Patent Application
20140060764
1. Field of the Invention
The present invention relates to a device and a method for drying a fibrous web.
2. Description of the Related Art
Generic drying devices which operate according to the impingement principle with hot air are already known in the state of the art in various arrangements in the embodiment of horizontal-air drying devices. In these devices the fibrous web which is to be dried is guided through the drying device through drying spaces which are arranged horizontally aligned and arranged in a vertical direction on top of one another. The fibrous web runs through the individual drying spaces consecutively horizontally from the infeed side of the drying device to the outfeed side, whereby the redirection of the fibrous web occurs through reversal between two drying spaces which are arranged above one another, with the assistance of turn rollers which are arranged on the infeed side and the outfeed side. The drying spaces are hereby defined by blower devices which are arranged on both sides of and at a distance from the theoretical web guidance path of the fibrous web. The fibrous web is treated on both sides with hot air in the drying spaces. The hot air supplied for this purpose by the blower devices serves as a heat transfer to the fibrous web. Due to the long web guidance path segments in the horizontal direction in such drying devices, it is necessary—in order to avoid excessive stress in the gravitational direction between the turn rollers which are arranged on both sides of a drying space—to support the fibrous web in this region by means of an air cushion. Stable operating conditions for the horizontal pass through the drying spaces can hereby only be ensured through low flow speeds of the drying medium which is to be applied, through special geometries of the discharge openings, in particular in the blower devices arranged below and acting upon the fibrous web, as well as through different distances between the discharge openings of the blower devices arranged above and below an individual web guidance path segment, or respectively the fibrous web. Since the blower device arranged below a web guidance path segment serves to form the necessary air cushion, the design, in particular the geometry, of the discharge openings of the blower device, their configuration and operational parameters, as well as the operational parameters and state variables of the drying medium, are to be adapted to this function. The layout, the design and the operating parameters of the blower device above the web guidance path segment acting on the other side of the fibrous web is to be selected so that this does not affect the formation of the air cushion. The possibility of a purposeful profiling of the drying medium to be applied onto the fibrous web side facing in the gravitational direction is not possible under these conditions. The greater distance of the blower devices disposed above a web guidance path segment impairs the heat exchange.
Due to the additionally required support for the fibrous web over each individual web guidance path segment a control of the drying rate over an individual web guidance path segment is not possible. Because of the multi-function of the drying medium which is applied to the fibrous web, only low drying rates are achievable.
An additional disadvantage with horizontal web guidance is that in the event of a web break, the web can only be removed from the drying spaces with difficulty and at great expense. Special devices are hereby required to avoid contamination of the individual blower devices as well as for their protection, for example in the form of grating.
Another drying device operating according to the impingement principle with hot air and with vertical fibrous web guidance which is arranged downstream of a pulp press is known from publication DE 699 09 999 T2. In this case however, a pulp having a very low dry content is guided through the drying device, continuously supported on a fabric belt.
What is needed in the art is a more effective and efficient method for drying a fibrous web and an associated drying device so that the aforementioned disadvantages are avoided. In particular, a drying device is needed in the art which is characterized by simple fibrous web guidance and at the same time easily realizable active control/adjustment of the drying rate along the web path, as well as a high drying rate in a small space. The individual drying spaces should be easily accessible and the fibrous web should be easily removable from them in the event of a web break. The engineering effort should be kept low.
The present invention provides a device and a method for drying a fibrous web which allows for control/adjustment of the drying rate along the web path and easy removal from individual drying spaces in the event of a web break. According to the present invention, the fibrous web is guided in an open draw with multiple redirection through the drying device, through a plurality of drying spaces which are arranged parallel to each other and represent web guiding path sections. The web is treated on both sides with a drying medium, for example hot air for heat transfer. More specifically, the present invention provides a method for drying a fibrous web in a drying device wherein the fibrous web is guided in an open draw without being supported by clothing, with multiple redirection through the drying device through a plurality of drying spaces which are arranged parallel to each other and represent web guiding path sections. The web is treated on both sides with a drying medium, for example hot air for heat transfer. The fibrous web is guided through the drying device alternately in a vertical direction and opposite to the direction of gravity, and vice versa. Guidance of the fibrous web through the drying device occurs therefore alternately unsupported by clothing from the bottom up and from the top down, or vice versa.
