JPS59138805A - Operating method of incinerator for waste and apparatus therefor - Google Patents

Abstract

PURPOSE:To incinerate waste completely and enable the occurrence of white smoke to be suppressed, by utilizing the energy of exhaust gas effectively, heating, if required, air for incineration, and elevating the temperature of the exhaust gas in some cases, or heating diluting air for preventing white smoke. CONSTITUTION:For instance, in summer, it is not required that the exhaust gas is heated, and it is only enough to take measures to promote the combustion. Air for the fuel that has been passed via a filter 1 and has been pressurized by a positive blower 2 is passed by operating valves, etc. via paths 10, 12, 13 to air preheaters 6, where it is heated, and then it is supplied via pipelines 14, 15 to the hearth of a fluid bed waste incinerator 3. The exhaust gas from the incinerator 3 is passed to paths 16, 17, 18, 20 to be discharged into the atmosphere from a stack (T). The temperature of the exhaust gas is lowered to a suitable temperature, and the exhaust gas is discharged into the atmosphere after the dust therein is collected by an electrostatic precipitator 5. According to the property of dust, the atmospheric temperature, visual observations on the state of occurrence of white smoke, etc., it is possible that the way of operation of the like can be suitably changed without regard to seasons.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides at least two air preheaters in parallel in a path for discharging exhaust gas from a waste incinerator, such as a fluidized bed waste incinerator, into the atmosphere. This article relates to operating methods and equipment for garbage incinerators that can be used depending on the nature of the garbage, atmospheric temperature, etc.

Garbage incineration equipment generally consists of an incinerator and a pipe line that releases the exhaust gas from the incinerator into the atmosphere, and the pipe line is equipped with a gas cooler, an air preheater (heat exchanger), and an electrostatic precipitator. One each is provided. And a mixture suitable for exhaust gas and electrostatic precipitator by gas cooler (below 350℃)
After being lowered to the lowest point, the dust is collected by a dust collector and then released into the atmosphere through the chimney. The air preheater heats the air for preventing white smoke by humidifying the combustion air supplied to the incinerator or the exhaust gas emitted from the electrostatic precipitator.

Here is a brief explanation of the mechanism by which white smoke is generated.
White smoke is produced when water vapor contained in exhaust gas condenses. Therefore, if the exhaust gas temperature is high and the high temperature state is maintained until it is released into the atmosphere and sufficiently diluted, the generation of white smoke will not be visible to the naked eye. In this way, white smoke is condensed water vapor and is not dust, so it does not pollute the atmosphere. However, if there is a mist component with large particle sizes in white smoke, large particle sizes may appear near the chimney. It cannot be said that there is no possibility that the mist will fall and cause local damage. Therefore, in order to eliminate the possibility of such damage occurring, measures are being taken to prevent the generation of white smoke. That is, a method has been adopted in which the exhaust gas is heated again and released.

This is because electrostatic precipitators are cheap and rarely break down, making them indispensable equipment for this type of incinerator, but they cannot process high-temperature exhaust gas. Therefore, usually 350
It is cooled down below ℃ and passed through an electrostatic precipitator. If this happens, the exhaust gas will become colder and start producing white smoke, so another heater is used to reheat the exhaust gas before releasing it.

By the way, as is clear from the above explanation, the degree of generation of white smoke varies depending on the temperature of the atmosphere in which exhaust gas is released.

It is difficult to occur in the summer due to high temperatures, and it is more likely to occur in the winter. Spring and autumn are in between and vary depending on the day. The nature of the waste that is incinerated also differs depending on the season. In other words, garbage from IIFI generally contains a lot of perishables, contains a large amount of moisture, and has a low calorific value, but garbage from winter, on the other hand, has a low moisture content and a high calorific value. Spring and autumn are in between.

Since the nature of the waste to be incinerated and the atmospheric temperature at which the exhaust gas is released vary throughout the area, in order to completely incinerate the waste and prevent the generation of white smoke, it is necessary to use the conventional equipment described above, that is, the 11N A single series of gas cooler, air preheater, and electrostatic precipitator was not sufficient for the incinerator. For this reason, a device was needed to further heat the exhaust gas coming out of the chimney.

