DE102007000706A1 - Device for degassing fluid/pasty medium such as coating color for coating paper web/cardboard, comprises low pressure chamber in which low pressure is generatable, and inlet arrangement, which guides the medium in the low pressure chamber - Google Patents

Abstract

The device for degassing a fluid or pasty medium such as coating color for coating paper web or cardboard, comprises a low pressure chamber (16) in which a low pressure is generatable, an inlet arrangement (12), which guides the medium in the low pressure chamber, an outlet arrangement (34), which discharges the medium from the low pressure chamber, a sling plate (24a, 24b) arranged in the low pressure chamber, a plump arrangement (30a) extending itself around the circumference of the sling plate, and a tempering arrangement. The device for degassing a fluid or pasty medium such as coating color for coating paper web or cardboard, comprises a low pressure chamber (16) in which a low pressure is generatable, an inlet arrangement (12), which guides the medium in the low pressure chamber, an outlet arrangement (34), which discharges the medium from the low pressure chamber, a sling plate (24a, 24b) arranged in the low pressure chamber, a plump arrangement (30a) extending itself around the circumference of the sling plate, and a tempering arrangement for controlling/regularizing the temperature of the section of the device. The medium in the low pressure chamber is guidable on the sling plate. The sling plate or sling edge is rotatable for the rotation around a vertical rotation axis. The plump arrangement reaches in the low pressure chamber against the medium delivering from the sling plate. The plump arrangement is implemented with plump edges arranged in circumference direction, and with openings arranged by a plump area and/or the plum edge in the circumference direction. The plump arrangement is arranged stationary in the low pressure chamber and is guided against a container wall limiting the low pressure chamber. The plump arrangement is formed by a section of a guiding arrangement intended in the low pressure chamber. A subjacent further sling plate guides the medium or the plump arrangement serves as guiding arrangement. The plump arrangement is separately guided against the guiding arrangement. The plump arrangement or plump element is held or arranged inside of the container wall or the guiding arrangement. The plump arrangement and/or the guiding arrangement guides in multi-sectional manner and/or is passed from the low pressure chamber. The plump arrangement comprises plump elements arranged to each other that form plump edges and/or plump areas. The plump elements project a section of a guiding element of the guiding arrangement by a holding circumferential part radially towards interior and are arranged in circumference direction. The plump arrangement comprises a group of plump elements that form plump edges and/or plump areas. The plump elements are formed by internal teeth of the circumference part of the plump arrangement. The internal teeth have asymmetrical teeth. The medium impact angle at the side of the teeth serving as plump area is enlarged against a symmetrical tooth formation. The plumping arrangement comprises a sieve arrangement, a grid arrangement or perforated element arrangement that has opening limited by a plump area and/or the plump edges. The sling plate is movable for the rotation around the vertical rotation axis. The sling plate comprises a stationary sling plate section and a sling edge movable for the rotation around the vertical rotation axis. The sling plate is arranged with a sieve edge serving as sling edge. The inlet arrangement guides the medium, which distributes itself around a center of an upper sling plate or stationary distribution plate. The inlet arrangement delivers the medium around the centre of the upper sling plate or stationarily distribution plate. The inlet arrangement comprises discharge opening, which delivers the medium simultaneously on the surface of the upper sling plate and/or distribution plate. The sling plates are vertically arranged above one another. The tempering arrangement heats a collecting section of the device in which the medium is collected. The tempering arrangement cools a section of the inlet arrangement or a section of the device arranged in flow direction of the medium upstream of the inlet arrangement. The drive unit is coolable for rotatably driving the sling plate and/or its sling edge by a rotational shaft and/or swivel of the rotational shaft and/or the rotational shaft by the tempering arrangement. The medium is guided or temperable with the interacting elements in the interior of the low pressure chamber through the tempering arrangement. The device is operatable with a pressure in the interior of the low pressure chamber equal or smaller than a loading vapor pressure of the medium. The medium comprises a binding agent and a pigment and has a solid material content of 50-80 wt.% and/or a viscosity of 700-4000 mPas. Independent claims are included for: (1) a coating device; and (2) method for degassing a fluid or pasty medium such as coating color for coating paper web or cardboard.

Description

The The invention relates to a device for degassing a liquid or pasty Medium, in particular a coating color for coating a substrate, in particular a paper web, a board web or the like, based on negative pressure or vacuum. Such devices are known under the name "degassing" or "vacuum fan" and include a vacuum chamber in which a negative pressure can be generated, an inlet arrangement, which the medium in the vacuum chamber introduces, an outlet assembly containing the medium from the vacuum chamber dissipates and at least one arranged in the vacuum chamber whirling disc, on the supplied into the vacuum chamber medium can be fed, wherein the whip dish or at least a sling edge of the same drivable for rotation about a substantially vertical axis of rotation is. Such venting or degassing devices typically also have at least a whiplash associated, at least partially around the circumference of the centrifuge plate extending baffle arrangement in the vacuum chamber, against the thrown off from the centrifugal disk Medium meets. Often Such devices have a plurality of vertically stacked centrifugal dish on. In such a device with several centrifugal plates, for example, referred to as Kaskadenentgaser or Kaskadenentlüfter can be, for example, reaches the entire volume flow to be degassed medium on the top centrifugal dish or on a stationary one Distributing plate. After spinning off the topmost whirl dish the centrifuged flow is collected and by means of return plates led to the underlying centrifugal plate, from which the medium then is thrown off again, etc ..

The Degassing effect is based on the fact that the medium under the negative pressure, if necessary vacuum, alternately strongly accelerated and then hit an impact surface and suddenly is slowed down a lot.

