JPH0355417A - Method for disposing combustion exhaust gas - Google Patents

Abstract

PURPOSE:To treat various noxious gases to bring the gases into a completely harmless state by a method wherein combustion exhaust gas is reacted to saturated steam generated through spray of H2O, and produced acid liquid is neutralized by a basic neutralizer. CONSTITUTION:High temperature exhaust gas containing a noxious material generated from a combustion chamber 2 flows to a reaction chamber 10. When a pump 39 is run and H2O is sprayed in the direction of the length of the reaction chamber 10 from a nozzle 12 through an injection nozzle 40 by means of a pipe 38 running from a fresh water tank 37, particulates of H2O decreases the temperature of exhaust gas and is simultaneously brought into a saturated steam state. The particulates make contact with a noxious material in exhaust gas and reacts thereto and changes properties into saturated steam. Agitation is caused through intermolecule attraction of the particulates. The particulates adsorb and collect dust contained in the exhaust gas as contact and collision are repeated. With this state, the particulates flow in a primary neutralizing chamber 11 and produces acid waste liquid. Since a proper amount of a neutralizing agent in a neutralizing agent tank 41 is sprayed in the primary neutralizing chamber 11 from above through a working nozzle 13 with the aid of a pump 43, acid foam particles and waste liquid are immediately neutralized.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method for treating combustion exhaust gas, and more specifically, it relates to a method for treating combustion exhaust gas, and more specifically to a method for treating HC1 and No. , or NO
This paper relates to methods for treating various harmful gases such as X and various harmful combustion exhaust gases such as CO, which is said to be the cause of global warming.

(Prior Art) Various efforts have been made to solve the problem of processing various industrial wastes.

For example, in addition to the original primary combustion chamber, a secondary combustion chamber is provided in the furnace, and the end-burning gas from the primary combustion chamber is drawn into the secondary combustion chamber, where it is reburned using an afterburner to reduce the concentration of soot and smoke. It has been proposed to dilute the However, this method is not very popular because it requires a large amount of combustion oil for re-combustion using an afterburner.

In addition, as shown in FIG. 5, a primary combustion chamber 101 and a secondary combustion chamber 3 are connected to each other through a smoke outlet 102 in the furnace, and furthermore, in the primary combustion chamber 101, there is a large number of air in the circumferential direction. spout 10
5 and a blower 1.
A certain amount of air is supplied into the primary combustion chamber 101 by 06, thereby burning the waste (not shown) placed on the rostol 108 from the inlet 107,
The end combustion gas in the primary combustion chamber 101 is drawn into the secondary combustion chamber 103 through the smoke intake port 102, and a large number of air jet ports 1) 0 are provided on the circumferential surface of the area disposed in the secondary combustion chamber 103. A fixed amount of air is injected into the end-burning gas from an external blower 1) 2 through a supply pipe 1) 1 having a gas supply pipe 1) 1 to forcibly re-combust the gas, which is then exhausted from the chimney 1) 4 to improve combustion efficiency. It has also been proposed to suppress the generation of harmful gases by increasing the amount of ash (109 and 1) 3 in the figure indicate the ash outlet).

(Problem to be Solved by the Invention) However, in the conventional structure shown in FIG. Insufficient air supply will not only cause incomplete combustion, but conversely, if too much air is supplied, combustion will further accelerate, resulting in incomplete combustion due to lack of oxygen. Also produces harmful non-flammable gases.

The combustion of substances has essential conditions due to the strange correlation between oxygen, combustion, and heat, and it is impossible to control the combustion conditions to an appropriate amount, especially for substances containing foreign substances such as waste.

In addition, since the temperature required for complete combustion of combustible materials is generally at least 1000°C or higher, the material of the supply pipes 104 and 1) facing into each combustion chamber in the furnace is made of, for example, special heat-resistant steel. It is impossible to withstand actual use unless you use it.

(Means for Solving the Problems) The present invention solves the various problems in the above-mentioned prior art and completely renders various harmful exhaust gases associated with the incineration of various industrial wastes harmless. The present invention relates to a method for treating combustion exhaust gas.

Furthermore, the present invention provides a method for treating combustion exhaust gas, which comprises a step of spraying H20 onto the combustion exhaust gas and reacting it with the foamed vapor generated, and a step of neutralizing the acidic liquid obtained by the reaction with a basic neutralizing agent. On the other hand, H! The process consists of a step of reacting with the foamed vapor generated by spraying 0, and a step of neutralizing the acidic liquid obtained by the reaction with a basic neutralizing agent. It also relates to a method for treating combustion exhaust gas that is repeated several times. (Function) H. Spraying O lowers the temperature of the exhaust gas while at the same time foaming and vaporizing H 2 O.

