JPS59197795A - Device for baking powdered and granular body raw material - 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 a rotary furnace-type firing apparatus for granular raw materials, which combines a raw material preheating device with an auxiliary combustion furnace and a steam boiler.

For example, high-temperature exhaust gas generated from a kiln that burns powder or granular materials such as cement, or exhaust gas generated from a raw material preheating device or a cooling device for fired materials attached to a kiln, is led to a steam boiler, etc., and the exhaust heat is Methods for recovering this have been widely used.

As mentioned above, directing all of the high-temperature exhaust gas from the kiln directly to the steam boiler is advantageous from the perspective of heat recovery, but from the perspective of the calcination equipment for powder and granular materials, it is superior in various aspects. There is a drawback that a raw material preheating device cannot be used.

In addition, the υ1 gas in the raw material preheating device and the cooling device for the fired products has a relatively low temperature, so even if these exhaust gases are introduced into the steam boiler, the heat recovery efficiency is low, and the heat recovery efficiency of the entire system is low. I can't wait.

On the other hand, in order to efficiently utilize the sensible heat of low-temperature exhaust gas, it is possible to install a hot blast furnace outside the system and use auxiliary combustion to raise the exhaust gas temperature to a level that is efficient for exhaust heat recovery. As a result, the structure is complicated and large, and equipment costs also increase.

Furthermore, when coal is used as a fuel for auxiliary combustion, ash processing equipment is also required, making the conditions even more dire.

The present invention was made in order to eliminate the above-mentioned drawbacks of the conventional technology, and by incorporating a steam boiler into a raw material preheating device with an auxiliary combustion furnace, it is possible to efficiently burn powder and granular materials and generate steam with an extremely simple structure. The purpose of this invention is to provide a powder and granular material sintering device that can be easily demonstrated.

Hereinafter, the present invention will be described in detail based on embodiments not shown in the drawings.

Reference numerals 183 and 9 are exhaust fans for all the flow of waste waste, 2 is a raw material feeder for supplying the material to be fired (hereinafter simply referred to as "raw material"), and 3 is a raw material preheating device. The raw material preheating device is constituted by conduits 12 connecting each of the 4.5° and 6.7 cyclones.

8 is the lowest cyclone 7 of the raw material preheating device 3 and the firing furnace 1
This is an independent cyclone installed between 4 and 4.

This cyclone 8 performs preheating of the raw material heating material and separation from the exhaust gas as described below.

11 is an auxiliary combustion furnace, 13 is a combustion device attached to the auxiliary combustion furnace 11,
14) A firing furnace for granular raw materials, 15 a combustion device attached to the firing furnace 14, 16 a cooling device for cooling the high-temperature product fired in the firing furnace 14, and 17 a cooling device 1.
an exhaust fan for discharging the air that has been cooled in step 6;
18 is a blower for sending cold air to the cooling device 16; 10;
is a steam boiler.

19 is a gas conduit connecting the combustion furnace 14 and the cyclone 8.

The exhaust gas from the combustion furnace 14 is passed through this exhaust gas conduit 19.
All are supplied to the steam boiler 10 via the cyclone 8.

Reference numeral 20 denotes an air conduit that connects the cooling device 16 and the auxiliary combustion furnace 11.

21 is a 1/1 gas conduit connecting the upper part of the auxiliary combustion furnace 11 and the upper part of the cyclone 7 at the lowest stage of the raw material preheating device 3.

Reference numeral 22 denotes an exhaust gas conduit for discharging the exhaust gas flowing through the raw material preheating device 3 through the exhaust fan 11 to the outside of the system.

This Jl) gas conduit 22 has two exhaust gas branch pipes 22a,
22b. The exhaust gas branch pipe 22a is connected to the steam boiler 10, and the other exhaust gas branch pipe 22b is connected to the auxiliary combustion furnace 11.

Note that in this figure, dotted line arrows indicate the flow direction of raw materials, and chain line arrows indicate the feeding direction of fuel.

The present invention is configured as described above, and with this configuration, the granular raw material is fired as follows.

The cement raw material is fed into the conduit 12 of the raw material preheating device by the raw material feeder 2, descends via the cyclone 4, 5, 6, and is repeatedly mixed and separated with the exhaust gas sucked in by the exhaust fan 1, and is auxiliary combustion. It is sent into the furnace 11.

The cement raw material is heated in the auxiliary combustion furnace 11 by the cold f, I'l of the material to be fired in the cooling device 3 (by the cold air sent in by the blower 18), and is heated by the hot air introduced through the air conduit 20. , and a part of the exhaust gas discharged from the uppermost cyclone 4 of the raw material preheating device 3 through the exhaust gas branch pipe 22b.

The raw materials and hot gas calcined in the auxiliary combustion furnace 11 are
The raw material is introduced into the lowermost cyclone 7 of the raw material preheating device 3.

The hot gas and the raw material are preheated and separated in the cyclone 7, and the raw material is introduced into the exhaust gas conduit 19.

The raw material introduced into the exhaust gas conduit 19 is introduced into the cyclone 8 together with the exhaust gas discharged from the firing furnace. On the other hand, the exhaust gas discharged from cyclone 7 is sucked into extremely high cyclone 6, and then continues to the upper stage of cyclone 5.4.
The raw materials are preheated.

