DE4336085A1 - Method for removing liquid from the surface of a wetted material to be treated and arrangement for carrying out the method - Google Patents

Abstract

Processes for the removal of fluid adhering to surfaces of objects to be treated by means of compressed-air jets emerging from orifices in air-jet devices and directed onto the objects to be treated are known. Processes of this type are used, for example, for removing electroplating fluid adhering to surfaces. The disadvantage of the known processes is that stainless drying is impossible or is possible only at a considerable outlay in terms of apparatus. A process and an arrangement, in which, for stainless drying, air-jet devices, from which the compressed-air jets emerge, are set in oscillating movement in at least one plane, are therefore described. As a result, the fluid on the surface of the object to be treated is essentially atomised and consequently removed rapidly from this. The remaining surface moisture can evaporate. Heated compressed air is used to assist the evaporation. <IMAGE>

Description

The invention relates to a method for removing a surface of Treatment-adhering liquid and an arrangement for carrying out the Procedure.

In the wet chemical treatment of material to be treated, hereinafter also In short, well-known, such as in electroplating systems, the task is with Transport the goods from one treatment bath to the next as little as possible Procrastinating treatment liquid. The liquid on the surface of the Good adherence must be removed from the bath after removal. After last treatment, this removal must be carried out until it is completely dry be performed. For certain, mostly decorative goods, this drying must stain-free.

This task is performed in the known systems for surface treatment unsatisfactorily solved economically and environmentally. This is how the Good from bathroom to bathroom after each excavation as long as possible drip time provided.

In addition, the goods are sometimes shaken or vibrated to remove adhering drops. Blowers are also known, such as. B. Jet sticks arranged on the baths. When lifting, the good turns on  led past the nozzles and blown. Dryers are powered by a motor bene blowing devices past the goods located there several times. In addition, the dryer air can be warmed to a complete liquid cause evaporation even in inaccessible areas of the goods ken. Solvents are also used for spot-free drying Squeeze out the treatment liquid and then evaporate faster on the goods.

A disadvantage of these known methods is that long draining or drying times are necessary. Evaporation of the adhering liquid requires additional energy and in the case of the use of solvents, the order burdened world. Nevertheless, the results are unsatisfactory. Adhesive drops the treatment liquid are carried over into the respective subsequent bath. They can only be partially removed from the upper by blowing from air jets remove surfaces. The blowing causes a momentary displacement of the drops a wind-sheltered place of the estate, however, a complete removal takes place not instead. The drops have a particularly disadvantageous effect when they are removed a completely spot-free product is produced for technical or decorative reasons should be, because an evaporating water drop always leaves in practice a visible stain on the surface.

EP 0486711 A1 describes a method and a device described for surface treatment systems that are also suitable for spot-free drying should be suitable without solvent. This is a further development of the nozzle blocks for air blowing described above. You are guided past the property and the air flows out of the nozzles high speed on the material to be dried. A microprocessor controls Solenoid valves that interrupt the air flow in quick succession. Thereby there are pulsating air blasts that adhere to the material to be dried  Reduce or destroy drops that are in the area of this air, d. H. that are captured by the air jets hitting the material perpendicularly.

The disadvantage of this method is that the air blasts on each side of the goods always hit the material to be dried from only one direction. The good would have to be plate-shaped in order to be able to reach all surface areas. As a rule, the material to be treated is shaped in many ways. Here reach parallel Blast only part of the surface to be treated. Especially with strong For decorative reasons, shaped fittings are free of stains required. And just here, not all surface areas are covered by the only vertical pulsating air jets. This leads to again Ineffectively long drying times and excessive air consumption.

The object of the invention is to provide a method which enables the the one dug out of a wet chemical bath or extended horizontally To remove well adhering liquid up to the complete drying and thereby to avoid the disadvantages of the known methods. Furthermore, the after Arrangements using this method are technically simple to implement enable.

