Automatic precise separation device and method of emulsion and paraffin

Abstract

An automatic precise separation device and method of emulsion and paraffin wax, which relates to the technical field of polytetrafluoroethylene production. It comprises a separator with a containing cavity for accommodating the layered emulsion and paraffin wax; a sight glass is installed on one side wall of the separator. The beneficial effects of the present application are: the present application adopts a non-contact laser detection method, utilizes the original sight glass of the separator and the polished stainless steel inner wall to form a reflection light path, and can realize precise liquid-liquid interface identification without structural modification of the equipment; the laser detection response speed is fast, combined with the preset detection point position and delay time control, which can accurately realize the automatic termination of the liquid discharge process, effectively avoid the mutual interference of emulsion and paraffin wax; at the same time, by introducing the time window anti-interference mechanism, the false trigger signal caused by factors such as liquid level fluctuation can be filtered out, ensuring the stability and reliability of the system operation; the whole separation process realizes full automatic control, significantly reduces the labor intensity and the risk of human error.

Description

Technical Field

[0001] This invention relates to the field of polytetrafluoroethylene (PTFE) production technology, specifically to an automatic and precise separation device and method for emulsion and paraffin. Background Technology

[0002] In the production process of polytetrafluoroethylene (PTFE) dispersion emulsion, during polymerization discharge, the PTFE dispersion emulsion and liquid-phase hot paraffin wax enter the paraffin separator together. Because the emulsion density is greater than that of paraffin wax, the emulsion, located in the lower layer, is discharged first and enters the separator first, while the less dense paraffin wax enters the separator subsequently. After both have entered the separator, due to the significant density difference, a stratification phenomenon naturally occurs: the lower layer is a milky white emulsion, and the upper layer is transparent paraffin wax.

[0003] Currently, the industry generally uses manual operation for separation. Operators observe the position of the two-phase interface through a sight glass installed on the side wall of the separator. When the interface drops to the lowest point at the bottom of the separator, the discharge valve is manually closed, allowing the emulsion to be completely discharged from the separator, thereby achieving the separation of the emulsion and the liquid phase paraffin.

[0004] However, this manual operation method has the following technical drawbacks: (i) Reliance on manual observation means that the accuracy of judgment is limited by the operator's condition. Operators need to stare at the viewing mirror for a long time and closely track changes in the interface, which can easily cause visual fatigue and decreased attention, leading to deviations in the judgment of the interface position and affecting the separation accuracy.

[0005] (ii) Manual operation is subject to lag, which affects product quality. The valve must be manually closed the moment the interface reaches the separation point. Due to the limitations of human reaction time, the operation is often delayed, causing some liquid paraffin to mix into the discharged emulsion, resulting in product contamination and reduced product quality.

[0006] (iii) Premature valve closure leads to product waste and system contamination. If operators close the valves prematurely to avoid paraffin contamination, some emulsion will not be discharged in time and will enter the paraffin recovery system along with the paraffin. This will not only waste the emulsion product, but also affect the quality stability of subsequent batches of products because the emulsion will be mixed with the recycled paraffin.

[0007] In summary, there is an urgent need for a device and method that can automatically and accurately detect the liquid-liquid interface and achieve automatic control of liquid discharge, so as to replace manual operation and improve separation accuracy and production efficiency. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings and defects of existing technologies by providing an automatic and precise separation device and method for emulsions and paraffin wax. This invention employs a non-contact laser detection method, utilizing the existing sight glass of the separator and the polished stainless steel inner wall to form a reflected light path, achieving accurate liquid-liquid interface identification without structural modifications to the equipment. The laser detection has a fast response speed, and combined with preset detection point positions and delay time control, it can accurately and automatically terminate the drainage process, effectively avoiding mutual interference between emulsions and paraffin wax. At the same time, by introducing a time window anti-interference mechanism, false triggering signals caused by factors such as liquid surface fluctuations can be filtered out, ensuring the stable and reliable operation of the system. The entire separation process is fully automated, significantly reducing the intensity of manual operation and the risk of human error.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: an automatic and precise separation device and method for emulsion and paraffin wax, comprising a separator having a receiving cavity for receiving the layered emulsion and paraffin wax; a sight glass, installed on one side wall of the separator, serving as a transparent observation window; a reflective surface, disposed on the inner wall of the separator opposite to the sight glass, being a polished stainless steel surface; a laser interface sensor, fixedly installed on the outside of the sight glass, whose optical path passes through the sight glass into the receiving cavity of the separator, is reflected by the reflective surface, and returns along the same path, used to detect the intensity of reflected light in real time and output an electrical level signal; a logic control unit, electrically connected to the laser interface sensor, receiving the electrical level signal and outputting control commands according to preset logic; a discharge valve, installed on the discharge pipe of the separator, used to control the discharge flow; and an actuator, electrically connected to the logic control unit, receiving control commands and driving the discharge valve to operate.

