Temperature control system of esterification process tower

Abstract

The utility model relates to the technical field of chemical production, in particular to a temperature control system of an esterification process tower, which comprises a process tower, a gas outlet arranged at the top of the process tower, a plurality of layers of tower plates arranged in the process tower, and a spraying device arranged between the gas outlet of the process tower and the plurality of layers of tower plates. Silk screen filler is arranged on two layers of tower plates close to the spraying device in the process tower, a first temperature sensor is arranged close to an air outlet in the top of the process tower, a second temperature sensor is arranged below the two layers of tower plates provided with the silk screen filler, and the first temperature sensor and the second temperature sensor are respectively connected with a controller. The problems of poor component separation effect and low esterification product quality of an esterification process tower can be solved.

Description

Technical Field

[0001] This utility model relates to the field of chemical production technology, specifically to a temperature control system for an esterification process tower. Background Technology

[0002] In batch polymerization processes, volatile gases generated in the esterification reactor enter the process tower for heat exchange. High-boiling-point substances condense in the process tower and return to the esterification reactor for further reaction; low-boiling-point substances are vaporized from the top of the process tower, further cooled by a cooler, and then enter a reflux tank. For example, in the PET batch polymerization process, a large amount of water is generated during the esterification stage. The process tower typically uses an esterification process tower with 16-18 trays. The operating temperature at the bottom of the process tower is approximately 195-198°C, and the steam temperature at the top of the process tower is approximately 100-105°C. The steam condenses in the cooler and enters the reflux tank. The condensate mainly consists of water and low-boiling-point substances such as acetaldehyde. However, in existing batch polymerization processes, unstable flow rates of volatile gases entering the process tower from the esterification reactor lead to uneven heat transfer within the process tower, resulting in large temperature fluctuations at the top of the process tower. This affects the separation of low-boiling-point and high-boiling-point substances, thus impacting esterification efficiency and reducing the quality of the esterified product. Utility Model Content

[0003] This invention provides a temperature control system for an esterification process tower, which can solve the problems of poor component separation and reduced quality of esterification products in the esterification process tower.

[0004] This application provides the following technical solution:

[0005] A temperature control system for an esterification process tower includes a process tower with an outlet at the top. The process tower contains multiple layers of trays, and a spray device is provided between the outlet and the multiple trays. Wire mesh packing is provided on two trays near the spray device. A first temperature sensor is provided near the outlet at the top of the process tower, and a second temperature sensor is provided below the two trays with wire mesh packing. The first and second temperature sensors are respectively connected to a controller.

[0006] Beneficial Effects: Multi-point monitoring is achieved through a first temperature sensor at the top and a second temperature sensor below the wire mesh packing layer. Combined with a controller to dynamically adjust the heat exchanger, the temperature distribution within the tower is precisely controlled. Especially for the temperature at the top of the tower, real-time temperature adjustment is implemented based on the detected temperature values, effectively responding to emergencies and preventing localized overheating or overcooling. It effectively controls gas phase components, preventing the escape of high-boiling-point substances and ensuring the stripping of low-boiling-point substances, thus improving product purity and yield. The wire mesh packing increases the gas-liquid contact area, promoting component separation and mass transfer. Combined with a spray device, it optimizes liquid distribution and enhances cooling. This further improves separation efficiency and heat exchange efficiency. Simultaneously, the wire mesh packing also functions as a defoamer, reducing the amount of liquid droplets carried by gas into the outlet, lowering the load on subsequent separation processes, optimizing the process, and reducing energy consumption. Multi-point temperature monitoring enhances the system's anti-interference capability, adapts to fluctuations in different operating conditions, reduces the need for manual intervention, and enables more precise temperature adjustment within the process tower. Moreover, compared with existing technologies, it can avoid the need to install a tower top cooler at the top of the process tower. The separation of materials can be achieved by controlling the temperature at the top of the process tower, avoiding heat exchange between hot and cold materials in the tower top cooler to prevent steam hammer, avoiding equipment damage, reducing equipment investment, reducing energy consumption, and effectively reducing production costs.

