DE102005004081A1 - Dishwashing agent-saving rotary atomizer - Google Patents

Abstract

Rotational sprayer has a symmetrical bell-shaped body (1) with nose part (2), cover part (3) with divergent surface (8) and steering gas ring (7) with at least one steering gas nozzle (13,13'). The divergent cover has a shoulder (11) between nose and cover part, which extends ring-like around the nose part and denotes an angle of at least 90[deg] of the exterior surface to the spray device. The nozzle is arranged so that its spray (14) hits the cover part inside the shoulder.

Description

The The invention relates to a rotary atomizer having the features of The preamble of claim 1. Such a rotary atomizer can for example, for the automatic painting of automobile bodies used commercially in the mass production of automobiles.

such rotary atomizers usually a rotatable bell body on, which is a hub part for connecting to a drive motor and a jacket part for spraying of the coating material. The drive motor is for example a pneumatic motor, with the help of the bell body with very high speed (some 10000 revolutions per minute) can be rotated. The resulting centrifugal forces act on the atomizing, liquid Coating material, which is introduced into the bell body, and accelerate it in the casing part in the direction of a spray-off edge, where it in the form of a mist of small droplets (short: spray) leaves the bell body of taken a gas stream and in the form of a Zerstäuberstrahls is accelerated in the direction of a substrate to be coated.

at such Rotationszerstäubern The problem may occur that parts of the coating material undesirable on the outside surface of the Sheath part of the bell body settle, for example due to splashes or Rückspritzern. These Deposits or residues may be present subsequent coating operations detach from the shell part and the quality affect the coating. This problem is especially evident when it is when the coating material to a paint of a particular color and in a subsequent coating process a paint a different color is used. Dissolve at a subsequent Coating process residues of a previous one Coating process, so can the subsequently applied paint Contain particles of the first paint with a different color. One such coated substrate may be unusable.

This problem is already known in the art. From the European patent EP 0 715 896 B1 For example, a rotary atomizer with a bell body, in which a detergent can be passed through special holes and channels within the bell body on its lateral outer surface, so that it can be cleaned between two coating operations. The rinsing agent is thereby moved by the centrifugal forces due to the rotation of the bell body through the holes or channels. It passes into a U-shaped annular space which lies on the outer surface of the bell body in the region of the transition between the hub part and the shell part and surrounds the hub part annularly. The opening of the U of the U-shaped annular space is facing away from the interior of the bell body. As a result of the centrifugal forces, the rinsing agent flows via the radially outer edge delimiting the annular space to the outer surface of the casing part of the bell body and is distributed over it. The rotary atomizer also has air nozzle rings whose nozzle jet impinges on the jacket part of the bell body outside of the U-shaped annular space. The rotary atomizer has a relatively complicated construction. Furthermore, there is a risk that deposits in the U-shaped annulus coating material, so for a satisfactory cleaning result relatively much detergent must be used, which adversely affects the operating costs.

Under the term "cleaning result" becomes the completeness the removal of coating material residues the outer surface of the shell part of the bell body Understood. The less disturbing Coating material residues on the Shell surface outside to remain after a cleaning process, the better the cleaning result.

Out US Pat. No. 6,341,734 B1 involves a further rotary atomizer a bell body out. The outer surface of the Sheath part of the bell body does not have any depression, e.g. the above-mentioned U-shaped annulus, on, in which coating material could settle. In which bell body are holes or channels for one dish soap provided in the area of transition between hub part and shell part directly on the outer surface of the Open jacket part. In the area of estuaries has the lateral surface a flattened shoulder area. Furthermore, gas nozzles are provided, their jets outside the Shoulder area, to the mouths Radially spaced meet the shell part. The rotary atomizer points a simpler design, the distribution of the detergent on the outside surface of the lateral surface of the bell body is unsatisfactory, however, so that a relatively large amount of detergent must be used, to achieve a good cleaning result.

