JPH04322765A - Immersion type phosphate treatment equipment and method for removing sludge - Google Patents

Abstract

PURPOSE:To obtain a chemically converted good film by efficiently collecting sludge deposited on the base of a tank by a simple method and discharging it to the outside of the system and filtrating it. CONSTITUTION:In an immersion type phosphate treatment equipment wherein a treating tank 1 containing treating liquid is equipped and phosphate treatment of a work is performed by immersing this work in the treating liquid, a stepped part is provided in at least either side of the outlet tank part 13 of the treating tank and the inlet tank part 12 thereof. A collection tank is positioned and formed in the part lower than the general face 1a of the bottom wall of this treating tank. Moreover a means for filtering the treating liquid is provided to this collection tank 15 via a pump. Further an injection means for guiding air or the treating liquid mixed with air is provided. Sludge by-produced in the treating tank is forcedly transferred into the collection tank 15. Frequency of periodical cleaning for drawing out the treating liquid from the treating tank is remarkably reduced. A large amount of sludge is nearly completely removed. Since the whole height of the equipment is low, the area of space is made favorable and the potential cost of the treating liquid is made inexpensive.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an immersion-type phosphate treatment device mainly used for pre-painting treatment of automobile bodies, etc., and the removal of insoluble phosphates (hereinafter referred to as sludge) in the treatment device. Regarding the method.

0002

[Prior Art] In the painting process for automobile bodies, etc.,
After a cleaning process to remove oil and dust adhering to the car body during the pressing process or welding process, a phosphate treatment process is provided to improve the corrosion resistance and adhesion of the electrodeposited coating. The phosphating process is a process that forms a phosphate film on the metal surfaces that make up the car body, and can be carried out using a full-dip type where the car body is completely immersed in the phosphate treatment liquid, or a full-dip type where only the underbody of the car body is submerged in the treatment liquid. Dip painting methods such as half-dip painting, in which the upper body is dipped and sprayed, are widely used. This type of immersion painting method is more effective than spray painting methods, especially in spray pockets such as inside the bag structure of the car body (areas that are not directly sprayed by a spray nozzle).
Excellent corrosion resistance and adhesion.

When chemical conversion treatment is performed using such an immersion phosphate treatment method, a large amount of sludge containing phosphate compounds as a main component is produced as a by-product due to the reaction between the phosphate treatment solution and the metal. Especially in large treatment tanks such as automobile bodies,
The by-product sludge is deposited on the bottom of the tank. If this amount of sludge accumulates in excess, it will float in the treatment liquid and adhere to the car body, causing dust defects.It will also disrupt the circulation of the treatment liquid, causing uneven formation such as step defects in the film. becomes. Therefore, in the conventional immersion type phosphoric acid solution treatment apparatus, as shown in FIG. 6, sludge is removed by guiding the treatment liquid 2 in the treatment tank 1 to a filtration device 3 installed outside the system. In addition,
In FIG. 6, "4" indicates a pump, and "5" indicates an overflow tank.

0004

[Problems to be Solved by the Invention] However, with this method of removing sludge, it is not possible to completely remove the sludge that has accumulated on the bottom of the tank. It was necessary to transfer the water to a ring tank and clean it.

On the other hand, as a method for collecting sludge deposited on the bottom of a tank, a processing apparatus disclosed in Japanese Utility Model Application Publication No. 157,918/1983 (see FIG. 7) is also known. This phosphate treatment device is constructed such that an inverted conical accumulation layer 6 is formed at the bottom of the treatment layer 1, and the treatment liquid 2 in this accumulation layer 6 is guided to a filtration device 3. This technology has problems such as increased material costs due to the increased capacity of the processing tank and space for the collecting tank. In other words, in the immersion painting method, it is necessary to keep a certain amount of processing liquid in the processing tank at all times, but as the capacity of the processing tank increases, it becomes necessary to install new equipment or replace the processing liquid. This increases the potential cost of Also,
In order to fully submerge the body in the processing liquid, the height from the conveyor that transports the body to the bottom of the processing tank is required.
Adding an accumulation tank to this would not be possible within the existing factory space and would require further capital investment. Furthermore, the same publication describes a method of introducing the sludge into the collection tank by injecting the treatment liquid or filtrate from the filtration device onto the sludge in the treatment layer, but a large amount of sludge is produced as a by-product and treatment There was a problem in that if it was deposited on the bottom of the tank, it could not be completely removed. The present invention has been made in view of the problems of the prior art, and it efficiently collects the sludge that accumulates on the bottom of the tank using a simple method, and discharges the sludge out of the system and filters it. The purpose is to obtain a chemical conversion coating.

