DE2263462A1 - SPRAY DEVICE FOR TREATMENT OF METAL SURFACES - Google Patents

Description

The invention relates to an improved spray device for treating metal surfaces with a chemical Aqueous solution containing reagent. .

In the metallic substances or materials processing industry, metal surfaces are applied to different Wise treated, e.g. by degreasing, for conversion coating with phosphate, chromate or oxalate or the like. Such Treatments are often carried out using a spray device, a typical of which is is shown in Figure 4 of the accompanying drawings. Fig. 4 Fig. 3 is a schematic sectional view of a conventional one

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Spray device, in which 1 denotes a metal substance to be treated, 2 denotes an overhead conveyor for transporting the metal substance and 3 denotes a spray chamber, the spray chamber at its inlet or outlet with lines or channels 4 provided with fans or blowers and 4 'is provided. The spray chamber 3 is usually divided into several zones depending on the type of treatment. The spray device shown in Fig. 4 is used for conversion coating with phosphate, the spray chamber 3 is divided into five zones, ie 3A, 3B, 3C, 3D and 3E, in which degreasing, rinsing with water, phosphating, rinsing with water and An - or acidification can be carried out. Each of the zones is provided with a nozzle 4A, 4B _1, 4C, 4D or 4E for spraying water or an aqueous solution containing a degreasing agent, a phosphating agent or an acidifying agent, which is hereinafter referred to as "chemical solution", into the spray chamber 3. Containers 6a to 6E, which are provided with pumps 5A to 5E for charging the nozzles 4A to 4E with water or the chemical solution, are each assigned to the zones 3A to 3E and serve as containers for water or the chemical solutions which are in the spray chamber 3 can be sprayed. The tanks 6A and 6C are equipped with heaters 7A and 7C, respectively.

If the metal substance 1 in zone 3A with a Aqueous solution containing degreasing agents and in the

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Zone 13 is treated with a likewise aqueous solution containing a phosphating agent, parts of these chemical solutions are dragged from zones 3A and 3C through the metal substance 1 into the adjacent zones 3B and 3D. Characterized the flushing water in the zones 3B and 3D _f is contaminated with the chemical solutions and the rinsing with water is not complete and satisfactory. This results in an impairment of the quality of the metallic substance 1. In order to avoid such impairments, fresh water is fed into the tanks 6B and 6D in order to maintain a high efficiency of the rinsing with water. In this case, an excess amount of the rinsing water originating from said fresh water supply overflows and is carried away as waste water. The wash water, of course, contains the chemicals used in Zones 3A and 3C, usually acidic or alkaline substances, metal ions, surfactants, oils and fats or the like. Discharge of such service water can cause serious damage to the environment. For this reason, it is desirable to remove harmful components from the process water. remove. However, since cleaning equipment is quite expensive, this removal or cleaning is not normally done.

The invention is to an improved spray device directed at which the production of domestic water in terms of quantity can be suppressed to a considerable extent. These

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The object can be achieved in that an evacuation device is arranged on the spray device, in particular above a zone in which a metal substance with a chemical solution is treated so that water contained in the process water is sucked off in vapor form. Particularly in performing the water rinse and abatement in a multi-stage system the amount of fresh water to be supplied can be the evacuation of the amount of water that approximately corresponds to the supplied, can be achieved in a satisfactory and easy manner.

In the spray device of the invention, a spray chamber is provided which has at least one treatment site where the metal substance with a chemical solution, and at least one rinsing site, where that brought about by the treatment site Metal substance is rinsed with water, includes. According to the invention, the device has one on the spray chamber arranged evacuation device, which preferably is attached above the treatment site. Furthermore is It is advantageous to divide the rinsing site into two or more zones, so that rinsing with water by means of one a multitude of stages comprising a system can be effected. Fresh water is fed into the last zone of the flushing area initiated and the water excess "coming from there" overflows into the adjacent zone. This overflow sets in successively from one to another zone of the irrigation site and finally to the treatment site, with the

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the latter can also be divided into two or more zones. The water that "with that of the metal substance when Transport brought about chemical solution is contaminated, is thus only from the rinsing site to the treatment site led away, all of these locations within the device are arranged themselves. When using such a system, the amount of fresh water to be supplied in the event that the rinsing site is divided into two zones is, to about 1/20 to 1/10 and in the event that the flushing site is divided into three zones, to about 1/50 to 1/20 if you compare the amount of fresh water required with that of a spray device, in which the flush location comprises a single zone.

