Wastewater treatment system and method

Abstract

The present invention relates to the field of wastewater treatment technology and provides a wastewater treatment system and method. The wastewater treatment system includes a wastewater tank, a distillation tower, a clean water tank, and a clean water tower. The distillation tower is connected to the wastewater tank via a first liquid supply line and a first liquid return line, respectively. The distillation tower is provided with a heating device. The clean water tower is connected to the clean water tank via a second liquid supply line and a second liquid return line, respectively. The top of the distillation tower is connected to the top of the clean water tower via a steam line, and the steam line is provided with an exhaust valve and a fifth valve. The wastewater treatment system and method provided by the present invention can perform water supply and drainage operations on the wastewater tower and the clean water tower. The deadweight of the wastewater in the distillation tower and the clean water in the clean water tower are used to create a negative pressure environment in the distillation tower and the clean water tower, respectively, replacing a vacuum pump to maintain the negative pressure environment. This can effectively reduce the energy consumption required to maintain the negative pressure environment, avoid vacuum pump failure, and other situations, thereby improving wastewater treatment efficiency and reducing repair and maintenance costs.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and in particular to a wastewater treatment system and method. Background Art

[0002] With the acceleration of industrialization, many production fields such as printing and dyeing, papermaking, chemicals, pesticides, oil production, and seafood processing will produce high-salt wastewater. High-salt wastewater refers to wastewater with a total salt content of at least 1%. This wastewater contains a variety of substances (including salt, oil, organic heavy metals and radioactive substances). Direct discharge of these wastewaters causes serious pollution and damage to the environment. Removing organic pollutants from saline wastewater is crucial to the environment. In view of the complex water quality components, high salinity and difficulty in treatment of high-salt wastewater, low-temperature vacuum distillation is generally used to treat high-salt wastewater and desalinate it.

[0003] Existing vacuum distillation technology requires the use of a vacuum pump to create a vacuum (negative pressure) environment, but using a vacuum pump to create a vacuum environment has many defects. First, the vacuum pump requires a lot of energy to maintain the vacuum. Second, the vacuum pump will inevitably inhale condensable gases during the distillation process, causing the vacuum pump to easily malfunction and shorten its lifespan. Summary of the Invention

[0004] The present invention provides a wastewater treatment system and method, which are used to solve the problems in the prior art of high energy consumption when maintaining a vacuum environment through a vacuum pump and the vacuum pump being prone to failure.

[0005] The present invention provides a wastewater treatment system, comprising:

[0006] wastewater ponds;

[0007] a distillation tower, the distillation tower being connected to the wastewater tank via a first liquid supply line and a first liquid return line, the first liquid supply line being provided with a first valve and a wastewater pump, the first liquid return line being provided with a second valve, and the distillation tower being provided with a heating device for heating the wastewater in the distillation tower;

[0008] clear pool;

[0009] a clean water tower, the clean water tower being connected to the clean water tank through a second liquid supply pipeline and a second liquid return pipeline, the second liquid supply pipeline being provided with a third valve and a clean water pump, and the second liquid return pipeline being provided with a fourth valve;

[0010] The top of the distillation tower is connected to the top of the clean water tower through a steam pipeline. The steam pipeline is provided with an exhaust valve and a fifth valve. The fifth valve is used to control the on-off of the steam pipeline.

[0011] According to a wastewater treatment system provided by the present invention, it also includes a pressure differential sensor and a control module. The pressure differential sensor is used to measure the air pressure difference between the distillation tower and the clean water tower. The fifth valve is a pneumatic switch valve. The control module is respectively connected to the pressure differential sensor and the fifth valve. The control module is used to control the opening and closing of the fifth valve according to the detection signal of the pressure differential sensor.

[0012] According to a wastewater treatment system provided by the present invention, the heating device includes a heating layer and a heating element, the heating layer is arranged on the outside of the distillation tower, the heating element is located between the heating layer and the outer wall of the distillation tower, and the heating element is wound around the distillation tower.

[0013] According to a wastewater treatment system provided by the present invention, the heating element includes a heating coil, and the heating coil is spirally wound around the distillation tower.

