JP2002228366A - Gas cooling tower integral with combustion furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent adhesion and accumulation of dust in gas in a gas cooling tower and to perform high efficient cooling through rectification of exhaust gas. SOLUTION: A gas rectifying device 15 formed such that a plurality of ceramic porous pipes 16 crossing a tower 11 and through which air is injected from an internal part are situated is situated at the internal part of the cooling tower 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas cooling tower for reducing the temperature of a high-temperature exhaust gas to a predetermined temperature. The present invention relates to a furnace-integrated gas cooling tower.

[0002]

2. Description of the Related Art Conventionally, in a facility such as a refuse incinerator or an ash melting furnace, after a gas containing unburned gas (CO, HC, etc.) is completely burned in a combustion furnace, the high-temperature exhaust gas is guided to a gas cooling tower. It is cooled down and sent to an exhaust gas treatment device such as a bag filter to remove suspended dust and is released into the atmosphere.

[0003] Generally, in a gas cooling tower, cooling water is sprayed so that the gas temperature at the outlet of the cooling tower becomes a predetermined temperature (allowable temperature sent to an exhaust gas treatment device such as a bag filter, for example, around 200 ° C). The gas temperature is lowered by cooling means by gas-liquid contact. By the way, FIG.
In the gas cooling tower 100 integrated with a combustion furnace as shown in the figure, the exhaust gas is directly introduced into the lower part of the cooling tower 100 from the outlet of the gas secondary combustion furnace 104, and the gas outlet 10
This is a method in which the gas temperature is reduced by spraying the cooling water by the cooling water nozzle 102 while the temperature rises to 1. Further, in the separately installed gas cooling tower 110 shown in FIG. 4B, the exhaust gas from the secondary combustion furnace 114 is guided to the exhaust gas inlet 111 above the cooling tower 110 by the duct 115 and flows into the cooling tower 110. In this method, the cooling water is sprayed from the upper part by a cooling water nozzle 113 while being sent out from the lower part of the tower by the gas discharge pipe 112 and cooled.

[0004]

However, in these systems, when the exhaust gas is introduced into the cooling tower, the flow of the gas flowing into the gas cooling tower is biased, which causes the adhesion and accumulation of dust in the cooling tower. This causes a problem that the gas is not cooled uniformly. In particular, if dust adheres or accumulates in the tower, a great deal of cost is required for removing the dust, which greatly affects the operating cost.

In a conventional gas cooling tower integrated with a combustion furnace, the gas temperature in the combustion furnace decreases due to radiation cooling between the gas cooling tower and the combustion furnace, which hinders combustion (reduction of combustion temperature). This makes it difficult to incinerate dioxins in unburned gas, etc.). Furthermore, if a situation occurs in which the cooling water does not completely evaporate due to gas drift and fluctuations in the amount of exhaust gas in the cooling tower, condensed water droplets fall into the combustion furnace, adversely affecting combustion in the furnace. On the other hand, a separately installed gas cooling tower requires a separate place for installing the gas cooling tower as compared with a gas cooling tower integrated with a combustion furnace.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and a combustion furnace capable of preventing dust contained in a gas from adhering or accumulating in a gas cooling tower, rectifying exhaust gas, and efficiently cooling the exhaust gas. It is an object to provide an integrated gas cooling tower.

[0007]

In order to achieve the above-mentioned object, a gas cooling tower integrated with a combustion furnace according to the present invention has a cooling tower inside, in which air is traversed inside the tower and air is blown from inside. A gas rectifier having a plurality of ceramic porous tubes to be ejected is provided.

According to the present invention, the high-temperature exhaust gas from the secondary combustion furnace is guided to the cooling tower, and the plurality of high-temperature exhaust gases installed in the cooling tower rise across the cooling tower and flow to the gas outlet. The gas flow is rectified by the gas rectifier in which the ceramic porous tubes are arranged, and when the gas flows through the gas rectifier, the gas can be made to flow almost uniformly. The spray of the cooling water from the nozzles generally works effectively to enhance the cooling effect. In addition, by balancing the gas flow, it is possible to prevent the dust contained in the tower from adhering and accumulating,
These processes can be omitted, and the operation efficiency can be improved. Further, in the case where the gas rectifier is directly connected to the upper part of the combustion furnace, the gas rectifier can prevent radiation cooling between the cooling tower and the combustion furnace, and can also prevent the gas temperature in the combustion furnace from being lowered. In addition, even if water droplets of the cooling water are generated, the water droplets can be prevented from directly falling into the combustion furnace.

In the first aspect of the present invention, the gas rectification device includes a plurality of ceramic porous tubes arranged in multiple stages at predetermined intervals, and supplies air into each ceramic porous tube from the outside and flows out of the tubes. It is good to be made the structure to make it. By doing so, the gas flows between the ceramic porous tubes arranged at the required intervals, so that an appropriate resistance can be given and the flow of the gas can be rectified. Then, the ceramic porous tube sends air into the inside and flows air out of the gap of the porous portion, thereby forming a film of air on the surface of the tube to prevent exposure to high temperature. The effect of enabling long-term use is obtained.

