JP6344251B2 - Combustible fuel injection system and combustible fuel injection method - Google Patents

Description

  The present invention relates to a combustible fuel injection system and a combustible fuel injection method.

Clinker, which is a raw material for cement, was prepared by pulverizing silica and limestone using a raw material crusher in a cement production facility, and the pulverized raw material was calcined at a predetermined temperature in a calcining furnace and calcined. Manufactured by firing raw materials at a higher temperature than calcining in a rotary kiln.
In the production of such clinker, in recent years, recycling using combustible waste has been promoted by using combustible waste or the like as combustible fuel and putting the combustible fuel into a calcining furnace.

One of the methods for charging flammable fuel into the calcining furnace is to provide a vortex chamber in the calcining furnace with a flammable fuel inlet into which the flammable fuel is charged, and to insert the flammable fuel into the flammable fuel inlet. (For example, refer to Patent Document 1).
In addition, the combustible fuel is put into the extraction duct, and the combustible fuel is heated by the high-temperature air flowing through the extraction duct while the injected combustible fuel moves in the extraction duct. There is a charging method for charging into a calcining furnace (for example, see Patent Documents 2 to 4).

JP 2006-248996 A Japanese Patent No. 5003036 Japanese Patent No. 4972944 Japanese Patent No. 4992513

  However, the degree of flammability of a combustible fuel depends largely on the moisture content of the combustible fuel, and the moisture content varies from rod to rod of the combustible fuel. However, combustible fuel with low combustibility (high moisture content) and combustible fuel with high combustibility (low moisture content) are mixed, so combustible fuel with low combustibility can be combusted. If the calcining furnace is put into a calcining furnace before it reaches a certain state, the combustion efficiency of the calcining furnace may be lowered.

  An object of the present invention is to provide a flammable fuel charging system and a flammable fuel charging method capable of efficiently loading a flammable fuel having high flammability and a flammable fuel having low flammability into a calcining furnace. It is to provide.

  The combustible fuel injection system and the combustible fuel injection method according to the present invention are as follows.

(1) a calcining furnace;
A rotary kiln for firing at a higher temperature than the calcining furnace;
An air quenching cooler for cooling the clinker discharged from the rotary kiln;
An extraction duct through which the gas recovered from the air quenching cooler flows;
A plurality of combustible fuel inlets for injecting powdered combustible fuel into the extraction duct or the calcining furnace,
Of the plurality of combustible fuel inlets, a first combustible fuel inlet is provided in the extraction duct,
Of the plurality of combustible fuel inlets, a second combustible fuel inlet is provided in the extraction duct or the calcining furnace,
The first calciner reach distance between the first combustible fuel inlet and the calciner is the second calciner reach distance between the second combustible fuel inlet and the calciner. Longer,
The average value of the moisture content of the combustible fuel introduced from the first combustible fuel inlet is greater than the average value of the moisture content of the combustible fuel introduced from the second combustible fuel inlet. Fuel injection system.

  (2) The bleed duct has a mixed region in which combustible fuel introduced from the first combustible fuel inlet and combustible fuel introduced from the second combustible fuel inlet are mixed. The combustible fuel injection system described in 1).

  (3) The average value of the moisture content of the combustible fuel that is input from the first combustible fuel input port to the extraction duct is 30 to 60%, and the extraction duct from the second combustible fuel input port The combustible fuel injection system according to (1) or (2), wherein the average moisture content of the combustible fuel input to is from 0 to 30%.

(4) Further, a combustible fuel sorting unit for sorting the combustible fuel into a plurality of combustible fuel groups based on an average value of a plurality of predetermined moisture contents,
The combustible fuel of the combustible fuel group having the highest average moisture content among the plurality of combustible fuel groups is input to the first combustible fuel inlet, (1) to (3) The combustible fuel injection system according to any one of the above.

  (5) A combustible fuel injection method using the combustible fuel injection system according to any one of (1) to (4).

  In the combustible fuel charging system, the first calcining furnace reach distance between the first combustible fuel charging port and the calcining furnace among the plurality of combustible fuel charging ports is the second combustible fuel charging port and the calcining furnace. A plurality of combustible fuel inlets are formed in the extraction duct or the calcining furnace so as to be longer than the reach distance of the second calcining furnace between the first and second calcining furnaces.

