An emulsion degassing device

Abstract

The utility model discloses an emulsion degassing device belongs to chemical equipment technical field, and this device includes comb type steam distribution pipe assembly and steam supply pipeline, and comb type steam distribution pipe assembly is welded from vertical center main pipe and multilayer horizontal annular branch pipe, and the lower wall of annular branch pipe is equipped with the dense downward steam blast hole, and this assembly is suspended in the kettle through the mounting seat of the reation kettle top cover, when degassing, steam enters the distribution pipe through the supply pipeline, and the spray hole of each layer branch pipe is evenly sprayed to the emulsion layer of different depth, makes residual monomer and VOC component synchronous high -efficient vaporization at each layer level, and is extracted by vacuum system, the utility model discloses simple structure, no moving part, steam distribution is even, and the degassing efficiency is high, and it is easy to install and clean, can reduce emulsion smell and VOC content greatly, is suitable for the degassing reconstruction of all kinds of existing reaction kettle.

Description

Technical Field

[0001] This utility model relates to the field of chemistry, and more particularly to chemical equipment, especially to a physical degassing device for removing residual monomers and volatile organic compounds (VOCs) from synthetic latex, specifically an emulsion degassing device. Background Technology

[0002] With increasingly stringent environmental protection regulations and higher demands for health and safety, waterborne resins are being used more and more widely in coatings, adhesives, textiles, papermaking and other fields. As an important form of waterborne resin, the environmental protection of the production process and the control of odor in the finished product of synthetic emulsions have become the focus of industry attention. After the emulsion polymerization reaction, some unreacted monomers, such as styrene and acrylates, are usually left behind. These residual monomers not only lead to excessive emissions of volatile organic compounds (VOCs), but also produce unpleasant irritating odors, which seriously affect the market acceptance and application performance of the products.

[0003] Currently, the main methods for eliminating residual monomers in emulsions in the industry include chemical degassing and physical degassing. Chemical degassing involves adding a high-temperature initiator (such as persulfate) to the emulsion to promote the continued polymerization of residual monomers. While effective, this method is difficult to completely eliminate all monomers and may introduce new chemical substances, affecting emulsion stability. Physical degassing, on the other hand, utilizes the low boiling point and volatility of residual monomers. A vacuum environment is established within the reactor, and steam is introduced as a heat and mass transfer medium, causing the monomers to rapidly vaporize and be extracted by the vacuum system with the steam flow. This method does not introduce new chemical substances, is environmentally friendly, and is currently the mainstream degassing process.

[0004] However, existing physical degassing devices and processes have significant drawbacks. Their structure involves introducing steam from the bottom of the reactor through a single inlet pipe or distributor. This method results in severely uneven steam distribution: after the high-temperature steam enters from the bottom, it first comes into contact with the low-temperature emulsion at the bottom. The steam rapidly condenses and releases latent heat, causing a sharp drop in steam temperature and carrying capacity. This prevents the emulsion located in the middle and upper parts of the reactor from fully contacting the steam with effective heat, resulting in low degassing efficiency, long degassing time, high energy consumption, and a still high residual monomer content in the final product.

[0005] To address the steam distribution problem, several improved solutions have been proposed. For example, Chinese invention patent CN201511010649.2 discloses a degassing method for carboxylated styrene-butadiene latex, which integrates the steam outlet onto the shaft and blades of the stirring device, allowing the steam to disperse during stirring. While this solution improves the mixing of steam and emulsion to some extent, it has the following inherent drawbacks: 1) It requires customized, complex hollow stirring shafts and blades, demanding high processing precision and incurring high manufacturing costs; 2) The long-term circulation of high-temperature, high-pressure steam within rotating components places extremely high demands on mechanical seals, making leakage prone to occur; 3) The complex structure of the stirrer makes it difficult to clean and maintain, and incomplete cleaning after polymerization may lead to cross-contamination; 4) This solution is strongly coupled with the stirrer, making it unsuitable for many existing reactors in the industry that lack hollow stirring capabilities, resulting in high equipment modification costs.

