JPH1128387A - Electrostatic precipitator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic precipitator in which exhaust gas at high temperature is introduced and also sensible heat of exhaust gas is effectively utilized. SOLUTION: Fine particles of solid or liquid contained in exhaust gas are captured by the electrostatic precipitator. A dust collection electrode 13 and a discharge electrode 12 are arranged in the inside of the electrostatic precipitator so that both electrodes are made orthogonal to the flow direction of exhaust gas. The dust collection electrode 13 is made a pipe for heat exchange of a boiler. Thereby, waste heat is efficiently recovered and also formation of dioxin is inhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric precipitator capable of collecting and collecting heat of combustion gas and generated gas discharged from a combustion device or a gas generator.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional electric precipitator, FIG. 2 (a) is a schematic perspective view thereof, and FIG. 2 (b) is a perspective view showing an electrode structure thereof. In FIG. 1, an electrostatic precipitator 1 is provided with an inlet 1 a through which exhaust gas flows into an outer frame and an outlet 1 b through which clean gas is discharged, and a discharge electrode 3 supported by a fixing rod 3 a inside the device. A plate-shaped dust collecting electrode 2 is provided. The discharge electrode 3 is electrically connected via the insulator 4, and a high DC voltage is applied to the discharge electrode 3 and the dust collection electrode 2. Further, a device for periodically hammering the dust layer adhering to the discharge electrode 3 and the dust collecting electrode 2 is provided, and the shot down dust is collected and discharged by a hopper or the like.

Normally, in the electric precipitator shown in FIG. 2, the exhaust gas is once cooled using a heat exchange function of a boiler or the like, and then the exhaust gas is sent into the device. In recent years, when the temperature level of the electrostatic precipitator is 400 ° C. or lower, it has become clear that dioxin is generated, and this type of electric precipitator is not used.

[0004] In the electric precipitator shown in Fig. 2, a plate-shaped precipitating electrode 2 and a discharge electrode 3 are arranged in parallel to the flow of exhaust gas. The electrode and the discharge electrode are arranged in series. FIG. 1A is a perspective view of the same, and FIG. 1B shows the electrode structure. In FIG. 1 (a), the electrostatic precipitator 1 has a discharge electrode 5 and dust precipitating electrodes 6a, 6b provided therein, and has an inlet 1a into which exhaust gas flows and an outlet 1b through which clean gas is discharged. Dust collection electrodes 6a and 6b are arranged respectively. The discharge electrode 5 is electrically connected via the insulator 7, and a high DC voltage is applied to the discharge electrode 5 and the dust collecting electrodes 6a and 6b. Further, a device for periodically striking a dust layer adhering to the discharge electrode 5 and the dust collecting electrodes 6a and 6b is provided. This electrostatic precipitator has a relatively simple structure and has the advantage of being able to treat relatively high temperature exhaust gas.

[0005]

As described above, as described above,
When the exhaust gas treatment temperature of the electric dust collector is 400 ° C. or lower, it is apparent that dioxin is generated. To suppress the generation of dioxin, it is preferable to treat the exhaust gas in a high temperature state. However, it is expensive to use an electric precipitator made of a material that can withstand high temperatures, which is not preferable from the viewpoint of economy. The structure of the electrostatic precipitator of FIG. 2 is complicated, and it is difficult to add a heat exchange function. Even if there is a Neuft type electrostatic precipitator suitable for relatively high temperature exhaust gas, 400
An electric precipitator having a structure that can withstand high-temperature exhaust gas of not less than ° C has a disadvantage that it is expensive. Further, in the conventional electric dust collector, an electric dust collector having a heat exchange function utilizing a sensible heat of the exhaust gas while suppressing the generation of dioxin by positively using the exhaust gas having a high temperature of 400 ° C. or more. Is not yet developed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an electric precipitator capable of introducing high-temperature exhaust gas and effectively utilizing the sensible heat of the exhaust gas. Is what you do.

