Range hood, grease detection method and cleaning control method

Abstract

The invention discloses a range hood, a grease detection method and a cleaning control method.The range hood comprises a centrifugal fan, the centrifugal fan comprises a volute and an impeller arranged in the volute, the impeller comprises blades, the surfaces of the blades are provided with organic silicon coatings, and the organic silicon coatings are provided with calcium silicate filler; the detection module comprises a transmitting module capable of transmitting pulse laser to the blade at the corresponding position and a receiving module for receiving the laser reflected by the blade; and the processing assembly is electrically connected with the detection module and can judge the oil film thickness, the grease type and the oxidation degree of the grease on the blade according to the spectral line of the laser received by the receiving module.

Description

Technical Field

[0001] This invention relates to an oil fume purification device, and more particularly to a range hood, a method for detecting grease in the range hood, and a cleaning control method for the range hood based on the grease detection results. Background Technology

[0002] Range hoods have become an indispensable kitchen appliance in modern homes. They operate on the principles of fluid dynamics, using a fan system installed inside to draw in and exhaust cooking fumes, and a filter to remove some of the grease particles.

[0003] After prolonged use, a large amount of oil and dust accumulates inside the casing of a range hood, especially in the fan system, where oil and dust buildup becomes severe. For example, a range hood disclosed in Chinese patent application number 202310919004.9 has a vertically arranged fan. When the impeller stops rotating, one side is at its lowest point. Accumulated grease gathers along the blade structure and drips down to this lowest position, resulting in more grease accumulation at this point than in other areas. This also means that the impeller's dynamic balance is disrupted, causing the entire unit to vibrate and requiring cleaning and maintenance (similar problems exist with other fan arrangements).

[0004] Most range hoods currently use accumulated impeller running time to remind users to maintain their appliances. However, firstly, different users have different cooking habits, resulting in significant differences in grease buildup on the impeller blades. In areas like Sichuan and Chongqing, grease may have accumulated heavily before the maintenance reminder time is due, while in areas with lighter diets, no obvious contamination may be visible even after several cycles. Therefore, relying solely on accumulated time for reminders is prone to misjudgment. If users find no obvious dirt after in-home cleaning or automatic cleaning, they may feel that the reminders are unpredictable, leading to a poor user experience.

[0005] Secondly, the position of the impeller during operation and after it stops results in different areas having varying levels of oil contact and accumulation. Some areas have thicker oil, while others have thinner oil. Time-based reminders cannot account for the actual oil accumulation in different areas. In some areas, the coating has peeled off, while in others, it is not cleaned properly.

[0006] Furthermore, relying solely on time-based reminders is prone to misjudgment. This can easily lead to situations where users find no obvious dirt after on-site or automatic cleaning, resulting in feelings that the manufacturer's judgment is uncontrollable, unintelligent, overcharged, and provides a poor user experience.

[0007] Finally, the types of oils (zoo oil and vegetable oil, which are rich in saturated and unsaturated fats respectively, are related to health, and dietary recommendations are necessary as a direction for the development of smart home appliances); and different types of cleaning agents and cleaning methods are needed to remove them more effectively. Existing manufacturers generally cannot identify the type of oil and recommend cleaning agents based on the degree of dirt, and their intelligence and cleaning ability are relatively poor. Summary of the Invention

[0008] The first technical problem to be solved by the present invention is to provide a range hood that improves the accuracy of pollution detection, in order to address the shortcomings of the prior art.

[0009] The second technical problem to be solved by the present invention is to provide a method for detecting grease in range hoods, which addresses the shortcomings of the prior art and improves the accuracy of contamination detection, and also enables multi-dimensional detection.

[0010] The third technical problem to be solved by the present invention is to provide a cleaning control method for range hoods that addresses the shortcomings of the prior art and improves cleaning efficiency and effectiveness.

[0011] The technical solution adopted by the present invention to solve the first technical problem mentioned above is as follows: a range hood, comprising a centrifugal fan, the centrifugal fan comprising a volute and an impeller disposed within the volute, the impeller comprising blades, the surface of the blades having an organosilicon coating, the organosilicon coating having calcium silicate filler; characterized in that:

[0012] The range hood also includes:

[0013] The detection module includes a transmitting module capable of emitting pulsed laser light towards a blade at a corresponding location and a receiving module capable of receiving the laser light reflected from the blade; and

[0014] The processing component, electrically connected to the detection module, can determine the thickness of the oil film, the type of oil, and the degree of oxidation on the blade based on the spectral lines of the laser received by the receiving module.

