air purifier

Abstract

To provide an air cleaner that can surely prevent a risk of fire due to a combustible gas in operation control of an electric dust collector 10 and does not unnecessarily lower dust collecting purification performance by frequently stopping the operation of the electric dust collector 10.SOLUTION: When an energization control unit that operates the electric dust collector 10 according to a detection status of a dust sensor or a gas sensor satisfies an operation prevention condition based on the gas sensor, the air cleaner is formed into a composition provided with an automatic operation prevention control mechanism that eliminates the risk of ignition by preventing to automatically operate the electric dust collector 10, the operation prevention condition is taken as that a state where the gas sensor detects a first predetermined value or less continues for a predetermined time.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an air purifier that removes dust such as dust, pollen, odor components, PM2.5, and viruses in the air to purify the air.

Background Art

[0002] A dust collection filter unit that adheres and removes dust in the air sucked in from the intake unit and passes through it to purify the air, or an electric dust collection unit that controls energization when it is determined that the dirt is severe (the dust level is high) by a dirt sensor (dust sensor or gas sensor), electrifies the dust in the passing air, and electrostatically adsorbs this dust to the dust collection electrode to remove it and purify the air is provided in the main body unit. An air purifier configured to blow out the purified air from the blowing unit through the dust collection unit such as the dust collection filter unit and the electric dust collection unit is well received.

[0003] For example, in such an air purifier, the dust collection filter unit may be detachably attached to the main body unit, and further, the electric dust collection unit may be detachably attached to the upstream side or the downstream side of the dust collection filter unit.

[0004] In addition, the electric dust collection unit of such an air purifier has, for example, a configuration in which a large number of ionization electrodes are arranged in parallel, and a large number of dust collection electrodes are arranged in parallel at intervals from each of these ionization electrodes. When it is desired to increase the dust collection and purification ability due to severe dirt (high dust level), energization control is performed through an electrode terminal portion that is in contact conduction with a voltage supply unit (high voltage power supply) to energize the ionization electrodes. For example, each of these ionization electrodes is used as a positive electrode, and each dust collection electrode spaced apart and opposed thereto is used as a negative electrode, and a voltage is applied. The dust in the passing air is electrified and electrostatically adsorbed to each of the negative dust collection electrodes to be removed, and the air is purified.

[0005] In such air purifiers, the amount of air blown by the air blower (fan) is usually controlled according to the level of the dust sensor and odor sensor (gas sensor), and the air is efficiently and quickly purified by the dust collection filter according to the degree of contamination. However, it is desirable to configure the air purifier to have an electrostatic precipitator in addition to the dust collection filter, as mentioned above, and to operate the electrostatic precipitator by controlling the power supply when the dust level is high, thereby further increasing the dust collection and purification capacity.

[0006] Furthermore, since these electrostatic precipitators operate by applying high voltage, there is a risk of ignition if, for example, a spray containing flammable gas generates more flammable gas than permitted. Therefore, some electrostatic precipitators are controlled to stop (prevent) their operation.

[0007] In other words, an air purifier has been proposed that includes an automatic operation prevention control mechanism in the power supply control unit of the electrostatic precipitator. This mechanism controls the operation of the electrostatic precipitator to prevent fire hazards when the maintenance indicator is lit or when the temperature is low to suppress the rise in ozone concentration, and also prevents the operation of the electrostatic precipitator to prevent fire hazards when the amount of flammable gas exceeds the permissible level due to spraying of flammable gases, etc.

[0008] For example, conventional automatic operation prevention control methods include, as described in Patent Document 1, a system that, when the power switch of the machine is turned on, detects the presence of flammable gas in the electrostatic precipitator, stops the operation of the electrostatic precipitator, cuts off the high voltage, and operates the blower to exhaust the flammable gas.

[0009] However, simply using a control system that stops the operation of the electrostatic precipitator when it detects the presence or absence of flammable gas may cause it to stop frequently, potentially preventing it from achieving sufficient dust collection and purification performance. Furthermore, simply lowering the sensitivity of this operation prevention system may not adequately eliminate the risk of ignition due to flammable gas.

[0010] Furthermore, even in simple gas alarms, as in Patent Documents 2 and 3, the system merely detects a decrease in electrical resistance due to flammable gas and activates an alarm when it determines that the gas concentration is high. Applying this to the automatic operation prevention control of an electrostatic precipitator results in the aforementioned problems. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Utility Model Publication No. 52-28285 [Patent Document 2] Japanese Public Gazette No. 50-12302 [Patent Document 3] Official Gazette No. 49-11997 [Overview of the project] [Problems that the invention aims to solve]

[0012] This invention aims to identify and solve these problems by providing a groundbreaking air purifier that is highly practical, reliably prevents the risk of ignition by flammable gases in the operation control of the electrostatic precipitator, and does not unnecessarily reduce dust collection and purification performance by frequently stopping the operation of the electrostatic precipitator. [Means for solving the problem]

[0013] The gist of the present invention will be explained with reference to the attached drawings.

