Desulfurization wastewater treatment system

Abstract

The invention discloses a desulfurization wastewater treatment system, comprising: a gypsum cyclone provided with an overflow port; the buffer box is internally provided with a buffer cavity, the buffer box is provided with an inlet and an outlet which are respectively communicated with the buffer cavity, and the inlet of the buffer box is communicated with the overflow port; the solid-liquid separation device is provided with a feed port and a discharge port, and the feed port of the solid-liquid separation device is communicated with the outlet of the buffer tank; a containing cavity is formed in the clear water tank, at least one opening communicated with the containing cavity is formed in the clear water tank, and the opening of the clear water tank is communicated with the discharging opening of the solid-liquid separation device; wastewater in the gypsum cyclone flows into the buffer tank through the overflow port to be buffered and then enters the solid-liquid separation device through the buffer tank to be subjected to solid-liquid separation, and clear liquid obtained after solid-liquid separation enters the clear water tank. The invention discloses a desulfurization wastewater treatment system, which can effectively solve the problem of how to quickly separate clear liquid from desulfurization slurry under the condition of not adding chemicals.

Description

Technical Field

[0001] The present application relates to the technical field of zero-discharge pretreatment of desulfurization wastewater from thermal power plants, and more specifically, to a desulfurization wastewater treatment system. Background Art

[0002] With increasing environmental protection requirements, many thermal power plants have installed zero-discharge wastewater systems. To prevent scaling and excessive dust buildup in these systems, these systems require an inlet solids content of no more than 1%, with some even requiring no more than 0.55%. To achieve these goals, existing zero-discharge wastewater systems are almost all equipped with pretreatment equipment.

[0003] While existing pretreatment devices can reduce the solids content of wastewater, they require additional dosing during the pretreatment process. For example, traditional triple-tank, cyclone, and reactor bed solutions all require dosing, incurring additional costs and storage space. Even when dosing isn't necessary, a static stand is still required. This requires very large containers for static stand, and the solid-liquid separation process takes a very long time, resulting in low wastewater treatment efficiency.

[0004] Therefore, a new desulfurization wastewater treatment system is urgently needed to solve the above problems. Summary of the Invention

[0005] In view of this, the purpose of this application is to propose a desulfurization wastewater treatment system that can effectively solve the problem of how to quickly separate clear water from desulfurization slurry without adding chemicals.

[0006] Based on the above purpose, the present application provides a desulfurization wastewater treatment system, comprising:

[0007] A gypsum cyclone, wherein the gypsum cyclone is provided with an overflow port;

[0008] A buffer box, wherein a buffer cavity is provided in the buffer box, an inlet and an outlet are provided on the buffer box, respectively connected to the buffer cavity, and the inlet of the buffer box is connected to the overflow port;

[0009] A solid-liquid separation device, wherein the solid-liquid separation device is provided with a feed port and a discharge port, and the feed port of the solid-liquid separation device is connected to the outlet of the buffer tank;

[0010] A clean water tank, wherein a receiving cavity is provided in the clean water tank, and at least one opening is provided on the clean water tank, which is in communication with the receiving cavity, and the opening of the clean water tank is in communication with the discharge port of the solid-liquid separation device;

[0011] The wastewater in the gypsum cyclone flows into the buffer tank through the overflow port for buffering, and then enters the solid-liquid separation device through the buffer tank for solid-liquid separation. The clear liquid after solid-liquid separation enters the clean water tank.

[0012] Optionally, the height of the buffer tank is lower than the height of the overflow port; the height of the solid-liquid separation device is lower than the height of the buffer tank; and the height of the clean water tank is lower than the height of the solid-liquid separation device.

[0013] Optionally, the height of the buffer tank is lower than the height of the overflow port; a first delivery pump is provided between the buffer tank and the solid-liquid separation device, and wastewater is delivered from the buffer tank to the solid-liquid separation device via the first delivery pump; the height of the clean water tank is lower than the height of the solid-liquid separation device.

[0014] Optionally, the first delivery pump includes one of a high-pressure screw pump, a centrifugal pump, and a submersible pump.

