JP7165985B2 - Wastewater treatment equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a wastewater treatment apparatus for treating wastewater discharged from a factory or the like, and more particularly to a wastewater treatment apparatus for evaporating and concentrating water from wastewater.

Conventionally, as a device for treating wastewater discharged from factories, etc., the wastewater stored in a storage tank is heated to evaporate the water content, thereby separating the persistent substances contained in the wastewater as solids. There is known a wastewater treatment device that does (see Patent Literature 1).

In addition, conventionally, there is an evaporation process in which water is evaporated by heating the wastewater in the storage tank, and when the position of the liquid level of the wastewater drops to a predetermined water level due to evaporation, wastewater before treatment is supplied (replenished) to the storage tank. Wastewater treatment systems are known in which the feeding step and are repeatedly performed to concentrate the wastewater. In the supply step, the level of the wastewater is detected by a water level sensor (water gauge) provided in the storage tank, and the wastewater is supplied based on the detection result.

JP 2009-220047 A

However, in the conventional configuration, when the wastewater in the storage tank is heated and the surface of the wastewater boils with air bubbles, the measurement value by the water level sensor becomes unstable, and there is a risk of misdetection of the position of the liquid surface. .

In order to prevent such an erroneous detection, it is conceivable to provide a water level tank for detecting the position of the liquid surface of the wastewater separately from the storage tank. In this case, the water level tank and the storage tank are connected by a connecting pipe in order to bring the liquid levels in both tanks to the same level. In this configuration, since the water level tank is not provided with a heating device, the liquid level does not bubble due to heating, and the liquid level position measured by the water level sensor is stable.

However, as the evaporation process and the supply process are repeated and the wastewater is concentrated, sludge or the like accumulates in the connecting pipe, the flow resistance in the connecting pipe increases, and the wastewater flows from the storage tank to the water level tank. is inhibited. In this case, even if the wastewater is supplied to the storage tank in the supply step, the change in the liquid level in the water level tank will not quickly follow the change in the liquid level in the storage tank, and the measured value of the liquid level position by the water level sensor will be changed. It will not match the position of the liquid level in the storage tank. Further, if the connecting pipe is clogged with sludge or the like, the wastewater will no longer flow from the storage tank to the water level tank, making it impossible to accurately measure the position of the liquid level in the storage tank. Further, when the concentration of the wastewater progresses and the wastewater separates into a hydrophobic liquid layer mainly composed of oil on the liquid surface side and a hydrophilic liquid layer mainly composed of water below it, the water level sensor There is a possibility that the upper surface of the hydrophobic liquid layer may be erroneously detected as the position of the liquid surface of the waste water in the storage tank.

SUMMARY OF THE INVENTION An object of the present invention is to accurately detect the water level of wastewater in a storage tank in a wastewater treatment apparatus.

Another object of the present invention is to facilitate cleaning of a flow path connecting a storage tank and a water level tank in a wastewater treatment apparatus.

(1) A wastewater treatment apparatus according to an embodiment of the present invention is a wastewater treatment apparatus that heats wastewater stored in a storage tank to evaporate moisture and concentrate the wastewater. The wastewater treatment apparatus includes a first tank provided side by side with the storage tank, a first channel connecting the tanks so that the wastewater can flow between the storage tank and the first tank, and A first sensor provided in a first tank for measuring the position of the liquid surface of the wastewater stored in the first tank; and a compressed air supply unit for moving the wastewater to the storage tank through the first flow path.

Because of this configuration, the wastewater in the first tank is agitated by sending compressed air to the first tank. This can prevent erroneous detection of the first sensor due to, for example, an oil layer floating on the liquid surface. Compressed air supplied to the first tank presses the wastewater in the first tank downward, thereby causing the wastewater in the first tank to rush through the first flow path to the reservoir. As a result, a high water flow is generated in the first flow path, sludge and the like accumulated in the first flow path can be removed, and the burden of the cleaning work on the operator can be reduced.

(2) The compressed air supply unit is provided in an air passage from a compressed air source to the air layer of the first tank, and includes an electrically operated valve that opens and closes the air passage, and an electrically operated valve that opens and closes the air passage when a predetermined condition is satisfied. and a first controller for driving the valve from closed to open.

(3) The first control unit is configured to drive the motor-operated valve from closed to open for a predetermined set time when the predetermined condition is satisfied.

(4) The predetermined conditions are that the liquid level of the wastewater in the storage tank is displaced to a second water level lower than a predetermined first water level, and that the number of replenishment times of the wastewater to the storage tank is predetermined. or that the rate of change of the measured value by the first sensor when the waste water is replenished to the storage tank becomes equal to or less than a predetermined reference rate. That is, the first control unit is controlled when the liquid level of the wastewater in the storage tank is displaced to a second water level lower than a predetermined first water level, or when the number of times the wastewater is replenished to the storage tank is When a predetermined set number of times is reached, or when the rate of change in the measurement value by the first sensor when the wastewater is replenished to the storage tank becomes equal to or less than a predetermined reference rate, the The motor-operated valve is driven from closed to open for a set time.

(5) The wastewater includes water and hydrophobic substances with a density less than water. The hydrophobic substance is, for example, an oil component. The present invention is suitable for such wastewater.

(6) The wastewater treatment apparatus of the present invention includes a second tank provided side by side with the storage tank, and a second tank connecting the tanks so that the wastewater can flow between the storage tank and the second tank. a channel, a surface liquid supply unit that sucks surface liquid near the surface of the wastewater in the storage tank and supplies it to the second tank, and a second tank that measures the amount of the hydrophobic substance in the second tank. It further comprises a sensor, and a surface liquid discharger for sucking and discharging surface liquid near the surface of the wastewater in the second tank based on the measurement result of the second sensor.

(7) The surface liquid supply unit includes a first pump provided in a third flow path from the storage tank to the second tank, and the waste water supplied to the storage tank up to a predetermined reference water level. and a second control unit for driving the first pump to suck the surface layer liquid near the surface of the wastewater in the storage tank.

(8) The surface liquid discharge part is provided in a fourth channel extending from the second tank, and sucks the surface liquid near the liquid surface of the wastewater in the second tank and discharges it from the fourth channel. When it is determined that the hydrophobic substance in the second tank is a predetermined amount based on the measurement result of the second pump and the second sensor, the second 2 pumps to suck and discharge the surface layer liquid near the surface of the wastewater in the second tank.

In addition, the present invention has a storage tank for storing wastewater, and a first tank which is provided side by side with the storage tank and is connected to the storage tank so that the wastewater can flow. Applied to a wastewater treatment apparatus capable of treating stored wastewater, it should be regarded as an invention of a method of supplying compressed air from a compressed air source to the first layer when a predetermined condition is satisfied during the treatment of the wastewater. can also

Advantageous Effects of Invention According to the present invention, it is possible to accurately detect the water level of wastewater in a storage tank in a wastewater treatment apparatus. Moreover, in the wastewater treatment apparatus, it is possible to easily wash the flow path connecting the storage tank and the first tank (water level tank).

