JP2002254093A - Sewage treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sewage treatment device that can detect the failure of a diffused aeration tube. SOLUTION: This sewage treatment device is provided with a sewage treatment tank which treats sewage and the diffused aeration tubes of one or more systems which spray the air supplied by a blower into the sewage in the sewage treatment tank. In addition, pressure sensors of one or more systems which detect an abnormality in pressure at the inlets of the diffused aeration tubes of one or more systems are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sewage treatment apparatus, and more particularly, to a sewage treatment apparatus having an air diffuser.

[0002]

2. Description of the Related Art A diffuser pipe is used for various purposes in a conventional sewage treatment apparatus. For example, JP-A-10-1928
Looking at the merged treatment septic tank described in Japanese Patent Publication No. 69, five to five air diffusers are used. The first air diffuser is used in a contact aeration tank. The contact aeration tank is maintained in an aerobic state, and the treated water is aerobically decomposed by aerobic microorganisms and nitrate bacteria and Nitrite decomposes ammonium nitrogen into nitrate or nitrite nitrogen by the action of nitrite bacteria. The second air diffuser is also used in the contact aeration tank, and detaches the biological film that has adhered to the contact material and proliferated and gradually thickened. The third air diffuser is provided in a first return pipe communicating between the bottom of the contact aeration tank and the upper part of the first anaerobic filter tank, and constitutes an air lift pump. The fourth diffuser pipe is arranged in a return pipe that communicates the settling tank and the inflow pipe of the water separation device, and also constitutes an air lift pump. The fifth diffuser is provided in an elution tank (electrolysis tank), and supplies air for oxidizing divalent iron ions eluted from the electrodes to trivalent iron ions. The air diffuser in the electrolytic cell has the following other functions. That is, since hydrogen gas is generated from the cathode of the electrode, the concentration of hydrogen gas in the tank is reduced. Clean the surface of the electrode. It has a function such as suspending a hardly soluble phosphate compound generated by the reaction of trivalent iron ions with orthophosphoric acid in sewage and discharging it to the next step.

[0003]

As described above, in the conventional sewage treatment apparatus, the air diffuser is often used as an apparatus having an important function, but no provision has been made for the preparation for failure. .

The present invention has been made by paying attention to such problems existing in the prior art. An object of the present invention is to provide a sewage treatment apparatus capable of detecting a failure of an air diffuser.

[0005]

In order to achieve the above object, a sewage treatment apparatus according to the present invention is provided with a sewage treatment tank to be treated and sewage in the sewage treatment tank supplied from at least one blower. And a system for diffusing air into the sewage, the system further comprising a pressure sensor for detecting an abnormal pressure on the inlet side of the diffuser. The sewage treatment apparatus according to the present invention includes a plurality of systems including a sewage treatment tank that treats sewage, and a plurality of diffuser pipes that blow air supplied from one blower into the sewage into the sewage in the sewage treatment tank. The sewage treatment apparatus may further include a pressure sensor for detecting an abnormality in the pressure on the inlet side of the air diffuser for each system of the air diffuser. Here, the sewage treatment tank refers to all tanks that store and treat sewage in a sewage treatment apparatus including the contact aeration tank and the electrolytic tank described above. Further, the abnormality of the pressure on the inlet side of the air diffuser means a high pressure exceeding a pressure range that can be regarded as a normal operation or a low pressure below this pressure range. Further, when formed as described above, it is possible to detect all cases where the amount of air supplied into the sewage becomes insufficient due to a blower failure or clogging of the air ejection holes in the air diffuser.

[0006] In the above, the sewage treatment tank comprises:
The diffuser pipe has a substantially rectangular shape in plan view, and the diffuser pipe has one side of the sewage treatment tank connected to a blower and extends toward another side opposite to the one side, and the blower The connection side with-is attached to the sewage treatment tank so that it can be replaced with the other side facing, the pressure sensor,
The air diffuser can be attached near the connection side with the blower. When formed in this way, the planar shape that facilitates handling of the sewage treatment tank is 4
It can be formed in a rectangular shape, and the attachment side of the air diffuser and the pressure sensor can be selected to be any one of two opposing sides. Therefore, when another tank of the wastewater treatment device is arranged along one side or when there is a wall, the air diffuser is connected to the blower side on the near side opposite to this one side. A pressure sensor can be attached to facilitate installation and maintenance work.

[0007] It is preferable that one or a plurality of systems of the air diffusers are removably inserted into the sewage treatment tank in a reversible direction. With this configuration, the connection side of the air diffuser with the blower can be easily changed to the opposite side depending on the installation location as described above.

