Low energy consumption salt water denitrification system

Abstract

The utility model discloses a kind of low-energy-consumption brine denitration systems, including membrane filter, plate heat exchanger, crystallizing tank and centrifuge connected in turn by process pipeline;The side portion of crystallizing tank is equipped with overflow, and overflow is connected with the cold medium import of plate heat exchanger by pipeline, and buffer tank is installed on pipeline;The cold medium export of plate heat exchanger is connected with output pipeline;Temperature sensor and regulating valve are installed on the pipeline between buffer tank and the cold medium import of plate heat exchanger, and on the output pipeline connected with the cold medium export of plate heat exchanger;Annular scraper of liftable motion is installed on the inner wall of crystallizing tank, and annular scraper top is connected with three hydraulic telescopic rods distributed in circumference.The utility model utilizes crystallizing tank overflow cold water precooling feed, greatly reduces the refrigeration load of cold water unit, reduces refrigeration energy consumption, can also keep tank wall clean and efficient heat transfer, avoid energy consumption rise due to scale formation.

Description

Technical Field

[0001] This utility model relates to a low-energy brine denitrification system, belonging to the field of denitrification technology. Background Technology

[0002] Membrane denitrification is essentially a combination of membrane concentration and cryogenic denitrification. This technology uses a high-polymer, non-porous membrane to physically separate sulfate ions, bringing the sulfate content in the concentrated brine to approximately 50 g / L. The concentrated brine is then frozen, causing sodium sulfate crystals to precipitate, which are then removed from the brine system by centrifugation. Membrane denitrification is characterized by being non-toxic, harmless, having zero emissions, and offering long-term stable operation with low energy consumption.

[0003] Currently, the hot concentrated water at 35-40 degrees Celsius flowing out of the membrane filter enters the crystallization tank, where it is cooled to about 4 degrees Celsius using a refrigeration unit to generate sodium sulfate crystals. The crystal slurry is then transported to a centrifuge for dehydration to produce sodium sulfate. This cooling and crystallization process mainly relies on external refrigeration equipment (chilled water units) to provide all the cooling capacity, resulting in significant operating costs for the refrigeration units.

[0004] Inside the crystallization tank, crystals easily form scale on the tank wall, creating a heat insulation layer that greatly reduces the heat transfer efficiency of the cooling jacket, leading to a decrease in cooling effect and further increasing energy consumption.

[0005] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Utility Model Content

[0006] This invention addresses the shortcomings of the prior art by providing a low-energy brine denitrification system. It can utilize the overflow cold water from the crystallization tank to pre-cool the feed, significantly reducing the cooling load of the chiller unit and lowering cooling energy consumption. It can also keep the tank walls clean and achieve efficient heat transfer, avoiding increased energy consumption due to scaling.

[0007] To solve the above technical problems, the present invention adopts the following technical solution: A low-energy brine denitrification system includes a membrane filter, a plate heat exchanger, a crystallization tank, and a centrifuge connected in sequence through process pipelines; An overflow port is provided on the upper side of the crystallization tank. The overflow port is connected to the cold medium inlet of the plate heat exchanger through a pipeline. A buffer tank is installed on the pipeline. The cold medium outlet of the plate heat exchanger is connected to the output pipeline. Temperature sensors and regulating valves are installed on the pipeline between the buffer tank and the cold medium inlet of the plate heat exchanger, and on the output pipeline connected to the cold medium outlet of the plate heat exchanger. The inner wall of the crystallization tank is equipped with a ring-shaped scraper that can be raised and lowered. The top of the ring-shaped scraper is connected to three hydraulic telescopic rods that are distributed in a circle.

[0008] Furthermore, temperature sensors, pressure sensors, and on / off valves are installed on the pipeline between the membrane filter outlet and the heat medium inlet of the plate heat exchanger, and on the pipeline between the heat medium outlet of the plate heat exchanger and the crystallization tank inlet of the crystallization tank.

[0009] Furthermore, the plate heat exchanger is connected in parallel with the connecting pipe, which connects the membrane filter outlet with the crystallization tank inlet, and an on / off valve is installed on the connecting pipe.