[0010] Furthermore, the reflective surface is a polished stainless steel surface that is part of the inner wall of the separator.

[0011] Furthermore, it also includes an anti-displacement fixing mechanism, which is fixedly connected to the laser interface sensor and is used to lock the laser interface sensor in the target installation position.

[0012] Furthermore, the output signal of the laser interface sensor is a switching signal.

[0013] Furthermore, the logic control unit is a DCS, PLC, or a dedicated embedded control module.

[0014] An automatic and precise separation method for emulsion and paraffin wax includes the following steps: A mixture containing emulsion and liquid paraffin wax is introduced into a separator, where the density difference causes the emulsion to naturally settle to the lower layer and the paraffin wax to float to the upper layer. During the discharge process of the separator, a laser interface sensor is used to detect the intensity of reflected light at a preset detection point, located at a predetermined distance D above the bottom of the separator. When the intensity of reflected light changes from low to high, it is determined that the liquid-liquid interface has passed the detection point, and a trigger signal is output to the logic control unit. After receiving the trigger signal, the logic control unit starts timing according to a preset delay time T, and after the timing ends, it sends a closing command to the actuator. The actuator drives the discharge valve to close, completing the automatic separation of the emulsion and paraffin wax.

[0015] Furthermore, the delay time T is dynamically set according to the discharge flow rate, pipeline length and valve response time, and the value range is 0.5 to 5 seconds.

[0016] Furthermore, the predetermined spacing D is 50±10mm.

[0017] Furthermore, it also includes an anti-interference step: the logic control unit only determines that the trigger is valid after detecting that the high-level signal has been continuously and stably exceeded a preset time window Δt, wherein the time window Δt is 0.2~1 seconds.

[0018] After adopting the above technical solution, the beneficial effects of the present invention are at least as follows: 1. This invention uses a laser interface sensor to identify the interface position between the emulsion and paraffin by detecting changes in the intensity of reflected light. The detection process does not require contact with the material, avoiding the risk of contamination that may be introduced by traditional contact sensors, and it has no mechanical wear and a long service life.

[0019] 2. By making full use of the glass sight glass and polished stainless steel inner wall of the separator, the laser interface sensor is installed on the outside of the sight glass, and the polished surface of the inner wall is used as the reflective surface. No structural modification of the separator body is required, making installation convenient, modification cost low, and easy to promote and apply on existing production lines.

[0020] 3. Laser detection has a response time in the millisecond range, far faster than manual observation and operation. By precisely setting the detection point position (predetermined spacing D) and delay time T, the drainage process can be precisely controlled, effectively avoiding interference between the emulsion and paraffin or emulsion residue, thus improving separation purity.

[0021] 4. A time window anti-interference step is introduced into the control logic. The system is only considered to be triggered when the high-level signal is continuously and stably exceeded for a preset time window Δt. This effectively filters out false trigger signals caused by liquid level fluctuations, liquid sloshing, or instantaneous disturbances, avoids valve malfunctions, and ensures the stability and reliability of the system operation.

[0022] 5. It realizes fully automated control of the emulsion and paraffin separation process, replacing traditional manual observation and operation, significantly reducing the labor intensity of operators, and avoiding product quality fluctuations caused by human error, which is conducive to improving production consistency and batch stability. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of the present invention.

[0025] Figure 2 This is a schematic diagram of the working state of the laser interface sensor in this invention.

