JPH06287043A - Method of burning cement clinker and burning device - Google Patents

Abstract

PURPOSE:To provide a method of burning cement clinker capable of controlling particle diameters in high precision by secure classification and smoothly producing high-quality cement clinker. CONSTITUTION:A fluidized bed burning furnace 3 is laid below a dispersing plate 2A of a fluidized bed granulating furnace 2, granulated materials are thrown through a falling hole 6 facing a fluidized bed of the fluidized bed granulating furnace to the fluidized bed burning furnace to give a device for burning cement clinker. The device is equipped with a blowing means 7 capable of jetting a gas from the falling hole 6 into the granulating furnace 2 at a flow velocity different from a flow velocity of a fluidizing gas flowing through a nozzle 2B of the dispersing plate 2A into the granulating furnace 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for firing a cement clinker using two furnaces, a fluidized bed granulating furnace and a fluidized bed firing furnace, and a firing apparatus used for carrying out the firing method.

[0002]

2. Description of the Related Art Cement clinker is manufactured by first granulating a raw material powder prepared by mixing and crushing limestone, silica sand, etc., firing it, and then cooling it. A calcination apparatus including two furnaces, a granulation furnace and a fluidized bed calcination furnace, is often used. A cement calcination device using a fluidized bed furnace has higher thermal efficiency than the conventional rotary kiln type calcination device, is advantageous in terms of installation space, fuel consumption, harmful exhaust gas (NO _x , CO _2, etc.), and is small in various amounts. This is because it is said to be suitable for production. further,
As described above, in the apparatus including the two furnaces as a main part, the steps of granulation and firing can be controlled separately, so that there is also an advantage that a cement clinker of excellent quality can be manufactured.

In the fluidized bed granulation furnace, the raw material powder that has been preheated and charged is fluidized by the high-temperature gas, and during the heat, parts of the vicinity of the surface are melted and adhere to each other to grow, and the particle size is several. mm particles (granulated material). However, the size of the particles (that is, the granulated particle size) at this time must be adjusted to an appropriate size according to the specifications of the equipment and the type of cement. If the particle size is too large, the granulated product in the granulation furnace and the subsequent firing furnace will not be fluidized easily, and proper combustion / firing cannot be performed. Conversely, if the particle size is too small, the granulation will be performed in the firing furnace. This is because the adhesion of the particles to each other progresses too much, which causes an inconvenient phenomenon called so-called agglomeration. This not only directly leads to the deterioration of the quality of the cement clinker, but also because it is necessary to avoid it, the operation of the firing device (for example, temperature control) becomes difficult and waste of thermal efficiency occurs.

Under these circumstances, it is necessary to classify only the granules grown in the granulation furnace, which have grown to have a predetermined particle size or more, and to introduce them into the firing furnace. It is described in JP-A-62-228875. A spouted bed (a type of fluidized bed) type granulation furnace and a fluidized bed firing furnace are directly connected via a throat part (passage gas passage), and the jet flow velocity of gas from the firing furnace to the granulation furnace is appropriately adjusted. By controlling, only the granulated product having a certain particle size or more is allowed to drop from the granulation furnace to the firing furnace through the throat portion, and the classification effect is obtained.

Regarding a firing apparatus having no two furnaces for granulation and firing, Japanese Patent Publication No. 44-32193 discloses a take-out tube having a classification function for a granulated product (fired grain) in a furnace body (granulation). (A firing furnace that also serves as a firing furnace) is disclosed.

