The invention relates to a fluidic component and to a cleaning appliance which comprises a fluidic component of this kind. The fluidic component is provided for the purpose of producing a moving fluid jet.
For the production of a fluid jet with a high speed or high momentum, the prior art contains nozzles which are designed to subject the fluid jet to a pressure which is higher than the ambient pressure. By means of the nozzle, the fluid is accelerated and/or directed or concentrated. In order to produce a movement of a fluid jet, the nozzle is generally moved by means of a device. To produce a moving fluid jet, an additional device is thus required apart from the nozzle. This additional device comprises moving component parts, which easily wear. The costs associated with production and maintenance are correspondingly high. Another disadvantage is the fact that a relatively large installation space is required overall owing to the moving component parts.
Fluidic components are furthermore known for the production of a moving fluid flow (or fluid jet). The fluidic components do not comprise any moving component parts serving to produce a moving fluid flow. As a result, in comparison with the nozzles mentioned at the outset, they do not have the disadvantages resulting from the moving component parts. However, a steep pressure gradient often occurs within the fluidic components in the case of the known fluidic components, and therefore cavitation, i.e. the formation of cavities (bubbles), can occur within the components as the liquid fluid flow flows through the fluidic components. As a result, there can be a massive reduction in the life of the components or failure of the fluidic components may be caused. Moreover, the known fluidic components are more suitable for the wetting of surfaces than for the production of a fluid jet with a high speed or a high momentum. Thus, a fluid flow emerging from a known fluidic component has the spray characteristic of a fan nozzle, which produces a finely atomized jet.
It is an underlying object of the present invention to provide a fluidic component which is designed to make available a moving fluid jet with a high speed or high pressure, wherein the fluidic component has high failure resistance and a correspondingly lower maintenance cost.
According to the invention, this object is achieved by a fluidic component having features as described herein.
Accordingly, the fluidic component comprises a flow chamber allowing a fluid to flow through. The fluid flow can be a liquid flow or a gas flow. The flow chamber comprises an inlet opening and an outlet opening, through which the fluid flow enters the flow chamber and reemerges from the flow chamber. The fluidic component furthermore comprises at least one means for changing the direction of the fluid flow at the outlet opening in a controlled manner, wherein, in particular, the means is designed to generate a spatial oscillation of the fluid flow at the outlet opening. The flow chamber has a main flow channel, which interconnects the inlet opening and the outlet opening, and at least one auxiliary flow channel as the at least one means for changing the direction of the fluid flow at the outlet opening in a controlled manner.
The fluidic component is distinguished by the fact that the inlet opening has a larger cross-sectional area than the outlet opening or that the inlet opening and the outlet opening have cross-sectional areas that are equal in size. Here, the cross-sectional areas of the inlet opening and of the outlet opening should each be taken to mean the smallest cross-sectional areas of the fluidic component through which the fluid flow passes when it enters the flow chamber and reemerges from the flow chamber.
This ensures that a fluid jet which oscillates in space (and time) emerges from the fluidic component, said jet having a high speed or a high momentum. The emerging fluid jet is furthermore compact, that is to say that the fluid jet fans out spatially or spreads apart only at a late stage (a long way downstream), not directly at the outlet opening.
In the arrangement according to the invention, it is possible to dispense with moving component parts for the production of an oscillating jet, and therefore costs and effort arising therefrom do not occur. Moreover, dispensing with moving component parts means that the generation of vibration and noise by the fluidic component according to the invention is relatively low.
Moreover, the occurrence of cavitation within the fluidic component (and the disadvantages resulting therefrom) is avoided through the choice according to the invention of the size ratio of the inlet opening to that of the outlet opening. Contrary to the prevailing opinion, the formation of the oscillating fluid jet is not impaired by the fact that the outlet opening has a smaller cross-sectional area than the inlet opening.
Owing to its compactness and high speed, the spatially oscillating fluid jet which emerges from the fluidic component according to the invention has a high removal and cleaning power when it is directed at a surface. The fluidic component according to the invention can therefore be employed in cleaning systems, for example. The fluidic component according to the invention is also relevant to mixing systems (in which two or more different fluids are supposed to be mixed with one another) and manufacturing systems (e.g. waterjet cutting). Thus, for example, the effectiveness of waterjet cutting can be increased with a pulsating fluid jet emerging from the fluidic component according to the invention.
