JPS5959243A - Stock powder preheating apparatus with waste heat-utilizing installation - Google Patents

Abstract

PURPOSE:To enhance the heat utilization efficiency of a waste heat-utilizing installation such as the boiler for a power generating turbine, by connecting the stock material discharge chute of a stock powder feeder to plural stages of heat exchange units including at least the uppermost stage heat exchange unit. CONSTITUTION:In a cement stock powder preheating apparatus 1 wherein a waste heat boiler 13 is attached to the exhaust gas line of a preheating apparatus 1 constituted by connecting four stages or more heat exchange units constituting stock powder collectors C1-C4, gas ducts 7a-7d and stock material chutes 8a-8d in an up-and-down direction, the stock material discharge chutes 5b, 5c of a stock powder feeder 5a are connected to plural stages of heat exchange units including at least the uppermost stage heat exchange unit. As the result, the temp. of exhaust gas can be raised and the supply amount of heat to the waste heat-utilizing installation is increased while the waste heat utilization efficiency thereof can be enhanced to a large extent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides efficient use of exhaust gas sensible heat in a raw material powder preheating device, such as a cyclone type multi-stage preheating device, attached to an apparatus for firing powdery raw materials such as cement raw materials and aluminum hydroxide. It relates to a device that can be easily recovered and reused.

Figure 1 shows an example of a device used to preheat and fire cement raw materials. It consists of a preheating device 1 formed by arranging calcining furnaces 2 with combustion devices in the vertical direction, a calcination furnace 8, and a clinker cooler 4.

The raw material powder A sent by a supply device 5avC such as a nuclear conveyor is sent to the duct 7R through the material discharge chute of the feeder 5b, and is sent to the uppermost cyclone C1 together with the upward airflow in the duct 7a. and cyclones C1, C2, C3 and raw material shoes) 8a, 8b
, 8C'fL, and during that time it is sequentially heated by hot air rising through gas ducts) 7a, 7b, and 7C, enters a calcining furnace 2 equipped with a burner 6a, and is calcined, then passes through Ganudak) 7d. The raw material enters the separation cyclone C4, and is then introduced into the firing furnace 8 through the firing furnace inlet end cover 12' through the raw material shoe.

High temperature air from the cooler 4 and firing fuel from the burner 6b are introduced into the firing furnace 8, and the firing 5y, 'i
The received clinker enters a clinker cooler 4 to be cooled, and is further carried out by a tallinker conveyor 11.

Reference numeral 9 indicates a surplus air induction fan, 10 a forced air blower, 18 an air extraction duct, 14 an exhaust gas induction ventilation fan, and 15 an exhaust gas duct.

The temperature of the exhaust gas discharged from the uppermost stage cyclone C1 of the preheating device 1 in such a baking apparatus depends on the heat exchange method of the preheating device 1 and the stage v1. It depends, but usually 350-400°C
There is still a considerable amount of thermal energy left.

Therefore, in order to use this exhaust gaff sensible heat more effectively, exhaust heat utilization equipment such as a boiler 16 is installed in the middle of the exhaust gas gaff (15) as shown in Figure 1, and steam is generated by heat exchange with the high-temperature exhaust gas. By generating heat and using it for power generation, etc., we aim to improve thermoeconomic efficiency. In addition, in order to deal with cases where the water pipe of the boiler 16 is damaged, a pipe buff duct 17 is provided to bypass the boiler 16, and a damper 18 is installed in the duct main pipe 15.
a-, a damper 18b is provided in the pie buffing duct 17, and the operation of the baking apparatus can be continued by opening and closing the damper 18b.

However, in such conventional exhaust heat utilization equipment, the temperature of the exhaust gas in the exhaust gas duct 15 is not that high, so the boiler 1
The temperature and pressure of the steam generated in step 6 do not rise sufficiently,
The power generation efficiency of the turbine t is low. Moreover, since the exhaust gas from the preheating device 1 is generally used as a heat source for drying the raw material powder, only the surplus can be used for heating in the boiler 16, and as a result, there is a shortage of available gas sensible heat to generate electricity. The efficiency of turbines used for this purpose is not high enough.

As a way to compensate for the lack of Cp amount, exhaust gas duct)
Although it is possible to install a combustion chamber at a suitable location in the 15th floor and supply fuel and combustion air to raise the exhaust gas temperature, it is difficult to install a combustion section other than a calciner or calciner in terms of equipment and operation. It's also not a good thing.

Moreover, when cheap stone ff' is used as fuel, it becomes difficult to dispose of combustion residual ash generated in the combustion chamber.

