Acrylonitrile anti-polymerization production system
The acrylonitrile anti-polymerization production system, designed with multi-head metering pumps and 5 filling points, solves the problem of easy polymerization of acrylonitrile in the distillation column, realizes stable production and long-term operation of acrylonitrile, and reduces energy consumption and product loss.
Patent Information
- Application Number
- CN202422641361.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2025-10-24
- Estimated Expiration
- 2034-10-31
AI Technical Summary
In existing technologies, acrylonitrile is prone to polymerization in distillation columns, leading to product loss and short operating cycles. Uneven injection of polymerization inhibitors also affects system stability.
The system employs a multi-head metering pump design and five polymerization inhibitor filling points, combined with calibration columns and pressure stabilizing valves, to ensure accurate addition of the polymerization inhibitor. The system connects the reactor, quench tower, quench aftercooler, absorption tower, distillation tower, and product tower via pipelines, and uses five parallel delivery pipelines to the critical locations via the polymerization inhibitor tank.
It effectively prevents acrylonitrile polymerization, reduces product loss, extends equipment operating cycle, reduces energy consumption, and improves the accuracy and stability of polymerization inhibitor addition.
Smart Images
Figure CN223464445U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to propylene nitrile production technical field, especially a kind of propylene nitrile anti polymerization production system. BACKGROUND
[0002] Propylene nitrile, chemical formula CH2=CHCN, molecular weight 53.06, colorless liquid, has peach kernel smell, slightly soluble in water, easily soluble in most organic solvents.Propylene nitrile is a kind of conjugated unsaturated nitrile, contains carbon-carbon double bond, carbon-nitrogen triple bond in molecule, propylene nitrile in aqueous phase system, extremely easy to occur polymerization reaction, if polymerization speed will be faster under oxidation-reduction system.To prevent the polymerization of propylene nitrile in rectifying column, avoid product propylene nitrile loss, improve device running cycle, an effective propylene nitrile production system and supporting technology that can prevent propylene nitrile polymerization are urgently needed to be developed.
[0003] The current technology is to use hydroquinone as polymerization inhibitor, respectively in the quencher, first rectifying column gas cooler, second rectifying column overhead and product column overhead Set injection point, but there are certain defects, on the one hand, hydroquinone as polymerization inhibitor, there is certain limitation to polymerization effect, on the other hand, using conventional metering pump injection, due to the back pressure of each injection point is low, it is difficult to ensure that injection amount is reasonably distributed, which affects the stable, long-period operation of propylene nitrile system. UTILITY MODEL CONTENT
[0004] To solve the above technical problems, the utility model provides a kind of propylene nitrile anti polymerization production system, can effectively prevent the polymerization of propylene nitrile in rectifying column, avoid product propylene nitrile loss, improve device system running cycle.
[0005] The utility model realizes by the following technical scheme:
[0006] The propylene nitrile anti polymerization production system, including reactor, quencher, quencher, absorption tower, first rectifying column, gas cooler, oil-water layer separator, second rectifying column, product column connected by pipeline in sequence, the propylene nitrile anti polymerization production system further includes polymerization inhibitor tank.
[0007] Preferably, the quencher and gas cooler are provided with a circulating water jacket clamp.
[0008] Preferably, the connecting pipeline between the quencher and the absorption tower is provided with a mechanical pump; the connecting pipeline between the absorption tower and the first rectifying column is provided with a mechanical pump; the connecting pipeline between the oil-water layer separator and the second rectifying column is provided with a mechanical pump; and the connecting pipeline between the second rectifying column and the product column is provided with a mechanical pump.
[0009] Preferably, the second rectifying column is provided with a second rectifying column reflux pipeline, and the second rectifying column reflux pipeline is provided with a mechanical pump.
[0010] The outlet of the polymerization inhibitor tank is provided with five polymerization inhibitor conveying pipes in parallel, which are connected with the outlet of the post-quench cooler, the inlet of the gas phase cooler, the second rectifying tower feed pipe, the second rectifying tower reflux pipe and five filling points of the second rectifying tower respectively.
[0011] Preferably, the polymerization inhibitor conveying pipes are all provided with metering pumps.
[0012] Preferably, the inlet of the metering pump is provided with a calibration column, the outlet of the metering pump is provided with a pressure stabilizing valve, and the metering pump is controlled by a motor.
[0013] Compared with the prior art, the utility model has the beneficial effects as follows:
[0014] 1. The utility model can effectively prevent the polymerization of acrylonitrile in the rectifying tower, avoid the loss of product acrylonitrile and improve the device system operation cycle.
[0015] 2. The design of the multi-head metering pump can not only reduce the total power and power consumption, but also reduce the pulsation influence and provide a larger adjustment ratio range.
[0016] 3. The five polymerization inhibitor filling points reduce the generation of polymers in the whole system.
[0017] 4. The calibration column is arranged at the inlet of the metering pump, the metering pump quantitative calibration process is increased, the actual use amount of each filling point is periodically metered and calibrated, and the accuracy of the polymerization inhibitor addition metering can be improved.
[0018] 5. The pressure stabilizing valve is arranged at the outlet of the metering pump, the pressure difference between the inlet and the outlet of the metering pump is improved; since the back pressure difference of the five filling points of the polymerization inhibitor is large, the pressure of the filling point with the lowest outlet back pressure is 0.05 MPa, the pressure difference with the inlet of the metering pump is basically 0, the pressure of the filling point with the highest outlet back pressure of the metering pump is 0.35 MPa, which leads to a large difference between the actual addition amount and the theoretical addition amount of the five filling points, and through the design of the pressure stabilizing valve arranged at the outlet of the metering pump, the pressure of the five pump outlet of the metering pump is unified, the pressure is set to 0.35-0.45 MPa, so that the stability of the polymerization inhibitor addition flow is ensured. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 It is a structure schematic diagram of an acrylonitrile anti-polymerization production system.