At this time, each fine particle of the foamed vapor reacts with the exhaust gas while repeatedly contacting and colliding with each other in a disturbed state with intermolecular attraction, and adsorbs the dust contained in the exhaust gas.

The bubble particles of the foamed vapor that have adsorbed harmful substances are gradually destroyed and collected as acidic waste liquid, and the foamed vapor that is not collected is further sprayed with a basic neutralizing agent as it passes through the neutralization chamber. and neutralize it together with the above acidic waste liquid.

Further, when the concentration of harmful substances contained in the exhaust gas is relatively high, the neutralization process using the above-mentioned neutralizing agent is repeated several times to completely render the substance harmless.

(Example) Below, the specific content of the present invention will be explained based on the example shown in the figure. 1 is a combustion furnace, 5 is a reaction section, 17 is a neutralization section, 37 is a fresh water tank, and 41 is a neutralization section. The medicine tank is shown.

The combustion furnace 1 is constructed of a furnace body having sufficient volume and heat resistance to accommodate various industrial wastes, and has flues 4 and 8 through partition walls 3 and 6.

The neutralization section 17 is installed at a certain distance from the combustion furnace 1, and is connected to the secondary neutralization chamber 20 through partition walls 18, 24, and 33.
The tertiary neutralization room 27 and the practice path 35 are in full form.

The reaction section 5 is interposed between the combustion furnace 1 and the neutralization section 17, and consists of a horizontal reaction chamber 10, a buried channel 9 extending vertically at both ends of the reaction chamber 1o, and a primary neutralization chamber 1). , one flue 9 is connected to the flue 4 of the combustion furnace l via a smoke window 7, and the other primary neutralization chamber 1l is connected to a secondary neutralization chamber 20 through a buried window 19.

Note that 25 and 34 indicate smoke windows.

The horizontal reaction chamber 10 has an injection port 12 at its end near the flue 9 that injects water in the length direction (vertical direction) of the primary neutralization chamber 1) in the length direction of the reaction chamber 10. In addition, there are a regular injection port 13 and an emergency injection port 14 that direct the injection toward the end near the primary neutralization chamber 1). Note that 15 indicates a plurality of separators arranged at regular intervals in the primary neutralization chamber 1). Primary neutralization room 1)
The secondary neutralization chamber 20 and the secondary neutralization chamber 2o are separated by a partition wall 18 and communicated with each other by a recessed window 19. Similarly, the secondary neutralization chamber 20 and the tertiary neutralization chamber 27 are separated by a partition wall 24 and a smoke window 25.
I am more familiar with it.

Furthermore, the upper part of the secondary neutralization chamber 20 has a regular injection port 2l, 2
2 and an emergency injection port 23, and regular injection ports 28, 29, and 30 are provided in the upper part of the tertiary neutralization chamber 27, respectively.

Reference numeral 36 indicates a chimney, which is installed above a flue 35 that is partitioned by a partition wall 33 and communicated with through a smoke window 34.

Furthermore, 16 is a waste liquid collection port formed at the bottom of the primary neutralization chamber, 26 and 31 are sloped surfaces for collecting waste liquid formed at the bottom from the secondary neutralization chamber to the tertiary medium phase chamber and the flue 35,
Reference numeral 32 indicates a waste liquid collection port formed in the valley of the slope.

The fresh water tank 37 contains a large amount of H. It has a volume for storing O, and is connected to the injection port 12 by a pipe 38 via a bomb 39.
The injection nozzle 40 is contacted.

The neutralizing agent tank 41 has a sufficient volume to store a basic neutralizing agent, has a PH meter 42 inside, and also has a bomb 4.
3 to the header 45 via the pipe 44, and the hesoders 45 and 47 via the pipe 46, and from the pipe 46 to the regular jet port 21 in the secondary neutralization chamber 20 via the pipe 48. , and are connected via pipes 49 to the regular spout 28 facing into the tertiary neutralization chamber 27, respectively. As neutralizing agents used here, ammonium carbonate, caustic soda, and calcium hydroxide may be used, but ammonium carbonate is expensive, and although calcium hydroxide has good neutralization efficiency, it suspends and precipitates, so it cannot be removed later. There are difficulties in processing.

Therefore, it is practical to use caustic soda, which is easily soluble in water.

Furthermore, the header 47 is connected to the regular spout 13 of the primary neutralization chamber 1) via the vibrator 5l, and the vibrator 50, 52, 5
3 and the regular injection ports 29 and 30 of the tertiary neutralization chamber 27,
and the regular injection port 22 of the secondary neutralization chamber 20, respectively.

Furthermore, header 45 and emergency injection port l of primary neutralization chamber 1)
4 and the emergency spout 23 of the secondary neutralization chamber 20 are connected by a pipe 54 with a solenoid valve 55 interposed in the middle.