In principle, the cross-sectional area of the inlet opening can be equal in size to or larger than the cross-sectional area of the outlet opening. The size ratio can be chosen in accordance with the desired characteristics (speed or momentum, compactness, oscillation frequency) of the emerging jet. However, other parameters, e.g. the size (e.g. the volume and/or component depth, component width, component length) of the fluidic component, the shape of the fluidic component, the type of fluid (gas, low-viscosity liquid, high-viscosity liquid), the level of the pressure at which the fluid flow enters the fluidic component, the entry speed of the fluid and the volume flow, can also influence the choice of size ratio. The oscillation frequency can be between 0.5 Hz and 30 kHz. A preferred frequency range is between 3 Hz and 400 Hz. The inlet pressure can be between 0.01 bar and 6000 bar above ambient pressure. For some applications, (referred to as) low-pressure applications, e.g. for washing machines or dishwashers, the inlet pressure is typically between 0.01 bar and 12 bar above ambient pressure. For other applications (referred to as high-pressure applications), e.g. for cleaning (vehicles, semifinished products, machines or stables) or mixing two different fluids, the inlet pressure is typically between 5 bar and 300 bar.
According to a preferred embodiment, the cross-sectional area of the inlet opening can be larger by a factor of up to 2.5 than the cross-sectional area of the outlet opening. According to a particularly preferred embodiment, the cross-sectional area of the inlet opening can be larger by a factor of up to 1.5 than the cross-sectional area of the outlet opening.
Moreover, the cross-sectional area of the outlet opening can have any desired shape, e.g. square, rectangular, polygonal, round, oval etc. A corresponding statement applies to the cross-sectional area of the inlet opening. In this case, the shape of the inlet opening can correspond to the shape of the outlet opening or differ therefrom. A round cross-sectional area of the outlet opening can be chosen, for example, in order to produce a particularly compact/concentrated fluid jet. Such a fluid jet can be used, in particular, in high-pressure cleaning systems or in waterjet cutting.
According to one embodiment, both the inlet opening and the outlet opening have a rectangular cross section. In this case, the inlet opening can have a greater width than the outlet opening.
In this case, the width of the inlet and outlet openings is defined in relation to the geometry of the fluidic component. For example, the fluidic component can be of substantially cuboidal design and, accordingly, can have a component length, a component width and a component depth, wherein the component length determines the distance between the inlet opening and the outlet opening, and the component width and component depth are each defined perpendicularly to one another and to the component length and wherein the component width is greater than the component depth. Thus, the component length extends substantially parallel to the main direction of extent of the fluid flow, which moves from the inlet opening to the outlet opening in accordance with the intended purpose. If the inlet and outlet openings are situated on an axis which extends parallel to the component length, the distance between the inlet and outlet openings corresponds to the component length. If the inlet and outlet openings are arranged offset relative to one another, that is to say said axis extends at an angle unequal to 0° relative to the component length, the component length and the offset between the inlet and outlet openings determine the distance between the inlet and outlet openings along the axis. In the case of a substantially cuboidal fluidic component, the ratio of component length to component width can be ⅓ to 5. The ratio is preferably in the range of 1/1 to 4/1. The component width can be in the range between 0.15 mm and 2.5 m. In a preferred variant embodiment, the component width is between 1.5 mm and 200 mm. Said dimensions depend, in particular, on the application for which the fluidic component is to be used.
By definition, the abovementioned width of the inlet and outlet openings extends parallel to the component width. According to one embodiment, a substantially cuboidal fluidic component can have a rectangular outlet opening with a width which corresponds to ⅓ to 1/50 of the component width and a rectangular inlet opening with a width which corresponds to ⅓ to 1/20 of the component width. According to a preferred embodiment, the width of the outlet opening can correspond to ⅕ to 1/15 of the component width, and the width of the inlet opening can correspond to ⅕ to 1/10 of the component width. The ratio of the component depth to the width of the inlet opening can be 1/20 to 5. This ratio is also referred to as the aspect ratio. A preferred aspect ratio is between 1/6 and 2. The size ratios mentioned also depend, in particular, on the application for which the fluidic component is to be used.
According to another embodiment, the fluidic component has a component depth which is constant over the entire component length. As an alternative, the component depth can decrease from the inlet opening toward the outlet opening (continuously (with or without a constant rise) or in steps). By means of the decreasing component depth, the fluid jet is pre-concentrated within the fluidic component, ensuring that a compact fluid jet emerges from the fluidic component. Expansion or spreading apart of the fluid jet can thus be delayed and therefore does not take place directly at the outlet opening but only further downstream. This measure is advantageous, for example, in cleaning systems or in waterjet systems. According to another alternative, the component depth can increase from the inlet opening toward the outlet opening, wherein the component width decreases in such a way that the cross-sectional area of the outlet opening is smaller than or equal in size to the cross-sectional area of the inlet opening.
