Crude acetic anhydride falling film evaporator

Abstract

The utility model discloses a crude acetic anhydride falling-film evaporator which comprises an evaporator shell, a feeding pipe fixedly mounted at the top end of the evaporator shell, a discharging pipe fixedly mounted at the bottom end of the evaporator shell, an upper partition plate fixedly mounted in an inner cavity of the evaporator shell, a lower partition plate fixedly mounted in the inner cavity of the evaporator shell, and a baffle plate fixedly mounted in the inner cavity of the evaporator shell, a plurality of heat exchange pipes are fixedly installed between the upper partition plate and the lower partition plate, a lifting base is arranged above the upper partition plate, and a plurality of blocking rods are fixedly bonded to the lifting base. The screw rod can be driven by the servo motor to rotate in the forward direction, so that the moving rod moves upwards on the screw rod under the guiding action of the two guide rods, when the moving rod moves upwards, the lifting seat can be driven by the connecting rod to move upwards, the plugging rods are pulled out of the heat exchange tube, and feed liquid can flow into the heat exchange tube after being accumulated at a certain height. Therefore, the feed liquid is uniformly distributed in each heat exchange tube, and the film forming effect of the feed liquid is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of falling film evaporators, in particular to a falling film evaporator for crude acetic anhydride. Background Art

[0002] Falling film evaporation is to add the feed liquid from the upper tube box of the falling film evaporator heating chamber, and evenly distribute it to each heat exchange tube through the liquid distribution and film forming device. Under the action of gravity, vacuum induction and airflow, it flows from top to bottom in a uniform film. During the flow process, it is heated and vaporized by the shell side heating medium, and the generated steam and liquid phase enter the separation chamber of the evaporator together. After the vapor and liquid are fully separated, the steam enters the condenser for condensation or enters the next effect evaporator as a heating medium, thereby realizing multi-effect operation, and the liquid phase is discharged from the separation chamber.

[0003] A falling film evaporator is required for the production and processing of crude acetic anhydride. However, when the existing falling film evaporator is in use, the feed liquid enters the upper cavity from the feed inlet at the top of the falling film evaporator, and enters the heat exchange tubes through the through holes on the surface of the cavity. In the above process, the feed liquid is easily unevenly distributed in each heat exchange tube, which will affect the film-forming effect of the feed liquid and further reduce the evaporation effect. Utility Model Content

[0004] The utility model aims to provide a crude acetic anhydride falling film evaporator to solve the problems raised in the above background technology.

[0005] To achieve the above object, the utility model provides the following technical solution: a crude acetic anhydride falling film evaporator, comprising:

[0006] An evaporator shell, wherein a feed pipe is fixedly installed on the top end of the evaporator shell, a discharge pipe is fixedly installed on the bottom end of the evaporator shell, an upper partition is fixedly installed in the inner cavity of the evaporator shell, a lower partition is fixedly installed in the inner cavity of the evaporator shell, a plurality of heat exchange tubes are fixedly installed between the upper partition and the lower partition, a lifting seat is provided above the upper partition, a plurality of sealing rods are fixedly bonded to the lifting seat, the plurality of sealing rods are movably inserted into the top end openings of the plurality of heat exchange tubes, and a driving assembly is provided in the inner cavity at the top end of the evaporator shell.

[0007] Preferably, the driving assembly includes a mounting seat, a mounting groove is formed on the bottom wall of the mounting seat, a servo motor is fixedly installed in the mounting groove, the output end of the servo motor is transmission-connected with a screw rod, a moving rod is threadedly connected to the screw rod, two connecting rods are fixedly welded on the bottom wall of the moving rod, and the bottom ends of the two connecting rods are fixedly welded to the top wall of the lifting seat.

[0008] Preferably, two guide rods are fixedly welded on the bottom wall of the mounting seat, the two guide rods are symmetrically arranged on both sides of the screw rod, and the two guide rods are both slidably connected to the moving rod.

[0009] Preferably, the mounting seat is configured to be conical in shape, and two inclined mounting rods are fixedly welded to the side wall of the mounting seat, and one end of the mounting rod away from the mounting seat is fixedly mounted on the inner wall of the evaporator shell.

