JP4017252B2 - Flue gas treatment equipment in an incinerator - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a flue gas treatment apparatus that captures mist-like suspended fine particles in flue gas discharged from, for example, an incinerator.
[0002]
[Prior art]
Smoke in the incinerator is a mixture of mist-like fine particles evaporated by heating and combustion and mixed in the exhaust. If the incinerated product contains synthetic resin, the synthetic resin is heated in this mist. Due to the decomposition, a large amount of fine particles of harmful substances such as dioxins are contained.
[0003]
When capturing fine particles of harmful substances such as dioxin contained in the flue gas from such an incinerator, for example, a filter (so-called bag filter) as shown in FIG. There is known a filter dust collector for filtering with a filter.
[0004]
However, in this bag filter type filter dust collector, although the dust collection rate is high, the pressure loss is as large as, for example, 100 to 200 mmAq, and the particle size that can be captured is generally 20 to 0.1 μm, particularly 0.1 μm or less. However, there is a problem in that an electrostatic dust collector having a large initial cost and a high running cost must be used in order to capture extremely fine mist particles.
[0005]
Therefore, a showering type cleaning tower (so-called jet scrubber) having a low initial cost and a low running cost as shown in FIG. 2 of JP-A-3-232514 is widely used.
[0006]
[Problems to be solved by the invention]
However, in the above-described shower ring type cleaning tower, water is supplied in the form of shower into the flue gas from the incinerator containing extremely minute mist-like particles, and the mist-like mist in the processing gas is supplied to the water droplets of the shower. There is a problem that a large amount of water is required because particles are brought into contact with each other.
[0007]
Further, in the case of capturing ultra fine mist particles in flue gas in contact with water supplied in a shower form, the so-called jet scrubber disclosed in JP-A-3-232514 is treated with water sprayed in a shower form. Since the gas is caused to flow, there is a problem that the contact efficiency with the processing gas is deteriorated.
Also, when shower water droplets are fed into stationary positive pressure or normal pressure flue gas, the water droplets push away the fine particles in the flue gas and fly away, so that the fine particles and the shower water droplets fly. In addition to low contact efficiency, the flow of shower-like water droplets tends to cause the smoke to flow along the direction of the shower.
[0008]
When a flow that flows in the downstream direction of the shower occurs in the processing gas in this way, the fine particles in the flue gas flow with the shower, and the contact between the microscopic mist particles in the flue gas and the water droplets in the shower is not performed well. There is also a problem that the trapping efficiency of the fine particles is greatly reduced.
Moreover, since generation | occurrence | production of harmful substances, such as dioxin contained in the flue gas from an incinerator, is easy to generate | occur | produce when combustion temperature is 800 degrees C or less, combustion temperature is set comparatively high.
[0009]
In order to increase the combustion temperature, a blower or the like is provided at the combustion port, and the air blown from the blower promotes combustion in the furnace and maintains the combustion temperature high. For this reason, the incinerator will be enlarged.
In addition, there is a problem that power consumption required for driving the motor of the blower is large, and not only the running cost is increased, but also control is required.
[0010]
The present invention has been proposed in view of the above-mentioned problems, and minimizes the generation of harmful substances contained in the flue gas discharged from the incinerator as much as possible, and forms a very fine mist such as generated harmful substances. To provide a flue gas treatment device in an incinerator that captures all the generation of particles and eliminates environmental pollution, and to make the incinerator and flue gas treatment device compact. It is intended.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, a flue gas treatment apparatus in an incinerator according to the present invention comprises an incinerator and a floating particulate trapping device that captures suspended particulates in flue gas discharged from the incinerator. There are a combustion port for supplying fuel with the air blow or the air blow and a smoke exhaust port for discharging the combustion exhaust gas to the outside of the furnace, and the suspended particulate trapping device has a sealable container storing the liquid for capturing particles, and a discharge port. A particulate trap tube that opens in a sealable container, a pressurizing pump that pressurizes the liquid for trapping particles stored in the sealable container, and a pressure fluid pressurized by the pressurizing pump is injected into the particulate trapping pipe. A jet pump having a jet nozzle and a suction chamber formed between the fine particle capturing pipe and the jet nozzle, the suction chamber of the jet pump being in communication with the smoke outlet of the incinerator, the jet nozzle and the fine particles Outside air between the capture tube Provided with a 引口, it is characterized in that the upper space of the sealable container is connected to the combustion port.