[0014] The air purifier comprises an intake unit 2 for drawing in outside air, a dust collection unit 3 for purifying the air by removing dust particles from the air drawn in by the intake unit 2, a discharge unit 4 for blowing out the purified air, and a blower unit 5 for creating the airflow that is drawn in by the intake unit 2 and blown out by the discharge unit 4. The dust collection unit 3 consists of an ionization electrode unit 7 equipped with an ionization electrode 6, and a dust collection electrode unit 9 equipped with a dust collection electrode 8 spaced apart from the ionization electrode 6. The electrostatic dust precipitator 10 is configured to apply a voltage to the ionization electrode 6 and the spaced-apart dust collection electrode 8 to electrostatically charge dust particles in the passing air and cause them to be electrostatically attracted to the dust collection electrode 8, and gas detection It is something that The present invention relates to an air purifier equipped with a gas sensor that indicates a lower value the greater the amount of gas, and an energizing control unit that energizes the ionization electrode 6 and applies the voltage to operate the electrostatic precipitator 10 according to the detection status of the gas sensor or, if a dust sensor is provided, according to the detection status of the dust sensor, and the energizing control unit is equipped with an automatic operation prevention control mechanism that, when the operation prevention condition based on the gas sensor is met, determines that the amount of flammable gas exceeds an acceptable range and prevents the ionization electrode 6 from energizing and automatically operating the electrostatic precipitator 10, thereby eliminating the risk of ignition, and the operation prevention condition is that the state in which the gas sensor detects a value of 1 or less than a predetermined value continues for a predetermined period of time.

[0015] Furthermore, the gas sensor is a semiconductor gas sensor, and the gas sensitivity is calculated based on the ratio of the resistance value measured by the gas sensor to a reference resistance value and used as the output of the gas sensor. The condition for preventing operation, in which it is determined that the flammable gas exceeds the permissible range, is when the gas sensitivity of the output of the gas sensor remains below the first predetermined value for a predetermined period of time. This is the characteristic of the air purifier according to claim 1.

[0016] Furthermore, the air purifier according to claim 2 is characterized in that the operation prevention condition is that the gas sensitivity, which is the output of the gas sensor, has been detected to be 0.1 or less, which is a first predetermined value, for a predetermined period of time.

[0017] Furthermore, the air purifier according to claim 1 is characterized in that when the output of the gas sensor becomes a second predetermined value greater than the first predetermined value, the operation of the ionization electrode 6 of the electrostatic precipitator 10 is permitted by energization, thereby terminating the operation of the automatic operation prevention control mechanism or automatically restarting the operation of the electrostatic precipitator 10.

[0018] Furthermore, a dust collection filter section 12, which is equipped with a dust collection filter 11 for collecting dust from the passing air, is provided downstream or upstream of the electrostatic dust precipitator 10 as a separate dust collection section 3 from the electrostatic dust precipitator 10, and the air is purified by the dust collection filter section 12 even when the electrostatic dust precipitator 10 is not operating, and the automatic operation prevention control mechanism provided in the energization control unit that automatically controls the operation of the electrostatic dust precipitator 10 is equipped with a control mechanism that returns to the operating mode before the prevention operation after the prevention operation is completed, characterized in that the air purifier is as described in claim 1. [Effects of the Invention]

[0019] As described above, the present invention is configured to reliably prevent the risk of ignition due to flammable gases in the operation control of the electrostatic precipitator, and moreover, it does not frequently stop the operation of the electrostatic precipitator, thereby unnecessarily reducing the dust collection and purification performance, resulting in a highly practical and groundbreaking air purifier. [Brief explanation of the drawing]

[0020] [Figure 1] This is a descriptive perspective view of this embodiment. [Figure 2] This is a cross-sectional view of this embodiment. [Figure 3]This is an exploded perspective view for explaining the state in which the detachable electric dust collection unit that can be slid and separated into two parts in this embodiment is taken out from the main body unit.

Mode for Carrying Out the Invention

[0021] The optimal embodiment of the present invention will be briefly described based on the drawings, showing the operation of the present invention.