For this reason, a combustible fuel with low combustibility is introduced into the first combustible fuel inlet located far from the calcining furnace, and a combustible fuel with high combustibility is introduced into the second combustible fuel near the calcining furnace. Can be put into the mouth.
And since the 1st calcining furnace reach distance is longer than the 2nd calcining furnace reach distance, the combustible fuel with low combustibility thrown in from the 1st combustible fuel input port is long called the 1st calcining furnace reach distance. When moving in the extraction duct for a distance (ie, for a long time), the heated air flowing in the extraction duct is heated to a highly flammable state and dried to reach the calcining furnace. In addition, the highly combustible combustible fuel introduced from the second combustible fuel inlet moves through the extraction duct for a short distance (that is, a short time) that is the reach distance of the second calcining furnace. Before reaching the calcining furnace, that is, in the bleed duct, it is difficult to be in a combustible state, and there is almost no possibility that the coating or the like adheres to the inside of the bleed duct due to the combustion of combustible fuel.

  In other words, each combustible fuel has a distance between the calcination furnace reach distance between each combustible fuel inlet and the calciner and the combustibility of the combustible fuel introduced from the combustible fuel inlet. The longer the calcining furnace reach distance between the charging port and the calcining furnace, the lower the combustibility of the combustible fuel charged from the combustible fuel charging port. The combustibility of the combustible fuel largely depends on, for example, the particle size and aspect ratio of the combustible fuel, the moisture content, and a combination thereof.

  Therefore, according to the present invention, the combustible fuel injection system and the combustible fuel injection method efficiently inject a combustible fuel having a high combustibility and a combustible fuel having a low combustibility into a calcining furnace. be able to.

It is a conceptual diagram explaining the combustible fuel injection | throwing-in system and combustible fuel injection | throwing-in method which concern on this invention. FIG. 2 is a partially enlarged view of the combustible fuel injection system shown in FIG. 1.

  With reference to FIG.1 and FIG.2, the combustible fuel injection | throwing-in system 10 and the combustible fuel injection | throwing-in method which are one of this embodiment of this invention are demonstrated.

As shown in FIG. 1, the combustible fuel injection system 10 is used in a cement clinker firing apparatus 1.
The cement clinker firing apparatus 1 is used when firing clinker raw materials such as limestone, clay, silicic acid raw materials, and iron oxide raw materials.

The cement clinker firing apparatus 1 includes four cyclones C1, C2, C3, and C4 in order from the bottom, a calcining furnace 60, a clinker raw material charging unit 70, a rotary kiln 40, an air quenching cooler 80, and a fan 82. Prepare.
The clinker raw material charging unit 70 is a rising duct and an inlet hood connected to the calcining furnace 60 and the cyclone C1 so that the clinker raw material flows from the calcining furnace 60 through the cyclone C1 to the rotary kiln 40.
The rotary kiln 40 is connected to a clinker material input unit 70, and a main fuel burner 50 is attached as a fuel calcination device for calcination of the clinker material at a higher temperature than the calcining furnace 60.
The air quenching cooler 80 is connected to the rotary kiln 40 and cools the clinker discharged from the rotary kiln 40.
The fan 82 is connected to the cyclone C4 via a pipe 81.

The cyclones C1, C2, C3, C4 and the other cyclones C1, C2, C3, C4 are connected by pipes 83, 85, 87. A shooter 89 is connected between the cyclone C2 and the calcining furnace 60. The cyclone C1 is connected to the calcining furnace 60.
Here, waste materials such as limestone, clay, silica, iron slag, coal ash, sludge, and main ash generated by incineration of municipal waste can be used as the clinker raw material.

As shown in FIG. 2, the combustible fuel charging system 10 includes a combustible fuel g1 having a low combustibility due to moisture content and a combustible fuel having a high combustibility based on the combustibility of the powder combustible fuel G. The flammable fuel g1 and the flammable fuel g2 thus sorted are put into the extraction duct 20, and the combustible fuel G0 heated and dried while moving in the extraction duct 20 is burned in the calcining furnace 60. It is a system to let you.
The combustible fuel input system 10 includes a calcining furnace 60, a rotary kiln 40, an air quenching cooler 80, a clinker raw material input unit 70, an extraction duct 20, a first combustible fuel input port 21, and a second combustible fuel. The fuel injection port 22 is provided. In the present embodiment, the combustible fuel input system 10 is described as having two combustible fuel input ports, but may be three or more.
The combustible fuel charging system 10 further includes a combustible fuel sorting unit 30. As will be described later, the combustible fuel sorting unit 30 classifies the combustible fuel G into a combustible fuel g1 having low combustibility and a combustible fuel g2 having high combustibility.

