Abstract:
The invention relates to a spray mixer for mixing and spraying at least two flowable components. The spray mixer ( 22 ) is provided with a tubular outer mixer housing ( 23 ) which extends in the direction of a mixer longitudinal axis ( 24 ) from a mixer start ( 25 ) to a distal mixer end ( 26 ). A mixer inner housing ( 29 ) which accommodates a mixer element ( 33 ) is arranged in the mixer outer housing ( 23 ). A mixer compressed air inlet ( 31 ) is arranged at the mixer start ( 25 ). The mixer compressed air inlet ( 31 ) is connected by means of a mixer compressed air channel ( 30 ) to an annular mixer compressed air outlet ( 32 ) which encloses a mixer outlet opening ( 35 ). In the operation of the spray mixer ( 22 ), compressed air is supplied via the mixer compressed air inlet ( 31 ), flows through the mixer compressed air channel ( 30 ) to the mixer compressed air outlet ( 32 ) and atomizes and sprays the material emerging from the mixer outlet opening ( 35 ). In order for the spray mixer to be easy to handle, the mixer outer housing ( 23 ), the mixer inner housing ( 29 ) and the mixer element ( 33 ) are combined in a single unit. This is achieved by connecting the indicated components to each other in a manner to secure against loss.

Description:
PRIORITY CLAIM 
     The present application is a National Stage of International Application No. PCT/EP2013/058281, filed on Apr. 22, 2013, which claims priority to European Patent Application No. 12167892.4 filed on May 14, 2012, the entire contents of which are being incorporated herein by reference. 
     BACKGROUND 
     The invention relates to a spray mixer for mixing and spraying at least two flowable components in accordance with the preamble of claim  1 . 
     Mixers for mixing at least two flowable components in the form of so-called static mixers are described, for example, in EP-A 0 749 776 and EP-A 0 815 929. These very compact mixers provide good mixing results, in particular also on the mixing of high-viscosity materials such as sealing compounds, two-component foams or two-component adhesives, despite a simple, material-saving design of their mixer structure. Such static mixers are usually designed for single use and are frequently used for products to be hardened in which the mixer can practically no longer be cleaned. 
     The components to be mixed are usually supplied to those mixers by a multicomponent cartridge. For this purpose, the mixer is arranged at a cartridge outlet opening via which the components to be mixed can be dispensed from containers of the multicomponent cartridge. 
     In some applications in which such static mixers are used, it is desirable to spray the two components onto a substrate after their mixing in the mixer. For this purpose, the mixed components are atomized at the outlet of the mixer by the action of a pressurized medium such as compressed air and can then be applied to the desired substrate in the form of a spray jet or spray mist. In particular more highly viscous coating media, e.g. polyurethane, epoxy resins or similar, can also be processed using these technologies. 
     A spray mixer for such applications is disclosed, for example, in U.S. Pat. No. 6,951,310 or in EP 2 286 925 A2. In this apparatus, a tubular mixer housing is provided which extends in the direction of a longitudinal mixer axis from a mixer start up to a distal mixer end. The mixer housing receives a mixing element for a static mixing. A sleeve is arranged at the distal end of the mixer housing and compressed air can be supplied to it via a mixer inlet for compressed air oriented perpendicular to the longitudinal mixer axis. The named sleeve and the mixer housing form a mixer passage for compressed air which is terminated in the direction of the mixer start and has a ring-shaped mixer outlet for compressed air at the mixer end which surrounds a mixer outlet opening. Compressed air which flows via the mixer passage for compressed air to the mixer outlet for compressed air and which atomizes the material exiting the mixer outlet opening is supplied via the mixer inlet for compressed air in operation of the mixer. 
     The supply of compressed air to the mixer inlet for compressed air takes place via a hose which is not described in more detail and which is likewise oriented perpendicular to the longitudinal mixer axis due to the named orientation of the mixer inlet for compressed air. 
     Such spray mixers are used in systems for mixing and spraying flowable components which are in particular used for the application of coatings in the maintenance of ship hulls, pipelines and steel constructions such as bridges. It is also necessary in this respect to coat points with difficult access. It can occur in the coating of such points that hoses or lines of the coating system such as the above-described compressed air hose get caught at projections of the component to be coated. In this respect, on the one hand, the named hoses and lines may be damaged, which results in the failure of the coating system and thus in repair costs and delays in the maintenance work. On the other hand, an operator of the coating system has to work very carefully and thus also slowly at tight points, which can result in a high time effort, and thus also cost effort, in the use of the coating system. 
