JPH0321388A - Method and apparatus for treating waste water - Google Patents

Abstract

PURPOSE:To efficiently treat waste water by cooling the surface part of a rotary body and allowing waste water to flow down along the surface of the surface part to freeze the same. CONSTITUTION:Waste water is sent to the nozzle 65 of piping 64 and sprayed to the surface part of a disc from the nozzle to be allowed to flow down. The waste water flowing down along the surface of the disc is stored in a receiving body 11 and again recirculated to the nozzle 65. The waste water sprayed to the surface of the disc cooled by the cooled disc to precipitate ice 45 in the waste water and the precipitated ice is bonded to the surface of the disc. The bonded ice is scraped off by a scraper/liquid collecting device 14 while melted by a heater 13 to be collected. The concentrate is successively sent to a waste water treatment apparatus to be further conc. and sent to a bleaching and fixing waste water tank 7. By this method, treated water can be efficiently separated.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is applicable to general silver salt photographic processing waste liquid, printing sensitive material and X-ray processing waste liquid, offset printing plate processing waste liquid, laboratory waste liquid, and other factories. The present invention relates to a method and apparatus for treating waste liquid etc. from.

(Prior Art) A crystallization operation is known as a means of purifying a solid by precipitating it from a liquid by cooling.

(Problems to be Solved by the Invention) The crystallization operation requires difficult operation control, and the equipment is large and complicated, so it is not practical as a waste liquid treatment method as it is.

The present invention provides a novel method and device that can efficiently and conveniently treat waste liquid.

(Means for Solving the Problems) The present invention cools the surface of a rotating body and causes the waste liquid to flow down onto the surface to freeze the waste liquid and generate a stirring phenomenon of waste liquid on the surface of the ice. There is.

The rotary body includes a rotating body, a means for flowing waste liquid onto the surface of the rotating body, a container for receiving the flowing waste liquid, and a means for taking out frozen matter formed on the surface of the rotating body.

(Operations and Examples) When cooling waste liquid to precipitate ice that coexists with waste liquid, the separation coefficient (pollution concentration of mother liquor/pollution concentration of precipitated ice) is determined by the rate at which ice is deposited on the surface of the rotating body (hereinafter referred to as freezing). It changes depending on the thickness of ice deposited on the surface area per 7 hours) and the concentration of the mother liquor. Figure 1 shows the relationship with respect to the bleach-fixing washing waste solution for general-use silver salt color photographs, and Figure λ shows the relationship with the fixing washing waste solution for general-use silver salt black-and-white photographs. The waste liquid in Figure 7 is frozen at a rate of 3. j Shout 4r as shown in Figure 7 below! When the above-mentioned waste liquid is treated continuously in a unit of stages, the concentration of the waste liquid in each stage at a reflux ratio of 7.2 can be calculated or calculated according to the diagram shown in Figure 3 (McCabe -
It is determined by the Thie le method).

As shown in the above diagram, the faster the freezing rate, the faster the
The higher the concentration, the lower the separation efficiency. Particularly when the concentration of the mother liquor is high, even if the freezing rate is slowed down, the separation efficiency does not increase much. The reason for this is that when ice freezes, ice with few impurities grows, but the liquid near the ice, which has a high concentration of impurities, freezes quickly and becomes trapped in the ice. When the impurity concentration is low, the trapped liquid has a small freezing point drop, so it freezes sequentially from the vicinity of the ice, pushing out the liquid with a high impurity concentration from the gap, so the effect is small, but when the impurity concentration is high, the freezing point depression is large. The ice is completely trapped without freezing, resulting in soft and watery ice, which reduces separation efficiency. Figure y illustrates this phenomenon. As a measure to avoid this phenomenon and increase separation efficiency, it can be prevented by stirring the liquid well and promptly reducing the concentration of impurities in the liquid near the water. It is assumed that this is because the impurity concentration is about the same as that of the surrounding liquid, so that there is no difference in freezing point and the liquid precipitates and solidifies sequentially from near the heat transfer surface, so the liquid is pushed out and less liquid is trapped. younger brother! The figure illustrates this phenomenon in comparison with Figure 2. FIG. 6 shows the effect of stirring on the fixing solution. As shown in the figure, the higher the concentration of the mother liquor, the greater the effect, and when the mother liquor concentration tag in the figure is 3θθppm, the separation efficiency increases by about 4 times.

