EP0519967B1 - Applicator head for media - Google Patents

Abstract

A discharge head is connected to a double pump for air and liquid. The air and liquid are separately passed by pump actuation through a flow calming member and then into a combining member in a way such that the air enters in the form of numerous individual jets and under a low pressure and at a low flow rate into a liquid-wetted screen unit provided in a widened chamber. In the vicinity of the screen unit which are supplied with liquid from a chamber, the liquid can be foamed in a stepwise manner with the aid of air until the foam is discharged ready for use through an end channel.

Description

The invention relates to a discharge head for media, which in particular should have means for precisely controlled flow influencing of at least one medium, in order to be able to convey this medium by hand-operated pumping within narrow tolerances of flow speed and / or volume per unit of time.

In particular, the discharge head should have means for bringing together at least two separately supplied or stored media, which can be different components of the same and / or different state of matter and interact chemically or physically with one another at the latest in the region of the discharge from an outlet opening, for example by mixing.

The media, in particular a gaseous and a liquid medium, should preferably cooperate in such a way that foam with precisely determinable properties, e.g. a very stable, finely structured foam is created.

For foam production or intensive mixing of the media, a manually operable discharge device can be provided, with which air and liquid are brought together and then pressed through a porous, permeable body. As a result, the discharge device can e.g. be suitable for numerous applications, especially for easy-to-foam, flowable media.

From US-A-2 624 622 a foaming gun has become known, in which compressed air from an annular nozzle surrounding a liquid nozzle enters a mixing chamber. It sucks in liquid from a container and mixes with it in the mixing chamber before it exits the mouth through foam screens.

The invention is further based on the object of providing a discharge head of the type mentioned, with which media which are relatively difficult to mix or foam can be brought together in such a way that a very precise structure of the mixing, preferably a particularly homogeneous mixing, is achieved can.

As a solution, it is proposed to use at least one medium before, in particular immediately before the flow stabilization, e.g. subject to that the flow rate is suddenly reduced. Irrespective of this, at least one medium can also be combined in a plurality of separate flow jets with at least one further medium, the medium expediently being exposed to the flow calming immediately before the combination as an undivided volume flow and then divided into the individual flow jets.

The media are only brought together immediately adjacent to or on at least one permeable sheet, such as a sieve, which is like a sponge can be wetted or soaked with the liquid medium at least on the inlet side such that its through openings are spanned with the liquid medium in the manner of liquid films. These openings can have a width of the order of about a hundredth of a millimeter or less, for example half a hundredth of a millimeter. The sieves can be stamped parts from a flat sieve material made of plastic or the like. and be assembled into a multi-layer sieve pack.

If two or more identical or graduated fine-pored sieve bodies are connected directly one behind the other, mixing takes place in successive stages during the passage until the desired degree of mixing or the desired foam structure is achieved. Adjacent sieve bodies can lie flat against one another and / or a small gap distance approximately in the order of their thickness of e.g. have significantly less than one millimeter from one another, which enables cross flows and, if appropriate, transverse expansions of the foam that forms between the input side and the output side within the entire screen arrangement along the screen surface. Where sieves are in contact with one another, their sieve openings, if necessary according to a probability distribution, are offset from one another in such a way that opening separations of one sieve cross openings of the other sieve.

To achieve the stated object, it can also be advantageous to bring the media transversely to an input side without prior merging directly to the screen body and to bring them together within the screen body only immediately and / or after this input side. Between the associated inlet openings of channels for media and the However, a gap distance of the order of magnitude mentioned can be provided on the input side of the screen body.

Advantageously, all of the entry openings associated with the merging for at least two media lie in a common surface or plane which is approximately perpendicular to the direction of flow and to which the sieve body adjoins at a constant distance or in a flat manner; the side of the sieve body facing away from it forms the outlet, so that flow paths which are several times longer and approximately rectified in parallel or in alignment are formed before and after the sieve body.

The gaseous medium is expediently supplied through at least one ring of relatively small openings, which surrounds a single or a plurality of substantially larger openings for supplying the liquid medium and is very close to the outer circumference of the central opening field formed thereby. In contrast, the chamber for merging, which may have the screen body, is expediently wider.

