JPS6347510B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a water film forming device for a dust collection electrode in a wet electrostatic precipitator.

(Prior Art) Conventionally, for example, gas generated from a blast furnace is purified and used as fuel gas, and a vertical wet type electrostatic precipitator is commonly used for gas purification. FIG. 7 is an explanatory diagram of a vertical wet electrostatic precipitator (hereinafter referred to as conventional example 1) provided with a cylindrical dust collecting electrode, and FIG. 8 is a partially enlarged view of FIG. 7.

In the figure, one inlet gas pipe, two gas rectifiers,
3 Gas rectifier cleaning device, 4 Dust collection electrode, 5 Discharge wire, 6 Dust collection electrode support plate, 7 Discharge wire hanging frame, 8 Discharge wire frame hanging rod, 9 Support insulator, 10 Insulator chamber, 13 Dust collection electrode cleaning Water supply piping, 14 outlet gas pipes, 15 manholes, 1
6 casings and 22 dust collection electrode cleaning water reservoirs are shown, respectively.

FIG. 9 is an explanatory diagram of a vertical wet electrostatic precipitator (hereinafter referred to as conventional example 2) equipped with a conventionally used segment-type dust collecting electrode, and FIG. 10 is a partial plan view of FIG. 9.
FIG. 11 is a partially enlarged view of FIG. 10. In the figure, the dust collecting box 17 includes dust collecting electrodes 4-1 arranged concentrically with the center of the casing 16, and dust collecting electrodes 4-1 arranged concentrically with the center of the casing 16.
The dust collecting electrode 4-2 is divided into segments. In addition, the dust collection electrode cleaning nozzle 25 is
1 side x 4 sides = 8 pieces/box are used.

By the way, according to Conventional Example 1, since it has a cylindrical dust collecting pole, the effective utilization ratio of the cross section of the box is small, and it is uneconomical. In addition, when cleaning the dust collection electrode, cleaning water is stored in the space 22 surrounded by the outside of the dust collection pipe and the dust collection pipe support plate, and the top of the dust collection pipe is washed by overflowing. The solid content accumulated in the water storage part impedes the cleaning effect and furthermore, it has the disadvantage of being the main cause of deterioration of dust collection performance.

On the other hand, in Conventional Example 2, cleaning is carried out from the cleaning water supply pipe 13 through the cleaning nozzle 25, but the cleaning is performed intermittently, and during cleaning of the dust collection electrode, the charged voltage decreases and the dust collection performance deteriorates. Furthermore, since intermittent cleaning is performed, even during the non-cleaning period after cleaning, there is a strong tendency for the dust collection performance to deteriorate as the amount of dust collected on the dust collection electrode increases. Furthermore, since the cleaning nozzle spray range is limited to a maximum of 120 degrees, it is possible to
There were problems such as the need for a surface nozzle.

(Problems to be Solved by the Invention) The present invention provides a water film forming device for a dust collection electrode that improves the efficiency of cleaning the dust collection electrode plate using an ultra-wide-angle cleaning nozzle.

(Means and effects for solving the problem) The present invention provides nozzles that form water films with different water volume distributions at one pair of corners of a box-shaped dust collection electrode, each of which is opposed to the other. 1 is a water film forming device for a dust collection electrode in a wet electrostatic precipitator, characterized in that:

The present invention will be explained in detail below with reference to the drawings.

The box-shaped dust collection box 26 of the present invention is formed by disposing dust collection electrodes 5 on four sides, and the discharge wire 4 is provided at the center. Therefore, the dust collection box 26 of the present invention forms two pairs of corners, and one pair of the corners is equipped with nozzles 25-1 and 25-2 that form water films with different water volume distributions.
Set up 5-2.

In the dust collecting box 26 of the present invention, preferably, the sub dust collecting electrode plate 5-1 is arranged in a continuous straight line toward the center of the cylinder, and the main dust collecting electrode plate 5-2 is arranged concentrically with the center of the cylinder. established and formed. Therefore, the water supply pipe 13 for cleaning water
can be arranged on the sub-dust collecting electrode plate 5-1 via a frame, but this is not particularly limited.

Conventional electrostatic precipitators have narrow collecting electrode spacing of 200 to 300 mm, and when the collecting electrodes are cleaned between these electrodes, water droplets are drawn toward the discharge electrode by electric force, causing bridging discharge and charging. Becomes unstable. To avoid this,
It is necessary to provide an R section extending in a direction away from the discharge electrode at the lower end of the dust collection pole, which has the disadvantage of deteriorating cross-sectional efficiency.

