KR100294854B1 - Apparatus and method for purifying exhaust gas and burner equipped with the apparatus - Google Patents

Abstract

PURPOSE: An exhaust gas purifying apparatus by chemical reaction is provided to inexpensively and efficiently remove harmful materials in the exhaust gas discharged from a burner such as a waste incinerator. CONSTITUTION: The apparatus for purifying exhaust gas comprises a reduced water forming device(12) forming strong reduced water having a strong reducing power from fresh water; a storage tank(13) storing the strong reduced water formed by the reduced water forming device(12); a spray system spraying the strong reduced water stored in the storage tank(13) onto an appropriate position inside a chimney(11); and a lattice plate(14) which is installed at the lower part where the strong reduced water is sprayed so as to retard flowing of the exhaust gas, thereby assisting reaction between the exhaust gas and the strong reduced water, wherein the reduced water forming device(12) further comprises a housing(17) at which an inlet port(15) and an outlet port(16) are installed, and an electrolyzer which is installed in the housing(17), wherein the inlet port(15) is installed at the lower part of one side wall so as to supply fresh water in an appropriate flow rate, and the outlet port(16) is installed at the upper part of the opposite side wall to the former side wall so as to slowly overflow the formed strong reduced water to the storage tank(13), and the spray system further comprises a pump(22) which is installed inside a water pipe line(21) connected from the storage tank(13), and a spray nozzle(23) which is mounted on the end of the pipe line(21).

Description

Exhaust purifier and method and combustion apparatus equipped with such exhaust purifier

The present invention relates to an exhaust purification apparatus and method for purifying exhaust gas discharged from an incinerator and the like, and more particularly, to an exhaust purification apparatus and method for removing dioxins from such exhaust. The invention also relates to a combustion apparatus in which such an exhaust purification apparatus is installed.

Among the environmental pollution, air pollution is mainly caused by the exhaust from chimneys installed in combustion facilities such as large factories, collective residential facilities or waste incinerators. About 90% of the pollutants contained in such exhausts are gross, and dioxins, which are organochlorine compounds, are seriously harmful in that they are not only toxic but also difficult to decompose in nature.

Generally, dioxins refer to a group of compounds containing polychlorodibenzo-P-dioxin (PCDD) and polychlorodibenzofuran (PCDF), such PCDDs or PCDFs having one or two benzene rings. Some of the hydrogen atoms in the benzene ring are replaced with chlorine atoms in parallel bonding with oxygen atoms in between. Below these compounds will be referred to collectively as dioxin.

Such dioxins can be produced during the combustion of organic matter, and are particularly one of the compounds produced under incomplete combustion conditions. That is, when the combustion environment in the combustion apparatus is a high temperature and full combustion condition in which sufficient oxygen is supplied, all the elements of organic matter are decomposed and oxidized, but the combustion environment does not reach the complete combustion condition due to factors such as temperature and oxygen supply. In this state, some of the organic matter is completely decomposed and cannot be oxidized, resulting in incomplete combustion. Dioxin is one such incomplete combustion product.

In recent years, waste disposal has been converted from landfill to incineration, which has the advantage that there is little debris and can utilize the heat of combustion. It is becoming a evacuation facility. For this reason, in such a facility, an exhaust purifier is installed to remove dioxin-containing crumbs from exhaust by using a filter dust collector or an activated activated carbon device. However, these existing exhaust purification apparatuses are not only expensive for installation and operation, but also have a small purification effect.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an exhaust purification apparatus which is not only low in cost and very effective in installation and operation.

In addition, the present invention monitors the combustion environment in a combustion device such as a waste incinerator, and when the combustion is performed under incomplete combustion conditions, the exhaust purification device according to the present invention is installed so as to purify the exhaust gas by operating the exhaust purification device according to the present invention. It is also intended to provide a device.

1 is a schematic diagram showing a part of a waste incinerator in which an exhaust purification apparatus according to the present invention is installed.

FIG. 2 is a schematic diagram showing an example of an electrolysis device used in the reduced water generation device of the exhaust purification device shown in FIG.

FIG. 3 is a schematic diagram showing another example of the electrolysis device used in the reduced water generation device of the exhaust purification device shown in FIG.

