KR20020073300A - Sewage treatment bath - Google Patents

Abstract

PURPOSE: To provide a sewage treatment tank in which the increase of the size of equipment is prevented, the space required for piping to be connected to this tank is reduced and sewage is prevented from being leaked directly from a piping joint part. CONSTITUTION: In the sewage treatment tank provided with a sewage flow-in pipe for allowing the sewage to flow in and a sewage flow-out pipe for allowing the sewage to flow out, the sewage flow-in pipe is installed so as to introduce the sewage from the upper surface toward the inside of a lower tank.

Description

Sewage Treatment Tank {SEWAGE TREATMENT BATH}

The present invention relates to a sewage treatment tank used for a sewage treatment facility for a business place and a domestic sewage treatment facility.

Usually, in the conventional sewage treatment tank, the sewage inflow pipe which introduces sewage into a treatment tank and the sewage outflow pipe which discharges sewage from a treatment tank are the elution tank (electrolysis tank) of FIG. 2 of Unexamined-Japanese-Patent No. 10-328672, for example. It was composed as follows. That is, the outflow pipe (sewage outflow pipe) was mounted in the horizontal direction on one side wall of this elution pipe, and the inflow pipe (sewage inflow pipe) was also mounted in the horizontal direction opposite to the other side wall.

By the way, when the inflow pipe is mounted horizontally with respect to the side wall like this elution tank, the bottom of the inflow pipe must be made high with respect to the top of the outflow pipe in order to prevent backflow of sewage. As a result, the dimension of the height direction of a processing tank becomes large, and there existed a problem that an apparatus enlarged. In addition, since the inflow pipe is mounted in the horizontal direction with respect to the side wall, it is necessary to bend the connecting pipe in the horizontal or vertical direction due to the positional relationship with other processing tanks connected to the inflow pipe, which makes the piping work difficult. There was. In addition, when leakage occurs at the connection portion between the inflow pipe and the connection pipe, there is a problem in that the sewage leaks directly into the treatment tank, so that the equipment around the contact portion is wetted with the sewage. In this case, there has been a problem that electrical components such as electrodes provided around the treatment tank are flooded.

The present invention has been made in view of the problems existing in such a prior art. The objective is to reduce the height in the height direction of the apparatus, to reduce the size of the apparatus, to facilitate the piping work connected to the treatment tank, and to prevent the leakage of sewage directly from the piping connection to the outside of the tank. It is to provide a sewage treatment tank which is eliminated.

1 is an external plan view of an electrolytic cell according to an embodiment of the present invention.

2 is a plan view of a state in which the service cover of the electrolytic cell according to the embodiment of the present invention is removed.

3 is a plan view of the service cover and the electrode unit of the electrolytic cell according to the embodiment of the present invention removed.

4 is a cross-sectional view taken along line IV-IV of FIG. 1, in which the electrode unit rows on the sewage outlet side are in a state where a separator is visible, and the electrode unit rows on the sewage inlet side are shown in a state where the side of the electrode unit is visible.

5 is a cross-sectional view taken along line VV of FIG. 2.

FIG. 6 is an enlarged view of part VI of FIG. 5.

7 is a partially enlarged view of the wastewater discharge port of the electrolytic cell according to the embodiment of the present invention.

8 is an enlarged view of the sensor unit of the electrolytic cell according to the embodiment of the present invention.

9 is a control circuit diagram of the electrode unit of the electrolytic cell according to the embodiment of the present invention.

10 is a system example when the electrolytic cell according to the embodiment of the present invention is applied to wastewater treatment for a business place.

♣ Explanation of symbols for main part of drawing ♣

1: tank body 3: cover body

5: electrode unit row 8: control panel

9: power source 11: sewage outflow pipe

15: shelf part 30: flat part

30a: Opening 35: Sewage inflow pipe

35a: Flanged piping 35b: Straight piping

35c: 90 degree elbow 35d: Connecting piping

51: electrode unit 51a: electrode plate

B: Medium flow adjusting tank C: Electrolytic bath

The sewage treatment tank according to the present invention for achieving the above object is a sewage treatment tank having a sewage inflow pipe for introducing the sewage, and a sewage outflow pipe for discharging the sewage, wherein the sewage treatment pipe is formed from an upper surface of one side of the sewage treatment tank. It is installed to introduce the sewage toward the inside of the lower jaw.

