JP3247188B2 - Method of stopping cement clinker firing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for stopping a cement clinker baking apparatus and a method for restarting the operation of the cement clinker baking apparatus stopped by the method.

[0002]

2. Description of the Related Art Conventionally, a construction as shown in FIG. 2 has been adopted as a firing apparatus for a cement clinker. That is, the cement raw material powder previously charged from the raw material charging chute 1 is sequentially supplied to the cyclone C1, C2, C3, and C4 in the suspension preheater 2 composed of cyclones C1, C2, and C4.
It is preheated via C2, C3 and C4.
Then, the preheated cement raw material powder is charged into a fluidized bed type or spouted bed type granulating furnace 3, and the granulated material that has been fluidized or jet sized in the granulating furnace 3 is supplied to the granulating furnace 3. Through a discharge chute 5 and a so-called L-valve 6 (airtight discharge device) from a discharge hole 4 provided in a side wall near the bottom, the fluid is injected into a fluidized bed firing furnace 7 arranged below the granulation furnace 3. (See FIG. 3). As shown in FIG. 3, a large number of nozzle holes 10 are provided at the throat portion between the granulating furnace 3 and the fluidized-bed baking furnace 7 and at the bottom of the fluidized-bed baking furnace 7, respectively.
Dispersion plates 10 and 11 having a perforated plate structure having a and 11a are disposed, through which jet gas is blown upward, and a fluidized bed is formed in both furnaces together with separately introduced fuel. ing. After being baked in the fluidized bed sintering furnace 7 in this way, it is finally recovered as a cement clinker through a fluidized bed cooler 8 and a moving bed cooler 9. In the figure, A1 indicates a heavy oil supply line.

[0003] In the cement clinker firing apparatus configured as described above, at the time of starting normal operation, it is operated as shown in FIG. That is, first, after igniting the hot air furnace (HAF) 20, the fluidized bed firing furnace (FBK)
A fluidized medium (BM) is charged into the furnace 7 and the fluidized bed firing furnace 7 is ignited. Thereafter, a fluidized medium (BM) is charged into a spouted bed granulation furnace (SBK) 3 and ignited. The spouted bed granulation furnace (S) of cement raw material powder preheated by the suspension preheater 2 is used.
BK) 3 and the operation is started. Therefore, a complicated operation is required to start the operation, and it usually takes about 24 hours to start the operation, the heat efficiency is poor, and the production amount is reduced.

[0004] Further, even when the operation is temporarily stopped for an emergency stop or a short-term stop, the particle size of the particles remaining in the granulating furnace 3 (generally about 3 mm) flows with the granulating furnace 3. Since the diameter of the nozzle hole 10a of the dispersing plate 10 disposed in the throat portion between the bed firing furnace 7 is smaller than the diameter of the nozzle hole 10a (generally, about 30 to 100 mm), it is formed through the nozzle hole 10a of the dispersing plate 10. Normally, all particles remaining in the granulation furnace 3 fall into the fluidized bed firing furnace 7. Therefore, in this case, when restarting the operation of the cement clinker firing apparatus, FIG.
As described above, the same operation as described above usually requires an operation start time of about 15 hours. In this case, too, the operation is complicated and time-consuming, the thermal efficiency is poor, and the production amount is reduced.

In order to solve these problems, a so-called "hot banking" operation stopping method has been conventionally implemented. That is, in this method, high-temperature particles remain in the furnace even after the operation is stopped, and when the operation is started, as shown in FIG. Since the inside fluidizes, if fuel is charged, the furnace is ignited by the hot particles remaining in the furnace.

However, even when this stopping method is used, in the fluidized-bed baking furnace 7, the particle size of the particles remaining in the fluidized-bed baking furnace 7 is relatively close to the diameter of the nozzle holes 11a of the dispersion plate 11. Therefore, this method is applicable. However, in the spouted bed granulation furnace 3, as described above, the particle size of the particles remaining in the granulation furnace 3 is reduced by the nozzle hole 10 a of the dispersion plate 10.
Is relatively small as compared with the hole diameter of the granules, so that all the particles remaining in the granulating furnace 3 through the nozzle holes 10a of the dispersion plate 10 fall into the fluidized bed firing furnace 7 and usually do not cause hot banking. It is. In addition, even when the scale of the cement clinker sintering apparatus itself is increased, the particles are dropped and discharged through the nozzle holes 10a and 10b of the dispersion plates 10 and 11 of both furnaces, which is not preferable because hot banking does not occur. .

