Dining oil fume pipeline flow field distribution measuring device and method

Abstract

The present application relates to catering oil fume pipeline flow field distribution measuring device and method, can effectively guarantee the uniformity of oil fume pipeline flow field distribution, and further guarantee the accuracy of oil fume monitor calibration result, the technical scheme includes: the present scheme in the case of as far as possible reduce the disturbance to oil fume pipeline flow field, by controlling annular gear ring rotates in oil fume pipeline, thereby realize the measurement of oil fume flow field distribution in different regions of oil fume pipeline cross section, so as to detect the abnormal flow field in a certain place, adjust the position relation of infrared measuring assembly, thereby realize the more fine measurement of the regional flow field in the cross section of oil fume pipeline, to realize the rapid positioning to the region of abnormal flow field, provide reliable technical support for subsequent oil fume monitor calibration and oil fume pipeline design optimization, installation (reference).

Description

Technical Field

[0001] This invention relates to the field of oil fume detection technology, specifically to equipment and methods for measuring the flow field distribution in catering oil fume ducts. Background Technology

[0002] With the rapid development of my country's catering industry, the problem of oil fume pollution has become particularly prominent. In order to reduce oil fume pollution, it is necessary to supervise catering enterprises. The traditional monitoring method is manual monitoring, with law enforcement managers conducting random visits and inspections to check whether catering enterprises are treating oil fumes in accordance with regulations. This method is time-consuming, inefficient, and cannot achieve good supervision. In order to increase work efficiency and strengthen supervision, automatic oil fume monitoring systems have been widely used. Currently, automatic oil fume monitoring systems typically use oil fume monitors installed at the outlet of oil fume ducts for sampling and monitoring. Most commonly used oil fume monitors operate on the principle of light scattering, analyzing the scattering of light by oil fumes to calculate the concentration of oil fumes. However, after long-term use, the accuracy and reliability of the measurements cannot be determined, necessitating periodic calibration. Typically, oil fume monitor calibration is performed in a laboratory and requires a matching oil fume duct with a uniform flow field. Currently, the flow field of oil fume ducts is mostly determined through simulation, which differs from the actual flow field of the duct. If the flow field distribution in the oil fume duct is uneven, it will severely affect the accuracy of the oil fume monitor calibration results. Therefore, equipment capable of measuring the flow field distribution in oil fume ducts is needed to confirm its uniformity, thereby ensuring the calibration of the oil fume monitor. In addition, due to space constraints, restaurant exhaust ducts in actual use generally have short straight sections and many bends, making installation quite complicated. If the installation is not done properly (such as poor sealing leading to exhaust leakage), it will cause significant differences in the local flow field of the duct, requiring duct flow field distribution measurement equipment to check whether the duct installation meets the requirements.

[0003] In view of the above, this application provides a device and method for measuring the flow field distribution in catering fume ducts to solve the above problems. Summary of the Invention

[0004] To address the above issues and overcome the shortcomings of existing technologies, this invention provides a device and method for measuring the flow field distribution in catering fume ducts. By rotating an infrared measuring component installed inside the fume duct, the flow field distribution of fumes in different areas of the duct's cross-section can be measured. Furthermore, the flow field distribution of fumes in multiple cross-sections within the duct can be detected as needed. This provides workers with a better understanding of the flow field distribution within the duct, offering reliable technical support for subsequent fume monitoring instrument calibration, duct design optimization, and installation (reference).

[0005] A flow field distribution measurement device for catering fume ducts, including a fume exhaust pipe, characterized in that an annular gear ring is coaxially rotatably installed inside the fume exhaust pipe and the annular gear ring is connected to a drive component located outside the fume exhaust pipe; a first track is installed on one axial side inside the annular gear ring and a second track is installed on the other axial side of the inner wall of the annular gear ring; and infrared measurement components are provided on the first track and the second track.

