JPS6270249A - Plural-system type powdery stock material preheater - 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 (Field of Industrial Application) The present invention relates to a multi-system preheating device for powdered raw materials such as cement, alumina, lime, etc.

(Prior Art) Conventionally, powder raw material preheating devices have various configurations, including an exhaust gas system preheating device that mainly uses exhaust gas from a firing furnace, and a preheating device that uses high temperature exhaust air from a cooling device for fired products. Some systems have multiple systems including a combustion gas system preheating device that mainly uses the combustion gas generated by combusting fuel in a calciner using a calcination furnace.

As mentioned above, in the calcining method in which each preheating device is installed in parallel with the gas flow, the combustion furnace exhaust gas does not pass through the calciner located in the combustion gas system, so the fuel is combusted in the calciner. It has the advantage that it has excellent performance and that the calciner can be constructed compactly.

However, in the above-mentioned calcination method, the combustion gas system preheating device can calcinate the powder raw material to a high degree by adjusting the quantity of fuel supplied, but the exhaust gas system preheating device can perform a high degree of calcination at a temperature of about 1000 to 1100°C. The amount of heat that can be used for calcination of the powder raw material while the exhaust gas from the firing furnace introduced in the preheating device is lowered to a temperature of about 850 to 950°C is 350 to 950°C. 45
The calcination rate of the powder raw material discharged from the exhaust gas system preheating device to the kiln is reduced because the amount of heat that can be used to preheat the powder raw material is insufficient until it is discharged after the temperature drops to around 0℃. If the amount of powdered raw material supplied to the exhaust gas system preheating device is restricted to such an extent that it cannot be heated to a high temperature or can be calcined to a high degree, excess heat that can be used for preheating will be discharged from the preheating device. The gas temperature will rise.

In order to eliminate such inconveniences, some of the preheating raw material in the exhaust gas system preheating device is branched and supplied to the combustion gas system preheating device, or fuel is also supplied to the exhaust gas system preheating device to prevent a shortage. It has been proposed to supplement the amount of heat for baking.

This conventional example will be explained in detail with reference to FIGS. 3 and 4.

FIG. 3 is a system diagram of a cement raw material firing apparatus and shows a first conventional example.

In the figure, reference numeral 1 denotes a firing furnace that obtains talin power by firing cement raw materials, and 2 denotes a cooling device that cools the talin powder discharged from the firing furnace 1 with an air flow.

The firing furnace 1 is connected to an exhaust gas system preheating device 3 that preheats the powder raw material with the exhaust gas from the firing furnace 1, and
The above cooling device 2 is connected to a combustion gas system preheating device 2!4 which uses exhaust air from the cooling device 2 to combust fuel as described later and preheats the powder raw material with the combustion gas. Further, the firing furnace 1 is connected to a cooling device 2 through an air passage 6, and high-temperature exhaust air from the cooling device 2 passes through this air passage 6 and is used for fuel combustion in the firing furnace 1.
sent to.

The exhaust gas system preheating device r13 will be explained.

This exhaust gas system preheating device 3 has powder separators CIt to CI4, such as cyclones, stacked vertically by a, with a gas outlet of each powder separator and a gas inlet of another powder separator above this powder separator. are connected to each other by a gas duct 7a. Further, the gas outlet of the firing furnace 1 and the gas inlet of the powder separator CSI at the lowest stage are also connected by a gas duct 7a. Furthermore, the gas outlet of the powder separator CI+ on the uppermost stage is connected to the exhaust gas fan 12a by a gas duct 7b.

The gas inlet of each of the powder separators described above and the powder outlet of another powder separator of this powder separator configuration are connected by raw material chutes 13, respectively. Further, a raw material supply port 16 into which a powder raw material is introduced is provided in the gas duct 7a on the gas inlet side of the powder separator CI+ at the uppermost stage. On the other hand, the powder discharge port to the powder separator C at the lowest stage is connected to the raw material shoe (1) in the firing furnace (1).
Connected by 4.

Next, the combustion gas system preheating device 4 will be explained.

This combustion gas system preheating device 4 is constructed similarly to the above-mentioned exhaust gas system preheating device 3, and has powder separators C stacked vertically.
2I''C 24 and an exhaust gas fan 12b, as well as gas ducts 7a, 7b, and raw material chutes 13.14 that connect these. The exhaust air from the cooling device 2 is used to combust the fuel between the gas inlet side gas duct 7a of the separator C24 and the powder outlet of the powder separator C23 located above the powder separator C24. A calcining furnace 8 is provided for preheating the raw material.This calcining furnace 8 is connected to the cooling device 2 by an exhaust air duct 9, and
The calciner 8 is provided with an independent fuel supply device 10 .

