JPH0432683B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a dust collector related to environmental purification technology, and proposes a dust collection method using a novel airflow distribution that is economical and has high dust capture efficiency. At the same time, it is an object of the present invention to provide a dust collector that implements this method.

[Conventional technology]

Conventional dust collectors generally drive a front-stage dust collector for rough removal and a high-performance rear-stage dust collector in series. For example, when processing 10,000 ^m3 per minute, a high-performance dust collector at the rear stage also operates at a rate of 10,000 ^m3 per minute. is driven to collect dust.

[Problem that the invention seeks to solve]

Therefore, in this type of dust collector, a high-performance post-stage dust collector, such as an electrostatic precipitator that uses electrophoresis, must have the same processing performance as the pre-stage dust collector for rough removal, and is expensive. As high-performance dust collectors become larger, installation costs and subsequent operating costs increase.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a dust collection method based on a novel airflow distribution that is excellent in economic efficiency, and a dust collection device using the method.

[Means for solving problems]

That is, the dust collection method of the present invention uses airflow distribution technology to take dust concentration and particle size into consideration, examines the range of particle diameters collected by the front-stage dust collector and the rear-stage dust collector using a centrifugal flow rate distributor, and The processing air volume is distributed to determine the processing air volume to be introduced to each dust collector,
Each dust collector independently collects dust within a preset particle size range.

In addition, the dust collector configured with this method introduces air containing dust and discharges coarse particles from the first stage outlet and fine particles from the second stage outlet, depending on the preset flow rate distribution. The first centrifugal flow distributor
A coarse dust collector capable of processing the flow rate is connected to the rear stage of the stage discharge port, and a coarse dust collector capable of processing the flow volume is connected to the rear stage of the second stage discharge port. The dust outlet of the coarse dust collector is connected to a dust hopper, and the blowdown flow from the dust hopper is returned to the front stage of the distributor via a blower.

[Effect]

In the method of the present invention, air containing dust is distributed to the coarse dust collector and the fine dust collector using a flow rate distributor, so the processing air volume is It becomes possible to keep the air volume processed by the fine dust collector low. Therefore, the processing capacity of the fine dust collector, which requires high performance, can be reduced and a smaller one can be used, which contributes to lowering the equipment cost and operating cost of the device of the present invention. be.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a dust collector using airflow distribution for carrying out the method of the present invention will be described below with reference to the drawings.

FIG. 1 is a piping diagram showing the overall configuration of the dust collector, and reference numeral 1 indicates air G containing dust sucked from the air inlet 11 through a preset flow rate distribution between the first stage exhaust port 12 and the air G containing dust. It is a centrifugal type flow distributor that discharges from a two-stage discharge port 13. The flow rate distributor 1
The air inlet 21 of the coarse dust collector 2 is connected to the rear of the first stage discharge port 12, and the air inlet 41 of the fine dust collector 4 is connected to the rear of the second stage discharge port 13. The exhaust port 22 of the particulate dust collector 2 and the exhaust port 42 of the particulate dust collector 4 are opened to the atmosphere E via an airflow distribution/merging machine 5.

Further, the dust discharge port 23 of the coarse dust collector 2 is connected to the dust hopper 6, and the blowdown flow B from the dust hopper 6 is returned to the air inlet 11 of the flow rate distributor 1 via the blower 7. Coarse dust D1 is collected from the downstream discharge port of the dust hopper 6, and fine dust D2 is collected from the discharge section of the fine dust collector 4.

As shown in FIG. 2, the coarse dust collector 2 has the following features:
A spout 25 is fixed to one end of a substantially cylindrical outer cylinder 24,
A pointed conical shaft 2 is located behind the shaft center position of the mouth tube 25.
6 is constructed, and a plurality of vanes 27 are fixedly spaced radially in the annular passage between the core shaft 26 and the outer cylinder 24 so as to be inclined at the same rate in the same circumferential direction, thereby forming a fluid forced rotation means 28. Become. Reference numeral 29 denotes an annular wind guide tube formed with an inclination angle θ in the inner diameter direction from the outer edge of the blade plate 27, and a guide with a smaller diameter than the small diameter part of the wind guide tube 29 is provided at the rear of the wind guide tube 29. Cylinder 30
A front-stage annular groove 31 is formed between the spaced-apart outer cylinders 24, and the dust discharge port 23a is protruded from a part of the front-stage annular groove 31. Further, the rear end of the guide tube 30 is spaced apart from the cylindrical transition tube 32 constituting the exhaust port 22, and becomes an air guide tube 33 that is inclined toward the outer tube 24. A rear dust discharge port 23b is provided protrudingly from a part of the rear annular groove 34, and forms the dust discharge port 23 together with the front dust discharge port 23a.