The task is solved with at least one device that blows the material to be treated, elongated air jet device with openings along the surface line. These Air jet device moves relatively and linearly on the material to be dried over, preferably cleaned and dried compressed air ver is applied. You and / or the one immediately surrounding the air jet device Air can be heated. The air jet device carries at least one at the same time oscillating motion that overlaps the relative linear motion. A torsional oscillation around the can be considered as oscillating movements  Longitudinal axis of the air jet device, without or with a linear vibration in Axis direction of the same. Furthermore, this torsional vibration and torsional vibrations of the Air outlet openings around one to the longitudinal axis of the air jet device parallel axis offset by an angle of approx. 90 °. In this case they are Air outlet openings designed as movable nozzles.

In a further embodiment of the invention, a plurality of stationary ren, parallel arranged air jet devices used. You run the oscillating movements in one or two directions. The linear relative A hoist moves the goods and moves them up and down.

In the embodiments of the invention, the frequencies and amplitudes, i.e. H. the vibration ranges of the oscillating movements as well as the slow ones Linear movement coordinated so that all surface areas of one Good things can be grasped.

The air jets are on the sides of a bath or dryer arranged so that all surfaces of the material to be dried can be blown at the same time nen. In the case of wet chemical processes, the goods to be treated are placed on product carriers hung up with known fasteners such as clips or racks and transported by transport vehicles through the plant. The length of the goods carrier is in the range of up to a few meters. The material to be treated forms on the goods carrier thus two large areas, namely a front and a back. Of Remove the adhering liquid from both sides. The following will to simplify the description of the invention always from a material to be treated assumed that attached to a goods carrier by a wet chemical system is transported. The invention extends expressly to the Area of horizontal continuous lines, generally without goods carriers work.  

According to the invention, at least on both sides of the material to be treated an oscillating air jet device moves relatively past. The air jet device can be horizontal, vertical or in any direction with respect to the goods carrier be arranged. It can move past the stationary goods carrier or the goods carrier moves with the goods to be blown at the air jet device tung over. In the electroplating industry, trolleys are known which have a Cabin equipped for spraying and draining the material while driving are. The air according to the invention can also be used in such transport vehicles beam devices are installed. The advantage here is that given Travel times from one treatment station to the next thanks to the Removal of the liquid from the surface of the goods leads to a deterioration in quality and a time saving is achieved.

Due to the oscillating movements of the elongated air jet device it is achieved that the air is not only from one direction on the to be dried Surface hits, but from different constantly changing directions. This ensures that all, even with strongly shaped items to be treated Surface areas covered by the air and all liquid adhering to it drops are removed. The complete removal of the drops and not only their current displacement is achieved in that with high oscillations speeds are worked. The comparatively sluggish drops cannot evade and atomize quickly enough in the sweeping Air jet. This is reinforced by the constantly changing Impact speed speed of the air on the product as a result of the swiveling of the nozzles Distance changes from its surface. The changes in the impact From the perspective of the goods, speed causes local fluctuations in air pressure. These and the directional component of the beam have permanent swirls  surface liquid resulting in the atomization of the drops in the Space supports and then the evaporation of the remaining moisture, which none Drops can form more until complete and therefore also stain-free Drying speeds up. This effect can be influenced by the choice of the Distance of the air jet device from the surface of the goods. As expedient It has turned out to be ugly, in the case of plate-shaped goods a small distance in centi meter range and for heavily shaped goods a larger distance in decimal area to choose.