[0015] By employing low-energy pulsed laser-induced breakdown spectroscopy (LIBS) technology, combined with calcium from the calcium silicate filler in the silicone coating as a substrate reference, the thickness, type, and degree of oxidation of different oils can be identified based on the differences in elemental composition. This enables online monitoring of oil thickness with an accuracy of 0.05 mm (more than 5 times higher than traditional infrared methods), and provides high accuracy in oil type identification (supporting classification of animal oil, vegetable oil, and mixed oil). It solves the problem that traditional detection methods cannot distinguish between oil types and oxidation levels online, and achieves non-high-precision detection of impeller dirt levels, facilitating subsequent intelligent cleaning decisions.

[0016] Furthermore, the transmitting module includes a pulsed light source and a focusing lens, and the receiving module includes a spectral detector and a collecting lens.

[0017] To facilitate the installation of the detection module, the detection module is installed on the annular wall of the volute, and the annular wall has an opening corresponding to the position of the detection module.

[0018] To reduce the impact of grease contamination on the detection module, the volute has a volute tongue. On the projection along the axis of the impeller, the projection point of the axis is O, the projection point of the end of the volute tongue is M1, and the projection point of the center of the contact between the detection module and the volute is M2. The angle formed between the line connecting M1 and O and the line connecting M2 and O is α, and the value of α is in the range of [20-60°].

[0019] The technical solution adopted by the present invention to solve the second technical problem mentioned above is: a method for detecting grease in a range hood, using the above-mentioned range hood, characterized in that: the grease detection method includes the following steps:

[0020] 1) Turn on the range hood;

[0021] 2) Conduct oil and fat testing:

[0022] 2.1) Start the detection module and control the transmitting module to send detection pulses to the blades of the impeller;

[0023] 2.2) The receiving module collects spectral data and determines whether the signal-to-noise ratio of the received data is greater than a preset threshold. If yes, it extracts the characteristic spectral lines of Ca, C, P, S, K, and Mg and proceeds to step 2.3); if no, it increases the detection pulse energy, transmits the detection pulse again, and repeats this step.

[0024] 2.3) Determine the thickness of the oil film, the type of oil, and the degree of oxidation of the oil accumulated on the blade.

[0025] Further, in step 2.3), the oil film thickness d on the blade (121) is calculated by the following method:

[0026]

[0027] Among them I c I represents the intensity of the received C element characteristic spectral line. Ca The intensity of the received Ca element characteristic spectral line is given by k, which is a scaling factor, and C0 is a reference correction term. k and C0 are preset.

[0028] Further, in step 2.3), the type of oil is identified by the following method:

[0029] If the characteristic spectral lines detected and generated by the receiving module (42) contain P and S spectral lines, it indicates the presence of animal oil; if the spectral lines contain K and Mg spectral lines, it indicates the presence of vegetable oil.

[0030] Further, in step 2.3), the degree of oxidation CI of the oil is determined by the following method:

[0031]

[0032] Where CI is the carbonyl index; I 1745 This refers to the intensity of the carbonyl characteristic peak; I 1460 The intensity of the bending vibration peak of the methylene group in the grease detected by the receiving module (42); T ref T represents the reference temperature; T represents the actual measured temperature.

[0033] Furthermore, in order to facilitate the removal of floating oil on the impeller surface and improve detection accuracy, in step 2.1), before the transmitting module (41) transmits the detection pulse, it first transmits a cleaning pulse with energy greater than that of the detection pulse.

[0034] The technical solution adopted by the present invention to solve the third technical problem mentioned above is: a cleaning control method for a range hood, wherein the range hood includes a cleaning device, and the cleaning control method for the range hood is performed after detecting the current oil film thickness d, oil type and oil oxidation degree according to the above-mentioned oil detection method, and the cleaning control method includes the following steps;

[0035] 3.1) The processing component queries the preset oil film thickness threshold dr and determines whether d > dr is true. If not, no cleaning is required; if so, cleaning is required, and proceed to step 3.2).

