EP0771592A1 - Jet nozzle - Google Patents

Abstract

The jet spray, especially for high pressure cleaning, comprises a channel through the spray head, ending in the jet mouth. The channel narrows towards the mouth and where they meet, is a well defined edge between channel wall and jet mouth wall. The width (b) and length at this opening (27) are fixed as is the angle ( alpha degrees ) between the channel wall (12) and the flow direction (17). b and alpha are related by the following equation: (ba - B).( alpha a - alpha 0) = C, where b is the width (mm), B = 0.785-0.875 mm, alpha 0 = 8.25-17.25 degrees and C = 12-13 degrees mm. ba and alpha a are optimal values.

Description

The invention relates to a jet nozzle, in particular for high-pressure cleaning devices with the features of the preamble of patent claim 1.

Such spray nozzles are used, for example, as flat jet nozzles for generating a fan-shaped jet in high-pressure cleaning devices. The spray nozzle has the task here of letting the water present emerge at a high pressure of 20 to 250 bar, so that a flat jet with a strip-like or almost linear spray pattern results. With such a jet, a cleaning effect is achieved in cleaning devices in that the highly accelerated water droplets emanating from the nozzle cause a mechanical removal effect on the impact surface to be cleaned. The aim in the development of such cleaning devices is to achieve a high cleaning effect, ie a good removal effect, with the lowest possible water consumption. A measure of this is the generated radiant force, which is defined as the force exerted by the incident beam on a given surface.

From EP 0 655 281 A1 a flat jet nozzle with a circular nozzle mouth is known. The nozzle has an inlet chamber, which is accommodated in a nozzle body and is essentially cylindrical and is closed at a front wall containing the nozzle mouth. The inside of the front wall, which delimits the inlet chamber, is hemispherical and defines a spherically curved wall. The actual nozzle mouth is formed by a circular cylindrical bore that leads coaxially to the inlet chamber through the front wall. In the transition between the cylinder bore and the spherically curved wall of the inlet chamber, an oval-shaped depression is formed, which defines two opposing pockets on either side of the cylinder bore. On the outside, the cylinder bore forming the nozzle mouth is surrounded by a flat surface.

The nozzle geometry mentioned causes the jet emerging from the nozzle mouth to be fanned out, so that a flat jet is formed.

A flat jet nozzle is also known from DE 4 213 226 A1, which likewise has a circular nozzle opening (nozzle mouth). The flat jet nozzle is formed by a base body which encloses an interior space leading to the nozzle mouth. In the area of the nozzle mouth, the interior is spherically curved and has two diametrically opposite depressions or pockets in the transition to the nozzle mouth. These are used to guide the flow in order to fan out the jet emerging from the nozzle mouth and thus generate a flat jet.

The shape of the depressions, their formation and symmetry as well as their dimensional accuracy is critical for the beam shape and the radiance.

From DE 4 341 870 A1, however, an ultra-high pressure flat jet nozzle is known which has a nozzle body with a conical feed channel. To form a nozzle mouth, a slot is made from the outside in the nozzle body, which crosses the conical feed channel. The resulting exit opening is defined by the intersection between the conical feed channel and the wedge-shaped slot.

The shape of the outlet opening causes the emerging jet to be fanned out and thus a flat jet to be generated.

In addition, flat jet nozzles are known from practice, which gave an oval nozzle mouth. A channel leading through a nozzle body ends in a spherical curvature on a front wall containing the nozzle mouth. A transverse groove is provided in the front wall of the nozzle, which cuts the channel in its spherically curved wall area on the front wall side.

The effectiveness of such nozzles needs to be improved.

The object on which the invention is based is derived from this to create a spray nozzle suitable for a cleaning device for generating a flat jet, with which an increased cleaning effect on surfaces processed by means of the flat jet is made possible.

This object is achieved by a spray nozzle with the features of claim 1.