[0015] Optionally, the gypsum cyclone is provided with a gypsum overflow slurry tank, and the gypsum overflow slurry tank is the buffer tank; or the gypsum cyclone is provided with a gypsum overflow slurry tank, and the buffer tank includes the gypsum overflow slurry tank.

[0016] Optionally, the solid-liquid separation device includes one of a plate and frame filter press and a centrifugal dehydrator.

[0017] Optionally, the desulfurization wastewater treatment system further includes a wastewater discharge device, which is connected to the clean water tank.

[0018] Optionally, the wastewater discharge device includes at least one of a triple-effect evaporation device or a flue gas concentration device.

[0019] Optionally, the height of the wastewater discharge device is lower than that of the clean water tank; or a second delivery pump is provided between the wastewater discharge device and the clean water tank, and the clean liquid is delivered from the clean water tank to the wastewater discharge device via the second delivery pump.

[0020] In addition, optionally, the second delivery pump includes one of a clean water pump, a centrifugal pump, and a vane pump.

[0021] As can be seen from the above, the desulfurization wastewater treatment system provided by the present application has the following advantages compared with the prior art: on the one hand, it can effectively solve the problem of how to quickly separate the clear water from the desulfurization slurry without adding medicine, which can effectively avoid adding medicine and reduce the cost of medicine consumption; at the same time, it can also effectively avoid long-term standing and speed up the water discharge speed. Moreover, it can also efficiently separate the suspended matter in the wastewater and retain the chloride ions in the clear liquid, thereby completing the chlorine removal task. On the other hand, water is taken directly from the overflow outlet of the gypsum cyclone 1, omitting the wastewater cyclone and the supporting wastewater cyclone pump, reducing part of the wastewater treatment equipment and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above features and technical advantages of the present application will become clearer and easier to understand through the following description of its embodiments in conjunction with the accompanying drawings.

[0023] Figure 1 This is a schematic diagram of the structure of the desulfurization wastewater treatment system used in the specific embodiment of this application.

[0024] Wherein the accompanying drawings are:

[0025] 1: Gypsum cyclone; 11: Overflow port; 2: Buffer tank; 3: First delivery pump; 4: Solid-liquid separation device; 5: Clean water tank; 6: Second delivery pump; 7: Wastewater discharge device. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of this application more clearly understood, the present application is further described below in conjunction with specific embodiments and with reference to the accompanying drawings. Identical parts are denoted by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings. The terms "inward" and "outward" refer to directions toward or away from the geometric center of a particular component, respectively.

[0027] Figure 1 This is a schematic diagram of the structure of the desulfurization wastewater treatment system used in the specific embodiment of this application, as shown in FIG. Figure 1 As shown, the desulfurization wastewater treatment system includes: a gypsum cyclone 1, a buffer tank 2, a solid-liquid separation device 4 and a clean water tank 5.

[0028] The gypsum cyclone 1 is provided with an overflow port 11 ; solid-containing wastewater (such as desulfurization wastewater to be treated) flows out of the gypsum cyclone 1 through the overflow port 11 .

[0029] The buffer box 2 is provided with a buffer cavity, and is provided with an inlet and an outlet respectively connected to the buffer cavity. The inlet of the buffer box 2 is connected to the overflow port 11. The solid wastewater enters the buffer cavity from the inlet and flows out from the outlet, and a buffering operation can be performed in the buffer cavity to achieve preliminary separation of solid and liquid.

[0030] The solid-liquid separation device 4 is provided with a feed port and a discharge port, and the feed port of the solid-liquid separation device 4 is connected to the outlet of the buffer tank 2; the buffered wastewater enters the solid-liquid separation device 4 from the feed port and flows out from the discharge port, and solid-liquid separation can be performed in the solid-liquid separation device 4.

[0031] A accommodating cavity is provided in the clean water tank 5 , and at least one opening communicating with the accommodating cavity is provided on the clean water tank 5 . The opening of the clean water tank 5 is communicated with the discharge port of the solid-liquid separation device 4 ; the opening of the clean water tank 5 can be used as both an inlet and an outlet.

[0032] The wastewater in the gypsum cyclone 1 flows into the buffer tank 2 through the overflow port 11 for buffering, and then enters the solid-liquid separation device 4 through the buffer tank 2 for solid-liquid separation. The clear liquid after solid-liquid separation enters the clean water tank 5.

