Wastewater process double reboilers of ammoximation device
By adding a second reboiler and a thermosiphon reboiler to the wastewater treatment process of the ammonia oxime unit, the problem of high low-pressure steam consumption was solved, achieving energy saving, consumption reduction, and improved wastewater treatment efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-28
- Publication Date
- 2026-03-24
AI Technical Summary
The existing ammonia oxime unit has a high consumption of low-pressure steam in the wastewater stripping process, which leads to increased production costs.
In the wastewater treatment process of the ammonia oxime unit, a wastewater stripping tower and a second reboiler are added. Combined with vertical and horizontal thermosiphon reboilers, the heat energy exchange between the steam condensate and the wastewater is utilized to reduce low-pressure steam consumption and improve mass and heat transfer efficiency.
It reduced the consumption of low-pressure steam and coal, reduced exhaust emissions, lowered production costs, and improved wastewater discharge standards.
Smart Images
Figure CN224030705U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of ammonia oximation device, specifically a kind of ammonia oximation device wastewater procedure double reboiler. BACKGROUND
[0002] Caprolactam (CPL) is one of important organic chemical raw materials, main use is through polymerization generation polyamide chip, can be further processed into nylon fiber, engineering plastics, plastic film etc., widely applicable in engineering plastics, film and artificial leather and other application fields.Caprolactam production process is long, energy consumption is high, so that circulating material is big, by-product and intermediate product is more, leading to complex composition of wastewater, wastewater has higher toxicity, belongs to high-concentration nitrogen-containing organic wastewater, it is one of the production wastewater difficult to handle in current petroleum chemical industry, wastewater is usually handled by ammonia oximation device wastewater stripping procedure operation.
[0003] In caprolactam production, cyclohexanone is a key step to cyclohexanone oxime, i.e.cyclohexanone is directly subjected to ammonia oxidation to generate cyclohexanone oxime using hydrogen peroxide under the action of titanium-silicon catalyst, the wastewater produced in this ammonia oximation process has COD as high as 2000~12000mg / l, so that the low-pressure steam consumption in general ammonia oximation device wastewater stripping procedure in production process is higher, greatly increasing production cost.
[0004] Based on this, the present application provides a kind of ammonia oximation device wastewater procedure double reboiler, which can eliminate the drawbacks of the prior art. UTILITY MODEL CONTENT
[0005] The utility model aims at providing a kind of ammonia oximation device wastewater procedure double reboiler to solve the problem of high low-pressure steam consumption in the wastewater stripping procedure in the background art, which leads to increased production cost.
[0006] To achieve the above object, the utility model provides the following technical scheme:
[0007] A kind of ammonia oximation device wastewater procedure double reboiler, including wastewater stripping tower, the side of the wastewater stripping tower is provided with wastewater stripping tower first reboiler, the top of the wastewater stripping tower is connected with wastewater stripping tower gas phase outlet, the bottom of the wastewater stripping tower is connected with wastewater stripping tower discharge pipe, the middle upper portion of the wastewater stripping tower is connected with wastewater feed pipe, the middle lower portion of the wastewater stripping tower is connected with wastewater stripping tower second reboiler, the wastewater stripping tower second reboiler is arranged in the side of the wastewater stripping tower away from the wastewater stripping tower first reboiler.
[0008] Preferably, the low-pressure steam inlet is connected to one side of the wastewater stripping tower first reboiler, and a first steam condensate discharge pipe is arranged below the low-pressure steam inlet and connected to the wastewater stripping tower first reboiler.
[0009] Preferably, the first reboiler and the second reboiler are connected to the wastewater stripping tower through a first conveying pipe and a second conveying pipe, one end of the first conveying pipe is connected to the middle and lower part of the wastewater stripping tower, the other end of the first conveying pipe is connected to the middle and upper part of the wastewater stripping tower first reboiler, one end of the second conveying pipe is connected to the bottom of the wastewater stripping tower, and the other end of the second conveying pipe is connected to the bottom of the wastewater stripping tower second reboiler.
[0010] Preferably, the top of the wastewater stripping tower second reboiler is provided with a wastewater stripping tower second reboiler discharge pipe, the other end of the wastewater stripping tower second reboiler discharge pipe is connected to the middle and lower part of the wastewater stripping tower, the bottom of the wastewater stripping tower second reboiler is provided with a wastewater stripping tower second reboiler feed pipe, and the other end of the wastewater stripping tower second reboiler feed pipe is connected to the bottom of the wastewater stripping tower.