Against this background, it was an object of the present invention to provide a rotary atomizer, which has a simple construction and in which for the cleaning of the outer surface of the Mantle part of his bell body only a little detergent must be used to achieve a good cleaning result.

The above-mentioned The object is achieved by the subject matter defined in the main claim solved. Preferred embodiments are in the subclaims Are defined.

object The present invention is accordingly a rotary atomizer with a rotationally symmetrical bell body, which is a hub part for Connecting with a drive motor has, as well as a jacket part for spraying a coating material in the form of a spray, wherein the spray direction parallel to the axis of rotation, further comprising a steering gas ring, the around the hub part is arranged symmetrically to the rotation axis, and the at least one in Absprührichtung aligned steering gas nozzle for molding the spray, the shell part being a divergent one Having outer surface, from the transition between the hub part and the jacket part up to a spray-off edge of the Sheath part extends, further comprising at least one outer scavenging duct for Conducting a detergent on the diverging outer surface. According to the invention the diverging outer surface at the transition between hub part and shell part on an area which is annular around the hub portion extends, and in the tangent to the outer surface with the spray direction one Angle of at most Include 90 ° (short: shoulder area). At least one gas nozzle is arranged so that you jet meets the shell part within the shoulder area.

The Absprührichtung does not reflect the trajectory of individual droplets of the spray, but instead the direction of the entire atomizer jet or spray cones.

When Coating material is preferably a paint in question.

When Steering gas is preferably used air, since air is the cheapest and most easily available and manageable gas represents. However, it is also conceivable that other gases are used as the steering gas, for example an inert gas or inert gas when air-sensitive coating materials are atomized.

Of the Term "detergent" includes in the context of present invention also solvents, Detergents and other liquid Agents suitable for removing coating residue.

Of the jet the at least one steering gas nozzle meets according to the invention within the shoulder area on the jacket part. Because a jet generally does not have a 100% defined extent, can non-essential parts of the jet, which are arranged in the edge region, inadvertently outside of the shoulder area hit the shell part. It is crucial that the center and the essential parts of the jet hit the shell part within the shoulder area.

Of the inventive rotary atomizer with bell body has a simple construction. Through the shoulder area nozzle jet striking the jacket part the at least one steering gas nozzle becomes a particularly tight and good fitting to the outer surface of the shell part Lenkgasstrom generated, in conjunction with the rotation of a especially good in the spray direction aligned and bundled Zerstäuberstrahl generated. As a result, very little or even none arise Coating material splashes or back splashes that are on the Outside surface of the Jacket part disturbing settle and by cleaning and use of detergent must be removed. Furthermore, the used by the improved flow of steering gas dish soap distributed more evenly on the outer surface to be cleaned. Both causes washing up liquid for the Cleaning the outer surfaces of the shell part of the bell body can be saved without the cleaning result deteriorates. Through the well-aligned and concentrated atomizer jet arises as well only a little overspray, so that coating material can be saved can and improves the painting result. By the simple Construction, the production costs for the rotary atomizer according to the invention are relatively low.

at an embodiment of the rotary atomizer according to the invention has the steering gas ring at least a nozzle ring on, consisting of two or more, preferably thirty up to sixty gas nozzles is formed, wherein at least the nozzle of the nozzle ring with the least Radial distance to the hub (in short: inner nozzle ring) are arranged so that her jet meets the shell part within the shoulder area. The gas nozzles are preferably equidistant arranged distributed on a radius around the hub part around. Thereby can be at reasonable complexity the device generates a further improved steering gas flow As a result, even less coating material residues arise, which removes detergent with great effort Need to become, and consequently as well the distribution of the detergent even more even and thus detergent-saving he follows.