     A spray mixer is described in U.S. Pat. No. 6,131,823 which has a handle and an outer mixer housing in the form of a sleeve. The handle and the sleeve are manufactured from aluminum. In a first work step, a mixer which is made from plastic and which is composed of an inner mixer housing and a mixing element arranged therein can be placed onto the handle. In a second work step, the sleeve can be put over the mixer and can be screwed to the handle. A compressed air passage is formed between the sleeve and the inner mixer housing and compressed air can be conducted via said compressed air passage from the handle to an outlet. The mixer is in this respect only provided for a single use, with the sleeve being used a multiple of times. The handle has ports for the flowable components and for compressed air. 
     U.S. Pat. No. 4,255,125 describes an atomization apparatus for a combustible material having a feed inlet for the combustible material and a further feed inlet for an atomization gas. The combustible material and the atomization gas are combined in an atomization chamber within the atomization apparatus and are subsequently conducted through a mixing element in the form of curved elements. 
     SUMMARY 
     In view of this, it is the object of the invention to propose a spray mixer for mixing and spraying at least two flowable components which can be handled simply. 
     The spray mixer for mixing and spraying at least two flowable components has a tubular outer mixer housing which extends in the direction of a longitudinal mixer axis from a mixer start up to a distal mixer end. In addition, it has an inner mixer housing arranged inside the outer mixer housing, at least one mixing element which is arranged in the inner mixer housing for mixing the components and a mixer passage for compressed air which extends from a mixer compressed air inlet to a mixer outlet opening. 
     The mixer inlet for compressed air is arranged at the mixer start. The mixer passage for compressed air thus extends from the mixer start to the mixer end along the spray mixer. In operation of the spray mixer, the latter is usually arranged at a multicomponent cartridge and projects away from it. No compressed air feed to the mixer end and thus no hose to the mixer end is necessary due to the arrangement of the mixer inlet for compressed air at the mixer start. The spray mixer can thus also be introduced into tight intermediate spaces without there being any risk of a compressed air hose catching anywhere. 
     The compressed air supply to the mixer inlet for compressed air can take place perpendicular to the longitudinal mixer axis. It can, however, also be inclined with respect to the longitudinal mixer axis and can in particular take place in the direction of the longitudinal mixer axis. 
     An inner mixer housing which receives the mixing element is arranged within the outer mixer housing. The mixer passage for compressed air is formed between the inner mixer housing and the outer mixer housing. The outer mixer housing and the inner mixer housing are therefore designed so that an intermediate space is formed between the two in the assembled state which is used as a mixer passage for compressed air. A particularly simple design of the spray mixer thus results. 
     In accordance with the invention, the outer mixer housing, the inner mixer housing and the mixing element are combined in one structural unit. This is achieved in that the outer mixer housing, the inner mixer housing and the mixing element are connected to one another captively (i.e. in a non-losable manner). For this purpose, in particular the individual components are mutually fixed via a cooperation of corresponding cut-outs or grooves and noses or beads. Such fixing arrangements are also called clip connections or click connections. The total spray mixer in particular forms one structural unit which is marketed as a unit. The placing or connecting of the spray mixer onto or to a multicomponent cartridge is thus particularly simple, since the named parts do not first have to be put together, but the spray mixer can rather be used without any previous assembly. 
     In an embodiment of the invention, the spray mixer is provided to be connected to a multicomponent cartridge in one work step. This is to be understood such that, without a previous assembly of individual components, the spray mixer can be connected to the multicomponent cartridge. 
     In an embodiment of the invention, the spray mixer has a mixer inlet connector which is arranged at the mixer start and which can be connected to the cartridge outlet connector of a multicomponent cartridge. The mixer inlet connector has at least one mixer inlet opening via which the components can be supplied. It moreover includes the mixer inlet for compressed air. Both the connections for the components to be mixed and the connector for the compressed air can thus be established via the one mixer inlet connector, which allows a particularly simple handling of the spray mixer since only one work step is necessary for connecting the spray mixer to the multicomponent cartridge. 
     The spray mixer can in this respect in particular be directly connected to the cartridge outlet connector of the multicomponent cartridge. It is, however, also possible that the connection takes place by means of a suitable connection element, for example in the form of suitable hoses. 
     The mixer inlet connector is in particular oriented in the direction of the longitudinal mixer axis. It is to be understood by this that the components and the compressed air flow in the direction of the longitudinal mixer axis through the mixer inlet connector. A particularly compact design of the spray mixer is thus achieved. 
