Device for preventing backflow and siphonage in the production of benzoyl chloride

Abstract

The utility model discloses a device is prevented to flow back and suck back in the benzoyl chloride production process, including anti -suck back bottle and absorption bottle, the anti -suck back bottle outer wall is equipped with air inlet pipe, air outlet pipe and air supplement balance pipe, the air outlet pipe is inserted into absorption bottle far from the one end of anti -suck back bottle, the air supplement balance pipe is used for external connection to inert gas source, and is installed only to allow inert gas to flow to the one -way valve assembly of anti -suck back bottle inside in air supplement balance pipe, this one -way valve assembly includes the sealing ring of fixed in the inner wall of air supplement balance pipe, inserts the sealing plug in sealing ring and is connected in the spring between sealing ring and sealing plug, the spring tight sealing plug is close to the sealing ring, the bottom of anti -suck back bottle is installed U -shaped tube, and the inside of U -shaped tube has the sealant. The utility model integrates two kinds of air pressure balance mechanism of U -shaped tube liquid seal and inert gas automatic pressure compensation, can eliminate system negative pressure from the root, and the cooperation of both, greatly improved the reliability of device.

Description

Technical Field

[0001] This utility model relates to the field of chemical production equipment technology, and in particular to a device for preventing backflow and backflow during the production of benzoyl chloride. Background Technology

[0002] In the production of benzoyl chloride, a large amount of byproduct hydrogen chloride (HCl) gas is often generated. This gas usually needs to be guided to an absorption device for treatment through pipelines. Since gases such as HCl are highly soluble in water or react rapidly with alkaline solutions, a significant negative pressure will be formed inside the absorption device during the absorption process. This negative pressure will cause the external atmospheric pressure to push the absorbent liquid back into the production reaction device, causing backflow. Backflow of the absorbent liquid will contaminate the reaction raw materials and products, leading to a decrease in product purity and even triggering side reactions.

[0003] Currently, the known methods for preventing backflow mainly involve installing safety bottles (buffer bottles) or simple one-way valves in the exhaust pipe. However, safety bottles can only temporarily store a small amount of backflowed liquid. If the negative pressure persists, their protective capability is limited. Furthermore, trace amounts of corrosive substances or impurities that may be present in chemical exhaust gases can easily cause mechanical one-way valves to malfunction and become stuck, leading to their failure. All of these methods suffer from insufficient reliability and cannot actively balance the system pressure to fundamentally eliminate the cause of backflow.

[0004] To address this issue, we propose a device to prevent backflow and backflow during the benzoyl chloride production process. Utility Model Content

[0005] The purpose of this invention is to provide a device for preventing backflow and backflow during the production of benzoyl chloride, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A device for preventing backflow during benzoyl chloride production includes an anti-backflow bottle and an absorption bottle. The anti-backflow bottle has an inlet pipe, an outlet pipe, and a gas replenishment and balancing pipe on its outer wall. The end of the outlet pipe away from the anti-backflow bottle is inserted into the absorption bottle, which contains absorbent liquid. The gas replenishment and balancing pipe is connected to an inert gas source and is equipped with a one-way valve assembly that allows only inert gas to flow into the anti-backflow bottle. The one-way valve assembly includes a sealing ring fixed to the inner wall of the gas replenishment and balancing pipe, a sealing plug inserted into the sealing ring, and a spring connecting the sealing ring and the sealing plug. The spring pulls the sealing plug to fit tightly against the sealing ring. A U-shaped tube is installed at the bottom of the anti-backflow bottle, and the inside of the U-shaped tube contains sealing liquid.

[0008] In a further embodiment, the bottom end of the vent pipe is inserted below the surface of the absorbent liquid.

[0009] In a further embodiment, a bucket-shaped guide portion is provided on the inner wall of the air replenishment and balancing pipe near the upper edge of the sealing ring.

[0010] In a further embodiment, the mouth of the absorption bottle is provided with a rubber stopper, and the vent pipe passes through the inside of the rubber stopper.

[0011] In a further embodiment, the sealing ring and sealing plug adopt a tapered surface structure that is wider at the bottom and narrower at the top.