[0010] Furthermore, the main body of the crystallization tank is provided with a cooling jacket, which is connected to the chiller unit through pipelines.

[0011] Furthermore, an agitator is installed inside the crystallization tank, and the agitator is driven to rotate by a motor at the top of the crystallization tank.

[0012] Furthermore, the main body of the hydraulic telescopic rod is fixed vertically to the top of the crystallization tank.

[0013] Furthermore, a crystal slurry outlet is provided at the bottom of the crystallization tank, and the crystal slurry outlet is connected to a centrifuge via a pipeline.

[0014] Compared with the prior art, the present invention, by adopting the above technical solution, has the following advantages: This invention utilizes the cold water overflowing from the crystallization tank to pre-cool newly introduced hot concentrated water in a plate heat exchanger, thereby reducing the cooling load of the chiller unit and lowering energy consumption. This invention can achieve precise temperature control of the precooling process, ensuring that the hot concentrate is precooled to a temperature close to the crystallization point but not to the point of premature crystallization in the pipeline, effectively preventing pipeline blockage and ensuring stable and continuous operation of the system. This invention can periodically and mechanically scrape off the crystalline scale layer adhering to the inner wall of the tank, keeping the tank wall clean and ensuring efficient heat transfer, thus ensuring a constant cooling effect and avoiding increased energy consumption due to scaling.

[0015] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the crystallization tank.

[0017] In the diagram, 1-membrane filter, 2-plate heat exchanger, 3-crystallization tank, 31-cooling jacket, 32-stirring blade, 33-crystallization tank inlet, 34-overflow port, 35-crystal slurry outlet, 36-annular scraper, 37-hydraulic telescopic rod, 4-connecting pipe, 5-chiller unit, 6-centrifuge, 7-buffer tank, 8-on / off valve, 9-regulating valve. Detailed Implementation

[0018] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described with reference to the accompanying drawings.

[0019] like Figure 1 and Figure 2 As shown in the figure, this utility model provides a low-energy brine denitrification system, including a membrane filter 1, a plate heat exchanger 2, a crystallization tank 3 and a centrifuge 6 connected in sequence through process pipelines.

[0020] Temperature sensors, pressure sensors, and on / off valves 8 are installed on the pipeline between the outlet of membrane filter 1 and the inlet of the heat medium of plate heat exchanger 2, and on the pipeline between the outlet of the heat medium of plate heat exchanger 2 and the inlet 33 of the crystallization tank 3.

[0021] The plate heat exchanger 2 is connected in parallel with the connecting pipe 4. The connecting pipe 4 connects the outlet of the membrane filter 1 with the inlet 33 of the crystallization tank 3. An on / off valve 8 is installed on the connecting pipe 4.

[0022] The main body of the crystallization tank 3 is provided with a cooling jacket 31. The cooling jacket 31 is connected to the chiller unit 5 through a pipeline. The chiller unit 5 provides cooling capacity to the crystallization tank 3.

[0023] An overflow port 34 is provided on the upper side of the crystallization tank 3. The overflow port 34 is connected to the cold medium inlet of the plate heat exchanger 2 through a pipeline. A buffer tank 7 is installed on the pipeline. The cold medium outlet of the plate heat exchanger 2 is connected to the output pipeline.

[0024] Temperature sensors and regulating valves 9 are installed on the pipeline between the buffer tank 7 and the cold medium inlet of the plate heat exchanger 2, and on the output pipeline connected to the cold medium outlet of the plate heat exchanger 2.

[0025] The crystallization tank 3 is equipped with a stirring blade 32 in its inner cavity. The stirring blade 32 is driven to rotate by a motor at the top of the crystallization tank 3, so that the crystallized material is evenly distributed, avoiding local crystals that are too large or too small, and ensuring the uniformity of product quality.

[0026] An annular scraper 36, capable of vertical movement, is installed on the inner wall of the crystallization tank 3. The top of the annular scraper 36 is connected to three hydraulic telescopic rods 37 arranged in a circular pattern. The main body of the hydraulic telescopic rods 37 is fixed vertically to the top of the crystallization tank 3. The hydraulic telescopic rods 37 provide power for the timed lifting and lowering of the annular scraper 36, which can scrape away the crystals on the inner wall of the crystallization tank 3.

