JP2001300361A - Cavitation nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new and effective cavitator. SOLUTION: This cavitation nozzle 101 is provided with a feed passage 103 for a high-pressure liquid 102 (high-pressure water), a nozzle 105 bored in the tip in the flow direction of the high-pressure liquid 102, an expanding cavity 106 furnished in succession to the tip face of the nozzle 105 and the cavitator 108 to cavitate the high-pressure liquid 102 jetted into an ambient liquid 409 from the nozzle 105, The cavitator 108 is composed of a conical body 109a with the diameter gradually increasing in the flow direction (in the direction of the arrow) of the high-pressure liquid 102 and a flange-shaped protrusion 109 provided circumferentially at the tip face of the conical body 109a and mounted on the center axis in the cavity 106.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the generation of a cavitation jet used for cleaning or the like, and more particularly to a cavitation nozzle for promoting cavitation.

[0002]

2. Description of the Related Art In a conventional nozzle, when a water jet is blown out in water at a higher speed than a nozzle installed in water, severe cavitation is generated by the water jet. Such underwater water jets are known as cavitation jets.
on jet). In the case of a normal water jet in the gas phase, the maximum impact pressure when the jet collides does not in principle exceed the jet pressure of the jet at the nozzle. Therefore, in order to increase the power of the water jet in the gas phase, the discharge pressure of the high-pressure pump must be increased, and the merit in terms of energy cost disappears. On the other hand, for cavitation jets,
In addition to the jet impingement pressure, the impact pressure generated during bubble collapse can be utilized. This impact pressure is 200MPa
(Approximately 200 kgf / cm ² ), and reaches several times the injection pressure of the water jet at the nozzle.

The cavitation jet having such characteristics is most suitable for cleaning in various fields, and the cleaning effect is enhanced by the synergistic effect of the cavitation impact pressure and the flushing of the jet water amount. Although there are a wide range of requirements for cleaning equipment, there are major demands such as high cleaning effect, elimination of special detergents, use of as little water as possible (low drainage), completion of work in a short time, and low energy cost. It is a request. Even in the case of cleaning using a cavitation jet, if the jet pressure of the water jet is increased in order to increase the cleaning performance, cavitation will increase. However, there is little advantage in considering energy costs. Any means of promoting cavitation without affecting energy costs would be very effective. This is a special nozzle structure provided with a so-called cavitation (cavitation promoting body).

The nozzles shown in FIGS. 10 and 11 are examples of the prior art, and are of a type having a cavitation-like function for promoting cavitation in a cavitation jet. In the nozzle 1 shown in FIG. 10, a bell-shaped enlarged cavity 3 is continuously provided on the outlet end face of the ejection hole 8. The cavitation jet in the bell-shaped enlarged cavity 3 is affected by pressure fluctuations caused by a circulating vortex generated around the jet, and the cavitation nucleus in the surrounding water (Cavitation nucleus)
i) is supplied. On the other hand, the nozzle 9 shown in FIG.
In this type, a cavitation 11 of a cylindrical body is inserted into 8, and vortices generated at the tip of the cylindrical body are supplied into the cavitation jet. In this nozzle, a conical enlarged cavity is provided at the outlet of the ejection hole. Even with the above nozzles, cavitation is promoted, but not enough. For example, these nozzles cannot meet the demands of creating powerful and powerful cavitation with low jet pressure water jets.

[0005]

In a conventional nozzle, a pressure fluctuation caused by a circulating vortex generated around a jet acts on a cavitation jet in an enlarged cavity extending from an outlet end face of an ejection hole. , And also bubble nuclei in the surrounding water. On the other hand, the other nozzles are of a type in which a cylindrical body is inserted into the ejection hole, and a vortex generated at the tip of the cylindrical body is supplied into the cavitation jet. In this nozzle, a conical enlarged cavity is provided at the outlet of the ejection hole. Even with the above nozzles, cavitation is promoted, but not enough. For example, there is a problem that these nozzles cannot respond to a demand for producing a powerful and powerful cavitation by a water jet having a low injection pressure.

[0006] It is an object of the present invention to provide a cavitation nozzle with a new and effective cavitator.

[0007]

In order to achieve the above object, a cavitation nozzle according to the present invention comprises: a supply passage for a high-pressure liquid; an ejection hole formed at a tip end in a flow direction of the high-pressure liquid; In a cavitation nozzle provided with an enlarged cavity portion continuously provided at the tip of the hole and a cavitator for cavitation of high-pressure liquid ejected into the surrounding liquid from the ejection hole, the cavitator has a cone whose diameter increases in the flow direction. And a flange-shaped projection provided around the distal end surface of the cone, and inserted on the central axis in the enlarged cavity.