[0022] The blower unit 5 sucks outside air into the main body unit 1 from the intake unit 2. As this air passes through the dust collection unit 3 of the main body unit 1, dust in the air is adhered or adsorbed and removed, and the air is purified and discharged from the blowing unit 4.

[0023] Specifically, for example, a dust collection filter unit 12 equipped with a dust collection filter 11 as the dust collection unit 3 is provided in this main body unit 1, and an electric dust collection unit 10 is also provided as another dust collection unit 3 on the upstream side or the downstream side of this dust collection filter unit 12. Then, the blower unit 5 sucks outside air into the main body unit 1 from the intake unit 2. As this air sequentially passes through each dust collection unit 3 (the electric dust collection unit 10 and the dust collection filter unit 12), dust is adhered or adsorbed and removed and purified, and is discharged from the upper blowing unit 4.

[0024] That is, for example, the air volume of the blower unit 5 is controlled according to the detection situation (degree of dirt) of the dust sensor, and dust in the air is captured and adhered and removed by the dust collection filter 11 of the dust collection filter unit 12 installed in the middle path of this air flow. If an electric dust collection unit 10 that operates by energization control is provided in a stacked state on the upstream side, when it is detected and determined by this dust sensor that the dirt is severe (the dust level is high) (when the energization operation conditions are satisfied), the electric dust collection unit 10 is energized and automatically operates, and dust in the air is electrostatically charged and electrostatically adsorbed to the dust collection electrode 8 and removed.

[0025] To explain further, the electrostatic precipitator 10 of the present invention consists of an ionization electrode section 7 equipped with an ionization electrode 6 and a dust collection electrode section 9 equipped with a dust collection electrode 8 disposed at a distance from the ionization electrode 6. A voltage (high voltage) is applied to the ionization electrode 6 and the dust collection electrode 8 which is spaced apart from it, thereby electrostatically activating dust in the passing air and causing it to be electrostatically attracted to the dust collection electrode 8. As mentioned above, for example, if the purification capacity of the dust collection filter section 12 is insufficient or to enhance it, the system is configured so that air passes through both, and when necessary, depending on the degree of contamination, that is, when the energizing operation conditions are met, the electrostatic precipitator 10 also operates automatically in addition to the dust collection filter section 12, thereby increasing the purification capacity.

[0026] Furthermore, in the present invention, as described above, the air is purified by the dust collection filter section 12 even when the electrostatic precipitator 10 is not operating. In addition, the purification capacity may be enhanced by automatically activating the electrostatic precipitator 10 by supplying current to the ionization electrode 6 using the automatic operation control mechanism of the current supply control section when necessary, i.e., when the above-mentioned energization operation conditions are met.

[0027] Furthermore, in this invention, the current control unit that operates the electrostatic precipitator 10 is equipped with an automatic operation prevention control mechanism that, when an operation prevention condition based on a gas sensor is met, prevents the ionization electrode 6 from being energized and the electrostatic precipitator 10 from being automatically activated. In other words, if it is operating, it stops the energization and cuts off the voltage application, thereby eliminating the risk of ignition. Since the operation prevention condition is that the gas sensor has detected a value below a first predetermined value for a predetermined period of time, the risk of ignition due to flammable gas can be reliably prevented, and the operation of the electrostatic precipitator 10 is not stopped frequently, which would unnecessarily reduce the dust collection and purification performance.

[0028] In other words, for example, by using a semiconductor gas sensor, calculating the gas sensitivity based on the ratio of the resistance value measured by this gas sensor to a reference resistance value and using this as the output of the gas sensor, and setting the operation prevention condition to the fact that the gas sensitivity of the output of this gas sensor has remained below the first predetermined value for a predetermined time, rather than simply detecting that it is below a predetermined value, the risk of ignition by flammable gas can be reliably prevented, and moreover, the operation of the electrostatic precipitator is not frequently stopped, which would unnecessarily reduce the dust collection and purification performance, resulting in a groundbreaking air purifier with excellent practicality. [Examples]

[0029] Specific embodiments of the present invention will be described with reference to the drawings.

[0030] This embodiment includes a main body 1 comprising an intake unit 2 for drawing in outside air, a dust collection unit 3 for purifying the air by removing dust particles from the air drawn in by the intake unit 2, a blowing unit 4 for blowing out the purified air, and a blowing unit 5 for creating the airflow that is drawn in by the intake unit 2 and blown out by the blowing unit 4. The embodiment also includes an airflow control unit that controls the amount of air blown by the blowing unit 5 according to the dust level and odor level (depending on the degree of soiling) detected and determined by a dust sensor and a gas sensor.

