JPS6150023B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a slit nozzle having a large number of fine slits.

Techniques that apply a high differential pressure using micropores as nozzles and apply various properties of the injected fluid generated when the fluid is injected from the nozzle have been widely used in various fields, and examples include combustion equipment. Types of equipment that utilize nozzles, such as fuel injection nozzles for oil burners and diesel engines, liquid injection nozzles for liquid injection drying and separation methods, liquid object injection nozzles for granulation equipment for finely granulating objects, and other types of equipment that use nozzles, such as water sprinkling and water injection. are extremely common.

Even though these nozzles are extremely versatile, almost all of them have a circular hole shape, so there is a limit to the minimum size due to processing, and it is not practical to freely process and manufacture nozzles of several microns. It's impossible.

However, with recent advances in science and technology, even finer liquid droplets or solid particles are now required in various fields.

As a method to deal with this, for example, synthetic membranes used for seawater desalination can be equipped with ultra-fine pores, but the membrane itself has a weak strength and cannot be used as a nozzle that can handle high pressure. It was hot.

This invention was made in view of the above-mentioned situation, and aims to provide a metal nozzle that has extremely fine slits and can withstand high pressure.

Hereinafter, this invention will be explained based on the drawings.

FIG. 1 is a perspective view showing one embodiment of the slit nozzle assembly according to the present invention, FIG. 2a is a perspective view of the hollow cylinder 1 of FIG. 1, and FIG.
FIG. 3 is an enlarged partial cross-sectional view taken along line A. Reference numeral 1 denotes a metal hollow cylinder (nozzle body), and a plurality of circular fluid passage holes 2 are bored in the cylinder wall. Further, a thread groove 3 with a fine pitch P is formed by cutting on the outer periphery of this cylindrical wall, and a thin metal wire W having a width (or diameter) B smaller than the pitch P is strongly inserted along the thread groove 3. The wires W are wound around each other to form a slight gap (slit) S=PB between adjacent wires W. Fig. 2b is a view corresponding to Fig. 2a when the fluid passage hole 2a in the cylindrical wall of the hollow cylindrical body 1a is rectangular, or Fig. 3b is a view equivalent to Fig. 3a when the wire Wa has a triangular cross section. A corresponding diagram is shown.

According to the above configuration, the thread groove 3 and the wire W
By increasing the dimensional accuracy of the slit S, the size of the slit S can be made approximately 1 micron, and the fluid passage hole 2 or 2a portion is as shown in FIGS. 4a and 4, respectively.
A large number of fine slits S as shown in the enlarged plan view of b can be obtained. These fine slits S
These fine slits function as a type of nozzle when high-pressure fluid is passed through them at high speed.

If S≈1 micron, the film thickness immediately after the fluid ejected from this slit nozzle can be made extremely thin, approximately 1 micron.
Such fine dimensions could not be achieved with conventional circular hole nozzles.

In addition, the material constituting this nozzle can be made of various highly corrosion-resistant steels such as 316 stainless steel, or titanium materials, so it can withstand the high differential pressure of the jet and has excellent heat resistance and corrosion resistance. Therefore, the range of applications as a nozzle is extremely wide.

Furthermore, unlike conventional circular hole nozzles, the cross-sectional shape of the wire that governs the shape of the nozzle can be freely selected to be most suitable for the intended use of the nozzle. If it is desirable that the run-up distance immediately before ejection is long in relation to the slit dimensions, the cross section of the wire Wb may be made so that the length l of the straight portion L is large, as shown in the enlarged cross-sectional view of Fig. 5. . Further, when disadvantages due to so-called "wrapping" occur, a triangular cross-section of the wire is more advantageous than a circular cross-section.

On the other hand, when considering the manufacturing process, the hollow cylinder 1 or 1a shown in FIGS. A so-called "burr" is generated by cutting, and it is necessary to remove it.
(This order is not adopted as it would be more difficult to remove burrs from the thread grooves if done in the subsequent process.) Moreover, when the wire W is wound on this thread groove 3,
When the fluid passage hole 2 is a circular hole as shown in Fig. 1, Fig. 2a, and Fig. 4a, the wire W passes over the center of the circular hole and when it passes over the end of the circular hole. Naturally, the span of the wire W is different depending on when the wire W is inserted, and the span is the longest when passing over the center of the circular hole.

