Wet desulphurization wastewater zero discharge treatment device

Abstract

The utility model discloses a zero-discharge treatment device for wet desulfurization wastewater, relates to the field of wastewater treatment, and aims to evaporate and crystallize the wet desulfurization wastewater by using heat of a filter bag type dust collector to realize zero discharge of the wastewater. According to the technical scheme, the wet desulphurization wastewater zero-discharge treatment device comprises a water pump and at least two water receiving plates placed on a top platform of a filter bag type dust collector, the water receiving plates are arranged at intervals and are connected in series through connecting pipes, wastewater can automatically flow to the last-stage water receiving plate from the first-stage water receiving plate, and the water receiving plates are connected in series through connecting pipes. Residual capacity is reserved in each water pan, the last-stage water pan is provided with an overflow pipe, and an outlet of the overflow pipe is connected into the wastewater pool; a water inlet pipe of the water pump is located in the waste water pool, a water outlet pipe of the water pump is connected into the first-stage water pan, a first liquid level switch is arranged in the waste water pool, a second liquid level switch is arranged in the last-stage water pan, and the first liquid level switch and the second liquid level switch are both electrically connected with a motor of the water pump.

Description

Technical Field

[0001] The utility model relates to the field of wastewater treatment, in particular to a treatment device that utilizes the heat of a bag filter to evaporate wet desulfurization wastewater and achieve zero discharge. Background Technique

[0002] At present, the wastewater generated by the wet desulfurization system is simply treated through precipitation, neutralization, and flotation processes to remove suspended solids and heavy metals in the wastewater, and it can only meet the requirements of the effluent water quality control index of the desulfurization wastewater treatment device in the "Water Quality Control Index for Limestone-Gypsum Wet Desulfurization Wastewater in Coal-Fired Power Plants" (DL / T 997-2020). Although the wastewater treated by this process has no solid particles, a large amount of harmful inorganic chlorides are still dissolved in the wastewater. If the wet desulfurization wastewater is not deeply treated but used for spraying roads or directly discharged, it will cause serious soil salinization, resulting in problems such as the inability of vegetation to grow and pollution of groundwater, which are serious environmental pollution problems.

[0003] The aluminum electrolysis flue gas purification system has a bag filter. The top of the dust collector has a platform with a relatively large area (about 500 square meters), and the average temperature on the surface of the platform is about 50 °C throughout the year. The heat of this platform can be fully utilized to evaporate and crystallize the wet desulfurization wastewater, achieving zero discharge of the wet desulfurization wastewater. The position at the top of the dust collector is high, and the load it can bear is not too large, and the wastewater cannot enter the interior of the dust collector, otherwise it will affect the function of the dust collector. Content of the Utility Model

[0004] The utility model provides a zero-discharge treatment device for wet desulfurization wastewater, aiming to utilize the heat of a bag filter to evaporate and crystallize the wet desulfurization wastewater, and achieve zero discharge of the wastewater on the premise of avoiding affecting the function of the dust collector.

[0005] The technical solution adopted by the utility model is: a zero-discharge treatment device for wet desulfurization wastewater, including a water pump and at least two water receiving trays placed on the top platform of the bag filter. Each water receiving tray is arranged at intervals and connected in series through a connecting pipe. The wastewater can flow by gravity from the first-stage water receiving tray to the last-stage water receiving tray, and each water receiving tray has a reserved residual capacity. The last-stage water receiving tray is provided with an overflow pipe, and the outlet of the overflow pipe is connected to a wastewater tank; the water pump is equipped with a motor, the inlet pipe of the water pump is located in the wastewater tank, the outlet pipe of the water pump is connected to the first-stage water receiving tray, a first liquid level switch is arranged inside the wastewater tank, and a second liquid level switch is arranged inside the last-stage water receiving tray. Both the first liquid level switch and the second liquid level switch are electrically connected to the motor of the water pump.

[0006] In order to avoid having various specifications for the water receiving trays, further: each water receiving tray is the same, and the residual capacity of each water receiving tray is the same.