[0031] Specifically, the air blowing section 5 from below upward draws in outside air from the intake sections 2, which are located in four directions (front, back, left, and right) around the bottom, i.e., all around, to the upper center. The dust collection section 3, which is located on the lower upstream side of the air blowing section 5 of the main body 1, i.e., along the entire length of the air passage, collects or adsorbs dust from the air, thereby purifying it.

[0032] Furthermore, in this embodiment, the dust collection unit 3 consists of a dust collection filter unit 12 equipped with a dust collection filter 11 and an electrostatic precipitator unit 10. The dust collection unit 3, consisting of the dust collection filter unit 12, is provided upstream (lower) of the blower unit 5 of the main body unit 1, and the electrostatic precipitator unit 10 is further layered and arranged upstream (lower) of this dust collection unit 3.

[0033] Therefore, the system is configured such that outside air is drawn in by the blower unit 5 from the intake unit 2 at the bottom of the main body unit 1, and this air is purified as dust adheres to or is adsorbed and removed as it passes through the dust collection unit 3 (electrostatic precipitator 10 and dust collection filter unit 12), and is then discharged from the upper outlet unit 4.

[0034] In other words, the amount of air blown by the blower unit 5 is controlled according to the detection status of the dust sensor and gas sensor, and the dust collection filter 11 of the dust collection filter unit 12, which is detachably attached to the entire path, efficiently captures and removes dust from the air. However, an electrostatic precipitator 10 that operates by power supply control is detachably installed upstream of this in a layered configuration. For example, when the dust sensor detects that the dirt is severe (high dust level) (when the first power supply operating condition is met), power is supplied and the electrostatic precipitator 10 operates automatically, causing dust in the air to be electrostatically charged, electrostatically attracted, removed, and purified (purification capacity is increased).

[0035] In other words, the dust collection unit 3 of this embodiment has a configuration in which the dust collection filter unit 12 and the electrostatic precipitator unit 10 are arranged in a layered arrangement, and when necessary depending on the degree of contamination, that is, when the aforementioned energizing operation conditions are met, the electrostatic precipitator unit 10 is also automatically activated in addition to the dust collection filter unit 12, thereby electrostatically charging and removing dust in the air, thereby enhancing the purification capacity.

[0036] Furthermore, the electrostatic dust collector 10 in this embodiment comprises an ionization electrode section 7 in which a large number of ionization electrodes 6 are arranged at intervals, a dust collection electrode section 9 in which a large number of dust collection electrodes 8 are arranged at intervals from each of the large number of ionization electrodes 6, and an electrode terminal section (contact terminal section) that makes contact and conduction with a voltage supply section (high voltage power supply terminal section) that applies voltage to each of the ionization electrodes 6 and each of the dust collection electrodes 8 that are spaced apart from them. By supplying current to the ionization electrodes 6 through this electrode terminal section and applying a voltage (high voltage) to the ionization electrodes 6 and the dust collection electrodes 8 that are spaced apart from them, dust in the passing air is electrostatically charged and electrostatically attracted to the large number of dust collection electrodes 8.

[0037] Furthermore, the electrostatic precipitator 10 is configured as a detachable unit and can be detachably attached to the main body 1. In addition, the dust collection electrode 9 can be slid from the ionization electrode 7 to separate into two parts, allowing the dust collection electrode 8 of the dust collection electrode 9 to be easily exposed during maintenance and allowing the adsorbed dust to be easily removed.

[0038] Furthermore, in this embodiment, as mentioned above, even when the electrostatic precipitator 10 is not operating, the airflow from the air blower 5 controlled by the airflow control unit and the dust collection filter 11 of the dust collection filter unit 12 adhere to the dust in the passing air, thereby purifying the air.

[0039] Furthermore, in this embodiment, the current control unit is provided which energizes the ionization electrode 6 and applies the voltage to operate the electrostatic precipitator 10. This current control unit is configured to include an automatic operation control mechanism which automatically operates the electrostatic precipitator 10 by energizing the ionization electrode 6 when the first current operation condition is met.

[0040] The first energization operation condition of this embodiment is configured such that the dust level detected and determined by the dust sensor is above a predetermined level, this state of being above the predetermined level continues for a predetermined time, and the output of the dust sensor required to reach this predetermined level is above a first threshold, and this condition is detected a predetermined number of times.

[0041] Specifically, in this embodiment, the premise is that a dust sensor detects and determines the dust occupancy rate and outputs the result. Multiple dust levels are provided to determine the degree of contamination according to the output (dust occupancy rate) of this dust sensor, and the level is determined according to the output of this dust sensor.

