Air supply system, filter cleaning method, and filter cleaning program

Abstract

This system uses a special sensor to detect when dust has accumulated on an electrostatic adsorption filter, and automatically cleans the filter of dust. [Solution] The air supply device comprises a fan that blows outside air into the interior, an electrostatic adsorption filter that collects dust from the air blown by the fan on the outside of the fan, an ammeter that measures the magnitude of the current flowing through the electrostatic adsorption filter, and a control unit that, when the magnitude of the current measured by the ammeter exceeds a threshold, cuts off the power supply to the electrostatic adsorption filter and changes the rotation of the fan in the reverse direction.

Description

Technical Field

[0001] The present invention relates to an air supply device, a filter cleaning method, and a filter cleaning program. Background Art

[0002] Generally, air supply devices and ventilation devices that take in air from outside the device into the device or from outdoors to indoors are provided with a dust collection filter to suppress the intrusion of dust. For example, Patent Document 1 discloses an electrostatic dust collector that uses a dust collection filter utilizing electrostatic adsorption. Prior Art Documents Patent Documents

[0003] Patent Document 1 Japanese Patent Application Laid-Open No. 57-147459 Summary of the Invention Problem to be Solved by the Invention

[0004] All disclosures of the above prior art documents are incorporated herein by reference. The following analysis is made by the inventors of the present invention.

[0005] By the way, when collected dust accumulates on a dust collection filter, the filter becomes clogged and the dust collection performance decreases, so it is necessary to clean the filter. Therefore, it is required to detect that dust adheres to the filter.

[0006] However, detecting dust adhesion to a filter has conventionally required special sensors or the like installed inside the device, for example, detecting filter clogging based on a temperature sensor inside the device, the rotation speed of a fan, or the current consumption of the fan, detecting mass change with a mass sensor, measuring light transmittance, or detecting the surface color of the air filter.

[0007] The object of the present invention is, in view of the above-mentioned problems, to provide an air supply device, a filter cleaning method, and a filter cleaning program that can detect the presence of dust on an electrostatic adsorption type filter without using a special sensor and contribute to automatically cleaning the dust from the filter. [Means for solving the problem]

[0008] In a first aspect of the present invention, an air supply device is provided, comprising: a fan that blows outside air into the interior; an electrostatic adsorption filter that collects dust from the air blown by the fan on the outside of the fan; an ammeter that measures the magnitude of the current flowing through the electrostatic adsorption filter; and a control unit that, when the magnitude of the current measured by the ammeter exceeds a threshold, cuts off the power supply to the electrostatic adsorption filter and changes the rotation of the fan in the reverse direction.

[0009] A second aspect of the present invention provides a filter cleaning method for an air supply device comprising a fan that blows outside air into the interior and an electrostatic adsorption filter that collects dust from the air blown by the fan on the outside of the fan, wherein the magnitude of the current flowing through the electrostatic adsorption filter is measured, and when the magnitude of the measured current exceeds a threshold, the power supply to the electrostatic adsorption filter is cut off and the rotation of the fan is changed to the reverse direction.

[0010] In a third aspect of the present invention, a filter cleaning program is provided for the control unit of an air supply device comprising a fan that blows external air into the interior and an electrostatic adsorption filter that collects dust from the air blown by the fan on the external side of the fan. The program performs the following actions: measuring the magnitude of the current flowing through the electrostatic adsorption filter; and, if the magnitude of the measured current exceeds a threshold, cutting off power to the electrostatic adsorption filter and changing the rotation direction of the fan. This program can be recorded on a computer-readable storage medium. The storage medium can be a non-transitory material such as semiconductor memory, hard disk, magnetic recording medium, or optical recording medium. The present invention can also be embodied as a computer program product. [Effects of the Invention]

[0011] According to each aspect of the present invention, it is possible to provide an air supply device, a filter cleaning method, and a filter cleaning program that can detect the presence of dust on an electrostatic adsorption type filter without using a special sensor, and contribute to automatically cleaning the dust from the filter. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 shows a method for clearing filter clogging in an air supply system. [Figure 2] Figure 2 shows the equivalent circuit of an electrostatic adsorption type filter in the air supply device of the present disclosure. [Figure 3] Figure 3 is a flowchart showing the procedure for cleaning the filter in the air supply device of this disclosure. [Figure 4] Figure 4 shows an example of the hardware configuration of the control unit of the air supply device. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the embodiments described below. In each drawing, the same or corresponding elements are appropriately denoted by the same reference numerals. Furthermore, it should be noted that the drawings are schematic, and the dimensional relationships and ratios of each element may differ from those of reality. Even between drawings, there may be parts where the dimensional relationships and ratios differ from each other.

[0014] [Air supply system] Figure 1 shows a method for clearing filter clogging in an air supply system. While Figure 1 assumes an air supply system that draws air from outside into the system, the method for clearing filter clogging described below is also applicable to air supply systems that draw air from outdoors into indoors.