As a means for changing the direction of the fluid flow at the outlet opening in a controlled manner, the flow chamber has at least one auxiliary flow channel. Part of the fluid flow, the auxiliary flow, is allowed to flow through the auxiliary flow channel. That part of the fluid flow which does not enter the auxiliary flow channel but emerges from the fluidic component is referred to as the main flow. The at least one auxiliary flow channel can have an inlet which is situated in proximity to the outlet opening and an outlet which is situated in proximity to the inlet opening. When viewed in the fluid flow direction (from the inlet opening to the outlet opening), the at least one auxiliary flow channel can be arranged at the side of (not after or before) the main flow channel. In particular, it is possible to provide two auxiliary flow channels, which extend at the side of the main flow channel (when viewed in the main flow direction), wherein the main flow channel is arranged between the two auxiliary flow channels. According to a preferred embodiment, the auxiliary flow channels and the main flow channel are arranged in a row along the component width and each extend along the component length. Alternatively, the auxiliary flow channels and the main flow channel can be arranged in a row along the component depth and each extend along the component length.
The at least one auxiliary flow channel is preferably separated from the main flow channel by a block. This block can have various shapes. Thus, the cross section of the block can taper when viewed in the fluid flow direction (from the inlet opening toward the outlet opening). As an alternative, the cross section of the block can taper or increase centrally between its end facing the inlet opening and its end facing the outlet opening. An enlargement of the cross section of the block with increasing distance from the inlet opening is also possible. Moreover, the block can have rounded edges. Sharp edges can be provided on the block, in particular in the vicinity of the inlet opening and/or the outlet opening.
According to one embodiment, the at least one auxiliary flow channel can have a greater or smaller depth than the main flow channel. It is thereby possible to exercise an additional influence over the oscillation frequency of the emerging fluid jet. Reducing the component depth in the region of the at least one auxiliary flow channel (in comparison with the main flow channel) reduces the oscillation frequency if the other parameters remain substantially unchanged. Accordingly, the oscillation frequency rises if the component depth is increased in the region of the at least one auxiliary flow channel (in comparison with the main flow channel) and the other parameters remain substantially unchanged.
Another possibility for influencing the oscillation frequency of the emerging fluid jet can be created by means of at least one separator, which is preferably provided at the inlet of the at least one auxiliary flow channel. The separator assists the splitting of the auxiliary flow from the fluid flow. Here, a separator should be taken to mean an element which projects into the flow chamber (transversely to the flow direction prevailing in the auxiliary flow channel) at the inlet of the at least one auxiliary flow channel. The separator can be provided as a deformation (in particular an inward protrusion) of the auxiliary flow channel wall or as a projection designed in some other way. Thus, the separator can be of (circular) conical or pyramidal design. The use of such a separator makes it possible not only to influence the oscillation frequency but also to vary the “oscillation angle”. The oscillation angle is the angle which the oscillating fluid jet covers (between its two maximum deflections). If a plurality of auxiliary flow channels is provided, a separator can be provided for each of the auxiliary flow channels or only for some of the auxiliary flow channels.
According to one embodiment, an outlet channel can be provided directly upstream of the outlet opening. The outlet channel can have a shape of the cross-sectional area which is constant over the entire length of the outlet channel and corresponds to the shape of the cross-sectional area of the outlet opening (square, rectangular, polygonal, round etc.). As an alternative, the shape of the cross-sectional area of the outlet channel can change over the length of the outlet channel. In this case, the size of the cross-sectional area of the outlet opening can remain constant (and this is then also the size of the outlet opening) or can vary. In particular, the size of the cross-sectional area of the outlet channel can decrease in the fluid flow direction from the inlet opening to the outlet opening. According to another alternative, the shape and/or size of the cross-sectional area of the main flow channel can vary from the inlet opening toward the outlet opening. Thus, in particular, the shape of the cross-sectional area (of the outlet channel or of the main flow channel) can change from rectangular to round (in the fluid flow direction from the inlet opening to the outlet opening). As a result, the fluid jet can be pre-concentrated already in the fluidic component, thus enabling the compactness of the emerging fluid jet to be increased. Furthermore, the size of the cross-sectional area of the outlet channel can vary, in particular can decrease in the fluid flow direction from the inlet opening to the outlet opening.
The shape of the outlet channel influences the oscillation angle of the emerging fluid jet and can be chosen in such a way that a desired oscillation angle is established. Apart from the abovementioned constant or variable shape of the cross-sectional area of the outlet channel, it is possible as a further feature for the outlet channel to be of rectilinear or curved design.
According to one embodiment, the fluidic component has a cavity which is designed as a widened portion of the outlet channel and, when viewed in the flow direction of the emerging fluid flow, extends around the entire outlet channel over a section of the outlet channel and transversely to the flow direction of the emerging fluid flow.
The parameters of the fluidic component (shape, size, number and shape of the auxiliary flow channels, (relative) size of the inlet and outlet openings) can be set in many ways. These parameters are preferably chosen in such a way that the pressure at which the fluid flow enters the fluidic component via the inlet opening is substantially dissipated at the outlet opening. Here, a slight pressure reduction in comparison with that at the outlet opening can take place already in the fluidic component (upstream of the outlet opening).