[0006] The beneficial effects of the above technical solution are as follows: (1) This scheme, while minimizing the interference to the oil fume flow field in the exhaust pipe, controls the rotation of the annular toothed ring in the exhaust pipe to measure the distribution of the oil fume flow field in different areas of the cross section of the oil fume pipe. After detecting an abnormal flow field in a certain place, the position relationship of the infrared measurement components is adjusted to achieve a more refined measurement of the regional flow field in the cross section of the exhaust pipe, so as to quickly locate the area where the abnormal flow field is generated. (2) In this scheme, the distribution of oil fume flow field in multiple sections of the oil fume duct can also be detected, which is more conducive to the staff to understand the distribution of oil fume flow field in the oil fume duct and to provide reliable technical support for subsequent oil fume monitoring instrument calibration and oil fume duct design optimization and installation (reference). Attached Figure Description

[0007] Figure 1 This is a cross-sectional schematic diagram of the exhaust pipe of the present invention; Figure 2 This is a schematic diagram of the AA section of the present invention; Figure 3 This is a schematic diagram of the first and second track structures of the present invention; Figure 4 This is a schematic diagram showing the state of the first and second tracks after they have been split according to the present invention; Figure 5 This is a schematic diagram of the state of the second track after it has rotated 90° according to the present invention; Figure 6 This is a schematic diagram of the BB section of the present invention; Figure 7 This is a schematic diagram of the CC section of the present invention. Detailed Implementation

[0008] The foregoing and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of the embodiments with reference to the accompanying drawings. The structural contents mentioned in the following embodiments are all based on the accompanying drawings.

[0009] Example 1: This solution provides a flow field distribution measurement device for restaurant fume ducts, such as... Figure 1 As shown, including exhaust pipe 1, the improvement of this solution lies in: An annular gear ring 2 is coaxially mounted inside the exhaust pipe 1, and the annular gear ring 2 is completely hidden inside the wall of the exhaust pipe 1 (i.e., the inner surface of the annular gear ring 2 is flush with the inner wall of the exhaust pipe 1), to ensure that the inner wall of the exhaust pipe 1 is a plane (reducing interference and influence on the oil fume flow field), such as Figure 3 As shown, a first track is fixedly installed on one side of the annular surface of the ring gear ring 2 (the first track is set along the length extension direction of the exhaust pipe 1), and a second track is rotatably installed on the other side of the annular surface of the ring gear ring 2. Infrared measuring components are provided on the first track and the second track. The ring gear ring 2 is connected to a drive component located outside the exhaust pipe 1. In this embodiment, the specific operation process is as follows: like Figure 2 As shown, the drive assembly drives the annular gear ring 2 to rotate at a certain speed (relatively slow) inside the exhaust pipe 1. The infrared measuring components located on the first and second tracks emit infrared light waves. The infrared light waves emitted by the infrared measuring components pass through the oil fumes inside the exhaust pipe 1. When the oil fumes move with the exhaust pipe 1 to the position of the infrared measuring components, the oil fumes and infrared light waves intersect and cause the infrared light waves to scatter. Through the linear relationship (directly proportional) between the intensity of the scattered light and the oil fumes, a definite correspondence is established. After calibration with the manufacturer's standard concentration, the accurate oil fume concentration is obtained (this is existing technology and will not be described or explained in detail here). like Figure 2 As shown, during the rotation of the annular gear ring 2 and the infrared measuring component within the exhaust pipe 1, the distribution of the oil fume flow field at the corresponding cross-sectional position within the exhaust pipe 1 can be measured. If the oil fume flow field in a certain area of ​​the cross-section is small or almost no oil fume passes through (as shown in areas S and S1 in the figure, which are symmetrical to each other), the intensity of the scattered light generated by the infrared light wave emitted by the infrared measuring component is small (the oil fume concentration in the above area is small, thus resulting in a small intensity of scattered light generated by the infrared light wave). When the infrared measuring component rotates with the annular gear ring 2 into the above area, the infrared light wave signal received by the infrared measuring component will produce a relatively obvious fluctuation. The fluctuation of the infrared light wave signal can then be used to determine if an abnormality has occurred in the oil fume flow field in the corresponding area (S or S1) of the corresponding cross-section within the exhaust pipe 1 (e.g., ...). Figure 2 As shown, when the infrared measurement component operates with the annular toothed ring 2 in the exhaust pipe 1 outside the S and S1 regions, assuming that the oil fume flow field distribution in this region is uniform, the infrared light wave signal is in a dynamic stable state, thus determining that the oil fume flow field distribution in the aforementioned region is uniform. like Figure 1As shown, in this embodiment, the position of the infrared measuring component relative to the exhaust pipe 1 can be adjusted by the first track and the second track, so that the infrared measuring component is located at different cross-sections inside the exhaust pipe 1, thereby realizing the measurement of the distribution of the oil fume flow field at multiple cross-sections inside the exhaust pipe 1. Because the distribution of the oil fume flow field at a single cross-section inside the exhaust pipe 1 cannot accurately reflect the distribution of the oil fume flow field inside the exhaust pipe 1, by moving the infrared measuring component (to realize the measurement of multiple cross-sections inside the exhaust pipe 1), the distribution of the oil fume flow field at multiple cross-sections inside the exhaust pipe 1 can be measured, which helps to better understand the distribution of the oil fume flow field inside the exhaust pipe 1. This embodiment, by setting an infrared measurement component inside the exhaust pipe 1, can help staff understand the distribution of the oil fume flow field inside the exhaust pipe 1, providing reliable technical support for subsequent calibration of the oil fume monitor and optimization of the oil fume duct design and installation (reference).

