A new sea water desalination pretreatment combined system

Abstract

This utility model discloses a novel combined system for seawater desalination pretreatment, comprising a regulating reservoir and an intake pumping station. The system includes a dissolved air flotation (DAF) unit with sand removal function, an ultrafiltration unit, and an ultrafiltration permeate tank, sequentially arranged at the rear end of the intake pumping station. By organically combining the novel DAF process with sand removal function with submerged ultrafiltration, the traditional complex pretreatment process is replaced, significantly reducing the process flow and the number of equipment. The DAF return water uses submerged ultrafiltration permeate, effectively avoiding clogging of the air release head and ensuring stable operation of the DAF unit. The ultrafiltration backwash water is returned to the DAF front-end treatment, realizing water resource recycling, reducing environmental impact, and improving the overall system stability. The combined process fully leverages the sand removal and suspended solids separation advantages of DAF, as well as the high-precision filtration capability of submerged ultrafiltration, to stably produce high-quality pretreated water, providing a reliable feedwater guarantee for subsequent seawater desalination processes.

Description

Technical Field

[0001] This utility model relates to the field of seawater desalination technology, specifically a novel combined seawater desalination pretreatment system. Background Technology

[0002] With the increasing severity of water scarcity, seawater desalination, as a technology for increasing water supply, has become an important way for my country to solve the problem of freshwater shortage in coastal areas. However, some seawater areas have high sediment content, suspended solids, and contain colloids and dissolved gases. Therefore, to ensure the long-term stable operation of the seawater desalination system, the raw seawater from these areas needs to be pretreated before entering the desalination system. Pretreatment is a necessary process before the seawater enters the desalination unit, such as killing marine organisms, reducing turbidity, removing suspended solids (for reverse osmosis), or degassing (for distillation), and adding necessary reagents. Pretreatment equipment typically includes flocculation sedimentation tanks and filters. In recent years, with the continuous growth in demand for seawater desalination, the stable operation and operating costs of seawater desalination pretreatment processes have become urgent problems to be solved.

[0003] In the field of seawater desalination, traditional pretreatment processes are typically quite complex, encompassing multiple stages such as coarse filtration, sedimentation, coagulation and sedimentation, multi-media filtration, activated carbon filtration, and ultrafiltration. These processes suffer from drawbacks such as complex equipment, large footprint, difficult operation and maintenance, and high investment costs. Furthermore, traditional processes are prone to problems such as clogging of the gas release head and issues with backwash water discharge, which not only increase operating costs but also affect system stability and treatment efficiency. With the ever-increasing demand for seawater desalination, there is an urgent need for a new technology and equipment that can simplify the process flow, reduce footprint, and improve operational stability. Utility Model Content

[0004] To address the aforementioned technical shortcomings, the purpose of this utility model is to provide a novel combined dissolved air flotation and submerged ultrafiltration equipment with sand removal function. By organically combining the two processes, it solves the problems existing in traditional seawater desalination pretreatment processes and achieves efficient and stable seawater desalination pretreatment.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] This utility model provides a novel combined system for pretreatment of seawater desalination, including a regulating reservoir and a water intake pumping station, comprising a dissolved air flotation device with sand removal function, an ultrafiltration device, and an ultrafiltration product water tank, which are sequentially arranged at the rear end of the water intake pumping station.

[0007] Preferably, the dissolved air flotation device includes:

[0008] The bottom of the concrete flocculation zone is equipped with a cone-shaped sludge discharge trough. The bottom of the sludge discharge trough is equipped with a sludge discharge pipe, and an electric valve is installed on the sludge discharge pipe to facilitate the control of sludge discharge.

[0009] The flotation zone has a continuous, steeply sloping sludge discharge channel at the bottom, with sludge discharge pipes installed inside. These pipes have evenly distributed sludge discharge holes and are equipped with backwashing ducts connected to a high-pressure backflushing system. When the sludge discharge pipes become clogged, they can be cleared through the high-pressure ducts. A duct at the top of the sludge discharge pipes connects to the high-pressure backflushing system to break up bridging formed by sludge and ensure smooth discharge of sludge from the bottom, preventing accumulation. A scum scraper is installed at the top of the flotation zone to remove scum from the surface. A flow stabilizing plate is also installed within the flotation zone.

[0010] The return water system is used to return the water in the ultrafiltration permeate tank to the dissolved air flotation equipment. The return water is selected from the submerged ultrafiltration permeate, which effectively avoids the problem of air flotation release head blockage caused by impurities in the return water in the traditional process, and improves the operational stability and service life of the dissolved air flotation equipment.

[0011] Preferably, the ultrafiltration equipment is further equipped with a backwash water system, which is used to send the water in the ultrafiltration equipment to the regulating water tank to effectively recycle and utilize this part of the water resources. At the same time, a steady flow mode is adopted to avoid the impact of water volume fluctuations on subsequent air flotation and ultrafiltration.

[0012] Preferably, the slope of the sludge discharge channel is 40°-60°.

[0013] Preferably, the ultrafiltration device is an immersion ultrafiltration device, which contains multiple membrane modules. These membrane modules are made of high-strength, fouling-resistant desalination ultrafiltration membrane materials, which can effectively remove impurities such as tiny particles, colloids, bacteria and macromolecular organic matter from seawater, providing high-quality pretreated water for subsequent seawater desalination.