FIG. 1 is a system diagram showing the configuration of a wastewater treatment system 10 according to an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the wastewater concentration device 11. As shown in FIG. FIG. 3 is a flow chart showing an example of a concentration process procedure executed by the control unit of the wastewater concentration device 11. As shown in FIG. FIG. 4 is a diagram showing the state of the wastewater concentration device 11 in the wastewater supply process. FIG. 5 is a diagram showing the state of the wastewater concentrating device 11 in the surface liquid removal step. FIG. 6 is a diagram showing the state of the wastewater concentration device 11 in the oil recovery step. FIG. 7 is a diagram showing the state of the wastewater concentrator 11 in the compressed air supply step. FIG. 8 is a diagram showing the state of the wastewater concentrator 11 in the concentrated water discharge process.

Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. It should be noted that the embodiment described below is merely an example that embodies the present invention, and does not limit the technical scope of the present invention.

[Wastewater treatment system 10]
FIG. 1 is a system diagram showing the configuration of a wastewater treatment system 10. As shown in FIG. FIG. 2 is a block diagram showing the configuration of the wastewater treatment system 10. As shown in FIG. The wastewater treatment system 10 is for treating wastewater discharged from a factory or the like. It decomposes and purifies persistent substances that are

In the following, the present embodiment will be described by exemplifying wastewater containing a cutting fluid used for lubrication and cooling during metal cutting as an object to be treated in the wastewater treatment system 10 . Here, the cutting fluid is a type A1 water-soluble cutting fluid defined in JIS K 2241, which has a lower density than water. Moreover, the waste water includes not only the cutting oil but also metal powder generated by cutting. The wastewater treatment system 10 is not limited to wastewater containing type A1 water-soluble cutting fluid, and for example, other water-soluble cutting fluids (types A2 and A3), or wastewater specified in JIS K 2241. Wastewater containing water-soluble cutting oil (types N1 to N4) may also be used.

As shown in FIGS. 1 and 2, the wastewater treatment system 10 is roughly divided into a wastewater concentration device 11 (an example of the wastewater treatment device of the present invention), a decomposition treatment device 12, and a control panel 30 (see FIG. 2). , and the wastewater concentrator 11 and the decomposition treatment device 12 are connected by a connection duct 14 so that gas including steam is sent from the wastewater concentration device 11 to the decomposition treatment device 12 .

[Wastewater Concentrator 11]
The wastewater concentrator 11 heats the wastewater stored in the treatment tank 16 to evaporate the water content and concentrate the wastewater. As shown in FIG. example), a separation tank 17 (an example of the second tank of the present invention), a water level tank 18 (an example of the first tank of the present invention), a first heater 22, a second heater 23, and a blower , a discharge pump 29 (an example of the first and second pumps of the present invention), and a control section 100 (see FIG. 2). Here, the control section 100 is an example of the first control section, the second control section, the third control section, the first pump control section, and the second pump control section of the present invention.

The treatment tank 16 is for storing wastewater to be treated. A predetermined amount of wastewater is stored inside the treatment tank 16 . In the process of concentrating the wastewater, the wastewater is stored in the treatment tank 16 so that the water level of the wastewater is between the later-described reference water level H1 (see FIG. 4) and make-up water level H2 (see FIG. 4).

In this embodiment, the wastewater that is stored in the treatment tank 16 and subjected to concentration treatment is, for example, wastewater (so-called industrial wastewater) that is used for industrial production in a factory or the like and discarded after use. As described above, the wastewater contains the A1 type water-soluble cutting fluid specified in JIS K 2241 (hereinafter sometimes simply referred to as "water-soluble cutting fluid"), the metal powder, and water. The A1 water-soluble cutting fluid contains an oil component (mineral oil, fatty oil, etc.), which is an example of a hydrophobic substance that is difficult to dissolve in water, and a surfactant as an emulsifier, and is emulsified by being diluted with water. It becomes a milky white emulsion. The content of the water-soluble cutting fluid in the wastewater is approximately 10 to 20%, and the remainder is mainly water.

Wastewater to be treated is stored in a separately installed wastewater tank 81 . This wastewater tank 81 is connected to the treatment tank 16 by a pipe 81A. The pipe 81A is provided with an electric valve 81B that is electrically driven to open and close, and a supply pump 81C. The supply pump 81C is provided between the waste water tank 81 and the electric valve 81B. The supply pump 81C is an electric pump for supplying wastewater from the wastewater tank 81 to the treatment tank 16 as required. The electric valve 81B and the supply pump 81C are driven and controlled by the control section 100 of the control panel 30 (see FIG. 2). The electric valve 81B is opened under the control of the controller 100, and the supply pump 81C is driven by the controller 100, whereby wastewater is supplied from the wastewater tank 81 to the treatment tank 16. FIG. Further, when the electric valve 81B is closed and the drive of the supply pump 81C is stopped, the supply of waste water is stopped. The electric valve 81B and the supply pump 81C constitute a wastewater supply unit that supplies the wastewater from the wastewater tank 81 to the treatment tank 16. As shown in FIG.

The first heater 22 heats the wastewater stored in the processing tank 16 and is provided in the processing tank 16 . The first heater 22 is of a unit type in which, for example, a gas burner 22A and a first heating control section 22B (see FIG. 2) that controls combustion by the gas burner 22A are integrally configured. The gas burner 22A is provided outside the processing bath 16 and burns gas in a combustion furnace 22C provided inside the processing bath 16 . After combustion, the exhaust gas is sent from the combustion furnace 22C to the exhaust pipe 31 connected to the treatment tank 16, and discharged from the exhaust pipe 31 to the outside.

The combustion furnace 22C is provided below the middle position in the height direction inside the processing tank 16, and is entirely placed in the liquid with the predetermined amount of wastewater stored in the processing tank 16. . The first heater 22 heats the wastewater by being driven by the controller 100 . Specifically, when a drive signal is sent from the control unit 100 to the first heating control unit 22B, the first heating control unit 22B operates the gas burner 22A based on the drive signal to control heating. The first heater 22 may have any configuration as long as it heats the wastewater in the treatment tank 16. Instead of the gas burner 22A or the combustion furnace 22C, an electric heater is used. may be

The air blower 24 (see FIG. 1) is an electrically driven blower. The air blower 24 blows out the steam generated from the waste water in the processing tank 16 by the heating by the first heater 22 from the processing tank 16 to the outside. The air blower 24 is connected to an intermediate duct 14A (see FIG. 1) that is part of the connecting duct 14 by a pipe 24A (see FIG. 1). The intermediate duct 14A is a duct member that extends upward from the upper surface of the processing tank 16. As shown in FIG. The air sent from the air blower 24 is sent into the intermediate duct 14A through the pipe 24A. In this embodiment, the air sent out by the air blower 24 is sent through the pipe 24A in a direction to generate an upward airflow inside the intermediate duct 14A. Gases including steam generated in the processing bath 16 are led to the connecting duct 14 by the air current of the air sent into the intermediate duct 14A, whereby the gas is discharged to the outside of the processing bath 16. As shown in FIG. The gas entering the connecting duct 14 is sent to the decomposition treatment device 12 through the connecting duct 14 .