Generally, in order to make the nozzle assembly, that is, the hollow cylinder 1, smaller and more economical, it is desirable to increase the number of slits as much as possible within a predetermined surface area of the hollow cylinder. It is necessary to reduce the wire size appropriately. Since the wire W is wrapped around the cylindrical surface with relatively high tension,
For thin wires, depending on the size of the span of the fluid passage hole, the difference may occur as shown in Figures 6a and b (Figure 6 is a sectional view taken along lines a-a and bb-b of Figure 4a, respectively, and the span is slightly exaggerated). ), the wire W
When the deflection state is different and the span is long, Figure 6a
When the span is short, it approaches a straight line, as shown in Fig. This causes a difference in level between adjacent wires, the size and shape of the constructed slits differ, and the shape of the nozzle becomes non-uniform. In order to prevent this, it is necessary to make the wire thicker, which tends to lead to an increase in the size of the nozzle and uneconomical use.

Further, the hollow cylinders 1 and 1a in FIGS. 2a and 2b are subjected to a distributed load of strong hoop compressive force on the entire cylinder surface due to the winding of the wire W, and the fluid passage holes 2 and 2a are Hollow cylinder 1,1 depending on the existence
Since the strength of a is reduced, the hollow cylinder tends to deform into a drum shape. This decrease in strength is naturally proportional to the size and number of fluid passage holes, so in order to increase the number of slits in the nozzle and compensate for the strength, it is necessary to increase the size and thickness of the hollow cylinder, and at the same time Since it is accompanied by an increase in weight, it tends to lead to economical and handling disadvantages.

FIG. 7 shows another embodiment of a hollow cylinder (nozzle body) that improves the above-mentioned drawbacks. A plurality of vertical grooves (axial grooves) 4 are arranged at equal intervals in the circumferential direction on the cylindrical surface of the hollow cylinder 1b, and a plurality of small-diameter fluid passage holes 2b are formed at the bottom of each groove. There are many holes in the center along the wall.

The above structure provides the following features. That is, (a) the spans are all the same except for both ends of the groove. (b) The optimum span (groove width) can be freely selected. (c) As shown in Fig. 8, the cross section of the portion 5 between each fluid passage hole 2b becomes a continuous annular body that supports the hoop compression load of the wire, prevents the strength from decreasing, and deforms the hollow cylinder into a drum shape. prevent it from happening. (d)
The total area of the slit can be substantially larger than that of the formations of FIGS. 2a, b. (e) Ultimately, an extremely uniform nozzle shape can be obtained. (f) The nozzle body can be made smaller and is lightweight and economical. (g) Commercially available pipe materials can be used as the material for the hollow cylinder, and the number of processing steps can be reduced compared to the types shown in FIGS. 2a and 2b. The shape also makes it easy to remove burrs.

Incidentally, the difference in level between adjacent wires that occurs at both ends of the vertical groove 11 does not become a drawback because it can be corrected by local "caulking" or the like. Further, in the example shown in FIG. 7, the vertical grooves 4 are arranged at equal intervals around the entire circumference, but it goes without saying that they may be arranged only in the required direction of the nozzle depending on the case.

FIG. 9 is a vertical sectional view showing yet another embodiment of the high-pressure nozzle body, and FIG. 10 is a -
FIG.

When using the wire-wound ultra-fine nozzle described above, the ejected liquid becomes fine particles, but the diameter of the fine particles is directly related to the injection pressure, and the diameter of the fine particles is directly related to the injection pressure.
Pressures as high as cm ² may be reached. At this time, even if the wire is wedge-shaped and engaged with the thread groove of the hollow body, the bending moment generated in the wire due to the high pressure opposing this becomes extremely large, so when using a thin wire, its span and pressure It is necessary to reduce the area, and at the same time, since the main body itself is subject to high internal pressure, sufficient pressure resistance is required.

FIG. 9 shows an embodiment of a high-pressure nozzle element that takes into account the above points, in which 10 is a cylindrical metal nozzle body having a mounting flange 10a, and 11 is a cylindrical metal nozzle body with a flange 11a inserted into the main body. Multiple circular blind holes drilled parallel to the direction, 1
Reference numeral 2 denotes a narrow groove having a narrow width b that penetrates the surface of the cylindrical main body from each blind hole.

On the surface of the cylindrical portion of the main body 10, a thread groove 13 with a fine pitch for winding a wire is formed by machining over the entire length of the narrow groove 12 in the axial direction.
Reference numeral 14 indicates a flange portion of a device to which this nozzle body 10 is to be attached.

