JP2000317348A - Centrifugal/inertial effect type classifying system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance classification efficiency by two-stage classification continuously performing centrifugal primary classification in a cylindrical part and inertial effect type secondary classification due to the barrier plate in an intermediate cylinder. SOLUTION: An intermediate cylinder 3 for obstructing the inflow of a revolving stream is provided between a cylinder 1 being a main body and a discharge port 5 and a brrair plate 6 having venting holes 7 is provided in the intermediate cylinder and a discharge port 8 is formed to the space above the barrier plate 6. By this constitution, centrifugal classification is performed in the cylindrical part and inertial effect type classification is next performed by the barrier plate 6. Further, by providing a discharge pipe having a venting hole to the center of the discharge port 8, two centrifugal and revolving inertial effect type classifications are performed around the discharge pipe at the same time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a classification system combining a classification system utilizing centrifugal force and a method utilizing the inertia effect of a fluid (Note 1). (Note 1) If the fluid suddenly changes the direction or speed of the flow, the particles cannot immediately follow the change, and will fall out of the streamline in order to continue their movement. This is called an inertia effect, and a classification method using this effect is called an inertia method. −−−− “Separation and Purification Technology Handbook” excerpted from Japan Science Association (Maruzen), p. 422. In the text, classification by this effect is referred to as inertial effect type classification for the sake of explanation.

[0002]

2. Description of the Related Art A conventional centrifugal classification system, as typified by a cyclone type classification device, is a system in which particles are classified only by using centrifugal force generated by a swirling air flow.

[0003]

By the way, three apparent forces, a centrifugal force, a centripetal force, and a Coriolis force, are physically applied to the swirling fluid. (Note 2) (Note 2) Patent gazette No. 2539318, page 2 Based on formulas (1), (2), (3) and FIG. Therefore, in addition to the centrifugal force, the turning centripetal force acts inside the cylinder of the cyclone device. In addition, the lower end of the outlet is about one-third from the upper end face of the cylindrical body, and therefore, in the lower cylindrical part (in the range of about two-thirds), a considerable amount of fine particles is centrifugal. The air is swirled up like a small tornado and heads toward the outlet. For this reason, in the cyclone method, the classification efficiency of the fine particle region has to be reduced, and it has been necessary to use the filter together with another filtering device (for example, a bag filter). Therefore, in this type of classifier, there is an urgent need to improve the classification efficiency from the viewpoint of environmental purification.

An object of the present invention is to remarkably improve the classification efficiency of a fine particle region by utilizing a tornado phenomenon theoretically generated in a swirling fluid. Note that the method of the present invention can be applied to both a gas and a liquid.

[0005]

To achieve the above object, there are mainly two means. First, the first means is between the cylindrical body of the main body and the outlet at the center of the upper end surface.
Concentrically, an intermediate cylinder with a diameter larger than the discharge port is provided,
The upper end is attached in contact with the upper end surface of the cylindrical body, and the lower end is open and shorter than the cylindrical body. Regarding the length of the intermediate cylinder, a longer one promotes the centrifugal effect, but is not always necessary when the mass of the particles is relatively large.
It may be short as in the embodiment.

A second means is to provide a shielding plate inside the intermediate cylinder, form a space above the discharging plate (hereinafter referred to as a discharging port), and provide a plurality of ventilation holes in the shielding plate. A small hole or slit is provided. (The vent may be a vertical ring-shaped gap formed by a laminated shielding plate as shown in FIG. 7 described later.)

The effects of the two means described above will be described. When the classifier according to the present invention is connected to an exhaust device and the particles are inhaled, a swirling flow is generated in the cylinder, and centrifugal force and centripetal force are exerted. Coarse particles are swirled down along the inner surface of the cylinder and fall into the dust tank. On the other hand, the fine particles are directed to the central outlet by the swirling counter-current, but are blocked by the intermediate cylinder and detour to the lower end while rotating along the outer wall of the intermediate cylinder. At this time, since the negative pressure increases as it goes below the intermediate cylinder, the turning speed is theoretically accelerated, and the centrifugal classification action is also improved. As described above, the first factor of the decrease in classification efficiency in the conventional method is largely improved by the action of preventing the inflow of the centripetal flow by the intermediate cylinder.