[0036] 3.2) Based on the currently detected type of grease and oxidation level, control the cleaning device to start the corresponding cleaning mode;

[0037] 3.3) After cleaning, the transmitting module re-transmits a detection pulse, calculates the oil film thickness d' detected during the re-inspection, and determines whether d' > dr is true. If not, it means that it is qualified and returns to standby. If it is, it means that it is unqualified and an alarm is triggered and a record is made.

[0038] Compared with existing technologies, the advantages of this invention are as follows: By using low-energy pulsed laser-induced breakdown spectroscopy (LIBS) technology, combined with the calcium element of calcium silicate filler in the organosilicon coating as a substrate reference, the thickness, oil type, and oxidation degree can be identified based on the differences in the elements rich in different oils. It can achieve online monitoring of oil thickness with an accuracy of 0.05mm (more than 5 times higher than the traditional infrared method), and the oil type identification accuracy is high (supporting classification of animal oil / vegetable oil / mixed oil). It solves the problem that traditional detection cannot distinguish oil type and oxidation degree online, and realizes non-high-precision detection of impeller dirt level, so as to make intelligent cleaning decisions in the future. Attached Figure Description

[0039] Figure 1 This is a side view of the range hood installed according to an embodiment of the present invention;

[0040] Figure 2This is a cross-sectional view (left-right cross-section) of a range hood according to an embodiment of the present invention;

[0041] Figure 3 This is a cross-sectional view (front and rear section) of a range hood according to an embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of the centrifugal fan and its cleaning device of the range hood according to an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of the centrifugal fan and its cleaning device of the range hood according to an embodiment of the present invention (and...). Figure 4 (Different perspectives);

[0044] Figure 6 This is a schematic diagram of part of the electrical box and cleaning device of a range hood according to an embodiment of the present invention;

[0045] Figure 7 This is a cross-sectional view of the fan system of a range hood according to an embodiment of the present invention;

[0046] Figure 8 This is a light path diagram of the detection module in an embodiment of the present invention;

[0047] Figure 9 This is a control principle diagram of a range hood according to an embodiment of the present invention;

[0048] Figure 10 This is a flowchart illustrating the cleaning control process of a range hood according to an embodiment of the present invention. Detailed Implementation

[0049] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0050] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Since the embodiments disclosed in this invention can be arranged in different directions, these terms indicating direction are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0051] See Figures 1 to 7 A range hood includes a centrifugal fan 1, which comprises a volute 11, an impeller 12 disposed within the volute 11, and a motor 13 for driving the impeller 12 to rotate. The fan system 1 can be housed within a fan frame 2. In this embodiment, the range hood is a top-mounted type, and also includes a smoke collection hood 3 located below the fan frame 2. Alternatively, it can be a side-mounted, low-mounted, or other existing types of range hoods. The centrifugal fan 1 includes a volute 11, an impeller 12 disposed within the volute 11, and a motor 13 for driving the impeller 12 to rotate.

[0052] After long-term use, grease will accumulate on the blades 121 of the impeller 12.

[0053] Therefore, the range hood also includes a detection module 4, which is disposed on the annular wall 112 of the volute 11. The detection module 4 is located on the outer side of the annular wall 112, and the annular wall of the volute 11 can have openings at positions corresponding to the detection module 4, so that the detection module 4 can emit laser light to the impeller 12 and receive laser light reflected from the impeller 12. See also Figure 9 The detection module 4 includes an emitting module 41 that can emit laser light and a receiving module 42 that can receive reflected laser light.

[0054] The volute 11 has a volute tongue 111. On the projection along the axis X of the impeller 12, the projection point of the axis X is O, the projection point of the end of the volute tongue 111 is M1, and the projection point M2 is the center of the contact point between the detection module 4 and the volute 11 (the center along the spiral line of the volute 11). For ease of measurement, all projection points are located on the same plane. The angle formed by the line connecting M1 and O relative to the line connecting M2 and O is α, and the value of α ranges from [20-60°]. Since oil easily accumulates at the volute tongue 111, the detection module 4 is offset from the volute tongue 111 by a certain angle. This allows for detection at the smallest possible distance and avoids oil contamination of the detection module 4. A larger angle would increase the distance, hindering detection.