[0026] Explanation of reference numerals in the attached diagram: Separator 1, Sight glass 2, Laser interface sensor 3, Discharge valve 4, Reflective surface 5, Logic control unit 6. Detailed Implementation

[0027] See Figures 1-2 As shown, the technical solution adopted in this specific embodiment is as follows: It includes: Separator 1 has a receiving cavity for receiving the layered emulsion and paraffin; Sight glass 2, installed on one side wall of separator 1, is a transparent observation window; The reflective surface 5 is located on the inner wall of the separator 1 opposite to the sight glass 2, and is a polished stainless steel surface. Specifically, the reflective surface 5 is the polished stainless steel surface that is provided on the inner wall of the separator 1. The laser interface sensor 3 is fixedly installed on the outside of the sight glass 2. Its optical path passes through the sight glass 2 and enters the receiving cavity of the separator 1. After being reflected by the reflective surface 5, it returns along the original path. It is used to detect the intensity of the reflected light in real time and output a level signal. The output signal of the laser interface sensor 3 is a switching signal. The logic control unit 6 is electrically connected to the laser interface sensor 3, receives level signals and outputs control commands according to preset logic. The logic control unit 6 is a DCS, PLC or a dedicated embedded control module. The discharge valve 4 is installed on the discharge pipe of the separator 1 and is used to control the discharge flow. The actuator is electrically connected to the logic control unit 6, receives control commands, and drives the discharge valve 4 to operate.

[0028] More specifically, it also includes an anti-displacement fixing mechanism, which is fixedly connected to the laser interface sensor 3 and is used to lock the laser interface sensor 3 in the target installation position.

[0029] An automated and precise separation method for emulsions and paraffin waxes, employing any automated and precise separation device for emulsions and paraffin waxes, specifically includes the following steps: S1, the mixture containing emulsion and liquid paraffin is introduced into separator 1, and the density difference is used to make the emulsion settle naturally to the lower layer and the paraffin float to the upper layer. S2, during the liquid discharge process of separator 1, the intensity of reflected light at the preset detection point is detected in real time by laser interface sensor 3. The preset detection point is located at a predetermined distance D above the bottom of the separator. S3, when the intensity of reflected light changes from low level to high level, it is determined that the liquid-liquid interface has passed the detection point, and a trigger signal is output to the logic control unit 6; S4, after receiving the trigger signal, the logic control unit 6 starts timing according to the preset delay time T, and sends a shutdown command to the actuator after the timing ends; S5, the actuator drives the discharge valve 4 to close, completing the automatic separation of emulsion and paraffin.

[0030] More specifically, the delay time T is dynamically set based on the discharge flow rate, pipeline length, and valve response time, with a value range of 0.5 to 5 seconds.

[0031] More specifically, the predetermined spacing D is 50±10mm.

[0032] More specifically, the anti-interference steps include: the logic control unit only determines that the trigger is valid after the high-level signal has been continuously and stably maintained for more than a preset time window Δt, where the time window Δt is 0.2 to 1 second.

[0033] The working principle of this invention is as follows: Inside the separator 1, the emulsion and liquid paraffin naturally separate due to their different densities. The denser, milky-white emulsion is located in the lower layer, while the less dense, transparent paraffin floats on the upper layer. When the discharge valve 4 is opened to drain the liquid, the lower layer of emulsion is discharged first, and the liquid level gradually drops. The laser interface sensor 3 is installed on the outside of the sight glass 2 on one side of the separator 1. Its light path passes through the sight glass 2 and horizontally enters the interior of the separator, illuminating the polished stainless steel reflective surface 5 on the opposite side of the sight glass before returning to the sensor. When the area traversed by the light path is still an emulsion layer, due to the high scattering characteristics of the milky-white emulsion, the laser is largely scattered and absorbed, resulting in extremely weak reflected light intensity returning to the sensor, and the sensor outputs a low-level signal. When the liquid-liquid interface drops to a detection point preset at a predetermined distance D above the bottom of the separator, and the area where the light path is located becomes a transparent paraffin layer, the laser can penetrate the paraffin and directly irradiate the polished stainless steel reflective surface, producing strong specular reflection. The sensor receives high reflected light intensity and outputs a high-level signal. The logic control unit 6 receives the level signal output by the laser interface sensor 3 in real time. When the signal changes from low to high, the logic control unit determines that the emulsion has been largely drained and the paraffin layer is about to reach the outlet. Instead of immediately closing the valve, it starts timing based on a preset delay time T. This delay time is set comprehensively based on process parameters such as the discharge flow rate, pipe length, and valve response time, ensuring that the lower layer of emulsion is completely discharged from the separator before the discharge valve 4 closes. To further improve the system's anti-interference capability, the logic control unit 6 also incorporates an anti-interference time window mechanism: only when the high-level signal remains stable for more than the preset time window Δt is it considered a valid trigger signal. This effectively filters out false triggers caused by liquid surface fluctuations, liquid sloshing, or instantaneous disturbances, preventing valve malfunctions. Through the synergistic effect of optical detection, signal processing, and delay control, this invention achieves precise and automatic control of the emulsion and paraffin separation process without manual intervention, ensuring the stability of separation effect and product quality.

