JP6040267B2 - Paint waste liquid separator - Google Patents

Description

The present invention relates to paint waste liquid separation device to separate the active coating components in the coating material waste, to a paint waste liquid separator you particularly effectively solid-liquid separation of the aqueous coating mist booth circulating water.

  2. Description of the Related Art Conventionally, as a coating method for articles having complicated shapes such as automobiles, building materials, and electrical appliances, a spray coating method in which a paint is sprayed in a coating booth is often used. In this spray painting method, the amount of paint that contributes to actual painting is approximately 30% to 70% of the sprayed paint, although the amount depends on the technique of painting, and the remainder is surplus paint. These surplus paints are generally captured by a water curtain or the like provided in the painting booth and collected in circulating water. Then, after the circulating water containing the surplus paint component is collected in the circulating water pit, the circulating water and the paint component are separated according to a predetermined method, and the separated paint component is recovered and discarded. In addition, the circulating water from which the paint component has been removed is reused for collecting excess paint.

  In the above surplus paint treatment method, when the paint used for painting is an oil-based paint, the collected paint component does not dissolve in the circulating water but exists as an adhesive solid. For this reason, if an appropriate amount of an aggregating agent generally called a spray mist treating agent is added to the circulating water, these coating components become a fine solid having no adhesive force and easily aggregate to form an aggregate. Then, by collecting the aggregate, the circulating water and the paint component can be solid-liquid separated relatively easily. However, in recent years, emission regulations for VOC (Volatile Organic Compounds) have been strengthened, and in the field of coatings, switching from conventional oil-based paints to non-organic solvent-based water-based paints has been rapidly progressing. Since these water-based paints are dispersed in the circulating water, it is difficult to separate the circulating water and the paint components compared to the oil-based paint.

  In response to the above problems, the inventor of the present application performs the invention described in [Patent Document 1] relating to a paint waste liquid separation apparatus and a paint waste liquid separation method having a high separation efficiency capable of solid-liquid separation of paint components with a small amount of flocculant. It was. The invention described in [Patent Document 1] improves the dispersibility of the flocculant by simultaneously mixing circulating water containing a paint component, a powdery flocculant, and air and stirring at high speed. Improves solid-liquid separation efficiency with circulating water.

Japanese Patent No. 4574640

  The invention described in [Patent Document 1] described above makes it possible to perform solid-liquid separation of water-based paint components with high efficiency. However, in actual painting sites, the concentration of paint components in the circulating water changes every moment, and organic chemicals for cleaning, insecticides, antifoaming agents, and other chemicals flow into the circulating water, causing solid liquid The load on the separation process may vary greatly.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a paint waste separator that having a stable processing capacity for the solid-liquid separation capacity is high load fluctuation.

The present invention
(1) A flocculant supply unit 52 for introducing a powdery flocculant into circulating water containing a paint component, and a high speed by sucking the flocculant and air introduced in the circulating water, the flocculant supply unit 52 And a slow stirring unit (aggregation tank 56) for stirring the mixed liquid obtained by the stirring of the coagulant mixing stirring unit 54 at a speed slower than that of the coagulant mixing stirring unit 54. In a paint waste liquid separator having
A pre-treatment unit 70 that performs pre-stirring of circulating water in the previous stage of the flocculant supply unit 52;
The pretreatment unit 70 includes a pretreatment tank 72 into which circulating water flows, a funnel-shaped water intake port 75 that is installed in the pretreatment tank 72 and sucks the circulating water and air, and is sucked by the water intake port 75. The agitation unit 76 that stirs the circulated water and air at a high speed and a discharge port 77 that discharges the circulated water mixed with the air by the agitation of the agitation unit 76, and the flocculant supply unit 52 includes the pretreatment The above-mentioned problem is solved by providing a paint waste liquid separator 80 in which a flocculant is added to the circulating water discharged from the unit 70 and the flocculant mixing and stirring unit 54 performs mixing and stirring.
(2) The paint waste liquid separation device 80 according to (1) is provided, wherein the opening area of the upper end of the water intake port 75 is 10% to 30% of the liquid surface area of the pretreatment tank 72. Thus, the above problem is solved.
(3) The stirring means 74 provided with the water intake port 75, the stirring part 76, and the discharge port 77 is suspended and installed in the pretreatment tank 72, and the position can be adjusted in the vertical direction. By providing the paint waste liquid separation device 80 according to the above (1) or (2) , the above problem is solved.
(4) By providing the paint waste liquid separating device 80 according to (3) above, the upper end of the water intake port 75 is located at a position 10 mm to 80 mm below the surface of the circulating water in the pretreatment tank 72. Solve the problem.