Further, the raw material chute 1 is connected to the powder discharge port of the powder separator CI3 at the second stage from the bottom in the exhaust gas system preheating device 3.
3 is connected to the calciner 8 of the combustion gas system preheating device 4 through a branch chute 15.

The high-temperature exhaust air that has been cooled by the cooling device 2 is burned in the firing furnace 1 to become exhaust gas, and in the exhaust gas system preheating device 3, it is sucked by the exhaust gas fan 12a and sent to the powder separator C at the lowest stage. from there to the top powder separator CI+. In addition, the combustion gas system preheating device 4
In this case, the exhaust air from the cooling device 2 is sent to the calciner 8.
This gas is sucked by the exhaust gas fan 12b and flows from the lowest powder separator C24 to the uppermost powder separator C21 (the flow of exhaust gas is indicated by solid arrows in the figure).

On the other hand, the powder raw materials inputted from each raw material supply port 16.16 are transferred to the powder separators CIl and C in the uppermost stage of each preheating device 3.4.
21 toward the lower stage, is fired in the firing furnace 1 to become tarinka, is cooled in the cooling device 2, and is transferred to the next process (the flow of the powder raw material is indicated by the broken line arrow in the figure).

In the above case, a part of the preheated powder raw material discharged from the second-stage powder separator C port from the bottom in the exhaust gas system preheating device 3 is transferred to the combustion gas system preheating device 5! It is branched and supplied to the calcining furnace 8 at t4. Therefore, the quantitative ratio of the powder raw material fed from the powder separator Ct3 to the gas inlet side gas duct 7a of the powder separator CI4 at the lowest stage is reduced. For this reason,
The powder raw material supplied to the firing furnace l from the lowest stage powder separator C in the exhaust gas system preheating device 3 is passed through the gas duct 7.
A high degree of calcination can be achieved while flowing through a. In addition, in the combustion gas system preheating device 4, the powder raw material can be highly calcined by adjusting the fuel supplied from the fuel supply device 10 into the calcining furnace 8.

Figure 4 shows the second conventional example, but this conventional example is similar to the third conventional example.
The basic configuration is the same as the first conventional example shown in the figure. Therefore,
Components having the same configuration are given the same reference numerals, and their explanations will be omitted.

In this conventional example, there is a gap between the gas inlet side gas duct 7a of the powder separator CM at the lowest stage of the exhaust gas system preheating device 3 and the powder outlet of the powder separator C13 located above the powder separator C. Another calcining furnace 18 is interposed, and this calcining furnace 1
8 is connected to an exhaust air duct 19 for supplying exhaust air from the cooling device 2 as necessary, and a fuel supply device 20 independent of the calciner 18 is provided.

Then, the powdered raw material input from the raw material supply port 16 of the exhaust gas system preheating device 3 is heated until it reaches the powder separator C port, and the entire amount is supplied into the exhaust gas from the firing furnace 1. In this case, the exhaust gas from the firing furnace 1 is insufficient in calorific value to highly calcinate these powder raw materials. Therefore, the powder raw material is highly calcined in the calciner 18 by supplying fuel from the fuel supply device 20 to the calciner 18 .

(Problems to be Solved by the Invention) In the first conventional example, the amount of exhaust gas introduced from the firing furnace 1 to the exhaust gas system preheating device 3 is mainly from the preheating devices 3.4 of both systems to the firing furnace 1. It is determined by the temperature and degree of calcination of the supplied powder raw material, and the amount of exhaust gas is smaller than the amount of combustion gas passing through the combustion gas system preheating device 4, that is, the ratio is (exhaust gas system) =
(Combustion gas system) = (35-40%) : (85
In addition, both of the preheating devices described above do not have a function to mutually adjust the amount of gas passing through both systems. For this reason.

The equipment of the combustion gas system preheating device 4 is much larger than that of the exhaust gas system preheating device 3, resulting in an equipment imbalance between the exhaust gas system preheating device 3 and the combustion gas system preheating device 4.

Therefore, there is a lack of commonality of parts between the preheating devices of both systems, and a level difference occurs on the floor surface of the support bridge, which is unfavorable not only in terms of structural design but also in terms of operability.