The merging or the screen body advantageously is followed by a buffer for the liquid medium which is separate from the feed for the further medium and which has one or more relatively narrow supply openings in the region of its end remote from the screen body, so that a larger quantity is always present on the screen body of liquid medium as a template, from which the sieve body can suck up by capillary action and from which the medium does not automatically flow back through the supply openings. The flow stabilization can follow one another in several stages, for example in axially one behind the other, coaxial and / or annular or widened chambers.

The annular chambers provided for the gaseous medium are connected to one another via continuously straight, parallel longitudinal channels, the width of which may be slightly larger and the number of which may be smaller than that of connecting channels which feed this medium directly to the merging or the sieve body. The respective channel or the respective chamber expediently has a substantially constant cross section over the entire length.

In particular when producing foam, the design according to the invention can ensure that the air enters the sieve chamber evenly distributed at relatively low pressure and low speed. Furthermore, the pressure and speed remain essentially constant even when the air is delivered by a pump, such as a thrust piston pump. This enables a very fine-grained and homogeneous foam to be produced. The fine sieve body forms a sufficiently effective closure for the supply of liquid when not in use, since it is designed with regard to the flow properties or viscosity of the liquid medium so that this medium does not flow through the sieve body by weight alone. This provides effective leak protection.

These and further features of preferred developments of the invention are apparent from the claims and also from the description and the drawings, the individual features being implemented individually or in groups in the form of subcombinations in one embodiment of the invention and in other areas, and can represent advantageous and protectable versions.

Fig. 1

einen erfindungsgemäßen Austragkopf im Schnitt;

Fig. 2

einen Ausschnitt der Fig. 1 in vergrößerter Darstellung;

Fig. 3

einen Querschnitt durch die Zusammenführung;

Fig. 4

einen Querschnitt durch eine Strömungsberuhigung und

Fig. 5

eine weitere Ausführungsform in einer Darstellung entsprechend Fig. 2.

An embodiment of the invention is shown in the drawings and is explained in more detail below. The drawings show:

Fig. 1

a discharge head according to the invention in section;

Fig. 2

a section of Figure 1 in an enlarged view.

Fig. 3

a cross section through the merge;

Fig. 4

a cross section through a flow calming and

Fig. 5

a further embodiment in a representation corresponding to FIG. 2.

The discharge head 1 is particularly suitable for use on a discharge device according to DE-OS 37 22 469, to which reference is made for further details and effects. It has a cap-shaped base body to be plugged onto the piston shaft of a fluid pump of the discharge device with a discharge nozzle 3 projecting approximately radially therefrom and forms a pressure handle with its cap end wall for pump actuation. The discharge nozzle 3, together with the base body 2, receives a foaming device 4 for separate feeding, intermediate storage, flow calming and subsequent merging with the formation of foam from a liquid medium and air. The discharge medium obtained emerges as a foam strand through an outlet opening 5 provided at the free end of the discharge nozzle 3.

For connection to the piston skirt and an outlet channel provided in it, the base body 2 is connected to the one Provide inside of its cap front wall freely protruding, socket-shaped plug-in connection 6. This is surrounded in a ring by a plug connection 7, which lies within the cap jacket and projects in the same direction, for an air pump 8 (not shown in detail), the cylinder of which is formed by the cap jacket and the one on the housing of the liquid Pump fixedly arranged, penetrated by the piston skirt sealed annular piston. The connection 6 has an angled feed duct 9 leading to the rear end of the discharge nozzle 3. A supply duct 11 of the air connection 7, which surrounds the connection 6 in a ring, likewise leads within the base body 2 into this rear end. Between the supply ducts 9, 11 and the outlet opening 5, only straight-line or parallel or symmetrical flow paths with changing inner widths are provided.