The complete drying is done according to the prior art by heating of the material to be treated. In addition, the last rinse bath with a Heating. In this case the property absorbs so much heat that during the subsequent drying in the circulating air dryer, the evaporation at the Surface is promoted from the inside out. It is supposed to be the drying process counteracting evaporative cold can be compensated. Is that to be dried Well, whether previously warmed or not, blown by cold air, this lengthens it the evaporation process. Another serious factor is that compressed air turns off flow relaxed from nozzles and thus cools down. This cold air in sizes order of a few cubic meters per minute in a forced air dryer with about equal volume to the material to be dried there with high Blown at speed, the hot dryer air circulates out of the dryer ner. The surface of the goods becomes cold. By the flow of cold air the evaporation of the residual moisture takes considerably longer. Therefore, fiction in accordance with advantageously heated compressed air for a material to be dried completely the air jet devices used. Is the good in a heated rinsing bath preheated, then warm air can ver during the entire blowing be applied. Warm air is advantageous to complete in the final phase and spot-free drying. For this, e.g. B. a heater in the  Compressed air line can be switched on. The warm air contributes to faster evaporation the residual moisture without the large thermal energy that is usual for dryers to have to spend, because the moisture on the property is targeted locally and with ver equally small amounts of air is heated. Contains a spot free too drying material to be treated threaded holes or blind holes, so it happens that even when using the air jet device according to the invention in this Lö small drops of liquid remain. They are followed by Circulating air drying evaporates. The drying spots are at these points of the Good neither technically but decoratively relevant.

In the invention it is advantageous that already with air pressures from 2 bar and one three times linearly running over the surface to be dried in each direction achieved very good drying results at a speed of 4 meters per minute become. The low pressure results in low air consumption. By Adjustment of the process parameters pressure, temperature of the compressed air, speed the relative motion, frequencies and amplitudes of the oscillating Movements, number and direction of the air jet devices as well as number and This can be done in the direction of the holes or nozzles of these air jet devices The method according to the invention is optimal for the material to be treated wet-chemically to adjust.

The invention is not limited to vertical immersion baths, but also to deal with wet chemical processes with horizontal transport deluding good. A common example of this is the treatment of leaders plates in a horizontal pass through wet chemical and / or electrolytic working systems. They are located on the top and bottom of the goods the air jet devices described. They are stationary or they run one additional movement with and against the transport device of the to be dried Printed circuit boards. The air jet devices oscillate in the same way  Way and at the same speeds as with calcification treatment of the Good.

The following drawings serve to explain the process further and the orders.

In detail shows

Fig. 1 Principle of an arrangement for removing liquid, which is located on the surface of parts in plan view.

Fig. 2 principle of a drying station with several air jet devices.

Fig. 3 arrangement of a dryer, which operates according to the invention drive Ver.

Fig. 1 shows in plan view a schematic representation of the inventive method. On a goods carrier 1 is the material to be treated, here parts 2 , which have been wetted by immersion in an aqueous bath or spraying with treatment agent. After removal, this liquid adheres to the surface of parts 2 . Drops do not fall off. These are blown off using the method according to the invention. The air jet devices 3 in the form of tubes 12, which are elongated in the depth of the drawing, are used for this purpose. You are on the front 4 and back 5 of the goods carrier 1st These air jet devices 3 have openings 6 in the form of bores or nozzles at a surface line or alternately offset at several surface lines. The distance of the holes or nozzles in the lower centimeter range can be regular or irregular depending on the requirements of the goods. The incoming compressed air is indicated with the arrows 7 . It flows out of the openings 6 onto the parts 2 to be dried. The air jet devices 3 are each pivoted about their axes by a drive, not shown, as the double arrows 8 represent. Several air jet devices can be swiveled by one drive. This has the advantage of completely synchronizing the swivel movements. By pivoting ken in the example of FIG. 1, approximately nine parts of the air flow are sequentially detected. The double arrow 9 indicates the swivel range, ie the amplitude of the torsional vibration of each part 2 is angela sen from a different direction, ie at a different angle. Swiveling takes place at a relatively high frequency, for example with five full torsional vibrations per second. Frequencies that differ widely from this can also be selected. The air jet devices oscillating in this way are moved slowly and approximately parallel to the parts 2 to be dried by a linear drive. This linear movement is represented by the arrows 10 in one direction and 11 in the opposite direction. The rapid pivoting movement and the slow linear movement of the air jet device overlap in such a way that each part 2 to be dried during an overall linear movement from one end of the goods carrier 1 to the other is blown very intensively at any time at a different angle. Thus, undercuts are achieved that cannot be detected with a constant blowing direction. The additional linear vibration of the air jet device 3 perpendicular to the plane of the drawing is not shown in Fig. 1 bar. The reference number 13 indicates this.

