JP4993585B2 - Cement clinker firing method and cement clinker firing device - Google Patents

Description

  The present invention relates to a cement clinker firing method and a cement clinker firing apparatus, and more particularly to a method and apparatus for firing a cement clinker using a low flash point fuel such as a waste solvent.

  Conventionally, attempts have been made to reduce the basic unit of expensive fossil fuels in cement production while using various wastes as substitutes for fuel in the cement production process, contributing to waste disposal. For example, in Patent Document 1, waste plastic and waste oil are mixed, and the slurry mixture is fed to an auxiliary fuel burner inserted in the center of a main fuel (pulverized coal) burner of a rotary kiln to assist the auxiliary fuel burner. A method of manufacturing a cement clinker that is blown into a rotary kiln from a fuel outlet and burned has been proposed.

  On the other hand, in Patent Document 2, when a waste oil having a low flash point generated by a tanker or the like is subjected to a combustion treatment, a high flash point oil is added to the waste oil to form a mixed oil, and the flash point of the mixed oil is investigated to obtain a target. A combustion method for waste oil is proposed in which combustion is performed as it is when the flash point is higher than the target flash point, and when the flash point is lower than the target flash point, high flash point oil is added to the mixed oil to increase the flash point and then burned. ing.

JP 2003-192406 A JP 57-2922 A

  As mentioned above, various wastes are conventionally used as a substitute for fuel in the cement manufacturing process. However, for waste solvents containing acetone, gasoline, alcohols, kerosene, light oil, and other organic solvent components, the flash point However, it was not considered a substitute for fuel in the cement manufacturing process because it was necessary to take measures against explosions.

  Therefore, the present invention achieves both waste treatment and reduction of fuel intensity in the cement manufacturing process by using low flash point fuel such as waste solvent as a substitute for fuel in the cement manufacturing process. An object of the present invention is to provide a cement clinker firing method and a cement clinker firing apparatus.

In order to achieve the above object, the present invention is a method for firing a cement clinker, in which a main fuel is blown from a main fuel flow path of a cement kiln burner, and a liquid disposed inside the main fuel flow path A low flash point fuel having a flash point of less than 21 ° C. is blown from the fuel flow path.

And according to the present invention, the low flash point fuel having a flash point of less than 21 ° C. can be used as a substitute for the fuel in the cement manufacturing process, so that waste processing such as waste solvent can be achieved, The low flash point fuel is blown from the liquid fuel flow path located inside the main fuel flow path such as oil coke powder, so that both fuels are mixed well and burned with high efficiency. It is also possible to reduce the fuel consumption rate.

In the above-described cement clinker firing method, an air flow path provided with a swirling means for air flow is provided between the main fuel flow path and the liquid fuel flow path, and the flow rate of air flowing through the air flow path is adjusted. can do. This adjusts the mixing state of the air flow, pulverized coal, etc. flowing through the main fuel flow path, and the low flash point fuel having a flash point of less than 21 ° C. , thereby optimizing the frame state in the cement kiln. It is possible to further improve the firing efficiency of the cement clinker.

  In the cement manufacturing fuel firing method, a swirling means may be provided in the main fuel flow path to swirl the main fuel flow. According to this, the combustibility of solid powder fuel such as pulverized coal can be improved, and the firing efficiency of the cement clinker can be further improved.

In the method for firing cement manufacturing fuel, the solid waste fuel can be blown from the solid waste fuel flow path disposed inside the main fuel flow path. According to this, since the solid waste fuel can be burned so as to be wrapped with the low flash point fuel having a flash point of less than 21 ° C. , the combustion efficiency of the solid waste other than the liquid waste such as the waste solvent is improved. It becomes possible to process simultaneously while improving, and it becomes possible to improve the processing efficiency of the whole waste.

Further, the present invention is a cement clinker firing device, wherein a plurality of concentric flow paths are provided, a main fuel flow path, and a liquid fuel flow path disposed inside the main fuel flow path, And a supply means for supplying a main fuel to the main fuel flow path and a low flash point fuel having a flash point of less than 21 ° C. to the liquid fuel flow path. . According to the present invention, as in the case of the above-described invention, it is possible to simultaneously treat waste such as a waste solvent and reduce the fuel consumption in the cement manufacturing process.

  In the cement clinker firing apparatus, an air flow path provided between the main fuel flow path and the liquid fuel flow path and provided with an air flow swirl means, and an air flow rate of the air flow path are adjusted. And adjusting means.

  In the cement clinker firing apparatus, the main fuel flow path can be configured to include a turning means for turning the main fuel flow.

  The cement clinker firing apparatus includes a solid waste fuel flow path disposed inside the main fuel flow path, and supply means for supplying the solid waste fuel to the solid waste fuel flow path. Can be configured.

As described above, according to the present invention, a low flash point fuel having a flash point of less than 21 ° C. can also be used as a substitute for fuel in the cement manufacturing process. It is possible to simultaneously achieve a reduction in fuel intensity in the manufacturing process.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an embodiment of a cement clinker firing apparatus according to the present invention. This cement clinker firing apparatus 1 is roughly divided into a burner 2, a main fuel tank 3, a low flash point fuel tank 4, and a first A solid waste fuel tank 5, a second solid waste fuel tank 6, a fan 7 and the like are provided, and various types of fuel are blown into the cement kiln 8 and burned to burn the cement clinker.