In this way, the opening of the sewage inlet pipe can be made higher than the top of the sewage inlet pipe to prevent backflow. As a result, the height of the bath can be made as low as the pipe diameter of the inlet pipe compared with the conventional one. In addition, since the connecting pipe connected to the sewage inlet pipe is connected at the upper part of the tank, the space for connecting the pipe to the previous process can be reduced, and the effective use of the saved space can facilitate the piping work. Can be. In addition, even if water leaks, for example, from the pipe connection part, the sewage does not leak directly to the outside of the treatment tank and leaks out to the upper portion of the tank, so that the leaked sewage can be treated so as not to flow out of the treatment tank. .

The effluent inflow pipe may be configured such that the direction of the pipe connecting portion to the outside is rotatable in the horizontal direction.

When formed in this way, the horizontal direction of the connecting pipe connected to the sewage inflow pipe can be freely selected. Therefore, the connecting pipe connected to the sewage inlet pipe can be arranged in the desired direction directly from the top of the tank. Therefore, the connection space can be further reduced by making the pipe of the sewage inlet pipe and the entire process suitable for the installation conditions. Can be.

The effluent inlet pipe may include a flanged pipe mounted vertically on the upper surface of the tank, a straight pipe mounted on the flanged pipe, and a 90 degree elbow mounted rotatably in a horizontal direction about the straight pipe. good.

When formed in this way, not only the horizontal direction but also the height position of the connection pipe connected to a wastewater inflow pipe can be selected freely. Therefore, the connection space can be further reduced by connecting the sewage inflow pipe and the tank of all the processes to the installation conditions.

The sewage treatment layer can be formed as an electrolytic treatment tank having at least one electrode composed of a pair of electrode plates and an acid pipe disposed in the lower sewage of the electrode. In this case, since the sewage does not leak directly to the outside of the tank as described above, there is no fear of flooding the electrical components such as a power supply device and a control panel arranged around the tank.

The electrolyzer has a wastewater outlet pipe on the side opposite to the wastewater inlet pipe, and has a shelf portion that collides the flow of sewage flowing into the tank below the wastewater inlet pipe, and the electrode has a pair of plate-shaped electrodes. A plurality of electrode units may be arranged in a direction orthogonal to the flow of sewage in the tank.

In this configuration, the surface of the electrode plate constituting the electrode unit and the flow of sewage become parallel. In addition, since the sewage flowing into the processing tank is dispersed in the shelf and flows in a uniform flow between the plurality of electrode plates, phosphorus trapping efficiency due to metal ions eluted from the electrode unit is uniform in each electrode unit. Phosphorus removal efficiency is improved.

EMBODIMENT OF THE INVENTION Hereinafter, the Example actualized by the electrolytic cell for the sewage treatment apparatus of this invention is demonstrated based on FIGS. 1 is an external plan view of an electrolytic cell according to an embodiment of the present invention, FIG. 2 is a plan view of a state where a service cover of an electrolytic cell according to an embodiment of the present invention is removed, and FIG. 3 is an electrolytic cell according to an embodiment of the present invention. 4 is a plan view of the service cover and the electrode unit is removed, Figure 4 is a cross-sectional view IV-IV of FIG. In Fig. 4, the electrode unit row on the sewage outlet side is in a state where the separator is visible, and the electrode unit row on the sewage inlet side is in the state where the side surfaces of the electrode unit are visible. 5 is a cross-sectional view taken along line V-V of FIG. 2, FIG. 6 is an enlarged view of part VI of FIG. 5, and FIG. 7 is a partially enlarged view of the wastewater discharge port.

First, a schematic configuration of an electrolytic cell for sewage treatment apparatus according to this embodiment will be described. The electrolytic cell container is a box-shaped container in which the planar shape is substantially rectangular, and includes two electrode units provided in the tank body 1 having a predetermined depth, the cover body 3 having a predetermined height, and the cover body 3. It consists of two service covers 4 of which the dimension of the height direction for closing the service port 31 is small (refer FIG. 4). And the electrode sub spot 31 of the lower part of the service cover 4 in the cover body 3 has the opening part 32 for electrode unit mounting in the bottom face, and the peripheral part of this opening 32 is an electrode unit ( It is formed in the recessed part 33 which functions as a support member of 51 (refer FIG. 4). The longitudinal direction (hereinafter, simply referred to as the longitudinal direction of the electrode plate 51a) in the planar shape of the electrode plate 51a of the electrode unit 51 from each recess 33 is defined by the long side of the tank body 1. In the same direction, the electrode units 51 are inserted so as to form a row at regular intervals in the direction orthogonal to the longitudinal direction of the electrode plate 51a, thereby forming the electrode unit rows 5 (FIGS. 2 and 4). , See FIG. 5). In addition, a wastewater discharge pipe 11 is provided at an upper side of the side wall which forms the short side of the tank body 1, and the cover body 3 near the side wall which forms a short side facing the side wall on which the wastewater discharge pipe 11 is provided. The wastewater inflow pipe 35 is provided so that wastewater may flow into the electrolytic cell from the upper part to the upper surface part of () (refer FIG. 1 etc.).

