JPH0442843A - Production of cement and apparatus therefor - Google Patents

Abstract

PURPOSE:To eliminate the steps for adjusting the particle size of clinker and the crushing and classification of cooled clinker by accompanying (semi)molten cement clinker to a spray gas ejected through a nozzle to effect the quenching of the clinker. CONSTITUTION:Cement clinker fired in a rotary kiln 2 of a cement production apparatus 1 is passed through a flame of a burner 3 to obtain a molten or semi-molten clinker, which is introduced into a keeping furnace 4 and kept in the above state. The clinker is passed through an outlet hole 12 and a melt- channel 13 of a nozzle 5 by energizing a blower fan 20, ejected through a nozzle 14 and quickly cooled and solidified. The spherical particles of the clinker formed the surface tension are stored in a storage chamber 7. The size of the obtained clinker particles can be adjusted to a desired level by controlling the amount and flow rate of the gas, blasted through the spray nozzles 17... of a spraying apparatus 15. A part of the spray gas heated at a high temperature by contacting with the clinker is sucked into a return pipe 9 and returned to a line 8.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a cement manufacturing method and an apparatus for manufacturing the same, which improve the cooling method of cement clinker and make it possible to manufacture superior cement.

[Prior art j] Conventionally, in order to produce cement such as Portland cement, raw materials were crushed and supplied to a suspension preheater for preheating, which was then fired in a rotary kiln, and then the resulting cement clinker was pulverized in a cooler.
quench with air.

Then, gypsum powder is added to the cooled cement clinker, and this is further pulverized again using a tube mill or the like to obtain cement of a desired particle size.

In other words, in this cement manufacturing method,
When cooling the cement clinker after firing, as mentioned above, simply send air from the cooler and bring it into contact with it.
This is because the cement talin force is rapidly cooled.

"Problems to be Solved by the Invention" By the way, in the case of cement clinker obtained by rapid cooling in this way, for example, in the case of cement clinker obtained by cooling with an air quenching cooler, its size is Usually, the average particle size is several IQcz to several CI
It becomes I+. However, in order to adjust the cement talin strength after cooling to the desired particle size, it is usually necessary to feed these clinkers into a tube mill or the like over a certain amount (for example, several Clinkers).
1+ or less) must be coarsely pulverized in advance to adjust the particle size to a certain level. Therefore, in the above-described method, the cooled cement clinker must be coarsely pulverized before being put into a tube mill or the like, which makes the manufacturing process complicated and makes continuous production difficult.

In order to solve this inconvenience, the inside of the tube mill is divided into two chambers, and coarse grinding is performed in the front chamber, and fine grinding is carried out in the back chamber. However, the process is still complicated, and the cement clinker obtained by crushing in this way is
Because it becomes angular in shape due to crushing,
Due to the large frictional resistance between particles, there is a problem in that fluidity and filling properties are slightly inferior when cement and water are kneaded.

"Means for Solving the Problem" Therefore, in the method for manufacturing cement according to claim 1 of the present invention, a spray gas is injected from a nozzle, and a molten or semi-molten cement clinker is entrained in the spray gas. A means for solving the above problem is to scatter the cement clinker from a nozzle, thereby rapidly cooling and solidifying the cement clinker.

The cement manufacturing apparatus according to claim 2 further includes a holding furnace that receives the cement clinker in a molten or semi-molten state in a rotary kiln or a vertical kiln and holds the cement clinker in a molten or semi-molten state; A nozzle that communicates with the cement clinker to eject the cement clinker, an injection gas that entrains the cement talin force guided into the nozzle and injects it outside the nozzle to scatter and cool it, and an injection means that injects the injection gas. The solution to the above problem is to include the following.

In the cement manufacturing apparatus according to claim 3, in the cement manufacturing apparatus according to claim 2, there is provided a storage chamber for receiving the cement clinker and the injection gas ejected from the nozzle, and a storage chamber for receiving the cement clinker and jet gas ejected from the nozzle, and a The solution to the above problem is to provide a return path for returning the exhaust gas in the storage chamber from the storage chamber.