Engaging Ru paint waste separation apparatus of the present invention, in front of the flocculant mixing agitation unit for agitating fast by sucking the coagulant and the circulating water and air, providing a pre-processing unit for stirring before the circulating water and air As a result, the solid-liquid separation ability is improved. Thereby, even if a certain load fluctuation arises in circulating water, the solid-liquid separation of a coating component can be performed stably.

It is a figure which shows the coating-material waste-liquid separator which concerns on this invention. It is a figure which shows the paint waste liquid separator which concerns on this invention using the existing paint waste liquid processing apparatus. It is a figure which shows the paint waste liquid processing system provided with the paint waste liquid processing apparatus which concerns on this invention.

It is described with reference to the drawings showing a preferred embodiment of the paint waste liquid separation equipment according to the present invention. In addition, the coating component in this application shall contain not only the coating component contained in circulating water but the other chemicals which aggregate and solid-liquid-separate by a flocculant.

  FIG. 1 is a view showing a paint waste liquid separating apparatus according to the present invention. FIG. 2 is a diagram showing an example in which a paint waste liquid separating apparatus according to the present invention is configured by adding a pretreatment unit to the paint waste liquid separating apparatus described in [Patent Document 1]. In addition, according to the structure shown in FIG. 2, since the present invention can be configured by adding a pretreatment unit to an existing paint waste liquid treatment apparatus, the introduction cost can be greatly suppressed.

  The paint waste liquid separation device 80 according to the present invention shown in FIG. 1 and FIG. 2 is fed by a flocculant supply unit 52 that feeds a powdery flocculant into circulating water containing paint components, and the flocculant supply unit 52. The flocculant, the circulating water, and the air are sucked and stirred at a high speed to agglomerate the paint components in the circulating water, and the aggregate and the circulating water aggregated by the stirring of the flocculant mixing and stirring section 54 And a slow stirring part (aggregation tank 56) for agglomerating and aggregating the agglomerates with each other at a speed slower than that of the aggregating agent mixing and agitation part 54, and in front of the circulating water. And a pretreatment unit 70 that performs stirring.

  The pretreatment unit 70 includes a pretreatment tank 72 into which the circulating water flows, and a stirring means 74 installed in the pretreatment tank 72. The stirring means 74 sucks the circulating water and air. A funnel-shaped water intake 75, a stirring part 76 for stirring (pre-stirring) the circulating water and air sucked at the water intake 75 at a high speed, and circulating water mixed with air by the pre-stirring of the stirring part 76 And a discharge port 77 for discharging.

  The pretreatment tank 72 constituting the pretreatment unit 70 has a substantially dome shape at the bottom, and a drain discharge valve 10a is installed on the bottom surface. The stirring means 74 is preferably installed in the pretreatment tank 72 by being suspended by the suspension bolt 40 or the like. Moreover, it is preferable that the vertical position can be adjusted by the suspension bolt 40 or the like. Further, as shown in FIG. 1, in a configuration in which the circulating water does not directly flow into the water intake port 75 of the stirring means 74, the flowing circulating water flows down to the flocculant mixing and stirring unit 54 side without passing through the stirring means 74. In order to prevent this, it is preferable to provide the partition plate 42 in the pretreatment tank 72. Further, as shown in FIG. 2, in the configuration in which the circulating water is directly supplied to the intake port 75 of the stirring means 74, the flow rate adjusting valve 8 or the like is provided in the intake hose 24 a that conveys the circulating water and the supplied water is supplied to the intake port 75. It is preferable that the amount of circulating water to be adjusted is adjustable.

  The intake port 75 of the stirring means 74 has a substantially conical or substantially pyramidal funnel shape with a wide upper end and a narrow lower end, and the circulating water flowing into the pretreatment tank 72 flows down through the intake port 75. And sucked into the stirring unit 76. At this time, by setting the position of the upper end of the water intake port 75 at a position 10 mm to 80 mm below the surface of the circulating water in the pretreatment tank 72, the water intake port 75 brings air (outside air) into the stirring unit 76 together with the circulating water. Suction at the same time. In addition, when the upper end position of the water intake port 75 is less than 10 mm from the water surface of the circulating water, the ratio of the air sucked by the stirring unit 76 becomes excessive, and the pre-stirring processing capacity deteriorates. Moreover, when the upper end position of the water intake port 75 exceeds 80 mm from the water surface of the circulating water, the ratio of the circulating water to be sucked becomes excessive, the mixing and stirring with air becomes insufficient, and the solid-liquid separation capability by the pretreatment unit 70 There is a possibility that the improvement effect of the above cannot be obtained. The position of the intake port 75 for sucking the circulating water and air at a suitable ratio varies depending on the viscosity of the circulating water, the concentration of the paint component, etc., but is usually 30 mm to 40 mm from the surface of the circulating water. Therefore, it is preferable to adjust the installation depth of the stirring means 74 so that the upper end of the water intake port 75 comes to this position.

