JP7789331B1 - air purifier - Google Patents

Abstract

An air purifier capable of accurately detecting the concentration of harmful substances in air that has passed through a filter is provided.
[Solution] The air purifier 1 comprises an intake port 11 for drawing in air, an exhaust port 12 for discharging air, a flow path 10 arranged between the intake port 11 and the exhaust port 12, through which air drawn in from the intake port 11 flows to the exhaust port 12, a first adsorption filter 20a arranged to block the flow path 10, and a first detection unit 50 for detecting harmful substances contained in air that has passed through the first adsorption filter 20a, the first detection unit 50 being on the outlet side of the first adsorption filter 20a and detecting harmful substances at multiple different positions on the cross section of the flow path 10.
[Selected Figure] Figure 3

Description

The present invention relates to an air purifier.

A known device for reducing the concentration of harmful substances in the air, such as volatile organic compounds and odorous substances, is one that has a fan and filter installed in the air flow path connecting the intake and exhaust ports (see Patent Document 1). In such devices, air containing a large amount of harmful substances is taken in through the intake port, and the harmful substances are removed from the air as the air passes through the filter. The air, with the concentration of harmful substances reduced to below a specified value, is then exhausted from the exhaust port.

In conventional air purifiers, a sensor that detects harmful substances contained in the air that has passed through the filter is installed at one location on the outlet side of the filter to detect the degree of filter breakthrough.

JP 2024-85154 A

Because the concentration of harmful substances in the air flowing into the filter and the flow of air flowing into the filter are not constant throughout the filter, the degree of filter breakthrough may vary depending on the position on the filter. Furthermore, if the filter is a breathable container filled with granular adsorbent material, the adsorbent filling rate may vary depending on the position on the filter.

However, conventional air purifiers measure the concentration of harmful substances in the air that has passed through the filter at one location, the outlet side of the filter. If filter breakthrough occurs earlier at a location farther from the sensor than at other locations, or if the adsorbent filling rate at a location farther from the sensor is lower than at other locations, it may not be possible to accurately detect the concentration of harmful substances in the air that has passed through the filter.

The present invention was made in consideration of these circumstances, and aims to provide an air purifier that can accurately detect the concentration of harmful substances in air that has passed through a filter.

The present invention includes the following embodiments:

[1] An air purifier comprising an intake port for drawing in air, an exhaust port for discharging air, a flow path provided between the intake port and the exhaust port through which air drawn in from the intake port flows to the exhaust port, a first filter provided to block the flow path, and a first detection unit for detecting harmful substances contained in air that has passed through the first filter, wherein the first detection unit is located on the outlet side of the first filter and detects harmful substances at multiple different positions on the cross section of the flow path.

[2] The air purifier described in [1] above, wherein the first detection unit includes a plurality of first suction tubes that suck air from different positions on the cross section of the flow path on the outlet side of the first filter, a sensor that detects harmful substances contained in the air sucked by the first suction tubes, and a switching unit that selectively switches between the plurality of first suction tubes to connect them to the sensor.

[3] The air purifier described in [2] above, wherein the suction port that draws air from the flow path into the first suction pipe opens toward the upstream side of the air flow in the flow path.

[4] The air purifier described in any one of [1] to [3] above, wherein the first filter includes a plurality of small filters arranged in parallel along the cross section of the flow path, and the first detection unit detects harmful substances at the outlet side of each of the plurality of small filters.

[5] The air purifier described in any one of [1] to [4] above, further comprising a second filter disposed downstream of the first filter in the air flow path so as to block the air flow path, and the first detection unit detects harmful substances contained in the air between the first filter and the second filter.

[6] The air purifier described in any one of [1] to [5] above, further comprising: a fan that is located downstream of the first filter in the air flow path and generates an air flow in the flow path; and a second detection unit that detects harmful substances contained in the air at the air intake of the fan.

[7] The air purifier described in [6] above, wherein the second detection unit includes a second suction pipe that draws in air from the fan inlet, and the first detection unit includes a plurality of first suction pipes that draw in air from different positions on the cross section of the flow path on the outlet side of the first filter, a sensor that detects harmful substances contained in the air drawn in by the first suction pipe or the second suction pipe, and a switching unit that selectively switches between the plurality of first suction pipes and the second suction pipes to connect them to the sensor.

According to the above embodiment, the concentration of harmful substances in the air that has passed through the filter in the air purifier can be accurately detected.

FIG. 1 is a front view of an air purifier according to an embodiment of the present invention. FIG. 1 is a front view of the interior of an air purifier according to an embodiment of the present invention. FIG. 1 is a view of the interior of an air purifier, seen from the front left, showing the arrangement of a first adsorption filter, a second adsorption filter, a fiber filter, a first detection unit, and a second detection unit in an air purifier according to an embodiment of the present invention. FIG. 1 is a perspective view of a first adsorption filter seen from diagonally above; A perspective view of the small filter container from diagonally above Cross-sectional view of the small filter, taken along a plane passing through the central axis of the small filter. A perspective view of the filter holding member seen from diagonally above. Front view of the inside of the air purifier with the filter separated from the divider AA cross-sectional view of FIG. BB cross section of FIG. An enlarged cross-sectional view of the main part of the air purifier with the filter separated from the partition plate. FIG. 10 is a view of the inside of the air purifier of Modification Example 1, showing the arrangement of the first adsorption filter, the second adsorption filter, the fiber filter, the first detection unit, and the second detection unit, as seen from the diagonal front left.

First, we will explain the overall configuration of the air purifier 1 of this embodiment.

