GB2279270A

GB2279270A - Air Cleaner

Info

Publication number: GB2279270A
Application number: GB9320057A
Authority: GB
Inventors: Shigeaki Miyahara; Haruaki Yamamoto
Original assignee: SAFETY CHECK JAPAN CO Ltd
Current assignee: SAFETY CHECK JAPAN CO Ltd
Priority date: 1993-06-28
Filing date: 1993-09-29
Publication date: 1995-01-04
Also published as: JP2530592Y2; GB9320057D0; JPH077722U

Abstract

An air cleaner which comprises a filter device (F) for removing dispersed particles contained in air, a supply-discharge device for supplying a separating liquid (L) to the filter device (F) and, at the same time, discharging the separating liquid (L) which has picked up the dispersed particles, and a fan (35) for aspirating air. The filter device (F) has a partition plate (55) adapted to isolate an inlet (33) and an outlet (34) from each other and to have its lower edge (55b) immersed in the separating liquid sotred in a pan (46). The supply-discharge device has a discharge system which discharges by means of overflow 70. A first supply system continuously supplies the separating liquid (L) to the pan (46), and a second supply system (39) supplies liquid when the level of water in the pan (46) is lower than the overflow level. The cleaner may be used as a deodoriser, the liquid containing an aromatic agent. <IMAGE>

Description

This invention relates to an air cleaner for removing particles and microorganisms dispersed in the air.

More particularly, the air cleaner of this invention is intended for use in kitchens, livestock sheds, beauty parlors, painting booths, food processing plants, and precision machine plants, adapted to be installed at the inlet to a ventilating system, inside a room, or in an air conditioner, able to remove oil, dust, odor, and microorganisms from air, and having improved fireproofness, cleanability, and lower maintenance costs.

The conventional grease filters for use in kitchens have been introduced to the art for example by Japanese Utility Model Laid-open No. SHO 57-123,6111, Japanese Utility Model Laid-open No. SHO 57-33,926, Japanese Utility Model Laid-open No. SHO 57-11,1135, and Japanese Utility Model Laid-open No. SHO 57-184,434.

As illustrated in Fig. 17, the grease filter 215 which is disclosed in Japanese Utility Model Laid-open No.

SHO 57-123,614 is attached to an inlet 218 of an exhaust duct 217 which is installed over a kitchen system 216. The exhaust duct 217 is provided at the other end thereof with a fan 219 which is adapted to guide to the outside of the room, the oil smoke emanating from the kitchen system 216.

A filter part 220 of this grease filter 215, as illustrated in Fig. 18, is provided with frames 221a and 221b which are horizontally separated from each other. The one frame 221a is provided with a plurality of guide plates 222 having a cross section roughly shaped like the letter S.

The other frame 221b is provided with a plurality of vanes 223 having a cross section roughly shaped like the letter V and disposed so as to allow free adjustment of the gaps between themselves and the guide plates 222. Further, to a connecting bar 225 which is energized by the traction of a spring 228, a plurality of rotary members 226 are connected.

During the normal operation of the grease filter 215, the rotary members 226 are tied with temperature-sensitive elements 228 so as to maintain the gaps between the guide plates 222 and the vanes 223 at a prescribed size. When the flame from the kitchen system 216 reaches the filter part 220 and the temperature of the filter part 220 is abnormally elevated, the temperature-sensitive elements 224 are bent so much as to set the rotary members 226 free. As a result, the connecting bar 225 is drawn with the resilient force of the spring 228 and the rotary members 226 are rotated to exert pressure on the guide plates 222. Consequently, the terminal parts of the adjacent guide plates 222 are brought into mutual contact to prevent the flame from reaching the interior of the exhaust duct 217.

When this grease filter 215 is put into operation, the oil smoke aspirated through an inlet 227 is passed through the gaps between the guide plates 222 and the vanes 223 and guided to the exhaust duct 217. At this time, because of the collision of the oil smoke against the guide plates 222 and the vanes 223, the oil droplets suspended in the air are attached to the guide plates 222 and the vanes 223 and hence are separated from the air.