As described above, it has been found that the separation efficiency can be improved by stirring the mother liquor.

Therefore, we have discovered a method of stirring the waste liquid on the surface of the frozen substance formed on the cooled disk surface by flowing the waste liquid down the surface of the disk in the form of a thin film.

Hereinafter, two of them will be explained with reference to the drawings.

FIG. 7 shows the case where waste liquid from the automatic photographic processor Mini Lapo (1) is treated. The developing waste liquid and bleach-fixing waste liquid generated from the developing tank (2) and bleach-fixing tank (3) of the Mini Lapo are transferred to tanks (6) and (7) through piping (4) and (5), respectively. The washing waste liquid from the washing treatment tank (8), which is introduced and generated in large quantities, is put into the waste liquid container αD of the waste liquid treatment device αQ via the pipe (9). The waste liquid that has flowed into the container is formed by a pump (60) on the piping (61), (62), the header (63), and the outer periphery of the rotating body, as detailed in FIG. 9 and the younger figure. Through the provided piping (64), the gap between the plurality of discs <211=
It is sent to the nozzle (65) of the pipe (64), and is allowed to flow down from the nozzle over the surface of the disk. The waste liquid that has flowed down the inner wall surface is collected in the container αD, and is again circulated to the nozzle (65) by the pump. The waste liquid poured onto the surface of the disk is cooled by the cooled disk, and the waste liquid becomes ice (frozen matter) @! 9 is precipitated.

The precipitated water adheres to the surface of the disk (younger brother//figure). By doing this, the waste liquid flows down while constantly stirring the surface of the ice deposited on the disk surface, and the impurity concentration of the waste liquid near the water is quickly reduced to an average concentration.

The water adhering to the disk is thawed by a means for taking it out, ie, in the illustrated one, it is thawed by a heater α3, and then scraped off by a scraper/collecting device G1. The vinegared treatment liquid is sent to the container of the next waste liquid treatment machine (on the right in the drawing) and undergoes the same treatment.

The thus treated liquid is sent as the M''Jk liquid by the bomb α6 and through the piping αO to the water-washing housing part α of the minilapo.

On the other hand, the concentrated liquid is sequentially sent to the waste liquid treatment device on the front side (on the left side in the drawing), further concentrated, and sent to the bleach-fixing waste liquid tank (7) labeled E via the pipe θB.

In the illustrated example, the waste liquid treatment device has s stages, but it can have other multiple stages or a single stage (including a batch type). A connecting pipe Q9 is provided between each of the waste liquid treatment devices, and returns a portion of the treated waste liquid to the preceding treatment device. The amount returned is a factor that keeps the concentration of waste liquid at each stage constant and determines the degree of purification and concentration.

In the younger brother diagram, rotating body 0 of the waste liquid treatment device has as large a surface area (ice precipitation area) as possible and operates at a slow ice growth speed. In addition, as a means of obtaining stable water crystals without seed crystals, a method is adopted in which water is attached to a heat transfer surface for cooling. This method cannot be used in existing crystallizers because the heat transfer coefficient decreases due to the adhesion of crystals and good crystals cannot be obtained, but it is the most suitable method for waste liquid treatment equipment due to its operability and stability. be. As a means of realizing these, a large number of hollow disks (7) are arranged in parallel with a spacer (d) interposed between them to form a gap Qυ, and the hollow space (to) of the disk (=cooling medium By passing a cooling liquid such as antifreeze, cooling gas, etc., and depositing ice on the surface of the disc, a compact and large surface area can be obtained.