[0014] According to a wastewater treatment system provided by the present invention, the end of the heating coil located at the bottom serves as a fluid inlet, and the end located at the top serves as a fluid outlet.

[0015] A wastewater treatment system provided according to the present invention further includes a steam supply device, which is connected to the heating coil and is suitable for supplying steam to the heating coil.

[0016] According to a wastewater treatment system provided by the present invention, the heating element includes a heating wire, and the heating wire is spirally wound around the distillation tower.

[0017] A wastewater treatment system provided according to the present invention further includes a solar power supply device, which is electrically connected to the heating wire.

[0018] The present invention also provides a wastewater treatment method using the above wastewater treatment system, comprising:

[0019] Open the exhaust valve, the first valve, the third valve, the wastewater pump and the clean water pump to pump the wastewater in the wastewater tank into the distillation tower, and pump the clean water in the clean water tank into the clean water tower;

[0020] closing the exhaust valve, the first valve, the third valve, the wastewater pump, and the clean water pump, and opening the second valve and the fourth valve, so that part of the wastewater in the distillation tower and part of the clean water in the clean water tower flow back into the distillation tower and the clean water tower under the action of gravity to form a negative pressure;

[0021] The waste water in the distillation tower is heated, and the fifth valve is controlled to open and close so that the steam in the distillation tower enters the fresh water tower for condensation.

[0022] According to a wastewater treatment method provided by the present invention, controlling the opening and closing of the fifth valve includes:

[0023] Detecting the pressure difference between the distillation tower and the water purification tower;

[0024] Determining whether the air pressure difference value reaches a first threshold;

[0025] If yes, control the fifth valve to open;

[0026] If not, the fifth valve is controlled to be closed.

[0027] The wastewater treatment system and method provided by the present invention can perform water supply and discharge operations on the wastewater tower and the clean water tower through the cooperation of the first liquid supply pipeline, the first liquid return pipeline, the second liquid supply pipeline, the second liquid return pipeline and the exhaust valve, and utilize the dead weight of the wastewater in the distillation tower and the clean water in the clean water tower to form a negative pressure environment in the distillation tower and the clean water tower respectively, replacing the vacuum pump to maintain the negative pressure environment. It can effectively reduce the energy consumption required to maintain the negative pressure environment, avoid the occurrence of vacuum pump failure, etc., which is conducive to improving wastewater treatment efficiency and reducing repair and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 This is a schematic diagram of the overall structure of a wastewater treatment system provided by the present invention;

[0030] Reference numerals:

[0031] 1. Wastewater tank; 2. Wastewater pump; 3. First valve; 4. Second valve; 5. Fluid outlet; 6. Fluid inlet; 7. Heating layer; 8. Distillation tower; 9. Clean water tower; 10. Steam pipeline; 11. Exhaust valve; 12. Fifth valve; 13. Pressure differential sensor; 14. Third valve; 15. Clean water pump; 16. Clean water tank; 17. Fourth valve. DETAILED DESCRIPTION

[0032] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0033] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0034] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on the specific circumstances.

[0035] In the embodiments of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," or "below" a second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0036] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0037] The following combination Figure 1A wastewater treatment system according to an embodiment of the present invention is described, comprising a wastewater tank 1, a distillation tower 8, a clean water tank 16, and a clean water tower 9. The distillation tower 8 is connected to the wastewater tank 1 via a first liquid supply line and a first liquid return line, respectively. A first valve 3 and a wastewater pump 2 are provided on the first liquid supply line, and a second valve 4 is provided on the first liquid return line. The distillation tower 8 is provided with a heating device for heating the wastewater in the distillation tower 8. The clean water tower 9 is connected to the clean water tank 16 via a second liquid supply line and a second liquid return line, respectively. A third valve 14 and a clean water pump 15 are provided on the second liquid supply line, and a fourth valve 17 is provided on the second liquid return line. The top of the distillation tower 8 is connected to the top of the clean water tower 9 via a steam line 10. An exhaust valve 11 and a fifth valve 12 are provided on the steam line 10. The fifth valve 12 is used to control the on / off of the steam line 10.