One Effective degassing or venting is especially in the Paper carton or Generally fibrous web finishing of great importance. At a such application is the medium in particular to a coating color, for example, from an aqueous Pigment dispersion exists, the possible with a certain film thickness apply evenly and to dry. Such an order, also referred to as a stroke, improves the printability as well as the optical properties of the web.

During the Preparation process of the medium, especially the coating color, As a rule, air enters the liquid or pasty medium. From this Bubbles form, which burst after the painting of the web and leave vacancies. The stroke is then no longer uniform. Already microbubbles with a diameter of less microns are highly disturbing, before especially with thin films.

Around an optimal stroke with closed stroke area and greater uniformity For this reason, degassing or venting is essential. There are many Method has become known, wherein the vacuum degassing or vacuum degassing (Vacuum vent or vacuum venting) has a special meaning.

The Requirements for the degassing of the type mentioned have increased, also because the media to be degassed now have properties which make degassing more difficult. These include, for example higher Solids content and higher Viscosities. Also, the quality requirements to the stroke quality meanwhile increased or the kind of the coating demands a special largely degassed medium (eg the curtain coating).

task The invention is an apparatus and a corresponding method to create a degassing, which have a high degassing effect and regarding the degassing device with comparatively low Space, especially in the vertical direction, manages.

To achieve this object, the invention provides an apparatus for degassing a liquid or pasty medium, in particular a coating color for coating a substrate, in particular a paper web, a board web or the like, comprising a vacuum chamber, in which a negative pressure can be generated, an inlet arrangement, which introduces the medium into the vacuum chamber, an outlet arrangement which discharges the medium from the vacuum chamber, at least one arranged in the vacuum chamber centrifugal plate, is supplied to the fed into the vacuum chamber medium, wherein the centrifugal disc or at least one spin edge thereof for rotation about a substantially vertical axis of rotation can be driven, and at least one of the centrifugal plate associated, at least partially extending around the circumference of the centrifuge bowl impaction in the vacuum chamber, against which centrifuged by the centrifugal disc medium hits. According to the invention, the impact arrangement is designed with a plurality of impact edges distributed at least in a circumferential direction and / or with a plurality of at least one impact surface and / or at least one respective impact edge bounded, at least in A circumferential direction distributed openings arranged and / or with a plurality of opposite a circumferential course of the baffle arrangement in a Mediumauftreffwinkel increasing direction inclined, at least distributed in a circumferential direction arranged baffles or baffle surface portions.

The Invention is based on the consideration to execute the baffle arrangement in such a way the media impinging thereon or the media droplets impinging upon them Impact with optimized effect deformed, reduced or distributed, especially under the action of comparatively large shear forces and Formation of a big one Media interface and possibly also further division and diversion of the medium or of Media droplets. This can be done by optimizing the impact angle on a respective Baffle section and by providing many individual refractive edges and providing multiple successive interactions of the medium with the baffle arrangement be achieved. It can thus achieve a very effective ventilation become. Is a better ventilation not required, so alternatively the throughput with equally good ventilation effect be increased as in the prior art.

According to the invention can so a compact, very efficient vacuum ventilator can be provided which has a small installation space, with a high medium throughput works and a great venting effect Has. It is a simple design of the breather possible, which also produced inexpensively can be. Drive vanes and other components on the centrifuge plate or the centrifugal plates, which could promote pollution not mandatory. Carrier, baffles and other components that are difficult to clean and / or difficult to exchange are dispensable, can but if desired be provided.

Advantageous the baffle arrangement can be stationary in be arranged the vacuum chamber and preferably opposite to a the vacuum chamber limiting container wall to be carried out separately. But it is quite possible that the container wall at least at least forms a portion of the baffle arrangement.

A appropriate possibility is that or a baffle arrangement of at least one section formed in the vacuum chamber guide assembly formed is, the collected centrifugal medium a deeper feeding another whirling dish, or that the baffle arrangement serves as such a guide arrangement.

alternative It is proposed that the or a baffle arrangement over a Run separately in the vacuum chamber provided guide arrangement and inside of the same is arranged, the collected thrown off Medium feeds to a deeper further centrifugal dish.

A appropriate possibility is further that the or a baffle arrangement or a plurality of baffles of the same on an inner side of the container wall or arranged and held on an inner side of the guide arrangement is.

Advantageous it can be provided that the impact arrangement and / or the guide arrangement executed in several parts and / or is removable from the vacuum chamber. It will be like this facilitates the cleaning and installation of the device.

A particularly expedient embodiment is characterized in that the impact arrangement comprises a plurality, possibly comprises a plurality of mutually separate impact elements, the bump edges and / or baffles form. The baffles can from a retaining peripheral part, preferably a section of a guide element the guide arrangement project radially inward and in the circumferential direction be arranged distributed. As a retaining peripheral part and a wall of the Pressurized container serve.

To another, very advantageous embodiment is provided that the impact arrangement at least one group of integrally connected Includes baffles that form baffles and / or baffles. Further, it is proposed that impact elements of teeth of an internal toothing a peripheral part, possibly a portion of a guide element of Guide arrangement or a separate peripheral part of the impact arrangement, are formed. But it should not be excluded that one Wall of the vacuum tank the peripheral part forms.

The against each other separate baffle elements or integrally connected Impact elements, possibly teeth, enable, that an angle between the trajectory of a media droplet and a respective baffle portion across from a simply extending only in the circumferential direction baffle surface is increased and an angle of 90 ° can or even reaches this. The media droplets are therefore hit maximally deformed and cut. There are high shear forces that for venting effect contribute. Furthermore, a large media surface emerge, through which the venting effect also much favored becomes.

Regarding the internal teeth will be on it thought that it has triangular or sawtooth-like teeth, preferably such unsymmetrical teeth that the medium incident angle is increased to serving as a baffle tooth side of a respective tooth against a symmetrical tooth formation.