[0007] Furthermore, the spraying device is connected to the reflux tank via a reflux pipeline, and the reflux pipeline is equipped with a heat exchanger and a reflux pump.

[0008] Beneficial effects: By using a reflux pump and heat exchanger, the temperature and flow rate of the spray liquid can be precisely controlled, which not only optimizes the mass and heat transfer efficiency of the esterification process tower, but also significantly improves the energy efficiency, stability and adaptability of the system. At the same time, it promotes the separation of low-boiling-point substances from high-boiling-point substances and improves product quality.

[0009] Furthermore, the process tower is provided with a cooling structure, which includes an outer shell, and a cooling cavity is formed between the outer shell and the outer wall of the process tower. The cooling cavity is connected to a coolant pipeline, and a cooling regulating valve is provided on the coolant pipeline.

[0010] Beneficial effects: The cooling chamber surrounds the outer wall of the process tower, improving heat exchange efficiency. Real-time control of the coolant flow rate via a cooling regulating valve allows for rapid response to temperature changes, flexibly adapting to different production loads or process requirements (such as start-up, shutdown, or fluctuations in operating conditions), achieving refined temperature management.

[0011] Furthermore, the cooling structure is detachably mounted on the process tower.

[0012] Furthermore, the outer shell of the cooling structure includes a first shell and a second shell, which are fitted together and mounted on the outer wall of the process tower.

[0013] Beneficial effects: No large-scale modifications to the process tower body are required; it can be quickly installed or disassembled through modular components, making it highly adaptable.

[0014] Furthermore, the cooling chamber is equipped with a spiral baffle to form a spiral cooling channel.

[0015] Beneficial effects: The spiral channel forces the coolant to flow spirally along the tower body axis, significantly increasing the flow path length of the coolant in the cavity, extending the contact time with the outer wall of the process tower, and fully absorbing heat.

[0016] Furthermore, the air outlet at the top of the process tower is connected to the inlet of the cooler, the outlet of the cooler is connected to the medium inlet of the reflux tank, the air outlet of the reflux tank is provided with an exhaust pipe, the exhaust pipe is provided with a pressure regulating valve, and the bottom of the process tower is provided with a heating device.

[0017] Beneficial effects: By installing a pressure regulating valve on the exhaust pipe, the pressure inside the process tower can be effectively controlled, ensuring the safe operation of the equipment, as well as the esterification efficiency and the quality of the esterification products.

[0018] Furthermore, a reflux bypass is provided between the liquid inlet and liquid outlet of the heat exchanger, and a regulating valve is provided on the reflux bypass.

[0019] Beneficial effects: By controlling the bypass opening through the regulating valve, the temperature and flow rate of the reflux liquid entering the process tower can be flexibly adjusted, improving the adaptability and reliability of the process tower temperature control system. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a temperature control system for an esterification process tower according to a first embodiment of the present invention;

[0021] Figure 2 This is a diagram showing the assembly of the process tower and its outer shell in Embodiment 2 of the temperature control system for an esterification process tower according to this utility model. Detailed Implementation

[0022] The following detailed description illustrates the specific implementation method:

[0023] The markings in the accompanying drawings include: process tower 1, heating device 101, spray device 102, wire mesh packing 103, cooler 2, reflux tank 3, reflux pump 4, heat exchanger 5, cooling structure 6, first shell 601, second shell 602, first temperature sensor T1, second temperature sensor T2, third temperature sensor T3, fourth temperature sensor T4, fifth temperature sensor T5, pressure regulating valve V1, first regulating valve V2, and second regulating valve V3.

