A self-cleaning variable optical path photoionization detector

Abstract

This invention discloses a self-cleaning variable optical path photoionization detector. By setting up a reinforcement structure, an optical path adjustment mechanism, and a self-cleaning mechanism, it achieves variable optical path based on ultraviolet lamp radiation. This greatly facilitates the applicability of the detector, thereby reducing the types of materials, procurement cycle, and detector cost. The variable optical path of the detector means a wider concentration detection range. One detector can be used in multiple scenarios without affecting the overall equipment size. The whole equipment does not need to be redesigned or compatible with different specifications of detectors. At the same time, the self-cleaning mechanism realizes the self-cleaning function, effectively reducing the equipment maintenance labor cost.

Description

Technical Field

[0001] This invention relates to the field of detection equipment technology, and more specifically to a self-cleaning variable optical path photoionization detector. Background Technology

[0002] A photoionization detector (PID sensor) is a detector used to detect low concentrations of volatile organic compounds (VOCs). High concentrations of VOCs are harmful to human life and production, posing a lethal and explosive risk. Due to its non-destructive measurement and high safety, the photoionization detector has a wider range of applications compared to other types of VOC gas detectors. Existing sensors have a fixed optical path and a fixed gas detection concentration range. If the detector is in an over-range state for extended periods, its lifespan will be shortened or it may even be damaged, requiring regular manual maintenance, cleaning, and recalibration.

[0003] However, for fixed optical path sensors, different range sensors need to be used depending on the testing environment, increasing the variety of materials, procurement cycle, and cost. Furthermore, incompatibility in structural dimensions may lead to redesign of the entire equipment, extending delivery time. Additionally, abnormal concentrations exceeding the equipment's range can cause abnormal measurement results or even damage. Moreover, prolonged operation can cause smudges to accumulate on the detector window, reducing measurement accuracy and requiring on-site cleaning and potentially recalibration, significantly increasing maintenance costs.

[0004] Therefore, how to achieve adjustable optical path and self-cleaning of photoionization detectors is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a self-cleaning variable optical path photoionization detector, which can adjust the optical path and perform self-cleaning, thereby reducing the use cost and maintenance cost of the detector.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A self-cleaning variable optical path photoionization detector includes: a reinforced structure, and a gas chamber, a vacuum ultraviolet lamp, a controller, an optical path adjustment mechanism, and a self-cleaning mechanism disposed within the reinforced structure.

[0008] The gas chamber is located above the vacuum ultraviolet lamp, and the vacuum ultraviolet lamp is fixed to the inner wall of the reinforced structure;

[0009] The optical path adjustment mechanism is fixed to the inner wall of the reinforced structure and is fixedly connected to the air chamber;

[0010] The self-cleaning mechanism is fixed to the inner wall of the reinforced structure and is designed to be in contact with the vacuum ultraviolet lamp.

[0011] The vacuum ultraviolet lamp, the optical path adjustment mechanism, and the self-cleaning mechanism are all electrically connected to the controller.

[0012] The beneficial effects of the above technical solution are that by controlling the optical path adjustment mechanism and the self-cleaning mechanism through the controller, the distance between the gas chamber and the vacuum ultraviolet lamp can be adjusted, thereby realizing optical path adjustment and automatic cleaning of the vacuum ultraviolet lamp, reducing the use cost and maintenance cost of the detector.

[0013] Preferably, the optical path adjustment mechanism includes a stepper motor, a fixing nut, a lead screw, and a guide structure; the fixing nut is sleeved on the outer wall of the lead screw and fixedly connected to the inner wall of the reinforcing structure; the top of the lead screw is fixedly connected to the air chamber, and the bottom end meshes with the output shaft of the stepper motor; the stepper motor is fixed to the bottom of the reinforcing structure and electrically connected to the controller; the guide structure is fixed on one side of the bottom surface of the air chamber opposite to the fixing nut.