The above-mentioned disk and spacer @ are fastened with bolts to a hollow rotating shaft rotatably supported by a waste liquid container αD (= bearing (c)), thereby forming a rotating body. The rotating body consists of a gear motor (d) housed on a support base, a gear (main) which is locked to the output shaft (■) of the gear motor with a key of 0υ, and the above-mentioned rotating shaft (to). It is rotated via a gear (end) that is fixed at the end with a key (end) and a lock nut (b). A tube (b) for feeding cooled antifreeze is inserted into the axial center of the rotating body (to), and the tube is fixed to the support base (to) by a retainer (to). The antifreeze in the pipe flows in front of the stopcock (7) and flows out into the hollow part of the disc through the nozzle hole bored in the nozzle structure 1 provided in the pipe. The liquid that flows out is partitioned by partition plates 11) arranged radially in the hollow part of the disc, and flows to cool the surface area of the disc. The cooled antifreeze liquid passes through the space above the tube (b) and collects the liquid, and then returns to the tube through the inlet port of the tube and is discharged.

The adhering ice is scraped off by the scraper α31 installed in the space between the discs, and the ice either melts naturally or is removed by a water heater α4 with the scraper fixed to the bottom with screws (Fig. 73). ) or an electric heater, etc., and use this as purified treated water, or as shown in the diagram {
=The treated water is sent to the container of the next waste liquid treatment device to further refine the treated water.

In addition, when the thickness of the disk is large, the scraper may be provided on the outer peripheral surface of the disk.

The water heater has a support portion O formed at the top of the container.
'7) The hot water flows and flows out through the pipes (to) and 0 holes supported by the pipes. The hot water is generated from the condenser (53) of the refrigerator stem, which consists of an evaporator, a compressor (St), a release valve (52), a condenser (53), etc., as shown in Fig. Created using heat.

The disk may be made into a hexagonal, male-gonal, or other polygonal shape, or the surface of the disk may be provided with fin-like unevenness, or the disk and the spacer may be integrally formed and an uneven surface may be provided on the surface. I can do it.

(Effects of the Invention) The present invention is configured as described above, and the waste liquid is concentrated by flowing down onto the surface of a rotating body having a large surface area and creating an agitated state on the surface of frozen matter deposited on the surface. The waste liquid and the treated water generated from the frozen matter can be efficiently separated.

[Brief explanation of drawings]

The drawings show examples of the present invention; 'qS/' is a graph showing the relationship between the separation coefficient and freezing rate for the bleach-fixing water washing waste of general-use silver salt color photographs, and the younger figure 2 is a graph showing the relationship between the separation coefficient and freezing rate of bleach-fixing water washing waste for general-purpose silver salt color photographs. A graph showing the relationship between separation coefficient and freezing rate for waste liquid washed with fixing water. Figure 3 is a graph showing the number of stages necessary for purifying the waste liquid and the concentration of each stage. The younger figure is a graph showing the freezing phenomenon in the case of waste liquid with high impurity concentration. Schematic diagram showing, brother! The figure is a schematic diagram showing the freezing phenomenon in the case of waste liquid with low impurity concentration, Figure 6 is a graph showing the effect of stirring on fixing waste liquid, younger brother Figure 7 is a schematic diagram, and Figure ♂ is an enlarged vertical cross section with some parts omitted. Figures and Figures 1 and 2 are enlarged cross-sectional views, and Figures 1 and 2 are partially omitted central horizontal cross-sectional views.
The younger brother // figure is an enlarged blood cut diagram of the nozzle part, the second figure is the 1-1 lfr plane view of figure ♂, the younger brother figure 73 is an enlarged sectional view of part of the scraper, and the younger brother figure 74t produces hot water. It is a schematic diagram showing a means.

Claims (1)

[Scope of Claims] 1. A waste liquid treatment method in which the surface of a rotating body is cooled, and the waste liquid is allowed to flow down onto the surface of the rotating body to freeze and take out the waste liquid. 2. A rotating body that has a surface portion with a plurality of voids formed along the circumferential direction to increase the surface area and cools the surface portion with a cooling fluid flowing into the space formed within the surface portion; A nozzle mechanism located in a gap in the surface of the rotating body to spray waste liquid onto the surface and let it flow down, a container for receiving the waste liquid that has flowed down to the surface of the rotating body, and a means for taking out frozen matter formed on the surface of the rotating body. Equipped with waste liquid treatment equipment.