JPH02122887A - Structure of floatation-separation vessel - Google Patents

Abstract

PURPOSE:To extremely miniaturize both the volume of the whole equipment and installation area by performing both functions of floatation and separation in one vessel and also shortening the time necessary therefor within several minutes. CONSTITUTION:Both floc formed in a flocculation tank 3 and water to be treated are introduced into a foam generating part 13 from the lower part and the floc is stuck with foams in the same chamber and buoyancy is obtained. This floc is intactly raised straightly in the vessel and thereby a deposited sludge layer 8 is successively formed on the water surface. The water level in the vessel is controlled by a water level regulating pipe 11 and sludge which is laminated from the lower part and has been reached the water level is always scraped with a skimmer 9 and discharged to the outside of the vessel. The treated water separated from floc is made downward flow directed to a discharge part 14 of the vessel bottom part and slowly transferred and discharged to the outside of the vessel through a discharge port 15 via the water level regulating pipe 11.

Description

DETAILED DESCRIPTION OF THE INVENTION (Invention-1) One of the currently widely used wastewater treatment methods is the coagulation flotation separation method. This method uses agglomerated flocs (slatch)
The advantages of this method are that the time required to separate the water from the effluent is shorter than that of the coagulation sedimentation method, and it does not require a large sedimentation equipment. However, the present invention mainly relates to the structure of an electrolytic levitation device.

Figure 1 shows the floating fraction ji! currently being implemented. This figure shows a typical structure of the device. In other words, the treated water is treated with chemicals in the reaction tank j of (1) and (2) and is then processed into the flocculation tank (3).
After forming flocs, the flocs flow into the "flotation tank" (4) from below.

In this flotation tank J, pressurized saturated water is discharged from the pressurized water nozzle in the case of the pressurized flotation method J, and water is electrolyzed by the electrodes (5) in the case of the electrolytic flotation method. A large amount of bubble generation takes place.

The flocs have air bubbles attached therein, and together with the flow of the treated water, they pass over the "partition wall A (6)" and are once transferred to the "separation tank J (7)".
After being diffused into the tank, it gradually floats up to form a slatch deposit layer (8) on the entire surface of the tank, and is discharged to the outside of the tank by a schema (9).

The treated water after separating the flocs is discharged to the outside of the tank from the outlet (10) at the end of the separation tank (7), but at this time, the water level at this outlet is always kept at the same level as the slatch accumulation layer. The water level is adjusted by a water level adjustment pipe (11).

In a separation tank with this type of structure, the time required for complete separation of flocs and treated water is at least 20 to 30 minutes, but this time is half of the time required for the entire treatment process. Therefore, in the case of current wastewater treatment equipment, 1 of the total equipment volume is required just for this separation tank.
The reality is that /2 is occupied.

The present invention is different from the above-mentioned flotation separation device in that it performs both flotation and separation functions within a single tank and shortens the time required to do so within a few minutes, thereby reducing the overall volume of the device. Moreover, we succeeded in significantly reducing the installation area.

The structure and function will be explained below based on FIG.

The first feature of the flotation separation tank U (12) structure according to the present invention is that the lower space of the tank is divided vertically, and the upper and lower parts are opened as a bubble generating section, D (13).
The other side is open at the top and has a water outlet (15) at the bottom.
).

Second, the space between the upper part of these two parts and the water surface is made into a common water area (16), and the structure is such that floating of flocs and separation of discharged water are carried out within this water area.

Third, a water level adjustment pipe (11) is provided at the outlet of the discharged water, and the water level is linked to the water level of the sludge layer.

Fourth, the size of this flotation separation tank (12) is such that the treated water is
A volume in which the water stays for about 4 minutes is sufficient, but the depth should be about 1 m or more.

The performance of the flotation tank A (12) with this structure is as follows.

(b) The flocs and treated water formed in the flocculation tank (3) enter the bubble generation section A (13) from below, form bubbles in the same chamber, become NHM, gain buoyancy, and rise straight into the tank. A slatch deposit layer (8) is successively formed on the water surface.In this case, the water level in the tank is controlled by a "water level control vibrator" (11), and is always maintained lower than the height of the tank wall. The slatch that has accumulated from below and reached that water level is constantly scraped off by the schema (9) and discharged to the outside of the tank.

(b) After removing flocs, the treated water is discharged from the "water discharge section" at the bottom of the tank!
The water slowly moves in a downward direction toward l (14), and then flows from r water outlet A (15) to water level adjustment pipe (11).
After that, it is discharged outside the tank.

(c) During this series of processes, the flocs gained buoyancy due to the air bubbles and the rising speed was about 3 m/min.

In a tank with a depth of 1 to 1.5 m, levitation is completed in about 30 seconds. On the other hand, the flow of treated water moving in the tank is a slow flow of about 0.5 to 1 m per minute, taking an average of 2 to 4 minutes to pass through the tank, and the normal floating blades on the flocs. As far as possible, this separation work between flocs and effluent water is reliably carried out.