The second heater 23 is provided in the duct from the treatment tank 16 to the oxidation catalyst 43 of the decomposition treatment apparatus 12, specifically the connection duct 14. As shown in FIG. The second heater 23 heats the gas (steam and air) inside the connecting duct 14 . The second heater 23 is of a unit type in which an electric heater 23A such as a halogen heater and a second heating controller 23B including a driver circuit for driving the electric heater 23A are integrally constructed. The electric heater 23A is provided inside the connection duct 14, and the second heating control section 23B is arranged outside the connection duct 14. As shown in FIG. The second heater 23 heats the gas in the connection duct 14 by being driven by the controller 100 . Specifically, when a drive signal is sent from the control unit 100 to the second heating control unit 23B, the second heating control unit 23B drives the electric heater 23A based on the drive signal to control heating. As long as the second heater 23 heats the gas in the connecting duct 14, it may be of any heating method among resistance heating method, infrared heating method, microwave heating method, dielectric heating method, and induction heating method. may be

A water supply pipe 28 extending from a water supply source (not shown) such as a water supply or a water tank is connected to the treatment tank 16 . The water supply pipe 28 is provided with an electric valve 28A for supplying or stopping water. The electric valve 28A is, for example, an electric ball valve. The control unit 100 of the control panel 30 controls the opening and closing of the electric valve 28A, so that water is supplied from the water supply pipe 28 to the treatment tank 16 as required.

The discharge pump 29 discharges the wastewater stored in the treatment tank 16 to the outside of the treatment tank 16 as needed. In this embodiment, the discharge pump 29 is used to send the surface layer liquid L1 of the wastewater from the treatment tank 16 to the separation tank 17, to send the oil layer L2 in the separation tank 17 to the external tank 82A, and to send the concentrated water in the treatment tank 16. to the external tank 82B. In other words, one discharge pump 29 can be used for the three purposes mentioned above. Thereby, the configuration of the wastewater concentration device 11 can be simplified.

A pipe 84 is connected to the bottom of the processing tank 16, and this pipe 84 is connected to a separately installed external tank 82A (see FIG. 1). The external tank 82A is for storing the oil component recovered from the separation tank 17. As shown in FIG. The discharge pump 29 is provided in the pipe 84 .

Further, the pipe 84 is provided upstream of the discharge pump 29 with an electric valve 84A that is electrically driven to open and close. The electric valve 84A is opened under the control of the control unit 100, and the discharge pump 29 is driven by the control unit 100, whereby the wastewater in the treatment tank 16 is discharged to the outside. Further, when the electric valve 84A is closed and the driving of the discharge pump 29 is stopped, the discharge of the waste water is stopped.

Further, four branch pipes 85 , 86 , 87 , 88 are connected to the pipe 84 . The branch pipe 85 branches from the downstream side of the motor-operated valve 84A, connects to the bottom of the processing tank 16, and connects to a cylindrical portion 61 provided inside the processing tank 16, which will be described later. The branch pipe 85 is provided with an electric valve 85A that is electrically driven to open and close. A path from the branch pipe 85 to the pipe 84 and the branch pipe 87 is an example of the third flow path of the present invention.

The branch pipe 86 is branched from a position downstream of the branch pipe 85 and upstream of the discharge pump 29 and connected to the oil discharge portion 65 provided in the separation tank 17 . The branch pipe 86 is provided with an electric valve 86A that is electrically driven to open and close. The path from the oil discharge portion 65 to the external tank 82A via the branch pipe 86 and the pipe 84 is an example of the fourth flow path of the present invention.

Also, the branch pipe 87 is branched from the downstream side of the discharge pump 29 and connected to the separation tank 17 . At a branch position between the branch pipe 87 and the pipe 84, an electric three-way valve 87A is provided. By controlling the electric three-way valve 87A by the control unit 100, switching is made between a route in which the wastewater flows from the upstream side of the pipe 84 to the downstream side and a route in which the wastewater flows from the pipe 84 to the branch pipe 87.

Also, the branch pipe 88 branches from a position downstream of the electric three-way valve 87A and extends to the external tank 82B adjacent to the external tank 82A. The external tank 82B is for storing the concentrated water discharged from the treatment tank 16 after the concentration treatment. At the branch position between the branch pipe 88 and the pipe 84, an electric three-way valve 88A is provided. By controlling the electric three-way valve 88A by the control unit 100, wastewater flows from the upstream side of the pipe 84 to the downstream side (the side of the external tank 82A), and the wastewater flows from the pipe 84 to the external tank 82B via the branch pipe 88. You can switch to the route to go.

The processing tank 16 is provided with a tubular portion 61 that guides the surface layer liquid L1 near the surface of the wastewater in the processing tank 16 to the bottom of the processing tank 16 and leads it to the branch pipe 85 . The tubular portion 61 extends upward from the bottom of the treatment tank 16 and reaches a predetermined reference water level H1. Here, the reference water level H1 is an example of the first water level of the present invention, and is the upper limit water level at which wastewater is stored in the treatment tank 16 in the process of concentrating the wastewater. Therefore, the upper end of the tubular portion 61 reaches near the liquid level of the wastewater in a state where the wastewater is stored in the processing tank 16 up to the reference water level H1. The lower end of the tubular portion 61 is connected to the bottom surface of the processing bath 16 and communicates with the branch pipe 85 outside thereof. In this state, the electric valve 85A is opened by the control unit 100, the electric three-way valve 87A is switched to the branch pipe 87 side (separation tank 17 side), and the discharge pump 29 is driven. The surface layer liquid L1 is sucked from the separation tank 17 and supplied to the separation tank 17 through the branch pipe 85, the pipe 84, and the branch pipe 87. As shown in FIG. The discharge pump 29, the cylindrical portion 61, and the control portion 100 that enable such supply are an example of the surface layer liquid supply portion of the present invention. Note that the surface layer liquid supply unit of the present invention is not limited to the above-described configuration. (Float collection skimmer) may be used.

Here, as the concentration process by the wastewater concentration device 11 progresses, the oil component, which is the main component of the water-soluble cutting fluid contained in the wastewater, separates from the wastewater and floats to the liquid surface. Therefore, the surface layer liquid L1 contains a large amount of the oil component. In this embodiment, the content of the oil component in the wastewater in the treatment tank 16 is reduced by moving the surface liquid L1 to the separation tank 17 . As a result, when the waste water in the treatment tank 16 is heated, it is possible to suppress the generation of soot and offensive odors caused by the oil component being heated to a high temperature. In addition, even if air bubbles generated from inside the waste water by heating burst on the liquid surface in the treatment tank 16, it is possible to prevent the oil component from scattering around and the oil mist containing the oil component from being sent to the connecting duct 14 together with the steam. .

