JPH09299726A - Device for removing sticky solid in waste gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new device for removing sticky solid in waste gas in which sticky solid contained in waste combustion gas is effectively removed from waste gas to prevent the solid from sticking on the device. SOLUTION: Outside a bent 22 of a U-shaped waste gas flow passage 21 in which waste gas flows, an opening 23 for separating sticky solid in waste gas G separated by centrifugal force is formed. On the opening 23, a water tank 24 for sealing the waste gas flow passage 21 and also taking in the separated sticky solid S is provided. Furthermore, in the water tank 24, a discharge means 25 for discharging the sticky solid S taken in water is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adherent solid substance removing apparatus for effectively removing adherent solid substances in exhaust gas generated in a waste liquid incinerator or the like.

[0002]

2. Description of the Related Art Generally, as industrial waste liquid, waste liquid having a pH of 2 or less, waste alkali having a pH of 11 or more, semiconductor factory waste liquid such as chlorosulfonic acid, chemical factory waste liquid, boiler cleaning water, PCB
There are various types of hazardous waste liquids such as printing plant waste liquid, leather manufacturing plant waste liquid, clothing factory waste liquid, cyan / hexavalent chromium / Zn plating waste liquid, laboratory waste liquid, solvent-containing waste liquid, etc. There are those that use various agents such as a pH adjusting agent, an inorganic condensing agent, and a polymer condensing agent. In this method, various chemicals are added to the waste liquid to coagulate and settle inorganic substances and polymer compounds in the waste liquid, the solid matter is removed in a condensing tank or the like, and then only the liquid component is discharged.

However, when treating a waste liquid with a chemical agent as described above, the chemical substance is used to make an inorganic substance or a high molecular compound into a solid content, and in order to separate and remove it, a treatment tank or a storage tank for treating the separated and removed solid content. This requires a device for solid content such as, which complicates the device and inevitably increases the equipment cost. Further, as a waste liquid treatment that does not cause such a problem, there is a method of evaporating the waste liquid and opening it to the atmosphere, but this also causes air pollution. Furthermore, it has been proposed to supply waste liquid to an incinerator for thermal decomposition (oxidation treatment), but in this case, one issue is how to use the heat of exhaust gas from the incinerator. .

Therefore, the present inventor can effectively pyrolyze the various waste liquids described above in Japanese Patent Application No. 6-65996 filed previously and effectively utilize the waste heat at that time. We are proposing a new waste liquid treatment device that can achieve this.

As shown in FIG. 3, this waste liquid treatment measure is as follows.
Incinerator 1 that treats waste liquid by pyrolyzing it at high temperature
A waste heat recovery means 2 for recovering the heat of the exhaust gas from the incinerator 1 as steam, and a waste liquid line 4 for supplying the waste liquid in the waste liquid tank 3 to the incinerator 1, and the waste heat recovery device 2 A heat exchanger 5 for raising the temperature of the waste liquid by the steam from
A flash drum 6 for flashing the waste liquid heated in the heat exchanger 5 to separate it into a gas and a liquid, and a part of the liquid separated by the flash drum 6 are returned to the upstream side of the heat exchanger 5 to exchange heat. It mainly comprises a circulation means 7 for preventing the evaporation of the waste liquid in the vessel 5.

First, the waste liquid to be treated passes through the waste liquid line 4 from the waste liquid tank 3 shown in the upper right of the figure and is heated in the heat exchanger 5 from, for example, about 20 ° C. to about 120 ° C. It enters the flash drum 6, where it is depressurized and partly evaporated. The gas component (vapor) evaporated here further passes through the waste liquid gas line 8 and a plurality of gas burners 9
While flowing from the a and 9b to the incinerator 1, a part of the liquid component passes through the liquid line 10 and a plurality of liquid burners 11a,
The liquid flowing from 11b to the incinerator 1 is returned to the waste liquid line 4 from the circulation line 7a of the circulation means 7 and merged with the waste liquid flowing therethrough to preheat the waste liquid.
In the liquid incinerator 1a located in the upper stage of the incinerator 1, since the heavy oil sent from the heavy oil tank 12 is injected from the fuel burner 13 and burned by oxygen in the air sent from the air fan 14, This combustion thermally decomposes the gas and liquid components. That is, in the incinerator 1, two-stage combustion occurs in the liquid incinerator 1a and the gas incinerator 1b,
The inside of the first-stage liquid combustion section 1a is maintained at about 1200 ° C. or higher, where waste liquid that has not evaporated in the flash drum 6 is burned, and the vapor from the flash drum 6 is incinerated with the liquid incineration section 1a and gas incineration. It is supplied to both parts 2b and heat-treated. Thereby, the solid matter and the cyan compound (heavy metal) contained in the waste liquid are treated. The solid matter in the waste liquid burns at 1200 ° C, and the cyan compound burns at 900 ° C or higher.