Therefore, the purpose of the present invention is to effectively utilize the energy of the exhaust gas generated from the waste incinerator, heat the incineration air if necessary, and heat the white smoke prevention air that increases or dilutes the exhaust gas temperature depending on the conditions. However, it is an object of the present invention to provide an incinerator operating method and an incinerator suitable for the method, whereby garbage is completely incinerated and the generation of white smoke can be suppressed without using any additional energy.

According to the method of the present invention, the exhaust gas system connecting the incinerator and the electrostatic precipitator is provided with at least two air preheaters (heat exchangers) in parallel, An incinerator operating method consisting of the following three types of operation depending on temperature etc. can be obtained.

(a) A first operating method in which incineration air is sent to two air preheaters to exchange heat with exhaust gas, and the high-temperature air is supplied to a fluidized bed waste incinerator.

(1)) Air for combustion is supplied directly to the waste incinerator, and air for white smoke prevention is sent to two air heaters to prevent temperature rise.
4. A second operating method in which the exhausted air is mixed with the exhaust gas discharged from the electrostatic precipitator to raise the temperature of the exhaust gas and dilute it.

(C) Part of the combustion air is sent directly to one air preheater, the rest is sent to one air preheater to make it high temperature, and then supplied to the waste incinerator, and the white smoke prevention air is sent to the other air preheater to raise the temperature. A third operating method involves heating and mixing the heated air with the exhaust gas discharged from the electrostatic precipitator to raise the temperature of the exhaust gas and dilute it partially.

Further, according to the trash incinerator of the present invention, the trash incinerator, two or more air preheaters provided in parallel in the exhaust gas path of the trash incinerator, and the exhaust gas path upstream or downstream of the air preheater a gas cooler provided, and an electrostatic precipitator provided in an exhaust gas path downstream of the air preheater and the gas cooler;
In a garbage incinerator equipped with a chimney located at the downstream end of the exhaust gas path, combustion air is guided from a forced blower to the garbage incinerator through two or more of the air preheaters in parallel (combustion air is a pipeline, a bypass pipeline that bypasses the air preheater in the combustion air pipeline, and air for white smoke prevention passing through the air preheater in parallel from a white smoke prevention fan. and an air pipe line for preventing white smoke leading to exhaust gas downstream of the electrostatic precipitator.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The incinerator operating method and waste incineration apparatus of the present invention will be explained in more detail below with reference to the accompanying drawings.

In FIG. 1, 1 is a filter provided on the suction side of the forced air blower 2. In FIG. 3 is a fluidized bed waste incinerator, and 4 is a gas cooler. The gas cooler is preferably of a type that sprays water directly onto the exhaust gas, and can also be provided just before the electric collector 5, that is, on the downstream side of the air preheater. A path 16 that leads the exhaust gas from the incinerator 3 to the chimney T branches in the middle, and an air preheater 6.7 is provided in each path 17.18. 8 is an induced draft fan, and 9 is a hot air generating furnace. Although not shown in the drawings, there are switching valves, diverter valves, etc. in the ventilation pipes, routes, etc., and these valves are controlled manually or automatically, preferably remotely. It looks like this.

Next, the driving method will be explained. First, let us explain about operation in the summer (shown by the solid line in Figure 1). During the summer, the atmospheric temperature is generally high and there is little risk of white smoke generation. Garbage also contains a lot of moisture and is difficult to burn.

Therefore, in the summer, there is no need to heat-treat the exhaust gas, and it is only necessary to promote combustion. Therefore, the pressurized combustion air is passed through the filter 1 and sent to the two air preheaters 6.7 through the channels 10 and 12.13 by appropriately operating the valves. sent, heated here and line 14.1
5 to the hearth of the fluidized bed waste incinerator 3. The exhaust gas from the incinerator 3 is routed 16.17.18.
20 and is released into the atmosphere from the chimney T. The exhaust gas is lowered to an appropriate temperature (below 350 degrees Celsius), and then the electricity collector 1!
[15] It is clear that the dust is removed and released into the atmosphere.