The present inventor focused on the above-mentioned circumstances, compensated for the lack of exhaust gas sensible heat by improving the raw material powder feeding mechanism to the preheating device,
We conducted research to increase the heat utilization efficiency of waste heat utilization equipment such as boilers for power generation turbines.

The present invention was completed as a result of such research, and
Its configuration is as shown in Figure 1, in which a multi-stage heat exchange unit consisting of a raw material powder collector, a gas duct, and a raw material chute is connected vertically, and an exhaust heat utilization equipment is installed in the exhaust gas line of the preheating device. The main feature of the raw material powder preheating device is that the raw F-+ discharge chute of the raw material powder feeder is connected to a plurality of heat exchange units including at least the uppermost heat exchange unit. .

The structure, function, and effect of the present invention will be fully explained below based on drawings showing embodiments, but the following are representative examples and do not limit the present invention, and the type, structure, number of stages, etc. of the heat exchange unit are Of course, it is within the technical scope of the present invention to change the specific configuration of the exhaust heat utilization equipment as necessary.

FIG. 2 is a schematic explanatory diagram showing an embodiment of the present invention, and the overall configuration can be understood based on FIG. 1. The characteristic part of this example is that the raw material powder A conveyed by the feeding device 5a is divided from the feeding devices 5b and 5c and is supplied to the preheating device 1, whereas some of the raw material powder A is Ganudaku (constituting the top heat exchange unit)
7a, and the other part skips the uppermost heat exchange unit and is short-circuited and sent to 7b, which constitutes the next stage heat exchange unit. As a result, the thermal efficiency in the preheating device 1 decreases corresponding to the decrease in the raw material powder supplied to the uppermost heat exchange unit, and as a result, the temperature of the exhaust gas finally discharged from the preheating device 1 increases, and the boiler 16 At the same time, the temperature and pressure of the generated steam increases, which significantly improves the power generation efficiency of the turbine. At this time, the exhaust gas temperature changes depending on the distribution ratio of the raw material powder supplied from the feeders 5b and 5C, and if the ratio of the amount of raw material powder supplied to the feeders 5b and 5C is increased, the exhaust gas temperature will drop, and the reaction force will cause the exhaust gas temperature to drop to the gas duct) 7b. If the supply ratio of is increased, the exhaust gas temperature will rise.

Therefore, the exhaust gas temperature can be adjusted by changing the distribution ratio to the feeders 5b and 5c depending on the temperature required to efficiently operate the exhaust heat utilization equipment. Moreover, as shown in FIG. 2, a temperature detector 19 is installed at a suitable location in the exhaust gas duct 15, and a supply area adjusting device 20 is provided on one or both of the supply devices 5C and 5b.
1 to the control device 21! Temperature sensor 1
Supply machine 5C or 5 so that the temperature detected by 9 becomes a predetermined value.
Supply temperature adjustment device 201r (b): If controlled, the exhaust gas temperature can be maintained as constant as possible even when the operating state of the firing device fluctuates. As a result, the amount of heat supplied to the exhaust heat utilization equipment (boiler 16) becomes constant, its operating condition becomes stable, and in the case of a power generator, a constant amount of power can be obtained at all times.

In addition, the setting of the amount of power generation can be adjusted as necessary, and furthermore, it is possible to minimize the increase in the amount of fuel used in the sintering device by directly supplying a portion of the raw powder to areas other than the top heat exchange unit. Can be done. The temperature detector 19 is installed in the exhaust gas duct) 15 to detect the temperature of the gas introduced into the exhaust heat utilization equipment, and is also installed in the cyclone C1 constituting the uppermost heat exchange unit of the preheating device 1 or in the same gas duct 7a. The temperature of the mixed flow of gas and raw material powder in the cyclone C1 or the temperature of the raw material in the raw material shoe 8a connected to the cyclone C1 as shown in FIG. 8 can also be used instead.

In the above example, the raw material powder Ai is distributed and supplied to the gas duct) 7Ji that constitutes the uppermost stage heat exchange unit and the next stage gas duct) 7b, but in the case of the latter, it is supplied to the heat exchange unit of the 8th stage and thereafter. It can be distributed and supplied to the lowermost calcination furnace 2 or the firing furnace 8 or directly. - The feeding position of the primary distributed raw material powder is not limited to each gas duct section, but may be supplied to the raw material discharge shoes (3a, 8b, etc.) of the heat exchange unit, or the main parts shown in Fig. 8. As shown, cyclone c2. c8...
Alternatively, a combination of a plurality of such distribution means may be employed.

