DE102006018760A1 - Method for the production of atomized spray from an application medium for application on a moving paper, cardboard or other fiber web, comprises atomization with an atomizing medium in a pneumatic atomizing nozzle - Google Patents

Abstract

The method for the production of atomized spray from an application medium for application on a moving paper, cardboard or other fiber web, comprises atomization with an atomizing medium (ZM) in a pneumatic atomizing nozzle that is implemented as a multiple-media nozzle (2) and addition of saturated steam to the multiple-media nozzle. An atomizing gas is used as atomizing medium and is mixed with the steam. The atomizing gas is mixed with the steam before the inlet into the multiple-media nozzle. The steam is supplied as atomizing medium to the multiple-media nozzle. The method for the production of atomized spray from an application medium for application on a moving paper, cardboard or other fiber web, comprises atomization with an atomizing medium (ZM) in a pneumatic atomizing nozzle that is implemented as a multiple-media nozzle (2) and addition of saturated steam to the multiple-media nozzle. An atomizing gas is used as atomizing medium and is mixed with the steam. The atomizing gas is mixed with the steam before the inlet into the multiple-media nozzle. The steam is supplied as atomizing medium to the multiple-media nozzle. The atomizing gas and a fresh water or condensed water are used as the atomizing medium and as the humidification medium. The atomizing gas is moistened with the saturated fresh water or condensed water. The humidification of the atomizing gas with the fresh water or condensed water takes place upstream to each of the multiple-media nozzles. The humidification of the atomizing gas with the fresh water or condensed water takes place in a central atomizing medium supply line, which is connected with a multitude of multiple-media nozzles. The humidification of the atomizing gas with the fresh water or condensed water takes place in the multiple-media nozzle. The atomizing gas is heated prior to the humidification and/or the atomizing gas saturated with moisture is cooled after humidification. A fresh water or condensed water is used as the only humidification medium or a further extra humidification medium. A double-media nozzle is used as multiple-media nozzle and fresh water or condensed water can be supplied to the multiple-media nozzle by means of an inlet for the application medium, alternately with the supply of the medium. The supply of fresh water or condensed water takes place during the interruption of the supply of the atomizing medium. The fresh water or condensed water can be supplied to the multiple-media nozzle, in addition to the medium. A triple-media nozzle is used as multiple-media nozzle. The atomizing medium, the fresh water or condensed water and the medium are simultaneously fed to the three-media nozzle over a separate inlet respectively and mixed. The atomizing medium and the fluid are atomized together in a first procedural step and in a further second procedural step the application medium is atomized into the formed atomizing medium/fluid mixture. The application medium is proportionately supplied to the triple-media nozzle. The fresh water or condensed water is supplied together to a multiple-media nozzle or a multitude of multiple-media nozzles. The mixing takes place in a mixing chamber (4), which is upstream to or integrated in the individual multiple-media nozzles and which is connected to a multiple of the multiple-media nozzles. The supply of the application medium and/or fresh water or condensed water is controlled. Air is used as an atomizing gas. The multiple-media nozzle or the media-transporting components of the multiple-media nozzle are cooled. An independent claim is included for a spray application device for application of cardboard- or paper web.

Description

The The invention relates to a method for producing spray an adjuvant, in particular a coating medium for the order on a moving fibrous web by atomization with a sputtering gas to spray mist particles in a spray applicator, in detail with the features of the preamble of the claim 1; a spray applicator.

To the Application of auxiliaries, for example in the form of coating color on a running fibrous web are roller applicators or material nozzles used. Roller applicators are very maintenance and cost intensive and very limited in their runability. When applying a roller applicator is also at high operating speeds the risk of Misting. Due to the adhesion forces between the roll surface and the application medium it comes to a demolition and Nebulizing the application film, which turns out to be drops on the fibrous web knock down and become unwanted Can cause irritation of the surface quality. Across from Commissioned works, the use of single-fluid nozzles, although less maintenance and cost-effective, the meterability of the spray medium is very limited, there is no atomization he follows. Furthermore, can in some circumstances undesirable Form strips in the paper web.

• 1. WO 2005/040497 A1
• 2. US 6,627,261 B1
• 3. WO 2001/02098.
• 4. DE 19820432 A1

Spray application devices, also called spray coaters, are known in a large number of designs from the prior art. In this regard, reference is made, for example, to the following documents:

• 1. WO 2005/040497 A1
• Second US 6,627,261 B1
• 3. WO 2001/02098.
• 4th DE 19820432 A1

WHERE 2005/040497 A1 discloses a spray coater for applying a coating medium on a paper web. This includes a contract chamber through which led the fiber web and coated with the application medium. The order chamber includes an entrance fee for the fibrous web and an exit and at least two in the Order chamber arranged nozzles for spraying an application medium on both sides of the surface of the fibrous web. Further the spray coater comprises spray elements, especially nozzles for spraying of water into the application chamber, i. outside the nozzle in the Nozzles environment. The spraying takes place here to avoid condensation and drying of the coating color.

In analogy, the document describes US 6,627,261 B1 a similar procedure.

WHERE 2001/02998 discloses an embodiment of Coating of a fibrous web with a spray arrangement. The individual application medium beams be by the job institution by guiding the order medium by at least one nozzle plate, comprising openings, which are directed in the direction of the fibrous web to be coated, generated. In this version steam is transferred to the free jet a separate nozzle introduced to prevent drying of the application medium.

In the DE 19820432 describes a method in which maintains an atmosphere of the rewetted application medium rewetting or / and moistening medium in the area of a nebulizer.

With a supplied Humidifying gas is moistened here the application area, so that the on the running surface applied layer is easier flowing and thus smoother. Inside the atomizer nozzle, in particular at the nozzle exit, can nevertheless deposits of the spray medium (of the atomized Order medium).

In the case of dual-fluid nozzles, ambient air drawn in is used with the humidity contained therein, generally between 40 and 60 percent. Such a spray device for applying a spray medium in the form of coating color by atomization with a sputtering gas to form a spray is known from the document DE 103 26 763 A1 previously known. When mixing the spraying medium with the air, a drying effect, which leads to deposits and precipitations at the nozzle outlet, may occur. The deposits in turn can lead to blockages of the individual nozzles, whereby such spraying devices can be subject to large order quantities fluctuations over the effective width.

