On-line discharging system for catalyst in acrylonitrile device reactor
By designing an online unloading system that combines a cyclone separator and an injector with nitrogen power, the problem of catalysts being unable to be unloaded online from the reactor in an acrylonitrile unit was solved. This enabled catalyst unloading without shutdown, improving production efficiency and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-20
- Publication Date
- 2026-04-03
AI Technical Summary
In existing technologies, the catalyst in the reactor of an acrylonitrile plant needs to be periodically unloaded to maintain its activity, but the shutdown process is lengthy and costly, and cannot be carried out under normal production conditions.
An online unloading system comprising a cyclone separator, an injector, and a catalyst buffer tank was designed. Using nitrogen as power, the catalyst is extracted by the injector and separated in the buffer tank. Nitrogen backflushing is used to loosen and transport the catalyst, thus achieving online unloading.
This allows for online catalyst discharge without shutdown, maintaining optimal fluidization in the reactor and reducing operating costs and time losses.
Smart Images
Figure CN224071918U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of chemical system technology, specifically to an online catalyst unloading system in an acrylonitrile unit reactor. Background Technology
[0002] The acrylonitrile unit reactor is a fluidized bed reactor. The catalyst activity within the reactor decreases as the reaction proceeds, requiring periodic replenishment of new catalyst to maintain average activity. As catalyst accumulates in the reactor, the bed density increases, leading to poorer fluidization and impacting product yield and quality. Therefore, some catalyst needs to be removed to maintain optimal fluidization. However, catalyst cannot be removed during normal production, necessitating shutdown for processing. This shutdown is time-consuming and costly. Utility Model Content
[0003] The purpose of this invention is to overcome the shortcomings of the existing technology and provide an online catalyst unloading system for an acrylonitrile plant reactor.
[0004] To achieve the above objectives, the technical solution of this utility model is: an online catalyst unloading system in an acrylonitrile unit reactor, characterized in that: it includes an acrylonitrile unit reactor, a cyclone separator, an injector, and a catalyst buffer tank, the top of the catalyst buffer tank is connected to the cyclone separator and the injector, the injector is respectively connected to a nitrogen pipeline and a sampling pipeline, and the other end of the sampling pipeline is connected to the catalyst sampling port of the acrylonitrile unit reactor.
[0005] Furthermore, the catalyst buffer tank is symmetrically provided with two gas inlets at the bottom, and the two gas inlets are respectively connected to nitrogen pipelines.
[0006] Furthermore, the bottom of the catalyst buffer tank is connected to the catalyst storage tank via a delivery pipeline, and a nitrogen branch line is connected to the delivery pipeline near the catalyst buffer tank. The other end of the nitrogen branch line is connected to a nitrogen pipeline at one of the gas inlets.
[0007] Furthermore, a conveying air duct is connected to the conveying pipeline.
[0008] Furthermore, the gas outlet of the cyclone separator is connected to a quench tower via a pipeline.
[0009] Furthermore, a second sight glass is provided on the gas outlet pipeline of the cyclone separator.
[0010] Furthermore, the catalyst buffer tank is provided with a first viewing mirror on its side wall.
[0011] Furthermore, the reactor gas outlet of the acrylonitrile unit is connected to a quench tower via a pipeline.
[0012] The beneficial effects of this invention are as follows: This invention allows for online unloading of catalyst from the acrylonitrile unit reactor without shutdown, maintaining a suitable catalyst level in the reactor to ensure fluidization efficiency. Using nitrogen as the injector power source eliminates the need for additional power equipment; the nitrogen enters the quench tower without adversely affecting unit operation. Two gas inlets at the bottom of the catalyst buffer tank are connected to nitrogen pipelines, serving as backflushing air lines for loosening the catalyst and pressurizing it during unloading. Attached Figure Description
[0013] Figure 1 This is a system diagram of this utility model.
[0014] In the diagram: 1. Acrylonitrile unit reactor; 2. Cyclone separator; 3. Injector; 4. Catalyst buffer tank; 5. Sampling line; 6. Delivery line; 7. Nitrogen branch line; 8. Delivery air line; 9. First sight glass; 10. Second sight glass. Detailed Implementation
[0015] Example:
[0016] like Figure 1 As shown, an online catalyst unloading system in an acrylonitrile unit reactor includes an acrylonitrile unit reactor 1, a cyclone separator 2, an injector 3, and a catalyst buffer tank 4. The top of the catalyst buffer tank 4 is connected to the cyclone separator 2 and the injector 3. The injector 3 is connected to a nitrogen pipeline and a sampling pipeline 5, respectively. The other end of the sampling pipeline 5 is connected to the catalyst sampling port of the acrylonitrile unit reactor 1.
