JPS598169B2 - Flue gas denitration equipment integrated with electrostatic precipitator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flue gas denitrification device integrated with an electrostatic precipitator that can simultaneously perform dust removal and denitration of combustion exhaust gas (hereinafter simply referred to as flue gas) in the same device.

Nitrogen oxides contained in exhaust gas (hereinafter referred to as NOx)
NH3, H2S, H2, CO
Recently, a so-called dry flue gas denitrification device has been developed, in which a reducing agent such as , CH4, etc. is added to the exhaust gas and brought into contact with a denitrification catalyst to reduce NOx to N2 and render it harmless.

However, in dry denitrification equipment using a catalyst as described above, dust, tar, and unburnt carbon (
Since the catalyst is poisoned by dust (hereinafter referred to as dust, etc.) and the activity characteristics of the catalyst are reduced, the removal of dust and the like from the exhaust gas becomes an important issue.

For this reason, conventionally, it was necessary to install an electrostatic precipitator upstream of the flue gas denitrification equipment and perform dust removal and denitration of the flue gas using separate equipment, which not only increased flue gas treatment costs, but also
The drawback was that it required a large installation space. The present invention was made to solve these deficiencies, and by integrating an electrostatic precipitator and an exhaust gas denitrification device, in other words, by providing a plurality of dust collecting plates in the main body, and by integrating these dust collecting plates. A plurality of discharge electrodes are arranged and arranged between the plates, cylindrical denitrification catalysts and discharge protrusions/catalyst supports are alternately attached to these discharge electrodes, and reducing agent addition means is further provided on the upstream side of the discharge electrodes. The object of the present invention is to provide a device that can simultaneously perform dust removal and denitration of exhaust gas in the same compact device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below based on embodiments shown in the drawings.

In Figures 1 and 2, 1J has an exhaust gas inlet 2 at one end, a clean gas outlet 3 at the other end, and a dust outlet 4 at the bottom.
This main body 1 is a device main body (hereinafter referred to as main body) having
A plurality of dust collecting plates 5 are provided within the exhaust gas flow at regular intervals parallel or substantially parallel to the exhaust gas flow. A plurality of rod-shaped discharge electrodes 6 are arranged and provided between these dust collecting plates 5. These discharge electrodes 6
Fig. 1 shows the case where they are arranged in series as an example, but as will be described later, they may be arranged in a staggered or triangular shape so that the denitrification catalyst attached to the discharge electrode and the exhaust gas can easily come into contact with each other. is desirable. The discharge electrode 6 is connected to a negative example of a high voltage generator (not shown) such as a high voltage DC power supply, and the dust collecting plate 5 is connected to the ground side to serve as a dust collecting electrode, and the dust-containing exhaust gas is collected between the two electrodes. When introduced, an electric charge is given to the dust, and the charged guest is configured to be attracted to the dust collecting plate 5. As shown in FIGS. 3 to 5, a cylindrical denitrification catalyst 7 and a discharge protrusion/catalyst support 8 are alternately attached to the discharge electrode 6, as shown in FIGS. 3 to 5.

That is, the discharge protrusion/catalyst support 8 is fixed or fixed at a predetermined position of the discharge electrode 6, and then the cylindrical denitrification catalyst 7 is placed on the discharge protrusion/catalyst support 8 and released into the denitration catalyst 7. It is attached by inserting the electrode 6. By repeating this operation, the denitrification catalyst 7 and the discharge protrusion/catalyst support 8 are alternately attached to the discharge electrode 6 in a beaded pattern. 10 is a wire that also serves as a discharge electrode, and 11 is a weight.

In this example, a case is described in which a cylindrical denitrification catalyst is used, but the catalyst is not limited to a cylindrical shape, and a catalyst previously formed into a polygonal or other arbitrary shape may be used.

It is also possible to use a structure in which a double cylinder is formed of wire mesh, a metal porous plate, etc., and the catalyst is filled in the double cylinder. In addition, although a rod-shaped member is shown as a discharge protrusion and a catalyst support, other shapes such as star, triangular, or polygonal shapes that have a protrusion for discharging and that can support a cylindrical catalyst may also be used. You can use this if you have one. Furthermore, a reducing agent addition means 12 for adding a reducing agent such as NH3, H2S, H2, CQCH4, etc. is provided between the discharge electrode equipped with the denitrification catalyst and the exhaust gas inlet 2 (see FIG. 2).

This reducing agent addition means is not limited to this position, and may be provided upstream of the discharge electrode to which the denitrification catalyst is attached, for example, near the exhaust gas population, or in the exhaust gas duct. In the device configured as described above, when the discharge electrode 6 is energized, corona discharge is performed from the discharge protrusion/catalyst support 8, and the dust in the exhaust gas at 200 to 400° C. introduced from the exhaust gas population 2 is charged. However, positive ions are immediately adsorbed to the discharge electrode 6 and neutralized, negative ions are adsorbed to the dust collecting plate 5 and removed, and the exhaust gas comes into contact with the bamboo-shaped denitrification catalyst 7 to remove the After NOx is decomposed and removed, it is discharged from the clean gas outlet.

The reaction formula in this denitrification step is as follows, taking as an example the case where ammonia is used as the reducing agent. As explained above, the device of the present invention integrates an electrostatic precipitator and a flue gas denitrification device into a compact structure, and is capable of efficiently performing dust removal and denitration of flue gas simultaneously in the same device. Another advantage is that the space required for installation can be reduced. Furthermore, the apparatus of the present invention has the effect of being able to treat exhaust gas at a high temperature of 200 to 400°C.

[Brief explanation of the drawing]

FIG. 1 is an explanatory plan view of the flue gas denitrification device integrated with the electrostatic precipitator of the present invention, FIG. 2 is an explanatory front view of the same, FIG. The figure is an enlarged sectional view taken along the line A--A in FIG. 3, and FIG. 5 is an enlarged view of a portion surrounded by a chain line circle in FIG. 3. 1... Device body, 2... Exhaust gas population,
3...Clean gas outlet, 4...Dust extraction port, 5...Dust collection plate, 6...Discharge electrode,
7...Denitration catalyst, 8...Discharge protrusion and catalyst support, 10...Wire, 11...
- Weight, 12...Reducing agent addition means.

Claims (1)

[Claims] 1 A plurality of dust collecting plates are provided in the main body, and a plurality of discharge electrodes are arranged between these dust collecting plates, and a cylindrical denitrification catalyst and a discharge protrusion/catalyst support are alternately arranged on these discharge electrodes. A flue gas denitrification device integrated with an electrostatic precipitator, characterized in that it is attached to a discharge electrode and a reducing agent addition means is provided on the upstream side of a discharge electrode.