The invention is therefore based on the object, a method for atomizing auxiliaries, in particular application media for application to a moving fibrous web further such that the disadvantages mentioned are avoided. In particular, an alternative to commissioned works and single-fluid nozzles for the application of application media in the form of organic or inorganic media, such as starch, paints or other chemicals should be created, with a good metering and atomization of the spray medium to be achieved with high efficiency. The process should be characterized by low cost and the required equipment for the order by a small footprint and be easily retrofitted in existing paper machines. Furthermore, the method and the device according to the invention are not intended to be limiting condition the paper machine speed. The solution according to the invention should be distinguished by good meterability for the application medium, which serves to avoid streaks and moisture esters on the fibrous web.

The inventive solution by the features of the claims 1 and 28 characterized. Advantageous embodiments are each in the subclaims described.

One Process for producing a spray of auxiliaries, in particular an application medium for application to a moving fibrous web, by atomization with a sputtering medium in a pneumatic multi-fluid nozzle Atomiser nozzle according to the invention thereby characterized that to reduce, preferably avoidance the drying of the spray particles in the atomizer nozzle at least a moistening medium is added.

The Addition of the humidifying medium prevented by the reduction the drying effect, the formation of deposits by the auxiliaries in and on the atomizer nozzle, in particular the outlet cross section. This can be a more stable and economical Operation of a multi-substance nozzle for the application of auxiliaries on a fibrous web with the same remaining order quantity, avoiding cloudiness and streaks of the order become. The addition takes place directly to the multi-component nozzle or indirectly via the in this to be bled together Media, but in any case before the outlet cross section of the spray at the multi-substance nozzle.

• a) gemäß einer ersten Ausführung ein Gas in der Nähe des Verflüssigungspunktes, insbesondere Dampf, vorzugsweise Sattdampf
• b) gemäß einer zweiten Ausführung ein Fluid verwendet.

As moistening medium is doing

• a) according to a first embodiment, a gas in the vicinity of the liquefaction point, in particular steam, preferably saturated steam
• b) uses a fluid according to a second embodiment.

fluids can in the form of liquids or Mixtures are present, preferably water is used. In style of the origin or provision can, for example to distinguish between fresh water or condensate.

According to one particularly advantageous embodiment will the atomizer nozzle both a fluid as well as steam is added, the steam being used as humidifying medium the atomizing gas replaced.

• a) direkt in die Mehrstoffdüse und/oder
• b) indirekt über den Eintrag oder die Vermischung mit dem Zerstäubungsmedium und/oder den Hilfsstoffen vor einer Mehrstoffdüse.

The supply of the humidifying medium takes place

• a) directly into the multi-fluid nozzle and / or
• b) indirectly via the entry or mixing with the sputtering medium and / or the excipients before a multi-fluid nozzle.

The Addition of moistening medium takes place directly into the multi-substance nozzle before exiting the nozzle, preferably in the area of the supply of excipient and / or atomizing medium. In both cases can with the fluid a separate flushing of the multi-fluid nozzle or mixing with the individual media can be achieved.

The Choice of atomizing medium and / or the type and the entry of the humidifying medium thus allows the realization of different functions in use the multi-substance nozzle, in particular in the form of a two-fluid nozzle or a three-fluid nozzle. In essence, will distinguished between three different functions with the added moistening medium can be carried out, wherein the individual functions at least partially combined with each other in a multi-fluid nozzle are feasible. This includes the cleaning function, the saturation function for the atomizing and the mixing and dosing function for the excipients. Each of these Functions for alone prevents in advance or removes deposits in retrospect, whereby spray applicators with at least one multi-fluid nozzle as a simple and cheaper Alternative to other application facilities significantly in importance win. A combination of functions increases the effect and allows the Improvement of additional functions, for example the simple one Dosability of the excipients.

forms the humidifying medium in the form of vapor, the atomizing medium, can depending on the version the multi-substance nozzle Cleaning effects when supplying only the atomizing medium and interruption the supply of excipient and / or supply of additional Moistening medium in the form of fluid to Mehrstoffdüse achieved become. Cleaning effects can further by the interruption of the supply of excipients and the Supply of fluid, such as cleaning fluid are enabled, in which case the entry of steam as a sputtering gas is not mandatory.

steam as moistening medium can also be used to saturate the sputtering gas be used. This is overheated Steam or so-called Brüdendampf used. This causes a cooling effect on contact with the atomizing gas, to condense liquid leads.

The use of steam offers the advantage that it no longer has any desire to extract moisture from the application medium. In both cases there is the possibility of extracting the steam from a delivery unit to other processes the simultaneous course with the spray order are characterized to use. This is particularly possible in in-line applications of the method in paper machines. It would also be conceivable to provide a separate steam supply for the spray application device.

• a) dem Zerstäubungsmedium oder
• b) den Hilfsstoffen oder
• c) der Mehrstoffdüse bei Unterbrechung der Hilfsstoffzufuhr und evt. der Zerstäubungsmediumzufuhr

zugeführt werden. Die Variante a) bewirkt eine Sättigung des Zerstäubungsgases, b) bietet den Vorteil einer guten Misch- und Dosierbarkeit. Die Variante c) ermöglicht eine Reinigungsfunktion. Die Varianten b) und c) sind dabei jeweils in Kombination miteinander und mit der Variante a) oder aber der Verwendung eines Zerstäubungsmediums in Form von Dampf einsetzbar. In diesem Fall sind mehrere, vorzugsweise zwei Befeuchtungsmedien vorgesehen.When fluid is used as the humidifying medium, it can be considered the sole humidifying medium

• a) the sputtering medium or
• b) the excipients or
• c) the multi-substance nozzle when interrupting the supply of excipients and possibly the Zerstäubungsmediumzufuhr

be supplied. The variant a) causes a saturation of the atomizing gas, b) offers the advantage of good mixing and metering. The variant c) enables a cleaning function. The variants b) and c) can be used in each case in combination with each other and with the variant a) or else the use of a sputtering medium in the form of steam. In this case, several, preferably two moistening media are provided.