(1) Overall Configuration of Air Purifier 1 The air purifier 1 is a device that draws in air containing harmful substances, such as volatile organic compounds (e.g., solvents) and odorants, removes the harmful substances from the air, and discharges air with a reduced concentration of harmful substances. The air purifier 1 can be applied to various workplaces where harmful substances are present. As an example, the air purifier 1 can be suitably used for ventilating workplaces where painting or degreasing is performed. Furthermore, the harmful substances that can be removed by the air purifier 1 are not particularly limited. For example, the air purifier 1 can be used to remove various volatile organic solvents, such as methyl ethyl ketone (MEK), isopropyl alcohol (IPA), methanol, ethanol, toluene, xylene, and acetone.

As shown in Figures 1 and 2, the air purifier 1 comprises a housing 2 having an inlet 11 and an outlet 12, a fan 13 that generates an air flow in an air flow path 10 from the inlet 11 to the outlet 12, a first adsorption filter 20a and a second adsorption filter 20b that remove harmful substances in the air flowing through the flow path 10, fiber filters 3a and 3b that remove dust and the like contained in the air, and a first detection unit 50 and a second detection unit 70 that measure the concentration of harmful substances contained in the air in the flow path 10.

In the following description, the direction in which the first adsorption filter 20a and the second adsorption filter 20b are removed from the housing 2 is referred to as the front, and the direction in which the first adsorption filter 20a and the second adsorption filter 20b are inserted into the housing 2 is referred to as the rear. Furthermore, left and right refer to the left and right when viewed from the front to the rear.

The intake port 11, which draws air into the housing 2, is formed on the bottom surface of the housing 2. The exhaust port 12, which exhausts air from the housing 2, is formed on the top surface of the housing 2. The air flow path 10 between the intake port 11 and the exhaust port 12 extends vertically within the housing 2.

A fan 13 is provided at the top of this flow path 10. The fan 13 has its intake port 13a (hereinafter referred to as the fan intake port 13a) facing downward, and its rotation axis extends vertically. Rotation of the fan 13 generates an air flow from bottom to top within the flow path 10. As indicated by the white arrows in Figure 2, air from outside the device is drawn in through the intake port 11 on the underside of the housing 2, and the drawn air rises through the flow path 10 and is discharged through the exhaust port 12 on the top of the housing 2. Operation of the fan 13 generates the air flow described above within the flow path 10; the direction in which the air flows is referred to as downstream, and the opposite direction as upstream. In this embodiment, the up-down direction roughly corresponds to the upstream and downstream directions of the air flow. The lower side of the flow path 10 provided within the housing 2 corresponds to the upstream side of the air flow, and the upper side of the flow path 10 corresponds to the downstream side of the air flow. Looking at the main components of the air purifier 1 from the perspective of the air flow in the flow path 10, the flow path 10 is lined up in the following order from upstream to downstream: intake port 11, fiber filter 3a, first adsorption filter 20a, second adsorption filter 20b, fiber filter 3b, fan 13, and exhaust port 12. Air taken into the housing 2 through the intake port 11 passes through each component in the above order before being discharged to the outside of the housing 2 through the exhaust port 12.

A check damper 11a is provided in the flow path 10 between the suction port 11 and the first adsorption filter 20a, that is, slightly above the suction port 11 and below the first adsorption filter 20a, as a backflow prevention device to prevent air from flowing back. The check damper 11a opens due to wind pressure while air is being sucked into the housing 2 through the suction port 11, but closes when the wind pressure disappears. As a result, when the fan 13 stops and air is no longer being sucked through the suction port 11, the check damper 11a closes, preventing air with a high solvent concentration inside the housing 2 from flowing back and leaking out of the device through the suction port 11.

Casters 5 are attached to each of the four corners on the underside of the housing 2, allowing the air purifier 1 to be easily moved. Air around the air purifier 1 passes between the casters 5 and is sucked into the air inlet 11.

The exhaust port 12 is located in a position that avoids being directly above the fan 13. Specifically, a horizontal wall 14a is provided directly above the fan 13. Vertical walls 14b are provided on three sides of the fan 13 (front, back, left, and right). A curved wall 14c with a downward convex shape is provided on the remaining side of the fan 13 (to the right in Figure 2), extending upward while moving away from the fan 13. The exhaust port 12 is located above the curved wall 14c and to the side of the horizontal wall 14a. The horizontal wall 14a, vertical wall 14b, and curved wall 14c form part of the inner wall of the air flow path 10.

The fan 13 blows air drawn in through the fan intake 13a in the direction of centrifugal force (diametrically outward from the rotation shaft). The air blown from the fan 13 flows along the curved wall 14c and is exhausted to the outside of the device through the exhaust port 12. With this configuration, compared to when the exhaust port 12 is located directly above the fan 13, the sound of the fan 13 is less likely to leak outside the device, and air is less likely to be drawn in near the exhaust port 12.

The first adsorption filter 20a and the second adsorption filter 20b are located within the air flow path 10, closer to the air inlet 11 than the fan 13 (lower in this embodiment). The first adsorption filter 20a and the second adsorption filter 20b are arranged vertically with a gap between them, starting from the bottom, with the second adsorption filter 20b being located downstream of the first adsorption filter 20a in the air flow path 10.

Air flowing through the flow path 10 passes through the first adsorption filter 20a and then the second adsorption filter 20b. The first adsorption filter 20a is designed to remove harmful substances from the air drawn in through the suction port 11, keeping the concentration of harmful substances in the air below a specified value. The second adsorption filter 20b is provided as a backup in case the first adsorption filter 20a breaks through.

In front of the first adsorption filter 20a and the second adsorption filter 20b, doors 4a and 4b are provided to close the openings 2a and 2b that penetrate the housing 2. An operator can open door 4a and replace the first adsorption filter 20a in the air flow path 10 through opening 2a, and open door 4b and replace the second adsorption filter 20b in the air flow path 10 through opening 2b.