The separation tank 17 is arranged side by side with the treatment tank 16, and is formed so as to be able to store waste water therein, similarly to the treatment tank 16. As shown in FIG. The separation tank 17 does not have an opening or a duct that communicates with the atmosphere, and is formed in a closed type. As will be described later, the separation tank 17 is used for the purpose of separating the oil layer L2 (see FIG. 1) containing the oil component and floating it to the surface of the liquid by storing waste water containing a large amount of oil component therein. The separation tank 17 has a sufficient capacity as long as it can be used for such purposes, and in the present embodiment, the capacity is smaller than that of the treatment tank 16 .

The water level tank 18 is arranged side by side with the processing tank 16, and, like the processing tank 16, is formed so that waste water can be stored therein. The water level tank 18 does not have an opening or a duct that communicates with the atmosphere, and is formed in a closed type. As will be described later, the water level tank 18 is used for storing waste water therein and measuring the water level of the waste water. The water level tank 18 is sufficient as long as it has a capacity applicable to such uses, and in the present embodiment, the capacity is smaller than that of the treatment tank 16 .

Both the separation tank 17 and the water level tank 18 have the same size in the height direction as the treatment tank 16 and are installed at the same position in the height direction.

As shown in FIG. 1, the lower part of the treatment tank 16 and the lower part of the separation tank 17 are connected by a connecting pipe 51 so that wastewater can flow between the two tanks. Further, the lower part of the separation tank 17 and the lower part of the water level tank 18 are connected by a connecting pipe 52 so that waste water can flow between the two tanks. Thereby, the lower part of the processing tank 16 and the lower part of the water level tank 18 are connected by the connecting pipes 51 and 52 via the separation tank 17 . Here, the connection pipe 51, the separation tank 17, and the connection pipe 52 that connect the treatment tank 16 and the water level tank 18 so that waste water can flow are an example of the first channel of the present invention. Also, the connecting pipe 51 that connects the treatment tank 16 and the separation tank 17 so that the waste water can flow is an example of the second channel and the first communication path of the present invention.

Since the treatment tank 16, the separation tank 17, and the water level tank 18 are connected by the connecting pipes 51 and 52, respectively, when the waste water is supplied to the treatment tank 16, the waste water spreads to each tank. The position (water level) of the liquid surface of the waste water in the tank also becomes the same height.

The upper part of the processing tank 16 and the upper part of the separation tank 17 are connected by a connecting pipe 53, and the upper air layer of the processing tank 16 and the upper air layer of the separation tank 17 are connected by the connecting pipe 52. there is Further, the upper part of the separation tank 17 and the upper part of the water level tank 18 are connected by a connecting pipe 54, and the upper air layer of the separation tank 17 and the upper air layer of the water level tank 18 are connected by the connecting pipe 54. there is The separation tank 17 and the water level tank 18 can communicate with the atmosphere through the treatment tank 16 by connecting pipes 53 and 54 . These connecting pipes 53 and 54 are closed by motor-operated valves 53A and 54A provided in the connecting pipes 53 and 54 when compressed air, which will be described later, is supplied to the water level tank 18. is open.

In the separation tank 17, a capacitive oil level sensor 63 (an example of the second sensor of the present invention, a sensor for measurement) that measures the amount of oil components (floating oil) floating in the upper layer of the wastewater in the separation tank 17 is provided. The oil level sensor 63 has a rod-shaped sensing part and is attached to the side surface of the separation tank 17 with the sensing part horizontally inserted from the side surface of the separation tank 17 . In this embodiment, the sensing part is arranged at a position spaced downward from the liquid surface of the separation tank 17 by a predetermined distance.

As described above, when the surface layer liquid L1 flows into the separation tank 17, the oil component contained in the surface layer liquid L1 floats, and the oil layer L2 containing the oil component is separated near the liquid surface. As the inflow of the surface liquid L1 increases, the oil layer L2 in the separation tank 17 gradually thickens. On the other hand, the components other than the oil component (hydrophilic liquid) stored in the separation tank 17 move to the treatment tank 16 through the connecting pipe 51 . Therefore, even if the surface layer liquid L1 flows into the separation tank 17, the water level of the liquid surface of the separation tank 17 and the water level of the liquid surface of the treatment tank 16 are the same. As the surface layer liquid L1 flows into the separation tank 17, the volume of the oil layer L2 gradually increases, and the interface between the oil layer L2 and the lower liquid layer L3 other than oil components gradually decreases. Then, when the oil layer L2 comes into contact with the sensing part of the oil level sensor 63, the oil level sensor 63 outputs a detection signal indicating that the oil layer L2 in the separation tank 17 has increased to a predetermined set amount. output to By receiving the detection signal, the control unit 100 recognizes that the oil layer L2 exists in the set amount.

The separation tank 17 is provided with an oil discharge section 65 for discharging the oil layer L2 near the liquid surface of the wastewater in the separation tank 17 to the outside of the separation tank 17 . The oil discharge part 65 is a pipe member having one port disposed in the oil layer L2 and the other port disposed outside the separation tank 17 . When the detection signal is input to the control unit 100, the control unit 100 opens the electric valve 86A, switches the electric three-way valves 87A and 88A to the external tank 82A side, and further drives the discharge pump 29. As a result, the oil is sucked from the oil layer L2 and discharged to the branch pipe 86. The oil component is sent to the external tank 82A through the branch pipe 86 and the pipe 84, and collected in the external tank 82A. The oil components collected in the external tank 82A are reused as regenerated fuel (regenerated heavy oil) or regenerated lubricating oil through regeneration processes such as centrifugation and filtration. The oil discharge section 65, the discharge pump 29, and the control section 100, which enable recovery of such oil components, are examples of the surface layer liquid discharge section of the present invention.

The water level tank 18 is provided with a liquid level sensor 34 (an example of the first sensor of the present invention). The liquid level sensor 34 detects the position of the liquid level of the waste water stored in the water level tank 18. Specifically, the liquid level sensor 34 sends a pulse signal toward the liquid level and reflects it from the liquid level. It is a guide pulse type sensor that detects the position of the liquid surface (water level) by receiving it. The liquid level sensor 34 indicates that the liquid level of the wastewater has reached the reference water level H1 (see FIG. 4) set in the water level tank 18, or the make-up water level H2 (see FIG. 4) lower than the reference water level H1. used to detect Here, the make-up water level H2 is an example of the second water level of the present invention.

In this embodiment, the reference water level H1 is set to the water level when 1000 liters of liquid is stored in the treatment tank 16 . Further, the replenishment water level H2 is set to the water level when 900 liters of liquid is stored in the treatment tank 16 . The replenishment water level H2 is a water level used to determine whether or not replenishment of wastewater is necessary due to the reduction of wastewater in the treatment tank 16 due to evaporation. The liquid level sensor 34 sends a detection signal corresponding to the position of the liquid level of the waste water to the control unit 100, and the control unit 100 detects that the level of the detection signal corresponds to the reference water level H1 or the make-up water level H2. , it is determined whether or not the liquid level has reached the reference water level H1 or the replenishment water level H2. For the liquid level sensor 34, for example, a float switch type or a capacitance type can be applied.