[0038] In the embodiment of the present invention, the first valve 3 on the first liquid supply pipeline is connected in series with the waste water pump 2, the third valve 14 in the second liquid supply pipeline is connected in series with the clean water pump 15, and the first return liquid pipeline and the first liquid supply pipeline, as well as the second return liquid pipeline and the second liquid supply pipeline, are arranged in parallel.

[0039] The wastewater treatment system of the embodiment of the present invention can create a negative pressure environment in the distillation tower 8 and the clean water tower 9 in the following manner: first, open the first valve 3, the third valve 14 and the exhaust valve 11, close the second valve 4 and the fourth valve 17, start the wastewater pump 2 and the clean water pump 15, and the water in the wastewater tank 1 can be pumped into the distillation tower 8 through the first liquid supply pipeline, and the water in the clean water tank 16 can be pumped into the clean water tower 9 through the second liquid supply pipeline. When the water levels in the distillation tower 8 and the clean water tower 9 reach a preset height, the first valve 3, the third valve 14, the exhaust valve 11, the wastewater pump 2 and the clean water pump 15 are closed, and the second valve 4 and the fourth valve 17 are opened. The wastewater in the distillation tower 8 flows back to the wastewater tank 1 through the first return liquid pipeline under the action of gravity, and the wastewater in the clean water tower 9 flows back to the clean water tank 16 through the second return liquid pipeline under the action of gravity. Since the exhaust valve 11 is closed, air cannot be added to the distillation tower 8 and the clean water tower 9, so a negative pressure can be formed in the distillation tower 8 and the clean water tower 9.

[0040] In the above scheme, the weight of the water can be used to create a negative pressure environment in the distillation tower 8 and the water purification tower 9. Moreover, since the remaining water in the distillation tower 8 and the water purification tower 9 is always affected by gravity, the negative pressure environment in the distillation tower 8 and the water purification tower 9 can be continuously maintained.

[0041] When distillation tower 8 and clean water tower 9 are under negative pressure, heating the wastewater in distillation tower 8 can increase the vaporization of water in distillation tower 8, raising the pressure in distillation tower 8 to a higher level than in clean water tower 9. Opening fifth valve 12 allows water vapor from distillation tower 8 to flow into clean water tower 9. Once inside clean water tower 9, the temperature of the water vapor decreases, causing some of the vapor to liquefy, resulting in distilled water. As water from distillation tower 8 flows into clean water tower 9, the water content in distillation tower 8 decreases. Under the negative pressure at the top of distillation tower 8, water from the wastewater tank can be replenished into distillation tower 8 through the first return line. Furthermore, the water vapor flowing from distillation tower 8 into clean water tower 9, after condensation, slowly flows under gravity into clean water tank 16.

[0042] In some embodiments of the present invention, the wastewater treatment system also includes a differential pressure sensor 13 and a control module. The differential pressure sensor 13 is used to measure the air pressure difference between the distillation tower 8 and the clean water tower 9. The fifth valve 12 is a pneumatic switch valve. The control module is connected to the differential pressure sensor 13 and the fifth valve 12 respectively. The control module is used to control the opening and closing of the fifth valve 12 according to the detection signal of the differential pressure sensor 13.

[0043] Optionally, the control module includes a first controller and a solenoid valve, the input end of the first controller is electrically connected to the pressure differential sensor 13, the output end of the first controller is electrically connected to the solenoid valve, the solenoid valve is arranged on the gas source pipeline of the fifth valve 12, and the first controller is configured to control the solenoid valve to close when the pressure differential value detected by the pressure differential sensor 13 does not reach a first preset value, thereby closing the fifth valve 12, and to control the solenoid valve to open when the pressure differential value detected by the pressure differential sensor 13 reaches the first preset value, thereby opening the fifth valve 12.

[0044] In the above solution, the opening and closing of fifth valve 12 can be controlled based on the pressure differential between distillation tower 8 and clean water tower 9. When the pressure differential does not reach a first preset value, steam in distillation tower 8 does not enter clean water tower 9 through the steam pipe. This prevents the distillation tower 8 and clean water tower 9 from being constantly connected, which would cause the temperature in clean water tower 9 to rise and affect the condensation effect.