A fiber filter 3a made of nonwoven fabric is provided upstream of the first adsorption filter 20a and the second adsorption filter 20b in the air flow path 10, for example, between the suction port 11 and the check damper 11a. Furthermore, a fiber filter 3b made of nonwoven fabric is provided downstream of the first adsorption filter 20a and the second adsorption filter 20b in the air flow path 10, for example, between the second adsorption filter 20b and the fan 13. The fiber filters 3a and 3b are arranged to block the air flow path 10, so that the air flowing through the flow path 10 passes through the fiber filters 3a and 3b. The lower fiber filter 3a removes dust from the air sucked in through the suction port 11. The upper fiber filter 3b removes powder generated by the adsorbent material 23 provided in the first adsorption filter 20a and the second adsorption filter 20b from the air that has passed through the first adsorption filter 20a and the second adsorption filter 20b.

As shown in Figures 1 to 3, the air purifier 1 further includes a first detection unit 50, a second detection unit 70, an alarm 8, and an operation unit 9.

While the air purifier 1 is operating, the first detection unit 50 measures the concentration of harmful substances in the air that has passed through the first adsorption filter 20a. In addition, in case the first detection unit 50 fails, the second detection unit 70 serves as a backup sensor to measure the concentration of harmful substances in the air that has passed through the first adsorption filter 20a and the second adsorption filter 20b while the air purifier 1 is operating.

The alarm 8 is a device that issues an alarm in response to the concentration of harmful substances measured by the first detection unit 50 and the second detection unit 70. The operation unit 9 is an interface that accepts operations by the operator on the air purifier 1. The first detection unit 50 and the second detection unit 70 will be described later.

(2) First adsorption filter 20a and second adsorption filter 20b
Next, the structure of the first adsorption filter 20a will be described. As shown in Figure 4, the first adsorption filter 20a comprises one filter holding member 40 and multiple small filters 21 that remove harmful substances from the air. The multiple small filters 21 are arranged in parallel with the flow path 10 and are individually detachably held by the filter holding member 40. The first adsorption filter 20a is arranged so as to block the flow path 10 and removes harmful substances from the air that passes through the small filters 21.

As shown in Figure 6, the small filter 21 has a large number of adsorbents 23 stored in the adsorbent storage section 30 of the filter container 22, for adsorbing solvents in the air. The multiple small filters 21 provided in the first adsorption filter 20a all have the same shape, structure, and size.

As shown in Figures 5 and 6, the filter container 22 includes an outer cylinder 24, an inner cylinder 25 disposed radially inward of the outer cylinder 24, a lower blocking plate 34 that blocks the lower opening of the inner cylinder 25, a single lower cover 26 disposed below the lower blocking plate 34 that blocks the gap between the outer cylinder 24 and the inner cylinder 25, and a blocking plate 27 that blocks the gap between the outer cylinder 24 and the inner cylinder 25 at the top. The filter container 22 forms an adsorbent storage section 30 that stores the adsorbent 23 between the outer cylinder 24 and the inner cylinder 25. Note that the terms "upper" and "lower" in the description of the filter container 22 refer to the blocking plate 27 as the upper portion and the lower cover 26 as the lower portion.

The outer cylindrical body 24 comprises a cylindrical porous portion 24a with numerous ventilation holes 24a1, and a mesh portion 24b arranged along the inner surface (inner surface) of the porous portion 24a. The porous portion 24a is formed by molding a metal plate with numerous ventilation holes 24a1 (such as a punched plate) into a cylindrical shape and welding the butt joints (two parallel sides of the original rectangular metal plate). The mesh portion 24b is made of a mesh formed by weaving wires such as metal wires together in a net-like pattern. The mesh portion 24b is arranged along the inner surface of the porous portion 24a so as to cover the ventilation holes 24a1 arranged in the porous portion 24a.

Like the outer cylinder 24, the inner cylinder 25 has a cylindrical porous portion 25a with numerous ventilation holes 25a1, and a mesh portion 25b made of a mesh that is provided along the inner surface of the porous portion 25a. The porous portion 25a is formed by forming a metal plate with ventilation holes 25a1 into a cylindrical shape and welding the butt joints (two parallel sides of the original rectangular metal plate). The mesh portion 25b is provided along the outer surface of the porous portion 25a so as to cover the ventilation holes 25a1 provided in the porous portion 25a from the outside.

The size of the ventilation holes 24a1, 25a1 provided in the outer cylindrical body 24 and the inner cylindrical body 25 may be large enough to allow the adsorbent 23 to pass through. Furthermore, the mesh size of the mesh sections 24b, 25b, i.e., the maximum gap between adjacent wires, is smaller than the diameter of the ventilation holes 24a1, 25a1 in the porous sections 24a, 25a, and is large enough to prevent the adsorbent 23 from passing through.

The lower region of the filter container 22 is a ventilation region 32 in which ventilation holes 24a1, 25a1 are formed in the outer cylinder 24 and the inner cylinder 25. On the other hand, the upper region of the filter container 22 is a non-ventilation region 33 in which ventilation holes 24a1, 25a1 are not formed in the outer cylinder 24 or the inner cylinder 25. The ratio of the vertical length of the non-ventilation region 33 to the vertical length of the filter container 22 is, for example, 10% or more and 30% or less.

The outer cylinder 24 and inner cylinder 25 are arranged concentrically when viewed from above and are fixed to the closure plate 27. Therefore, the distance between the outer cylinder 24 and inner cylinder 25 is constant at all points.

The closure plate 27 is a generally circular plate with a hole 27a in the center. The outer diameter of the closure plate 27 is larger than the diameter of the outer cylindrical body 24. The inner diameter of the closure plate 27 (the diameter of the hole 27a) is the same as the inner diameter of the inner cylindrical body 25.