Next, each part of the electrolytic cell described above is demonstrated more concretely.

The tank body 1 is a place where wastewater flows in and elutes metal ions from the electrode into the wastewater, and is formed with a high volume required for this treatment. And as shown in FIG. 4, as above-mentioned, the sewage outflow pipe 11 is installed in the horizontal direction in the upper part of the one side wall which forms a short side. Moreover, the packing 11a is provided in this wastewater outflow pipe 11. The lower part of the sewage outflow pipe 11 of this side wall is comprised as the inclined surface part 12 inclined so that a bottom part may be located in the center side of the tank main body 1. As shown in FIG. Incidentally, the inclined surface portion 13 is formed on the side wall facing the inclined surface portion 12 so as to have a symmetrical shape with the inclined surface portion 12.

These inclined surface portions 12 and 13 are formed in the vicinity of the lower portion of the electrode unit row 5 so as to generate convection of sewage in the electrolytic cell. In addition, shelf portions 14 and 15 protruding outwardly are formed at the top portions of the inclined surface portions 12 and 13, and function as a fixed surface when an electrolytic cell is installed on the lower surface of the shelf portions 14 and 15. (See FIG. 4). In addition, the shelf portion 15 on the sewage inlet side has a larger area than the shelf portion 14 on the sewage outlet side so as to function as the sewage dispersion surface flowing into the electrolytic cell, and covers the upper portion of the shelf portion 15. It is a space which receives wastewater from the wastewater inflow pipe 35 attached to the sieve 3.

In addition, the intermediate portion of the electrode unit rows 5 on the bottom surface of the tank body 1 is formed in a smooth mountain-shaped portion 16 having the same inclination angle as those of the inclined surface portions 12, 13, The center part of the space clamped by the shape part 16 and the said inclined surface parts 12 and 13 is comprised so that it may become the center of the electrode unit row | line | column 5, and the sludge discharge port 17 is provided in this part. The sludge discharge port 17 is closed by a rubber stopper 17a, and on the outer surface side of the sludge discharge port 17, a pipe coupler 17b is interposed between the packing 17e by a bolt 17c and a nut 17d. (See Fig. 7).

In addition, the diffuser fixing ribs 19 are provided at two positions (eight positions in total) of the electrode unit rows so as to sandwich the sludge discharge ports 17 (see FIG. 3). The rib 19 is provided with a cutout groove 19a for fitting the diffuser to the upper end of the rib 19 so as to fix the diffuser 25 in a slightly floating state from the bottom (see FIG. 7). Moreover, the support legs 22 are formed in four places on the bottom face of the tank main body 1. As shown in FIG. This electrolytic cell can also be seated using this support leg 22.

In addition, the upper edge portion of the tank body 1 forms a flange portion 23, and a downward rib 24 for improving the strength of the edge portion is formed.

As the cover body 3 can be understood well from FIG. 4, the wiring space of the relay terminal box 6 for the power cable of the electrode unit 51 or the power cable 62 is located above the electrode unit row 5. It has a height necessary for securing the upper surface, and the upper surface constitutes the upper surface of the electrolytic cell. Moreover, the lower end of the circumferential edge has the flange part 34 which abuts on the upper edge flange part 23 of the said tank main body 1, and the bending piece 34a by which the front-end | tip of this flange part 34 was bent downwardly further. It is comprised so that it may be covered by the upper end of the tank main body 1. As shown in FIG. The cover body 3 and the tank body 1 are fixed to the flange portions 23 and 34 by means of a screw 34b, for example, by screw fastening.

Moreover, above the said shelf part 15 in the cover body 3, the flat part 30 of the small space which entered a little from the upper surface is formed, and the opening part 30a is provided in this flat part 30, The sewage inflow pipe 35 is attached to the opening 30a. The sewage inflow pipe 35 is rotatably mounted to the flanged pipe 35a having a mounting flange below, a straight pipe 35b connected to the flanged pipe 35a, and a straight pipe 35b. It consists of a 90 degree elbow 35c, and the connection pipe 35d which supplies wastewater in a previous process is attached to this 90 degree elbow 35c. Moreover, this wastewater inflow pipe 35 part is formed so that a front shape may become narrow with this cover body 3 and the tank main body 1 mentioned above.