[0006] Therefore, there is an urgent need to develop a physical degassing device for emulsions that is simple in structure, has uniform steam distribution, high degassing efficiency, strong adaptability, is easy to maintain, and is inexpensive. Utility Model Content

[0007] The purpose of this invention is to address the shortcomings of existing technologies by providing an emulsion degassing device. This device utilizes a unique multi-layered comb-shaped steam distribution structure to achieve uniform, multi-point steam injection in the vertical direction of the reactor, ensuring that emulsions in different liquid layers can fully contact fresh hot steam. This significantly improves degassing efficiency and thoroughness, while also offering advantages such as simple structure, flexible installation, reliable operation, convenient maintenance, and low cost.

[0008] To achieve the above objectives, this utility model provides an emulsion degassing device for installation in a reaction vessel with a vacuum system, which includes a comb-type steam distribution pipe assembly and a steam supply pipeline.

[0009] The comb-shaped steam distribution pipe assembly includes a vertically arranged central main pipe and multiple horizontally arranged annular branch pipes; the top of the central main pipe is provided with an upper connecting flange and the bottom is closed; the multiple annular branch pipes are spaced apart along the axial direction of the central main pipe, and each layer is vertically connected to the central main pipe; multiple steam injection holes are opened on the lower pipe wall of each layer of annular branch pipe along the circumferential direction.

[0010] The steam supply pipeline is connected to the upper connecting flange for introducing external steam.

[0011] Furthermore, the present invention provides an emulsion degassing device in which the diameter of the steam nozzle is 1.0 mm to 3.0 mm, the center distance between adjacent steam nozzles is 50 mm to 100 mm, and the axial direction of all steam nozzles is vertically downward or the angle between the vertically downward direction and the axial direction is less than 45 degrees.

[0012] Furthermore, the emulsion degassing device provided by this utility model takes into account that the pressure on the outer wall of the lower annular branch pipe is greater than that of the upper one, so steam will preferentially escape from the steam nozzles of the upper layer. Specifically, the diameter of the steam nozzles in any annular branch pipe is larger than the diameter of the steam nozzles in the annular branch pipe above it. This design effectively balances the amount of steam escaping from each layer.

[0013] Furthermore, the present invention provides an emulsion degassing device, wherein the number of layers of the annular branch pipe is 3 to 8; the axial distance between two adjacent layers of annular branch pipe is 200mm to 500mm; and the distance between the bottommost annular branch pipe and the bottom end of the central main pipe is 100mm to 300mm.

[0014] Furthermore, this utility model provides an emulsion degassing device, wherein the top cover of the reactor is provided with a tubular mounting seat; the tubular mounting seat includes a sleeve penetrating the top cover and a mounting flange located above the sleeve; the central main pipe passes through the sleeve, and the upper connecting flange is fastened to the mounting flange; a sealing component is provided between the sleeve and the central main pipe.

[0015] Furthermore, the present invention provides an emulsion degassing device, wherein a steam pressure regulating valve, a steam flow meter, and a shut-off valve are sequentially provided on the steam supply pipeline.

[0016] Furthermore, the present invention provides an emulsion degassing device in which the comb-shaped steam distribution pipe assembly is made of austenitic stainless steel, heat-resistant alloy steel, or carbon steel with a polytetrafluoroethylene coating.

[0017] Furthermore, the present invention provides an emulsion degassing device, wherein a stirrer is also provided inside the reaction vessel, and the comb-shaped steam distribution pipe assembly is located entirely outside the rotation range of the stirrer.

[0018] Furthermore, the present invention provides an emulsion degassing device in which the central main pipe and the multiple layers of annular branch pipes are fixedly connected by welding to form a rigid integral pipe frame structure.

[0019] Compared with the prior art, the emulsion degassing device of this invention has the following advantages:

[0020] 1. High degassing efficiency and good effect: Through multi-layer annular branch pipes and densely distributed steam nozzles, steam can be injected simultaneously and uniformly at multiple different depths in the reactor. This breaks the "temperature gradient" and "concentration gradient" caused by traditional bottom air intake, allowing the entire emulsion in the reactor to effectively contact the high-heat steam, promoting the rapid and synchronous vaporization of residual monomers and VOC components, which are then quickly extracted by the vacuum system. Actual tests show that, under the same conditions, its degassing thoroughness is far superior to that of single-point air intake.