The one or more pressure sensors are housed in one switch box, and a space for mounting the switch box is provided near the connection side of the air diffuser with the blower and on the other side facing the blower. It can also be configured as follows. With this configuration, when the connection side of the air diffuser with the blower is changed according to the installation conditions as described above, the mounting position of the pressure sensor can be easily changed to the front side at the same time. Thus, the pressure sensor can be installed near the entrance of the air diffuser, so that the length of the pipe connecting the pressure sensor and the inlet of the air diffuser is shortened, and accurate detection is possible. Since the connection side of the air diffuser and the pressure sensor are on the front side, installation and maintenance work is easy.

Further, when an abnormality of the pressure on the inlet side of the air diffuser is detected by the one or more pressure sensors,
It may be configured to further include an abnormality countermeasure device that operates. Further, the abnormality countermeasure device may be an alarm device. With this configuration, it is possible to immediately know the abnormality of the blower or the air diffuser, and to quickly take a countermeasure.

Further, the sewage treatment tank is an electrolytic tank provided with at least a pair of electrodes for eluting divalent metal ions into sewage, and the abnormality countermeasure device stops all power supply to the electrodes. You may comprise so that it may be a control panel.
With this configuration, even if the supply of air from the air diffuser is reduced or stopped, the generation of hydrogen gas generated from the cathode of the electrode is prevented, and the danger of explosion due to an increase in the concentration of hydrogen gas can be avoided. . In addition, generation of a poorly soluble phosphate compound is suppressed, and an accident such as a short circuit between the electrodes due to the deposition of the compound between the electrodes can be prevented.

Further, the sewage treatment apparatus according to the present invention comprises: a planar and substantially rectangular electrolytic cell provided with a plurality of electrodes for eluting divalent metal ions into sewage; and a blower for supplying air to the air diffuser. A sewage treatment apparatus including a power supply that supplies power to the electrode unit, wherein the plurality of electrodes are:
The pair of opposing sides of the electrolytic cell are arranged so as to cross each other, and are formed as two rows of electrode units. The diffuser tubes are arranged in the row direction at the lower part of each electrode unit row, and are configured as separate systems. Further, each of the air diffusion tubes of each system has a pressure sensor for detecting an abnormality in the pressure on the inlet side of the air diffusion tube, and the two pressure sensors are housed in one switch box, and the space for mounting the switch box is the above-mentioned space. It may be formed between the electrode unit rows and in the vicinity of the opposite side crossed by the electrode unit rows. With this configuration, the electrode units are arranged in two rows instead of one row to reduce the dimension in the width direction of the tank, so that it is possible to prevent stagnation of sewage at the end in the width direction of the tank. Therefore, it is possible to prevent a decrease in the phosphorus removal efficiency due to a decrease in the phosphorus capture efficiency due to ions eluted from the electrode unit at the tank end (there is no reaction even if the ions are eluted because there is little phosphorus). In addition, since the pressure sensor can be attached to any of the pair of opposite sides of the electrolytic cell, if the installation location is facing the wall or if it is installed immediately next to other equipment of the drainage facility, In addition, a pressure sensor can be attached to the front side in consideration of workability during maintenance. Since two pressure sensors are attached to one switch box, workability is improved and installation space is small. In addition, the pressure sensor is mounted by effectively utilizing the dead space formed between the electrode unit rows, and is mounted near the inlet side of the two diffuser tubes, so that pressure detection becomes accurate. . By the way, if it is installed not in between the electrode units, but in a place biased to one electrode unit, the distance between the diffuser and the pressure sensor attached to the lower part of the other electrode unit becomes longer,
The pressure loss at one pressure sensor increases, making accurate pressure detection difficult.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention for an electrolytic cell for a sewage treatment apparatus will be described below with reference to FIGS. FIG. 1 is an external plan view of the electrolytic cell according to the present embodiment, FIG. 2 is a plan view of the electrolytic cell according to the present embodiment with an upper lid removed, and FIG. FIG. 4 is a plan view in a state where an upper lid and an electrode unit according to the present invention are removed, and FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. In FIG. 4, the electrode unit row on the sewage flow outlet side shows the separator, and the electrode unit row on the sewage flow inlet side shows the electrode unit side view. 5 is a cross-sectional view taken along line VV in FIG. 2, FIG. 6 is an enlarged view of a portion VI in FIG. 5, and FIG. 7 is an enlarged view of a sludge discharge port.

First, a schematic configuration of an electrolytic cell for a sewage treatment apparatus according to this embodiment will be described. The container of the electrolytic cell is a box-shaped container having a substantially rectangular planar shape, and includes a tank body 1 having a predetermined depth, an inner lid 3 having a predetermined height, and 2 provided on the inner lid 3. It is composed of two upper lids 4 having a small dimension in the height direction for closing the electrode unit service port 31 at a location. The lower part of the upper lid 4 in the inner lid 3 has an opening 32 for mounting an electrode unit on the bottom surface.
Is formed in the concave portion 33 functioning as a support member.
The longitudinal direction (hereinafter, simply referred to as the longitudinal direction of the electrode plate 51a) of the electrode plate 51a of the electrode unit 51 from each of the recesses 33 is the same direction as the long side of the tank body 1 and the longitudinal direction of the electrode plate 51a. The electrode units 51 are inserted so as to form a row at regular intervals in a direction perpendicular to the direction, and the electrode unit row 5 is formed. Further, a sewage outlet 11 is provided on the upper portion of the short side wall of the tank body 1, and the upper surface of the inner lid 3 near the short side wall facing the side wall on which the sewage outlet 11 is provided. Sewage inlet 3 so that sewage flows into the electrolytic cell below from above.
5 are provided.

