DE1752212A1 - Plant for coating objects - Google Patents

Description

A 19504 Ka / Ka

The DeYILBISS COMPANY $ 00 Phillips Avenue,
l'oledo, Ohio, USA

Plant for coating objects

The invention relates to an installation for .beschichten of articles and devices for spraying the Gegenstän- Λ, wherein substantially reduced amounts of air are required than before and in which the .uuft is conducted in low-turbulence flow to the spray heads and the articles.

The main reason for a .Luftzu- and exhaustion in systems for coating objects, preferably, by spraying, iAFC to see that in the air

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suspended spray particles should be kept at a concentration below the critical explosion limit. The amounts of air required for this are relatively small. A considerably larger volume will be However, it is used in spray systems to protect the operator large volumes of air are needed to absorb the excess To remove spray and to prevent spray build-up on the spray devices, as the build-up is frequent Bring interruptions and cleaning work with them. Size Air volumes would also be reduced significantly can if the spray devices can be located in a similar area as the operator.

According to the invention, a system for coating objects in two chambers with a wall between them are divided, which is arranged in the! Sähe of spray heads and has an inlet surrounding the spray heads for the guidance of the air from the area behind the spray heads * in the direction of the objects that are being coated will roll. The air can from a spray chamber to a

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of the spray heads and the. Inlet distant point be withdrawn in order to lead the air to where it is at the is most needed and to keep the turbulence in the air flow as small as possible. The operator is then as well as a device that moves the spray heads back and forth including various actuators with associated structural elements on that side of the wall arranged in the system for coating, which is opposite the objects to be coated. The one through the inlet, the one the spray heads surrounds ^ incoming air can be moved at a relatively high speed, even at Use of relatively small volumes of air because the size of the opening is limited. This speed works are such that there is no possibility of excess spray material flowing back through the opening and come into contact with the operator or parts of the spray device. This way are when applied relatively small air volumes the operator and the components are protected against excess spraying agents. When the air enters the spray chamber through the limited opening, it can expand so that the Air speed is reduced significantly. In this way the spray particles are not proportionate to one another carried high speed against the objects to be coated, in general a considerable part of the Spray particles as excess in the behind the counter

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standing area is worn.

The considerable saving in air volumes enables a considerable reduction in the size of the fan and the air ducts. This lowers both the investment and the operating costs of the overall facility. In addition, the air supplied to the spray chamber is heated, especially P as a convenience for the operator. The cost of heating is often a significant cost of the total cost of ownership of spray systems. By a substantial reduction of the required amounts of air for the spray chamber and the üLosten be for the ^A air ufheizung considerably reduced.

In some applications, the spray heads are moved back and forth in the direction of the center plane of the system, if . the size of the objects to be coated is different. With this in mind, the spray heads are at thicker objects moved away from the central plane of the system and offset in the direction of the central plane of the system, when it comes to thinner objects · In such In some cases, the mutual arrangement of the spray heads and the inlet through which the air enters the changes Spray chamber is introduced in order to change the flow properties in the area of the spray heads. To the properties the air flow constantly and evenly counter-

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To hold over the spray head are according to the invention. Walls or panels provided that a relatively narrow "Form air inlet around the spray heads and are arranged in such a way that they are moved back and forth with the spray heads" the can. A wall-forming component of the spray chamber is provided with a passage that connects to the diaphragm in this way cooperates that practically no air can flow between the walls of the passage and the diaphragm. In this way the air flowing into the Jiammer arrives at a constant rate Flow pattern in the area of the spray heads, regardless of the respective position of the spray heads opposite the objects to be coated to ensure a constant flow of air to maintain the properties of the spray heads.

The object of the invention is therefore primarily to create a spray system that is considerably smaller Luftverbrauah has as previously usual, <so that significantly lower operating costs arise.

In this context, according to the invention, a spray system is to be created which has guide devices which are described in c Spray chamber air coming from an area behind the spray heads to the respective workpiece without turbulence conduct.

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In addition, according to the invention, a spray system is to be created which has a spray chamber and an air supply chamber intended for an operator, as well as spray devices with a limited opening between the chambers, through which opening air and spray particles enter the Spray chamber are carried, with the contamination of the components belonging to the spray device by a Excess of spray is reduced.