The jet nozzle defined in claim 1 enables a significantly increased compared to similarly configured jet nozzles, the wall angle of which at the edge of the passage to the nozzle mouth and the width of the passage outside the claimed area Effectiveness. This manifests itself in a greatly increased jet power or increased jet pressure with otherwise constant parameters such as water pressure, distance of the nozzle mouth from the surface to be treated, water consumption and spray angle. The jet pressure is determined via the force exerted by the jet in the area of impact on a test surface with a fixed surface area.

The area claimed by claim 1 is illustrated in a diagram, the ordinate of which describes different widths b of the passage between the channel and the nozzle mouth that deviates from the circular shape. The abscissa marks different wall angles. The area corresponds to an approximately hyperbolic curved, tubular area. Jet nozzles, the passage width b and the wall angle α of which form a pair of values within the range, give a high jet power at a given water pressure without increased water consumption. For pairs of values consisting of passage width and wall angle, which lie outside the aforementioned tubular area, the jet power of corresponding nozzles decreases with increasing distance from the area. In order to narrow down an optimal solution, the limits of the range can be drawn more closely, with narrower tolerance ranges then applying to the constants A, B and C. In this case, however, the aim should be that the width b of the passage is in a range from 0.95 to 2.45 mm. Correspondingly, the angle α between the channel wall adjoining the edge and the outflow direction is between 15 ° and 80 °. The outflow direction is defined as the longitudinal axis of the nozzle and is concentric with the channel. The fan-shaped jet emerging from the spray nozzle spreads in the outflow direction. This means that the imaginary longitudinal axis of the nozzle, which corresponds to the outflow direction, lies symmetrically in the fan-shaped flat jet.

Simple manufacture and at the same time reliable formation of a symmetrical flat jet is achieved if the channel is rotationally symmetrical up to the passage. However, different shapes are possible if necessary.

The edge marking the transition between the feed channel and the nozzle mouth is preferably continuously curved and thus has no straight section. This is advantageous for a uniform formation of a flat jet. The nozzle mouth deviates from the circular shape and approximates or corresponds to the shape of an ellipse.

The passage is preferably defined by a groove which runs transversely to the outflow direction and intersects the narrowing channel on the end face. The resulting passage, which resembles an ellipse in shape, has different wall angles along its circumference, i.e. Angle between the channel wall on the edge and the outflow direction. However, the dimensional relationship according to the invention applies in particular when measuring transversely to the groove.

The groove intersecting the channel preferably has a curved bottom, so that the nozzle mouth can be understood, for example, as a cut between a ball and a cylinder wall. This is the case, for example, if, in addition, the wall of the channel adjoining the passage is spherically curved. The wall can be curved with respect to a single center of curvature or can be designed differently from it.

Such nozzle shapes do not require recesses, pockets or the like made in the channel. The wall of the channel adjoining the passage can thus be smooth. This increases manufacturing security and significantly simplifies production.

The formation of a flat jet is promoted if ribs are formed on both sides of the nozzle mouth, which have mutually opposite, at least sectionally flat wall sections. The resulting flow conditions in front of the nozzle mouth then lead to a favorable jet pattern.

The channel leading through the nozzle body can narrow from a large connection diameter to a comparatively small diameter of an essentially cylindrical section adjoining the passage. This is preferably done without sales, i.e. with frustoconical transition sections. These prevent impairment of the spray pattern and dynamic pressure losses.

The specified measures are intended in particular for spray nozzles with an opening angle of 15 ° to 35 °. In this area, the increase in radiance is particularly emphasized by the specified dimensioning.

A one-piece design of the nozzle body prevents misalignments during installation and removal and thus ensures the desired spray pattern.

