JPH0832959B2 - Chemical conversion equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a chemical conversion treatment device for performing a chemical conversion treatment performed on an object to be processed as a pretreatment for electrodeposition coating or the like.

[Conventional technology]

BACKGROUND ART Conventionally, when electrodeposition coating is applied to an automobile body or the like, a chemical conversion treatment using a zinc phosphate-based treatment agent or the like is performed as a pretreatment (base treatment).

In this case, there is a problem that sludge is usually generated in such chemical conversion treatment, and conventionally, in order to remove such sludge, the chemical conversion treatment liquid is taken out from the treatment tank and introduced into a thickener (concentrator). However, after removing the sludge, a clear chemical conversion treatment liquid is returned to the treatment tank.

[Problems to be Solved by the Invention]

However, the introduction of the chemical conversion treatment liquid containing thickener hesslide from the treatment tank in this way causes a considerable heat loss to the chemical conversion treatment liquid by flowing in the pipe connecting the treatment tank and the thickener. Occurs.
Moreover, since the thickener is provided, the installation area of the device becomes large. In this case, if the thickener volume is reduced, the sludge removal efficiency decreases, and there is a problem that sufficient sludge removal cannot be performed. Furthermore, in the conventional treatment equipment, when returning the clear chemical conversion treatment liquid, from which sludge has been removed with a thickener, to the treatment tank, the solution is discharged upward from the bottom, so the sludge settles at the bottom of the tank. It also has the problem of being easy.

The present invention has been made in view of the above circumstances, it is possible to satisfactorily remove sludge in the chemical conversion treatment liquid housed in the chemical conversion treatment tank, and eliminate the inconvenience of depositing sludge on the bottom of the tank, Moreover, it is an object of the present invention to provide a chemical conversion treatment device that does not require a large installation area.

[Means for solving the problem]

In order to achieve the above-mentioned object, the present invention comprises a chemical conversion treatment tank containing a chemical conversion treatment liquid, and a plurality of straightening vanes arranged inside the treatment tank, which overflows from the treatment tank. An overflow tank for causing the sludge in the chemical conversion treatment liquid to settle by flowing the chemical conversion treatment liquid between the plurality of straightening vanes, and a circulation pump for returning the chemical conversion treatment liquid in which the sludge in the overflow tank has settled to the treatment tank. And a circulation pipe in which is interposed, and is disposed along the bottom of the processing pipe in close proximity to the bottom of the processing bath, and the discharge port of the chemical conversion treatment liquid is directed toward the inside of the processing bath. A plurality of riser pipes for discharging the chemical conversion treatment liquid toward the bottom wall of the treatment tank are provided, and the upper end of the straightening plate is the same as the liquid surface of the chemical conversion treatment liquid in the overflow tank or Higher than that And a lower end of the rectifying plate disposed at a predetermined distance from the bottom wall of the overflow tank, the upper end being lower than the liquid surface of the chemical conversion treatment liquid, and the lower end contacting the bottom wall of the overflow tank. A plurality of straightening plates arranged in parallel are alternately arranged in parallel, and sludge in the chemical conversion liquid flows while the chemical conversion liquid that has flowed into the overflow tank repeatedly rises and falls between the straightening plates. There is provided a chemical conversion treatment device characterized by being configured to settle.

Here, the volume of the overflow tank is 1 / of the processing tank.
It is preferably 1 to 1/3, especially about 1/2 in terms of sludge removal efficiency and downsizing of the entire apparatus. Further, it is preferable to install the rectifying plates in such a number that the chemical conversion treatment liquid stays in the overflow tank for about 1 to 10 minutes and sufficiently removes sludge, and the rectifying plates can be removed. It is preferable from the viewpoint of maintainability such as clear stream.

