TWI660116B - Exhaust gas treatment equipment - Google Patents

Abstract

An exhaust gas treatment device for treating nitrous oxide exhaust gas with methane, and comprising an exhaust gas delivery pipe, a methane input pipe, and a heating portion. The exhaust gas delivery pipe is used to deliver the nitrous oxide exhaust gas. The methane input tube is used to supply methane. The heating portion includes a reaction furnace, a preheating tube extending through the bottom wall of the reaction furnace, and a plurality of vertical heating rods disposed in the reaction furnace and surrounding the preheating tubes at an angle to each other. The nitrous oxide waste gas in the exhaust gas supply pipe is mixed with the methane in the methane input pipe, and then flows into the preheating pipe to be preheated, and then enters the reaction furnace and is heated by the heating rod to be heated at a predetermined temperature. Decomposition reaction.

Description

Exhaust gas treatment equipment

The present invention relates to an exhaust gas treatment device, and more particularly to an exhaust gas treatment device.

Nitrous oxide (N ₂ O) is widely used in the semiconductor industry process and can be as high as 99.999%. However, nitrous oxide and carbon dioxide (CO ₂ ) are both greenhouse gases, and the effect of nitrous oxide is about 296 times that of carbon dioxide. Therefore, based on the concept of environmental protection and sustainable development of the earth, it is necessary to find ways to reduce the concentration of nitrous oxide emitted in industrial manufacturing processes.

Referring to Figure 1, a prior art exhaust gas treatment apparatus 1 includes an inlet scrubbing unit 11 in communication with a front end manufacturing apparatus (not shown), a reaction unit 12 in communication with the inlet scrubbing unit 11, and an outlet in communication with the reaction unit 12. The washing unit 13 and a water tank 14 for holding the washing wastewater.

The inlet washing unit 11 introduces an external water source, and uses a direct spray of water to react the exhaust gas with water to remove water soluble or water in the exhaust gas. The components of the reaction. Then, the wastewater generated after the washing is guided into the water tank 14.

The reaction unit 12 is for performing a heating decomposition reaction on the exhaust gas to precipitate a component which is heated and crystallized in the exhaust gas. The crystalline salt produced after the partial analysis can be directly physically scraped off and additionally subjected to targeted treatment.

The outlet washing unit 13 also introduces an external water source to wash the exhaust gas after the thermal decomposition reaction again to remove the components of the exhaust gas which are soluble in water or reactive with water. The waste water after washing the exhaust gas is also guided to the water tank 14 and discharged after being subjected to specific treatment. As a result, the exhaust gas washed by the outlet washing unit 13 is discharged to the outside by the power supplied from the fan 15.

However, as the awareness of environmental protection rises, the emission standards for exhaust gas are also increasing. Therefore, the washing and heating decomposition reactions of nitrous oxide exhaust gas have gradually failed to meet the emission standards. Therefore, as shown in the novel patent No. M528512 of FIG. 2, a gas treatment device 9100 for treating nitrous oxide waste gas with methane is disclosed, which comprises a pipe unit 91, a reaction chamber seat 92, and a heating unit. 93. The pipe unit 91 includes a methane conveying pipe 911, an air conveying pipe 912, a process gas conveying pipe 913 capable of supplying nitrous oxide, and an end portion 9141 connecting the methane conveying pipe 911, the air conveying pipe 912. A manifold 914 with the process gas delivery tube 913. The manifold 914 defines a premixing runner 9140. The reaction chamber holder 92 is connected to the other end portion 9142 of the manifold 914 and includes a reaction space 9210 defined The cavity wall 921, an air inlet 922 extending through the cavity wall 921 and communicating with the premixing flow path 9140, and an exhaust port 923 extending through the cavity wall 921. The heating unit 93 is adjacent to the reaction chamber 92 and can be used to heat the reaction space 9210 such that the temperature of the reaction space 9210 is not lower than 600 degrees Celsius. However, the gas treatment device 9100 shown in the above-mentioned new patent No. M528512 of the Republic of China has a low reaction efficiency, and thus cannot effectively reduce the nitrous oxide emission concentration. Therefore, it is necessary to find a solution.

Accordingly, it is an object of the present invention to provide an exhaust gas treatment apparatus.

Accordingly, the exhaust gas treating apparatus of the present invention is suitable for treating nitrous oxide exhaust gas with methane, and comprises an exhaust gas delivery pipe, a methane input pipe, and a heating portion. The exhaust gas delivery pipe is used to deliver the nitrous oxide exhaust gas. The methane input tube is used to supply methane. The heating portion includes a reaction furnace, a preheating tube extending through the bottom wall of the reaction furnace, and a plurality of vertical heating rods disposed in the reaction furnace and surrounding the preheating tubes at an angle to each other. The nitrous oxide waste gas in the exhaust gas supply pipe is mixed with the methane in the methane input pipe, and then flows into the preheating pipe to be preheated, and then enters the reaction furnace and is heated by the heating rod to be heated at a predetermined temperature. Decomposition reaction.