[0055] The range hood also includes a cleaning device for cleaning the centrifugal fan 1, see also Figures 2-6 The cleaning device includes a water tank 51 for storing cleaning media, which can be water or cleaning agent. The water tank 51 can be connected to tap water or other containers. The cleaning device also includes a heating or steam generating module 52, a water pump or water valve 53, a three-way valve 54, a first conduit 551, a second conduit 552, a third conduit 553, a spray arm 56, and a drive mechanism 57.

[0056] The first conduit 551 connects the heating or steam generating module 52 and the spray arm 56 to enable fluid communication between them. The spray arm 56 extends within the volute 11 of the centrifugal fan 1, located between the wall of the volute 11 and the impeller 12, and preferably extends in a direction parallel to the axial direction of the centrifugal fan 1. The spray arm 56 is provided with nozzles 561, which can be used to spray heated or steam-state cleaning media onto the blades 121 of the impeller 12 (or partially onto the volute 11). The spray arm 56 may also be provided with brush heads 562, which can be used to remove grease from the blades 121. A drive mechanism 57 is located outside the volute 11 and is used to drive the spray arm 56 to rotate about its own axis (in a direction parallel to the axial direction of the centrifugal fan 1). It can be any existing rotary drive module, such as a motor. This allows the direction of the nozzle 561 and / or brush head 562 to be changed by driving the spray arm 56 to achieve thorough cleaning, or to rotate the nozzle 561 and / or brush head 562 toward the wall of the volute 11 when cleaning is not required, reducing the risk of grease blockage and grease accumulation.

[0057] The range hood also includes an electrical box 6, which includes a power board 61 and a radiator 62 for heat dissipation of the power board 61. The radiator 62 can be in the form of heat dissipation fins. The three-way valve 54 is a valve body with one inlet and two outlets. The water tank 51 is connected to one inlet of the three-way valve 54 via a water pump or water valve 53 through a second conduit 552 (the water pump or water valve 53 is located at the connection between the water tank 51 and the second conduit 552 to control whether cleaning medium is supplied). One outlet of the three-way valve 54 is connected to the heating or steam generation module 52, and the other outlet is connected to the water tank 51 via a third conduit 553. The second conduit 552 can bend through the heat dissipation fins of the radiator 62, through which the cleaning medium in the water tank 51 enters the second conduit 552 via a water pump or water valve 53. The cleaning medium in the second conduit 552 exchanges heat with the radiator 62. After being preheated, the cleaning medium enters the three-way valve 54 and then enters the heating or steam generation module 52 to be heated or vaporized, thereby spraying and cleaning through the nozzles 561 on the spray arm 56. Unused cleaning medium can enter the third conduit 553 through the three-way valve 54 and then return to the water tank 51.

[0058] See Figure 9The range hood of this embodiment further includes a processing component 7, which has a processor. The motor 13 (and its drive module) of the centrifugal fan 1, the heating or steam generating module 52 of the cleaning device, the water pump or water valve 53, the drive mechanism 57, and the detection module 4 are all electrically connected to the processing component 7. In addition, the processing component 7 may also be electrically connected to a switch module 71, a storage module 72, and a lamp module 73, which are the same as in the prior art. The processing component 7 can control the laser emission of the emitting module 41 of the detection module 4, such as the emission time and emission frequency, and determine the thickness and type of oil film accumulated on the blades 121 based on the laser received by the receiving module 42.

[0059] The main components of the grease are hydrocarbons (CH bonds), rich in carbon (C) (spectral line 247.8 nm). Generally, the impeller 12 (blade 121) is a galvanized steel substrate with a silicone coating 1211 on the surface, achieving corrosion resistance and easy cleaning. The silicone coating 1211 often incorporates inorganic fillers (such as calcium silicate) to improve mechanical properties, heat resistance, or corrosion resistance. The galvanized steel substrate mainly consists of iron (Fe) and zinc (Zn), but the zinc layer is easily oxidized in high-temperature and high-humidity environments to form zinc oxide (ZnO; the galvanized steel surface itself is also a dense zinc oxide layer to prevent further corrosion). Its surface structure is dense, but its spectral response is weak (Zn spectral lines are mostly located in the ultraviolet region at 213.8 nm, close to C and easily interfered with). Calcium silicate (CaSiO3) is often added to the electrophoretic silicone coating 1211 as an inorganic filler to enhance wear resistance, resulting in the enrichment of calcium (Ca) on the surface of the silicone coating 1211. The ratio of the spectral intensity of carbon to that of calcium (corresponding to the 393.3 nm spectral line, which is less susceptible to arc interference) is directly proportional to the oil film thickness. Using the Ca / C spectral intensity ratio can eliminate the following interferences: laser energy fluctuations, changes in optical system transmittance, and differences in plasma temperature at different locations.