[0042] In other words, the automatic operation control mechanism provided in the power supply control unit of this embodiment is configured to increase the dust level (increase the dust level to the maximum level) when the output of the dust sensor (dust occupancy rate) is detected to be above a first threshold for a predetermined number of times, or when the output of the dust sensor is detected to be above a third threshold, which is greater than the first threshold, once.

[0043] To elaborate further on the dust level, in this embodiment, the dust level is set to four levels, from level zero (clean, no dirt) to level 3, depending on the output of the dust sensor (P output (%)), i.e., the detected dust occupancy rate. For example, when a P output of a% or more is detected b times or more per minute at level zero, the dust level is raised from level zero to level 1. When a P output of c% (greater than a%) or more is detected d times or more per minute, or when a P output of e% (greater than c%) or more is detected once, the dust level is raised from level 1 to level 2. Furthermore, when a P output of f% (at least greater than a%) or more is detected g times (greater than d times) or more per minute, or when a P output of h% (greater than both e% and f%) or more is detected once, the dust level is raised from level 2 to the maximum level 3. In this embodiment, with the same sensitivity setting, c% and f% are set to the same value, for example, 6% for intermediate sensitivity.

[0044] Furthermore, the dust occupancy rate (P output %), which is the condition for each level-up of the dust level based on the dust occupancy rate of these P outputs, can be changed simultaneously by adjusting the sensitivity setting, and the system is configured to allow adjustment of the operating sensitivity of the airflow control of the blower unit 5 and the automatic operation control of the electrostatic precipitator 10.

[0045] In this embodiment, the configuration allows for changing the sensitivity by automatically changing the dust occupancy rate (P output %), which is the condition for raising the dust level. In this embodiment, the first energizing operation condition for automatically controlling the operation of the electrostatic precipitator 10 based on this P output (threshold) is set to the following conditions: the dust level is at or above the maximum level 3, this state of being at or above level 3 continues for a predetermined time (for example, 3 minutes), and the P output of the dust sensor required to reach level 3 is at or above the first threshold (the P output f%, for example, 6%), which is detected a predetermined number of times g (for example, 4 times).

[0046] In other words, in this embodiment, the automatic operation control mechanism is provided in the power supply control unit for operating the electrostatic precipitator 10 to automatically control the operation of the electrostatic precipitator 10. Four dust levels are provided, from zero to three, depending on the degree of contamination. The amount of air blown is increased as the dust level rises, and the electrostatic precipitator 10 is automatically activated when the dust level is high and the first power supply operation condition is met. Moreover, the operation condition is set not only to a high dust level, but also to the fact that this high dust level continues for a predetermined time and the P output is detected to be above the first threshold (f% or higher) for a predetermined number of times (g times) for the dust level to rise. As a result, the dust collection filter unit 12 is activated only when the contamination is severe and the purification capacity is insufficient, thereby increasing the purification capacity and quickly purifying the air. At the same time, the frequency of operation is suppressed, and the risk of reduced component lifespan and increased ozone concentration due to high voltage application is reliably prevented.

[0047] Furthermore, the frequency of sudden changes in the rotation speed of the air blower unit 5 is suppressed, reducing the impact on component lifespan.

[0048] Furthermore, the automatic control mechanism provided in the power supply control unit of this embodiment is configured such that when a second power supply operating condition is met, in which the output of the dust sensor (the P output) is detected (detected once) to be greater than or equal to a second threshold (for example, the dust occupancy rate i%, for example, 12%) which is greater than the first threshold (dust occupancy rate f%, for example, 6%), the ionization electrode 6 is energized and the electrostatic precipitator 10 is automatically activated, even if the first power supply operating condition is not met.

[0049] In other words, in this embodiment, the control mechanism for automatically controlling the operation of the electrostatic precipitator 10, i.e., the automatic operation control mechanism of the energization control unit, is configured to energize and automatically operate when the dust level is at a predetermined level (maximum level 3), a predetermined time (for example, 3 minutes or more) has elapsed, and the P output has been detected to be at or above the first threshold (dust occupancy rate f%, for example, 6%) for a predetermined number of consecutive times (for example, 4 data points (16 seconds)) (when the first energization operation condition is met), or when the P output has been detected to be at or above the second threshold (dust occupancy rate i%, for example, 12%) once (for example, when the second energization operation condition is met) while the dust level is at level 3.