Becomes the atomizing medium in the form of atomizing gas supplied a fluid, the gas is saturated and has no endeavor, the spray medium to be applied, In particular, excipient to extract moisture and thereby a To cause drying, as the moisture absorption capacity decreases or exhausted is. The supply of a fluid to the sputtering medium in the form of gas takes place in the simplest case corresponding moistening, which is an injection or spraying a Liquid, preferably water. To increase the recording capacity is before the entry, in particular the mixing of the fluid with the atomizing the latter is heated, preferably heated. The warming takes place temporally and spatially before mixing.

The Supply of the humidifying medium to the atomizing medium, in particular Gas, takes place either upstream of the multi-fluid nozzle or depending on execution the multi-substance nozzle in the nozzle. For versions it is the addition of the humidifying medium before the multi-fluid nozzle conceivable, the humidification in one, a plurality of corresponding More nozzles to provide assigned common central supply line or for each multi-fuel nozzle individually.

at Addition of the humidifying medium in the multi-fluid nozzle, the mixing with the atomizing gas either before the entry of the excipients or simultaneously with this.

A another alternative or additional option to the individual variants of use as a sputtering medium and saturation the atomizing gas represents the introduction of a fluid into the multi-fluid nozzle. This can be used as an alternative to the supply of excipients purely for cleaning purposes or adding to the excipients, i. Mixing with the excipients. The mixing with the excipients' offers the advantage a precise metering of the excipients.

The Feed over the excipients, for example about a mixing chamber for Fluid and excipient allows the supply of excipients in high concentration. The mixing with fluid improves the dosability.

In all variants, the introduction of moistening medium in the sputtering medium and / or preferably mixed with the excipients. Accordingly, the provision of moistening medium is also to ensure. The individual media, adjuvant and / or moistening medium, in particular Fluid can be metered with regard to the supply to the multi-fluid nozzle, in particular by influencing, preferably controlling the volume flows.

The Incorporation of the fluid may further be associated with a single multi-fluid nozzle or a plurality of multi-component nozzles are assigned together.

Device-wise the implementation of these methods in a spray application device to order of excipients comprising at least one pneumatic multi-fluid nozzle, in particular at least a two-fluid nozzle and according to one particularly advantageous embodiment a three-fluid nozzle, comprising a first inlet for at least indirect coupling with a Delivery unit for excipients and a second inlet for at least indirect coupling with an atomizing medium supply unit. The spray applicator comprises at least according to the invention a device for at least indirectly introducing a moistening medium in the multi-fluid nozzle. At least indirectly means either directly or via further transmission elements, in the form of lines or function chambers, for example May be present mixing chambers, connectable. Preferably, however, there is always a direct one here Coupling. In the mixing chamber of the corresponding multi-fluid nozzle takes place doing a mixing and atomizing the introduced auxiliaries.

• – eine Befeuchtungseinrichtung
• – eine Dampfbereitstellungseinheit
• – eine Fluidbereitstellungseinheit

The means for introducing the moistening medium may comprise at least one of the following means, depending on the location and type of addition:

• - A humidifier
• - a steam supply unit
• A fluid supply unit

According to one Particularly advantageous development of the fluid is the sputtering medium supplied together with the excipients. The mixing in the multicomponent nozzle can be single-stage or two-stage. For single-stage execution the auxiliaries with the fluid and the sputtering gas in a nozzle, preferably a multi-fuel nozzle, mixed together. The mixing takes place between the individual media either at the same time or else offset in time. At a time staggered to each other Mixing is first the fluid, especially in the form of water, with the atomizing gas mixed, and injected in a second step, the excipient, which then entrained by the resulting mixture of atomizing medium and fluid becomes. In this case, preferably two are interconnected Mixed areas in the multi-fluid nozzle integrated.

A different possibility consists in the addition of fluid to the excipients, for example in a mixing chamber and subsequent supply to the multi-component nozzle. The Mixing chamber can be either a single or one Plurality of nozzles be assigned together. When executed and assigned to a Nozzle can the mixing chamber can be placed either in the nozzle or outside it. This possibility offers the advantage that the excipient in high and especially in Any concentration can be performed up to the mixing chamber. Furthermore, can with such a device when interrupting the supply of excipients be switched to a cleaning operation by only Injected water will, that is The system is run without excipient only with pure water.

According to one Advantageous further development of the individual multi-fluid nozzle is independent of the execution at least one device for adjustment, in particular control associated with the supply of the amount of excipients and / or fluid. These includes in the simplest case corresponding valve devices. at this can be a single valve device or any supply line for excipient and / or water or cleaning fluid separately assigned valves.

at a spray applicator With a plurality of such multi-fluid nozzles, the mixing ratio can be individual each nozzle be set when each nozzle over one separate control valve for Excipient and the fluid features. It is also conceivable, however, a common control or regulating device for too a group of combined nozzles.

According to one Particularly advantageous development, the supply of excipient completely interrupted. Furthermore, with this embodiment a be driven separate cleaning cycle. At the same time the nozzle only becomes fed the fluid, the design of the cable connections and the cable cross-sections such that within a preferred period of time, preferably t <5 Seconds, more preferably t <1 Flushed through second can be. This prevents that when the web breaks the auxiliary material into the environment sprayed and deposits can form there, especially in use in appropriate coating systems on the stiffening parts.

The individual versions can used separately. The particular embodiment of saturation of the atomizing medium is with the individual versions the addition of fluid can be combined.

Begrudge is that it is appropriate if the multi-substance nozzle themselves or their media-leading ones Parts cooled become. This avoids deposits within the nozzle.