[0006]

With the techniques described in the above two publications, it is not always possible to obtain favorable results in terms of both particle size controllability and product quality. First, according to the recent test and research conducted by the inventors, the method according to the former (Japanese Patent Laid-Open No. 62-228875) transfers from the throat part to the firing furnace even if the fine granules have a predetermined particle size or less. It often falls (so-called direct drop), and it has been found that it is difficult to perform classification with sufficient accuracy to meet recent quality demands only by that means. The throat part, which is the gas passage for forming the spouted bed, has a large diameter (usually several hundred millimeters), and there is a considerable distribution (bias) in the gas flow velocity passing through its cross section, and it also drops once. It is thought that it is difficult to uniformly classify granules with a certain particle size as a boundary because the gas flow velocity in the throat changes due to the drop when the start. On the other hand, in the latter technique (Japanese Patent Publication No. 44-32193), granulation and firing are performed in a single furnace, so that regardless of the accuracy of classification, the level of product quality is normal (no classification function). Lower than in a furnace-type firing system. Further, in the one-furnace type apparatus, the granule extraction pipe provided in a relatively low temperature portion must be provided in the high temperature portion of about 1300 ° C. in the two-furnace type apparatus, and therefore the technique of the publication is directly applied to the two-furnace apparatus. It is not easy to apply to the type of baking equipment.

An object of the present invention is to provide a cement clinker calcination method capable of controlling a particle size with high accuracy by reliable classification and smoothly producing a high quality cement clinker, and a calcination apparatus for realizing the method. Is to provide.

[0008]

The method for firing a cement clinker according to the present invention (claim 1) uses a fluidized bed granulating furnace and a fluidized bed firing furnace, and the former is formed through a drop port facing the fluidized bed. A method of firing a cement clinker by introducing granules into the latter, the flow rate being determined separately from the flow rate of the fluidizing gas flowing into the fluidized bed granulation furnace through the other opening from the above drop port. The method is characterized in that a gas is blown into the fluidized bed granulation furnace and the granulated material to be fed into the firing furnace is classified by the gas.

The cement clinker firing apparatus of the present invention (claim 2) is provided with a fluidized bed firing furnace below the dispersion plate of the fluidized bed granulation furnace, and the granulated material is passed through the former drop port facing the fluidized bed. A device for firing the cement clinker by charging the latter into the fluidized bed from the drop port at a flow rate different from the flow rate of the fluidizing gas flowing into the fluidized bed granulation furnace through the nozzle of the dispersion plate. Ventilation means capable of blowing gas is provided in the granulation furnace. As for this apparatus, as described in claim 3, it is more preferable to provide a throttle portion for blowing up the above gas at a predetermined flow rate in the granulation material input pipe that continues downward from the above drop port. .

[0010]

The cement clinker calcination method of the present invention is one in which the granulated material is charged into the fluidized bed calcination furnace while being classified through the drop opening facing the fluidized bed of the fluidized bed granulation furnace. There are various characteristics. That is, first, since only this drop port is not the path of the fluidizing gas into the granulation furnace (the same gas also flows into the granulation furnace through the other openings), the above-mentioned throat portion and On the other hand, the cross section of the opening of this drop opening does not become large, so that the gas flow velocity in the cross section is not likely to be biased and the accuracy of classification is improved. Secondly, the flow velocity of the gas blown out from this drop port is determined separately from the flow velocity of the fluidizing gas passing through the other openings, so the classification particle size can be set independently of the operating conditions of the granulating furnace and the firing furnace, Moreover, it is easy to avoid the influence of disturbance and maintain the accuracy of classification.

Further, since this firing method uses two furnaces, a fluidized bed granulation furnace and a fluidized bed firing furnace, the quality of the granulated and fired cement clinker itself can be made high.

The cement clinker firing apparatus of the present invention comprises:
Be sure to carry out the above firing method as follows. In other words, the fluidized bed granulation furnace has a dispersion plate (perforated plate), and most of the fluidizing gas flows into the granulation furnace through the nozzles (holes) of the dispersion plate, so the drop port is used for such fluidization. It does not reach the main route of gas. Therefore, the opening cross section of the drop port may be small, and the gas blown out from the drop port can be independently determined in accordance with the classified particle diameter by the ventilation means, separately from the fluidizing gas. Therefore, with this device, it is possible to easily and highly accurately classify the granulated product at the drop port, and it is possible to smoothly obtain a high-quality cement clinker. The drop port is not limited to the central part of the dispersion plate (furnace body), but can be arbitrarily set at the side part or the upper part of the fluidized bed (overflow part) above the dispersion plate. It is easy to avoid the problem of heating the tubes and the like by the gas from the firing furnace to the granulation furnace.