The chemical conversion treatment apparatus of the present invention, having the above-mentioned configuration, directly receives the chemical conversion treatment liquid containing the sludge overflowing from the processing tank in the overflow tank connected to the processing tank, and the straightening plate in the overflow tank. When flowing between
Sludge with a large specific gravity can be efficiently settled, and the clear chemical conversion treatment liquid and the sludge can be well separated, and by returning this clear chemical conversion treatment liquid to the treatment tank with a circulation pump,
The chemical conversion treatment liquid in the treatment tank can always be kept clear.
In this case, in particular, the rectifying plate has its upper end positioned at the same level as or higher than the liquid surface of the chemical conversion treatment liquid in the overflow tank, and its lower end positioned at a predetermined distance from the bottom wall of the overflow tank. Overflow is made by alternately arranging the straightening vanes arranged and the straightening vanes whose upper end is lower than the liquid level of the chemical conversion treatment liquid and whose lower end is in contact with the bottom wall of the overflow tank. Sludge in the chemical conversion treatment liquid was allowed to settle while the chemical conversion treatment liquid flowing into the tank flowed up and down repeatedly between the baffles, so even if the volume of the overflow tank was reduced, It has a long flow path and can reliably remove sludge in the chemical conversion treatment liquid to clarify the chemical conversion treatment liquid. Further, the clear chemical conversion treatment liquid from which sludge has been removed in the overflow tank is returned to the inside of the processing tank by being discharged into the processing tank from the discharge port of the riser pipe provided at the bottom of the processing tank, and by this discharge flow The chemical conversion treatment liquid in the treatment tank is agitated. In this case, in the device of the present invention, the clear treatment liquid is discharged from the outlet of the riser pipe toward the bottom wall of the treatment tank. Since it is configured, sludge does not settle on the bottom wall of the processing tank, uniform and good agitation is performed, and thus sludge in the processing tank can be sent to the overflow tank without leaving, A uniform chemical conversion treatment can be applied to the object to be treated.

As described above, in the chemical conversion treatment apparatus of the present invention, the overflow tank connected to the processing tank also serves as a thickener, so that the thickener can be used without reducing the volumes of the processing tank and the thickener (overflow tank). The equipment can be downsized compared to the conventional chemical conversion equipment provided separately, and the sludge does not settle at the bottom of the treatment tank, and the sludge can be removed satisfactorily. It has excellent maintainability.

An embodiment of the present invention will be described below with reference to the drawings.

〔Example〕

The drawings show a chemical conversion treatment apparatus according to an embodiment of the present invention, which is preferably used for performing a chemical conversion treatment on a specific object as a pretreatment for electrodeposition coating.

In the figure, reference numeral 1 is a chemical conversion treatment tank in a rectangular box, and an overflow tank 2 is connected to the treatment tank 1 so that the chemical conversion treatment liquid in the processing tank 1 overflows and flows into the overflow tank 2. .

In the overflow tank 2, a plurality of (10 in the drawing) straightening vanes 3 are arranged at predetermined intervals so as to be detachable along the vertical direction. In this case, processing tank 1
The first, third, fifth, seventh, and ninth straightening vanes 3a from the side have their upper ends at the same level as or higher than the liquid level of the chemical conversion treatment liquid in the overflow tank 2, and their lower ends at the overflow tank 2 It is arranged so as to be spaced a predetermined distance from the bottom wall of the second, fourth, sixth, eighth,
The tenth straightening plate 3b is arranged such that its upper end is lower than the liquid surface of the chemical conversion treatment liquid and its lower end is in contact with the bottom wall of the overflow bath 2, so that the treatment liquid overflowing from the treatment bath 1 is treated. Flow downward between the tank 1 and the first straightening vane 3e, then flow upward between the first straightening vane 3a and the second straightening vane 3b, and the same flow is repeated. At that time, sludge in the chemical conversion treatment liquid is settled at the bottom of the overflow tank to flow, and the 10th straightening plate of the overflow tank and the side wall forming the final passage of the chemical conversion treatment liquid are circulated. One end of a circulation pipe 6 for sequentially interposing a pump 4 and a heat exchanger 5 is connected,
The other end of the pipe 6 is immersed in the chemical conversion treatment liquid in the treatment tank 1. One end of a riser pipe 7 is connected to the other end of the pipe 6, and the riser pipe 7 is arranged horizontally in the vicinity of the bottom along the bottom and the lower surface of the riser pipe. Is formed with a plurality of discharge ports 8 so as to discharge the chemical conversion treatment liquid to the bottom of the processing tank 1. The discharge ports 8 discharge the discharge flow at an angle from directly downward to near the horizontal direction. It is set to ensure good liquid circulation in the processing tank. A heating device 9 is attached to the heat exchanger 5.