[0007] To reduce the risk of failure of the second liquid level switch, further: the number of water receiving trays is at least four, and 1 to 2 water receiving trays near the last water receiving tray are respectively provided with second liquid level switches, and each second liquid level switch is electrically connected to the motor of the water pump.

[0008] To avoid the risk of wastewater overflowing from parts other than the overflow pipe, further: the diameter of the overflow pipe is not less than the diameter of the water outlet pipe of the water pump.

[0009] To ensure the strength of the overflow pipe, the water inlet pipe and the water outlet pipe of the water pump and adapt to high-temperature conditions, specifically: the overflow pipe, the water inlet pipe and the water outlet pipe of the water pump are all seamless steel pipes.

[0010] The water receiving tray is made of a material that is corrosion-resistant, high-temperature-resistant, has good thermal conductivity and high strength. Specifically: the water receiving tray is made of metal or plastic. For example, the material of the water receiving tray is steel, PPH polypropylene or FRP fiberglass.

[0011] The first liquid level switch and the second liquid level switch are used to reflect the liquid level of the wastewater. Specifically: the first liquid level switch and the second liquid level switch are both float switches.

[0012] To facilitate the control of the water pump, further: flow regulating valves are provided on both the water inlet pipe and the water outlet pipe of the water pump.

[0013] The beneficial effects of the present utility model are as follows: The wet desulfurization wastewater is pumped into the first-stage water receiving tray by the water pump, the wastewater automatically flows to the last-stage water receiving tray, and the wastewater with a residual capacity is retained in each water receiving tray. The excess wastewater flows into the wastewater tank through the overflow pipe. The bag filter heats each water receiving tray to promote the evaporation and crystallization of the wastewater, and finally realizes the zero discharge of the wastewater. The crystalline substances left in each water receiving tray can be cleaned manually. A first liquid level switch is provided in the wastewater tank, and the first liquid level switch is electrically connected to the motor of the water pump, so that the motor of the water pump does not start when there is no wastewater in the wastewater tank, avoiding damage to the water pump and the motor. Each water receiving tray is connected in series through a pipeline, and the wastewater can flow from the first-stage water receiving tray to the last-stage water receiving tray by gravity. As long as there is wastewater in the lowest-positioned water receiving tray, there must be wastewater in other water receiving trays. A second liquid level switch is provided inside the last-stage water receiving tray, and the second liquid level switch is electrically connected to the motor of the water pump. When the wastewater in each water receiving tray has evaporated or is nearly evaporated, the water pump can automatically supplement wastewater to the water receiving tray. Each water receiving tray is placed at intervals on the top platform of the bag filter, and the gravity of each water receiving tray is not concentrated, avoiding excessive load on the top platform of the dust collector caused by the water receiving tray. Each water receiving tray is located outside the dust collector and does not affect the dust removal function of the dust collector. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic diagram of an embodiment of the wet desulfurization wastewater zero-discharge treatment device of the present utility model.

[0015] Reference numerals: water pump 1, top platform 2 of bag filter dust collector, water receiving tray 3, connecting pipe 4, overflow pipe 5, waste water tank 6, first liquid level switch 7, second liquid level switch 8, flow regulating valve 9. Detailed implementation manners

[0016] The present utility model will be further described below with reference to the accompanying drawings.

