JPS5843954Y2 - Electricity ↓ - Electrical neutralization device for mechanical circulating air purification system - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of an electrical neutralization device in an electro-mechanical circulating air purification system.

In an electromechanical circulating air purification system, most of the fine particles of 1 μ or less (submicron particles) floating in air-conditioned spaces such as indoors are positively charged, and the electric charge of the fine particles forms an electric field in the room. However, a so-called space charge (SPACECHARGE) is formed, and the movement of these fine particles is proportional to the charge/mass ratio, and the movement force is often greater than that of indoor airflow caused by normal ventilation. Due to the space charge of the former, fine particles are rapidly deposited on walls, ceilings, floors, or human bodies that are electrically grounded (approximately O potential)5, while the latter are not carried by the return air flow and remain stagnant in the indoor space forever. In view of the problem that even if high-performance filters and electrostatic precipitators are adopted, these cannot be collected and filtered, the present applicant filed Japanese Patent Application No. 5,113,0666 (name of invention: Electro-mechanical method). This is a new circulating air purification system proposed by the company (Circulating Air Purification System).

That is, as shown in FIG. 1, which is an example of a circulating air purifying unit 2 installed in an air-conditioned space 1, an air source-applied mechanical filtration device 4 installed in a ventilation air passage 3 of a circulating air purifying unit 2 is used. The unrecoverable charged particles C in the air are electrically neutralized in individual particles by the electrical neutralization device 5 and released into the air-conditioned space together with ventilation air, while the released neutralized particles are By adsorbing a large number of charged fine particles C floating in the air-conditioned space 1 to N,
The accumulation of fine particles with the neutralized fine particles N as the core becomes huge,
This is an electro-mechanical circulating air purification system that forms an air purification cycle in which the giant particles G are transported to the return air and collected and recovered by the mechanical filtration device 4, Before the pollutant particles 〇 in the air in the air-conditioned space 1 attach to the surfaces of objects or the human body, they are adsorbed by the artificially electrically neutralized neutralized particles N, accumulate, become large, and are absorbed by the air return flow. The charged fine particles C can be collected by a filter 4 having normal performance, thereby making it possible to completely purify the air.

By the way, as shown in FIG. 2, the electrical neutralization device 5 is a combination of a primary electrode 6 to which a high DC voltage is applied and a secondary electrode 7 to which a high frequency AC voltage is applied. , the spacer is configured to be attached to the member 9 to compensate for the assembly gap 8 that occurs between the inner peripheral surface of the ventilation air passage 3 and the outer periphery of the electrical neutralization device 5. When installing the neutralization device 5 in a ventilation air passage such as a duct, the width and length of the spacer member 9 are adjusted because the cross-sectional area of the ventilation air passage varies widely. For this reason, the assembly interval 8 may become large.

In this case, some of the charged fine particles temporarily negatively charge the clustered charged fine particles due to the attachment interval 8, and the connected fine particles are separated and decomposed by repulsion due to charges of the same sign.
The primary electrode for effective neutralization in the next process is now electrically bypassed to reach the secondary electrode, and the separated and decomposed charged particles are transferred between the primary electrode and the secondary electrode. The electric field between the two electrodes gradually reduces the charging effect of the primary electrode to avoid electrical interference, and the secondary electrode is no longer able to sufficiently neutralize the air, resulting in a decrease in air purification efficiency. A problem arises.

This idea was made in view of the above-mentioned conventional problems, and covers the outer periphery of an electrical neutralization device consisting of a primary electrode and a secondary electrode at a predetermined interval. By providing a hood member that protrudes forward with a predetermined dimension, even if the cross-sectional areas of ventilation air passages such as ducts are different, charged particles can be
The second electrode is guided so as not to be electrically bypassed, thereby improving air purification efficiency.

Hereinafter, embodiments of this invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 3, in the circulating air purifying unit 2 which employs an electro-mechanical circulating air purifying system, air is sucked into the ventilation air passage 3 from the air-conditioned space 1 through the suction port 11 by the fan motor 10. Return air is filtered by a pre-filter 12 that can collect large dust particles and a main filter 13 that can collect small dust particles, and charged particles C in the ventilation air that cannot be completely collected by the main filter 13 are removed. , electrically neutralized by an electrical neutralization device 5,
While the ventilation air is discharged from the outlet 14 into the air-conditioned space 1, the giant particles G that have accumulated and become giant as described above are carried to the return air together with small and large dust particles and are returned through the intake port 11. Large dust is sucked into the ventilation air passage 3, and large dust is filtered out by the pre-filter 12, and fine dust and giant particles G are removed.
This forms an air purification cycle in which the main filter 13 collects, filters, and collects the air.

