JPS59141446A - Raw material powder baking device with waste heat utilizing equipment - 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 is an exhaust heat system that aims to rationally and economically recover and utilize gaseous sensible heat discharged from an apparatus for firing cement raw materials and powder raw materials such as aluminum hydroxide. The present invention relates to a raw material powder unsintering device with utilization equipment.

As an example of this type of raw material powder unburning device, a schematic process diagram of a cement raw material burning device is shown in FIG.

The apparatus shown in 1 mainly includes cyclones C1 to C3 as raw material powder collectors, a separation cyclone (4), and a preheating device 1 in which a calcining furnace 2 with a combustion device is arranged vertically, and a calcining furnace 3. and a Tallinn power cooler 4.The raw material powder sent to the duct 7a by the feeder 5 to the cement raw material firing device is heated by the hot gas rising inside the duct h7a and carried there. It flows into the cyclone c1, and after being separated from the hot gas in the cyclone C1, it enters the next gas duct 7b through the raw material shoe) 8a,
Thereafter, the raw material powder is sequentially heated through the same process, passes through cyclones C2 and c3, and is finally supplied to the calcining furnace 2 equipped with a burner 6a through the raw material shoe) 8c, where it is calcined and then enters the separation cyclone c4. , then raw material shoe) 8d
It is introduced into the kiln 3 through the kiln 12.

High-temperature air from a cooler 4 and firing fuel from a burner 6b are introduced into the firing furnace 3 through an outlet port 15. After entering the container 4 and being cooled, it is transferred to a container 11 and then transported out. In addition, 9 is a ventilator that induces surplus air in the cooler, 1° is a forced air blower that supplies cooling air to the cooler, 13 is a combustion air duct that guides the high temperature air in the cooler to the calciner, and I4 is a duct for combustion air. An exhaust gas line leads the exhaust gas from the uppermost cyclone of the preheating device 1 to a boiler 16, which is an example of exhaust heat utilization equipment, and 15 indicates an exhaust gas induced draft fan, and the broken line arrows in the figure indicate the flow of raw material powder, and the solid line arrows indicate the flow of raw material powder. Shows the flow of gas or air.

The temperature of the exhaust gas discharged from the preheating device 1 in such a baking apparatus depends on the heat exchange method and the number of stages of the preheating device. Normally, the temperature is about 350 to 400"C, and there is still a considerable amount of thermal energy left. Equipment to effectively utilize the sensible heat of exhaust gas is exhaust heat utilization equipment such as the boiler 16, which can be used to combine waste heat with The steam obtained through heat exchange generates electricity.
Efforts are being made to improve thermal economy.

However, in such conventional exhaust heat utilization equipment, the exhaust gas temperature in the exhaust gas duct 14 is 350 to 400. '
Since the temperature is not so high as that of C, the temperature and pressure of the steam generated in the boiler 16 are not sufficiently increased, resulting in low power generation efficiency at the turbine.

Moreover, since the exhaust gas from the preheating device I￥t is generally used as a heat source for drying raw materials, only the surplus can be used for heating in the boiler 16, resulting in a lack of available gas sensible heat. However, the efficiency of power generation turbines is not high enough.

As a way to solve these problems, it may be possible to combine a portion of the surplus air after heat recovery by the combustion air in the cooler 4 with the exhaust gas from the preheating device. Since the temperature of the surplus air is already low, even though it is effective as a means to compensate for the sensible heat of the exhaust gas, it is not sufficient to increase the exhaust gas temperature.

In addition, as another method to compensate for the temperature and calorific deficiencies in the exhaust gas from the preheating device, a combustion chamber is installed at an appropriate location in the exhaust gas line 14 leading to the exhaust heat utilization equipment, and fuel and combustion air are supplied to increase the temperature of the exhaust gas. Although it is conceivable to increase the temperature, it is not preferable in terms of equipment or operation to provide a combustion section other than the kiln or calciner. Moreover, when cheap coal is used as fuel, it becomes difficult to dispose of the combustion residual ash generated in the combustion chamber.

The present invention aims to improve the heat utilization efficiency of the waste heat utilization equipment attached to the raw material powder unsintering apparatus described above, which is not fully satisfactory. In a raw material powder unsintering device, which is a firing device configured by sequentially connecting a Laspen 932 type preheating device, a firing furnace, and a cooler, and having an exhaust heat utilization equipment attached to the exhaust gas line of the preheating device, The combustion air passage through which high-temperature air from the cooler passes is connected to the exhaust gas line by a high-temperature air conduit, and the exhaust gas from the preheating device and the high-temperature air from the cooler are combined and guided to the exhaust heat utilization equipment. It exists in the way it is done.