According to another embodiment, the fluidic component has two or more outlet openings. These outlet openings can be formed by arrangement of a flow divider directly upstream of the outlet openings. The flow divider is a means for splitting the fluid flow into two or more subsidiary flows. In order to achieve the effects, mentioned at the outset, of the fluidic component according to the invention with just one outlet opening, even in the embodiment with two or more outlet openings, each outlet opening can have a smaller cross-sectional area than the inlet opening, or all the outlet openings and the inlet opening can each have cross-sectional areas that are equal in size. Alternatively, it is also possible for just one of the two/of the plurality of outlet openings to have a smaller cross-sectional area than or a cross-sectional area of the same size as the inlet opening. A fluidic component with two or more outlet openings is suitable for producing two or more fluid jets which emerge from the fluidic component in a pulsed manner with respect to time. Here, a (minimal) local oscillation can occur within a pulse.
The flow divider can have various shapes but common to all of them is that they widen downstream in the plane in which the emerging fluid jet oscillates and transversely to the longitudinal axis of the fluidic component. The flow divider can be arranged in the outlet channel (if present). Moreover, the flow divider can extend deeper into the fluidic component, e.g. into the main flow channel. In this case, the flow divider can be arranged in such a symmetrical way (with respect to an axis which extends parallel to the component length) that the outlet openings are identical in shape and size. However, other positions are also possible, and these can be chosen in accordance with the desired pulse characteristic of the emerging fluid jets.
According to another embodiment, the fluidic component comprises a fluid flow guide, which is arranged downstream adjoining the outlet opening. The fluid flow guide is substantially tubular (e.g. with a cross-sectional area of constant size and a constant shape of the cross-sectional area) and can be moved by the fluid flow as said flow changes direction. The cross-sectional area of the fluid flow guide can correspond to the cross-sectional area of the outlet opening. No influence is exercised over the direction of the emerging fluid flow by means of the movement of the fluid flow guide. The fluid flow guide merely forms a means (passive construction element) for the additional concentration of the oscillating emerging fluid jet. The fluid flow concentrated in this way fans out or spreads apart only further downstream than a fluid flow which emerges from a fluidic component without a fluid flow guide. Particularly in cleaning systems, this property can be desired.
In one embodiment, the outlet opening is adjoined on the downstream side by a fluid flow guide which, without acting on the direction of the fluid flow is movable by the fluid flow as said flow changes direction. Also the fluid flow guide may be rigidly connected to a flow guiding body, which is arranged upstream of the outlet opening and is movable by the fluid flow as said flow changes direction.
In order to avoid influencing the emerging oscillating fluid jet, a bearing arrangement, by means of which the fluid flow guide is secured movably on the outlet opening, can be provided, for example. Various joint configurations that can be used in principle are known in practice. For example, a ball joint or a solid body joint is possible. As an alternative, the fluid flow guide and/or the bearing arrangement can be manufactured from a flexible material.
It is also possible for the cross-sectional area of the outlet opening of the fluid flow guide to be implemented differently. The outlet opening of the fluid flow guide is the opening from which the fluid flow emerges from the fluid flow guide (and thus from the fluidic component). Thus, shapes for the cross-sectional area of the outlet opening of the fluid flow guide which have been described in the context of the outlet opening of the fluidic component without a fluid flow guide are possible. It is also possible for the shape of the cross-sectional area of the fluid flow guide to vary over the length of the fluid flow guide. Thus, a rectangular cross-sectional area in the region of the bearing arrangement (i.e. at the inlet of the fluid flow guide) can be provided which merges downstream into a round cross-sectional area.
According to another embodiment, the fluidic component has a widened outlet portion, which adjoins the outlet opening downstream of the outlet opening. In particular, the widened outlet portion immediately (directly) adjoins the outlet opening downstream of the outlet opening. The widened outlet portion can be of funnel-shaped design, for example. In particular, the widened outlet portion can have a cross-sectional area (perpendicularly to the fluid flow direction), the size of which increases downstream of the outlet opening. In this case, the outlet opening can form the point with the smallest cross-sectional area between the flow chamber and the widened outlet portion.
The widened outlet portion can be used to concentrate a fluid jet which undergoes a high pressure reduction at the outlet opening and hence spreads apart at the outlet opening. The widened outlet portion can therefore (at least partially) counteract the spreading apart of the fluid jet. By means of the concentration of the fluid jet, it is possible to achieve an increase in the removal or cleaning power of the fluidic component.
