JPS58193748A - Electric dust collector - Google Patents

Abstract

PURPOSE:To prevent the dew condensation in a dust collectring chamber in the stage of resuming dust collection, by interposing shut-off devices in the respective gas flow passages between the plural dust collecting chambers and an outlet duct discretely thereby flowing gases backward in the dislodging state of the dust in each dust collecting chamber. CONSTITUTION:Plural dust collecting chambers 3a, 3b, 3e are communicated with a common inlet duct 8 and outlet duct 14 in an electric dust collector juxtaposed with the chambers 3a, 3b, 3c. A valve 18a for suction is closed and a valve 20a is opened and the application of voltage to a discharging electrode 4a and a dust collecting electrode 5a is stopped in the stage of dislodging the dust in the chamber 3a. When a fan 22 is operated, part of the gas flowing into the duct 8 enters the chamber 3a through a duct 21 and a gas introducing port 19a, and flows backward in the chamber 3a. Both electrodes 4a, 5a are oscillated mechanically to dislodge the dust stuck and aggregated thereon. The dust scattered again is admitted by the back wind into the other chambers 3b, 3c under working.

Description

[Detailed description of the invention] A high direct current voltage is applied between the discharge and dust collecting electrodes installed in the industrial dust room of the present invention, and in this state, the dust mixed in the gas flowing between the two electrodes is removed. This relates to an electric industrial dust machine that collects dust using a discharge electrode or a dust collection electrode, and also has multiple dust collection chambers installed in parallel and dust is removed from any one of the dust collection chambers. This relates to an electric industrial dust machine that allows the dust collection operation to continue using another dust collection room even when the When dusting is carried out, if the dust is sent to another room by the outside air introduced into the room, the electrodes for collecting dust in the room being dusted off will be cooled by the outside air. Next, when a dust-containing gas is introduced, the temperature difference between the gas and the gas causes dew condensation, or when a large amount of cold outside air is introduced, the electrode is rapidly cooled (for example, /
00'C to 20''C), resulting in condensation, and such condensation resulted in various Nm.

Therefore, the present invention seeks to provide an electrostatic dust collector which eliminates the above-mentioned drawbacks.

Below, drawings showing embodiments of the present application will be described.

Three dust collection chambers 3m, 3b, and 3c are formed in the case l by the partition walls of case l, 2 m, and 2 b#i, but these two are mutually exclusive, or even further. You can also do more. Also, these dust collection rooms are 3m long.
, 3b, and 3o are the minimum lengths at which the desired dust collection rate can be obtained without considering re-scattering of dust as described later. In addition, in the drawings, the lowercase letters of the alphabet attached to numerical codes indicate that the parts of the dust collection chamber indicated by the attached code correspond to other dust collection chambers indicated by the same code. In the following explanation, the alphabet #i will be omitted to avoid clutter of explanation, unless it is particularly necessary. 4 is a well-known discharge electrode provided in the dust collection chamber 3, 5Fi
It is also a well-known dust collecting electrode, and is configured to apply a well-known DC high voltage between both poles and 4 and 5 to cause a corona discharge between the two poles, thereby collecting dust. .

6m, 6b, and 6c indicate gas inflow ports in the dust collection chambers 3m, 3b, and 2Ic, respectively, and are communicated with a common artificial duct 8 via these Fi cocoon chambers 7. 9 is a distribution vane provided on the inlet side of the front chamber 7, and is provided to evenly distribute the dust-containing gas flowing from the inlet duct 8 to the inlets 6 of the collection chambers 6. Next, 12 is an outlet in the dust collection chamber 3, and 13a, ub, and uc are communication pipes, one end of which is connected to the outflow [412], and the other end is connected to a common outlet (412). The intestine is a ventilator that can move gas in the direction of the arrow, and a well-known trickle-type or centrifugal ventilator is used. Next, the edict is a suction valve, which is exemplified as a shutoff device, interposed at the communication pipe port, and by closing this valve, the flow of gas from the dust collection chamber 3 to the outlet pipe 14 can be shut off. It's Nishide. Reference numeral 19 denotes a gas inlet ['' connected to a part of the communication pipe U, each of which is equipped with a valve that can be opened and closed. A blower O is installed in the 2111 communication duct.