[0010] Preferably, a steam input pipe is fixedly mounted on the evaporator shell, and a condensed water discharge pipe is fixedly mounted on the evaporator shell.

[0011] Compared with the prior art, the beneficial effects of the utility model are:

[0012] When the utility model is in use, the feed liquid is injected into the cavity above the upper partition of the evaporator shell through the feed pipe, and the liquid level of the feed liquid in the cavity gradually rises. When the liquid level height is about to reach the position of the lifting seat, the servo motor is started. After the servo motor is started, it drives the screw to rotate forward, so that the moving rod moves upward on the screw under the guidance of the two guide rods. When the moving rod moves upward, the lifting seat can be driven upward by the connecting rod, and multiple blocking rods are pulled out of the heat exchange tube, so that the feed liquid can accumulate to a certain height and then flow into the heat exchange tube, so that the feed liquid is evenly distributed in each heat exchange tube, thereby improving the film-forming effect of the feed liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a three-dimensional structural schematic diagram of a crude acetic anhydride falling film evaporator proposed by the utility model;

[0014] Figure 2 This is a cross-sectional front view of the evaporator shell in the crude acetic anhydride falling film evaporator proposed by the utility model;

[0015] Figure 3 The utility model provides a crude acetic anhydride falling film evaporator. Figure 2 The structure diagram at A is enlarged;

[0016] Figure 4 This is a top structural diagram of the connection between a lifting seat and a blocking rod in a crude acetic anhydride falling film evaporator proposed by the utility model.

[0017] In the figure: 1. Evaporator body; 2. Feed pipe; 3. Discharge pipe; 4. Upper partition; 5. Lower partition; 6. Heat exchange tube; 7. Lifting seat; 8. Sealing rod; 9. Mounting seat; 10. Mounting groove; 11. Servo motor; 12. Screw; 13. Moving rod; 14. Connecting rod; 15. Guide rod; 16. Mounting rod; 17. Steam input pipe; 18. Condensate discharge pipe. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0019] See also Figure 1-4 The utility model provides a technical solution: a crude acetic anhydride falling film evaporator, comprising:

[0020] An evaporator shell 1, wherein a feed pipe 2 is fixedly installed at the top end of the evaporator shell 1, a discharge pipe 3 is fixedly installed at the bottom end of the evaporator shell 1, an upper partition 4 is fixedly installed in the inner cavity of the evaporator shell 1, a lower partition 5 is fixedly installed in the inner cavity of the evaporator shell 1, a plurality of heat exchange tubes 6 are fixedly installed between the upper partition 4 and the lower partition 5, a lifting seat 7 is arranged above the upper partition 4, a plurality of blocking rods 8 are fixedly bonded to the lifting seat 7, and the plurality of blocking rods 8 are movably inserted into the top end openings of the plurality of heat exchange tubes 6, and a driving assembly is arranged in the inner cavity at the top end of the evaporator shell 1.

[0021] The driving assembly includes a mounting seat 9, a mounting groove 10 is provided on the bottom wall of the mounting seat 9, a servo motor 11 is fixedly installed in the mounting groove 10, an output end of the servo motor 11 is transmission-connected with a screw rod 12, a moving rod 13 is threadedly connected to the screw 12, two connecting rods 14 are fixedly welded on the bottom wall of the moving rod 13, the bottom ends of the two connecting rods 14 are fixedly welded on the top wall of the lifting seat 7, the servo motor 11 can drive the screw rod 12 to rotate after starting, when the screw 12 rotates forward, the moving rod 13 can move upward on the screw 12, and when the moving rod 13 moves upward, the lifting seat 7 can be driven to move upward through the connecting rod 14.

[0022] Two guide rods 15 are fixedly welded on the bottom wall of the mounting seat 9. The two guide rods 15 are symmetrically arranged on both sides of the screw rod 12. The two guide rods 15 are both slidably connected to the moving rod 13. The arranged guide rods 15 can guide and position the moving rod 13 to prevent the moving rod 13 from rotating with the screw rod 12.

