JPS58190847A - Cement raw material calcining kiln - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a spouted bed type cement raw material calciner.

Conventionally, a spouted bed type cement material calcining furnace shown in FIG. 1 has been known, and this has the following advantages.

(1) Since it is a spouted bed type, the residence time of the raw material in the furnace is long (about 10 seconds), and the raw material can be calcined at a relatively low temperature.

(2) In the flame generation area of the calciner burner, the raw material falling from the top is thrown up by the combustion air and combustion gas, so the raw material concentration is diluted and the amount of heat absorbed is small, so the fuel ignites. Good sex. Therefore, even if the fuel is changed from heavy oil to coal, which has poor combustibility, relatively high combustion performance can be maintained.

Due to these advantages, this cement raw material calcining furnace has been widely used in recent years, but this calcining furnace also has the following disadvantages.

(1) Since kiln exhaust gas with a low oxygen concentration comes into contact with the lower part of the tip of the frame forming area, the combustibility of this area is poor.

(2) Since the calcining furnace is installed upright above the kiln exhaust gas duct, there is a height restriction when applying it to an existing kiln with a suspension breheater.

Furthermore, there is also a conventional example shown in FIG.

This is a method in which cooler bleed air is introduced from the bottom of the furnace.
Since it is not installed vertically above the kiln exhaust gas duct, it has the advantage of not being subject to height restrictions when converting an existing kiln with a suspension breheater to a kiln with a calciner, but on the other hand, it has the following disadvantages: be.

(1) Since the fuel is introduced into the spouted layer where the raw material concentration is high, the heat generated by combustion of the fuel is immediately absorbed by the raw material.
Therefore, a high-temperature flame is not generated in the furnace, and therefore, when the fuel is changed from heavy oil to coal, which has poor combustibility, a reduction in combustion performance is inevitable.

(2) Compared to the calciner shown in Figure 1, the relative velocity between the fuel and the combustion air is lower, so the mixing with the combustion air is poor, and the combustion rate of the fuel is lower, resulting in fuel efficiency that is the same as in Figure 1. high compared to

(3) Since combustion air is not introduced from the side wall of the furnace, falling raw materials hit the flame, lowering the flame temperature and impairing the ignitability of the fuel.

The present invention aims to provide a spouted bed type cement raw material calcining furnace that improves these disadvantages. The lower part is formed in the shape of an inverted cone, an opening is provided at the bottom of the inverted cone-shaped part, and a duct for introducing high temperature air from a clinker cooler is connected to the opening, whereby raw material is supplied to the inverted cone-shaped part. forming a first spouted layer part, connecting a cylindrical part directly above the inverted cone-shaped part, and connecting a side wall duct to the side wall of the cylindrical part for dividing and introducing high-temperature air from the clinker cooler; A fuel supply pipe is provided adjacent to the side wall duct, the upper part of the cylindrical part is formed into a conical shape, and a second cylindrical part whose lower part is in the shape of an inverted cone is provided on the upper part, A second spouted bed part for the raw material is formed in the inverted cone-shaped part, a third spouted bed part is formed in the same manner as necessary, and a discharge pipe for combustion gas and calcined raw material is formed in the upper part of the final cylindrical part. A cement raw material calcining furnace is characterized in that it is equipped with.

EMBODIMENT OF THE INVENTION Hereinafter, the cement raw material calcining furnace according to the present invention will be explained with reference to the drawings.

Figures 1 and 2 show a conventional cement raw material calcining furnace.
a is a rotary kiln, b is a cement raw material calciner, C is a seven-mention raw material calciner exit duct, d is a rotary kiln exhaust gas duct, e is a high temperature air introduction duct from a clinker cooler, f is a fuel supply pipe, and g is a The first raw material spouted layer section, h is the second raw material spouted layer section, i is the part of the frame that is lacking in oxygen due to contact with the kiln exhaust gas, and J is the raw material chute from the suspension breheater. These types of calciners have the disadvantages mentioned above.

Figures 3 to 6 show the cement raw material calciner according to the present invention, 1 is the cement raw material calciner, 2 is a discharge pipe for calciner combustion gas and calcining raw material, and 3 is a high temperature discharge pipe from the clinker cooler. An air introduction duct, 4 a fuel supply pipe, 5 a first raw material spouted layer section, 6 a second raw material spouted layer section, 7 a third raw material spouted layer section, 8 an orifice section, 9 a frame, 10 11 is a suspension breheater 75) A raw material chute, and 11 is a duct for introducing high temperature air from the clinker cooler at the bottom of the furnace body.