Next, the winter driving method (indicated by the dotted line in FIG. 1) will be explained. In winter, the atmospheric temperature is low and white smoke is likely to occur. Also, garbage is relatively dry and generates a large amount of heat. Therefore, it is not necessary to heat the exhaust gas in winter, nor is it necessary to heat the combustion air. Therefore, the combustion air is
The gas is directly supplied from the forced air blower 2 to the incinerator 3 through the path 21 without undergoing heat exchange with the exhaust gas. On the other hand, the air for preventing white smoke is passed through the route 22.23.2 by the blower 30.
4 to two air preheaters 6.7, the heated air joins into path 25. This white smoke prevention air is mixed with exhaust gas at the confluence point 28 to raise the temperature of the exhaust gas and dilute it. However, if the temperature of the exhaust gas does not rise sufficiently, part or all of the white smoke prevention air is replaced with hot air. It is heated in a generating furnace 9. The exhaust gas coming out of the chimney T is sufficiently heated and diluted, so no white smoke is produced.

Finally, we will discuss operating methods during the spring and autumn seasons (indicated by the chain line in Figure 1). In spring and autumn, white smoke is more likely to be generated than in summer, so the exhaust gas needs to be slightly heated.

Garbage contains less moisture than summer garbage, but more than winter garbage. Therefore, the combustion air supplied to the incinerator needs to be slightly heated. Therefore, in this case, two air preheaters 6.
Use 7 properly. That is, a part of the combustion air from the forced air blower 2 is sent to the air preheater 7 through the path 31, and the remaining part is short-circuited through the path 32. Then, these airs are merged and passed through the path 33 to create a yaki 1! Supply to jl furnace 3. On the other hand, the air for preventing white smoke is heated in the other air preheater 6 by the same operation as described above. It is clear that whether the hot air is passed through the hot air generating furnace 9 or the bypass 26 is selected depending on the atmospheric temperature, exhaust gas temperature, etc.

Although the simplified method of operation has been explained above by dividing it into spring, autumn, winter, summer, etc., it is possible to change the operation method as appropriate regardless of the season, depending on the nature of the garbage, the temperature of the atmosphere, and visual observation of the white smoke generation status. Of course.

FIG. 2 is a diagram showing a garbage incinerator according to the present invention, and parts corresponding to those in FIG. 1 are given the same reference numerals.

An air pipe a (corresponding to the path 10 in FIG. 1, hereinafter the same reference numerals in parentheses) having the filter 1 is connected to the forced air blower wA2. The forced air blower 2 has pipe b (two routes, 32.
33) to form a combustion air line leading to the incinerator 3. Here, pipe C1 (route 31) branches from pipe Sukara, and cl further branches into pipe dr (route 13.15), d
2 (route 12.14). d 1
, d2 pass through preheaters 6 and 7 provided in parallel, and then merge to become conduit C2 and merge into conduit C2. A bypass pipe line is formed between the branch point with C1 and the confluence point with C2. Quenching [j Furnace 3 is connected to pipe e (
It is connected to the gas cooler 4 via line 16), then to the preheater 6.7 via line f, branch pipes g (line 17) and h (line 18), and further to the confluence pipe 1 (line 19. 20
) is connected to an electric precipitator 5 and an induced blower 8, forming an exhaust gas line that ultimately reaches the chimney T.

On the other hand, the blower 30 is connected to pipe j (route 22) and branch pipe 1 (
Ilfi channels 23) and k2 (channel 24) are connected to the preheater 6.7, respectively, and a confluence pipe g (channel 25.2) is connected to the preheater 6.7.
7) is connected to the hot air generating furnace 9 through a confluence point 2 with the pipe i.
8 to form an air line for preventing white smoke that finally reaches the bottom of the chimney. Here, the pipe e is provided with a pipe m (route 26) that bypasses the hot air generating furnace 9. 4 in the diagram
0 is a valve provided in the conduit. It doesn't matter whether it's manual or automatic.

In the waste incineration apparatus shown in FIG. 2, the process of inflow and outflow of combustion air, air for preventing white smoke, and exhaust gas and its operation are exactly the same as in the case of FIG. 1, so a description thereof will be omitted.