  The extraction duct 20 is a pipe that connects the air quenching cooler 80 and the calcining furnace 60 so that the gas recovered from the air quenching cooler 80 flows to the calcining furnace 60. In the bleed duct 20, air at a temperature (for example, 800 ° C.) that can sufficiently dry the combustible fuel g1 and the combustible fuel g2 flows.

The first combustible fuel input port 21 is formed in the bleed duct 20 so that the flammable fuel g <b> 1 having low combustibility can be input to the bleed duct 20. The second combustible fuel inlet 22 is formed in the extraction duct 20 so that the combustible fuel g <b> 2 having high combustibility can be input into the extraction duct 20.
The first combustible fuel input port 21 and the second combustible fuel input port 22 each have an opening / closing mechanism that controls the input of the combustible fuel g1 and the combustible fuel g2. By this opening / closing mechanism, the first combustible fuel input port 21 and the second combustible fuel input port 22 are made ready for input so that the combustible fuel g1 and the combustible fuel g2 are simultaneously input to the extraction duct 20, The second flammability is set so that only the first flammable fuel inlet 21 can be turned on so that only the flammable fuel g1 is put into the bleed duct 20, or only the flammable fuel g2 is put into the bleed duct 20. The first combustible fuel input port 21 and the second combustible fuel input port 22 are set so that only the fuel input port 22 can be input, or both the combustible fuel g1 and the combustible fuel g2 are not input to the extraction duct 20. It is also possible to make it impossible to input.

Here, the first calcining furnace reach distance a between the first combustible fuel inlet 21 and the calcining furnace 60 is the second temporary calcining distance between the second combustible fuel inlet 22 and the calcining furnace 60. It is longer than the furnace reach distance b. For this reason, it is preferable to introduce the combustible fuel g1 having low combustibility into the first combustible fuel inlet 21 and to introduce the combustible fuel g2 with high combustibility into the second combustible fuel inlet 22.
The first calcining furnace reach distance a moves in the extraction duct 20 while the low combustibility combustible fuel g1 input from the first combustible fuel input port 21 is heated by the gas flowing in the extraction duct 20, The distance is such that the combustible fuel g1 when reaching the calcining furnace 60 is in a substantially combustible state.
The second calcining furnace reach distance b travels in the extraction duct 20 while the highly combustible combustible fuel g2 input from the second combustible fuel input port 22 is heated by the gas flowing in the extraction duct 20, The distance is such that the combustible fuel g2 when reaching the calcining furnace 60 is in a substantially combustible state.

  Further, since both the first combustible fuel input port 21 and the second combustible fuel input port 22 are formed in the extraction duct 20, the extraction duct 20 is input from the first combustible fuel input port 21. The single region 20a in which only the combustible fuel g1 is moved, the combustible fuel g1 input from the first combustible fuel input port 21, and the combustible fuel g2 input from the second combustible fuel input port 22 are provided. And a mixed area 20b that moves. Therefore, the combustible fuel g1 moves in the extraction duct 20 by the length of the single region 20a (first calcining furnace reach distance a−second calcining furnace reach distance b = difference distance c).

The first calcining furnace reach distance a is, for example, preferably 1 to 50 m, more preferably 3 to 30 m, and more preferably 6 to 15 m from the viewpoint that it takes time to ignite as the moisture content of the combustible fuel increases. Is even more preferred.
The second calcining furnace reach distance b is, for example, preferably from 0 to 10 m, more preferably from 0 to 8 m, and even more preferably from 0 m to 6 m from the viewpoint that the time until ignition is shortened as the water content is smaller.

  The combustible fuel sorting unit 30 includes a sorting device main body 35, a first discharge pipe 31, and a second discharge pipe 32. Since the combustibility of the combustible fuel greatly depends on, for example, the particle size, aspect ratio, moisture content, and combination of the combustible fuel, in this embodiment, the sorting apparatus main body 35 uses the combustible fuel G as the combustible fuel G. In addition, it has a function of sorting into a plurality of combustible fuel groups based on an average value of a plurality of predetermined moisture contents. The first exhaust pipe 31 connects the sorting device main body 35 and the first combustible fuel input port 21 so that the combustible fuel g <b> 1 having low combustibility is discharged to the first combustible fuel input port 21. The second discharge pipe 32 connects the sorting device main body 35 and the second combustible fuel input port 22 so that the highly combustible combustible fuel g2 is discharged to the second combustible fuel input port 22.

  The average moisture content of the combustible fuel g1 input from the first combustible fuel input port 21 is larger than the average value of the moisture content of the combustible fuel g2 input from the second combustible fuel input port 22. Sort as follows.