[0027] The bottom of the crystallization tank 3 is provided with a crystal slurry outlet 35, which is connected to the centrifuge 6 through a pipeline.

[0028] The specific working principle of this utility model is as follows: The hot concentrated water flowing out of the membrane filter 1 is first pre-cooled in the plate heat exchanger 2, and then crystallized in the crystallization tank 3. The crystallized slurry is then separated in the centrifuge 6 to obtain sodium sulfate.

[0029] This invention utilizes the cold water overflowing from the crystallization tank 3 to pre-cool newly entering hot concentrated water in the plate heat exchanger 2, reducing the cooling load of the chiller unit 5 and lowering energy consumption. Pressure and temperature sensors are added at the hot concentrated water inlet and outlet of the plate heat exchanger 2, and temperature sensors are added at the cold water inlet and outlet of the plate heat exchanger 2. The regulating valve 9 can control the cold water flow rate based on the outlet temperature of the plate heat exchanger 2, achieving both a reduction in the temperature of the hot concentrated nitrate brine and preventing premature crystallization that could clog the pipes.

[0030] This invention utilizes a liftable scraper to prevent scale buildup on the tank walls and ensure a constant cooling effect.

[0031] The above description provides examples of the preferred embodiments of this utility model. Any aspects not detailed herein are common knowledge to those skilled in the art. The scope of protection of this utility model is determined by the claims. Any equivalent modifications based on the technical teachings of this utility model are also within the scope of protection of this utility model.

Claims

1. A low-energy brine denitrification system, characterized in that: It includes a membrane filter (1), a plate heat exchanger (2), a crystallizer (3), and a centrifuge (6) connected in sequence through process piping; An overflow port (34) is provided on the upper side of the crystallization tank (3). The overflow port (34) is connected to the cold medium inlet of the plate heat exchanger (2) through a pipeline. A buffer tank (7) is installed on the pipeline. The cold medium outlet of the plate heat exchanger (2) is connected to the output pipeline. Temperature sensors and regulating valves (9) are installed on the pipeline between the buffer tank (7) and the cold medium inlet of the plate heat exchanger (2) and on the output pipeline connected to the cold medium outlet of the plate heat exchanger (2). The inner wall of the crystallization tank (3) is equipped with a ring scraper (36) that can be raised and lowered. The top of the ring scraper (36) is connected to three hydraulic telescopic rods (37) that are distributed in a circle.

2. The low-energy brine denitrification system as described in claim 1, characterized in that: Temperature sensors, pressure sensors, and on / off valves (8) are installed on the pipeline between the outlet of the membrane filter (1) and the inlet of the heat medium of the plate heat exchanger (2), and on the pipeline between the outlet of the heat medium of the plate heat exchanger (2) and the inlet (33) of the crystallization tank (3).

3. The low-energy brine denitrification system as described in claim 1, characterized in that: The plate heat exchanger (2) and the connecting pipe (4) are connected in parallel. The connecting pipe (4) connects the outlet of the membrane filter (1) with the inlet (33) of the crystallization tank (3). An on / off valve (8) is installed on the connecting pipe (4).

4. The low-energy brine denitrification system as described in claim 1, characterized in that: The main body of the crystallization tank (3) is provided with a cooling jacket (31), which is connected to the chiller unit (5) through a pipeline.

5. The low-energy brine denitrification system as described in claim 1, characterized in that: The crystallization tank (3) is equipped with a stirring blade (32) in its inner cavity. The stirring blade (32) is driven to rotate by a motor at the top of the crystallization tank (3).

6. The low-energy brine denitrification system as described in claim 1, characterized in that: The main body of the hydraulic telescopic rod (37) is fixed to the top of the crystallization tank (3) in the vertical direction.

7. The low-energy brine denitrification system as described in claim 1, characterized in that: The bottom of the crystallization tank (3) is provided with a crystal slurry outlet (35), which is connected to the centrifuge (6) through a pipeline.

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