By the way, as the wastewater is concentrated, sludge or the like accumulates in the connecting pipes 51 and 52, the flow resistance in the connecting pipes 51 and 52 increases, and the flow of wastewater from the treatment tank 16 to the water level tank 18 is obstructed. In this case, even if the treatment tank 16 is replenished with the amount of wastewater that has decreased due to evaporation, the rise in the liquid level in the water level tank 18 does not quickly follow the rise in the liquid level in the treatment tank 16, and the liquid level sensor The position of the liquid level measured by 34 does not coincide with the position of the liquid level in the processing tank 16 . Also, if the connecting pipes 51 and 52 are clogged with sludge or the like, wastewater will not flow from the treatment tank 16 to the water level tank 18, and the position of the liquid level in the treatment tank 16 cannot be measured accurately.

In addition, as the wastewater is concentrated, the oil component in the wastewater begins to separate, and the oil component flows not only into the treatment tank 16 but also into the water level tank 18, and reaches the liquid surface of the water level tank 18. An oil layer may also appear. When the liquid level sensor 34 is a guide pulse type sensor, when an oil component appears on the liquid surface of the water level tank 18, the liquid level sensor 34 detects the interface with the liquid layer other than the oil component below the oil layer. may be detected as the liquid level of wastewater, resulting in erroneous detection.

For this reason, the wastewater concentrator 11 of the present embodiment supplies compressed air to the water level tank 18 to agitate the wastewater in the water level tank 18 to subdivide the oil component, and the water level tank 18 and the separation tank 17 are used for treatment. It is configured to generate a high water flow in the connecting pipes 51 and 52 communicating with the tank 16 to wash (clean) the connecting pipe 51 .

Specifically, the wastewater concentrator 11 includes an air pipe 71 that connects an externally installed compressed air source (not shown) and the air layer of the water level tank 18 (cavity above the liquid surface of the wastewater). (an example of the air passage of the present invention) is provided. The compressed air source is, for example, a tank in which compressed air of a predetermined pressure is stored, or an air compressor. The air pipe 71 is provided with a solenoid valve 71A (an example of the motor-operated valve of the present invention) for opening or closing the air path in the air pipe 71 . The solenoid valve 71A is operated under the control of the control unit 100 to open and close the air path from the compressed air source to the air layer of the water level tank 18 . By opening the electromagnetic valve 71A from the closed state, compressed air is supplied to the air layer of the water level tank 18, and the waste water in the water level tank 18 is agitated by the compressed air. Moreover, the waste water or compressed air pushed downward by the compressed air moves vigorously to the treatment tank 16 through the connecting pipes 51 and 52 . Note that the electromagnetic valve 71A and the control unit 100 that enable such supply of compressed air are examples of the compressed air supply unit of the present invention.

When compressed air is supplied to the upper air layer of the water tank 18, the connecting pipes 53 and 54 are closed by the electric valves 53A and 54A. Therefore, compressed air does not flow into the separation tank 17 and the treatment tank 16 from the connecting pipes 53 and 54 .

[Decomposition treatment device 12]
The decomposition treatment apparatus 12 is provided on an exhaust gas guide path from the treatment tank 16 to the connection duct 14 and the exhaust duct 44, and includes a cylindrical housing 41, an oxidation catalyst 43, and an exhaust duct 44. ing.

The housing 41 is formed in a cylindrical shape with a circular cross section extending in the vertical direction. One side (entrance side) of the housing 41 is connected to the outlet side of the connection duct 14, allowing the gas guided from the connection duct 14 to flow inside. An exhaust duct 44 is connected to the other side (outlet side) of the housing 41 . The gas (steam) sent from the connection duct 14 is guided upward through the interior of the housing 41 and flows into the exhaust duct 44 . That is, inside the housing 41, an upward airflow is generated.

The oxidation catalyst 43 is provided inside the housing 41 . The oxidation catalyst 43 is a metal catalyst containing platinum as a main component, and is a so-called metal honeycomb catalyst having a honeycomb structure. When the gas containing steam sent from the connecting duct 14 passes through the inside of the honeycomb structure, the persistent substance contained in the gas and the oxidation catalyst 43 undergo an oxidation reaction, and the substance is decomposed. .

[Control panel 30]
The control panel 30 controls the heating of the wastewater in the processing tank 16 by the first heater 22, the heating of the gas (steam or air) by the second heater 23, the wastewater to the processing tank 16 by the supply pump 81C, etc. Supply control, wastewater discharge and circulation control by the discharge pump 29, etc., oil component discharge control for discharging the oil component of the oil layer L2 by the discharge pump 29, etc., compressed air supply control by the solenoid valve 71A, etc. .

As shown in FIG. 2, the control panel 30 is internally provided with a control section 100 such as a sequencer. Further, the housing of the control panel 30 is provided with a liquid crystal monitor 106, an operation unit 107 for manually operating the electromagnetic valve 71A, and the like.

Connected to the control unit 100 are the liquid crystal monitor 106, the operation unit 107, the first heating control unit 22B, the second heating control unit 23B, the electromagnetic valve 71A, various sensors, various pumps including the discharge pump 29, various electric valves, and the like. They are configured to allow mutual communication of signals and data with each other. The liquid crystal monitor 106 displays the water level of the wastewater in the treatment tank 16 based on the output of the liquid level sensor 34 .

The control unit 100 is a computer having a CPU 101, a ROM 102, a RAM 103, an EEPROM 104 (registered trademark), etc., and controls the wastewater treatment system 10 in an integrated manner. A control program is stored in the ROM 102, and the CPU 101 reads out and executes the control program to execute a concentration process, which will be described later. Note that the concentration processing will be described later.

[Concentration processing]
Next, while referring to the state diagrams of FIGS. 4 to 8 and using the flowchart of FIG. 3, an example of the concentration process procedure executed by the control unit 100 of the wastewater concentrator 11 will be described, and the wastewater treatment method will be explained. (including compressed air supply method). Here, FIG. 3 is a flow chart showing an example of the procedure of concentration processing executed by the control unit 100 of the wastewater concentrator 11. As shown in FIG. 4 shows the state of the wastewater concentrator 11 in the wastewater supply process, FIG. 5 shows the state of the wastewater concentrator 11 in the surface liquid removal process, and FIG. 6 shows the state of the wastewater concentrator 11 in the oil recovery process. 7 shows the state of the wastewater concentrator 11 in the compressed air supply process, and FIG. 8 shows the state of the wastewater concentrator 11 in the concentrated water discharge process. Also, S11, S12, . The processing in each step is performed by the control unit 100 , more specifically by the CPU 101 executing the control program in the ROM 102 .