[0034] The above is only used to illustrate the technical solution of the present invention and is not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention, as long as they do not depart from the spirit and scope of the technical solution of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. An automatic and precise separation device and method for emulsion and paraffin wax, characterized in that: It includes: Separator (1) has a receiving cavity for receiving the layered emulsion and paraffin; The viewing mirror (2) is installed on one side wall of the separator (1) and is a transparent observation window; The reflective surface (5) is located on the inner wall of the separator (1) opposite to the sight glass (2) and is made of polished stainless steel. The laser interface sensor (3) is fixedly installed on the outside of the sight glass (2). Its optical path passes through the sight glass (2) and enters the receiving cavity of the separator (1). After being reflected by the reflective surface (5), it returns along the original path and is used to detect the intensity of the reflected light in real time and output a level signal. The logic control unit (6) is electrically connected to the laser interface sensor (3), receives level signals and outputs control commands according to preset logic; The discharge valve (4) is installed on the discharge pipeline of the separator (1) to control the discharge flow. The actuator is electrically connected to the logic control unit (6), receives control commands and drives the discharge valve (4) to operate.

2. The automatic and precise separation device for emulsion and paraffin according to claim 1, characterized in that: The reflective surface (5) is a polished stainless steel surface that is part of the inner wall of the separator (1).

3. The automatic and precise separation device for emulsion and paraffin according to claim 1, characterized in that: It also includes an anti-displacement fixing mechanism, which is fixedly connected to the laser interface sensor (3) and is used to lock the laser interface sensor (3) at the target installation position.

4. The automatic and precise separation device for emulsion and paraffin according to claim 1, characterized in that: The output signal of the laser interface sensor (3) is a switching signal.

5. The automatic and precise separation device for emulsion and paraffin according to claim 1, characterized in that: The logic control unit (6) is a DCS, PLC or a dedicated embedded control module.

6. An automated and precise method for separating emulsions and paraffin wax, characterized in that, It employs an automatic and precise separation device for emulsions and paraffin wax according to any one of claims 1-5, specifically including the following steps: S1, the mixture containing emulsion and liquid paraffin is introduced into separator (1), and the density difference is used to make the emulsion settle naturally to the lower layer and the paraffin float to the upper layer; S2, during the discharge process of the separator (1), a laser interface sensor (3) is used to detect the intensity of reflected light at a preset detection point in real time. The preset detection point is located at a predetermined distance D above the bottom of the separator. S3, when the intensity of the reflected light is detected to jump from low level to high level, it is determined that the liquid-liquid interface has passed the detection point, and a trigger signal is output to the logic control unit (6); S4, after receiving the trigger signal, the logic control unit (6) starts timing according to the preset delay time T, and sends a shutdown command to the actuator after the timing ends; S5, the actuator drives the discharge valve (4) to close, completing the automatic separation of emulsion and paraffin.

7. The automatic and precise separation method for emulsion and paraffin according to claim 6, characterized in that: The delay time T is dynamically set according to the discharge flow rate, pipeline length and valve response time, and the value range is 0.5 to 5 seconds.

8. The automatic and precise separation method for emulsion and paraffin according to claim 6, characterized in that: The predetermined spacing D is 50±10mm.

9. The automatic and precise separation method for emulsion and paraffin according to claim 6, characterized in that: It also includes an anti-interference step: the logic control unit only determines that the trigger is valid after the high-level signal is detected to be stable for more than a preset time window Δt, where the time window Δt is 0.2 to 1 second.

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