In a further development, the steering gas ring has at least one further outer nozzle ring whose nozzles have a greater radial distance from the hub than the nozzles of the inner nozzles wreath and wherein the jet of the jet hits the shell part outside the shoulder region. As a result, an even better atomized spray jet can be generated.

at A further development of the steering gas ring is integral with the bell body educated. As a result, the radial distance between the gas nozzles and The hub part fixed so that no misalignment can take place. As a result, a deterioration of the steering gas flow by misalignment be prevented, so that a consistent quality of the coating result, a consistently small amount of coating material residues and ensures a consistently good distribution of the detergent is.

at An embodiment of the rotary atomizer according to the invention includes tangents Outer surface in the shoulder area with the spray direction an angle of 70 to 90 °, preferably from 90 ° (under consideration the currently technically usual or possible low tolerances). Such a trained shoulder area supports in interaction with the rotation and / or the steering gas flow the even distribution of detergent on the outside surface of the Sheath part of the bell body and wear it to improve the cleaning result and to save detergent at.

at a further embodiment of the rotary atomizer according to the invention the outer surface of the Shell part bell-shaped educated. This is a flow dynamic favorable Form that the formation of a close-fitting stream of steering gas for optimal distribution of detergent supported on the shell part and thus contributes to reducing the need for flushing.

at In a further development of the bell body is designed so that the shoulder area with respect the axis of rotation to the outside arched area adjacent, preferably a conically widening to the outside Area adjacent. This geometric shape has proven to be fluid dynamic very cheap exposed to effect a close-fitting flow of gas.

Of the bell body can also at least partially, preferably in the region of the outer surface, a Have coating with an anti-adhesive. The anti-adhesive takes care of it a low adhesion of coating material splashes or re-spatters, so less or even no dish soap must be used to remove coating residue. In this case, the coating material splashes or back splashes adhere bad or not on the bell body, but still flow while the coating process, e.g. as a result of rotational centrifugal forces, in Essentially complete from. Indicates the bell body Such a non-stick coating, so may possibly less Außenspülkanäle provided become. Will ever no detergent for removing the coating material splashes or back splashes needed because this e.g. Completely flow away, it may even be possible to completely dispense with external rinsing channels become.

at The anti-adhesion agent may be a nanoparticle containing Act composition, in particular containing a nanoparticle Lacquer (short: Nanolack). The use of nanoparticles has the Advantage that surfaces with tailor made Properties, especially with very low free energy, can be created on which very little coating material spatter or splashback stick, so that their removal is particularly low detergent is required.

Suitable non-sticking agents can be purchased, for example, from the company NANO-X GmbH, for example as coating compositions which impart so-called "easy-to-clean" and non-stick properties to a surface treated therewith, and as additives for coating compositions, paints and coatings A suitable anti-adhesive agent of this company is, for example, x- ^clean® EC 4008.

at a preferred embodiment of the rotary atomizer according to the invention opens at least an outdoor rinse duct at the transition between hub part and shell part on the outer surface. This has to do with regard to on one as possible even distribution of detergent on the outer surface of the Jacket part proved to be particularly advantageous.

there It is further preferred if at least two outer rinsing channels are provided, preferably eight to twenty outer rinsing channels and in particular ten to sixteen outdoor rinse channels. Thereby can dish soap Already fairly evenly distributed on the outside surface of the Jacket part are applied before it is further distributed there, without that the design effort for the rotary atomizer on the moderation elevated.

In a particularly preferred embodiment of the rotary atomizer according to the invention, the at least one outer scavenging duct opens into at least one nozzle ring, preferably into the inner nozzle ring. Thereby, the rinsing agent can be distributed in a cleaning process by the steering gas flow on the outer surface of the shell part. In the context of the present invention has been shown that such a very gleichmä ßige distribution of detergent can be achieved, so that only a small amount of detergent must be used to achieve a good cleaning result. Furthermore, there is the possibility of performing a rinsing process with a good cleaning result and low consumption of detergent even at a standstill, ie without the bell body being rotated, in particular if more than one steering gas nozzle is provided. In addition, the possibility opens up to clean the gas nozzles with detergent, since the coating material can spray back under unfavorable circumstances up to the shaping air nozzles and can be distracting there.