In the following description, for convenience of explanation, the processing tank 16, the separation tank 17, and the water level tank 18 are all empty, the motor-operated valves 53A, 54A are open, and the motor-operated valves 84A, 85A, 86A, 53A are in an open state. is in the closed state and the electromagnetic valve 71A is in the closed position.

In step S<b>11 , the control unit 100 performs a wastewater supply process (wastewater supply step) for supplying wastewater to the treatment tank 16 . Specifically, the control unit 100 controls the electric valve 81B to move the electric valve 81B from the closed position to the open position, and drives the supply pump 81C. Thus, the supply of wastewater from the wastewater tank 81 to the treatment tank 16 is started.

When the wastewater is supplied to the treatment tank 16 by the supply pump 81C, as shown in FIG. Waste water flows into the water level tank 18 through the connecting pipe 52 from the .

After that, when the waste water is stored up to the reference water level H1, the control unit 100 stops supplying the waste water. Specifically, when the control unit 100 determines that the liquid level of the wastewater has reached the reference water level H1 based on the detection signal from the liquid level sensor 34, the control unit 100 returns the electric valve 81B to the closed position, 81C is turned off to stop the wastewater supply.

In the next step S12, the control unit 100 performs a heating evaporation process (heating evaporation step) for heating and evaporating the wastewater stored in the treatment tank 16. FIG. Specifically, the control unit 100 sends a control signal to the first heating control unit 22B to operate the gas burner 22A of the first heater 22 to burn gas in the combustion furnace 22C. At this time, the first heating control unit 22B performs heating control so that the waste water boils and the water content evaporates. The control unit 100 also sends a drive signal to the second heating control unit 23B to drive the electric heater 23A of the second heater 23 . At this time, the second heating control unit 23B controls the heating of the electric heater 23A by PID control so that the inlet temperature of the oxidation catalyst 43 becomes a temperature at which the difficult-to-decompose substances can be oxidized. Further, the control unit 100 drives the air blower 24 to send air into the connection duct 14 . As a result, the water vapor generated in the treatment tank 16 is sucked into the connecting duct 14 , then blown to the housing 41 through the connecting duct 14 and sent to the oxidation catalyst 43 side.

The amount of wastewater stored in the treatment tank 16 is gradually reduced by performing the above-described heat evaporation treatment. When the amount of water stored in the treatment tank 16 decreases and the water level drops, the water levels in the separation tank 17 and the water level tank 18 also drop by the same amount.

The heating and evaporation process is continued until heating is stopped in step S23, which will be described later.

In the next step S13, the controller 100 determines whether or not the water in the treatment tank 16 has decreased to the replenishment water level H2. This determination process is performed based on the detection signal from the liquid level sensor 34 . When the control unit 100 determines that the liquid level of the wastewater has decreased to the make-up water level H2 (YES in S13), the processing of the next step S14 is performed.

In step S14, the control unit 100 performs a wastewater replenishment process (wastewater replenishment step) for replenishing the treatment tank 16 with wastewater. Since this wastewater replenishment process is the same process as the process of step S11 described above, detailed description thereof will be omitted here.

Further, when the wastewater replenishment is completed, the control unit 100 counts up the number of times of replenishment and stores the count value (the number of times of replenishment) in the RAM 103 . After that, in the next step S15, the control unit 100 determines whether or not the number of replenishment times has reached a predetermined set number of times N1 (an example of the set number of times of the present invention). Here, when it is determined that the number of replenishment times has not reached the set number of times N1, the control section 100 returns to step S13 and performs the processes after step S13. On the other hand, when it is determined that the number of times of replenishment has reached the set number of times N1, the control section 100 performs the process of step S16.

The set number of times N1 is determined to be the number of times that oil content appears in the surface layer liquid L1 of the treatment tank 16 as the concentration of the wastewater progresses.

In the next step S16, the control unit 100 performs a surface liquid removing process (surface liquid removing step) in which the surface liquid L1 near the surface of the wastewater in the processing tank 16 is sucked and transferred to the separation tank 17. Specifically, the control unit 100 operates the electric three-way valve 87A from the closed position to the open position in a state where wastewater is stored in the treatment tank 16 up to the reference water level H1, and moves the electric three-way valve 87A to the branch pipe 87 side ( separation tank 17 side), and the discharge pump 29 is driven. As a result, the surface liquid L1 is sucked from the upper end of the cylindrical portion 61 and flows into the separation tank 17 through the branch pipe 85, the pipe 84, and the branch pipe 87. When the surface layer liquid L1 flows into the separation tank 17, the oil component contained in the surface layer liquid L1 rises to the surface, and an oil layer L2 containing the oil component is separated near the liquid surface.

When it is determined that the surface liquid removal process has been performed for a certain period of time, or that a certain amount of the surface liquid L1 has flowed into the separation tank 17, the control unit 100 returns the motor-operated valve 85A to the closed position. The three-way valve 87A is also returned to its original position, the discharge pump 29 is stopped, and the surface liquid removing process is completed.

In the next step S17, the control unit 100 determines whether or not the oil layer L2 in the separation tank 17 exists in a predetermined set amount. Such determination can be made based on the detection signal (measurement result) from the oil level sensor 63 as described above.

When it is determined in step S17 that the oil layer L2 exists in the set amount, the control unit 100 performs an oil recovery process (oil recovery step) of sucking and recovering the oil layer L2 in the separation tank 17 . Specifically, the control unit 100 operates the electric valve 86A from the closed position to the open position, switches the electric three-way valves 87A and 88A to the external tank 82A side, and drives the discharge pump 29 .

As a result, as shown in FIG. 6 , the oil layer L2 in the separation tank 17 is sucked and discharged from the oil discharge portion 65 to the branch pipe 86 . Then, the oil component discharged to the branch pipe 86 is sent to the external tank 82A through the branch pipe 86 and the pipe 84, and recovered in the external tank 82A.

When it is determined that the oil component recovery process has been performed for a certain period of time or the oil component of the oil layer L2 has been recovered in the external tank 82A, the control unit 100 returns the electric valve 86A to the closed position to discharge the oil. The pump 29 is stopped to end the oil recovery process. When the oil recovery process ends, the control unit 100 performs the process of step S19.

On the other hand, when it is determined in step S17 that the oil layer L2 is less than the set amount, the control unit 100 performs the process of step S19 without performing the oil recovery process.

At step S19, the controller 100 determines whether the water in the treatment tank 16 has decreased to the replenishment water level H2. Since this determination process is the same process as the process of step S13 described above, detailed description thereof will be omitted here. In step S19, when the control unit 100 determines that the liquid level of the wastewater has decreased to the make-up water level H2 (YES in S19), the processing of the next step S20 is performed.

In step S20, the control unit 100 determines whether or not the number of replenishments has reached a predetermined set number of times N2 (an example of the set number of times of the present invention). Here, the set number of times N2 is a numerical value larger than the above-described set number of times N1, and is set to the number of times for obtaining the desired concentrated water (for example, waste water with a water content of about 30%). In this embodiment, the set number of times N2 is set to 2000 times. The set number of times N2 is arbitrary, and is determined according to the water content in the wastewater, the volume of the treatment tank 16, the set temperature of the wastewater to be heated (eg, 105° C. in this embodiment), and the like.