[0014] The beneficial effects of the above technical solution are as follows: the upper half of the lead screw is provided with a thread that mates with the fixed nut, and the lower half is provided with teeth that mesh with the output shaft of the stepper motor. The controller starts the stepper motor, which drives the lead screw to rotate. The engagement of the thread on the upper half of the lead screw with the fixed nut causes the lead screw to move up and down, thereby raising or lowering the air chamber and changing the distance between it and the vacuum ultraviolet lamp. At the same time, the spring pin can move in the same direction as the fixed nut to provide support, reset, and balance. The guide structure moves up and down with the lead screw, guiding the rise and fall of the air chamber. Appropriate strength of the elastic material, reasonable clearance, and appropriate lubrication conditions can all meet the requirements for guiding stability and can all serve as guide structures.

[0015] Preferably, the self-cleaning mechanism includes two sets of scraping units, which are arranged on opposite sides of the vacuum ultraviolet lamp.

[0016] Preferably, the scraping unit includes a rotating magnet and a scraping brush. The two sets of rotating magnets are arranged on opposite sides of the vacuum ultraviolet lamp and are electrically connected to the controller. The scraping brush is fixed on the rotating magnet and contacts the window of the vacuum ultraviolet lamp. The two sets of rotating magnets in the two scraping units rotate in opposite directions.

[0017] Preferably, the energy of the vacuum ultraviolet lamp is increased by controlling the controller to further achieve self-cleaning. When ultraviolet photons encounter contaminants on the mirror surface, they can interact, activating organic molecules. Hydrocarbons absorb ultraviolet light and undergo photosensitivity, thus being decomposed. Oxygen molecules in the air also absorb ultraviolet light to generate atomic oxygen and ozone. Atomic oxygen and ozone are chemically reactive, and ozone can further decompose oxygen and atomic oxygen. The decomposition of residual hydrocarbons on the lamp surface after photosensitization and their reaction with atomic oxygen generate gases such as CO2 and H2O, thus further removing residual organic impurities from the lamp surface.

[0018] The beneficial effect of the above technical solution is that the scraping unit is equipped with a rubber brush or a soft, dense brush. The rotating magnet is controlled by the controller to rotate, which drives the scraping brush to swing back and forth, thereby driving the rubber brush or soft, dense brush to brush on the window of the vacuum ultraviolet lamp to achieve a self-cleaning effect.

[0019] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a self-cleaning variable optical path photoionization detector. By setting a reinforcement structure, an optical path adjustment mechanism and a self-cleaning mechanism, the optical path can be variable based on ultraviolet lamp radiation. This greatly facilitates the application range of the detector, thereby reducing the types of materials, procurement cycle and detector cost. The variable optical path of the detector means a wider concentration detection range. One detector can be used in multiple scenarios without affecting the overall equipment size. The whole equipment does not need to be redesigned or compatible with different specifications of detectors. At the same time, the self-cleaning mechanism realizes the self-cleaning function, effectively reducing the equipment maintenance manpower cost. Attached Figure Description

[0020] 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0021] Figure 1 The attached figure is a schematic diagram of the overall structure of the self-cleaning variable optical path photoionization detector provided by the present invention;

[0022] Figure 2 The attached figure is a top view schematic diagram of the self-cleaning variable optical path photoionization detector provided by the present invention;

[0023] Figure 3 The attached figure is a top view of the vacuum ultraviolet lamp, lead screw, and self-cleaning mechanism provided by the present invention.

