JP2000354749A - Cavitation generating device, fluid mixing device using the same and mixing projection used in latter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate a cavitation having a larger negative pressure by partially blocking the region (open hole), between the outer peripheries of chords on both upper and lower sides in crossing sections of a pair of semi-elliptic blade discs in a guide vane, with a narrowing means such as a baffle plate. SOLUTION: A fluid is forcibly sent inside a tube body 2 in the direction shown by an arrow, partitioned into two branched streams by a partition plate 5 and guided to two semi-elliptic blade discs 4a, 4b while rectified to change into spiral currents. Such sudden partition and current transformation generate the shearing stress to mix fine liquid particles and air bubbles in the fluid. The fluid current is narrowed and accelerated by the current change route formed by the plate 5, the discs 4a, 4b and the inner wall of the body 2 to generate a negative pressure in an expanded region on the downstream side of the guide vane 3. The fluid current is further accelerated since the open hole 6 is throttled with the narrowing means 7 to generate the cavitation having a large negative pressure in the axial center part of the body 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cavitation (cavitation) generating device for generating a local negative pressure in a fluid passing through a pipe, and to an improvement of a fluid mixing device using the device.

[0002]

BACKGROUND OF THE INVENTION As a first step for amplifying the mixing and stirring of a fluid and promoting various reactions, cavitation (cavitation phenomenon) is generated in a fluid passing through a tube. There are various types of cavitation generating means, but among them, the chord sides of a pair of semi-elliptical blades intersect obliquely, and the chord side edge on the upstream side of the intersection divides the cross section of the tubular body into two. Using a guide vane closed with a triangular partition plate, with the partition edge of the guide vane partition plate facing upstream, the arc edge of the semi-elliptical blade is connected to the inner wall of the tube and into the tube Attention has been paid to those forming a variable flow path.

[0003]

In the above-mentioned cavitation generating apparatus, the fluid is accelerated by a pair of blades while being rectified into two shunts by a partition plate while the fluid passes through the guide vanes in the pipe. In this way, a large centrifugal acceleration is applied to change the flow to a swirl flow, and cavitation is generated in the fluid downstream of the guide vane. Due to the large open area formed by the upstream chord edge at the intersection of the downstream chord edge and the other semi-elliptical blade, the acceleration of the fluid was naturally limited.

A first object of the present invention is to further improve the above-mentioned cavitation generating apparatus and to provide an apparatus for generating cavitation of a larger negative pressure.

A second object of the present invention is to provide a fluid mixing device using the above-mentioned cavitation generating device.

[0006]

In order to achieve the first object, the present invention relates to a tube for pumping a fluid, comprising: a pair of semi-elliptical blades having a chord side edge crossed at an angle; A cavitation having a guide vane in which a space between the chord side edges upstream of the intersection is closed with a partition plate that bisects the cross section of the tube body and the arc side edges of a pair of semi-elliptical blades are joined to the inside wall of the tube. In the apparatus, the area (opening opening) between the downstream chord edge of the intersection of one semi-elliptical vane of the guide vane and the upstream chord edge of the intersection of the other semi-elliptical vane is narrowed by a baffle plate or the like. It is characterized by being partially closed by means.

The overhanging member of the opening of the guide vane may be a plate integral with the partition plate that bisects the cross section of the tubular body. A configuration in which a part or the whole is bent or curved toward the channel narrowing side may be adopted.

In order to attain the second object, the present invention provides a fluid mixing apparatus comprising: a pipe for pumping a fluid: a pair of semi-elliptical blades crossing chord side edges in an inclined manner; Between the chord-side edges of the upper part of the pipe with a partition plate that bisects the cross section of the tubular body, and at the intersection of one of the semi-elliptical blades with the downstream chord edge and the other with the semi-elliptical blade with the upstream of the intersection A guide vane in which the open area between the chord edges is partially closed by a narrowing means such as a baffle plate and the arc-side edges of the pair of semi-elliptical blades are joined to the inner wall of the pipe; And a plurality of protrusions radially protruding from the inner wall surface on the downstream side.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The cavitation generator 1 of the present invention is composed of a pipe 2 for pumping a fluid composed of gas, liquid, fluidized solid or a mixture thereof in the direction of the arrow, and a guide vane 3 installed in the pipe 2. I have.

The guide vane 3 includes a pair of semi-elliptical vanes 4
a, 4b, the chord-side edges 5a, 5b intersect in an inclined manner, and the space between the chord-side edges on the upstream side of the intersection is closed with a partition plate 5 that bisects the cross section of the tubular body 2, and one semi-elliptical shape is formed. Wing board 4
Area formed by the downstream chord edge at the intersection of a and the upstream chord edge at the intersection of the other semi-elliptical wing 4b.
6 is partially closed by a narrowing means 7 such as a baffle plate, and is installed by connecting the arc-side edges 8a, 8b of a pair of semi-elliptical blades 4a, 4b to the inner wall of the tube 2. ing.