The solution according to the invention explained below with reference to figures. This is in detail the following is shown:

1a illustrates in schematic simplified representation of a first variant of a first embodiment of a spray application device according to the invention;

1b illustrates in schematic simplified representation of a second variant of the first embodiment of the present invention designed spray applicator;

2a illustrates a first variant of a second embodiment of a spray application device according to the invention;

2 B illustrates a second variant of a second embodiment of a spray application device according to the invention;

3a illustrates a first variant of a third embodiment of a spray application device according to the invention;

3b illustrates a second variant of a third embodiment of a spray application device according to the invention;

4a illustrates a first variant of a fourth embodiment of a spray application device according to the invention;

4b illustrates a second variant of a fourth embodiment of a spray application device according to the invention;

5 illustrates in schematic simplified representation of a fifth embodiment of a spray application device according to the invention;

6 illustrates a combination of an embodiment according to the 1a with an execution according to 5 ;

7 illustrates an embodiment according to 1a with an execution according to 3a ;

8th illustrates an embodiment according to 1a in combination with a version according to 4a ,

In front the description of the individual embodiments are the following Definition of terms: The spray medium to be applied, which is also used as the application medium denotes at least one excipient. Under this are understood organic or inorganic substances. To this belong Strength, Water with additives, for example surfactants, pigments, coating color, Chemicals, i. all media that affect the properties the fibrous web condition, in particular the surface properties. Under fibrous web is in particular a paper or board web Understood.

A spray applicator 1 comprises at least one pneumatic atomizer nozzle serving as a multi-fluid nozzle 2 is executed. The multi-substance nozzle 2 serves to spray application of auxiliaries on a moving fibrous web. In this, the present as liquids adjuvants H are transferred by sputtering in the disperse state. It produces sprays with very small drops and narrow diameter distributions. For a two-phase flow in the form of the spray N to be able to leave the outlet cross-section of the atomizer nozzle, the liquids within the atomizer nozzle must be mixed with an atomization medium ZM, in particular an atomizing gas stream. The multi-substance nozzle 2 according to the various embodiments of the invention is at least as a two-fluid nozzle 3 executed, in an embodiment of the invention as a three-fluid nozzle.

The 1a and 1b illustrate in a schematic simplified representation of the basic structure of a spray application device 1 and a method of applying according to a first embodiment of the invention. The spray applicator 1 comprises at least one pneumatic atomizing nozzle serving as a two-fluid nozzle 3 is executed. The two-fluid nozzle 3 includes a mixing chamber 4 , a first inlet 5 and a second inlet 6 , wherein over the first inlet 5 the auxiliary substances H to be applied to the mixing chamber 4 while being supplied via the second inlet 6 the supply of a sputtering medium ZM takes place. The mixing chamber 4 downstream of the outlet cross-section 7 carrying nozzle part 8th , The liquids, which are in the form of the excipients, must already within the multi-fluid nozzle 2 be mixed with the sputtering medium ZM, which is present as a sputtering gas, so that they as a two-phase flow the nozzle outlet cross-section 7 leave. The atomization produces sprays with small drops and narrow diameter distribution. If air is used as sputtering gas ZG at room temperature with an air humidity of between 50 and 60%, the disadvantages described in the prior art can be observed. Therefore, according to the invention via the second inlet 6 to be supplied atomizing gas ZG enriched with a fluid, preferably saturated. The saturated atomizing gas is designated ZGG. The saturation is in the simplest case via a humidifier 9 realized which the inlet 6 at the multi-substance nozzle 2 upstream. The sputtering gas ZG, which is still in unsaturated form, is passed through a sputtering gas supply unit 10 provided, which at least indirectly, ie directly or via, for example, further connecting lines with the individual multi-fluid nozzle 2 is coupled. The humidifier 9 is between atomizing gas supply unit 10 and multi-fluid nozzle 2 arranged. In the illustrated case, the atomizing gas supply unit 10 via a central atomizing gas supply line 11 that with the single multi-fluid nozzle 2 , Preferably a plurality of such nozzles, additionally indicated here 2.1 and 2.2 coupled, connected. The humidifier 9 is preferably in the central atomization gas supply line 11 arranged. This comprises a device for introducing moistening medium 12 , in particular a liquid / Kondensateinspritzeinrichtung 15 , The liquid to be injected is preferably water. This can be present as fresh water or as a waste product of other parallel processes, for example in the form of condensate K or boiler feed water. The task of the humidifier 9 is to saturate the sputtering gas ZG, so that this has no more aspiration, the auxiliary H, with which it in the two-fluid nozzle 3 is mixed to dry, since the moisture absorption capacity of the atomizing gas ZGG is exhausted. About the humidifier 9 enters the atomizing gas supply line 11 injected a liquid. The overflowing unsaturated sputtering gas ZG tears into the central atomizing gas supply line 11 with incoming liquid, flows to the two material nozzle 3 and mixes in the mixing chamber 4 with those over the first inlet 5 introduced auxiliary substances H. The mixture thus produced then passes into the nozzle part 8th , To ensure that the atomizing gas ZG enters the multi-fluid nozzle 2 is saturated, this may be to increase its moisture absorption capacity in addition to the humidifier 9 via a heating device 13 be heated. The fluid F is injected at a temperature T _F <T _ZG , so that a part of the injected liquid in the supply line 11 separates again after cooling. The effect can be through one of the moistening device 9 downstream cooling device 14 increase. The facilities 13 and 14 are optional and not mandatory. The function of this can also be taken over by a heat exchanger. The heating and / or cooling can be done directly by heat radiation and heat transfer, ie the atomizing gas contacts the heat or cooling source directly or indirectly.

in the second case is the atomizing gas ZG free of direct contact with the heat or cooling source.

When atomizing ZG is preferably used air, in particular ambient air. Other gases are also conceivable. The first possibility however, is particularly advantageous in terms of availability. The liquid, with which the atomizing gas saturated is, is preferably water. Other liquids are conceivable.

The 1b illustrates an embodiment according to 1a in which, however, as dampening medium no fluid but steam D, ie a gas in the vicinity of its liquefaction point in the central supply line 11 is introduced and mixed with the guided there sputtering gas ZG. Preferably, vapor vapor, that is superheated steam is used. This achieves rapid saturation of the atomizing gas ZG when using air as a sputtering gas. The steam D is via an aggregate 16 sucked the atomizing gas station and there with the atomizing gas ZG in the atomizing gas supply line 11 mixed. The in the atomizing gas supply line 11 present atomizing gas ZG causes cooling of the sucked steam D and thus a drop in temperature, whereby the resulting mixture of steam and atomizing gas saturates. The so saturated atomizing gas is designated ZGG. The moistening with steam D can take place at any point in the system, but preferably still in the central atomizing gas supply line 11 to here only a corresponding suction 16 to provide for a variety of multi-fluid nozzles or spray applicators.