According to one embodiment, the widened outlet portion can have a width which increases (continuously) downstream of the outlet opening. In this case, the width is the extent of the widened outlet portion which lies in the plane in which the emerging fluid flow oscillates. In this case, the depth of the widened outlet portion can be constant. The depth of the widened outlet portion is the extent of the widened outlet portion which is oriented substantially perpendicularly to the plane in which the emerging fluid flow oscillates. Depending on the area of application of the fluidic component, the depth of the widened outlet portion can increase or decrease downstream (in comparison with the component depth at the outlet opening). By means of a downstream-oriented reduction in component depth in the region of the widened outlet portion, it is possible to achieve further focusing of the emerging fluid jet.
According to one embodiment, the widened outlet portion can be delimited by a wall which encloses an angle in the plane in which the emerging fluid jet oscillates within an oscillation angle, wherein the angle of the widened outlet portion is 0° to 15°, preferably 0° to 10°, larger than the oscillation angle. Thus, the widened outlet portion does not influence the magnitude of the oscillation angle but merely the spreading apart of the emerging fluid jet. This angle magnitude is appropriate, for example, for fluidic components which, without a widened outlet portion, produce a uniform distribution of the fluid on the surface to be sprayed. The selected angle of the widened outlet portion can also be smaller than the oscillation angle, e.g. if, without a widened outlet portion, the fluidic component produces a nonuniform distribution of the fluid on the surface to be sprayed or if the oscillation angle is to be reduced.
Downstream of the outlet opening it is possible to provide an outlet channel, the boundary walls of which enclose an angle in the plane in which the emerging fluid jet oscillates, wherein the angle of the outlet channel can be larger than the oscillation angle and also larger than the angle of the widened outlet portion. The angle of the outlet channel is preferably larger at least by a factor of 1.1 than the angle of the widened outlet portion. According to a particularly preferred embodiment, the angle of the outlet channel is in a range extending from 1.1 times the angle of the widened outlet portion to 3.5 times the angle of the widened outlet portion.
The invention furthermore relates to an injection system and to a cleaning appliance which each comprise a device for producing a fluid jet, said device being the fluidic component according to the invention. The injection system is provided for the purpose of injecting a fuel into a combustion engine, e.g. an internal combustion engine or a gas turbine, which is used in motor vehicles, for example. In particular, the cleaning appliance is a dishwasher, a washing machine, an industrial cleaning system or a high-pressure cleaner.
The invention is explained in greater detail below by means of illustrative embodiments in conjunction with the drawings.
A fluidic component 1 according to one embodiment of the invention is illustrated schematically in
The flow chamber 10 comprises an inlet opening 101, via which the fluid flow 2 enters the flow chamber 10, and an outlet opening 102, via which the fluid flow 2 leaves the flow chamber 10. The inlet opening 101 and the outlet opening 102 are arranged on two opposite sides of the fluidic component 1. The fluid flow 2 moves substantially along a longitudinal axis A of the fluidic component 1 in the flow chamber 10 (said longitudinal axis connecting the inlet opening 101 and the outlet opening 102 to one another) from the inlet opening 101 to the outlet opening 102.
The longitudinal axis A forms an axis of symmetry of the fluidic component 1. The longitudinal axis A lies in two planes of symmetry S1 and S2 which are perpendicular to one another, relative to which the fluidic component 1 is mirror-symmetrical. As an alternative, the fluidic component 1 can be of non-(mirror-)symmetrical construction.
To change the direction of the fluid flow in a controlled manner, the flow chamber 10 has not only a main flow channel 103 but also two auxiliary flow channels 104a, 104b, wherein the main flow channel 103 is arranged between the two auxiliary flow channels 104a, 104b (when viewed transversely to the longitudinal axis A). Immediately behind the inlet opening 101, the flow chamber 10 divides into the main flow channel 103 and the two auxiliary flow channels 104a, 104b, which are then combined again immediately ahead of the outlet opening 102. The two auxiliary flow channels 104a, 104b are arranged symmetrically with respect to axis of symmetry S2 (
The main flow channel 103 connects the inlet opening 101 and the outlet opening 102 to one another substantially in a straight line, with the result that the fluid flow 2 flows substantially along the longitudinal axis A of the fluidic component 1. Starting from the inlet opening 101, the auxiliary flow channels 104a, 104b each extend initially at an angle of substantially 90° to the longitudinal axis A in opposite directions in a first section. The auxiliary flow channels 104a, 104b then bend, with the result that they each extend substantially parallel to the longitudinal axis A (in the direction of the outlet opening 102) (second section). In order to recombine the auxiliary flow channels 104a, 104b and the main flow channel 103, the auxiliary flow channels 104a, 104b change direction once again at the end of the second section, with the result that they are each oriented substantially in the direction of the longitudinal axis A (third section). In the embodiment in
The auxiliary flow channels 104a, 104b are a means for influencing the direction of the fluid flow 2 which flows through the flow chamber 10. For this purpose, the auxiliary flow channels 104a, 104b each have an inlet 104a1, 104b1, which is formed substantially by that end of the auxiliary flow channels 104a, 104b which faces the outlet opening 102, and each have an outlet 104a2, 104b2, which is formed substantially by that end of the auxiliary flow channels 104a, 104b which faces the inlet opening 101. Through the inlets 104a1, 104b1, a small part of the fluid flow 2, the auxiliary flows 23a, 23b (
The auxiliary flow channels 104a, 104b each have a cross-sectional area which is virtually constant over the entire length of the auxiliary flow channels 104a, 104b (from the inlet 104a1, 104b1 to the outlet 104a2, 104b2). As an alternative, the size and/or shape of the cross-sectional area can vary over the length of the auxiliary flow channels. In contrast, the size of the cross-sectional area of the main flow channel 103 increases continuously in the flow direction of the main flow 23 (i.e. in the direction from the inlet opening 101 to the outlet opening 102), wherein the shape of the main flow channel 103 is mirror-symmetrical with respect to the planes of symmetry S1 and S2.