When dust collection is carried out in the usual manner with the above configuration, the suction valve is opened and the valve 20 is closed, and the above-mentioned valve is placed between the discharge fi4 and the dust collection pole. A voltage is applied, and the exhaust fan is operated in this state. Then, the gas sucked into the inlet duct 8 comes to flow to the outlet duct 14 via the collection chamber 3. In this state, when gas containing dust is inhaled from the inlet duct,
This gas passes through the distribution vane 9 and the front chamber 7 to 6 collection chambers of 3 m.

It flows into 3b and 3c. As is well known, in these dust collection chambers 3, dust is collected by a discharge electrode 4 and a dust collection electrode 5, and the purified gas is discharged from the air outlet 14 through a communication pipe port and an exhaust fan. be discharged.

While dust collection continues in this manner, if dust adheres to the discharge &4 and dust collection electrode 5 and the dust collection efficiency begins to decrease, the dust is removed. This removal operation is performed as follows.

When dust is to be removed from, for example, the dust collection chamber 3a among the plurality of dust collection chambers, the suction valve Mia is first closed, the valve 20a is opened, and the application of voltage to the poles 4a and sa is stopped. Also, the blower η is activated. Then, a part of the gas that has flowed into the inlet duct 8 flows into the dust collection chamber 3a from the gas inlet 19a through the duct 21t, and flows back inside the dust collection chamber 3a.

Here, mechanical vibrations such as hammering are collected by the dust collecting electrode 5a and the discharge electrode 4.
When the dust that has adhered and aggregated is brushed off (generally for several minutes), most of the dust falls into the hopper at the bottom of the dust collection chamber.

In addition, some dust is re-dispersed, but this flows back into the front chamber 7 due to the above-mentioned headwind, and further flows into other dust collection chambers 3b and 3c during operation, where it is collected. . Therefore, the dust collection effect on the gas discharged from the inflow L1 (output L1) 8) is not reduced.

After completing this type of brushing operation, the discharge electrode 4 &
A voltage is applied between the F
As a result, dust is collected in the dust collection chamber 3a in the same way as in the case described above. Below is the dust collection room 31
By repeatedly brushing off the dust at intervals of 1.3 CF (:), a high dust collection efficiency can be maintained at all times.

Incidentally, such a cleaning operation may be carried out periodically and sequentially, and the reduction in the discharge current of the discharge 4ik4 in each prefectural chamber 3 or the concentration of gas containing soot at the outlet ν of each prefectural chamber 3 may be detected. , It is also possible to automatically perform the above-mentioned turtle removal operation when these values reach certain set values.

In addition, in the above-mentioned blowing operation, the dust was brushed off by applying a back wind and mechanical vibration to the dust collection chamber 3, but depending on the nature of the dust, this may be done only by the back wind from the back wind device.
Alternatively, it may be performed only by mechanical vibration. To remove the dust, the mechanical vibration is performed with the valve 18m stopped (several minutes), and then the valve 20m is opened and the blower η is activated to cause the gas to flow back (Wk seconds). But that's fine.

Next, to give an example of dust collection, when dust mainly composed of iron oxide from an arc furnace for main wire is collected using such an electrostatic dust collector, when the inlet concentration of the dust is 3 g/NdC), the outlet concentration is 20 rag/Nu/ (Dust collection efficiency 9?, 3%)
The length of the dust collecting chamber is 3 m, which is sufficient to maintain the following conditions, and it is less than half the length of the commonly used dry electrostatic dust collecting equipment of 6 m or more with three rooms in series.

In the case of electric dust collectors, the dust collection efficiency will be low unless the flow velocity of the dust-containing gas flowing between each prefecture's spark poles is made uniform.
In the case of the embodiment described above, each suction valve u+a, Ml
b. By adjusting the opening angle of IBe, the amount of air flowing through each prefecture chamber 3m, 3b, and 3c can be easily adjusted.

