feeders 213a and 213b can be arranged in various shapes as needed. In addition, the temperature sensor 214 is disposed between the microwave feeders 213a and 213b to which the microwave is not irradiated.

When the microwave is used as a heat source as in the present invention, it is preferable that the choke 218 is formed of an aluminum material having a high microwave permeation resistance on the inlet and the outlet to prevent leakage. Reference numerals 216 and 217 denote a connecting portion and a fixing portion for connecting the upper plate and the lower plate of the lower coal stabilizing device, respectively.

In addition, the wave-type oscillating flow plate 215 has its direction vector controlled from the inlet to the outlet as shown in FIG. 5, and has a wavy shape for smooth mixing and adsorption with the heavy oil powder And it is preferable to configure the Teflon material which transmits most of the microwave because the permeation resistance of the microwave is very low.

The high-quality coal storage unit includes a high-grade coal rotary feeder 24 transported through the high-grade coal discharge opening 23 of the low-grade coal drying and stabilizing unit, and a high-quality coal storage tank 25 for storing the transported high- .

When passing through the apparatus described above, low-grade coal having a moisture content of 30% or more and a calorific value of 4,500 kcal / kg or less has a moisture content of 10% or less and a high calorific value with a calorific value of 6,500 kcal / kg or more. It is also possible to prevent spontaneous combustion of high-grade coal.

The apparatus for upgrading the low grade coal includes a vapor phase powder collector (28) for collecting powder in the dry steam sucked by the steam suction part (22) attached to the upper part of the lower coal stabilization device (21) A heavy oil recirculation blower 27 recirculating the powder, a powder suction pump 29 for sucking the dried steam after collecting the powder, a condenser 30 for condensing the sucked vapor phase air, a gas in the condensed condensed water Liquid separator 31 for separating the gas-liquid separator 31 from the gas-liquid separator, a condensed-water storage tank 32 for storing the condensed water coming down from the gas-liquid separator, and a circulation pump 33 for sending the condensed water to the cooling water. The recovered heavy oil powder is recycled.

In addition, the upgrading device for low grade coal may further include an accessory part including a vibration flow device lower spring 34, a vibration supply device 35, and a vibration flow device support 36.

In order to prevent leakage of microwaves, the apparatus for upgrading the low grade coal according to the present invention is made of aluminum oxide (Al 2 O 3) material, and the perforated plate 211 provided with the air inlet 20 has corrosion resistance and wear resistance The vibration flow plate 215 is made of a Teflon material having a low permittivity for the purpose of permeating the supplied microwave. The temperature of the mixture in the mixture of the low-grade coal and the heavy oil shavings The temperature sensor 214 for measurement is preferably made of a stainless steel shielding material.

Hereinafter, the present invention will be described in more detail with reference to the following examples.

Configuration of the device

The microwave feeder is 2.45 GHz, 2 kW, 220 V, single-phase, and two vibrating feeders 35 of 0.45 kW capacity are mounted on both sides to uniformly oscillate the vibrating fluidized bed body. The overall shape of the low carbon carbon steel is the same as that of the second scheme. The apparatus volume is 100 cm for the perforated plate 211 and the wavy oscillating flow plate 215 is 200 cm long, 30 cm wide, and 30 cm high. A stainless steel shielded thermocouple was used as the temperature sensors 214a and 214b and a diameter of a mounting part for installing the thermocouples was set to 1 cm. The steam suction part 22, the lower coal inlet 17, the heavy oil powder inlet 18, The area of 2inch x 2inch was used. The size of the pores 211a of the perforated plate was 1/5-1 / 10 of the particle size of 10 to 30 mm of the low grade coal particles, and the number of circles having a diameter of 5 mm was set to 7 short axes and 22 long axes, As shown in Fig. 5, the plate 215 has a thickness of 2 cm on the bottom side 215a, a maximum height side 215b of 5 cm, and a width 215c of 20 cm.

Experimental conditions for using the above apparatus are as follows.

Coal: Indonesia imported one type of coal

Total moisture content: 36.4%

Coal size: 20mm particle size

Vibration flow rate: 12 cm / min

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Primary Drying Method: Perforated Plate Heating Air Contact

Primary drying temperature: See Table 1 below

Primary dry air injection rate: 2m / s

Primary dry air injection volume: 0.36㎥ / min

Condensation prevention and air circulation for upper circulation: 0.72㎥ / min

Secondary Drying Method: Microwave irradiation and Molecular Rotation

Secondary drying temperature: See Table 1 below

Second drying time: see Table 1 below

Low-grade coal throughput: 20 kg / hr

Feed amount of heavy oil powder: 5 kg / hr

≪ Example 1, Comparative Examples 1 to 3 >

The upgrading of the low grade coal was performed using the conditions shown in Table 1 below. The results are shown in Table 2.