[0050] Therefore, in this embodiment, even when the level reaches 3, it is conceivable that the indoor air can be immediately purified in the vicinity of that level simply by controlling the increase in the airflow rate, i.e., by the dust collection filter unit 12 alone. Therefore, if the first energization operating condition is set so that the electrostatic precipitator 10 is only activated when the air is not purified after leveling up to level 3, and further if the P output of the first energization operating condition (dust occupancy rate f%, for example 6% or more) is detected a predetermined number of times (for example, g times, which is 4 times), there is a risk that the operation of the electrostatic precipitator 10 will be delayed even if the contamination is quite severe. In this configuration, the first energizing condition is replaced with a second energizing condition (as an OR condition), and when it is detected once that the P output is greater than the first threshold (dust occupancy rate f%) and greater than or equal to the second threshold (dust occupancy rate i%, for example, 12%), that is, when a detection is detected once where the absolute value of the P output is large (not the number of detections), the electrostatic precipitator 10 is automatically activated without waiting for the first energizing condition to be met. This configuration allows for rapid detection and automatic activation when the degree of contamination is extreme, thereby quickly increasing the purification capacity.

[0051] Furthermore, this second threshold, which determines an extremely high level of contamination, is set to a value higher than that frequently detected by normal household dust, so it will not activate frequently and will not impair the user experience.

[0052] To further elaborate on the dust level-up control mechanism, as mentioned above, the automatic operation control mechanism provided in the energization control unit of this embodiment is a control mechanism that raises the dust level (for example, from level 2 to level 3) when the P output of the dust sensor is detected to be at or above the first threshold (dust occupancy rate f%) for raising the level from dust level 2 to the maximum dust level 3 a predetermined number of times, or when the output of the dust sensor is detected to be at or above a third threshold (dust occupancy rate h%) which is greater than the first threshold, once.

[0053] Specifically, as described above, this control mechanism is configured to raise the dust level when the output of the dust sensor is detected to be above the first threshold (a%, c%, or f%) multiple times within the determination time, and the level determination conditions are set such that the number of times the output is detected to be above the first threshold within the determination time increases as the dust level increases (for example, from level 1 to level 2, c% is detected d times (2 times), while from level 2 to level 3, f% (which is the same as c%) is detected g times (4 times)).

[0054] Therefore, the system is configured to raise the dust level in accordance with the number of detections where the P output exceeds the threshold, without raising the threshold itself, allowing for a quicker level-up when the dirt is severe. On the other hand, considering that waiting for multiple detections might delay the level-up when the dirt is extremely severe, the system is configured to raise the level even with just one detection above a high threshold, enabling quicker determination and purification of the degree of dirt, thereby improving the user experience.

[0055] In this embodiment, a gas sensor is provided, and multiple odor levels are set to be detected and determined by this gas sensor. The airflow control unit is configured to control the airflow amount of the air blower 5 by taking into account this odor level in addition to the dust level.

[0056] Therefore, because gas sensors (odor sensors) exhibit less fluctuation compared to dust sensors, they can determine the appropriate level even with fewer detection cycles.

[0057] Furthermore, the automatic operation control mechanism of the electrostatic precipitator 10 in this embodiment is configured to perform various controls, such as power supply prohibition control and continuous power supply limit control, in order to improve safety, operability, and user experience.

[0058] Furthermore, even if the electrostatic precipitator 10 does not operate due to power-on prohibition control based on such power-on prohibition conditions, the dust is purified by the dust collection filter 12 as described above, so the user experience is not significantly impaired.

[0059] Furthermore, even if the user switches from automatic operation mode to a fixed operation mode according to the user's preference, the airflow rate will remain fixed. However, in this embodiment, the operation control of the electrostatic precipitator 10 is automatically controlled as described above, and the aforementioned effects are always achieved.

[0060] Next, an embodiment of the automatic operation prevention control mechanism in the energization control of the electrostatic precipitator 10, which is the main component of the present invention and prevents the risk of ignition by flammable gas, will be described.

[0061] As described above, the electrostatic precipitator 10 operates by applying a high voltage. Therefore, if the amount of flammable gas exceeds the permissible limit, for example, due to spraying a flammable gas, there is a risk of ignition. In such cases, the system is configured to control the power supply to prevent (stop) the operation of the electrostatic precipitator 10.

[0062] Specifically, the system is configured to stop the operation of the electrostatic precipitator 10 if there is a risk of ignition due to flammable gas, and to prevent it from stopping operation if there is no such risk, thereby reliably preventing the risk of ignition while avoiding frequent shutdowns.

[0063] In other words, the electrostatic precipitator 10 does not prevent operation in the event of other odors that may occur in normal daily life, such as an increase in odor level due to cigarette smoke. Instead, it is configured to automatically stop operation by fulfilling the prevention conditions before a situation arises where a flammable gas spray is continuously emitted for a predetermined period of time or longer, i.e., before a dangerous situation arises where the risk of ignition due to the flammable gas increases, thus preventing such a situation from occurring.