The closure plate 27 is welded to the entire upper end of the outer cylinder 24 and the entire upper end of the inner cylinder 25. This prevents air from entering the adsorbent storage section 30 through the gap between the outer cylinder 24 and the closure plate 27, or between the inner cylinder 25 and the closure plate 27. Furthermore, because the outer diameter of the closure plate 27 is larger than the diameter of the outer cylinder 24, a flange portion 27b extending radially outward from the outer cylinder 24 is provided around the entire circumference of the outer cylinder 24.

A rod-shaped handle 28 is provided on the upper surface of the closure plate 27 to span the hole 27a. The handle 28 is joined to the upper surface of the closure plate 27 by welding.

The lower blocking plate 34, which blocks the opening at the bottom of the inner cylinder 25, is a circular plate with no holes and the same diameter as the inner cylinder 25. This lower blocking plate 34 is welded to the entire lower end of the inner cylinder 25. This prevents air from entering the radially inside of the inner cylinder 25 from below.

The lower cover 26 comprises a plate portion 26a provided below the lower closure plate 34 and a peripheral wall portion 26b protruding upward from the periphery of the plate portion 26a. The plate portion 26a is a circular plate with a diameter slightly larger than that of the outer cylinder 24. The peripheral wall portion 26b is provided around the entire periphery of the plate portion 26a.

6 , the lower cover 26 is provided on the underside of the lower blocking plate 34 and is fastened to the lower blocking plate 34 with fasteners 35 such as bolts. When the lower cover 26 is fixed to the lower blocking plate 34, the plate portion 26a comes into contact with the lower end of the outer cylindrical body 24 and the lower blocking plate 34. This prevents air from leaking between the plate portion 26a and the outer cylindrical body 24, between the plate portion 26a and the inner cylindrical body 25, and between the inner cylindrical body 25 and the lower blocking plate 34.

The area surrounded by the outer cylinder 24, inner cylinder 25, bottom lid 26, and closing plate 27 is the adsorbent storage section 30, which is filled with adsorbent 23. The adsorbent storage section 30 can be said to be cylindrical with a thickness in the radial direction. The lower end of the space between the outer cylinder 24 and inner cylinder 25 is the filling port for filling the adsorbent 23 into the adsorbent storage section 30. An operator can remove the bottom lid 26 and fill the adsorbent 23 into the adsorbent storage section 30 through the filling port.

As described above, the outer cylinder 24 and the inner cylinder 25 have air vents 24a1 and 25a1, the bottom cover 26 blocks the entire radially inner side of the outer cylinder 24 from below, and the blocking plate 27 blocks the area between the outer cylinder 24 and the inner cylinder 25 from above. Therefore, air can pass through the adsorbent storage section 30 between the radially outer area of the outer cylinder 24 and the radially inner hollow portion 25c of the inner cylinder 25. Air cannot pass through the blocking plate 27 and the bottom cover 26.

The adsorbent 23 used in the first adsorption filter 20a and the second adsorption filter 20b is granular and capable of adsorbing harmful substances. The adsorbent 23 can be selected appropriately depending on the harmful substances to be removed from the air. However, when removing organic solvents such as methyl ethyl ketone (MEK), isopropyl alcohol (IPA), methanol, ethanol, toluene, xylene, and acetone from the air as harmful substances, zeolite (porous crystalline aluminosilicate) is a particularly preferred adsorbent 23 due to its excellent adsorption of these harmful substances, its ability to be regenerated in a short time, and its low loss during regeneration. The average particle size of the adsorbent 23 is not limited, but is, for example, 1.2 to 1.6 mm.

The adsorbent 23 is preferably filled up to the top of the adsorbent storage section 30. Repeated transport of the small filters 21 and loading and unloading of the small filters 21 into and from the filter holding member 40 causes repeated collisions between the adsorbent 23 and the filter container 22, and between the adsorbents 23 themselves, which can cause the adsorbent 23 to wear and reduce in volume. Even if the amount of adsorbent 23 decreases and creates space at the top of the adsorbent storage section 30, such space is only formed in the non-ventilated area 33, which does not have ventilation holes 24a1, 25a1; the ventilation area 32, which has ventilation holes 24a1, 25a1, remains filled with adsorbent 23. Therefore, air passing through the small filters 21 can always pass through the adsorbent storage section 30 through the ventilation area 32, which is filled with adsorbent 23.

The outer cylinder 24, inner cylinder 25, lower closure plate 34, lower lid 26, closure plate 27, and handle 28 are made of heat-resistant metal. Here, heat resistance of the metal means that it is less likely to deform even when the filter container 22 and the adsorbent 23 are exposed to heated air when the adsorbent 23 is regenerated.

As shown in Figure 2, the filter holding member 40 is a plate-like member that is arranged perpendicular to the direction of air flow in the flow path 10, i.e., horizontally. Specifically, as shown in Figures 4 and 7, the filter holding member 40 includes a flat plate portion 40a, an annular rib 40b that protrudes upward from the periphery of the plate portion 40a, a sealing material 40c that is provided at the upper end of the annular rib 40b, and flange portions 40d that protrude outward in the left-right direction from both left and right edges of the plate portion 40a.

The plate portion 40a is provided with multiple filter insertion holes 41 for installing small filters 21. In this embodiment, as shown in Figure 7, the filter holding member 40 has a total of six filter insertion holes 41: three on the left and right sides and two on the front and back.

The filter insertion holes 41 are holes that penetrate the filter holding member 40 from top to bottom. The inner diameter of the filter insertion holes 41 is slightly larger than the diameter of the outer cylindrical body 24 of the small filter 21 and smaller than the diameter of the flange portion 27b of the closure plate 27 of the small filter 21. Furthermore, on the upper surface of the plate portion 40a of the filter holding member 40, a ring-shaped seal 42 is provided around each filter insertion hole 41. The outer diameter of the seal 42 is equal to or smaller than the diameter of the flange portion 27b of the closure plate 27 of the small filter 21.

