JP4360477B2 - Waste treatment equipment for cement firing - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cement firing waste treatment apparatus that pretreats industrial waste and supplies it to a cement firing facility.
[0002]
[Prior art]
As schematically shown in FIG. 2, the cement plant includes a cyclone preheating device (suspension preheater 2) that preheats the raw material with exhaust gas from the rotary kiln on the upstream side of the rotary kiln type firing furnace (rotary kiln 1). A new suspension preheater kiln (NSP kiln) in which a calcining furnace 3 is provided between the preheater and the rotary kiln is mainly used. This NSP kiln is a system in which 50 to 60% of the required fuel is burned in the calcining furnace 3 and the decarboxylation reaction of the powder raw material is efficiently promoted and fed to the kiln. (1) The kiln inlet raw material The apparent decarboxylation rate is high, the specific firing capacity is more than twice that of the SP kiln, and the productivity is high. (2) Since only 40-50% of the required fuel on the kiln side is available, the heat load of the firing zone is high. It has features such as low life and long life, (3) relatively low calcining furnace outlet gas temperature (for example, 850 to 900 ° C.), and low NOx generation amount.
[0003]
In such an NSP kiln, when a cement raw material is introduced into the inlet of the uppermost cyclone heat exchanger (hereinafter simply referred to as a cyclone) constituting the suspension preheater, the introduced raw material exchanges heat with exhaust gas in the cyclone. Then, it is centrifuged and falls downward from the lower end of the cyclone that is thinned in the shape of an inverted cone. This raw material is further supplied to the inlet gas flow path of the lower cyclone, entrained by the gas, enters the cyclone and is centrifuged. In this way, the raw material is sequentially transferred to the lower cyclone while being heated by the exhaust gas, finally calcined in a calcining furnace, and supplied to the rotary kiln from the lower part of the lower cyclone again.
[0004]
[Problems to be solved by the invention]
In recent years, a large amount of industrial waste (hereinafter referred to as waste combustibles) such as automobile tires and plastics has been generated, and in order to process this and reduce it significantly, some NSP kilns are used. It has been broken.
As shown in FIG. 2, conventionally, the combustible material 4 (tire chips and plastics) is supplied between the rotary kiln 1 and the calcining furnace 3 (for example, a rising duct), incinerated there, and the generated ash is removed from the rotary kiln 1. Was supplied as a part of the cement raw material, and the combustion exhaust gas was supplied to the preheater 2 to recover heat.
[0005]
However, there is a problem that even if such waste combustibles are supplied to the rising duct and used as fuel, they can contribute to calcination of raw materials but cannot contribute to calcination. Further, when the waste combustible material contains a large amount of moisture, the heat of evaporation lowers the operating temperature of the NSP kiln, resulting in a heat loss, and there is a risk of hindering stable operation.
[0006]
The present invention has been made to solve such problems. That is, an object of the present invention is to process a large amount of waste combustible material and greatly reduce the amount of fuel, so that fluctuations in operating temperature due to moisture are small, and fuel from garbage is used more effectively for clinkering fuel. An object of the present invention is to provide a waste treatment apparatus for cement firing that can reduce the main fuel of the kiln.
[0007]
[Means for Solving the Problems]
According to the present invention, the externally heated kiln (12) for carbonizing the waste combustible material (4) with the high temperature gas (6) and generating the carbonized gas (7), and the suspension preheater (2) ), A high temperature chlorine bypass gas (6a) generated in the rotary kiln (1) and a low temperature generated in the clinker cooler (5b) in the cement kiln ( 5) including the rotary kiln (1 ) and the clinker cooler (5b). A high-temperature gas supply device (14) for supplying a high-temperature gas mixed with a cooler exhaust gas (6b) to the external heating kiln, and a dry distillation gas generated in the external heating kiln are supplied to a burner (5a) of a cement firing facility. There is provided a waste treatment apparatus for cement firing, comprising a dry distillation gas supply line (16).