In both cases, a condensing in the multi-fluid nozzle 2 and thus a moistening of the medium-flow through parts of the multi-fluid nozzle 2 to favor, this can additionally be cooled specifically. This can be done for example by a cooling medium in the form of gas or liquid, in which case an indirect cooling is selected. In the case shown, the guide channels for at least one cooling medium at the multi-material nozzle are here by way of example in dash-dotted representation 2 shown for the purpose of moistening the media-carrying walls. The single coolant channel is guided in the immediate vicinity of the application medium leading channels and nozzle components and is here with 25 designated.

Clarify the 1a and 1b the use of a sputtering gas ZG for atomizing a coating medium, wherein the sputtering gas ZG is saturated with a fluid or vapor to avoid dehydration of the coating medium, shows 2 in a schematic simplified representation of the use of steam D as moistening medium, which simultaneously forms the sputtering medium ZM and is therefore denoted by ZD. Saturated steam is preferably used. The saturated steam itself no longer strives to dry the spraying medium, since the moisture absorption capacity is already exhausted. In this case, the spray applicator is 1 a steam delivery unit 26 as a sputtering medium delivery unit, via a sputtering medium supply line 11 with the second inlet 6 at the multi-substance nozzle 2 connected. The vapor as the sputtering medium is preferably present in the form of saturated steam. Wet steam should be avoided as there is a risk of drop formation. The atomizing steam can be provided via a separate steam generating device or is provided in a steam generating device shared with other systems.

The in the 1a . 1b and 2 illustrated basic principles of saturation of the sputtering medium prior to mixing with the excipient to form the Sprühauftragsmediums represent two basic possibilities of the inventive solution, the drying of the spray application medium and consequent unwanted deposits on the nozzle exit 7 avoid. In both versions according to 1a and 1b is the means for introducing moistening medium from a moistening device 9 educated. In the execution according to 2 will be the device 12 from the atomizing steam providing unit 26 educated.

Both versions use the first inlet 5 exemplary in the 1a . 1b and 2 the entry of excipients H or water, either as a spray medium or cleaning medium.

The spray application device 1 , which has a plurality of multi-fluid nozzles, as in the 1 and 2 shown, only one such Zerstäubungsmediumbereitstellungsseinheit be assigned, in which case only a central atomizing medium supply line is required, which with the individual multi-fluid nozzles 2.1 to 2.n is connectable, preferably constantly connected. On the other hand, it is also conceivable to associate individual multi-fluid nozzles with a separate delivery system.

The two-fluid nozzles 3 according to the 1a . 1b and 2 are with inner mixing chamber 4 educated.

The 3 to 5 illustrate possibilities of direct addition of a fluid F to the multi-fluid nozzle 2 and / or via mixing with the auxiliary substances H.

In the in the 3 to 5 The illustrated embodiments will be the device 12 for introducing moistening medium from a fluid supply unit.

The 3a and 3b clarify example using a spray applicator 1 Another solution to the problem of avoiding dehydration of the application medium. In this case, the excipient H in a multi-component nozzle 2 , in particular a three-fluid nozzle 17 injected and metered into this atomized. The adjuvant H can in high concentration of the three-fluid nozzle 17 be supplied. In this case, two liquids are mixed and atomized with the aid of the atomizing gas or the hydraulic pressure of one of the supplied media. It is between a single-stage atomization, as in 3a clarified and a two-step, as in 3b distinguished.

The ternary nozzle 17 includes at least three inlets, a first inlet 5 for adjuvant H, a second inlet 6 for the atomization medium ZM, in particular atomizing gas ZG and a third inlet 18 for the fluid F, in particular in the form of water W or a cleaning fluid. Depending on the version of the three-fluid nozzle 17 the atomization of the excipient H by means of the atomizing gas ZG can be made to two different variants. The 3a illustrates a version with single-stage atomization. In this case, the over the individual inlets 5 . 6 and 18 mixed media almost simultaneously mixed. This means that both the over the first inlet 5 registered adjuvants H as well as the third inlet 18 registered liquid simultaneously in a mixing chamber 4 in which further the atomizing gas is introduced via the second inlet 6 is introduced, which atomizes the excipient / liquid mixture and entrains. Preferably, the introduction of the sputtering medium ZM takes place in the flow direction in the multi-component nozzle 2 behind the introduction of the excipients H and the fluid F into the mixing chamber 4 ,

In contrast clarifies 3b in a schematic simplified representation of an embodiment of the three-fluid nozzle 17 with two-stage atomization. In this are the inlets 5 . 6 and 18 arranged such that in a first stage first the fluid F, in particular the water W with the over the inlet 6 registered atomizing medium ZM, in particular sputtering gas ZG is atomized and is injected with further flow of Zerstäubungsgas- / fluid mixture of the excipient and atomized by the Zerstäubungsgas- / liquid mixture and entrained. This solution allows the adjuvant to be mixed in any concentration. The individual mixing ratios can be adjusted individually per multi-fluid nozzle, especially if each multi-fluid nozzle 2 via a corresponding control and / or regulating device for auxiliary substances H and / or the fluid F; preferably in the form of control valves. These are exemplary here with 27 for the supply of adjuvant and 28 for the fluid supply called.

The in the 3a and 3b shown multi-fluid nozzles in the form of three-fluid nozzles also offer the advantage that to clean the system this completely driven without excipient H and the inlet 18 Cleaning liquid, for example in the form of water, can be supplied and thus flows through the three-fluid nozzle. The supply of atomizing gas ZG and auxiliary H can then be dispensed with. This means that the inlets over these inlets 5 and 6 are blocked or decoupled from the corresponding supply units for excipient H and sputtering medium ZM.