[0045] According to an embodiment of the present invention, the wastewater treatment system includes a heating device comprising a heating layer 7 and a heating element. The heating layer 7 is disposed outside a distillation tower 8, and the heating element is located between the heating layer 7 and the outer wall of the distillation tower 8. The heating element is wound around the distillation tower 8. The heating element can provide heat to the distillation tower 8, thereby increasing the temperature within the distillation tower 8.

[0046] Optionally, the heating layer 7 is made of heat-insulating material to reduce external heat loss.

[0047] In an optional embodiment, the heating element includes a heating coil. When a fluid medium is passed through the heating coil, the fluid medium transfers its temperature to the distillation tower 8 to heat the distillation tower 8. The heating coil is spirally wound around the distillation tower 8, thereby achieving more uniform heating of the distillation tower 8.

[0048] Optionally, the bottom end of the heating coil serves as the fluid inlet 6 , and the top end serves as the fluid outlet 5 , which can achieve a better heating effect.

[0049] Optionally, the wastewater treatment system further comprises a steam supply device, the fluid inlet 6 of the heating coil is connected to the outlet of the steam generator, the fluid outlet 5 of the heating coil is connected to the inlet of the steam generator, and the steam supply device is suitable for supplying steam to the heating coil.

[0050] In some embodiments of the present invention, the heating element includes a heating wire, which is spirally wound around the distillation tower 8. The heating wire generates heat when connected to a power source, thereby heating the distillation tower 8.

[0051] Optionally, the wastewater treatment system further comprises a solar power supply device, which is electrically connected to the heating wire and utilizes solar power generation to provide electrical energy to the heating wire, thereby reducing energy consumption.

[0052] It should be noted that the heating element in the embodiments of the present invention includes at least one of a heating coil and a heating wire. That is, the heating wire and the heating coil can be installed simultaneously or alternatively. Preferably, the heating element includes the heating coil and the heating wire, and both the heating coil and the heating wire are spirally structured and staggered.

[0053] Optionally, the wastewater treatment system further includes a temperature measuring device, wherein a detection end of the temperature measuring device is located in the distillation tower 8 and is used to detect the temperature of the liquid in the distillation tower 8 .

[0054] Optionally, the temperature measuring device includes a temperature sensor, a second controller and an alarm. The temperature sensor is arranged in the distillation tower 8 and is used to measure the temperature value in the distillation tower 8. The input end of the second controller is electrically connected to the temperature sensor, and the output end of the second controller is electrically connected to the alarm. The second controller is configured to control the alarm to sound an alarm when the temperature value in the distillation tower 8 is lower than the second threshold and / or higher than the third threshold, wherein the second threshold is lower than the third threshold.

[0055] Optionally, the temperature measuring device is connected to a control circuit of the heating element so as to control the operation of the heating element according to the measurement result of the temperature measuring device.

[0056] An embodiment of the present invention further provides a wastewater treatment method using the above wastewater treatment system, comprising:

[0057] S100, open the exhaust valve 11, the first valve 3, the third valve 14, the wastewater pump 2 and the clean water pump 15, pump the wastewater 2 in the wastewater tank 1 into the distillation tower 8, and pump the clean water 15 in the clean water tank 16 into the clean water tower 9.

[0058] In this step, since the exhaust valve 11 is opened, the air in the distillation tower 8 and the clean water tower 9 can be discharged when water is delivered by the waste water pump 2 and the clean water pump 15, thereby preventing the air in the distillation tower 8 and the clean water tower 9 from being squeezed.

[0059] S200, close the exhaust valve 11, the first valve 3, the third valve 14, the wastewater pump 2 and the clean water pump 15, and open the second valve 4 and the fourth valve 17, so that part of the wastewater in the distillation tower 8 and part of the clean water in the clean water tower 9 flow back under the action of gravity to form a negative pressure in the distillation tower 8 and the clean water tower 9.

[0060] S300 , heating the wastewater in the distillation tower 8 , and controlling the opening and closing of the fifth valve 12 to allow the steam in the distillation tower 8 to enter the clean water tower 9 for condensation.