Now, when high-temperature air from the clinker cooler is introduced through the air introduction duct 11, since the lower part of the furnace body is formed in an inverted cone shape, the first raw material spouted bed section 5 is introduced into the inverted cone shape. It is formed.

Fuel is supplied from the fuel supply pipe 4 to the upper part of this spouted bed section 5, and high temperature air for combustion is also supplied from the clinker cooler through the introduction duct 34, so that the spouted bed section 5
Combustion of the fuel takes place above, so that a hot flame is formed above this spouted layer section 5.

In this case, in a conventional calcining furnace as shown in Figure 1,
Because the underside of the frame comes into contact with the exhaust gas from the kiln,
Frame part 1 where combustion is insufficient due to lack of oxygen
existed.

In the present invention, exhaust gas from the kiln is not supplied to this frame portion iζ, but instead combustion air is supplied through the high-temperature air introduction duct 11 from the clinker cooler, so that sufficient combustion is carried out.

In addition, in the conventional calciner shown in FIG. 2, the raw material concentration in the fuel ignition region was too large to form a high-temperature flame, but in the present invention, the high-temperature flame portion 9 exists, so combustion performance is good. (The combustion rate increases exponentially as the combustion temperature increases).

The raw material calcined in the first spouted bed section 5 is led together with the combustion gas to the second spouted bed section 6, where heat exchange is performed again, and then passed through the cement raw material and gas discharge pipe 2 to the final stage. It is carried to the lower cyclone, where it is separated from the exhaust gas and supplied to the kiln 12. In this case, as shown in FIG. 7, it may be connected to the riser duct of the kiln.

The one shown in FIG. 4 is one in which the top furnace wall of the second spouted bed section 6 is formed flat so that the raw material and combustion gas can be discharged without turning over, and the one shown in FIG. Top drain pipe 2
Fig. 6 shows an example in which a third spouted layer section 7 is provided, and its function is basically the same as the embodiment shown in Fig. 3G. The calcining furnace of the invention is shown applied to a cement kiln with a suspension preheater, where 13 is a clinker cooler and 14 is a suspension preheater.

According to the device of the present invention, since there is no oxygen-deficient part in the frame forming area ζ, good combustion performance can be ensured, and furthermore, when applied to an existing kiln with a suspension preheater, height restrictions due to the layout can be avoided. I can't accept it.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams showing a conventional calcination furnace, FIGS. 3 to 6 are explanatory diagrams showing a calcination furnace of the present invention, and FIGS. 7 and 8 are explanatory diagrams showing a calcination furnace of the present invention. It is an explanatory view in which the furnace is applied to a cement kiln with a suspension preheater. 1...Calcination furnace 2...Discharge pipe 3.11...Cooler bleed air introduction duct 5...First raw material spouted bed section 6...・
...Second raw material spouted layer section 7 ...Third raw material spouted layer section I2 ...Cement kiln patent applicant Akira Ito, representative patent attorney for Nippon Cement Co., Ltd. Figure 1 Cause 2 Le1, j,′, , .゛・,-1. Procedural amendment 4N: (Voluntary) June 30, 1980 Kazuo Wakasugi, Commissioner of the Patent Office 1. Indication of the case 1982 Patent Application No. 71527 2. Name of the invention: Cement raw material calcining Relation to Furnace 3, Amendment Person Case Patent Applicant Address 1-6-1 Otemachi, Chiyoda-ku, Tokyo Name
Nippon Cement Co., Ltd. Representative Tamotsu Harashima 4 Agent 101 Address 5 Abe Building, 2-42 Kanda Jimbocho, Chiyoda-ku, Tokyo Details subject to amendment! (Full text engraving) 6. Contents of the amendment As attached, 259-

Claims (1)

[Claims] The raw material input chute from the suspension breheater is connected to the side wall of the calciner, the lower part of the furnace body is formed into an inverted cone shape, an opening is provided at the bottom of the inverted cone shape, and the feed from the clinker cooler is provided in the opening. connecting a duct for introducing hot air, thereby forming a first spouted bed section of the raw material in the inverted cone-shaped section;
A cylindrical part is connected directly above the inverted conical part, a side wall duct for dividing and introducing high-temperature air from the clinker cooler is connected to the side wall of the cylindrical part, and a fuel supply pipe is connected close to the side wall duct. The upper part of the cylindrical part is formed into a conical shape, a second cylindrical part whose lower part is in the shape of an inverted cone is provided on the upper part, and a second cylindrical part of the raw material is placed in the second inverted conical part. A spouted bed part is formed, a third spouted bed part is formed in the same manner as required, and a discharge pipe for combustion gas and calcined raw material is provided in the upper part of the final cylindrical part. kiln