JPH0416705B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fluidized bed kiln in a cement clinker manufacturing apparatus, and more particularly, to a fluidized bed kiln that efficiently burns granules of cement raw material powder. .

[Conventional technology]

Conventionally, as a cement clinker manufacturing device, for example, as shown in Japanese Patent Publication No. 13738/1983,
This cement consists of a suspension preheater that combines multiple cyclones, a spouted bed granulation furnace, a fluidized bed calcining furnace, a cooling device, etc., and the lower part of the spouted bed granulation furnace and the upper part of the fluidized bed calciner are connected by an exhaust gas duct. Clinker manufacturing equipment is known.

In the above-mentioned conventional equipment, the preheated raw material from the suspension preheater is introduced into a conduit connecting the cooling device and the granulation furnace, and is mixed with high-temperature cooled air extracted from the cooling device, and the material is manufactured while exchanging heat. It is characterized by being transported to a grain furnace. This eliminates the problem of molten raw material sticking and growing on the inner wall of the conduit that connects the cooling device and the granulation furnace, resulting in a coating, and reduces the amount of heat recovered from the cement clinker cooling device. This has the effect that it can be used extremely effectively.

In the apparatus described in the above-mentioned Japanese Patent Publication No. 60-13738, the inside of the fluidized bed granulation furnace is maintained at a liquid phase generation temperature range of approximately 1250 to 1350℃, but the burner of the spouted bed granulation furnace is It is installed on the side wall of the straight body of the granulation furnace, and relatively low-temperature combustion air extracted from the cooling device containing the calcined raw material is introduced so as to cover the vicinity of the inner wall surface of the spouted bed granulation furnace. Because there are
The fuel from the burner does not form localized high-temperature regions in the spouted bed where the temperature difference with the surrounding area of the bed is large.
Therefore, the temperature distribution within the spouted bed is approximately uniform. Since no local high-temperature areas are formed in the spouted bed and the temperature is almost uniform, the amount of liquid phase component produced by partially melting the cement raw material powder is small. the result,
Granules are only produced with small particle sizes, and the rate of granulation of cement raw material powder is slow, and particles with irregular sizes are likely to be produced. On the other hand, if the temperature of the spouted bed is increased in order to increase the amount of liquid phase produced, the bed temperature will rise uniformly, causing agglomeration (agglomeration of particles) in the spouted bed, resulting in a stable A spouted bed cannot be formed.

In order to solve the above problems, the present inventors
We have developed a cement clinker production device that is equipped with a burner at the bottom of a spouted bed granulation furnace to form a localized high-temperature region within the spouted bed to promote granulation, and has already been published in Japanese Patent Application No. 1987-75131 (Japanese Patent Application Publication No. 75131). A patent application has been filed as No. 62-230657).

[Problem that the invention seeks to solve]

However, the above-mentioned Japanese Patent Publication No. 60-13738,
In the apparatus of Japanese Patent Application No. 61-75131 (Japanese Patent Application No. 62-230657), as shown in FIG. However, there was a disadvantage that the cement clinker particles adhered to each other and blocked the discharge chute 9.

Furthermore, since the cement clinker is slowly cooled in the range of 1350 to 1200° C. while being transferred from the fluidized bed kiln 2 to the cooling device 10, there is a disadvantage that the quality of the fired cement clinker deteriorates. 8 is an airtight discharge device (commonly called L valve).

The present invention was made in view of the above points, and the fluidized bed of a fluidized bed kiln is divided into two by a partition plate, and the cement clinker is fired in one fluidized bed, and the cement clinker is rapidly cooled in the other fluidized bed. The object of the present invention is to provide a fluidized bed kiln that can avoid blockage troubles in the discharge chute between the fluidized bed kiln and the cooling device when discharging fired cement clinker. be.

Note that Publication No. 60-636 states that the lower fluidized bed discharge port of the spouted bed type fluidized bed firing furnace body is divided into two parts, one of which is provided on the axis to connect the main flow pipe, and is mainly used for fluidized bed firing. In addition, a firing furnace has been proposed in which the particle size distribution in the layer is controlled by connecting a classification tube in a branched manner at an eccentric point to contribute to classification. .