"Operation" According to the method for producing cement according to claim 1 of the present invention, the cement clinker in a molten or semi-molten state is scattered from the nozzle by being entrained in the spray gas, and is rapidly cooled. Since the force is coagulated into a spherical powder, it is possible to control the particle size (dimensions) and sphericity (shape) of the cement clinker obtained by controlling the flow rate and velocity of the atomizing gas.

Further, according to the cement manufacturing apparatus according to the second aspect, the manufacturing method according to the first aspect can be carried out suitably.

Furthermore, according to the cement manufacturing apparatus according to claim 3, a part of the spray gas that is injected together with the cement clinker from the nozzle and is heated to a high temperature by contacting the molten or semi-molten cement clinker, Since the cement clinker is returned to the channel through the return channel, the cement clinker heated to a molten or semi-molten state is prevented from cooling and solidifying in the channel.

Embodiment FIGS. 1 and 2 are diagrams showing an embodiment of the manufacturing apparatus according to claims 2 and 3 of the present invention, and in FIG. 1, reference numeral 1 indicates a cement manufacturing apparatus. This cement manufacturing equipment 1 (hereinafter abbreviated as manufacturing equipment 1) includes a rotary kiln 2, a burner 3 that generates a flame in an outlet 2a of the rotary kiln 2, and a cement clinker that receives cement clinker from the rotary kiln 2. A holding furnace 4 that holds the material in a molten or semi-molten state, a nozzle 5 communicating with the holding furnace 4, an injection means 6 provided in the nozzle 5, a storage chamber 7 provided in the ejection direction from the nozzle 5, The holding furnace 4 is provided in the storage chamber 7 and is connected to the rotary kiln 2.
It generally consists of a return pipe 9 that communicates with a path 8 to the pipe.

Rotary kiln 2 has a suspension system that preheats the raw material powder.
This is placed on the downstream side of the suspension heater (path shown), and is used to fire the raw material powder that has been preheated and calcined by the suspension preheater. A burner 3 is disposed on the discharge side of the rotary kiln 2. Burner 3 uses combustible gases such as propane butane, propylene, acetone, and hydrogen, liquid fuels such as heavy oil and light oil, or petroleum, and even solid fuels such as oil coke. A combustion-supporting gas is supplied to eject a high-temperature flame from the crater 3a, and a fuel supply section 10 and a combustion-supporting gas introduction section 11 are respectively arranged on the side opposite to the crater 3a. be. Moreover, this burner 3 is arranged so that its fire port 3a is directed toward the discharge port 2a of the rotary kiln 2, thereby generating a flame within the discharge port 2a, and the cement clinker discharged from the rotary kiln 2 is It is used to make it into a molten or semi-molten state using flame.

The holding furnace 4 houses the cement clinker derived from the rotary kiln 2 in a molten or semi-molten state,
The cement clinker is kept in a molten or semi-molten state, and is equipped with high-frequency heating means, electric heating means, etc.
It is possible to maintain the temperature at about 1600°C.

This holding furnace 4 has a lead-out hole 12 formed in its bottom portion and penetrating from the inside of the furnace to the bottom side.

Further, the manufacturing apparatus 1 is provided with a nozzle 5 communicating with the outlet hole 12 of the holding furnace 4. As shown in FIG. 2, this nozzle 5 has a molten metal flow path 13 in its center that communicates with the outlet hole 12, and a spout 14 at the tip of the molten metal flow path 13, which will be described later. The spray device sprays molten or semi-molten cement clinker from the spout 14 and rapidly cools and solidifies the cement clinker. Here, the nozzle 5 is connected to the holding furnace 4
It may be directly attached to the bottom surface of the tube, or it may be indirectly attached via a molten metal flow pipe (not shown). Further, the molten metal flow path 13 communicating with the outlet hole 12 may be configured so that the molten or semi-molten cement clinker stored in the holding furnace 4 is ejected by falling naturally due to its own weight, or the molten metal flow path The cement clinker may be forcibly ejected by pressurizing the inside of the cement clinker 13 or the like. In addition,
If it is installed indirectly through a molten metal flow pipe, the molten metal flow pipe is provided with heat retention means or heating means, and the cement clinker
Of course, it must be maintained in a molten or semi-molten state. In addition, this nozzle 5 has
A spray device 15 is provided for introducing the spray gas.