The main flow channel 103 is separated from each auxiliary flow channel 104a, 104b by a block 11a, 11b. In the embodiment from
Separators 105a, 105b in the form of inward protrusions (of the boundary wall of the flow chamber 10) are furthermore provided at the inlet 104a1, 104b1 of the auxiliary flow channels 104a, 104b. In this case, an inward protrusion 105a, 105b projects at the inlet 104a1, 104b1 of each auxiliary flow channel 104a, 104b beyond a section of the circumferential edge of the auxiliary flow channel 104a, 104b into the respective auxiliary flow channel 104a, 104b and changes the cross-sectional shape thereof at this point, reducing the cross-sectional area. In the embodiment in
In the embodiment from
The separators 105a, 105b are formed in the boundary wall of the flow chamber 10, substantially opposite that end of the blocks 11a, 11b which faces the outlet opening 102. In particular, the separators 105a, 105b can be arranged at a distance from plane of symmetry S2 which is within the average width of the blocks 11a, 11b. The average width of a block 11a, 11b is the width which the block 11a, 11b has over half its length (when viewed in the flow direction).
Arranged upstream of the inlet opening 101 of the flow chamber 10 is a funnel-shaped extension 106, which tapers in the direction of the inlet opening 101 (downstream). The length (along the fluid flow direction) of the funnel-shaped extension 106 can be greater by a factor of at least 1.5 than the width bIN of the inlet opening 101. The funnel-shaped extension 106 is preferably larger by a factor of at least 3 than the width bIN of the inlet opening 101. The flow chamber 10 also tapers, namely in the region of the outlet opening 102. The taper is formed by an outlet channel 107, which extends between the separators 105a, 105b and the outlet opening 102. In this case, the funnel-shaped extension 106 and the outlet channel 107 taper in such a way that only the width thereof, i.e. the extent thereof in plane of symmetry S1 perpendicularly to the longitudinal axis A, decreases downstream in each case. The taper has no effect on the depth, i.e. the extent in plane of symmetry S2 perpendicularly to the longitudinal axis A, of the extension 106 and of the outlet channel 107 (
The inlet opening 101 and the outlet opening 102 each have a rectangular cross-sectional area. These each have the same depth (extent in plane of symmetry S2 perpendicularly to the longitudinal axis A,
For cleaning applications which typically operate with inlet pressures of over 14 bar, the fluidic component 1 can have an outlet width bEX of 0.01 mm to 18 mm. The outlet width bEX is preferably between 0.1 mm and 8 mm. The ratio of the width bIN of the inlet opening 101 to the width bEX of the outlet opening 102 can be 1 to 6, preferably between 1 and 2.2. In this case, the dimensions of the component depth in the region of the inlet opening 101 and of the outlet opening 102 should be chosen so that the cross-sectional area of the outlet opening 102 is smaller than or equal in size to the cross-sectional area of the inlet opening 101. The component width b can be greater by a factor of at least 4 than the outlet width bEX. The component width b is preferably greater by a factor of 6 to 21 than the outlet width bEX. The component length 1 can be greater by a factor of at least 6 than the outlet width bEX. The component length 1 is preferably greater by a factor of 8 to 38 than the outlet width bEX. The widest point of the main flow channel (the largest distance between the blocks 11a, 11b when viewed along the width of the fluidic component 1) can be greater by a factor of 2 to 18 than the outlet width bEX. This factor is preferably between 3 and 12.
In
Images a) and c) illustrate the streamlines for two deflections of the emerging main flow 24, which correspond approximately to the maximum deflections. The angle which the emerging main flow 24 covers between these two maxima is the oscillation angle α (
First of all, the fluid flow 2 is passed via the inlet opening 101 into the fluidic component 1 at an inlet pressure of 56 bar. In the region of the inlet opening 101, the fluid flow 2 undergoes virtually no pressure loss since it is allowed to flow unhindered through into the main flow channel 103. Initially, the fluid flow flows along the longitudinal axis A in the direction of the outlet opening 102.