To another, very advantageous embodiment is provided that the impact arrangement a sieve arrangement, grid arrangement or Lochelementanordnung comprises, which of at least one baffle or the bounce edges bounded openings having.

For example can have at least one baffle be formed by a grid or a perforated plate. By providing of many refractive edges, there is a distribution of the impinging Media droplets. One part of the medium stays at the baffle, the other part hits through the baffle therethrough. It can media droplets also be partially distracted. The result is the vent favoring high shear forces, and also the resulting, comparatively large media surface contributes to one good ventilation effect essential in.

Prefers is provided that the or at least a centrifugal plate as Whole for rotation about the substantially vertical axis of rotation drivable is.

It But it is also thought that the whip dish or at least a whiplash a stationary distribution plate section and one for rotation about the substantially vertical axis of rotation having drivable sling edge. It can be a particularly even distribution the medium can be achieved on the centrifugal plate in the circumferential direction, possibly there occurring media accumulations in a feed area not immediately by centrifugal forces radially outward be thrown, but first distribute on the whip dish can. Such a configuration of one or more centrifugal plates is of fundamental Interest, also independent from the embodiment of the invention Baffle assembly.

To another independent Aspect of the invention is therefore provided an apparatus for degassing a liquid or pasty Medium, in particular a coating color for coating a substrate, in particular a paper web, a board web or the like, comprising a vacuum chamber in which a negative pressure can be generated is an inlet assembly, which the medium in the vacuum chamber introduces, an outlet assembly containing the medium from the vacuum chamber dissipates, at least in the vacuum chamber arranged centrifugal plate, can be supplied to the fed into the vacuum chamber medium Wherein at least one slinger from the whip dish for rotation is drivable about a substantially vertical axis of rotation. According to the invention, it is provided that the whip plate or at least one whip dish a stationary Distribution plate section and one for rotation around the substantially having a vertical axis of rotation driven dribble.

Advantageous can the Scheuderteller be executed with a Siebrand, through which the medium must pass, and then thrown off to become. As a result, the degassing effect is enhanced. in the Trap of execution the or a whip dish with a stationary distribution plate section The Siebrand can serve as a sling edge. In front of the whip dish associated impact arrangement, possibly baffle arrangement, another can Effective area, z. B. a sieve arrangement may be provided. It will be special to a stationary effective area thought, from which the medium under the action of gravity too one below lying centrifugal plate or to a collection area of the vacuum chamber arrives.

Generally it is proposed that the inlet arrangement the medium so supplies, that the medium is a center of an upper whip dish or stationary Distribution plate distributed. In particular, it is proposed that the inlet arrangement the medium around the center of the upper centrifuge plate or stationary distribution plate distributed. Ideal is an even distribution as possible around the circumference of the centrifuge plate or distribution plate to a ensure optimum ventilation effect. An even distribution is that especially at the topmost centrifuge plate or at the stationary distribution plate important, since the distribution provided here determines the distribution of the medium in the device as a whole, also with respect to the lower whiplash plates, strongly influenced.

you may be appropriate, that the inlet arrangement has a plurality of distributed around the center discharge openings having the medium at the same time on the surface of the release upper whip dish or distribution plate. It will for the Equalization of Distribution thought that the discharge openings a beam broadening Outlet geometry for dispensing a fan or / and funnel-shaped jet of the medium. The discharge openings may, for example, flat fan nozzles, Tongue nozzles, vane nozzles, Gießkannenkopfdüsen or Atomizing nozzles formed be. It can for example, three to six nozzles, preferably four nozzles, be provided. Appropriately, the Nozzles exchangeable accomplished be.

It should be noted, however, that also non-broadening discharge openings come into consideration. For this purpose, it is thought that the individual discharge openings are comparatively small and present in larger numbers. It can be achieved so that due to a small distance between the individual openings, the rays of the medium meet closely next to each other on the upper centrifuge plate or distribution plate and virtually connect with each other and thus give a uniform distribution of the medium over the entire circumference. One might also think of providing one or more slot nozzles extending around the circumference.

Is appropriate a multipart design of the Medium supply, for easy installation and cleaning.

As already addressed, can several vertically stacked arranged whiplash be present.

It can - as already addressed - in the Vacuum chamber return plates or return funnel be arranged, which thrown off from an upper whip dish Medium after hitting at least one baffle to a feed lower-lying whirling dish. Such leadership and return arrangements can expediently multipart accomplished be.

One the negative pressure chamber having vacuum or vacuum container can at least one sight glass, at least one further connection for a pressure measurement, at least one connection for a vacuum breaker (for the continuous and quick lifting of the Negative pressure).

The Apparatus may further be provided with a temperature control arrangement for controlling be carried out a temperature of at least a portion of the device. As a tempering medium water or steam can be used, which is preferably in a cooling medium circuit or heated medium circuit out becomes. It can be heated, for example, with tempered water, ideally with a temperature control. Especially useful is a bottom of the vacuum tank to heat, so that the collected medium before flowing through the outlet assembly is heated. This allows the venting at saturation vapor pressure in the lower part of the deaerator be reached quickly during operation and the venting is favored. An upper area of the breather may be appropriate a slightly lower temperature to be held by condensation possible contamination the components and exterior walls to act. This can be achieved without special cooling measures, though the medium entering the vacuum chamber itself is not yet is so warm, for example, was pre-cooled. For example, can Medium at a temperature of 24 ° C are supplied. That in the bottom Chamber area collected medium can then, for example, a temperature from 35 ° C exhibit. At 56 hPa is for this temperature is the saturation vapor pressure reached. By further reducing the pressure, the medium may 35 ° C in a state corresponding to a "cooking" being held.