The amplitudes 9 and 13 and the frequencies of the oscillating movements as well as the path and the speed of the linear movement can be individually adjusted to the material to be dried and fixed. In a further embodiment of the invention, these sizes are automatically set depending on the material to be dried by the control of the wet chemical system. Manual adjustments of these amplitudes and frequencies are also possible.

In Fig. 2, for example, three stationary air jet devices 3 are shown on each side of the items 14 to be marked with dash-dotted lines in a drying station. The torsional vibrations indicate the double arrows 15 and the linear vibrations the double arrows 16 . The slow linear relative movement of the material to be treated 14 to the air jet devices 3 is indicated by the double arrow 17 . A lifting mechanism, not shown, slowly moves the goods up and down.

A practical application is described below using the example of a dryer. Fig. 3 shows a perspective view of a dryer, as used for example in electroplating systems. The air jet devices 3 for the front and rear of the parts 2 are carried by slide guides 19 and moved linearly in the direction of arrows 10 and 11 . The drives hidden in the drawing are supplied with energy via energy chains 20 . In addition, they supply the compressed air to the air jet devices via flexible hoses. The spars 21 also serve to hold these hoses. The swivel drives 22 are shown here in the example as a cylinder. Its linear movement is deflected into the swiveling movement 8 of the air jet device 3 . This pivoting movement can also be achieved by means of a rotating drive. The rotating movement is converted into the torsional vibration using a cam or an eccentric. The arrow 13 indicates the linear vibration. The drive for this can be arranged in the region of the guide 23 or in the head 18 of the air jet device. The tube 12 engages at its lower end in a guide 23 in order to maintain a uniform distance from the parts 2 to be dried, which are shown here without a goods carrier.

The drives for the slow linear movements 10 , 11 of the air jet lines 3 from the front and rear can be synchronized with one another. This makes it possible to maintain defined positions with respect to one another, which is of advantage if the compressed air jets on both sides, depending on the material to be treated, distract each other or support their effect, that is, by the locally and currently different air pressures. To optimize the fluid swirling described, both the slow linear movements and the fast swiveling movements and / or the linear vibrations can be synchronized on both sides.

In Fig. 3 there is a horizontal linear movement from the right to the left side of the dryer and vice versa. For constructional or drying reasons, it can also be expedient to carry out this movement with the air jet device lying horizontally from top to bottom and back. This can be achieved with the known methods and means of mechanical engineering and will therefore not be described in more detail here.

In a further embodiment of the invention, the acceleration of the Drying process, each offset by 90 ° on the front and rear Air jet devices used. They move linearly and independently of one another other horizontally and vertically in the dryer. This has the advantage that it is too dry parts are blown from further directions. Doubling the Air jet devices therefore reduce the drying time for molded goods less than the half.  

For the recovery of valuable materials and to avoid carryover losses there is the possibility to immobilize the air jet devices in immersion baths To be arranged horizontally and parallel to the goods carrier, on the side of the badbe above the bath level. The linear movement is here when lifting of the product carrier from the bathroom. The lifting speed must be so slow be chosen that the relative linear movement possible here only once sufficient to achieve the required recovery.

It is understood that further combinations of air jet devices and their Arrangements at different angles can be realized. Furthermore, that Air jet devices are synchronized with each other in all their movements can or can be driven completely unsynchronized.

The use in a dryer includes that this with the known order air heating devices and / or vibration devices is additionally equipped, that a combination of drying techniques is used.