Since the excess water is ultimately directed to the treatment site, the chemical solution contained therein can be diluted as the amount of water increases. As a result of the evacuation devices arranged on the spray chamber, however, the water is continuously evacuated. The dilution of the chemical solutions and the increase in the amount of water can thus be prevented. The treatment site is often heated to temperatures of approximately 40 to 70 ^° C. in order to carry out the treatment of the metal substance with the chemical solution in an effective manner. Such heating is obviously advantageous for the evaporation or evaporation of the water. One kg of air, for example, 0.0488 kg of water at 40 ° C and 0.276 kg at 70 ⁰ C included. Thus, the amount of of the can

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The rinsing site at the treatment site is brought into equilibrium with the water evaporating at the treatment site by using appropriate evacuation facilities and / or selects heating devices.

The invention is explained in more detail below, reference being made to the drawings, which are preferred Relate to embodiments of the invention. Show it:

Fig. 1 is a schematic sectional view of an embodiment of the spray device of the invention;

2 shows a schematic sectional view along the line H-II of Figs. 1 and

3 shows a schematic sectional view through a part another embodiment of the spray device of the invention.

In the device shown in FIGS. 1 and 2, a metal substance to be treated, 12 "is an overhead conveying device for transporting the metal substance and a spray chamber which is connected to lines or ducts 14 and 14 'at the entrance and with fans or blowers Output is equipped. The transport device 12 runs through the spray chamber 13 »which is divided into seven zones

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When using the device for the conversion coating with phosphate, the degreasing, rinsing with water, phosphating, rinsing with water and acidification in zone 13A, zones 13B and 13B ¹ , zone 13C, zones 13D and 13D ¹ or zone 13E. These zones are each provided with nozzles 14A, 14B, 14B ', 14C, 14D, 14D' and 14E for spraying water or a chemical solution and pumps 15A, 15B, 15B ¹ ', 15C, 15D, 15D' and 15E for directing of the water or the chemical solution on the nozzles, the pumps being arranged on the tanks 16A, Los, 16B ", IOC, ISO, IOD" and 16E, which are used to collect the water or the chemical solution sprayed in the spray chamber 13 to serve. The tanks 16A and 16C are each equipped with heating devices 17A and 17C which serve to heat the chemical solutions in the tanks.

The reference numerals 18B ¹ and 18D 'denote lines for supplying fresh water to the tanks 16B' and 16D '. 18B and 18D designate lines for supplying the water which has overflowed an'den tanks T6B 'and 16D ¹ into tanks TOB and 16D. 18A and 18C denote pipes for supplying the water overflowed from the tanks 16B and 16D to the tanks 16A and 16C. The lines 18B ^! and 18D ¹ are provided with valves 19B ¹ and 1-9D ¹ and furthermore with auxiliary lines 21B 'and 21D ¹ , the latter being provided with magnetic valves 20B ¹ and 20D ¹ , respectively. the

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Lines or pipes 18A, 18B, 18C and 18D are ₁ to form the lines 22A, 22B, 22C and 22D, which are provided with magnetic valves 2OA, 2OB, 2OC and 20D branched executed. The tanks 16A and 16C are provided with lines 24A and 24C, respectively, which are equipped with magnetic valves 23A and 23C for supplying fresh water therein. Liquid level gauges 25A and 25C are provided in the tanks 16A and 16C to measure the liquid level by means of the measuring instruments 26A and 26C, respectively.

When the liquid level below a predetermined level drops and this is measured by the measuring instrument, the magnetic valves 20B _'f 20D · and / or 23A, 23C via the switch circuits 27A and 27C is operated so that fresh water in the tank 16B ¹ 16D ¹ and / or I6A, 16C is initiated. It is usually advantageous to raise the liquid level only by operating the solenoid valves 20B ¹ and 20D ^1. When the liquid level rises above a predetermined level, the solenoid valves 2OA, 2OC and / or 2OB, 2OD are actuated via the circuits 28A and 28C, and the flushing water, which from the tanks I6B,

1OD '
16D and / or 16B ', / has overflowed through the lines 10A, 18C and / or 18B, 18D, is led away via the lines 22A, 22C and / or 22B, 22D. The rinsing water contaminated with chemicals is thus removed from the device. In order to avoid this result, the capacities or outputs of the blowers 31A and 31C are made sufficiently large

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and controls the amount of fresh water to be supplied so well or precisely that the liquid levels in the tanks 16A and 16C do not rise above a predetermined level. Further, the opening of the valves 19B 'and 19D ^{1 is} preferably appropriately adjusted so that the ^{amount of fresh water to be introduced into the tanks 16B 1} and IOD ¹ is kept at such a value that it is smaller than that of the decreasing amount the chemical solution in tanks I6A and 16C. As a result, there is always a tendency for the fluid level to decrease.