Is appropriate a cooling the application medium immediately before entering the vacuum chamber or directly during the feeder. This is particularly important if the application medium from the production or processing even more Temperature has. Advantage of a cold medium before degassing, that a lower pressure can be set before the saturation vapor pressure is reached. The background is that with less pressure less Gas is dissolved in the medium and correspondingly more gas through a vacuum pump or vacuum pump can be deducted.

Is appropriate in particular, a cooling at least a part of the container wall, for example with water. In this context, a temperature control is advantageous. By condensation, a deposition of the medium is prevented or reduced, which is especially true in non-flushed or non-flushable areas is advantageous.

Cooling in particular Water can also be provided near a vertical drive shaft. For example, one can see an area where the shaft enters the vacuum chamber enters, rinse with water or another cooling medium, in particular at one Seal assembly. Thus, frictional heat can be removed from the seal assembly and can Deposits on the shaft are avoided. Is the wave as typical provided, made of metal, so can the shaft on this Be cooled very well, also by taking advantage of the heat conduction of the metal to cool areas inside the vacuum chamber.

to Tempering of the vacuum chamber limiting wall or of wall sections, the vacuum chamber in a complete or partially realized double-walled container.

It can Also individual tempering arranged outside of the container be. It can also cooling lines arranged so and possibly extend into the vacuum chamber so, that they return surfaces or Reverse funnel temper or heat dissipate from these can.

In In this context, it is specifically proposed that the tempering heats a collecting portion of the device, in which from collects the at least one centrifuge disc dispensed medium. It can be provided that the tempering a section the inlet arrangement or a flow direction of the medium upstream of the Inlet assembly arranged portion of the device cools.

Further is thought that the tempering at least one Section of a wall surrounding the vacuum chamber cools. Another appropriate possibility is that a drive unit for the rotary drive of the centrifuge plate or whose spin edge by means of at least one rotary shaft and / or a rotary bearing of the rotary shaft and / or the rotary shaft at least partially by means the tempering coolable is.

It can leading the medium or interacting elements inside the vacuum chamber be tempered by the tempering.

Preferably is the device with a pressure inside the vacuum chamber equal to or less than a saturation vapor pressure of the medium operable. It is especially thought that with her a liquid or pasty Application medium can be degassed, which is at least one binder and at least one pigment, and preferably a solids content between 50 to 80% by weight or / and a viscosity between 700 and 4000 mPas.

The The invention further relates to an applicator device comprising at least a commissioned work for applying a liquid or pasty medium, in particular a coating color, for coating a substrate, in particular a paper web, a board web or the like. According to the invention is a Inventive device for bleed provided the medium, the commissioned work directly or indirectly connected to the outlet assembly or connectable. The commissioned work, which preferably as a curtain commissioned work accomplished is, can a slot nozzle comprising the medium directly or indirectly on the substrate emits.

It For example, it is related to an application of the invention with a curtain coater with slot or slide nozzle with 1: 1 direct order. For other order types, for example "JetFlow F "is the device according to the invention also usable, but not so urgently needed there here usually a final dosage is followed. Concerning the applications the device according to the invention exist basically no restrictions.

The The invention further provides a method, in particular an application method and / or degassing processes, which are prepared using a device according to the invention carried out becomes.

• – Einlassen des Mediums in die Unterdruckkammer,
• – Verteilen des Mediums im Inneren der Unterdruckkammer unter Abschleudern des Mediums von wenigstens einem Schleuderteller,
• – Auslassen des Mediums aus der Unterdruckkammer.

The invention further relates to a method for degassing a liquid or pasty medium, in particular a coating color for coating a substrate, in particular a paper web, a board web or the like. This device (which may be an inventive device according to the above-mentioned aspects of the invention) comprises a vacuum chamber in which a negative pressure can be generated, an inlet arrangement which introduces the medium into the vacuum chamber, an outlet arrangement which extracts the medium from the vacuum chamber discharges and at least one arranged in the vacuum chamber centrifugal plate, is fed to the fed into the vacuum chamber medium, wherein the centrifugal plate or at least one spin edge thereof for rotation about a substantially vertical axis of rotation can be driven. The method according to the invention comprises - for degassing the medium - the following steps:

• - introducing the medium into the vacuum chamber,
• Distributing the medium in the interior of the vacuum chamber while centrifuging the medium from at least one centrifuge plate,
• - Leaving the medium from the vacuum chamber.

• – Spülen der Unterdruckkammer und darin befindliche Komponenten mit einem Spülmedium.

The method preferably further comprises the step of degassing the medium:

• - Rinsing the vacuum chamber and components therein with a flushing medium.

Usually, the specified steps for degassing or venting of the medium are carried out simultaneously, since the medium is usually fed continuously, degassed and removed. Such a degassing operation can, in principle, be maintained for any length of time. Depending on the production requirements, operating times of a few hours to a few days are common. Regarding the distribution of the medium, it should be noted that it is not important that the distribution is uniform. It is particularly important that the medium receives a large surface, so that the venting effect is improved. If the deaerator or deaerator is not in the degassing or venting mode, it can then be cleaned for a new venting or degassing operation to be carried out later by flushing the vacuum chamber. This can be done manually or - preferably - automated. Such a cleaning is especially important when different media are to be degassed. Furthermore, it is also useful for the use of a breather only with respect to a medium to clean, so that no residual media or components of the medium remain, which later can only be removed with difficulty and impair the quality of later supplied medium or could interfere with the venting operation ,

A development It is proposed that the device with a control unit coupled, which after interrupting the supply of the medium the supply of the flushing medium starts to rinse the step to perform the device.