The raw material and exhaust gas introduced into the cyclone 8 are preheated and separated within the cyclone 8, and the raw material is passed through the raw material introduction pipe 2.
3 into the firing furnace 14, and the exhaust gas is sucked into the steam boiler 10 via the exhaust gas conduit 19a. An exhaust fan 9 is connected to the steam boiler 10.

Due to the negative pressure generated by this exhaust fan 9, the exhaust gas that has come from the firing furnace 14 via the exhaust gas conduit 79 and a part of the exhaust gas from the raw material preheating device that has been sucked in by the exhaust fan 1 and has passed through the exhaust gas branch pipe 22a are steamed. Suction into boiler 1o.

This exhaust gas exchanges heat with the distributed water in the steam boiler 1o to heat the distributed water, and is discharged outside the system as waste gas by the exhaust fan 9.

The ratio between the amount of gas for steam generation and the amount of gas for preheating the raw material is determined depending on the steam conditions and amount to be generated in the entire system.

However, since the entire amount of high-temperature exhaust gas is supplied to the steam boiler 1o, it is necessary to secure the amount of heat and gas necessary for the operation of the raw material preheating device 3. sufficient heat and gas m must be generated.

Further, as the combustion air necessary for combustion in the firing furnace 14 and the auxiliary combustion furnace 11, job air of the cooling device 3 attached to the firing furnace 14 is used. That is, the bleed air from the high temperature section of the cooling device 3 is directly introduced into the firing furnace 14, and the bleed air from the intermediate temperature section is guided to the auxiliary combustion furnace 11.

In this way, the cooling device 3 discharges only low-temperature exhaust gas that has no utility value to the outside of the system.

Furthermore, if the temperature of the exhaust gas at the inlet of the steam boiler 10 is too high and there is a risk that raw material dust floating in the exhaust gas may fuse to the boiler and cause a failure, the exhaust gas temperature of the raw material preheating device 3 may be is configured to introduce a portion into the steam boiler 10.

In addition, although the sensible heat of the exhaust gas from the raw material preheating device is fully utilized as described above, if there is sufficient room for F gas, this exhaust gas is introduced into a low-temperature section such as the economizer of steam boiler 1o. and to recover even more heat.

Furthermore, circulating and reusing the exhaust gas from the raw material preheating device 3 means that the amount of exhaust gas in the entire system is reduced, and the capacity of the dust collection equipment installed at the subsequent stage can be reduced.

By the way, when firing cement raw materials using a kiln equipped with a raw material preheating device, if raw materials with a large amount of alkali or chlorine are used, this alkali, etc. will evaporate and condense into the raw material preheating device. As the dust is circulated and concentrated, the raw material dust with a lower melting point may fuse to the inner walls of the cyclone, dust, etc., and cause blockage problems.

In order to prevent such inconveniences, bypass equipment for gases containing alkalis, etc. should be installed in order to discharge some of the gases containing alkalis, etc., which are gaseous in the high-temperature area of the firing system, to the outside of the raw material preheating device. However, if such a configuration is adopted, the high temperature gas and floating high temperature raw material dust are discharged from the system, which has the disadvantage that the heat consumption required for cement 1 to sintering increases.

However, in the present invention, it is assumed that a part of such gas is led to the steam boiler 10, so if the required amount of raw material dust collected on the steam boiler side is discharged outside the system, concentrated alkali etc. It is possible to prevent problems caused by

At the same time, the content of alkali and the like in the fired cement clinker can also be reduced.

As described above, according to the present invention, there is no need for special equipment, no increase in heat consumption m of the entire system, and since condensed raw material dust such as alkali is extracted from the low temperature section, handling is easy. becomes.

Therefore, from a different perspective, it can be said that it is an efficient bypass facility for gases containing alkali and chlorine.

Furthermore, in actual operation, by adjusting the amount of fuel consumed in the auxiliary combustion furnace or firing furnace, the time between steam generation from the steam boiler can be adjusted within a considerable range without changing the amount of calcination of the granular raw material. You can get the flexibility of driving by being able to move around.

[Brief explanation of drawings]

The figure is a schematic configuration diagram showing one embodiment of the present invention. 1 is an exhaust fan, 2 is a raw material feeder, 3 is a raw material preheating device, 4.
5.6.7 and 8 are cyclones, 9 is an exhaust fan, 10 is a steam boiler, 11 is an auxiliary combustion furnace, 12 is a conduit, 13 is a combustion device for the auxiliary combustion furnace, 14 is a firing furnace, and '15 is a combustion device for a firing furnace. , 16 is a cooling device, 17 is an exhaust fan, 18 is a blower, 19
．． 19a is an exhaust gas conduit, 20 is an air conduit, 21.22 is an exhaust gas conduit, 22a and 22b are exhaust gas branch pipes, and 23 is a raw material introduction pipe. Patent applicant: Ube Industries, Ltd.

Claims (1)

[Claims] In a powder raw material firing apparatus equipped with a raw material preheating device with an auxiliary combustion furnace, a steam boiler is installed alongside the raw material preheating device, and the R
Another knife 8 is provided below the cyclone 7 at the lowest stage of the material preheating device to connect the cyclone 8 and the steam boiler, and also to branch the steam boiler and the discharge side of the cyclone 4 at the top stage of the material preheating device. A granular raw material characterized in that the steam boiler is connected to the cyclone 8 to supply all of the exhaust gas of the firing furnace and a part of the exhaust gas generated in the auxiliary combustion furnace and the raw material preheating device. firing equipment.