JP5911091B2 - Cement baking equipment - Google Patents

Description

  The present invention relates to a cement firing apparatus that reduces the amount of heat required for firing a cement clinker while maintaining a high clinker production capacity.

  As shown in FIG. 2, a general cement baking apparatus includes a suspension preheater (hereinafter referred to as “preheater”) 22, a calcining furnace 23, a rotary kiln 25, a clinker cooler 26, an exhaust wind turbine 27, and the like. The

  The preheater 22 has cyclones arranged in multiple stages (four stages in this example), the cement raw material R is supplied to the inlet gas duct of the uppermost cyclone 22a, and the chute 22c connected to the raw material outlet of the lowermost cyclone 22b is a rotary kiln 25. Connected to.

  The calcining furnace 23 includes a burner (not shown) that ejects fuel F1 such as pulverized coal, and high-temperature air H from the clinker cooler 26 is introduced as combustion air.

  The rotary kiln 25 has an L / D calculated from the kiln length (L) and the inner diameter (D) of 11 to 20, and burns the decarboxylated raw material M supplied from the lowermost cyclone 22b. A burner (not shown) for ejecting the fuel F3 is provided.

  The clinker cooler 26 is provided to cool the cement clinker C discharged from the rotary kiln 25 with the cooling air A.

  The exhaust wind turbine 27 attracts the cooling air A or the like introduced into the clinker cooler 26 through the rotary kiln 25, the calcining furnace 23, and the preheater 22, and introduces it into a boiler or the like that performs waste heat power generation at the subsequent stage.

  In the cement firing device 21 having the above configuration, the cement raw material R is charged into the preheater 22 and preheated inside each cyclone, calcined in the calcining furnace 23, and calcined in the rotary kiln 25 to produce cement clinker C. . The cement clinker C discharged from the rotary kiln 25 is cooled by the clinker cooler 26 with the cooling air A and then sent to the cement pulverization process.

  However, in the cement burning device 21, the scale of the rotary kiln 25 is large, so the heat dissipated is increased, and the installation occupation area of the facility and the driving power are increased.

  Therefore, Patent Literature 1 and the like disclose a cement firing device including a preheater, a spouted bed granulation furnace (hot granulation device), a fluidized bed firing furnace, and a cooling device. In the cement baking apparatus having such a configuration, the rotary kiln is not used, so the heat dissipated can be reduced, the recovered heat from the clinker cooling apparatus can be used efficiently, and the cement powder raw material can be formed into pellets. Since the clinker firing, which is a solid-phase reaction, easily proceeds by firing after granulation, the calorific intensity of cement clinker firing can be reduced.

JP-A-62-230656

  However, in the cement firing apparatus provided with the spouted bed granulation furnace, fluidized bed firing furnace, cooling device and the like described in Patent Document 1 and the like, the required air amount increases in proportion to the increase in the clinker production amount. The clinker production amount per day is limited to a scale of about 2000 tons or less, and it is difficult to increase the size. Therefore, in order to obtain a production amount exceeding about 2000 t / d, it is necessary to install a plurality of the cement firing devices, which leads to an increase in equipment cost and operation cost.

  Therefore, the present invention has been made in view of the above-described problems in the prior art, and provides a cement firing apparatus capable of reducing the amount of heat required for cement clinker firing while maintaining high clinker production capacity. The purpose is to do.

In order to achieve the above object, the present invention provides a cement firing device, a preheater for preheating cement raw material, a hot granulating device for hot granulating the preheated cement raw material, and a kiln length (L). The L / D calculated from the inner diameter (D) is 5 or more and 10 or less, and includes a rotary kiln for firing the hot granulated cement raw material, and the hot granulation apparatus includes combustion air and spouted bed formation The exhaust gas of a clinker cooler attached to the rotary kiln is used as the working gas.