[0010] Example 2, based on Example 1, such as Figure 2 As shown, the infrared measurement component includes an infrared transmitter 3 installed on the first track and an infrared receiver 4 installed on the second track. The infrared transmitter 3 emits infrared light waves, which pass through the oil fume flow field in the exhaust pipe 1 and are received by the infrared receiver 4. When the infrared light waves pass through the oil fume flow field, they intersect with the oil fume and are scattered. Based on the infrared light wave signal received by the infrared receiver 4, the oil fume flow field in the corresponding area of ​​the exhaust pipe 1 can be measured. When both infrared transmitter 3 and infrared receiver 4 are outside regions S and S1, the infrared light wave signal received by infrared receiver 4 will not fluctuate significantly (it is in a dynamic stable state). However, if either infrared transmitter 3 or infrared receiver 4 is within the aforementioned region, then during the movement of the infrared light wave from infrared transmitter 3 to infrared receiver 4, there is no oil fume distribution (or only a small amount of oil fume distribution) in part of the path, which reduces the scattered light generated by the infrared light wave. This leads to significant fluctuations in the infrared light wave signal received by infrared receiver 4, thus indicating that the oil fume flow field distribution in the aforementioned region is abnormal. In this scheme, the distribution of the oil fume flow field in the corresponding cross section of the exhaust pipe 1 can be scanned and measured 360° by infrared transmitter 3 and infrared receiver 4 installed on the first and second tracks.

[0011] Example 3, based on Example 1, such as Figure 7 As shown, an annular groove 5 is coaxially provided on the inner wall of the exhaust pipe 1 and rotatably mounted with the annular gear ring 2, and a tooth system 6 is evenly distributed on the outer wall of the annular gear ring 2. The drive assembly includes a meshing hole 7 provided on the outer wall of the exhaust pipe 1, and a small gear 8 that meshes with the tooth system 6 is rotatably mounted in the meshing hole 7. Figure 1As shown, the pinion 8 is driven by the motor 9, and a sealing box 10 is provided on the outer wall of the exhaust pipe 1 to cover the pinion 8 (to prevent the oil fumes in the exhaust pipe 1 from leaking out through the gap between the annular gear ring 2 and the annular groove 5 and through the meshing hole 7). In actual operation, the control motor 9 operates at a certain power and drives the ring gear 2 to rotate inside the exhaust pipe 1 through the meshing between the pinion 8 and the gear system 6. Due to the large radius difference between the pinion 8 and the ring gear 2, a deceleration effect is achieved, so that when the pinion 8 rotates at a relatively fast speed, the ring gear 2 maintains a relatively slow speed while rotating inside the exhaust pipe 1 (if the ring gear 2 rotates too fast inside the exhaust pipe 1, it will affect the measurement accuracy of the infrared measurement component).