In the conventional grease filter constructed as described above, the so-called collision separation method which consists in effecting seizure of the oil in air by causing the air to collide against a plate member and enabling the oil selectively to adhere fast to the plate member is adopted. The grease filter of this type is destined by its construction to suffer from copious deposition of oil on the plate member after protracted use.

Particularly when the grease filter happens to be installed close comparatively close to the fire used in the kitchen, there arises the possibility that the oil adhering to the plate member will catch fire.

Indeed, the grease filter is furnished with firepreventing members (such as, for example, the temperaturesensitive elements 224, rotary members 226, and connecting bar 225). Since the grease filter is so constructed that even these fire-preventing members are prone to deposition of the oil thereon, there ensues the possibility that the fire-preventing members will fail to operate smoothly in case of emergency.

Further, the conventional grease filter is at a disadvantage in suffering from extremely poor operational efficiency due to the troublesome work of removing the oil adhering fast to the guide plates 222 and the vanes 223. As a result, the maintenance costs of the grease filter is automatically boosted.

The grease filter relying on the principle of collision separation is available exclusively for the seizure of oil and other similar substances which are in the form of particles of a relatively large size. It, therefore, has the drawback that it cannot be utilized for the seizure of minute particles such as of odor, dust, and microorganisms.

This invention has been produced for the solution of various drawbacks suffered by the prior art as described above. It has an object of providing an air cleaner which excels in fireproofness and cleanability, permits stable and safe seizure of oil, odor, dust, and microorganisms, and abounds in versatility of utilization as a result.

To accomplish the object described above, this invention provides an air cleaner which comprises a filter device for removing dispersed particles contained in air with a separating liquid, a supply-discharge device for supplying the separating liquid to the filter device and, at the same time, discharging the separating liquid which has seized the dispersed particles, and a fan for aspirating air. The filter device is provided with a partition plate which is adapted to effect mutual isolation of an inlet and an outlet both formed in a filter box and dip itself in the separating liquid held in a pan disposed in the bottom part of the filter box in such a length that the lower edge thereof will reach a prescribed depth therein. The supplydischarge device is provided with a discharge system which discharge by overflowing the separating liquid in the pan, a first supply system for supplying the separating liquid into the pan, and a second supply system for supplying the separating liquid into the pan whenever the level of the separating liquid inside the pan falls below the overflow level.

In the air cleaner constructed as described above, since the lower edge of the partition plate of the filter device is dipped in the separating liquid held in the pan, the surface of the separating liquid is divided into the surface on the outlet side and the surface on the inlet side. When air is aspirated through the outlet, therefore, the air pressure on the outlet side becomes lower than the air pressure on the inlet side and the level of the separating liquid on the inlet side falls below the level of the separating liquid on the outlet side. When the level of the separating liquid on the inlet side becomes lower even slightly than the lower edge of the partition plate, the air containing dispersed particles aspirated through the inlet passes through the gap consequently formed below the lower edge of the partition plate and floats in the form of bubbles to the raised surface of the separating liquid on the outlet side. Owing to the passage of the air through the separating liquid, the dispersed particles can be separated from the air and seized in the separating liquid with high efficiency.

While the removal of the dispersed particles is occurring, the separating liquid is supplied into the pan via the first supply system of the supply-discharge device and the level of the separating liquid inside the pan is raised above the inlet of the discharge system. As a result, the separating liquid in the pan overflows and gets discharged via the discharge system. Since the removed dispersed particles are released from the filter device as a consequence of the discharge of the overflowing separating liquid, the removed dispersed particles do not remain inside the filter device. This fact enables the air filter to excel in fireproofness and cleanability. When the level of the separating liquid in the pan falls below the overflow level, the separating liquid is freshly supplied into the pan through the second supply system. Since the separating liquid in the pan is maintained at a prescribed level as a result of this replenishment, the seizure of the dispersed particles by the separating liquid can be stably carried out.

The supply-discharge device is preferably provided further with switch means for opening and shutting the first supply system, upper-limit level detecting means for detecting the upper-limit level which is higher than the first level, control means for imparting a shutting motion to the switch means and shutting the first supply system when the upper-limit level detecting means detects the upper-limit level, and- alarm issuing means for issuing an alarm when the upper-limit level is detected.

