JPS6283032A - Stock powder preheating apparatus with calcinator - Google Patents

Abstract

PURPOSE:To promote the fuel combustion capacity of an incinerator, by providing a coarse powder separation means and a fine powder separation means to a powder separator while providing a coarse powdery stock material decomposing chamber equipped with feeders of high temp. air and fuel and a main incinerator to the incinerator. CONSTITUTION:The coarse powdery stock material collected by a coarse powder separation part 22 passes through a preheating stock material chute 14'' and subsequently distributed into coarse powder chutes 14e'', 14f'' by a coarse powder distributor 24. The fine powdery stock material collected by a fine powder separator 23 passes through a preheating stock material chute 14' and subsequently distributed to fine powder chutes 14a', 14b' by a fine powder distributor 14d and a part of the fine powder is mixed with the coarse powdery stock material of the coarse powder chute 14e'' to be supplied to a decomposing chamber 20b. The remaining fine powdery stock material is supplied to the lower chamber 20a'' of a main incinerator 20a through the fine powder chute 14f''.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a raw material powder child heating device with a calciner, and in particular, a device with a calciner for firing cement raw materials, alumina raw materials, limestone powder, etc. This invention relates to a raw material powder child heating device.

"Prior Art" First, an outline of a conventional cement raw material preheating device will be explained using FIGS. 6 and 7.

Figure 6 is a diagrammatic system diagram showing the steps of preheating, calcining, firing, and cooling cement raw material powder.The solid arrows in the figure indicate the flow of hot gas, and the dashed arrows indicate the flow of raw material powder. There is.

This device mainly consists of a preheating device 1. Inlet end cover 12 of the firing furnace 3 whose dust outlet will be described later
Separation cyclone C1 connected to the furnace 3, such as a rotary kiln for clinker firing. and a clinker cooling device 4.

In such a cement raw material firing device, the input chute 5
The raw material powder introduced from
It descends sequentially passing through 3.

On the other hand, the firing furnace 3 and the inlet end ff of this firing furnace 3
High-temperature exhaust gas supplied from the calcining furnace 2 provided in communication with the calcination furnace 12 is sucked by the induced draft fan 8 and rises inside the raw material preheating device 1 . Therefore, within the duct 7 and within the cyclones 01 to C3, mixing, heat exchange, and separation of the raw material powder and the high-temperature gas are repeated.

The preheated raw material powder is introduced from the raw material preheating device 1 into the calcining furnace 2 through the preheated raw material chute 14.

Furthermore, a bleed air duct 13 extending from the clinker cooling device 4 is connected to such a calcining furnace 2. Therefore, the high temperature firing air generated in the clinker cooling device 4 is introduced into the calcining furnace 2. In the calciner 2, combustion occurs using this high-temperature combustion air and fuel supplied from its own burner 61, and the raw material powder is heated by receiving the combustion heat and the heat of the exhaust gas obtained from the calciner. is calcined.

In this way, the calcined raw material powder enters the separation cyclone C1 as a powder separator connected to the combustion gas outlet 2r side of the calciner 2 together with the combustion gas and is separated.
The calcined raw material shoe) 15 is sent to the inlet end cover 12,
It is placed in a firing furnace 3. Next, the raw material powder is transferred to a firing furnace 3.
The combustion heat of the fuel supplied from the burner 6 installed on the lower end side undergoes the necessary heat treatment in the firing furnace 3 to become clinker, which is then cooled by the cooling device 4 and used for clinker cooling. The air is supplied by the forced air blower 10, and a part of the air (high temperature exhaust gas) heated by exchanging heat with the clinker is distributed and introduced into the calciner 2 and the calciner 3 as described above. The air is exhausted by the induced draft fan 9. Then, the clinker discharged from the clinker cooling device 4 is transported to the next process by a conveyor 11.

FIG. 7 is a conceptual diagram showing in more detail the structure around the calcining furnace in FIG. 6, and the structure and function of the calcining furnace will be explained with reference to these figures as follows.

