JPS6240653Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is based on intermediate floating impurities, sedimentary impurities, and buoyant impurities that float on the surface of the processing liquid (these are collectively called This invention relates to a liquid absorption device used when circulating a processing liquid in order to remove impurities (hereinafter referred to as impurities).

Various processing solutions are placed in a liquid tank to perform the desired processing, while circulation is performed to remove impurities that occur and accumulate in the processing solution. It has been widely practiced in various other industrial fields.

To explain this circulation process using an example of plating processing, Fig. 1 is an explanatory diagram of a conventional circulation system in which one of the liquid tanks for plating is omitted and the liquid absorption device is shown by a cutout. In the figure, 1 is a liquid tank, 2 is a processing liquid, 3 is a liquid suction device, and 4 is a liquid suction pipe, which is connected to the suction side of the pump 5 via a valve without a reference numeral. The discharge pipe 6 on the discharge side of the pump is directly connected to the strainer 7, and the processing liquid pressurized into the inside 7a of the strainer is
The liquid passes through the bed 7c, which has a precoat layer made of a suitable additive on the bed 7b, and is discharged through the liquid sending pipe 8 after impurities are removed and the liquid is clean. The purified processing liquid is then heated or cooled through a heat exchanger 9, and then passed through a liquid supply pipe 10 to the liquid suction device 3 as shown in the sectional view of the liquid tank in FIG. The liquid is refluxed into the liquid tank 1 through the liquid supply port 11 provided on the side, thus performing circulation.

On the other hand, in rare cases gas agitation is not performed in such processing, but generally this is done to make the composition and temperature of the processing liquid in the liquid tank uniform, and to remove impurities from the workpiece being immersed in the processing liquid. In order to avoid adhering to the surface and causing processing defects, air or an inert gas is constantly blown into the processing liquid through the vent hole 13 of the ventilation pipe 12 provided at the bottom of the liquid tank as shown in the figure to create an upward gas flow. It is customary to prepare 14 and stir the treatment liquid with gas.

In the conventional circulation method explained above, the treated liquid in the liquid tank is distributed as a whole to the liquid supply port 1, as shown by the dotted arrow in Fig. 2, regardless of the presence or absence of gas agitation.
The liquid flows from the liquid suction device 1 side toward the liquid suction device 3 and moves. Therefore, intermediate floating impurities in the processing liquid are sequentially sucked in from the liquid suction device 3 and removed by the filter along with the overall flow of the processing liquid. However, buoyant impurities and precipitable impurities in the treatment liquid have serious drawbacks, such as significantly inhibiting the efficiency and effectiveness of circulation and causing various problems in practical use, for the reasons described below.

First, buoyant impurities float to the surface of the treated liquid when gas agitation is not performed, and when gas agitation is performed, they surround fine gas bubbles with some of the intermediate buoyant impurities. The wafer absorbs this, further increases its buoyancy, and floats above the surface of the processing liquid. Floatable and floating impurities that float on the surface of the treated liquid can be removed as they are during plating treatment, etc.
It adheres to the surface of the object to be treated when it is placed in and taken out of the liquid, causing processing defects, but it accumulates on the liquid surface near the liquid suction device 3 during the overall flow of the processing liquid, and accumulates. As shown in FIG. 2, a thick floating aggregate layer 15 is formed, which further causes processing defects of the object to be processed. This floating aggregate layer cannot be removed using conventional equipment, so workers have to remove it several times a day using fibrous absorbent or absorbent paper, or pump it out and throw it away, which is a time-consuming process. This has the disadvantage that workers may fall into the liquid tank, which requires additional work, and even these problems cannot be completely removed, often resulting in poor processing. be.

Further, the precipitated impurities settle to the bottom of the liquid tank on the side closer to the liquid suction device, and are gradually sucked into the liquid suction device and removed along with the flow of the processing liquid. However, when the liquid suction device 3 is simply located at one side of the liquid tank as in the conventional device, the precipitated impurities that have settled on the bottom of the liquid tank at a location away from the liquid suction device remain without being removed, and the treatment operation is interrupted. As it continues, it will continue to accumulate or deposit locally. Therefore, in the past, the processing operation was interrupted at regular intervals, all of the processing liquid in the liquid tank was transferred to another container through a filter, and the empty liquid tank was thoroughly cleaned. The treated liquid was returned to the liquid tank through the filtration vessel, an extremely unproductive work. This results in a decrease in production, wastage of expensive processing fluids associated with this work, and an increase in management costs due to the interruption of the original processing work.Therefore, it is not financially viable to perform such cleaning work frequently. This has become a serious drawback.

The present invention has been made to overcome the above-mentioned drawbacks found in conventional liquid circulation suction devices.

As shown in the partially cutaway explanatory diagram of FIG. 3, the present invention has a pocket part 16 on one side of the liquid tank 1 into which the processing liquid flows due to a head difference, and a pocket part 16 into which the processing liquid flows into the inner bottom of the pocket side liquid tank. A liquid suction device 17 that sucks the liquid evenly across the width direction of the liquid tank is provided, and the pocket portion 1
A regulating valve 22 is provided in a liquid suction pipe 21 extending from the bottom of the pump 6 to the suction side of a pump (not shown), and a regulating valve 23 is provided in a liquid suction pipe 4 extending from the liquid suction device 17 to the pump suction side. .