Next, each part of the electrolytic cell described above will be described more specifically. The tank body 1 is where the wastewater flows in and metal ions are eluted from the electrode into the wastewater, and is formed to have a height volume necessary for this treatment. And, as described above, a pipe is provided as a sewage outlet 11 at an upper portion of one short side wall forming a short side so as to be led out in the horizontal direction. The sewage outlet 11 is provided with a packing 11a. The lower part of the side wall of the sewage outlet 11 is formed as an inclined surface part 12 which is inclined so that the bottom is located at the center side of the tank body 1. Also,
The side wall facing the inclined surface portion 12 is also provided with the inclined surface portion 12.
The inclined surface portion 13 is formed so as to have a symmetrical shape. These inclined surface portions 12 and 13 are formed near the lower portion of the electrode unit row 5 so as to generate convection of wastewater in the tank. Further, shelves 14, 15 projecting outward are formed on the tops of the inclined surfaces 12, 13, and the lower surfaces of the shelves 14, 15 function as fixing surfaces when the electrolytic cell is installed. The shelf 15 on the sewage inflow side has a larger area than the shelf 14 on the sewage outflow side so as to function as a sewage dispersion surface flowing into the electrolytic cell. Is a space for receiving sewage from a sewage inlet 35 attached to the inner lid 3.

An intermediate portion of the electrode unit row 5 on the bottom surface of the tank body 1 is formed into a smooth angled portion 16 having the same inclination angle as the inclined surfaces 12, 13, and the angled portion 16 and the inclined portion 16 are formed. The central portion of the space sandwiched between the surface portions 12 and 13 is configured to be the center of the electrode unit row 5, and a sludge discharge port 17 is provided in this portion. The sludge discharge port 17 is closed by a rubber stopper 17a.
7b is packing 1 by bolt 17c and nut 17d.
It is attached via 7e, 17f (see FIG. 7).

Further, ribs 19 for fixing the diffuser tube are provided at two places (a total of eight places) of each electrode unit row so as to sandwich the sludge discharge port 17 therebetween. This rib 19 is a diffuser 25
Rib 1 so that it is slightly lifted from the bottom
9 is provided with a notch 19a for fitting the diffuser tube at the upper end (see FIG. 7). Further, support legs 22 are formed at four places on the bottom surface of the tank body 1. The electrolytic cell can be placed using the support legs 22.
The upper end edge of the tank body 1 forms a flange portion 23, and a downward rib 24 is formed to improve the strength of the edge portion.

As can be clearly understood from FIG. 4, the inner lid 3 is provided above the electrode unit row 5 to secure a wiring space for the power cable relay terminal box 6 and the power cable 62 of the electrode unit 51. It has the required height, and its upper surface constitutes the upper surface of the electrolytic cell. The lower end of the peripheral edge has a flange portion 34 in contact with the flange portion 23 at the upper end edge of the tank body 1, and further, the bent piece 3 having the tip end of the flange portion 34 bent downward.
4a, and is formed so as to cover the upper end of the tank body 1. The inner lid 3 and the tank main body 1 are fixed to the flange portions 23 and 34 by screws or the like with screws 34b.

A flat space 30 having a small space slightly depressed from the upper surface is formed above the shelf 15 in the inner lid 3, and a sewage inlet 35 is attached to the flat surface 30. The sewage inflow port 35 is provided with a flanged pipe 35a having a mounting flange below, a straight pipe 35b connected to the flanged pipe 35a, and a straight pipe 35.
90 ° elbow 35c rotatably attached to b
A communication pipe 35d for supplying sewage from the previous process is attached to the 90-degree elbow 35c.
The portion of the sewage inlet 35 is formed so that the inner lid 3 and the tank body 1 both have a tapered planar shape.

In a portion from the sewage inflow port 35 to the side wall facing the sewage inflow port 35, a concave portion 33 having a substantially rectangular planar shape having a long side in a direction perpendicular to the long side of the electrolytic cell is provided. Two are formed. The depth is lower than the peripheral edge of the inner lid 3 and slightly higher than the sewage level in the tank body 1. An electrode unit insertion opening 32 is provided on each bottom surface having this depth.