That is, the calcining furnace 2 has a vertical cylindrical outer shape and a narrowed part 2.
The combustion chamber 28 is composed of a lower combustion chamber 28 and an upper mixing chamber 2b, which communicate with each other across the boundary. The lower end of the combustion chamber 2a is an inverted conical part whose cross section is gradually reduced downward, and is connected to the firing furnace 3 via the inlet end lining 2 through the opening 2J.

Further, in the lower side wall of the combustion chamber 21, in the radial or tangential direction thereof, there is provided an opening 2e of a bleed air duct 13 for guiding high temperature air supplied from the clinker cooling device 4 as combustion air.
The combustion chamber 2. is connected to the combustion chamber 2. Burner 6 blows fuel toward the high temperature air flowing into the
6 is installed. Furthermore, the combustion chamber 2a and the mixing chamber 2I
.

are respectively connected to the preheating material chutes 14 extending from the cyclone C3 of the material preheating device 1, while the combustion gas outlet 24 of the mixing chamber 2 is connected to the separation cyclone C4.
It is connected to the.

In this case, the preheated raw material chutes 14 are formed into two preheated raw material chutes 14□ by a branch member 14a equipped with a distribution valve 14e whose mounting angle can be adjusted.

It is branched into 14+. Branch chute 14. is the combustion chamber 2 of the calcining furnace 2. Furthermore, the branch chute 14I is connected to the mixing chamber 2T.

In addition, the branch chutes 143 and 14I, and the combustion chamber 2□
There are no particular limitations on the connection position between the mixing chamber 2 and the mixing chamber 2, but as shown in FIG.
Combustion chamber 2. The location is chosen such that no local hot spots are formed in the combustion zone formed within.

Alternatively, the above connection position is such that the preheated raw material powder also flows from the branch unit 148 to the combustion chamber 2! When the raw material powder is introduced into the combustion chamber 2. The combustion chamber 2. The position is such that a dense first spouted layer is formed within the jet.

Further, the above connection position is such that when the preheated raw material powder is introduced into the mixing chamber 2I from the branch chute 14, the raw material powder is transferred from the intermediate constriction part 2C of the calciner 2 to the mixing chamber 2I,
It is set at such a position that a second spouted layer is formed in the mixing chamber 2b in cooperation with the combustion gas in the combustion chamber 2° rising and flowing into the mixing chamber 2b.

In the conventional apparatus having such a configuration, only a part of the preheated raw material conveyed from the raw material preheating device is supplied to the combustion chamber 2°, so that all of the preheated raw material is supplied to the combustion chamber 21.
The temperature inside the combustion chamber 21 can be sufficiently increased compared to the case where the fuel is introduced into the combustion chamber 21.

Therefore, in the combustion chamber 28, combustion of the fuel, heating of the raw material powder, promotion of the decarboxylation reaction, etc. are performed in a preferable state due to the temperature increase in the combustion chamber 2&.

That is, within the combustion chamber 21, the combustion speed of the fuel is
．． As the combustion temperature within the combustion chamber increases exponentially, sufficient combustion can be achieved with a small amount of excess air.

Also, based on the large temperature difference between the combustion gas and the feedstock,
Since the combustion heat of the fuel can be effectively and quickly transferred to the raw material powder, the amount of fuel consumed in the calciner can be reduced.

Even when solid fuel such as pulverized coal or low-grade fuel is used, the required combustion time is shortened due to the increase in combustion temperature, so the volume of the calciner can be selected to be small.

Furthermore, since the temperature inside the combustion chamber 28 is much higher than the calcination reaction temperature of the raw material powder, which is determined by the partial pressure of carbon dioxide in the combustion gas in the combustion chamber 28, the temperature inside the combustion chamber 2. The raw material powder supplied to the combustion chamber 2. It will be quickly calcined inside.