The pre-filter 12 is a filter made of a material with low ventilation resistance that collects relatively large dust particles, and the main filter 13 is made of NBS (NATIONAL BU
REAU OF 5TANDARDS) A fiber filter with an average efficiency of about 55% based on atmospheric dust standards according to a dust spot test is preferable from the viewpoint of low ventilation resistance and dust collection efficiency. Although the filter 12 can collect microscopic dust and the aforementioned giant particles G that cannot be completely collected by the filter 12, it has a characteristic that it cannot fully collect fine particles of 1 μm or less and odor molecules.

Each filter 12.13 can be replaced periodically.

Incidentally, a germicidal lamp 15 is provided between the pre-filter 12 and the main filter 13.

On the other hand, the air passage 3 on the downstream side (above) of the main filter 13 has a rectangular one made up of a plurality of parallel cylindrical electrodes to which a high DC voltage is applied, as shown in detail in FIG. The secondary electrode 6 is disposed in a plane approximately perpendicular to the airflow, and is slightly larger than the primary electrode 6, which is made of a mesh electrode on the downstream side and applies a high-frequency AC voltage. A rectangular secondary electrode 7 is arranged at a constant distance W from the primary electrode 6 in a plane approximately perpendicular to the air flow, and the primary electrode is covered with an insulating material 17. 2 through...
Next, an electrical neutralization device 5 configured by being attached to the electrode 7 is arranged.

The primary electrode 6 has a tubular body 18 made of an aluminum pipe with a diameter of about 10 mm. . . . 18 is integrated into a framework, and each tube body 18.・・・・・・18 intervals P
is set to approximately 5Qmm.

Therefore, when a DC high voltage of about 20,000 V is applied to the primary electrode 6, each tube 18.・・・・・・A positive DC high electric field with relatively uniform strength is formed between 18 and 18, and the charged fine particles C group that enters the electric field are temporarily negatively induced by a strong electrostatic flux. Charging occurs, and as a result, electrical connections are broken by charges of the same sign, the agglomerates are separated and decomposed, and the entire charged fine particles are reorganized.

Next, the secondary electrode 7 has a zinc coating with a diameter l~2
It is constructed by weaving approximately 5 mm square iron wire lengthwise and horizontally into a mesh M approximately 5 mm square, which is stretched over a frame.

When a high frequency AC voltage is applied to this secondary electrode 7, ■
While gradually reducing the charging effect of the primary electrode 6 using the electric field between the secondary electrode 6 and the secondary electrode 7 and avoiding electrical interference,
Charged fine particles C passing through the mesh and being neutralized
is subjected to intense alternating positive and negative charges and is rapidly neutralized due to the exchange or release effect of positive and negative charges.

As shown in FIGS. 5 and 6, an electrical neutralization device 5
For this purpose, a rectangular cylindrical hood member 20 is provided which covers the outer periphery of the primary electrode 6 and the secondary electrode 7 which are integrally combined at a predetermined interval 19, and the secondary electrode is attached to the hood member 20. 7 is attached via the insulating material 21, while the upright portion 1) 20a of the downstream end of the hood member 20 is attached to the spacer member 9 fixed to the ventilation air passage 3.

The hood member 20 is made of a conductor such as an iron plate.

In this way, the outer periphery of the electrical neutralization device 5 and the hood member 2
0, a constant interval 19 is formed which is narrower than the above-mentioned assembly interval 8 and is always constant regardless of the cross-sectional area of the ventilation air passage 3.

This interval 19 is the same as that for each tube 18 of the primary electrode 6.・・・・・・
- It is preferable to set the dimension to be almost the same as the interval P (approximately 50 to 75 mm) of 18.

Further, the upstream end of the hood member 20 may have approximately the same dimensions as the upstream surface of the primary electrode 6, but it is preferable that the upstream end of the hood member 20 protrudes forward from the upstream surface with a dimension 22 that is approximately the same as the above-mentioned interval P. 1
This is preferable from the viewpoint of rectifying the airflow passing through the second electrode 6.