In addition, two portions of the electrode service port 31 having a substantially planar shape having a long side in a direction orthogonal to the long side of the electrolytic cell are provided in the portion from the sewage inflow pipe 35 to the side wall facing the sewage inflow pipe 35. Formed. The electrode service port 31 is constituted by a recessed part 33 whose depth is lower than the circumferential edge of the cover 3 and slightly above the sewage surface in the tank body 1. . And the opening part 32 for electrode unit insertion is provided in each bottom surface of the recessed part 33 which has this depth.

The electrode unit 51 is an electrode in which a pair of rectangular iron plate-shaped electrodes is formed into one set, and these two electrode plates 51a are held at predetermined intervals by the upper holder 51b. The terminal 51c for connecting a power cable is provided in the upper surface of this holder 51b, and this terminal 51c and the electrode plate 51a are connected in the holder 51b. The electrode unit 51 is arranged such that the longitudinal direction of the electrode plate 51a is the longitudinal direction of the electrolytic cell, and the plurality of electrode units 51 are arranged in a direction orthogonal to the longitudinal direction of the electrode plate 51a. The holder 51b has a width larger than the width (dimensions in the longitudinal direction) of the electrode plate 51a, and the openings for inserting the electrode unit of the cover body 3 are formed in both portions protruding from the electrode plate 51a. The pinhole 51e which engages with the pin 36 arrange | positioned around the periphery 32 is provided one by one. The pinhole 51e has a large diameter portion on the lower side so that the pin 36 can be easily inserted, and a small diameter portion on the upper side to improve the accuracy of the fixed position. Moreover, the handle 51d is provided in the upper surface part of the holder 51b (refer FIG. 4-FIG. 6).

And the separator 52 is attached between the electrode units 51 (refer FIG. 5, FIG. 6). The separator 52 is made of plastic, which is an insulating material. The separator 52 has a flat plate portion 52a approximately the same as the size of the electrode plate 51a, and the upper portion is a wide support portion 52b similar to the electrode holder 51b. On both sides of the support portion 52b, a hole for engaging with the pin 37 arranged around the opening of the electrode unit insertion opening of the cover body 3 or the bolt 38 mounted to the cover body 3 ( 52c) are provided one by one. Moreover, the handle 52d (refer FIG. 4) is provided in the upper surface part of the support part 52b. In addition, the pins 37 and the bolts 38 are alternately arranged. The lower portion of the center separator 52 located on the sludge discharge port 17 is connected via a rubber stopper 17a for closing the sludge discharge port 17.

When the separator 52 and the electrode unit 51 are inserted, the separator 52 is first inserted while being coupled to the pin 37 or the bolt 38. Next, the electrode unit 51 is inserted while being coupled to the pin 36. At this time, the holder 51b of the electrode unit 51 is settled on the support part 52b of the separator 52 (refer FIG. 6). Next, the fixing plate 53 having a substantially L-shaped cross section is seated on the holder 51b of the electrode unit 51 while engaging the bolt 38. In addition, 53a is a shock absorbing material and an insulating material attached to the fixing plate 53. Then, the service nut 39 is fastened to the bolt 38 and finally fixed. Therefore, the longitudinal direction of the electrode plate 51a becomes the longitudinal direction of the electrolytic cell on the sewage inflow pipe 35 side and the sewage outflow pipe 11 side, and the electrode is perpendicular to the longitudinal direction of the electrode plate 51a. The unit 51 and the separator 52 are alternately arranged, and the electrode unit rows 5 in which the eight electrode units 51 and the seven separators 52 are arranged, respectively, are formed. That is, two rows of electrode unit rows are formed so as to traverse a pair of opposite sides of the electrolytic cell. The center line of the electrode unit rows 5 is configured to pass through the center of the sludge discharge port 17 described above.

In the cover body 3, between the electrode unit row 5 and the sewage inflow pipe 35, and between the electrode unit row 5 and the sewage discharge port 11, the tank main body 1 described above. Located in the upper portion of the inclined surface portion 12, 13 in the relay terminal, the relay terminal box 6 for connecting the electrode unit 51 to the power source is disposed at a position above the electrode unit 51 of this portion, have. Each relay terminal box 6 has a substantially rectangular shape, and four relay terminals 61 are arranged in the longitudinal direction. The relay terminal boxes 6 are arranged in two so that the longitudinal direction thereof becomes the column direction of the electrode unit rows 5. Therefore, the arrangement direction of the four relay terminals 61 and the column direction of the electrode unit rows 5 coincide with each other. In FIG. 2 and FIG. 4, 62 is a power cable which connects one electrode unit 51 to one relay terminal 61. In FIG. In addition, in FIG.2 and FIG.3, 63 is the power supply cable which connects a power supply and each relay terminal box 6. In addition, in FIG.