The mutual positional relationship between the bubble generating part It (13) and the water discharge part J (14) according to the present invention is as long as they share the basic principle of sharing a common water area A (16) above each other. It is by no means fixed; for example, the positional relationship in Figure 2 can be changed to the positional relationship in Figure 4, or the positional relationship in Figure 3 can be changed to the positional relationship in Figure 4.
If necessary, it is also possible to provide a effluent water retention tank (17) and install a water level adjustment pipe (11) therein as shown in FIGS.

(Invention-2) The most widely used method to enhance the effect of electrolysis is to lower the electrical resistance of water, and one of the methods used is to add common salt. In the conventional method, the salt concentration of the entire treated water was increased by adding it at the initial reaction tank stage (1) and (2). This method has been adopted in the conventional method because the entire amount of treated water passes through the electrode.

The purpose of the present invention is to reduce the amount of added salt as much as possible, and at the same time to reduce the salt concentration in the effluent water discharged outside the system as much as possible. It is divided into an upper water flow (20) that should be installed in the flow and a lower water flow (21) with a low flow rate.
5) In the process of entering below and passing upward through the Ti electrode, it undergoes electrolysis and becomes a source of bubbles, and the upward water flow flows above the electrode and mixes with rising bubbles generated from the electrode. It is a form.

At this time, salt is added exclusively to the downward flow with a small flow rate (21
) The salt water inlet J (22) is used to significantly reduce the amount of salt added. The amount of electricity is proportional to the electrical resistance value of the water (in this case, the salt concentration), so as long as the salt concentration remains the same, there will be no change in the amount of bubbles generated even if the amount of water passing through is small. Therefore, no decrease in floc flotation efficiency was observed due to changes to this method.

(Invention-3) The present invention aims to adjust the electrical resistance of treated water in response to changes in the amount of current, which is a barometer of the amount of electrolyzed bubbles, and to maintain a constant amount of current at all times. This is a system that increases or decreases the amount of industrial salt water added to the treated water immediately before treatment, and as a means of doing so, if the set amount of current (ampere) is insufficient, the industrial salt water supply pump is rotated to increase or decrease the amount of industrial salt water added to the treated water. The device is characterized by being equipped with an electric circuit that has the function of stopping the rotation if the rotation occurs.

The concentration of industrial salt water in this case depends on changes in the conditions of the treated water, but generally a concentration of 10% or more is used.

[Brief explanation of drawings]

Common to Figures 1, 2, 3, 4, 5, and 6 ■, 1st reaction tank 79 Separation tank 2, 2nd reaction tank 8. Sludge accumulation layer 3, coagulation tank 9. Schema-4, flotation tank 1
0. Outlet port 5, electrode 11. Water level adjustment vibro, bulkhead 12. Flotation separation tank Bubble generation section Water discharge section Water outlet Common area Discharge water Retention tank Sludge discharge port Auxiliary upper water flow Lower water flow Saline water inlet Saline water tank Saline water pump Unveyor Tarter Katsura Wood line Hitokita No Sumio Diagram 1 Procedure Written amendment (method) Indication of the case 1986 Patent No. 276124 Name of the invention Person who makes structural amendments to the flotation separation tank Relationship to the case Patent applicant address 1-28-2 Fujimidai, Kunitachi-shi, Tokyo Invention of the application Name column 3, brief description of drawings in the specification column/1≧\Contents of amendment Delete lines 13 and 14 from the top of page 9 of the specification and insert the following sentence. Figure 1 shows the structure of a conventional flotation tank. Figure 2 shows the structure of a conventional flotation tank. Figure 2 shows the structure of a conventional flotation tank. Electrodes and a drain pipe are installed at the bottom of the tank, and the flocs are floated and removed in the common water area above, and the waste water is separated. Figure 3 shows the structure of a flotation separation tank with a water level adjustment pipe installed at the tip of the pipe.The flotation separation tank has a water discharge tank that is connected to the flotation tank at the bottom, and a water level adjustment pipe is installed in the water discharge tank. The structural diagram of the tank, Figure 4, shows the floating portion iii with the electrodes and water outlet located in the opposite position from those shown in Figure 2! Figure 5 is a structural diagram of the tank. Figure 6 is a structural diagram of a flotation tank with a flotation tank and a water discharge tank installed in the opposite positions from those shown in Figure 3. A structural diagram of the structure of the electrolytic cell divided into two parts and the control line that controls the operation of the electrolyte supply pump depending on the amount of current flowing through the electrodes.

Claims (3)

[Claims] (1) In an electrolytic flotation separation device for coagulated wastewater, a bubble generation part and a discharge water part are provided at the bottom of one tank, and the area between the top of these two parts and the water surface is a common water area, and within that common water area The structure of a flotation separation tank is characterized in that it simultaneously floats flocs and separates discharged water. (2) Structure of an electrolytic flotation tank in which the flow of passing wastewater is divided into an upward flow and a downward flow, and electrodes are installed between the two. (3) A structure of a salt water supply device characterized in that the amount of salt added to electrolytically treated water is increased or decreased in accordance with the amount of electricity consumed for electrolytic bubble generation in an electrolytic flotation device.