In the case of the calcination apparatus according to the third aspect, the so-called second classification can be performed by the gas blown up in the narrowed portion on the way of the granulated material reaching the calcination furnace. That is, among the granulated substances that have entered the drop port, those having a particle size smaller than a predetermined particle size are selected again by blowing back into the granulating furnace through the drop port. Since this type of classification can be performed twice, classification with a higher degree of accuracy is possible with this device, and the quality of the cement clinker is also positively affected.

[0014]

EXAMPLE A cement clinker firing apparatus as a first example of the present invention is shown in FIGS. FIG. 1 is a vertical sectional view of a container in which a fluidized bed granulating furnace 2 and a fluidized bed firing furnace 3 are integrated, and FIG. 2 is an overall system diagram of a firing apparatus including the same.

In FIG. 2, reference numeral 1 is a cyclone 1A to.
A three-stage suspension preheater including 1C, 2 is a fluidized bed granulating furnace, 3 is a fluidized bed firing furnace, and 4 and 5 are cooling devices (coolers). A fluidized bed type is adopted for the granulating furnace 2, the firing furnace 3 and the primary cooling device 4 of each furnace, and the secondary cooling device 5 is a packed bed. Granulator 2
The firing furnace 3 and the firing furnace 3 are directly connected to each other with the former facing upward, and are formed into an integrated container (see FIG. 1). However, a dispersion plate (perforated plate) is provided in each of the granulation furnace 2 and the firing furnace 3. ) 2A
It has 3A.

This baking apparatus is normally operated as follows. The cement raw material powder charged into the system from the charging chute 1K is the suspension preheater 1 (cyclone 1A).
~ 1C) and then preheated and then charged into the granulating furnace 2. In the fluidized bed 2X of the granulating furnace 2, the raw material powder is agglomerated into particles of several millimeters size, and the granulated material has several falling openings 6 facing the fluidized bed 2X and opening to the side of the dispersion plate 2A. To the firing furnace 3 via the charging pipes 9. Firing furnace 3
The granulated product calcined in (1) is sent to the cooling device 4 through the supply pipe 3B (not shown in FIG. 1) to be primarily cooled, and is secondarily cooled in the cooling device 5 to be recovered as a cement clinker. On the other hand, hot air from the cooling devices 4 and 5 is sent to the granulation furnace 2 and the suspension preheater 1 via the firing furnace 3.

In this firing apparatus, the granulation material supplied from the granulation furnace 2 to the firing furnace 3 has a function of classifying the granulation material at the drop port 6 and its periphery so as to limit the particle size to a certain value or more. I have. That is, a certain particle size (for example, 2 m
m) The followings are blown back into the furnace (on the dispersion plate 2A) by the air flow rising from below to the dropping port 6, and only coarse particles that are not blown back are sent to the firing furnace 3 through the dropping port 6. Is configured as follows. Details are as follows.

(A) First, as shown in FIG. 1A, the upper surface of the dispersion plate 2A is formed into a conical surface so that an inclined surface of 0 to 30 ° is formed toward each of the drop openings 6. This is because the granulated material that has grown to a size that is not fluidized by the hot air blown up from the nozzle 2B is rolled toward the drop port 6 on this surface.

(B) A nozzle 2C having an opening larger than the nozzles 2B of the other parts is provided in the part of the dispersion plate 2A near the drop port 6 (see FIG. 1 (b)). Large diameter nozzle 2C
Since the flow velocity of the hot air blown up from the nozzle is higher than the flow velocity from the other nozzle 2B, a minute one of the granulated substances rolling or flowing in the vicinity of the drop port 6 is the nozzle 2C.
Blow back into the furnace with hot air blown up from the
Can be kept away from.

(C) An L valve 8 which is a known airtight discharging means is connected between the drop port 6 and the charging pipe 9. The L-valve 8 deposits the granulated material inside, blocks the aeration by the material sealing action of the granulated material itself, and extrudes the granulated material by pushing out with compressed air or mechanical means (not shown). Pay out. By providing this, it is possible to block the blowing of hot air from the firing furnace 3 through the feeding pipe 9 and smoothly feed the granulated material into the firing furnace 3.