Clarify the 3a and 3b the mixture of the individual media adjuvant H, humidifying medium fluid F and sputtering medium ZM, in particular sputtering gas ZG in the multi-fluid nozzle 2 by execution of this as three-fluid nozzle 17 by injection of the media, this principle can also be used with a two-fluid nozzle 2 be practiced as in 4a and 4b is exemplified. The two-fluid nozzle 3 In turn, this includes a first inlet 5 and a second inlet 6 , Wherein, via the second inlet 6 the atomization gas is injected. The first inlet 5 is over a mixing chamber 19 which is outside of the two-fluid nozzle 3 can be arranged or directly associated with this, ie a structural unit forms with this, with the supply lines or supply facilities for auxiliary substances H and / or fluid, in particular water connected. The mixing chamber 19 has in the illustrated case three inlets, a first inlet 20 for adjuvant H, a second inlet 21 for fluid F, especially water and an outlet 22 for that in the mixing chamber 19 present mixture.

4a illustrates an embodiment of a two-fluid nozzle 3 with assignment of a common mixing chamber 19 to several nozzles 2.1 . 2 and 2.2 , In the first step, the fluid F, in particular the water, passes through the inlet 21 with the adjuvant H, which passes over the inlet 20 is fed, mixed. The excipient / fluid mixture then passes through the outlet 22 that with the inlet 5 at the two-fluid nozzle 3 is coupled into the mixing chamber 4 this. The coupling takes place here via a central supply line 23 , The excipient / fluid mixture is in the multi-fluid nozzle 2 atomized with atomizing medium ZM, in particular atomizing gas ZG.

At the end of the operation, the auxiliary feed to the mixing chamber 19 be interrupted and it is only fluid F, especially water, the mixing chamber 19 fed and over this the nozzle part 8th , so that here a cleaning cycle can be driven by rinsing. The duration of the rinsing process should be so short that the mixing chamber 19 as well as the connecting lines to the individual nozzles and the nozzle once within a period t <5 seconds, preferably <1 second has been flushed with pure water. This prevents that when the web breaks the auxiliary H is sprayed into the environment and can form deposits there.

The 4b illustrates an embodiment according to 4a but with a single two-fluid nozzle 3 each with its own mixing chamber 19 assigned. This can be done either by upstream or by connection to the two-fluid nozzle 2 , The fluid F is then in the mixing chamber 19 mixed with the excipient H. Again, at the end of the operation of the mixing chamber 19 only fed water and so drove a cleaning cycle.

The switch to the cleaning operation can in the simplest case by one of the supply line for excipient H to the mixing chamber 19 associated switching valve take place, which interrupts the supply of excipient H. It is also conceivable to control or regulate the supply of the individual media F and adjuvant H to be mixed. These are in the simplest case, the supply lines to the mixing chamber 19 corresponding valve devices, by way of example and independently of the specific embodiment with respect to the control function 27 and 28 designated, assigned.

5 illustrates an embodiment of a spray application device 1 comprising a multi-fluid nozzle 2 , in particular two-fluid nozzle 3 which is conventionally operable, but in which a separate cleaning operation is possible. This is achieved by the rapid switching from spraying operation with auxiliaries H to the cleaning operation with a cleaning liquid, for example water. The two-fluid nozzle 3 is over the inlet 5 with the supply line 24 for adjuvants H connected. This is preferably a central supply line 24 for excipients H, containing a plurality of nozzles, here 2 . 2.1 . 2.3 can be coupled. The second inlet 6 is with a utility line 11 connected to the atomizing gas, in particular the supply line 11 , There is also a supply line 29 for the humidifying medium, in particular fluid F in the form of water W or cleaning liquid provided, which also with the first inlet 5 can be coupled. The coupling between the first inlet 5 and the supply line 24 for adjuvant and the supply line 29 for water or cleaning liquid takes place alternatively and optionally. This can be realized for example via corresponding valve devices. In order to enable separate operation, a switching valve, preferably a three / two-way valve is provided which allows only two switching positions, a first switching position in which the supply line 24 with the first inlet 5 is connected and a second switching position, in which the supply line 29 for water or cleaning fluid with the inlet 5 connected is. Furthermore, control devices are then provided, which control the fluid flows from the central supply line 24 for excipients H to the inlet 5 or of fluid F, in particular water W or cleaning fluid to the inlet 5 the two-fluid nozzle 3 can control. Another possibility is the assignment of corresponding switching and control valves in the individual lines, as in 5 with example 27 and 28 shown.

With this solution, a quick changeover from spraying operation with auxiliaries to the cleaning operation of a cleaning liquid can take place. This clogging of the multi-fluid nozzles and lines is avoided in polluting auxiliary substances H. The cleaning operation is preferably designed such that the web tear the auxiliary material is not sprayed too long in the environment and can form there, for example, on Funging parts deposits. The multi-substance nozzle 2 is operated alternatively with two substances, so that can be switched from adjuvant to a cleaning liquid. At the end of operation of the multi-component nozzle is supplied by switching the valves only the cleaning liquid. The required duration of the rinsing process is dimensioned so short that the entire volume of the line to the nozzle and the nozzle itself has been traversed within a time t <5 seconds, preferably <1 second with water / cleaning liquid. This is achieved by the smallest distances between directional valve and nozzle as well as small line and nozzle volumes.

According to a particularly advantageous embodiment, the pressure in the line of the fluid F is behind the valve device 28 higher than in the auxiliary H after the switching valve 27 , that is, pw> ph. Thus, the supply of the auxiliary substances H to Mehrstoffdüse 3 be backwashed, especially when opening the valve 28 ,

The execution according to the 1 to 5 can prevent deposits on the nozzle outlet 7 the multi-substance nozzle 2 each to be used alone. According to a particularly advantageous embodiment, however, combinations of each in the 1 and 2 illustrated methods with those in the 3 to 5 conceivable. In the in the 6 to 8th Exemplary reproduced combinations of the multi-component nozzle two humidifying media supplied, once on the humidification of the sputtering gas ZG and further either by direct fluid supply to the nozzle or a mixing chamber.

The 6 illustrates an embodiment according to 1 in combination with a version according to 5 , This is analogous to that in the 1 illustrated procedure, the atomizing gas with a humidifying medium in the form of liquid saturated of the two-fluid nozzle 3 fed. The supply of auxiliary substances H takes place via the inlet 5 , to the optional also in the 5 illustrated supply line 29 for water or cleaning fluid can be coupled.