Lines 30A and 30C are mounted on the spray chamber 13, through which the air in the zones 13A and 13C is evacuated. The fans 31A and 31C are provided in the lines 30A and 30C, respectively, for removing water in vapor form in an amount equal to that of the water overflowing through the lines 18A and 18C into the tanks 16A and 16C. In order to prevent splashing of the chemical solution, spray devices 32A and 32C are usually provided at the entrance of lines 30A and 30C. Furthermore, capacitors 35 and 35 'are provided in lines 30A and 30C in order to condense the water vapor contained in the evacuated air into containers 36 and 36'. The water condensed in this way is extremely pure and can be used as part of the fresh water to be fed ^{into the tanks 16B 'and 16D 1.}

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The fan 34, the lines 33A, 33B, 33B ¹ , the fan 34 'and the lines 33C, 33D, 33D ¹ and 33E are not essential to the device of the invention. Their arrangement is advantageous to introduce fresh air around the conveyor 12, which along the upper

Wall of the spray chamber is arranged so that an adhesion of the sprayed or drained rinse water and the chemical Solution that can cause corrosion of the conveyor 12 is reduced to a minimum. Lines 14 and 14 are also not for the device of the invention, but can if desired to prevent release, splashing or dripping the rinsing water and the chemical solution and moist air from the device in an advantageous manner are provided.

According to another advantageous embodiment of the invention shown in FIG. 2, the input of the line is 30A provided with a fork into two branches so that the air in the spray chamber 13 evacuates with greater uniformity can be.

According to the embodiment of the invention shown in FIG. 3, the water passed from one tank to another is not simply allowed to be transferred, but is sprayed into the latter. The flushing water collected in the tank 16D 'is thus conveyed ^{through the pump 15D f} and the line 14D ^1.

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tet and a part of the same w ^ rd sprayed in the zone 13D '. The other part of the rinse water continues to flow through line 40D 'and valve 41D' and over the line 42D 'sprayed into zone T3D. Similarly- will the water collected in the tank 16D by the pump 15D and line 14D, and a part of it is passed into the zone 13D sprayed. The other part will continue through the line 40D passed to the next, not shown Zone to be sprayed with water for rinsing. ' if the next zone is not intended for rinsing with water but for some other treatment, you can Rinse water just from the '16D tank to the next one, no overflow tank shown. In such a case, line 4OD can be omitted. -

If the evacuation is carried out in the apparatus of the invention shown in FIGS. 1 and 2 while the temperature of the chemical solution in the tanks 16A and 16C is maintained at 40 to 70 ^° C., those in FIGS. 5 and 6, respectively, are obtained curves shown, which show the relationship between the temperature of the evacuated air and the evacuated flushing water amount and between the temperature of the chemical solution and the temperature of the evacuated air, under the following conditions :. Atmospheric pressure, 22 ° C; relative humidity 72 %; Power of each of the blowers 51A and 51C 60m ^ / min for air. From 20 ⁰ C.

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In Fig. 5, the solid and broken lines represent the measured and calculated values on the humidity scale in the case where the humidity of the evacuated air is 100 % . The reason why the measured value is partly above the calculated value can be assumed to be that part of the chemical solution sprayed in the spray chamber 13 is entrained in the evacuated air. Even in this case, the measured value is almost the same as the calculated one.