[0015] As shown in Figure 1, the air supply device 1 is equipped with an electrostatic adsorption filter 3 and a fan 2. Under normal use, when the fan 2 draws air from outside the device into the device, the electrostatic adsorption filter 3 collects dust from the air. On the other hand, if dust adheres to the electrostatic adsorption filter 3 and its dust collection capacity decreases, the fan 2 is rotated in reverse to blow air from inside the device to outside, thereby cleaning the dust attached to the electrostatic adsorption filter 3. At this time, the effect of removing dust attached to the electrostatic adsorption filter 3 can be enhanced by turning off the power supply to the electrostatic adsorption filter 3 or by applying a reverse voltage.

[0016] As described above, although there is a method for cleaning dust adhering to the electrostatic adsorption filter 3, the method of cleaning the dust cannot be performed unless it is possible to detect that dust is adhering to the electrostatic adsorption filter 3. Therefore, the air supply device 1 and filter cleaning method of this disclosure use the following mechanism to detect that dust is adhering to the electrostatic adsorption filter 3 and to automatically clean the dust from the filter 3.

[0017] Figure 2 shows the equivalent circuit of an electrostatic adsorption filter in the air supply device of this disclosure. As shown in Figure 2, the equivalent circuit of the electrostatic adsorption filter can be considered as a parallel circuit of a capacitor C1 and a resistor R1. The air supply device of this disclosure includes a power supply that powers the electrostatic adsorption filter, a switch that controls the power supply to the electrostatic adsorption filter, and an ammeter that measures the magnitude of the current flowing through the electrostatic adsorption filter. Note that resistor R2 is the resistance of the entire circuit and does not require a special resistor.

[0018] As described above, the equivalent circuit of an electrostatic adsorption filter is a parallel circuit of a capacitor C1 and a resistor R1, but the actual configuration of an electrostatic adsorption filter is also a capacitor. Specifically, like a capacitor, an electrostatic adsorption filter applies a voltage between electrodes that are placed with a gap between them, and uses the electric field generated between the electrodes to collect dust.

[0019] An electrostatic adsorption filter functions based on this operating principle, so when dust is collected, the amount of current flowing through the electrostatic adsorption filter increases. It is assumed that no current flows between the electrodes of the electrostatic adsorption filter, but when dust adheres to the electrodes, current starts to flow between the electrodes. When this is expressed as an equivalent circuit, the resistance R1 decreases and the current flowing through the resistance R2 increases. Furthermore, the configuration allows the current flowing through the resistance R2 to be measured by an ammeter. Therefore, in the electrostatic adsorption filter of the air supply device of the present disclosure configured with the equivalent circuit shown in FIG. 2, when dust is collected, the measured value of the ammeter increases. In the air supply device of the present disclosure, utilizing this phenomenon, dust adhering to the electrostatic adsorption filter is detected using the measured value of the ammeter, and the electrostatic adsorption filter shown in FIG. 1 is cleaned.

[0020] [Filter Cleaning Method] FIG. 3 is a flowchart showing the procedure of the filter cleaning method for the air supply device of the present disclosure. As shown in FIG. 3, in the filter cleaning method for the air supply device of the present disclosure, first, power supply to the electrostatic adsorption filter is turned on, and a fan is rotated in the forward direction (step S1). Next, the magnitude of the current flowing through the electrostatic adsorption filter is measured (step S2).

[0021] Then, it is determined whether or not the measured current magnitude is equal to or greater than a threshold value (step S3). Here, for the threshold value, the current magnitude corresponding to a state where dust adheres to the electrostatic adsorption filter and the filter needs to be cleaned can be determined in advance through experiments or the like and used. When the measured current magnitude is not equal to or greater than the threshold value (step S3: NO), the process returns to step S2 to continue measuring the magnitude of the current flowing through the electrostatic adsorption filter.

[0022] If the measured current is greater than or equal to the threshold (step S3; YES), the power supply to the electrostatic adsorption filter is turned off and the fan is rotated in the reverse direction (step S4). As previously mentioned with reference to Figure 1, the operation in step S4 has the effect of cleaning dust from the electrostatic adsorption filter. Also, as previously mentioned, instead of turning off the power supply to the electrostatic adsorption filter, it is possible to enhance the dust cleaning effect on the electrostatic adsorption filter by applying a reverse voltage.

[0023] Finally, once the dust has been removed from the electrostatic adsorption filter, the power supply to the electrostatic adsorption filter is turned on and the fan is rotated in the forward direction (step S5). This completes the series of processes for cleaning the filter in the air supply unit. If the air supply unit is to be used again, return to step S2 and continue measuring the magnitude of the current flowing through the electrostatic adsorption filter.

[0024] [Example Hardware Configuration] Figure 4 shows an example of the hardware configuration of the control unit of the air supply device. That is, the control unit of the air supply device 1 uses the hardware configuration shown in Figure 4, and by executing the filter cleaning method described above as a program, it is possible to realize each function of the air supply device 1. However, the hardware configuration example shown in Figure 4 is just one example of a hardware configuration that realizes each function of the control unit of the air supply device 1, and is not intended to limit the hardware configuration of the air supply device's control unit. The control unit of the air supply device 1 may include hardware not shown in Figure 4.