[0060] Therefore, low-energy pulsed laser-induced breakdown spectroscopy (LIBS) technology (which uses an ultrashort pulsed laser to focus on the sample surface to form plasma, and then analyzes the plasma emission spectrum to determine the material composition and content of the sample) can be used. Combined with the calcium element of the calcium silicate filler in the organosilicon coating 1211 as a substrate reference, the different types of oils can be distinguished based on the differences in the elements they contain (① animal oils such as lard / tallow contain phosphorus and sulfur, and the plasma sparks formed by the local vaporization of the laser will flash a specific blue-green light; ② vegetable oils such as rapeseed oil / peanut oil contain potassium, magnesium, etc., and the plasma sparks formed by the local vaporization of the laser will flash a purplish-red light). The degree of oil oxidation can also be judged by the duration of the sparks formed by the local vaporization of the pulsed light (fresh oil generally has a simple composition, and the sparks flash quickly, such as disappearing in 0.1 seconds; while oxidized and deteriorated oil will produce sticky oxides, and the sparks flash slowly, such as disappearing in 0.5 seconds. The longer the sparks last, the more severe the oil oxidation). This solves the problem that traditional detection methods cannot distinguish between different types of grease and the degree of oxidation online, and enables non-high-precision detection of impeller dirt levels and intelligent cleaning decisions.

[0061] Specifically, in combination Figure 8 The transmitting module 41 includes a pulsed light source 411 and a focusing lens 412, while the receiving module 42 includes a spectral detector 421 and a collecting lens 422, capable of detecting the wavelength and corresponding spectral intensity of light. By controlling the transmitting module 41 of the detection module 4 to illuminate the impeller 12 with a pulsed laser, the oil film 100 (oil film refers to the form of a film formed after the accumulation of grease) on the silicone coating 1211 of the blades 121 of the impeller 12 is locally vaporized by the laser into plasma 101 (that is, "burning" out a small spark with very low energy). Preferably, a dual-pulse laser emission can be used. First, a slightly higher energy cleaning pulse (e.g., 3 mJ) is used to remove surface oil and avoid interfering with deeper signals. Then, a low-energy detection pulse (e.g., 1.5 mJ) is emitted to excite the grease on the silicone coating 1211 and the underlying calcium element within the silicone coating 1211, with an energy density of 0.3 J / cm³. 2 Below the coating damage threshold (1.2 J / cm) 2 Therefore, it will not damage the silicone coating.

[0062] See Figure 10 The control method for the range hood of the present invention includes the following steps:

[0063] 1) Turn on the range hood. At this time, the system can perform self-test and impeller positioning.

[0064] 2) Conduct oil and fat testing:

[0065] 2.1) Start the detection module 4 and control the transmission module 41 to transmit pulses to the blades 121 of the impeller 12. It can directly transmit low-energy detection pulses, or transmit slightly higher-energy cleaning pulses before transmitting detection pulses.

[0066] 2.2) The receiving module 42 collects spectral data and determines whether the signal-to-noise ratio of the received data is greater than a preset threshold, such as 30dB. If yes, it extracts the characteristic spectral lines of Ca / C / P / S / K / Mg, etc., and proceeds to step 2.3); if no, it increases the detection pulse energy, such as by 10%, and repeats this step after transmitting the detection pulse again. In this step, the signal-to-noise ratio is generally obtained by taking the logarithm of the ratio of the corresponding peak value to the average Beijing noise value, and the spectral detector 421 can output it directly.

[0067] 2.3) The characteristics of the oil film 100 on the blade 121 can be judged from the following aspects, and after the judgment is completed, proceed to step 3):

[0068] 2.3.1) Calculate the thickness d (μm) of the oil film 100 on blade 121:

[0069] When the detection pulse laser emitted by the emission module 41 penetrates the oil film 100, the carbon (C) in the oil film 100 and the calcium (Ca) in the organosilicon coating 1211 of the blade 121 are simultaneously excited. The thicker the oil film 100, the higher the intensity of the C spectral line I. c The higher the strength, the greater the Ca content in the coating, which serves as a stable substrate reference. Ca The thickness is positively correlated with the coating thickness, thus yielding the following information:

[0070]

[0071] Among them I c I represents the intensity of the received characteristic spectral line of carbon (C) (247 nm, unit: photon count). Ca The received characteristic spectral line intensity of calcium (Ca) is 393.3 nm (unit: photon count), k is a proportionality constant, and the laboratory calibration value C0 is a baseline correction term, which is determined in advance by the laboratory.