[0012] In a further embodiment, the sealing cone surface of the sealing plug is covered with a sealing layer.

[0013] In a further embodiment, the sealing fluid completely submerges the U-shaped area of ​​the U-tube.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] This invention integrates two pressure balancing mechanisms: U-tube liquid sealing and automatic inert gas pressure replenishment. The sealing liquid inside the U-tube forms the first physical barrier, which can reliably block the backflow of the absorbent liquid. The one-way valve assembly, which opens based on the pressure difference, forms the second active defense line, which can eliminate the negative pressure in the system at the source. The two work together to form a redundant safety design, which greatly improves the reliability of the device. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 This is a schematic diagram of a half-section of the anti-backflow bottle of this utility model;

[0018] Figure 3 This is a schematic diagram of a half-section of the absorption bottle of this utility model;

[0019] Figure 4 This is a schematic diagram of a half-section of the air replenishment and balance pipe of this utility model.

[0020] In the diagram: 1. Anti-backflow bottle; 2. Inlet pipe; 3. Outlet pipe; 4. Gas replenishment and balance pipe; 5. Absorption bottle; 6. Absorption liquid; 7. Rubber stopper; 8. U-tube; 9. Sealing liquid; 10. Sealing ring; 11. Sealing plug; 111. Sealing layer; 12. Spring; 13. Guide section. Detailed Implementation

[0021] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not 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. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Please see Figure 1-4 A device for preventing backflow and backflow during the production of benzoyl chloride, mainly composed of an anti-backflow bottle 1 and an absorption bottle 5.

[0025] The anti-backflow bottle 1 is a hollow glass bottle with three pipes welded to its outer wall: an inlet pipe 2, an outlet pipe 3, and a gas replenishment and balancing pipe 4. The inlet pipe 2 and the outlet pipe 3 are located on opposite sides of the side wall of the anti-backflow bottle 1, while the gas replenishment and balancing pipe 4 is located at the top of the anti-backflow bottle 1. The inlet pipe 2 is used to connect to the tail gas outlet of the upstream benzoyl chloride reactor. The end of the outlet pipe 3 away from the anti-backflow bottle 1 is inserted into the absorption bottle 5. The absorption bottle 5 contains an alkaline absorbent liquid 6 for treating acidic tail gas. For sealing and fixation, a rubber stopper 7 is plugged at the mouth of the absorption bottle 5. The outlet pipe 3 passes through the rubber stopper 7 and extends below the surface of the absorbent liquid 6 to ensure that the tail gas can be fully absorbed.

[0026] At the bottom of the anti-backflow bottle 1, a U-shaped tube 8 is installed. The U-shaped tube 8 can be integrally formed with the anti-backflow bottle 1 or can be connected by a flange seal. The U-shaped tube 8 contains an appropriate amount of sealing liquid 9 (such as water, paraffin oil or saturated salt water). The liquid level must completely submerge the U-shaped area to form a reliable liquid seal.

[0027] The gas replenishment and balancing pipe 4 is used to connect to an inert gas source (such as a nitrogen cylinder). Inside the gas replenishment and balancing pipe 4, a mechanical one-way valve assembly is installed. This assembly includes a sealing ring 10 fixed to the pipe wall, a movable sealing plug 11, and a spring 12 connecting the two. The sealing ring 10 and the sealing plug 11 adopt a matching tapered surface structure that is wider at the bottom and narrower at the top to enhance the sealing effect. The spring 12 provides tension in its natural state, so that the sealing plug 11 fits tightly against the sealing ring 10, thereby closing the airflow passage. To further optimize the performance, a sealing layer 111 made of rubber or polytetrafluoroethylene can be wrapped on the tapered sealing surface of the sealing plug 11. In addition, a funnel-shaped guide part 13 is provided on the inner wall of the gas replenishment and balancing pipe 4 at the upper edge of the sealing ring 10 to facilitate guiding the airflow to impact the center of the sealing plug 11.

[0028] Workflow:

[0029] During normal exhaust: the tail gas (such as HCl) generated by the reactor enters the anti-backflow bottle 1 through the inlet pipe 2, and the gas enters the absorption bottle 5 through the outlet pipe 3 and is absorbed by the absorption liquid 6. At this time, the system pressure is normal, and the one-way valve assembly is kept closed under the tension of the spring 12.