In the lower portion of each of the electrode unit rows 5, two diffusers 25 are arranged as diffusers forming one system (refer to FIGS. 3 and 4), and the distal ends of the two diffusers 25 are provided. Is connected by a connector 28. The diffuser 25 is raised along one wall of the side wall that forms the long side of the electrolytic cell, that is, the opposite wall of the opposing pair, which connects the connecting pipes 26 and 27 for connecting to the external blower 80. (See FIG. 3, FIG. 5) It is led out from the notch groove 21 (refer FIG. 4, FIG. 5) of the upper end of the cover body 3. As shown in FIG. And the center side riser 26 is connected to the blower 80, and the stopper 29 is attached to the front-end | tip of the opposite center side riser 27. As shown in FIG. Therefore, air is supplied to the mass production engine 25 from the center riser 26. In addition, the two system diffusers 25 provided in correspondence with the two rows of electrode unit rows 5 respectively connect the connecting pipes 81 to the blowers 80 separately as shown in FIG. It is connected through.

In addition, the notch groove 21 is also provided symmetrically with the upper end of the surface (that is, the side wall on the right side in FIG. 5) facing the upper end shown in FIG. 4 and FIG. In addition, the diffuser 25 is fitted to the notch groove 19a provided in the rib 19 of the tank main body 1 as mentioned above. Therefore, when the diffuser 25 is reversed and mounted, the connection pipe 81 with the blower 80 can also be performed through the notch groove of the upper end part of the side wall of FIG.

In the cover body 3, the electrode service port 31 having the opening 32 for inserting the electrode unit on the bottom surface of the recessed part 33 has a service cover as shown in Figs. 1, 4 and 5. It is covered by (4). The service cover 4 protects a person from being electrocuted by the terminal 51c or the like of the electrode unit 51. The service cover 4 is closed during normal use and is opened when the electrode unit 51 is replaced. In addition, the lid 4 is fixed to the cover 3 by the screw 41, but in order to facilitate the opening and closing, two handles 42 are formed on the upper surface of the service lid 4.

Next, the planar part 70 which forms a recessed part is formed in the two places where the corner parts of the said 2 recessed part 33 adjoin. And between the service cover 4 in any one of this flat part 70, two safety switches 71 which operate by opening and closing of the service cover 4, and two diffusers The sensor unit 7 which accommodates the two pressure sensors 75 which detects and operates the abnormality of the inlet side pressure of 25 is provided.

Next, this sensor unit 7 will be described with reference to FIG. 8. 8 is an enlarged view of the sensor unit 7.

As shown in FIG. 8, the switch box 79 is sized to cover both corner portions of the adjacent service cover 4 in plan view, and the height direction is the flat part 70 and the service cover 4. It is a numerical value stored in between. Moreover, the safety switch 71 is comprised from the switch body 72 accommodated in the inside of the switch box 79, and the magnet 73 attached via the cover attached to the back surface of the service cover 4, When the service cover 4 is closed, the reed switch in the switch body 72 is turned ON by the action of the magnet 73, and when the service cover 4 is opened, the magnet 73 is the switch body 72. ), The magnet 73 does not act on the switch main body 72, and the reed switch in the switch main body 72 is turned OFF, thereby interrupting the power circuit of the electrode unit 51. It is designed to. In addition, although these safety switches 71 are not shown in one box in FIG. 8, two safety switches 71 are attached corresponding to the edges of the two service covers 4 so as to detect opening and closing of each of the two service covers 4. It is. That is, in the switch box 79, the switch main body 72 is the same height at the position corresponding to the corner part of the two service covers 4, and eventually at the position symmetrical with respect to the center line of the cover body 3. Each is mounted in place. In addition, as described above, the side adjacent to the two service lids 4 in correspondence with being able to be attached to any one of the two flat portions 70 on the two opposite sides of the switch main body 72. The magnets 73 are mounted on the back of the two corner portions 2 (four locations in total), respectively (see Fig. 1).