[0011] Preferably, the side of the wastewater stripping tower second reboiler discharge pipe is provided with a steam condensate input pipe and a second steam condensate discharge pipe, and the steam condensate input pipe is arranged below the second steam condensate discharge pipe.
[0012] Preferably, the inside of the wastewater stripping tower, the wastewater stripping tower first reboiler and the wastewater stripping tower second reboiler is provided with a temperature detector and a pressure detector.
[0013] Preferably, the wastewater stripping tower first reboiler is a vertical thermosyphon reboiler, and the wastewater stripping tower second reboiler is a horizontal thermosyphon reboiler.
[0014] Preferably, the inside of the first steam condensate discharge pipe and the second steam condensate discharge pipe is provided with a flow monitoring meter.
[0015] Compared with the prior art, the utility model has the beneficial effects as follows:
[0016] Compared with the prior art, the utility model has the beneficial effects as follows: The double-reboiler wastewater process of the ammoximation device saves low-pressure steam, reduces coal consumption, reduces the amount of waste gas discharged, reduces production cost, enhances mass and heat transfer effect, improves waste water discharge index, and sets the wastewater stripping tower of the ammoximation device as a double-reboiler heat source, which is also a steam condensate and steam double heat source, and has wide application range and good practicability. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the existing technology.
[0018] Figure 2 This is a schematic diagram of the overall structure of this utility model.
[0019] Figure 3 This is a schematic diagram of the structure of the second reboiler of the wastewater stripping tower of this utility model.
[0020] Figure labeling: 1. Wastewater stripping tower; 2. First reboiler of wastewater stripping tower; 3. Vapor outlet of wastewater stripping tower; 4. Wastewater feed pipe of wastewater stripping tower; 5. Second reboiler of wastewater stripping tower; 6. Low-pressure steam inlet; 7. First steam condensate discharge pipe; 8. First conveying pipe; 9. Second conveying pipe; 10. Discharge pipe of second reboiler of wastewater stripping tower; 11. Feed pipe of second reboiler of wastewater stripping tower; 12. Steam condensate input pipe; 13. Second steam condensate discharge pipe; 14. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.
[0022] In this embodiment, as Figure 2 and Figure 3As shown, the arrows indicate the flow directions of gas and liquid. A double reboiler for the wastewater process of an ammonia oxime treatment unit includes a wastewater stripping tower 1. A wastewater tank (not shown) is located on one side of the stripping tower 1 and is connected to a wastewater inlet pipe 5. A first reboiler 2 is located on one side of the stripping tower 1. The reboiler provides the necessary heat for the stripping process, separating volatile substances from the liquid phase in the wastewater. The density difference between the two phases in the stripping tower 1 and the reboiler creates a thermosiphonic motion. The liquid in the reboiler is heated and vaporized, forming a vapor-liquid mixture in the condensate discharge pipe. This mixture has a lower density than the liquid in the inlet pipe. This density difference allows the liquid at the bottom of the stripping tower 1 to be continuously "siphoned" into the reboiler. The vapor-liquid mixture after thermal vaporization automatically returns to the tower, providing a gas phase flow for the stripping process. This facilitates the transfer of volatile substances in the wastewater from the liquid phase to the gas phase, thereby achieving separation. The top of the wastewater stripping tower 1 is connected to the wastewater stripping tower gas phase outlet 3, the bottom of the wastewater stripping tower 1 is connected to the wastewater stripping tower discharge pipe 4, and the upper middle part of the wastewater stripping tower 1 is connected to the wastewater inlet pipe 5, which facilitates the delivery of wastewater into the wastewater stripping tower 1. The lower middle part of the wastewater stripping tower 1 is connected to the wastewater stripping tower second reboiler 6, which is located on the side of the wastewater stripping tower 1 away from the wastewater stripping tower first reboiler 2. Before the device is put into use, it is checked whether the device can be used normally. Then, wastewater is delivered into the wastewater stripping tower 1 through the wastewater inlet pipe 5, so that the device enters the ready-to-use state.
[0023] Among them, such as Figure 2 and Figure 3 As shown, a low-pressure steam inlet 7 is connected to the side of the first reboiler 2 of the wastewater stripping tower away from the wastewater stripping tower 1. Low-pressure steam can be added to the interior of the first reboiler 2 of the wastewater stripping tower through the low-pressure steam inlet 7 to replenish heat in time and ensure the normal operation of the wastewater stripping tower 1, thereby compensating for the deficiency of insufficient steam condensate collection. A first steam condensate discharge pipe 8 is provided below the low-pressure steam inlet 7. The first steam condensate discharge pipe 8 is connected to the first reboiler 2 of the wastewater stripping tower and is used to collect steam condensate.