The utility model has the advantages that the inside of the reaction furnace is heated by a plurality of heating rods disposed in the reaction furnace to generate extremely high temperature, so that the nitrous oxide exhaust gas and the methane gas can be synchronized in an extremely high temperature environment. Thermal decomposition and redox reaction Therefore, the concentration of the nitrous oxide exhaust gas can be lowered with high efficiency.

2‧‧‧Pre-washing department

3‧‧‧ heating department

31‧‧‧Reaction furnace

311‧‧‧ bottom wall

312‧‧‧ Around the wall

32‧‧‧Preheating tube

33‧‧‧heating rod

34‧‧‧Insulation unit

341‧‧ Air layer

342‧‧‧Ceramic cotton layer

343‧‧‧Water layer

4‧‧‧The latter part of the washing department

5‧‧‧Exhaust gas pipeline

6‧‧‧methane input pipe

7‧‧‧ Entrance Department

81‧‧‧Exhaust Department

82‧‧‧Sink

Other features and effects of the present invention will be apparent from the following description of the drawings, wherein: FIG. 1 is a device configuration diagram illustrating a conventional exhaust gas treatment device; FIG. 2 is a device configuration diagram illustrating the Republic of China No. M528512; FIG. 3 is a schematic view showing the flow direction of the gas in the embodiment of the exhaust gas treating apparatus of the present invention; FIG. 4 is a device configuration diagram illustrating the embodiment; FIG. 5 is a perspective view illustrating the implementation In the example, the heating portion of the exhaust gas treatment device; and FIG. 6 is a cross-sectional view illustrating the heating portion.

Referring to Fig. 3, the exhaust gas treating apparatus of the present invention comprises a front-stage water washing section 2, a heating section 3 located downstream of the front-stage water washing section 2, a rear-stage water washing section 4 located downstream of the heating section 3, and a water washing section located at the front section. The portion 2, the heating portion 3, and the water tank 82 below the rear water washing portion 4 are suitable for treating nitrous oxide exhaust gas from the front water washing portion 2 with methane (as indicated by an arrow indicating the flow direction of the gas).

Referring to Figure 4, an embodiment of the exhaust gas treatment apparatus of the present invention includes an inlet portion 7. The front stage water washing unit 2, an exhaust gas delivery pipe 5, a methane input pipe 6, the heating unit 3, the rear stage water washing unit 4, an exhaust unit 81, and the water tank 82.

The intake port of the inlet portion 7 communicates with a front end manufacturing apparatus (not shown) and serves to cause nitrous oxide exhaust gas from the front end manufacturing apparatus to enter the exhaust gas treating apparatus of the present invention.

The intake port of the front-stage water washing unit 2 communicates with the air outlet of the inlet portion 7, and is flushed with fresh water to remove components such as dust and water-soluble gas in the nitrous oxide exhaust gas by means of wet washing.

Then, the nitrous oxide exhaust gas after the preliminary washing leaves the front stage water washing section 2 and enters the exhaust gas delivery pipe 5. At this time, the methane gas enters the methane inlet pipe 6 and is mixed with the nitrous oxide exhaust gas in the exhaust gas delivery pipe 5, and then flows into the heating portion 3.

Referring to Figures 4, 5 and 6, the heating portion 3 includes a reaction furnace 31, a preheating tube 32 extending through the bottom wall 311 of the reaction furnace 31, and a plurality of preheating tubes 32 disposed in the reaction furnace 31 and spaced around each other at an angle. The vertical heating rod 33 of the preheating tube 32 and an insulation unit 34.

The nitrous oxide waste gas in the exhaust gas delivery pipe 5 is mixed with the methane in the methane feed pipe 6 and then preheated into the preheating pipe 32 of the heating unit 3, and then enters the reaction furnace 31 and is heated by the heating rod 33. , heating decomposition at a predetermined temperature It should be used to destroy or oxidize the nitrous oxide waste gas. In the present embodiment, the predetermined temperature is greater than 850 ° C to 950 ° C, and the number of the heating bars may be six, but the invention is not limited thereto.

The heat insulating unit 34 is coated on the outer surface of the surrounding wall 312 of the reaction furnace 31, and provides an insulation effect in the form of an insulating jacket. In the present embodiment, the heat insulating unit 34 has an air layer 341 which protects the reaction furnace 31, a ceramic wool layer 342, and a water liquid layer 343 which are arranged from the inside to the outside.

Since the self-ignition temperature of the methane gas is about 550 ° C, the methane gas flowing into the reaction furnace 31 undergoes a combustion reaction with the air to continuously generate heat, so that the temperature in the reaction furnace 31 is continuously increased, thereby contributing to the inside of the reaction furnace 31. The temperature reaches the cracking temperature of the nitrous oxide off gas itself. Next, the nitrous oxide gas as the oxidizing agent is subjected to a redox reaction with methane gas as a reducing agent, and the reaction formula is as follows: 4N ₂ O+CH ₄ → CO ₂ + 2H ₂ O + 4N ₂ .