  Further, the average value of the moisture content of the combustible fuel g1 introduced into the extraction duct 20 from the first combustible fuel inlet 21 is, for example, from the viewpoint that the drying time becomes longer as the moisture content of the combustible fuel increases. 30 to 60% is preferred, 30 to 55% is more preferred, and 30 to 50% is even more preferred. In addition, the average moisture content of the combustible fuel g2 that is input from the second combustible fuel input port 22 to the extraction duct 20 is 0 to 30% from the viewpoint that the smaller the water content, the longer the drying time. Preferably, 5 to 30% is more preferable, and 10 to 30% is more preferable.

A combustible fuel charging method using the combustible fuel charging system 10 will be described.
First, the combustible fuel G is introduced into the combustible fuel sorting unit 30. The combustible fuel G at this time is wood waste, plastic, rubber, etc., and these are not subjected to aggressive drying treatment to improve combustibility. Therefore, combustible fuel G has low combustibility. The combustible fuel g1 and the highly combustible combustible fuel g2 are mixed.

  The combustible fuel sorting unit 30 is divided into two combustible fuel groups according to the combustibility of the input combustible fuel G, that is, the moisture content. That is, the combustible fuel sorting unit 30 is input to the low combustible combustible fuel g1 input to the first combustible fuel input port 21 and the second combustible fuel input port 22 according to the moisture content. Into highly combustible combustible fuel g2.

The combustible fuel sorting unit 30 inputs a combustible fuel g1 having a low combustibility and a combustible fuel g2 having a high combustibility through a first exhaust pipe 31 and a second exhaust pipe 32, respectively. It is introduced into the mouth 21 and the second combustible fuel inlet 22.
The injected combustible fuel g1 and combustible fuel g2 are sent to the calcining furnace 60 as combustible fuel G0 heated and dried while moving in the extraction duct 20 through which high-temperature air flows.

  Furthermore, the first calcining furnace reach distance a between the first combustible fuel inlet 21 and the calcining furnace 60 is the second calcining distance between the second combustible fuel inlet 22 and the calcining furnace 60. Since it is longer than the furnace reach distance b, the combustible fuel g1 input from the first combustible fuel input port 21 moves the difference distance c from the combustible fuel g2 input from the second combustible fuel input port 22. While being heated excessively for the time, the contained water is evaporated and dried. For this reason, the combustible fuel g1 input from the first combustible fuel input port 21 reaches the calcining furnace 60 in a state of being heated and dried so as to be sufficiently combustible.

  In other words, the combustible fuel g1 input from the first combustible fuel input port 21 that is far from the calcining furnace 60 is first supplied to the first combustible fuel input port 21 and the second combustible fuel input port 22. By moving the single region 20a of the bleed duct 20 in the meantime, it is heated for the time of moving the difference distance c, and thereafter, the mixed region 20b of the bleed duct 20 is moved. At this time, if the combustible fuel g2 is introduced from the nearby second combustible fuel inlet 22, the combustible fuel g1 and the combustible fuel g2 are mixed in the mixed region 20b. The mixed combustible fuel g1 and combustible fuel g2 are further heated and dried by moving through the mixed region 20b of the extraction duct 20. The heated and dried combustible fuel G0 is sent to the calcining furnace 60.

The calcining furnace 60 burns the heated and dried combustible fuel G0 sent from the extraction duct 20. At this time, the combustible fuel g1 having low combustibility is also sufficiently heated and dried when it reaches the calcining furnace 60, so that it can be completely combusted in the calcining furnace 60.
Further, since the combustible fuel g2 having high combustibility moves only in the mixed region 20b of the extraction duct 20, the heating time in the extraction duct 20 is shorter than the heating time of the combustible fuel g1 having low combustibility. For this reason, there is almost no fear of the bleed duct 20 being damaged by the combustible fuel g2 having high flammability burning in the bleed duct 20.

  As is clear from the above description, the combustible fuel charging system 10 includes the first calcining furnace reach distance between the first combustible fuel charging port 21 and the calcining furnace 60 among the plurality of combustible fuel charging ports. A plurality of combustible fuel input ports are formed in the extraction duct 20 so that a is longer than the second calcining furnace reach distance b between the second combustible fuel input port 22 and the calcining furnace 60. . For this reason, the combustible fuel g1 having low combustibility is introduced into the first combustible fuel inlet 21 far from the calcining furnace 60, and the combustible fuel g2 having high combustibility is disposed near the calcining furnace 60. 2 Can be introduced into the combustible fuel inlet 22.