The discharge nozzle 3 is inserted as a self-contained assembly with its rear end in a corresponding flange area of the one-piece base body 2, at the connection 7 of which an outlet valve unit of the air pump 8 directly attached to the associated pump chamber can be fastened. The outlet nozzle 3 or the foaming device 4 consists of three nested sleeve parts, namely two inner sleeve parts 12, 13 and an outer sleeve 14 forming the outlet opening 5. The sleeve part 12 is used with a core 15 protruding beyond the rear end of the outer sleeve 14 and inside receiving fastening end 16, which has two sections 17, 18 which are offset in diameter from one another, for plug-in or snap connection to the flange part of the base body 2.

A subsequent, slightly expanded section 19 lies within one through the rear end of the outer sleeve 14 formed receiving sleeve 21, the constant inner circumference of which connects to an end channel via an annular shoulder.

The section 19 merges over an approximately flat annular shoulder into an end section 20 with a substantially reduced outside diameter, onto which the longer sleeve part 13 is attached. The sleeve part 12 and the sleeve part 13 can form an assembly module with a constant outer diameter in the region of the section 19 and the sleeve part 13 and can be inserted with tension into the receiving sleeve 21.

The core 15 formed in one piece with the connection 6 engages from the rear end of the sleeve part 12 into the central bore of the sleeve part 12, which has a constant width almost over its entire length. Between the outer circumference of the core 15 and the inner circumference of this bore are provided in the form of longitudinal grooves evenly distributed over the circumference longitudinal channels 22, which extend beyond the front end of the core 15 and at the rear ends of the feed channel 9 connects via an annular gap. Between the front ends of the mandrel-shaped core 15 and the sleeve part 12, the interior thereof forms a continuously constant, elongated chamber 23.

The air supply duct 11 adjoins the rear end of a chamber 24 which lies in front of the annular gap for the supply ducts 22 and surrounds it in an annular manner and which is bounded on its front end face by the rear end of the section 18 and on the inner circumference by the section 17. From the front end face of the chamber 24 there is a ring of connecting channels 25 which are arranged uniformly about the central axis 10 and extend as far as the front annular shoulder of the section 19 and lie completely in the bore within the jacket of the sleeve part 12. At the front ends of the connecting channels 25 connects a further, annular chamber 26, which is correspondingly delimited on the one hand by the sections 19, 20 and on the other hand by the sleeve part 13, can be larger than the chamber 24 and also has approximately square cross sections.

The front end wall of the chamber 26 is adjoined by a multiplicity of connecting channels 27, which are narrower and substantially shorter than the connecting channels 25 and arranged in a ring around the chamber 23. The connecting channels 27 are formed by longitudinal grooves on the inner circumference of the sleeve part 13 and delimited by the outer circumference of the end section 20 and, like the connecting channels 25, each have a constant width over their length. They extend to the bottom end wall 29 of a chamber provided as a junction 28 for the media; this end wall 29 is formed by the front end face of the sleeve part 12 and an inner ring surface lying in its plane of an enlarged inner portion of the sleeve part 13. The described channel arrangement forms a flow stabilization 30 for the supplied air which is located immediately before the junction 28 and which, like the liquid, is essentially only guided or enters and exits axially.

In the chamber 32 of the junction 28, the width of which is greater than that of all the other channels connected on the inlet side, the liquid is foamed with the air in such a way that the foam from the outlet 31 opposite on the face side enters an approximately constantly wide, elongated end channel 33, whose front end forms the outlet opening 5 and in which the foam can still stabilize completely. The slightly further end channel 33 compared to the chamber 23 is narrower than the chamber 32.

While all the other channels and chambers are free of built-in parts or protruding parts and consistently smooth-walled, the chamber 32 is essentially completely filled with a sieve unit 37, the fine-meshed or microporous sieves 38 of which are perpendicular to the direction of flow and to the central axis 10 in a uniform, slight manner Distances are one behind the other and engage with their peripheral edges 39 tightly in the inner circumference 36 of the chamber 32. The inlet openings 34, 35 for liquid and air, which are located in a common plane and are formed by the ends of the chamber 23 and the connecting channels 27, are located at a radial distance within the inner circumference 36 immediately adjacent to the end face of the first sieve 38 and at substantially equal distances therefrom. These sieves 38 and the chamber 32 cause a further throttling and calming of the air flow, which penetrates the pores of the sieve with entrainment of the liquid, so that the foaming can begin or take place between adjacent sieves 38 and the foam that is formed also due to the volume increase occurring through the others Sieve 38 is pressed. The foam is then compressed slightly in the area of the narrower outlet 31. The length of the chamber 32 can be less than its width, four sieves 38 being arranged one behind the other in the case shown. The chamber 32 can be supplied with further liquid from the chamber 23 at any time.