[0008]
According to the configuration of the present invention, the combustible waste (industrial waste containing chlorine and moisture) is dry-distilled by the external heating kiln (12), and the dry-distilled gas generated by the dry distillation gas supply line (16) is removed from the cement firing facility. Since it supplies to a burner (5a), the main fuel of the kiln for the calorific value of this dry distillation gas can be reduced.
Moreover, since the dry distillation ash treated with the external heating kiln (12) is not supplied to the cement firing facility, the adverse effects of chlorine and moisture can be avoided, and a large amount of waste combustibles can be treated to significantly reduce the amount. Can do.
[0009]
According to a preferred embodiment of the present invention, the external heating kiln (12) includes a hollow cylindrical inclined kiln (12a) and a heating duct (12b) for indirectly heating the inclined kiln from the outside. The waste combustibles passing through the inclined kiln are dry-distilled at a high temperature.
[0010]
With this configuration, the combustible waste (4) can be combusted at a high temperature without burning the combustible waste (4) and without consuming excess fuel, and combustible gas suitable for combustion in the burner (5a) ) Can be generated.
[0011]
The high temperature gas supply device (14) includes a high temperature gas supply line (14a) that mixes the chlorine bypass gas (6a) and the cooler exhaust gas (6b) and supplies the mixture as a high temperature gas (6) to the external heating kiln, It comprises a damper device (14b) provided in one or both of the chlorine bypass gas (6a) and the cooler exhaust gas (6b), and a temperature adjusting device (14c) that controls the damper device to adjust the temperature of the hot gas.
[0012]
With this configuration, a high-temperature gas of about 500 ° C. suitable for dry distillation of combustible waste by mixing a high-temperature chlorine bypass gas (6a) of about 1050 ° C. and a low-temperature cooler exhaust gas (6b) of about 250 ° C. (6) can be adjusted.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to a common part and the overlapping description is abbreviate | omitted.
[0014]
FIG. 1 is a configuration diagram of a cement firing waste treatment apparatus according to the present invention. The waste processing apparatus 10 for cement firing according to the present invention includes an external heating kiln 12, a high-temperature gas supply apparatus 14, and a dry distillation gas supply line 16.
[0015]
The external heat kiln 12 includes a hollow cylindrical inclined kiln 12a and a heating duct 12b that indirectly heats the inclined kiln 12a from the outside. A high temperature gas 6 suitable for dry distillation is supplied to the heating duct 12b, and the waste combustible material 4 passing through the inclined kiln 12a is indirectly heated to dry dry at a high temperature to generate a dry distillation gas 7 as a combustible gas. The temperature of the hot gas 6 should be a temperature suitable for efficiently carbonizing the waste combustible material 4 (for example, about 500 ° C.).
[0016]
The hot gas supply device 14 includes a hot gas supply line 14a, a damper device 14b, and a temperature control device 14c.
The high-temperature gas supply line 14a is a high-temperature (about 1050 ° C.) chlorine bypass gas 6a extracted from the preheater 2 to prevent the chlorine gas generated in the rotary kiln 1 or the calcining furnace 3 from staying, and the low temperature from the clinker cooler 5b. This is a gas line in which the cooler exhaust gas 6b (about 250 ° C.) is mixed and supplied to the external heating kiln 12 as the high-temperature gas 6.
The damper device 14b is provided in one or both of the chlorine bypass gas 6a and the cooler exhaust gas 6b (both in this example), and adjusts the flow rate of each line.
Furthermore, the temperature adjusting device 14 c includes a temperature detector that detects the temperature of the hot gas 6, and controls the damper device 14 b to adjust the temperature of the hot gas 6. In this figure, 14d is a damper device for releasing a part of the gas in the high temperature gas supply line 14a to the outside.