  And since the combustible fuel g1 with low combustibility moves in the extraction duct 20 for a long first calcining furnace reach distance a (that is, for a long time), when the extraction duct 20 is moved, the combustible fuel g1 is in a state with high combustibility. Is heated to dryness and reaches the calcining furnace 60. Therefore, the combustible fuel g1 having low combustibility and the combustible fuel g2 having high combustibility are efficiently heated and dried so as to be combustible. Can be thrown in. Further, since the highly combustible combustible fuel g2 moves within the extraction duct 20 for a short second calcining furnace reach distance b (that is, for a short time), before the combustible fuel g2 reaches the calcining furnace 60, That is, it is difficult to be combustible while moving in the bleed duct 20, and there is almost no possibility that the coaching or the like adheres to the inside of the bleed duct 20 due to the combustion of the combustible fuel g2.

In the present embodiment, the second combustible fuel input port 22 is described as being formed in the extraction duct 20, but the second combustible fuel input port 22 may be formed in the calcining furnace 60. In this case, the second calciner reach distance b is zero.
Moreover, although the combustible fuel g1 and the combustible fuel g2 have been described as being input from the first combustible fuel input port 21 and the second combustible fuel input port 22, respectively, the first combustible fuel input port 21 and It is sufficient if the second combustible fuel inlet 22 is formed. The state where the combustible fuel g1 is input from the first combustible fuel input 21 and the combustible fuel g2 is the second combustible fuel input 22. It is not always necessary that the state of being inserted from is always performed simultaneously. Therefore, when there is only the combustible fuel g1, only the state where the combustible fuel g1 is introduced from the first combustible fuel inlet 21 may be used, and similarly, there is only the combustible fuel g2. Alternatively, only the state in which the combustible fuel g2 is introduced from the second combustible fuel inlet 22 may be used.

C1 to C4 Cyclone a First calciner reach distance b between the first combustible fuel inlet and the calciner Second calciner reach distance between the second combustible fuel inlet and the calciner g1 Combustible fuel with low combustibility g2 Combustible fuel G with high combustibility Combustible fuel G0 before sorting Combustible fuel 1 after heating and drying 1 Cement clinker calciner 10 Combustible fuel input system 20 Extraction duct 20a Extraction duct 20a Region 20b Extraction duct mixed region 21 First combustible fuel input port (combustible fuel input port having a plurality of combustible fuel input ports)
22 2nd combustible fuel inlet (another combustible fuel inlet of a plurality of combustible fuel inlets)
30 Combustible Fuel Sorting Unit 31 First Discharge Pipe 32 Second Discharge Pipe 35 Sorting Device Main Body 40 Rotary Kiln 50 Main Fuel Burner 60 Calciner 70 Clinker Raw Material Feeding Port 80 Air Quenching Cooler

Claims (5)

A calciner,
A rotary kiln for firing at a higher temperature than the calcining furnace;
An air quenching cooler for cooling the clinker discharged from the rotary kiln;
An extraction duct through which the gas recovered from the air quenching cooler flows;
A plurality of combustible fuel inlets for injecting powdered combustible fuel into the extraction duct or the calcining furnace,
Of the plurality of combustible fuel inlets, a first combustible fuel inlet is provided in the extraction duct,
Of the plurality of combustible fuel inlets, a second combustible fuel inlet is provided in the extraction duct or the calcining furnace,
The first calciner reach distance between the first combustible fuel inlet and the calciner is the second calciner reach distance between the second combustible fuel inlet and the calciner. Longer,
The average value of the moisture content of the combustible fuel introduced from the first combustible fuel inlet is greater than the average value of the moisture content of the combustible fuel introduced from the second combustible fuel inlet. Fuel injection system.   The bleed duct has a mixed region in which flammable fuel introduced from the first combustible fuel inlet and flammable fuel introduced from the second flammable fuel inlet are mixed. The combustible fuel injection system described.   The average moisture content of the combustible fuel that is input from the first combustible fuel input port to the extraction duct is 30 to 60%, and is input from the second combustible fuel input port to the extraction duct. The combustible fuel injection system according to claim 1 or 2, wherein the average moisture content of the combustible fuel is 0 to 30%. Further, the combustible fuel includes a combustible fuel sorting unit that sorts the combustible fuel into a plurality of combustible fuel groups based on an average value of a plurality of predetermined moisture contents,
The combustible fuel of the combustible fuel group having the highest average moisture content among the plurality of combustible fuel groups is input to the first combustible fuel input port. The flammable fuel injection system according to crab.   A combustible fuel injection method using the combustible fuel injection system according to any one of claims 1 to 4.

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