As shown in Figure 4, one small filter 21 is inserted into each of the filter insertion holes 41. This results in two filter rows, each with three small filters 21 lined up in the left-right direction, arranged front to back, resulting in a first adsorption filter 20a with multiple small filters 21 arranged along the plate portion 40a.

The small filter 21 is inserted into the filter insertion hole 41 from above. As a result, the adsorbent storage section 30 of the small filter 21 passes through the filter insertion hole 41 and is lower than the plate section 40a of the filter holding member 40, and the flange section 27b of the closure plate 27 of the small filter 21 cannot pass through the filter insertion hole 41 and rests on the plate section 40a of the filter holding member 40. The seal 42 is sandwiched between the flange section 27b and the plate section 40a of the filter holding member 40. This blocks the gap between the underside of the flange section 27b and the upper surface of the plate section 40a of the filter holding member 40. In addition, the entire ventilation area 32 of the small filter 21 is lower than the portion blocked by the seal 42.

As shown in Figure 4, the closure plates 27 between two adjacent small filters 21 are in contact with or close to each other. This allows the six small filters 21 to be arranged fairly densely within the limited area of the filter holding member 40.

As shown in Figure 4, a pressing member 43 is provided on the plate portion 40a of the filter holding member 40 to press the closure plate 27 of the small filter 21 inserted into the filter insertion hole 41 toward the plate portion 40a of the filter holding member 40. The pressing member 43 is a plate that is long in the left-right direction and has a constant width in the front-to-back direction. Three pressing members 43 are provided for one filter holding member 40.

Near the front end of the filter holding member 40, one pressing member 43 presses down from above the front portions of the closure plates 27 of the three small filters 21 arranged in a row. Near the rear end of the filter holding member 40, one pressing member 43 presses down from above the rear portions of the closure plates 27 of the three small filters 21 arranged in a row. In addition, at the center of the filter holding member 40 in the front-to-rear direction, one pressing member 43 presses down from above the closure plates 27 of all the small filters 21 arranged in two rows. Each pressing member 43 is fixed to the filter holding member 40 by a screw 44, which serves as a fastener.

By holding the small filter 21 down with the pressing member 43 in this way, the small filter 21 is less likely to float from the plate portion 40a of the filter holding member 40.

In this way, the gap between the flange portion 27b of the small filter 21 (the flange portion 27b of the blocking plate 27) and the plate portion 40a of the filter holding member 40 is blocked by the seal 42, the gap between the upper end of the outer cylinder 24 and the upper end of the inner cylinder 25 is blocked by the blocking plate 27, and the entire radially inner side of the outer cylinder 24 is blocked by the lower cover 26 at the lower end of the outer cylinder 24. Air can also pass through the adsorbent storage section 30 between the radially outer portion of the outer cylinder 24 and the radially inner hollow portion 25c of the inner cylinder 25.

The annular rib 40b of the filter holding member 40 is a protruding wall that protrudes upward from the plate portion 40a and is provided on the periphery of the plate portion 40a so as to surround the multiple small filters 21. A sealant 40c is provided around the entire periphery of the upper end of the annular rib 40b. The upper end of the sealant 40c is located above the small filters 21 resting on the upper surface of the plate portion 40a, as well as the pressing members 43 and screws 44 provided to press down on the small filters 21 from above.

Flange portions 40d are provided on both the left and right edges of the plate portion 40a, and extend across the entire front-to-rear direction of the plate portion 40a. As shown in Figure 2, the flange portions 40d are supported by slide rails 15 that extend in the front-to-rear direction and are provided on the inner walls on both the left and right sides of the flow channel 10.

The slide rail 15 comprises an outer rail 15a fixed to the inner wall of the flow path 10 and an inner rail 15b that is slidable in the front-to-rear direction relative to the outer rail 15a. A support portion 15c is fixed to the inner rail 15b, and the flange portion 40d of the filter holding member 40 is placed on the upper surface of the support portion 15c. In addition, the support portion 15c is provided with a dam plate 15d that faces the left and right ends of the front and rear surfaces of the filter holding member 40 placed on the support portion 15c in the front-to-rear direction.

The filter holding member 40 placed on the support portion 15c moves in the front-to-rear direction together with the support portion 15c as the inner rail 15b slides in the front-to-rear direction relative to the outer rail 15a. Meanwhile, the filter holding member 40's front-to-rear movement relative to the support portion 15c is restricted by a barrier plate 15d provided on the support portion 15c. Furthermore, when the filter holding member 40 is pushed upward by the lifting device 16, the filter holding member 40 moves upward and the flange portion 40d moves upward away from the upper surface of the support portion 15c.

As shown in FIG. 1, an opening 2a is provided on the front surface of the housing 2 for inserting and removing the first adsorption filter 20a into and from the flow path 10. Slide rails 15 are provided on the inner walls on both the left and right sides of the flow path 10 at the same vertical positions as the openings 2a. The inner rails 15b of the slide rails 15 can be pulled out to the outside of the flow path 10 through the openings 2a in the housing 2.

As shown in FIG. 2, a partition plate 17 is provided above the first adsorption filter 20a within the flow path 10, and an elevator device 16 is provided below the first adsorption filter 20a.

The partition plate 17 is a plate-shaped member that is arranged within the flow path 10 perpendicular to the direction of air flow in the flow path 10, i.e., horizontally. The partition plate 17 is arranged above the first adsorption filter 20a inserted into the flow path 10. The partition plate 17 has an opening 17a that penetrates the partition plate 17 vertically, inside the sealing material 40c that is provided in an annular shape on the filter holding member 40.

When the lifting device 16 receives a predetermined operation, such as rotation of the rotary handle, while the filter holding member 40 is supported on the slide rail 15 as shown in Figures 8 and 11, it pushes the filter holding member 40 supported on the slide rail 15 upward. This causes the first adsorption filter 20a to move upward, and the seal material 40c provided on the filter holding member 40 comes into contact with the underside of the partition plate 17 as shown in Figures 2 and 10.