[0008] The turning centrifugal flow detouring to the lower end of the intermediate cylinder shifts to the following movement. That is, since the inside of the lower end is at a lower pressure than the outside, the swirling speed increases as it flows into the intermediate cylinder, and rises rapidly while converging to the center like a small tornado. Then, the swirling updraft collides with the shielding plate, which is the second means, and develops the following operation.

[0009] The swirling ascending airflow colliding with the shielding plate is radiated as a film of the swirling airflow in all circumferential directions, and performs the following specific classification process. First, since a small ventilation hole or slit connected to the discharge port is formed on the entire surface of the shielding plate, the airflow film running on the shielding plate operates as follows. That is, since the gas has an extremely small mass, the gas is suddenly changed in the direction from the vent hole to the discharge port side and is sucked. However, since the fine particles have a much larger mass than the gas, they pass through the small air holes as they are due to the inertia effect, reach the inner wall of the intermediate cylinder, and descend. The above is the outline of the classifying action due to the inertial effect performed on the shielding plate. In the text, this classification method is hereinafter referred to as an inertial effect type classification method.

As described above, the feature of the present invention is that the primary classification of the centrifugal force type in the cylindrical portion and the secondary classification of the inertia effect type by the shielding plate in the intermediate cylinder are continuously performed by the same apparatus. That's what we did. Therefore, while the conventional classification method represented by the cyclone method is a one-step classification using only centrifugal force, the method of the present invention employs a two-step classification of centrifugal force and inertia effect type to improve the classification efficiency in each step. It is a hurry.

Further, the method of the present invention can be developed from two-stage classification to three-stage classification by developing various applications, and can be used in a general dust collection field by using together with other filtration techniques. It can be used in a wide variety of fields such as flameproof and heat-resistant incineration ash field and environmental field for water and air pollution.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a basic embodiment of the system of the present invention, and FIG. 2 is an AA sectional view of FIG. The cylinder 1 of the main body is detachably mounted on a dust tank 2, and a suction port 4 is provided in a cutting line direction on a side of the cylinder near the upper end.
The discharge port 5 is attached to the center of the upper end surface of the. Also, one or more (four in this embodiment) vortex stop plates 14 are radially mounted inside the dust tank 2 to reduce the vortex. A cylindrical intermediate cylinder 3 which is concentric with the discharge port 5 and shorter than the cylinder 1 is mounted inside the cylinder 1 with its upper end in contact with the upper end surface of the cylinder 1 and its lower end is left open. The shielding plate 6 is arranged inside the intermediate cylinder so as to partition the intermediate cylinder, and a discharge port 8 is formed in the intermediate cylinder above the intermediate plate.

Here, the specifications of each member will be described.
First, the cylinder 1 is not tapered downward like a conventional cyclone. The diameter of the intermediate cylinder 3 is set to be sufficiently larger than the diameter of the discharge port 5. The shield plate 6 has a plurality of small ventilation holes 7 formed on the surface thereof, and plays a role of causing a swirling flow rising from below to collide with this member and performing classification by the inertia effect in the ventilation holes 7 on the surface. I have. Also, as shown in the partial view of FIG.
It may be an arc-shaped slit 7 'or a radial slit 7 ", or may be a triangular or quadrangular shape (not shown). These vents may be formed on the entire surface of the shielding plate. It is preferable to avoid the central part of the shielding plate that collides with it, and the smaller the ventilation hole, the higher the classification efficiency, but it is necessary to consider clogging. A convex or concave surface having a curved center, an edged 6 'as shown in FIG. 3 or an umbrella-shaped 6 "as shown in FIG.

Next, the outlet 5 will be described. This penetrates the center of the upper end surface of the cylinder 1 and communicates with the discharge port 8 as shown in FIG. In FIG. 1, the lower end of the discharge port extends slightly inward from the upper end surface of the cylinder 1, but may be flush with the upper end surface.