     A particularly configured multicomponent cartridge is required for this embodiment of the spray mixer in accordance with the invention which has a cartridge passage for compressed air having a cartridge inlet for compressed air and a cartridge outlet for compressed air. A separate compressed air hose is thus no longer at all necessary for the compressed air supply of the spray mixer, which allows a particularly simple and reliable handling of the spray mixer. 
     The mixer inlet connector in particular has two separate mixer inlet openings, that is one separate mixer inlet opening for each component. A particularly effective mixing of the two components is thus made possible. If more than two components are to be mixed and sprayed using the spray mixer, the mixer inlet connector in particular has a separate mixer inlet opening for each component. 
     The mixing element is in particular designed as a static mixing element. In contrast to a dynamic mixer which has a rotating mixing element for mixing the components, a static mixer has a fixed-position mixing element which allows an efficient mixing of the components due to its special geometry. This allows a particularly inexpensive design of the spray mixer. 
     In an embodiment of the invention, the mixing element and the mixer inlet connector are designed in one piece. The spray mixer thus has particularly few individual parts, which makes its manufacture and its assembly particularly simple and inexpensive. 
     It is, however, possible that the mixing element and the mixer inlet connector are made as two separate components. 
     In an embodiment of the invention, the outer mixer housing, the inner mixer housing and the mixing element are made of plastic. The spray mixer thus has a particularly low weight and can also be manufactured inexpensively. The components can be composed of, for example, polypropylene, polyamide, polycaprolactam (polyamide 6) or polybutylene terepththalate). Other suitable plastics are, however, also possible. 
     The manufacture of the outer mixer housing, of the inner mixer housing and of the mixing element in particular takes place by means of an injection molding process. The components can thus be manufactured simply in very large volumes and particularly inexpensively. 
     Further advantages, features and details of the invention result with reference to the following description of embodiments and with reference to drawings in which elements which are the same or have the same function are provided with identical reference numerals. 
     There are shown: 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  a multicomponent cartridge for receiving a multicomponent cartridge for receiving flowable components with a spray mixer plugged on; 
         FIG. 2  a spray mixer connected to a multicomponent cartridge; 
         FIG. 3  a dispensing device for a multicomponent cartridge of  FIG. 1 ; and 
         FIG. 4  a spray mixer in a second embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In accordance with  FIG. 1 , a multicomponent cartridge  10  has a first container  11  for receiving a first component and a second container  12  for receiving a second component. The first and second containers  11 ,  12  have a cylindrical base shape having a first cylinder axis  13  and a second cylinder axis  14 . The two containers  11 ,  12  are arranged paraxially next to one another. The containers  11 ,  12  are connected to one another and have a minimal spacing from one another. A notch  15  thus results between the two containers which extends in parallel to the two cylinder axes  13 ,  14 . The multicomponent cartridge  10  is thus designed as a so-called side-by-side cartridge. The containers  11 ,  12  of the multicomponent cartridge  10  have the same diameter. A mixing ratio of the components on the dispensing from the containers  11 ,  12  thus amounts to 1:1. Other diameters, and thus mixing ratios, are also possible however, such as 1:2, 1:4, 1:10 or higher. 
     At en end face of the containers  11 ,  12  they each have a filling opening  16 ,  17  which extends over the total end face of the containers  11 ,  12 . The containers  11 ,  12  can be filled with a corresponding flowable component via the filling openings  16 ,  17 . The filling openings  16 ,  17  are closed by a respective piston  18 ,  19  in the representation of  FIG. 1 . The pistons  18 ,  19  are inserted after the filling of the containers  11 ,  12 . The components can be dispensed by displacing the pistons  18 ,  19  away from the filling openings  16 ,  17  via two cartridge outlet openings which are arranged at a side of the multicomponent cartridge  10  disposed opposite the filling openings  16 ,  17 . The cartridge outlet openings cannot be seen in the representation of  FIG. 1 . 
     A cartridge passage for compressed air  20  runs in the notch  15  between the two containers  11 ,  12 . The cartridge passage for compressed air  20  has a circular cross-section and extends from a cartridge inlet for compressed air  21  to a cartridge outlet for compressed air not shown in  FIG. 1 . The cartridge inlet for compressed air  21  is arranged in a plane with the filling openings  16 ,  17  of the containers  11 ,  12 . The cartridge outlet for compressed air is located in the area of the cartridge outlet openings. The cartridge passage for compressed air  20  thus extends over the total length of the containers  11 ,  12  and thus also of the multicomponent cartridge  10 . 