Furthermore, when the lifting device 16 receives a predetermined operation while the sealing material 40c is in contact with the underside of the partition plate 17 as shown in Figures 2 and 10, it moves the filter holding member 40 downward and supports the filter holding member 40 on the slide rail 15 as shown in Figures 8 and 11.

To insert the first adsorption filter 20a into the flow path 10 provided in this housing 2, the door 4a is opened to expose the opening 2a, and the inner rail 15b is then pulled outward from the flow path 10. The flange portion 40d of the filter holding member 40 is then placed on the support portion 15c of the inner rail 15b, and the first adsorption filter 20a is supported by the slide rail 15. The first adsorption filter 20a is then stored in the flow path 10 by sliding the inner rail 15b backward together with the first adsorption filter 20a (see Figures 8 and 11).

After storing the first adsorption filter 20a in the flow path 10, the lifting device 16 moves the first adsorption filter 20a upward, and the sealing material 40c provided on the filter holding member 40 adheres to the outside of the opening 17a of the partition plate 17 so as to surround the opening 17a. The door 4a is then closed to block the opening 2a (see Figures 2 and 10).

As a result, the only path for air to pass from the space below the filter holding member 40 to the space above the filter holding member 40 is the small filter 21. In other words, in order for air below the filter holding member 40 to flow above the filter holding member 40, air flows from a location radially outside the outer cylinder 24, which is the inlet side of the small filter 21, into the adsorbent storage section 30, as shown by the white arrow in Figure 2. The air that has passed through the adsorbent storage section 30 then flows out to a location radially inside the inner cylinder 25, rises through the radially inner hollow portion 25c of the inner cylinder 25, which is the outlet side of the small filter 21, and flows above the filter holding member 40.

In the first adsorption filter 20a provided in the flow path 10 as described above, multiple small filters 21 are arranged along the cross section of the flow path 10 (a cross section perpendicular to the air flow in the flow path 10), and the multiple small filters 21 are arranged in parallel. In other words, below the multiple small filters 21, all air flows together through the single flow path 10, but the air flow branches at the locations of the multiple small filters 21, and air flows simultaneously and in parallel through each of the multiple small filters 21. After passing through the multiple small filters 21, the air again flows together through the single flow path 10.

To remove the first adsorption filter 20a from the flow path 10, first open the door 4a to expose the opening 2a. Then, move the first adsorption filter 20a downward using the lifting device 16, and support the filter holding member 40 on the slide rail 15. Then, pull out the inner rail 15b to the outside of the flow path 10, and remove the first adsorption filter 20a supported by the support portion 15c of the inner rail 15b.

The second adsorption filter 20b has a similar structure to the first adsorption filter 20a. The second adsorption filter 20b is also provided with the same filter holding member 40 as the first adsorption filter 20a. Multiple small filters 21 are also inserted into the filter holding member 40 of the second adsorption filter 20b.

The filter container 22 used in the second adsorption filter 20b differs from the filter container 22 used in the first adsorption filter 20a in that their vertical lengths are different. Specifically, the filter container 22 used in the second adsorption filter 20b is shorter in vertical length than the filter container 22 used in the first adsorption filter 20a. Therefore, the small filter 21 used in the second adsorption filter 20b has a smaller capacity of adsorbent 23 than the small filter 21 used in the first adsorption filter 20a. Because the small filter 21 of the second adsorption filter 20b only needs to function temporarily when the small filter 21 of the first adsorption filter 20a breaks through, the small filter 21 of the second adsorption filter 20b may have a smaller capacity of adsorbent 23. Other than their vertical lengths, the small filter 21 of the first adsorption filter 20a and the small filter 21 of the second adsorption filter 20b are the same. Therefore, the diameter of the adsorbent storage section 30 is the same for the small filters 21 of the first adsorption filter 20a and the small filters 21 of the second adsorption filter 20b.

As shown in Figure 2, the second adsorption filter 20b, like the first adsorption filter 20a, has flanges 40d on both left and right edges of the plate portion 40a supported by slide rails 15 extending in the front-to-rear direction and provided on the inner walls on both the left and right sides of the flow path 10, and can be moved up and down by an elevator device 16.

On the front surface of the housing 2, an opening 2b for inserting and removing the second adsorption filter 20b is provided above the opening 2a, and a door 4b for opening and closing the opening 2b is provided. The second adsorption filter 20b is inserted and removed from the flow path 10 in the same manner as the first adsorption filter 20a, by opening the opening 2b with the door 4b.

(3) First Detector 50 and Second Detector 70
As shown in FIGS. 2, 3 and 9, the first detection unit 50 includes a plurality of first suction tubes 51, a first sensor 52, and a switching unit 53.

The multiple first suction pipes 51 have suction ports 54 at one end that are positioned on the outlet side of the first adsorption filter 20a. The other ends of the multiple first suction pipes 51 are connected to a switching unit 53. The first suction pipes 51 take in air that has passed through the first adsorption filter 20a through the suction ports 54 and introduce it into the switching unit 53.

The suction ports 54 of the multiple first suction pipes 51 are provided at different positions on the cross section of the flow path 10 on the outlet side of the first adsorption filter 20a. In other words, the multiple first suction pipes 51 have their suction ports 54 open above the first adsorption filter 20a at the same vertical position but at different positions in the left-right and front-to-back directions. As a result, each of the multiple first suction pipes 51 sucks air from a different position on the cross section of the flow path 10 on the outlet side of the first adsorption filter 20a.

Specifically, one suction port 54 of each first suction pipe 51 is provided above the hollow portions 25c corresponding to the outlet sides of the multiple small filters 21 provided in the first adsorption filter 20a. The suction ports 54 provided above the hollow portions 25c open downward toward the air that passes through the small filters 21 and flows upward through the hollow portions 25c, and face upstream in the air flow. Each of the multiple first suction pipes 51 is designed to suck in air from the outlet side of a different small filter 21.