[0033] Compared to traditional systems that require dosing, desulfurization wastewater treatment systems do not require dosing, eliminating both drug costs and storage space. Compared to traditional static sedimentation separation systems, desulfurization wastewater treatment systems can rapidly achieve solid-liquid separation, eliminating the need for large sedimentation vessels and prolonged static periods. They can also effectively dechlorinate desulfurization wastewater, avoiding the additional expense of treating pollutants such as heavy metals and COD (Chemical Oxygen Demand). COD is a chemical reaction that measures the oxygen equivalent consumed by the reducing inorganic and organic matter (usually organic matter) in a water sample that needs to be oxidized. It is a very important indicator for determining whether the water environment is polluted).

[0034] The above-described desulfurization wastewater treatment system, on the one hand, effectively solves the problem of how to quickly separate clear water from the desulfurization slurry without adding chemicals, effectively avoiding the need for chemical addition and reducing drug consumption costs; it also effectively avoids long periods of static standing, accelerating water output. Furthermore, it can efficiently separate suspended matter from the wastewater, retaining chloride ions in the clear liquid, thereby completing the chlorine removal task. Furthermore, by directly drawing water from the overflow outlet of the gypsum cyclone 1, the wastewater cyclone and its associated wastewater cyclone pump are omitted, reducing some wastewater treatment equipment and costs.

[0035] There are multiple ways to circulate the desulfurization wastewater to be treated. One feasible approach is to place each device at different heights, creating a height difference between the devices. This allows the desulfurization wastewater to automatically flow from the upstream device to the downstream device through gravity, thereby reducing energy consumption and lowering treatment costs. Another feasible approach is to install a transfer pump between some devices to provide the flow of the desulfurization wastewater to be treated, thereby reducing geographical restrictions, rationalizing space utilization, and improving the layout of the various devices in the entire system.

[0036] Optionally, the height of the buffer tank 2 is lower than the height of the overflow port 11; the height of the solid-liquid separation device 4 is lower than the height of the buffer tank 2; and the height of the clean water tank 5 is lower than the height of the solid-liquid separation device 4. With this arrangement, after the desulfurization wastewater to be treated flows out of the overflow port 11 of the gypsum cyclone 1, it can automatically flow to the buffer tank 2 due to gravity. One function of the buffer tank 2 is to act as a buffer, reducing the impact of the desulfurization wastewater to be treated flowing out of the overflow port 11 on the downstream treatment device, reducing the turbulence generated by the fluid during flow, and improving the stability of the fluid flow. Another function is to temporarily store the desulfurization wastewater to be treated, and it can also play a role of precipitation, thereby having a positive impact on subsequent treatment.

[0037] After being buffered by the buffer tank 2, the desulfurization wastewater to be treated flows smoothly into the solid-liquid separator 4. The solid-liquid separation operation in the solid-liquid separator 4 separates the desulfurization wastewater into solids (forming sludge) and a clear liquid. The solids are then discharged from the solid-liquid separator 4 after sedimentation and collection, and are then taken away by a sludge truck for subsequent treatment, such as landfill. The clear liquid flows out of the solid-liquid separator 4 into the clean water tank 5 for subsequent treatment, such as disinfection, before being discharged.

[0038] Optionally, the buffer tank 2 is located at a lower height than the overflow port 11; a first delivery pump 3 is provided between the buffer tank 2 and the solid-liquid separator 4, through which wastewater is delivered from the buffer tank 2 to the solid-liquid separator 4; and the clean water tank 5 is located at a lower height than the solid-liquid separator 4. The first delivery pump 3 is provided between the buffer tank 2 and the solid-liquid separator 4, and the first delivery pump 3 can deliver the desulfurization wastewater to be treated at a lower location to a higher location. Therefore, there is no need to consider the height difference between the buffer tank 2 and the solid-liquid separator 4, and the upper space can be more rationally utilized, reducing geographical restrictions on the system.