That is, in the cavitation generating apparatus 1 of the present invention, by providing the guide vane 3 with the separate constriction means 7, a large centrifugal acceleration is applied to the fluid passing through the guide vane 3 and the downstream side of the guide vane 3. Cavitation (cavitation phenomenon) of a larger negative pressure is generated in the pipe.

The narrowing means 7 in the embodiment shown in FIG. 1 is formed of a plate integral with the partition plate 5, and the intersection of the downstream chord edge of one semi-elliptical blade and the other semi-elliptical blade. The opening 6 is narrowed by the narrowing means 7 by partially closing the space between the chord edges on the upstream side with a part of the rectangular partition plate 5.

When the stenosis means 7 is formed of a plate integral with the partition plate 5, the partition plate 5 is not limited to a square shape as shown in FIG. 1, but may have a larger closed area as shown in FIGS. It may be a polygon (see FIG. 2) or a polygon with a smaller closed area (see FIG. 3).

The stenosis means 7 may be provided locally at the corner of the opening 6, as shown in FIGS.

Further, as shown in FIG. 7, the constriction means 7 of the guide vane 3 according to the present invention bends the whole or a part of the semi-elliptical blades 4a and 4b (particularly, the downstream side of the intersection) to the upstream side, Alternatively, the opening may be narrowed by narrowing the opening between the downstream chord edge at the intersection of one blade and the upstream chord at the intersection of the other blade.

Next, the operation of the cavitation generator according to the present invention will be described. A fluid (for example, a mixed fluid of air and water) that is pumped through the pipe 2 in the direction of the arrow is divided into two branches by the partition plate 5 and guided to the two semi-elliptical blades 4a and 4b while being rectified. As a result, it is transformed into a spiral flow with a strong twist. At this time, the fluid generates a large shear stress in the fluid due to abrupt division and current change by the partition plate 5 and the vanes 4a, 4b,
The turbulent flow of the fine liquid particles and the fine bubbles is mixed.

Further, the fluid is constricted by the partition plate 5, the pair of semi-elliptical blades 4a and 4b, and the variable flow path formed by the inner wall of the tube 2, as compared with the cross-sectional area of the tube 2. As a result, the pressure is accelerated, and a negative pressure proportional to the square of the fluid peripheral velocity is generated in the enlarged area downstream of the guide vane 3, but the present invention further narrows the opening by the constriction means 7. The peripheral velocity of the fluid that has passed through the guide vane 3 is further increased, and a pressure increasing portion is formed on the outer peripheral side of the pipe 2 in an enlarged area downstream of the guide vane 3. Cavitation with large negative pressure occurs.

FIG. 8 shows the cavitation generator 1
This shows a fluid mixing device 9 which uses a guide vane 3 provided with the above-described constriction means 7 in the pipe 2 and a peripheral wall of the pipe downstream of the guide vane 3. Then, a plurality of protrusions 10 are fixed radially,
When the swirling flow of the fluid to which a large centrifugal acceleration is applied as described above collides with the projection 10, an intense mixing / stirring action as described below is generated.

When the fluid to be pumped into the pipe 2 is, for example, a mixed fluid of gas (air) and liquid, the guide vane 3
Swirling fluid passed through and given a large centrifugal acceleration,
Due to the above-mentioned cavitation, the liquid having a large mass moves to the fluidized bed side to form a liquid layer, and the gas having a small mass moves to the inside of the liquid layer and is in contact with the liquid layer. Form a layer and swirl faster than the liquid layer. Therefore, in the process of forming the liquid layer and the gas layer, the fine particles of the liquid and the fine bubbles collide violently, and an intense turbulent vortex is generated at the interface between the liquid layer and the gas layer due to strong fluid friction.

The projection 10 is attached such that the head 11 is directed toward the axis of the pipe 2 with respect to the swirling flow, and the head 11 is higher than the liquid layer.

The liquid layer of the swirling flow takes in the kinetic energy of the gas layer at a higher speed than the liquid layer and goes up to the head of the projection 10 to form a liquid film on the surface of the head of the projection 10. ,
This liquid film is exfoliated by a gas layer having a speed higher than the liquid layer speed, is formed into a large amount of fine particles, and is scattered radially in a gas layer at the rear to cause gas-liquid mixing.