[0014] The beneficial effects of this utility model are as follows:

[0015] 1. Simplified process and reduced footprint: By organically combining the new dissolved air flotation process with sand removal function with the submerged ultrafiltration process, the traditional complex pretreatment process is replaced, which greatly reduces the process flow and the number of equipment; the integrated and compact design makes the device structure more compact, saving about 20%-50% of the footprint compared with the traditional process.

[0016] 2. Improved operational stability: The dissolved air flotation (DAF) return water uses submerged ultrafiltration permeate, effectively avoiding the problem of air release head clogging and ensuring the stable operation of the DAF equipment; at the same time, the ultrafiltration backwash water is returned to the front end of the DAF treatment, realizing the recycling of water resources, reducing the impact on the environment, and improving the operational stability of the entire system; the design of the DAF sand removal system enables the device to operate stably in extreme environments such as typhoons and when the incoming water has a high sand content.

[0017] 3. Water quality assurance: The combined process fully leverages the advantages of dissolved air flotation in sand removal and suspended solids separation, as well as the high-precision filtration capability of submerged ultrafiltration, to stably produce high-quality pretreated water, providing a reliable feed water guarantee for subsequent seawater desalination processes. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the structure of a novel desalination pretreatment combined system provided in this embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the coagulation and flocculation zone in an embodiment of this utility model;

[0021] Figure 3 This is a schematic diagram of the air flotation zone in an embodiment of the utility model.

[0022] Explanation of reference numerals in the attached drawings: 1. Regulating water storage tank; 2. Water intake pump room; 3. Dissolved air flotation equipment; 4. Ultrafiltration equipment; 5. Ultrafiltration product water tank; 6. Sludge discharge pipe; 7. Electric valve; 8. Sludge discharge flower pipe; 9. Air duct; 10. Sludge scraper; 11. Flow stabilizer. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Example 1, such as Figures 1-3As shown, a novel desalination pretreatment combined system includes a regulating reservoir 1 and a water intake pumping station 2, and includes a dissolved air flotation device 3 with sand removal function, an ultrafiltration device 4, and an ultrafiltration product water tank 5, which are sequentially arranged at the rear end of the water intake pumping station 2.

[0025] Furthermore, the dissolved air flotation device 3 includes:

[0026] The bottom of the coagulation and flocculation zone is equipped with a cone-shaped sludge discharge trough. The bottom of the sludge discharge trough is equipped with a sludge discharge pipe 6, and an electric valve 7 is installed on the sludge discharge pipe.

[0027] The air flotation zone has a continuous, steeply sloping sludge discharge channel at the bottom, with a slope of 40°-60°. Sludge discharge pipes 8 are installed inside the sludge discharge channel, with evenly distributed sludge discharge holes. A backwashing air duct is installed inside the sludge discharge pipe 8, connected to a high-pressure backflushing system. When the sludge discharge pipe 8 is blocked, it can be cleared through the high-pressure backflushing system. An air duct 9 is installed at the top of the sludge discharge pipe, connected to the high-pressure backflushing system, to break up bridging formed by sludge and ensure that the sludge at the bottom can be smoothly discharged, preventing accumulation. A scum scraper 10 is installed at the top of the air flotation zone to scrape off scum from the surface of the air flotation zone. A flow stabilizing plate 11 is also installed within the air flotation zone.

[0028] The return water system is used to return the water in the ultrafiltration product water tank 5 to the dissolved air flotation equipment 3. The return water is selected from the submerged ultrafiltration product water, which effectively avoids the problem of air flotation release head blockage caused by impurities in the return water in the traditional process, and improves the operational stability and service life of the dissolved air flotation equipment 3.

[0029] Preferably, the ultrafiltration device 4 is also equipped with a backwash water system, which is used to send the water in the ultrafiltration device 4 to the regulating water tank to effectively recycle and utilize this part of the water resources. At the same time, a steady flow mode is adopted to avoid the impact of water volume fluctuations on subsequent air flotation and ultrafiltration.

[0030] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A novel combined seawater desalination pretreatment system, comprising a regulating reservoir and an intake pumping station, characterized in that, It also includes a dissolved air flotation (DAF) device with sand removal function, an ultrafiltration device, and an ultrafiltration product water tank, which are sequentially installed at the rear end of the water intake pumping station; the DAF device includes: The coagulation and flocculation zone is equipped with a cone-shaped sludge discharge trough at the bottom, and a sludge discharge pipe is provided at the bottom of the sludge discharge trough, on which an electric valve is installed. The air flotation zone has a continuous, steeply sloping sludge discharge channel at the bottom, with sludge discharge pipes installed inside the channel. Sludge discharge holes are evenly distributed on the sludge discharge pipes, and a backwashing air duct is installed inside each pipe, connected to a high-pressure backflushing system. An air duct at the top of the sludge discharge pipes is also connected to the high-pressure backflushing system. A scum scraper is installed at the top of the air flotation zone to remove scum from the surface. A flow stabilizing plate is also installed within the air flotation zone. A reflux water system is used to return water from the ultrafiltration permeate tank to the dissolved air flotation equipment.

2. The novel desalination pretreatment combined system as described in claim 1, characterized in that, The ultrafiltration equipment is also equipped with a backwash water system for sending water from the ultrafiltration equipment to the regulating water tank.

3. The novel desalination pretreatment combined system as described in claim 1, characterized in that, The slope of the sludge discharge channel is 40°-60°.

4. The novel desalination pretreatment combined system as described in claim 1, characterized in that, The ultrafiltration device is an immersion ultrafiltration system, which contains multiple membrane modules.

Images