Fig. 1

eine als Flachstrahldüse ausgebildete Sprühdüse für ein Hochdruckreinigungsgerät, in vergrößerter, perspektivischer und teilweise geschnittener Darstellung,

Fig. 2

die Sprühdüse nach Fig. 1 im Längsschnitt,

Fig. 3

die Sprühdüse nach den Fig. 1 und 2 in einer Draufsicht auf den Düsenmund,

Fig. 4

die Sprühdüse nach den Fig. 1 bis 3 im Längsschnitt, in ausschnittsweiser Darstellung des Düsenmundbereiches, mit besonderer Darstellung eines Durchganges von einem zu dem Düsenmund führenden Kanal zu dem Düsenmund und in diesem Bereich vorhandenen Maßen,

Fig. 5

den Wertebereich für an der Sprühdüse vorhandene und im Zusammenhang mit Fig. 4 erläuterte Maße, mit denen eine erhöhte Strahlkraft erreicht wird; und

Fig. 6

den Verlauf der Strahlkraft einer Düse, deren Abmessungen ein innerhalb des in Fig. 5 gekennzeichneten Wertebereiches liegendes Wertepaar bilden, und den Verlauf der Strahlkraft einer Düse, deren Abmessungen ein außerhalb des Bereiches liegendes Wertepaar bilden, in schematischer Darstellung.

In the drawing, an embodiment of the invention is shown. Show it:

Fig. 1

a spray nozzle designed as a flat jet nozzle for a high-pressure cleaning device, in an enlarged, perspective and partially sectioned illustration,

Fig. 2

1 in longitudinal section,

Fig. 3

1 and 2 in a plan view of the nozzle mouth,

Fig. 4

1 to 3 in longitudinal section, in a sectional representation of the nozzle mouth region, with a special representation of a passage from a channel leading to the nozzle mouth to the nozzle mouth and dimensions available in this region,

Fig. 5

the range of values for dimensions available at the spray nozzle and explained in connection with FIG. 4, with which an increased jet power is achieved; and

Fig. 6

The course of the jet power of a nozzle, the dimensions of which form a value pair lying within the value range identified in FIG. 5, and the course of the jet power of a nozzle, the dimensions of which form a value pair lying outside the area, in a schematic representation.

1 shows a spray nozzle designed as a flat jet nozzle 1, as is used for high-pressure cleaning devices and the like. The flat jet nozzle 1 serves to eject a fan-shaped water jet with which surfaces to be cleaned are to be processed. The flat jet nozzle 1 has a one-piece nozzle body 2 made of a metal or a suitable ceramic. If necessary, the nozzle body 2 can also be divided into several parts. The nozzle body 2 is rotationally symmetrical except for its nozzle mouth region 3 and has at its end remote from the nozzle mouth region 3 a threaded connection or a flange 4 which can be fastened to a spray head with suitable fastening means such as a union nut (not shown) or the like.

A channel 6 leads through the nozzle body 2 and is designed as a concentric or coaxial bore to the nozzle body 2, the diameter of which decreases towards the nozzle mouth region 3. A cylindrical channel section 8 of relatively large diameter adjoins a conical inlet area 7 located directly at the flange 4 and merges with a conical transition area 9 into a cylindrical channel section 11. As can be seen in particular from FIG. 2 and from FIG. 4, which illustrates the enlarged nozzle mouth region 3, the channel section 11 narrows towards the nozzle mouth region 3 and has a curved wall 12.

As can be seen from FIGS. 2 and 3, the nozzle mouth region 3 is formed by two ribs 13, 14 (flat edge) which are spaced apart and parallel to one another and are integrally formed on the nozzle body 2 and are separated by a groove 16. The groove 16 runs between the ribs 13, 14 across the nozzle body 2 and is thus arranged at right angles to a longitudinal central axis 17, which as Longitudinal axis of the channel 6 is defined. The groove 16 has rounded side walls 18, 19, which each follow an arc and are thus formed like a groove.

Approximately in the center of the groove 16 there is a groove-like recess 21 which is open towards the outside and has a groove 22 which is rounded in a groove-like manner and groove walls 23, 24 which are at least sectionally flat and which are arranged at a distance parallel to one another and opposite one another (FIG. 4).