"Problems to be Solved by the Invention" In this way, the preheated raw material fed into the calciner is distributed between the upstream and downstream sides of the calciner when viewed in the flow direction of the raw material powder in the calciner. Although conventional raw material firing apparatuses that can supply raw materials have various advantages as described above, on the other hand, they also include the following problems and are not fully satisfactory.

For example, when looking at the flow direction of the raw material powder in the calcination furnace, the residence time of the raw material powder supplied downstream in the calcination furnace is relatively short, so the calcination reaction of the coarse powder in the raw material powder occurs. In addition, when the raw material powder supplied to the upstream side is particularly fine, it tends to cause coating on the wall surface of the heating furnace when heated at high temperature. The combustion atmosphere cannot be made very high temperature,
This also causes the calcination reaction of the coarse powder in the raw material powder supplied downstream to be extremely insufficient.On the other hand, in order to suppress the occurrence of such coating,
If raw materials that do not cause this coating are supplied, or if a furnace wall material that is difficult to form a coating is used, the adhesion of the coating to the calciner wall will be eliminated to a certain extent. , the combustion atmosphere inside the furnace is highly heated, especially on the upstream side, which can promote the calcination of raw materials and the combustion of fuel, but on the other hand, a large amount of NOx is generated inside the calcination furnace, and this rise in atmospheric temperature In contrast, harmful NOx will increase exponentially.

In addition, the tendency for the amount of NOx generated to increase is that when the calcination rate of the raw material reaches 85% or more, the rate of increase in temperature increases rapidly for a certain amount of increase in the decomposition rate. (
For example, this becomes particularly noticeable when trying to obtain a firing raw material of 90 to 95% or more.

``Object of the Invention'' Therefore, the main object of the present invention is to promote the combustion performance of fuel in the calciner, further improve the calcining performance of raw material powder, and - reduce the fuel consumption of the entire calciner. It is an object of the present invention to provide a preheating device with a calcining furnace that suppresses the generation of harmful gases such as , and NOx.

"Means for Solving the Problems" In order to achieve the above object, the main means adopted by the present invention are: a preheating device equipped with at least one powder separator; In a raw powder heating device with a calciner having a calciner disposed between a preheating device and a calciner, the at least one powder separator is configured to feed coarse raw material to the calciner. The calciner is equipped with a coarse powder separating means and a fine powder separating means for sending the fine powder raw material to the calciner, and the calciner takes in high temperature air for combustion from the calciner side and A coarse powder raw material decomposition chamber equipped with a fuel supply device for combustion together with high-temperature air is connected to the above-mentioned calcining furnace to receive the exhaust gas in the furnace, and this coarse powder raw material decomposition chamber is connected to the calcining furnace to receive the exhaust gas in the furnace. and a main calciner equipped with a fuel supply device for fuel,
The coarse powder raw material and the fine powder raw material sent from the coarse powder separating means and the fine powder separating means are transferred to the main calcination furnace and the decomposition chamber through appropriate coarse powder chutes and fine powder chutes, respectively. The main point is that it can be distributed in predetermined amounts.

"Function" For example, coarse powder that is difficult to be calcined is supplied to a coarse powder raw material decomposition chamber with a relatively high oxygen concentration, and undergoes sufficient heat treatment during the long residence time before entering the kiln. Ru. At the same time, the fine powder that is easily calcined is supplied to the main calcining furnace, so that the entire raw material powder is calcined uniformly and highly.

On the other hand, the fuel is also supplied into an atmosphere with a high oxygen concentration, and the amount of raw material powder supplied can be adjusted, so that the main calciner does not have a high temperature atmosphere.
Occurrence of oX etc. can be suppressed.

``Effects of the Invention'' According to the present invention, regardless of the particle size of the supplied raw material powder, the calcination performance is able to calcinate almost uniformly and highly, and the fuel can be heated while suppressing the generation of NOx. It is possible to obtain high combustion performance, and as a natural consequence of the good performance of both, the fuel consumption of the firing apparatus as a whole can be significantly reduced.

Furthermore, due to its good combustibility, it is suitable for use with solid fuels and low-grade fuels.