[0012]
In addition, an internal pressure adjusting means for the sealable container is provided in the air passage extending from the discharge port of the particulate trapping tube to the combustion port through the upper space of the sealable container, and the jet pump is disposed in front of the injection nozzle. The pressurized fluid is injected into the protective tube from the injection nozzle to form a negative pressure in the protective tube, and air is sucked by the negative pressure formed in the protective tube to mix the fluid in the protective tube It is also one of the features that the mixed jet jet pump is configured to form a negative pressure in the particulate trapping pipe by jetting the mixed jet jet stream from the protective pipe to the particulate trapping pipe.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a flue gas treatment apparatus in an incinerator according to the present invention will be described below with reference to the drawings.
FIG. 1 is a partially cutaway front view showing a schematic configuration of an incinerator attached to an incinerator and a flue gas treatment apparatus attached to the incinerator. In the figure, reference numeral 1 denotes the apparatus as a whole.
[0014]
The incinerator 2 is partitioned into a combustion section 4 and a flue section 5 communicating with each other at an upper portion by a partition wall 3 rising from the bottom 2 a of the inner chamber of the furnace. A combustion port 7 facing the crater portion of the combustion burner is provided below the rooster 6.
[0015]
An incinerated product inlet 8 is opened on the combustion section side wall 2b above the rooster 6 and an ash scraping opening 9 is opened on the combustion section side wall 4a below the rooster 6.
Further, a smoke exhaust port 10 is formed in the upper wall 2c portion of the flue portion 5, and this smoke exhaust port 10 is connected to a suction pipe 12 for supplying smoke to a floating particulate trap 11 which will be described later. A sediment scraping port 13 is provided in the partial side wall 2d.
[0016]
The incineration material inlet 8, the ash scraping port 9, and the sediment scraping port 13 are respectively closed by a cover plate 14.
The floating particulate trap 11 includes a substantially rectangular parallelepiped sealed storage container 16 storing water 15, a pressure pump 18 that sucks and pressurizes the water 15 in the storage container 16 from a water inlet 17, and a pressure pump And negative pressure forming means 19 for injecting water 15 pressurized at 18 to form a negative pressure.
[0017]
The negative pressure forming means 19 is formed with a straight tubular particle capturing tube 21 in front of the injection nozzle 20, and a suction chamber 22 is provided between the injection nozzle 20 and the end of the particle capturing tube 21 on the injection nozzle 20 side. Is formed.
A smoke exhaust suction port 23 and an outside air suction port 24 are formed in the suction chamber 22, and the smoke exhaust suction port 23 communicates with the smoke exhaust port 10 of the incinerator 2 through the suction pipe 12. 24 is provided with an adjustment valve 25 for controlling the amount of outside air to be sucked.
[0018]
Also, the upper wall 16a of the storage container 16 is provided with an internal pressure adjusting means 26 of the storage container 16 and a covered cylindrical centrifuge 27. The discharge port of the particulate trapping tube 21 is provided on the side wall 27a of the centrifuge 27. 28 is opened tangentially.
[0019]
The internal pressure adjusting means 26 is configured to urge a relief hole 29 formed in the upper wall 16a of the storage container 16 to be closed by a ball-shaped valve body 31 with a spring 30, and opens the valve body 31 to open a relief hole. The pressure adjusting gas discharged from 29 is discharged to the outside through the discharge port 32.
Further, a space portion (upper space) 33 is formed on the liquid level of the water 15 stored in the sealed storage container 16, and this space portion 33 is connected to the combustion port 7 of the incinerator 2 by the air passage 34. It is connected.