[0072] 2.3.2) Identify oil types:

[0073] The characteristic spectral lines detected and generated by the spectrometer 421 can be matched to the type of fat. The characteristic identifiers are shown in Table 1 below. For example, if light corresponding to wavelengths P and S is detected, it can be determined that the accumulated fat is animal fat.

[0074] Oil type Feature identifier Typical spectral line combinations animal fat High phosphorus (P) / sulfur (S) content P: 213.6nm + S: 545.3nm vegetable oil High potassium (K) / magnesium (Mg) content K: 766.5nm + Mg: 279.5nm

[0075] Table 1. Correspondence between oil types and characteristic spectral lines.

[0076] 2.3.3) Assess the degree of oxidation:

[0077] Oils and fats oxidize to form carbonyl compounds (C=O), whose infrared absorption peak is located at 1745 cm⁻¹. -1 The methylene (CH2) absorption peak in the oil is at 1460 cm⁻¹. -1 As an internal standard reference, its stability is unaffected by oxidation. Therefore, the degree of oxidation can be quantified by the ratio of the characteristic peak intensities of their infrared spectra.

[0078]

[0079] Where CI is the carbonyl index (dimensionless, characterizing the degree of oxidation); I 1745 This refers to the characteristic peak intensity of the carbonyl group (C=O) at 1745 cm⁻¹. -1 Location, unit (au); I 1460 This refers to the peak intensity of the methylene (CH2) bending vibration (1460 cm⁻¹). -1 Location, unit (au); T ref Reference temperature (298K, 25℃); T: Actual detected temperature (unit: K), where the spectral detector 421 can detect temperature by analyzing the thermal radiation spectrum of an object.

[0080] Because increased temperature enhances molecular vibrations, leading to an overall increase in peak intensity, the temperature ratio Tref / T is introduced to eliminate the interference of ambient temperature on the peak intensity ratio. The oxidation degree CI classification can be referenced in Table 2 below:

[0081]

[0082] Table 2: Oxidation Degree Grading Table

[0083] 3) Cleaning control steps:

[0084] 3.1) Processing component 7 queries the preset oil film thickness threshold dr. This threshold can be set as needed or based on experience, such as 0.5μm. It then determines whether the currently detected thickness d > dr. If not, no cleaning is required, and the machine's health record is updated with the current oil detection result. If so, cleaning is required, and the process proceeds to step 3.2).

[0085] 3.2) Based on the currently detected oil type and oxidation level, the corresponding cleaning mode is activated. The recommended cleaning scheme is shown in Table 3 below, achieving dynamic optimization of cleaning parameters: the cleaning time can be adjusted based on the oxidation index CI and the basic cleaning time t. base t clean =t base (1+0.5×CI):

[0086] Table 3: Oil Types, Oxidation Levels, and Corresponding Cleaning Solutions

[0087] The above cleaning scheme is only a recommendation; users can also set other cleaning schemes as needed. The above cleaning scheme can be achieved by controlling the temperature, cleaning time, and adding different cleaning media to the water tank 51.

[0088] 3.3) After cleaning, the transmitting module 41 transmits a detection pulse again, calculates the oil film thickness d' detected during the re-inspection, and determines whether d' > dr is true. If not, it means that it is qualified and returns to standby. If it is, it means that it is unqualified and an alarm is triggered and a record is made.

[0089] The term "fluid connectivity" as used in this invention refers to the spatial relationship between two components or parts (hereinafter referred to as the first part and the second part, respectively), that is, a fluid (gas, liquid, or a mixture of both) can flow from the first part along a flow path and / or be transported to the second part. This can be a direct connection between the first part and the second part, or an indirect connection between the first part and the second part through at least one third party. This third party can be a fluid channel such as a pipe, channel, conduit, guide, hole, or groove, or a chamber or combination thereof that allows fluid to flow through.