Note that "multiple suction ports 54 located at different positions on the cross section of the flow path 10" does not necessarily mean that the multiple suction ports 54 are located exactly at the same position on the cross section of the flow path 10, but also means that each suction port 54 is located at approximately the same distance from the first adsorption filter 20a in the air flow direction. "Approximately the same distance" refers to a range in which the flow direction of air that has passed through the first adsorption filter 20a does not substantially change. In the present embodiment, when the second adsorption filter 20b is located downstream of the first adsorption filter 20a in the air flow direction so as to block the flow path 10, the concept of "positions on the same cross section of the flow path 10" also includes the position between the first adsorption filter 20a and the second adsorption filter 20b.

The other ends of the multiple first suction pipes 51 are connected to the primary side (inlet side) of the switching unit 53, and the first sensor 52 is connected to the secondary side (outlet side). The switching unit 53 connects one selected from the multiple first suction pipes 51 connected to the primary side to the first sensor 52. As a result, the first suction pipe 51 selected by the switching unit 53 sucks air from the flow path 10 through the suction port 54 and introduces it to the first sensor 52.

The first sensor 52 is, for example, a suction-type gas sensor having a suction pump (not shown). The suction pump sucks air that has passed through the first adsorption filter 20a from the first suction pipe 51 via the switching unit 53, and measures the concentration of harmful substances in the sucked air.

While the air purifier 1 is running, the first detection unit 50 operates the first sensor 52, and the switching unit 53 periodically switches from multiple first suction pipes 51 to the single first suction pipe 51 connected to the first sensor 52. As a result, the first detection unit 50 periodically draws air from different positions on the cross section of the flow path 10 on the outlet side of the first adsorption filter 20a into the first sensor 52 via the first suction pipe 51 and switching unit 53, and detects the concentration of harmful substances at each position.

As shown in Figures 2 and 3, the second detection unit 70 includes a second suction pipe 71 and a second sensor 72. The second suction pipe 71 has a suction port 74 at one end that is located at the suction port 13a of the fan 13. Here, the suction port 13a of the fan 13 refers not only to the opening through which the fan 13 takes in air, but also to the spatial region located near the opening, which is the starting point from which gas in the flow path 10 begins to flow toward the inside of the fan 13 due to the suction action of the fan 13. In this embodiment, one second suction pipe 71 is provided, and the suction port 74 is located in the space formed between the suction port 13a of the fan 13 and the fiber filter 3b by extending the suction port 13a downward. The suction port 74 opens downward relative to the air flowing upward through the fiber filter 3b, and faces upstream in the air flow. The other end of the second suction pipe 71 is connected to the second sensor 72. The second sensor 72 is, for example, a suction-type gas sensor with a suction pump, similar to the first sensor 52. The second detection unit 70 sucks air that has passed through the fiber filter 3b by the suction pump through the second suction pipe 71 and measures the concentration of harmful substances in the sucked air.

(4) Effects In the air purifier 1 of this embodiment, the first detection unit 50 detects harmful substances at multiple different positions on the cross section of the flow path 10 on the outlet side of the first adsorption filter 20a. Therefore, even if the concentration of harmful substances in the air that has passed through the filter varies on the cross section of the flow path 10, the concentration of harmful substances in the air that has passed through the filter can be accurately detected.

In the air purifier 1 of this embodiment, while the air purifier 1 is operating, the switching unit 53 provided in the first detection unit 50 selectively switches between multiple first suction tubes 51 and connects them to the sensors 52. This makes it possible to detect harmful substances at multiple locations using fewer sensors 52 than the number of measurement locations, allowing the air purifier 1 to be manufactured at reduced cost.

In this embodiment, the suction port 54 of the first suction pipe 51 opens facing upstream in the air flow direction in the flow path 10, making it easier for air in the flow path 10 to be drawn into the first suction pipe 51 through the suction port 54.

In this embodiment, a different suction port 54 of the first suction pipe 51 is provided for each of the multiple small filters 21 arranged in parallel along the cross section of the flow path 10, making it possible to detect the degree of breakthrough for each small filter 21.

In this embodiment, the first detection unit 50 detects harmful substances contained in the air between the first adsorption filter 20a and the second adsorption filter 20b, making it possible to detect breakthrough of the small filter 21 of the first adsorption filter 20a before breakthrough of the small filter 21 of the second adsorption filter 20b.

In this embodiment, a second detection unit 70 is provided to detect harmful substances contained in the air at the intake port 13a of the fan 13. This means that even if the first detection unit 50 fails, the concentration of harmful substances contained in the air discharged from the air purifier 1 can be detected. Furthermore, because the air that has passed through each small filter 21 of the second adsorption filter 20b joins together at the intake port 13a of the fan 13, the concentration of harmful substances can be accurately detected without having to detect the concentration of harmful substances at multiple positions on the cross section of the flow path 10.

(5) Modifications While the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as set forth in the claims.

Several modified examples are described below, but any one of the modified examples may be applied to the above embodiment, or any two or more of the modified examples may be applied in combination.

(5-1) Modification example 1
In the above embodiment, the first detection unit 50 and the second detection unit 70 each have separate sensors 52, 72, but the first detection unit 50 and the second detection unit 70 may also share the sensor 52.

That is, as shown in FIG. 12, the other end of the second suction pipe 71 of the second detection unit 70 is connected to the primary side of the switching unit 53 of the first detection unit 50, along with the multiple first suction pipes 51 of the first detection unit 50. The switching unit 53 connects a selected one of the multiple first suction pipes 51 and second suction pipes 71 connected to the primary side to the first sensor 52. Air is sucked from the flow path 10 through the suction ports 54, 74 of the first suction pipe 51 or second suction pipe 71 selected by the switching unit 53 and introduced into the first sensor 52.