Claims (29)

1. A method for removing a liquid adhering to the surface of the material to be treated, characterized in that at least one langge stretched air jet device ( 3 ) with openings ( 6 ) arranged on its longitudinal side moves reiatively on the material to be dried before and that this movement at least one oscillating movement of the air jet device ( 3 ) is superimposed in such a way that the parts ( 2 ) are blown into the air from changing directions with different impact speeds. 2. The method according to claim 1, characterized in that the air jet direction ( 3 ) carries out torsional vibrations about its longitudinal axis. 3. The method according to claim 1 and 2, characterized in that the air jet device ( 3 ) executes linear vibrations in the axial direction. 4. The method according to claim 1 and 2, characterized in that movable nozzles of the air jet device ( 3 ) perform torsional vibrations around axes which are offset by an angle of approximately 90 ° from the longitudinal axis of the air jet device. 5. The method according to claims 1, 2 and 3, characterized in that the air jet device ( 3 ) carries out torsional vibrations about its longitudinal axis and linear vibrations in the axial direction. 6. The method according to claims 1, 2 and 4, characterized in that the air jet device ( 3 ) perform torsional vibrations about its longitudinal axis and its movable nozzles torsional vibrations about axes which are offset by an angle of 90 ° to the longitudinal axis. 7. The method according to at least one of claims 1 to 6, characterized records that the air jet device on the parts to be dried is moved. 8. The method according to at least one of claims 1 to 6, characterized records that the parts to be dried past the air jet device be moved. 9. The method according to at least one of claims 1 to 8, characterized records that in a drying station several air jets are stationary and that the goods are moved past them. 10. The method according to at least one of claims 1 to 9, characterized records that the linear and / or oscillating movements of the air blasting devices the front and the back of the to be dried Treated goods are synchronized with each other. 11. The method according to at least one of claims 1 to 10, characterized records that the linear and / or oscillating movements of the air blasting devices the front and the back of the to be dried Good things run unsynchronized.   12. The method according to at least one of claims 1 to 11, characterized records that the linear and oscillating movements of the air jet directions in their frequency and amplitude are fixed. 13. The method according to at least one of claims 1 to 11, characterized records that the linear and oscillating movements of the air jet directions in their frequency and amplitude depending on the type of drying parts can be changed automatically or by hand. 14. The method according to at least one of claims 1 to 13, characterized records that heated air to blow on the parts to be dried is used. 15. The method according to claim 14, characterized in that the heated Compressed air is only used at the end of the drying process. 16. The method according to at least one of claims 1 to 15, characterized records that heated air to support the drying process is used. 17. The method according to at least one of claims 1 to 16, characterized records that the air jet device horizontally, vertically or in one Angle to this is moved linearly. 18. The method according to at least one of claims 1 to 17, characterized records that several and arranged in different directions to each other Nete air blasting devices are used on each side.   19. The method according to at least one of claims 1 to 18, characterized records that the parts to be dried horizontally by at least two Air jet devices are transported through. 20. Arrangement for removing a liquid adhering to the surface of the material to be treated, in particular for carrying out the method according to claims 1 to 19, characterized in that tubes ( 12 ) with openings ( 6 ) and drives for linear movement and oscillating pivoting of the tubes ( 12 ) with openings ( 6 ) in a dryer and hoses for supplying compressed air to the pipes are provided. 21. The arrangement according to claim 14, characterized in that the openings ( 6 ) are boreholes. 22. The arrangement according to claim 14, characterized in that the openings ( 6 ) are nozzles. 23. The arrangement according to claim 22, characterized in that the nozzles one have common swivel drive. 24. The arrangement according to at least one of claims 20 to 23, characterized in that the openings ( 6 ) are made at regular or irregular intervals on at least one surface line of the tube ( 12 ). 25. The arrangement according to at least one of claims 20 to 24, characterized in that the tube ( 12 ) is pivotally mounted in a longitudinal axis. 26. The arrangement according to at least one of claims 20 to 25, characterized in that a linear drive or a rotating drive with an eccentric or cam is used for pivoting the tube ( 12 ). 27. The arrangement according to at least one of claims 20 to 26, characterized in that the tube ( 12 ) is provided with an axially acting vibratory drive. 28. The arrangement according to at least one of claims 20 to 27, characterized in that the oscillating tubes ( 12 ) are placed horizontally and stationary on the sides of an immersion bath. 29. Arrangement according to at least one of claims 20 to 28, characterized in that the air jet devices ( 3 ) are attached to the trolley.