[0061] During this step, since negative pressure is already established within distillation tower 8 and clean water tower 9, heating distillation tower 8 can rapidly vaporize the water within distillation tower 8. The heating temperature, slightly above ambient temperature (the temperature within clean water tower 9), can be reduced energy consumption and contribute to cost savings. During the heating process of the wastewater within distillation tower 8, a temperature sensor can be used to monitor the temperature within distillation tower 8. The operation of the heating device is controlled based on the temperature of the wastewater within distillation tower 8, thereby maintaining the temperature of the wastewater within distillation tower 8 within a suitable range.

[0062] According to the wastewater treatment method of the embodiment of the present invention, controlling the opening and closing of the fifth valve 12 in step S300 includes:

[0063] S310, detecting the pressure difference between the distillation tower 8 and the water purification tower 9;

[0064] S320, determining whether the air pressure difference value reaches a first threshold;

[0065] S330: If yes, control the fifth valve 12 to open;

[0066] S340: If not, control the fifth valve 12 to close.

[0067] It should be noted that there is no particular order for step S330 and step S340 in the embodiment of the present invention.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A wastewater treatment system, characterized in that: include: wastewater ponds; a distillation tower, the distillation tower being connected to the wastewater tank via a first liquid supply line and a first liquid return line, the first liquid supply line being provided with a first valve and a wastewater pump, the first liquid return line being provided with a second valve, and the distillation tower being provided with a heating device for heating the wastewater in the distillation tower; clear pool; a clean water tower, the clean water tower being connected to the clean water tank through a second liquid supply pipeline and a second liquid return pipeline, the second liquid supply pipeline being provided with a third valve and a clean water pump, and the second liquid return pipeline being provided with a fourth valve; The top of the distillation tower is connected to the top of the clean water tower through a steam pipeline. The steam pipeline is provided with an exhaust valve and a fifth valve, and the fifth valve is used to control the on-off of the steam pipeline. The heating device includes a heating layer and a heating element, wherein the heating layer is arranged outside the distillation tower, the heating element is located between the heating layer and the outer wall of the distillation tower, and the heating element is wound around the distillation tower; It also includes a pressure differential sensor and a control module. The pressure differential sensor is used to measure the air pressure difference between the distillation tower and the water purification tower. The fifth valve is a pneumatic switch valve. The control module is connected to the pressure differential sensor and the fifth valve respectively. The control module is used to control the opening and closing of the fifth valve according to the detection signal of the pressure differential sensor.

2. The wastewater treatment system according to claim 1, characterized in that The heating element includes a heating coil, and the heating coil is spirally wound on the distillation tower.

3. The wastewater treatment system according to claim 2, characterized in that The end of the heating coil located at the bottom serves as a fluid inlet, and the end located at the top serves as a fluid outlet.

4. The wastewater treatment system according to claim 2, characterized in that It also includes a steam supply device, which is connected to the heating coil and is suitable for supplying steam to the heating coil.

5. The wastewater treatment system according to any one of claims 2 to 4, characterized in that: The heating element includes a heating wire, and the heating wire is spirally wound around the distillation tower.

6. The wastewater treatment system according to claim 5, characterized in that: It also includes a solar power supply device, which is electrically connected to the heating wire.

7. A wastewater treatment method using the wastewater treatment system according to any one of claims 1 to 6, characterized in that: include: Open the exhaust valve, the first valve, the third valve, the wastewater pump and the clean water pump to pump the wastewater in the wastewater tank into the distillation tower, and pump the clean water in the clean water tank into the clean water tower; closing the exhaust valve, the first valve, the third valve, the wastewater pump, and the clean water pump, and opening the second valve and the fourth valve, so that part of the wastewater in the distillation tower and part of the clean water in the clean water tower flow back into the distillation tower and the clean water tower under the action of gravity to form a negative pressure; The waste water in the distillation tower is heated, and the fifth valve is controlled to open and close so that the steam in the distillation tower enters the fresh water tower for condensation.

8. The wastewater treatment method according to claim 7, characterized in that: The controlling the opening and closing of the fifth valve comprises: Detecting the pressure difference between the distillation tower and the water purification tower; Determining whether the air pressure difference value reaches a first threshold; If yes, control the fifth valve to open; If not, the fifth valve is controlled to be closed.

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