D) The drop port 6 is provided with a gate 6A capable of adjusting the opening area of the drop port 6 by increasing / decreasing it from the side of the furnace body.

(E) The vent pipe 7A is connected between the dropping port 6 and the L valve 8 and the upper part of the firing furnace 3 (the lower part of the dispersion plate 2A of the granulation furnace 2), and the valve 7B is connected in the middle thereof. To do. Since the pressure below the dispersion plate 2A is higher than the pressure above the dispersion plate 2A and the vicinity of the drop port 6, hot air at an arbitrary flow rate is sent above the L valve 8 by the ventilation pipe 7A and the valve 7B, and the classified particle size (from the drop port 6 That is, it is possible to blow out hot air at a flow rate according to the diameter of the granulated material to be blown back into the furnace. That is, the ventilation pipe 7A and the valve 7B function as a so-called ventilation means 7 to the drop opening 6. For example, when the classification particle diameter is set to 2 mm, the flow velocity of the hot air blown out from the dropping port 6 may be set to about 20 m / s.

By virtue of the above constitutions (a) to (e), in this firing apparatus, the particle size of the granulated product reaching the firing furnace 3 through the dropping port 6 and the charging pipe 9 can be limited to a substantially constant grain size. Granulator 2
Then, the raw material powder gradually grows larger, but in the case of this device, the fine particles are blown up by the hot air and fall into the falling port 6.
It can not enter, on the other hand, it has a predetermined particle size (it can be arbitrarily determined according to the type of product, application, etc.
The granulated material that has reached m) easily enters the falling port 6 and the firing furnace 3
Because it leads to. By adjusting the opening degree of the valve 7B of the ventilation means 7 and adjusting the gate 6A, the amount of hot air blown out from the dropping port 6 can be determined separately from the operating conditions of the granulating furnace 2 and the firing furnace 3, and at the dropping port 6 Since the classification is performed by the nozzle 2C prior to classification, the classification accuracy is accurate and stable.

Next, FIG. 3 shows a main part of a cement clinker burning apparatus which is a second embodiment of the present invention. Also in this example, the firing furnace 13 is integrally provided below the dispersion plate 12A of the granulation furnace 12, and the granulated product generated in the granulation furnace 12 is discharged from the falling port 16 opening to the side of the dispersion plate 12A. Input pipe 19
Then, it is put into the firing furnace 13. In this way, the granulated material to be charged into the firing furnace 13 is classified at the portion such as the dropping port 16 and the charging pipe 19, that is, the particle diameter is limited to a certain particle size or more.

In this example, the hot air throttle portion 19A is provided at a part of the charging pipe 19 between the drop port 16 and the L valve 18 (other airtight discharging means such as a rotary valve may be used) therebelow. There is a big feature in the provision. Also,
The lower portion of the throttle portion 19A and the upper portion of the firing furnace 13 are connected by a ventilation pipe 17A with a valve 17B to form a ventilation means 17 for the throttle portion 19A and the drop port 16. As a result, apart from the hot air flowing into the granulating furnace 12 through the nozzle 12B of the dispersion plate 12A, a part of the hot air in the firing furnace 13 is adjusted in flow rate through the ventilation means 17 and is supplied to the charging pipe 19. It is blown out into (the fluidized bed of) the granulating furnace 12 through the narrowed portion 19A and the dropping port 16. If the drop opening 16 (having an opening adjustment type gate 16A) and the throttle portion 19 (a similar gate or the like may be provided here) are set to have an appropriate opening cross-sectional area according to the classification particle size, The granules are classified twice in each of the drop port 16 and the narrowed portion 19A, which results in highly accurate classification results. It is preferable that the narrowed portion 19A has a smaller opening cross-sectional area than the drop opening 16 to slightly increase the flow velocity of the hot air, and the length thereof is twice or more the opening dimension.