On the other hand, the pressure sensor 75 is a state in which the air output port of the diffuser 25 is clogged, that is, when the pressure on the discharge side of the blower 80 rises abnormally so that air is not supplied to the sewage, or the blower In the case where the diaphragm type is used as 80, when the diaphragm constituting the blower 80 breaks, the discharge side pressure of the blower 80 is abnormally low so that no air is supplied to the sewage. The case is detected as an abnormal pressure. In addition, the pressure sensor 75, as shown in Fig. 3 or 5, through the pressure induction pipe (76, 77) connecting pipe which connects the diffuser 25 of the two systems to the blower 80 separately And 81 respectively. In addition, although only one pressure sensor 75 is shown in FIG. 8, two pressure sensors 75 are mounted at the same height at the same height at a position symmetrical with respect to the center line of the cover body 3.

Next, the control circuit of the electrode unit will be described with reference to FIG. 9, only one electrode unit column 5 is shown. In practice, however, the other electrode unit rows 5 are similarly connected, but are not shown for simplicity.

As shown in Fig. 9, the eight electrode units 51 arranged in one row of the electrode unit rows 5 are additionally supplied via the control panel 8 via two relay terminal boxes 6. It is connected to (9). On the control panel 8, ON and OFF information of two safety switches 71 and two pressure sensors 75 are input. When the opening of the service cover 4 is detected by either of the safety switches 71 or by the operation of one of the pressure sensors 75, it is detected that the air is not normally supplied from the diffuser 25. In this case, the power supply circuit of the electrode unit 51 is cut off.

The electrolytic cell configured as described above is configured as the following system. In the case where the use is wastewater treatment for a business place, for example, as shown in FIG. 10, the wastewater reaches the electrolytic cell C via the active sludge tank A and the intermediate flow adjusting tank B, and the electrolytic cell D A coagulation sedimentation tank D is provided on the rear end side of the back panel). On the other hand, in the case of a domestic merger treatment septic tank, it is comprised and used by the system as described in Unexamined-Japanese-Patent No. 10-192869, Unexamined-Japanese-Patent No. 10-258283, and Unexamined-Japanese-Patent No. 2000-189977. Hereinafter, the operation in the case of using the electrolytic cell will be described for the case of being used as a wastewater treatment system for a workplace.

The sewage drained from the workplace is first decomposed by microorganisms in the BOD component in the activated sludge tank (A), and the sewage in the activated sludge tank (A) is a fixed amount of sewage through the intermediate flow adjusting tank (B). Is introduced. At this time, the sewage falls from the upper part of the electrolytic cell C to the shelf part 15 of the tank body 1 and is dispersed, and becomes a substantially uniform flow to the sewage outflow pipe 11 through the electrode units 51. Flow. In particular, in the present embodiment, the electrode unit rows 5 are arranged in two rows in a direction orthogonal to the flow direction of the sewage, and the width direction of the bath is reduced, thereby preventing the sewage from stagnating at the widthwise end of the bath. do. Therefore, the information deposition efficiency by the ions eluted from the electrode unit 51 at the end of the tank is lowered and the phosphorus removal efficiency can be prevented from being lowered.

At this time, two iron ions are eluted from the anode of the electrode unit 51 by the electrolytic action of the electrode unit 51, and hydrogen gas is generated from the cathode. On the other hand, divalent iron ions are oxidized to trivalent iron ions due to aeration from the diffuser 25. Moreover, the concentration of hydrogen gas is reduced by the air calculated from this diffuser 25, and the risk of explosion is avoided. Trivalent iron ions react with orthophosphoric acid in sewage to form poorly soluble phosphorus compounds. The sludge containing the phosphorus compound is actively suspended in the electrolytic cell C by the aeration from the diffuser 25, and the sludge is discharged through the sewage outflow pipe 11 to the coagulation sedimentation tank D, which is the next step. . In this coagulation sedimentation tank (D), the suspended matter containing the phosphorus compound is precipitated and removed.

In addition, air is calculated from the diffuser 25 toward the bottom of the tank main body 1, and the bubble bubbles rise upwards, and on the sidewalls of the sewage inflow side and the sewage outflow side of the tank main body 1. The inclined shape of the mountain-shaped portion 16 in the center portion of the bottom surface of the tank body 1, which is the middle of the inclined surface portions 12, 13 and the electrode unit rows 5, is provided near the lower portion of the electrode unit rows 5. Since the sewage flows from the periphery of the diffuser 25 toward the bottom of the tank body 1, the sewage is effectively convection in the electrolytic cell C, and the discharge of the suspended matter is smoothly performed. Moreover, since the longitudinal direction of the electrode plate 51a becomes the same as the longitudinal direction of the tank, consequently, sewage flows along the plate-like surface of the electrode plate 51a, and convection generated in the tank is also caused by the electrode plate. By flowing along the plate-like surface of 51a, the flow velocity of this convection can be made quick and an efficient phosphorus compound can be suspended. In addition, the cleaning action of the surface of the electrode plate 51a caused by convection and aeration prevents sludge from remaining between the electrode plate 51a of the electrode unit 51, thereby avoiding an accident such as short circuit of the electrode. Can be.