  Further, the opening area of the upper end of the water intake port 75 is preferably 10% to 30% of the surface area of the circulating water in the pretreatment tank 72, that is, the inner diameter area of the pretreatment tank 72, particularly 15% to 20% is preferred. In addition, when the opening area of the intake port 75 is less than 10% of the liquid level, there is a possibility that the pre-stirring of the circulating water is biased due to the intake region of the intake port 75 being narrow and a part of the circulating water being stopped. . Further, when the opening area of the water intake port 75 exceeds 30% of the liquid surface area, the water intake port 75 covers the liquid surface in the pretreatment tank 72 over a wide range. There is a possibility of bias.

  The stirring unit 76 stirs the circulating water and air sucked at the water intake port 75 at high speed, and it is preferable to use a well-known submersible pump installed upside down so that the suction port faces upward. According to this configuration, since a known submersible pump can be used as the agitation unit 76, the introduction cost of the paint waste liquid separating device 80 and the paint waste liquid treatment system 100 can be reduced. The submersible pump used for the stirring means 74 is preferably one that can adjust the rotation speed in a range of about 1500 rpm to 3600 rpm and allows a certain amount of cavitation (stirring including air). The same applies to the coagulant mixing and stirring unit 54 described later.

  Further, the discharge port 77 of the stirring means 74 discharges the circulating water pre-stirred by the stirring unit 76, and is installed toward the lower side of the pretreatment tank 72. Thereby, the circulating water discharged from the discharge port 77 agitates the circulating water in the pretreatment tank 72 and partly flows down to the coagulant supply unit 52 side.

  The flocculant supply unit 52 is located between the pretreatment unit 70 and the flocculant mixing and stirring unit 54, and a predetermined amount of the powder flocculant is added to the circulating water prestirred in the pretreatment unit 70 intermittently or at a constant speed. It is preferable to use a hopper that supplies and can control the supply amount. Note that the flocculant supply unit 52 shown in this example includes a flocculant discharge port 53 on a flocculant mixing rod 62 provided between the pretreatment tank 72 and the flocculant mixing and stirring unit 54, and this flocculant discharge port. An example in which the flocculant is introduced into the circulating water through the outlet 53 is shown. However, the installation position of the coagulant supply unit 52 is not particularly limited to this example. For example, the coagulant supply unit 52 is provided above the water intake 60 of the coagulant mixing and stirring unit 54, and the water intake 60 sucks. The flocculant may be added directly to the circulating water after the pre-stirring.

  The flocculant mixing and stirring unit 54 located at the subsequent stage of the flocculant supply unit 52 is installed inside the flocculant tank 56 that functions as a slow stirring unit, and the flocculant charged in the flocculant supply unit 52 and the pretreatment unit. The circulating water pre-stirred in 70 and the air are taken in from the funnel-shaped water intake 60 and stirred at a high speed. Like the stirring means 74 of the pretreatment unit 70, a known submersible pump is used upside down. It is preferable to do. Then, by the mixing and stirring by the flocculant mixing and stirring unit 54, the flocculant in the circulating water expands and aggregates while taking in the paint component in the circulating water to form an aggregate of the paint component. As a result, the circulating water containing the paint component is solid-liquid separated into an aggregate of the paint component and the circulating water.

  The discharge port 55 of the flocculant mixing and stirring unit 54 is installed downward of the coagulation tank 56 similarly to the pretreatment unit 70, and discharges the mixed water of the aggregate and circulating water toward the bottom of the coagulation tank 56. To do. And the mixed water in the coagulation tank 56 is stirred at a slower speed than the coagulant mixing and stirring unit 54 by discharging the mixed water. Thereby, the aggregate produced | generated in the coagulant | mixing agent mixing stirring part 54 adheres to the surrounding aggregate in the aggregation tank 56 as a slow stirring part, and grows into a bigger aggregate.