In this way, in the present invention, at least two raw material powder feeders are provided to the preheating device, one feeder sends the raw material powder to the uppermost heat exchange unit, and the other feeders feed the raw material powder to the second stage heat exchange unit. By configuring the raw material to be sent to the subsequent heat exchange unit or firing furnace, the temperature of the exhaust gas is increased at the expense of slightly sacrificing the preheating efficiency of the raw material powder in the preheating device 1.
Accordingly, it becomes necessary to increase the amount of fuel used in the calcining furnace 2 or the firing furnace 8. However, this increased amount of heat is used to increase the amount of heat recovered in the exhaust heat utilization equipment due to the increase in exhaust gas temperature and to improve the heat utilization efficiency.
In terms of overall energy economy, this is a considerable improvement over the conventional example. Since the amount of fuel originally used in the calcination furnace 2 and calcination furnace 8 is increased, there is no fear that the equipment and operational burden will increase compared to the case where fuel is supplied to the exhaust gas line. In addition, even when a solid fuel such as a fine powder is used as the fuel, the ash produced by combustion is consumed as part of the cement raw material in the sintering device, so special ash processing equipment is not required. Another advantage obtained by using the apparatus of the present invention is that the effect of suppressing the adhesion of fine powder to water pipes such as the boiler 16 is suppressed. That is, when the entire amount of raw material powder is supplied to the top heat exchange unit as in the conventional example, a large amount of fine powder that cannot be captured by the cyclone C1 is sent along with the exhaust gas toward the boiler 16, and this adheres to the water pipes. However, if all the feedstock is distributed and supplied to the heat exchange units from the second stage onward as in the device of the present invention, the amount of fine powder carried out with the exhaust gas from the cyclone C1 will be reduced, and the boiler 16 will be Adhesion to the water pipes and the resulting decrease in heat transfer efficiency can be suppressed, and the frequency of treatments such as steam blowing for removing the adhering fine powder can be reduced.

As mentioned above, there are various possible positions for distributing and supplying the raw material powder to heat exchange units other than the top heat exchange unit.
As shown in FIG. 2, when connecting the short-circuit Schutler from the raw material supply device 58 to the second-stage heat exchange unit, the entire amount of raw material powder can be supplied to the second-stage heat exchange unit as necessary. At this time, since the uppermost cyclone C1 is used exclusively for powder collection, the amount of raw material powder flowing into the waste heat utilization equipment can be minimized. In an example with such a configuration, the entire amount of raw material powder is transferred to the gas duct 7b.
When the exhaust gas temperature of the preheating device l is approximately 60°C compared to the conventional example in which the entire amount is also supplied to Ganudak) 7a.
The increase in fuel consumption in calciner 2 is l Kg.
It was about 49 kcal per clinker.

When using the device of the present invention, as shown in the figure, the calciner 2 equipped with a combustion device is connected to the gas duct constituting the lowermost stage heat exchange unit (LC) of the preheating device, and the preheating device R1 waste is It is preferable to absorb the temperature increase by adjusting the operating conditions of the calciner 2 and stabilize the operating conditions of the calciner 8, but it is also possible to apply it to a normal type preheating device that does not include the calciner 2. It is. Furthermore, in order to increase the heat utilization efficiency of the exhaust heat utilization equipment, the present invention device increases the exhaust gas temperature at the expense of preheating efficiency as described above. In FIG. 2, the feeder 5C is fully closed and the feeder 5b is fully closed, so that the raw powder A is not short-circuited and the preheating device 1 is used to achieve the highest thermal efficiency.

In addition, although the figure shows an example in which the l-series preheating device 1 is combined with one firing furnace B, in addition, two
At least one of the preheating devices installed in the base row or higher
By applying the idea of the present invention to the base train, it is possible to combine the exhaust gas from multiple trains and guide it to the exhaust heat utilization equipment, or to supply the raw material powder to the preheating device by using the surplus air of the clinker cooler 4. It is also possible to adopt a configuration in which the preliminary gas is heated, and all such changes in design should be considered to be within the technical scope of the present invention. In addition to the boiler for power generation turbines as shown in the figure, waste heat utilization equipment includes various types of auxiliary equipment for firing equipment, such as raw material drying equipment such as rotary lead wires, and raw material drying and simultaneous pulverization equipment using roller mills, ball mills, etc. Examples include equipment and various nearby thermal translation equipment.

The present invention is roughly configured as described above, but the point is that the raw material powder is distributed and supplied to the heat exchange unit at the uppermost stage of the preheating device and the heat exchange units Y at the second and subsequent stages. It was possible to raise the exhaust gas temperature, thereby increasing the amount of heat supplied to the exhaust heat utilization equipment and significantly increasing its heat utilization efficiency. This increase in the amount of recovered energy is more than enough to compensate for the increase in fuel used in the firing furnace, etc., and the energy economy of the entire preheating, firing, and waste heat utilization equipment has been significantly improved.