As described above, the electrolytic cell C does not retain the sludge in its own tank. Therefore, the sludge in the electrolytic cell C does not need to be discharged in particular, and it serves as the replacement of the electrode unit 51. I can finish it. The exchange of the electrode unit 51 is necessary for the electrode plate 51a to melt and be consumed by eluting iron ions at the anode. In this embodiment, both the positive electrode and the negative electrode are made of iron, and polarity switching is periodically performed in order to avoid the consumption of only one electrode. Moreover, since the separator 52 is arrange | positioned between the adjacent electrode units 51, consumption of each electrode plate 51a becomes substantially uniform. On the other hand, in the absence of the separator 52, the electrode plate 51a positioned in the middle causes electrolytic action on both sides, and dissolves at twice the speed of the electrode plate 51a at the outermost electrode plate. (51a) A uniform consumption can be achieved.

In the electrolytic cell C operating as described above, the timing at which the electrode plate 51a is consumed is calculated in advance, and the electrode unit 51 is periodically replaced. In this case, the service cover 4 is first opened. Then, the power plate 62 connected to the relay terminal 61 of the relay terminal box 6 is removed, and the fixing plate of the substantially L-shaped cross section which fixes the electrode unit 51 and the separator 52 ( 53) Remove. In this case, since the relay terminal box 6 and the electrode unit 51 are connected in such a manner as to be adjacent to each other, the wiring of the power cable 62 can be neatly arranged, and the electrode unit 51 can be attached and detached. The operation can be performed easily. When the separator 52 in the center is removed when the electrode unit 51 is replaced, the lower portion of the separator 52 is connected to the rubber plate 17f through the chain 55, so that the rubber stopper is easily attached. You can pull out (17a).

In addition, when the service cover 4 in either direction of the electrode unit 51 is opened, the magnet 73 mounted on the back of the service cover 4 does not act on the switch in the switch body 72. By the operation of either of the safety switches 71, the power supply circuits of the electrode unit rows 5 in both rows are necessarily cut off. Therefore, even if the worker touches the electrode unit 51 or the sewage around the electrode unit 51, there is no risk of electric shock.

According to this embodiment comprised as mentioned above, there exist the following outstanding effects.

Sewage inflow pipe 35 is provided in the small space 30 which slightly recessed in the upper surface of the cover body 3, and it connects to the opening 30a, and discharges sewage toward the inside of the electrolytic cell C from the upper side to the lower side. Since it is comprised so that it may flow in, when the opening of the horizontal sewage inflow pipe 35 (in this case, the connection with the opening 30a) is made higher than the uppermost part of the sewage outflow pipe 11, sewage will not flow back. Therefore, the height of the electrolytic cell C can be lowered by the pipe diameter of the sewage inflow pipe compared with the conventional one. In addition, since the connection pipe 35d connected to the sewage inflow pipe 35 is connected at the upper part of the electrolytic cell C, the space required for the pipe connection with the intermediate flow rate adjustment tank B, which is the previous step, can be reduced. . Therefore, when it is necessary to bend the connecting pipe in the horizontal or vertical direction by the positional relationship with other electrolyzers, this saving space can be utilized to facilitate the pipe work. In addition, even if water leaks from the piping connection part, for example, the sewage does not leak directly to the outside of the electrolytic cell C, and leaks to the upper part of the electrolytic cell C. It becomes possible to process so that it does not go out. Moreover, although the power supply 9 and the control panel 8 which supply an electric current to the electrode unit 51 are arrange | positioned outside the electrolytic cell C, it is safe because there is no possibility that the sewage will leak over these electrical components.

In addition, the sewage inflow pipe 35 is fitted with a straight pipe 35b on a flanged pipe 35a mounted on the upper surface of the electrolytic cell C, and the 90 degree elbow 35c rotates about the straight pipe 35b as an axis. Since it is possible to mount, the horizontal direction and the height position of the connection pipe 35d connected to the sewage inflow pipe 35 can be freely selected. Therefore, the connection space can be reduced by connecting the sewage inflow pipe 35 and the piping connection of the intermediate flow rate adjustment tank B which are all processes to suit installation conditions.