  Next, the operation of the paint waste liquid separating apparatus 80 and the paint waste liquid separating method according to the present invention will be described with reference to the schematic configuration diagram of the paint waste liquid treatment system 100 shown in FIG. FIG. 3 is a diagram in which the paint waste liquid separation device 80 of FIG. 1 is applied to the paint waste liquid treatment system 100.

  First, surplus paint generated in a painting booth (not shown) is collected in circulating water by a water curtain or the like, and flows into the circulating water pit 22 through the return pipe or the return water channel 20. The circulating water flowing into the circulating water pit 22 is temporarily stored here and supplied to the pretreatment unit 70 of the paint waste liquid separating device 80 by the water intake device 24. In FIG. 3, a float-type water intake pump is used for the water intake device 24 and the upper layer of the circulating water stored in the circulating water pit 22 is taken, but the water intake device 24 is not limited to this configuration. A well-known liquid conveying means such as a submersible pump can be used. FIG. 3 shows an example in which the circulating water taken by the water intake device 24 is conveyed to the flow rate adjusting rod 32 via the water intake hose 24 a and flows into the pretreatment tank 72 via the flow rate adjusting rod 32. The excess circulating water conveyed to the flow rate adjusting rod 32 is returned to the circulating water pit 22 via the drainage rod 32a.

Then, the circulating water containing the paint component flowing into the pretreatment tank 72 is sucked into the stirring unit 76 together with air from the water intake port 75 of the stirring means 74 and is stirred at a high speed. At this time, the rotation speed of the stirring unit 76 is preferably 1500 rpm to 3000 rpm. Thereby, the paint component in the circulating water is redispersed and air is mixed with the circulating water. The circulating water pre-stirred by the stirring unit 76 is discharged from the discharge port 77. The discharged circulating water agitates the circulating water in the pretreatment tank 72, and part of the circulating water flows down to the flocculant mixing rod 62 over the partition plate 42. A part of the circulating water discharged from the discharge port 77 is again taken into the stirring unit 76 from the water intake port 75 and again subjected to pre-stirring. The stirring unit 76 preferably has a capacity of 5 V / min or more when the effective amount of water in the pretreatment tank 72 is V, and the average residence time of the circulating water in the pretreatment tank 72 (pre-stirring time) ) Is preferably integrated so that its ability can be adjusted within a range of 1 min to 10 min. Thereby, the pretreatment tank 72 performs sufficient pre-stirring treatment on the circulating water. Or it corresponds to the pretreatment step paint waste separation process.

  In the circulating water flowing down the coagulant mixing tank 62, the powder coagulant is supplied from the coagulant supply unit 52 intermittently or at a constant supply rate. At this time, the optimum amount of the flocculant varies depending on the type, composition, concentration, type of flocculant and the like of the paint component in the circulating water. Therefore, it is preferable to use a flocculant supply unit 52 that can adjust the amount of flocculant charged.

The circulating water charged with the flocculant is discharged to the water intake 60 of the flocculant mixing and stirring unit 54 and is stirred at high speed in the flocculant mixing and stirring unit 54 together with air. The flocculant stirred at a high speed takes in the air drawn in as fine bubbles and takes in the paint component in the circulating water to expand and agglomerate to form an aggregate of the paint component. As a result, the paint component dissolved in the circulating water and the circulating water are separated into solid and liquid. The mixed liquid of the aggregate and circulating water is discharged from the discharge port 55 to the aggregation tank 56. Or it corresponds to coagulant mixing and stirring process of paint waste separation process.

The mixed liquid of the aggregate and circulating water discharged to the aggregation tank 56 is gently stirred in the aggregation tank 56 by the flow rate generated by the discharge. As a result, the aggregates generated in the flocculant mixing and stirring unit 54 adhere to the surrounding aggregates and grow into larger aggregates indicated by “●” in FIG. 3. The grown agglomerates float on the surface layer of the agglomeration tank 56 due to the buoyancy of the internal bubbles. And it is discharged | emitted by the floating tank 30 with circulating water. Or it corresponds to slow stirring step of paint waste separation process.

  A cylindrical tube having a predetermined length is connected to the discharge port 55 of the coagulant mixing and stirring unit 54, and the mixed water is fed into the cylindrical tube at a speed slower than that of the coagulant mixing and stirring unit 54 and faster than that of the coagulating tank 56. Secondary stirring may be used. According to this configuration, the aggregate can grow to a certain size in a narrow cylindrical tube, and can grow into a larger aggregate in the slow stirring portion.