By introducing a one-time random or selective disturbance, the fluid flow 2 is deflected sideways in the direction of the side wall of one block 11a which faces the main flow channel 103, with the result that the direction of the fluid flow 2 deviates to an increasing extent from the longitudinal axis A until the fluid flow has been deflected to the maximum extent. By virtue of the “Coanda effect”, the majority of the fluid flow 2, the “main flow” 24, adheres to the side wall of one block 11a and then flows along this side wall. A recirculation zone 25b forms in the region between the main flow 24 and the other block 11b. In this case, the recirculation zone 25b grows the more the main flow 24 adheres to the side wall of one block 11a. The main flow 24 emerges from the outlet opening 102 at an angle relative to the longitudinal axis A which varies with respect to time. In
A small part of the fluid flow 2, referred to as the auxiliary flow 23a, 23b, separates from the main flow 24 and flows into the auxiliary flow channels 104a, 104b via the inlets 104a1, 104b1 thereof. In the situation illustrated in
The main flow 24 is therefore pressed against the side wall of block 11a by the momentum (of auxiliary flow 23b). At the same time, the recirculation zone 25b moves in the direction of the inlet 104b1 of auxiliary flow channel 104b, thereby disturbing the supply of fluid to auxiliary flow channel 104b. The momentum component which results from auxiliary flow 23b therefore decreases. At the same time, the recirculation zone 25b shrinks, while another (growing) recirculation zone 25a forms between the main flow 24 and the side wall of block 11a. During this process, the supply of fluid to auxiliary flow channel 104a also increases. The momentum component which results from auxiliary flow 23a therefore increases. The momentum components of the auxiliary flows 23a, 23b continue to come closer and closer together until they are equal and cancel each other out. In this situation, the entering fluid flow 2 is not deflected, and therefore the main flow 24 moves approximately centrally between the two blocks 11a, 11b and emerges without deflection from the outlet opening 102.
As the situation progresses, the supply of fluid to auxiliary flow channel 104a increases more and more, and therefore the momentum component which results from auxiliary flow 23a exceeds the momentum component which results from auxiliary flow 23b. As a result, the main flow 24 is forced further and further away from the side wall of block 11a, until it adheres to the side wall of the opposite block 11b owing to the Coanda effect (
The recirculation zone 25a will then move and block the inlet 104a1 of auxiliary flow channel 104a, with the result that the supply of fluid will fall again here. Subsequently, auxiliary flow 23b will supply the dominant momentum component, with the result that the main flow 24 will once again be forced away from the side wall of block 11b. The changes described now take place in the reverse order.
Owing to the process described, the main flow 24 emerging at the outlet opening 102 oscillates about the longitudinal axis A in a plane in which the main flow channel 103 and the auxiliary flow channels 104a, 104b are arranged, with the result that a fluid jet that sweeps backward and forward is produced. In order to achieve the effect described, a symmetrical construction of the fluidic component 1 is not absolutely necessary.
For each of the three snapshots a), b) and c) from
Cross sections through two further embodiments of the fluidic component 1 are illustrated in
The flow divider 108 in each case has the form of a triangular wedge. The wedge has a depth which corresponds to the component depth t. (The component depth t is constant over the entire fluidic component 1.) Thus, the flow divider 108 divides the outlet channel 107 into two subordinate channels with two outlet openings 102 and divides the fluid flow 2 into two subordinate flows, which emerge from the fluidic component 1. Owing to the oscillation mechanism described in the context of
In the embodiment from
Another embodiment of the fluidic component 1 having the fluid flow guide 109 from
The flow guiding body 110 described with reference to
Thus, auxiliary flow channel 104a has a greater width at the inlet 104a1 thereof and at the outlet 104a2 thereof than in a section between the inlet 104a1 and the outlet 104a2. For the widths bNa1, bNa2, bNa3 of auxiliary flow channel 104a which are illustrated in
Auxiliary flow channel 104b has a greater width at the inlet 104b1 thereof than at the outlet 104b2 thereof. For the widths bNb1, bNb2 of auxiliary flow channel 104b which are illustrated in
In
By means of the change in the cross-sectional area of the auxiliary flow channels 104a, 104b, the production process (casting, sintering) of the fluidic component 1 can be simplified since foreign matter can be removed easily from the fluidic component during manufacture. Moreover, the finished fluidic component can be cleaned more easily, this being significant, for example, when the fluidic component is used with a fluid that is laden with foreign matter (particles). In the variant in which the cross section increases from the outlet of the auxiliary flow channel toward the inlet of the auxiliary flow channel, the fluidic component is self-flushing during operation. In the variant in which the cross section increases from the inlet of the auxiliary flow channel toward the outlet of the auxiliary flow channel, the fluid drains completely from the fluidic component when the fluidic component is switched off (i.e. when no more fluid is passed into the fluidic component). It is thus possible to avoid the accumulation of fluid in the fluidic component after it has been switched off and the proliferation of pathogens (e.g. legionella) present in the fluid or the deposition of mold, soap residues, limescale or other dirt. Draining of the fluidic component after switching off can be promoted by dispensing with separators.