That is, in Example 1, the primary drying was followed by secondary drying in parallel with the microwave drying. Comparative Example 1 was carried out in the same manner as in Example 1, except that no heavy oil was added. In Comparative Example 2, only microwave drying was performed without primary drying, and in Comparative Example 3, 2 The car did not dry itself.

Experimental condition table Primary drying Secondary drying Microwave irradiation Heavy meal powder Example 1 8 minutes at 120 ° C 17 minutes at 120 ° C adding Comparative Example 1 8 minutes at 120 ° C 17 minutes at 150 ° C No additives Comparative Example 2 Not implemented 17 minutes at 150 ° C No additives Comparative Example 3 25 minutes at 120 ° C Not investigated No additives

 Characteristics of Low-grade Coal Heavy Oil Powder and High-grade Coal supply High-grade coal Low grade coal Heavy meal powder Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Total moisture (% by weight) 36.4 5.65 5.0 11.8 13.5 25.3 Ash (wt%) 3.0 7.08 3.21 3.09 3.08 2.89 Volatiles (wt%) 50.1 11.56 47.59 45.06 45.04 38.78 Fixed carbon (wt%) 42.9 70.80 44.2 40.05 38.38 33.03 Fuel cost 0.86 4.28 0.93 0.89 0.85 0.85 Calorific value (Kcal / kg) 6291 7553 7210 6950 6800 5300 C (% by weight) 69.76 95.24 71.03 71.02 70.58 70.5 H (wt%) 4.82 0.3 4.59 4.67 4.97 5.12 N (% by weight) 1.15 1.56 1.16 1.14 1.13 1.14 S (% by weight) 0.12 1.14 0.16 0.14 0.13 0.15 O (% by weight) 24.13 N.D. 23.06 23.03 23.19 23.09 Particle size Particle size 20mm Particle size 74 μm ㅡ ㅡ ㅡ ㅡ

Here, the fuel ratio is a fixed carbon content / volatile content (FC / VM).

As shown in Table 1 and Table 2, the water content of the low grade coal is about 36.4 (about 36%) and the heat amount is 6,291 Kcal / kg as the dry standard, which is higher than the anthracite coal but less than 6,500 kcal / kg of coal for coal- It is. The fuel ratio is 0.86, which is similar to the sub-bituminous series, and it can be confirmed that it is suitable for the specification as the fuel for the thermal power plant when the moisture is dried to 10% or less. In addition, the heavy oil power ash powder used as an additive has a moisture content of 5.65%, a calorific value of 7,553 Kcal / kg, and a fixed carbon content of 70.80%, which is very high.

According to the present invention, in the case of Example 1 in which the heavy oil powder and microwave were irradiated, the moisture content of the high-grade coal produced was extremely low as 5.0%, and the heat amount was very high as 7,210 kcal / kg. In particular, the fuel cost has a characteristic of 0.93. The properties of Table 2 were found to be suitable as raw materials for combustion of coal-fired power plants. However, in the case of Comparative Examples 1 to 3 corresponding to other methods, it was found to be very difficult to dry to a moisture content of 10% or less.

<Experimental Example 1>

The pyrophoricity of the high-grade coal produced in Examples 1 to 4 was investigated using a bench scale test apparatus, and the results are shown in FIG.

The spontaneous ignitability was measured by placing a sample of a certain volume (diameter: 106 mm, height: 350 mm) in a bench test apparatus, raising the temperature to 50 ° C. in a nitrogen atmosphere and then changing the atmosphere to dry air, Was evaluated by comparing the time until the temperature reached 80 占 폚 and 150 占 폚.

The control shown in FIG. 6 also shows the experimental results of the bituminous coal used in the coal-fired power plant.

As shown in FIG. 6, the high-grade coal of Example 1 according to the present invention was found to have high purity and high activity in the air, The time for reaching 80 DEG C and 150 DEG C was measured to be very long as compared with the coals of bituminous coal and other comparative examples by the disturbance, and as a result, it is found that the self-ignitability is relatively low.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system diagram of a high-grade coal-making apparatus according to the present invention; FIG.

Fig. 2 is an enlarged view of the main part of Fig.

3 is an enlarged view of the perforated plate shown in Fig.

4 is a cross-sectional view along the line A-A in Fig.

5 is an enlarged cross-sectional view of the oscillating flow plate shown in Fig.

6 is a graph showing the results of the spontaneous ignitability test.