The electrode unit 51 is a set of two rectangular plate electrodes made of iron, and these two electrode plates 51a are held at predetermined intervals by an upper holder 51b. A terminal 51c for connecting a power cable is provided on the upper surface of the holder 51b, and the terminal 51c and the electrode plate 51a are connected in the holder 51b. In the electrode unit 51, the longitudinal direction of the electrode plate 51a is the longitudinal direction of the electrolytic cell.
Are arranged so that a plurality of electrode units 51 are arranged in a direction perpendicular to the longitudinal direction. The holder 51b has a width larger than the width (dimension in the longitudinal direction) of the electrode plate 51a, and is disposed around the electrode unit insertion opening 32 of the inner lid 3 at both portions protruding from the electrode plate 51a. The pin holes 51e that engage with the pins 36 are provided one by one. The lower portion of the pin hole 51e has a large-diameter portion to facilitate insertion of the pin 36, and the upper portion has a small-diameter portion to improve the accuracy of the fixed position. In addition, holder 5
A handle 51d is provided on the upper surface of 1b.
To FIG. 6).

A separator 52 is provided between the electrode units 51. This separator 52
Is made of plastic which is an insulating material, the size of the flat plate portion 52a is substantially equal to the size of the electrode plate 51a, and the upper portion thereof is formed as a wide support portion 52b like the electrode holder. A hole 52c is provided for engaging the pin 37 disposed around the electrode unit insertion opening of the inner lid 3 or the bolt 38 attached to the inner lid 3, one by one. Has a handle 52
b is provided. The pins 37 and the bolts 38 are alternately arranged. In addition, a sludge discharge port 17 is located below the central separator 52 located above the sludge discharge port 17.
Is connected via a chain 55.

When inserting the separator 52 and the electrode unit 51, first, the separator 52 is
Or, it is inserted while engaging with the bolt 38. Then
The electrode unit 51 is inserted while engaging with the pin 36. At this time, the holder 51b of the electrode unit 51 rides on the support 52b of the separator 52 (FIG. 6).
reference). Next, the fixing plate 53 having a substantially L-shaped cross section is
While holding the holder 51b of the electrode unit 51.
Place on top. 53a is a cushioning / insulating material attached to the fixing plate 53. Then, the service nut 39 is fastened to the bolt 38 and finally fixed. Thereby, the sewage inlet 35 side and the sewage outlet 11 side,
The longitudinal direction of the electrode plate 51a is the longitudinal direction of the electrolytic cell, and the electrode units 51 and the separators 52 are alternately arranged in a direction orthogonal to the longitudinal direction of the electrode plate 51a. The electrode unit rows 5 in which the separators 52 are arranged are formed. That is, two electrode unit rows are formed so as to cross a pair of opposite sides of the electrolytic cell. The center line of the electrode unit row 5 is configured to pass through the center of the sludge discharge port 17 described above.

Also, in the inner lid 3, between the electrode unit row 5 and the sewage inflow port 35 and between the electrode unit row 5 and the sewage outflow port 11, the inclined surfaces 12, 13 of the tank body 1 described above are provided. The electrode unit 51 is located at an upper portion, and is located above the electrode unit 51 in this portion.
A relay terminal box 6 for connecting the power supply to a power supply is arranged. Each relay terminal box 6 has a substantially rectangular shape, and has four relay terminals 61 arranged in the longitudinal direction. Two relay terminal boxes 6 are provided so that the longitudinal direction thereof is the row direction of the electrode unit rows 5. Therefore, the arrangement direction of the four relay terminals 61 and the row direction of the electrode unit row 5 match. Note that FIG.
Reference numeral 62 in FIG. 4 denotes a power cable for connecting one electrode unit 51 to one relay terminal 61.
Reference numeral 63 in FIGS. 2 and 3 denotes a power cable for connecting the power supply to each relay terminal box 6.

Below the electrode unit rows 5, two air diffusion tubes 25 are arranged as air diffusion devices forming one system (see FIGS. 3 and 4). These two air diffusers 25
Are connected by a communication pipe 28. The diffuser pipe 25 is connected to the communication pipes 26 and 27 for connecting to the external blower 80 along one wall of the long side of the electrolytic cell, that is, along one wall of a pair of opposed walls. Raised (see FIGS. 3 and 5), notch 37 at the upper end of inner lid 3
(See FIGS. 4 and 5). And
The riser pipe 26 on the center side is connected to the blower 80, and a blind plug 29 is attached to the tip of the riser pipe 27 on the opposite side of the center. Supplying air. Further, the air diffusers having the above-described configuration provided corresponding to the two electrode unit rows 5 are connected to separate blowers 80 via communication pipes 81 as shown in FIG. In addition,
The notch 37 is also provided symmetrically at the upper end of the surface facing the upper end shown in FIGS. 4 and 5. As described above, the diffuser tube 25 is fitted and attached to the notch 19a provided in the rib 19 of the tank body 1. Accordingly, when the air diffuser 25 is mounted in a different direction, the communication pipe 81 to the blower 80 can be provided on the opposite side of the drawing.