In the first invention and the second invention, it is preferable that the plurality of ceramic porous tubes constituting the gas rectifier are provided at least vertically in a two-stage staggered arrangement (a third invention). This allows the gas rising from below to flow between the plurality of the arranged ceramic porous tubes without going straight, thereby enhancing the rectifying effect. Further, since the inside of the tower is projected and vertically divided by the plurality of ceramic porous tubes, radiant cooling between the cooling tower and the combustion furnace can be reliably shut off.

Further, in the first invention to the third invention, when a plurality of ceramic porous tubes of the gas rectification device are arranged in multiple stages, the air piping to be supplied to each is divided into each stage, and It is preferable that an on-off valve be provided in each stage pipe so as to be switchable. In this manner, the supply of air to the ceramic porous tube can be selected according to the amount of gas sent to the cooling tower, the amount of air consumption can be reduced according to the exhaust gas processing capacity, and the running cost can be reduced. Reduction can be achieved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a specific embodiment of a combustion furnace-integrated gas cooling tower according to the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram of an ash melting treatment apparatus provided with a combustion furnace-integrated gas cooling tower according to the present invention.
FIG. 2 is a schematic diagram showing a part of the gas cooling tower of the present embodiment with a cutout, and FIG. 3 is a diagram showing an arrangement of ceramic porous tube groups in a gas rectifier.

The gas cooling tower according to this embodiment is mainly used in a process of treating exhaust gas from a secondary incinerator in a melting treatment apparatus for fly ash and the like generated due to waste treatment and incineration of industrial waste. .

In the ash melting apparatus 1 shown in FIG. 1, exhaust gas containing unburned gas generated in the incineration process in the ash melting furnace 2 is passed through a gas discharge port 2a provided in the upper part of the ash melting furnace 2 and ducted. The exhaust gas containing the unburned gas is secondarily burned in the secondary combustion furnace 4 by the secondary combustion furnace 3, and its temperature is reduced to a predetermined temperature by a cooling tower 10 provided at an upper portion thereof. The gas is sent to a bag filter 6 by a duct 5 to remove dust, and the purified gas is sucked by an exhaust fan 7 to be released from the stack 8 to the atmosphere. In the figure, reference numeral 4a denotes an air feeder to the secondary combustion furnace, 21 denotes an ash feeder for feeding fly ash A to be melted to the ash melting furnace 2, 22 denotes a feed screw,
Reference numerals 23 and 23 'denote electrodes of an ash melting furnace, 24 denotes a discharge processing device for crushing B, and 25 denotes a conveyor for discharging dust captured by a bag filter.

The cooling tower 10 provided on the furnace top of the secondary combustion furnace 4 has a flow of exhaust gas guided from the secondary incinerator 4 to the cooling tower 10, which is evenly dispersed in the tower 11 and flows to a gas outlet 12. The gas rectifier 15
Is provided, and a spray nozzle 13 for cooling water is disposed at an intermediate portion in the tower, so as to cool flowing exhaust gas. In the drawing, reference numeral 14 denotes a cooling water supply pipe, and 17 denotes a supply air pipe.

The gas rectifier 15 has a plurality of ceramic porous tubes 16 arranged laterally at required intervals, and is arranged in a plurality of stages, and is supported by a tower wall in a state of vertically dividing the inside of the tower. I have. One end of each ceramic porous tube 16 is closed, and air is supplied from the other end to the inside by piping from the outside of the tower so that the porous body passes through the porous body and flows out from the peripheral surface of the tube. Have been. The supply air pipe 17 for each ceramic porous pipe 16 is divided into a plurality of pipes arranged in a multilayer (multi-stage) and divided into respective layers, and a control valve 1 is provided for each of the divided pipes.
If 8 is provided, the supply of air can be controlled according to the amount of exhaust gas.

The ceramic porous tube 16 used in the gas rectifier 15 has a heat-resistant temperature of about 1400 ° C., and has an operating range of 50 to 100 mmH ₂ O,
Desirably 80~100mmH ₂ O ventilation resistance becomes such porosity and thickness (e.g., a thickness of 10m with internal diameter 40mm
m, a porosity of about 30%) can be used to form a uniform air film thickness of the airflow flowing out of the surface of the ceramic porous tube 16.

The arrangement of the ceramic porous tubes 16 basically gives the exhaust gas flowing in the cooling tower 11 divided up and down by the gas rectifier 15 an appropriate resistance so that the flow is biased. To prevent this from happening,
The number of ceramic porous tubes 16 arranged in one row and the number of layers arranged in multiple layers are determined in consideration of the amount of exhaust gas and the amount of dust contained in the exhaust gas. FIG. 2 shows the manner of arrangement, and the number is not limited.