In the embodiment shown in FIGS. 1 and 2 constituted by the members having the above-described properties, when the powder airflow is sucked through the suction port 4, the airflow descends as a swirling airflow. At that time, the coarse particles fall into the dust tank 2 while rotating on the inner wall of the cylinder 1 by centrifugal force. On the other hand, the fine particles try to move toward the center by centripetal force, but are blocked by the intermediate cylinder 3 and descend while rotating along the outer wall of the intermediate cylinder. Since the cylinder portion sandwiched between the cylinders 1 and 2 has a negative pressure as it goes downward, the turning speed is accelerated based on the theory of centrifugal force, and therefore, the classification is carefully performed while increasing the centrifugal force, and the intermediate cylinder 3 is selected. To the bottom of The process so far is the classification of the centrifugal force in the cylindrical portion, which is the first feature of the method of the present invention.

The centripetal flow that has diverted to the lower end of the intermediate cylinder flows into the intermediate cylinder 3, reversely ascends toward the shielding plate 6, and proceeds to the second classification process. The process will be described below.

Since the inside of the intermediate cylinder has a further negative pressure, the turning speed of the inflowing fine particles is further accelerated and turns upward toward the shielding plate 6 like a small tornado. Then, when it collides with the shielding plate, it is dissipated as a swirling film flow in all circumferential directions. As shown in FIG. 2, a large number of small round holes 7 (or arc-shaped slits 7 'or radial slits 7 ") are formed in the shielding plate 6, and a high negative pressure is generated in the discharge port 8. Therefore, the following phenomenon occurs.
That is, a gas having an extremely small mass is rapidly turned from the vent hole 7 and is sucked into the discharge port 8. However, since the fine particles have a much larger mass than the gas, they cannot follow the rapid change of the flow, and most of the fine particles go straight on the ventilation holes 7 to reach the inner wall of the intermediate cylinder 3 and descend. The above is the outline of the centrifugal effect type classification, which is the second feature of the method of the present invention.

As described above, the method of the present invention has a significant feature in that the centrifugal primary classification and the inertial effect type secondary classification are integrated into one apparatus and continuously performed. Thus, the origin of the name of the present invention is also here.

Next, another embodiment will be described.
FIG. 3 is a longitudinal sectional view of the dust tank, and the dust tank is omitted because it is common to that of FIG. FIG. 4 is a sectional view taken along line BB of FIG. Only the differences between the members of this embodiment and the embodiment of FIG. 1 will be described. The discharge pipe 10 is fitted in the center of the discharge port 8, the upper end is fitted to the discharge port 5, and the lower end is joined to the shielding plate 6 '. Keep it. The shielding plate 6 ′ has a downward edge around it, and fits with the intermediate cylinder 3 with an appropriate gap. Note that this shield plate is also provided with the same ventilation holes 7 (or 7 ', 7 ") as shown in FIG.

A large number of small round or polygonal ventilation holes 9 are formed in the side surface of the discharge pipe 10, and these ventilation holes may be vertical grooves 9 'or horizontal grooves 9 "as shown in FIG. These vents have the same functional purpose as the vents of the shielding plate: the venting hole 7 of the shielding plate 6 ′ controls the inertial effect classification of the plane swirling flow, while the venting hole 9 of the discharge pipe 10.
(9 ′, 9 ″) is configured to control the inertial effect type classification of the vertical swirling flow.

Next, the flange 12 on the upper end surface of the cylinder 1 will be described. This is provided to make it easy to clean the inside of the discharge port 8. The discharge port 5 is attached to the center and is detachable from the upper end surface of the cylinder 1. The shielding plate 6 ′ is also taken out together, so that these members and the inside of the discharge port 8 can be easily cleaned. Further, a dust tank not shown is common to FIG.