In the third embodiment shown in FIG. 4, the opening / closing gate 2 in the charging pipe 29 connected from the granulating furnace 22 to the firing furnace 23.
Another gate 28 is provided below the drop opening 26 having 6A. This gate 28 is used as a part of the above-mentioned throttle portion and as a part of the airtight discharging means which replaces the L valve. That is, a part of the hot air from the firing furnace 23 usually passes through the inside of the charging pipe 29 that also serves as the ventilation means 27 and is blown out from the dropping port 26 at a predetermined flow rate to exert the classification function of the granulated product, If the narrowed portion 29A whose opening is adjusted by 28 is made narrow, the granulated material having a particle size equal to or larger than the classified particle diameter falls from the dropping port 16 and is blown up by the narrowed portion 29A to be interposed between both gates. Drift Therefore, after a lapse of an appropriate time, the gate 28 is first closed, and then the gate 26A is closed and the gate 28 is fully opened. By repeating such a procedure, it is possible to intermittently discharge the granulated product while maintaining airtightness. Become.

In this example, as shown in FIG.
A is formed into a mountain shape so as to have an inclination toward each drop port 26, and a nozzle 22C having an opening larger than the normal nozzle 22B is formed near the drop port 26. This is for the same purpose as in the case of the first embodiment (FIGS. 1 and 2). In addition,
On the contrary, the dispersion plate 23A of the firing furnace 23 is formed in a mortar shape and has its central portion lowered, and a discharge pipe 23C for coarse particles and a rotary valve 23D are connected to the central portion.

Next, FIG. 5 shows a fourth embodiment of the present invention, in which the granule dropping port 36 from the granulating furnace 32 to the firing furnace 33 is formed in the central portion of the dispersion plate 32A of the granulating furnace 32, and An example in which a narrowed portion 39A for hot air is provided below that is shown. FIG. 5 (a) is the simplest one, in which a cylinder 32D is extended to the lower central part of a mortar-shaped dispersion plate 32A having a large number of nozzles 32B, and the inside of the cylinder 32D also serves as a ventilation port for the granulated product. 36. The hot air flowing from the firing furnace 33 to the granulation furnace 32 separately passes through the nozzle 32B of the dispersion plate 32A and the above-described drop port 36, but the portion of the hot air passing through the drop port 36 that contacts the inner peripheral surface (so-called boundary). In the layer, a low-speed flow having a substantially constant flow velocity is generated depending on the roughness of the inner peripheral surface and the kinematic viscosity coefficient of hot air, which is hardly influenced by the flow velocity of other portions. Therefore, in the apparatus of FIG. 5 (a), the granulated material in the granulation furnace 32 falls from the periphery of the dropping port 36, which is the low speed portion, around the coarse particles. However, since it is not possible to expect a classification action for falling from the drop port 36 in this way, it is a so-called second-stage classification part, that is, the throttle part 39A.
Is provided. That is, a granulated material having a relatively wide range of particle diameters falls from the periphery of the dropping port 36, and among them, those having a minute particle diameter are blown back by the hot air that blows up the narrowed portion 39A and again granulated through the nozzle 32B and the like. Since it enters into (the fluidized bed of) the furnace 32, only the particles having a certain particle size or more are finally charged into the firing furnace 33 through the charging pipe 39. Falling port 36
Will be installed on the central axis of the furnace.
However, the dispersion plate 32A (the cylinder 32D thereof) and the granulation furnace 32 thereon
Since it is not connected to (furnace body) and the like, the occurrence of thermal stress due to restraint is small, and therefore there is almost no thermal problem due to the high-temperature hot air from the firing furnace 33.

When only a granulated product having a particle size of 2 mm or more is charged into the firing furnace 33, the opening cross-sectional area of each part may be determined so that the hot air flow velocity is as follows. First, the nozzle 32B of the dispersion plate 32A is provided with a flow velocity of 50 to 60 m / s so that coarse particles do not enter. Therefore, the flow velocity near the center of the drop port 36 is also 50 to 60.
m / s, but as mentioned above, 1
There is a boundary layer of 0 m / s or less. And the narrowed portion 39
In order to blow back granules of 2 mm or less, 20 m /
A flow rate of the order of s is required.

