JPS58146460A - Cyclone separator - Google Patents

Abstract

PURPOSE:To capture fine particulate dust efficiently, by coupling plural stages of outside cylindrical blocks in series, providing outlet and inlet pipes for air flow to the outside cylindrical block in the 1st stage, and connecting a dust capturing part to the outside block in the final stage. CONSTITUTION:The body of a cyclone separator is formed into the multistage type wherein outside blocksI, II are coupled to each other in series. The blocks I, II consisting of combinations of cylindrical parts 2, 20 and conical parts 3, 30. The parts 3, 30 are provided with throats 31, 301 of a small diameter part and diffusers 32, 302 of an inverted conical shape. An inlet pipe 1 and an outlet pipe 4 for air flow are connected to the part 2 of the blockIin the preceding stage and a dust capturing part 5 is connected to the diffuser 302 of the succeeding block II. If dusty air flow 6 contg. fine particles smaller in the order of microns or below is introduced into the cyclone through the pipe 1, the particles are separated and captured efficiently in the dust capturing chamber 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is intended for use in purifying the exhaust gas of internal combustion engines such as automobiles, for example, by separating and collecting fine dust of napkin carbon, which is mainly composed of carbon contained in exhaust black smoke, from the exhaust stream. This invention relates to a cyclone separator suitable for

As a solid-gas separator that separates fine particles in gas from gas,
If the target particle has a diameter of several micrometers or more,
Cyclone separators are often used because they have a simple structure and are inexpensive.

The conventional general structure of this type of cyclone separator will be explained with reference to FIG. In the figure, the cyclone separator is composed of a cyclone body consisting of a cylindrical part 2 and a conical part 3, each having an inlet pipe 1 and an outlet pipe 4, and a dust collecting part 5. When air containing dust is introduced from the inlet pipe l in the direction of arrow 6.

First, to explain the movement of the airflow, the airflow containing dust introduced tangentially from the inlet pipe l toward the cylindrical part 2 becomes the main airflow 61 that swirls around the cylindrical part 2 and the conical part 3, but most of the airflow contains dust. is the reversed airflow 62 from the end of the conical part 3
The small amount of airflow that did not become the zero-reversed airflow 62 that is finally discharged from the outlet pipe 4 as the outflow airflow 7 enters the dust collection section 5, becomes an airflow 63, and swirls around the dust collection section. After that, the outlet pipe 4 passes through the center of the cyclone separator.
is discharged from. Next, to explain the movement of dust, centrifugal force acceleration 2 acts on the dust contained in the main airflow 61 rotating in the cylinder @2 and cone @3, and its magnitude is generally smaller than the gravitational acceleration g. 300 to 2000 times more. Therefore, the dust moves along the inner wall surfaces of the cylindrical portion 2 and the conical portion 3 due to the action of the centrifugal acceleration, and together with the action of the gravitational acceleration, the dust falls to the dust collection portion 5 and is deposited thereon.

By the way, in this type of conventional cyclone separator, the particle size limit is 2 to 3 x m, and it is difficult to separate finer dust such as carbon contained in the exhaust gas of the internal combustion engine mentioned above. The main component is 0.2μ or less.
Sufficient collection efficiency could not be obtained for fine Sapunkuron dust of armpit size, and it could not be put to practical use as it was.

That is, in a cyclone with a tangential lid that separates dust using a so-called centrifugal effect, a higher centrifugal effect can be obtained especially when the circumferential velocity of the swirling flow is high in the inlet side region. However, if the particle size of the dust is submicron, even if it is concentrated near the wall of the cyclone due to centrifugal force, if the circumferential velocity of the swirling flow is high, the dust particles will not coagulate sufficiently. The small-diameter particles settle along the cyclone wall. For this reason, the dust once separated from the main airflow 61 is also carried toward the outlet pipe 4 on the reversed airflow 62 that reverses at the end of the conical part 3, and a large amount of dust is transferred into the collection part 5. The proportion of collected particles decreases.For this reason, sufficient collection efficiency cannot be obtained with submicron fine particle dust.

For this purpose, in order to process fine dust particles of micron size or less, conventionally, an electric industrial dust machine or the like is combined in the front stage of a cyclone separator, and the fine particle size dust is agglomerated and coarsened in the electric industrial dust process in the previous stage, and then Attempts have been made to introduce the system into a cyclone separator for separation and collection, but this method requires high equipment costs and cannot take full advantage of the features of the cyclone separator, which is simple in structure and easy to maintain. There is. From this point of view, there is a strong demand for the development of a cyclone separator that can efficiently collect particulate dust smaller than 100 yen, for example, for purifying the exhaust gas of the internal combustion engine installed in the above-mentioned automobile.

This invention was developed in consideration of the above points, and its purpose is to improve the dust collection efficiency by promoting aggregation of sub-micron fine dust inside the main body of the cyclone separator and making it coarse. It is an object of the present invention to provide a cyclone separator in which the separation limit particle size range is expanded by increasing the particle size range.

According to the present invention, an air flow containing dust is introduced into the cylindrical portion, which is formed by combining a cylindrical portion and a conical portion with a throat connected to the cylindrical portion.

This is achieved by configuring the mouth pipe and the outlet pipe by connecting dust collecting parts to the conical parts of the final stage outer cylindrical block, respectively.

The present invention will be described in detail below based on illustrated embodiments.

First, the overall configuration of the embodiment will be explained with reference to FIG.

That is, according to the present invention, the main body of the cyclone separator is constructed as a multi-stage type (two stages in the illustrated example) in which outer cylinder blocks indicated by reference numeral 1.1 are connected directly to each other in IJ. The outer cylindrical block 1.1 of each stage is connected to the cylindrical portion 2.
20, a conical part connected to a cylindrical part, and configured as a combination of parts 3 and 30.