[0021] 2. High steam utilization rate and low energy consumption: Steam is directly injected into the corresponding liquid layer from multiple layers, which reduces the heat loss and condensation caused by the steam contacting the cold emulsion during the rising process, improves the utilization efficiency of steam thermal energy, and can shorten the degassing time or reduce steam consumption when achieving the same degassing standard.

[0022] 3. Simple structure and reliable operation: The entire device is a static pipeline structure with no moving parts or complex internal cavities, which completely avoids the mechanical seal problems, wear and leakage risks that exist in the hollow stirring shaft solution. The failure rate is extremely low and the operation is highly stable.

[0023] 4. Flexible installation and strong adaptability: The device is installed through the standard interface on the top of the vessel (such as the original feed port, manhole or reserved port), requiring almost no modification to the reactor body. It can be widely used in existing glass-lined reactors and stainless steel reactors of various sizes and forms. The equipment modification cost is low and it is easy to promote.

[0024] 5. Easy to clean and maintain: After the degassing operation is completed, the entire comb tube assembly can be easily lifted out of the reactor for thorough external cleaning to prevent material from sticking to the wall and cross-contamination. It is also easy to check and unclog the nozzles when they are blocked.

[0025] 6. Low manufacturing cost: The pipes used are standard industrial pipes, and the processing technology only involves cutting, bending, drilling and welding. No precision machining is required, and the manufacturing cost is far lower than that of complex hollow agitators. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of an emulsion degassing device according to the present invention.

[0027] The components include: 1. Central main pipe; 2. Ring branch pipe; 3. Upper connecting flange; 4. Steam nozzle; 5. Sleeve; 6. Mounting flange; 7. Agitator. Detailed Implementation

[0028] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0029] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," and "connected," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within 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.

[0031] like Figure 1 As shown, the core component of the emulsion degassing device of this utility model is a comb-shaped steam distribution pipe assembly. This assembly consists of a central main pipe 1 and four layers of annular branch pipes 2 welded to it. The central main pipe 1 is made of 316L stainless steel pipe with a diameter of 38×3mm. The total length is determined according to the liquid level of the reactor and is about 2.5 meters. The four layers of annular branch pipes 2 are made of 316L stainless steel pipe with a diameter of 25×2.5mm and are bent into a ring with a diameter slightly smaller than the inner diameter of the reactor. Counting from the top, the first layer of annular branch pipe 2 is about 300mm away from the upper connecting flange 3, and the distance between adjacent layers is 500mm.

[0032] In the lower half of the pipe wall of each layer of annular branch pipe 2, a hole of Φ1.0mm-Φ3.0mm is drilled every 80mm along the circumference as a steam jet hole 4. All drilling directions are strictly vertical downward. This design can prevent emulsion from flowing back into the pipe when the machine stops, and ensure that the diameter of the steam jet hole 4 of the lower layer annular branch pipe 2 is larger than that of the steam jet hole 4 of the upper layer annular branch pipe 2.

[0033] The reactor top cover utilizes a DN80 manhole as an installation interface. The sleeve 5 of the tubular mounting base is welded at the manhole location, and the mounting flange 6 is located above the sleeve 5. The central main pipe 1 passes through the sleeve 5, and the connecting flange 3 on it is fastened to the mounting flange 6 with bolts. The annular gap between the sleeve 5 and the central main pipe 1 is filled with polytetrafluoroethylene sealing filler and pressed with a gland to achieve dynamic sealing (considering the slight alignment adjustment during installation) and vacuum sealing.

[0034] The steam supply pipeline is connected to the upper connecting flange 3 via a gasketed flange. A steam pressure regulating valve is installed on the pipeline to control the steam inlet pressure at about 0.3MPa. A steam flow meter is used to monitor steam consumption. A shut-off valve is used to open and close the steam. A quick-connect fitting can be configured at the end of the pipeline to facilitate quick disconnection after degassing and to lift out the distribution pipe for cleaning.

[0035] The reactor itself is equipped with a conventional anchor stirrer 7 and a drive motor, which are used to moderately stir the emulsion before and during degassing to promote heat and mass transfer. All components of the comb tube assembly are arranged outside the rotation envelope of the stirring blades to ensure no interference during operation.