[0007]

Means for Solving the Problems The present invention has been made to achieve the above object, and the invention of claim 1 has the following features.
In an electrostatic precipitator for trapping solid or liquid fine particles contained in exhaust gas, inside the device, a dust collecting electrode and a discharge electrode arranged to be orthogonal to a flow direction of the exhaust gas are arranged in a flow direction of the exhaust gas. An electric dust collecting apparatus, wherein the dust collecting electrode has a heat exchange action. In this configuration, the high-temperature exhaust gas flows into the device through the dust collecting electrode that also serves as the heat exchange pipe, so that the high-temperature exhaust gas is cooled by the heat exchange pipe, and is corona-discharged with the discharge electrode. The dust is negatively charged and attracted to the dust collecting electrode, and the dust is collected by the dust collecting electrode also serving as a heat exchange pipe. On the other hand, the heat transfer medium (for example, water) in the heat exchange pipe is heated by the sensible heat of the exhaust gas and turns into steam to generate water circulation, and the electric dust collector is given a function as a boiler. I have.

According to a second aspect of the present invention, there is provided an electrostatic precipitator for trapping solid or liquid fine particles contained in an exhaust gas, wherein the dust collector is arranged inside the device so as to be orthogonal to the exhaust gas outflow direction. Electrodes are arranged on the inflow side of the exhaust gas and on the outflow side where the clean gas flows out, and discharge electrodes arranged orthogonal to the outflow direction of the exhaust gas are arranged almost in the middle of the dust collection electrode. The electrode is a heat exchange pipe, and is connected to the heat exchange pipe of the boiler. In this configuration,
Since the high-temperature exhaust gas flows into the device after passing through the dust collecting electrode also serving as a heat exchange pipe, the high-temperature exhaust gas temperature is cooled by the heat exchange pipe, and as described above, the heat exchange pipe is used. Dust is collected on the dust collecting electrode that also serves as the dust collecting electrode.
Further, the dust collecting electrodes are provided on the inflow side and the outflow side of the exhaust gas, so that the heat exchange function is effectively performed, and has a function as a boiler. In order to form an electric precipitator having such a heat exchange function, in the electric precipitator shown in FIG. 2, the dust collecting electrode and the discharge electrode are parallel to the exhaust gas inflow direction and are structurally complicated. There is impossible. 3, the dust collecting electrode, discharge electrode,
Since it is a structure arranged like a dust collecting electrode and has a relatively simple structure, a heat exchange action can be given to these dust collecting electrodes in terms of space.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the electric dust collecting apparatus of the present invention. FIG. 1 (a) is a schematic perspective view, and FIG. 1 (b) is a partially cutaway perspective view of an electrode structure. In FIG. 1A, an electrostatic precipitator 10 is a Neuerft type electric precipitator, and includes an outer frame 10a provided with an inlet 11a through which exhaust gas flows and an outlet 11b through which clean gas is discharged. Inside, the discharge electrode 12 fixed to the discharge electrode frame 16 and the dust collection electrode 13 serving also as a heat exchange pipe are provided. The discharge electrode 12 is electrically connected via a insulator 14, and a high DC voltage is applied to the discharge electrode 12 and the dust collection electrode 13. Further, the discharge electrode 12 and the dust collection electrode 1
An apparatus or the like is provided for periodically hammering the dust layer adhering to 3. 17 is a high pressure joint.

The dust collecting electrode 13 also serving as a heat exchange pipe is constituted by a boiler tube 15, and is arranged so as to be perpendicular to the exhaust gas inflow direction. Boiler tube 15
An input header tube 13a and an output header tube 13b are connected to the upper end and the lower end, respectively, by pipes or the like. The dust collecting electrode 13 is located on the inflow side of the exhaust gas (inlet 11a).
The discharge electrodes 12 are arranged at their central portions so as to be orthogonal to the inflow direction of the exhaust gas, and the sensible heat of the exhaust gas mainly passes through the boiler tube 15. As a result, the heat transfer medium absorbs the sensible heat, and the heat transfer medium circulates in the input header pipe 13a, the boiler tube 15, and the output header pipe 13b as indicated by arrows. In the electrostatic precipitator having this configuration, the superficial velocity of the exhaust gas (the leading velocity when there is nothing in the flow path) is 0.7 m / s.
Since it is around ec, by changing the size and arrangement of the heat transfer pipes such as the boiler tube 15, it is possible to obtain a structure and an arrangement that can obtain an optimal heat exchange performance. Thus, the heat exchange function can be provided to the dust collecting electrodes 13 on the exhaust gas inflow side and the clean gas outflow side. Of course, a high DC voltage is applied to the discharge electrode 12 and the dust collecting electrode 13, the charge by the DC high voltage is charged to the discharge electrode 12, corona discharge occurs, and the dust (dust) is negatively charged. Dust collection electrode 13
a, 13b. The dust is collected on the dust collecting electrodes 13a and 13b which also serve as heat exchange pipes. In this way, the basic performance of the electric precipitator is maintained.