The centrifugal type flow rate distributor 1 is constructed as shown in FIGS. 3 and 4, and a plurality of fins 14 are installed in the radial direction at the inner end of an air inlet 11 opened at one end of a cylindrical main body 10. A vortex generating mechanism 16 is constructed so as to project from the vortex in one direction, and has a baffle plate 15 fixed to the end thereof. Also, the first stage discharge port 1
2 opens in the tangential direction of the airflow generated by the vortex generation mechanism 16 on the outer periphery of the annular flow control panel 17 fixed to the inner periphery of the substantially central portion of the main body 10, and the second stage discharge port 13 An opening is opened in the tangential direction of the airflow generated by the vortex generation mechanism 16 on the outer periphery of the ten end plate 18 on the near side. The opening diameter of the flow control panel 17 is adjusted by the division ratio of coarse dust and fine dust to be separately discharged to the first stage discharge port 12 and the second stage discharge port 13.

The coarse dust collector 2 with the above configuration has an air inlet 21
The air G containing coarse dust introduced from the core shaft 26
When the air hits the vane plate 27 after passing between the air pipe and the mouth pipe 25, the air moves from the guide tube 29 toward the guide tube 30 while spirally turning at high speed along the inclination angle of the vane plate 27. During this movement, the coarse dust contained in the air G is separated in the outer circumferential direction by the centrifugal force caused by the high speed rotation of the air G, enters the front annular groove 31, and passes through the front annular groove 31 to the dust outlet. 23a
The dust is sent to the dust hopper 6 from there.

Further, residual dust that has moved backward beyond the guide tube 30 enters the rear annular groove 34 by a similar centrifugal separation action and is collected from the rear dust discharge port 23b.

Therefore, the air G rotating and moving in the direction of the guide tube 30 does not contain coarse dust, and the dust that can be 100% collected by the coarse dust collector 2 is therefore The formula for calculating the minimum particle size δ is shown below.

For example, the diameter d of the air intake port 21 and the exhaust port 22
The minimum particle size δ of dust that can be collected in the coarse dust collector 2 in Fig. 2 where the relationship between the length of teeth, δ: Particle diameter (10 ⁴ cm) ρ: Particle true density (g/cc) μ: Static viscosity coefficient of gas (g/cm・s) d: Main body inlet diameter (cm) r: Rotation radius = 0.15 d (cm) ) L: 2d (cm) L: 0.35d (cm) Given.

That is, the above formula 1 was obtained based on the experimental results using the component device of the present invention, and in particular, based on the relationship ratio between the inlet flow velocity and the circumferential velocity. It was derived by considering the particle size that moves by centrifugal force over a distance in the rotational direction of the guide tube 30 of l=0.35d. And in order to derive the general formula,
Relative velocity of sedimentation using the following equation 2 based on centrifugal force and particle size
It is based on VR.

Vr＝δ ² ×ρp×uθ ² /18×μ×r×10 ^-8 (cm/sec)...
Equation 2 Vr: Relative velocity of sedimentation uθ: Rotational speed component (cm/sec) δp: Particle true density (g/cc) μ: Static viscosity coefficient of gas (g/cm・s) r: Radius of rotation = (cm) δ : Particle diameter (10 ^-4 cm) uz: Inlet flow rate (cm/sec) Regarding formula 2 calculated above, (1) The relative sedimentation velocity Vr is the particle size per L/uz second.
It is the speed (cm/sec) of moving over a distance of .

(2) In the structure of the example, the relational expression between uθ and uz is uθ=1.2uz shall be.