The fibrous web is guided over guiding devices, such as turn rollers, for example through a plurality of drying spaces arranged parallel to each other and extending in a width direction of the drying device and in a vertical direction, and at the transition between two adjacent drying spaces. The individual drying space is hereby defined by blower devices arranged on both sides of the web guidance path and each representing one blower unit.
The vertical direction is consistent with the direction extending substantially perpendicular to a horizontal reference plane. Substantially in the vertical direction means that also deviations, that is variances in the range of approximately ±20° of the web path from the vertical direction are still possible and are included in this term. The horizontal reference plane may, for example, be described by a floor, machine floor or a base.
A web guidance path segment is to be understood to be the web path segment theoretically characterized by the guidance of the fibrous web. The individual vertically aligned web guidance path segment intended for guidance of the fibrous web is defined by the arrangement of the individual turn rollers which are allocated to the respective drying space for transferring into/transferring out of the respective adjacent drying space.
The vertical guidance of the fibrous web offers the advantage that the fibrous web, in the event of a breakdown or web break, can be removed from the individual drying space quickly and at the lowest possible expense, in particular since it can continue to run in the direction of gravity in catch- and/or processing devices located below the individual drying spaces.
Due to the multiple returns, very long web guidance paths are realizable in the drying device. The individual web guidance path segments extending in the vertical direction can be realized by utilizing the overall height that is theoretically available for the drying device, thereby being able to provide high drying efficiencies in a machine direction, in other words viewed in a longitudinal direction of the drying device within a minimal construction space.
The solution according to the present invention moreover offers the advantage of a simple and targeted treatment of the fibrous web with drying medium, since this is no longer required for stabilizing the fibrous web when guiding it through the drying device, but has only to assume the task of the heat transfer.
By eliminating the dual function of the drying medium, the individual blower devices can be arranged at small distances from the web guidance path segment and thereby from the fibrous web, thereby improving efficiency. Higher flow velocities and thereby higher drying rates are possible.
The dry content of the fibrous web at the infeed to the drying device is thereby at least approximately 45%, for example 50%.
In accordance with one arrangement of the device according to the present invention, the individual sides of the fibrous web, at least in a region of a web guidance path segment inside an individual drying space are treated equally with drying medium. This means that the fibrous web in this web guidance path segment is treated equally on both fibrous web sides. The individual operating parameters of the blower devices which are arranged on both sides of the fibrous web and state variables of the drying medium emerging from the blower devices are equal in this region. This improves the uniformity of the fibrous web.
In order to influence the dry profile of the fibrous web, the individual fibrous web sides, at least in one region of a web guidance path segment inside an individual drying space, can also be treated differently with drying medium. This option allows possibly for example upstream one-sided or different two-sided treatment of the fibrous web prior to running into the drying device.
In accordance with one embodiment of the present invention, treatment of one fibrous web side can be profiled in an individual drying space in a width direction of the drying device and/or over the entire extension of the drying space in a vertical direction, and can be controlled and/or regulated incrementally or infinitely, for example in one or in a plurality of zones. The advantage exists in the possible profiling of the drying efficiency and thereby the drying rate in the different directions of the fibrous web and thereby in the ability to influence the characteristics of the fibrous web which are subject to drying. This allows uniform drying over the entire fibrous web width while avoiding excessive drying of the edge regions. Moreover, changing edge conditions can be can be locally targeted in a timely fashion. The present invention, by its configuration, permits optimization of the drying process in all regions of an individual web guidance path segment.
A uniform treatment of a fibrous web side in an individual drying space in the width direction and over the entire extension of the drying space in the vertical direction is also conceivable.