If the conversion coating with phosphate is carried out by means of the device of the invention shown in FIGS. 1 and 2, specifically using an alkaline degreasing solution or a zinc-phosphate solution in zones 13A and 13C under the conditions specified below, this is Required amount of fresh water to be added 200 to 300 1 / hour. in each of lines 18B ¹ and 18D ¹ . The amount of water corresponding to the amount of fresh water supplied is removed in the form of steam by evacuation, whereby no water at all is drained as service water:

Area of the treated outer boxes of an elek surface (Average) tri-view refrigerator,

100 m2 / hour

Temperature of the liquid 70 ⁰ C speed in the tank 16A

Temperature of the liquid in the tank I6C 65 C

atmospheric temperature 20 to 25 ⁰ C relative humidity 70 to 75 % water temperature 12 7/1 0 7 2 ¹⁸ ° ^C

When using a conventional device according to 4 for the above conversion coating with phosphate 2000 to 4000 liters of fresh water per hour are required to be introduced into each of the * tanks 6b and 6D. This means, that an amount of used water corresponding to the amount of fresh water supplied, which is contaminated with the chemical used, overflows and out of the device Will get removed.

From this comparison it can be seen that the amount of fresh water to be supplied is considerably reduced (for example to about 1/10) and the removal of service water, which originates from the fresh water supply, is avoided by using the device of the invention. Furthermore, there is a considerable advantage of the invention in that the chemical which has once got into the rinsing water as a contaminant is recovered and can be used again in the original chemical solution. The consumption of chemical solution is made much more cost-effective, for example by an amount of 10 to 30 %.

In the devices shown in FIGS. 1 and 2 of the According to the invention, two zones are provided for each rinse with water. The number of such zones can generally be 2 to 8, preferably 2 to 5. -

Furthermore is. the device of the invention using the example

the application in the successive implementation of the Degreasing, rinsing with water, phosphating, rinsing with water and acidifying have been described. she However, it can also be used to carry out a single chemical treatment and rinse with water as well as for the Performances of two types of chemical treatments or multiple with water rinse can be applied.

For a better understanding of the invention, the following Reference is made to an embodiment which uses the devices shown in FIGS. 1 and 2 relates to the treatment of automobile body series.

2 60 bodies, each with a surface area of 40 m

were degreasing, rinsing with water, phosphating, subjected to rinsing with water and acidification. There were three zones for each water rinse. By using such a water rinse in a three-stage system, a sufficient rinsing effect of the Water is achieved by adding fresh water at a rate of 500 to 1000 l / h. fed. (When using a A conventional device in which each water rinse is performed in a single stage is a fresh water supply at a speed of 20,000 to 30,000 l / h. required to achieve adequate water flush.)

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If the required amount of fresh water to be added is 2000 l / h. is set, this corresponds to the increase in the chemical solution in the tank intended for it. The fan can thus be designed so that it can evacuate this amount of water in vapor form. If the temperature of the chemical solution is 60 ⁰ C, the water should. evaporation according to FIGS. 4 and 5 be 0.12 kg water / kg air (dry). Accordingly, the evacuation amount can be calculated as follows:

2000 / 0.12 = 17000 kg air (dry) / hour.

This amount of evacuation can easily be achieved with a commercially available blower.

Furthermore, the various devices contained in the device of the invention can be complete or can be partially automated in a manner known per se.

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Claims (5)

Claims 1. Spray device for treating a metal surface with an aqueous solution containing a chemical reagent with subsequent rinsing with water, characterized in that an evacuating device on a spray chamber is arranged so that the air in the chamber is evacuated together with evaporated water will. 2. Spray device according to claim 1, characterized in that the rinsing with water means a multiple stage system is feasible. 3. Spray device for treating a metal surface with an aqueous containing a chemical reagent Solution, characterized in that it comprises a spray chamber which has a treatment site where the aqueous Solution is sprayed onto the metal surface, and a rinse site where rinse water is applied to the treated site and from there brought about metal surface is sprayed, and that the rinsing site in an as last zone provided zone and at least one further zone is divided, with line facilities between - 16 309827/1072 these zones and the treatment site are provided so that the water after rinsing from the last zone in sequence through all the other zones to the treatment site can flow and with a feed device for delivery of fresh water provided in the last zone and an evacuation facility is arranged above the treatment site so that water can be removed therefrom in vapor form can. 4. Method of treating a metal surface with an aqueous solution containing a chemical reagent at a treatment site with subsequent rinsing of the Metal surface at a rinsing site, where treatment and Rinsing takes place essentially by spraying, which means that fresh water is delivered to the rinsing site delivered, carried away from there and. to the place of treatment forwarded and finally removed in vapor form will. 5. The method according to claim 4, characterized in that g e k e η η draw t that the flushing site in two zones or several is divided. - 17 30982771072 Lee r side