[0012] Example 4, based on Example 2, such as Figure 3 As shown, the first track includes a first frame 11 fixedly installed on the inner wall of the annular toothed ring 2, and a first conveyor belt 12 is provided on the first frame 11 (the infrared emitting end 3 is installed on the first conveyor belt 12, and can be fixed to the first conveyor belt 12 by adhesive or other suitable means), such as Figure 4 As shown, a first power roller 13 and a passive roller (not shown in the figure) are respectively provided at both ends of the first frame 11. The first conveyor belt 12 is fitted on the first power roller 13 and the passive roller and is driven by the first power roller 13. The first power roller 13 is a built-in power roller, that is, a drive motor 9 is provided inside the roller and drives the roller to rotate (by setting the motor 9 inside the roller, it is better to avoid setting it on the outside, and minimize the impact on the flow of oil fumes in the exhaust pipe 1, and minimize the impact on the oil fume flow field in the exhaust pipe 1). Since the built-in power roller is existing technology, it will not be explained or described in detail here.

[0013] Example 5, based on Example 2, such as Figure 3 As shown, the second track includes a second frame 14 rotatably mounted on the inner wall of the annular toothed ring 2, and a second conveyor belt 15 is provided on the second frame 14 (the infrared receiver 4 is mounted on the second conveyor belt 15 and can be fixed to the first conveyor belt 12 by adhesive or other suitable means). A second power roller 16 and a passive roller (not shown in the figure) are respectively provided at both ends of the second frame 14. The second conveyor belt 15 is matched with the second power roller 16 and the passive roller and is driven by the second power roller 16 (its structure is the same as that of the first power roller 13). like Figure 1As shown, the infrared receiver 4 is installed on the up-line belt of the second transmission belt 15, and the infrared transmitter 3 is installed on the down-line belt of the first transmission belt 12. In actual operation, by controlling the first transmission belt 12 and the second transmission belt 15, the positions of the infrared receiver 4 and the infrared transmitter 3 are made to correspond, so that the infrared light wave emitted by the infrared transmitter 3 passes through the oil fume flow field in the exhaust pipe 1 and is received by the infrared receiver 4, thereby determining the distribution of the oil fume flow field in a certain section of the exhaust pipe 1. like Figure 3 As shown, the second frame 14 is rotatably mounted on the inner wall of the annular gear ring 2, and is driven by the third power roller 17 (which has the same structure as the first and second power rollers 16) mounted on the inner wall of the annular gear ring 2. By controlling the rotation of the third power roller 17, the second frame 14 is driven to rotate along the length extension direction of the exhaust pipe 1. In specific operation: like Figure 2 As shown, when the annular toothed ring 2 drives the infrared receiver 4 and the infrared transmitter 3 (which are located at the two ends of the axial direction in the exhaust pipe 1 respectively) to rotate in the exhaust pipe 1, if the infrared receiver 4 detects that the infrared light wave signal it receives produces obvious fluctuations, it indicates that there is an abnormal area of ​​oil fume flow field distribution on the path of the infrared light wave emitted by the infrared transmitter 3, but its specific location cannot be accurately determined. If region S (S1) is an abnormal area of ​​oil fume flow field (i.e., the area far from the center of exhaust pipe 1), if one of the components in the infrared measurement assembly rotates into region S (S1) along with the annular toothed ring 2, the infrared light wave signal will produce a significant fluctuation. However, it is impossible to know whether the abnormal distribution of oil fume flow field is in the area near the infrared receiver 4 or in the area near the infrared transmitter 3, making it impossible for staff to accurately determine the area where the oil fume flow field distribution is abnormal. At this time, the operator controls the third power roller 17 to start, which drives the second frame 14 to rotate upwards by 90° (changing it from a horizontal to a vertical position). Figure 5 As shown, the operator then controls the first conveyor belt 12 and moves the infrared transmitter 3 mounted on it to a position directly above the second frame 14. Then, the operator controls the second conveyor belt 15 and moves the infrared receiver 4 mounted on it to a position on the second frame 14 facing the infrared transmitter 3 (as shown). Figure 6 As shown in the diagram, the infrared receiver 4 is positioned at the end of the second frame 14. Note: When setting the second frame 14, its length is matched with the radius of the exhaust pipe 1, so that when the second frame 14 rotates 90°, the infrared receiver 4 is positioned as close as possible to the center of the exhaust pipe 1. At this time, the path of the infrared light wave emitted from the infrared transmitter 3 is equivalent to the radius of the exhaust pipe 1 (i.e., as shown in the diagram). Figure 6The direction of the line in the middle is equivalent to the position of the infrared receiver 4 in the exhaust pipe 1 remaining unchanged. When the infrared receiver 4 and the infrared transmitter 3 rotate in the exhaust pipe 1 along with the ring toothed ring 2, only when the infrared transmitter 3 moves to the S (S1) area will the infrared light wave signal generate a significant fluctuation, thereby eliminating the S1 (S) area and thus accurately locating the area where the oil fume flow field in the exhaust pipe 1 is abnormal. If the abnormal area of ​​the oil fume flow field is located near the center of the exhaust pipe 1, that is, the infrared receiver 4 installed on the second track is always in the abnormal area of ​​the oil fume flow field, then no matter where the annular toothed ring 2 drives the infrared transmitter 3 and the infrared receiver 4 to rotate, the detected infrared light wave signal will be within a dynamic and stable range, that is, there will be no obvious fluctuations (because the infrared receiver 4 is always in the abnormal area of ​​the oil fume flow field). This allows the staff to determine that the abnormal area of ​​oil fume in the exhaust pipe 1 is located at the center of the exhaust pipe 1. Note: In this scheme, the second track is only adjusted from a horizontal to a vertical state when an abnormal distribution area of ​​oil fume flow field is detected in exhaust pipe 1 (but precise positioning is not yet possible). Figure 2 Transform into Figure 6 (state), because: when the second orbital changes to Figure 6 When in the normal state, the second track, which is in a vertical state, has a significant impact on the movement of oil fumes in the exhaust pipe 1 (its windward surface is large, thus disrupting the movement trajectory of the oil fume flow field). Therefore, the second track is only adjusted from horizontal to vertical when an abnormal area of ​​the oil fume flow field is detected in the exhaust pipe. When in normal detection, both the second and first tracks are in a horizontal state, and they do not have a significant impact on the movement of oil fumes in the exhaust pipe 1.

