JPH0729068B2 - Pre-milling mill exhaust gas condensation prevention device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for preventing dew condensation of exhaust gas from a preliminary crushing mill in a facility for crushing a mixed raw material such as cement by a preliminary crushing mill and a secondary crushing mill in two stages. .

[Prior Art] For example, in the case of producing a crushed and mixed product such as cement, a baked clinker is mixed with gypsum and limestone containing 10 to 20% of water by a mill and crushed.

In addition, the exhaust gas from the mill is removed by a filter to prevent pollution.

[Problems to be Solved by the Invention] However, since the dust in the exhaust gas has substantially the same composition as the cement and also contains water vapor, dew condensation occurs when the temperature of the exhaust gas falls below the dew point of the water vapor, causing dew condensation. The water comes into contact with the dust having substantially the same composition as the cement captured in the filter, and the dust is hardened to rapidly impair the function of the filter.

Further, even if the dust is not the same composition as the cement, the water condensed by the filter becomes sticky and the dust collecting function deteriorates.

In order to prevent this, it is necessary to raise the temperature of the exhaust gas to be equal to or higher than the dew point of water vapor, and it is necessary to input a large amount of heat energy from the outside.

The present invention has been made in view of such a situation, in a facility for pulverizing a mixed raw material such as cement in two stages by a preliminary pulverizing mill and a secondary pulverizing mill, the preliminary pulverizing mill without inputting a large amount of heat energy from the outside. The purpose is to keep the exhaust gas above the dew point temperature.

[Means for Solving the Problem] The present invention provides a damper in which a secondary crushing mill exhaust gas flow path is connected to a preliminary crushing mill, and a branch flow path branched from the secondary crushing mill exhaust gas flow path can be adjusted in opening degree. The present invention relates to a device for preventing dew condensation of exhaust gas from a preliminary crushing mill, which is connected to an exhaust gas flow path from the preliminary crushing mill.

[Operation] Therefore, in the present invention, by introducing the secondary pulverizing mill exhaust gas, which has been heated to a high temperature by the heat energy naturally generated in the secondary pulverizing mill, into the preliminary pulverizing mill, the preliminary pulverizing mill is connected to the preliminary pulverizing mill exhaust gas passage. Condensation of the exhaust gas of the preliminary crushing mill can be prevented by raising the exhaust gas of the preliminary crushing mill to a temperature above the dew point temperature.

At this time, by adjusting the opening of the damper of the branch flow path, a part of the exhaust gas of the secondary pulverizing mill is branched and the flow rate of the exhaust gas of the secondary pulverizing mill leading to the preliminary pulverizing mill is suppressed to the necessary minimum. It is possible to suppress the pressure loss caused by passing through the mill, and thus it is possible to suppress the pressure loss of the entire exhaust gas system to the necessary minimum. On the other hand, on the side of the preliminary crushing mill exhaust gas flow path, the secondary crushing mill exhaust gas with a relatively high temperature from the branch flow path is introduced in the middle thereof, so that the temperature of the preliminary crushing mill exhaust gas is raised again immediately before dust removal. As a result, the function of the dust remover is prevented from deteriorating due to dew condensation.

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

FIG. 1 shows an embodiment of the present invention, in which a raw material supply conveyor 3 is provided above a raw material input port 2 of a preliminary crushing mill 1 and a raw material crushed by the preliminary crushing mill 1 is fed to a secondary crushing mill 4. Send it for further fine crushing. The exhaust gas flow path 5 of the secondary crushing mill 4 is connected to the preliminary crushing mill 1 through the raw material charging port 2, the secondary crushing mill exhaust gas flow path 5 is branched, and the branched flow path 6 is subjected to the preliminary crushing. It is connected to the exhaust gas passage 7 of the mill 1 and a damper 8 is provided in the branch passage 6 so that the opening degree can be adjusted. In the figure, 9 indicates a dust remover and 10 indicates a fan.

With the above-described structure, for example, a supply ore containing about 1% of water is supplied from the raw material inlet 2 to the preliminary crushing mill 1 at a flow rate of 150 tons per hour and crushed by the preliminary crushing mill 1. Evaporated water in 1 is Becomes

The supplied ore crushed by the preliminary crushing mill 1 is sent to the secondary crushing mill 4 and further crushed. In the secondary crushing mill 4, the driving energy and the mechanical frictional force are converted into heat energy to raise the temperature, so that the exhaust gas discharged from the secondary crushing mill 4 reaches about 100 ° C. and is discharged at 1000 m ^{3 /} min. It The evaporated water in the exhaust gas of the secondary crushing mill is the same as the preliminary crushing mill 1.
It contains almost the same amount of water as the carrier air.