[0039] After flowing out of overflow port 11 of gypsum cyclone 1, the desulfurization wastewater to be treated automatically flows to buffer tank 2 due to gravity. After being buffered by buffer tank 2, the desulfurization wastewater to be treated reduces impact and turbulence, and can be smoothly pumped away by first delivery pump 3 and delivered to solid-liquid separation device 4. Compared with the automatic flow method, the delivery by first delivery pump 3 speeds up the flow rate of the desulfurization wastewater to be treated, thereby accelerating the processing speed of the entire system and improving wastewater treatment efficiency.

[0040] To meet the needs of wastewater treatment, the first delivery pump 3 optionally includes one of a high-pressure screw pump, a centrifugal pump, and a submersible pump. The head of the high-pressure screw pump, centrifugal pump, and submersible pump can all meet the requirements of the subsequent solid-liquid separation device 4, thereby enabling rapid delivery of the desulfurization wastewater to be treated. The number of first delivery pumps 3 can be set according to different needs, such as one or more. When there are multiple first delivery pumps 3, they can work simultaneously to meet the delivery of large amounts of wastewater, or some can be used and some can be on standby, so that they can be replaced in the event of a failure or maintenance, avoiding interruptions in wastewater treatment operations.

[0041] Optionally, the gypsum cyclone 1 is provided with a gypsum overflow slurry tank, which serves as a buffer tank 2; or the gypsum cyclone 1 is provided with a gypsum overflow slurry tank, which serves as a buffer tank 2. The clean water tank 5 can be a separate tank, or a gypsum overflow slurry tank on the gypsum cyclone 1, or the gypsum overflow slurry tank can be used in conjunction with a separate tank to serve as the clean water tank 5.

[0042] When the gypsum cyclone 1 is not provided with a gypsum overflow slurry tank, a separate box body can be provided as a buffer box 2 to buffer and collect the desulfurization wastewater to be treated that flows out of the overflow port 11. When the gypsum cyclone 1 is provided with a gypsum overflow slurry tank, the gypsum overflow slurry tank can be used as a buffer box 2 to buffer and collect the desulfurization wastewater to be treated that flows out of the overflow port 11. At the same time, when the gypsum cyclone 1 is provided with a gypsum overflow slurry tank, a separate box body can also be provided to cooperate with the gypsum overflow slurry tank as a buffer box 2. The two can buffer and collect the desulfurization wastewater to be treated at the same time, or they can be used in turn in a one-in-one-out standby manner, thereby facilitating subsequent repairs, maintenance, and other operations on the buffer box 2.

[0043] To ensure effective solid-liquid separation, the solid-liquid separation device 4 optionally includes a plate-and-frame filter press or a centrifugal dehydrator. Taking the plate-and-frame filter press as an example, the inlet of the plate-and-frame filter press can have a certain solid content, but it does not need to be too low. The solid content of the desulfurization wastewater to be treated, which flows out of the upstream gypsum cyclone 1, is approximately 5%. This overflow solid content meets the requirements of the plate-and-frame filter press, and no further separation is required through the wastewater cyclone. The plate-and-frame filter press can efficiently separate suspended matter from the desulfurization wastewater to be treated, retaining chloride ions in the clear liquid, thereby completing the chlorine removal task. During use, after the plate-and-frame filter press performs solid-liquid separation on the desulfurization wastewater to be treated, the solid content in the desulfurization wastewater to be treated is reduced to 0.1% to 0.15%, thereby meeting the downstream zero-discharge inlet requirements for wastewater. The separated solid matter undergoes sedimentation, collection, and other operations, and is discharged from the solid-liquid separation device 4 and taken away by a sludge truck for subsequent treatment, such as landfill. The clear liquid can flow out of the solid-liquid separation device 4 to the clean water tank 5 for subsequent treatment, such as disinfection, before being discharged. In addition, it should be noted that the purpose of desulfurization wastewater is to remove chloride ions rather than other pollutants from the system, so only one solid-liquid separation is required to achieve the above goal.

[0044] The quantity of solid-liquid separator 4 can be provided according to different demands, such as can be one, also can be multiple, when solid-liquid separator 4 is multiple, can be to work simultaneously, meet the processing of a large amount of wastewater, can also be part use, part standby, be convenient to when malfunction or carry out overhaul, replace and use, avoid the situation that wastewater treatment operation is interrupted.For example, when the amount of wastewater is less, more normally, single solid-liquid separator 4 can be used to meet the solid-liquid separation, chlorine discharge demand within a period of time.When the amount of wastewater is larger, require continuous waste discharge, can adopt multiple solid-liquid separator 4 to work in turn and realize continuous working requirement, also can use in turn by the mode of one with several standby, thereby be convenient to follow-up solid-liquid separator 4 is repaired, maintenance and other operations.