In consequence of the incorporation of such additional means as mentioned above, when the level in the pan reaches the upper-limit level, the control means imparts a shutting motion to the switch means disposed in the first supply system to stop the supply of the separating liquid from the first supply system and make the alarm issuing means issue an alarm. The separating liquid, therefore, is prevented from leaking out of the pan and the operator tending the air cleaner is able to discern the occurrence of discharge problems in the discharge system of the supply discharge device.

The supply-discharge device is preferably provided further with lower-limit level detecting means for detecting the lower-limit level higher than the height of the lower edge of the partition plate and lower than the second level and alarm issuing means for issuing an alarm when the lowerlimit level is detected.

In consequence of the incorporation of such additional means as mentioned above, since the alarm issuing means issues an alarm when the level of the separating liquid in the pan reaches the lower-limit level, the operator tending the air cleaner is able to discern the occurrence of defective supply of separating liquid in both the first supply system and the second supply system of the supply-discharge device.

Desirably, the supply-discharge device is provided further with time setting means adapted to set the time for starting the supply of the separating liquid from the first supply system and the time for stopping the supply of the separating liquid from the first supply system. Then, the control means begins. to control the opening or. shutting motion of the switch means when the starting time or stopping time set by the time setting means expires. The convenience of the air cleaner can be enhanced by having the opening or shutting motion of the switch means to be controlled by means of a timer as described above.

The invention may be carried into practice in various ways and some embodiments will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a diagram disclosing the entire construction of one example of the air cleaner of this invention as embodied in a kitchen.

Fig. 2 is a cross section disclosing the state in which the filter device shown in Fig. 1 is at a stop as viewed from the front side.

Fig. 3 is a cross section disclosing the state in which the same filter device is in operation as viewed from the front side.

Fig. 4 is a cross section disclosing the state in which the same filter device is in motion as viewed laterally.

Fig. 5 is a cross section disclosing the essential part of a partition plate and a lateral wall of the same filter device.

Fig. 6 is a perspective view disclosing the appearance of a control box of control means.

Fig. 7 is a block diagram disclosing a control system of the control means.

Fig. 8 is a flow chart disclosing the operation of the air cleaner.

Fig. 9 is a flow chart disclosing the process for checking the safety of supply and discharge of water.

Fig. 10 is a cross section disclosing a second example of the filter device.

Fig. 11 is a cross section disclosing a third example of the filter device.

Fig. 12 is a cross section disclosing a fourth example of the filter device.

Fig. 13 is a cross section disclosing a fifth example of the filter device.

Fig. 14 is an oblique view disclosing a sixth example of the filter device.

Fig. 15 is a cross section taken through Fig. 111 along the line A-A.

Fig. 16 is a cross section disclosing a seventh example of the filter device.

Fig. 17 is a diagram disclosing the entire construction of an air cleaner using the conventional grease filter.

Fig. 18 is a cross section disclosing the grease filter shown in Fig. 17.

Now, one embodiment of this invention will be described below with reference to the accompanying drawings.

The entire construction of an air cleaner used in a kitchen will be outlined below. This air cleaner 30, as illustrated in Fig. 1, is composed of a filter device F set in place inside a hood 32 which is suspended from a ceiling 31 of the kitchen and adapted to remove dispersed particles contained in air and a supply-discharge device W serving the purpose of supplying the separating liquid L to the filter device F and, at the same time, discharging the separating liquid L which has seized the dispersed particles.

In the present embodiment, the oil smoke which emanates from a kitchen system 16 corresponds to the dispersed particles which have been described thus far. To be ideal, the separating liquid L in question is capable of dissolving the oil and incapable of catching fire. In the present embodiment, such a familiar liquid as water or an aqueous solution of non-foaming detergent is used as the separating liquid L.