[0017] As Figure 1 shown, the zero-discharge treatment device for wet desulfurization waste water of the present utility model includes a water pump 1 and at least two water receiving trays 3 placed on the top platform 2 of the bag filter dust collector. The water pump 1 is used to pump waste water into the water receiving trays 3. The water receiving trays 3 are placed on the top platform 2 of the bag filter dust collector. By using the heat of the top platform 2 of the bag filter dust collector, the waste water in the water receiving trays 3 evaporates and crystallizes. Personnel regularly inspect each water receiving tray 3. When there is too much crystallization in the water receiving tray 3, the program is stopped, and then the crystallization is manually cleaned. The water receiving trays 3 are arranged at intervals and connected in series through a connecting pipe 4, and the waste water can flow from the first-stage water receiving tray 3 to the last-stage water receiving tray 3 by gravity. The water receiving trays 3 are made of materials that are corrosion-resistant, high-temperature resistant, good in heat conductivity and high in strength. The water receiving trays 3 can be made of metal or plastic. For example, the material of the water receiving tray 3 is steel, PPH polypropylene or FRP fiberglass. The water receiving trays 3 can be of any shape, such as rectangular. The depth of the water receiving trays 3 should not be too large to avoid the self-weight of the water receiving trays 3 and the weight of the waste water inside exceeding the weight that the top platform 2 of the bag filter dust collector can bear. For example, the depth of the water receiving tray 3 is about 150 mm, which is convenient for the evaporation of the waste water. The connecting pipe 4 can be a feeding pipe or a metal pipe, such as a seamless steel pipe. Each water receiving tray 3 has a reserved residual capacity, and the residual capacity refers to the effective volume of the water receiving tray 3 under the condition of being provided with the connecting pipe 4. The sizes of the water receiving trays 3 are equal or unequal. In order to avoid having multiple specifications for the water receiving trays 3, the water receiving trays 3 are the same, and the residual capacities of the water receiving trays 3 are the same.

[0018] The water pump 1 is equipped with a motor. The inlet pipe of the water pump 1 is located in the waste water tank 6, and the outlet pipe of the water pump 1 is connected to the first-stage water receiving tray 3. The water pump 1 is used to pump the waste water in the waste water tank 6 into the first-stage water receiving tray 3. For example, the water pump 1 is a three-phase asynchronous motor water pump. To facilitate the control of the water pump 1, flow regulating valves 9 are provided on both the inlet pipe and the outlet pipe of the water pump 1. The last-stage water receiving tray 3 is provided with an overflow pipe 5, and the outlet of the overflow pipe 5 is connected to the waste water tank 6, thus forming a circulation channel of waste water tank 6 → water pump 1 → water receiving tray 3 → overflow pipe 5 → waste water tank 6. To avoid the risk of waste water overflowing from parts other than the overflow pipe 5, the diameter of the overflow pipe 5 is not less than that of the outlet pipe of the water pump 1. Each water receiving tray 3 contains waste water with a remaining capacity. At this time, even if the water pump 1 is still pumping waste water into the water receiving tray 3, the waste water can completely flow back into the waste water tank 6 through the overflow pipe 5. To ensure the strength of the overflow pipe 5 and the inlet and outlet pipes of the water pump 1 and to adapt to high-temperature conditions, the overflow pipe 5 and the inlet and outlet pipes of the water pump 1 are preferably metal pipes, such as seamless steel pipes.

[0019] A first liquid level switch 7 is provided inside the waste water tank 6. The first liquid level switch 7 is electrically connected to the motor of the water pump 1. The first liquid level switch 7 is used to reflect the liquid level of the waste water tank 6, and can ensure that the motor of the water pump 1 can only start when there is a certain amount of waste water inside the waste water tank 6. A second liquid level switch 8 is provided inside the last-stage water receiving tray 3. The second liquid level switch 8 is electrically connected to the motor of the water pump 1. The second liquid level switch 8 is used to reflect the liquid level of the corresponding water receiving tray 3. The first liquid level switch 7 and the second liquid level switch 8 can select existing float switches.