In this modified example, while the first sensor 52 is operating, the switching unit 53 switches from the multiple first suction tubes 51 and second suction tubes 71 to one suction tube connected to the first sensor 52 at regular intervals.

This allows the first detection unit 50 to detect the concentration of harmful substances at different positions on the cross section of the flow path 10 on the outlet side of the first adsorption filter 20a, as well as the concentration of harmful substances on the outlet side of the second adsorption filter 20b.

In this modified example, the sensor 52 of the first detection unit 50 is shared with the second detection unit 70, eliminating the need to provide a sensor 72 in the second detection unit 70, allowing the air purifier 1 to be manufactured at reduced costs.

(5-2) Modification example 2
In the above embodiment, the first adsorption filter 20a is divided into a plurality of small filters 21 that are individually detachable, but it may also be a continuous filter large enough to block the entire air flow path 10.

(5-3) Modification example 3
In the above embodiment, granular zeolite is used as the adsorbent 23 in the first adsorption filter 20a and the second adsorption filter 20b, but various other adsorbents such as activated carbon and silica gel can also be used.

(5-4) Modification example 4
In the above embodiment, the second adsorption filter 20b, which has the same adsorbent material 23 as the first adsorption filter 20a, is provided downstream of the first adsorption filter 20a in the air flow in the flow path 10, but a filter having a different adsorbent material 23 from that of the first adsorption filter 20a may be provided. Also, only the first adsorption filter 20a may be provided in the flow path 10 as a filter that adsorbs harmful substances, and other filters such as the second adsorption filter may not be provided in the flow path 10. The second adsorption filter may not be provided downstream of the first adsorption filter 20a in the air flow in the flow path 10.

(5-5) Modification example 5
In the above-described embodiment, the suction ports 54, 74 of the first suction pipe 51 and the suction ports 74 of the second suction pipe 71 are positioned so that they open toward the upstream side of the air flow direction in the flow path 10, but the suction ports 54, 74 may be positioned so that they open toward the downstream side of the air flow direction in the flow path 10, or so that they open in a direction perpendicular to the air flow direction in the flow path 10.

1...air purifier, 2...housing, 2a...opening, 2b...opening, 3b...fiber filter, 4a...door, 4b...door, 10...flow path, 11...intake port, 12...exhaust port, 13...fan, 15...slide rail, 15a...outer rail, 15b...inner rail, 15c...support portion, 15d...dam board, 16...lifting device, 17...partition board, 17a...opening, 20a...first adsorption filter, 20b...second adsorption filter, 21... Small filter, 22...filter container, 23...adsorbent, 40...filter holder, 40a...plate, 40b...annular rib, 40c...sealing material, 40d...flange, 41...filter insertion hole, 42...seal, 43...pressing member, 44...screw, 50...first detection unit, 51...first suction tube, 52...first sensor, 53...switching unit, 54...suction port, 70...second detection unit, 71...second suction tube, 72...second sensor, 74...suction port

Claims (6)

An intake port for drawing in air,
An exhaust port for discharging air
a flow path provided between the suction port and the exhaust port, through which air drawn in from the suction port flows to the exhaust port;
a first filter provided to block the flow path;
a first detection unit that detects the substance to be removed that is contained in the air that has passed through the first filter,
The first detection unit is an air purifier that detects removal target substances at a plurality of different positions on a cross section of the flow path on an outlet side of the first filter,
the first filter includes a plurality of small filters arranged along a cross section of the flow path;
The first detection unit detects the substances to be removed at the outlet side of each of the plurality of small filters.
An intake port for drawing in air,
An exhaust port for discharging air
a flow path provided between the suction port and the exhaust port, through which air drawn in from the suction port flows to the exhaust port;
a first filter provided to block the flow path;
a first detection unit that detects the substance to be removed that is contained in the air that has passed through the first filter,
The first detection unit is an air purifier that detects removal target substances at a plurality of different positions on a cross section of the flow path on an outlet side of the first filter,
a second filter provided downstream of the first filter in the air flow path so as to block the air flow path;
The first detection unit detects a substance to be removed that is contained in the air between the first filter and the second filter.
An intake port for drawing in air,
An exhaust port for discharging air
a flow path provided between the suction port and the exhaust port, through which air drawn in from the suction port flows to the exhaust port;
a first filter provided to block the flow path;
a first detection unit that detects the substance to be removed that is contained in the air that has passed through the first filter,
The first detection unit is an air purifier that detects removal target substances at a plurality of different positions on a cross section of the flow path on an outlet side of the first filter,
An air purifier comprising: a fan that is provided downstream of the first filter in the air flow path and generates an air flow in the flow path; and a second detection unit that detects substances to be removed that are contained in the air at the intake port of the fan.
the second detection unit includes a second suction pipe that draws air from an intake port of the fan,
The air purifier of claim 3, wherein the first detection unit comprises a plurality of first suction tubes that suck in air from different positions on the cross section of the flow path on the outlet side of the first filter, a sensor that detects substances to be removed that are contained in the air sucked in by the first suction tubes or the second suction tubes, and a switching unit that selectively switches between the plurality of first suction tubes and the second suction tubes to connect them to the sensor.
An air purifier as described in any one of claims 1 to 4, wherein the first detection unit comprises a plurality of first suction tubes that suck in air from different positions on the cross section of the flow path on the outlet side of the first filter, a sensor that detects substances to be removed that are contained in the air sucked in by the first suction tubes, and a switching unit that selectively switches between the plurality of first suction tubes to connect them to the sensor.
The air purifier according to claim 5 , wherein a suction port that draws air from the flow path into the first suction pipe opens toward an upstream side of the air flow in the flow path.