The air outlet of the air pump 8 can be valve-free or via a valve not preloaded in the manner of a pressure relief valve with a freely movable valve body, so that the flow rate and the pressure of the conveyed air can be controlled essentially solely by the manually actuated actuating pressure. To discharge certain liquids, the air outlet of the pump can also be provided with a pressure relief valve. The same applies to an outlet valve of the liquid pump, which serves to refill the chamber 23 simultaneously with the air delivery. The chamber 23 also serves to calm the flow, so that both the air and the liquid are supplied to the junction 28 only at low pressure and low flow velocity.

In FIG. 5, the same reference numerals are used for corresponding parts as in the other figures, but with the index "a", which is why all the description parts apply mutatis mutandis to all embodiments. Any features or configurations in the embodiments can be provided in any combination or additively in further embodiments.

5, the chambers 24a, 26a, 32a and the channels 25a, 27a are formed by two sleeve parts 12, 40 which engage with one another over the majority of their length. As a result, the connection channels 25a can be delimited on one long side by the outer circumference of the inner sleeve part 40 and on all other long sides by a groove in the inner circumference of the outer sleeve part 12a, as described with reference to the channels 27. The bottom of this groove forms the associated, radially outer boundary of the chamber 26a, the side flanks of which, like the chamber 24a, are formed by two opposing annular shoulders on the one hand of the sleeve part 40 and on the other hand of the sleeve part 12a.

The annular shoulder of the outer sleeve part 12a lying further forward in the flow direction merges into a channel section which has approximately the same inner width as the inner circumference 36a and is constant from this annular shoulder to the outlet 31a. The front end of the sleeve part 40 engages in a rear part of this inner channel in such a way that only the connecting channels 27a remain free. For this purpose, the front end section 20a of the sleeve part 40 is reduced in outer diameter compared to the section adjoining the rear annular shoulder of the chamber 26a and is provided over the circumference with longitudinal webs 44 which engage in corresponding longitudinal grooves on the inner circumference of the inner channel by insertion. The longitudinal grooves 45 can end or be longer at the front end 29a of the sleeve part 40 or at the front ends of the webs 44 and thus approximately at the rear end of the chamber 32a, or can go as far as the outlet 31a.

Not only the rear fastening end 16a of the sleeve part 40, but also the rear end 18a of the sleeve part 12a are each fixed in corresponding bores in the base body 2a by engagement or pressing. Only the rear fastening end 18a of the sleeve part 12a is axially secured with respect to the base body 2a by a snap connection, while the inner sleeve part 40 is secured against forward movements by the stop of its front end on the sleeve part 12a.

The chamber 23a has a rear channel section 42 and a narrower, front channel section 43 which runs smoothly through to the inlet opening 34a. The feed channels 22a form channel sections 41 in the area of the core 15a, which are delimited in a closed cross-section over the circumference. The bore receiving the core 15a extends with a constant inner width beyond the front end of the core 15a by an amount that is smaller than its width. Then this bore passes into the slightly widened section 42, which connects to the rear end of the channel section 43 via an annular, conical shoulder and is longer in relation to its inner width. The longer channel section 43 is narrower than the bore receiving the core 15a. The bottom surfaces of the grooves forming the channel sections 41 go continuously up to the conical annular shoulder, but the groove depth is correspondingly smaller due to the expansion of the channel section 42 in its area. As a result, the liquid can leave the inlet opening 34a as an enveloping stream which has been formed on the inner circumference of the channel section 43. The air also leaves the inlet openings 35a in a corresponding envelope stream formed from individual longitudinal streams.