The recess 21 intersects the channel section 11 of the channel 6 in the region of its spherically curved wall 12, a passage 27 defined by an edge 26 being formed. The edge 26, as can be seen in particular from FIG. 3, is continuously curved and reminds of an ellipse in plan view. It is defined by the intersection of the semi-cylindrical bottom 22 of the recess 21 with the spherically curved wall 12 of the channel section 11. The radius of curvature R of the wall 12 can exceed the diameter of the channel 11. The centers of curvature lie, for example, on a circle concentric to the channel. The radius of curvature of the bottom 22 of the recess 21, however, is significantly smaller and corresponds to half the distance of the groove walls 23, 24 from each other. The recess 21 is cut so deep that the edge 26 in the region of the small semiaxis of the passage 27 (direction of the small semiaxis in FIG. 3, marked with a dash-dotted line 29) almost reaches the plane groove walls 23, 24.

The width b of the passage 27 measured along the line 29 is, depending on the desired throughput, between 0.9 and 2.5 mm and is only slightly less than the distance between the groove walls 23, 24 from one another.

wobei α_A den Wandungswinkel darstellt, bei dem die maximale Strahlkraft erreicht wird. In Abstand zu der Linie 29 weicht der Wandungswinkel von dem Wert α_A ab. Umgekehrt gilt für die optimale Breite b_A: $${\mathit{\text{b}}}_{\mathit{\text{A}}}\text{=}\frac{\text{35,5}}{{\text{(α}}_{\mathit{\text{A}}}\text{-12,75)·2,793}}\text{+ 0,83 [}\mathit{\text{mm}}\text{].}$$

If a tangent T is applied to the edge region of the wall 12 in the region of the line 29, this has an angle α to the longitudinal central axis 17 which, depending on the selected width b, is in the range from 15 ° to 80 °. Depending on the width b in mm, the angle α _A is optimally determined by the following relationship: $${\text{α}}_{\mathit{\text{A}}}\text{=}\frac{\text{35.5}}{\text{(}\mathit{\text{b}}\text{- 0.83) * 2.793}}\text{+ 12.75 [°]}$$

where α _{A represents} the wall angle at which the maximum radiant power is reached. The wall angle deviates from the value α _A at a distance from the line 29. Conversely, for the optimal width b _A : $${\mathit{\text{b}}}_{\mathit{\text{A}}}\text{=}\frac{\text{35.5}}{{\text{(α}}_{\mathit{\text{A}}}\text{-12.75) x 2.793}}\text{+ 0.83 [}\mathit{\text{mm}}\text{].}$$

für die Kurve C1 sowie die Formeln $$\begin{array}{c}\begin{array}{c}\begin{array}{}\text{(5)}{\mathit{\text{b}}}_{\mathit{\text{C2}}}\text{= (}{\mathit{\text{b}}}_{\mathit{\text{A}}}\text{- 0,045)}\mathit{\text{mm und}}\end{array}\\ \begin{array}{}\text{(6)}{\text{α}}_{\mathit{\text{C2}}}{\text{= (α}}_{\mathit{\text{A}}}\text{- 4,5)°}\end{array}\end{array}\end{array}$$

für die Kurve C2.The curve resulting for different pairs of values satisfying the above equation for the width b and the wall angle α is shown in FIG. 5 and labeled A. This is a hyperbola, in the vicinity of which comparably good results for radiance are achieved. The range is delimited by curves C1 and C2, which also represent hyperbolas and are determined in connection with equation 1 by the following formulas: $$\begin{array}{c}\begin{array}{c}\begin{array}{}\text{(3)}{\mathit{\text{b}}}_{\mathit{\text{C1}}}\text{= (}{\mathit{\text{b}}}_{\mathit{\text{A}}}\text{+0.045)}\mathit{\text{mm}}\end{array}\\ \begin{array}{}\text{(4)}{\text{α}}_{\mathit{\text{C1}}}{\text{= (α}}_{\mathit{\text{A}}}\text{+4.5) °}\end{array}\end{array}\end{array}$$