[0017]
The dry distillation gas supply line 16 supplies the dry distillation gas 7 generated in the external heating kiln 12 to the burner 5 a of the cement burning equipment 5. The main fuel 9 is also supplied to the burner 5a, and both the main fuel 9 and the dry distillation gas 7 are burned by the same burner. In addition to the burner 5a for the main fuel 9, a burner for the dry distillation gas 7 may be provided separately.
[0018]
According to the configuration of the present invention described above, the combustible waste 4 (industrial waste containing chlorine and moisture) is dry-distilled by the external heating kiln 12, and the dry distillation gas 7 generated by the dry distillation gas supply line 16 is converted into the cement firing equipment 5. Therefore, the main fuel of the kiln corresponding to the calorific value of the dry distillation gas 7 can be reduced.
Moreover, since the dry distillation ash processed with the external heating kiln 12 is not supplied to the cement baking equipment 5, the bad influence by a water | moisture content can be avoided, and a large amount of combustible waste can be processed and it can reduce significantly.
[0019]
The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the invention.
[0020]
【The invention's effect】
As described above, according to the present invention, a high-temperature (about 1400 ° C.) frame can be formed by burning dry distillation gas of waste (waste combustible material) with a burner of a cement firing kiln. Heat can be transferred more efficiently.
In other words, it is necessary to form a frame with a burner at the fired portion of the cement raw material, but it is not possible to make a frame with the method of directly putting garbage into the cement kiln, and better garbage ( Effective use of dry distillation gas).
[0021]
Therefore, the waste processing apparatus for burning cement according to the present invention can process a large amount of combustible waste and can greatly reduce the amount of waste, there is little fluctuation in operating temperature due to moisture, and fuel from garbage is more effectively used as fuel. By using it for clinkering, the main fuel of the kiln can be reduced.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a cement firing waste treatment apparatus according to the present invention.
FIG. 2 is an overall configuration diagram of a conventional NSP kiln.
[Explanation of symbols]
1 firing furnace (rotary kiln), 2 suspension preheater,
3 calcining furnaces, 4 industrial waste (combustible waste),
5 cement firing equipment, 5a burner, 5b clinker cooler,
6 high temperature gas, 6a chlorine bypass gas, 6b cooler exhaust gas,
7 dry distillation gas, 8a, 8b exhaust gas treatment device, 9 main fuel,
10 Waste treatment equipment for cement firing,
12 external heating kiln, 12a inclined kiln, 12b heating duct,
14 hot gas supply device, 14a hot gas supply line,
14b damper device, 14c temperature control device,
16 Carbonization gas supply line

Claims (3)

An externally heated kiln (12) for carbonizing waste combustibles (4) with hot gas (6) to generate dry distillation gas (7);
Suspension preheater or suspension preheater with calciner (2), high temperature chlorine bypass gas (6a) generated in the rotary kiln (1) in the cement kiln ( 5) equipped with the rotary kiln (1) and clinker cooler (5b ) And a high-temperature gas supply device (14) for supplying a high-temperature gas, which is a mixture of low-temperature cooler exhaust gas (6b) generated in the clinker cooler (5b), to the external heating kiln,
A waste treatment apparatus for cement firing, comprising a dry distillation gas supply line (16) for supplying a dry distillation gas generated in an external heating kiln to a burner (5a) of a cement firing facility.   The externally heated kiln (12) includes a hollow cylindrical inclined kiln (12a) and a heating duct (12b) that indirectly heats the inclined kiln from the outside, and passes through the inclined kiln. The waste treatment apparatus for cement firing according to claim 1, wherein carbonization of the waste is performed at a high temperature.   The high temperature gas supply device (14) includes a high temperature gas supply line (14a) that mixes the chlorine bypass gas (6a) and the cooler exhaust gas (6b) and supplies the high temperature gas (6) to the external heating kiln, and a chlorine bypass It comprises a damper device (14b) provided in one or both of the gas (6a) and the cooler exhaust gas (6b), and a temperature control device (14c) that controls the temperature of the high-temperature gas by controlling the damper device. The waste treatment apparatus for cement firing according to claim 1.

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