     The first container  11 , the second container  12  and the passage for compressed air  20  are made in one piece. In addition, no separate component are likewise required for the cartridge outlet openings, not shown, and the cartridge outlet for compressed air so that the total multicomponent cartridge  10  is thus made in one piece. The multicomponent cartridge  10  is manufactured from plastic by means of an injection molding process. Polypropylene, polyamide, polycaprolactam (polyamide 6) or polybutylene terepththalate can be used for this purpose. 
     A spray mixer  22  is arranged on the side of the multicomponent cartridge  10  disposed opposite the filling openings  16 ,  17 . The spray mixer  22  is connected via a cartridge outlet connector, not shown in  FIG. 1 , to the multicomponent cartridge  10  such that connections arise to the cartridge outlet openings and to the cartridge outlet for compressed air. The components dispensed from the containers  11 ,  12  are mixed by the spray mixer  22  and are atomized and sprayed by means of the compressed air supplied via the cartridge passage for compressed air  20 . The design of the spray mixer  22  is shown more precisely in  FIG. 2 . 
     The spray mixer  22  for mixing and spraying at least two flowable components is shown in a sectional representation in  FIG. 2 . The section runs in parallel to the cylinder axes  13 ,  14  between the two containers  11 ,  12  with respect to  FIG. 1 . A small part of the multicomponent cartridge  10  is moreover shown in  FIG. 2 . A part of the container  11  of the multicomponent cartridge  10  which lies behind the section plane is shown dotted for better understanding. 
     The spray mixer  22  has a mainly tubular outer mixer housing  23  which extends in the direction of a longitudinal mixer axis  24  from a mixer start  25  up to a distal mixer end  26 . The spray mixer  22  is connected to the multicomponent cartridge  10  at the mixer start  25 . 
     The outer mixer housing  23  has a constant cross-section in a middle region and tapers a little toward the mixer end  26 . The outer mixer housing  23  widens toward the mixer start at the opposite side and forms a part of a mixer inlet connector  27  by means of which the spray mixer  22  is connected to a cartridge outlet connector  28  of the multicomponent cartridge  10 . 
     An inner mixer housing  29  is arranged within the outer mixer housing  23  and has an outer contour corresponding to the contour of the outer mixer housing  23  so that a ring-shaped hollow space which serves as a mixer passage for compressed air  30  results between the outer mixer housing  23  and the inner mixer housing  29 . Compressed air can be supplied to the mixer passage for compressed air  30  via a mixer inlet for compressed air  31  which likewise forms a part of the mixer inlet connector  27 . The mixer inlet for compressed air  31  is thus arranged at the mixer start  25 . The compressed air is conducted via the mixer passage for compressed air  30  to a mixer outlet for compressed air  32  which is located at the mixer end  26 . 
     A static mixing element  33  which serves for mixing the two components is arranged within the inner mixer housing  29 . The mixing element  33  is made in one piece with a mixer inlet opening  34  via which a first component can be supplied to the spray mixer  22 . The mixing element  33  has a second mixer inlet opening via which a second component can be supplied. It is, however, not in the sectional plane shown so that this second mixer inlet opening is not shown in  FIG. 2 . The mixer inlet opening  34  has a circular cross-section and likewise forms a part of the mixer inlet connector  27 . 
     The two mixer inlet openings are connected to corresponding cartridge outlet openings, with only one cartridge outlet opening  36  being visible in  FIG. 2  which is connected to the mixer inlet opening  34 . The cartridge outlet opening  36  is part of the cartridge outlet connector  28 . 
     At the mixer end  26 , the inner mixer housing  29  has a mixer outlet opening  35  via which the components mixed by the mixing element  33  can exit the inner mixer housing  29 . The mixer outlet for compressed air  32  is arranged around the mixer outlet opening  35 . The mixed components exiting the mixer outlet opening  35  are thus atomized and sprayed. In addition, grooves or similar can also be arranged in the region of the mixer outlet opening  35  and of the mixer outlet for compressed air  32  which provide a swirling of the compressed air and thus an effective atomization of the mixed components. 
     The mixer inlet for compressed air  31  is connected to a cartridge outlet for compressed air  37  of the multicomponent cartridge  10  which provides the cartridge passage for compressed air  20  with compressed air. The cartridge passage for compressed air  20  kinks in the direction of the longitudinal mixer axis  24  for this purpose. The mixer inlet for compressed air  31  and the cartridge outlet for compressed air  37  have a ring-shaped cross-section and are arranged around the mixer inlet openings  34  and the cartridge outlet openings  36 . The mixer inlet for compressed air  31  is in this respect a part of the mixer inlet connector  27  and the cartridge outlet for compressed air  37  is a part of the cartridge outlet connector  28 . 