Liquid suction device 17 of the present invention installed at the bottom of the liquid tank
As shown in the figure, is a closed cylinder whose length corresponds to the width of the liquid tank 1, and as shown in the front view of FIG. A large number of liquid suction holes 19 are perforated in the part so as to become denser as the distance from the liquid suction pipe increases, and a gap is left between the hole and the bottom of the liquid tank via the seat plate 20. As mentioned above, the liquid suction device 17 is made rough on the side closer to the liquid suction pipe 4, and the liquid suction holes are formed so as to become denser as the distance from the hole increases. Approximately the same amount of processing liquid is sent from the bottom of the liquid tank to the suction side of the suction pump.

When gas agitation is performed as shown in FIG. 3, a shield plate 18 is provided along the suction device, which is effective as an inflow barrier for preventing the suction of gas bubbles (part of the gas flow).

The pocket part 16 can be formed by cutting out the partition wall 1' of the part of the liquid tank 1 corresponding to the pocket part 16 so as to be one step lower, as shown in the sectional view in FIG. Together with the floating collection layer 15, the liquid overflows through this notch, flows into the pocket due to the drop, and is sent to the pump suction side via the liquid suction pipe 21.

Note that the drawings shown in FIGS. 3 to 5 show one embodiment of the present invention, and the present invention is not limited to the configuration shown in these figures. For example, the drawings shown in FIGS. Instead of the liquid hole 19, a slit-like liquid suction groove whose width gradually increases may be used. Also,
Although the pocket portion 16 is shown protruding from the liquid tank in the drawing, it may be installed inside a partition box provided in the liquid tank, or it may be installed on the wall side where the liquid suction device 17 is installed. It can also be placed across the width.
The liquid suction device shown in Figure 4 is a cylinder with one end closed, but it is also possible to use a T-shaped or L-shaped closed cylinder with both ends closed and a liquid suction pipe erected vertically from around the center to suit the liquid tank. It can be a body.

Since the device of the present invention is constructed as described above, by adjusting the control valves 22 and 23 respectively, the processing liquid can be sucked out from either the liquid suction device 17 or the pocket portion 16. It is also possible to suck out the processing liquid from both at any ratio and send it to the filter.

Generally, both control valves are adjusted as appropriate depending on the state of occurrence of the floating aggregate layer 15.

When using the device of the present invention as explained above,
Regardless of the presence or absence of gas agitation during circulation, the following excellent effects can be obtained. First, the liquid suction device of the present invention installed at the bottom of the liquid tank sucks the processing liquid from the bottom of the liquid tank evenly over its entire length from the liquid suction hole drilled on the lower side of the closed cylinder. The precipitated impurities are sucked in on average and do not form localized deposits on the bottom of the tank. Therefore,
It is possible to greatly reduce the number of times the original processing work must be temporarily interrupted to clean the inside of the liquid tank, which is a serious drawback in terms of management. Next, impurities floating on the surface of the processing liquid in the liquid tank constantly flow into the pocket part provided in the device of the present invention due to the head along with the processing liquid and are continuously removed.
5 will no longer occur, and impurities of the floating aggregate layer will no longer adhere to the surface of the object to be processed and cause processing defects. Furthermore, unlike in the past, it is no longer necessary for workers to interrupt the treatment work and remove the floating aggregate layer on the liquid surface by adsorption with various adsorbents, or to pump it out and throw it away, which is dangerous for security reasons. It becomes completely unnecessary. Furthermore, both of the above-mentioned effects can be achieved simultaneously by appropriately adjusting the flow rate control valves provided in the piping paths from both the liquid suction device and the pocket part to the pump suction side. As a result, the processing liquid in the tank and the bottom and inner wall surfaces of the tank are always kept clean for a long period of time.
Moreover, it is possible to completely eliminate the occurrence of processing defects of the processed material due to impurities during operation.

As described above, although the present invention has a simple configuration, it overcomes various drawbacks of conventional devices and exhibits excellent practical effects.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conventional circulation device in which one of the liquid tanks is omitted and a part is shown by a notch;
Fig. 2 is a sectional view of a liquid tank of a conventional device, Fig. 3 is a partially cutaway explanatory view of a liquid tank with an embodiment of the device of the present invention, and Fig. 4 is a front view of an embodiment of the liquid suction device. Fifth
The figure is a sectional view of the liquid tank pocket. 1...Liquid tank, 1'...Partition wall, 2...Processing liquid, 2'...Liquid level, 3...Liquid suction device, 4...Liquid suction pipe, 5...Pump, 6...Discharge pipe , 7... Over container, 7a... Inside of over container, 7b... Floor body, 7
c...Floor, 8...Liquid pipe, 9...Heat exchanger, 1
0...Liquid feed pipe, 11...Liquid supply pipe, 12...Vent pipe, 13...Vent hole, 14...Gas flow, 15...
Floating collection layer, 16... pocket part, 17... liquid suction device, 18... shielding plate, 19... liquid absorption hole, 20...
... Seat plate, 21 ... Liquid suction pipe, 22 ... Control valve, 23
……Control valve.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In an apparatus for circulating processing liquid in a liquid tank, a pocket portion is provided on one side of the liquid tank into which the processing liquid flows due to a drop, and the processing liquid is also provided at the bottom of the liquid tank on the pocket side. A liquid suction device is provided for sucking the liquid evenly across the width direction of the liquid tank, and a flow rate regulating valve is provided in each piping route from the pocket portion and the liquid suction device to the pump suction side of the filter device. Liquid suction device for circulation. 2 The liquid absorption device installed at the bottom of the liquid tank is a closed cylinder with a length corresponding to the width of the liquid tank, and it absorbs approximately the same amount of processing liquid from any point along the entire length of the cylinder. A liquid suction device for circulation according to claim 1, which is provided with a suction hole through which liquid can be sucked from below.