Next, regarding the longitudinal slit 11 on the side surface of the intermediate cylinder 3, one or more (in this embodiment, equally divided into two) slits are formed on the entire circumference. The purpose of this is to introduce a swirl flow from the outside, to create a swirl flow in the discharge port,
This is to create a centrifugal and swirling inertia effect type classification by the ventilation hole 9 around 0. In addition, the exhaust pipe 1
This includes the ability to blow off the surface of No. 0 and reducing clogging by automatic cleaning (self-cleaning).
The vertical slit 11 may be a plurality of round or square holes arranged in the vertical direction, and the length may be shorter than that of the discharge pipe 10.

The vertical slit 11 will be supplemented once more. FIG. 9 is an enlarged view of a portion “C” of FIG. 4 and shows a different form of the slit cross section.
(B) shows a cross-sectional form in which the side wall of
Is a cross-sectional configuration in which the slit is pushed outward, and (c)
Indicates a cross-sectional shape expanded inward. In this case, since the latter (b) and (c) have a place where the swirling flow stagnates, the powder is deposited R as shown in the figure and clogging is likely to occur.
In this respect, the form (a) has less deposition and is preferable from the viewpoint of self-cleaning. The slit configuration for preventing clogging is the same as in the case of the vertical groove-shaped vent hole 9 'in FIG. In FIG. 6, the vertical slit is omitted because the outer shape of the shielding plate is reduced and the swirling flow is introduced from below.

Introducing the swirl-assisted swirl flow from the outer periphery of the shield plate into the discharge port 8 as shown in FIG. There is almost no effect because the proportion of particles is very small.

It should be noted that the ring-shaped air holes formed by the above-described laminated shielding plate will be described. FIG. 7 shows the embodiment. In the figure, reference numeral 6a denotes a disk-shaped shield plate, and a donut-shaped shield plate 6b having a hole having substantially the same diameter as the disk-shaped shield plate is stacked with a suitable gap provided by a support (not shown) to form a ventilation hole. This structure has the effect of reducing the ventilation resistance by laminating a ring disk having the same diameter as the shielding plate 6a between the two.

FIGS. 3 and 4 constructed as described above
In this embodiment, when the powder particles are sucked through the inlet 4, the coarse particles undergo the primary classification by the centrifugal force in the cylindrical portion of the cylinder 1 and enter the dust tank 2. Fine particles are in the middle cylinder 3
And enters the intermediate cylinder 3 around the lower end of the armature, collides with the shielding plate 6 ′ as a swirling ascending airflow, and undergoes inertial effect type secondary classification through the vent hole 7. The ultrafine particles further flowing into the discharge port 8 (although the swirl flow disappears as it is) are urged by the external swirl flow from the vertically long slit 11 of the intermediate cylinder to generate a swirl flow, and the centrifugal and swirling inertia effects It receives both effects of mold classification at the same time, and receives so-called third classification. The third classification will be described below.

The ultrafine particles in the discharge port in this embodiment are simultaneously subjected to the following two types of classification.
That is, since the inside of the discharge pipe 10 has the highest negative pressure, the swirling flow in the vicinity thereof is accelerated and is rotating at high speed. Therefore, relatively heavy particles undergo centrifugal classification and descend from the inner wall of the intermediate cylinder 3.
Finer fine particles are subjected to a swirling inertia type classification in the vent hole 9 of the exhaust pipe, and gas flows into the discharge pipe 10, but the fine particles continue to swirl around the same, and gradually become above the shielding plate 6 '. Descends. The above is the outline of the third classification that occurs around the discharge pipe 10.

Although the procedure for cleaning the inside of the discharge port of this embodiment has already been described, it is omitted here. In addition, it is also effective to use a well-known reverse injection cleaning method using an air pulse. The above is the outline of the classification process of this embodiment.

Next, an embodiment in which a filter is used in combination with the system of the present invention will be described. FIG. 5 is a longitudinal sectional view, in which a dust tank is omitted. Regarding constituent members of each part of this device, parts different from FIG. 1 and FIG. 2 will be described. First, a cylindrical filter F of the same length is detachably attached to the outside of the discharge pipe 10, and an umbrella-shaped shielding plate 6 ″ is detachably attached to the lower end of the discharge pipe 10. The other components are the same as those in Fig. 2. Now, supplementing the umbrella-shaped shielding plate 6 ", this configuration can be achieved by sliding down the accumulation of powder in the discharge port 8. This is only to reduce the deposition. The ventilation holes of the shielding plate 6 "may have any of the shapes described above.

