JPH07330395A - Adjustment of color of cement clinker - Google Patents

Abstract

PURPOSE:To provide a method for adjustment capable of keeping the color of cement clinker almost constant. CONSTITUTION:In the case where the temperature detected by a two-color pyrometer 14 is lower than the target temperature, the output of an auxiliary burner 5A is increased. In the case where the temperature detected by the two-color pyrometer 14 is higher than the target temperature, the output of the auxiliary burner 5A is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of adjusting the color of a cement clinker, and more particularly to a method of adjusting the color of a cement clinker by adjusting the degree of oxidation of iron contained in the cement clinker.

[0002]

2. Description of the Related Art An outline of a cement clinker burning facility will be described with reference to FIG.

A raw material crushed by a raw material mill is heated by a suspension preheater 1 and then fired by a rotary kiln 2 to produce a clinker. This clinker falls from the rotary kiln 1 onto the grate 3 a of the cooler 3. The clinker cooled by the cooler 3 is then supplied to the finishing mill and crushed together with gypsum and the like to become cement.

A housing 4 is provided so as to surround the end of the rotary kiln 2 and the grate 3a of the cooler 3. A burner 5 is provided on the upper portion of the housing 4, and a combustion flame (burner frame) is formed toward the inside of the rotary kiln 2.

Fuel such as heavy oil and pulverized coal is supplied to the burner 5 through a fuel pipe 6, and a blower 7 is also provided.
Is supplied with air. This air is divided into a straight flow and a swirl flow in the burner 5.

The fuel ejected from the burner 5 is burned by this primary air and the secondary air that has exchanged heat with the cement clinker in the cooler 3. The combustion gas flows in the order of the rotary kiln 2 and the suspension preheater 1, is collected by the electric dust collector 8, and is then discharged from the chimney 9.

[0007]

In order to make the color tone of the cement clinker taken out from the cooler 3 constant, conventionally, the color of the produced cement is measured and the content of MgO or Fe ₂ O _{3 of the} cement raw material is conventionally measured. Is changing the ratio of. However, this method has a problem that the time lag for adjusting the color of the cement clinker is extremely long and the fluctuation range of the color of the clinker is large.

It is an object of the present invention to provide a method capable of adjusting the color of a cement clinker so that it is always substantially constant.

[0009]

The method for adjusting the color of a cement clinker according to the present invention measures the temperature of the cement clinker falling from a rotary kiln to a cooler and keeps the temperature constant near the burner of the rotary kiln. It is characterized in that the output of an auxiliary burner provided in the above is controlled to make the color of the cement clinker constant.

[0010]

[Function] The color of the cement clinker is greatly affected by the degree of oxidation of iron contained in it.

Oxidation of the cement clinker occurs primarily during the fall from the end of the rotary kiln to the cooler grate. That is, during this period, the clinker is at a high temperature, the atmosphere and the temperature are also extremely high, and the O ₂ concentration in the atmosphere is 21% (O _{2 in the} atmosphere).
%)It has become. When the temperature of the clinker falling from the end of the rotary kiln is high, the clinker is highly oxidized, and the clinker has a blackish tone. On the contrary, when the clinker temperature falling from the end of the rotary kiln is low, the clinker is less oxidized and the clinker becomes whitish.

According to the present invention, the output of the auxiliary burner is controlled so that the temperature of the clinker falling from the end of the rotary kiln is constant, whereby the output from the end of the rotary kiln is dropped to the cooler grade. The clinker undergoes a uniform degree of oxidation and the clinker has a uniform color tone.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic cross-sectional view showing the structure near the end of a rotary kiln and the upper part of a cooler housing, in which a main burner 5 and an auxiliary burner 5A are installed in a housing 4, and burner frames 10, 10A Is formed in the rotary kiln 2. Heavy oil is supplied to the burners 5 and 5A through the fuel pipes 6 and 6A, and air from the blowers 7 and 7A is supplied through the pipes 11 and 11A.

The blowers 7, 7A are provided with dampers 12, 12A for adjusting the primary air amount.

A two-color pyrometer 14 for measuring the temperature of the clinker 15 falling from the rotary kiln 2 is installed in the housing 4. The output of the auxiliary burner 5A is controlled so that the clinker temperature detected by the two-color pyrometer 14 falls within a predetermined range.

That is, when the temperature detected by the two-color pyrometer 14 is lower than the target temperature, the output of the auxiliary burner 5A is increased.

On the contrary, when the temperature detected by the two-color pyrometer 14 exceeds the target temperature, the output of the auxiliary burner 5A is decreased.

In order to increase or decrease the output of the auxiliary burner 5A, it is sufficient to control the supply amounts of heavy oil and air to the auxiliary burner 5A.

In the present embodiment, by adjusting the output of the auxiliary burner 5A between 0 and 20% of the output of the main burner 5, the fluctuation of the temperature of the falling clinker 15 is ± 10 ° C.
It was possible to produce a cement clinker having a constant color tone.

[0020]

As described above, according to the present invention, a cement clinker having a constant color tone can be stably manufactured.

In the present invention, the output of the main burner is kept constant and only the output of the auxiliary burner is adjusted. This auxiliary burner is smaller than the main burner and is easier to control.
Further, by keeping the output of the main burner constant, the combustion operation of the main burner becomes stable.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating an example method.

FIG. 2 is a perspective view showing a cement burning facility.

[Explanation of symbols]

 2 Rotary kiln 5 Main burner 5A Auxiliary burner 7,7A Blower 12,12A Damper 14 Two-color pyrometer

Claims (1)

[Claims] 1. The temperature of a cement clinker falling from a rotary kiln to a cooler is measured, and the output of an auxiliary burner provided near the burner of the rotary kiln is controlled so that this temperature becomes constant, whereby the cement clinker's output is controlled. A method for adjusting the color of a cement clinker, which is characterized by making the color constant.