Reference numeral 10 is an excess machine, and one end of the excess machine is immersed in the treatment liquid in the treatment tank 1, and the first valve 11 and the overpump 1
2. The other end of the first pipe 14 in which the second valve 13 is sequentially interposed is connected, and the one end of the second pipe 15 is connected,
The other end of the second pipe 15 is immersed in the treatment liquid in the treatment tank 1 so that the treatment liquid can be passed if necessary.

In addition, at the bottom of the side wall of the overflow tank 2, a third
One end of a third pipe 17 interposing the valve 16 is connected, and the other end of the third pipe 17 is connected between the first valve 11 of the first pipe 14 and the overpump 12. Furthermore, the first pipe
One end of a fourth pipe 19 which interposes a fourth valve 18 is connected between the overpump 12 of 14 and the second valve 13.
The other end of the pipe is arranged above the substitution tank 20. A sludge tank 21 is disposed below the replacement tank 20, one end of a fifth pipe 22 is connected to the side wall of the replacement tank 20, and the other end of the fifth pipe 22 is connected to the first pipe 14. It is connected between the connecting portion of the third pipe 17 and the overpump 12. Therefore,
As a result, the chemical conversion treatment liquid containing a large amount of sludge deposited at the bottom of the overflow tank 2 is introduced into the substitution tank 20,
The sludge separated from the chemical conversion treatment solution is the sludge tank.
The chemical conversion treatment liquid separated from the sludge and separated from the sludge is returned to the treatment tank 1 through the fifth pipe 22 through the excess pump 12 and the excess machine 10 in order.

When chemical conversion treatment is performed using the chemical conversion treatment apparatus, the chemical conversion treatment is performed by immersing the object to be treated in a treatment liquid containing a chemical conversion treatment agent such as phosphate in the treatment tank 1. The chemical conversion treatment liquid in the treatment tank 1 overflows into the overflow tank 2, and the chemical conversion treatment liquid flowing into the overflow tank 2 causes sludge in the chemical conversion treatment liquid to settle when flowing between the straightening vanes 3. The clear chemical conversion treatment liquid in which the sludge has settled is circulated by the circulation pump 4 which is interposed in the circulation pipe 6 connected to the center of the side wall at a position of 1/2 to 1/3 from below the overflow tank 2. And is returned to the processing tank 1 via the heat exchanger 5. At this time, the chemical conversion treatment liquid is discharged from the discharge port 8 of the riser pipe 7 toward the bottom of the treatment tank 1, and the treatment liquid in the treatment tank 1 is uniformly stirred by this discharge inflow.

According to the above-described chemical conversion treatment device, the overflow bath 2 is provided in series with the treatment bath 1, the chemical conversion treatment liquid overflows into the overflow bath 2, and the formation between the straightening plates 3 arranged in the overflow bath 2 is performed. It is configured to remove sludge in the chemical conversion treatment liquid when the treatment liquid flows,
Since the overflow tank also serves as a thickener, it is not necessary to separately provide a thickener, and therefore the area occupied by the entire apparatus can be reduced, and the processing liquid from the processing tank 1 to the overflow tank 2 also serving as a thickener can be reduced. Since the transfer is performed by overflow, the heat loss of the processing liquid is small. Further, the chemical conversion treatment liquid from which sludge has been removed in the overflow tank 2 is discharged through the discharge port 8 of the riser pipe 7.
Further, since the sludge is discharged toward the bottom wall of the processing tank 1, sludge is not deposited on the bottom wall of the processing tank, and uniform and good agitation is performed by the discharge flow, so that a chemical conversion ram is not generated. A uniform chemical conversion treatment can be performed, and the sludge in the treatment tank 1 can be sent to the overflow tank 2 without being left on the bottom wall or the like. Further, in this example, the excess pump 12 from the treatment tank 1 is used. Since the treatment liquid can be taken out by the operation of 1, and returned to the treatment tank 1 after passing through the excess machine 10, very excellent sludge removal can be performed, and therefore maintenance performance such as tank cleaning is very excellent. In fact, when a chemical conversion treatment tank similar to the one shown in the drawing was constructed and put into operation, the excess machine 10 was washed once a week and the overflow tank 2
The cleaning time was reduced, and the maintenance time was reduced. In this case, the overflow tank 2
Since the inner rectifying plate 3 is removable, the overflow tank 4 can be easily cleaned. Moreover, in the chemical conversion treatment apparatus of this example, the sediment containing a large amount of sludge from the overflow tank 2 is introduced into the substitution tank 20, where the chemical conversion treatment liquid is collected and passed through the overpump 12 and the excess machine 10 to the treatment tank 1. Since it is returned, the loss of the chemical conversion treatment liquid due to the sludge removal can be made very small.