[0007] In view of the above situation, the present invention is capable of restarting in a short time without going through complicated steps such as charging a fluid medium at the time of restarting, as in the conventional shutdown method. An object of the present invention is to provide a possible method of stopping a cement clinker firing device and a method of restarting operation of the cement clinker firing device stopped by the stopping method.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems and objects of the prior art, and comprises a granulating furnace and a firing furnace connected below the granulating furnace. A dispersion plate having a perforated plate structure having a large number of nozzle holes is provided at the bottom of the baking furnace, and a dispersion plate having a perforated plate structure having a large number of nozzle holes is provided at a throat portion between the granulating furnace and the baking furnace. A cement clinker firing device,
A jet gas is blown from below through the two dispersion plates, and together with the fuel gas separately introduced into both furnaces, while granulating the cement raw material powder which has been preheated by a preheating means such as a suspension preheater and put into a granulation furnace. A stopping method for stopping the operation of a cement clinker firing apparatus for firing granulated material which has been granulated in the granulating furnace and charged into a firing furnace, wherein (1) supply of cement raw material powder is performed. After the shutdown, a step of continuing the injection of the jet gas until the temperature of the granulated material in both furnaces becomes a temperature having no adhesion, and (2) immediately before stopping the injection of the jet gas, A step of introducing a large lump having a particle diameter capable of closing the nozzle holes of both dispersion plates, and (3) a step of stopping the injection of the jet gas after the large lump is introduced. Firing equipment It is the stop method.

Further, the present invention is characterized in that, in the above-mentioned stopping method, the large lump has a small apparent density and a fluidization start speed slightly higher than the superficial velocity at the time of charging. It is a stop method.

Further, the present invention relates to a method for starting operation of a cement clinker firing apparatus which has been stopped by the above-described method for stopping a cement clinker firing apparatus, wherein (1) the large lump is put in. A step of injecting jet gas into both furnaces to fluidize granules and the like staying in the respective furnaces; and (2) chunks for discharging large lumps respectively disposed near the bottoms of the furnaces Discharging the large lumps charged into the respective furnaces, (3) supplying fuel to each of the fluidized furnaces, and igniting the respective furnaces, (4) Starting a cement raw material powder, which has been preheated by a preheating means such as a suspension preheater, into a granulating furnace.

Further, according to the present invention, in the above-mentioned method for starting the operation of the cement clinker firing apparatus again, instead of discharging the large lumps put into the respective furnaces through the large lumps discharging chute, (a) Either the large lumps introduced into the respective furnaces are discharged through the nozzle holes of the dispersion plates respectively disposed in the furnaces, or (b) through the nozzle holes of the dispersion plates respectively disposed in both the furnaces. And, while discharging a large lump of a size smaller than the particle size of the nozzle hole put into each furnace,
A method of discharging large lumps having a size larger than the particle diameter of the nozzle hole charged into each furnace, via large chute discharging chutes respectively arranged near the bottoms of both furnaces. .

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the accompanying drawings.

FIG. 1 is a spouted bed granulating furnace for carrying out a method for stopping a cement clinker firing apparatus according to the present invention and a method for restarting operation of the cement clinker firing apparatus stopped by the method. FIG. 3 is a partially enlarged sectional view of a fluidized bed firing furnace.

In the figure, reference numeral 103 denotes a spouted bed granulation furnace, and a lower portion thereof becomes a cone portion 103a, and a raw material inlet 120 and a large lump discharge chute 122 are provided on the side wall of the cone portion 103a, respectively. Further, a chute 105 for discharging granulated matter and a large lump inlet 114 are provided on the upper side wall of the cone portion 103a. The discharge chute 105 is connected to an inlet 107a of a fluidized bed firing furnace 107 connected below the spouted bed granulation furnace 103 via an L valve 106 as in the conventional case.

On the other hand, in a throat portion 115 between the spouted bed granulation furnace 103 and the fluidized bed firing furnace 107, a dispersion plate 110 having a perforated plate structure having a number of nozzle holes 110a is provided. Reference numeral 124 denotes a fuel supply port.