One Such method, in which after the use of the device for Degassing automatically a rinsing sequence with a cleaning medium, possibly water, is introduced, is very useful, also with regard to warranty the functionality and possibly order quality in the case of a coating medium, in particular coating medium. The Vacuum chamber can automatically from the order medium circuit separated and switched into a cleaning medium circuit. The completion of the cleaning can be done manually or automatically, after a pre-set period of time.

The Invention will be described below with reference to the figures embodiments explained in more detail.

1 shows a rough schematic cross section of a degassing device according to the invention according to an embodiment.

2 shows a rough schematic cross section through the degassing of 1 according to section line AA, however, according to a conventional embodiment of such a degassing device.

3 shows a rough schematic cross section of the degassing of 1 according to section line AA according to a first embodiment of the invention.

4 shows in the subfigures 4a ) and 4b ) in question alternative embodiments of the first embodiment.

5 shows in the subfigures 5a ) to 5e ) Other alternative embodiments of the first embodiment.

6 shows a rough schematic cross section of the degassing of 1 according to a section line AA according to a second embodiment of the invention.

7 shows in the subfigures 7a ) and 7b ) a possible embodiment of a Pralisiebs or impact grid of the second embodiment.

8th shows a rough schematic cross section of the degassing of 1 according to section line AA according to a third embodiment of the invention.

9 shows in the subfigures 9a ) to 9c ) further alternative embodiments of the third embodiment variant.

10 shows in a rough schematic cross section a candidate development of the degassing of 1 ,

1 shows an embodiment of a degassing device 10 , which is used to degas a via a supply line 12 supplied medium, for example, a coating or coating medium, is used. It can be a high-viscosity coating color.

The device comprises a vacuum container 14 which is connected via at least one connection (not shown) to a vacuum pump or vacuum pump, in a vacuum chamber defined by the container 16 Underpressure, if necessary, a vacuum, to generate defined. It is understood that the vacuum container may be provided with a sight glass, a pressure measurement port, a vacuum breaker port, and the like. The vacuum connection and other connections are in 1 at 18 symbolically represented.

In preferably rotationally symmetrical executed vacuum tank 14 is a vertically extending drive shaft 20 rotatably mounted, which is driven by a drive unit (possibly motor, in particular electric motor) for rotation, for example with a rotation of about 1000 min ^-1 . The drive unit 22 can on one in the 1 not shown in detail lid of the vacuum tank 14 be attached or integrated with this.

The drive shaft 20 carries in the embodiment of two coaxially arranged, vertically staggered whiplash 24a and 24b , which can also be referred to as a slinger, turntable or the like. Each spinner disc has, starting from its outer circumference a defined distance to an inner surface 26 egg ner container wall of the vacuum tank 14 on. Conventionally, such an inner surface often serves as a baffle for spun from the plate medium.

The upper whiplash 24a is a funnel-like guide element 28 (also referred to as return funnel) assigned. Conventionally, an inner surface directed radially inward in an upper region of such a guide element often serves as a baffle surface for the upper centrifugal disk 24a centrifuged medium as in 2 shown. Due to the rotation (arrow R) of the whirl plate 24a result due to the centrifugal force and inertia trajectories, for example, according to the arrows B for from the edge of the plate or a Siebring 36a spun-off medium droplets, which at a comparatively flat angle of incidence α on the inner surface 29 of the guiding element 28 to meet.

In contrast, the invention provides a special baffle arrangement which allows or contributes to a more efficient venting than in the prior art. In the embodiment, the upper whip dish 24a the baffle arrangement 30a and the lower whiplash 24b the baffle arrangement 30b assigned. Exemplary embodiments of the impact arrangement according to the invention 30a (and according to the baffle arrangement 30b ) are in the 3 to 9 illustrated and will be explained in more detail below.

The impact arrangement according to the invention 30a , against which from the upper whip dish 24a spun off medium, can in the embodiment of the 1 from the guide element 28 be formed or executed separately from this. From the baffle arrangement, possibly a baffle arrangement, draining medium is provided with a lower funnel section 31 of the guiding element 28 the lower whiplash 24b fed. That of the lower whiplash 24b spun-off medium strikes against a baffle arrangement according to the invention assigned to the lower centrifuge plate 30b , which may be formed by the wall of the vacuum tank and, alternatively, by at least one separate impact component. According to the state of the art, that would be from the lower centrifuge plate 24b spun-off medium, for example, simply against the rotationally symmetrical inner surface 26 meet and it would be a similar situation as after 2 with only comparatively flat angles of incidence α for the impinging media droplets. According to the invention, the baffle arrangement 30b for example, analogous to the embodiments according to the 3 to 9 be executed.

That on the lower baffle arrangement 30b The appropriate medium drains from this and then continues to run over the inner surface 26 down or drips from the baffle assembly down and collects in a lower area 33 the vacuum chamber 16 , In this lower area according to 1 collected, degassed by the action of the negative pressure and the effect of the centrifugal plates and the baffle medium is with 32 referred to and can from the vacuum tank 14 through an outlet 34 be deducted, in particular for application by means of an associated commissioned work, possibly curtain applicator, on a moving fibrous web (possibly paper or board web).

The fundamental Operation of such a degassing device is general in the art known and need not be explained further. For degassing effect carries next the adjustable, for example, the saturation vapor pressure of the medium adjustable negative pressure and the strong acceleration of the medium or of medium droplets on the whiplash plates and the sudden deceleration of the medium or of medium droplets by the baffle arrangements, possibly baffle arrangements, at.

An important consideration is the most even distribution of the medium in the vacuum vessel, especially the upper centrifugal plate 24a , This could - in deviation from 1 - the supply line 12 For example, several feed the fan-like medium nozzles, the distributed as circumferentially medium jet as evenly distributed around the drive shaft 20 on the upper whip dish 24a submit.

