| WO/1998/006257 | METHOD AND SPRAYER BOOM FOR SPRAYING A FIELD CROP WITH A PLANT PROTECTIVE LIQUID |
| JP05329402 | SPRAY NOZZLE |
| JP02261559 | SPRAY GUN |
| Claims 1. Fluid ejector comprising a first tube (1; 101) and a second tube (3; 103), the first tube (1; 101) and the second tube (3; 103) having outlet ends (10, 11; 110, 111) adjacent each other, the first outlet end (10; 110) of the first tube having a first diameter (Dl), the second outlet end (11; 111) of the second tube (3; 103) having a second diameter (D2), the first tube (1; 101) being equipped with holes (13; 113) in the area of its outlet end (10; 110), c h a r a c t e r i s e d in that the holes (13; 113) define a portion (12; 112) of the first tube (1; 101), said portion (12; 112) having a length (L) in the longitudinal direction of the first tube (1; 101), the portion (12) of the first tube (1; 101) being located inside the second tube (3; 103), and that the second diameter (D2) is larger than the first diameter (Dl) . 2. Fluid ejector according to claim 1, c h a r a c t e r i s e d in that the length (L) of the portion (12; 112) is larger than the second diameter (D2) of the second tube (3; 103). 3. Fluid ejector according to claim 1 or 2, c h a r a c t e r i s e d in that the first tube (1) is partly located outside the second tube (3) . 4. Fluid ejector according to claim 1 or 2, c h a r a c t e r i s e d in that the first tube (101) is wholly located inside the second tube (103) . 5. Fluid ejector according to any of the previous claims, c h a r a c t e r i s e d in that the ratio between the first diameter (Dl) and the second diameter (D2) is: 2xDl ≤ D2. 6. Fluid ejector according to any of the previous claims, c h a r a c t e r i s e d in that each hole (13) is partly defined by a first edge portion (14) that is located outside the outside contour of the first tube (1). 7. Method to mix two fluids that run in first and second tubes (1, 3), the first tube (1) being located inside the second tube (3), c h a r a c t e r i s e d in that a first fluid (5) of the first tube (1) is a gas, that a second fluid (7) of the second tube (3) is a liguid, that the speed of the first fluid (5) is higher than the speed of the second fluid (7), that the pressure of the first fluid (5) is lower than the pressure of the second fluid (7), and that mixing of the fluids (5, 7) takes place in a portion (12) of the first tube (1) where a part of the second fluid (7) enters the first tube (1) . 8. Method according to claim 7, c h a r a c t e r i s e d in that the second fluid (7) enters the first tube (1) via holes (13) . |
Technical Field of the Invention
The present invention relates to a fluid ejector comprising a first tube and a second tube, the first tube being located inside the second tube, the first tube and the second tube having outlet ends adjacent each other, the first outlet end of the first tube having a first diameter, the second outlet end of the second tube having a second diameter, the first tube being equipped with holes in the area of its outlet end. The invention also relates to a method for mixing two fluids.
Prior Art
From US-A-3, 531, 050 a two-phase homogenizer is previously knpwn, said homogenizer comprising two coaxial conduits, the " inner conduit transporting water and the outer conduit transporting steam. The inner conduit is equipped with slots to allow the steam to enter the inner conduit and to mix with the water flowing in the inner conduit.
From GB 7841 a water jet condenser is previously known, said device comprising tube means transporting water. The steam is supplied to the water stream by an arrangement of oblique openings that fed steam to the water transporting tube means. The steam is fully absorbed in the water and hence no steam is allowed to emit through the nozzle of the device.
Objects and Features of the Invention
A primary object of the present invention is to present - a fluid ejector of the type defined above, said fluid ejector being based on pressure difference that produces a fluid stream of high speed.
A further object of the present invention is to have a structural simplicity since the ejector holds no movable parts.
A further object of the present invention is to present a design that facilitates the mixing of two parallel fluids.
At least the primary object of the present invention is realized by a fluid ejector and a method that have been given the features of the appended independent claims. Preferred embodiments of the invention are defined in the dependent claims . Brief Description of the Drawings
Below embodiments of the fluid ejector according to the present invention will be described, reference being made to the accompanying drawings, where:
Figure 1 shows a section through the outlet end of a fluid ejector according to the present invention;
Figure 2 shows the outlet end in an enlarged scale of the
fluid ejector according to figure 1;
Figure 3 shows in a more enlarged scale a portion of the
outlet end of the fluid ejector according to figure 1;
Figure 4 shows a section through the outlet end of an
alternative embodiment of a fluid ejector according to the present invention; and
Figure 5 shows in an enlarged scale a portion of the outlet end of the fluid ejector according to figure 4.
