JPS6121715A - Particle flocculator - Google Patents

Abstract

PURPOSE:To arrange so that a dust collector may have not to handle microparticle content of dusty gas through the application of a high voltage between a positive corona generating electrode and a negative corona generating electrode. CONSTITUTION:If a positive corona generating electrode 3 and a negative corona generating electrode 4 are connected to a high voltage power supply 10 through a connection wire 8, 9, a corona discharge generates, releasing a positive ion from the electrode 3 and a negative ion from the electrode 4. The positive ion sticks to microparticles near the electride 3 and the negative ion to microparticles near the electrode 4. These microparticles move being attracted by the electrodes 4, 3. During the movement, both microparticles combine together sucked by the Coulomb force. These combined microparticles again pick up the ion, undergoing the process of futher combination and flocculation thus forming coarse particles.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application i The present invention relates to a particle aggregation device that contributes to improving collection efficiency in a dust collector.

Conventional Structure and Problems Conventionally, cyclone type dust collectors, electric dust collectors, bag filter type dust collectors, etc. are known as dust collectors that introduce dust-containing gas and release clean gas. These dust collectors can sufficiently collect coarse particles, but if there are fine particles in the dust-containing gas, the following problems occur.

In other words, in a cyclone type dust collector, when the particles become fine, the centrifugal force effect cannot be expected as in the case of coarse particles, so the collection efficiency becomes extremely poor. In an electrostatic precipitator, the mobility of fine particles is very slow, and in order to collect even the fine particles, it is necessary to slow down the gas flow rate and increase the size of the dust collector, resulting in a very high equipment cost. In addition, in the case of a bag filter type dust collector, the mesh of the filter must be made extremely fine, which has the disadvantage that making the mesh so fine increases pressure loss and increases operating costs. .

As described above, the current situation is that it is difficult to sufficiently collect fine particles at low cost using the conventional dust collector itself.

OBJECTS OF THE INVENTION The object of the present invention is to provide a particle agglomeration device with a simple structure, which functions by coagulating and coarsening fine particles in dust-containing gas before a dust collector so that the fine particles do not need to be handled by the dust collector. shall be.

Structure of the Invention The particle agglomeration device of the present invention is provided with a positive corona generating electrode and a negative corona generating electrode, applies positive and negative high voltages to both electrodes, and introduces a dust-containing gas between the two electrodes to collect dust in the dust-containing gas. It is characterized by being made to coalesce and agglomerate the particles.

According to this configuration, it is possible to charge the fine particles in the introduced dust-containing gas to (T) and (→, and these charged fine particles coalesce and aggregate due to the attraction force due to the Coulomb force between them and become coarse. Therefore, by installing the particle agglomeration device of the present invention in the front stage of the dust collector and introducing the dust-containing gas through this particle aggregation device into the dust collector, it is possible to release dust-containing gas without fine particles. Dust-containing gas accompanied by particles can be efficiently treated with a conventional dust collector, and operating costs can be reduced.

Embodiment and Function An embodiment of the present invention will be described below with reference to FIGS. 1 to 8.

FIG. 1 shows the state in which the particle agglomeration device of the present invention is used. (1
) is a dust collector, and (2) is a particle agglomeration device installed before the dust collector (1).
4) is introduced, and this introduced dust-containing gas flow (4) is introduced.
) is made into a dust-containing gas flow (toughened) without fine particles and sent to the dust collector (1).
) represents the clean gas released after collecting coarse particles and particles.

FIG. 2 shows the basic configuration of the particle agglomeration device (2). (3)
and (4) are a positive corona generating electrode and a negative corona generating electrode which are arranged with their electrode surfaces facing each other, and both have a large number of needle-like protrusions (5) standing on the electrode surfaces. (6) and (7) are side plates, which form a gas passage with the electrodes (3) and (4).

Note that the electrode (3) is connected to the electrode (3) through this side plate (6) (7).
(4) Side plate (6) (
7) is made of an insulating material, or an insulator (not shown) is interposed between the electrode (3) (4) and the side plate (6) (7) to ensure sufficient dielectric strength. There is. (8J (9) represents the connection line to the high voltage power supply.