Aggregates discharged to the levitation tank 30 float near the water surface of the levitation tank 30. Note that an aeration function may be provided in the levitation tank 30, and bubbles generated by the aeration function may be attached to the aggregate to further increase the buoyancy of the aggregate. Then, the aggregate floating near the water surface of the levitation tank 30 is scraped off by a scraping device 36 such as a scraper, and is discharged to, for example, a collection carriage 39 via a discharge port 38. Or corresponding to the step of separating paint waste separation process.

  The recovery cart 39 is provided with an inner casing having a draining mechanism such as a filtration flexible container and a punching metal, and water passing through the draining mechanism is discharged to the circulating water pit 22 as circulating water. Further, the circulating water in the levitation tank 30 is discharged to the drainage basin 35 through the drainage port 30 a provided in the lower layer of the levitation tank 30 and returns to the circulation water pit 22. Aggregates (referred to as paint sludge or paint residue) accumulated on the collection carriage 39 are discarded according to a predetermined method.

  The circulating water pit 22 is provided with a circulating water intake port 28a connected to the circulating pump 28, and the circulating water in the circulating water pit 22 is supplied to the painting booth by the circulating pump 28. Then, the surplus paint is collected and returned to the circulating water pit 22 through the return pipe or the return water channel 20 again. The above is the outline of the paint waste liquid treatment system 100.

  Next, the verification experiment result for improving the solid-liquid separation ability by pre-stirring will be described. First, aqueous solutions of water-based paints having a concentration of 1.0%, 1.2%, and 1.3% were prepared in a container having a capacity of 1 t, respectively. When the paint color of the water-based paint used was 1.0%, orange and blue mica metallic were used. Moreover, only 1.2% was used in 1.2% and 1.3%. Next, pre-stirring by the pretreatment unit 70 was performed on these samples for 0 minute (no pre-stirring), 1 minute, 5 minutes, 10 minutes, and 15 minutes. Next, 1 L of a sample after pre-stirring was collected, and a powder flocculant was immediately added, followed by stirring with a stirrer at 1500 rpm for about 1 minute. The addition amount of the powder flocculant was 7.0% (0.7 g) and 8.5% (0.85 g) with respect to 1 L of the aqueous solution at a concentration of 1.0%. The concentration was set to 7.0% (0.7 g) at 1.2% and 1.3%. Next, after each sample after stirring was allowed to stand, the agglomerated paint sludge was separated, and the amount of suspended matter (SS) and turbidity (NTU) of the separated sample were measured. Further, the water content of the separated paint sludge was measured. The amount of suspended solids was evaluated by subjecting the sample to suction filtration with a glass fiber filter having a pore size of 1 μm, drying the filtered residue at 105 ° C. to 110 ° C. for 1 hour, and then measuring the weight of the residue. Turbidity was measured and evaluated with a turbidimeter. The water content of the paint sludge was evaluated by measuring the weight of the collected paint sludge before and after drying.

Here, Table 1 shows the measurement results of suspended solids, and Table 2 shows the measurement results of turbidity.

  From Tables 1 and 2, it can be seen that the amount of suspended solids and the turbidity tend to decrease by pre-stirring by the pre-treatment unit 70. In particular, under the condition of a pre-stirring time of 10 minutes, a marked decrease in the amount of suspended matter and turbidity was observed in all samples compared to the case without pre-stirring. In addition, under the condition that the aqueous paint concentration is 1.0% and there is no pre-stirring, the solid-liquid separation is insufficient when the addition amount of the powder flocculant is 7.0%, and the solid-liquid separation is not possible even when the addition amount is 8.5%. In contrast to the instability, solid-liquid separation was stably performed at an addition amount of 7.0% when pre-stirring was performed for 10 minutes. From this, it can be seen that the amount of the powder flocculant used can be reduced by about 17.6% by performing pre-stirring for an appropriate time. Further, when the coagulant is not reduced, the solid-liquid separation ability can have a surplus of 17.6% of the coagulant.

  In the case of pre-stirring for 10 minutes, solid-liquid separation was stably carried out to a water-based paint concentration of 1.2% under the condition that the powder flocculant addition amount was 7.0%. From this, it can be seen that by performing pre-stirring for an appropriate time, solid-liquid separation can be performed stably even if the concentration (load) of the coating component increases by about 20%.

Next, Table 3 shows the measurement results of the moisture content of the paint sludge.