If the width of the wire wound on the thread groove 13 is B, then the load on one wire is pressure x B x
b, span is b. Therefore, when the pressure is high, by reducing b, the bending strength of the relatively fine wire can be made sufficient, and the nozzle body 10 can also have a structure with sufficient pressure resistance. Even if the injection pressure is high, there is little deformation of the main body or wire, and sufficient dimensional accuracy can be maintained even with injection nozzles as small as 1 micron.

As explained above, the present invention has a nozzle structure in which a plurality of fluid passage holes are bored in a cylindrical wall,
Moreover, a thin wire is spirally wound along the thread grooves in a hollow cylinder with thread grooves formed at a minute pitch on the surface of the cylindrical wall, so that fine slits are formed between adjacent wires. , we can provide a nozzle that ejects an extremely thin film of fluid using a fine slit of 1 micron, which was previously unattainable. It is made into fine particles to a size determined by various conditions such as pressure, etc.), fluid temperature, viscosity, etc. This has fineness that cannot be achieved with conventional circular hole nozzles, and has extremely good mass productivity. Due to the uniform fineness of the fine particles, this significantly increases the efficiency of jet drying, making it possible to use a large number of new techniques for the production of colloidal ultrafine particles, for chemical reactions, and for improving combustion efficiency. This can be a novel nozzle useful for development.

In addition, the materials of such hollow cylinders and wires include metals that have the strength to withstand high differential pressure (for example, highly corrosion-resistant steel such as 316 stainless steel, general steel,
By selecting the material (such as titanium), the shape of the wire, and the cross section that forms an appropriate nozzle shape, it is possible to cover a very wide range of objects.

Furthermore, the uniformity of the slits can be further improved by forming the plurality of fluid passage holes at the bottoms of the plurality of vertical grooves arranged on the surface of the hollow cylinder. The homogeneous fine particles significantly increase the efficiency of injection drying, making it extremely effective for the production of colloidal ultrafine particles, chemical reactions, improving combustion efficiency, and the development of a wide range of new technologies. It can be used.

Furthermore, the hollow portion of the hollow cylinder is formed by a plurality of circular holes, and the plurality of fluid passage holes are formed by:
By forming a narrow groove that passes through the circular hole and the cylindrical wall, the bending strength of the wire and the pressure resistance strength of the nozzle body can be increased, so that it is possible to cope with high injection pressure.

[Brief explanation of the drawing]

1 to 8 are explanatory diagrams of this invention,
Fig. 1 is a perspective view showing one embodiment of the slit nozzle assembly, Fig. 2a is a perspective view of the hollow cylinder (nozzle body) of Fig. 1, and Fig. 2b is a perspective view of another embodiment of the hollow cylinder. The perspective view, FIG. 3a, is an enlarged partial sectional view taken along line A-A in FIG. 1, FIG. 3b is a view corresponding to FIG. Figure 3a when the fluid passage hole is circular and rectangular, respectively
5 is an enlarged view of the cross section of the deformed wire,
Figures 6a and b are a-a of Figure 4a, respectively.
FIG. 7 is a perspective view corresponding to FIG. 2 showing another embodiment of the hollow cylinder, FIG. 8 is a sectional view taken along the - line, and FIG. A vertical cross-sectional view showing an example, FIG.
It is a sectional view taken along the - line in the figure. 1, 1a, 1b...Hollow cylinder, 2, 2a, 2b
...Fluid passage hole, 3...Thread groove, 4...Vertical groove, 1
1... Circular hole, 13... Thin groove, P... Pitch, W,
Wa, Wb...Wire.

Claims (1)

[Scope of Claims] 1. A thin wire is spirally inserted into a hollow cylinder in which a plurality of fluid passage holes are bored in the cylindrical wall and thread grooves with minute pitches are formed on the surface of the cylindrical wall. A slit nozzle characterized by forming fine slits between adjacent wires. 2. The slit nozzle according to claim 1, wherein the plurality of fluid passage holes are respectively formed in the bottoms of the plurality of vertical grooves formed on the surface of the cylindrical wall. 3. Claims characterized in that the hollow part of the hollow cylinder is formed by a plurality of circular holes, and the plurality of fluid passage holes are formed in the shape of narrow grooves passing through the circular holes and the cylindrical wall. The slit nozzle according to item 1.