[0014] Example 6, a method for measuring the flow field distribution in restaurant fume ducts, using the flow field distribution measurement equipment for restaurant fume ducts described in Examples 1-5, includes the following steps: S1: Control the first transmission belt 12 and the second transmission belt 15 and make the infrared receiver 4 and the infrared transmitter 3 in corresponding positions. Then, drive the annular toothed ring 2 to rotate at a certain speed in the exhaust pipe 1 through the drive component to scan and measure the oil fume flow field in the corresponding section of the exhaust pipe 1 in 360°. S2: During the rotation of the ring gear 2, if the infrared measurement component detects fluctuations in the infrared signal, there is an abnormal distribution area of ​​the oil fume flow field within the corresponding cross section of the surface. The abnormal distribution of the oil fume flow field causes changes in the oil fume concentration within the corresponding cross section of the exhaust pipe 1 (i.e., the oil fume concentration is lower in the abnormal oil fume flow field area and higher in other areas), which causes the infrared light waves emitted by the infrared measurement component to produce different degrees of scattered light, resulting in fluctuations in the infrared light wave signal. In order to more accurately identify the abnormal areas of the oil fume flow field in the exhaust pipe 1, the staff controlled the drive component to stop working, and then controlled the second frame 14 to rotate 90° to make it vertical. S3: Control the first conveyor belt 12 to move and drive the infrared transmitter 3 towards a position closer to the annular toothed ring 2; control the second conveyor belt 15 to move and drive the infrared receiver 4 towards a position closer to the center of the annular toothed ring 2. Figure 6 As shown, the infrared transmitter 3 installed on the first transmission belt 12 is moved to a position directly above the second transmission belt 15, while the infrared receiver 4 installed on the second transmission belt 15 is located directly below the infrared transmitter 3, and the two are on the same straight line (which enables the transmission and reception of infrared light wave signals). S4: Subsequently, the control drive component drives the ring gear 2 to continue rotating, which can achieve more accurate measurement of the oil fume flow field in the exhaust pipe 1, thereby accurately determining the area where there is an abnormal distribution of oil fume flow field in the exhaust pipe 1. This provides a reference for the subsequent layout and installation position of the oil fume detection sensor (try to avoid the above-mentioned area when installing the oil fume detection sensor, so as to avoid the inability to accurately measure the oil fume concentration parameters in the exhaust pipe 1), and also provides reliable technical support for the subsequent modification of the exhaust pipe 1.