[0024] Example 1

[0025] like Figure 1As shown, a temperature control system for an esterification process tower includes a process tower 1. The process tower 1 has an outlet at its top and an inlet at its bottom for connecting to the esterification reactor. A heating device 101 is located at the bottom of the process tower 1. The outlet at the top of the process tower 1 is connected to the inlet of a cooler 2 via a pipeline. The outlet of the cooler 2 is connected to the medium inlet of a reflux tank 3 via a pipeline. The outlet of the reflux tank 3 is equipped with an exhaust pipe, and a pressure regulating valve V1 is installed on the exhaust pipe. The process tower 1 contains 16-18 trays. Two additional trays can be added above the existing trays according to process requirements to control the top temperature of the esterification process tower 1. A spray device 102 is installed between the outlet of the process tower 1 and the multiple trays. The spray head of the spray device 102 is located above the trays, and the spray device 102 is connected to the reflux tank 3 via a reflux pipeline. A heat exchanger 5 and a reflux pump 4 are installed on the reflux pipeline. The heat exchanger 5 includes a heat exchange liquid pipeline, and a heat exchange regulating valve is installed on the heat exchange liquid pipeline to control the temperature of the heat exchanger 5. Wire mesh packing 103 is installed on the two layers of trays near the spray device 102 inside the process tower 1. A first temperature sensor T1 is installed on the process tower 1 near the top outlet of the process tower 1. A second temperature sensor T2 is installed below the two layers of trays with wire mesh packing 103. A third temperature sensor T3 is installed on the reflux pipeline at the inlet end of the heat exchanger 5, and a fourth temperature sensor T4 is installed on the reflux pipeline at the outlet end. A fifth temperature sensor T5 is installed on the outlet pipeline of the cooler 2. The cooler 2 includes a coolant pipeline, and a cooling regulating valve is installed on the coolant pipeline to control the flow rate of the coolant in the cooler 2.

[0026] The first temperature sensor T1, the second temperature sensor T2, the third temperature sensor T3, the fourth temperature sensor T4, the fifth temperature sensor T5, the heat exchange regulating valve of the heat exchanger 5, the cooling regulating valve of the cooler 2, the reflux pump 4, and the heating device 101 are respectively connected to the controller.

[0027] The temperature control system of esterification process tower 1 operates as follows:

[0028] Volatile gases generated in the esterification reactor enter process column 1 through the inlet at the bottom. After passing through the heating device 101 at the bottom of process column 1, they move towards the top, undergoing heat exchange. The condensate formed after cooling high-boiling-point substances returns to the esterification reactor for further reaction. Low-boiling-point substances are extracted from the outlet at the top of process column 1, cooled by cooler 2, and the resulting condensate enters the reflux tank 3 for storage. The controller collects the system temperature values ​​in real time using temperature sensors T1, T2, T3, T4, and T5, controlling cooler 2, reflux pump 4, heat exchanger 5, and heating device 101 to ensure the separation effect of process column 1. Cooler 2 on the reflux line is controlled by the temperature values ​​and their differences detected by temperature sensors T1, T2, T3, and T4.

[0029] For example, in the PET batch polymerization process, the first temperature sensor T1 monitors the temperature at the top of process tower 1 in real time. When the steam temperature at the top of process tower 1 exceeds the threshold (e.g., greater than 105℃ or less than 100℃), the controller controls the heat medium feed regulating valve of the heat medium supply pipe of the heating device 101 to regulate the temperature inside the process tower. At the same time, the temperature of the spray liquid of the spray device is adjusted through the heat exchanger 5 to achieve emergency cooling of the top of the process tower, ensuring effective separation of high-boiling-point substances from low-boiling-point substances. When the temperature detected by the first temperature sensor T1 reaches the threshold, the temperature of the spray liquid of the spray device is controlled in conjunction with the temperature detected by the second temperature sensor T2, so that the temperature inside the process tower quickly and gradually returns to the threshold range.