Another object of the invention is to provide a system for coating objects to create the spray heads has, which are movable towards and away from a spray chamber, as well as guide devices for a relatively constant air flow from behind the spray heads located area against the objects to be coated, regardless of the position of the spray heads in relation to the objects.

Other objects and advantages of the invention will become apparent if the invention is explained in more detail below on the basis of preferred exemplary embodiments with reference to the drawings, the drawings show:

1 shows a perspective view of a system for coating objects, partially in section;

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Fig. 2 is a side view of the in -Big. 1 shown system on average;

Fig. 3 is a plan view of the ^ nlage of FIGS. 1 and 2 as iioriz ontal Schni 11;

4 shows a slightly enlarged illustration of a part a spray device according to 5'ig. 3;

Fig. 5 is a partial view of another embodiment a spray system as a horizontal section;

6 is a view of another embodiment of a Spray device and air inlets as horizontal section.

Spray system according to the invention is generally designated 10 and comprises a central spray chamber 12, which is preferably somewhat wider than the widest object to be coated in the system, vle spray system can be provided with an overhead conveyor 14 for a semi-continuous operation . The conveyor device extends longitudinally through the chamber 12 in the center. While the conveyor device 14 is shown as an overhead device, in FIG

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a/
However, the system can also be used with floor conveyors. In either case, the object is preferably electrically grounded via its support when an electrostatic coating is applied. The length of the chamber 12 depends essentially on the operations associated with the coating. For example, in an automobile body shop, a first part of the length of the chamber is used to coat the sides of the body, while a second part is used to coat the top, top and trunk lid, and a third part is available for finishing work.

The principle of the invention can also be applied to any conventional systems for coating in which objects conveyed through a side opening in the .hammer, coated there and removed again through the same opening will. However, the application of the invention in connection with a continuously operating plant is particular advantageous, in which openings are provided on both sides, namely an opening for the feed and an opening for the removal of the objects. The air is directed directly to the area where it is needed is, namely in the area of the spray heads. The air flow is also directed towards the objects to be coated. The air that passes through the back and front of the system

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created for feeding and removing the workpieces The coating process can pass through openings do not affect significantly.

A relatively high speed is only required within the limited opening in the area of the spray heads and no longer across the entire chamber area, as was previously necessary. The air is allowed to expand to its entry into the spraying chamber through the restricted aperture to M. Your speed will be reduced considerably. As a result, there is no air that carries the spray particles at high speed to the objects to be coated and into the area behind them. This condition would favor an increase in the excess of spray material. The high-speed air occurring only in the area of the spray head opening is sufficient to prevent deposits of spray particles on the spray heads and in the air supply chamber, where the particles contaminate the spray equipment and pose a danger to the operator could form. Since a considerably smaller volume of air is required for the spray system and only a sufficient amount is needed to achieve the required speed within the opening, the line network and the blowers used can be kept considerably smaller. This results in both lower investment costs and lower operating costs.

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It also reduces the cost of heating the air. This very important cost factor is particularly important in a cool climate.

The substantial reduction achievable in terms of air volumes using the invention is achieved shown using the example of a conventional system for coating. In the sprayer, which measures 3.657 m by 3.657 m, became an air volume of 6796 liters / lake. needed to have a Air speed of 50.8 cm / 8ec. maintain in the chamber. While a significantly slower speed would be needed to keep the concentration of the volatile spray particles below the critical explosion limit hold, a significantly higher speed is necessary to remove the excess of spray and a to avoid excessive contamination of the spray device and a considerable danger for the operator. It was a wall is used to put the spray system in a spray chamber in which the objects are coated, and in a To share air supply chamber that Baum provides for the sprayer and the operator. In the wall in the area of the spray heads, an opening with a width of 762 m and a height of 3 »657 η provided. At this Opening was an air volume of only 1 557 «6 liters / lake, required to have an air velocity of 55.88 cm / lake, in to achieve the opening. This speed was out-

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sufficient to. to prevent spray particles from getting into the openings and from here to get into the air supply chamber. Still, after flowing through the confined air, the air expanded Opening so that the spray particles do not come into contact with a excessive speed against the objects and into the area behind them.