In the inner cover 3, a concave portion 33 provided with an electrode unit insertion opening 32 on the bottom surface is covered by an upper cover 4, as shown in FIGS. The upper cover 4 protects a person from being electrically shocked by the terminal 51c of the electrode unit 51 or the like, and is closed during normal use and opened when the electrode unit 51 is replaced.
The upper lid 4 is fixed to the inner lid 3 with screws 41, but two handles 42 are formed on the upper surface of the upper lid 4 to facilitate opening and closing.

Next, at two places where the corners of the two recesses 33 are adjacent to each other, a plane portion 70 forming a recess is formed. A lid switch 71 that operates by opening and closing the upper lid 4 and a pressure sensor 75 that operates by detecting an abnormality in the inlet-side pressure of the air diffuser 25 between the upper lid 4 and the upper lid 4 at any one of the planar portions 70. Is stored.

Next, the sensor unit 7 will be described with reference to FIG. FIG. 8 is an enlarged view of the sensor unit 7. As shown in FIG. 8, the lid switch 71
The switch body 72 attached inside the switch box 79 and the magnet 7 attached inside the top cover 4
When the upper lid 4 is closed, the reed switch in the switch main body 72 is turned on by the action of the magnet 73, and when the upper lid 4 is opened, the magnet 73 is connected to the switch main body 72. The reed switch in the switch main body 72 is designed to be turned off by stopping the operation. In addition, two lid switches 71 are provided corresponding to the corners of the two upper lids 4 so as to detect opening and closing of the two upper lids 4 respectively.

On the other hand, the pressure sensor 75 is used when the air outlet of the air diffuser 25 is clogged, the pressure on the discharge side of the blower 80 rises abnormally, and air is not supplied to the sewage. In the case where a diaphragm type is used as 80 and the diaphragm constituting the blower 80 is damaged, that is, the pressure on the discharge side of the blower 80 is abnormally low, and air is supplied to the wastewater. The case where it is not performed is detected as abnormal pressure. The pressure sensor 75 is connected to a communication pipe 81 connecting the air diffuser 25 to the blower 80 via pressure introduction pipes 76 and 77, as shown in FIG. 3 or FIG.

Next, a control circuit of the electrode unit will be described with reference to FIG. FIG. 9 shows only one electrode unit row 5. However, actually, the other electrode unit row 5 is connected in the same manner, but is not shown for simplification. As shown in FIG. 9, eight electrode units 51 arranged in one electrode unit row 5 are connected to a power supply 9 via two relay terminal boxes 6 and further via a control panel 8. I have. The control panel 8 has two lid switches 71 and two pressure sensors 75 turned on and off.
F information has been input. Either lid switch 7
When the opening of the upper lid 4 is detected by 1 or when it is detected that air is not normally supplied from the air diffuser 25 by the operation of one of the pressure sensors 75, the power supply circuit of the electrode unit 51 is turned off. It is configured to be turned off. That is, in the present embodiment, the abnormality countermeasure device that operates when the pressure sensor 75 detects an abnormality in the inlet-side pressure of the air diffuser 25 includes the control panel 8 that stops supplying power to the electrode unit 51. Applicable. Reference numeral 78 denotes a control circuit wire.

The electrolytic cell configured as described above is configured as the following system. In the case of wastewater treatment for business use, for example, as shown in FIG. 10, sewage is guided to an electrolytic cell C via an activated sludge tank A and an intermediate flow rate adjusting tank B, A coagulation sedimentation tank D is provided. On the other hand, in the case of a household combined treatment septic tank, Japanese Patent Application Laid-Open Nos. 10-192869 and 10-258283.
And a system as described in JP-A-2000-189977. The operation of the present electrolytic cell when used as a wastewater treatment system for business sites will be described below.

The sewage discharged from the business site is firstly degraded by microorganisms in the activated sludge tank A in which the BOD component is decomposed, and the sewage in the activated sludge tank A is electrolyzed as a fixed amount of sewage through the intermediate flow control tank B. It is introduced into the tank C. At this time, the sewage falls from the upper part of the electrolytic cell C onto the shelf 15 of the tank body 1 and is dispersed, and flows almost uniformly to the sewage outlet 11 through between the electrode units 51. In particular, in the present embodiment, the electrode unit rows 5 are arranged in two rows in a direction substantially orthogonal to the flowing direction of the sewage, and the dimension in the width direction of the tank is reduced, so that the sewage stagnates at the width direction end of the tank. Is prevented. Therefore, it is possible to prevent the phosphorus trapping efficiency due to the ions eluted from the electrode unit 51 at the tank end from decreasing and the phosphorus removing efficiency from decreasing.