[0024] In the attached diagram: 1-Stepper motor, 2-Lead screw, 3-Spring pin, 4-Air chamber, 5-Rotating electromagnet one, 6-Rotating electromagnet two, 7-Vacuum UV lamp, 8-Scraper one, 9-Scraper two, 10-Controller, 11-Reinforcing structure, 12-Fixing nut, 13-Window. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] This invention discloses a self-cleaning variable optical path photoionization detector, comprising: a reinforced structure 11, and a gas chamber 4, a vacuum ultraviolet lamp 7, a controller 10, an optical path adjustment mechanism, and a self-cleaning mechanism disposed within the reinforced structure 11; the gas chamber 4 is located above the vacuum ultraviolet lamp 7, which is fixed to the inner wall of the reinforced structure 11; the optical path adjustment mechanism is fixed to the inner wall of the reinforced structure 11 and is fixedly connected to the gas chamber 4; the self-cleaning mechanism is fixed to the inner wall of the reinforced structure 11 and is in contact with the vacuum ultraviolet lamp 7; the vacuum ultraviolet lamp 7, the optical path adjustment mechanism, and the self-cleaning mechanism are all electrically connected to the controller 10.

[0027] To further optimize the above technical solution, the optical path adjustment mechanism includes a stepper motor 1, a fixing nut 12, a lead screw 2, and a guide structure 3; the fixing nut 12 is sleeved on the outer wall of the lead screw 2 and is fixedly connected to the inner wall of the reinforcing structure 11; the top of the lead screw 2 is fixedly connected to the air chamber 4, and the bottom end is engaged with the output shaft of the stepper motor 1; the stepper motor 1 is fixed at the bottom of the reinforcing structure 11 and electrically connected to the controller 10; the guide structure 3 is fixed on one side of the bottom surface of the air chamber 4 opposite to the fixing nut 12.

[0028] To further optimize the above technical solution, the self-cleaning mechanism includes two sets of scraping units, which are arranged on opposite sides of the vacuum ultraviolet lamp 7.

[0029] To further optimize the above technical solution, the scraping unit includes a rotating magnet and a scraping brush. Two sets of rotating magnets are arranged on opposite sides of the vacuum ultraviolet lamp 7 and are electrically connected to the controller 10. The scraping brush is fixed on the rotating magnet and contacts the window 13 of the vacuum ultraviolet lamp 7. The two sets of rotating magnets of the two scraping units rotate in opposite directions.

[0030] To further optimize the above technical solution, the energy of the vacuum ultraviolet lamp is increased by controlling the controller to further achieve self-cleaning.

[0031] Example 1

[0032] In one specific embodiment, the guide structure is a spring needle, including a sleeve, a spring and a guide needle. The guide needle is elastically connected to the sleeve by the spring. A guide platform is provided below the guide structure and fixed on the side wall of the reinforcement structure, and is in contact with the free end of the guide needle. When the distance between the gas chamber and the vacuum ultraviolet lamp is adjusted, the guide needle of the guide structure moves up and down with the lead screw through the action of the spring, but its free end is always in contact with the guide platform, thereby ensuring that the gas chamber only moves up and down, and plays a guiding role.

[0033] To further optimize the above technical solution, a partition is installed inside the reinforcement structure 11. The vacuum ultraviolet lamp 7 and the guide table are fixed on the upper surface of the partition, and the output shaft of the stepper motor extends out of the partition and meshes with the bottom end of the lead screw. The partition divides the interior of the reinforcement structure into two relatively independent cavities, which facilitates later maintenance and repair.

[0034] Example 2

[0035] In one specific embodiment, the integral component is installed inside the reinforcement structure 11;

[0036] The gas to be tested diffuses into the gas chamber 4, and the controller 10 drives the vacuum ultraviolet lamp 7 to ionize the gas to be tested.

[0037] When the concentration of the gas being measured changes significantly, the controller 10 drives the stepper motor 1 to move the lead screw 2 on the fixed nut 12 to adjust up and down. At the same time, the spring needle 3 moves in the same direction as the lead screw 2 to support and reset the balance.

[0038] The photoionization detector can be remotely controlled internally or externally to activate the self-cleaning mode. Once activated, the controller 10 drives rotating magnet 5 to move scraper 8 in a semi-circular motion on the surface of the window 13 of the vacuum ultraviolet lamp 7. Simultaneously, the controller 10 drives rotating magnet 6 to move scraper 9 in a semi-circular motion on the same surface. The scraper 8 driven by rotating magnet 5 and the scraper 9 driven by rotating magnet 6 move in opposite directions and are in a complementary interactive motion, which can better and more thoroughly clean the surface of the vacuum ultraviolet lamp 7 window. After each cleaning cycle, the vacuum ultraviolet lamp 7 also increases its energy to further remove residual organic impurities from the lamp surface.