[0020] Each water receiving tray 3 is connected in series through pipes, and waste water can flow by gravity from the first-stage water receiving tray 3 into the last-stage water receiving tray 3. As long as there is waste water in the water receiving tray 3 with the lowest position, there must be waste water in other water receiving trays 3. The second liquid level switch 8 is electrically connected to the motor of the water pump 1. When the waste water in each water receiving tray 3 has evaporated or is nearly evaporated, the water pump 1 can automatically replenish waste water to the water receiving tray 3. To reduce the risk of failure of the second liquid level switch 8, the number of water receiving trays 3 is at least four. One or two water receiving trays 3 close to the last-stage water receiving tray 3 are respectively provided with the second liquid level switch 8, and each second liquid level switch 8 is electrically connected to the motor of the water pump 1. For example, in Figure 1In the illustrated embodiment, two water receiving trays 3 close to the last-stage water receiving tray 3 are respectively provided with second liquid level switches 8, that is, the last three-stage water receiving trays 3 are all provided with second liquid level switches 8. When the second liquid level switch 8 of any one of the last three-stage water receiving trays 3 is at the bottom water level and the first liquid level switch 7 in the waste water tank 6 is at the high water level, the water pump 1 is automatically started, and the waste water is injected into the first-stage water receiving tray 3. The waste water fills the water receiving trays one by one until the residual capacity is reached. When the second liquid level switch 8 of any one of the last three-stage water receiving trays 3 is at the high water level, the water pump 1 is automatically stopped. If all the second liquid level switches 8 fail due to faults, the waste water can enter the waste water tank 6 through the overflow pipe 5. When the personnel find that there is waste water overflowing from the overflow pipe 5, the water pump 1 can be stopped and the second liquid level switch 8 can be repaired. When the first liquid level switch 7 in the waste water tank 6 is at the low water level, the water pump 1 will not be automatically started regardless of the position of any second liquid level switch 8. Only when the first liquid level switch 7 in the waste water tank 6 is at the high water level can the water pump 1 be started. When at least one second liquid level switch 8 is at the low water level, the water pump 1 is automatically started.

Claims

1. Wet desulfurization wastewater zero - discharge treatment device, characterized in that: It includes a water pump (1) and at least two water receiving trays (3) placed on the top platform (2) of a bag filter. Each water receiving tray (3) is arranged at intervals and connected in series through a connecting pipe (4). Waste water can flow by gravity from the first-stage water receiving tray (3) to the last-stage water receiving tray (3), and each water receiving tray (3) has a reserved residual capacity. An overflow pipe (5) is provided on the last-stage water receiving tray (3), and the outlet of the overflow pipe (5) is connected to a waste water tank (6); the water pump (1) is equipped with a motor. The inlet pipe of the water pump (1) is located in the waste water tank (6), and the outlet pipe of the water pump (1) is connected to the first-stage water receiving tray (3). A first liquid level switch (7) is arranged inside the waste water tank (6), and a second liquid level switch (8) is arranged inside the last-stage water receiving tray (3). Both the first liquid level switch (7) and the second liquid level switch (8) are electrically connected to the motor of the water pump (1).

2. The zero-emission treatment device for wet desulfurization wastewater according to claim 1, characterized in that: Each water receiving tray (3) is the same, and each water receiving tray (3) has the same residual capacity.

3. The zero-emission treatment device for wet desulfurization wastewater according to claim 1, characterized in that: The number of water receiving trays (3) is at least four. One or two water receiving trays (3) close to the last-stage water receiving tray (3) are respectively provided with a second liquid level switch (8), and each second liquid level switch (8) is electrically connected to the motor of the water pump (1).

4. The zero-emission treatment device for wet desulfurization wastewater according to claim 1, wherein: The diameter of the overflow pipe (5) is not less than the diameter of the outlet pipe of the water pump (1).

5. The zero-emission treatment device for wet desulfurization wastewater according to claim 1, wherein: The overflow pipe (5), as well as the inlet pipe and outlet pipe of the water pump (1), are all seamless steel pipes.

6. The zero-emission treatment device for wet desulfurization wastewater according to any one of claims 1 to 5, characterized in that: The water receiving tray (3) is made of metal or plastic.

7. The zero-emission treatment device for wet desulfurization wastewater according to claim 6, characterized in that: The material of the water receiving tray (3) is steel, PPH polypropylene or FRP fiberglass.

8. The zero-emission treatment device for wet desulfurization wastewater according to any one of claims 1 to 5, characterized in that: Both the first liquid level switch (7) and the second liquid level switch (8) are float switches.

9. The zero-discharge treatment device for wet desulfurization wastewater according to any one of claims 1 to 5, characterized in that: Flow regulating valves (9) are provided on both the inlet pipe and the outlet pipe of the water pump (1).

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