When it is determined in step S20 that the number of replenishments is less than the set number of times N2, the control section 100 proceeds to step S21. Further, when it is determined in step S20 that the number of replenishments has reached the set number of times N2, the control section 100 proceeds to step S23.

In step S21, the control unit 100 performs a primary compressed air supply process (primary compressed air supply step) for supplying compressed air to the water level tank 18 for a predetermined set time T1 (an example of the set time of the present invention). That is, the control unit 100 performs the primary compressed air supply process when the number of times of replenishment reaches the set number of times N1 in step S15. Further, the control unit 100 performs the primary compressed air supply process when the number of replenishments reaches the set number of times N1 and the liquid level of the waste water drops from the reference water level H1 to the replenishment water level H2. Specifically, the control unit 100 operates the electric valves 53A and 54A from the open position to the closed position, and operates the solenoid valve 71A from the closed position to the open position. It should be noted that the fact that the number of replenishments has reached the set number of times N1 is an example of a predetermined condition of the present invention. Further, it is an example of the predetermined condition of the present invention that the liquid level of the waste water has decreased from the reference water level H1 to the make-up water level H2.

As a result, as shown in FIG. 7, the compressed air from the compressed air source (not shown) is delivered to the water level tank 18 through the air pipe 71 . The compressed air supplied to the water level tank 18 agitates the waste water in the water level tank 18, subdivides the oil layer floating on the liquid surface, and eventually re-emulsifies the oil. As a result, erroneous detection of the liquid level sensor 34 caused by an oil layer on the liquid surface of the water level tank 18 can be prevented.

Further, by supplying compressed air to the water level tank 18, the waste water in the water level tank 18 is pressed downward, and the waste water in the water level tank 18 passes through the connecting pipe 52, the separation tank 17, and the connecting pipe 51 to the treatment tank. Move to 16 vigorously. As a result, a high water flow is generated in the connecting pipes 51 and 52, and sludge and the like accumulated in the connecting pipes 51 and 52 can be removed. That is, the insides of the connecting pipes 51 and 52 are washed.

When the set time T1 elapses, the control unit 100 returns the motor-operated valves 53A and 54A and the solenoid valve 71A to their original positions, and performs the primary compressed air supply process.

The set time T1 is arbitrary, and for example, it is conceivable to set it to a time proportional to the number of times of replenishment. As the number of replenishments increases, the concentration of the waste water progresses, the oil component in the water level tank 18 increases, and sludge tends to accumulate in the connecting pipes 51 and 52. It is preferable to change the set time T1 to a time corresponding to the number of times of replenishment stored in the RAM 103 when the replenishment is performed.

When the primary compressed air supply process ends, in the next step S22, the control unit 100 performs the same process as the processes in steps S11 and S14 described above, that is, a waste water replenishment process (waste water replenishment process) for replenishing the treatment tank 16 with waste water. process). After that, the control unit 100 returns to step S16 and performs the processes after step S16.

Determining that the number of replenishments is the set number of times N2 in step S20 means that the wastewater in the treatment tank 16 has been sufficiently concentrated. Accordingly, when it is determined that the number of replenishments is the set number of times N2, the control section 100 terminates the heating and evaporation process of step S12 (S23). That is, the control unit 100 stops the first heater 22, the second heater 23, and the air supply blower 24.

Then, in the next step S24, the control unit 100 performs secondary compressed air supply processing (secondary compressed air supply process). That is, the control unit 100 performs the secondary compressed air supply process when the number of times of replenishment reaches the set number of times N2 in step S20. Since the secondary compressed air supply process is the same process as the process of step S20, description thereof will be omitted. It should be noted that the fact that the number of replenishments has reached the set number of times N2 is an example of a predetermined condition of the present invention.

Here, the set time T2 is set for the next time when all the sludge accumulated in the bottoms of the water level tank 18 and the separation tank 17 and the sludge accumulated in the connecting pipes 51 and 52 can be sent into the treatment tank 16. It is set to a time sufficiently longer than the set time T1. Further, in step S24, the secondary compressed air supply process may be intermittently performed multiple times.

Thereafter, in step S25, the control unit 100 performs a concentrated water discharge process (concentrated water discharge step) for discharging the concentrated water accumulated in the treatment tank 16 after the concentration process. Specifically, the control unit 100 operates the electric valve 84A from the closed position to the open position, switches the electric three-way valves 87A and 88A to the external tank 82B side, and drives the discharge pump 29 . As a result, as shown in FIG. 8, the concentrated water is discharged from the bottom of the processing tank 16, passes through the pipe 84 and the branch pipe 88, and is stored in the external tank 82B.

Since the wastewater concentrator 11 is configured as described above, the surface layer liquid L1 of the treatment tank 16 is moved to the separation tank 17 . As a result, the content of the oil component in the wastewater in the treatment tank 16 is reduced. As a result, when the waste water in the treatment tank 16 is heated, it is possible to suppress the generation of soot and offensive odors caused by the temperature of the oil component. In addition, even if air bubbles generated from inside the waste water by heating burst on the liquid surface in the treatment tank 16, it is possible to prevent the oil component from scattering around and the oil mist containing the oil component from being sent to the connecting duct 14 together with the steam. .

In addition, since the water level tank 18 for measuring the water level of the wastewater is provided separately from the treatment tank 16, even if the liquid surface bubbles due to the bubbles generated by heating, the position of the liquid surface in the treatment tank 16 can be accurately determined. can be measured to

Since the compressed air from the compressed air source is sent to the water level tank 18 through the air pipe 71, the waste water in the water level tank 18 is agitated and the oil layer floating on the liquid surface is subdivided. The oil is re-emulsified. As a result, erroneous detection of the liquid level sensor 34 caused by an oil layer on the liquid surface of the water level tank 18 can be prevented.

In addition, the compressed air supplied to the water level tank 18 presses the waste water in the water level tank 18 downward, whereby the waste water in the water level tank 18 passes through the connecting pipe 52, the separation tank 17, and the connecting pipe 51 to the treatment tank 16. move vigorously to As a result, a high water flow is generated in the connecting pipes 51 and 52, and sludge and the like accumulated in the connecting pipes 51 and 52 can be removed.

In the above-described embodiment, an example is described in which the primary compressed air supply process is performed when the number of replenishment times of wastewater reaches the set number of times N1. When the surface drops (displaces) from the initial reference water level H1 to the makeup water level H2, the primary compressed air supply process may be performed before the waste water supply process (S14) is performed. In this case, it is an example of the predetermined condition of the present invention that the liquid level of the wastewater is lowered (displaced) from the initial reference water level H1 to the make-up water level H2.