62 indicates a waste liquid tank equipped with a PH meter 63, and a waste liquid sampling port 1.
6 and 32 via drain pipes 64 and 65, and a PH meter 68 is interposed in the drain pipe 64.

Reference numeral 61 denotes a drainer for separating the waste liquid in the waste liquid tank 62 and removing drainage, and is connected to the waste liquid tank 62 by a suction pipe 66 and to the fresh water tank 37 by a purified water pipe 67.

Reference numeral 56 indicates a neutralizing agent tank, one of which is connected to the neutralizing agent tank 41 through a pipe 58, and the other is connected to the neutralizing agent tank 41 with a vibrator.
61 suction pipes 66, respectively, and metering pumps 57, 59 are interposed in the vias 158, 60, respectively.

69 represents an operation panel, and the details of the connections are omitted from the illustration, but bombs 39, 43, PH total 42, 63, 6
8, Solenoid valve 55, metering bomb 57, 59, thickener 6
1 and are electrically connected to each other, and the PH total is 42
, 63, 68, etc. Automatic operation is possible in response to changes in measured values, etc.

(Function) In other words, in the above structure, the high temperature exhaust gas containing harmful substances generated from the combustion chamber 2 is transferred to the flue 4, the smoke window 7, and the flue 8.
The reaction chamber 10 is horizontal.

At this time, the operation panel 69 is operated to drive the bomb 39, and the H! Spray 0.

Sprayed H! At the same time as the temperature of the exhaust gas is lowered, the fine particles marked with ○ turn into foam and vapor due to the temperature of the exhaust gas, and when they come into contact with harmful substances in the exhaust gas, they react and transform into acidic foam and vapor. Further, the particles are disturbed by the intermolecular attraction of each fine particle, and while repeating contact and collision with each other, they adsorb and collect the dust contained in the exhaust gas, and flow into the primary neutralization chamber 1).

The bubble particles of the foamed vapor flowing into the primary neutralization chamber 11 are gradually destroyed and turned into acidic waste liquid.

In the primary neutralization chamber 1), an appropriate amount of the neutralizing agent in the neutralizing agent tank 41 is sprayed from above from the regular injection port 13 by the pump 43 by operating the operation panel 69, so that the acidic bubble particles and waste liquid are immediately removed. Neutralized. As the acidic bubble particles descend through the primary neutralization chamber 1), they come into pressure contact with the plurality of separators 15, which further promotes the waste liquid of the acidic bubble particles, and most of the acidic bubble particles turn into waste liquid and reach the bottom. The waste liquid is collected from the waste liquid collection port 16 through the drain pipe 64 into the waste liquid tank 62. The acidic bubble particles that are not liquefied as waste are introduced into the secondary neutralization chamber 20 through the smoke window 19, and a certain amount of neutralizing agent is injected from the upper regular injection ports 2l and 22 in the neutralization chamber, and comes into contact with the acidic bubble particles. The liquid is neutralized, turned into waste liquid, and dripped onto the slope 26. When passing through the secondary neutralization chamber together with the primary neutralization chamber 1), most of the harmful dust in the exhaust gas is removed and neutralized.
The acidic foam particles flow into the tertiary neutralization chamber 27 through the tertiary neutralization chamber 27, where the neutralizing agent is similarly injected from the upper regular injection ports 28, 29, and 30, so that the acidic foam particles are completely neutralized and the remaining acidic foam particles are removed. When the liquid is turned into waste liquid and passes through the flue 35 through the slope bow of the bottom or the smoke window 34 and rises, the waste liquid drips onto the bottom surface of the flue and the waste liquid flows from the waste liquid collection port 32 through the drain pipe 65. It is stored in the tank 62.

The purified exhaust gas, from which harmful substances have been completely removed, is discharged outward from the chimney 36.

Furthermore, if the concentration of harmful substances contained in the wandering gas discharged from the combustion chamber 2 exceeds the acidic value preset and stored in the operation panel 69, the PH meters 63 and 68 will be set to the P }1 value on the operation panel 69. Further, the solenoid valve 55 is released by a command from the operation panel 69, and in addition to the injection of the neutralizing agent from each of the normal injection ports described above, the primary neutralization chamber 1 is injected via the pipe 54.
) and the emergency injection port 23 of the secondary neutralization chamber 20.

In addition, if the neutralizing agent is injected excessively or the concentration of harmful substances in the exhaust gas decreases, the pH value measured by the PH meter
When the value increases and exceeds the above set value on the operation panel 69, the solenoid valve 55 is closed in response to a command from the operation panel 69, and the injection of the neutralizing agent from each emergency injection port 14, 23 is stopped.

Further, the sifukuner 61 takes in the accumulated drained liquid from the drained liquid tank 62 via the suction vibrator 66 and pumps it into the metering bombs 58 and 59.
The neutralizing agent is mixed with the neutralizing agent through the neutralizing agent tank 56 through the pipe 60 while completely neutralizing the drained liquid, separating it from the slatch, restoring it to neutral transparent water, and transferring it to the clean water tank. Return within 37%.