[0006]

[Means for Solving the Problems] The present invention to achieve the above objects includes a treatment tank containing a treatment liquid, and a phosphate treatment for the workpiece by immersing the workpiece in the treatment liquid. In the type phosphate treatment apparatus, a step is provided in at least one of the outlet section or the inlet section of the treatment tank to form an accumulation tank located below the general surface of the bottom wall of the treatment tank. A treatment liquid filtering means is provided in this accumulation tank via a pump, and an injection means for guiding the treatment liquid mixed with air or air is provided to forcibly move the sludge produced as a by-product in the treatment tank into the accumulation tank. This is an immersion type phosphate treatment equipment characterized by: Further, in an immersion phosphate treatment method in which a work is phosphate treated by immersing the work in a treatment liquid,
By providing a step in at least one of the outlet section and the inlet section of the processing tank containing the processing liquid, a collecting tank is formed that is located below the general surface of the bottom wall of the processing tank, and air or air The above object can also be achieved by a sludge removal method characterized by injecting a treatment liquid mixed with .

[0007]

[Function] In the present invention configured as described above, the general surface of the bottom wall of the processing tank is improved by providing a stepped portion in the accumulation tank formed in at least one of the outlet section and the entry section of the processing tank. Since it is configured to be located further down, the overall height of the entire processing tank can be minimized, allowing for effective use of space, as well as minimizing the increase in the total capacity of the processing tank, reducing the potential cost of processing liquid. can do. In addition, by providing an injection means for guiding air or a treatment liquid mixed with air, the sludge produced as a by-product in the treatment tank is forcibly moved into the collection tank.
The injection pressure can be increased, and even if a large amount of sludge is produced as a by-product and deposited at the bottom of the processing tank, the sludge can be completely removed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an apparatus configuration diagram showing one embodiment of the present invention, FIG. 2 is an enlarged plan view showing the vicinity of the stacking layer of the same embodiment, and FIGS. 3 to 5 are main parts showing modified examples of the stacking tank according to the present invention. FIG.

First, as shown in FIG. 1, the processing tank 1 according to the present embodiment has an inclined surface 1 corresponding to the transport path of the workpiece 10.
1 are provided in a tank entry section 12 and a tank exit section 13, and an overflow tank 5 is connected to the tank exit section 13. Since the overflow tank 5 is provided to keep the liquid level in the processing tank 1 constant, it may be provided in the tank outlet section 13 as shown in FIG. It can also be provided in A work 10 such as an automobile body is mounted on a hanger (not shown) and conveyed by an overhead conveyor 14. The conveyance method shown in FIG. 1 employs a continuous dipping method in which the overhead conveyor 14 is tilted at the entry section 12 of the processing tank 1 and the workpieces 10 are continuously immersed. Without being limited to the method, it is also possible to adopt a so-called batch dipping method in which a drop lifter of an overhead conveyor is provided at the upper part of the processing tank 1 and the treatment tank 1 is immersed one by one. Although the batch dipping method is inferior in productivity to the continuous dipping method, it is possible to reduce the capacity of the treatment tank, which reduces the installation space for treatment equipment and is advantageous in terms of the potential cost of the treatment liquid. .

A collecting tank 15 is provided on the bottom wall of the tank entry section 12 and the tank exit section 13 of the processing tank 1 according to this embodiment. This accumulation tank 15 has an entry part 12 and an exit part 1 of the processing tank 1 located below the general surface 1a of the bottom wall of the processing tank 1.
A stepped portion 16 is formed in each of the processing tank 3, and consideration is given so that the total height L of the processing tank 1 does not become too high. In addition, the collection tank 15 in the plan view of FIG. 2 is formed in a conical or pyramidal shape that becomes sharp toward the blowing port 17, and efficiently collects the sludge produced in the treatment tank 1. It is now possible to do so. The number of such conical or pyramidal portions is not limited to three as in this embodiment, and may be appropriately selected depending on various conditions such as the capacity of the treatment tank 1 and the amount of sludge produced as a by-product. Further, the accumulating tank 15 may be provided in at least one of the tank input section 12 and the tank output section 13, and this selection is also made depending on various conditions such as the capacity of the processing tank 1 and the amount of sludge produced as a by-product.

The shape of the accumulation tank 15 of the present invention is not limited to that shown in FIG. 1, but may be formed in the shape shown in FIG. 3, FIG. 4, or FIG. 5. Accumulating tank 15a shown in FIG.
The bottom wall of the accumulation tank 15a and the inclined surface 11 of the processing tank 1 are further formed to have a sharp tip toward the direction of the blow-in port 17, and the accumulation tank 15b shown in FIG. The stepped portion 16 between the storage tank 15b and the storage tank 15b is inclined. In addition, the accumulation tank 15c shown in FIG. Suitable for installing industrial equipment and filtration equipment. In short, the accumulation tank 15 according to the present invention
is located below the general surface 1a of the bottom wall of the processing tank 1 so that the total height L of the processing tank 1 does not become high. It suffices if the stepped portion 16 is formed in the step. In addition, in the accumulation tank 15 according to this embodiment, especially in a phosphate treatment apparatus using a continuous immersion method as shown in FIG. Because of this, the inclined surface 11
This has the advantage that the extra space underneath can be used effectively.