The apparatus shown in FIGS. 5 (b) and 5 (c) is a modified example of the same embodiment, in which the drop port 36 is tapered downward and a notch groove 36B is formed in a part thereof. It is a thing. Since the low-speed boundary layer is likely to be formed on the inner peripheral surface because the falling port 36 is opened downward, and the same is true for the inner surface of the groove 36B, the granulated material can fall stably (and Similarly, it is blown back at the narrowed portion 39A).

FIG. 6 shows a drop port 36 for the embodiment of FIG.
A fifth embodiment in which the flow velocity of the hot air inside is adjustable is shown.
In this example, the nozzle 42B is similar to the fourth embodiment.
A cylinder 42D is provided on a mortar-shaped dispersion plate 42A with a granule, and the inside of the cylinder 42D serves as a drop port 46 (also serves as ventilation means 47).
Place 6A. A rod 46B extends horizontally to the valve 46A and extends to the outer wall of the granulation furnace 42. If this is operated to change the position vertically, the valve 46A causes the drop port 4 to move.
The lower opening area of 6 can be adjusted. By changing the area, it is possible to adjust the falling amount of the granulated product through the drop port 46, and it is also possible to control the residence time of the granulated product in the granulating furnace 42 and the like. However, among the granulated substances falling from the drop port 46 in this way, those that do not have a predetermined particle size are
It is blown back by the hot air that blows up the narrowed portion 49A below it, and passes through the nozzle 42B and enters the fluidized bed of the granulation furnace 42 again. Since the valve 46A is formed in a wedge shape that faces upward, it also exerts an effect of colliding the aggregated granules with the granules and scattering them.

The diameter and length of the drop port 46 and the narrowed portion 49A may be determined according to the following criteria. First, the diameter D of the narrowed portion 49A is determined so that the hot air has a flow velocity corresponding to the particle diameter of the granulated product to be classified (that is, to be blown back). The diameter d of the drop port 46 is d / D
Is set to 0.2 to 0.3. If d / D is 0.2 or more, the flow velocity near the center of the drop port 46 is
Even if the flow velocity is equal to the flow velocity in 2B, the granulated material is likely to fall from the vicinity of the periphery of the drop port 46. For the lengths l and L of the drop port 46 and the narrowed portion 49A, l = α × d, L =
β × D, and both α and β have a size of 0.5 to 2. When l and L are too small, even granules smaller than the classified particle size pass downward through the drop port 46 and the narrowed portion 49A. However, if the above range is reached, this is done in the middle of each portion. This is because the fine granules are blown back upward and effective classification is possible.

Although some embodiments have been introduced above, the present invention can also be carried out as follows.
For example, a) The drop port may be provided not at the level of the upper surface of the dispersion plate of the fluidized bed granulation furnace but at a position above the fluidized bed so that the flowing granulated material overflows and flows into it. That is, in the example of FIG. 1 (and FIG. 3 etc.), an opening as a drop port 6 is provided on the side wall of the granulation furnace 2 above the dispersion plate 2A, and in the example of FIG. 32D is extended above the dispersion plate 32A and opened in the fluidized bed. Then, the granulated material is classified by providing ventilation means or the like to the drop port.

B) Classification gas (hot air) sent to the drop port
May be introduced from another device such as the cooling device 4 or 5 in FIG. 2 instead of the firing furnace. In that case, since the temperature of the gas is somewhat low, there is an advantage that the melt adhesion (aggregation) of the granulated materials is prevented.

C) The outer wall of the granulating furnace or the firing furnace, the nozzle of the dispersion plate, the dropping port, the charging pipe, the narrowing portion, etc. are not limited to circular cross sections, but may be squares or other polygons. It goes without saying that it is acceptable.