Therefore, when the damper 8 causes 70% of the exhaust gas of the secondary crushing mill to flow into the exhaust gas passage 7 of the preliminary crushing mill and 30% of the exhaust gas is introduced into the preliminary crushing mill 1, the exhaust gas of the secondary crushing mill is introduced into the preliminary crushing mill 1. The evaporated water of Becomes

The exhaust gas of the preliminary crushing mill is about 100 ° C. and 300 m ³ / min, the evaporated water is the total amount of evaporated water in the exhaust gas of the secondary crushing mill introduced with the evaporated water from the supply ore, that is, 40 m ³ / min,
The dew point temperature is about 60 ℃.

As a result, the exhaust gas of the preliminary grinding mill from the preliminary grinding mill 1 to the exhaust gas passage 7 of the preliminary grinding mill is heated to the dew point temperature or higher and is sent to the dust remover 9 without dew condensation. About 10 introduced into the exhaust gas flow path 7
The dust is removed by the dust remover 9 together with the exhaust gas of the secondary grinding mill at 0 ° C. and 700 m ³ / min.

At this time, by adjusting the opening degree of the damper 8 of the branch flow path 6, a part of the secondary crushing mill exhaust gas is branched and the flow rate of the secondary crushing mill exhaust gas guided to the preliminary crushing mill 1 can be minimized. The pressure loss caused by passing through the preliminary crushing mill 1 can be suppressed, and thus the pressure loss of the entire exhaust gas system can be suppressed to the necessary minimum.

On the other hand, on the side of the preliminary crushing mill exhaust gas flow path 7, the secondary crushing mill exhaust gas having a relatively high temperature is introduced from the branch flow path 6 at a midway portion thereof, so that the preliminary crushing mill exhaust gas is again discharged immediately before dust removal. Since the temperature is raised, the functional deterioration of the dust remover due to dew condensation can be prevented more reliably.

The dew condensation prevention device for the exhaust gas of the preliminary crushing mill of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made without departing from the scope of the present invention.

[Effects of the Invention] As described above, according to the dew condensation prevention device for the exhaust gas of the preliminary crushing mill of the present invention, various excellent effects as described below can be obtained.

(I) By connecting the exhaust gas passage of the secondary pulverizing mill to the preliminary pulverizing mill, the exhaust gas of the secondary pulverizing mill having a high temperature due to the heat energy naturally generated in the secondary pulverizing mill can be introduced into the preliminary pulverizing mill. As a result, it is possible to prevent the dew condensation of the exhaust gas of the preliminary crushing mill by increasing the temperature of the exhaust gas of the preliminary crushing mill from the preliminary crushing mill to the exhaust gas flow path of the preliminary crushing mill and to prevent the condensation of the exhaust gas of the preliminary crushing mill from outside. It is possible to eliminate or remarkably reduce the need to input heat energy, thereby achieving total energy saving.

(II) The opening of the damper of the branch passage is adjusted by connecting the branch passage branched from the exhaust passage of the secondary grinding mill to the exhaust passage of the preliminary grinding mill through a damper capable of adjusting the opening. Since the flow rate of the exhaust gas of the secondary crushing mill leading to the preliminary crushing mill can be suppressed to the necessary minimum, the pressure loss caused by passing through the preliminary crushing mill can be suppressed, and therefore the pressure loss of the entire exhaust gas system can be reduced. It can be suppressed to the necessary minimum.

(III) Preliminary crushing mill If the exhaust gas of the secondary crushing mill having a relatively high temperature from the branch flow path is introduced just before the dust remover on the downstream side of the exhaust gas flow path, the preliminary crushing will be performed again immediately before dust removal. The temperature of the mill exhaust gas can be raised, and the deterioration of the dust remover function due to dew condensation can be prevented more reliably.
A stable operation can be performed.

[Brief description of drawings]

FIG. 1 is an illustration of an embodiment of the apparatus of the present invention. Reference numeral 1 is a preliminary pulverizing mill, 4 is a secondary pulverizing mill, 5 is a secondary pulverizing mill exhaust gas passage, 6 is a branch passage, 7 is a preliminary pulverizing mill exhaust gas passage, 8 is a damper, and 9 is a dust remover.

Claims (1)

[Claims] 1. A secondary crushing mill exhaust gas flow path is connected to a secondary crushing mill exhaust gas flow path, and a branching flow path branched from the secondary crushing mill exhaust gas flow path is connected to a preliminary crushing mill exhaust gas flow path through a damper whose opening can be adjusted. Condensation prevention device for exhaust gas from the preliminary crushing mill, which is connected to the.