The chemical conversion treatment apparatus of the present invention is not limited to the above embodiment, and various modifications may be made within the scope of the present invention.

〔The invention's effect〕

In the chemical conversion treatment apparatus of the present invention, since the overflow tank connected to the processing tank also serves as a thickener, it is not necessary to separately provide a thickener, and furthermore, the space between the straightening vanes arranged in the overflow tank can be increased. Since the flow of the chemical conversion treatment liquid is long while repeating the descent, the sludge in the chemical conversion treatment liquid can be reliably removed. For this reason, the entire apparatus can be downsized without reducing the volume of the processing tank or thickener (overflow tank), and the overflow method is adopted to introduce the chemical conversion treatment liquid into the thickener (overflow tank). Therefore, the heat loss of the processing liquid is small. Also, by discharging sludge-removed clear chemical conversion treatment liquid toward the bottom wall from the discharge port of the riser pipe located at the bottom of the treatment tank, the treatment liquid is returned to the treatment tank and the treatment flow is caused by the discharge flow. Since the treatment liquid in the treatment tank is agitated, sludge does not settle at the bottom of the treatment tank, and uniform and good agitation is performed.Therefore, almost no sludge in the treatment tank remains in the overflow tank. In addition to being able to send, it is possible to perform uniform chemical conversion treatment on the object to be treated.

[Brief description of drawings]

 The drawings are flow sheets showing an embodiment of the present invention. 1 ... Chemical conversion treatment tank, 2 ... Overflow tank 3 ... Rectifier plate, 4 ... Circulation pump 6 ... Circulation pipe, 7 ... Riser pipe 8 ... Discharge port, 20 ... Replacement tank

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-52-12767 (JP, A) JP-A-54-142660 (JP, A) Actual Kaihei 1-147255 (JP, U)

Claims (1)

[Claims] 1. A chemical conversion treatment tank containing a chemical conversion treatment liquid, and a plurality of straightening plates arranged inside the chemical conversion treatment tank, the plurality of chemical conversion treatment liquids overflowing from the treatment tank. An overflow tank in which sludge in the chemical conversion treatment liquid settles by flowing between the straightening plates and a circulation pump for returning the chemical conversion treatment liquid in which the sludge in the overflow tank has settled to the treatment tank. A pipe, and a pipe connected to the end of the circulation pipe, arranged near the bottom of the processing tank and along the bottom, and forming a plurality of chemical conversion treatment solution discharge ports toward the inside of the processing tank. The riser pipe for discharging the chemical conversion treatment liquid toward the bottom wall of the treatment tank, and the upper end of the straightening plate has a height equal to or higher than the liquid level of the chemical conversion treatment liquid in the overflow tank. Position, the bottom edge is -The flow straightening plate is arranged so as to be spaced apart from the bottom wall of the flow tank by a predetermined distance, the upper end is lower than the liquid surface of the chemical conversion treatment liquid, and the lower end is arranged in contact with the bottom wall of the overflow tank. A plurality of such straightening plates are alternately arranged in parallel, and the sludge in the chemical conversion liquid is settled while the chemical conversion liquid flowing into the overflow tank repeatedly flows between the straightening plates while rising and falling. Chemical conversion treatment device characterized by.