[0024] Among them, such as Figure 2 and Figure 3 As shown, a first conveying pipe 9 and a second conveying pipe 10 connect the first reboiler 2 of the wastewater stripping tower and the wastewater stripping tower 1. One end of the first conveying pipe 9 is connected to the lower middle part of the wastewater stripping tower 1, and the other end of the first conveying pipe 9 is connected to the upper middle part of the first reboiler 2 of the wastewater stripping tower. One end of the second conveying pipe 10 is connected to the bottom of the wastewater stripping tower 1, and the other end of the second conveying pipe 10 is connected to the bottom of the first reboiler 2 of the wastewater stripping tower. This facilitates heat energy exchange between the wastewater stripping tower 1 and the steam condensate through self-siphon circulation, thereby reducing the consumption of low-pressure steam inside the wastewater stripping tower 1.
[0025] As shown in Figure 2 and Figure 3 , the top of the waste water stripping tower second reboiler 6 is provided with a waste water stripping tower second reboiler discharge pipe 11, the other end of which is connected to the middle and lower part of the waste water stripping tower 1, and the bottom of the waste water stripping tower second reboiler 6 is provided with a waste water stripping tower second reboiler feed pipe 12, the other end of which is connected to the bottom of the waste water stripping tower 1. When the waste water stripping tower second reboiler 6 starts to work, the liquid at the bottom of the waste water stripping tower 1 forms a self-siphon circulation under the action of the density difference between gas and liquid phases, and continuously flows into the inside of the waste water stripping tower second reboiler 6. At this time, the steam condensate also enters the inside of the waste water stripping tower second reboiler 6 under the guidance of the pipeline. The steam condensate exchanges heat with the waste water on the surface of the heat exchange tube bundle. The high-temperature heat of the steam condensate is transferred to the low-temperature waste water, and the temperature of the steam condensate itself is reduced, while the temperature of the waste water is increased by absorbing heat. Through heat exchange, the waste water obtains a certain amount of heat before entering the waste water stripping tower 1, thereby reducing the amount of low-pressure steam required for subsequent warming and vaporization in the waste water stripping tower 1.
[0026] As shown in Figure 2 and Figure 3 , one side of the waste water stripping tower second reboiler discharge pipe 11 is provided with a steam condensate input pipe 13 and a second steam condensate discharge pipe 14. The steam condensate input pipe 13 is arranged below the second steam condensate discharge pipe 14. The second steam condensate discharge pipe 14 is used to collect the steam condensate.
[0027] As shown in Figure 2 and Figure 3 , the inside of the waste water stripping tower 1, the waste water stripping tower first reboiler 2 and the waste water stripping tower second reboiler 6 are provided with temperature detectors and pressure detectors. The temperature inside the waste water stripping tower 1 after heat exchange is controlled at 101-1050℃, and the top pressure is controlled at 10-60KPa. The temperature is monitored by the temperature detector. According to the flow rate, properties of the waste water and the operation requirements of the waste water stripping tower 1, the flow rate of the steam is accurately adjusted to ensure that the reboiler provides appropriate heat to make the waste water reach the expected vaporization degree. The pressure is monitored by the pressure detector to avoid excessive high or low pressure inside the reboiler, thereby avoiding affecting the normal operation of the reboiler.
[0028] As shown in Figure 2As shown, the first reboiler 2 of the wastewater stripping tower is a vertical thermosiphon reboiler, which is existing technology. This design results in a short residence time for the liquid inside, making it less prone to scaling, easy to clean, and convenient to adjust. The second reboiler 6 of the wastewater stripping tower is a horizontal thermosiphon reboiler. The heating medium in the horizontal thermosiphon reboiler flows inside the tube. The feed is introduced into the reboiler from the bottom of the wastewater stripping tower 1 through the feed pipe 12. The liquid boils and vaporizes inside the second reboiler 6, forming a low-density vapor-liquid mixture. Due to the density difference between the liquid in the feed pipe 12 and the second steam condensate discharge pipe 14, a static pressure difference is generated, which becomes the driving force for the natural circulation of the fluid. The circulation rate is high, which can prevent the accumulation of high-boiling-point components, reduce the scaling rate, and facilitate cleaning.