In the filter device F, an inlet 33 for aspirating the air to be cleaned and an outlet 34 for discharging the cleaned air are formed. To this outlet 311 is connected an exhaust duct 36 which is fitted with a fan 35. When the fan 35 is set operating, the air inside the kitchen is aspirated through the inlet 33 into the filter device F and the dispersed particles such as oil contained in the air are seized by the separating liquid L. The air consequently cleaned is introduced through the outlet 34 into the duct 36 and thence blown out of the kitchen via an outblowing mouth 37.

The supply-discharge device W is provided with a first supply system 38 for supplying the separating liquid L in a prescribed flow volume to the filter device F, a second supply system 39 for supplying the separating liquid L to the filter device F when the level of the separating liquid L inside the filter device F falls below a prescribed level, and a discharge system 110 for discharging the separating liquid L from inside the filter device F. It is further provided with a control device (control means) 42 adapted to control with a timer the opening or shutting motion of a solenoid valve (switch means) 111 which is disposed in the first supply system 38. This control device 42 also serves the purpose of issuing a prescribed alarm when a defect is detected in the discharge system 40 or when defective supply of water is detected in the first and second supply systems 38 and 39.

First, the filter device F will be described in detail below.

The filter device F, as illustrated in Figs. 2 to 11, is provided with a filter box 45 assuming the general shape of a box and containing an opening on the upper side thereof and a pan 46 attached to the lower part of the filter box 45 and adapted to store therein the separating liquid L. The filter box 45 is composed of inclined lateral walls 47 shown in Fig. 2 and Fig. 3 and a front and a rear wall 48 and 49 shown in Fig. 11. The pan 46 is fastened with screws to the lower ends of the front and rear walls 118 and 49. Fitting flanges 50 are formed one each at the upper ends of the lateral walls 47. The filter device F of the present embodiment is fixed to the ceiling 31 of the kitchen by driving screws 52 home into the ceiling 31 through a plurality of fitting holes 51 formed in the fitting flanges 50. The inlet 33 for aspirating air is formed between the lateral wall 47 of the filter box 45 and the pan 46 and the outlet 34 for discharging the air is formed in the upper side of the filter box 115. This outlet 34 communicates with the duct 36 which is connected to an opening part 53 of the ceiling.

A partition plate 55 for separating the inlet 33 and the outlet 311 from each other is attached jointly to the lateral walls 47. The partition plate 55, as illustrated on a magnified scale in Fig. 5, has a lower end part 55a thereof bent toward the vertical direction and has formed in an upper end part thereof an oblong hole 57 for allowing passage therethrough of a pin 56 which is set in place on the lateral wall 47. This partition plate 55 is fixed to the lateral wall 47 by having a butterfly bolt 58 tied to a screw part formed at the leading end of the pin 56. The partition plate 55, as illustrated in Fig. 2, has a lower edge 55b thereof dipped by a prescribed length m in the separating liquid L stored in the pan 116. For the purpose of uniformizing the dipping length m of the lower edge 55b, the lower edge 55b of the partition plate 55 is desired to be laid substantially horizontally. The dipping length m is a magnitude which is to be determined by such factors as the volume of wind to be discharged by the fan 35 and the size of the filter device F. In the present embodiment, the dipping length m can be set or adjusted easily by moving the partition plate 55 along the pin 56. The thoroughness with which the inlet 33 side and the outlet 34 side are mutually isolated is desired to be ensured by having a seal member (not shown), for example, interposed between the lateral edge in the longitudinal direction of the partition plate 55 and the front and rear walls 48 and 49 of the filter box 45.

The filter device F is provided on the downstream side of the partition plate 55 with a separating member 61 which is furnished with a plurality of air vents 60. This separating member 61 serves the purpose of allowing the air which has passed under the lower edge 55b of the partition plate 55 during the operation of the filter device F to pass through the air vents 60 thereby effecting removal from the air of such water particles as are suspended therein, further separating dispersed particles such as of oil having a relatively large specific gravity, and rectifying the stream of air. The separating member 61 is fitted with an upper side retaining plate 62 and a lower side retaining plate 63 which jointly play the part of holding this separating member 61 in place.