  As shown in FIGS. 2 and 3, the burner 2 includes a plurality of concentric flow paths, a main fuel flow path 21, an air flow path 22 disposed inside the main fuel flow path 21, and A liquid fuel flow path 23, a first solid waste fuel flow path 24, and a second solid waste fuel flow path 25 are provided inside the air flow path 22. A plurality of swirl vanes 21 a and 22 a that swirl the fuel flow and air flow of each flow path are fixed to the main fuel flow path 21 and the air flow path 22.

  The main fuel tank 3 is provided for temporarily storing a solid powder fuel as a main fuel, and stores, for example, pulverized coal obtained by drying and pulverizing coal. A main fuel tank 3 shown in FIG. 1 includes a blower 9 for pumping pulverized coal discharged from the main fuel tank 3 and a conduit 10 for introducing the pulverized coal into the main fuel flow path 21 of the burner 2. And are attached.

The low flash point fuel tank 4 is provided for temporarily storing the low flash point fuel, and stores waste solvent or the like as the low flash point fuel . The lower the flash point of the low flash point fuel, the better the combustibility. Therefore, the low flash point fuel used here is combustible classified as the first petroleum defined by the Fire Service Act with a flash point of less than 21 ° C. Liquid.

The low flash point fuels, specifically, acetone, gasoline, waste solvents contain other organic solvent components of that or the like. In addition, the low flash point fuel is not limited to a liquid waste solvent or the like, but includes those in the state of an emulsion, a slurry, or the like. In addition, when low flash point fuels of different types or even of the same type are mixed and stored in the low flash point fuel tank 4, the contained substances react with each other to generate heat, precipitate, solidify, etc. Therefore, before mixing and storing these low flash point fuels, perform a premix test with a small amount of sample to check for heat generation, precipitation, solidification, etc. It is desirable to keep it. The low flash point fuel tank 4 is provided with a pump 11 for supplying low flash point fuel and a pipe 12 for introducing the low flash point fuel into the liquid fuel flow path 23 of the burner 2.

  The first solid waste fuel tank 5 is provided for temporarily storing solid waste fuel. As the solid waste fuel, waste fuel such as biomass and meat-and-bone meal can be used. Biomass is a biological organic resource (but excluding fossil fuel) that can be used as a fuel, such as waste crushed ground, construction waste wood ground, wood powder and sawdust. Applicable. The first solid waste fuel tank 5 includes a blower 13 for pumping the solid waste fuel discharged from the first solid waste fuel tank 5, and the solid waste fuel as the first solid waste fuel of the burner 2. A conduit 14 for introduction into the working channel 24 is attached.

  The second solid waste fuel tank 6 is the same as the first solid waste fuel tank 5 and stores waste fuel such as biomass and meat-and-bone meal. The second solid waste fuel tank 6 includes a blower 15 for pumping the solid waste fuel discharged from the second solid waste fuel tank 6, and the solid waste fuel as the second solid waste fuel of the burner 2. A pipe line 16 for introduction into the use flow path 25 is attached.

  The types of solid waste fuel stored in the first and second solid waste fuel tanks 5 and 6 may be the same or different. When different types of solid waste fuel are stored in the first and second solid waste fuel tanks 5 and 6, the waste fuel stored in the first solid waste fuel tank 5 and the second solid fuel The waste fuel stored in the waste fuel tank 6 may be mixed in the middle of the pipelines 14 and 16 and supplied to the burner 2 in a mixed state.

  The fan 7 is provided for supplying air to the burner 2, and the fan 7 is provided with a pipe line 17 for introducing the air blown from the fan 7 into the air flow path 22 of the burner 2. A damper 18 for controlling the air flow rate in the pipe 17 is provided in the middle of the pipe 17.

  In the cement clinker firing apparatus 1 having the above-described configuration, after each fuel is stored in the main fuel tank 3, the low flash point fuel tank 4, the first solid waste fuel tank 5, and the second solid waste fuel tank 6, the blower 9, 13, 15 and the pump 11 are operated to supply the fuel stored in the fuel tanks 3 to 6 to the burner 2. In parallel with this, the fan 7 is operated and blown to the burner 2.

  Then, at the same time as the pulverized coal is blown from the main fuel flow path 21 of the burner 2, the low flash point fuel, the first, from the liquid fuel flow path 23, the first and second solid waste fuel flow paths 24, 25. And the second solid waste fuel is blown, and each fuel is burned in the cement kiln 8 to burn the cement clinker. At this time, the use ratio of the low flash point fuel in the total fuel for the kiln burner is preferably 10 to 90%. When the ratio of the low flash point fuel is less than 10%, the fuel raw material in the cement manufacturing process is used. On the other hand, when the unit reduction effect is small and exceeds 90%, there is a problem that the brightness of the flame is insufficient and sufficient radiant heat transfer cannot be given to the object to be fired.