In eiaesi another case they were in a 12.1 ^ 2 m long plant with continuous operation 42480 liters / lake, originally needed to ensure a suitable flow. This system was used to produce vehicle bodies to be coated, and a 3.048 m long area at the exit was used for finishing work. As a system after the invention was used in this system, the JLfUftbedarf could be reduced to only 16922 liters / lake. He could have been lower, but it became the previous one The air extraction system is still used within the last work area, which takes up about a quarter of the length of the system.

An object A can be moved by the rammer 12 on hooks 16 hanging down and held by the conveyor 14. The objects pass through an opening 18 (cf. FIG. 3) into the chamber 12 and leave it through an opening 20. Each of these openings can be adjusted by sliding doors, around the openings in each case

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keep it narrow, as is the width of the objects to be coated requires.

Both sides of the article can be coated by spray devices 22 comprising coating heads or spray heads 24 attached to suitable support supports 26. The spray heads are supplied with raw material from a container which can be located in an area remote from the spray area. The support 26 is preferably movable to and fro to ensure that long objects are evenly coated by the plurality of spray heads. A suitable drive for the min and fro movement can be accommodated in a housing 28. The entire unit, which comprises the spray heads, the support frame and the housing for the drive, can be arranged on a vague 30 with baths 32 which can be moved on rails 4. This arrangement allows the spray heads to be moved away from the chamber in seal to maintain a predetermined distance between the spray heads and the adjacent surfaces of the objects to be coated, "the spray heads can also be reciprocated at any one time object to be coated, if the width of this object varies from one to the other, a remotely located energy source (not shown; is provided to produce an electrostatic field in a conventional manner next to the spray heads.

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Me sprayers 22, each of which has a series of spray guns and their actuators are in separate, external air supply chambers 36 on each Side of the spray chamber 12 housed and separated from this by side or partition walls 38. The air for the spray chamber 12 is supplied via the chambers 36, in the present case Example from the area around the building in which the spray system is housed. A main line is required for this purpose 40 connected to two branch lines 42, which in turn are in communication with the supply chamber 36, the main supply line 40 has an inlet opening located outside the building. A heater 44 and a suitable fan 46 are provided in the main supply pipe 40 for supplying and warming up the outside air.

The air from the supply chamber 36 passes through openings 48 inside the side or partition walls 38 into the spray chamber 12, the side walls of the openings 48 being formed by side plates 50 are formed · The air volume only needs to be sufficient to achieve an air velocity in the openings 48 which is sufficient to cause a deposition of spray particles to prevent on the spray heads 34 or the relevant parts in the air supply chamber 36. The necessary Air flow in the spray chamber, which is intended to prevent

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that the spray equipment is dirty and hazards occur for the operator, then comes much closer to the amount that is needed to the Keep particle concentration below the smallest explosion limit.

In order to keep the flow properties in the area of the spray heads 24 constant, regardless of their position, is an aperture or inlet 52 formed by inwardly facing plates or walls 54 on each of the Carriage 30 attached and movable with this. How special 4, the outer parts 56 of the panels 54 extend close to the side walls 50, so that practically no air can pass between these parts. Inner edges 58 of the aperture plates 54 form an opening of constant area around the Spray heads 24, so that the area of this opening and the position of this opening with respect to the spray heads are constant remains independent of the position of the spray heads

In order to maintain a soft air flow and to reduce the turbulence to the smallest possible value, is the air is aspirated from the chamber 12 at a location remote from the inlets 48. In the system shown are the openings for extracting the air from the system in the bottom of the spray chamber 12 in the form of a grate

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intended. The suction openings can extend across the extend all or part of the floor on the side of the chamber away from the spray heads lies. The air sucked through the grating 60 can with the help of exhaust fans 68 through deeper exhaust chambers or water tanks 62 and from here through vertical Discharge lines 64 are led up with nozzle 66. From the nozzle 66 water is sprayed over baffles 67 in order to the air on its way through the exhaust lines 64 to clean. As shown, the vent lines in the air supply chamber 36 are spaced apart Places the chamber arranged. The chambers 36 have entrance doors 70 for an operator to work in the chambers 36 can work without danger from spray particles, from which the chambers are completely kept free.