The fluidized bed firing furnace 107 is provided with a clinker discharge port 123 on a side wall thereof, and a dispersion plate 111 having a perforated plate structure having a large number of nozzle holes 111a at the bottom thereof. Furthermore, this dispersion plate 11
1, a large lump discharge chute 132 is provided, and a large lump input port 134 is provided on a side wall of the fluidized bed firing furnace 107.

In such a configuration, first, when the operation is stopped, the following operation method is performed.

First, after the supply of the cement raw material powder is stopped from the raw material input port 120, the temperature of the granulated material in both furnaces is about 1150 ° C. or less, which is a temperature at which there is no adhesion, preferably about 11 ° C.
The blowing of the jet gas (air) is continued until the temperature becomes equal to or lower than 00 ° C., and the nozzle holes 110a,
111a prevents the granulated material or the like from adhering to the nozzle holes or forming a nodule and clogging.

Next, just before the injection of the jet gas is stopped, a large lump is introduced from the large lump inlet 114 of the spouted bed granulation furnace 103 and a large lump is introduced from the large lump inlet 134 of the fluidized bed firing furnace 107. I do.

In this case, the size of the mass to be charged is
The size is not particularly limited as long as it is a size that can close the nozzle holes 110a and 111a, and the nozzle hole can be closed if it is at least 1/3 or more with respect to each hole diameter of the nozzle hole.

The shape of the large lump can be various shapes such as, for example, spherical, hollow, and porous, and is not particularly limited. Furthermore, the material is not particularly limited, and lightweight aggregates, alumina, ceramic, cement clinker, stainless steel, and the like can be used.Preferably, those that do not melt in the furnace, It is preferable that it does not affect the quality of the final product, cement clinker, even if it is mixed or partially mixed with the product.

Although various materials and shapes can be applied to the large block as described above, it is important that the charged large block can be uniformly diffused in the furnace to close the entire nozzle hole. And, in order to be easily fluidized and discharged by air blowing at the time of re-operation, it is necessary that the apparent density is small and the fluidization start speed is slightly higher than the superficial velocity at the time of charging. It is essential that the shape, dimensions and specific gravity satisfy this requirement. Preferably, for example, if the density of the fluidized medium in the spouted bed granulation furnace is 3 kg / l, the apparent density of large lumps is 1.5 to 2.0 kg / l, and the superficial velocity is 3. If it is 0 m / s, it is preferable that the fluidization start speed of the large lump in the fluid medium is about 3.0 to 3.5 m / s. In addition, as the amount of the large lump to be introduced, if a large lump of about 10 times the number of the nozzle holes is introduced,
It is possible to close all nozzle holes.

As described above, after the large lump is introduced, the push blowers 23 and 24 and the hot blast stove 2 as shown in FIG.
5, and the sp fan 26 is stopped to stop the injection of the jet gas and to stop the operation of the entire apparatus.

As a result, the large lump particles are gradually
The nozzles are diffused and settled throughout the nozzle holes 110a and 11a of 0 and 111, and the nozzle holes are closed. Granules and the like stay in each furnace at a high temperature, and the apparatus can be easily restarted. The operation of the device is stopped when possible.

Next, when the apparatus whose operation has been temporarily stopped in such a state is restarted, the following operation method is performed.

First, the injection blowers 23 and 24 are operated to blow the jet gas into the two furnaces into which the large lumps have been charged, so that the granules and the like retained in the respective furnaces are fluidized.

Next, from the large chute discharge chute 122 of the spouted bed granulation furnace 103 and the large chute discharge chute 132 of the fluidized bed firing furnace 107, the large chute having a size larger than the particle diameter of the nozzle hole introduced into each furnace. Drain the lump. The nozzle holes 110a, 111a of the dispersion plates 110, 111 of both furnaces.
, A large lump having a size smaller than the particle diameter of the nozzle hole charged into each furnace is discharged.

After the large lumps are discharged as described above, the operation of the push-in blowers 23 and 24 and the sp fan 26 is started to supply the fuel into the fluidized furnaces, respectively. The high temperature particles remaining in the furnace easily ignite the two furnaces, and the cement raw material powder preheated by the preheating means such as the suspension preheater 2 is fed into the granulating furnace from the raw material inlet 120 to restart the operation of the entire apparatus. Is done.

