JP3228867B2 - Waste gas incinerator exhaust gas collection equipment and its operation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas collection system for a refuse incinerator provided with a bag filter and a white smoke prevention device, and a method of operating the same.

[0002]

2. Description of the Related Art Conventionally, when the temperature of exhaust gas decreases when the incinerator is started / stopped or when the inside of the furnace is cleaned, moisture in the exhaust gas condenses in the bag filter, and calcium chloride in the filter cloth deliquesces, causing clogging. And dew-point corrosion on casings and pipes. As a countermeasure, a bypass pipe is connected to the exhaust gas inlet and outlet pipes of the bag filter, so that low-temperature exhaust gas is discharged by bypassing the bag filter via the bypass pipe. Also,
In some cases, the bag filter is divided into a plurality of parts, and a part of the bag filter is used exclusively for low-temperature exhaust gas. further,
When cleaning the inside of the furnace, if polluted exhaust gas is generated, the polluted exhaust gas is discharged as it is through a bypass pipe, or a dedicated bag filter for cleaning is provided separately from a bag filter for constant operation and discharged through the filter.

[0003]

However, if the exhaust gas is bypassed as described above, a problem of air pollution due to the low-temperature exhaust gas occurs at the time of starting and stopping. If the bag filter is divided into a plurality of sections, the manufacturing cost increases, and the filter cloth in the section to be used is inevitably blocked or corroded. Then, there is a problem of an increase in equipment cost and an installation space.

[0004] In recent refuse incineration facilities, if the exhaust gas discharged from the chimney contains a large amount of water, white smoke is formed from the chimney for a long time especially when the atmospheric temperature is low such as in winter. In order to prevent this, a white smoke prevention device that blows high-temperature air into the exhaust gas to dilute the water and then discharges the diluted water is often provided.

An object of the present invention is to provide a waste gas incinerator exhaust gas collecting apparatus and a method for operating the same, which can solve the above-mentioned problems by focusing on the installed white smoke preventing apparatus.

[0006]

Means for Solving the Problems To achieve the above object, a waste gas incinerator for a refuse incinerator according to the present invention has a dust filter and a dust filter interposed in the exhaust gas pipe of the refuse incinerator. A white smoke prevention air supply pipe for supplying high temperature air for preventing white smoke from a white smoke prevention device is connected to the discharge side of an exhaust gas pipe. A heating air supply pipe connected to the air supply pipe and having a distal end connected to an exhaust gas pipe at the bag filter inlet is provided, and a first opening / closing means is interposed at the distal end side of the white smoke prevention air supply pipe, and a heated air supply pipe is provided. A second opening / closing means is interposed at the end of the pipe, and the first opening / closing means is provided based on a signal from exhaust gas temperature detecting means provided at the bag filter inlet when starting up, shutting down, and cleaning the inside of the incinerator. Operate the second opening / closing means, and Heated by supplying hot air to the white smoke prevention device in the inlet of the exhaust gas, it is provided with a flue gas temperature control device for controlling the temperature of the exhaust gas.

[0007] The method of operating the flue gas dust collection equipment of a refuse incinerator is such that a dust filter is interposed in the exhaust gas pipe of the refuse incinerator, and a white smoke prevention device is provided on the discharge side of the exhaust gas pipe. When operating the waste gas incinerator of a refuse incinerator to which high-temperature air is supplied, the high-temperature air generated by the white smoke prevention device must be It is introduced into the exhaust gas at the inlet and heats the exhaust gas to maintain the temperature of the exhaust gas at an appropriate temperature.

[0008] According to the above configuration, the exhaust gas is heated by using the high-temperature air generated by the white smoke prevention device, so that the bag filter can be used without using a new facility or an expensive special bag filter. The introduced exhaust gas can be heated to remove dust, preventing clogging of the filter cloth and dew-point corrosion of casings and pipes due to deliquescence of calcium chloride, and preventing the release of polluted exhaust gas to the atmosphere. it can.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, an embodiment of an exhaust gas collecting apparatus for a refuse incinerator according to the present invention will be described with reference to FIG.