Furthermore, since the coarse powder raw material is mainly supplied to the coarse powder decomposition chamber, it is possible to prevent coating on the furnace wall.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

"Example" FIG. 1 is a diagrammatic system diagram of a raw material powder unsintering apparatus including a raw material powder child heating apparatus with a calcination furnace according to an embodiment of the present invention, and FIG.
The figure is a conceptual diagram showing the structure near the calcination furnace in Figure 1 in an enlarged manner and in more detail, Figure 3 is a view taken along the ■-■ arrow in Figure 2, and Figures 4 and 5 are the views in Figure 2. Vl (V
) -Vl (V) Fig. 4 shows the connection relationship between the extraction duct and the coarse powder chute to the decomposition chamber, and Fig. 5 shows a modification of the connection relationship in Fig. 4.

Note that the following example is only one specific example of the present invention, and the technical scope of the present invention is not limited by this example. The same reference numerals will be used to describe elements that are common to the raw material powder heating device with furnace and its related equipment.

In FIG. 1, the cement raw material powder firing apparatus includes a preheating device 1', a calcining furnace 2', a firing furnace 3, and a cement talin, corresponding to each component of the conventional firing apparatus shown in FIG. It is equipped with a power cooling device 4, etc. this house,
Since the kiln 3 and the cement talin cooling device 4 have the same structure and function as those shown in FIG. 6, their explanations will be omitted here. The preheating device 1' and the calcining furnace 2' are different in structure and function from those shown in FIG. 6, and are characteristic components of this embodiment.

That is, as can be seen from FIG. 1, in the preheating device 1', instead of the preheating cyclone C3 shown in FIGS. 6 and 7, a fine powder separation section 23 and a coarse powder separation section of the same type are used. Powdered bone jl [5cz' consisting of 22 and In addition, in the calcining furnace 2', the
In place of the calciner 2 shown in the figure, a main calciner 20 of the same type is also provided with an independent fuel supply bag W (burner) 68.
1, and a coarse powder material decomposition chamber 20b (hereinafter referred to as a decomposition chamber) connected to this via a connecting portion 21.

What is noteworthy here is that the fine powder separation section 23 connects the calciner 208 and the decomposition chamber 20 through the preheated raw material chute 14'.
b, and the coarse powder separation section 22 is also connected to the main calciner 20a and the decomposition chamber 2 through the preheated raw material chute 14''.
0I. In other words, the main calcination furnace 20. Preheated raw material powder is supplied to the decomposition chamber 20I and the fine powder separation section 23 and the coarse powder separation section 22, respectively.

These characteristic components will be explained in detail below with reference to FIG. Main calcining furnace 20. Almost similarly to the case of the calcining furnace 2 shown in FIG. ' and the lower chamber 2 in the furnace that communicates with it.
It is divided into 08'. Then, the furnace upper chamber 20.
' is connected to the separation cyclone C4 via the combustion gas outlet 20a, and the lower furnace chamber 20a'' is connected to the artificial end cover 12 of the firing furnace 3.
The part that connects it in a continuous manner is shaped like this.

Decomposition chamber 201. is formed of a cylinder and a part of a cone in its external shape, and has a main calciner 20° and a bleed air extending from the cooling device 4 (Fig. 1) toward the main calciner 208. It is arranged between the duct 13 and the duct 13. and,
Main calcining furnace 20. and the lower furnace chamber 20 . ′, and the angle α between the cylinder axis and the horizontal.

is set to be larger than the angle of repose of the raw material.

The decomposition chamber 20I is equipped with an independent fuel supply device (burner) 6c facing the cylinder axis (the central axis of the decomposition chamber). As a result, combustion occurs here between the high temperature so-called combustion air sent through the bleed air duct 13 and the fuel in the burner 6c.

On the other hand, as shown in FIG.
8 to the fine powder separating section 23, and the opening 28 is provided with a vane 34, and the upper end of the coarse powder separating section 22 is connected to the outlet as shown in FIG. A duct 26 is provided. This outlet duct 26 is connected via a duct opening 29 to a duct 7 that connects the fine powder separation section 23 and the preheating cyclone C2 (FIG. 1). However, the outlet duct 26 may be
Can be omitted.