The lower side retaining plate 63 has a lower edge 63a thereof forming a prescribed gap 64 between itself and the pan 116. This gap 611 functions as a passage for the separating liquid L so as to ensure formation of one equal level of the separating liquid L in the space S1 formed between the partition plate 55 and the separating member 61 and the space S2 formed between the two separating members 61. The two longitudinal edges 61a of the separating member 61 are set in place so as to apply fast to the front and rear walls 48 and 49 of the filter box 115 (Fig. 11). The separating member 61 is desired to be set in place through the medium of a seal member, for example, so as to prevent the air of the space S1 from flowing into the space S2 without passing through the separating member 61. Further, the lower edge 63a of the lower side retaining plate 63 is dipped in the separating liquid L to a greater depth than the lower edge 55b of the partition plate 55 in order that the air which has passed under the lower edge 55b of the partition plate 55 may be prevented from passing under the lower side retaining plate 63 and floating directly into the space S2. The air which has passed under the partition plate 55 is prevented from passing in the form of bubbles under the lower edge 63a of the lower side retaining plate 63 for the following reason. If the air is passed under the lower edge 63a of the lower side retaining plate 63 and guided to the outlet 311 without being passed through the separating member 61, it is filled with a large amount of moisture. When this moist air flows down the duct 36, it causes formation of rust on the duct 36 and the fan 35.

Since the air is not allowed to pass in the form of bubbles under the lower edge 63a of the lower side retaining plate 63 and further since the separating member 61 is provided for the air cleaner, the dispersed particles such as of oil which is insoluble in water are finally seized between the partition plate 55 and the separating member 61.

Even when the fan 35 has a great aspirating force, the possibility that the dispersed particles will be caused to float off the surface of the separating liquid and guided to the duct 36 is nil.

In the present embodiment, the separating member 61 is formed of a porous material 65 which contains a multiplicity of continuous pores. Specifically, it is desirable to use a foamed ceramic material as the porous material 65. To be more specific, a ceramic material which is formed such as of alumina, zirconia, or zirconia-mullite, for example, and has a void ratio of not less than 70% is a desirable example. The pore diameter depends on the aspirating force of the fan 35 to be used and the kind of the dispersed particles to be removed. Generally, when dispersed particles such as of oil having a large particle diameter are to be removed, a foamed ceramic material having a relatively large pore diameter is used. For the removal of minute particles such as odor particles, it is preferable to use a foamed ceramic material having a relatively small pore diameter. Let the "cell number" stand for the number of cells which are formed in the ceramic matrix within a linear distance of 1 inch, for example, and a foamed ceramic material having a cell number of 6 is suitable for the removal of dispersed particles such as of oil having a relatively large particle diameter and a foamed ceramic material having a cell number of 110 is suitable for the removal of minute particles such as of an odor.

The porous material 65 to be used for the separating member 61 is not required to be limited to such foamed ceramic materials as mentioned above. Organic materials such as porous membranes of macromolecular substances, metallic materials such as foamed metals, and glass wool are usable instead. The substance for the porous material 65 is decided by such factors as the type and particle diameter of the dispersed particles to be removed. By aptly varying the type of substance, the filter device F is able to remove dispersed particles of all kinds such as oil, odor, dust, and microorganisms. Thus, the filter device F has a high versatility.

Now, the supply-discharge device W provided with the first supply system 38, second supply system 39, and discharge system 40 will be described in detail below.

The discharge system 40 is provided, as illustrated in Fig. 2, with an overflow pipe 70 which is attached to the central part of the pan 46 of the filter device F. An inlet 72 of this overflow pipe 70 is disposed at a position higher than the lower edge 55b of the partition plate 55. The height of this inlet 72 is large enough for the lower edge 55b of the partition plate 55 to be dipped in the separating liquid L even when the partition plate 55 is moved to the highest allowable position. The lower edge 55b of the partition plate 55, therefore, never fails to dip into the separating liquid L when the level of the separating liquid inside the pan 46 is higher than the inlet 72 of the overflow pipe 70 and the separating liquid L is overflowing.

The first supply system 38 is intended to supply the separating liquid L at a prescribed flow volume into the pan 46 and, as illustrated in Fig. 4, is provided with a first feed pipe 71 which is disposed close to the inner side of the rear wall 119. While the filter device F is operating, the separating liquid L is continuously supplied in the prescribed flow volume through a first inlet 73 disposed at the terminal part of the first feed pipe 71 into the pan 116.