[0020]
The air from the fuel device 35 is injected into the air passage 34 near the combustion port 7 and mixed to be supplied to the combustion port 7.
As described above, the incinerator 2 and the suspended particulate trap 11 are connected by the suction pipe 12 and the air passage 34 so that the exhaust gas from the incinerator 2 is recycled and does not leak directly to the outside. It is a method.
[0021]
Next, the operation of the flue gas treatment apparatus 1 in the incinerator configured as described above will be described.
First, the pressurizing pump 18 is driven to pressurize the water in the storage container 16 and supply the water to the injection nozzle 20, and the linear injection is performed from the injection nozzle 20 to the fine particle capturing pipe 21.
When the high-pressure fluid jetted to the particulate trapping tube 21 flies in a plurality of granular forms (mist droplets), the Bernoulli's fluid flows between the flying water particles of the jet stream 36 and the surrounding stationary gas. While generating a negative pressure due to the velocity difference of the theorem, the front part of the water particles of the jet stream 36 flying in the particulate trapping tube flows while compressing the air.
[0022]
Then, the water particles in the jet flow 36 form a negative pressure around the particles, and in the front part of the particles, the air is compressed while air flies and travels through the fine particle capturing tube 21 and gradually spreads. The particle trap tube 21 is fully expanded.
[0023]
When the water particles of the jet stream 36 are fully expanded in the fine particle capturing tube 21, the negative pressures around the particles are fused together, and the fused negative pressure and the compressed air in the front part of the particles are fused together. As a result of the synergistic action with the combined particles, the soot acts like a continuous piston P acting toward the discharge port 28 side of the particulate trapping pipe, and in the vicinity of the injection nozzle 20 of the particulate trapping pipe 21. A large amount of negative pressure is formed at high pressure.
[0024]
When the negative pressure formed in the vicinity of the injection nozzle 20 of the fine particle capturing pipe 21 acts on the suction chamber 22 in this way, the smoke exhausted from the incinerator 2 is sucked into the suction chamber 22 through the suction pipe 12 from the smoke outlet 10. Outside air metered by the control valve 25 is sucked into the suction chamber 22 from the outside air suction port 24.
The smoke and the outside air sucked into the suction chamber 22 are attracted to the water particles forming the jet flow from the peripheral surface portion of the strong negative jet flow along with the jet flow. Therefore, all of the flue gas and the outside air come into contact with the particles of the jet stream, and harmful substances such as dioxins and soot contained in the flue gas adhere to the water particles forming the jet stream and are captured.
[0025]
A jet stream that captures harmful substances such as dioxins and soot flows into the centrifugal separation unit 27 and is separated into solid, gas, and liquid when swirling here. Here, the solid, liquid, and liquid separated are flown down into the water 15 in the storage container 16, the solid is settled and deposited on the bottom of the storage container 16, and the gas is a space portion of the storage container 16. The pressure in the space 33 is increased.
[0026]
When the pressure in the space portion 33 of the storage container 16 is increased, the air in the space portion 33 is supplied with the fuel to the combustion port 7 of the incinerator 2 through the air passage 34 with the increased pressure.
[0027]
At this time, the air in the space portion 33 supplied to the combustion port 7 includes the outside air sucked from the outside air suction port 24 together with the combustion exhaust gas. The combustion of the incinerator 2 is promoted by this outside air, and the inside of the incinerator 2 This temperature can be maintained at, for example, 800 ° C. or higher, at which a harmful substance such as dioxin is hardly generated when the synthetic resin is incinerated.
Further, when the pressure in the space portion 33 of the storage container 16 becomes higher than a predetermined value, the valve body 31 of the internal pressure adjusting means 26 opens the relief hole 29 against the elastic force of the spring 30, and the space portion 33 of the storage container 16. Since air is discharged, the pressure in the space portion 323 of the storage container 16 is always maintained at a predetermined value, and the temperature in the incinerator 2 is also maintained in a stable state of 800 ° C. or higher.