  Further, at the time of fuel combustion in the cement kiln 8, it is preferable to adjust the flow rate of the swirling air flow from the air flow path 22 of the burner 2 via the damper 18 so as to optimize the frame state in the furnace. Specifically, when a low flash point fuel is used, the cement clinker tends to be fired on the front side of the kiln, so it is effective to lengthen the flame.

  Next, when low flash point fuel is used in combination with main fuel and solid waste fuel (Example), and when low flash point fuel is not used and only main fuel and solid waste fuel are used (Comparative Example) A test example will be described. Table 1 shows the test results of the firing tests of the cement clinker of Examples and Comparative Examples. In addition, the low flash point fuel of an Example used the waste solvent (refer Table 2) which contains benzene as a main component and has a real calorific value of about 9000 kcal / kg. In addition, as the first and second solid waste fuels, biomass and meat-and-bone meal were used in both Examples and Comparative Examples.

  From Table 1, the examples show that the clinker f. It turns out that CaO is falling. This is because a solid fuel such as pulverized coal with insufficient volatile matter and a low flash point fuel with insufficient flame brightness are burned in a mixed state to compensate for the shortcomings of both fuels and to obtain an appropriate combustion state. Therefore, the flammability of pulverized coal can be improved, a frame with a short black zone can be formed, and the radiant heat necessary to fire high-quality cement clinker can be obtained without maintaining the combustion temperature excessively high. It can be obtained sufficiently, and it is estimated that this is a result of improved clinker firing efficiency.

In addition, the use of low flash point fuel not only reduces the amount of pulverized coal used as the main fuel, but also improves the combustibility, thereby reducing the fuel intensity in the cement manufacturing process considering the entire fuel. It became possible to reduce it. According to a trial calculation, the combustion contribution ratio of the waste solvent calculated by the following formula was 107%.
Waste solvent combustion contribution rate = (coal loss associated with waste solvent x coal calorific value) / (waste solvent usage x waste solvent calorific value)

As described above, according to the present embodiment, a low flash point fuel having a flash point of less than 21 ° C. can be used as a fuel for cement production while maintaining a high quality cement clinker. It becomes possible to process the waste of this.

In the above embodiment, solid waste fuel is used in combination with pulverized coal and low flash point fuel having a flash point of less than 21 ° C. , but it is not always necessary to use solid waste fuel. The cement clinker may be fired using only a low flash point fuel having a flash point of less than 21 ° C.

  Further, one or two air flow paths are further provided outside the main fuel flow path 21 so that adjustment for obtaining an optimum flame can be easily performed according to the type of solid powder fuel used. You can also do it.

It is the schematic which shows one Embodiment of the cement clinker baking apparatus concerning this invention. It is a front view which shows the burner of FIG. FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2 (in order to clarify the cross-sectional structure, the thickness of the burner member and the refractory shown in FIG. 2 are omitted).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cement clinker baking apparatus 2 Burner 3 Main fuel tank 4 Low flash point fuel tank 5 First solid waste fuel tank 6 Second solid waste fuel tank 7 Fan 8 Cement kiln 9 Blower 10 Pipe line 11 Pump 12 Pipe line 13 Blower 14 Pipe line 15 Blower 16 Pipe line 17 Pipe line 18 Damper 21 Main fuel flow path 21a Swirling blade 22 Air flow path 22a Swirling blade 23 Liquid fuel flow path 24 First solid waste fuel flow path 25 Second solid waste Fuel flow path

Claims (8)

The main fuel is blown from the main fuel flow path of the cement kiln burner, and the low flash point fuel having a flash point of less than 21 ° C. is blown from the liquid fuel flow path disposed inside the main fuel flow path. A method for firing cement clinker, which is characterized.   The air flow path provided with an air flow swirling means is provided between the main fuel flow path and the liquid fuel flow path, and the flow rate of air flowing through the air flow path is adjusted. 2. A method for firing a cement clinker according to 1.   The cement clinker firing method according to claim 1 or 2, wherein swirling means is provided in the main fuel flow path to swirl the main fuel flow.   4. The method for firing cement clinker according to claim 1, wherein solid waste fuel is blown from a solid waste fuel flow path disposed inside the main fuel flow path. A cement kiln burner having a plurality of concentric flow paths, a main fuel flow path, and a liquid fuel flow path disposed inside the main fuel flow path,
A cement clinker firing apparatus comprising: a supply means for supplying main fuel to the main fuel flow path and supplying low flash point fuel having a flash point of less than 21 ° C to the liquid fuel flow path. An air flow path provided between the main fuel flow path and the liquid fuel flow path, and provided with an air flow swirling means;
6. The cement clinker firing apparatus according to claim 5 , further comprising an adjusting means for adjusting an air flow rate of the air flow path. The cement clinker firing apparatus according to claim 6 , wherein the main fuel flow path includes swirling means for swirling the main fuel flow. A solid waste fuel flow path disposed inside the main fuel flow path;
The cement clinker firing apparatus according to claim 5, 6 or 7 , further comprising supply means for supplying the solid waste fuel to the solid waste fuel flow path.

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