[0023] The mounting seat 9 is configured to be conical in shape, and two inclined mounting rods 16 are fixedly welded on the side wall of the mounting seat 9. The end of the mounting rod 16 away from the mounting seat 9 is fixedly mounted on the inner wall of the evaporator shell 1. The conical mounting seat 9 facilitates the introduction of the feed liquid onto the upper partition 4 when the feed pipe 2 is feeding.

[0024] A steam input pipe 17 is fixedly installed on the evaporator shell 1, and a condensed water discharge pipe 18 is fixedly installed on the evaporator shell 1. The steam input pipe 17 facilitates the input of high-temperature gas into the evaporator and the heat exchange of the heat exchange tube 6. The condensed water discharge pipe 18 facilitates the discharge of condensed water after heat exchange.

[0025] Working principle: When the utility model is in use, the feed liquid is injected into the cavity above the upper partition 4 of the evaporator shell 1 through the feed pipe 2, and the liquid level in the cavity gradually rises. When the liquid level is about to reach the position of the lifting seat 7, the servo motor 11 is started. After the servo motor 11 is started, it drives the screw 12 to rotate forward, so that the moving rod 13 moves upward on the screw 12 under the guidance of the two guide rods 15. When the moving rod 13 moves upward, it can drive the lifting seat 7 to move upward through the connecting rod 14, and pull out the multiple blocking rods 8 from the heat exchange tube 6, so that the feed liquid can accumulate to a certain height and then flow into the heat exchange tube 6, so that the feed liquid is evenly distributed in each heat exchange tube 6, thereby improving the film-forming effect of the feed liquid.

[0026] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0027] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A crude acetic anhydride falling film evaporator, characterized in that: include: An evaporator shell (1), wherein a feed pipe (2) is fixedly mounted on the top end of the evaporator shell (1), a discharge pipe (3) is fixedly mounted on the bottom end of the evaporator shell (1), an upper partition (4) is fixedly mounted in the inner cavity of the evaporator shell (1), a lower partition (5) is fixedly mounted in the inner cavity of the evaporator shell (1), a plurality of heat exchange tubes (6) are fixedly mounted between the upper partition (4) and the lower partition (5), a lifting seat (7) is arranged above the upper partition (4), a plurality of blocking rods (8) are fixedly bonded to the lifting seat (7), and the plurality of blocking rods (8) are movably plugged into the top end openings of the plurality of heat exchange tubes (6), and a driving component is arranged in the inner cavity at the top end of the evaporator shell (1).

2. A crude acetic anhydride falling film evaporator according to claim 1, characterized in that: The driving assembly comprises a mounting seat (9), a mounting groove (10) is provided on the bottom wall of the mounting seat (9), a servo motor (11) is fixedly installed in the mounting groove (10), an output end of the servo motor (11) is drivingly connected to a screw rod (12), a moving rod (13) is threadedly connected to the screw rod (12), two connecting rods (14) are fixedly welded to the bottom wall of the moving rod (13), and the bottom ends of the two connecting rods (14) are fixedly welded to the top wall of the lifting seat (7).

3. A crude acetic anhydride falling film evaporator according to claim 2, characterized in that: Two guide rods (15) are fixedly welded on the bottom wall of the mounting seat (9), the two guide rods (15) are symmetrically arranged on both sides of the screw rod (12), and the two guide rods (15) are both slidably connected to the moving rod (13).

4. A crude acetic anhydride falling film evaporator according to claim 2, characterized in that: The mounting seat (9) is configured to be in a conical shape, and two inclined mounting rods (16) are fixedly welded to the side wall of the mounting seat (9); one end of the mounting rod (16) away from the mounting seat (9) is fixedly mounted on the inner wall of the evaporator shell (1).

5. A crude acetic anhydride falling film evaporator according to claim 1, characterized in that: A steam input pipe (17) is fixedly mounted on the evaporator shell (1), and a condensed water discharge pipe (18) is fixedly mounted on the evaporator shell (1).

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