Next, embodiments embodying the present invention will be described in detail with reference to the accompanying drawings starting from FIG. These examples are representative examples and do not limit the present invention, and the type, structure, and number of stages of the raw material powder collector, the type and arrangement of the calciner,
It is within the technical scope of the present invention to appropriately change the design of not only the structure but also the specific configuration of the waste heat utilization equipment.

FIGS. 2 and 3 are schematic process diagrams showing embodiments of the present invention, and the same reference numerals are used for elements common to those shown in FIG. 1.

In FIG. 2, a high temperature air conduit 17 is connected at one end to the combustion air duct 13 from the cooler 4 to the calciner 2, and at the other end to the preheater exhaust gas line 14 leading to the boiler 16. A part of the high-temperature air passing through the combustion air decks 1 to 13 to the calciner 2 is transferred to the high-temperature air conduit 1.
7 and joins with the exhaust gas of the preheating device t, the boiler 16
It is expected to be introduced into In the conventional firing apparatus shown in FIG. 1, the combustion air from the cooler 4 to the calcining furnace 2 is generally at a temperature of 700 to 900°C. Since the high-temperature air to be combined with the exhaust gas of the combustion air is simultaneously sucked through the combustion air duct 3, the air temperature decreases corresponding to this amount of air, but it is sufficient to raise the exhaust gas temperature of the preheating device by 2. be. For this reason, the amount and temperature of the hot gas introduced into the boiler 16 increases, the recovery = m in the boiler 16 increases, and the amount of power generation increases significantly. The pressure increases significantly, and the power generation efficiency of the turbine using this pressure is significantly improved.

At this time, the temperature of the combustion air to the calciner 2 decreases, but the decrease in sensible heat associated with this decreases in the combustion equipment W6a attached to the calciner 2.
This will be covered by increasing the amount of fuel supplied from

In this way, in a firing device equipped with a calciner 2 in the final heat exchange stage of the preheating device 1, the high temperature air from the cooler 4 that is combined with the exhaust gas of the preheating device is sent to the calciner 2 as combustion air. Duct 13
It is easy to arrange because it can be induced through the calcination furnace 2, and the temperature drop of the combustion air to the calcination furnace 2 can be absorbed by adjusting the operating conditions of the calcination furnace 2, so that the operating conditions of the calcination furnace 3 are not affected. Since there is no need to feed, the entire firing apparatus including the firing furnace 3 can be operated stably. A dust collector CO such as a cyclone is installed in the high-temperature air conduit 17, and the clinker dust collected here is returned to a suitable firing device such as the calcination furnace 2 or the sintered end mold 12 of the calcination furnace. .

Fig. 3 shows another embodiment of the present invention, and to explain the differences from Fig. 2, the preheating device 1 does not have a calcining furnace, and the lowermost cyclone C4 is equipped with a gas duct) 7d. Direct firing furnace inlet end ri! , 12 and the hot air from the cooler 4 to be combined with the exhaust gas of the preheating device 1 is extracted from the outlet end mold 15 as a passage for the combustion air to the kiln 3 and passed through the hot air conduit 17. be attracted. At this time, clinker dust from the dust collector CO installed in the high temperature air conduit 17 is returned to the cooler 4, and a cold air suction duct 22 equipped with a flow rate regulator 23 is installed at an appropriate position in the high temperature air conduit F. By connecting to the preheater, the temperature of the high-temperature air before it is combined with the exhaust gas can be adjusted.

Incidentally, the decrease in the temperature of the combustion air to the firing furnace 3 can be compensated for by increasing the fuel supplied from the combustion device 6b attached to the outlet end mold 15.

FIG. 4 is a partial system diagram showing another means for adjusting the high temperature air temperature.
An example is shown in which the other end of the cooling machine 4 is connected to the cooling machine 4, and a part of the surplus air in the cooling machine is used for temperature adjustment of the high-temperature air.

As explained above, the high-temperature air extracted from the combustion air passage from the cooler 4 to the firing furnace 3 or the calcining furnace 2, and whose temperature has been adjusted by suction air as necessary, is sent to the pre-rho device 1. At this time, the higher the amount of high-temperature air is, the higher the temperature of the exhaust gas after the merge is, so as shown in Figures 2 and 3, the high-temperature air By installing a flow rate regulator 18 at a suitable location in the conduit 17 and adjusting the amount of high-temperature air using the flow rate regulator 18 according to the temperature required to efficiently operate the exhaust heat utilization equipment, the exhaust heat can be reduced. It is possible to increase the temperature of the exhaust gas introduced into the equipment to be used to any desired temperature.

Further shown is a hot air conduit 1 to an exhaust gas line 14.
A temperature detector 19 is disposed in the exhaust gas line leading to the exhaust heat utilization equipment on the downstream side of the junction of 7, and an opening regulator 21 is connected to the flow rate regulator 18, and the detector ]9
By connecting the regulator 21 and the controller 20 to the control device 20 and controlling the amount of high-temperature air so that the exhaust gas temperature detected by the detector 19 is a predetermined value, exhaust heat can be utilized even when the operating status of the baking equipment changes. The temperature of waste gas introduced into the equipment can be maintained as constant as possible. As a result, the amount of heat supplied to the waste heat utilization equipment becomes constant, its operating state becomes stable, and in the case of a power generator, a constant amount of electric power can always be obtained.

