Cooling device for acetic anhydride production

Abstract

This invention provides a cooling device for acetic anhydride production, including a cooling cylinder. The lower end of the cooling cylinder has a gas inlet pipe and a support, while the upper end has a gas outlet pipe. Inside the cooling cylinder, along its axis, are a primary spiral coil and a secondary spiral coil. Both the primary and secondary spiral coils have water inlets at one end and water outlets at the other. The lower end of the primary spiral coil has a primary swirl vane, and a secondary swirl vane is located between the primary and secondary spiral coils. This invention utilizes gradient cooling through two stages of variable-diameter spiral coils, combined with two stages of swirl vanes to enhance the turbulence of high-temperature ketene gas, significantly improving the cooling efficiency of ketene gas and reducing energy consumption, making it suitable for continuous industrial production.

Description

Technical Field

[0001] This utility model belongs to the technical field of acetic anhydride production equipment, specifically relating to a cooling device for acetic anhydride production. Background Technology

[0002] Acetic anhydride, also known as acetic anhydride or anhydrous acetic acid, is an important organic chemical raw material. It is chemically very reactive, has a strong acetic acid odor, a sour taste, is hygroscopic, slightly soluble in water, and slowly hydrolyzes in water to form acetic acid. It is soluble in organic solvents such as alcohols, ethers, and acetone. Acetic anhydride is often used as an acetylation reagent, and is also used in the manufacture of pharmaceuticals, dyes, cellulose acetate, initiators, and bleaching agents. It is also widely used in the rubber industry, textile industry, semiconductor manufacturing industry, and organic synthesis.

[0003] Currently, the industry commonly uses the ketene process for the industrial production of acetic anhydride. Also known as the acetic acid cracking process, the ketene process uses acetic acid as a raw material and triethyl phosphate as a catalyst to produce acetic anhydride at high temperatures. The entire process is carried out in two steps. First, gas-phase acetic acid is cracked to produce ketene and water, with an optimal reaction temperature of 730-750℃. Then, the ketene is condensed and cooled, exiting from the high-boiling-point acetic anhydride, acetic acid, and water, and reacts with recycled acetic acid to convert it into acetic anhydride. The acetic anhydride production process requires rapid cooling of the high-temperature ketene gas. However, existing technologies using water coolers for cooling ketene have a simple structure and still suffer from the following problems: uneven heat exchange between the cooling water and the gas, leading to localized overheating or cooling blind spots; and the inability of single-temperature cooling water to achieve gradient cooling, affecting cooling efficiency. Utility Model Content

[0004] To address the problems existing in the prior art, the purpose of this utility model is to provide a cooling device for acetic anhydride production, which can significantly improve the cooling efficiency of ketene gas through two-stage gradient cooling and turbulent flow enhancement by swirl blades, and is suitable for industrial continuous production.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A cooling device for acetic anhydride production includes a cooling cylinder. The lower end of the cooling cylinder has a gas inlet pipe and a support, and the upper end has a gas outlet pipe. Inside the cooling cylinder, along its axis, are a primary spiral coil and a secondary spiral coil. Each of the primary and secondary spiral coils has a water inlet at one end and a water outlet at the other end. The lower end of the primary spiral coil has a primary swirl vane, and a secondary swirl vane is located between the primary and secondary spiral coils.

[0007] Furthermore, the gas inlet pipe is equipped with a gas control valve.

[0008] Furthermore, the diameter of the primary spiral coil is 1.5 times that of the secondary spiral coil.

[0009] Furthermore, the water inlet is equipped with a water inlet control valve, and all water inlets are installed on the same side of the cooling cylinder, while all water outlets are installed on the other side of the cooling cylinder. The water inlet method of the cooling cylinder is top inlet and bottom outlet.

[0010] Furthermore, the first-stage swirling blade and the second-stage swirling blade have the same structure, and the cooling cylinder is provided with through-hole baffles for supporting the first-stage swirling blade and the second-stage swirling blade respectively. The first-stage swirling blade and the second-stage swirling blade are rotatably connected to the upper end of the through-hole baffles by bearings.

[0011] Furthermore, temperature sensors are installed inside both the gas outlet pipe and the water outlet pipe.

[0012] Furthermore, an electrical control box is provided on the outer wall of the cooling cylinder. The electrical control box is electrically connected to the gas control valve and the temperature sensor respectively, and controls the state of the gas control valve and the water inlet control valve according to the temperature detected by the temperature sensor.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] This invention provides a cooling device for acetic anhydride production. It uses a two-stage variable diameter spiral coil for gradient cooling, and a two-stage swirl vane to enhance the turbulence of high-temperature ketone gas. This allows the cooling water to fully contact the high-temperature ketone gas for heat exchange, resulting in a better cooling effect. At the same time, by intelligently and dynamically adjusting the gas flow rate and cooling water flow rate, it not only reduces energy consumption but also saves manpower, making it more practical. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model.

[0016] In the diagram: 1 Cooling cylinder, 2 Gas inlet pipe, 3 Support, 4 Gas outlet pipe, 5 Primary spiral coil, 6 Secondary spiral coil, 7 Water inlet, 8 Water outlet, 9 Primary swirl vane, 10 Secondary swirl vane, 11 Through-hole baffle. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0018] The terms "upper," "lower," and "one" used in this utility model are merely for clarity of description and are not intended to limit the scope of implementation of this utility model. Any changes or adjustments to their relative relationships, without substantially altering the technical content, shall also be considered within the scope of implementation of this utility model.