The scattered fine particles of the liquid in the gas-liquid mixture move toward the original liquid layer due to the effect of the large centrifugal force of the swirling flow. A large amount of fine bubbles float in the liquid, move away from the liquid layer and move inward, and generate a centripetal force of the bubbles.

Thus, in addition to gas-liquid mixing due to shear stress when passing through the guide vane 3 and gas-liquid mixing / stirring when colliding with the projection 10, the liquid fine particles moving outward due to centrifugal force Then, due to the continuous collision of the microbubbles moving inward due to the centripetal force, gas-liquid is mixed violently, and a high degree of gas-liquid reaction is achieved.

As the shape of the projection 10, as shown in FIG. 9, besides a projection having a hemispherical head and a frustum neck, a simple column as shown in FIG. Can be. The fluid mixing device of the present invention is used for aeration, neutralization, emulsification, and other various mixing, stirring, and reactions. In this case, as shown in FIG. 11, in this case, the fibrous material is hardly entangled, and even if entangled, it easily comes off with the flow. It is desirable to make.

In the apparatus of the present invention, the partition plate 5 of the guide vane 3 can be used in any form such as downward, upward, or sideways according to the purpose of use. For example, when the device of the present invention is used for aeration, the partition plate 5 is installed in water such that the partition sides of the partition plate 5 face downward (opposite direction in FIG. 8),
Blow air from below the guide vanes. Further, when used in a reaction apparatus, it can be used by being horizontally or vertically interposed in the middle of a flow pipe of a processing fluid.

[0026]

According to the present invention, the centrifugal acceleration of the helical fluid passing through the guide vanes is increased by providing the narrowing means in the guide vane changing flow path, thereby generating a large negative pressure cavitation in the downstream pipe. Can be done.

Further, the fluid mixing device using the cavitation generator greatly promotes the mixing and stirring of the fluid, and can exert an extremely high effect on various reactions and treatments.

By making the shape of the projection on the downstream side of the guide vane a tapered projection with a curved surface, even if the fibrous object is mixed in the fluid, it does not become entangled, and maintenance becomes easy.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a schematic configuration of a cavitation generator according to the present invention.

FIG. 2 is a view showing another embodiment of the stenosis means.

FIG. 3 is a view showing another embodiment of the stenosis means.

FIG. 4 is a view showing another embodiment of the stenosis means.

FIG. 5 shows another embodiment of the stenosis means.

FIG. 6 shows another embodiment of the stenosis means.

FIG. 7 is a view showing another embodiment of the stenosis means.

FIG. 8 is a partially cutaway perspective view showing a schematic configuration of a fluid mixing device according to the present invention.

FIG. 9 is an embodiment view of a protrusion.

FIG. 10 is an embodiment view of a protrusion.

FIG. 11 is an embodiment view of a protrusion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cavitation generator 2 ... Tube 3 ... Guide vane 4a, 4b ... Semi-elliptical blade 5a, 5b ... Chord side edge of semi-elliptical blade 6 ... Opening opening 7 ... Stenosis means 8 ... Semi-elliptical blade 9: Fluid mixing device 10: Projection 11: Head

[Reference number] PAS99014

Claims (5)

[Claims] 1. A pipe for pumping fluid: a partition plate which crosses the chord side edges of a pair of semi-elliptical blades in an inclined manner, and bisects the cross section of the pipe body between chord side edges upstream of the intersection. And a guide vane having arcuate sides of a pair of semi-elliptical blades joined to the inner wall of the pipe, and a downstream chord at an intersection of one of the semi-elliptical blades. A cavitation generator characterized in that an opening between the edge and the upstream chord edge at the intersection of the other semi-elliptical blade is partially closed by a narrowing means such as a baffle plate. 2. The cavitation generator according to claim 1, wherein the constriction means is a plate integral with the partition plate. 3. The cavitation generating apparatus according to claim 1, wherein the narrowing means has a structure in which a chord edge downstream of the intersection of the semi-elliptical blade is bent or curved to the narrowing side of the flow path. 4. A pipe for pumping fluid: a partition plate which crosses the chord side edges of a pair of semi-elliptical blades in an inclined manner and bisects the cross section of the pipe body between the chord side edges upstream of the intersection. And partially open the opening between the downstream chord edge at the intersection of the one semi-elliptical blade and the upstream chord at the intersection of the other semi-elliptical blade with a narrowing means such as a baffle plate. A guide vane that is closed and has a pair of semi-elliptical blades with arc-side edges joined to the inner wall of the pipe; and a plurality of protrusions radially protruding from the inner peripheral wall of the pipe downstream of the guide vane. Fluid mixing device having 5. The fluid mixing device according to claim 4, wherein the projection is a mountain-shaped projection formed with a curved surface.