Both whip dishes are with a sieve ring 36a respectively. 36b equipped, which rotates with the respective centrifuge plate and through which the medium supplied to the centrifugal plate occurs under the action of centrifugal force, and then from the plate or its Siebring outwards against the associated baffle arrangement 30a respectively. 30b to be hurled.

According to the in 3 illustrated embodiment is the baffle arrangement 30a from a symmetrical sawtooth or triangular internal toothing 40 educated. The teeth extending in a vertical direction over a certain height serve with a tooth flank surface as the respective baffle surface element or respective baffle surface. Opposite the situation of 2 the angle of incidence is significantly increased and it can easily be achieved with a corresponding mutual design an impact or impact angle of 90 °, as in 3 indicated. Due to the large or 90 ° approximate or corresponding incidence angle, a respective medium droplet is deformed or distributed as much as possible upon impact. High levels unfold Shear forces and also results in a large media surface, so that a total of a very effective ventilation is achieved.

As in 4a ) illustrates the gearing 40 be realized in solid material, for example in the upper portion of the guide element 28 or alternatively, a separate impact element. 4b ) shows a variant in which the teeth 40 from a correspondingly deformed sheet 41 is formed, which opposite the guide element 28 is carried out separately. Such a separate impact element can, for example, by means of a stator assembly on the guide element 28 be held, which itself by a stator assembly on the wall of the vacuum tank 14 can be held.

5 shows in the subfigures a) to e) alternatively in question tooth forms of the teeth 40 forming teeth 42 , These are just examples. Basically, there are no restrictions on the intended tooth shape in terms of size, symmetry or non-symmetry, etc. It should be selected such a tooth shape and relative arrangement that as possible an impact angle of 90 ° for the medium droplets is achieved.

Another embodiment is in 6 shown. Here it is with 30a ' designated, the upper centrifugal plate associated impaction of a grid or hole element ring 50 (possibly perforated plate ring) formed, which has a plurality of holes or openings 52 (see. 7a ) and 7b )) having. Ringwandungsabschnitte 54 of the grid or hole element ring 50 form a baffle or baffles and a plurality of refractive edges for impinging droplets of media. Due to the many refractive edges, there is a fragmentation of the impacting media droplets. One part of the medium remains at the baffle, the other part occurs at a respective opening 52 through the baffle. The medium droplets are also partially deflected. High shear forces occur and due to the large surface area of the media, the venting effect can develop very well.

In the embodiment of the 8th is that now with 30a '' designated impact arrangement of a plurality of separate, individually arranged baffle elements 60 formed on the inner surface 29 of the guiding element 28 arranged distributed in the circumferential direction and held there. It will also be an opposite to the situation of 2 increased impact angle for those of the whirl dish 24a reached thrown off media droplets. According to 8th extend as simple pieces of sheet metal exactly in the direction radially inward. 9 shows in the subfigures a) to c) other possible embodiments. The angle of inclination of the baffle elements with respect to the circumferential direction is in principle arbitrary, and should ideally be adjusted so that the angle of incidence corresponds to approximately 90 °. It is so - as already in relation to the embodiment of the 3 designed - ensures that impinging droplets are maximally deformed or divided and act high shear forces and the medium spread over a large surface, so that a total of a very effective ventilation is obtained.

The embodiment of 10 differs from the embodiment of 1 on the one hand by a tempering 66 , which is disposed at an upper portion of the negative pressure chamber, to a bearing portion of the rotary shaft 20 , the rotary shaft 20 and to cool other adjacent parts of the device. This includes the tempering 66 one the rotary shaft 20 circulating channel 68 in which a cooling fluid circulates. Other local cooling arrangements known to those skilled in the art may alternatively be used.

Furthermore, further tempering arrangements 66 ' . 66 '' and 66 ''' provided, which one but also the tempering 66 to look at.

With the tempering arrangement 66 ' is a section of the supply line 12 or generally an inlet arrangement of the degassing cooled. Through the tempering arrangement 66 '' are medium-conducting portions of the wall or mediated by the wall medium-conducting components inside the vacuum chamber 16 cooled. Specifically, a first cooling channel is running 68a around a section of the supply line 12 that is outside the vacuum chamber 16 lies. Second cooling channels 68b circulate annularly on the outside of the wall of the vacuum tank 14 each at the level of the two whiplash plates 24a . 24b , By thermally conductive materials, in particular for a stator assembly, as well as a cooling of the guide element 28 and the baffle arrangements 30a and 30b be achieved. The tempering arrangement 66 '' has, for example, a heating channel 70 on, the ring around the container wall in the lower area 33 runs.

The cooling channels 68a and 68b During operation, a cooling medium flows through them and either forms part of a common cooling medium circuit so that they can be operated by a single cooling unit (not shown) or belongs to individual cooling medium circuits, so that the temperature of individual sections of the device can be adjusted separately.

The heating channel 70 is flowed during operation of a heating medium and is part of a heating medium circuit. It is possible to adjust the temperature of the accumulating degassed medium 32 In which, for example, the saturation vapor pressure can be set by means of a coordinated adjustment of the negative pressure and the temperature of the medium.

By cooling the device in certain areas can be counteracted in particular an accumulation of medium and thus the maintenance of the device can be facilitated. In the embodiment, in particular, the guide element and the baffle arrangements against which the medium thrown off by the centrifuge plates bounces are cooled. For this purpose, it makes sense to produce these components and the components holding stand or the like made of thermally conductive material, as already mentioned. It is also possible that cooling channels and / or heating channels in the vacuum chamber 16 have been led in there to specifically cool certain areas or components or to heat. Preferred is a controlled cooling or heating based on a temperature detection by sensor elements.