[0025] As shown in Figure 4, the hardware configuration that the control unit 10 may employ includes, for example, a CPU (Central Processing Unit) 11, a main memory 12, an auxiliary memory 13, and an IF (Interface) unit 14, all interconnected by an internal bus.

[0026] The CPU 11 executes each command included in the filter cleaning program run by the control unit (computer) 10. The main memory 12 is, for example, RAM (Random Access Memory) and temporarily stores various programs, such as the filter cleaning program run by the control unit (computer) 10, for processing by the CPU 11.

[0027] The auxiliary storage device 13 is, for example, an HDD (Hard Disk Drive) and can store various programs, such as the filter cleaning program executed by the control unit 10, for medium to long term. The filter cleaning program can be provided as a program product recorded on a non-transitory computer-readable storage medium.

[0028] The IF unit 14 provides an interface for the input and output of the control unit 10.

[0029] The control unit 10, which employs the hardware configuration described above, implements each function of the air supply device 1 by executing the aforementioned filter cleaning method as a program.

[0030] Furthermore, the disclosures of the above-mentioned patent documents and other materials cited are incorporated into this document by reference. Within the framework of the full disclosure of the present invention (including the claims), further modifications and adjustments to the embodiments or examples are possible based on the fundamental technical concept. Also, within the framework of the full disclosure of the present invention, various combinations or selections (including partial deletions) of various disclosure elements (including each element of each claim, each element of each embodiment or example, each element of each drawing, etc.) are possible. In other words, the present invention naturally includes the full disclosure, including the claims, and various modifications and alterations that a person skilled in the art could make in accordance with the technical concept. In particular, with respect to the numerical ranges described in this document, any numerical value or sub-range included within that range should be interpreted as being specifically described, even if not otherwise stated. Furthermore, the disclosures of the above-mentioned cited documents may, if necessary, be used in part or in whole as part of the disclosure of the present invention, in accordance with the spirit of the present invention, and these may also be considered to be included in the disclosures of this application. [Explanation of Symbols]

[0031] 1. Air supply system 2 Fans 3 filters 10 Control Unit 11 CPU 12 Main storage 13 Auxiliary storage device 14 IF section

Claims

1. A fan that blows outside air into the interior, An electrostatic adsorption filter that collects dust from the air blown by the fan, located outside the fan, An ammeter for measuring the magnitude of the current flowing through the electrostatic adsorption type filter, A control unit that, when the magnitude of the current measured by the ammeter exceeds a threshold, cuts off the power supply to the electrostatic adsorption filter and reverses the rotation of the fan, An air supply device equipped with the following features.

2. The air supply device according to claim 1, wherein the threshold value is predetermined as the magnitude of the current when dust adheres to the electrostatic adsorption type filter and the filter needs to be cleaned.

3. The air supply device according to claim 1 or 2, wherein the control unit cuts off the power supply to the electrostatic adsorption filter and further applies a reverse voltage to the electrostatic adsorption filter when the magnitude of the current measured by the ammeter exceeds a threshold.

4. An air supply device comprising a fan that blows outside air into the interior, and an electrostatic adsorption filter that collects dust from the air blown by the fan on the outside of the fan, The magnitude of the current flowing through the electrostatic adsorption type filter is measured, If the measured current exceeds a threshold, the power supply to the electrostatic adsorption filter is cut off, and the fan's rotation is reversed. How to clean the filter.

5. The filter cleaning method according to claim 4, wherein the threshold is predetermined as the magnitude of the current when dust adheres to the electrostatic adsorption type filter and the filter needs to be cleaned.

6. The filter cleaning method according to claim 4 or 5, wherein when the magnitude of the current measured by the ammeter exceeds a threshold, the power supply to the electrostatic adsorption type filter is cut off, and a reverse voltage is further applied to the electrostatic adsorption type filter.

7. The control unit of an air supply device, which includes a fan that blows outside air into the interior and an electrostatic adsorption filter that collects dust from the air blown by the fan on the outside of the fan, A process for measuring the magnitude of the current flowing through the electrostatic adsorption type filter, When the magnitude of the measured current exceeds a threshold, the power supply to the electrostatic adsorption filter is cut off and the rotation of the fan is reversed. The filter cleaning program to run.

8. The filter cleaning program according to claim 7, wherein the threshold is predetermined as the magnitude of the current when dust has accumulated on the electrostatic adsorption type filter and the filter needs to be cleaned.

9. The filter cleaning program according to claim 7 or 8, which causes the control unit to perform a process of cutting off the power supply to the electrostatic adsorption filter and further applying a reverse voltage to the electrostatic adsorption filter when the magnitude of the current measured by the ammeter exceeds a threshold.

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