Detailed Description of Preferred Embodiments of the Present Invention
The fluid ejector according to figures 1-3 comprises a first tube 1 and a second tube 3. In the disclosed embodiment the first tube 1 runs partly outside the second tube 3 and partly inside the second tube 3. In the area of the outlet end of the fluid ejector according to the present invention the first tube 1 runs inside the second tube 3 and more precisely the first tube 1 and the second tube 3 are coaxial in the area of the outlet end of the fluid ejector according to the present invention. In the outlet end area a centre axis is designated by C-C, said centre axis being common for both the first tube 1 and the second tube 3. In the disclosed
embodiment the first tube 1 and the second tube 3 have
constant diameters Dl and D2 respectively.
In the first tube 1 a first fluid 5 is flowing and in the second tube 3 a second fluid 7 is flowing. In the figures the first fluid 5 is symbolised by white arrows while the second fluid 7 is symbolised by black arrows.
As is evident from figure 1 the first tube 1 intersects the second tube 3 when passing from the external position to the internal position. The intersecting 9 is a sealed
arrangement visa the second fluid 7 that is flowing in the second tube 3.
In. the disclosed embodiment the first outlet end 10 of the first tube 1 is inside the second tube 3, i.e. the second outlet end 11 of the second tube 3 extends beyond the first outlet end 10 of the first tube 1.
In the area of the first outlet end 10 a portion 12 of the first tube 1 is equipped with a number of holes 13, said holes 13 being shown more in detail in figures 2 and 3. The portion 12 defines a length L in the longitudinal direction of the first tube 1. Preferably, the length L is larger than the second diameter D2 of the second tube 3.
As regards the ratio between the diameter Dl of the first tube 1 and the diameter D2 of the second tube 3 the following is to be said. Of course D2 > Dl. More precisely 2xDl < D2.
In figure 3 a part of the portion 12 is disclosed in larger scale. From figure 3 the structural design of the holes 13 is evident. Generally, the holes 13 of the disclosed embodiment are similar to the holes of a grater for household purposes. As is evident from figure 3 each hole 13 is partly defined by a first edge portion 14 that is located outside the outside contour of the first tube 1. Each hole 13 is also further defined by second parallel edge portions 15 that are · inclined towards the centre of the first tube 1 in direction of the flow direction of the first fluid 5. In the disclosed embodiment the second edge portions 15 form an angle of 171° with the contour line of the first tube 1. This angle should only be considered as a non-limiting example.
Generally, the design of the holes 13 facilitates the entry of the second fluid 7 into the first tube 1 where the second fluid 7 mixes with the first fluid 5. From figures 1-3 it is understood that the second fluid 7 partly enters the first tube 1 and partly continues to flow in the second tube 3.
Preferably, the fluid ejector described above has a first fluid 5 that constitutes of a gas, e.g. air or nitrogen. The second fluid 7 constitutes water. The first tube 1 is connected to a blower (not shown) and the second tube 3 is connected to a pressurized water source (not shown) .
The functional process of the fluid ejector according to the present invention as depicted in figures 1-3 is as
follows.