[0045] To better treat the wastewater, the desulfurization wastewater treatment system optionally includes a wastewater discharge device 7, which is connected to the clean water tank 5. This device can further treat the clear liquid in the clean water tank 5 to meet the inlet water quality requirements of the subsequent wastewater discharge route. Typically, the clean water tank 5 has two openings: one opening connects to the discharge port of the solid-liquid separator 4, and the other opening connects to the wastewater discharge device 7.

[0046] Optionally, the wastewater discharge device 7 includes at least one of a triple-effect evaporator or a flue gas concentrator. The triple-effect evaporator enables continuous evaporation and concentration, offering advantages such as high heat transfer efficiency and short material heating time. The flue gas concentrator collects and processes waste gas, preventing pollutants from contaminating the environment.

[0047] There are multiple ways for the clear liquid in the clean water tank 5 to flow. Optionally, the height of the wastewater discharge device 7 is lower than that of the clean water tank 5; there is a height difference between the wastewater discharge device 7 and the clean water tank 5, so that the clear liquid can automatically flow from the clean water tank 5 to the wastewater discharge device 7 by gravity, thereby reducing energy consumption and lowering treatment costs. A second delivery pump 6 is provided between the wastewater discharge device 7 and the clean water tank 5. The clear liquid is delivered from the clean water tank 5 to the wastewater discharge device 7 via the second delivery pump 6. The second delivery pump 6 provides the clear liquid with flow power, thereby reducing geographical restrictions, making rational use of space, and improving the layout of each device in the entire system. At the same time, compared with the automatic flow method, the delivery by the second delivery pump 6 speeds up the flow rate of the clear liquid, thereby speeding up the wastewater treatment speed and improving the wastewater treatment efficiency.

[0048] Optionally, the second delivery pump 6 includes one of a clean water pump, a centrifugal pump, and a vane pump. The clean water pump, the centrifugal pump, and the vane pump can all meet the head requirement, thereby being able to quickly deliver the clear liquid.

[0049] The number of the second delivery pumps 6 can be set according to different needs, such as one or more. When there are multiple second delivery pumps 6, they can work simultaneously to meet the treatment of a large amount of wastewater, or some can be used and some can be kept on standby, so that they can be replaced in case of failure or maintenance, thereby avoiding interruption of wastewater treatment operations.

[0050] The following is a further detailed introduction to the desulfurization wastewater treatment system provided by this application.

[0051] The operation of the desulfurization wastewater treatment system provided in this application is introduced. It should be noted that this specific embodiment is for illustrative purposes only and cannot be used as an improper limitation of this application.

[0052] (1) The desulfurized wastewater to be treated flows out from the overflow port 11 of the gypsum cyclone 1. The solid content of the desulfurized wastewater to be treated is about 5%. The outflowing desulfurized wastewater to be treated flows into the buffer tank 2.

[0053] (2) Buffer tank 2 is equipped with two high-pressure screw pumps, which transport the desulfurization wastewater to be treated to the plate and frame filter press through the high-pressure screw pumps; the head of the high-pressure screw pump can meet the dehydration requirements of the downstream plate and frame filter press, and the two high-pressure screw pumps are one for use and one for backup;

[0054] (3) The plate and frame filter press achieves solid-liquid separation for the desulfurization wastewater to be treated. The suspended solids enter the sludge and are then transported away by vehicle. The chloride ions enter the clear water tank 5 with the clear liquid. The solid content of the clear liquid treated by the plate and frame filter press is only 0.1%, which fully meets the inlet water quality requirements of each wastewater zero discharge route at the back end. There are two plate and frame filter presses, one for use and one for backup.