However, the firing furnace described in Publication of Utility Model Publication No. 1983-636 is related to a spouted bed type firing furnace, and cannot be directly applied to a fluidized bed type firing furnace, and its technical philosophy is different. It is.

[Means for solving problems]

The fluidized bed kiln according to the first invention of the present application will be described with reference to the drawings.The main components of the fluidized bed kiln are a suspension preheater 3, a spouted bed granulator 1, a fluidized bed kiln 2, and a cooling device 10. In a clinker production apparatus, a fluidized bed 24 of a fluidized bed kiln 2 is separated by a partition plate 26 into a first fluidized bed 27 having a granule inlet 14 and a fuel supply port 15, and a second fluidized bed having a particle extraction port. 28, and at the same partition position, the wind box 30 is partitioned by a partition plate 31,
It is characterized in that the cooling air supply pipe 16 is connected to the wind box of the second fluidized bed 28.

The fluidized bed firing furnace of the second invention of the present application has a first differential pressure gauge 20 connected to the first fluidized bed 27, a second differential pressure gauge 21 connected to the second fluidized bed 28, and an airtight discharge connected to the particle extraction port. An air pulse introduction line 23 equipped with a control valve 22 is connected to the device 8, and this control valve 22 and the first
The differential pressure gauge 20 and the second differential pressure gauge 21 are connected via a calculator 34 so that the differential pressure in the second fluidized bed 28 is always smaller than the differential pressure in the first fluidized bed 27. There is.

The fluidized bed firing furnace of the third invention of the present application has a thermometer 35 connected to the second fluidized bed 28, and a thermometer 35 connected to the second fluidized bed 28.
The control damper 17 of the cooling air supply pipe 16 connected to the wind box of the fluidized bed increases the air supply amount when the temperature of the second fluidized bed 28 is high, and
8 is characterized in that it is connected via an arithmetic unit 36 so as to reduce the amount of air supplied when the temperature of the air conditioner 8 is low.

In the fluidized bed firing furnace of the fourth invention of the present application, a thermometer 35 is connected to the second fluidized bed 28, a fuel supply pipe 38 equipped with a control valve 37 is connected to the second fluidized bed 28, and the control valve 37 is connected to the second fluidized bed 28. and the thermometer 35 are controlled by a computer so that when the temperature of the second fluidized bed 28 is high, the amount of fuel supplied is decreased, and when the temperature of the second fluidized bed 28 is low, the amount of fuel supplied is increased. It is characterized in that it is connected via 36.

In the fluidized bed firing furnace of the present invention, the first
Although the fluidized bed 27 is a large fluidized bed and the second fluidized bed 28 is a small fluidized bed, the invention is not necessarily limited to this, and the above-mentioned reverse can also be used.

[Effect]

In the first invention, cement clinker is baked in the first fluidized bed 27, and the cement clinker baked in the second fluidized bed 28 is rapidly cooled by a cooling device.

In the second aspect of the invention, an air pulse is sent to the airtight discharge device 8 for discharge so that the pressure difference in the second fluidized bed 28 is always smaller than the pressure difference in the first fluidized bed 27 .

In the third invention, the amount of air is controlled so that the bed temperature of the second fluidized bed 28 is constant.

In the fourth invention, a small amount of fuel is controlled to be supplied so that the bed temperature of the second fluidized bed 28 is constant.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, unless there is a specific description, the shapes of the components described in this example, their relative positions, etc. are not intended to limit the scope of the present invention to these, but are merely illustrative examples. Only.

Example 1 In FIG. 1, cement raw material is preheated by combustion exhaust gas from a spouted bed granulation furnace 1 and a fluidized bed calcining furnace 2 in a suspension preheater 3 consisting of cyclones C ₁ , C ₂ , C ₃ , and C ₄ . While the cyclone
It is transferred in the order of C ₄ →C ₃ →C ₂ →C ₁ , passed through a double flap damper 4, and charged into the spouted bed granulation furnace 1 where it is granulated. 5 is a flap damper, and 6 is an induction fan.