     The components and the compressed air flow from the cartridge outlet connector  28  to the mixer inlet connector  27  along the longitudinal mixer axis  24 . They are thus oriented in the direction of the longitudinal mixer axis  24 . 
     The connection between the mixer inlet connector  27  and the cartridge outlet connector  28  is secured by a retainer nut  38  which is arranged around the mixer inlet for compressed air  31  and the cartridge outlet for compressed air  37 . Other securing means are also possible instead of the retainer nut, such as a bayonet closure, for example. 
     The outer mixer housing  23 , the inner mixer housing  29  and the mixing element  33  are connected to one another via click connections known per se and are thus combined in one structural element, with the click connection not being shown in any detail. Furthermore, the mixer inlet connector  27  and the retainer nut  38  are captively connected to the other components so that the total spray mixer  22  forms one structural unit. 
     For the connection of the spray mixer  22  to the multicomponent cartridge  10 , the spray mixer  22  is placed onto the multicomponent cartridge  10  and the connection is subsequently secured using the retainer nut  38 . The placing on and securing is in this respect considered as one work step. 
     The individual components of the spray mixer  22  are manufactured from plastic by means of an injection molding process. Polypropylene, polyamide, polycaprolactam (polyamide 6) or polybutylene terepththalate can likewise be used for this purpose, for example. 
     The multicomponent cartridge  10  is inserted into a dispensing device to dispense the components out of the containers  11 ,  12  of the multicomponent cartridge  10 . A dispensing device  40  is shown in schematic form in a sectional representation in  FIG. 3 . The dispensing device  40  has a receiver element  41  for receiving a multicomponent cartridge. The receiver element  41  has a rectangular cross-section. A multicomponent cartridge can be inserted from above into the receiver element  41  via an opening, not shown, of the receiver element  41 . The receiver element  41  has an opening  43  at a front side  42  of the dispensing device  40  which is positioned so that the cartridge outlet connector of the multicomponent cartridge can project through the opening  43 . 
     The dispensing device  40  has a first actuation element  44  and a second actuation element  45 . The first actuation element  44  is arranged so that it can displace the piston of the first container and thus actuate it with an inserted multicomponent cartridge. The second actuation element  45  is arranged so that it can displace the piston of the second container and thus actuate it with an inserted multicomponent cartridge. The two actuation elements  44 ,  45  each have an actuation rod  46 ,  47  which can be displaced in the direction of the opening  43  by means of compressed air. 
     The dispensing device  40  has a device outlet for compressed air  48  between the two actuation rods  46 ,  47 , but arranged in a different plane. Since the device outlet for compressed air  48  is arranged in a different plane, it is shown by dashed lines in  FIG. 3 . The device outlet for compressed air  48  is arranged so that it is connected to the cartridge inlet for compressed air with an inserted multicomponent cartridge. The device outlet for compressed air  48  is connected to a device inlet for compressed air  50  by means of a device passage for compressed air  49 . The dispensing device  40  can be connected to a customary compressed air supply via the device inlet for compressed air  50 . 
     The device inlet for compressed air  50  is arranged at a device handle  51  which is connected to the receiver element  41 . The device handle  51  serves to allow an operator to securely hold the dispensing device  40 . In addition, an activation button  52  is arranged at the dispensing device  51  by means of which the operator can trigger the dispensing, mixing and spraying of the components. 
     An alternative embodiment of a spray mixer is shown in  FIG. 4 . The spray mixer  122  in accordance with  FIG. 4  has a similar design to the spray mixer  22  of  FIG. 2 . For this reason, only the differences of the two spray mixers will be looked at. 
     In contrast to the spray mixer  22  of  FIG. 2 , the spray mixer  122  of  FIG. 4  does not have any ring-shaped mixer inlet for compressed air which is oriented in the direction of a longitudinal mixer axis  124 . Instead, the spray mixer  122  has a mixer inlet for compressed air  131  which is arranged at a mixer start  125  and is oriented perpendicular to the longitudinal mixer axis  124 . The mixer inlet for compressed air  131  likewise opens into a mixer passage for compressed air  130 . The spray mixer  122  can be connected to a customary compressed air supply via the mixer inlet for compressed air  131 . 
     A multicomponent cartridge to which the spray mixer  122  of  FIG. 4  can be connected thus does not have any cartridge outlet for compressed air, but rather only one or two cartridge outlet openings for the components.