Profiling occurs depending on at least one of the following parameters defining the operational mode and/or geometry of an individual blower device and/or state variable of the drying medium and/or parameters of the fibrous web:
In order to avoid fibrous web breaks an additional arrangement of the present invention provides that a plurality of drying spaces which are arranged parallel to each other and extend in a cross direction and a vertical direction of the drying device, the turn rollers coupling them and thereby the web guidance path segments defined by them are combined into a group. Several groups, however at least two, may be provided in a drying device. The individual groups are arranged and formed such that the extension of the web guidance path segments progressing through the individual drying spaces viewed in the vertical direction from an infeed into the drying device to the outfeed from the drying device increases in size from group to group. In consideration of the formation and the operating parameters of the drying device, the group having the maximum extension is arranged such that it is reached only when a predetermined minimum dry-content of the fibrous web is achieved. This is the dry content which is necessary to be able to let the fibrous web hang freely over the maximum span of the web guidance path, without it tearing. The dry content of the fibrous web in the region of the infeed into the drying device is, for example between 45% and 50%, and on the outfeed side approximately 90%, whereby at least one drying curve is provided between the two.
An additional arrangement of the present invention provides that always a plurality of drying spaces which are arranged parallel to each other and extend in the cross direction and the vertical direction of the drying device, and the turn rollers coupling them are combined into a group, whereby the individual groups are arranged and formed such that the speed of the fibrous web in the individual groups can be controlled separately. This offers the advantage of an individual adjustment of the tension of the fibrous web and thereby the stress upon it.
Advantageously the supply of the individual blower devices occurs through a drying medium supply system which is allocated to at least one individual blower device and can be connected with same. According to a further embodiment of the present invention, the moist drying medium which is present after the drying process in the individual drying space is processed and is again supplied as drying medium via the blower devices to the drying space. For this purpose, the drying medium which is to be supplied to a drying space and the drying medium enriched with moisture from the drying space is led between two adjacent blower devices of one or different blower units in a loop with optional in-line warming—or for example, heating devices. This is realized through recirculating blowers which are arranged on both sides of a blower unit and which are connected with the suction side with the dryer space and with the pressure side with a blower device. Separate suction devices in the region of the individual drying space can thereby be eliminated.
In order to improve access to the drying spaces for the purpose of maintenance and cleaning, the width of the individual drying space is variably adjustable in the machine direction. In the event of a web break the fibrous web can thereby be quickly and securely guided into catch—and processing devices which are arranged below the drying device.
In order to ensure a safe web removal in the event of a web break or other malfunction, the fibrous web is severed consecutively or simultaneously between the individual web guidance path segments in the individual drying spaces. The separation occurs, for example in the return region between to drying spaces which are arranged following each other in the direction of web travel.
According to the present invention, the drying device for drying a fibrous web, including blower devices arranged on both sides of the theoretical web guidance path for the application of drying medium onto the fibrous web which is guided in the drying space formed by them further provides the individual blower devices are arranged extending in the cross direction of the drying device and extending in the vertical direction. The drying spaces progressing in the vertical direction are limited. A plurality of drying spaces progressing in the vertical direction are arranged adjacent to each other to accommodate web guidance path segments in the machine direction and above and below an individual drying space, turn rollers are provided for transferring the fibrous web between two adjacent drying spaces. Two turn rollers allocated to a drying space for connection with the adjacent drying space define web guidance path segments. The drying device is free of a fibrous web supporting clothing.
The repeated reversal allows very long web guidance paths inside the drying device. The thereby formed individual web guidance path extending in the vertical direction can be realized by utilizing the overall height that is theoretically available for the drying device, thereby realizing the high efficiencies in the machine direction, in other words viewed in the longitudinal direction of the drying device within a minimal construction space. Apart from the redirection, the fibrous web is guided essentially only in the vertical direction and is stabilized through gravitational force. This allows for a targeted local and timely treatment of the fibrous web with drying medium, since this is its main function and only needs to serve to heat the fibrous web and is not required for formation of stabilizing air cushions. By eliminating the dual function of the drying medium, the individual blower devices can be arranged at small distances from the web guidance path segment and thereby from the fibrous web, thereby improving efficiency.
In accordance with one embodiment of the present invention the individual blower devices which are always arranged on both sides of an individual web guidance path segment represent one blower unit. The individual blower device can be arranged to be subdivided into blower zones in the cross direction and/or in the vertical direction of the drying device, whereby a device or controller for individual and/or joint control of the individual zones is provided.
The individual blower device includes, for example, a plurality of blow boxes arranged in the vertical direction in blower towers which are arranged extending in the cross direction of the drying device and which are supported on a frame.