[0036] Work process:

[0037] 1. Installation: Hoist the cleaned comb-shaped steam distribution pipe assembly into the reactor through the top cover mounting port, fix it in place, and connect the steam pipeline;

[0038] 2. Establish vacuum: Close all feed valves, turn on the vacuum system connected to the vacuum extraction port, and pump the pressure inside the vessel to -0.09MPa;

[0039] 3. Steam degassing: Start the agitator at low speed, slowly open the steam pipeline shut-off valve, and adjust the pressure regulating valve to allow steam to enter the comb tube assembly at a set flow rate (e.g., 200 kg / h). The steam is distributed to each layer of annular branch pipes 2 via the central main pipe 1, and finally evenly sprayed out from hundreds of downward steam nozzles 4, making full contact with the emulsion in each liquid layer. The residual monomers are heated and vaporized, and continuously extracted by the vacuum system with the steam flow.

[0040] 4. Process maintenance: Maintain the set steam flow rate, vacuum level and stirring speed. The degassing process lasts for about 60 minutes. The degree of degassing can be monitored by online VOC detection or timed sampling analysis.

[0041] 5. End of operation: After the predetermined degassing time or target is reached, first close the steam shut-off valve and stop the steam supply. Continue to maintain vacuum and stirring for about 5-10 minutes to remove the residual steam in the vessel. Then stop vacuuming and stirring.

[0042] 6. Disassembly and cleaning: Open the reactor, disconnect the quick-connect fittings of the steam pipeline, lift out the entire comb-shaped steam distribution pipe assembly, and rinse it clean with hot water or cleaning agent for future use.

[0043] Any aspects of this utility model not described in detail are well-known technologies to those skilled in the art.

[0044] The preferred embodiments of this utility model have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of this utility model without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of this utility model through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. An emulsion degassing device for installation inside a reaction vessel equipped with a vacuum system, characterized in that, Includes comb-type steam distribution pipe assembly and steam supply piping; The comb-shaped steam distribution pipe assembly includes a vertically arranged central main pipe and multiple layers of horizontally arranged annular branch pipes; the top of the central main pipe is provided with an upper connecting flange and the bottom is closed; the annular branch pipes are spaced apart along the axial direction of the central main pipe, and each layer of annular branch pipes is vertically connected to the central main pipe; multiple steam injection holes are opened on the lower pipe wall of each layer of annular branch pipes along the circumferential direction. The steam supply pipeline is connected to the upper connecting flange for introducing external steam.

2. The emulsion degassing device according to claim 1, characterized in that, The diameter of the steam nozzle is 1.0 mm to 3.0 mm, the center distance between adjacent steam nozzles is 50 mm to 100 mm, and the axial direction of all steam nozzles is vertically downward or the angle between the axial direction and the vertically downward direction is less than 45 degrees.

3. The emulsion degassing device according to claim 2, characterized in that, The diameter of the steam nozzle in any layer of the annular branch pipe is larger than the diameter of the steam nozzle in the annular branch pipe above it.

4. The emulsion degassing device according to claim 1, characterized in that, The number of layers of the annular branch pipe is 3 to 8; the axial distance between two adjacent layers of annular branch pipe is 200mm to 500mm; and the distance between the bottommost annular branch pipe and the bottom of the central main pipe is 100mm to 300mm.

5. The emulsion degassing device according to claim 1, characterized in that, The reactor is provided with a tubular mounting base on its top cover; the tubular mounting base includes a sleeve that penetrates the top cover and a mounting flange located above the sleeve; the central main pipe passes through the sleeve, and the upper connecting flange is fastened to the mounting flange; a sealing component is provided between the sleeve and the central main pipe.

6. The emulsion degassing device according to claim 1, characterized in that, The steam supply pipeline is equipped with a steam pressure regulating valve, a steam flow meter, and a shut-off valve in sequence.

7. The emulsion degassing apparatus according to any one of claims 1 to 6, characterized in that, The comb-shaped steam distribution pipe assembly is made of austenitic stainless steel, heat-resistant alloy steel, or carbon steel with a polytetrafluoroethylene coating.

8. The emulsion degassing apparatus according to any one of claims 1 to 6, characterized in that, The reactor is also equipped with a stirrer, and the comb-shaped steam distribution pipe assembly is located outside the rotation range of the stirrer.

9. The emulsion degassing device according to claim 1, characterized in that, The central main pipe and the multiple layers of annular branch pipes are fixedly connected by welding to form a rigid integral pipe frame structure.

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