Further, the setting of the amount of power generation can be adjusted as necessary, and furthermore, an increase in the amount of fuel used in the firing apparatus due to extraction of a portion of the combustion air can be minimized.

In this way, in the present invention, since a part of the combustion air to be supplied to the firing device is used by combining it with the exhaust gas from the preheating device, the amount and temperature of the gas to be supplied to the exhaust heat utilization equipment can be controlled by adjusting the amount and temperature of the gas to be supplied to the exhaust heat utilization equipment. Since it can be made sufficiently suitable for efficient use of waste heat, the function of the exhaust heat utilization equipment can be fully demonstrated compared to the conventional membrane UN. At this time, since the temperature of the combustion air used in the sintering device decreases, the amount of fuel used in the sintering device increases.

However, this increased amount of heat is recovered with added value in the exhaust heat utilization equipment, and not only does it not become a heat loss, but also
This greatly improves the energy economy of the preheating, firing, and waste heat utilization equipment as a whole. Moreover, since it only increases the amount of fuel originally used in the calcining furnace 2 and firing furnace 3,
There is no fear that the equipment and operational burden will increase compared to the case where fuel is supplied to the exhaust gas system.

In addition, even when solid fuel such as pulverized coal is used as fuel, the ash produced by combustion is consumed as part of the cement raw material in the calcination device, so no special ash processing equipment is required.

However, in the present invention, in order to increase the heat utilization efficiency of the exhaust heat utilization equipment, the exhaust gas temperature is increased at the expense of the smoking efficiency as described above, so when the exhaust heat utilization equipment is not operated, for example, , the flow rate regulator 18 in FIG. 3 is fully closed, ρ high temperature air is not extracted from the combustion air road, and the firing apparatus can be used to achieve maximum thermal efficiency.

In the embodiment described above, only a power generation boiler was explained as the waste heat utilization equipment, but this also applies to raw material drying equipment such as a rotary dryer, or raw material drying and simultaneous pulverization equipment using a roller mill, ball mill, etc. Examples include various auxiliary equipment for firing equipment and various heat receiving equipment in the vicinity.

[Brief explanation of drawings]

FIG. 1 is a schematic process diagram showing an example of a conventional raw material powder unsintering device, and FIGS. 2 and 3 are schematic process diagrams of a raw material powder unsintering device with exhaust heat utilization equipment, which are embodiments of the present invention, respectively. FIG. 4 is a partial system diagram illustrating means for regulating hot air temperature that may be used in these embodiments. (Explanation of symbols) 1...Preheating device 2...Calcination furnace 3...Calcination furnace 4...Cooler 13...Combustion air duct 14...Exhaust gas line 16...Boiler, etc. Exhaust heat utilization equipment 17... High temperature air conduit 18.23... Flow rate network regulator 19... Temperature detector 22.24... Air suction duct) C1 to C4... Raw material powder collector CO...
・Dust collector. Applicant Kobe Steel Co., Ltd. Agent Patent Attorney Takeo Honjo Figure 1 ■ × 1 Figure 2 Figure 3 3 Figure 4 7 Akira

Claims (1)

[Scope of Claims] 1. A firing device consisting of a suspension-type preheating device, a firing furnace, and a cooler connected in order from the supply side of raw material powder, and equipped with exhaust heat utilization equipment in the exhaust gas line of the preheating device. In the raw material powder unsintering device, the combustion air passage through which high-temperature air from the cooler passes and the exhaust gas line are connected by a high-temperature air conduit, and the exhaust gas from the preheating device and the high-temperature air from the cooler are connected. A raw material powder unsintering device for waste heat utilization equipment, characterized in that the raw material powder is combined with air and guided to the waste heat utilization equipment. 2. The suspension type preheating device is configured to include a calciner, and the other end of a high-temperature air conduit that connects one end to the exhaust gas line is connected to a combustion air duct that connects the calciner and the cooler. A raw material powder unsintering device with exhaust heat utilization equipment as set forth in claim 1. 3. The raw material with exhaust heat utilization equipment as set forth in claim 1 or 2, wherein an air suction duct is provided in the high temperature air conduit so that the temperature of the high temperature air in the high temperature air conduit is adjusted. Powder unfiring equipment. 4. Claims 1 to 3, wherein the flow rate of high-temperature air in the high-temperature air conduit is adjusted according to the exhaust gas temperature in the exhaust gas line leading to the exhaust heat utilization equipment.
Raw material powder unsintering equipment with exhaust heat utilization equipment as described in 2.