Device for reducing wastewater discharge

Abstract

The utility model discloses a device for reducing wastewater discharge. The device comprises a light organic matter stripping tower, a reboiler, a condensate pump, a stripping tower buffer tank, a feeding pump, a feeding preheater and a feeding cooler. Compared with the prior art, by adding the pipeline from the light organic matter stripping tower to the stripping tower buffer tank and conveying the light organic matter to the sewage treatment plant, the sewage treatment capacity is increased, the wastewater discharge generation amount is reduced, the amount of natural gas used for burning a large amount of wastewater is saved, the device operation cost is reduced, and meanwhile, the number of harmful substances discharged into the atmosphere is reduced; environmental pollution is reduced, and environmental protection is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, and particularly relates to a device for reducing wastewater discharge. Background Art

[0002] At present, the normal process of the acrylonitrile evaporation section is that the bottom liquid of the light organic matter stripping tower goes to the quench tower and then is sent to the wastewater tank area for incineration. This process generates a large amount of wastewater and consumes a large amount of natural gas for incineration treatment, resulting in relatively high production costs and energy consumption. Therefore, it is necessary to develop a new type of device for reducing wastewater discharge. Summary of the Utility Model

[0003] Purpose of the utility model: To solve the above problems, the utility model provides a device for reducing wastewater discharge, which increases wastewater treatment, reduces the amount of wastewater discharged, saves a large amount of natural gas used for incinerating wastewater, reduces the operating cost of the device, and at the same time reduces the amount of harmful substances discharged into the atmosphere.

[0004] Technical solution: To achieve the above purpose, the device for reducing wastewater discharge described in the utility model includes a light organic matter stripping tower, a reboiler connected in parallel with the light organic matter stripping tower, a condensate pump connected to the light organic matter stripping tower, a stripping tower buffer tank connected to the condensate pump, a feed pump connected to the stripping tower buffer tank, a feed preheater connected to the feed pump, and a feed cooler connected to the feed preheater.

[0005] Further, the top of the light organic matter stripping tower is used to input untreated wastewater, and the light organic matter stripping tower is used to collect condensate.

[0006] Further, a part of the condensate is sent to other sections through the condensate pump for reuse.

[0007] Further, another part of the condensate enters the stripping tower buffer tank through the condensate pump, then is transported by the feed pump, and then is cooled by the feed preheater and the feed cooler.

[0008] Further, for the cooled condensate, a part is used as pump seal water, filtered by a precision filter and then enters the seal water storage tank, and another part is sent to the sewage treatment plant after passing through a hydrogen peroxide mixer.

[0009] Further, the light organic matter stripping tower has a valve tray.

[0010] Advantageous effects: Compared with the prior art, the utility model has the following remarkable effects: By adding a pipeline from the light organic matter stripping tower to the stripping tower buffer tank, the bottom liquid of the light organic matter stripping tower is sent back from the light organic matter stripping tower to the stripping tower buffer tank and directly sent to the sewage treatment plant, increasing the amount of wastewater treated, reducing the amount of wastewater discharged, and reducing emissions to the atmosphere. Description of the Drawings

[0011] Figure 1 It is a process schematic diagram of the present utility model. Specific embodiments

[0012] The present utility model discloses a device for reducing wastewater discharge. Please refer to Figure 1 As shown in the figure, the device for reducing wastewater discharge provided by the present utility model will be further described in detail below: The device for reducing wastewater discharge includes a light organic matter stripping column 1, a reboiler 2 connected in parallel with the light organic matter stripping column 1, a condensate pump 3 connected to the light organic matter stripping column 1, a stripping column buffer tank 4 connected to the condensate pump 3, a feed pump 5 connected to the stripping column buffer tank 4, a feed preheater 6 connected to the feed pump 5, and a feed cooler 7 connected to the feed preheater 6.