[0064] In other words, in this embodiment, for example, when the maintenance indicator is lit or when the temperature is low (to suppress the rise in ozone concentration), the electrostatic precipitator 10 is controlled to prevent operation (normal power supply prohibition control). In addition, to prevent the risk of ignition when the amount of flammable gas exceeds the permissible level due to continuous spraying of a spray containing flammable gas, an automatic operation prevention control mechanism is provided in the power supply control unit of the electrostatic precipitator 10. This mechanism sets conditions for operation prevention and controls the electrostatic precipitator 10 to prevent its operation (stop it if it is operating) when these conditions are met.

[0065] Furthermore, the gas sensor in this embodiment is a semiconductor gas sensor, and the gas sensitivity is calculated based on the ratio of the resistance value measured by this gas sensor to a reference resistance value, and this is set as the output of the gas sensor. The operation prevention condition is set to the state in which the gas sensitivity of this gas sensor output is less than or equal to the first predetermined value for a predetermined period of time.

[0066] Specifically, the activation prevention condition in this embodiment requires that the gas sensitivity, which is the output of the gas sensor, detects a value of 0.1 or less, which is the first predetermined value, for a predetermined period of time (for example, 10 seconds) (continuous detection).

[0067] In this embodiment, the semiconductor gas sensor has oxygen adsorbed on its semiconductor surface. This oxygen removes electrons from the semiconductor, resulting in a high resistance value in clean air. However, when reducing gases such as hydrogen or carbon monoxide are present, the oxygen on the semiconductor surface reacts with the reducing gas. This reduces the resistance value as the oxygen is consumed, and the ratio of this reduced resistance value to a reference resistance value is used as the gas sensitivity, which is then used as the sensor output.

[0068] The gas sensitivity, which is the output of this gas sensor, differs in its response to time between flammable gases and other gases. Furthermore, in the case of flammable gases, it decreases exponentially over time. By utilizing this difference, the first predetermined value of the operation prevention condition, which serves as the criterion for determining operation prevention (operation stoppage), is determined and set based on experimental results, so that the generation or increase in concentration of dangerous flammable gases can be detected instantaneously.

[0069] Specifically, for example, smoking a few cigarettes in a room of a certain size, using a normal amount of disinfectant alcohol, or spraying something containing flammable gas, such as a deodorizing spray, for a few seconds only reduces the gas sensitivity to about 0.3.

[0070] However, repeated experiments revealed that even when such a deodorizing spray is sprayed continuously for a considerable period (for example, 10 seconds), the gas sensitivity finally drops to below 0.1, but there is still no risk of ignition. Furthermore, the risk of ignition only increases if ventilation is not performed for more than 60 seconds.

[0071] Based on these experimental results, in this embodiment, the first predetermined value is set to 0.1, and the operation prevention condition is set when this value of 0.1 or less is continuously detected for, for example, 10 seconds or more. When this operation prevention condition is met, the operation of the electrostatic precipitator 10 is stopped, and the operation of the electrostatic precipitator 10 is stopped at least 20 seconds after a deodorizing spray containing flammable gas is continuously sprayed, thereby reliably preventing the risk of ignition.

[0072] Furthermore, by setting the first predetermined value to 0.1, the electrostatic precipitator 10 is configured not to stop operating in the event of odors that occur in normal daily life and pose no danger, thereby preventing frequent shutdowns that would reduce the dust collection and purification performance of the electrostatic precipitator 10 or impair the user experience.

[0073] In this embodiment, when the gas sensor reaches a second predetermined value (for example, 0.8) that is greater than the first predetermined value (for example, 0.1), the system is configured to allow the ionization electrode 6 of the electrostatic precipitator 3 to be energized and to terminate the operation of the automatic operation prevention control mechanism (returning to a normal state where no prevention operation occurs) or to automatically restart the operation of the electrostatic precipitator 3.

[0074] Specifically, for example, if it is detected that the gas sensitivity has risen again to a predetermined multiple (for example, 0.8 times) of the gas sensitivity when the operation of the electrostatic precipitator 10 has been stopped due to the aforementioned operation prevention conditions being met, the system is configured to allow the supply of high voltage and terminate the operation stop control of the electrostatic precipitator 10 or to automatically restart it.

[0075] Furthermore, in this embodiment, as described above, a dust collection filter section 11, which is equipped with a dust collection filter 10 that collects dust from the passing air, is provided downstream of the electrostatic precipitator 3 as a separate dust collection section 3 from the electrostatic precipitator 10, so that the air is purified by the dust collection filter section 11 even when the electrostatic precipitator 10 is not operating.