As a result, the main flow of exhaust gas in the fine powder separation section 23 flows into the coarse powder separation section 22 (as indicated by the solid line arrow B).

), the exhaust gas bypass flow (
A solid arrow B2) will be formed.

Moreover, in this case, the coarse powder separating section 22 is different from the fine powder separating section 23.
The exhaust gas that enters becomes a swirling airflow, and among the raw material powder (broken line arrow A) that is thrown in while riding on this swirling airflow, the raw material powder with a relatively coarse particle size is subjected to a large centrifugal force and becomes fine powder. It is provided so that this coarse powder raw material can be reliably captured when it is pressed against the inner surface of the separating section 23.

Therefore, as shown by the dashed arrow A, the preheating cyclone C
2 (Fig. 1) passes through the duct 7 and enters the fine powder separation section 23. When the raw material powder enters the fine powder separation section 23 through the duct 7 and rides on the swirling airflow (solid line arrow B1) generated within the fine powder separation section 23, the relative particle size of the raw material powder is reduced. The coarse raw material powder is strongly influenced by the centrifugal force caused by the swirling airflow, is pressed against the inner surface of the cyclone, and is captured by the coarse powder separating section 22. In addition, the raw material powder having a relatively fine particle size is collected inside the cyclone and descends inside the fine powder separating section 23 by riding the swirling air current.

Note that the medium-sized raw material powder is located at an appropriate position in the swirling air current, and a part of it flows into the coarse powder separation section 22 together with the coarse raw material and is captured there. As a result, the collection efficiency of the coarse powder raw material can be improved. Further, the amount and roughness of the collected coarse powder material can be easily adjusted by controlling the inflow of exhaust gas amount by the adjustment damper 27 provided in the outlet duct 26.

Incidentally, in this embodiment, as shown in FIG. 3, the connection of the coarse powder separating section is radial, and the vanes 34 are configured to directly face the swirling flow of the fine powder separating section. However, the direction of the connection may be tangential or at a certain angle to the radial direction, or the vane 734 may be installed in the same direction as the swirling flow, or the two vanes 34 may be installed in the same direction and facing each other. It is also possible to install Depending on the situation, it is also possible to install a plurality of coarse powder separation chambers in the fine powder separation section.

In such a configuration, the preheated raw material chute 14', which is a supply route for sending the uncalcined raw material from the powder separator 03' to the calciner 2', forms a so-called supply route for the fine powder raw material, and the preheated raw material The shade 14'' forms, so to speak, a supply path for the coarse powder raw material.The preheated raw material chute 14' forms almost the same supply route as the preheated raw material chute 14 shown in FIG. From the lower end of the fine powder distributor 14a (branching member in FIG. 7) equipped with a distribution valve 14e and a fine powder shoe) 141', there is a path connected to the decomposition chamber 20I, and from the fine powder distributor 14a. , fine flour choux) 14
I, ', the main calciner 20 as seen from the flow direction of the exhaust gas
．． The route is divided into a route connected to the downstream side from the connecting part 21 of.

However, here, compared to the preheated raw material chute 14 shown in FIG. 7, the fine powder chute 14 branched from the fine powder distribution tFi 14a. ' is the main calcining furnace 20. The difference is that it is connected to the decomposition chamber 20 rather than to the lower part of the main body. and,
Furthermore, it is branched from the fine powder distributor 14a and is connected to the main calcining furnace 2.
The fine powder shoe) 1i' connected to the main calcination furnace 20
Although it is connected to the fine powder supply port 30 at the upper end of the lower furnace chamber 208'', which is an example of the raw material supply port □, there is another fine powder supply port 30□ (the upper furnace chamber 20゜Top)
, 30h (near the top of the fuel supply bag 'f16Il) at one or more locations, or other locations not shown, so that the fine powder raw material can be supplied from one or more locations. be able to.