The cement raw material that has not been granulated in the spouted bed granulator 1 is returned to the spouted bed granulator 1 via the cyclone _C1 . The granules that have accumulated and grown in the spouted bed granulation furnace 1 are discharged to the fluidized bed firing furnace 2 by an L-shaped airtight discharge device 7 using a material seal for the granules, where they are again heated to 1400 to 1500°C. It is fired in The fired cement clinker is discharged by an L-shaped airtight discharge device 8 (hereinafter referred to as L valve 8) to a cooling device 10 such as a fluidized bed cooler, where it is cooled, and then passed through an airtight discharge device (seal valve) 11 into a product. is extracted as.

On the other hand, the cooling device 10 is
The cooling device supplied to the furnace exchanges heat with the fired clinker and is supplied as combustion air to the fluidized bed firing furnace 2 via the air conduit 19. Excess air from the cooling device 10 is discharged outside the system via a dust remover (not shown).

The combustion air led to the fluidized bed calcination furnace 2 is used as twisting air in the fluidized bed calcination furnace 2 and the spouted bed granulation furnace 1, and is discharged from the spouted bed granulation furnace 1 as combustion exhaust gas, and is passed through the suspension preheater 3. After the cement raw material is preheated while passing through the cyclones C ₁ →C ₂ →C ₃ →C ₄ in order, it is exhausted to the atmosphere by an induction fan 6 through a dust remover (not shown). 13 is an exhaust gas duct connecting the lower part of the spouted bed granulation furnace and the upper part of the fluidized bed firing furnace, and 18 is a burner.

In the cement clinker production apparatus configured as described above, the fluidized bed 24 of the fluidized bed kiln 2 is separated by the partition plate 26, the granule inlet 14, the fuel supply inlet 15
and a first fluidized bed 27 having a large lump extraction port 32
(hereinafter referred to as the large fluidized bed 27) and a second fluidized bed 28 (hereinafter referred to as the small fluidized bed 2) having a small particle extraction port 33.
8), and at the same partitioning position, the wind box 30 is partitioned by a partition plate 31, and the cooling air supply pipe 16 is connected to the wind box of the small fluidized bed 28.

In the large fluidized bed 27 of the fluidized bed firing furnace 2 configured as described above, the granules granulated from the cement raw material powder in the spouted bed granulation furnace 1 are heated at a firing temperature of 1400 to
Calcined into cement clinker at 1500℃. The fired cement clinker particles overflow the partition plate 26 and are transferred to the small fluidized bed 28.

In the small fluidized bed 28, the high temperature cement clinker particles are cooled by fluidized air at room temperature, and are maintained at a bed temperature (for example, 1200 to 1000°C) lower than the firing temperature (bed temperature) of the large fluidized bed 27. . Therefore, the cement clinker fired in the large fluidized bed 27 is transferred to the small fluidized bed 28 and simultaneously cooled to the bed temperature of the small fluidized bed 28. As a result, the fired cement clinker is rapidly cooled in the 1350-1200°C range, and a high quality product can be obtained.

The cement clinker that has been rapidly cooled to 1200 to 1000° C. in the small fluidized bed 28 is discharged to the cooling device 10 while maintaining airtightness through the L valve 8, and is further cooled. At this time, since the surface of the rapidly cooled cement clinker has no stickiness, particles do not adhere to each other in the discharge chute 9, and can be discharged smoothly. Moreover, even if it is slowly cooled in the discharge chute 9, it is rapidly cooled in a high temperature range, so there is no adverse effect on quality. Coarse particles that overflow the partition plate 26 and are not transferred are discharged from the large lump extraction port 32 to the outside of the system via the large lump discharge chute.

Example 2 In this example, as shown in FIG. 2, a first differential pressure gauge 20 is installed in the large fluidized bed 27, and a second differential pressure gauge 2 is installed in the small fluidized bed
1 is connected, and an air pulse introduction line 23 equipped with a control valve 22 is connected to an airtight discharge device 8 connected to a small particle extraction port 33. , large fluidized bed 27
The connection is made through the computing unit 34 so that the differential pressure in the small fluidized bed 28 is always smaller than the differential pressure in the small fluidized bed 28 .