(Effects of the Invention) As described above, the present invention includes a step of spraying H20 onto combustion exhaust gas and reacting it with foamed vapor generated, and a step of reacting the acidic liquid obtained by the reaction with a basic neutralizing agent. Because it consists of a neutralization process, HC generated from the incineration of various industrial wastes, especially polymeric wastes,
Harmful gases such as I, NO1 or NOX,
Or CO! When treating high-temperature combustion exhaust gas containing various harmful substances such as H2O, the temperature of the exhaust gas is lowered by spraying H2O, and at the same time, the H2O is foamed and vaporized, and the reaction adsorbs harmful dust in the exhaust gas and turns it into acidic waste liquid. Furthermore, by neutralizing this acidic waste liquid with a neutralizing agent, it is possible to completely render it harmless.

Group 4: The exhaust gas generated when industrial waste mixed with approximately 30% polymeric waste was incinerated was treated under the following conditions, and the relationship between the temperature change of the exhaust gas and treatment efficiency was observed. The results shown in the graph in the figure were obtained.

Processing conditions heat generation? 4.0 0 0Kcal/
kg combustion amount: approx. 300 kg/h Exhaust gas temperature: reaction chamber inlet 450-500℃H! O
Temperature: 15°C HtO spray amount: Reaction chamber population 25e/min Continuous spraying Neutralizer (NaOH): PH12 saturated solution 0.81) 7s
in continuous sprayingAs is clear from the graph in Figure 4, when H2O is sprayed on high temperature exhaust gas to lower the exhaust gas temperature,
When the temperature dropped to 450''C, the reaction efficiency of HtO with foamed vapor reached 100%.The concentration of the wastewater after neutralization with the neutralizing agent was PH6-7.

Next, the test results by public institutions are shown below.

Note) The absorption towers are 0.75φ x 2ml and 0.5φ x 1.5
A structure in which m1 groups were connected in series was used. The improvement record shows the test results at the Agency of Industrial Science and Technology's Resource Technology Laboratory, and as is clear from this, the desulfurization rate is 100%.
Therefore, combustion exhaust gas can be completely rendered harmless using a relatively simple method. In addition, if the neutralization process using the neutralizing agent described above is repeated several times, it is possible to neutralize the acidic waste liquid more completely, and it is possible to treat wandering gas containing higher concentrations of harmful substances. becomes possible.

Furthermore, in addition to the regular injection nozzle in each neutralization chamber, by automatically opening and closing a solenoid valve and injecting more neutralizer from an emergency injection nozzle, it is possible to prevent changes in the concentration of harmful substances in combustion exhaust gas. can be adequately addressed.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of the main parts of a combustion exhaust gas treatment device used to carry out the method of the present invention, Fig. 2 is a plan cross-sectional view taken along line A-A in Fig. 1, and Fig. 3 is a cross-sectional view of the apparatus in Fig. 1. FIG. 4 is a graph showing the relationship between exhaust gas temperature change and treatment efficiency as a result of an embodiment of the method of the present invention; FIG. FIG. 2 is a cross-sectional view of the main parts of the waste combustion treatment device. 1 - Combustion furnace 2 - Combustion chambers 4, 8,
9, 35-... 1 buried path 5... 1 reaction part 7, l
9, 25, 34... - One smoke window 10 - Reaction chamber 1A... 1. Primary neutralization chamber l2...
・One injection port 13, 21, 22, 28, 29, 30・
...1... Regular injection port 14, 23... Emergency injection port 15... Sebarator 16, 32
−・・・・1・Drainage collection port 17・1・−・・Medium
Japanese room 20, 1-111, secondary neutral Japanese room 27,
・−・−・Tertiary neutralization room 37−−−−1−1 Shimizu tank
39, 43--・Bomb 41--・Neutralizer tank 42, 63, 68--・PH total 45, 47-・
- Hesogu 55... Solenoid valve 56
---One neutralizing agent tank 57, 59...
Fixed amount bomb 6l - Thickener 6
2... Waste liquid tank 64, 6!5 - Drain pipe 69... Operation panel No. 5 Figure 108 1) 3

Claims (2)

[Claims] (1) The process of spraying H_2O onto the combustion exhaust gas and reacting it with the foamed vapor generated, and the process of neutralizing the acidic liquid obtained by the reaction with a basic neutralizing agent. Processing method. (2) It consists of a step of spraying H_2O onto the combustion exhaust gas and reacting it with the foamed vapor generated, and a step of neutralizing the acidic liquid obtained by the reaction with a basic neutralizing agent. 2. The method for treating combustion exhaust gas according to claim 1, wherein the neutralization step using the abrasive agent is repeated several times.