However, the variable width of the auxiliary flow channels 104a, 104b which is described with reference to
The shapes of the fluidic components 1 in
A fluidic component 1 according to another embodiment of the invention is illustrated schematically in
If the cross-sectional area of the outlet opening 102 is smaller than the cross-sectional area of the inlet opening 101, the pressure within the fluidic component 1 can increase and thus reduce the tendency for cavitation. As a result, the input pressure, which can be higher than 14 bar (above ambient pressure) but can also be over 1000 bar and is preferably between 20 bar and 500 bar, is dissipated essentially only at the outlet opening 102. Owing to the large pressure decrease directly at the outlet opening 102, the emerging fluid jet can tend to spread apart (in all directions). This spreading apart can be counteracted (at least partially) by means of the widened outlet portion 12. By means of the widened outlet portion 12, it is possible to achieve concentration of the emerging fluid jet (perpendicularly to the planes of symmetry S1 and S2). By means of this concentration of the fluid jet, an increase in the removal or cleaning power of the fluidic component 1 can be achieved.
The widened outlet portion 12 is of funnel-shaped design and has a cross-sectional area which increases in the fluid flow direction (from the inlet opening 101 to the outlet opening 102), starting from the outlet opening 102. In this case, the depth of the widened outlet portion 12 is constant, while the width of the widened outlet portion 12 increases in the fluid flow direction. According to
The walls delimiting the widened outlet portion 12 enclose an angle γ in the plane in which the emerging fluid jet oscillates. In the embodiment from
The walls delimiting the outlet channel 107 enclose an angle 3 in the plane in which the emerging fluid jet oscillates. The angle 3 of the outlet channel 107 can be larger than the oscillation angle α and also larger than the angle γ of the widened outlet portion 12. The angle β of the outlet channel 107 is preferably larger than the angle γ of the widened outlet portion 12 by a factor of at least 1.1. According to a particularly preferred embodiment, 1.1*γ≤β≤3.5*γ.
The widened outlet portion 12 has a length lout which adjoins the component length l. The length lout of the widened outlet portion 12 can correspond at least to the width bEX of the outlet opening 102. The length lout of the widened outlet portion 12 can preferably be greater by a factor of at least 1.25 than the width bEX of the outlet opening 102. The length lout of the widened outlet portion 12 can preferably be greater by a factor of 1 to 32 than the outlet width bEX, in particular preferably by a factor of 4 to 16. At this ratio, a fluid jet of high jet quality can be produced.
The separators 105a, 105b are formed by an inward protrusion of the wall of the auxiliary flow channels 104a, 104b. In this case, the inward protrusion has a shape which describes a circular arc in plane of symmetry S1. The radius of the circular arc can vary. For example, the radius of the circular arc can be 0.0075 to 2.6 times, preferably 0.015 to 1.8 times and, in particular, preferably 0.055 to 1.7 times the outlet width bEX.
In the illustrative embodiment in
A fluidic component 1 according to another embodiment of the invention is illustrated schematically in
The auxiliary flow channels 104a, 104b each extend initially at an angle of substantially 90° to the longitudinal axis A in opposite directions in a first section, starting from the inlet opening 101. The auxiliary flow channels 104a, 104b then bend (substantially at a right angle), with the result that they each extend substantially parallel to the longitudinal axis A (in the direction of the outlet opening 102) (second section). A third section adjoins the second section. The change in direction at the transition from the second to the third section is substantially 90°.
In contrast to the fluidic component 1 from
The shape of the fluidic components 1 having a widened outlet portion 12 is shown purely by way of example in
Number | Date | Country | Kind |
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102015222771.5 | Nov 2015 | DE | national |
202016104170.8 | Jul 2016 | DE | national |
This application is a continuation of U.S. application Ser. No. 15/773,344 filed May 3, 2018, which is the United States National Phase patent application of International Patent Application Number PCT/EP2016/077864, filed on Nov. 16, 2016, which claims priority of German Patent Application Number 10 2015 222 771.5, filed on Nov. 18, 2015 and of German Utility Model Application Number 20 2016 104 170.8, filed on Jul. 29, 2016, the disclosures of which are hereby incorporated in their entirety by reference.
Number | Date | Country | |
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Parent | 15773344 | May 2018 | US |
Child | 17511708 | US |