[0076] In this embodiment, the automatic operation prevention control mechanism provided in the current control unit that automatically controls the operation of the electrostatic precipitator 10 is configured to return to the operating mode before the prevention operation (stop) after the prevention operation is completed (after the operation of the electrostatic precipitator 10 has been stopped by this prevention operation).

[0077] Therefore, even after the electrostatic precipitator 10 stops operating, the air is purified with an airflow rate corresponding to the odor level or dust level, and indoor air purification continues and indoor air is circulated. As a result, localized increases in the concentration of flammable gases are eliminated, and the risk of ignition is eliminated early on.

[0078] Furthermore, similar to the automatic operation control mechanism of the electrostatic precipitator 10 in this embodiment, the automatic operation prevention control mechanism is also configured to perform various controls, such as power supply prohibition control and continuous power supply restriction control, as described above, in order to improve safety, operability, and user experience. For example, power supply operation prohibition conditions such as when maintenance is announced, when the temperature is low, and when the rotation speed of the blower unit 5 (fan) decreases are also used as operation prevention conditions.

[0079] Furthermore, the present invention is not limited to this embodiment, and the specific configuration of each constituent element can be designed as appropriate. [Explanation of Symbols]

[0080] 1. Main body 2. Intake section 3. Dust collection unit 4. Air outlet 5. Air blower 6. Ionization electrode 7. Ionization electrode section 8. Dust collection electrode 9 Dust collection electrode section 10 Electrostatic precipitator 11 Dust collection filter 12 Dust collection filter section

Claims

1. An air purifier comprising an intake section for drawing in outside air, a dust collection section for purifying the air by attaching to and removing dust from the air drawn in from the intake section, a discharge section for blowing out the purified air, and a blower section for creating the airflow that is drawn in from the intake section and blown out from the discharge section, The dust collection unit consists of an ionization electrode section equipped with an ionization electrode and a dust collection electrode section equipped with a dust collection electrode disposed at a distance from the ionization electrode. The electrostatic dust collection unit is configured such that a voltage is applied to the ionization electrode and the dust collection electrode separated therefrom to electrostatically charge dust in the passing air and cause it to be electrostatically attracted to the dust collection electrode. It is equipped with a gas sensor that detects gas, and the higher the amount of gas, the lower the value it displays. The system is equipped with an energizing control unit that energizes the ionization electrode and applies the voltage to activate the electrostatic dust collector, depending on the detection status of the gas sensor or, if a dust sensor is provided, depending on the detection status of the dust sensor. This current control unit is configured to include an automatic operation prevention control mechanism that, when the operation prevention conditions based on the gas sensor are met, determines that the flammable gas exceeds an acceptable range, prevents the ionization electrode from being energized and the electrostatic precipitator from being automatically activated, thereby eliminating the risk of ignition. The air purifier is characterized in that the condition for preventing operation is that the gas sensor has detected a value of 1 or less for a predetermined period of time.

2. The air purifier according to claim 1, characterized in that the gas sensor is a semiconductor gas sensor, the gas sensitivity is calculated based on the ratio of the resistance value measured by the gas sensor to a reference resistance value and used as the output of the gas sensor, and the condition for preventing operation in which it is determined that the flammable gas exceeds the permissible range is when the state in which the gas sensitivity of the output of the gas sensor is less than or equal to the first predetermined value continues for a predetermined time.

3. The air purifier according to claim 2, characterized in that the operation prevention condition is that the gas sensitivity, which is the output of the gas sensor, has been detected to be 0.1 or less, which is a first predetermined value, for a predetermined period of time.

4. The air purifier according to claim 1, characterized in that when the output of the gas sensor becomes a second predetermined value greater than the first predetermined value, the operation of the ionization electrode of the electrostatic precipitator is permitted by energization, thereby terminating the operation of the automatic operation prevention control mechanism or automatically restarting the operation of the electrostatic precipitator.

5. A dust collection filter section is provided downstream or upstream of the electrostatic precipitator, which is equipped with a dust collection filter that collects dust from the passing air. This section is provided as a separate dust collection unit from the electrostatic precipitator, and the air is purified by the dust collection filter section even when the electrostatic precipitator is not operating. The air purifier according to claim 1, characterized in that the automatic operation prevention control mechanism provided in the current supply control unit that automatically controls the operation of the electrostatic dust precipitator is configured to return to the operating mode before the prevention operation after the prevention operation is completed.

Images