Therefore, whereas conventional configurations required a complicated rectifier with large pressure loss to be installed in the front chamber, we have made it possible to use a rectifier with a simple structure, which makes cleaning easier. Furthermore, the length l of the front chamber can also be shortened.

Further, in the case of the above embodiment, instead of using the communication duct 21 and the blower η, each gas introduction 019 may be connected to the point indicated by GO in the figure by another duct ψ.

As described above, in this invention, a plurality of dust collection chambers 3 are arranged in parallel, and these dust collection chambers 3#i are connected to a common inlet duct 8 and an outlet duct) 14, and each Since a gas introduction port and a shutoff device are individually installed between the dust chamber 3 and the outlet duct ν, it does not matter which dust collection chamber 3 dust is to be removed. Even in cases where the dust collection chamber 3 is air-tight, it is possible to remove the dust that remains floating forever in the dust collection chamber 3 by selectively closing the shut-off device associated with each dust collection chamber and supplying dust removal gas from the gas introduction port. The gas flowing back through the collection chamber 3 can be used to flow into another dust collection chamber and collect the dust there, and the dust collection pause time for dust removal can be quickly returned to the normal operating state. In addition, since the present invention is an electric dust collector, the inlet side and the outlet side of the dust collection chamber are in communication with each other, which prevents dust from floating in the dust collection chamber and becoming trapped. Even if there is a possibility that the dust may flow out toward the exit, the dust is removed as described in hh for each prefecture chamber 3 selected, so floating dust can be avoided. This has the effect of preventing airborne dust from flowing toward the exit duct 14, and at the same time allows the floating dust to pass through another dust collection chamber, allowing only clean gas to flow out from the outlet duct.

In this way, it is possible to remove the re-dispersed dust during dust removal without flowing it to the subsequent stage, which essentially eliminates the need to collect the re-dispersed dust at the subsequent stage. This also has the advantage that the length of the dust collection chamber can be set to the minimum length that allows the desired dust collection efficiency to be obtained without considering re-scattering due to brushing off.

Furthermore, in the above case, the gas flowing in from the inlet duct 8 can be collected by operating the other dust collection chamber 3, and the dust collection function of the electrostatic dust collector as a whole can always be performed continuously. There is also.

Furthermore, in the present invention, even if the gas is made to flow back into the dust collection chamber 3 in order to send out the gas in which the dust is suspended in the above-mentioned #ii< Since the gas having substantially the same temperature as the circulating gas is caused to flow back, when restarting the dust collection operation after brushing off the dust, the inside of the dust collection chamber 3C)1
It is possible to substantially eliminate the temperature difference between 11H,s and the newly introduced dust-containing gas, and there is an effect that there is no need to worry about condensation as in the conventional case.

[Brief explanation of the drawing]

The drawings show an embodiment of the present application, and the first it! fft!
A schematic horizontal sectional view of a dry electrostatic precipitator. 3m, 3b, 3c... Dust collection chamber, 4... Discharge electrode, 5
... Dust collection electrode, 8 ... Inlet duct, 14 ... Outlet duct, intestine ... Suction valve, m ... Gas inlet.

Claims (1)

[Claims] A plurality of dust collection chambers each equipped with an electrode for dust collection inside are arranged in parallel, one end of each of the dust collection chambers is connected to a common artificial duct, and the other end of the above dust collection chamber is connected to a common artificial duct. Each of the above-mentioned dust collection chambers is connected to a common outlet duct, and a cutoff device is installed between each of the above dust collection chambers and the outlet duct, and is capable of blocking the flow of gas from the dust collection chamber to the outlet duct. Furthermore, gas for transport is individually introduced between each prefecture chamber and each cutoff device, and the gas is passed backwards from the outlet side to the inlet side of each prefecture chamber. The electrical appliance is characterized in that it is provided with gas inlet ports each configured to obtain a gas, and further configured to feed gas having substantially the same temperature as the gas flowing through the inlet duct into the gas inlet ports. Industrial dust machine