[0030] Example 2

[0031] The difference between this embodiment and Embodiment 1 is that a cooling structure 6 is provided on the outer wall of the process tower 1, corresponding to the two layers of tower plates with wire mesh packing 103 and the spray device 102. The cooling structure 6 is detachably installed on the outer wall of the process tower 1 by bolts. The cooling structure 6 includes an outer shell, which includes a first shell 601 and a second shell 602 symmetrically arranged. The first shell 601 and the second shell 602 are fitted together by bolts onto the outer wall of the process tower 1 (e.g., ...). Figure 2 As shown, both the first shell 601 and the second shell 602 are equipped with sealing gaskets. A cooling chamber is formed between the outer shell and the outer wall of the process tower 1. The cooling chamber is connected to a coolant pipeline, and a coolant regulating valve is installed on the coolant pipeline to control the coolant flow rate of the cooling structure 6. The coolant regulating valve is connected to a controller. The coolant regulating valve of the cooling structure 6 is controlled by the temperature values ​​and their difference detected by the first temperature sensor T1 and the second temperature sensor T2. In conjunction with the spray device, it performs emergency cooling on the top of the process tower to ensure the separation effect of the substances.

[0032] Example 3

[0033] The difference between this embodiment and embodiment two is that a spiral baffle is provided inside the cooling chamber to form a spiral cooling channel.

[0034] Example 4

[0035] The difference between this embodiment and Embodiment 1 is that a first regulating valve V2 is sequentially installed on the reflux pipeline at the inlet end of the heat exchanger 5. A reflux bypass is provided between the inlet and outlet ends of the heat exchanger 5. The inlet end of the reflux bypass is located between the first regulating valve V2 and the third temperature sensor T3, and the outlet end of the reflux bypass is located between the fourth temperature sensor T4 and the process tower 1. A second regulating valve V3 is installed on the reflux bypass. During the esterification reaction, when the reflux temperature detected by the third temperature sensor T3 exceeds the threshold, the first regulating valve V2 opens and the second regulating valve V3 closes. The reflux liquid enters the process tower 1 after heat exchange in the heat exchanger 5. When the reflux temperature detected by the third temperature sensor T3 is within the threshold range, or when the heat exchanger 5 malfunctions, the first regulating valve V2 closes and the second regulating valve V3 opens. The reflux liquid enters the process tower 1 through the reflux bypass.

[0036] The above are merely embodiments of this utility model, and the utility model is not limited to the field covered by this embodiment. Commonly known structures and characteristics in the solutions are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A temperature control system for an esterification process column comprising a process column, characterized in that, The process tower is provided with a gas outlet, the process tower is provided with multiple layers of tower plates, the process tower gas outlet and multiple layers of tower plates are provided with a spraying device, two layers of tower plates close to the spraying device in the process tower are provided with wire mesh packing, a first temperature sensor is arranged close to the process tower top gas outlet, a second temperature sensor is arranged below the two layers of tower plates provided with wire mesh packing, and the first temperature sensor and the second temperature sensor are connected with a controller.

2. The temperature control system for an esterification process column of claim 1, wherein: The spraying device is connected with a reflux tank through a reflux pipeline, and a heat exchanger and a reflux pump are arranged on the reflux pipeline.

3. The temperature control system for an esterification process column of claim 1, wherein: The process tower is provided with a cooling structure, the cooling structure comprises an outer shell, a cooling cavity is formed between the outer shell and the outer wall of the process tower, the cooling cavity is communicated with a cooling liquid pipeline, and a cooling adjusting valve is arranged on the cooling liquid pipeline.

4. The temperature control system for an esterification process column of claim 3, wherein: The cooling structure is detachably mounted on the process tower.

5. The temperature control system for an esterification process column of claim 4, wherein: The outer shell of the cooling structure comprises a first shell and a second shell, and the first shell and the second shell are assembled on the outer wall of the process tower.

6. The temperature control system for an esterification process column of claim 3, wherein: A spiral partition is arranged in the cooling cavity to form a spiral cooling channel.

7. The temperature control system for an esterification process column of claim 1, wherein: The gas outlet at the top of the process tower is connected with the inlet end of a cooler, the outlet end of the cooler is connected with the medium inlet of a reflux tank, the gas outlet of the reflux tank is provided with an exhaust pipeline, a pressure adjusting valve is arranged on the exhaust pipeline, and a heating device is arranged at the bottom of the process tower.

8. The temperature control system for an esterification process column of claim 2, wherein: A reflux bypass is arranged between the liquid inlet end and the liquid outlet end of the heat exchanger, and an adjusting valve is arranged on the reflux bypass.

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