[0055] (4) The clean water tank 5 is equipped with a clean water pump to deliver the clean liquid to the subsequent wastewater zero discharge device; there are two clean water pumps, one for use and one for backup;

[0056] (5) The clear liquid in the clean water tank 5 is transported to the wastewater zero discharge device of the three-effect drying route through the clean water pump, and can also be connected to the wastewater zero discharge device of the low-temperature flue gas drying route.

[0057] In summary, from the above description and practice, it can be seen that the technical solution provided by this application has the following advantages compared with the prior art: on the one hand, it can effectively solve the problem of how to quickly separate clear water from the desulfurization slurry without adding medicine, which can effectively avoid adding medicine and reduce the cost of medicine consumption; at the same time, it can also effectively avoid long-term standing and speed up the water discharge speed. Moreover, it can also efficiently separate suspended matter in wastewater, retain chloride ions in the clear liquid, and thus complete the chlorine removal task. On the other hand, water is taken directly from the overflow outlet of the gypsum cyclone 1, omitting the wastewater cyclone and the supporting wastewater cyclone pump, reducing part of the wastewater treatment equipment and reducing costs.

[0058] Those skilled in the art should understand that the above description is only a specific embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the scope of the present application should be included in the scope of protection of the present application.

Claims

1. A desulfurization wastewater treatment system, characterized in that: include: A gypsum cyclone, wherein the gypsum cyclone is provided with an overflow port; A buffer box, wherein a buffer cavity is provided in the buffer box, an inlet and an outlet are provided on the buffer box, respectively connected to the buffer cavity, and the inlet of the buffer box is connected to the overflow port; A solid-liquid separation device, wherein the solid-liquid separation device is provided with a feed port and a discharge port, and the feed port of the solid-liquid separation device is connected to the outlet of the buffer tank; A clean water tank, wherein a receiving cavity is provided in the clean water tank, and at least one opening is provided on the clean water tank, which is in communication with the receiving cavity, and the opening of the clean water tank is in communication with the discharge port of the solid-liquid separation device; The wastewater in the gypsum cyclone flows into the buffer tank through the overflow port for buffering, and then enters the solid-liquid separation device through the buffer tank for solid-liquid separation. The clear liquid after solid-liquid separation enters the clean water tank.

2. The desulfurization wastewater treatment system according to claim 1, characterized in that: The height of the buffer tank is lower than the height of the overflow port; the height of the solid-liquid separation device is lower than the height of the buffer tank; the height of the clean water tank is lower than the height of the solid-liquid separation device.

3. The desulfurization wastewater treatment system according to claim 1, characterized in that: The height of the buffer tank is lower than the height of the overflow port; a first delivery pump is provided between the buffer tank and the solid-liquid separation device, and wastewater is delivered from the buffer tank to the solid-liquid separation device via the first delivery pump; the height of the clean water tank is lower than the height of the solid-liquid separation device.

4. The desulfurization wastewater treatment system according to claim 3, characterized in that: The first delivery pump includes one of a high-pressure screw pump, a centrifugal pump, and a submersible pump.

5. The desulfurization wastewater treatment system according to claim 1, characterized in that: The gypsum cyclone is provided with a gypsum overflow slurry tank, and the gypsum overflow slurry tank is the buffer tank; or the gypsum cyclone is provided with a gypsum overflow slurry tank, and the buffer tank includes the gypsum overflow slurry tank.

6. The desulfurization wastewater treatment system according to claim 1, characterized in that: The solid-liquid separation device includes one of a plate and frame filter press and a centrifugal dehydrator.

7. The desulfurization wastewater treatment system according to claim 1, characterized in that: The desulfurization wastewater treatment system further includes a wastewater discharge device, which is connected to the clean water tank.

8. The desulfurization wastewater treatment system according to claim 7, characterized in that: The wastewater discharge device includes at least one of a triple-effect evaporation device or a flue gas concentration device.

9. The desulfurization wastewater treatment system according to claim 7, characterized in that: The height of the wastewater discharge device is lower than that of the clean water tank; or a second delivery pump is provided between the wastewater discharge device and the clean water tank, and the clean liquid is delivered from the clean water tank to the wastewater discharge device via the second delivery pump.

10. The desulfurization wastewater treatment system according to claim 9, characterized in that: The second delivery pump includes one of a clean water pump, a centrifugal pump, and a vane pump.

Images