In the exhaust gas pipe 2 of the refuse incinerator 1, a temperature control tower 3 for spraying water into the exhaust gas from the upstream side to adjust the exhaust gas temperature, a bag filter 4, an exhaust fan 5, and an exhaust chimney 6 are interposed. is set up. The bag filter 4 is provided with a hot air circulation device 7 for preventing dew point corrosion due to dew condensation due to a decrease in temperature during a period when the refuse incinerator 1 is stopped, and also prevents white smoke of exhaust gas discharged from the chimney. White smoke prevention device 8 is provided.

The hot-air circulation device 7 includes a hot-air gas recovery pipe 13A connected to a hot-air gas heater 12 from upstream of the flow rate adjusting second air damper 11 between the bag filter 4 and the exhaust fan 5. A circulation fan 14 interposed in the exhaust gas recovery pipe 13A and a hot air gas circulation pipe 13B connected from the circulation air heater 12 to the inlet of the bag filter 4 are sequentially provided. The hot air gas damper 1 for adjusting the flow rate of the hot air gas is provided in the hot air gas recovery pipe 13A and the hot air gas circulation pipe 13B.
5A and 15B are interposed respectively, and based on the detection value of the second exhaust gas temperature detector 16 of the exhaust gas pipe 2 at the outlet of the bag filter 4, the heating temperature of the heater of the hot air gas heater 12 is controlled and circulated. The amount of circulating hot air by the fan 13 is controlled to maintain the circulating hot air gas at about 150 ° C.

When the exhaust gas to be removed is at a low temperature at which dew condensation or calcium chloride deliquesce may occur, such as during start-up / stop and when cleaning the furnace, conditions of the heating gas for blowing high-temperature gas into the exhaust gas to heat the exhaust gas are as follows. (A) The gas contains little or no harmful substances, especially HCl, SO _x , NO _x , and (b) no new equipment is installed.
(C) The amount of heated air can sufficiently heat the exhaust gas, and the amount of heated air does not exceed the capacity of the bag filter 4.

To satisfy this, the present invention utilizes a white smoke prevention device 8. This white smoke prevention device 8
In order to prevent the exhaust gas from being emitted as white smoke due to the moisture contained in the exhaust gas in winter when the atmosphere is cold, high-temperature air at around 200 ° C is blown into the exhaust gas to dilute the moisture in the exhaust gas. It is to let. In the white smoke prevention device 8, since the maximum amount of heated air is set to an amount capable of preventing white smoke from the exhaust gas at the time of maximum incineration of the refuse incinerator 1, the maximum amount of generated air is generated at the time of startup, shutdown, or cleaning of the furnace. The amount of exhaust gas generated is extremely smaller than the amount of exhaust gas at the time of maximum incineration. Therefore, the exhaust gas can be sufficiently heated and heated, and the capacity of the bag filter 4 does not exceed the capacity.

That is, the white smoke prevention device 8 includes a white smoke prevention air heater 22 capable of heating the air supplied by the blower fan 21 to about 200 ° C .; A white smoke prevention air supply pipe 23 for supplying high-temperature white smoke prevention air to the exhaust gas pipe 2 between the chimneys 6, and a first opening / closing means as a first opening / closing means near the outlet side of the white smoke prevention air supply pipe 23. 1 An air damper 24 for heated air is interposed, and a flow detector 25 for white smoke prevention air is provided. The heating source supplied from the heating source supply pipe 26 to the air heater 22 is high-temperature low-pressure / high-pressure steam from another incinerator in operation or combustion gas from a city gas / kerosene burner.