In designing the device of the present invention, only a mechanism for distributing and supplying the raw material to the raw material powder supply section is added, so the burden on equipment is extremely light and it is easy to apply to existing equipment. It is.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram showing a known raw material powder child heat/calcination and waste heat utilization equipment, Fig. 2 is a schematic explanatory diagram showing an embodiment of the present invention, and Fig. 8 is a schematic explanatory diagram showing another embodiment of the present invention. FIG. l... Preheating device 2... Calcining furnace C1-C4.
...Raw material powder collector 8...Calcination furnace 4...Clinker cooler 5...Raw material supply device 7...Gas duct 8...
Raw material shoe) 15...Exhaust gas duct 16...
Exhaust heat utilization equipment A...Raw material powder applicant Kobe Steel, Ltd. No. 2-273- Figure 3 Procedural amendment October 4, 1981 1, Indication of case 1982 Patent Application No. 170484 2 Name of the invention: Cement raw powder preheating device with attached hot heat boiler (corrected today) 3. Relationship with the case of the person making the amendment Patent applicant: 3-18 (119) Wakihama-cho, Chuo-ku, Kobe City, Kobe Steel, Ltd. Representative Fuyuhiko Maki 4, Agent Shinko Hill 2-3-7 Dojima, Kita-ku, Osaka 530 "Title of the invention", "Scope of claims", "Detailed description of the invention" and ``The name of the brief explanation of the drawing has been corrected to ``Cement raw powder preheating device with exhaust heat foiler attached.'' (2. Scope of Claims) will be corrected as shown in the attached sheet. (3) The specified location of the specification will be corrected as shown in the attached errata. (4) Figure 3 will be replaced with the attached sheet. Patent Scope of Claims (1) Exhaust heat in the exhaust gas line of a preheating device constructed by vertically connecting four or more stages of heat exchange units each consisting of a raw material powder collector, a gas duct, and a raw material chute.
The raw material powder preheating device is characterized in that the raw material discharge chute of the raw material powder feeder is connected to a plurality of heat exchange units including at least the uppermost heat exchange unit. Exhaust heat fly - Old model with 2nd grade attached -
Fabric laying raw material powder preheating device. (2. The device for preheating raw material powder according to claim 1, wherein the raw material discharge shaft of the raw material powder feeder is connected to the uppermost heat exchange unit and the next stage heat exchange unit. (3) A cement raw material powder preheating device according to claim 1 or 2, which comprises a calciner equipped with a combustion device connected to a gas duct constituting the lowest stage heat exchange unit. In any one of claims 1 to 3,
■Temperature detection that detects any one of the temperature of the exhaust gas introduced into the waste heat boiler, the temperature of the mixed flow in the top heat exchange unit, the temperature of the gas discharge part of the same unit, or the temperature of the powder discharge part of the same unit. ■Top heat exchange unit and/or
or a supply amount adjustment device of a feeder that supplies raw material powder to heat exchange units other than the top stage; a control device for actuating the quantity regulating device;
A cement raw material powder preheating device equipped with:

Claims (1)

[Scope of Claims] (1) Number of exhaust heat utilization @
Exhaust heat utilization equipment, characterized in that, in the raw material powder preheating device which is made up of all accessories, the raw material discharge chute of the raw material powder feeder is connected to a plurality of heat exchange units including at least the uppermost stage heat exchange unit. Comes with a 7C raw powder child heating device. (2. In claim 1, the raw material powder preheating device is formed by connecting the raw material discharge shoe of the raw material powder feeder to the uppermost heat exchange unit and the next stage heat exchange unit. (3) Patent Claim 1 or 2: A raw material powder preheating device in which a calciner equipped with a combustion device is fully connected to a gas duct constituting a heat exchange unit at the lowest stage. (4) Claims 1 to 2 In any of Section 8,
■Temperature that detects any one of the temperature of the exhaust gas introduced into the exhaust heat utilization equipment, the temperature of the mixed flow in the top heat exchange unit, the temperature of the gas discharge part of the same unit, or the temperature of the powder discharge part of the same unit. a detector, ■ a supply amount adjustment device of a feeder that supplies the raw material powder to the heat exchange unit at the top stage and/or heat exchange units other than the top stage, and ■ the temperature detected by the temperature detector becomes a predetermined value. The raw material powder preheating device is completely equipped with a control device that operates the supply amount adjusting device according to a signal from the temperature sensor.