With this configuration, when the electrodes (3) and (4) are connected to the high-voltage power supply σ1 via the connecting wires (8) and (9), corona discharge occurs and (a) ions are emitted from the electrode (3). From (4), (→ ions are released, and as shown in Figure 8, the dust-containing gas to be treated is treated as a dust-containing gas flow without fine particles. In other words, when corona discharge occurs, As shown in FIG. 8(a), the electrode (3) of the fine particles
(→ ions are attached to the fine particles (G1) in the vicinity of (
The fine particles (G2) near the electrode (4) are charged with →, and ions are attached to them (←) and charged with →. The fine particles (G1) charged with → are attracted to the electrode (4) side. He moved and moved (
→ The charged fine particles (G) are attracted to the electrode (3) and move, and during this movement, the charged fine particles (G,) and (G2) encounter each other, and the two are attracted by Coulomb force. and merge as shown in (g) in Figure 8(b).At this time,
If the fine particles are conductive, they discharge due to coalescence, and the combined particles (g) retain a charge equal to the difference between the charges (g) and (→charge). If the charges are equal, the charge becomes zero. Note that if the fine particles are non-conductive, some of the charge may be discharged, but most of them retain their initial charge and become coalesced particles (c), and even after coalescing, the fine particles continue to dissipate from each other. (Gl)
(G2)'s (g) charge and (→ charge act as attraction and have the effect of increasing the cohesive force. However, in this case, the amount of apparent charge of the coalesced particle (0) is smaller than that of the initial fine particle ( This is the difference in the amount of charge between Gl) and (G2), and becomes zero when the charges are equal.

Figure 8 (C
), the (g) ions and (→ ions) attach and become electrically charged, so the charged fine particles (Gl) (G
2) As in the case of the combined particle (electrode (3) of l)
A coalesced particle (Dl) near the electrode (→) is charged to the electrode (
4) and moves near the electrode (4) (→
The charged combined particles (D2) are attracted to the electrode (3) and move. These combined particles (D, )'' and (D2) encounter oppositely charged particles on the way, as shown in Figure 8(d).
They are attracted to each other by Coulomb force and coalesce and aggregate as shown in (P4). The charged state of the particles after coalescence is the same as that of the fine particles (Gl) (G,).

While repeating the steps shown in FIGS. 8(a) to 8(d), the particles coalesce, aggregate, and become coarser.

In the above embodiment, needle-like protrusions (5) were provided on the electrode surfaces of the electrodes (3) and (4) to facilitate the generation of corona discharge. The same effect can be expected by using a pleated projection instead.

As described in the detailed description of the invention, the particle aggregation device of the present invention is provided with a positive corona generating electrode and a negative corona generating electrode, applying positive and negative direct voltages to both electrodes, and introducing dust-containing gas between the two electrodes. As a result, ←) ions generated by corona discharge and (→
Ions adhere to fine particles in the introduced dust-containing gas (
Fine particles charged to (g) and (→) are generated near the positive corona electrode and near the negative corona electrode, respectively, and the charged fine particles are charged to opposite polarities while moving toward the counter electrode. The particles are attracted by the Coulomb force and coalesce, gradually becoming coarse particles, and a dust-containing gas flow with fine particles can be easily constructed, processed into a dust-containing gas flow without fine particles, and released. If a particle agglomeration device is installed before and after the dust collector, the fine particles will be aggregated into coarse particles, making it easier to collect, and the dust collector will collect the coarse particles without considering the collection of fine particles. Therefore, the particle aggregation device of the present invention can contribute to reducing the cost of the entire dust collector and the operating cost.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the usage state of the particle agglomeration device of the present invention, Figure 2
The figure is a perspective view of essential parts of an embodiment of the particle aggregation device of the present invention, and FIG. 8 is an explanatory diagram of the fine particle aggregation process.

Claims (1)

[Claims] 1. A positive corona generating electrode and a negative corona generating electrode were provided, and positive and negative high voltages were applied to both electrodes, and a dust-containing gas was introduced between the two electrodes to cause particles in the dust-containing gas to coalesce and agglomerate. Particle agglomeration device.