On the other hand, the preheated raw material chute 14'' is connected to a coarse powder distributor 2 which performs the same function as the fine powder distributor 14a from the lower end of the coarse powder separating section 22.
4, fine powder chute 14. 'Connected to decomposition chamber 2
The route from the coarse powder distributor 24 to the coarse powder chute 146'' communicating with the main calciner 208 through the coarse powder chute 14+'' is connected to the lower chamber 20. ” and the route connected to.

Incidentally, FIGS. 4 and 5 show how the bleed duct 13 and the fine powder chute 14a' are connected to the decomposition chamber 20I. In FIG. 4, the bleed air duct 13 is connected in the radial direction of the decomposition chamber 20I, and the fine powder shoe) 14. ' is shown connected to the decomposition chamber 20b. In the modification shown in FIG. 5, the bleed air duct 13 is tangentially connected to the decomposition chambers 20, and the fine powder chute 14. ' is shown connected to the bleed air duct 13.

Next, the function of the powder preheating device with a calcination furnace having the above configuration will be explained. First, in FIG. 1, the raw material powder preheated by the preheating cyclone C2 is
Powder separator C1' rides on the exhaust gas sent from 1.
When flowing into the raw material powder, the coarse raw material having a relatively large particle size among the raw material powders is separated and collected by the coarse powder separating section 22, and the remaining raw material powder is separated and collected by the fine powder separating section 23.

Next, as shown in FIG. 2, the coarse powder raw material collected by the coarse powder separator 22 passes through a preheated raw material shade 14'', and then is appropriately adjusted to a coarse powder shader 14e in a coarse powder distributor 24. ``and 141'', and all or part of it passes through the fine powder chute 14m' to the decomposition chamber 2.
0I, and the remainder is supplied to the lower furnace chamber 208'.

On the other hand, the fine powder raw material collected by the fine powder separation section 23 is
After preheating the raw material (Sony) 14" through ij1, distribute the fine powder to 1
4a, fine powder shoe) 14m' and 141. ', and some of it is distributed to the coarse powder chute 14e.
It is mixed with the coarse powder raw material and supplied to the decomposition chamber 20b.

In addition, the decomposition chamber 20I.

The particle size distribution of the raw material supplied to is set to a range coarser than the particle size of the raw material powder before being classified in the powder separator C1. In addition, the remaining fine powder raw materials are fine powder shoe) 14+
" is supplied to the lower furnace chamber 20.9 of the main calcining furnace 208.

Now, for example, particles with a small particle size take less time to completely calcinate, and the higher the temperature in the atmosphere and the lower the partial pressure of carbon dioxide in the atmosphere, the faster the calcination reaction proceeds. (Mjiller
Based on the known theory regarding the calcining reaction of cement raw materials, etc.),
Regarding combustion, it is a well-known fact that the higher the oxygen partial pressure of the combustion air, the faster the fuel burns.

Therefore, when the uncalcined raw material is supplied to the calciner 2' in a configuration like this embodiment, the coarse raw material whose decomposition reaction progresses relatively slowly is usually transferred to the bleed duct 13 and the burner 6c.
The combustion air obtained from the decomposition chamber 201. provides a low partial pressure of carbon dioxide and a relatively high oxygen atmosphere that increases the combustion rate of the fuel. Calcining can be carried out at an extremely fast reaction rate. On the other hand, since a part of the fine powder raw material can be supplied at the same time and the amount thereof can be adjusted, the decomposition chamber 20I.

It is possible to prevent the internal temperature from rising excessively and to suppress the generation of NOx while maintaining high calcining performance and high combustion performance.

Moreover, the remaining amount of the fine powder raw material supplied to the main calcining furnace 20& is limited to the lower chamber 20&. Even when the temperature of `` is set to the same temperature as that given to the calcined raw materials shown in Figures 6 and 7, the calcination has proceeded almost completely, and especially when the calcined material is Pass through the baking material chute 15,
When the particles are finally discharged into the firing furnace 3, calcination is almost completed regardless of the particle size. Therefore, the calcining performance as a whole was significantly improved.