This spraying device 15 serves as the above-mentioned spraying means 6, and as shown in FIG. A plurality of spray nozzles 17 (second
The control section (not shown) controls the flow rate and flow velocity of the spray gas ejected from the spray nozzle 17. The spray nozzles 17 are oriented so that their injection ports 18 are concentrated at a point P on the extension line from the injection port 14 of the molten metal flow path 13, and each of these spray nozzles 17 The positions of the spray nozzles 17, 17, which are centrally opposed to each other, are arranged point-symmetrically. The control section is composed of a needle valve and the like for regulating the flow rate of the pressurized gas, and is composed of a known flow rate adjustment means.

Further, a storage chamber 7 is provided below the holding furnace 4 in the jetting direction of the nozzle 5 . This storage chamber 7 is connected to the nozzle 5
This is for storing the cement clinker ejected from the tank and the cement clinker rapidly solidified by receiving the injection gas, and guiding it to a storage tank (not shown). A pipe (return path) 9 is connected.

The return pipe 9 has a separator 19 and a blower fan 20 installed therein, and is piped so as to communicate with the path 8 from the rotary kiln 2 to the holding furnace 4. When activated, the exhaust gas in the storage chamber 7 is sucked, and the cement talin force entrained in this exhaust gas is
After being separated by the separation device 19, this is returned to the route 8. Here, the cement clinker separated from the exhaust gas in the separator 19 is guided to a storage tank (not shown) and joins the cement clinker from the storage chamber 7.

Next, a method according to claim 1 will be explained based on a method for manufacturing cement clinker using the manufacturing apparatus 1 having such a configuration.

First, the cement clinker fired in the rotary kiln 2 is passed through the high-temperature flame of the burner 3 in its discharge port 2a, is molten or semi-molten, and is sent to the holding furnace 4, and then inside the holding furnace 4. The cement clinker is maintained in a molten or semi-molten state.

Next, this cement clinker is passed through the outlet hole 12 and the molten metal channel 13 of the nozzle 5 and is injected from the spout 14. At the same time, the spray nozzle 17... The atomizing gas is injected while controlling the flow rate and flow velocity of the atomizing gas. In this case, in order to control the spray gas, it is necessary to conduct experiments to determine the relationship between the flow rate and flow velocity and the solidification of the cement clinker and its spheroidization, and then determine the flow rate and flow velocity of the spray gas based on the results. preferable.

When the atomizing gas is injected in this way, the cement clinker injected from the ejection port 14 receives the atomizing gas from around the point P on the extension line of the molten metal flow path 13, and as a result, the cement clinker is injected from the atomizing gas. It is entrained and scattered in a conical shape as shown in FIG. 2, and is rapidly cooled and solidified into a spherical powder. That is, when the cement clinker is entrained in the spray gas and scattered, it becomes minute droplets, which solidify by being further rapidly cooled and become spheroidized by the surface tension. Regarding the spherical cement clinker obtained by solidification, it is preferable that its shape, that is, its sphericity, be closer to a true sphere in terms of fluidity and filling properties, and its size, that is, its particle size, should also be similar to that of a true sphere. The average particle size is 10 to 50 from the viewpoint of
It is preferable that the particle diameter be about μ shoulder, and therefore, in controlling the flow rate and flow velocity of the above-mentioned atomizing gas, it is desirable to control the sphericity and particle size so as to obtain the above-mentioned sphericity and particle size.

Further, at the same time as these operations are performed, the blower fan 20 is activated. Then, a part of the spray gas that is injected from the nozzle 5 together with the cement clinker and heated to a high temperature by contacting the molten or semi-molten cement clinker is sucked into the return pipe 9. Then, the cement clinker entrained in the gas is separated by a separator 20 and then returned to the path 8. Therefore, the cement clinker heated to a molten state or a semi-molten state by the burner 3 is not cooled in the path 8 housed in the holding furnace 4, and the return gas (a part of the spray gas) heated to the high temperature is
It is kept warm by the following steps and introduced into the holding furnace 4 while maintaining its molten state or semi-molten state.

Thereafter, the obtained cement clinker is taken out from the storage chamber 7, and an appropriate amount of gypsum powder is mixed with it to obtain cement.