In this example, the air pulse for operating the L valve 8 is injected so that the bed pressure difference ΔP ₂ in the small fluidized bed 28 is always smaller than the bed difference pressure ΔP ₁ in the large fluidized bed 27 . As a result, mutual mixing of cement clinker in the large fluidized bed and cement clinker in the small fluidized bed is eliminated. That is, from the large fluidized bed 27 to the small fluidized bed 2
8, but the reverse movement is not performed. As a result, the large fluidized bed 27 can be cooled without lowering the bed temperature. In other words, rapid cooling can be performed without increasing combustion consumption. The other configurations are the same as in the first embodiment.

Example 3 In this example, as shown in FIG. 2, a thermometer 35 is connected to the small fluidized bed 28, and this thermometer and the small fluidized bed 28
The control damper 17 of the cooling air supply pipe 16 connected to the wind box increases the air supply amount when the temperature of the small fluidized bed 28 is high, and increases the air supply amount when the temperature of the small fluidized bed 28 is low. It is configured to be connected via a computing unit 36 so as to reduce the amount of data.

In order to ensure stable product quality, it is necessary to keep the quenching effect in the small fluidized bed 28 constant. Therefore, in order to keep the bed temperature of the small fluidized bed constant, when the bed temperature is high, the forcing fan 1 is
Increase the amount of fluidizing air from 2. If the bed temperature is low, reduce the amount of fluidizing air. However, the amount of fluidizing air is within the range in which the fluidizing medium can be fluidized. The other configurations are the same as in the first embodiment. Note that a portion of the surplus air from the cooling device 10 may be extracted and used as the air supplied to the small fluidized bed 28.

Example 4 In this example, as shown in FIG. 2, a thermometer 35 is connected to the small fluidized bed 28, and a control valve 37 is connected to the small fluidized bed 28.
A fuel supply pipe 38 equipped with the control valve 3 is connected to the control valve 3.
7 and the thermometer 35 to reduce the fuel supply amount when the temperature of the small fluidized bed 28 is high.
8 is connected via a computing unit 36 to increase the amount of fuel supplied.

The bed temperature in the small fluidized bed 28 is
depends on the amount of hot fired cement clinker and fluidizing air supplied. Therefore, if the hourly production of cement clinker has to be reduced due to some operational disturbance, the bed temperature of the small fluidized bed 28 will decrease, the superficial flow rate will decrease,
The fluidization state of the small fluidized bed 28 deteriorates, making it difficult to rapidly cool the cement clinker and transfer it to the L valve 8.

In this case, if a small amount of fuel is supplied to the small fluidized bed 28 and the bed temperature of the small fluidized bed 28 is maintained at a certain temperature, the superficial flow velocity necessary for fluidization can be secured and a good fluidized state can be maintained. can. Therefore, stable operation and good product quality can be maintained. Moreover, if the bed temperature of the small fluidized bed 28 is also controlled by the amount of fuel, a product with more stable quality can be obtained. The other configurations are the same as in the first embodiment.

〔Effect of the invention〕

Since the present invention is configured as described above, it has the following effects.

(1) Cement clinker particles can be smoothly transferred within the discharge chute of a fluidized bed kiln without adhering to each other, and clogging of the discharge chute can be prevented.

(2) Since the fired cement clinker is rapidly cooled in the 1350-1200°C range, the quality of the fired product is good.

(3) When configured to control the temperature of a small fluidized bed, products of stable quality can be obtained.

(4) If the configuration is such that the bed pressure difference in the small fluidized bed is always smaller than the bed difference pressure in the large fluidized bed, there will be no mutual mixing of particles in the large fluidized bed and particles in the small fluidized bed. , it is possible to rapidly cool the large fluidized bed without lowering the bed temperature (firing temperature), and not only can energy savings be achieved, but also stable product quality can be obtained.

[Brief explanation of drawings]