At this time, divalent 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, the diffuser 25
The divalent iron ions are oxidized to trivalent iron ions by aeration from the air. Further, the concentration of the hydrogen gas is reduced by the air blown out from the air diffuser 25, thereby avoiding the danger of explosion. Trivalent iron ions react with orthophosphoric acid in sewage and are formed into poorly soluble phosphorus compounds. The sludge containing the phosphorus compound is positively floated in the electrolytic cell C by aeration from the diffuser pipe 25, and is discharged from the sewage outlet 11 to the coagulation sedimentation tank D which is the next step. Then, the suspended matter containing the phosphorus compound is precipitated and removed in the flocculation / sedimentation tank D.

At this time, air is blown out from the air diffuser 25 toward the bottom surface of the tank body 1, so that foamy bubbles rise upward, and the slopes provided on the side walls of the tank body 1 on the sewage inflow side and the sewage outflow side. Since the inclined shape of the angled portion 16 at the center of the bottom surface of the tank body 1 which is located between the surface parts 12 and 13 and the electrode unit row 5 is formed near the lower part of the electrode unit row 5, sewage flows around the air diffuser 25. , The wastewater is drawn toward the bottom of the tank body 1, and the sewage effectively causes convection in the electrolytic cell C, so that the suspended matter is smoothly discharged. In addition, that the longitudinal direction of the electrode plate 51a is the same as the longitudinal direction of the tank, that is, sewage flows along the plate-like surface of the electrode plate 51a, and convection generated in the tank also causes the convection of the electrode plate 51a. By flowing along the plate-like surface, the flow velocity of the convection can be increased, and the phosphorus compound can be efficiently suspended. Further, by the action of cleaning the surface of the electrode plate 51a by the convection and the aeration, the sludge is prevented from staying between the electrode plates 51a of the electrode unit 51, and an accident such as a short circuit of the electrodes is avoided.

As described above, since the electrolytic cell C does not store sludge in its own cell, it is usually unnecessary to discharge the sludge in the electrolytic cell C, and when the electrode unit 51 is replaced, It can be done only by doing it together. The replacement of the electrode unit 51 is necessary because the electrode plate 51a is melted and consumed by eluting iron ions from the anode. In the present embodiment, both the anode and the cathode are made of iron, and the polarity is periodically changed in order to avoid depletion of only one electrode. Further, since the separators 52 are arranged between the adjacent electrode units 51, the consumption of each electrode plate 51a is substantially uniform. If the separator 52 is not provided, the electrode plate 51a located in the middle is subjected to electrolytic action on both sides, and is melted at twice the speed of the outermost electrode plate 51a. It becomes impossible to achieve uniform consumption.

In the electrolytic cell C operating as described above,
The time when the electrode plate 51a is worn out is calculated in advance, and the electrode unit 51 is periodically replaced. At this time, the upper lid 4 is first opened. Then, the power cable 62 connected to the relay terminal 61 of the relay terminal box 6 is removed, and the fixing plate 53 having a substantially L-shaped cross section fixing the electrode unit 51 and the separator 52 is removed. In this case, since the relay terminal box 6 and the electrode unit 51 are connected in a substantially adjacent manner, the wiring of the power cable 62 can be neatly arranged, and the work of attaching and detaching the electrode unit 51 can be easily performed. . When the upper cover 4 is opened, the magnet 73 embedded in the upper cover 4 does not act on the switch section in the switch body 72, and the power supply circuits of the two electrode unit rows 5 are turned off. In addition, there is no possibility that the worker is accidentally electrocuted.

When the center separator 52 is removed when the electrode unit 51 is replaced, the lower portion of the separator 52 is connected to the rubber plate 17a via the chain 55, so that the rubber stopper 17a is easily pulled out. be able to

Further, in this embodiment, since the pressure sensor 75 for detecting an abnormality of the pressure on the inlet side of the air diffuser 25 is provided, the failure of the blower 80 or the clogging of the air ejection hole in the air diffuser 25 may cause the pressure sensor 75 to fail. All cases where the amount of air supplied into the sewage is insufficient can be detected. That is, during the operation of the electrode unit 51, if an abnormality occurs in the system of the diffuser tube 25 for the above-mentioned reason and the aeration is not normally performed in the electrolytic cell C, the pressure sensor 75 is activated. Then, the control panel 8 operates as an abnormality countermeasure device, and the supply of power to the electrode unit row 5 is cut off. In this case, if the operation of the electrode is continued as it is, the electrolytic reaction continues almost normally, and the concentration of hydrogen gas generated from the cathode rises, causing a danger of explosion. Further, since it becomes impossible to clean the electrode surface by convection and aeration of the wastewater in the tank, it becomes difficult to discharge sludge, and there is a risk of short-circuiting between the electrode plates 51a. However, in the present embodiment, such a danger can be avoided because the power supply circuit of the electrode unit row 5 is cut off by the control panel 8 as the abnormality countermeasure means.

Further, in the electrolytic cell of the present embodiment, since two electrode unit rows 5 are formed so as to cross a pair of opposite sides of the electrolytic cell, the width of the cell is reduced in size. Stagnation can be prevented at the widthwise end of the tank. Therefore, a decrease in the phosphorus trapping efficiency due to ions eluted from the electrode unit at the tank end (there is no reaction even if the ions are eluted because there is little phosphorus) can prevent a decrease in the phosphorus removal efficiency.