[0039] During the above process, only in cleaning mode will the scraper 8 driven by rotating magnet 5 and the scraper 9 driven by rotating magnet 6 briefly remain on the surface of vacuum UV lamp 7. At other times, they will leave the surface of vacuum UV lamp 7 to avoid affecting the normal ionization of the gas being tested.

[0040] This invention proposes variable optical path and self-cleaning features that enable the detector to adapt to a wider range while reducing manual maintenance, wherein:

[0041] ① Variable optical path: By controlling the rotation of the motor to drive the lead screw to move the gas chamber, the distance between the gas chamber and the ultraviolet lamp is changed, which can adapt to higher or lower detection ranges. At the same time, the energy of the ultraviolet lamp is also controlled synchronously according to different concentrations to improve detection accuracy and extend the service life of the ultraviolet lamp.

[0042] ② Detector self-cleaning: The detector can achieve self-cleaning periodically or as needed by controlling the interactive movement of two rotating electromagnets, a rubber brush, and a soft, dense brush. In addition, by increasing the energy of the ultraviolet lamp, ultraviolet photons can interact with contaminants on the mirror surface, activating organic molecules. Hydrocarbons absorb ultraviolet light and undergo photosensitivity, thus being decomposed. Oxygen molecules in the air also absorb ultraviolet light to generate atomic oxygen and ozone. Atomic oxygen and ozone are chemically active, and ozone can further decompose oxygen and atomic oxygen. The hydrocarbons remaining on the lamp surface decompose after photosensitization and react with atomic oxygen to generate gases such as CO2 and H2O. In this way, residual organic impurities on the lamp surface are further removed.

[0043] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0044] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A self-cleaning variable optical path photoionization detector, characterized in that, include: The reinforced structure, as well as the air chamber, vacuum ultraviolet lamp, controller, optical path adjustment mechanism and self-cleaning mechanism set in the reinforced structure; The gas chamber is located above the vacuum ultraviolet lamp, and the vacuum ultraviolet lamp is fixed to the inner wall of the reinforced structure; The optical path adjustment mechanism is fixed to the inner wall of the reinforced structure and is fixedly connected to the air chamber; The self-cleaning mechanism is fixed to the inner wall of the reinforced structure and is designed to be in contact with the vacuum ultraviolet lamp. The vacuum ultraviolet lamp, the optical path adjustment mechanism, and the self-cleaning mechanism are all electrically connected to the controller; The self-cleaning mechanism includes two sets of scraping units, which are arranged on opposite sides of the vacuum ultraviolet lamp. The scraping unit includes a rotating magnet and a scraper. Two sets of rotating magnets are arranged on opposite sides of the vacuum ultraviolet lamp and are electrically connected to the controller. The scraper is fixed on the rotating magnet and contacts the window of the vacuum ultraviolet lamp. The two sets of rotating magnets in the two scraping units rotate in opposite directions. The controller controls the increase of the vacuum ultraviolet lamp energy to further achieve self-cleaning.

2. The self-cleaning variable optical path photoionization detector according to claim 1, characterized in that, The optical path adjustment mechanism includes a stepper motor, a fixing nut, a lead screw, and a guide structure; the fixing nut is sleeved on the outer wall of the lead screw and fixedly connected to the inner wall of the reinforcement structure; the top of the lead screw is fixedly connected to the air chamber, and the bottom end meshes with the output shaft of the stepper motor; the stepper motor is fixed to the bottom of the reinforcement structure and electrically connected to the controller; the guide structure is fixed on one side of the bottom surface of the air chamber opposite to the fixing nut.

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