[0028]
Here, since a small amount of harmful substances contained in the form of mist when released from the smoke exhaust port 10 of the incinerator 2 are trapped in the water particles of the jet flow in the particulate trapping pipe 21, Even if the air in the space portion 33 of the storage container 16 discharged from the relief hole 29 in order to keep the pressure in the space portion 33 of the container 16 at a predetermined value, this causes environmental pollution and the like. There is no.
[0029]
In the above embodiment, the water 15 in the storage container 16 pressurized by the pressurizing pump 18 is directly injected from the injection nozzle 20 to the fine particle capturing pipe 21, but as shown in FIG. A protective tube 36 is disposed between the nozzle 20 and the particulate trapping tube 21, an intake port 37 is formed between the spray nozzle 20 and the protective tube 36, and the jet stream ejected from the spray nozzle 20 forms a protective tube 36. In addition to forming a negative pressure, the air sucked from the intake port 37 with this negative pressure is mixed with the jet flow of the protective tube 36 to form an air-mixed jet, and then the mixed air jet is passed from the protective tube 36 to the particulate trapping tube 21. It can also be made to inject into.
[0030]
When such a mixed jet forms a negative pressure in the particulate trap tube 21 to suck the exhaust gas into the suction chamber 22, bubbles contained in the mixed jet flow are mixed with the mixed jet flow and the inner surface of the particulate trap tube 21. Therefore, it is possible to prevent a decrease in the flow force of the mixed jet flowing in the fine particle capturing pipe 21 and to form a strong negative pressure.
[0031]
Further, as shown in FIG. 3, a plurality of injection nozzles 20 for injecting water 15 in the storage container 16 pressurized by the pressure pump 18 are provided so as to face the large-diameter particle capturing pipe 21, and the plurality of injection nozzles 20 are provided. If the jet stream is sprayed evenly onto the particulate trap tube 21, the position where the jet stream spreads in the particulate trap tube 21 approaches the jet nozzle 10 side, and the length of the particulate trap tube 21 can be shortened. Can be achieved.
[0032]
Further, a protective tube 36 may be provided in front of each of the plurality of injection nozzles 20 shown in FIG. 3 to form an air mixture jet, and this air mixture jet may be injected into the particulate trapping tube 21 (FIG. 4). reference).
[0033]
In this case, as a matter of course, the fine particle capturing tube 21 can be formed by a plurality of tubes corresponding to the protective tubes 36 as shown in FIG.
In addition, in the above embodiment, the outside air suction port 24 is formed in the suction chamber 22, but as shown in FIGS. 2, 4, and 5, the outside air is sucked through the suction port 37, and the inside of the protective tube 36. Of course, when the air-fuel mixture jet is formed, the outside air suction port 24 formed in the suction chamber 22 can also be used as the air intake port 37.
[0034]
【The invention's effect】
As described above, the flue gas treatment apparatus in the incinerator according to the present invention forms a negative pressure by the jet flow injected into the fine particle capturing pipe opened in the container whose discharge port can be sealed, and incinerate at this negative pressure. The smoke exhausted from the furnace is sucked, and the sucked smoke is brought into contact with the jet stream flowing through the particulate trapping tube to trap the suspended particulates, and the jet stream capturing the particulates is pressurized again. Since it can be pressurized and recycled with a pump, there is an advantage that the running cost can be greatly reduced without requiring a large amount of water as in the conventional showering system.
[0035]
In addition, since the exhaust smoke containing suspended particulates is sucked in by the negative pressure generated by the jet flow, the fine particles in the sucked exhaust smoke are captured in contact with the jet stream that runs as water droplets. Therefore, there is an advantage that the trapping efficiency of the fine particles can be remarkably improved as compared with the conventional jet scrubber type.
[0036]
In addition, while exhausting the smoke with the negative pressure generated by the jet flow, using the internal pressure in the sealable container that is increased by the exhaust gas discharged from the discharge port and the outside air sucked from the outside air suction port Since the air is blown to the combustion port of the incinerator, the blower attached to the combustion port of the incinerator can be eliminated as in the prior art.