[0020] Wherein: 1, reactor; 2, quench tower; 3, post-quench cooler; 4, absorption tower; 5, first rectifying tower; 6, gas phase cooler; 7, oil-water layering device; 8, second rectifying tower; 9, product tower; 10, polymerization inhibitor tank; 11, second rectifying tower reflux pipe; 12, polymerization inhibitor conveying pipe; 13, second rectifying tower feed pipe; 14, filling point; 15, metering pump; 16, calibration column; 17, pressure stabilizing valve. DETAILED DESCRIPTION
[0021] The preferred scheme of the utility model will be further described below in combination with the drawings.
[0022] Example 1
[0023] As Figure 1 shown, the acrylonitrile anti-polymerization production system comprises a reactor 1, a quenching tower 2, a post-quenching cooler 3, an absorption tower 4, a first rectifying tower 5, a gas-phase cooler 6, an oil-water separator 7, a second rectifying tower 8 and a finished product tower 9 connected in sequence through pipelines.
[0024] The post-quenching cooler 3 and the gas-phase cooler 6 are provided with circulating water jacket clamps.
[0025] The connecting pipeline between the post-quenching cooler 3 and the absorption tower 4 is provided with a mechanical pump; the connecting pipeline between the absorption tower 4 and the first rectifying tower 5 is provided with a mechanical pump; the connecting pipeline between the oil-water separator 7 and the second rectifying tower 8 is provided with a mechanical pump; and the connecting pipeline between the second rectifying tower 8 and the finished product tower 9 is provided with a mechanical pump.
[0026] The second rectifying tower 8 is provided with a second rectifying tower reflux pipeline 11, and the second rectifying tower reflux pipeline 11 is provided with a mechanical pump.
[0027] Five polymerization inhibitor conveying pipelines 12 are arranged in parallel at the discharge port of the polymerization inhibitor tank 10, and are connected to the outlet of the post-quenching cooler 3, the inlet of the gas-phase cooler 6, the second rectifying tower feeding pipeline 13, the second rectifying tower reflux pipeline 11 and the five filling points 14 at the top of the second rectifying tower 8, respectively.
[0028] The polymerization inhibitor conveying pipelines 12 are all provided with metering pumps 15.
[0029] A calibration column 16 is arranged at the inlet of the metering pump 15, a pressure stabilizing valve 17 is arranged at the outlet of the metering pump 15, and the metering pump 15 is controlled by a motor.
[0030] The working process of the utility model is as follows:
[0031] In the acrylonitrile anti polymerization production system, acrylonitrile is generated in the reactor 1, cooled by the quenching tower 2 and the quenched cooler 3, enters the absorption tower 4, and is absorbed by the physical absorption method. The acrylonitrile aqueous solution after absorption enters the first rectifying tower 5 for preliminary rectification, the vapor phase overhead discharge enters the oil-water separator 7 after being condensed by the gas phase cooler 6, most of the water is removed in the oil-water separator 7, enters the second rectifying tower 8 for purification, and finally enters the finished product tower 9. In the production process, the polymerization inhibitor tank 10 outputs the polymerization inhibitor, which is injected from five filling points 14, the pressure of the pressure stabilizing valve 17 is set to 0.35-0.45 MPa, the stability of the polymerization inhibitor injection flow is ensured, and the actual usage of each filling point 14 is periodically metered and calibrated to improve the accuracy of the polymerization inhibitor injection metering.
Claims
1. An acrylonitrile anti-polymerization production system, characterized by: Including reactor (1), quench tower (2), post-quench cooler (3), absorption tower (4), first rectification tower (5), gas phase cooler (6), oil-water separator (7), second rectification tower (8), product tower (9) connected in turn by pipeline, also including polymerization inhibitor tank (10), the second rectification tower (8) is equipped with second rectification tower reflux pipeline (11); The discharge port of the polymerization inhibitor tank (10) is provided with five polymerization inhibitor conveying pipelines (12) side by side; The polymerization inhibitor conveying pipelines (12) are respectively connected with the outlet of the post-quench cooler (3), the inlet of the gas phase cooler (6), the second rectification tower feed pipeline (13), the second rectification tower reflux pipeline (11) and the five filling points (14) on the top of the second rectification tower (8); The polymerization inhibitor conveying pipelines (12) are each provided with a metering pump (15); The inlet of the metering pump (15) is provided with a calibration column (16).
2. The acrylonitrile anti-polymerization production system according to claim 1, characterized in that: The post-quench cooler (3) and the gas phase cooler (6) are provided with circulating water jacket clamps.
3. The acrylonitrile anti-polymerization production system according to claim 1, characterized in that: The connecting pipeline between the post-quench cooler (3) and the absorption tower (4) is provided with a mechanical pump, the connecting pipeline between the absorption tower (4) and the first rectification tower (5) is provided with a mechanical pump, the connecting pipeline between the oil-water separator (7) and the second rectification tower (8) is provided with a mechanical pump, the connecting pipeline between the second rectification tower (8) and the product tower (9) is provided with a mechanical pump, and the second rectification tower reflux pipeline (11) is provided with a mechanical pump.
4. The acrylonitrile anti-polymerization production system according to claim 1, characterized in that: The outlet of the metering pump (15) is provided with a pressure stabilizing valve (17).
5. The acrylonitrile anti-polymerization production system according to claim 1, characterized in that: The metering pump (15) is controlled by a motor.