[0029]

According to the method for stopping the cement clinker firing apparatus of the present invention as described above, (1) after the supply of the cement raw material powder is stopped, the temperature of the granulated material in both furnaces decreases the adhesion. By the step of continuing the injection of the jet gas until the temperature does not have, the nozzle holes of the dispersion plate are not blocked by granules or the like. (2) Immediately before the stop of the injection of the jet gas, Injecting a large lump having a particle size capable of closing the nozzle holes of both dispersing plates, and then stopping the injection of the jet gas after the large lump is introduced, the large lump particles are gradually diffused throughout the nozzle holes of the dispersing plate. It is possible to sediment and close each nozzle hole, and it is possible for granules etc. to stay in each furnace in a high temperature state, and then to restart the operation easily by stopping the injection of jet gas. The equipment is shut down when possible .

Further, according to the restarting method for restarting the operation of the cement clinker firing apparatus stopped by the stopping method of the present invention as described above, (1) the furnaces from which the large lumps are discharged The process of injecting the jet gas to fluidize the granules and the like staying in each furnace fluidizes the large lumps charged together with the high-temperature granules and the like staying in both furnaces, 2) (a) discharging large lumps charged into the respective furnaces through nozzle holes of the dispersion plates respectively disposed in the both furnaces, and / or (b) respectively disposing the large lumps in the furnaces. The large lumps charged into the respective furnaces are discharged through the nozzle holes of the dispersing plate, and (3) the fuel is supplied only into the two fluidized furnaces, and the fuel is introduced into the two furnaces. Both furnaces are easily ignited by the remaining hot particles, and (4) By starting to feed the cement raw material powder preheated by the preheating means such as the suspension preheater into the granulation furnace, the cement clinker firing device can be restarted reliably and stably in a relatively short time and with a simple operation. Is done.

Therefore, according to the present invention, (a) even if the apparatus itself is scaled up, the nozzle holes of the dispersing plate are closed by the large lumps which are surely charged, so that the spouted bed and the fluidized bed are heated to a high temperature. (B) simultaneously with the operation of the ventilation system, the spouted bed granulation furnace and the fluidized bed sintering furnace are maintained. (C) Almost no consumption of the initial fluid medium (BM) at the start of operation, (d) the apparent density of large lumps is small, and the superficial velocity at the time of charging When the fluidization start speed is close to the above, the large block for closing the nozzle is sufficiently diffused and settles, so that the input amount may be small. It is.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a spouted bed granulation for implementing a method of stopping a cement clinker firing device of the present invention and a restart operation method for restarting operation of the cement clinker firing device stopped by the stopping method. It is a partial expanded sectional view of a furnace and a fluidized-bed firing furnace.

FIG. 2 is a drawing schematically showing an overall configuration of a cement clinker firing apparatus.

FIG. 3 is a partially enlarged cross-sectional view of a conventional spouted bed granulating furnace and a fluidized bed firing furnace.

FIG. 4 is a flowchart for explaining an outline for starting the entire conventional cement clinker firing apparatus.

FIG. 5 is a flowchart illustrating an outline for starting a re-operation after stopping the entire conventional cement clinker firing apparatus.

FIG. 6 is a flowchart illustrating an outline for starting a restart of the entire baking apparatus of the cement clinker stopped by the hot banking method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Material input chute 2 ... Suspension preheater 3 ... Granulation furnace 4 ... Discharge hole 5 ... Discharge chute 6 ... L valve (airtight discharge device) 7 ... Fluidized bed firing furnace 8 ... Fluidized bed cooler 9 ... Moving bed cooler 10, 11 ... Dispersion plates 10a, 11a ... Nozzle holes 20 ... Hot blast stove (HAF) 22 to 24 ... Blow-in blower 25 ... Hot blast stove 26 ... sp fan 103 ... Spouted bed granulation furnace 103a ... Cone section 105 ... Discharge chute 106 ... L valve 107: Fluidized bed firing furnace 107a: Input ports 110, 111: Dispersion plates 110a, 111a: Nozzle holes 114: Large lump input port 115: Throat section 120: Raw material input port 122: Large lump discharge chute 123: Clinker discharge port 124: Fuel supply port 132 ... Large lump discharge chute 134 ... Large lump inlet A1 ... Heavy oil supply line C1-C4 ... Cyclone