Next, the combustion exhaust gas discharged from the incinerator 2 by this combustion is cooled in the waste heat boiler 2a of the waste heat recovery means 2 from 850 ° C. to 300 ° C., for example, and then connected to the downstream side thereof. After being collected by the cyclone 15, it is further cooled to 250 ° C. by the cooler 16 or the air preheater, and then slaked lime is mixed and neutralized through the exhaust fan 17, and then collected again by the bag filter 18. Then chimney 1
9 will be released into the atmosphere. Cyclone 1
5 and the ash containing the heavy metals captured by the bag filter 18 are separately sent to a processing system for recycling or disposal and processed. On the other hand, in the waste heat boiler 2a, steam is generated by heat recovery, and this steam is supplied to the heat exchanger 5 as a heating medium for raising the temperature of the waste liquid as described above, and after the temperature of the waste liquid flowing through the line 4 is increased, It is returned to the heat boiler 2a and circulates again as a cooling medium for cooling the exhaust gas.

[0008]

By the way, as described above, many solids contained in the waste liquid are pyrolyzed at a high temperature and treated by being burnt in two stages in the incinerator 1. Solid matter having a high melting point, such as sand and heavy metals, is discharged as it is together with the exhaust gas, and is collected by the bag filter 18 or the like on the downstream side thereof. However, NaCl (sodium chloride) contained in the waste liquid
Solids with a low melting point, such as
After flowing out of the incinerator together with the exhaust gas in the molten state, it is solidified by being cooled by the waste heat boiler 2a in the post-process and adheres to the heat transfer tube or the like in the waste heat boiler 2a to grow, resulting in heat conduction. There are cases in which there are inconveniences such as a decrease in the rate and a hindrance to the flow of exhaust gas.
Then, when such a phenomenon occurs, it is necessary to stop all the operation of the apparatus to remove the solid matter that has adhered and grown, and there is a drawback that the operation efficiency of the entire apparatus and thus the reliability are greatly reduced. there were.

Therefore, the present invention has been devised in order to effectively solve such a problem, and its purpose is to effectively remove the adhesive solid matter contained in the combustion exhaust gas from the exhaust gas. It is intended to provide a novel device for removing adherent solid matter in exhaust gas, which can be removed to prevent adherence to the device.

[0010]

In order to solve the above-mentioned problems, the present invention provides an adhering solid substance in exhaust gas separated by centrifugal force to the outside of a curved portion of a U-shaped exhaust gas flow path for flowing exhaust gas. An opening for separation is formed, and a water tank for sealing the exhaust gas flow path and for taking in the separated adherent solid matter is formed in the opening, and further, the adherent solid taken in water is formed in the water tank. It is provided with a discharging means for discharging a substance.

That is, when adhering solids in the exhaust gas discharged from an incinerator such as a waste liquid incinerator pass through the curved portion of the U-shaped exhaust gas passage, they are separated from the exhaust gas by centrifugal force and It will flow into the water tank through the formed opening. On the other hand, the exhaust gas from which this adhesive solid matter has been separated,
Since the opening of the exhaust gas passage is sealed with the water in the water tank, the exhaust gas flows directly to the downstream side of the exhaust gas passage, and does not flow out of the opening. Then, the adherent solid substance taken into the water in the water tank precipitates in the water tank as it is, and is taken out of the water tank by the discharging means provided in the water tank for disposal.

Therefore, the adhered solid matter does not adhere to and grow on the heat transfer tube of the waste liquid boiler downstream of the incinerator, and the troublesome removal work can be omitted, and the reliability of the waste liquid incinerator as a whole can be reduced. Can be greatly improved.

[0013]

Next, a preferred embodiment of the present invention will be described.

An apparatus 20 for removing adherent solid matter from exhaust gas according to the present invention, as shown in FIG. 2, recovers waste heat from the waste liquid incinerator 1 for discharging exhaust gas containing adherent solid matter. The exhaust gas passage 19 connecting to the waste heat recovery means 2 is provided and used, and as shown in FIG. 1, the curved portion 22 of the U-shaped exhaust gas passage 21 through which the exhaust gas flows.
An opening 23 is formed outside, a water tank 24 is formed in the opening 23, and a solid matter discharging means 25 is provided in the water tank 24.

The exhaust gas passage 21 is made of a U-shaped pipe in which the combustion exhaust gas flows and the curved portion 22 is positioned in the direction of gravity, and the upstream end portion of the exhaust gas passage 21 contains the adhering solid S. The waste liquid incinerator 1 that discharges the exhaust gas G is connected, and the above-mentioned waste heat recovery means is connected to the downstream end.

The opening 23 outside the curved portion 22 is formed so as to be located at the lowermost end of the curved portion 22, and as shown in the figure, the exhaust gas G flowing in the exhaust gas flow passage 21 in a curved manner.
The adhesive solid S flowing from the inside to the outside of the curved portion 22 by centrifugal force is separated and discharged directly below the exhaust gas passage 21 through the hood 22a.