The cavitator has a structure in which the rear end of the conical body is fixed to the tip of the rod-shaped body, and the rod-shaped body is inserted into the enlarged cavity by passing the rod-shaped body through the ejection hole. It is inserted so that it can enter and exit the ejection hole, and is configured to be positioned in the enlarged cavity by the movement of the rod-shaped body, or the diameter of the flange-shaped projection is set within a range of 0.1 times or more and less than 0.45 of the tip diameter of the enlarged cavity. A configuration may be used.

That is, a substantially conical body whose diameter is increased in the flow direction and a flange-like projection provided around the distal end of the conical body are provided as cavitators in an enlarged cavity portion connected to the front end surface of the ejection hole. . The cavitator of this cone is
It is provided at the tip of a rod (rod-like body) passing through the ejection hole, and can be moved or protruded or retracted by operating the rod to change its position in the enlarged cavity. Since the rod is inserted into the ejection hole, the ejection hole has an annular gap. By selecting the maximum diameter of the conical cavitator (diameter of the flange-shaped protrusion at the tip) from the range of 0.1 to 0.45 times the maximum diameter of the enlarged cavity (diameter of the outlet end) The object of the present invention is achieved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, a supply flow path 103 for a high-pressure liquid (high-pressure water) 102, an ejection hole 105 formed at the end in the flow direction of the high-pressure liquid 102, and a continuous connection with the end surface of the ejection hole 105. A cavitation nozzle 101 having an enlarged cavity 106 and a cavitation 108 for ejecting into a surrounding liquid 409 from an ejection hole 105 for cavitation of the high-pressure liquid 102. ) And a flange-like projection 109 provided around the distal end surface of the cone 109a, which is gradually inserted into the enlarged cavity 106. It has a certain configuration.

The cavitator 108 has a rear end of a cone 109a fixed to a front end of a rod 107,
A configuration in which the rod 107 is inserted into the enlarged cavity 106 by inserting the rod 107 into the ejection hole 105, or the rod 10 is inserted into the ejection hole 105.
7 is inserted so as to be able to move in and out, and the diameter of the flange-shaped protrusion 109 or the configuration positioned in the enlarged cavity 106 by the movement of the rod-shaped body 107 is 0.1 times or more 0.4 times the tip diameter of the enlarged cavity 106.
A configuration formed in a range of less than 5 may be used.

That is, the high-pressure water 102 is supplied to the tip of the cavitation nozzle 101 through the supply channel 103, and is decompressed and accelerated by the radially contracting portion (diaphragm portion) 104, and is discharged.
Blows into the water at high speed to create a cavitation jet. A bell-shaped enlarged cavity 106 is provided at the tip end of the ejection hole 105. In the cavitation nozzle of the present invention, a cavitator 108 having a substantially conical body 109a and having a flange-like projection 109 on the outer periphery of the tip is provided so as to protrude into the enlarged hollow portion 106 from the outlet of the ejection hole 105 as a starting point. The cavitator 108 is a conical body 109a that is supported by a rod 107 that penetrates into the ejection hole 105 and that gradually spreads downstream. Since the rod 107 penetrates the center of the ejection hole 105, the water flow is spouted at a high speed through the annular ejection passage 110 which is a ring-shaped gap.

The cavitator 108 can be moved in and out of the enlarged cavity 106 forward (downstream direction) and rearward (upstream direction) to adjust the position by moving the rod 107 in and out. FIG. 2 shows an embodiment in which the cavitator 108 protrudes forward from the position shown in FIG. When the cavitator 108 is installed in this way, the position of the peak of the impact pressure in the axial direction of the cavitation jet (in this region, for example, in the case of cleaning, the cleaning effect is maximized) can be shifted downstream. it can. For example,
When the object to be cleaned is away from the installation position of the cavitation nozzle 101, the position of the cavitation nozzle 108 is adjusted, and when the object to be washed is away from the installation position of the cavitation nozzle 101, the position of the cavitation nozzle 101 is not changed. In addition, it is possible to maintain the cleaning effect in the best condition. When moving the cavitator 108 forward with reference to the position shown in FIG.
The state of the annular ejection flow channel 110 in FIG.
FIG. 3 shows another embodiment in which the cavitator 108 is set backward with respect to the position shown in FIG. 1, see the following description.