According to this invention for achieving the above object, there is provided an exhaust purification apparatus for purifying exhaust by chemically reacting harmful substances of exhaust emitted from a combustion device to produce harmless substances. Such an exhaust purification apparatus includes a reduction water generator for generating strong reduced water having strong reducing power from fresh water, a reservoir for storing strong reduced water generated by the reduced water generator, and a strong reduced water stored in such a reservoir at an appropriate position in the exhaust path. A spraying device for spraying, and a grating plate installed downstream of the position where the strong reduced water is sprayed to delay the flow of the exhaust to assist the chemical reaction between the exhaust and the strong reduced water. The reduced aquatic growth value is an electrolytic device using a high frequency AC power or DC power.

In addition, according to the present invention, an exhaust purifying apparatus including a combustion chamber and an exhaust path, and purifying exhaust by chemically reacting harmful substances to generate harmless substances when the concentration of harmful substances in exhaust components exceeds a reference value, is additionally provided. A combustion device is provided that includes. Such a combustion device includes a combustion environment monitoring device for monitoring the combustion environment in the combustion chamber, an exhaust component analysis device for periodically collecting exhaust gas and analyzing the components, and spraying strong reducing water in the exhaust path to chemically react with harmful substances in the exhaust gas. An exhaust purifying apparatus for purifying exhaust by generating a harmless substance, and a control apparatus for controlling the operation of the exhaust purifying apparatus in accordance with the combustion environment and the exhaust components.

According to the present invention, there is also provided an exhaust purification method for purifying exhaust gas discharged from a combustion device by chemical reaction. Such an exhaust purification method includes a reduction water generation step of electrolyzing fresh water to generate strong reduction water having a strong reducing power, a reduction water storage step of storing strong reduction water generated in the reduction water generation step, and combustion monitoring the combustion environment in the combustion chamber. Environmental monitoring step, exhaust component analysis step of periodically collecting exhaust gas and analyzing the components, and when the combustion environment is incomplete combustion condition or the concentration of harmful substances in exhaust components exceeds the standard value Chemical reaction step of chemically reacting with the substance.

The above and other objects and details of the invention will become apparent from the description of the embodiments set forth below.

EXAMPLE

Hereinafter, with reference to the drawings, a preferred embodiment of an exhaust purification apparatus and a combustion apparatus provided with such an exhaust purification apparatus will be described in detail.

FIG. 1 schematically shows a part of a waste incinerator and an exhaust purification apparatus installed in such waste incinerator.

The waste incinerator includes a combustion chamber (not shown) and a chimney 11 which passes from the upper side of the combustion chamber to the outside. In such a chimney 11 the exhaust flows in the direction indicated by the arrow.

In addition, the exhaust purification apparatus includes a reduced water generator 12 for generating strong reduced water having strong reducing power from general fresh water such as tap water, and a storage tank 13 for storing strong reduced water generated by such reduced water generator 12; A spraying device for spraying the strong reduced water stored in such a reservoir 13 to an appropriate position in the chimney 11, and installed downstream of the position where the strong reduced water is sprayed to delay the flow of the exhaust to assist the reaction of the exhaust and strong reduced water The grating board 14 is included.

The reduced water generating device 12 is installed at the lower end of one side wall to supply fresh water at an appropriate flow rate, and an outlet for slowly flooding the generated strong reduced water generated at the upper end of the side wall opposite to the reservoir 13 ( And a housing 11 in which 16 is installed, in which an electrolytic device is installed.

Exemplary electrolytic devices are shown in FIG. 2 and FIG. 3, wherein FIG. 2 is an electrolytic device using a high frequency AC power source, and FIG. 3 is an electrolytic device using a DC power source.

The electrolytic apparatus shown in FIG. 2 has a power source 121 that receives power of 100 to 200 V at 50 Hz or 60 Hz and supplies power of 15 to 24 V at 28 KHz, and two main electrodes 123 connected to the power source 121. , 124, and two auxiliary electrodes 125 and 126 disposed one by one at each side of each of the two main electrodes 123 and 124 and grounded. The main electrodes 123 and 124 are preferably titanium platinum carbon electrodes or alumina electrodes, and the auxiliary electrodes 125 and 126 are preferably magnesium electrodes.

The redox potential and dissolved oxygen of fresh water electrolyzed by such an electrolytic apparatus are shown in Table 1 below. This measurement was performed by treating 30 liters of fresh water using 28KHz, 24V input power.