The output of the exhaust fan 68 is slightly below the output of the feed fan 46, so that a little more positive Pressure is maintained within the chamber 12 to thereby allow the influx of airborne particles how to prevent dust from entering the chamber 12 through the openings 18 and 20 located at the ends.

While the suction openings are arranged in the bottom of the chamber 12 in the embodiment shown, the Extraction openings also in the side walls directly opposite

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the spray heads be arranged so that the! air flow in such a case is guided across the system and around the objects. In both cases, the Evacuation openings are provided away from the inlets 48 to to bring about a soft air flow and a very small

to achieve possible degree of turbulence in the chamber. If the spray heads and air inlets are hardly at the top of the system ^ are arranged, such as next to a ceiling spray device, the suction openings can in turn be arranged in the floor, as shown, or in deeper parts the side walls of the spray chamber. While the spray heads are shown as device-operated spray heads they can also be operated manually by an operator in the air supply chamber 36.

A somewhat modified appendix 72 is partly in - ^ ig. 5 shown. This spray system comprises a continuous ψ operation on a suitable conveyor for conveying the articles A through the equipment. In this case, the objects A to be coated on both sides differ in thickness by no more than a few centimeters. For this reason, the spray heads 74 are held by fixed guide housings 76. The spray heads can be moved back and forth, but they do not need to be in the direction of and from the workpieces

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to be moved this way.

In this case the spray system is in an existing one a housing surrounded barely 78 housed, the with a Provide compressed air supply by blower 80 if desired Can be, although this is not absolutely necessary, if the bar is large enough and a sufficient number of has openings. As with the plant 10 walls or divide -Guide plate «82 the spray system into a ^ spray chamber 84 and Air supply chambers 86. The total amounts of air for the spray chambers are supplied through inlet ports 88 with side panels 89 supplied, which direct the air inwards.

As in the previous example for a spray system, the air flows in this case at a relatively higher rate Speed through the openings 88, so that a proportionate small air volume a sufficient speed creates to prevent kickbacks from spray, Never guide housing 76 and similar parts stay clean, and a .Bedienungsperson can stay in or next to the air supply chambers 86 without danger.

The air is placed at points remote from the inlets 88 sucked off, the jjuft from the inlets to the suction outlets flows behind the objects A. In this case

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the outlets are provided with a large number of baffles 90, which the air passes through on a winding path to exhaust ducts 91, which with the usual exhaust fans (not shown; are equipped.

The air flow in a spray system often changes during a period if the conditions here-

fe for change, for example if filters are partially clogged. In such a case, the pressure differential between the air supply and spray chambers may fluctuate; also the shape of the flow can change. In order to keep this change as small as possible and to add additional air to the area between the objects A, blind-like openings 92 can be provided in the side walls 82, which are arranged next to the inlets 88 in the present example are. The openings 92

. supplied air is used to reduce the pressure gradient between the Compensate chambers with increasing air flow into the spray chamber, when the pressure gradient increases and vice versa. The blind-like openings also reduce the appearance, excess spray adheres to objects adjacent to those to be coated.

It is clear that the spray system 72 according to Flg. 5 of the previously described in several respects

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separates · The spray heads 74 are stationary in the present case arranged. The air supply chambers 86 do not have any direct Air supply on. The air is sucked off the opposite side wall of the sprayer, finally Blind-like guide openings serve to control the Balancing and influencing air flow.

From Fig. 6 a slightly modified spray device can be seen. In this case, the spray heads 94- are attached in two rows to supports -Jb , which are fastened to components 100 and a housing 102 via connecting cross members 98. In the present case, the housing 102 is mounted on rails 106 by means of a carriage 104 for movement in the direction of the workpiece and away from it. Where the rows of spray heads ⁰ A are more than 1.22 m apart, an inlet 108 is provided with a central guide vane or wall 110 which blocks the space within the opening 108 between the rows of spray heads 94. The vane 110 may be attached to a wall or screen 112 that surrounds both rows of spray heads and has side plates 114 that cooperate with side plates 116 adjacent the edges of the opening 108. The spray heads and the cover can be partially carried by a trolley mounted above, at least in the present case, and moved back and forth with the carriage 104

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will. In particular when the guide housing 102 and the spray heads 9 ** · are arranged in a stationary manner, the diaphragm 112 and the baffle. 110 can also be arranged in a stationary manner opposite the opening 108.