By providing this hood member 20, all of the charged particles C carried by the ventilation airflow pass through the strong electric field formed by the primary electrode 6, so that the conventional assembly interval 8
Compared to this, the charged fine particles C do not electrically bypass the primary electrode 6.

The results of a circulating air purification test conducted in a certain room with a steady dust source using the electrical neutralization device 5 equipped with the bypass prevention hood member 20 described above will be described below.

The number of fine particles (×105 pieces/Ft3
), and the measurement time (minutes) is plotted on the horizontal axis in Figures 7 and 8.
As shown in the figure.

FIG. 7 is a data graph for fine particles with a particle size of 0.3 μm or more, showing data B with the bypass prevention hood member 20 attached, its average value data B', and data with the bypass prevention hood member 20 not attached. Data A and its average value Data A' are shown.

FIG. 8 is a data graph for fine particles having a particle size of 0.5 μm or more, and the other details are the same as in FIG. 7.

A summary of the data graphs in FIGS. 7 and 8 is shown in the table below.

As is clear from the above table, the bypass prevention member 20
By installing this, indoor airborne dust was reduced by 20-25%.

As is clear from the above explanation, this invention is a device that provides a hood member to the electrical neutralization device, so even if the cross-sectional areas of ventilation air passages such as ducts are different, the connection between the primary electrode and the A constant strong electric field interval is always formed between them, and the charged fine particles no longer electrically bypass the primary electrode, resulting in a strong electric field interval, and the charged fine particles Since there is no need to electrically bypass the air, the dust reduction rate increases and air purification efficiency improves.

Therefore, there is no need to manufacture electrical neutralization devices of various sizes to match the cross-sectional areas of ventilation air passages such as ducts, and the sizes can be standardized.

In addition, the hood member has various advantages such as an extremely simple structure, can be manufactured at low cost, and can be easily assembled into existing electrical neutralization equipment, and has great practical value. It's big.

[Brief explanation of drawings]

Figure 1 is a side view of an air-conditioned space in which a circulating air purification unit is installed, Figure 2 is a sectional view of a conventional electrical neutralization device,
Fig. 3 is a longitudinal sectional view of a circulating air purification unit incorporating an electrical neutralization device according to this invention, Fig. 4 is an exploded perspective view of the electrical neutralization device, and Fig. 5 is an electric neutralization device according to this invention. A cross-sectional view of the target neutralization device, FIG. 6 is a perspective view of FIG. 5, and FIGS.
) is a measurement data graph in which elapsed measurement time (minutes) is plotted on the horizontal axis. 1... Air conditioning space, 2... Circulating air purification unit, 3... Ventilation air passage, 4...
...Mechanical filtration device, 5...Electrical neutralization device, 6...Primary electrode, 7...Secondary electrode, 8...・Assembly interval, 9...Spacer part, 17°21...Insulating material, 19...
- Spacing, 22...Dimensions.

Claims (1)

[Scope of utility model registration request] An electrical neutralization device 5 consisting of a combination of a primary electrode 6 that applies a DC high voltage and a secondary electrode 7 that applies a high frequency AC voltage is connected to the inner peripheral surface of the ventilation air passage 3 and the electrical neutralization device 5. The mechanical filtration device 4 is configured to be attached to a spacer member 9 that compensates for the assembly gap 8 that occurs between the outer circumferential surface of the neutralization device 5 and is installed in the ventilation air passage 3 as an air source. Charged particles in the air that cannot be recovered are electrically neutralized by the electrical neutralization device 5, and released into the air-conditioned space together with the ventilation air, so that the charged particles floating in the air-conditioned space are adsorbed, An electric machine that accumulates and enlarges fine particles with neutralized fine particles as the core, and transports these huge particles to the return air so that they can be collected and filtered by the mechanical filtration device 4 and recovered. In the circulating air purification system according to this method, the outer periphery of the electrical neutralization device 5 is covered with an interval 19 that is approximately the same as the interval P between the tube bodies 18 of the primary electrode 6, and the area in front of the primary electrode 6 is To approximately the same dimension 22 as the above distance P
An electric machine characterized in that a hood member 20 of a conductor protruding from the hood is provided, a secondary electrode 7 is attached to the hood member 20 via an insulating material 21, and the hood member 20 is attached to the spacer member 9. Electrical neutralization device for circulating air purification system.