As can be seen from Table 1, the electrolyzed reduced water has much more dissolved oxygen than freshwater before treatment due to the oxygen atoms generated during the electrolysis process. Therefore, even when such reducing water is exposed to the atmosphere, it is difficult for oxygen having oxidizing power to dissolve from the atmosphere, and therefore the holding time of the reducing potential is long. In addition, electrolysis of water molecules is not a reaction to decompose into an acid and an alkali, but a reaction as shown by the following Chemical Formulas 1 and 2 below. Therefore, as shown in Table 1, the difference in acidity before and after electrolysis is not so large.

As shown in FIG. 2, the electrolytic apparatus shown in FIG. 3 receives power of 100-200V AC at 50Hz or 60Hz, but the power supply 122 supplies power of DC9-28V, and the anode 121 connected to the power supply 122. ) And a cathode 128, and an ion exchange membrane 129 disposed between the anode 127 and the cathode 128. It is preferable that both the anode 127 and the cathode 128 are titanium platinum electrodes.

The water electrolyzed by the direct current electrolytic apparatus also has the same characteristics as the water electrolyzed by the high frequency alternating current electrolytic apparatus shown in FIG.

Fresh water introduced into the reduced water generating device 12 as described above becomes strong reduced water having a potential of -600 to -800 mV by electrolysis, and is discharged and stored in the storage tank 13.

On the other hand, the spray apparatus includes a pump 22 installed in the water channel 21 leading from the reservoir 13 and a spray nozzle 23 mounted at the end of such a channel 21. The pump 22 withdraws the strong reduced water from the reservoir 13 and pressurizes it to the pressure required for spraying and then supplies it to the nozzle 23. It is preferable that a plurality of nozzles 23 are installed at a suitable position for evenly spraying strong reduced water over the entire flow path cross-sectional area in the chimney 11. Furthermore, in order to increase the contact opportunities between the inelastic particles of the exhaust and the sprayed bodies of the strongly-reduced water and to ensure sufficient reaction time, it is desirable to make the exhaust flow somewhat turbulent, and if it does not seriously affect the exhaust emission, It is preferred to spray the strong reduced water in the direction countercurrent to the flow.

The spray of strong reduced water sprayed into the chimney 11 becomes an instant supercritical water to form a strong reducing atmosphere. In such a strongly reducing atmosphere, a reaction in which chlorine contained in dioxins is replaced with hydrogen occurs and dechlorination proceeds. In order to increase the amount of decomposition with respect to the total amount of dioxins contained in the ingot, it is preferable to keep the ingot at 350 ° C to 550 ° C in a low oxygen atmosphere to promote dechlorination of the dioxin. In addition to dioxins, the lower the concentration is significantly NO _X, SO _X in the mourning.

The reaction between the sprayed bodies of the strongly reduced water and the various components of the mourning proceeds even more violently as it passes through the grid 14. It is preferable that the grating | lattice board 14 arrange | positions a honeycomb-shaped grating continuously, and it is desirable that the grating density is as compact as possible within the range which does not inhibit the flow of exhaust.

The reaction between the sprayed bodies of the strongly reduced water and the various components of the mourning proceeds even more violently as it passes through the grid 14. It is preferable that the grating | lattice board 14 arrange | positions a honeycomb-shaped grating continuously, and it is desirable that the grating density is as compact as possible within the range which does not inhibit the flow of exhaust.

On the other hand, in the combustion chamber of the combustion apparatus, various sensors (not shown) including a temperature sensor and an oxygen sensor are arranged, which are connected to a control computer (not shown) that controls the operation of the combustion device. The control computer identifies the combustion environment in the combustion chamber from the various data in the combustion chamber sensed by the sensors. In addition, the control computer periodically collects the exhaust gas by using a separate means provided in the exhaust passage and analyzes the components to obtain data on the concentration of harmful substances in the exhaust gas. If the combustion environment is an incomplete combustion condition or if dioxin above the specified value is detected in the exhaust components, the control computer operates the pump 22 to spray the strong reduced water into the chimney 11.

Although the combustion apparatus according to the present invention has been described above using the waste incinerator as an example, the combustion apparatus according to the present invention is not limited to such a waste incinerator.

It will be apparent to those skilled in the art that various changes, modifications, or adjustments may be made to the preferred embodiments described above without departing from the spirit of the invention. Therefore, this invention will include such changes, modifications and adjustments, and the protection scope of this invention will be defined by the claims.