[0029] Among them, such as Figure 2 As shown, both the first steam condensate discharge pipe 8 and the second steam condensate discharge pipe 14 are equipped with flow meters, so that when the steam condensate collected by the ammonia oxime unit is sufficient, the second reboiler 6 of the wastewater stripping tower can be shut down.
[0030] During operation, wastewater from the wastewater tank enters the wastewater stripping tower 1 through the wastewater feed pipe 5. The steam condensate collected by the ammonia oxime unit is transported to the second reboiler 6 of the wastewater stripping tower through the steam condensate input pipe 13. After heat exchange, the wastewater stripping tower 1 is kept at a suitable temperature and pressure. When the steam condensate collected by the ammonia oxime unit is insufficient, low-pressure steam is added to the first reboiler 2 of the wastewater stripping tower through the low-pressure steam inlet 7. When the steam condensate collected by the ammonia oxime unit is sufficient, the first reboiler 2 of the wastewater stripping tower is shut down. The heat exchange between the steam condensate and the wastewater in the second reboiler 6 of the wastewater stripping tower is relied upon to provide sufficient heat for the wastewater stripping tower 1, achieving more efficient and energy-saving operation.
[0031] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that cannot be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. An ammonia oxime plant wastewater process double reboiler characterized by, The application relates to a waste water stripping tower (1), which is provided with a waste water stripping tower first reboiler (2) on one side, is connected with a waste water stripping tower gas phase outlet (3) at the top, is connected with a waste water stripping tower discharge pipe (4) at the bottom, is connected with a waste water feeding pipe (5) at the middle upper part, is connected with a waste water stripping tower second reboiler (6) at the middle lower part, and is provided with the waste water stripping tower second reboiler (6) on the side, away from the waste water stripping tower first reboiler (2).
2. An ammonia oxonation device wastewater process double reboiler according to claim 1, characterized by, The waste water stripping tower first reboiler (2) is connected with a low-pressure steam inlet (7) on the side, away from the waste water stripping tower (1), and is provided with a first steam condensate discharge pipe (8) below the low-pressure steam inlet (7), which is connected with the waste water stripping tower first reboiler (2).
3. An ammonia oxonation device wastewater process double reboiler according to claim 1, characterized by, The waste water stripping tower first reboiler (2) and the waste water stripping tower (1) are connected with a first conveying pipe (9) and a second conveying pipe (10), one end of the first conveying pipe (9) is connected with the middle lower part of the waste water stripping tower (1), the other end of the first conveying pipe (9) is connected with the middle upper part of the waste water stripping tower first reboiler (2), one end of the second conveying pipe (10) is connected with the bottom of the waste water stripping tower (1), and the other end of the second conveying pipe (10) is connected with the bottom of the waste water stripping tower first reboiler (2).
4. The dual reboiler of claim 1, wherein, The waste water stripping tower second reboiler (6) is provided with a waste water stripping tower second reboiler discharge pipe (11) at the top, the other end of the waste water stripping tower second reboiler discharge pipe (11) is connected with the middle lower part of the waste water stripping tower (1), the waste water stripping tower second reboiler (6) is provided with a waste water stripping tower second reboiler feeding pipe (12) at the bottom, and the other end of the waste water stripping tower second reboiler feeding pipe (12) is connected with the bottom of the waste water stripping tower (1).
5. An ammonia oxonation device wastewater process double reboiler according to claim 4, characterized by, The waste water stripping tower second reboiler discharge pipe (11) is provided with a steam condensate input pipe (13) and a second steam condensate discharge pipe (14) on one side, and the steam condensate input pipe (13) is arranged below the second steam condensate discharge pipe (14).
6. An ammonia oxonation device wastewater process double reboiler according to claim 1, characterized by, Temperature detectors and pressure detectors are arranged in the waste water stripping tower (1), the waste water stripping tower first reboiler (2) and the waste water stripping tower second reboiler (6).
7. An ammonia oxonation device wastewater process double reboiler according to claim 1, characterized by, The waste water stripping tower first reboiler (2) is a vertical thermosyphon reboiler, and the waste water stripping tower second reboiler (6) is a horizontal thermosyphon reboiler.
8. The dual reboiler of claim 2, wherein, Flow monitoring meters are arranged in the first steam condensate discharge pipe (8) and the second steam condensate discharge pipe (14).