A first fluid/high speed air stream 5 flows through the first tube 1, said high speed air stream being generated by the blower. The pressure of this air stream depends on the blower outlet pressure and reducing the cross-section of the first tube 1 will reduce the air stream pressure and increase the speed of the air stream (Bernoulli's laws). Normally, the pressure of this air stream is less than 1 bar. A second fluid/a water stream 7 flows through the second tube 3, said water stream emanating from the pressurized water source. The pressure of this water stream depends on the outlet pressure of the water pump and changing the cross-section of the second tube 3 will effect the water pressure and the speed
(Bernoulli's laws). Normally, the pressure in the second tube 3 is between 3 and 8 bar. The low pressure high-speed air stream in the first tube 1 will suck in the high-pressure water from the water stream jacket that surrounds the portion 12, i.e. the water will enter the first tube 1 through the holes 13 of the portion 12. In this connection it should be pointed out that that the entering of water in the first tube 1 takes place while both fluids 5 and 7 are flowing in the same direction. In the first tube 1, inside the portion 12, a high-speed air-water mixed stream will be established. At the second outlet end 11 of the second tube 3 there will be two streams, the stream coming from the first tube 1 being a low- pressure high-speed air-water stream while the stream in the second tube 3, outside the first tube 1, being a high-pressure relatively low-speed water stream. These two streams will combine into one unified high-speed stream due to the pulling effect of the inner stream. Figures 4 and 5 disclose an alternative embodiment of the ejector according to the present invention. The fluid ejector according to figures 4 and 5 comprises a first tube 101 and a second tube 103. In the disclosed embodiment the first tube 101 runs inside the second tube 103 and the first tube 101 is coaxial with the second tube 103. In the area of the outlet end of the fluid ejector according to figures 4 and 5 the out.let end of the first tube 101 is located inside the second tube 103, i.e. the second tube 103 extends beyond a first outlet end 110 of the first tube 101. The second tube 103 defines a second outlet end 111, said second outlet end
111 having a diameter D2 while the outlet end 110 of the first tube 101 has a diameter Dl . Of course D2 > Dl . More precisely 2xDl < D2.
An inlet end of the first tube 101 is designated by the reference numeral 116. Intermediate the inlet end 116 and the outlet end 110 the first tube 101 defines an intermediate portion having an essential reducing of the cross-sectional area of the first tube 101. Thus, an inlet portion 101A of the first tube 101 has a cross-sectional area that is several times the cross-sectional area of an oulet portion 101B.
In the area of the first outlet end 110 a portion 112 of the first tube 101 is equipped with a number of holes 113, said portion 112 being part of the outlet portion 101B. The holes 113 are shown more in detail in figure 5. The portion
112 has a length L in the longitudinal direction of the first tube 101. Preferably, the length L is larger than the second diameter D2 of the second outlet end 111 of the second tube 103.
As regards the structural design of the holes 113 it could preferably be corresponding to ' the structural design of the holes 13.
As is evident from figures 4 and 5 the second tube 103 has a constant cross-sectional area in the region where the second tube 103 surrounds the first tube 101.
The second tube 103 is connected to a pressurized water source (not shown) . The first tube 101 is not connected to any external source. The functional process of the fluid ejecto according to the present invention as depicted in figures 4 and 5 is as follows .
The embodiment of the ejector that is shown in figures 4 and 5 is fed with only one fluid/pressurized water stream at the inlet end (not shown) of the second tube 103. The
fluid/pressurized water stream advances up to the inlet end 116 of the first tube 101. A part of the fluid/the pressurized water stream 105 will then continue in the first tube 101 while the rest of the fluid/the pressurized water stream 107 will continue in the second tube 103. The part of the fluid 105 that continues in the first tube 101 will be imparted to an increased speed due to the reduced cross-sectional area of the first tube 101. Due to the increased speed the fluid in the intermediate portion 101B will have a decreased pressure. (Bernoulli's laws). The low pressure high-speed fluid/water stream 105 in the first tube 101 will suck in the
fluid/pressurized water 107 from the water stream jacket that surrounds the portion 112 that is equipped with holes 113, i.e. the water from the second tube 103 will enter the first tube 101 through the holes 113 of the portion 112.
Feasible Modifications of the Invention
The design of the holes 13; 113 that has been described above should only be considered as examples. Thus, within the scope of the present invention numerous hole designs are feasible. In exemplifying and non-restricting purpose it could be mentioned that the holes may taper in direction towards the interior of the first tube. Generally, the holes could have an oval cross-section. Generally, the holes could be inclined relative to the longitudinal centre axis C-C of the ejector. In the flowing direction the holes are inclined towards the first outlet end of the first tube.
Instead of air as a fluid it is feasible to use
nitrogen, N, or carbondioxid, C0 2 .
The fluid ejector according to the present invention could be used in several application and different
combinations of fluids could be used. It should specifically be pointed that as regards the embodiment according to Figs. 1-3 the fluid of the first tube 1 could be high pressure water and the fluid of the second tube 3 could be a high speed, low pressure air stream. In such a case the design of the holes needs to be changed in order to direct the water outwards through the vectored holes of the first tube.
In order to " create a venturi effect the portion 12; 112 may have a slightly diminishing cross-sectional area. Between the portion 12; 112 and the first outlet end 10; 110 the first tube 1; 101 may have a slightly widening cross-sectional area. The same principle could also be applied to the second tube 3; 103.
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