The front end 13a of the sleeve part 12a is reduced in outer width and lies essentially without contact in a front bore section 47 of the outer sleeve 14a, which merges into the rear end of the end channel 33a via an inner annular shoulder. To the rear, the bore section 47 merges via an annular shoulder into a slightly enlarged bore section 46, in which the further section of the sleeve part 12a engages tightly and with limited stops. Both the rear end of the outer sleeve 14a and a rear ring shoulder of the sleeve part 12a abut on a common ring shoulder of the base body 2a, the rear end of the outer sleeve 14a expediently engaging in a recess on the outer circumference of the base body 2a.

The end channel 33 or 33a is used for the finished development and stabilization of the foam and is therefore smooth-walled and free from edges or abrupt changes in its width. 5, the end channel 33a is widened at an acute angle from the rear end to the outlet opening 5a, and its length is greater than its central width. This allows the foam on the way through the end channel 33a to expand slightly radially and to assume an even finer structure. In the region of the outlet opening 5a, the front edge of the end channel 33a is convexly rounded in cross section, so that here too the foam is not released abruptly from its circumference.

The feed channel 11a of the connection 7a is formed by a tubular connection piece, onto which a valve housing of an outlet valve of the air pump can be snapped and thereby fastened. As a result, this valve or the associated valve seat is located directly adjacent to the chamber 24a, into which the supply channel 11a opens radially.

The sleeve parts 12a, 40 and the outer sleeve 14a can be assembled in pairs or all to pre-assembled modules. The sleeve part 40 can also be preassembled in front of the sleeve part 12a and the outer sleeve 14a on the base body 2a, after which the sleeve part 12a and the outer sleeve 14a can be assembled one after the other or as an assembly. This results in simple assembly.

Claims (13)