The structural feature of the embodiment shown in FIG. 5 is that removing the flange 12 not only facilitates cleaning of the discharge port 8 but also removes the shielding plate 6 ″ and removes the filter F from the lower end of the discharge pipe 10. That it can be easily replaced.

Here, the filter F will be supplementarily described.
The material of the filter may be pulp, fibrous polymer, or sponge-like porous material. Further, a conventionally known cartridge filter having a pleated shape of these sheet materials formed into a tubular shape may be used. A high-precision hepafilter (having a collection efficiency of 0.3 μm particles of 99.97
%) Etc. can be freely attached. FIG. 5 shows an embodiment in which a cartridge filter is provided with a perforated cylinder cover.

In the embodiment of the method of the present invention constituted by the above-mentioned constituent members, the classification process of the particles is performed as follows. The perforated cylindrical cover of the filter F corresponds to the case where the diameter ratio of the discharge pipe 10 is large as described in the embodiment of FIG.
A series of classification processes up to the perforated cylinder cover of the filter F in the inside can be regarded as completely the same as in the case of the embodiment of FIG. Therefore, a series of three steps from the first to the third classification is similarly performed. And finally, all the steps are completed via the filtration step of the filter F.

The feature of this embodiment is that, by combining the classification method of the present invention with the filtration method, the overall accuracy of this classification device can be enhanced to the final filtration accuracy of the filter. Next, the significance and prospects of this are described. That is, by such compounding, the application can correspond to a wide range of particle size distribution, and a commercially available filter can be used, and a filter having any accuracy can be selected according to the purpose. In addition, since the process of high-efficiency classification according to the method of the present invention is performed in two stages or three stages before these stages,
The replacement life of the filter can be significantly extended.
Next, an embodiment of a large-capacity dust collecting device utilizing this advantage will be described.

FIG. 8 is a longitudinal sectional view of an embodiment of the present invention in which a plurality of filters are incorporated, and the dust tank is omitted. First, a plurality of discharge pipes 10 are arranged in parallel on the upper end surface of the cylinder 1, provided in communication with the discharge port 8, and a filter F is fitted and attached to each of them. Discharge pipe 10
End plates 15 are detachably attached to the upper end surfaces of the discharge pipes 10, respectively, so as to close the upper end surfaces of the discharge pipes 10 and to hold the filter. A cover 13 covers these filter portions and is detachably attached to the cylinder 1. Other components are the same as those in FIG.

With the present embodiment configured as described above,
Briefly explaining the classification process, the classification process from the suction port 4 to the discharge port 8 is performed through two-stage classification of centrifugal force classification and inertia effect classification because the components are common to those of the embodiment of FIG. Then, it enters the discharge pipe 10 on the upper end surface of the cylinder 1 and is filtered and discharged by a filter. The filter can be easily replaced by removing the cover 13 and the end plate 15. The above is the outline of the present embodiment. The feature of this embodiment is that the life of the filter can be prolonged and a high-efficiency, large-capacity dust collector can be easily provided.

[0036]

The present invention has the following effects.

First, as shown in the embodiment of FIG. 1, the conventional cyclone is performed by a two-stage classification in which a centrifugal primary classification in a cylindrical portion and an inertial effect type secondary classification using a shielding plate in a middle tube are continuously performed. Classification efficiency can be improved much more than one-stage classification using only a centrifugal force method such as the method.

As shown in the embodiment of FIG. 3, a discharge pipe 10 is provided in the discharge port 8 and a high-speed swirling flow is generated around the discharge pipe 10 to simultaneously classify centrifugal and swirling inertia effect types (tertiary classification).
The classification efficiency can be further improved by adding three-stage classification to the previous one-stage and two-stage classification.