at a likewise preferred embodiment of the rotary atomizer according to the invention are at least two Außenspülkanäle provided by which at least a first at the transition between the hub part and the shell part opens onto the outer surface and at least a second in at least a nozzle ring opens preferably in the inner nozzle ring. Thereby can the advantages of the two embodiments disclosed above with each other be combined.

at In a further development, at least two first outer rinsing channels are provided, preferably eight to twenty first outer rinsing channels and in particular ten to sixteen first outdoor rinse channels. Thereby can dish soap Already fairly evenly distributed on the outside surface of the Jacket part are applied before it is further distributed there, without that the design effort for the rotary atomizer on the moderation elevated.

at a variant of the rotary atomizer according to the invention has the sprayer edge at least one guiding element for the coating material on. This makes the education special small coating material drops favored. It has been shown that the risk of coating material splashes or re-spatters is lower, the smaller the coating material droplets are. The smaller the Coating material droplets the less coating material spatters or re-splashes are have to So detergent-consuming be removed.

The at least one guide element can be formed as grooves, which is technically very easy to implement, for example by milling of channels. The grooves can with respect to the axis of rotation be radially aligned (in short: longitudinal grooves), be inclined in or against the direction of rotation, as a cross grooves be formed or the like. Through the grooves, the coating material at the spoiler edge to the outside directed. As a result, the coating material is clean on the inner surface of the jacket part and leaves the trailing edge in a precisely defined manner as a channeled droplet jet. This prevents turbulence at the trailing edge leading to coating material spatters or -rejections to lead could.

The Invention will be described below with reference to the figures in the figures illustrated concrete embodiments and the associated Description closer explained. Show

1 a detail of a first embodiment of a rotary atomizer according to the invention;

2 a detail of a second embodiment of a rotary atomizer according to the invention;

3 a bell body of a rotary atomizer according to the invention with guide element;

4 an atomizing jet (a) of a rotary atomizer according to the invention; (b) a conventional rotary atomizer.

1 shows an embodiment of the present invention. Schematically illustrated is a section of a cross section through a rotary atomizer according to the invention. The rotary atomizer has a rotationally symmetrical bell body ( 1 ) with hub part ( 2 ) for connection to a drive motor (not shown), a shell part ( 3 ) for spraying a coating material in the form of a spray and a transition ( 4 ) between hub part ( 2 ) and shell part ( 3 ). Furthermore, the rotation axis ( 5 ) illustrates. The direction of discharge is indicated by the arrow ( 6 ). 1 further shows a part of a steering gas ring ( 7 ) around the hub part ( 2 ) is arranged symmetrically. The shell part ( 3 ) has a spray direction ( 6 ) diverging outer surface ( 8th ) arising from the transition ( 4 ) of the hub part ( 2 ) over the shell part ( 3 ) to the spray-off edge ( 9 ). On the outer surface ( 8th ) may be applied an anti-adhesive agent (not shown).

The bell body ( 1 ) has an outer rinsing channel ( 10 ), through which a rinsing agent from a supply line (not shown) in the interior of the hub part ( 2 ) on the outer surface ( 8th ) can be directed. The external rinsing channel ( 10 ) ends at the transition ( 4 ) on the outer surface ( 8th ). Shown is only an external rinsing channel ( 10 ); however, the rotary atomizer may have two or more external rinsing channels ( 10 ) exhibit.

At the transition ( 4 ) between hub part ( 2 ) and Shell part ( 3 ), the bell body ( 1 ) a shoulder area ( 11 ), in which tangents ( 12 ) to the outer surface ( 8th ) with the discharge direction ( 6 ) parallel to the axis of rotation ( 5 ), an angle α of about 85 °. The shoulder area ( 11 ) extends annularly around the hub part ( 2 ).