[0030] During liquid seal anti-backflow: When the absorbent liquid 6 rapidly absorbs the tail gas, causing a large negative pressure in the system, the pressure inside the anti-backflow bottle 1 decreases. At this time, the atmospheric pressure inside the absorbent bottle 5 will push the absorbent liquid 6 upward along the gas outlet pipe 3, while the external atmospheric pressure will simultaneously push the sealing liquid 9 in the U-shaped tube 8 into the bottle. Since the U-shaped tube 8 forms a reliable liquid seal, the static pressure generated by the height difference of its liquid column is sufficient to balance the negative pressure, thereby effectively blocking the path of the absorbent liquid 6 flowing back to the anti-backflow bottle 1 and the upstream reaction equipment through the gas outlet pipe 3.

[0031] During automatic pressure replenishment and balancing: If the negative pressure of the system continues to increase and exceeds the preset tension of spring 12, a sufficient pressure difference is formed between the inside of the anti-backflow bottle 1 and the outside of the gas replenishment and balancing pipe 4. This pressure difference pushes the sealing plug 11 to move downward against the tension of spring 12, disengaging it from the sealing ring 10. The one-way valve opens, and the external inert gas (such as nitrogen) then enters the anti-backflow bottle 1 through the gas replenishment and balancing pipe 4 to replenish the system pressure. When the internal pressure rises and the pressure difference decreases to below the tension of spring 12, the sealing plug 11 resets under the action of spring 12, re-adhere to the sealing ring 10, and shuts off the airflow. This process automatically maintains the system pressure within a safe range, fundamentally eliminating the negative pressure cause of backflow.

[0032] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0033] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A device for preventing backflow and backflow during the production of benzoyl chloride, characterized in that: The system includes an anti-backflow bottle (1) and an absorption bottle (5). The anti-backflow bottle (1) has an inlet pipe (2), an outlet pipe (3), and a gas replenishment and balancing pipe (4) on its outer wall. The outlet pipe (3) is inserted into the absorption bottle (5) at the end away from the anti-backflow bottle (1). The absorption bottle (5) contains an absorbent liquid (6). The gas replenishment and balancing pipe (4) is used to connect to an inert gas source. The gas replenishment and balancing pipe (4) is equipped with a device that allows only inert gas to flow into the anti-backflow bottle (1). The one-way valve assembly includes a sealing ring (10) fixed to the inner wall of the gas replenishment balance tube (4), a sealing plug (11) inserted into the sealing ring (10), and a spring (12) connected between the sealing ring (10) and the sealing plug (11). The spring (12) pulls the sealing plug (11) to fit tightly against the sealing ring (10). A U-shaped tube (8) is installed at the bottom of the anti-backflow bottle (1), and the U-shaped tube (8) contains sealing liquid (9).

2. The device for preventing backflow and backflow during the production of benzoyl chloride according to claim 1, characterized in that: The bottom end of the vent pipe (3) is inserted below the surface of the absorbent liquid (6).

3. The device for preventing backflow and backflow during the production of benzoyl chloride according to claim 1, characterized in that: The inner wall of the air replenishment balance pipe (4) is provided with a bucket-shaped guide (13) near the upper edge of the sealing ring (10).

4. The device for preventing backflow and backflow during the production of benzoyl chloride according to claim 1, characterized in that: The absorption bottle (5) is provided with a rubber stopper (7) at the bottle mouth, and the gas outlet pipe (3) passes through the inside of the rubber stopper (7).

5. The device for preventing backflow and backflow during the production of benzoyl chloride according to claim 1, characterized in that: The sealing ring (10) and sealing plug (11) adopt a tapered surface structure that is wider at the bottom and narrower at the top.

6. The device for preventing backflow and backflow during the production of benzoyl chloride according to claim 1, characterized in that: The sealing cone surface of the sealing plug (11) is covered with a sealing layer (111).

7. The device for preventing backflow and backflow during the production of benzoyl chloride according to claim 1, characterized in that: The sealing liquid (9) completely submerges the U-shaped area of ​​the U-tube (8).

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