[Brief explanation of drawings]

FIG. 1 is a diagrammatic system diagram of a raw material powder unsintering device including a raw material powder child heating device with a calcination furnace according to an embodiment of the present invention;
The figure is a conceptual diagram showing the structure near the calcination furnace in Figure 1 in an enlarged manner and in more detail, Figure 3 is a view taken along the ■-■ arrow in Figure 2, and Figures 4 and 5 are the views in Figure 2. Vl (V
)-VI (V) A view in the direction of the arrows, FIG. 4 shows the connection relationship between the bleed air duct and the coarse powder shade to the decomposition chamber, FIG. 5 shows a modification of the connection relationship in FIG. 4, and FIG. 6 7 is a diagrammatic system diagram of a raw material powder unfiring device including a conventional raw material powder child heating device with a calcining furnace, which is the background of this invention, and FIG. 7 is an enlarged view of the configuration near the calcining furnace in FIG. It is a system diagram shown in more detail. (Explanation of symbols) 1'... Preheating device 2'... Calcining furnace 20,
・・Main calcination furnace 20I, ・・(coarse raw material) decomposition chamber 6m= 6b, 6c・・・Fuel supply device (burner) 1
4', 14''...Preheated raw material chute 14a, 24...
・Fine powder distributor 141', 14b'...Fine powder shade 14e''
, 14 H''-Coarse powder chute C3... Preheating cyclone 22... Coarse powder separation section 23... Fine powder separation section.

Claims (1)

[Claims] 1. A temporary calciner comprising a preheating device equipped with at least one powder separator and a calcining furnace disposed between the preheating device and a calcining furnace when viewed in the flow direction of the raw powder. In the raw material powder heating device with a calciner, the at least one powder separator includes a coarse powder separation means for feeding the coarse raw material to the calciner, and a fine powder separating means for feeding the fine powder raw material to the calciner. a coarse powder material decomposition chamber comprising a powder separation means, the calciner taking in high-temperature air for combustion from the calcining furnace side, and having a fuel supply device for combustion together with the taken-in high-temperature air; The main calciner is equipped with the coarse raw material decomposition chamber in a communicating manner, is connected to the calciner to receive the exhaust gas in the furnace, and is equipped with a fuel supply device for the fuel for calcining. The coarse powder raw material and the fine powder raw material sent from the coarse powder separating means and the fine powder separating means are passed through the coarse powder chute and the fine powder chute, respectively, to the main calcination furnace and the decomposition furnace. A raw material powder preheating device with a calcination furnace, which can be distributed in predetermined amounts to the chambers. 2. A patent claim in which the high-temperature air introduced into the decomposition chamber is introduced upstream from the input position of the coarse powder raw material and fine powder raw material into the decomposition chamber, as viewed in the flow direction of the high-temperature air. A raw material powder preheating device with a calcining furnace according to item 1. 3. The raw material powder preheating device with a calcination furnace according to claim 1 or 2, wherein the decomposition chamber is provided so as to be inclined with respect to the horizontal at an angle of repose of the raw material powder or more. 4. The fine powder separating means includes a fine powder separating section, the coarse powder separating means includes a coarse powder separating section, and the coarse powder separating section includes:
A vane is connected to the side wall of the fine powder separation section so as to allow communication therebetween, and a vane is attached to the inlet of the separation section, and a part of the exhaust gas passing through the fine powder separation section is introduced in a bypass manner. A raw material powder preheating device with a preheating furnace according to any one of items 1 to 3. 5. The exhaust gas outlet hole formed in the coarse powder separation section is communicated with the exhaust gas outlet side formed in the fine powder separation section through an appropriate duct section, and the amount of gas communicated with the duct section is 5. The raw material powder preheating device with a preheating furnace according to claim 4, which is equipped with an adjusting means for adjusting the temperature.