The 7 illustrates in schematic simplified representation of a combination of the saturation of the atomizing gas according to the invention 1 in a multi-fluid nozzle according to 3 , here for example 3a , The operation of the multi-component nozzle remains unchanged, only the sputtering gas is supplied in the saturated state, so that there is no drying of the water / excipient mixture more.

The 8th illustrates in schematic simplified representation a combination of an embodiment according to 1 in combination with 4 , The functioning is analogous to that in the 4 however, the atomizing gas ZG is already present in the saturated state ZGG.

The embodiments according to the 6 to 8th can also be modified so that instead of the intended saturation of the sputtering gas ZG by a fluid F, the sputtering gas is supplied in the form of vapor D.

1

Sprühauftragseinrichtung

2

multicomponent nozzle

3

two-fluid nozzle

4

mixing chamber

5

first inlet

6

second inlet

7

Nozzle outlet cross section

8th

atomizer

9

humidifying

10

Zerstäubungsmediumbereitstellungseinheit

11

central Zerstäubungsmediumversorgungsleitung

12

Facility for introducing the humidifying medium

13

heater

14

cooling device

15

Liquid / condensate injection

16

aggregate

17

three-component nozzle

18

inlet

19

mixing chamber

20

inlet

21

inlet

22

output

23

central supply line

24

supply line for excipient

25

cooling channel

26

Steam supply unit

27

Tax- and / or control valve

28

Tax- and / or control valve

29

supply line

H

excipient

ZM

atomizing

ZG

atomizing

ZGG

saturated atomizing

F

fluid

K

condensate

W

water

Claims (47)