A drying medium supply system is allocated to the individual blower device alone or to several together which, in the simplest case, includes a drying medium supply unit coupled with the blower device. In one arrangement according to the present invention, viewed in the cross direction of the drying device, recirculating blowers are arranged on both sides of the individual blower unit, whose suction sides are connected with the drying space and pressure sides with a blower device of the blower unit, forming a circulation system, whereby upstream from the connection of the pressure side with the blower device a heating device for heating of the drying medium which is to be brought into the blower device can be located. In a further development, the recirculating blowers allocated to a blower device are advantageously arranged in the vertical direction one above the other and supported in a blower tower. This can be constructed separately or as a component of the frame. The blower tower can be constructed so that it can be moved away from the drying device.
In an additional embodiment of the present invention, the drying medium supply system includes at least one fresh air supply and at least one exhaust air removal which can be connected with one and/or a plurality of loops. Fresh air supply and exhaust air removal have no fluidic connection with each other, but can however be optionally coupled thermally in an advantageous manner, for example through a heat exchanger. The heat of the exhaust air can thereby be purposefully and effectively used for heating the supply air to the blower devices.
To ensure a secure operation, a plurality of drying spaces arranged parallel to each other and extending in the cross direction and in the vertical direction of the drying device and the turn rollers connecting them with each other form a group. At least two groups are provided inside the drying device. The individual groups are arranged and formed such that the extension of the web guidance path segments progressing through the individual drying spaces viewed in the vertical direction from an infeed into the drying device to the outfeed from the drying device increases in size from group to group.
In an alternative or additional embodiment of the present invention, a device or controller for controlling the speed of the fibrous web, for example the rotational speed of the turn rollers is allocated to at least one individual group for adjusting the web tension.
To improve removal of fibrous web residues after a web break and for the purpose of cleaning, an apparatus or device for adjusting the width of at least one single drying space in the machine direction is provided. This device can include a mechanism for sliding and/or pivoting or a combination of both movements of the blower device. In one arrangement of the present invention, the device includes rotatable mounting units for two adjacently located blower devices of different blower units. The individual mounting unit includes a rocker arm rotatably mounted on the frame of the drying device on opposite ends of which the blower devices are flexibly hinged. Pivoting occurs through engagement of an adjusting device on a force application surface on the rocker arm. In accordance with one embodiment of the present invention, the activation of a plurality of mounting units can occur forcibly coupled.
In a further embodiment of the present invention, at least one knock-off device is provided which—in the event of malfunctions—severs the fibrous web in the region between two drying spaces, as a result of which the remainder of the fibrous web falls in the direction of gravity. If several knock-off devices are provided, these can become effective simultaneously or consecutively between two drying spaces.
The arrangement of the effective region of individual knock-off devices can occur according to one of the following options:
The individual knock-off device can be configured or arranged so that its effective region is such that it extends at least over a section of the drying device in the cross machine direction or is movable, whereby this section can be constantly predetermined or adjustable. In this case, the fibrous web is only partially severed, whereby the remaining fibrous web due to the weight of it tears in the gravitational direction.
In one embodiment of the present invention, the individual knock-off device is configured or can be arranged so that its effective region is such that it extends at least over the extension of the fibrous web in the cross machine direction, for example the extension of the drying device in the cross machine direction.
Regarding the configuration and mounting of the individual knock-off device, there are a multitude of options. The individual knock-off device includes at least one knock-off element which is mounted on a stationary or movable support. In the latter instance, the support can be movable, for example sliding in the vertical direction and/or the machine direction and/or the cross machine direction. Moreover, in addition or alternatively to the aforementioned option, the support can be pivoted. Mounting on the support depends on the selection of the type of knock-off element and the form of the movability of the support. In the case of a movable support, the knock-off element may also be mounted stationary on it.
On a stationary or movable support the individual knock-off element can be mounted on it movably in the cross machine direction, and in contrast to this possibly also pivoted.