In such a manufacturing apparatus 1, as described above in connection with the manufacturing method using the same (by controlling the flow rate and velocity of the atomizing gas, the desired particle size (dimensions) and spherical shape of the obtained cement clinker can be obtained. In addition, the obtained spherical cement clinker has less frictional resistance between particles due to its spherical shape, and therefore has better fluidity than conventional cement talin force. In addition, the particle size control results in good filling properties.

Furthermore, since the cement clinker that has been molten or semi-molten by the burner 3 is kept warm by the return gas and introduced into the holding furnace 4, there is no need to re-melt the once solidified cement clinker in the holding furnace 4. Since it is sufficient to simply maintain the molten state or semi-molten state, the amount of heat consumed in the holding furnace 4 is small, and therefore an increase in the overall energy cost can be suppressed.

In the above embodiment, a rotary kiln was used as a device for extracting the fired cement clinker, but a vertical window may be used instead.

Further, in the above embodiment, the cement talin was melted or semi-molten by the high-temperature flame of the burner 3, but the present invention is not limited to this, and instead of the burner 3, other heating means may be used. , the cement clinker may be in a molten or semi-molten state.

"Effects of the Invention" As explained above, the method for producing cement according to claim 1 of the present invention is such that cement clinker in a molten or semi-molten state is entrained in a spray gas, so that it is scattered from a nozzle and rapidly cooled. Since the cement clinker is solidified into a spherical powder, the resulting cement clinker can be adjusted to the desired particle size by controlling the flow rate and velocity of the atomizing gas. Productivity can be increased by eliminating the need for a classification process. In addition, by controlling the flow rate and velocity of the atomizing gas, it is possible to adjust the resulting cement clinker to the desired sphericity, resulting in less frictional resistance between particles, which improves fluidity compared to conventional cement. Also, by controlling the particle size, it is possible to produce spherical cement with improved filling properties.

Further, the cement manufacturing apparatus according to claim 2 is suitable for carrying out the manufacturing method according to claim 1,
In addition, when spherical cement is produced using this method, there is no need for a pulverization process after cooling, so cement clinker can be processed continuously and in large quantities, making it possible to produce cement clinker with excellent spherical properties at a low cost. It can be manufactured in

In the cement manufacturing apparatus according to claim 3, a part of the atomized gas that is injected together with the cement clinker from the nozzle and is heated to a high temperature by contacting the molten or semi-molten cement clinker is sent to the return path. Since the cement clinker is heated to a molten or semi-molten state, it can be prevented from cooling and solidifying in the passage, thereby reducing heat consumption in the holding furnace. This makes it possible to suppress the rise in overall energy costs and reduce production costs.

[Brief explanation of the drawing]

1 and 2 are diagrams showing an embodiment of the cement manufacturing apparatus according to claims 2 and 3 of the present invention, in which FIG. 1 is a schematic configuration diagram of the manufacturing apparatus, and FIG. 2 is a schematic diagram of a nozzle. FIG. 3 is a side sectional view showing the configuration. 1... Cement production equipment, 2... Rotary kiln, 4... Holding furnace, 5...
・Nozzle, 6-・Injection means, 7...Storage chamber, 8
Route, 9-Return pipe, 15--Spray device.

Claims (3)

[Claims] (1) Spray gas is injected from a nozzle, and molten or semi-molten cement clinker is entrained in the spray gas to scatter the cement clinker from the nozzle, thereby rapidly cooling and solidifying the cement clinker. A method for producing cement, characterized by: (2) In a cement manufacturing apparatus equipped with a rotary kiln or a vertical kiln, a holding furnace that receives molten or semi-molten cement clinker in the rotary kiln or vertical kiln and holds it in a molten or semi-molten state; , a nozzle communicating with the holding furnace to eject the cement clinker; an injection gas that entrains the cement clinker guided into the nozzle and injects it outside the nozzle to cool it by scattering; and an injection gas that injects the injection gas. 1. A cement manufacturing device comprising a jetting means. (3) The cement manufacturing apparatus according to claim 2, further comprising a storage chamber for receiving cement clinker and injection gas ejected from the nozzle; A cement manufacturing device characterized by having a return path for returning exhaust gas.