Continuing on the front page (72) Inventor Makoto Nakatsuka 1 Sumitomo Cement Co., Ltd., Kanda Midoshiro-cho, Chiyoda-ku, Tokyo (72) Inventor Isao Hashimoto 1-1-1, Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries, Ltd. Inside the Akashi Plant (72) Inventor Tatsuya Watanabe 3-1-1 Higashi-Kawasaki-cho, Chuo-ku, Kobe-shi, Hyogo Kawasaki Heavy Industries, Ltd.Kobe Plant (72) Inventor Mikio Murao 3-1-1, Higashi-Kawasaki-cho, Chuo-ku, Kobe, Hyogo Prefecture 1 Kobe Plant, Kawasaki Heavy Industries, Ltd. (56) References JP-A-59-104008 (JP, A) JP-A-60-20019 (JP, A) JP-A-59-88346 (JP, A) JP 62-241546 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C04B ^7/ 00-7/60

Claims (5)

(57) [Claims] 1. A dispersing plate having a perforated plate structure having a number of nozzle holes provided at a bottom portion of the baking furnace, comprising a granulation furnace and a baking furnace connected below the granulation furnace. What is claimed is: 1. A cement clinker baking apparatus in which a dispersion plate having a perforated plate structure having a large number of nozzle holes is provided in a throat portion between furnaces, wherein a jet gas is blown from below through both the dispersion plates, Along with the fuel gas introduced into the inside, while granulating the cement raw material powder which has been preheated by a preheating means such as a suspension preheater and charged into a granulating furnace, it is granulated in the granulating furnace and charged into a firing furnace. This is a stopping method for stopping the operation of a cement clinker firing apparatus for firing granules, in which (1) after the supply of cement raw material powder is stopped, the temperature of the granulated material in both furnaces has an adhesive property. Spout gas until not temperature Continuing the blowing, (2) immediately before stopping the blowing of the jet gas, charging a large lump having a particle size capable of closing the nozzle holes of both dispersing plates into each of the two furnaces, and (3) And c. Stopping the injection of the jet gas after the large lump has been charged. 2. The stopping method according to claim 1, wherein the large mass has a small apparent density and a fluidization start speed slightly higher than the superficial velocity at the time of charging. 3. An operation start method for restarting a cement clinker firing device stopped by the method for stopping a cement clinker firing device according to claim 1 or 2, wherein (1) A step of injecting a jet gas into both furnaces into which the large lumps have been introduced to fluidize granulated materials and the like staying in the respective furnaces; and (2) disposing them near the bottoms of both furnaces, respectively. Discharging the large lumps charged into the respective furnaces through the mass chutes for discharging the large lumps; and (3) supplying fuel to the two fluidized furnaces and igniting the respective furnaces. And (4) a step of starting charging of the cement raw material powder preheated by a preheating means such as a suspension preheater into a granulating furnace. 4. An operation start method for restarting a cement clinker firing device stopped by the method for stopping a cement clinker firing device according to claim 1 or 2, wherein (1) A step of injecting a jet gas into both furnaces into which the large lumps have been introduced to fluidize granules and the like staying in the respective furnaces; and (2) dispersing the granules respectively disposed in the furnaces. Discharging the large lumps charged into the respective furnaces through the nozzle holes of the plate; and (3) supplying fuel to each of the fluidized furnaces and igniting the respective furnaces. And (4) a step of starting charging of the cement raw material powder preheated by a preheating means such as a suspension preheater into a granulating furnace. 5. An operation start method for restarting a cement clinker firing device stopped by the method for stopping a cement clinker firing device according to claim 1 or 2, wherein (1) A step of injecting a jet gas into both furnaces into which the large lumps have been introduced to fluidize granules and the like staying in the respective furnaces; and (2) dispersing the granules respectively disposed in the furnaces. Through the nozzle holes of the plate, while discharging a large lump having a size smaller than the particle diameter of the nozzle hole charged into each furnace, through a large lump discharge chute arranged near the bottom of both furnaces Discharging large lumps having a size larger than the particle diameter of the nozzle holes introduced into each furnace; and (3) supplying fuel to each of the fluidized furnaces and igniting the respective furnaces. Process and
(4) a step of starting the feeding of the cement raw material powder preheated by a preheating means such as a suspension preheater into a granulating furnace, the method comprising: