JP2000128592A - Cement firing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cement firing equipment capable of being reasonably structured where heat recovery is performed with high efficiency by introducing a high temp. extraction gas from a kiln directly to a heat exchanger. SOLUTION: This cement firing equipment is constituted so that the high temp. extraction gas extracted from the inlet position of the rotary kiln 11 and a waste gas from a preheater 12 are supplied through a hot gas supply passage 24 to the heat exchanger 30, where fine particles are fluidized to generate a jet stream layer, the solid matter is separated in a separator 40 and the raw material portion separated in the separator 40 is returned to the rotary kiln 11 through a kiln return passage 51.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cement burning facility provided with a pre-heater for utilizing kiln gas discharged from a kiln and capable of extracting a part of the kiln gas.

[0002]

2. Description of the Related Art In a cement manufacturing process, a firing step of firing a mixed material to form a cement clinker is performed by a kiln (SP) having a suspension pre-heater provided with a pre-heater having a plurality of stages of cyclones at an inlet side of a rotary kiln. Or a kiln (NSP) with a new suspension pre-heater in which a temporary firing furnace is interposed between the cyclone and the kiln.

[0003] In a sintering facility equipped with such a preheater, fuel is blown into a rotary kiln with a burner and burned to bake the raw materials to form a cement clinker, and kiln gas discharged from the rotary kiln is guided to the preheater. And is used for preheating the raw materials.

[0004] When the raw material or fuel contains a large amount of volatile components such as alkali, chlorine or sulfur, the entire kiln gas containing these volatile components is supplied to the preheater. Operational troubles such as blockage due to adhesion to the vehicle may be caused. For this reason,
In order to avoid such a driving trouble, a part of the kiln gas is bled. That is, when a raw material or fuel having a high volatile content is used, kiln gas supplied from the rotary kiln to the pre-heater is extracted to suppress the amount of kiln gas so as not to cause an operation trouble.

[0005] FIG. 3 is a conceptual diagram of an example of a cement sintering facility configured to be able to bleed kiln gas. In the illustrated configuration, bleed gas is obtained by bleeding a part of kiln gas c supplied from kiln a to preheater b. The gas d is introduced into the cooling chamber e, mixed with the cooling air g from the cooling fan f in the cooling chamber e to lower the temperature, sprayed with water in the next stabilizer h to further lower the temperature, and collected by the electrostatic precipitator i. After dusting, the air is exhausted through an exhaust fan j.

Further, as shown in FIG. 4, after the cooling chamber e in the above-described configuration, it is combined with the kiln gas c exhausted from the preheater b via the classifier k and the high-temperature dust collector m and supplied to the boiler n. There is also proposed a configuration in which heat is recovered by the boiler n and then exhausted by an exhaust fan o.

[0007]

However, the configuration shown in FIG. 3 is for cooling and discharging high-temperature bleed gas extracted from the kiln, which wastes heat and cools it for cooling. A configuration such as a room and a stabilizer was required, which was extremely irrational.

On the other hand, in the configuration shown in FIG. 4, although it is thermally more rational to recover heat by the boiler, it is necessary to cool the extracted gas in the cooling chamber, collect the dust in the high-temperature dust collector, and then guide the extracted gas to the boiler. The heat recovery was low. In other words, if the extracted gas from the kiln is introduced directly into the boiler, dust containing volatile matter will adhere to the boiler tube wall and cause problems such as a decrease in heat transfer efficiency and blockage of the gas flow path. Is indispensable, and therefore, the extracted gas must be cooled to a heat-resistant limit temperature that the high-temperature dust collector can withstand, and a high heat recovery rate cannot be expected.

[0009] The present invention has been made in view of the above-mentioned problems, and it is possible to perform high-efficiency heat recovery by directly guiding high-temperature extracted gas from a kiln to a heat exchanger.
It is an object of the present invention to provide a cement burning facility that can be rationally configured.

[0010]

According to a first aspect of the present invention, there is provided a cement firing apparatus provided with a pre-heater utilizing kiln gas discharged from a kiln, wherein a part of the kiln gas is extracted. A heat transfer pipe through which a heat recovery fluid flows is provided and a fluid medium is accommodated therein, and the exhaust gas discharged from the pre-heater and the extracted gas extracted from the preheater are heated gas. Supplied from below through the supply path,
A heat exchanger in which the fluidized medium forms a spouted bed; and a heat-exchanged gas from the heat exchanger is supplied via a heat-exchanged gas path to separate solid components contained in the heat-exchanged gas. And a solid component return path for returning the solid component recovered by the separator to the kiln.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a conceptual configuration diagram of a cement burning facility according to the present invention.

The illustrated cement sintering facility 1 is provided with a preheater 12 having a plurality of stages of cyclones connected to an inlet side of a rotary kiln 11.
Is supplied to the preheater 12. A bleed passage 21 is connected to the inlet portion of the rotary kiln 11 so that the kiln gas reaching the preheater 12 via the bleed passage 21 can be bleed halfway.

An exhaust path 22 having an exhaust fan 23 is connected to the exhaust side of the preheater 12, and exhaust gas from the preheater 12 is exhausted through the exhaust path 22.

The bleed passage 21 and the exhaust passage 22 are merged and integrated into a hot gas supply passage 24.

The hot gas supply path 24 is connected to an air supply port below the heat exchanger 30, and the exhaust port of the heat exchanger 30 is connected to a separator 40 via a heat exchanged gas path 25. An exhaust port 40 is provided with a dust collector 27 and an exhaust path 29 having an exhaust fan 28 at an end thereof.

The separator 40 has a kiln return path 5 connected to the inlet of the rotary kiln 11.
1, heat exchanger return path 5 connected to heat exchanger 30
2 and the waste passage 53 are connected.

As shown in an enlarged sectional view of FIG. 2, the heat exchanger 30 is provided with a plurality of water tubes 31 as heat transfer tubes therein, and is supplied from below through a hot gas supply passage 24. A fine-grain clinker 32 as a fluid medium capable of forming a spouted bed 33 by the hot gas HG to be discharged is accommodated, and water as a heat recovery fluid is supplied from an inlet-side header 31A provided outside the water pipe 31. Is introduced, and the introduced water is heated by heat exchange with the hot gas HG, becomes steam, and is discharged to the outlet header 31B. The generated steam is supplied to a steam turbine 61 connected to a generator 62.

In the above configuration, the high-temperature bleed gas extracted from the inlet portion of the rotary kiln 11 and the exhaust gas from the preheater 12 join to form the hot gas supply path 2.
4 to the heat exchanger 30 and the heat exchanger 30
After the heat recovery, the raw materials and solid components such as fine-grain clinker from the heat exchanger 30 are separated by the separator 40, and the remaining dust is collected by the dust collector 27, and then discharged through the exhaust fan 28. Is done.

In the heat exchanger 30, the fine-grain clinker 32 is fluidized by the hot gas HG supplied from the lower portion thereof to form a spouted bed 33 therein, and the water pipe 31 is directly or fine-grained from the hot gas HG. Is heated indirectly by using the water as a heat exchange medium, and the water flowing inside becomes steam, and the outlet header 3
Discharge to 1B. The steam discharged to the outlet header 31B drives the generator 62 via the steam turbine 61, whereby the heat energy of the hot gas HG can be recovered as electric power.

Here, the bleeding through the bleeding path 21 is performed when a raw material or fuel having a high volatile content is used.
Bleed gas contains a large amount of volatile components. When such a gaseous gas having a high volatile content is directly supplied to the heat exchanger 30, dust containing the volatile content adheres to the water pipe 31 and causes problems such as a decrease in heat transfer efficiency and a blockage of the gas flow path. However, in the configuration of the present application,
The extracted gas is mixed and diluted with the exhaust gas from the preheater 12, and the fine clinker 32 fluidized in the heat exchanger 30 not only functions as a heat exchange medium but also cleans the surface of the water pipe 31. Therefore, dust containing volatile matter is prevented from adhering to the pipe wall.

The separator 40 separates the raw material dust contained in the extracted gas and the fine-grained clinker accompanying the heat exchanger 30. The separated raw material dust is returned to the rotary kiln 11 through the kiln return path 51, The grain clinker is returned to the heat exchanger 30 via the heat exchanger return path 52. Other dust is discarded through the discard path 53 together with the dust collected by the dust collector 27. Opening / closing control of these paths 51, 52, 53 is performed automatically by a worker manually or after automatic accumulation by an automatic controller, in consideration of the content of volatile matter by sampling of raw materials.

According to the above configuration, the heat of the exhaust gas and the bleed gas from the preheater 11 can be recovered by the heat exchanger 30, and the raw material dust separated and recovered by the separator 40 is passed through the kiln return path 51. The product yield can be improved because it can be returned to the rotary kiln 11 via a separator. Further, it is not necessary to provide a separator and a dust collector in each of the exhaust gas path 22 and the bleeding path 21 from the pre-heater 11, so that a single set can be used. Can be simplified.

[0024]

As described above, according to the cement sintering equipment of the present invention, the heat transfer pipe through which the heat recovery fluid flows is provided, the fluid medium is stored, and the cement is discharged from the preheater. The exhaust gas and the extracted gas are
A heat exchanger which is supplied from below through a hot gas supply path and in which the fluidized medium forms a spouted bed; and a heat exchanged gas from the heat exchanger is supplied via the heat exchanged gas path and By having a separator that separates the solid components contained in the heat-exchanged gas and a solid component return path that returns the solid components recovered by the separator to the kiln, the dust containing volatile components is used. The exhaust gas and the bleed gas from the pre-heater can be directly introduced into the heat exchanger while preventing the trouble, and the heat can be recovered by the heat exchanger. In addition, since the raw material dust separated and recovered by the separator can be returned to the kiln via the kiln return path, the product yield is improved. It is not necessary to provide each of them, and only one set is required, so that the configuration can be simplified.

That is, the high-temperature extracted gas from the kiln can be directly guided to the heat exchanger to perform heat recovery with high efficiency, and can have a rational configuration.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram of a cement burning facility according to the present invention.

FIG. 2 is an enlarged sectional view of a heat exchanger.

FIG. 3 is a conceptual configuration diagram of a conventional example.

FIG. 4 is a conceptual configuration diagram of another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cement baking equipment 11 Rotary kiln (kiln) 12 Preheater 24 Hot gas supply path 25 Heat exchanged gas path 30 Heat exchanger 31 Water pipe (heat transfer pipe) 32 Fine grain clinker (fluid medium) 33 Spout bed 40 Separator 51 Kiln return path (Solid component return path)

Claims (1)

[Claims] 1. A cement sintering facility equipped with a pre-heater that uses kiln gas discharged from a kiln, wherein a part of the kiln gas is configured to be bleedable. A heat pipe is provided and a fluid medium is accommodated therein. Exhaust gas discharged from the pre-heater and the extracted gas are supplied from a lower portion thereof through a hot gas supply path, and the fluid medium is jetted. A heat exchanger that forms a layer, a heat-exchanged gas from the heat exchanger is supplied through a heat-exchanged gas path, and a separator that separates a solid component contained in the heat-exchanged gas, And a solid component return path for returning a solid component recovered by the separator to the kiln.