Also, the conical part 3.30 is the throat of the small diameter part 31°301
and an inverted cone-shaped differential user 3 connected to the throat
It consists of 2,302 units. The inlet pipe 1 and the outlet pipe 4 are connected to the cylindrical part 2 of the front block (2) as in the conventional structure, while the dust collection part 5 is connected after the diffuser 302 of the rear block 1.

With this configuration, when a dust-containing airflow 6 containing fine dust of less than a ton is introduced from the inlet pipe 1, the main airflow 61 that descends while swirling inside the cyclone body as shown by the arrow 2 in Fig. 3 (51) is as follows. , after a part of it passes through the front block I, it further enters the rear block ■, and eventually the reverse airflow 62
As a result, it heads to the exit pipe 4. Even on the way to the second final stage, a part of the main airflow 61 gradually turns into a reversed airflow and heads toward the outlet pipe 4.

In this case, especially in the conical portions 3 and 30, the cross section of the passage is gradually narrowed, so that the effect of reversing the downward airflow is strongly exerted. As a result, the flow rate of the descending air within the cyclone body is as shown in Figure 3).
It decreases as it goes from the front block I to the rear block I and then to the collection section 5, as shown in FIG.

In addition, to explain in more detail how the main airflow 61 flows, the main airflow 61 that has descended while turning at a relatively high speed around the conical part 3 of the front block The rest passes through 31 and proceeds to the differential user 32. This Defney the 3
Since the cross section of No. 2 is enlarged, the swirling speed of the main airflow is greatly reduced. Next, enter the cylindrical part 20 of the rear boot stock ■,
Here, the airflow that has become somewhat unstable during the stage of passing through the differential L-za 32 returns to a rectified swirling flow. Next, the conical portion 30 (lower) 301 flows down while turning around the differential user 302.

It should be noted that the latter block (2) follows the same process as the preceding block (I).

Due to the flow of the main airflow 61 as described above, the dust contained in the introduced airflow 6 is
1 In the process of passing through the conical part 3, the dust is subjected to a large eccentric effect and becomes concentrated on the outer circumferential side, but at this stage, the dust is not sufficiently aggregated and coarsened.

However, in the conventional configuration shown in FIG. 1, most of the main airflow 61 is halved from the end of the conical portion 3.

In the embodiment, the air passes through the differential user 32 and then enters the cylindrical portion 20 of the rear block (2) through the differential user 32 along with this main airflow. Furthermore, since the airflow that has entered the cylindrical portion 20 via the differential user has a significantly reduced wind speed as described above, the aggregation of dust particles is accelerated in this portion.

As a result, the dust becomes coarse, large-diameter particles and forms a primary conical portion 30. Throat 301. It is efficiently collected via the differential user 302 and deposited inside the dust collector s5.

Note that most of the fresh air 61 is reversed before the throat 301 in the conical portion 30 of the rear block I, and flows out toward the outlet pipe 4.

Figure 4 is a particle size distribution diagram of the dust collected in each part of the cyclone main body based on test results conducted using the cyclone separator having the above configuration. As is clear from this figure, most of the dust extracted from the person at the fixed point near the inlet pipe 1 is dust with a very small particle size. On the other hand, it has been demonstrated that the large-diameter second-stage pro was neglected, which caused the dust to coagulate and coarsen inside the cyclone body. Also, the amount of dust to be treated is 0.2p.
According to the test results conducted as a grade, the collection efficiency was 81
It was confirmed that the new model is approximately 30 times cheaper than the conventional model shown in the figure. Although the illustrated example shows a two-stage type, three or more stages of outer cylinder blocks may be connected in series. In addition, the collection efficiency of the cyclone body hardly changes even if it is operated in an upright position with the axis straight, or in a horizontal position with the cyclone body lying on its side.

As is clear from the above description, according to the configuration of the present invention, the fine dust contained in the introduced airflow is subjected to a large centrifugal force within the first stage outer cylindrical bag, and is separated from the main airflow. The particles gather toward the wall surface of the outer cylinder, and are rapidly aggregated and coarsened in the subsequent outer cylinder block under low-speed swirling airflow. Therefore, even fine dust of submicron size or smaller can be efficiently separated and collected in the dust collection chamber, and the separation limit particle size range can be expanded to that extent compared to the conventional method.

Therefore, it is possible to provide a cyclone separator that exhibits excellent performance for purifying the exhaust gas of internal combustion engines, particularly for treating fine dust of less than a micron size.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the configuration of a conventional cyclone separator. FIG. 2 is a configuration diagram of an embodiment of the present invention, and FIG. 3(a). (b) is a flow state diagram of the airflow inside the cyclone main body and a flow rate distribution diagram of the descending airflow in FIG. 2, respectively. FIG. 4 is a diagram showing the particle size distribution of dust inside the cyclone body based on the test results. l...Inlet pipe, 2.20...Cylindrical part, 3.
30... Conical part. 4... Outlet pipe, 5... Guest collection section, 31.3
01...throat, 32,302...def user,
I, I... Outer cylinder pusher.

Claims (1)

[Claims] l) A plurality of outer cylindrical blocks formed by combining a cylindrical portion 2 and a circular female portion 7 with a throat connected to the cylindrical portion as a unit stage.
outer cylinder blocks are connected in series, and an inlet pipe and an outlet pipe are connected to the cylindrical part of the first stage outer cylinder boot stock, and a dust collection part is connected to the conical part of the final stage outer cylinder boot stock. A cyclone separator characterized by comprising: 2. A cyclone separator according to claim 1, characterized in that the cyclone separator is equipped with an inverted cone-shaped differential user whose conical portion is connected to the foot of the female portion a. .