An air inlet 17 is provided at the conical or pyramidal tip of the accumulating tank 15 according to this embodiment, and a blowing pipe 18 is connected to the air inlet 17 to guide the processing liquid 2 in the processing tank. . The processing liquid 2 introduced into the blowing pipe 18 is guided to a filtration device 3 (filter) by a pump 4, and then returned to an overflow tank 5.

Riser pipes 19 are provided at predetermined intervals on the bottom wall of the processing tank 1 according to this embodiment, and a plurality of nozzles are attached to the riser pipes 19. Air is supplied to the riser pipe 19 from an air source 20,
Alternatively, this air mixed with the filtrate filtered by the filtration device 3 is introduced, and this air or the filtrate mixed with air is injected from a nozzle in the direction shown by the arrow in FIG. The accumulated sludge is forcibly moved into the accumulation tank 15. Particularly when there is a large amount of sludge deposited on the bottom wall of the treatment tank 1, by guiding only air to the riser pipe 19, the injection pressure can be increased and the sludge accumulation efficiency can be improved. "21" is a switching valve provided in the return pipe 22 from the filtration device 3 to the overflow tank 5, "23" is a switching valve provided in the pipe 24 leading from the filtration device 3 to the riser pipe 19, and "25" is an air source 2
This is a switching valve provided in the air pipe 26 extending from the riser pipe 19 to the riser pipe 19.

Next, the procedure for carrying out the phosphate treatment according to the present invention will be explained. First, after a predetermined processing liquid 2 is supplied into the processing tank 1 and the overflow tank 5, the workpiece 10 is placed into the processing tank 1 by the overhead conveyor 14, and phosphate treatment is started. At the same time that the work 10 enters the tank, the liquid level in the processing tank 1 rises, and a liquid amount equal to the volume of the work 10 flows into the overflow tank 5. Although not shown, the processing liquid 2 is supplied from the overflow tank 5.
A separate path is provided for guiding the liquid into the processing tank 1, so that the processing liquid 2 in the processing tank 1 is appropriately agitated to prevent uneven processing of the work 10. Work 1
0 completes the treatment and takes out the tank, the liquid level in the processing tank 1 will drop, but as mentioned above, the circulating liquid from the overflow tank 5 is returned to the processing tank 1, so the liquid level in the processing tank 1 will drop. The surface automatically restores to a fixed position.

The sludge produced by this phosphate treatment is deposited on the bottom wall of the treatment tank 1, but most of the sludge is accumulated by the injection of air or filtrate mixed with air from the riser pipe 19. After moving into the tank 15 and being sucked by the pump 4, it is removed from the system by the filtration device 3. However, if the workpiece 10 has a complicated shape such as a car body, the riser is not used while the workpiece 10 is being treated with phosphate, that is, while the workpiece 10 is in the treatment tank 1. Preferably, only the filtrate is injected from the tube 19. This is to prevent air pockets from forming in the workpiece 10, and also because the supply of air accelerates the decomposition of the accelerator added to the processing liquid. Therefore, it is necessary to inject air or a filtrate mixed with air from the riser pipe 19 when no work 10 is in the processing tank 1.

As described above, according to the phosphate treatment apparatus and sludge removal method according to the present embodiment, even when a large amount of sludge is produced as a by-product and accumulates on the bottom wall of the treatment tank, air cannot be mixed in. By doing so, the injection pressure from the riser pipe can be increased, thereby making it possible to forcibly move the sludge completely into the accumulation tank. Moreover, by reducing the height dimension of the accumulation tank, existing space can be used, and no extra equipment investment is required. moreover,
The potential cost of the treatment liquid can also be suppressed by reducing the capacity of the treatment tank.

[0017] Next, further embodiments of the present invention will be enumerated and explained. Commercially available cold rolled steel (100 x 300
x 0.8 mm) test plate using a medium alkaline degreaser (“Surf Cleaner #SD400-A” manufactured by Nippon Paint Co., Ltd.)
1.6% by weight, “Surf Cleaner #SD400-B”
0.8% by weight) at a temperature of 40° C. for 2 minutes, and then washed with water. Next, this test plate was coated with a surface conditioner (“Surf Fine #5N-10” manufactured by Nippon Paint Co., Ltd.).
0.1% for 30 seconds at room temperature, and then
Phosphate chemical treatment solution (Zn: 0.1%, Ni: 0.06
%, PO4: 1.5%, NO3: 0.3%, F: 0
．． 0.06%, NO2: 0.013%), the total acidity was 21.
The immersion treatment was carried out for 2 minutes under the following conditions: point, free acidity 0.9 point, and temperature 43°C. In addition, this total acidity point is the 0.1N required to take 10ml of the treatment solution and add phenolphthalein as an indicator to turn it red.
The free acidity point is the number of ml of NaOH in
This refers to the number of ml of 0.1N NaOH required to turn blue when 10 ml of the treatment solution is sampled and bromophenol blue is added as an indicator.