According to the present invention, since the cement raw material is granulated in a molten state by hot granulating the cement raw material at a high temperature in the hot granulator, one of the processes performed in the conventional rotary kiln is performed. The part can be carried out with a hot granulator, and the kiln length of the rotary kiln in the present invention can be reduced to about half of the conventional one . As a result, the heat dissipated from the shell of the rotary kiln can be greatly reduced, and while maintaining the clinker production capacity high, the calorific intensity of the cement clinker firing is 3 to 3 compared to when using a conventional rotary kiln. It can be reduced by about 8%.

  In addition, since the raw material supplied to the conventional rotary kiln is powder, there is a problem that the moving speed in the kiln is not stable because it adheres to the inner wall of the kiln. Therefore, since the raw material is granular, the moving speed in the kiln is relatively stable and the heat transfer is good, which leads to the reduction of the calorific value.

Furthermore, in the present invention, the amount of powder present in the clinker discharged from the rotary kiln and entering the clinker cooler is reduced, so that heat exchange between the clinker and the cooling air is improved in the clinker cooler, and the quality of the clinker is improved. At the same time, the secondary air used as the kiln combustion air becomes high temperature, and it is possible to further reduce the calorific value.
Furthermore, in the hot granulator, since the exhaust gas of the clinker cooler attached to the rotary kiln is used as the combustion air and the spouted bed forming gas, the high-temperature air generated in the cement firing device is used, so The unit can be further reduced.

  In the cement baking apparatus, a calcining furnace is provided between the preheater and the hot granulator, the cement raw material preheated by the preheater in the calcining furnace is calcined, and the calcined cement raw material is heated. Hot granulation can be performed with an intergranular granulator. According to the present invention, similar to the above-described invention, the kiln length of the downstream rotary kiln can be shortened, and by reducing the heat dissipated from the kiln shell, while maintaining the clinker production capacity high, cement clinker firing The caloric intensity can be reduced.

  Moreover, the said cement baking apparatus WHEREIN: In the said hot granulation apparatus, the said cement raw material can be granulated to 1 mm or more and 20 mm or less.

  As described above, according to the present invention, it is possible to provide a cement firing apparatus capable of reducing the amount of heat required for firing a cement clinker while maintaining a high clinker production capacity.

It is a whole lineblock diagram showing one embodiment of a cement baking apparatus concerning the present invention. It is a whole block diagram which shows an example of the conventional cement baking apparatus.

  Next, the form for implementing this invention is demonstrated in detail, referring FIG.

  FIG. 1 shows an embodiment of a cement baking apparatus according to the present invention. This cement baking apparatus 1 includes a preheater 2, a calcining furnace 3, a hot granulator 4, a rotary kiln 5, and a clinker cooler. 6 and an exhaust wind turbine 7 or the like.

  In the preheater 2, cyclones are arranged in multiple stages (four stages in the present embodiment), a cement raw material R is supplied to the inlet gas duct of the uppermost cyclone 2a, and a chute 2c connected to the raw material outlet of the lowermost cyclone 2b is provided. Connected to the hot granulator 4. The number of cyclones is not limited to four.

  The calciner 3 includes a burner 3a that ejects fuel F1 such as pulverized coal, and high-temperature air H of the clinker cooler 6 is introduced as combustion air. As the calcining furnace 3, a fluidized bed type, spouted bed type or airflow type combustion furnace can be used.

  The hot granulation apparatus 4 includes a burner 4a that ejects fuel F2 such as pulverized coal, forms a spouted layer with the high-temperature air H blown from the lower side of the apparatus, and melts the supplied cement raw material R. Provided for granulation. A chute 4 b provided at the lower part of the hot granulator 4 is connected to the rotary kiln 5.

  In the rotary kiln 5, the L / D calculated from the kiln length (L) and the inner diameter (D) is 5 to 10, and the molten granule P supplied from the hot granulator 4 is fired. A burner 5a for ejecting fuel F3 such as pulverized coal is provided.