Further, in the second conventional example, the insufficient amount of heat for calcination in the exhaust gas system preheating device 3 is supplemented by supplying fuel to the calcination furnace 18. However, even with this arrangement, compared to the combustion gas system preheating device 4, in the exhaust gas system preheating device 3, the amount of heat that can be used for preheating is smaller than the amount of heat that can be used for calcination. There is a slight surplus by the amount of exhaust gas introduced.

Therefore, if the amount of fuel supplied to the calcination furnace 18 of the exhaust gas system preheating device 3 is increased in an attempt to obtain a high degree of calcination with the exhaust gas system preheating device 3 equivalent to that of the combustion gas system preheating device 4, this The temperature of the exhaust gas from the exhaust gas system preheating device 3 increases, resulting in a disadvantage that a good heat balance cannot be obtained between the exhaust gas system preheating device 3 and the combustion gas system preheating device 4.

(Object of the Invention) This invention has been made in view of the above-mentioned circumstances, and is designed to simultaneously perform calcination of powder raw materials in a multi-system preheating device consisting of an exhaust gas system preheating device and a combustion gas system preheating device. The purpose is to simultaneously improve the equipment and thermal balance between the two preheating devices by providing a function to adjust the amount of gas passing through both preheating devices.

(Structure of the Invention) A feature of the present invention to achieve the above object is that an independent fuel supply device is provided on the gas inlet side of the powder separator at the lowest stage of the exhaust gas system preheating device, and the exhaust gas system preheating device The powder discharge port of the second-stage powder separator from the bottom is connected to the calciner side of the combustion gas system preheating device.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 and 2. The basic configuration of these embodiments is the same as that of the conventional example. Therefore, the same components are given the same reference numerals, and the explanation thereof will be omitted.

FIG. 1 shows a first embodiment.

This powder separator C4 is installed between the powder discharge port of the powder separator C port at the second stage from the bottom in the exhaust gas system preheating device 3 and the gas inlet of the powder separator CI4 at the lowest stage of the exhaust gas system preheating device 3. An independent fuel supply amount 2-20 is provided in the gas inlet side gas duct 7a.

Then, the powder raw material inputted from the raw material supply loe 6 of the exhaust gas system preheating device 3 is branched at the second-stage powder separator C port from the bottom, and a portion is supplied to the calciner 8 of the combustion gas system preheating device 4. , the other part is supplied to the gas inlet side gas duct 7a of the powder separator C at the lowest stage of the exhaust gas system preheating device 3, and is highly pre-heated and scorched by the fuel supplied from the fuel supply device 20 to this gas duct 7a. achieved.

At this time, it is preferable to maintain the same degree of calcination of the powder raw materials in each preheating device for stable operation of the sintering device.
For this purpose, it is desirable to heat the powder raw materials discharged from the lowest stage of each preheating device to the firing furnace 1 to about the same temperature. Therefore, the powder separator CI4 at the lowest stage of each preheating device
Since the hot gas temperature of each preheating device discharged upward from 024 is approximately the same, the amount of powdered raw material supplied to each preheating device is approximately proportional to the amount of hot gas passing through each preheating device. If adjusted, the second stage powder separator C from the bottom of each preheating device! 3+ The powder raw material discharged from C73 can be preheated to the same extent. For this reason, the top powder separator CII
Since the temperature of the gas discharged from the +C7+ is also about the same, each preheating device can have a similar temperature distribution, achieving preferable temperature conditions in terms of thermal efficiency and operability.

FIG. 2 shows a second embodiment, in which the powder discharge port of the powder separator 0 days from the second stage from the bottom of the exhaust gas system preheating device 3 in the first embodiment and the powder discharge port of the lowest stage of the exhaust gas system preheating device 213 are shown. This powder separator CI
Another calcining furnace 18 is interposed in the gas inlet side gas duct 7a of No. 4, and an exhaust air duct 19 that supplies exhaust air from the cooling device 2 is connected to this calcining furnace 18. Furnace 18 is provided with an independent fuel supply device 20 .

According to this configuration, since the amount of calcination in the exhaust gas system preheating device 3 can be increased, the amount of passing hot gas can also be relatively increased, and the amount of hot gas passing through the combustion gas system preheating device 4 can be decreased.

Although 1 and more are based on the illustrated example, the exhaust gas system preheating device 3
Depending on the amount of fuel supplied to the lowest stage of the powder separator C, as in the first embodiment, the gas inlet side gas duct 7a of the lowest stage powder separator C,
Alternatively, as in the second embodiment, the gas duct 7a may be provided with a calcination furnace 18; The installation of the exhaust air duct 19 is not essential.