As a result of the phosphate chemical conversion treatment, the amount of sludge produced as a by-product was 4 g/m2 (dry sludge amount) on average. Phosphate chemical conversion treatment under these conditions is carried out using the treatment apparatus according to the present invention shown in FIG.
Each case using the conventional processing apparatus shown in FIG. 6 was performed five times, and the removal rate of by-product sludge was compared. The results are shown in Table 1.

[0019]

[Table 1]
Sludge removal rate% This device
85 90 83 85
90 Conventional device
60 70 70 65
60 As is clear from this test result, by using this device, the sludge removal rate in the processing tank can be increased compared to the conventional device shown in Figure 6, and the problem of dust defects due to sludge adhesion to the workpieces has been resolved. be done. In addition, the process can be carried out without disturbing the liquid circulation, and the work required to clean the process tank regularly is greatly reduced, improving work efficiency.

On the other hand, even when compared with the conventional apparatus having the accumulation tank shown in FIG. 7, when the sludge accumulation prevention ability of the processing apparatus according to the present invention and the apparatus shown in FIG. The height of the accumulation tank of the device can be reduced by 50% or less compared to the accumulation tank of conventional devices.

[0021]

As described above, according to the present invention, there is provided an immersion type phosphate treatment which includes a treatment tank containing a treatment liquid and performs phosphate treatment on the workpiece by immersing the workpiece in the treatment liquid. In the processing apparatus, a step is provided in at least one of the outlet section and the inlet section of the processing tank, thereby forming an accumulation tank located below the general surface of the bottom wall of the processing tank, and in which air or Since an injection means for guiding the treatment liquid mixed with air is provided and the sludge produced as a by-product in the treatment tank is forcibly moved into the collection tank,
The frequency of regularly removing the processing liquid from the processing tank and transferring it to a separate tank (settling tank) for cleaning is greatly reduced, and in addition, when a large amount of sludge is produced as a by-product and accumulates at the bottom of the processing tank, Even if it does exist, it can be almost completely removed. Furthermore, since the height of the device can be set lower than that of conventional accumulation tanks, it can be adequately handled using existing factory space, and capital investment can be reduced. Moreover,
Since the increase in the capacity of the treatment tank can be suppressed as much as possible,
Potential cost of processing liquid can be reduced.

[Brief explanation of drawings]

FIG. 1 is an apparatus configuration diagram showing an embodiment of the present invention.

FIG. 2 is an enlarged plan view showing the vicinity of the stacked layers of the same embodiment.

FIG. 3 is a sectional view of a main part showing a modification of the accumulation tank according to the present invention.

FIG. 4 is a sectional view of a main part showing another modification of the accumulation tank according to the present invention.

FIG. 5 is a sectional view of a main part showing another modification of the accumulation tank according to the present invention.

FIG. 6 is an apparatus configuration diagram showing a conventional phosphate treatment apparatus.

FIG. 7 is an apparatus configuration diagram showing a conventional phosphate treatment apparatus.

[Explanation of symbols]

1...processing tank,
1a... General surface of the bottom wall of the processing tank, 2... Processing liquid,
10...Work, 12...Tank entry section,
13... Output tank, 15... Accumulation tank,
16...Step part, 19...Riser pipe (injection means), 20...Air source.

Claims (2)

[Claims] 1. An immersion-type phosphate treatment apparatus comprising a processing tank containing a processing liquid and performing phosphate treatment on a workpiece by immersing the workpiece in the processing liquid, comprising: an outlet section of the processing tank; Alternatively, by providing a stepped portion on at least one of the tank entry portions, an accumulation tank located below the general surface of the bottom wall of the processing tank is formed, and a processing liquid filtration means is provided in this accumulation tank via a pump. An immersion type phosphate treatment apparatus, further comprising an injection means for guiding air or a treatment liquid mixed with air, and forcibly moving sludge produced as a by-product in the treatment tank into the accumulation tank. 2. An immersion-type phosphate treatment method in which a workpiece is phosphate-treated by immersing the workpiece in a treatment liquid, wherein at least one of the outlet part and the input part of the treatment tank containing the treatment liquid is provided. By providing a stepped portion on either side, a collecting tank is formed which is located below the general surface of the bottom wall of the processing tank, and air or a processing liquid mixed with air is injected in the direction of the collecting tank, and the processing tank is injected into the processing tank. A sludge removal method characterized by forcibly moving sludge produced as a by-product into a collection tank.