  From Table 3, the average moisture content of the paint sludge without pre-stirring is 86.2%, whereas the average moisture content of the paint sludge with pre-stirring is 83.9%. It can be seen that it decreases by 2.4%. From this, it can be seen that the pre-stirring causes the coating components to aggregate relatively densely, resulting in a relatively hard coating sludge. Thereby, the paint waste liquid separating apparatus 80 according to the present invention can improve the handleability of the paint sludge and reduce the disposal cost.

Next, BOD (biochemical) of paint color orange, aqueous paint concentration 1.0%, powder flocculant addition amount 7.0%, pre-stirring 0 minutes, 10 minutes of circulating water (after paint sludge separation) Table 4 shows the measurement results of oxygen demand) and COD (chemical oxygen demand).

  It can be seen from Table 4 that both BOD and COD were pre-stirred and the amount of organic matter in the circulating water decreased due to the improved solid-liquid separation ability. From this, it can be seen that the paint waste liquid separation device 80 according to the present invention reduces the load on the treatment facility when the circulating water is treated as waste water.

  In addition, the improvement of the solid-liquid separation capability by pre-stirring is that the paint components are dispersed in advance by stirring the circulating water and air before the flocculant is charged, and the flocculant is charged while maintaining this dispersed state. In addition, it is considered that the coating components are taken up more efficiently by the flocculant by stirring at a high speed.

As described above, Ru engages the present invention paint waste liquid separator 80, before the circulating water and air in front of the flocculant mixing and stirring 54 stirring at high speed by sucking the coagulant and the circulating water and air By providing the pre-processing part 70 to stir, solid-liquid separation capability further improves. Thereby, even if a certain load fluctuation arises in circulating water, the solid-liquid separation of a coating component can be performed stably. Moreover, since the solid-liquid separation capability is improved, the amount of the flocculant used can be reduced as compared with the conventional case. As a result, the amount of paint sludge discharged can be reduced, and the processing cost and the environmental load can be reduced.

Further, engagement Ru paint waste liquid separation device 80 in the present invention, it is possible to obtain a small paint sludge moisture content, it is possible to achieve the improvement in the handling property of the paint sludge, and reduce disposal costs. Furthermore, Ru engages the present invention paint waste liquid separation device 80, it is possible to reduce the organic matter in the circulating water, in addition to that can extend the life of circulating water, the treatment facility during wastewater treatment of the circulating water The load can be reduced.

  The paint waste liquid separation method, paint waste liquid separation device 80, and paint waste liquid treatment system 100 shown in this example are preferable examples of the present invention. Therefore, the procedure of each process and the shape of each part including each tank and partition plate 42 are shown. The arrangement, the agglomerate collection mechanism, the piping between the tanks, the arrangement of the baskets and other configurations are not limited to the above examples, and the present invention can be modified without departing from the scope of the present invention. It is possible to implement.

52 Flocculant supply section
54 Flocculant mixing and stirring unit
56 Coagulation tank (slow stirring section)
70 Pre-processing section
72 Pretreatment tank
74 Stirring means
75 Water intake
76 Stirrer
77 Discharge port
80 Paint waste liquid separator

Claims (4)

A flocculant supply unit for introducing a powdery flocculant into circulating water containing a paint component;
A flocculant mixing and stirring unit that sucks the circulating water and the flocculant charged in the flocculant supply unit and stirs the air at a high speed;
In the paint waste liquid separating apparatus having a slow stirring unit that stirs the mixed liquid obtained by stirring in the flocculant mixing stirring unit at a speed slower than that of the flocculant mixing stirring unit,
Having a pretreatment unit for pre-stirring the circulating water in the previous stage of the flocculant supply unit,
The pretreatment unit includes a pretreatment tank into which circulating water flows, a funnel-shaped water intake port that is installed in the pretreatment tank and sucks the circulating water and air, and the circulating water and air sucked through the water intake port. And a discharge port for discharging circulating water mixed with air by stirring of the stirring unit, and the flocculant supply unit is added to the circulating water discharged by the pretreatment unit. And the flocculant mixing and stirring unit performs mixing and stirring. The opening area of the upper end of the intake port, the paint waste liquid separating apparatus according to claim 1, wherein the 10% to 30% of the area of the liquid surface of the pretreatment tank. A water inlet and stirring unit is stirring means having a discharge opening placed hanging down before processing tank, to claim 1 or claim 2, characterized in that it is possible further positioning of the vertical direction The paint waste liquid separator described. 4. The paint waste liquid separator according to claim 3 , wherein the upper end of the water intake port is located at a position of 10 mm to 80 mm below the surface of the circulating water in the pretreatment tank.

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