FIG. 4 shows a cavitation nozzle 1001 having a cavitator 1008 inserted therein as another embodiment of the present invention.
Is a sectional view of a nozzle gun 1015 for use in the present invention. The cavitator 1008 is supported by a long rod (rod-like body) 1007 and penetrates through the ejection hole 1005. In the ejection hole 1005, a plurality of annular spacers 1011 are attached to the long rod 1007 and inserted into the supply flow path 1003 in order to accurately perform “centering”. The cavitation nozzle 1001 is provided at the tip of a thick-walled cylindrical nozzle gun 1005, and a supply flow path 1003 is formed at the center of the nozzle gun 1005. At the end (rear) of the nozzle gun 1005 opposite to the nozzle 1001, a rod 1007 penetrates. This penetrating part is formed by the screw feed mechanism 1012 and the stopper seal 1013. The screw feed mechanism 1012 is a cavitator
This is for moving and adjusting the 1008 in the front-back direction. For this adjustment, a handle 1014 is provided at the rear end of the rod 1007. When supplying high-pressure water 1002 to this nozzle gun 1005, the stopper seal 1013
The position of 1007 (in other words, cavitator 1008) is fixed and leakage is prevented.

Next, the operation of the present embodiment will be described. Figure 5
4 schematically illustrates the phenomenon and action of a cavitation nozzle embodying the present invention. A cavity area 417 is formed at the tip of the cavitator 405 having a substantially conical shape, and a large amount of vortex cavitation 410 is generated around the cavity area 417 and flows in 411 from the inside of the jet. On the other hand, vortex cavitation 412 originating from the jet interface also flows in from the jet interface sea 413, and the vortex cavitation development area 414 includes vortex cavitation 410 generated by the almost conical cavitator 405 inside the jet, and vortex cavitation 410 generated from the jet interface and generated inside the jet And the vortex cavitation 412 that has flowed into the area is mixed and coalesced, resulting in a region where extremely severe vortex cavitation has developed. This region is the second peak of the cavitation jet 415 created by the cavitation nozzle according to the present invention. By the way, a hollow area 417 is created behind the conical cavitator 405, and the water core part diffuses into the water due to the action of the vortex cavitation 410 around it, so the first peak exists in this cavitation jet 415 do not do.

FIG. 6 shows a comparison of impact pressure distribution curves between the prior art shown in FIG. 10 and the embodiment of the present invention shown in FIG. The impact pressure amount P generated by cavitation on the vertical axis is determined by the second conventional technology (FIG. 10).
It was dimensionlessly expressed by dividing by two peak impact pressures P ^* . Cavitation according to an embodiment of the present invention.
You can see that the jet has the following three features. The first peak, which is highly erosive, disappears. The impact pressure in a region corresponding to the second peak (there is no strict description because there is no first peak) is large. The region of the second peak approaches the nozzle as compared with the conventional technology.

According to the present invention, when the nozzle is used for cleaning, it is advantageous in that the base material is not damaged. On the other hand, is the most significant feature of the present invention in that cleaning can be performed efficiently. Further, by moving the position of the cavitator, it is possible to change the position of the impact pressure peak, that is, the region where the effect of cavitation is strongest. As shown in FIG. 7, when the cavitator is protruded forward (downstream of the jet) from the state of FIG. 1 indicated by a broken line, the region of the impact pressure peak is shifted to the downstream of the jet. On the other hand, when the cavitator is pulled rearward (upstream of the nozzle) as described later, the region of the peak impact pressure shifts to a position closer to the nozzle.

FIG. 8 shows the prior art shown in FIG. 10 and FIG.
Time required for cleaning with respect to the embodiment of the present invention
Are shown in comparison. The cleaning time t on the vertical axis is the
Cleaning time t in FIG. 10^*Dimensionless by dividing by
It has become. That is, t / t in the prior art^*= 1.0 and
Become. On the other hand, in the embodiment of the present invention, t / t ^*
= 0.44, significantly reducing the cleaning time
Could be mentioned. Cavitation inserted into nozzle
Is generally a nozzle to generate cavitation
Wear is faster than the body. Fig. 9 shows the conventional technology (Fig. 10).
Cavitation in the embodiment of the present invention
It is a comparison of the amount of wear with the theta. On the vertical axis
The amount of wear Δm is the cavitator in the conventional technology (Fig. 10).
Amount of wear Δm^*Dimensionless by dividing by.
Δm / Δm in conventional technology^*= 1.0. This and ratio
In comparison, in the case of the cavitator according to the present invention, Δm / Δm^*=
1.04, although there is a slight difference, both cavities
The wear amount of the pieces may be considered to be substantially equal.

Another embodiment of the present invention will be described with reference to FIG. Vessel 1 with almost conical cavitator 108
It is designed to pull back to the 05 side (rear). Since the conically widened portion of the cavitator 108 blocks the outlet of the ejection hole 105, the annular ejection passage 110 of the ejection hole 105 becomes narrow, and the ejection flow rate decreases even at the same ejection pressure. Since the cavitator 108 itself is also located inside the enlarged cavity 106, the position of the second peak of the impact pressure distribution also approaches the ejection hole side as shown in FIG.