(3) The radius of rotation r and the particle movement distance l are the mouthpiece 25
For the pipe diameter d, r=0.15d l=0.35d. Depending on the vortex generation situation and the characteristics of the direct cyclone, l×uz/L=δ ² ×δp×(1.2uz) ² /uz×ρp×r×10 ^-
8 ...Equation 3 holds true. Therefore, from Equation 3, δ in Equation 1 can be obtained, and this δ is considered to be the minimum particle size that can be collected 100% by the apparatus of the present invention.

In deriving Equation 1 above, consideration is given to a flow of the fluid to be treated that is almost parallel to the tangential direction due to the angle of the vane plate 27 and the angle of the wind guide tube 29. Then, depending on the angle of the blade plate 27,
The relationship between the speed of dust moving from the fluid inlet to the outlet and the centrifugal force applied to the dust with the resistance of the device makes it possible to average and fix it, making it possible to keep the minimum particle size δ of the dust that can be collected constant. .

Therefore, if ρp=1g/cc uz=15m/sec at room temperature, becomes.

Also, if ρp=1g/cc uz=10m/sec at room temperature, becomes.

The processing air volume (m/min) and input flow rate (m/s) are determined based on the particle diameter δ calculated above, and the flow rate distribution of the flow rate distributor 1 is adjusted.

Through this adjustment, the coarse dust of 10μ or more centrifuged by the flow rate distributor 1 is removed from the first stage discharge port 12.
The dust is sent to the coarse dust collector 2, and 100% of the dust is separated by the coarse dust collector 2 and sent to the dust hopper 6. As a result, a high-performance fine dust collector is produced. The collector 4 only needs to process the treated air G distributed from the second-stage discharge port 13, and the amount of air to be treated is significantly reduced, so the processing capacity can be reduced and the device can be made more compact.

In addition, in this embodiment, a configuration in which the distribution of the flow rate is divided into two stages is explained, but if necessary, the configuration may be such that the distribution is divided into three stages or multiple stages, and each dust collector is collected by an independent dust collector. You can also.

[Effects of the Invention] As described above, according to the dust collection method and dust collection device based on airflow distribution of the present invention, the fine dust collector that requires high performance is miniaturized, so the installation cost of the entire device and its subsequent use are reduced. The present invention has the feature that it is possible to reduce operating costs, and the effects of the present invention are extremely large.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of the entire device showing an embodiment of the dust collector implementing the dust collection method based on airflow distribution of the present invention, and Fig. 2 is a cross-sectional view of a half section of the coarse dust collector. A side view, FIG. 3 is a front sectional view of the flow rate distributor, and FIG. 4 is a sectional view taken along the - line in FIG. 3. 1...Flow rate distributor, 12...First stage discharge port, 1
3... Second stage discharge port, 16... Vortex generation mechanism, 1
7...Flow control panel, 2...Coarse dust collector, 4...
...Fine dust collector, 5...Air flow distribution/merging machine, 6...
...Dust hopper, 7...Blower, G...Air to be treated, D1...Coarse dust, D2...Fine dust.

Claims (1)

[Scope of Claims] 1. Considering the dust concentration and particle size of the fluid to be treated, the range of particle diameters collected by a plurality of dust collectors is examined, and the processing is performed using a centrifugal flow rate distributor based on the range of particle diameters collected. A dust collection method based on air flow distribution, characterized in that air volume is distributed and introduced to each dust collector, and each dust collector independently collects dust in a preset particle size range. 2. A centrifugal flow rate distributor that introduces dust-containing air and discharges a coarse particle portion from a first stage discharge port and a fine particle portion from a second stage discharge port according to a preset flow rate distribution; a coarse dust collector connected to the rear stage of the first stage discharge port of the flow rate distributor and capable of processing the flow rate;
A fine dust collector is connected to the rear stage of the second stage discharge port of the flow rate distributor and is capable of processing the flow rate, and a fine dust collector is connected to the rear stage of the dust discharge port of the coarse grain dust collector and is capable of processing the flow rate. 1. A dust collection device using air flow distribution, comprising a dust hopper that returns a blowdown flow to a stage upstream of the distributor via a blower.