for curve C1 and the formulas $$\begin{array}{c}\begin{array}{c}\begin{array}{}\text{(5)}{\mathit{\text{b}}}_{\mathit{\text{C2}}}\text{= (}{\mathit{\text{b}}}_{\mathit{\text{A}}}\text{- 0.045)}\mathit{\text{mm and}}\end{array}\\ \begin{array}{}\text{(6)}{\text{α}}_{\mathit{\text{C2}}}{\text{= (α}}_{\mathit{\text{A}}}\text{- 4.5) °}\end{array}\end{array}\end{array}$$

for curve C2.

With pairs of values lying within the range defined by curves C1 and C2, flat jet nozzles 1 are obtained, the jet power of which is illustrated in FIG. 6 by a tolerance range I. The diagram is based on example nozzles with a spray angle of 25 °. The radiance is increased in all specimens with constant water consumption and the same water pressure by a third compared to conventional flat jet nozzles, which are in the tolerance range II and whose dimensions are outside the area marked with the curves C1, C2 in FIG. 5. Tests have shown that when using the flat jet nozzles as jet nozzles for high-pressure cleaning, the cleaning effect is considerably improved (more than a third).

The range limits B1, B2 within which particularly good results are achieved are defined by equations 7 to 10 in conjunction with equation 1: $$\begin{array}{c}\begin{array}{c}\begin{array}{}\text{(7)}{\mathit{\text{b}}}_{\mathit{\text{B1}}}\text{= (}{\mathit{\text{b}}}_{\mathit{\text{A}}}\text{+ 0.032)}\mathit{\text{mm}}\text{,}\end{array}\\ \begin{array}{}\text{(8th)}{\text{α}}_{\mathit{\text{B1}}}{\text{= (α}}_{\mathit{\text{A}}}\text{+ 3.2) °,}\end{array}\\ \begin{array}{}\text{(9)}{\mathit{\text{b}}}_{\mathit{\text{B2}}}\text{= (}{\mathit{\text{b}}}_{\mathit{\text{A}}}\text{- 0.032)}\mathit{\text{mm and}}\end{array}\\ \begin{array}{}\text{(10)}{\text{α}}_{\mathit{\text{B2}}}{\text{= (α}}_{\mathit{\text{A}}}\text{- 3.2) °.}\end{array}\end{array}\end{array}$$

As can also be seen from FIG. 6, the jet force is largely constant over the entire jet width, so that a uniform result can be achieved during cleaning work with the flat jet nozzle 1. However, if necessary, a central or edge-emphasized beam can also be obtained by specifying the remaining dimensions.

wobei:

die Breite b in Millimetern (mm) und
der Winkel α in Grad (°) gemessen sind,
die Konstante B im Bereich zwischen 0,785 mm und 0,875 mm, die Konstante α_o
zwischen 8,25° und 17,25°,
und
die Konstante C in einem Bereich von 12,3 °mm bis 12,6 °mm liegt.

A flat jet nozzle 1 for high-pressure cleaning devices has a nozzle mouth which is formed by the cut of a depression 21 formed from the outside into a nozzle body 2 with a semicircular base 22 and a channel 6 leading to the nozzle mouth. The channel 6 is formed in the nozzle body 2 and in the area of the cut with the recess 21 it has a spherically curved wall 12. At the resulting edge, which defines a passage from the channel 6 to the depression 21, the width of the passage and the angle of the wall 12 adjacent to the edge 26 against the longitudinal central axis 17 are dimensioned such that a point defined by this pair of values is located within an area delimited by hyperbolas. This tolerance range is given by the equation: $$\text{(}{\mathit{\text{b}}}_{\mathit{\text{A}}}\text{-}\mathit{\text{B}}{\text{) · (Α}}_{\mathit{\text{A}}}{\text{- α}}_{\mathit{\text{O}}}\text{) =}\mathit{\text{C.}}\text{,}$$

in which:

the width b in millimeters (mm) and
the angle α is measured in degrees (°),
the constant B in the range between 0.785 mm and 0.875 mm, the constant α _o
between 8.25 ° and 17.25 °,
and
the constant C is in a range from 12.3 ° mm to 12.6 ° mm.