According to the experiments conducted by the present inventors, there is a close relationship between the spark starting voltage and the dust collection electrode spacing, and FIG. 6 was obtained. That is, it has been found that if the distance between the dust collecting electrodes is set to 450 mm or more, the charge can be stabilized even during cleaning without providing the above-mentioned R section at the lower end of the dust collecting pole. Also, the amount of washing water is
The charge became stable between 0.4t/Hr/m and 2.0t/Hr/m. Therefore, as a preferred embodiment of the present invention, the interval between the dust collecting electrodes is set to 450 mm or more.

The nozzles provided in the water film forming device of the present invention form water films with different water volume distributions. An example is shown in FIG. In the figure, the nozzle 25 has a flow channel formed in the nozzle body, and has a collision plate 33 horizontally perpendicular to the nozzle axis at the outlet of the flow channel via a back plate. The collision plate 33 is provided with a linear branching groove 32 extending toward the periphery. A desired notch 34 is therefore formed in the impingement plate through the back plate, which determines the spread angle of the water jetted from the nozzle.

According to the nozzle configuration of the present invention, water film patterns with different water volume distributions can be formed over a wide range by the notches 34 of the collision plate 33 and the flow dividing grooves 32. That is, it is a nozzle that has a divergence angle of 200° or more, and the amount of water at both ends is greater than the amount of water at the middle.

According to experience, when using a commercially available cleaning nozzle with a spread angle of about 120° on the top of the dust collection pole, if the nozzle is placed inside the inscribed circle of the dust collection pole, the distance between the discharge wire and the nozzle will be reduced. When the distance between the discharge wire and the dust electrode plate becomes shorter than the distance between the discharge wire and the nozzle, a spark discharge is caused between the discharge wire and the nozzle, and cleaning water is sprayed, the distance between the water film and the discharge wire becomes even shorter and the charging becomes unstable.

On the other hand, if the nozzle is arranged in a region formed by the inscribed circle of the dust collecting electrode plate and the dust collecting electrode plate, the phenomenon of spark discharge between the discharge wire and the nozzle can be avoided. However, in this case, with commercially available nozzles of about 120°, in order to wash the entire area of the dust collecting electrode, it is necessary to arrange two nozzles per corner, and to arrange them at all corners.

In this case, the amount of cleaning water at the corner portions is large, and the amount of water near the contacts is small, resulting in a disadvantage that the cleaning effect is uneven. Furthermore, when thickener circulating water is used, the number of nozzles is large and the hole diameter of each nozzle is small, which often causes clogging problems, which is the main cause of unstable dust collection performance.

On the contrary, according to the present invention, one corner or two
Only one nozzle needs to be used in each corner, and the cleaning effect of the dust collecting electrode can be made almost uniform.Since the number of nozzles is reduced, the amount of water sprayed per nozzle can be increased, which increases the hole diameter and makes it difficult for blockages to occur. .

(Effects of the Invention) The present invention can form a water film on two surfaces of the dust collection electrode by providing an ultra-wide-angle water spray nozzle at the corner of the dust collection pole, so the number of nozzles is reduced to 1/2 compared to the conventional example. Reduced to 4. Furthermore, by setting the distance between the dust collecting electrodes to be 450 mm or more, cleaning water is constantly passed through to collect dust, resulting in high dust collection efficiency and great industrial effects.

[Brief explanation of drawings]

Fig. 1 is a partial plan view of the dust collector of the present invention, Fig. 2 is a partially enlarged view of Fig. 1, Fig. 3 is a partial perspective view of Fig. 2, and Fig. 4 is a main part of the nozzle of the present invention. An explanatory diagram of
Fig. 5a is a view taken along arrow A-A in Fig. 4, b is an explanatory diagram of the action of a, Fig. 6 is a diagram of spark starting voltage and dust collection electrode spacing, and Fig. 7 is an explanatory diagram of a conventional example. 8 is a partially enlarged view of FIG. 7, FIG. 9 is an explanatory diagram of another conventional example, FIG. 10 is a partial plan view of FIG. 9, and FIG.
FIG. 3 is a partially enlarged perspective view of the figure. 4...discharge wire, 5...dust collection electrode, 13...washing water piping,
25...Nozzle.

Claims (1)

[Scope of Claims] 1. A wet type, characterized in that a nozzle that forms a water film with a different water volume distribution is disposed at one pair of corners of the box-shaped dust collection electrode, each pair of which faces each other. A water film forming device on the dust collecting electrode in an electrostatic precipitator. 2. A water film forming device for a dust collecting electrode in a wet electrostatic precipitator according to claim 1, which is provided with a box-shaped dust collecting electrode in which the interval between the dust collecting electrode plates is 450 mm or more.