  The clinker cooler 6 is provided for cooling the cement clinker C discharged from the rotary kiln 5, and is cooled through a lattice element having a plurality of lattice plates, a lattice beam communicating with the lattice element, the lattice beam, and the lattice element. The air supply means etc. which supply the air A to the upper direction of a lattice board are comprised.

  The exhaust wind turbine 7 attracts the cooling air A or the like introduced into the clinker cooler 6 through the rotary kiln 5, the hot granulator 4, the calcining furnace 3, and the preheater 2, and performs a subsequent waste heat power generation, It introduce | transduces into raw material systems, such as a stabilizer (humidity control tower) which temperature-controls and humidity-controls exhaust gas G2, and a dryer, a mill, etc. for producing | generating the cement raw material R supplied to the preheater 2. FIG.

  Next, operation | movement of the cement baking apparatus 1 which has the said structure is demonstrated, referring FIG.

  Cooling air A is introduced into the clinker cooler 6, the cooling air A or the like is attracted by the exhaust wind turbine 7, and the fuel F 3 ejected from the burner 5 a is used as combustion air in the rotary kiln 5. The fuel F1 ejected from the burner 3a is combusted, the fuel F2 ejected from the burner 4a is combusted by the hot granulator 4, and the temperature of the cyclone of these devices and the preheater 2 is increased.

  The cement raw material R is put into the preheater 2 and preheated inside each cyclone, and then put into the calcining furnace 3 and calcined. The calcined decarboxylated raw material M is supplied from the calcining furnace 3 to the hot granulator 4 through the lowermost cyclone 2b and the chute 2c.

  The inside of the hot granulator 4 becomes about 1300 ° C. by the combustion of the fuel F 2 ejected from the burner 4 a, and the decarbonation raw material M is melted at the center inside the hot granulator 4 while the clinker cooler 26. A spouted layer is formed by the high-temperature air H from which the particle size is adjusted, and a molten granulated product P having a particle size of about 1 mm to 20 mm is obtained. The molten granulated product P is put into the kiln bottom of the rotary kiln 5 through the chute 4b and is baked in the rotary kiln 5 to generate cement clinker C. The cement clinker C discharged from the rotary kiln 5 is cooled by the cooling air A by the clinker cooler 6 and then sent to the cement pulverization step.

  As described above, in the present embodiment, since the cement raw material is melted and granulated by the hot granulator 4, the kiln length of the downstream rotary kiln 5 can be shortened. Thereby, the heat dissipated from the shell of the rotary kiln 5 can be greatly reduced while maintaining the clinker production capacity high, and the amount of heat required for firing the cement clinker can be greatly reduced.

In the above embodiment, the cement firing apparatus 1 is provided with the calcining furnace 3.
It is also possible to perform both calcination of the cement raw material R and hot granulation in the hot granulation apparatus 4 without providing the above .

DESCRIPTION OF SYMBOLS 1 Cement baking apparatus 2 Preheater 2a Uppermost cyclone 2b Lowermost cyclone 2c Chute 3 Calcining furnace 3a Burner 4 Hot granulator 4a Burner 4b Chute 5 Rotary kiln 5a Burner 6 Clinker cooler 7 Exhaust windmill

Claims (3)

A preheater for preheating cement raw materials;
A hot granulator for hot granulating the preheated cement raw material;
L / D calculated from kiln length (L) and inner diameter (D) is 5 or more and 10 or less, and includes a rotary kiln for firing the hot granulated cement raw material,
The hot granulation apparatus uses a clinker cooler exhaust gas attached to the rotary kiln as combustion air and spouted bed forming gas.   A calcining furnace is provided between the preheater and the hot granulator, the cement raw material preheated by the preheater in the calcining furnace is calcined, and the calcined cement raw material is heated by the hot granulator. The cement baking apparatus according to claim 1, wherein granulation is performed between the two. In a granulator between they said heat cement burning device according to claim 1 or 2, characterized in that granulating the cement raw material 1mm 10mm or more or less.

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