At the lower part of each electrode unit row 5, diffuser tubes 25 are arranged in the row direction, each of which is configured as a separate system. Further, for each diffuser tube 25 of each system, an inlet side of the diffuser tube 25 is provided. Pressure sensor 7 for detecting abnormal pressure
Since the number 5 is provided, it is possible to detect a case where a problem occurs in any of the systems of the air diffuser tubes 25 and the supply of air to the wastewater is insufficient.

The two pressure sensors 75 are housed in one switch box 79, and the switch box 7
9 is formed between the electrode unit rows 5 and in the vicinity of the opposing sides that the electrode unit rows 5 traverse, so that the installation location faces the wall or the drainage facility In the case where the pressure sensor 75 is installed immediately beside other equipment, the pressure sensor 75 can be attached to the near side in consideration of workability during installation and maintenance. Further, the switch box 79 is attached by effectively utilizing the dead space formed between the electrode unit rows 5. Further, since the pressure sensors 75 are attached near both the inlet sides of the air diffusers 25, the piping 77 for introducing the pressure is shortened, and the pressure is accurately detected. The air diffuser 25 can be fitted into the notch 19a formed in the rib 19 of the tank body 1 in a reversible manner, and the piping direction is reversible. The side can easily be changed to the opposite side.

The control panel 8 for stopping the supply of electric power to the electrode unit 51 is provided as an abnormality countermeasure device that operates when an abnormality is detected in the pressure on the inlet side of the diffuser tube 25. Even if the supply of air from 25 is reduced or stopped, the generation of hydrogen gas at the cathode of the electrode unit 51 and the generation of divalent iron ions at the anode are immediately stopped. Therefore, the danger of explosion due to an increase in the hydrogen gas concentration can be avoided. Further, the generation of the poorly soluble phosphoric acid compound is stopped, and the compound is deposited between the electrode plates 51a, whereby an accident such as a short circuit between the electrode plates 51a can be prevented.

The present invention can be embodied as follows. First, in this embodiment, an example in which the electrolytic cell C is used as a sewage treatment tank is shown, but the present invention can be embodied in another tank such as a contact aeration tank. Further, although two rows are shown as the electrode unit rows 5 in the electrolytic cell, the present invention is not particularly limited to this, and one electrode unit row 5 may be used. May be used. Further, the air diffuser 25 is not of two systems as in the present embodiment, but may be of one system. For example, in the present embodiment, two diffuser tubes 25 are arranged below each electrode unit row 5, but these diffuser tubes 25 are connected to a common blower 80 and configured as one system diffuser tube. You may. Further, in the present embodiment, the control panel 8 that shuts off the supply of power to the electrode unit 51 when the pressure sensor 75 is operated is shown as the abnormality countermeasure device, but it is an alarm device such as an alarm buzzer. Is also good. In particular, when implementing the present invention in a cell other than the electrolytic cell C, there is no such thing as an electrode that must be stopped immediately, and it may be preferable to first notify the operator of the occurrence of an accident. This is effective in such a case.

[0043]

As described above, the present invention has the following advantages. According to the first to ninth aspects of the present invention, since the pressure sensor that detects the abnormality of the inlet-side pressure of the air diffuser is provided, all cases where the amount of air supplied to the sewage is insufficient are detected. The device can be used with confidence.

According to the third aspect of the present invention, the connection between the air diffuser and the blower and the installation of the pressure sensor can be located on the front side, so that the workability at the time of installation and maintenance of the sewage treatment apparatus is improved. Is improved.

According to the fourth aspect of the present invention, since the air diffuser is mounted in a fitting manner, the connection of the air diffuser to the blower can be easily changed to the near side.

According to the fifth aspect of the present invention, the switch box containing the pressure sensor can be easily located on the front side. Therefore, the distance between the pressure sensor and the inlet side of the air diffuser can be shortened, and the accuracy of pressure detection can be improved.

According to the invention of claim 6, there is provided an abnormality countermeasure device which operates when the pressure sensor operates, and according to the invention of claim 7, as this abnormality countermeasure device, Since the alarm device is provided, it is possible to immediately know the failure of the air diffuser.

According to the invention described in claim 8, since the abnormality countermeasure device stops the supply of electric power to the electrode, when the supply of air from the air diffuser is reduced or stopped, the abnormality countermeasure device stops hydrogen supply. Prevents gas concentrations from rising and prevents explosion hazard. In addition, it is possible to prevent accidents such as the insoluble phosphate compound accumulating between the electrodes and shorting between the electrodes.