The inventive solution is suitable, for example for drying of fibrous webs consisting of cellulose fibers.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
Referring now to the drawings, and more particularly to
According to the present invention, drying device 1 is a vertical drying device according to the impingement principle. Fibrous web F is guided through drying device 1 in an open web draw and with several redirections, in other words repeated directional changes, between an infeed 4 into drying device 1 and an outfeed 5 from drying device 1, essentially only in the vertical direction. Deviations of +20° from the vertical direction are possible. Drying device 1 is in the embodiment of a blower device, or respectively air drying device. Along its web guidance path, fibrous web F is treated on both sides with drying medium, for example with hot air. In contrast to the horizontal air drying devices known from the current state of the art, the hot air acting upon fibrous web F in the inventive solution, serves primarily only to transfer heat to fibrous web F and due to the vertical guidance of fibrous web F is not necessary for stabilization of the guidance of fibrous web F.
The application of the drying medium occurs by blower devices 2.na and 2.nb with n≧1 which are arranged on both sides of fibrous web F along the web guidance path, at a distance to same and thereby effective on different fibrous web sides. Blower devices 2.na and 2.nb which are arranged on both sides of fibrous web F along a web guidance path segment form a blower unit 2.n with n≧1. The individual blower devices 2.na and 2.nb, in this case 2.1a to 2.na and 2.1b to 2.nb are arranged in such a way that the blower devices 2.na, 2.nb of always one blower unit 2.n limit a drying space 3.n progressing in the vertical direction, with n≧1. Viewed in machine direction MD, blower units 2.1 to 2.n with blower devices 2.1 to 2.na and 2.1b to 2.nb limit here a plurality of drying spaces 3.1 to 3.n progressing in the vertical direction. These are arranged parallel to each other in machine direction MD and adjacent to each other. Guidance of fibrous web F occurs herein in the vertical direction—in other words from top to bottom or vice versa. Drying spaces 3.1 to 3.n accommodate hereby the vertically progressing web guidance path segments. The web guidance between two adjacent drying spaces 3.n-1 and 3.n occurs through turn rollers 6, 7.
The web guidance path of fibrous web F thereby includes a plurality of web guidance path segments, arranged parallel to each other and progressing in the vertical direction which are coupled together via turn rollers 6 and 7 and are arranged inside drying spaces 3.n.
Referring now to
Moreover, treatment of fibrous web F with drying medium can be adjusted as a function of the state variable of the drying medium (temperature, pressure),—discharge speed and/or volume flow of drying medium from the blower device and/or the values characterizing at least indirectly the operational mode of drying device 1, for example traveling speed of fibrous web F.
For adjustment, for example control and/or regulating, a control device 8 is provided. Depending on predefined set points for the drying efficiency that is to be achieved or values characterizing same at least indirectly, individual blower devices 2.1a, 2.1b to 2.na, 2.nb are controlled. This is clarified in an example through coupling of the outputs of controller 8 with the control devices of blower devices 2.1a, 2.1b by issuing the hereby necessary manipulated variables Y2.1a and Y2.1b for blower devices 2.1a, 2.1b.
In contrast to
Moreover there is the possibility alternatively or in addition of profiling of the drying medium over a desired application region on fibrous web F. Such possibilities are shown in
In a section from a view onto blower device 2.1a in the CD/z-plane,
The size of the zone can be constant or can vary in cross machine direction CD and/or in vertical direction.
In all embodiments of the present invention, the treatment of fibrous web F with drying medium can occur selectively, linearly or over an area. An area treatment covering the entirety of the fibrous web is strived for. The drying medium can hereby be applied by blower device 2.1a through a plurality of individual nozzles 9.1 to 9.n having a round cross section as shown in
A further development of the present invention provides that inside individual drying spaces 3.1 and 3.n, grating is to be provided on the blower devices in front of the outlet openings for the drying medium to protect them from contamination from fibrous web F in the event of a web break.
Referring now to
It can be seen that fibrous web F is not immediately guided in the vertical direction through drying device 1 utilizing the maximum possible height of same. The web guidance path segments following infeed region 4 are characterized by a smaller extension in the vertical direction and thereby height than the following web guidance path segments. This is recognized on the different vertical offset of turn rollers 6 and 7 which characterize a web guidance segment and which are arranged above and below the individual drying space. Upper turn rollers 6 are thereby arranged in the vertical direction at one level and at a distance from each other in machine direction MD, whereas lower turn rollers 7 are arranged at different height levels.