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Claims (1)

31 / A 19504 KaAa Claims 1.) Plant for coating objects, for example for painting by spraying, characterized in that that a central spray chamber (12) with a the/ Conveyor device (14) for the zn. coat objects A and an air supply chamber (36) as well as for the introduction of air from the air supply chamber (36) in the central spray chamber (12) an air inlet (48) are formed between the two chambers (12), (36) and a spray head (24) in the area of the air inlet (48) for spraying the objects A with spray substances and an air suction device (60), (62), (64), (68) acting on the chamber (12) for a low-turbulence Air flow from the inlet (48) through the chamber (12) along the spray head (24) to a vent (64) are located at a location remote from the inlet (48). 2.) Plant according to claim 1, characterized in that the 109820/0687 Air suction device (60 *), (62) in the bottom of the spray chamber (12) is arranged. 3.) Plant according to claim 1-2, characterized in that that the conveyor device (14) the objects A at least partially in the path of the air flow from the Air inlet (48) to the air suction device (60), (62) P carries. 4.) Plant according to claims 1-3, characterized in that the air supply chamber is closed all around and has a singing door (70) through which an operator the air supply chamber (36) can enter. 5 ·) Plant according to claims 1-4, characterized in that an additional, smaller inlet opening (52) is formed between the air supply chamber C36) and the spray chamber (12) is. 6.) Plant according to claims 1-5, characterized in that Supply lines (40), (42) and a fan (46) establish a connection between the air supply chamber (36) and the surrounding Create outside air for a direct supply of outside air to the supply chamber (36) 109820/0587 7ο) System according to claims 1-6, characterized in that a spray chamber (12) is formed, a conveying device (14) in the chamber (12) for transporting the objects to be "coated" and a spray head (24) is provided are, a carriage (50) carries the spray head (24) for movement to the respective object and away from this, a partition (58) is provided for the spray chamber (12) and the air supply chamber (56), which has an opening (48) between the two chambers, arranged on the opening (48) side plates (50) are, which form a passage in the direction of movement of the carriage (.50), and screens (54) on the. dare (50) are attached, which are movable with this and an air inlet (52) around the spray head (24) form. 8.) Plant according to claims 1-7, characterized in that the aperture plates forming the air inlet (52) (54) to close to the side plates forming the passage (50) so that the air flow between the air supply chamber (.56) and the spray chamber (12) essentially on the air inlet (52) around the Spray head ^ 24) is limited in any working position of the * carriage (50) compared to the respective Item A. 109820/0587 IV 9.) Plant according to claims 1-8, characterized in that that the side plates (50) forming the passage have a length which is at least equal with the length of the path that the carriage (30) can cover. 1u.) System according to claim 1 - 9i characterized in that that the air inlet (, 52) on the carriage 00) through inclined diaphragm plates (54) is formed, whose outer edges (56) reach close to the side walls (50) of the passage (48) and the inner edges (58) form an inlet opening around the air to seal the inside of the path of the particles from the spray heads ^ 24) go out. 11.) Plant according to claim 1-10, characterized in that the openings of the jjuft from the suction device Air inlet openings (52; are remotely located. 12 .; Plant according to claims 1-11, characterized in that a common wall (82) has a further inlet opening 92 between the spray chamber (84) and the air supply chamber (78). 13 "; Plant according to claims 1 - 12, characterized in that 109820/0587 the air supply chamber (36J is closed all around and an entrance door (70) through which one Operator enter the -wift feed chamber (36; can. 14 .; Plant according to claim 1-13 »characterized in that that the air inlet (48; with the help of parallel side walls (5o) is formed, which on the partition wall (38) are fixed, and the inlet (52) with the help of is lumbar plates (.54) is formed, which is partially the spray heads (24; are arranged all around and have a frustoconical shape in horizontal cross section have with outer edges ^ 56), which are in the immediate Near next to the plates (50) in all positions of the spray heads (24) are arranged o 109820/0587