It is difficult to provide a heat transfer function to the discharge electrode 12 by using the discharge electrode 12 as a hollow steel pipe and feeding a heat transfer medium into the hollow steel pipe because a high DC voltage is applied to the discharge electrode 12. However, a heat pipe having an independent heat exchange function as the discharge electrode 12 can be used.
In this case, it is necessary to cool the upper part of the heat pipe with air or an inert gas, and the discharge electrode 12 can be cooled although the equipment is somewhat complicated.

Further, the dust collecting electrode 13 is configured as described above, so that even if exhaust gas such as high temperature combustion gas of 400 ° C. or more flows into the apparatus from the inlet 11a, the heat transfer in the boiler tube 15 is performed. The sensible heat of the medium is absorbed, and the high-temperature exhaust gas can be reduced to 400 ° C. or less by the heat exchange action. Therefore, normal carbon steel can be used as the material of the dust collecting electrode 13. Of course, it is clear that a material other than carbon steel may be used as the material of the dust collecting electrode 13.

[0013]

As described above, according to the present invention, the sensible heat of the exhaust gas can be used as a heat source of the boiler, and the sensible heat of the waste heat can be efficiently recovered. This has the effect of providing a possible electric precipitator. Further, according to the present invention, by disposing a dust collecting electrode having a heat exchange function at an inflow port of exhaust gas of an electric dust collecting device, the combustion gas or generated gas discharged from a combustion device or a gas generator is cooled. Therefore, there is an advantage that the dust collecting electrode can be sent to the electric dust collecting device without any need, and since the dust collecting electrode is a boiler tube, the dust collecting electrode can be formed with an inexpensive material. Furthermore, according to the present invention, there is no need to cool high-temperature exhaust gas such as combustion gas and send it to the electrostatic precipitator, which has the effect of suppressing the generation of dioxin.

[Brief description of the drawings]

FIG. 1 (a) is a perspective view showing an embodiment of an electric precipitator of the present invention, and FIG. 1 (b) is a partially cutaway perspective view showing a precipitating electrode and a discharge electrode.

FIG. 2A is a perspective view showing an example of a conventional electric precipitator, and FIG. 2B is a partially cutaway perspective view showing the precipitating electrode and discharge electrode.

FIG. 3A is a perspective view showing another example of the conventional electric dust collector, and FIG. 3B is a partially cutaway perspective view showing the dust collecting electrode and the discharge electrode.

[Description of Signs] 10 Electric precipitator 10a Outer frame 11a Inlet 11b Outlet 12 Discharge electrode 13 Dust collecting electrode 13a Input header tube 13b Output header tube 14 Insulator 15 Boiler tube 16 Discharge electrode frame

Claims (2)

[Claims] 1. An electrostatic precipitator for trapping solid or liquid fine particles contained in an exhaust gas, wherein a dust collecting electrode and a discharge electrode arranged so as to be orthogonal to a flow direction of the exhaust gas inside the device. An electrostatic precipitator arranged in the flow direction, wherein the precipitating electrode has a heat exchange action. 2. An electrostatic precipitator for trapping solid or liquid fine particles contained in an exhaust gas, wherein a dust collecting electrode arranged perpendicular to a flow direction of the exhaust gas is provided inside the device. Discharge electrodes arranged on the outflow side where the clean gas flows out, and discharge electrodes arranged so as to be orthogonal to the outflow direction of the exhaust gas are disposed almost in the middle of the dust collection electrode, and the dust collection electrode is a heat exchange pipe. And an electric precipitator connected to a heat exchange pipe of a boiler.