Regarding all embodiments, an automatic flushing by supplying a cleaning medium, such as water, possibly with cleaning additive, be realized. The flushing is preferably carried out fully automatically under the control of an associated control unit. The cleaning medium can via the supply line 12 as well as additional rinsing feeds or rinsing nozzles are supplied.

All embodiments or variants may - as based on the embodiment of 10 by way of example with temperature control devices for the preferably controlled, highly preferably controlled cooling or heating of different device regions or device components. In this way, for example, for the venting operation, a negative pressure corresponding to the saturation vapor pressure of the medium can be set. Hard-to-clean areas can be kept at a reduced temperature level to achieve condensation of water vapor so that impinging media will not settle but drain more easily.

About the respective outlet 34 withdrawn medium can be fed directly to further processing or application. It is specifically (but not exclusively) intended to paint a fibrous web.

A Device for degassing a liquid or pasty medium, in particular a coating color for coating a substrate, in particular a paper web, a board web or the like, comprising a vacuum chamber in which a negative pressure can be generated is an inlet assembly, which the medium in the vacuum chamber introduces, an outlet assembly containing the medium from the vacuum chamber dissipates, at least one as a whole or at least in sections, in particular concerning a spinning edge for rotation about a substantially vertical Rotary axis drivable, arranged in the vacuum chamber whirling dish, can be supplied to the fed into the vacuum chamber medium and at least one associated with the whipper dish, at least partially around the circumference of the centrifuge plate extending baffle arrangement in the vacuum chamber, against the thrown from the centrifuge bowl Medium meets, characterized by the fact that the baffle arrangement with a plurality of distributed at least in a circumferential direction Baffle edges and / or with a plurality of at least one baffle and / or limited by at least one respective baffle, at least arranged in a circumferential direction openings arranged and / or with a Plurality of opposite a circumferential course of the baffle arrangement in a medium Aufaufwinkel magnifying Direction inclined, at least distributed in a circumferential direction arranged baffles or baffle sections accomplished is.

10

degassing

12

supply line

14

Pressurized container

16

Vacuum chamber

18

Connections and like

20

drive shaft

22

drive unit

24a, b

Whirling plate

26

palm

28

vane

29

baffle

30a, b 30a ', 30a' '

baffle assembly

31

funnel section

32

degassed medium

33

lower Area of the vacuum tank

34

outlet

36a, b

Siebrand

40

internal gearing

41

sheet metal part

42

tooth

50

grid or hole element ring

52

opening

54

Ringwandungsabschnitt

60

Baffle element

66 66 ', 66' '', 66 '' '

Temperature control order

68a, b

cooling channel

70

heating duct

R

direction of rotation

B

trajectory

Claims (33)