In addition, the number of series of preheating devices constituting each system of the exhaust gas system preheating device 3 and the combustion gas system preheating head 4, the type and number of stages of powder separators constituting each preheating device, the type of calcining furnace, etc. are as described above. It is not limited to the examples.

(Effects of the Invention) According to the present invention, an independent fuel supply device is provided on the gas introduction side of the powder separator at the lowest stage of the exhaust gas system preheating device,
In addition, a part of the preheated raw material discharged from the powder separator in the second stage from the bottom of the preheating device is supplied to the calciner side of the combustion gas system preheating device, so that the fuel supplied from this fuel supply device is Due to this adjustment, the powder raw material fed into the lowest stage of the exhaust gas system preheating device is highly calcined before reaching the gas inlet of the powder separator at the lowest stage.

On the other hand, the powder raw material fed into the combustion gas system preheating device is also highly calcined in the calcining furnace of this device.

At this time, since a fuel supply device was installed in the exhaust gas system preheating device, the amount of combustion gas from this fuel supply device was added to the amount of combustion gas from the firing furnace, increasing the amount of hot gas passing through the exhaust gas system preheating device. do. At the same time, even if the powder raw material discharged from the powder separator at the second stage from the bottom of the exhaust gas system preheating device to the gas duct on the gas inlet side of the powder separator at the lowest stage is increased, it can be calcined. Therefore, the powder raw material branched and supplied to the calcination furnace of the combustion gas system preheating device can be reduced by the amount of calcination increased in the exhaust gas system preheating device, and the amount of heat required for calcination in the calcination furnace is also reduced.

Therefore, the amount of hot gas passing through the combustion gas system preheating device is reduced, and the balance between the amount of hot gas passing through the combustion gas system preheating device and the exhaust gas system preheating device can be improved. Therefore, a good equipment balance can be obtained between the exhaust gas system preheating device and the combustion gas system preheating device.

In addition, because the powder discharge port of the second-stage powder separator from the bottom of the exhaust gas system preheating device was connected to the calcination furnace side of the combustion gas system preheating device, the amount of heat that could be used for the above calcination in the exhaust gas system preheating device A balance can be obtained with the amount of heat that can be used for preheating.

As described above, in this invention, the amount of preheating raw material branched and supplied from the exhaust gas system preheating device to the combustion gas system preheating device and the amount of fuel supplied to both preheating devices are set to yA, so that the distance between the two preheating devices is reduced by yA. Powder raw materials can be calcined to a high degree while maintaining equipment and thermal balance.

[Brief explanation of drawings]

1 and 2 show an embodiment of the present invention, FIG. 1 is a system diagram of a cement raw material firing apparatus in the first embodiment, and FIG. 2 is a diagram corresponding to FIG. 1 showing a second embodiment. , Figures 3 and 4
The figures show a conventional example, and FIG. 3 is a first conventional example, which corresponds to FIG. 1, and FIG. 4 is a second conventional example, which corresponds to FIG. 1. 1. Firing furnace, 2. φ cooling device, 3.. Exhaust gas system preheating device, 4.phi. Combustion gas system preheating device, 7as. Gas duct, 8. Calcining furnace, 10. Fuel supply device, 13. Raw material. Chute, 14--raw material chute, 15-φ branch chute, 18--calciner, 20''-fuel supply device, C
ll-Cl4. c2I~C24...Powder separator.

Claims (1)

[Claims] 1. A firing furnace for firing the powder raw material, a cooling device for cooling the fired product discharged from the firing furnace with an air flow, an exhaust gas system preheating device for preheating the powder raw material with the exhaust gas from the firing furnace, and the above-mentioned cooling. A combustion gas system preheating device is provided which burns fuel using exhaust air from the device and preheats the powder raw material with the combustion gas, and each of the preheating devices is vertically stacked and connected to each other to form a plurality of powders. Each has a separator group, and the powder discharge ports of the powder separators at the lowest stage of each preheating device are respectively connected to the firing furnace, while the gas inlet of the powder separator located at the lowest stage of the combustion gas system preheating device is connected to the firing furnace. Powder raw material calcination with a calciner interposed between the port and the powder discharge port of another powder separator above this powder separator to preheat the powder raw material by burning fuel using exhaust air from a cooling device. In the apparatus, an independent fuel supply device is provided on the gas inlet side of the powder separator at the lowest stage of the exhaust gas system preheating device, and the powder discharge port of the powder separator at the second stage from the bottom of the exhaust gas system preheating device is connected to the combustion gas. A multi-system powder raw material preheating device characterized by being connected to the calcining furnace side of the system preheating device.