FIG. 1 is a flow sheet showing an example of a cement clinker manufacturing apparatus equipped with a fluidized bed kiln according to the present invention;
FIG. 2 is an explanatory diagram showing another example of the fluidized bed firing furnace of the present invention, and FIG. 3 is an explanatory diagram showing the surroundings of a conventional fluidized bed firing furnace. C ₁ to _{C 4} ... cyclone, 1 ... spouted bed granulation furnace, 2
... Fluidized bed firing furnace, 3... Suspension preheater, 4... Double flap damper, 5... Flap damper, 6... Induction fan, 7, 8... Airtight discharge device, 9
...Exhaust chute, 10...Cooling device, 11...Airtight discharge device, 12...Pushing fan, 13...Exhaust gas duct, 14...Granule inlet, 15...Fuel supply port, 1
6... Cooling air supply pipe, 17... Control damper, 18...
Burner, 19... Air conduit, 20... First differential pressure gauge, 2
DESCRIPTION OF SYMBOLS 1...Second differential pressure gauge, 22...Control valve, 23...Air pulse introduction line, 24...Fluidized bed, 26...Partition plate, 2
7... First fluidized bed (large fluidized bed), 28... Second fluidized bed (small fluidized bed), 30... Wind box, 31... Partition plate, 32...
Large lump extraction port, 33... Small particle extraction port, 34... Computing unit, 35... Thermometer, 36... Computing unit, 37... Control valve, 38... Fuel supply pipe.

Claims (1)

[Claims] 1. Suspension preheater, spouted bed granulation furnace,
In a cement clinker manufacturing device whose main components include a fluidized bed kiln and a cooling device, the fluidized bed of the fluidized bed kiln is separated by a partition plate into a first fluidized bed having a granule inlet and a fuel supply port, and a first fluidized bed having a granule inlet and a fuel supply inlet, A fluidized bed firing furnace characterized in that the furnace is partitioned into a second fluidized bed having an extraction port, a wind box is partitioned by a partition plate at the same partition position, and a cooling air supply pipe is connected to the wind box of the second fluidized bed. 2 Suspension preheater, spouted bed granulation furnace,
In a cement clinker manufacturing device whose main components include a fluidized bed kiln and a cooling device, the fluidized bed of the fluidized bed kiln is separated by a partition plate into a first fluidized bed having a granule inlet and a fuel supply port, and a first fluidized bed having a granule inlet and a fuel supply inlet, At the same time, the wind box is partitioned by a partition plate at the same partition position, a cooling air supply pipe is connected to the wind box of the second fluidized bed, and a first fluidized bed is connected to the first fluidized bed. A pressure gauge is connected to the second fluidized bed, a second differential pressure gauge is connected to the second fluidized bed, an air pulse introduction line equipped with a control valve is connected to an airtight discharge device connected to the particle extraction port, and the control valve is connected to the first differential pressure gauge and the second differential pressure gauge. and the differential pressure gauge.
A fluidized bed firing furnace characterized in that the furnace is connected via a computing unit so that the bed pressure difference in the second fluidized bed is always smaller than the bed pressure difference in the fluidized bed. 3 Suspension preheater, spouted bed granulation furnace,
In a cement clinker manufacturing device whose main components include a fluidized bed kiln and a cooling device, the fluidized bed of the fluidized bed kiln is separated by a partition plate into a first fluidized bed having a granule inlet and a fuel supply port, and a first fluidized bed having a granule inlet and a fuel supply inlet, At the same time, a wind box is partitioned by a partition plate at the same partition position, a cooling air supply pipe is connected to the wind box of the second fluidized bed, and a thermometer is connected to the second fluidized bed. the thermometer and a control damper of the cooling air supply pipe connected to the wind box of the second fluidized bed;
It is characterized by being connected via a computing unit so that when the temperature of the second fluidized bed is high, the amount of air supplied is increased, and when the temperature of the second fluidized bed is low, the amount of air supplied is decreased. Fluidized bed kiln. 4 Suspension preheater, spouted bed granulation furnace,
In a cement clinker manufacturing device whose main components include a fluidized bed kiln and a cooling device, the fluidized bed of the fluidized bed kiln is separated by a partition plate into a first fluidized bed having a granule inlet and a fuel supply port, and a first fluidized bed having a granule inlet and a fuel supply inlet, At the same time, a wind box is partitioned by a partition plate at the same partition position, a cooling air supply pipe is connected to the wind box of the second fluidized bed, and a thermometer is connected to the second fluidized bed. A fuel supply pipe equipped with a control valve is connected to the second fluidized bed, and the control valve and the thermometer are connected to each other to reduce the fuel supply amount when the temperature of the second fluidized bed is high. A fluidized bed firing furnace, characterized in that the furnace is connected via a computing unit so as to increase the amount of fuel supplied when the temperature of the fluidized bed is low.