The white smoke prevention device 8 is provided with a heated air supply pipe 31 according to the present invention, which uses hot air for white smoke prevention for exhaust gas heating during startup, shutdown, and furnace cleaning. I have. That is, the base end of the heated air supply pipe 31 is connected to the white smoke prevention air supply pipe 23, and the front end is connected to the exhaust gas pipe 2 between the first air damper 17 and the bag filter 4. A second heated air air damper 32 as a second opening / closing means is interposed in the vicinity of the connection portion. Further, a first exhaust gas temperature detector 18 as exhaust gas temperature detecting means is interposed in the exhaust gas pipe 2 on the downstream side of the connecting portion, and based on a detection signal of the first exhaust gas temperature detector 18, a second heated air air damper is provided. An exhaust gas temperature control device 33 for operating the exhaust gas 32 is provided, whereby the flow rate of the heated air is controlled so that the temperature of the exhaust gas can be controlled to an appropriate temperature for the bag filter 4. Reference numeral 19 denotes an exhaust gas flow rate detector that detects the flow rate of the exhaust gas discharged from the temperature control tower 3.

Next, an operation method of the exhaust gas dust collecting equipment of the above waste incinerator will be described. 1. While the refuse incinerator 1 is at rest, the warm air gas circulation device 7 performs a warm-up operation. That is, the first air damper 17 and the second air damper 11 are closed, and the warm air air damper 15 is closed.
A and 15B are opened. Then, while the circulation fan 14 is started, heating power is supplied to the hot air gas heater 12 to heat the circulation gas, and the second exhaust gas temperature detector 16
The output of the circulating fan 14 and the heating temperature of the hot air gas heater 12 are controlled by the detection signal to maintain the temperature of the circulating hot air gas at about 150 ° C., thereby preventing dew point corrosion and the like due to condensation of water vapor. .

2. In the state where the atmospheric temperature is low during the operation of the refuse incinerator 1 and the white smoke is discharged from the chimney 6 by the steam from the exhaust gas, the white smoke prevention device 8 is operated. That is, while the blower fan 21 is started, a heating source is supplied to the air heater 22 and the first heated air damper 3 is turned on.
2 is opened, high-temperature white smoke prevention air is supplied into the exhaust gas, and the moisture in the exhaust gas is diluted.

3. When the waste incinerator 1 is started up after a pause, After the flow rate detector 25 confirms that the first heated air air damper 24 is in the closed state and the second heated air air damper 32 is in the closed state in the state where the hot air gas circulation device 7 is operating, the air A heating source is supplied to the heater 22 to be heated. . The first air damper 17 and the second air damper 11 are opened, the exhaust fan 5 is started, and the inside of the refuse incinerator 1 is heated by the auxiliary burner. At this time, the exhaust gas temperature at the outlet of the temperature control tower 3 is about 20 ° C. (room temperature). . The blower fan 21 of the white smoke prevention device 8 is started, the second heated air air damper 32 is opened, and heated air is supplied from the heated air supply pipe 31 into the exhaust gas to heat it, and the exhaust gas temperature control is started. The heating air at this time is 20
Desirably around 0 ° C, and the temperature of the exhaust gas is 120 ° C,
Based on a signal from the first exhaust gas temperature detector 18, the exhaust gas temperature control device 33 controls the exhaust gas temperature control device to become a set value. . When the exhaust gas reaches 120 ° C. due to the heating of the refuse incinerator 1, the second heated air air damper 32 is closed, the supply of the heated air is stopped, and the white smoke prevention device 8 is stopped.
At this time, if white smoke is generated in the exhaust gas during operation, the operation of the white smoke prevention device 8 is continued, the second heated air opening / closing damper 24 is opened, and the heated air is discharged from the exhaust gas before exhaust. And the generation of white smoke is prevented. . Hot air air dampers 15A, 15 of the hot air gas circulation device 7
B is closed, the circulation fan 14 is stopped,
The hot air gas heater 12 is stopped. . When the temperature in the refuse incinerator 1 reaches 850 to 900 ° C., the start-up is completed.

4. When the refuse incinerator 1 is shut down from the operation, the operation is performed in the reverse order, and when the temperature detected by the first exhaust gas temperature detector 18 reaches 120 ° C., the second heated air air damper 32 is opened to open the heated air. Heating is started by supplying heated air into the exhaust gas from the supply pipe 31, and the hot air gas circulation device 7 is also started. After the shutdown is completed, the exhaust fan 5 is stopped, the second heated air air damper 32 is closed, and the air heater 22 and the blower fan 21 are stopped. The operation of the hot air gas circulation device 7 is continued.