[0019] Reference Figure 1 A cooling device for acetic anhydride production includes a cooling cylinder 1. The lower end of the cooling cylinder 1 is provided with a gas inlet pipe 2 and a support 3, the support 3 supporting the cooling cylinder 1. The upper end of the cooling cylinder 1 is provided with a gas outlet pipe 4. Inside the cooling cylinder 1, along its axis, are a primary spiral coil 5 and a secondary spiral coil 6, the diameter of the primary spiral coil 5 being 1.5 times that of the secondary spiral coil 6. Both the primary spiral coil 5 and the secondary spiral coil 6 have a water inlet 7 at one end and a water outlet 8 at the other end. The water inlet 7 is located on the same side of the cooling cylinder 1, and the water outlet 8 is located on the other side of the cooling cylinder 1. The water inlet of the cooling cylinder 1 is from top to bottom. The lower end of the primary spiral coil 5 is provided with a primary swirl vane 9, and a secondary swirl vane 10 is located between the primary spiral coil 5 and the secondary spiral coil 6. The primary swirl vane 9 and the secondary swirl vane 10 have identical structures, and the cooling cylinder 1 is equipped with corresponding through-hole baffles 11 for supporting the primary swirl vane 9 and the secondary swirl vane 10. The primary swirl vane 9 and the secondary swirl vane 10 are rotatably connected to the upper end of the through-hole baffles 11 via bearings. The gas inlet pipe 2 is equipped with a gas control valve, the water inlet pipe 7 is equipped with a water inlet control valve, and temperature sensors are installed in both the gas outlet pipe 4 and the water outlet pipe 8. An electrical control box is installed on the outer wall of the cooling cylinder 1. The electrical control box is electrically connected to the gas control valve and the temperature sensor, and controls the state of the gas control valve and the water inlet control valve according to the temperature detected by the temperature sensor.

[0020] The working principle of this specific embodiment is as follows: High-temperature ketene gas enters the cooling cylinder through the gas inlet pipe and flows upward. First, it passes through the through-hole baffle at the bottom of the cooling cylinder, where the gas obliquely pushes the first-stage swirl vanes to rotate, forming a rotating upward airflow. Then, it passes through the second-stage swirl vanes, forming a strong swirling flow. Ultimately, the high-temperature ketene gas undergoes turbulent intensification, enabling it to fully contact the first-stage and second-stage spiral coils for heat exchange. Since the diameter of the first-stage spiral coil is 1.5 times that of the second-stage spiral coil, meaning the second-stage spiral coils are arranged relatively densely, the high-temperature ketene gas achieves gradient cooling, thus improving cooling efficiency. Cooling water then enters the cooling cylinder through the inlets of the first-stage and second-stage spiral coils to cool the ketene gas. The cooled ketene gas is then discharged from the outlet pipe and exited from the cooling cylinder, completing the cooling process. During the high-temperature ethylene ketone gas cooling process, temperature sensors can monitor the water temperature at the outlet of the two-stage spiral coil and the gas temperature at the outlet of the cooling cylinder in real time. This allows for convenient control of the water inlet control valve and the gas control valve based on the water temperature at the outlet and the gas temperature at the outlet, thereby changing the water flow rate at the cooling water inlet and the inlet rate of the high-temperature ethylene ketone gas. This enables intelligent dynamic adjustment, saving energy and improving cooling efficiency.

[0021] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A cooling device for acetic anhydride production, comprising a cooling cylinder, characterized in that, The cooling cylinder is provided with a gas inlet pipe and a support at its lower end, and a gas outlet pipe at its upper end. Inside the cooling cylinder, a primary spiral coil and a secondary spiral coil are provided along its axis. One end of the primary spiral coil and the secondary spiral coil are provided with a water inlet, and the other end is provided with a water outlet. The lower end of the primary spiral coil is provided with a primary swirl vane, and a secondary swirl vane is provided between the primary spiral coil and the secondary spiral coil.

2. The cooling device for acetic anhydride production according to claim 1, characterized in that, The diameter of the primary spiral coil is 1.5 times that of the secondary spiral coil.

3. A cooling device for acetic anhydride production according to claim 1, characterized in that, All water inlets are installed on the same side of the cooling cylinder, and all water outlets are installed on the other side of the cooling cylinder. The cooling cylinder is installed with water entering from the top and exiting from the bottom.

4. A cooling device for acetic anhydride production according to claim 1, characterized in that, The first-stage and second-stage swirling blades have the same structure, and the cooling cylinder is provided with through-hole baffles for supporting the first-stage and second-stage swirling blades respectively. The first-stage and second-stage swirling blades are rotatably connected to the upper end of the through-hole baffles by bearings.

5. A cooling device for acetic anhydride production according to claim 1, characterized in that, The gas inlet pipe is equipped with a gas control valve, the water inlet is equipped with a water inlet control valve, and temperature sensors are installed in both the gas outlet pipe and the water outlet. An electrical control box is installed on the outer wall of the cooling cylinder. The electrical control box is electrically connected to the gas control valve and the temperature sensor, and controls the state of the gas control valve and the water inlet control valve according to the temperature detected by the temperature sensor.

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