Also, as shown in the embodiment of FIG. 5, the filter F is attached to the discharge pipe 10 so that the classification function and the filtration function can be combined, so that the total classification accuracy can be improved to the filtration accuracy of the filter, and the filter function can be improved. The replacement life can be significantly extended, and the economic effect can be improved.

Although not shown, it is easy to make a structure obtained by combining FIGS. 5 and 8 as a combination with a filter, and to provide a filter with a long life and a high performance and large capacity dust collector. Can also be easily achieved.

Further, since members other than the filter can be made of metal or ceramic material, it can be used in high temperature specifications, and in addition to the dust collection field, a flame-extinguishing device or a special adsorption catalyst (for example, activated carbon) in the combustion field can be used. By filling the inside of the discharge port, it can be used as a device for removing dioxin or the like or a deodorizing device.

Further, by making the dust tank deep, filling it with water, and immersing the lower end of the intermediate cylinder in the water surface, it can be used in wet dust collectors, and can be used in fields such as high-temperature dust collection, flame suppression and deodorization. .

As described above, the method of the present invention can contribute to various environmental fields such as purification of air and water pollution by using various filtration techniques and catalyst techniques.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a basic embodiment of the method of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a longitudinal sectional view of a further embodiment of the present invention, in which a dust tank portion is omitted.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is a longitudinal sectional view of an embodiment in which a filter is used in combination with the method of the present invention, in which a dust tank portion is omitted.

FIG. 6 is a partial longitudinal sectional view showing a vertical groove shape and a horizontal groove shape of a vent hole of a discharge pipe.

FIG. 7 is a partial longitudinal sectional view of a laminated shielding plate.

FIG. 8 is a longitudinal sectional view of an embodiment in which a plurality of filters are incorporated in the system of the present invention, in which a dust tank portion is omitted.

9 is an enlarged view of a portion C in FIG.
FIG. (A) Cross-sectional form when a slit portion is punched. (B) Cross section when the slit portion is pushed outward. (C) Cross section when the slit portion is pushed inward.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cylinder 10 Discharge pipe 2 Dust tank 11 Vertical slit 3 Intermediate cylinder 12 Flange 4 Suction port 13 Cover 5 Discharge port 14 Vortex stop plate 6, 6 ', 6 "shield plate 15 End plate 6a, 6b Laminated shield plate 7, 7 ', 7 "Ventilation hole of shielding plate F Filter 8 Drain port R Deposition of powder 9,9', 9" Vent hole of discharge pipe

Claims (3)

[Claims] 1. A dust tank 2 and a vertical cylinder 1 fitted thereon are open at the lower end to the dust tank 2, a discharge port 5 is provided at the center of the upper end face, and a tangential direction of a side face near the upper end is provided. In a centrifugal classifier provided with a suction port 4 horizontally, an intermediate cylinder 3 concentric with the discharge port 5 and having a diameter larger than that of the cylinder is mounted at the upper end in contact with the upper end surface of the cylinder 1, and the lower end is opened to open the cylinder 1. It is kept shorter and a shield plate 6 is provided horizontally on its inner surface. A discharge port 8 communicating with the discharge port 5 is provided above the shielding plate 6, and a plurality of ventilation holes 7 are formed in the shielding plate 6.
(7 ′, 7 ″). 2. A vent hole 9 is provided in the center of the discharge port 8.
Exhaust pipe 10 having (9 ′, 9 ″), and the upper end
The lower end is provided in contact with the shielding plate 6 (6 ', 6 "), and one or more longitudinal slits 11 are provided in a side wall of the discharge port 8 (a side wall of the intermediate cylinder 3). Centrifugation
Inertial effect type classification method. 3. A lower end of an exhaust pipe 10 in an exhaust port 8 is detachably connected to a shielding plate 6, (6 ′, 6 ″), and a cylindrical filter F having the same length as this is attached to and detached from the exhaust pipe 10. 3. The centrifugal / inertial effect type classification system according to claim 1, which is fitted as possible.