[0017] The catalyst buffer tank 4 has two symmetrical gas inlets at its bottom, each connected to a nitrogen pipeline. The bottom of the catalyst buffer tank 4 is connected to a catalyst storage tank via a delivery pipeline 6. A nitrogen branch line 7 is connected to the delivery pipeline 6 near the catalyst buffer tank, and the other end of the nitrogen branch line 7 is connected to the nitrogen pipeline at one of the gas inlets of the catalyst buffer tank 4. A delivery air pipeline 8 is connected to the delivery pipeline 6.
[0018] The gas outlet of the cyclone separator 2 is connected to the quench tower via a pipeline. A second sight glass 10 is provided on the gas outlet pipeline of the cyclone separator. The catalyst buffer tank 4 has two first sight glasses 9 on its side wall, arranged vertically.
[0019] The gas outlet of reactor 1 in the acrylonitrile unit is connected to a quench tower via a pipeline.
[0020] Working principle: The catalyst sampling port of reactor 1 in the acrylonitrile unit serves as the catalyst extraction port. The injector 3, powered by nitrogen, extracts the reaction gas containing the catalyst from reactor 1. The extracted reaction gas enters the catalyst buffer tank 4, and then, after separation by the cyclone separator 2, it is sent to the quench tower. The separated catalyst remains in the catalyst buffer tank 4. Catalyst loss is observed through the second sight glass 10, and the catalyst level in the catalyst buffer tank 4 is observed through the two first sight glasses 9. Two gas inlets at the bottom of the catalyst buffer tank 4 are connected to nitrogen pipelines, serving as backflushing air lines for loosening the catalyst and pressurizing it during unloading. A nitrogen branch line 7 and a conveying air line 8 are connected to the conveying pipeline 6 at the bottom of the catalyst buffer tank 4, transferring the catalyst to the catalyst storage tank via nitrogen and conveying air.
[0021] The embodiments described above are merely preferred solutions of this utility model and are not intended to limit this utility model in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.
[0022] In the description of this utility model, it should be understood that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
Claims
1. An online catalyst discharge system for an acrylonitrile unit reactor, characterized in that: It includes an acrylonitrile unit reactor (1), a cyclone separator (2), an injector (3) and a catalyst buffer tank (4). The top of the catalyst buffer tank (4) is connected to the cyclone separator (2) and the injector (3). The injector (3) is connected to a nitrogen pipeline and a sampling pipeline (5) respectively. The other end of the sampling pipeline (5) is connected to the catalyst sampling port of the acrylonitrile unit reactor (1).
2. The online catalyst discharge system in the reactor of an acrylonitrile unit according to claim 1, characterized in that: The catalyst buffer tank (4) is symmetrically provided with two gas inlets at the bottom, and the two gas inlets are respectively connected to nitrogen pipelines.
3. The online catalyst discharge system in the reactor of the acrylonitrile unit according to claim 2, characterized in that: The catalyst buffer tank (4) is connected to the catalyst storage tank at the bottom via a delivery pipeline (6). A nitrogen branch line (7) is connected to the delivery pipeline (6) near the catalyst buffer tank (4). The other end of the nitrogen branch line (7) is connected to a nitrogen pipeline at one of the gas inlets.
4. The online catalyst discharge system in the reactor of an acrylonitrile unit according to claim 3, characterized in that: The delivery pipeline (6) is connected to a delivery air pipeline.
5. The online catalyst discharge system in the reactor of an acrylonitrile unit according to claim 1, characterized in that: The gas outlet of the cyclone separator (2) is connected to the quench tower via a pipeline.
6. The online catalyst discharge system in the reactor of an acrylonitrile unit according to claim 5, characterized in that: The cyclone separator (2) is equipped with a second sight glass (10) on the gas outlet pipeline.
7. The online catalyst discharge system in the reactor of an acrylonitrile unit according to claim 1, characterized in that: The catalyst buffer tank (4) is provided with a first sight glass (9) on its side wall.
8. The online catalyst discharge system in the reactor of an acrylonitrile unit according to claim 1, characterized in that: The gas outlet of the reactor (1) in the acrylonitrile unit is connected to a quench tower via a pipeline.