Further, when the waste water replenishing process in step S14 is performed, if the rate of change of the measured value measured by the liquid level sensor 34 of the water level tank 18 at any time becomes equal to or less than the predetermined reference rate, the A primary compressed air supply process may be performed. In this case, it is an example of the predetermined condition of the present invention that the rate of change of the measured value is equal to or less than a predetermined reference rate.

For example, when wastewater is supplied to the treatment tank 16 when no sludge is accumulated in the connecting pipes 51 and 52, the wastewater smoothly flows into the water level tank 18 through the connecting pipes 51 and 52. The water level 18 rises at approximately the same rate as the actual liquid level change rate in the treatment tank 16 . On the other hand, if the connecting pipes 51 and 52 are clogged with sludge and the flow path is narrowed, the wastewater will not quickly flow into the water tank 18 through the connecting pipes 51 and 52 . In this case, the water level in the water level tank 18 rises at a speed slower than the actual change speed of the liquid level in the treatment tank 16 . Therefore, when the change speed of the measured value of the liquid level sensor 34 is equal to or less than the reference speed, it is considered that sludge is accumulated in the connecting pipes 51 and 52. In this case, the primary compressed air supply process is performed, sludge can be effectively removed from the connecting pipes 51 and 52 . The reference speed is, for example, the rate of change in the measured value when wastewater is replenished with no sludge accumulated in the connecting pipes 51 and 52, or a rate determined based on this rate of change. can be done.

Further, in the above-described embodiment, an example in which the control unit 100 performs the primary compressed air supply process or the secondary compressed air supply process when the above-described predetermined conditions are satisfied has been described. Not limited to configuration. For example, when the operator operates the operation unit of the control panel 30, at the operation timing, the control unit 100 performs the primary compressed air supply process or the compressed air supply process similar to the secondary compressed air supply process. may

Moreover, in the above-described embodiment, the wastewater concentrator 11 provided with the separation tank 17 was illustrated, but the present invention is not limited to the configuration having the separation tank 17 . For example, the present invention can also be applied to a wastewater concentrating device that is not provided with the separation tank 17 and does not have the function of removing the oil layer L2 from the separation tank 17 . In this case, the lower portions of the water level tank 18 and the treatment tank 16 are connected by connecting pipes 52, and the upper portions of the respective tanks are connected by connecting pipes 54. FIG.

In addition, in the above-described embodiment, as an example of the surface layer liquid discharge section, the configuration including the oil discharge section 65, the discharge pump 29, and the control section 100 was illustrated, but the present invention is not limited to this configuration. For example, a floating matter recovery device (floating matter recovery skimmer) that sucks the oil layer L2 while floating on the liquid surface of the wastewater in the separation tank 17 is provided, and the oil component sucked by the floating matter recovery device is separately provided. The present invention can also be applied to a configuration in which the water is sent to the external tank 82A through a pipe.

In the above-described embodiment, the discharge pump 29 serves as both the first and second pumps of the present invention. and for sending the concentrated water in the processing tank 16 to the external tank 82B, and a separately provided discharge pump is used to send the oil layer L2 in the separation tank 17 to the external tank 82A. However, the present invention is applicable.

10: Wastewater treatment system 11: Wastewater concentration device 12: Decomposition treatment device 14: Connection duct 14A: Intermediate duct 16: Treatment tank 17: Separation tank 18: Water level tank 22: First heater 23: Second heater 24: Transfer Air blower 24A: Piping 28: Water supply pipe 28A: Electric valve 29: Discharge pump 30: Control panel 31: Exhaust pipe 34: Liquid level sensor 51-54: Connecting pipe 53A: Electric valve 54A: Electric valve 61: Cylindrical part 63: Oil level sensor 65: Oil discharge part 71: Air pipe 71A: Solenoid valve 81: Waste water tank 81A: Pipe 81B: Electric valve 81C: Supply pump 82A: External tank 82B: External tank 84: Pipe 84A: Electric valve 85~ 88: Branch pipe 85A: Electric valve 86A: Electric valve 87A: Electric three-way valve 88A: Electric three-way valve 100: Control unit 101: CPU
102: ROM
103: RAM
104: EEPROM
106: LCD monitor 107: Operation unit H1: Reference water level H2: Replenishment water level L1: Surface layer liquid L2: Oil layer L3: Liquid layer

Claims (8)

A wastewater treatment apparatus for concentrating wastewater by heating wastewater stored in a storage tank to evaporate water,
a first tank provided side by side with the storage tank;
a first channel connecting the tanks so that the wastewater can flow between the storage tank and the first tank;
a first sensor provided in the first tank for measuring the level of the wastewater stored in the first tank;
a compressed air supply unit that supplies compressed air to the air layer of the first tank to move the wastewater of the first tank to the storage tank through the first flow path. processing equipment. The compressed air supply unit
a motor-operated valve provided in an air passage from a compressed air source to the air layer of the first tank for opening and closing the air passage;
2. The wastewater treatment apparatus according to claim 1, further comprising a first control unit that drives said motor-operated valve from closed to open when a predetermined condition is satisfied. 3. The wastewater treatment apparatus according to claim 2, wherein said first control unit drives said motor-operated valve from closed to open for a predetermined set time when said predetermined condition is satisfied. The predetermined condition is that the liquid level of the wastewater in the storage tank is displaced to a second water level lower than a predetermined first water level, and the number of times the wastewater is replenished to the storage tank is set in advance. or the change rate of the measured value by the first sensor when the waste water is replenished to the storage tank becomes equal to or less than a predetermined reference rate. Or the waste water treatment device according to 3. 5. The wastewater treatment apparatus according to any one of claims 1 to 4, wherein the wastewater contains water and hydrophobic substances having a density lower than that of water. a second tank provided side by side with the storage tank;
a second channel connecting the tanks so that the wastewater can flow between the storage tank and the second tank;
a surface liquid supply unit that sucks the surface liquid near the liquid surface of the wastewater in the storage tank and supplies it to the second tank;
a second sensor that measures the amount of the hydrophobic substance in the second tank;
6. The wastewater treatment apparatus according to claim 5, further comprising a surface liquid discharge unit that sucks and discharges the surface liquid near the liquid surface of the wastewater in the second tank based on the measurement result of the second sensor. . The surface layer liquid supply unit is
a first pump provided in a third flow path from the storage tank to the second tank;
a second control unit that drives the first pump to suck surface liquid near the surface of the wastewater in the storage tank when the wastewater is replenished to a predetermined reference water level in the storage tank; 7. The wastewater treatment system of claim 6, comprising: The surface layer liquid discharge part is
provided in a fourth flow path extending from the second tank, sucking the surface layer liquid near the liquid surface of the wastewater in the second tank and discharging it from the fourth flow path to the outside of the second tank; 2 pumps;
When it is determined that the amount of the hydrophobic substance in the second tank is a predetermined amount based on the measurement result of the second sensor, the second pump is driven to drive the waste water in the second tank. 8. The wastewater treatment apparatus according to claim 6, further comprising a third control section for sucking and discharging the surface layer liquid near the liquid surface.

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