[0036]

EFFECT OF THE INVENTION The cement clinker firing method and apparatus according to the present invention (claims 1 and 2) use two furnaces, a fluidized bed granulation furnace and a fluidized bed firing furnace, for suitable granulation and firing. In addition to the above, the particle size of the granulated product to be fed from the former to the latter can be adjusted with high accuracy, so that a high-quality cement clinker can be smoothly fired. In addition, the granulation product does not grow to an excessively large particle size in the granulation furnace, so the granulation efficiency is high.Agglomeration does not easily occur in the granulation furnace / firing furnace, so the fluidized bed is stabilized in each furnace. There is also an advantage that the device is easy to operate.

In the case of the firing apparatus according to claim 3, since the classification can be performed substantially twice, the classification can be performed with higher accuracy.

[Brief description of drawings]

FIG. 1 (a) is a vertical cross-sectional view showing a fluidized bed granulating furnace and a fluidized bed firing furnace in a cement clinker firing apparatus as a first embodiment of the present invention, and FIG. 1 (b) shows the same. It is a bb arrow line view in (a).

FIG. 2 is an overall system diagram of a firing apparatus including the granulation furnace and the firing furnace of FIG.

FIG. 3 is a vertical cross-sectional view showing the main parts of a cement clinker firing device as a second embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view showing a main part of a cement clinker firing device as a third embodiment of the present invention.

FIG. 5 (a) is a vertical cross-sectional view showing the main parts of a cement clinker firing apparatus as a fourth embodiment of the present invention,
The same (b) is a longitudinal sectional view showing an example in which a part of the same (a) is modified,
(c) is a cc arrow line view in the same (b).

FIG. 6 (a) is a vertical cross-sectional view showing the main parts of a cement clinker firing apparatus as a fifth embodiment of the present invention,
The same (b) is an enlarged view of a part thereof.

[Explanation of symbols]

 2 ・ 12 ・ 22 ・ 32 ・ 42 Granulation furnace 2A ・ 12A ・ 22A ・ 32A ・ 42A Dispersion plate 2B ・ 12B ・ 22B ・ 32B ・ 42B Nozzle 3 ・ 13 ・ 23 ・ 33 ・ 43 Baking furnace 6 ・ 16 ・ 26 ・36/46 Falling port 7/17/27/37/47 Ventilation means 9/19/29/39/49 Input pipe 19A / 29A / 39A / 49A Throttling part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuji Mukai, 1 Kanda Mitoshiro-cho, Chiyoda-ku, Tokyo Sumitomo Cement Co., Ltd. Cement Co., Ltd. (72) Inventor Isao Hashimoto 1-1 Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries, Ltd. Akashi Factory (72) Inventor Mikio Murao 3-1-1 Higashikawasaki-cho, Chuo-ku, Kobe, Hyogo Kawasaki Heavy industry Co., Ltd. Kobe factory (72) Inventor Shozo Kanamori 3-1-1 Higashikawasaki-cho, Chuo-ku, Kobe city, Hyogo prefecture Kawasaki Heavy industry Co., Ltd., Kobe factory

Claims (3)

[Claims] 1. A method for firing a cement clinker by using a fluidized bed granulation furnace and a fluidized bed firing furnace, and introducing the granulated material into the latter through a drop opening facing the fluidized bed of the former, From the drop port, a gas is blown into the fluidized bed granulation furnace at a flow rate determined separately from the flow rate of the fluidizing gas flowing into the fluidized bed granulation furnace through another opening, and the granulation is introduced into the firing furnace. A method for firing a cement clinker, characterized by classifying an object with the gas. 2. An apparatus for firing a cement clinker by providing a fluidized bed firing furnace below a dispersion plate of a fluidized bed granulation furnace and introducing the granulated material into the latter through a drop opening facing the fluidized bed of the former. There is a ventilation means capable of blowing gas into the fluidized bed granulation furnace from the drop port at a flow rate different from the flow velocity of the fluidizing gas flowing into the fluidized bed granulation furnace through the nozzle of the dispersion plate. A cement clinker firing device characterized by being provided with. 3. The cement clinker calcination apparatus according to claim 2, wherein a throttling portion for blowing up the gas at a predetermined flow rate is provided in the granulation material input pipe that continues downward from the drop port.