Description of the Related Art

1: Low grade coal storage tank 2: Low grade coal rotary feeder

3: Diaphragm 4: Heavy oil powder storage tank

5: Heavy oil powder powder differentiator 6: Heavy oil powder storage tank

7: Heavy oil powder bag filter 8: Rotary valve

9: Heavy oil powder feed screw 10: Blower

11: Pressure gauge 12: Flow meter

13: heat exchanger 14: heater

15: bypass valve 16: temperature measuring instrument

17: Lower coal input port 18: Heavy oil powder input port

19: heating air inlet 212: nozzle

20: air inlet 211: perforated plate

21: Low grade coal stabilization device 215: Vibrating flow plate

213a and 213b: microwave feeders 214a and 214b: temperature sensors

22: Steam suction part 23: High quality coal outlet

24: High-grade coal rotary feeder 25: High-grade coal storage tank

26: Heavy oil fine powder discharge part 27: Heavy oil cake powder recirculation blower

28: Vapor phase powder collector 29: Powder suction pump

30: condenser 31: gas-liquid separator

32: condensate reservoir 33: circulation pump

34: oscillating flow device lower spring 35: vibration supply device,

36: vibrating flow device support

Claims (6)

The heavy coal having a particle size of 10 to 30 mm and a moisture content of 30% or more is firstly dried by injecting heated air at 100 to 130 캜, and a heavy oil powder having a particle size of 74 탆 or less is added to the low- To 20 parts by weight, and then the mixture is dried at 120 to 150 ° C. using a microwave as a heat source. A low grade coal supply unit including a low grade coal storage tank for storing low grade coal, a low grade coal rotary feeder for conveying the stored low grade coal downward and a diaphragm; A heavy oil cake powder storage tank in which the heavy oil cake powder is stored, a heavy oil cake powder cake pulverizer for pulverizing the heavy oil cake powder to a particle size of 74 탆 or less, a heavy oil cake powder storage container for storing the pulverized heavy oil cake powder, A heavy oil powder feeder comprising a heavy oil cake powder bag filter for collecting the powder to be fed, a rotary valve for feeding the heavy oil cake powder downward and a heavy oil cake powder feed screw; A heating air supply unit including a blower, a heat exchanger for recovering heat of the dried and stabilized high-quality coal, and a heater for heating the heat exchanged air with air for drying; A low-grade coal inlet through which the coal transferred through the low-grade coal supply unit is input, a heavy oil feed inlet through which the heavy oil powder fed through the heavy oil feeder is fed, and hot air fed through the heated- A heated air inlet for injecting the coal through the formed nozzle, a perforated plate having an air inlet at one side for passing the injected heated air through the low grade coal injected through the low grade coal inlet to primarily dry the low grade coal, A low-grade coal stabilizer for mixing the dried low-grade coal and the heavy-oil fly ash as a heat source at a temperature of 120 to 150 ° C, a steam suction unit for sucking the steam decomposed in the drying process of the low-grade coal, High-grade coal outlet for discharging stabilized coal, fine-grained fine-grained fine particles in the form of matrix A fine powder discharge portion comprises a lower coal drying for discharging end and the stabilizing unit; And a high-grade coal storage unit including a high-grade coal rotary feeder for feeding the high-grade coal discharged through the high-grade coal discharge port and a high-quality coal storage tank for storing the transferred high-quality coal. The method of claim 2, The low-grade coal stabilization device comprises: a wave-type vibration flow plate for uniform mixing of the primary dried low-grade coal and the heavy oil powder introduced from the heavy oil powder input port; And a temperature sensor for measuring a temperature inside the mixture of the low-grade coal and the heavy-oil shavings, and a microwave supplier for microwave-drying the mixture of the heavy-oil shavings. The method of claim 2, Wherein the apparatus for upgrading the low grade coal comprises: a vapor phase powder collector for collecting powder in the dry steam sucked by the steam suction unit attached to the upper portion of the low grade coal stabilizer; a heavy oil recycle powder recirculating the recovered powder A condenser for condensing the sucked vapor phase air, a gas-liquid separator for separating the gas in the condensed condensed water, a condensate reservoir for storing the condensed water from the gas-liquid separator, Further comprising a decomposition gas-phase powder recovery unit including a circulation pump for sending the condensed water to the cooling water. The method of claim 2, Wherein the low grade coal upgrading apparatus comprises: Further comprising an accessory device comprising a vibrating flow lower spring, a vibrating feed device, and a vibrating flow device support. The method of claim 3, Wherein the vibrating flow plate is made of a material having a low permittivity so that the supplied microwave can be transmitted.

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