Claims

1. A range hood, comprising a centrifugal fan (1) including a volute (11) and an impeller (12) disposed in the volute (11), the impeller (12) including blades (121) with a silicone coating (1211) on the surfaces of the blades (121), the silicone coating (1211) having a calcium silicate filler; characterized in that: the range hood further comprises: a detection module (4) including a transmitting module (41) capable of emitting pulsed laser light to the blades (121) at corresponding positions and a receiving module (42) capable of receiving the reflected laser light from the blades (121); and a processing assembly (7) electrically connected to the detection module (4) and capable of determining the oil film thickness, type and oxidation degree of the oil on the blades (121) according to the spectral lines of the laser light received by the receiving module (42).

2. The hood according to claim 1, characterized in that: The transmitting module (41) includes a pulsed light source (411) and a focusing lens (412), and the receiving module (42) includes a spectral detector (421) and a collection lens (422).

3. The hood according to claim 1 or 2, characterized in that: The detection module (4) is disposed on a ring wall (112) of the volute (11), and the ring wall (112) is holed at a position corresponding to the detection module (4).

4. The hood according to claim 3, characterized in that: The volute (11) has a volute tongue (111), and in a projection along an axis (X) of the impeller (12), a projection point of the axis (X) is O, an end projection point of the volute tongue (111) is M1, and a projection point of a center of a contact between the detection module (4) and the volute (11) is M2, a line connecting M1 and O forms an angle a with a line connecting M2 and O, and the value of a is in a range of [20-60°].

5. A method of detecting oil of an extractor hood, using the extractor hood according to any one of claims 1 to 4, characterized in that: The oil detection method includes the following steps: 1) starting the range hood; 2) performing oil detection: 2.1) starting the detection module (4) and controlling the transmitting module (41) to emit a detection pulse to the blades (121) of the impeller (12); 2.2) the receiving module (42) collects spectral data and determines whether a signal-to-noise ratio of the received data is greater than a preset threshold value, if yes, extracts characteristic spectral lines of Ca, C, P, S, K and Mg, and proceeds to step 2.3); if no, increases the detection pulse energy, emits the detection pulse again, and repeats the step; 2.3) determining the oil film thickness, type and oxidation degree of the oil accumulated on the blades (121).

6. The method of claim 5, wherein: In step 2.3), the oil film thickness d on the blades (121) is calculated by the following method: where I c is the received intensity of the characteristic spectral line of the element C, I Ca is the received intensity of the characteristic spectral line of the element Ca, k is a proportionality coefficient, and C0is a reference correction term, k and C0being preset.

7. The method of claim 5, wherein: In step 2.3), the type of the oil is identified by the following method: If the spectral lines of P and S exist in the characteristic spectral lines detected by the receiving module (42) and generated, it indicates that animal oil exists; if the spectral lines of K and Mg exist, it indicates that vegetable oil exists.

8. The method of claim 5, wherein: In step 2.3), the oxidation degree CI of the oil is determined by the following method: wherein CI is the carbonyl index; I 1745 is the intensity of the carbonyl characteristic peak; I 1460 is the intensity of the bending vibration peak of methylene detected by the receiving module (42) in the oil; T ref is the reference temperature; T is the actual detection temperature.

9. The method of claim 5, wherein: In step 2.1), before the transmitting module (41) emits the detection pulse, a cleaning pulse with energy greater than that of the detection pulse is emitted.

10. A cleaning control method of a range hood including a cleaning device; characterized by: The cleaning control method of the range hood is performed after the oil film thickness d, the oil type, and the oil oxidation degree are detected by the oil detection method according to any one of claims 5-9, and the cleaning control method comprises the following steps: 3.1) The processing assembly (7) queries a preset oil film thickness threshold dr, and determines whether d>dr is true. If not, cleaning is not required, and if yes, cleaning is required, and step 3.2) is entered; 3.2) According to the currently detected oil type and oxidation grade, the cleaning device is controlled to start a corresponding cleaning mode; 3.3) After cleaning, re-inspection is performed, the emission module (41) emits a detection pulse again, the re-inspected oil film thickness d' is calculated, and it is determined whether d'>dr is true. If not, it indicates that the product is qualified, and the standby state is returned. If yes, it indicates that the product is unqualified, and an alarm is given and a record is made.

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