In order to arrange the ceramic porous tubes 16 in a multilayer (multi-stage) arrangement, as shown in FIG. 3, a staggered arrangement (a) in which the upper and lower arrangements are shifted by a half pitch.
A grid pattern (b) in which the upper and lower arrays are aligned, and a lattice-type array in which the upper and lower arrays are alternately arranged can be adopted, and further, such as a combination of these arrangements, can be selected according to the exhaust gas to be treated. . In the above arrangement procedure, if a staggered arrangement is employed, the inside of the tower is cut off when viewed two-dimensionally, so that the effect of cooling radiation between the inside of the cooling tower 10 and the combustion furnace 4 is ensured. There are advantages that can be eliminated.

The gas cooling tower 10 configured as described above is
Since the above-mentioned gas rectifier 15 is arranged in the lower part of the tower, when high-temperature exhaust gas generated in the secondary combustion furnace 4 is fed, the exhaust gas is discharged into a plurality of ceramic porous tubes arranged in the gas rectifier 15. Since the gas flows through the narrow gap formed by the upper portion 16 and flows into the upper portion of the tower 11, the flow of the exhaust gas is dispersed by the flow resistance therebetween, is rectified, and flows to the upper portion of the tower. Therefore, the exhaust gas is efficiently cooled by coming into contact with the cooling water sprayed upward from the cooling water spray nozzle 13 provided in the middle part of the tower 11, is efficiently cooled, is reduced to a predetermined temperature, and is cooled at the upper part of the tower. It is discharged from the gas outlet 12.

Further, with such a configuration, the space inside the gas cooling tower 10, the inside of the combustion furnace 4, and the space are shut off by the gas rectifier 15, so that the gas temperature inside the combustion furnace 4 due to radiant cooling is prevented from lowering. And does not cause a decrease in combustion efficiency. Further, even if the cooling water spray does not completely evaporate and falls as water droplets in the gas cooling tower 10, the cooling water spray is received by the ceramic porous tubes 16 arranged in the gas rectifier 15, This prevents water drops from falling into the combustion furnace 4. Therefore, there is no effect on the combustion furnace.

Further, since the air film layer is formed on the surface of each of the ceramic porous tubes 16 of the gas rectifier 15 by the air supplied into the tubes, adhesion and deposition of dust contained in the exhaust gas can be prevented. It is possible to prevent exhaust gas rectification operation. In addition, since cleaning and removal of dust can be omitted, the operation is not hindered, and the effect that the equipment can be operated for a long period of time can be obtained together with the improvement of the cooling effect.

As described above, when the ceramic porous tubes 16 are arranged in multiple stages and air is supplied to those tubes, the air supply pipes 17 are divided for each arrangement stage and the control valves are individually provided. By providing 18, for example, when the amount of exhaust gas to be cooled is large, air is supplied to all pipes, and when the amount of exhaust gas is small, air supply to, for example, the row of tubes is stopped. Control can be performed, and by doing so, the amount of consumed air can be reduced and the operating cost can be reduced.

Although the above description has been made of the apparatus used in the exhaust gas treatment equipment connected to the ash melting furnace, it can be used in a refuse incinerator according to the gist of the present invention.

[Brief description of the drawings]

FIG. 1 is a schematic view of an ash melting treatment apparatus including a combustion furnace-integrated gas cooling tower according to the present invention.

FIG. 2 is a schematic view of the gas cooling tower according to the present embodiment with a part cut away.

FIG. 3 is a diagram showing an arrangement of ceramic porous tube groups in a gas rectifier.

FIG. 4 is a schematic view showing a conventional gas cooling tower integrated with a combustion furnace (a) and a separately installed gas cooling tower (b).

[Explanation of symbols]

 1 2 Ash melting furnace 4 Secondary combustion furnace 6 Bag filter 10 Gas cooling tower 11 Inside tower 12 Gas outlet 13 Cooling water spray nozzle 15 Gas rectifier 16 Ceramic porous tube 17 Supply air piping 18 Control valve

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hitoshi Inami 2- 2-33 Kinrakuji-cho, Amagasaki City, Hyogo Prefecture Inside Takuma Co., Ltd. F-term in Takuma Co., Ltd. (reference) 4K056 CA20 DB05

Claims (4)

[Claims] 1. A combustion furnace comprising a cooling tower provided with a gas rectifier having a plurality of ceramic porous tubes arranged to blow air from inside the cooling tower across the tower. Body type gas cooling tower. 2. The gas rectifying device is configured such that a plurality of ceramic porous tubes are arranged in multiple stages at predetermined intervals, and air is supplied into each ceramic porous tube from the outside to flow out of the tube. The combustion furnace-integrated gas cooling tower according to claim 1. 3. The gas cooling tower integrated with a combustion furnace according to claim 1, wherein the plurality of ceramic porous tubes constituting the gas rectifier are provided at least vertically in a two-stage staggered arrangement. 4. When a plurality of ceramic porous tubes of a gas rectification device are arranged in multiple stages, an air pipe to be supplied to each is divided into stages, and an on-off valve is provided in each stage. The combustion furnace-integrated gas cooling tower according to any one of claims 1 to 3, which is configured to be switchable.