In the electrolytic cell C, the sewage flows from the sewage inflow pipe 35 to the sewage outflow pipe 11, but the electrode unit 51 is approximately perpendicular to the long side of the electrolytic cell (that is, approximately orthogonal to the flow of sewage). Direction), the surface of the electrode plate 51a constituting the electrode unit 51 follows the flow of sewage, and the flow of the sewage is smooth. In addition, since the lower part of the sewage inflow pipe 35 has a shelf portion 15 to collide with the flow of sewage flowing into the electrolytic cell C, the sewage introduced into the electrolytic cell C is dispersed in the shelf portion 15. Since a uniform flow flows between the plurality of electrode units 51, the phosphorus trapping efficiency due to iron ions eluted from the electrode unit 51 is uniformized in the electrode units 51 of each unit, and the phosphorus removal efficiency is increased. Is improved.

In addition, this invention can also be specified as follows.

In the present embodiment, an example in which the electrolytic cell C is used as the sewage treatment tank is shown, but may be embodied in another treatment tank such as a contact aeration tank.

Moreover, although the example in which the wastewater outflow pipe 11 was installed in the horizontal direction was shown in the electrolytic cell C in the Example, it is not limited to this. For example, the opening may be lifted upward from the lower surface to be pulled out of the lower surface of the electrolytic cell C at an appropriate height.

In addition, in the electrolytic cell C in this embodiment, although the arrangement | positioning in two rows as the electrode unit rows 5 is shown, it is not specifically limited to this, One row of electrode unit rows 5 may be sufficient, and one is It may be a small one using an electrode of.

In addition, the diffuser 25 may not be a plural system (two systems in this case) as in this embodiment, but may be one system. For example, in this embodiment, although two systems of diffusers 25 are arranged below each electrode unit row 5, these diffusers 25 are connected to a common blower 80 to provide one system. You may comprise with an diffuser.

In addition, in this embodiment, although an iron material was used as an electrode, it is not limited to this, You may use the other metal which elutes the metal ion which reacts with a phosphate ion, for example, aluminum.

Since this invention is comprised as mentioned above, it has the following effects.

According to the invention of Claims 1 to 5, the height of the treatment tank can be made low, and the treatment tank can be downsized. In addition, the space of the connecting pipe connected to the sewage inflow pipe can be reduced. In addition, it is possible to prevent the leakage of sewage out of the treatment tank directly from the connecting portion of the connecting pipe.

In addition, according to the invention of claim 2, since the horizontal direction of the connecting pipe connected to the sewage inlet pipe can be freely selected, the connection space is further reduced by connecting the sewage inlet pipe and the treatment tank of all the steps according to the installation conditions. can do.

In addition, according to the invention of claim 3, since the horizontal direction and the connection height position of the connecting pipe connected to the sewage inflow pipe can be freely selected, the sewage inflow pipe and the treatment tank of the electric field are suitably connected to the installation conditions. The space can be further reduced.

Further, according to the invention of claim 4, since the sewage does not leak directly to the outside of the treatment tank, it is possible to prevent the ingress of electrical components such as a power supply device and a control panel arranged around the electrolytic cell.

In addition, according to the invention of claim 5, since the sewage flowing into the tank is dispersed in the shelf part, the information deposition efficiency due to the metal ions eluted from the electrode unit is uniform in the electrode units of each part, thereby improving the phosphorus removal efficiency.

Claims (5)

In a sewage treatment tank having a sewage inflow pipe for introducing sewage and a sewage outflow pipe for outflowing sewage, the sewage inflow pipe is provided to introduce sewage from the upper surface of one side of the sewage treatment tank toward the inside of the lower tank. Sewage treatment tank, characterized in that. The method of claim 1, The sewage inflow pipe is configured to be rotatable in a horizontal direction in a direction of a pipe connecting portion to the outside. The method according to claim 1 or 2, The sewage inflow pipe includes a flanged pipe mounted vertically on the upper surface of the tank, a straight pipe mounted on the flanged pipe, and a 90 degree elbow mounted rotatably in a horizontal direction about the straight pipe. Sewage treatment tank, characterized in that. The method of claim 3, wherein The sewage treatment tank is an electrolytic treatment tank having at least one electrode composed of a pair of electrode plates and an acid pipe disposed in the lower sewage of the electrode. The method of claim 4, wherein The electrolyzer has a wastewater outlet pipe on the side opposite to the wastewater inlet pipe, and has a shelf portion that collides with the flow of sewage flowing into the tank below the wastewater inlet pipe, and the electrode is a pair of plate-shaped electrodes. A sewage treatment tank comprising a plurality of electrode units formed in a direction orthogonal to a flow of sewage in a tank.