Process for producing spray (N) from an adjuvant (H), in particular a coating medium for application to a running paper, board or other fibrous web, by atomization with a sputtering medium (ZM) in a multi-fluid nozzle ( 2 . 2.1 . 2.2 . 3 . 17 ) executed pneumatic atomizer nozzle, characterized gekenn characterized in that at least one humidifying medium in the multi-fluid nozzle ( 2 . 3 . 17 ) is added. Method according to claim 1, characterized in that that steam (D) is used as the humidification medium. Method according to claim 2, characterized in that that saturated steam is used. Method according to claim 2 or 3, characterized that as atomizing medium (ZM) a sputtering gas (ZG), which is mixed with the steam (D). A method according to claim 2 or 3, characterized in that the atomizing gas (ZG) with the vapor (D) in front of an inlet ( 6 ) in the multi-fluid nozzle ( 2 ) is mixed. A method according to claim 2 or 3, characterized in that the steam (D) as atomizing medium (ZM) of the multi-fluid nozzle ( 2 ) is supplied. Method according to claim 1, characterized in that that as a sputtering medium (ZM) an atomizing gas (ZG) and as a humidifying medium, a fluid (F) can be used and the atomizing gas (ZG) is moistened with the fluid (F), preferably saturated. A method according to claim 7, characterized in that the moistening of the atomizing gas (ZG) with the fluid (F) of the individual multi-fluid nozzle ( 2 ) upstream. A method according to claim 8, characterized in that the moistening of the atomizing gas (ZG) with fluid (F) in one, with a plurality of multi-fluid nozzles ( 2 . 2.1 . 2.2 ) central atomizing medium supply line ( 11 ) he follows. A method according to claim 7, characterized in that the humidification of atomizing gas (ZG) with fluid (F) in the multi-fluid nozzle ( 2 . 3 . 17 ) he follows. Method according to one of claims 7 to 10, characterized that the atomizing gas (ZG) heated before humidification and / or the moisture-enriched atomizing gas (ZGG) after humidification chilled becomes. Method according to one of claims 1 to 11, characterized that as the only moistening medium or another additional moistening medium a fluid (F) is used. A method according to claim 12, characterized in that as a multi-component nozzle ( 2 ) a two-fluid nozzle ( 3 ) is used and the fluid (F) alternatively to the supply of excipients (H) of the multi-fluid nozzle ( 2 . 3 . 17 ) via an inlet ( 5 ) for the excipients (H) can be fed. Method according to claim 13, characterized in that the supply of fluid (F) when the supply of atomizing medium (ZM) is interrupted he follows. A method according to claim 12, characterized in that the fluid (F) in addition to the excipients (H) of the multi-fluid nozzle ( 2 . 3 . 17 ) can be fed. Process according to claim 15, characterized in that as a multi-substance nozzle ( 2 ) a three-fluid nozzle ( 17 ) and the atomizing medium (ZM), the fluid (F) and the auxiliaries (H) at approximately the same time the three-fluid nozzle ( 17 ) each have its own inlet ( 5 . 6 . 18 ) are fed and mixed. Process according to claim 15, characterized in that as a multi-substance nozzle ( 2 ) a three-fluid nozzle ( 17 ) is used and the sputtering medium (ZM) and the fluid (F) are atomized together in a first process step and in a further second process step, the excipient (H) is injected into the formed sputtering medium / fluid mixture. Process according to Claim 16 or 17, characterized in that the adjuvant (H) is metered into the three-substance nozzle ( 17 ) is supplied. Method according to one of claims 12 to 15, characterized in that the fluid (F) of a multi-fluid nozzle ( 2 . 3 . 17 ) or a plurality of multi-fluid nozzles ( 2 . 2.1 . 2.2 . 3 . 17 ) is supplied together, Method according to one of claims 12 to 15, characterized in that the fluid (F) is supplied to the auxiliary substances (H) and is mixed with these. A method according to claim 20, characterized in that the mixing in one of the multi-fluid nozzle (( 2 . 2.1 . 2.2 . 3 ) upstream mixing chamber ( 19 ), which with a multiplicity of multi-substance nozzles ( 2 . 2.1 . 2.2 . 3 ) is connected. A method according to claim 20, characterized in that the mixing in one of the individual multi-fluid nozzle ( 2 . 2.1 . 2.2 . 3 . 17 ) upstream or in this integrated mixing chamber ( 19 ) he follows. Method according to one of claims 15 to 22, characterized that the supply of excipient (H) and / or fluid (F) controlled becomes. Method according to one of claims 7 to 23, characterized that as a sputtering medium a sputtering gas (ZG), preferably air is used. Method according to one of claims 1 to 24, characterized that as the fluid (F) fresh water (W) or condensate (K) is used. Method according to one of claims 1 to 25, characterized in that the multi-component nozzle ( 2 . 2.1 . 2.2 . 3 . 17 ) itself or the media-carrying parts of the multi-fluid nozzle ( 2 . 2.1 . 2.2 . 3 . 17 ) are cooled. Method according to one of Claims 1 to 26, characterized as auxiliary substance (H) organic or inorganic liquids, coating color, Surfactants, chemicals or starch be applied. Spray application device ( 1 ) for the application of auxiliaries (H), in particular application medium, on a fibrous web, in particular cardboard or paper web with at least one multi-component nozzle ( 2 . 2.1 . 2.2 . 3 . 17 ), comprising a first inlet ( 5 ) for coupling to an auxiliary delivery unit (H) and a second inlet ( 6 ) for coupling to a sputtering medium providing unit ( 10 . 26 ), characterized in that at least one device for at least indirectly introducing a moistening medium into the multi-substance nozzle ( 2 . 2.1 . 2.2 . 3 . 17 ) is provided. Spray application device ( 1 ) according to claim 28, characterized in that the at least one device ( 12 ) for at least indirectly introducing a moistening medium as moistening device ( 9 ) and in the connection between the atomizing medium supply unit ( 10 ) with the multi-fluid nozzle ( 2 . 2.2 . 2.2 . 3 . 17 ) is arranged. Spray application device ( 1 ) according to claim 29, characterized in that the moistening device ( 9 ) a spraying device ( 15 ) for a liquid or a condensate (K). Spray application device ( 1 ) according to claim 29, characterized in that the moistening device ( 9 ) a steam suction device ( 16 ) connected to the connecting line ( 11 ) between atomization medium delivery unit ( 10 ) and second inlet ( 6 ) at the multi-substance nozzle ( 2 . 2.1 . 2.2 . 3 . 17 ) is coupled. Spray application device ( 1 ) according to claim 29 to 31, characterized in that the moistening device ( 9 ) An institution ( 13 ) upstream for heating the atomizing medium (ZM) and / or a device for cooling ( 14 ) is subordinate. Spray application device ( 1 ) according to claim 29, characterized in that the device ( 12 ) for at least indirectly introducing a humidifying medium the atomizing medium supply unit and the connecting line to the inlet ( 6 ) and the atomizing medium supply unit from a steam supply unit ( 26 ) is formed. Spray application device ( 1 ) according to claim 29 to 33, characterized in that this a plurality of multi-component nozzles ( 2.1 . 2.2 . 2 . 3 . 17 ), each multi-fluid nozzle ( 2.1 . 2.2 . 2 . 3 . 17 ) a separate atomization medium delivery unit ( 10 . 26 ) assigned. Spray application device ( 1 ) according to claim 29 to 33, characterized in that this a plurality of multi-component nozzles ( 2.1 . 2.2 . 2 . 3 . 17 ), wherein a plurality of the multi-fluid nozzles ( 2.1 . 2.2 . 2 . 3 . 17 ) with an atomizing medium delivery unit ( 10 . 26 ) central supply line ( 11 ) are connected. Spray application device ( 1 ) according to claims 29 to 35, characterized in that the device ( 12 ) comprises a fluid supply unit which at least indirectly with the multi-fluid nozzle ( 2 . 2.1 . 2.2 . 3 . 17 ) is connectable. Spray application device ( 1 ) according to claim 36, characterized in that the fluid supply unit alternatively to the excipient supply unit (H) to the first inlet ( 5 ) can be coupled. Spray application device ( 1 ) according to claim 36, characterized in that the multi-substance nozzle ( 2 . 2.1 . 2.2 ) as a three-fluid nozzle ( 17 ), comprising a further third inlet ( 18 ) for the fluid (F). Spray application device ( 1 ) according to claim 38, characterized in that in the multi-material nozzle, a first mixing area is provided, which with the inlets ( 18 . 6 ) is coupled to the atomizing medium (ZM) and the fluid (F) and another second, the first subordinate mixing area, which is connected to the inlet (ZM) 5 ) is coupled for auxiliaries. Spray application device ( 1 ) according to claim 38, characterized in that a common Mixing area provided with the individual inlets ( 5 . 6 . 18 ) for the sputtering medium (ZM), the fluid (F) and the adjuvants (H) is coupled. Spray application device ( 1 ) according to claim 37, characterized in that a mixing chamber ( 19 ), which has a first inlet ( 20 ) for excipients (H) and a second inlet ( 21 ) for fluid (F) and an outlet ( 22 ) connected to the first inlet ( 5 ) of the multi-substance nozzle ( 2 . 2.1 . 2.2 . 3 . 17 ) is coupled. Spray application device ( 1 ) according to claim 41, characterized in that the mixing chamber ( 19 ) at least one device for interrupting or coupling and / or controlling the feed quantity of auxiliary substance (H) and / or fluid (F) to the mixing chamber ( 19 ) assigned. Spray application device ( 1 ) according to one of claims 41 or 42, characterized in that the multi-substance nozzle ( 2 . 2.1 . 2.2 . 3 ) as a two-fluid nozzle ( 3 ) is executed. Spray application device ( 1 ) according to one of claims 41 or 42, characterized in that each individual multi-fluid nozzle ( 2 . 2.1 . 2.2 . 3 ) each have a mixing chamber ( 19 ) which is outside or in the multi-fluid nozzle ( 2 ) is arranged integrated. Spray application device ( 1 ) according to one of claims 41 or 42, characterized in that the mixing chamber ( 19 ) each of a plurality of multi-fluid nozzles ( 2 . 2.1 . 2.2 ) is assigned together. Spray application device ( 1 ) according to one of claims 28 to 45, characterized in that means for controlling the inlet of the sputtering medium and / or the moistening medium and / or the auxiliary substances (H) are provided. Spray application device ( 1 ) according to one of claims 28 to 46, characterized in that the individual multi-fluid nozzle ( 2 . 2.1 . 2.2 . 3 . 17 ) a cooling device ( 25 ) assigned.