1. Discharge head for media, with a combining means (28,28a) for at least two separate media which are to be mixed or foamed, an outlet (5,5a) and, for at least one of the media, a flow calming means (30,30a) connected upstream of at least one of the combining means (28,28a), with the combination of the media taking place directly adjacent to or at a permeable flat body (38).
2. Discharge head according to claim 1, characterized in that at least one flow path for the supply of a medium is widened at least once and then narrowed again at least once, the flow path preferably being subdivided in at least one narrowed region into several individual channels, which are connected to at least one common and widened area, particularly spaced upstream of the combining means (28).
3. Discharge head according to claims 1 or 2, characterized in that for at least one flow calming means (30) there is at least one calming chamber (24,26,32) having a widened flow cross-section compared with at least one connected channel or an associated inlet and which is preferably annular and/or at least one medium inlet on the one hand and at least one medium outlet on the other are connected to approximately facing chamber walls.
4. Discharge head according to one of the preceding claims, characterized in that the outlet cross-section of at least one calming chamber (24,26,32) is larger than its inlet cross-section and/or smaller than its effective cross-section, that in particular the calming chamber has a larger number of outlets than inlets, whose width is approximately the same as that of the associated channels and that preferably at least one calming chamber (26) is connected by means of at least one outlet, particularly via at least one substantially linear and/or constant cross-section-possessing connecting channel (27) to the combining means (28), the inlets (35) for the combining means (28) being arrangeable in at least one ring.
5. Discharge head according to one of the preceding claims, characterized in that at least one flow path for the supply of one medium has at least two successive, widened and in particular roughly identically large chambers (24,26), whereof a rear chamber is constructed as a distributing chamber (24) for delivery and connecting channels (11, 25) of a front calming chamber (26), which in particular has a smaller spacing from the combining means (28) than the chambers (24, 26) from one another and that preferably between at least one calming chamber (24, 26) and the combining means (28) is provided at least one elongated connecting channel, such as a ring of connecting channels (27), which in particular are in each case substantially linear and/or have constant cross-sections.
6. Discharge head according to one of the preceding claims, characterized in that at least one calming chamber (23) for at least one medium is elongated, bore-like and/or connected to at least one supply channel (22) located between a jacket and a core (15), that in particular the through cross-section of the chamber is much larger than the overall through cross-section of the supply channels and that preferably at least one chamber (26) for the supply of a medium is positioned laterally immediately adjacent to at least one chamber (23) for the supply of a further medium and is in particular located in annular manner around said chamber (23), the flow directions of both media upstream of the combining means (28) and in particular at least as from at least one distributing chamber can be parallel to one another in the manner of a coaxial guide.
7. Discharge head according to one of the preceding claims, characterized in that for at least one medium there is a volume-limited supply by a pump stroke in the manner of a feed cycle and/or that for at least one medium the supply pressure is controllable manually or in substantially valve-free manner and preferably for at least one medium there is a pump with a pump chamber, particularly two commonly operable thrust piston pumps being arranged substantially equiaxially and successively.
8. Discharge head according to one of the preceding claims, characterized in that the combining means (28) is constructed for the intense mixing of the media, particularly for foam production from a liquid and a gaseous medium and preferably has a reaction chamber (32), in whose inlet-side end wall (29) is provided at least one ring of small inlets (35) for a medium and at least one inlet (34) for at least one further medium located within said ring.
9. Discharge head according to one of the preceding claims, characterized in that to a chamber (32) forming the combining means (28) is connected a calming chamber (23) particularly provided for a liquid medium substantially with its full width and directly by one end and/or a calming chamber (26) for a gaseous medium by means of a plurality of connecting channels (27) and that preferably the through-flow width of the liquid inlet (34) is much larger than the total through-flow width of all the gas inlets (35).
10. Discharge head according to one of the preceding claims, characterized in that a medium-permeable chamber (32) for at least one medium is multiply subdivided and is in particular substantially completely in fine-porous structure form or has at least one or more flat screens (38), preferably at least one medium inlet (34, 35) for the chamber (32) is directly connected to the pores of the structure, whilst avoiding empty spaces, or the combining means (28) of the media is provided substantially exclusively within the fine-porous structure.
11. Discharge head according to one of the preceding claims, characterized in that a chamber (32) for the combined media is connected in the flow direction to a discharge or end channel (33) at the most roughly equally wide as compared with the chamber (32) and in particular in the flow direction has a smaller extension than its width and preferably a ring of medium inlets (35) is closer to its inner circumference (36) than its central axis (10) and/or a central medium inlet (34) is closely surrounded by said ring.
12. Discharge head according to one of the preceding claims, characterized in that the combining means (28) and/or the flow calming means (30) have axially, interengaged sleeve portions, particularly a first sleeve portion (12) surrounding bore-like connecting channels (25) on one sleeve jacket and a calming chamber (23) located within the same and on whose front, reduced end portion (20) is engaged a second sleeve portion (13) bounding the combining means (28) at least at the outer circumference, connecting channels (27) together with said end portion (20) and/or an annular calming chamber (26) at least at the outer circumference and preferably the second sleeve portion (13) is surrounded by an outer sleeve (14) either completely and/or the first sleeve portion (12) is surrounded except for a connecting and fixing end (16) receiving a core (15) in a sleeve bore and bounding a rear annular chamber (24) at least at the inner circumference and the sleeve (14) forms an outlet connection (3) projecting over the combining means (28) and having the outlet (5).
13. Discharge head according to claim 12, characterized in that an inner sleeve portion (40) and an outer sleeve portion (12a) bound between their facing circumferential surfaces, particularly by longitudinal grooves, connecting channels (25a), at least one calming chamber (26a) and/or connecting channels (27a), that preferably a front end (29a) of the inner sleeve portion (40) bounds a chamber (32a) at the rear end and that in particular a chamber (23a) located within the inner sleeve portion (40) has at least two longitudinally interconnected longitudinal portions (42, 43) of different passage cross-sections and preferably a wider longitudinal portion (42) is provided with longitudinal grooves and is connected in the flow direction to a smooth-walled, narrower longitudinal portion (43), which passes through to the front end (29a) of the inner sleeve portion (40).

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