The water tank 24 has a hood 22 of the opening 23.
The tank body 24a located immediately below a is filled with water so that the water surface is located at a position higher than the lower end of the hood 22a, and the separated adherent solid matter S is taken out of the opening 23. The water is used to seal the opening 23 so that the exhaust gas G does not flow out of the opening 23. The water tank 24 is provided with a water supply line 34 and a liquid level gauge 32. When the liquid level falls below a predetermined height, the valve 33 of the water supply line 34 is opened to supply water to the water tank 24 side. By supplying the liquid, a constant liquid level is always maintained.

The solids discharging means 25 bridges the endless belt 29 between the belt pulley 26 located at the bottom of the water tank and the belt pulley 27 located on the liquid surface of the water tank 24 while inclining as shown in the drawing. , A plurality of scraping members 30 are provided on the outer surface of the endless belt 29. By driving one belt pulley 27 with a motor 28, the endless belt 29 is caused to travel in the direction of the arrow shown in the drawing, and is moved onto the endless belt 29. Belt pulley 2
The discharge port 35 located at the lower part of 7 is dropped to the conveying means 31 side and discharged. In the above, first, the exhaust gas G containing the adherent solid matter S flows from the incinerator 1 to the exhaust gas flow passage 21 side, passes through this in a U-shape, and flows to the waste heat recovery means side not shown. . At this time, since gravity and centrifugal force are applied to the exhaust gas G, the adherent solid matter S contained in the exhaust gas G flows to the outside of the curved portion 22 of the exhaust gas passage 21 and passes through the opening 23. Will be separated from the exhaust gas G. Therefore, this removing device 20
Since the adherent solid matter S does not flow into the waste heat treatment apparatus or the like on the downstream side of, the adherence of the adherent solid matter S to the waste heat treatment apparatus or the like is prevented in advance. In addition, this exhaust gas passage 2
Since the opening 23 of No. 1 is sealed by the water filled in the hood 22a and the water tank 24, the exhaust gas passage 2
The exhaust gas G passing through 1 does not flow out of the opening 23. On the other hand, the adherent solid matter S separated in the exhaust gas passage 21 reaches the water surface of the water tank 24 through the opening 23, is cooled and solidified by the water, and then settles in the water tank 24 to solidify. Reaching the discharging means 25,
The solids discharging means 25 discharges the solids outside the water tank 24 for processing.

As described above, according to the present invention, the exhaust gas is caused to flow through the U-shaped exhaust gas passage, and the adhered solid matter contained therein is effectively removed by using centrifugal force and gravity, so that the incinerator It is possible to prevent the adhering solid matter from flowing into the waste heat boiler and the like on the downstream side. In addition, this removal device can remove not only sticky solids but also general solids such as sand and heavy metals that have not been thermally decomposed in the incinerator at the same time. There is also a secondary effect that the load of the dust removing means can be greatly reduced. Incidentally, in the present embodiment, the device of the present invention is attached to the waste liquid incinerator, and the case where the exhaust gas is described has been described, but the device of the present invention is not limited to this, for example, a thermal power plant, Needless to say, it can be applied very easily to exhaust gas discharged from various incinerators such as a refuse incinerator. Further, in the present embodiment, the case where the curved portion of the exhaust gas flow path is positioned in the gravity direction has been described, but if the water sealing of the opening can be performed well, the same effect as described above can be achieved even when positioned in the horizontal direction. Can be obtained.

[0020]

In summary, according to the present invention, since it is possible to easily remove the adherent solid matter in the exhaust gas discharged from the waste liquid incinerator or the like, the waste heat boiler or the like on the downstream side of the incinerator can be easily removed. The inflow of adherent solid matter can be prevented in advance. Therefore, the adhered solid matter does not adhere to and grow on the heat transfer tubes of the waste liquid boiler on the downstream side of the incinerator, and it is not necessary to perform a troublesome removal work, and the reliability of the entire waste liquid incinerator is greatly improved. You can

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention.

FIG. 2 is an overall configuration diagram showing a waste liquid treatment apparatus provided with the device of the present invention.

FIG. 3 is an overall configuration diagram showing a conventional waste liquid treatment apparatus.

[Explanation of symbols]

 20 Adhesive Solids Removal Device 21 Exhaust Gas Flow Path 22 Curved Part 23 Opening 24 Water Tank 25 Solids Discharge Means

Claims (1)

[Claims] 1. An opening for separating adherent solid matter in exhaust gas separated by centrifugal force is formed outside a curved portion of a U-shaped exhaust gas flow path for flowing exhaust gas, and the exhaust gas flow is formed in this opening. Exhaust gas characterized by forming a water tank for sealing the passage and taking in the separated adherent solid matter, and further comprising a discharge means for discharging the adherent solid matter taken in water in the water tank Adhesive solids removal device inside.