This other embodiment is suitable for a case where the same nozzle is used and a small portion is cleaned with a small amount of water, for example. As described above, according to the other embodiment, the operation (for example, washing with water) according to the situation becomes possible by operating the cavitator provided in the same nozzle.

The operation of the present invention will be described. When the nozzle having the cavitator according to the present embodiment is used, a vortex is periodically emitted from the tip of the mounting head of the cavitator protruding forward to the center of the enlarged cavity. In the low pressure part (vortex core) of these vortices, bubble nuclei (Cavitation nucle
i) is excited to cause cavitation and grow as vortex cavitation. Cavitation not only originates from the shear layer on the surface of the jet, but also grows in the center of the jet.
Vortex cavitation is powerful and the entire submersible water jet will be filled with powerful vortex cavitation. Thus, cavitation in the cavitation jet is promoted by using the cavitation nozzle according to the present invention. Vortex cavitation at the center of the jet eliminates the phenomenon of creating a highly erosive (first peak). It can be said that this characteristic is suitable for applications such as cleaning in which the soundness of the base material of the nozzle itself must be ensured.

In the enlarged cavity, the pressure fluctuation caused by the circulating vortex generated around the jet and the action of supplying the bubble nucleus are maintained regardless of the presence or absence of the cavitator of the present invention.

According to the present invention, the cavitation is promoted by providing the cavitation, so that when applied to cleaning, the effective cleaning area is increased. And the cleaning time can be shortened, and the working efficiency can be improved. Therefore, the amount of washing wastewater can be reduced as the amount of used water decreases. In addition, there is a possibility that the base material may be damaged.
One peak disappears. By controlling the position of the second peak at which the power of cavitation is maximized, the standoff distance (distance between the nozzle and the object) can be freely selected according to the application. The degree of damage to the cavitator provided in the nozzle is almost the same as in the prior art.

[0024]

According to the present invention, since the cavitation is promoted by adjusting the position of the movable cavitator, the effective cleaning area at the time of cleaning can be increased, and the cleaning time can be reduced, thereby improving the work efficiency. Is done. As the amount of water used is reduced, the amount of washing wastewater is also reduced. Furthermore, the effect of the first peak, which damages the base material, disappears, and the position of the second peak, at which the power of cavitation is maximized, is controlled, so that the standoff distance can be freely selected according to the application. is there.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing the operation of FIG.

FIG. 3 is a diagram showing another embodiment of the present invention.

FIG. 4 is a cross-sectional view of a nozzle gun showing another embodiment of the present invention.

FIG. 5 is a diagram illustrating the operation of the present invention.

FIG. 6 is a graph illustrating the effect of the present invention.

FIG. 7 is a graph illustrating the effect of the present invention.

FIG. 8 is a graph illustrating the effect of the present invention.

FIG. 9 is a graph illustrating the effect of the present invention.

FIG. 10 is a diagram showing a conventional technique.

FIG. 11 is a diagram showing a conventional technique.

[Explanation of symbols]

 101, 1001 Cavitation nozzle 102, 1002 High-pressure water 103, 1003 Supply flow path 105, 1005 Spout hole 106, 1006 Enlarged cavity 107, 1007 Rod 108, 1008 Cavitation 109, 1009 Flange-shaped protrusion 109a, 1009a Conical 110, 1010 Annular ejection channel 1015 Nozzle gun 409 Ambient liquid

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3B201 AB01 BB03 BB22 BB36 BB90 BB92 CC21 4F033 AA04 BA04 CA01 DA01 EA01 JA02

Claims (4)

[Claims] 1. A high-pressure liquid supply flow path, an ejection hole formed at a tip in a flow direction of the high-pressure liquid, an enlarged hollow portion connected to the tip of the ejection hole, and a periphery of the ejection hole. In a cavitation nozzle including a cavitator for cavitation of the high-pressure liquid ejected into a liquid, the cavitator has a conical body whose diameter increases in the flow direction, and a flange provided on a distal end surface of the conical body. A cavitation nozzle comprising: a projection-like body; and being inserted on a central axis in the enlarged cavity. 2. The cavitation nozzle according to claim 1, wherein the cavitator has a rear end of a conical body fixed to a tip of a rod-shaped body, and is inserted into the enlarged cavity by passing the rod-shaped body through an ejection hole. A cavitation nozzle to be worn. 3. The cavitation nozzle according to claim 1, wherein the cavitator is inserted so that a rod-shaped body can be inserted into and ejected from an ejection hole, and is positioned in the enlarged cavity by the movement of the rod-shaped body. A cavitation nozzle characterized in that: 4. The cavitation nozzle according to claim 1, wherein the cavitator is formed such that the diameter of the flange-shaped projection is within a range of 0.1 times or more and less than 0.45 of the tip diameter of the enlarged cavity. Cavitation nozzle.