In this embodiment, the inside of the reaction furnace 31 is mainly heated by the six heating rods 33 provided in the reaction furnace 31, so that the predetermined temperature (greater than 850 ° C to 950 ° C) which is extremely high in temperature is generated, and the oxidized second is generated. Nitrogen exhaust gas is thermally decomposed and redoxed simultaneously with methane gas to break down molecular bonds and decompose into nitrogen in an extremely high temperature environment. Sub, oxygen, and hydrogen ions. Since the bonding strength between the various ionic bonds is different, for example, the binding between the oxygen ions and the hydrogen ions is stronger than the binding between the oxygen ions and the nitrogen ions, the molecules are recombined after the cooling, so that the one is efficiently reduced. The concentration of the nitrous oxide exhaust gas.

The rear stage water washing portion 4 is disposed downstream of the heating portion 3, and is used to wash the product after the heat decomposition reaction again and to lower the temperature.

The exhaust portion 81 is disposed downstream of the rear stage water washing portion 4, and is configured to mix the gas washed by the rear stage water washing portion 4 with the outside air to reduce the concentration of various components in the gas.

The water tank 82 is disposed under the heating unit 3, the front water washing unit 2, and the rear water washing unit 4, and is configured to receive the waste liquid generated after the wet washing of the front water washing unit 2 and the rear water washing unit 4.

In the present embodiment, after the reaction efficiency test of the exhaust gas treating apparatus of the present invention, the test result is: when the flow rate of nitrous oxide is 5 LPM (liter/min) and the flow rate of methane is 4 LPM, the destruction removal efficiency ( Destruction Removal Efficiency (DRE) was 91%; and when the flow rate of nitrous oxide was 16 LPM and the flow rate of methane was 3 LPM, the DRE was 92%. That is to say, in the embodiment of the present invention, if the amount of nitrous oxide used is controlled at 3 to 4 LPM, the optimum treatment efficiency can be obtained. In addition, compared with the aforementioned new patent announcement No. M528512 of the Republic of China In the present invention, if the amount of methane used in the prior art patent publication is the same, the amount of nitrous oxide which can be treated by the present invention is four times that of the novel patent publication, so that the invention obviously has high reaction efficiency. Therefore, the nitrous oxide emission concentration can be effectively reduced.

In summary, the present invention heats the inside of the reaction furnace 31 by a plurality of heating rods 33 disposed in the reaction furnace 31, so that an extremely high temperature (greater than 850 ° C to 950 ° C) is generated, and the oxidized second is produced. Since the nitrogen exhaust gas and the methane gas can be thermally decomposed and redox-reacted simultaneously in an extremely high temperature environment, the concentration of the nitrous oxide exhaust gas can be efficiently reduced, so that the object of the present invention can be achieved.

However, the above is only the embodiment of the present invention, and the scope of the invention is not limited thereto, and all the simple equivalent changes and modifications according to the scope of the patent application and the patent specification of the present invention are still Within the scope of the invention patent.

Claims (7)

An exhaust gas treatment device for treating nitrous oxide waste gas with methane, and comprising: an exhaust gas delivery pipe for conveying the nitrous oxide waste gas; a methane input pipe for supplying methane; and a heating portion including a reaction furnace, a preheating pipe extending through the bottom wall of the reactor, a plurality of vertical heating rods disposed in the reactor and angularly spaced apart from each other, and a surrounding of the reactor An insulation unit on the outer surface of the wall, wherein the nitrous oxide waste gas in the exhaust gas supply pipe is mixed with the methane in the methane input pipe, and then flows into the preheating pipe to be preheated, and then enters the reaction furnace to be heated by the heating rod. Heating to perform a thermal decomposition reaction at a predetermined temperature, the insulating unit having an air layer, a ceramic wool layer, and a water-liquid layer arranged from the inside to the outside. The exhaust gas treatment device of claim 1, wherein the predetermined temperature is greater than 850 ° C to 950 ° C. The exhaust gas treating apparatus according to claim 1, wherein the number of the heating bars is six. The exhaust gas treatment device according to claim 1, further comprising an inlet portion between a front end manufacturing device and the exhaust gas delivery pipe, and a front water washing portion, wherein the nitrous oxide exhaust gas from the front end manufacturing device is The inlet portion enters, flows to the front portion of the water washing portion for water washing, and then flows into the exhaust gas delivery pipe. The exhaust gas processing device according to claim 4, further comprising a setting on the plus A rear-stage water washing portion downstream of the heat portion for washing the product after the heat decomposition reaction and lowering the temperature. The exhaust gas treatment device according to claim 5, further comprising a water tank disposed under the heating portion, the front water washing portion, and the rear water washing portion, for receiving the front water washing portion and the rear water washing portion for washing The waste liquid produced. The exhaust gas treatment device according to claim 5, further comprising an exhaust portion disposed downstream of the water washing portion of the rear portion for mixing the gas washed by the water washing portion of the rear portion with outside air to reduce the gas The concentration of the various ingredients.