As can be seen from the above description, according to the present invention, it is possible to efficiently remove harmful substances such as dioxin in the exhaust discharged from various combustion apparatuses installed in a waste incinerator or a factory or a group residential facility. The exhaust purification apparatus according to the present invention is very inexpensive for installation and operation thereof, and is very easy to maintain and repair.

Claims (5)

It is for purifying the exhaust discharged from the combustion apparatus, and it is a regeneration water generating device that generates reducing water, a reservoir for storing the reducing water generated by the reducing water producing device, and spraying the reducing water stored in such a storage tank at an appropriate position in the exhaust furnace. An exhaust purification apparatus comprising a spraying device and a lattice plate installed downstream of a position where reducing water is sprayed by such a spraying device to retard the flow of the exhaust and assist the chemical reaction between the exhaust and the reducing water. It consists of a power supply for supplying power, two main electrodes connected to such a power supply, and two auxiliary electrodes arranged on each side of each of the two main electrodes, respectively, and grounded. It is an electrolytic device to generate a strong reduced water having, the spray device is a reservoir And a spray nozzle for spraying the pressurized strong reduced water to pressurized to the pressure necessary for spraying and spraying the pressurized strong reduced water over the entire flow path cross section upstream of the grating plate in the exhaust passage. A combustion apparatus including a combustion chamber and an exhaust path, comprising: a combustion environment monitoring device for monitoring a combustion environment in a combustion chamber; an exhaust component analysis device for periodically collecting exhaust gas and analyzing the components; An exhaust purification apparatus for purifying exhaust by chemically reacting with harmful substances in the exhaust and generating a harmless substance, and a control apparatus for controlling the operation of the exhaust purification apparatus in accordance with the combustion environment and the exhaust components. A reducing water generating device to be produced, a storage tank for storing the reducing water produced by the reducing water generating device, a spraying device for spraying the reducing water stored in such a storage tank at an appropriate position in the exhaust passage, and a position where the reducing water is sprayed by such spraying device. It is installed downstream to support the chemical reaction between exhaust and reducing water by delaying the flow of exhaust. It includes a plate, and the reduced aquatic growth value includes a power supply for supplying a high frequency AC power, two main electrodes connected to such a power supply, and two auxiliary electrodes disposed on each side of each of the two main electrodes, one grounded An electrolytic device configured to electrolyze fresh water to produce strong reduced water having a strong reducing power, wherein the spraying device draws the strong reduced water from the storage tank and pressurizes the pressurized strong reduced water in the exhaust furnace to pressurize it to the pressure necessary for spraying. And a spray nozzle for spraying the entire flow path cross section upstream of the grating plate. 3. The combustion apparatus according to claim 2, wherein said reduced aquatic growth value of said exhaust purification apparatus is an electrolytic device that electrolyzes fresh water to produce strong reduced water having a strong reducing power. The combustion device according to claim 2 or 3, wherein the combustion device is a garbage incinerator. In the exhaust purification method for purifying the exhaust discharged from the combustion device, a reduced water generation step of generating a strong reduced water having a strong reducing power by electrolysis of fresh water, and a reduced water storage step of storing the strong reduced water generated in the reduced water generation step A combustion environment monitoring step of monitoring the combustion environment in the combustion chamber; an exhaust component analysis step of periodically collecting exhaust gas and analyzing the components; and the combustion environment is an incomplete combustion condition or the concentration of harmful substances in the exhaust components exceeds a reference value. And a chemical reaction step of spraying the strong reduced water into the exhaust furnace to chemically react with the harmful substances, wherein the chemical reaction step involves spraying the strong reduced water into the exhaust furnace upstream of the grating plate installed in the exhaust furnace. Delay the flow to promote the chemical reaction of the exhaust and reducing water, The electrochemical apparatus includes a power supply for supplying high frequency AC power, two main electrodes connected to the power supply, and two auxiliary electrodes disposed on each side of each of the two main electrodes and grounded. In the step, using a spraying apparatus including a pump for extracting the strong reduced water from the reservoir and pressurized to the pressure required for spraying, and a spray nozzle for spraying the pressurized strong reduced water upstream of the grating plate in the exhaust passage over the entire passage cross-sectional area. Exhaust purification method.