A plurality of drying spaces which are arranged parallel to each other and extend in cross machine direction CD and in the vertical direction, and associated turn rollers 6, 7 and the thereby defined web guidance path segments are combined into groups, in this case I to VI. Inside individual groups I to VI the drying spaces or individual web guidance path segments are, for example, arranged with constant extension in the vertical direction. The height of the individual drying spaces or respectively the extension of the web guidance path segments progressing through them increases from group to group. Fibrous web F is thereby guided over the maximum extension of drying device 1 in the vertical direction in group V only from the time when fibrous web F reaches a predefined dry content. The entire available space, originating from floor 11 is thereby, for example used.
Infeed 4 into drying device 1 can be implemented through an automatic transfer system, for example through a rope transfer.
In the region of outfeed 5 from drying device 1a cooling region 26 may be provided. Here, fibrous web F is treated only with ambient air which is, for example, supplied via non-illustrated centrifugal blowers to the also non-illustrated blower devices which are arranged along the respective web guidance path segment on both sides of fibrous web F. Cooling region 26 includes here group VI.
To supply individual blower devices 2.1a to 2.na, 2.nb with the necessary hot air, drying medium supply system 12 is provided. This includes blowers which supply blower devices 2.1a, 2.1b to 2.na, 2.nb with the required drying medium at the required process parameters. These are functionally coupled with the associated blower devices.
In order to ensure smooth operation it is moreover necessary to also remove the moist air from individual drying spaces 3.1 to 3.n. Blowers are also used for this. Recirculation blowers may be used which, in addition to removal of the moist drying medium, for example moist air, also serve to blow in heated drying medium, such as air as the drying medium.
The supply of fresh air through drying medium supply system 12 is illustrated in a schematically simplified depiction with a view onto CD/Z plane of drying device 1 in
For this purpose they are equipped with at least one supply opening in the lower region, for example on the floor of the first level, and with at least one discharge opening in the vertical direction in the upper region, for example an upper corner or a side wall of the upper level of blower tower 27. Exhaust air removal 28 and fresh air supply 29 are however coupled energetically, for example thermally in order to utilize the heat contained in the exhaust air AL to preheat supply air ZL. The coupling occurs, for example, through at least one heat exchanger 30 which can be in different embodiments and through which the two mediums are guided in parallel flow or counter flow. In the simplest case, exhaust air AL is guided around a wall section in the path for supply air ZL.
Constructively, individual turn rollers 6, 7 and blower devices 2.1a, 2.1b to 2.na, 2.nb of individual blower units 2.1 to 2.n and/or recirculating blowers 13 and heating devices 14 or respectively blower towers 27 respectively are supported on frame 15, an example of which is illustrated in
In this case, individual blower tower 27 consists of these and frame components of frame 15. The support structure for recirculating blower 13 and heating device 14 is however, for example, provided by a separate frame component 31, as illustrated in
The configuration of mounting unit 20 is shown exemplary in detail in
In contrast to the configuration in
According to the embodiment of the present invention shown in
According to an advantageous further development grating 35.1a-35.nb is provided inside individual drying spaces 3.1 and 3.n. In the example these are shown in
Referring now to
The knock-off elements, for example knock-off blades 34.1, 34.2 are for example mounted on support 33.1, 33.2 which extends for example in cross machine direction CD and are movable in this direction at least over a partial section of the support. Moreover, the mounting may be movable relative to support 33.1, 33.2 perpendicular to the direction of extension in the cross machine direction, or pivoted.
An alternative arrangement which is not illustrated here consists in the appropriate movability of support 33.1, 33.2 in the cross machine direction.
Severing of fibrous web F occurs in the upper region of the drying device, in particular in the region of upper turn rollers 6. In
While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2011 006 698.5 | Apr 2011 | DE | national |
This is a continuation of PCT application No. PCT/EP2012/055483, entitled “METHOD FOR DRYING A FIBROUS WEB IN A DRYING DEVICE, AND DRYING DEVICE”, filed Mar. 28, 2012, which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2012/055483 | Mar 2012 | US |
| Child | 14046105 | US |