FIG. 3 is a diagram showing another embodiment of the waste incineration apparatus according to the present invention, in which a part of the combustion air pipe line of the waste incineration apparatus and a part of the white smoke prevention air pipe line are integrated and shared. Show what you have. In Figure 3, pipes n and o are connected to pipes d1 and 2 in Figure 2, pipe p is connected to pipe d2 in Figure 2, and pipe q is connected to pipe 2 in Figure 2. The pipes d1 and 1 are integrated, respectively.

That is, the pipes n, o, p, and q are used both as a combustion air pipe and as an air pipe for preventing white smoke. In this way, by making a part of the pipe common and using it for both the combustion air pipe and the white smoke prevention air pipe, equipment can be simplified.

Furthermore, since the number of opening/closing valves 40 is reduced, labor savings in valve opening/closing and other main operations can be achieved. The other configurations and operations are substantially the same as those described with reference to FIGS. 1 and 2, so explanations will be omitted.

As explained above, according to the present invention, at least two air preheaters are installed in parallel on the path that releases exhaust gas into the atmosphere, and these are used selectively, so that the garbage is completely combusted and the white smoke is eliminated. This is prevented by utilizing the heat of the exhaust gas without providing any other heating means. In particular, when one air preheater is used to heat air for combustion and the other preheater is used to heat air to prevent white smoke, a pressure of 200 On+IIIAQ or more is required to form a fluidized bed, and pressure loss in the system is required to prevent white smoke. Since a culm degree of 200 mmAq is required, applying the present invention to incineration equipment using a fluidized bed incinerator will also bring about an energy saving effect.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a schematic diagram showing an example of a fluidized bed waste incineration fJl equipment that implements the method of the present invention, and Fig. 2 is a block diagram showing an example of the equipment that implements the present invention. FIG. 3 is a block diagram showing another example.

Claims (1)

[Claims] (1) In a waste incineration facility in which an air preheater and an electrostatic precipitator are installed at a crossroads where exhaust gas generated from a waste incinerator is discharged into the atmosphere, at least two air preheaters are connected in parallel.
Depending on the nature of the waste to be incinerated, the atmospheric temperature at which exhaust gas is released, etc.,
) A method of operating a garbage incinerator characterized by switching between three types of operation. (a) The first operation method is to send incineration air to two air preheaters to exchange heat with the exhaust gas, and then supply the high-temperature air to the waste incinerator; (b) the combustion air is directly dumped and incinerated. The air supplied to the furnace to prevent white smoke is sent to two air preheaters to raise its temperature, and the heated air is mixed with the exhaust gas coming out of the electrostatic precipitator to raise the temperature of the exhaust gas and dilute it. (C) Part of the combustion air is sent directly to one air preheater, the rest is sent to one air preheater to make it high temperature, and then supplied to the waste incinerator, and the white smoke prevention air is sent to the other air preheater. The third operating method involves increasing the temperature of the exhaust gas by mixing the heated air with the exhaust gas discharged from the electrostatic precipitator to increase the temperature of the exhaust gas and partially diluting the exhaust gas. (2) A method for operating a garbage incinerator according to claim 1, wherein the air for white smoke prevention raised by an air preheater is further heated in a hot air generator. (3) A garbage incinerator; two or more air preheaters installed in parallel in the exhaust gas path of the waste incinerator; a gas cooler installed in the exhaust gas path upstream or downstream of the air preheater; In a garbage incinerator equipped with an electrostatic precipitator provided in an exhaust gas path downstream of a gas cooler and a chimney located at the downstream end of the exhaust gas path, two or more of the air preheaters are used to force combustion air from the blower. are passed in parallel to the waste incinerator (a combustion air pipe, a bypass pipe that bypasses the air preheater in the combustion air pipe, and a white smoke prevention air pipe that bypasses the air preheater). A waste incineration device characterized by comprising: an air pipe line for preventing white smoke that leads from the blower to the exhaust gas downstream of the electrostatic precipitator via two or more of the air preheaters in parallel. 4. The waste incineration apparatus according to claim 3, wherein a part of the combustion air pipe line and a part of the white smoke prevention air pipe line are common.