Claims (18)

Spray nozzle, in particular for high-pressure cleaning devices,
with a channel leading through a nozzle body, which ends on its outflow side in a nozzle mouth defining an outflow direction and which narrows towards the nozzle mouth, wherein a self-contained edge is defined between the narrowing channel and the nozzle mouth, in which the channel wall in the nozzle mouth wall merges and forms a passage with a defined width b and a defined length 1,
characterized,
that the width b of the passage defined by the edge and the angle α measured at least at one point between the channel wall (12) hitting the edge (26) and the outflow direction (17) lie in a range of values which is defined by the following equation : $$\text{(}{\mathit{\text{b}}}_{\mathit{\text{A}}}\text{-}\mathit{\text{B}}{\text{) · (Α}}_{\mathit{\text{A}}}{\text{- α}}_{\mathit{\text{O}}}\text{) =}\mathit{\text{C.}}\text{,}$$

where: the width b in millimeters (mm) and
the angle α is measured in degrees (°),
the constant B in the range between 0.785 mm
and 0.875 mm, the constant α _o between 8.25 °
and 17.25 °, and the constant C is in a range of 12 ° to 13 ° mm. Spray nozzle according to claim 1, characterized in that the angle α between the wall (12) of the channel (6) and the outflow direction (17) is the angle measured at a narrow point of the passage (27). Spray nozzle according to claim 1, characterized in that the constant B is in the range between 0.798 mm and 0.862 mm, the constant α _{o is} in a range between 9.55 ° and 15.95 ° and the constant C is 12.6 ° mm. Spray nozzle according to claim 1, characterized in that the constant B is 0.83 mm and the constant α _o 12.75 °. Spray nozzle according to Claim 1, characterized in that the length 1 of the passage (27) lies in a range which is between 1.1 times and twice the width b of the passage (27). Spray nozzle according to claim 1, characterized in that the width b of the passage (27) is in a range from 0.95 to 2.45 mm Spray nozzle according to Claim 1, characterized in that the angle α between the channel wall (12) adjoining the edge (26) and the outflow direction is between 15 ° and 80 °. Spray nozzle according to claim 1, characterized in that the channel (6) up to the passage (27) is rotationally symmetrical. Spray nozzle according to claim 1, characterized in that the edge (26) of the passage (27) is continuously curved. Spray nozzle according to claim 1, characterized in that the passage (27) is defined by a groove (recess 21) which cuts the nozzle body (2) transversely to the outflow direction and which intersects the channel (6) narrowing on the nozzle mouth side. Spray nozzle according to claim 10, characterized in that the groove (recess 21) has a bottom (22) curved in the transverse direction. Spray nozzle according to claim 1, characterized in that the wall (12) of the channel (6) adjoining the passage (27) is spherically curved. Spray nozzle according to claim 1, characterized in that the wall (12) of the channel (6) adjoining the passage (27) is smooth. Spray nozzle according to Claim 1, characterized in that the nozzle mouth (3) adjoining the passage (27) is delimited by two mutually opposite, essentially planar and parallel wall sections (23, 24) which are separated from one another. Spray nozzle according to claim 1, characterized in that the channel (6) is designed without a shoulder. Spray nozzle according to claim 1, characterized in that the channel (6) leading through the nozzle body (2) narrows from a large connection diameter to a comparatively small diameter of an essentially cylindrical section (11) adjoining the passage. Spray nozzle according to claim 1, characterized in that the spray nozzle (1) is designed as a flat jet nozzle for generating a fan-shaped jet with an opening angle (spray angle) of 15 to 25 °. Spray nozzle according to claim 1, characterized in that the nozzle body (2) is formed in one piece.

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