The steering gas ring ( 7 ) is substantially rotationally symmetrical, with the axis of rotation ( 5 ) as symmetry axis. He has two nozzle rings, the forty inner gas nozzles ( 13 ) (inner nozzle ring) and forty outer gas nozzles ( 13 ' ) (outer nozzle ring) are formed, wherein the gas nozzles ( 13 . 13 ' ) of a nozzle ring are arranged distributed equidistantly on a radius. For reasons of clarity, however, only four gas nozzles are shown, of which only two are designated ( 13 . 13 ' ). The gas nozzles ( 13 . 13 ' ) are in the direction of discharge ( 6 ) to form a spray of sprayed coating material. Here are the gas nozzles ( 13 ) of the inner nozzle ring arranged so that its jet ( 14 ) in the shoulder area ( 11 ) on the shell part ( 3 ) meets. The jets ( 14 ' ) of the gas nozzles ( 13 ' ) of the outer nozzle ring meet outside the shoulder area ( 11 ) on the shell part ( 3 ). For clarity, are representative of all jets of gas nozzles ( 13 . 13 ' ) only two jets ( 14 . 14 ' ).

The outer surface ( 8th ) is bell-shaped. It borders on the shoulder area ( 11 ) an area in which the shell part ( 3 ) with respect to the axis of rotation ( 5 ) is curved outward. This is adjoined by another area in which the shell part ( 3 ) extended conically outwards.

Further Details of a rotary atomizer are the person skilled in principle known. They are therefore for reasons of clarity not shown.

2 shows another embodiment of the present invention. Schematically illustrated is a section of a cross section through a rotary atomizer according to the invention. The rotary atomizer is constructed similar to the rotary atomizer 1 , but has the following differences: bell body ( 1 ) and steering gas ring ( 7 ) are integrally formed; they are external rinsing channels ( 10 . 10 ' ) provided in the inner nozzle ring or the inner gas nozzles ( 13 ), so that detergent from a supply line (not shown) in the interior of the hub part ( 2 ) in the gas nozzles ( 13 ), from where it can be directed to the outer surface by means of the flow of steering gas ( 8th ) and can be evenly distributed there. Only two external rinsing channels are shown ( 10 . 10 ' However, the rotary atomizer may have more outer rinsing channels. Not shown are further outer rinsing channels, which at the transition ( 4 ) between hub part ( 2 ) and shell part ( 3 ) on the outer surface ( 8th ), as may be provided in a further embodiment of the present invention.

3 shows the rotary atomizer 1 which is a guiding element for promoting the formation of particularly small coating agent droplets ( 15 ) for the coating agent. The guide element is along the spray edge ( 9 ) and in the form of longitudinal grooves ( 16 ) formed in the spray-off edge ( 9 ) are milled. From the longitudinal grooves ( 16 ) are shown seventeen, wherein for the sake of clarity only one, representing all, is provided with a reference numeral.

4 Figure 2 shows a comparison between simulated trajectories of coating agent droplets in (a) a rotary atomizer according to the invention and (b) a prior art rotary atomizer not according to the invention. It can be clearly seen that the steering air flow from the steering gas ring ( 7 ) in the case of the rotary atomizer (a) according to the invention close to the bell body ( 1 ) and thereby a clean, well-aligned and bundled atomizing jet ( 18 ), in which only a very small amount of coating agent residues, such as spatter or back splashes, are to be feared. In contrast, in the case of the rotary atomizer (b) not according to the invention, the shaping air flow is unclean, so that a diffuse spray jet ( 18 ), in which many coating agent residues, in particular from the secondary jet ( 17 ), it is to be feared that the solvents have to be removed expensively.

The comparison thus shows that in the simply constructed rotary atomizer according to the invention for the cleaning of the outer surface ( 8th ) only a small amount of detergent must be used to achieve a good cleaning result.