[0013] Using this utility model to purify the untreated wastewater, first send the untreated wastewater to the top of the light organic matter stripping column 1. This stripping column has 30 valve trays, and the required heat is provided by the reboiler 2 with 0.3 MPa steam as the heat source. The reboiler 2 is a vertical thermosyphon reboiler, and the amount of low-pressure steam in the reboiler 2 is controlled by a flow indicating regulator. A part of the condensate collected by the light organic matter stripping column 1 is sent to other sections for reuse through the condensate pump 3. Among them, steam is generated at the top of the organic matter stripping column 1. This steam contains trace amounts of free ammonia and light organic matter stripped from the condensate at the top of the quadruple-effect evaporator and is sent to the quench tower as stripping steam; Another part of the condensate collected by the light organic matter stripping column 1 enters the stripping column buffer tank 4 through the condensate pump 3, then is transported by the feed pump 5, and after being cooled by the feed preheater 6 and the feed cooler 7, a part is used as pump seal water and enters the seal water storage tank after being filtered by a precision filter, and another part is sent to the sewage treatment plant after passing through a hydrogen peroxide mixer. In addition, during the initial operation, keep 1 m at the outlet of the light organic matter stripping column 1 3The flow rate of / h is ensured to ensure the up-to-standard discharge of the discharged wastewater and the normal operation of the water treatment plant. After five days of normal production operation without any abnormalities and ensuring stable production operation, gradually reduce the flow rate of the outlet of the light organic matter stripping tower 1 to the quench tower. The bottom liquid of the light organic matter stripping tower 1 is detected once at fixed intervals to ensure the stability of the wastewater indexes. The wastewater indexes are: CN≤10mg / L, CODcr≤3000mg / L, AN≤150mg / L, pH value is 7-10, ammonia nitrogen≤40mg / L, total nitrogen≤500mg / L, total phosphorus≤2mg / L, dissolved total solids≤500mg / L, suspended solids≤70mg / L. If the wastewater exceeds the middle-section water indexes, immediately reduce the flow rate of the outlet of the light organic matter stripping tower 1 to the light organic matter stripping tower system and switch to the lower section of the quench tower. The operating indexes of the light organic matter stripping tower are: CN≤7.41mg / kg, COD≤2849mg / kg, AN≤76.9mg / kg, pH = 8.04, ammonia nitrogen≤11.59mg / kg, total nitrogen≤424.99mg / kg, dissolved total solids≤291mg / kg, suspended solids≤160mg / kg. The indexes for the wastewater treatment plant are: CN≤10mg / kg, COD≤3000mg / kg, AN≤150mg / kg, pH is 7-10, ammonia nitrogen≤40mg / kg, total nitrogen≤500mg / kg, dissolved total solids≤500mg / kg, suspended solids≤70mg / kg. If there are fluctuations in individual indexes, the wastewater should be returned to the light organic matter stripping tower system to make the wastewater indexes fully up to standard. Through this utility model, the amount of wastewater from the quench tower to the incinerator is reduced, the amount of incineration wastewater generated by the acrylonitrile unit is decreased, and at the same time, the amount of acrylonitrile wastewater sent to the wastewater tank area is reduced by 2.5m 3 / h, reducing the consumption of natural gas by 350 Nm 3 / h, saving costs by 32,400 yuan per day, reducing the corresponding amount of treated wastewater, reducing the emissions to the atmosphere, and protecting the environment.

Claims

1. A device for reducing wastewater discharge, characterized in that, It includes a light organic matter stripping column (1), a reboiler (2) connected in parallel with the light organic matter stripping column (1), a condensate pump (3) connected to the light organic matter stripping column (1), a stripping column buffer tank (4) connected to the condensate pump (3), a feed pump (5) connected to the stripping column buffer tank (4), a feed preheater (6) connected to the feed pump (5), and a feed cooler (7) connected to the feed preheater (6).

2. The device for reducing wastewater discharge according to claim 1, wherein The top of the light organic matter stripping column (1) is used to input untreated wastewater, and the light organic matter stripping column (1) is used to collect condensate.

3. The device for reducing wastewater discharge according to claim 2, wherein A part of the condensate is sent to other sections for reuse through the condensate pump (3).

4. The device for reducing wastewater discharge according to claim 3, characterized in that, Another part of the condensate enters the stripping column buffer tank (4) through the condensate pump (3), then is transported by the feed pump (5), and then cooled by the feed preheater (6) and the feed cooler (7).

5. The device for reducing wastewater discharge according to claim 4, wherein, For the cooled condensate, a part of it is used as pump seal water, which enters the seal water storage tank after being filtered by a precision filter, and another part is sent to the sewage treatment plant after passing through a hydrogen peroxide mixer.

6. The device for reducing wastewater discharge according to claim 1, characterized in that The light organic matter stripping column (1) is equipped with valve trays.

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