[0015] In Example 7, based on Example 6, in S1, the infrared transmitter 3 and the infrared receiver 4 can be adjusted to different cross-sectional positions by controlling the movement of the first conveyor belt 12 and the second conveyor belt 15. This allows for the measurement of the distribution of the oil fume flow field in different cross-sections within the exhaust pipe 1. Compared to measuring the distribution of the oil fume flow field in only a single cross-section within the exhaust pipe 1, this method can measure the distribution of the oil fume flow field in multiple cross-sections, thus more accurately reflecting the true distribution of the oil fume flow field within the exhaust pipe 1.

[0016] The above description is only for illustrating the present invention and should be understood as not being limited to the above embodiments. Various modifications that conform to the spirit of the present invention are within the protection scope of the present invention.

Claims

1. A device for measuring the flow field distribution in restaurant fume ducts, comprising an exhaust pipe (1), characterized in that, The exhaust pipe (1) is coaxially mounted with an annular gear ring (2) and the annular gear ring (2) is connected to a drive assembly located outside the exhaust pipe (1). A first track is installed on one axial side of the inner wall of the annular gear ring (2) and a second track is installed on the other axial side of the inner wall of the annular gear ring (2). Infrared measuring components are provided on the first track and the second track. The infrared measurement component includes an infrared transmitter (3) mounted on a first track and an infrared receiver (4) mounted on a second track; The first track includes a first frame (11) fixedly installed on the inner wall of the annular toothed ring (2) and a first conveyor belt (12) is provided on the first frame (11), and the first conveyor belt (12) is driven by a first power roller (13); The second track includes a second frame (14) rotatably mounted on the inner wall of the annular toothed ring (2) and a second conveyor belt (15) is provided on the second frame (14), the second conveyor belt (15) being driven by a second power roller (16); The inner wall of the annular toothed ring (2) is equipped with a third power roller (17), and the second frame (14) is driven by the third power roller (17).

2. The flow field distribution measurement device for catering fume ducts according to claim 1, characterized in that, The inner wall of the exhaust pipe (1) is coaxially provided with an annular groove (5) that is rotatably mounted with the annular gear ring (2), and the outer wall of the annular gear ring (2) is evenly provided with a tooth system (6). The driving component includes a meshing hole (7) provided on the outer wall of the exhaust pipe (1) and communicating with the annular groove (5). A small gear (8) that meshes with the tooth system (6) is rotatably mounted in the meshing hole (7), and the small gear (8) is driven by a motor (9) installed on the outer wall of the exhaust pipe (1).

3. A method for measuring the flow field distribution in restaurant fume ducts, comprising the equipment for measuring the flow field distribution in restaurant fume ducts according to any one of claims 1-2, characterized in that, Includes the following steps: S1: Control the first and second transmission belts and make the infrared receiver and infrared transmitter in corresponding positions. Then, drive the ring gear ring to rotate at a certain speed in the exhaust pipe through the drive component to measure the oil fume flow field in the exhaust pipe. S2: During the rotation of the ring gear, if the infrared measurement component detects fluctuations in the infrared signal, it controls the drive component to stop working and then controls the second frame to rotate 90° to make it vertical. S3: Control the first conveyor belt to move and drive the infrared transmitter to move toward the position close to the annular toothed ring; control the second conveyor belt to move and drive the infrared receiver to move toward the position close to the center of the annular toothed ring. S4: The control drive component drives the ring gear to continue rotating, enabling more accurate measurement of the oil fume flow field inside the exhaust pipe.

4. The method for measuring the flow field distribution in catering fume ducts according to claim 3, characterized in that, In step S1, by controlling the movement of the first and second transmission belts, the infrared transmitter and receiver are adjusted to different cross-sectional positions to measure the distribution of the oil fume flow field in different cross-sections of the exhaust pipe.

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