[5] Even when the exhaust gas is discharged by the cleaning inside the furnace, the exhaust gas may be heated and introduced into the bag filter 4 in the same manner as at the time of startup.

According to the above embodiment, the heated air generated by the white smoke prevention device 8 is supplied to the low-temperature exhaust gas generated when the incinerator 1 is started, when it is stopped and when the inside of the incinerator is cleaned. Since the temperature rises to about ° C. and passes through the bag filter 4, the polluted exhaust gas is not discharged into the atmosphere as in the case of using a conventional bypass pipe. Further, it is possible to prevent clogging of the filter cloth and dew point corrosion due to deliquescence of calcium chloride generated when low-temperature exhaust gas is passed through some sections of the conventional bag filter. Further, there is no need to discharge polluted exhaust gas during furnace cleaning, and it is not necessary to provide a bag filter dedicated to furnace cleaning.

[0022]

As described above, according to the exhaust gas dust collection equipment for a refuse incinerator and the method of operating the same according to the present invention, the exhaust gas is heated using the high-temperature air generated by the white smoke prevention device. By using this method, the exhaust gas introduced into the bag filter can be heated and dedusted without using new equipment or expensive special bag filters, clogging of the filter cloth due to deliquescence of calcium chloride, casing and piping. Dew point corrosion can be prevented, and the emission of polluted exhaust gas to the atmosphere can be prevented.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of an exhaust gas dust collection facility of a refuse incinerator according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Waste incinerator 2 Exhaust gas pipe 3 Temperature control tower 4 Bag filter 5 Exhaust fan 6 Exhaust chimney 7 Hot air gas circulation device 8 White smoke prevention device 18 1st exhaust gas temperature detector 21 Blow fan 22 Air heater 23 White smoke prevention Air supply pipe 24 First air damper for heated air 25 Flow rate detector 31 Heated air supply pipe 32 Air damper for second heated air 33 Dust collection exhaust gas temperature control device

Continuation of front page (56) References JP-A-3-87511 (JP, A) JP-A-7-204433 (JP, A) JP-A-1-262916 (JP, A) JP-A-4-141214 (JP) JP-A-4-168235 (JP, A) JP-A-6-88113 (JP, A) JP-A-5-28423 (JP, U) JP-A-5-76515 (JP, U) JP 6-7813 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01D 46/00-46/54

Claims (2)

(57) [Claims] A dust filter is interposed in the exhaust gas pipe of a refuse incinerator, and a white smoke preventing air supply pipe for supplying high temperature air for preventing white smoke from a white smoke preventing device is provided. In the exhaust gas collection equipment of a refuse incinerator connected to the discharge section side of the heating air supply pipe having a base end connected to the white smoke prevention air supply pipe and a front end connected to the exhaust gas pipe at the bag filter inlet. The first opening / closing means is interposed at the tip end of the white smoke prevention air supply pipe, and the second opening / closing means is interposed at the tip end of the heated air supply pipe.
At the time of shutdown and cleaning of the furnace, the first opening / closing means and the second opening / closing means are operated based on the signal of the exhaust gas temperature detecting means provided at the bag filter inlet, and the white smoke prevention device detects high temperature in the exhaust gas at the bag filter inlet. An exhaust gas collection system for a refuse incinerator, comprising an exhaust gas temperature control device for supplying and heating air to control the temperature of exhaust gas. 2. A refuse incinerator in which a dust collecting bag filter is interposed in the exhaust gas pipe of the refuse incinerator and high-temperature air for preventing white smoke is supplied from a white smoke prevention device to a discharge portion of the exhaust gas pipe. When operating the exhaust gas dust collection equipment, when starting up, shutting down, and cleaning the inside of the incinerator, high-temperature air generated by the white smoke prevention device is introduced into the exhaust gas at the bag filter inlet to heat the exhaust gas. And a method for operating an exhaust gas collection facility of a refuse incinerator, wherein the exhaust gas temperature is maintained at an appropriate temperature.