1

bell body

2

hub part

3

jacket part

4

crossing between hub part and jacket part

5

axis of rotation

6

Absprührichtung

7

Steering gas ring

8th

Outside surface of the casing part

9

spray edge

10 10 '

Außenspülkanäle

11

shoulders

12

tangent

13 13 '

Steering gas nozzles

14 14 '

jets

15

vane

16

longitudinal groove

17

secondary beam

18

Zerstäuberstrahl

Claims (17)

A rotary atomizer with a rotationally symmetrical bell body, which has a hub part for connection to a drive motor, and a jacket part for spraying a coating material in the form of a spray, wherein the spray direction is parallel to the axis of rotation, further comprising a steering gas ring which is arranged around the hub part symmetrical to the axis of rotation and at least one spray nozzle aligned in the spray direction for molding the spray, the shell portion having a diverging outer surface extending from the transition between the hub portion and skirt portion to a spray edge of the skirt portion, further comprising at least one outer rinsing channel for directing a rinse agent onto the body divergent outer surface, characterized in that the diverging outer surface at the transition between the hub part and the shell part has a region which extends annularly around the hub part, and in the tangent to the outer surface with the A Bsprührichtung an angle of at most 90 ° include (shoulder area), and that the at least one steering gas nozzle is arranged so that its jet jet within the shoulder region on the shell portion. rotary atomizers according to claim 1, characterized in that the steering gas ring at least a nozzle wreath comprising two or more, preferably thirty to sixty gas nozzles formed is, wherein at least the nozzles the nozzle wreath with the smallest radial distance to the hub (inner nozzle ring) are arranged so that their jet meets the shell part within the shoulder area. rotary atomizers according to claim 2, characterized in that the steering gas ring at least another, outer nozzle ring having, whose nozzles a larger radial Distance to the hub have as the nozzles of the inner nozzle ring and wherein the jet of the jet outside of the shoulder area meets the jacket part. rotary atomizers according to one of the claims 1 to 3, characterized in that the steering gas ring in one piece with the bell body is trained. rotary atomizers according to one of the claims 1 to 4, characterized in that tangents to the outer surface in the shoulder area with the spray direction an angle of 70 to 90 °, preferably of 90 °. rotary atomizers according to one of the claims 1 to 5, characterized in that the outer surface of the jacket part is bell-shaped. rotary atomizers according to one of the claims 1 to 6, characterized in that at the shoulder area a in terms of the axis of rotation to the outside corrugated Area adjacent, preferably to a conically widening outward area borders. rotary atomizers according to one of the claims 1 to 7, characterized in that the bell body at least partially, preferably in the region of the outer surface, a coating with having an antiblocking agent. rotary atomizers according to claim 8, characterized in that it is the anti-adhesive agent nanoparticle containing composition is preferred a nanoparticle-containing paint (nanolack). rotary atomizers according to one of the claims 1 to 9, characterized in that the at least one outer scavenging duct at the transition between the hub part and the shell part opens onto the outer surface. rotary atomizers according to claim 10, characterized in that at least two outer rinsing channels provided are preferably eight to twenty outer rinsing channels, more preferably ten to sixteen outdoor rinsing channels. rotary atomizers according to one of the claims 1 to 9, characterized in that the at least one outer scavenging duct in at least a nozzle ring opens preferably in the inner nozzle ring. rotary atomizers according to one of the claims 1 to 9, characterized in that at least two Außenspülkanäle provided of which at least a first at the transition between hub part and shell part opens onto the outer surface and at least a second opens into at least one nozzle ring, preferably in the inner Nozzle ring. rotary atomizers according to claim 13, characterized in that at least two first Außenspülkanäle provided are preferably eight to twenty first outer rinsing channels, more preferably ten to sixteen first outer rinsing channels. rotary atomizers according to one of the claims 1 to 14, characterized in that the spray-off edge at least one guide element for the Coating material has. rotary atomizers according to claim 15, characterized in that the at least one guide element is formed as grooves. rotary atomizers according to claim 16, characterized in that the grooves with respect to the axis of rotation are radially aligned (longitudinal grooves), in or inclined against the direction of rotation or as a cross groove are formed.