Apparatus for degassing a liquid or pasty medium, in particular a coating color for coating a substrate, in particular a paper web, a cardboard web or the like, comprising: - a vacuum chamber ( 16 ), in which a negative pressure can be generated, - an inlet arrangement ( 12 ), which introduces the medium into the vacuum chamber, - an outlet arrangement ( 34 ), which discharges the medium from the vacuum chamber, - at least one arranged in the vacuum chamber whirling plate ( 24a . 24b ), is fed to the fed into the vacuum chamber medium, wherein the spin plate or at least one sling edge ( 36a ; 36b ) thereof for rotation about a substantially vertical axis of rotation is driven, - at least one of the centrifugal plate associated, at least partially extending around the circumference of the centrifuge plate impaction arrangement ( 30a ; 30b ; 30a ' . 30a '' ) in the vacuum chamber, against which thrown off from the centrifugal disc medium, characterized in that the impact arrangement with a plurality of at least distributed in a circumferential direction arranged baffles or / and with a plurality of at least one baffle ( 54 ) and / or openings bounded by at least one respective baffle edge and distributed at least in a circumferential direction (US Pat. 52 ) and / or with a plurality of opposite a circumferential course of the baffle arrangement in a direction of medium Aufaufreffwinkel increasing direction, at least distributed in a circumferential direction arranged baffles ( 42 ; 60 ) or baffle sections. Apparatus according to claim 1, characterized in that the impact arrangement ( 30a ; 30b ; 30a '; 30a '' ) stationary in the vacuum chamber ( 16 ) is arranged and is preferably carried out separately relative to a container wall bounding the vacuum chamber. Apparatus according to claim 2, characterized in that the or a baffle arrangement ( 30a ) of at least a portion of a guide arrangement provided in the vacuum chamber ( 28 ), the collected centrifuged medium to a lower lying further centrifugal plate ( 24b ), or that the baffle arrangement serves as such a guide arrangement. Apparatus according to claim 2, characterized in that the or a baffle arrangement ( 30a ) in relation to a guide arrangement provided in the vacuum chamber ( 28 ) is executed separately and arranged inside thereof, the collected centrifuged ( 24b ) Supplies medium to a deeper further centrifugal dish. Device according to claim 2 or 4, characterized in that the or a baffle arrangement ( 30a ; 30a '' ) or a plurality of impact elements ( 60 ) thereof on an inner side of the container wall or on an inner side of the guide arrangement ( 28 ) is arranged and held. Device according to one of the preceding claims, characterized in that the impact arrangement and / or the guide arrangement executed in several parts and / or is removable from the vacuum chamber. Device according to one of the preceding claims, characterized in that the impact arrangement ( 30a '' ) a plurality of mutually separate impact elements ( 60 ) which form baffles or / and baffles. Device according to claim 7, characterized in that the impact elements ( 60 ) of a holding peripheral part, preferably a portion of a guide element ( 28 ) of the guide arrangement project radially inwards and are distributed in the circumferential direction. Device according to one of the preceding claims, characterized in that the impact arrangement ( 30a ) at least one group of one-piece contiguous impact elements ( 42 ) which form baffles or / and baffles. Device according to claim 9, characterized in that impact elements of teeth ( 42 ) an internal toothing ( 40 ) of a peripheral part, possibly of a section of a guide element ( 28 ) of the control arrangement or a separate peripheral part ( 41 ) of the baffle arrangement, are formed. Apparatus according to claim 9 or 10, characterized in that the internal toothing ( 40 ) has triangular or sawtooth teeth, preferably such unsymmetrical teeth ( 42 ) that the medium incident angle is increased to a serving as a baffle tooth side of a respective tooth against a symmetrical tooth formation. Device according to one of the preceding claims, characterized in that the impact arrangement ( 30 '' ) comprises a sieve arrangement, grid arrangement or perforated element arrangement which corresponds to that of at least one impact surface ( 54 ) or the baffle edges limited openings ( 52 ) having. Device according to one of claims 1 to 12, characterized in that the or at least one whiplash ( 24a . 24b ) as a whole is drivable for rotation about the substantially vertical axis of rotation. Device according to one of claims 1 to 12 or according to the The preamble of claim 1, characterized in that the whirl dish or at least one centrifuge disc a stationary distribution disc portion and one for rotation about the substantially vertical axis of rotation having drivable sling edge. Device according to one of claims 1 to 14, characterized in that the centrifugal disc ( 24a ; 24b ) with a possibly serving as a sling Siebrand ( 36a ; 36b ) is executed. Device according to one of the preceding claims, characterized characterized in that the inlet arrangement feeds the medium such that the medium is centered around an upper whip dish or stationary distribution plate distributed. Device according to claim 16, characterized in that that the inlet arrangement the medium around the center of the upper whip dish or stationary Distributed distributing disc. Device according to claim 17, characterized in that that the inlet arrangement has a plurality of distributed around the center Having discharge openings, which the medium at the same time on the surface of the upper whip dish or distribute distribution plate. Device according to one of the preceding claims, characterized in that several centrifugal discs ( 24a . 24b ) are arranged vertically one above the other. Device according to one of the preceding claims, further comprising a tempering arrangement ( 66 . 66 ' . 66 '' . 66 ''' ) for controlling a temperature of at least a portion of the device. Device according to claim 20, characterized in that the tempering arrangement ( 66 ''' ) heats a collecting portion of the device in which collects from the at least one centrifuge disc discharged medium. Device according to claim 19 or 10, characterized in that the tempering arrangement ( 66 ' ) cools a portion of the inlet assembly or a portion of the apparatus located upstream of the inlet assembly in the flow direction of the medium. Device according to one of claims 20 to 22, characterized in that the tempering arrangement ( 66 '' ) cools at least a portion of a wall surrounding the vacuum chamber. Device according to one of claims 20 to 23, characterized in that a drive unit ( 22 ) for the rotary drive of the centrifuge plate or its centrifugal edge by means of at least one rotary shaft ( 20 ) and / or a rotary bearing of the rotary shaft and / or the rotary shaft at least in regions by means of the tempering arrangement ( 66 ) is coolable. Device according to one of claims 20 to 24, characterized in that medium-conducting or interacting elements in the interior of the vacuum chamber by the tempering ( 66 '' ) are temperature controlled. Device according to one of the preceding claims, characterized in that it has a pressure inside the vacuum chamber ( 16 ) is equal to or less than a saturation vapor pressure of the medium operable. Device according to one of the preceding claims, that with her a liquid or pasty application medium can be degassed, which at least one binder and at least a pigment, and preferably a solids content between 50 to 80% by weight or / and a viscosity between 700 and 4000 mPas having. Applicator device comprising at least one applicator for applying a liquid or pasty medium, in particular a coating color, for coating a substrate, in particular a paper web, a cardboard web or the like, with a device ( 10 ) according to any one of the preceding claims, wherein the applicator directly or indirectly at the outlet arrangement ( 34 ) is connected or connectable. Applicator according to claim 28, wherein the preferably has a slot nozzle as a curtain applicator, which emits the medium directly or indirectly to the substrate. Process, in particular order procedure and / or Degassing process performed using a device according to one of the preceding Claims. Method for degassing a liquid or pasty medium, in particular a coating color for coating a substrate, in particular a paper web, a board web or the like, using a device for degassing a liquid or pasty medium, in particular a coating color for coating a substrate, in particular a paper web, a board web or the like, if desired according to one of claims 1 to 30, comprising: - a vacuum chamber ( 16 ), in which a negative pressure can be generated, - an inlet arrangement ( 12 ), which introduces the medium into the vacuum chamber, - an outlet arrangement ( 34 ), which discharges the medium from the vacuum chamber, - at least in the vacuum chamber arranged centrifugal plate ( 24a . 24b ), is fed to the fed into the vacuum chamber medium, wherein the spin plate or at least one sling edge ( 36a ; 36b ) thereof for rotation about a substantially vertical axis of rotation can be driven, comprising - for degassing of the medium - the steps: - Inlet of the medium in the vacuum chamber ( 16 ), - distributing the medium in the interior of the vacuum chamber while centrifuging the medium of at least one centrifugal disc ( 24a . 24b ), - discharging the medium from the vacuum chamber. The method of claim 31, after degassing the medium further comprising the step of: - purging the vacuum chamber ( 16 ) and components contained therein with a flushing medium. Method according to claim 32, characterized in that in that the device is coupled to a control unit, which after interrupting the supply of the medium, the supply of the flushing medium starts to rinse the step to perform the device.