According to the ninth aspect of the present invention, since the electrode units are arranged in two rows, sewage is prevented from stagnating at the widthwise end of the tank, and the phosphorus removal efficiency is reduced due to a decrease in the phosphorus capture efficiency. The drop can be prevented. In addition, since two systems of pressure sensors are housed in one switch box and can be attached to any of a pair of opposite sides of the electrolytic cell, workability is improved, installation space is reduced, and workability is reduced. Not only is improved, but also the pressure can be accurately detected because it is mounted near the inlet side of both diffuser tubes on the near side.

[Brief description of the drawings]

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

FIG. 2 is a plan view in a state where an upper lid of the electrolytic cell according to the embodiment of the present invention is removed.

FIG. 3 is a plan view in a state where an upper lid and an electrode unit according to the embodiment of the present invention are removed.

FIG. 4 is a sectional view taken along line IV-IV in FIG. 1, in which the electrode unit row on the sewage outlet side shows a separator, and the electrode unit row on the sewage inlet side shows the side of the electrode unit. .

FIG. 5 is a sectional view taken along line VV in FIG. 2;

FIG. 6 is an enlarged view of a portion VI in FIG. 5;

FIG. 7 is an enlarged view of a sludge discharge port portion of the electrolytic cell according to the embodiment of the present invention.

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

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

FIG. 10 is an example of a system in the case where the electrolytic cell according to the embodiment of the present invention is applied to the treatment of business wastewater.

[Explanation of symbols]

1 tank body, 3 inner lid, 4 upper lid, 5 electrode unit row, 7 sensor unit, 8 control panel, 9 power supply,
25 diffuser tube, 51 electrode unit, 51a electrode plate, 7
0 plane part, 76, 77 piping, 75 pressure sensor, 79 switch box, 80 blower.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Akihiro Fukumoto 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Toshiki Okumi 2-chome Keihanhondori, Moriguchi-shi, Osaka No.5-5 Sanyo Electric Co., Ltd. F-term (Reference) 4D029 AA01 AB05 BB10 DD05 4D061 DA08 DB09 EA07 EA08 EB01 EB05 EB14 EB20 EB28 EB37 EB38 EB39 ED06 GA30 GB30 GC20 5C086 AA34 AA41 BA30 DA10 FA20 DA10

Claims (9)

[Claims] 1. A sewage treatment system comprising: a sewage treatment tank for treating sewage; and a system of diffuser pipes for blowing air supplied from at least one blower into the sewage in the sewage treatment tank. A sewage treatment apparatus, further comprising: a pressure sensor that detects an abnormality in an inlet pressure of the air diffuser. 2. A sewage treatment apparatus comprising: a sewage treatment tank for treating sewage; and a plurality of systems of diffuser pipes for blowing air supplied from one blower into the sewage in the sewage treatment tank. And a pressure sensor for detecting an abnormality of the pressure on the inlet side of the air diffuser for each system of the air diffuser. 3. The sewage treatment tank has a substantially square planar shape, and the diffuser pipe has one side of the sewage treatment tank connected to a blower and extends toward the other side facing the one side. The pressure sensor is connected to the blower in the air diffuser tube, and is connected to the blower in such a manner that a connection side with the blower can be replaced with another side facing the blower. The sewage treatment apparatus according to claim 1, wherein the sewage treatment apparatus can be attached near the side. 4. The sewage treatment apparatus according to claim 3, wherein the one or more systems of the diffuser pipes are removably inserted into the sewage treatment tank in a reversible manner so as to be fitted into the sewage treatment tank. . 5. The one or more pressure sensors,
The switch box is housed in one switch box, and the installation space for the switch box is
5. The sewage treatment apparatus according to claim 3, wherein the sewage treatment apparatus is provided near the connection side of the sewage and on the other side facing the connection side. 6. The apparatus according to claim 1, further comprising an abnormality countermeasure device which is activated when an abnormality in the inlet side pressure of the air diffuser is detected by the one or more pressure sensors. The sewage treatment apparatus according to claim 1. 7. The sewage treatment apparatus according to claim 6, wherein the abnormality countermeasure device is an alarm device. 8. The sewage treatment tank is an electrolysis tank provided with at least a pair of electrodes for eluting divalent metal ions into sewage, and the abnormality countermeasure device stops all power supply to the electrodes. The sewage treatment apparatus according to claim 7, which is a control panel. 9. A substantially rectangular electrolytic cell having a plurality of electrodes for eluting divalent metal ions into sewage, a blower for supplying air to the air diffuser, and supplying power to the electrode unit. A plurality of electrodes are formed as two rows of electrode units arranged side by side across a pair of opposite sides of the electrolytic cell,
The air diffuser is arranged in the column direction at the lower part of each electrode unit row and is configured as a separate system, and further, for each of the air diffusers of each system, a pressure sensor for detecting an abnormality of the inlet side pressure of the diffuser pipe. The two pressure sensors are housed in one switch box, and the space for installing the switch box is between the electrode unit rows,
A sewage treatment apparatus, wherein the electrode unit row is formed in the vicinity of an opposing side crossed.