As a result, the entire apparatus can be reduced in size, and there is an advantage that the initial cost and the running cost can be further reduced by eliminating the cost and labor required for driving the blower and its controller.
[0037]
Further, in the case where the internal pressure adjusting means of the sealable container is provided in the air passage extending from the discharge port of the fine particle capturing pipe to the combustion port through the upper space of the sealable container, the container that can be sealed by the internal pressure adjusting means By simply adjusting the internal pressure, the amount of air blown to the combustion port can be easily adjusted, the combustion temperature can be set to a temperature at which no harmful substances are generated, and the generation of harmful substances is prevented as much as possible to prevent environmental pollution. There is also an advantage that can be.
[0038]
In the case where the jet pump is a mixed-type jet pump, when the mixed-jet flow injected from the protective tube to the particulate trapping tube flows through the particulate trapping tube, the bubbles contained in the jet flow are mixed with the mixed-jet flow. Friction with the inner surface of the particulate trap tube is reduced to prevent a decrease in the flow rate of the mixed jet flow, so that the mixed jet flow can maintain the flow in a strong state and form a strong negative pressure There is also an advantage of being able to.
[Brief description of the drawings]
FIG. 1 is a partially cutaway side view showing a schematic configuration of a suspended particulate trap attached to an incinerator.
FIG. 2 is a longitudinal side view of the portion when the jet pump is an air-mixing type jet pump.
FIG. 3 is a longitudinal side view of the portion in the case where a jet pump is formed by a plurality of injection nozzles.
FIG. 4 is a vertical side view of the portion in the case where a mixed tube is formed by forming a protective tube in front of a plurality of injection nozzles.
FIG. 5 is a longitudinal side view of a portion where a protective tube is formed in front of a plurality of injection nozzles to form an air-mixing jet pump and a particulate trapping tube is formed in each of the protective tubes.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Smoke treatment apparatus 2 ... Incinerator 7 ... Combustion port 10 ... Smoke exit 11 ... Floating particulate capture device 15 ... Liquid for particle capture (water)
16 ... Sealable container 18 ... Pressure pump 20 ... Injection nozzle 21 ... Particulate trap tube 22 ... Suction chamber 24 ... Outside air suction port 28 ... Discharge port 33 ...・ Upper space

Claims (3)

Composed of an incinerator and a suspended particulate trap that captures suspended particulates discharged from the incinerator, and the incinerator discharges combustion exhaust gas to the outside of the furnace, supplying a combustion port that supplies fuel along with blowing or blowing. The suspended particulate trapping device having a smoke exhaust port is stored in a sealable container that stores a liquid for capturing particles, a particulate trap tube in which a discharge port opens to the sealable container, and a sealable container. A pressurizing pump for pressurizing the particle capturing liquid, an injection nozzle for injecting a pressure fluid pressurized by the pressurizing pump to the microparticle capturing tube, and a suction chamber formed between the microparticle capturing tube and the spraying nozzle; The jet pump has a jet pump, the suction chamber of the jet pump communicates with the smoke exhaust port of the incinerator, an outside air suction port is provided between the injection nozzle and the particulate trap tube, and the upper space of the sealable container Connected to the combustion port Flue gas treatment apparatus in the incinerator characterized and. 2. The incinerator according to claim 1, wherein an internal pressure adjusting means for the sealable container is provided in an air passage extending from the discharge port of the fine particle capturing pipe to the combustion port through the upper space of the sealable container. Smoke removal equipment. The jet pump has a protective tube in front of the injection nozzle, injects pressurized fluid into the protective tube from the injection nozzle to form a negative pressure in the protective tube, and air is generated by the negative pressure formed in the protective tube. A mixed-air jet pump that sucks the fluid in the protective tube into a mixed-jet flow and injects the mixed-jet flow from the protective tube to the particulate trap tube to form a negative pressure in the particulate trap tube. A flue gas treatment apparatus in an incinerator according to claim 1 or 2.

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