Since the level of the separating liquid within the pan 116 is raised as a consequence of the supply thereof through the first inlet 73, the discharge through the overflow pipe 70 and the supply through the first inlet 73 are continuously carried out.

The second supply system 39 is intended to supply the separating liquid L into the pan 116 when the level of the separating liquid L falls below the prescribed level and, as illustrated in Fig. 4, is provided with a second feed pipe 74 which is disposed close to the inner side of the front wall 48. This second feed pipe 74 is fitted with a float valve 77 which is composed of a float 75 and a valve part 76 adapted to be opened and shut accordingly as the float 75 rises or falls. While the filter device F is in operation, the float valve 77 operates as follows to maintain the separating liquid L stored in the pan 46 in an overflowing state.

When the level of the separating liquid L falls below the height of the inlet 72 of the overflow pipe 70, namely when the separating liquid L inside the pan 46 falls below the overflowing level (hereinafter referred to as "overflow level"), the float valve 77 descends as a consequence of the fall of the level and opens the valve part 76. As a result, the separating liquid L is supplied into the pan 46 through a second inlet 78 which is disposed in the terminal part of the second feed pipe 74.

Conversely, when the level of the separating liquid L rises above the overflow level, the float valve 77 shuts the valve part 76 as the float 75 ascends as a consequence of the rise of the level. As a result, the supply of the separating liquid L is stopped. When the filter device F is at rest or when the separating liquid L is in an overflowing state, the second supply system 39 is not operated and the separating liquid L is not supplied through the second inlet 78.

For the sake of detecting the level of the separating liquid L, the pan 46 is provided therein, as illustrated in Fig. 4, with an upper-limit level sensor 79 as means for detecting the upper-limit level and a lowerlimit level sensor 80 as means for detecting the lower-limit level. The upper-limit level to be detected by the upperlimit level sensor 79 means a level which is higher than the height of the inlet 72 of the overflow pipe 70 and which prevents the separating liquid L from leaking out of the pan 46. The lower-limit level to be detected by the lower-limit level sensor 80 means a level which is lower than the level at which the float valve 77 is set operating and which is higher than the height of the lower edge 55b of the partition plate 55. The lower-limit level is also a level such that the lower edge 55b of the partition plate 55 is kept dipped in the separating liquid L even when the partition plate 55 is moved to the highest allowable position. These level sensors 79 and 80 are both formed of a floating type sensor. The upper-limit level sensor 79 issues an ON signal when it detects the upper-limit level and the lower-limit level sensor 80 issues an ON signal when it detects the lower-limit level. These level sensors 79 and 80 are accommodated in a sensor box 81 which is disposed close to the inner side of the rear wall 49.

A discharge pipe 82 which is connected to the overflow pipe 70, as illustrated in Fig. 1, is connected to a grease trap 83. The separating liquid L which has flowed into the overflow pipe 70 is deprived of oil at the grease trap 83 and is then discharged into a discharge conduit 84.

A feed pipe 85 adapted to supply the separating liquid L and connected to a supply source (not shown) is branched on the downstream side of a main valve 86 into the first feed pipe 71 and the second feed pipe 711. The first feed pipe 71 is provided with a bypass 87. This bypass 87 is provided with the solenoid valve initial supply of the separating liquid L into the filter device F is started and when the separating liquid L is supplied in a large amount for the purpose of cleaning the interior of the filter device F or promoting the replacement of the separating liquid L with a new supply. There are times when a plurality of filter devices F are required to be installed, depending on the dimensions of the kitchen.

To another filter device F which is indicated with an imaginary line in Fig. 1, the branches from the first and second feed pipes 71 and 74 are connected.

The supply-discharge device W is further provided with the control device 112 which functions to control the opening and shutting motions of the solenoid valve 111. In the illustrated embodiment, the first feed pipe 71 is provided with one solenoid valve 111. Exclusively by opening and shutting the solenoid 41, the supply of the separating liquid L to the plurality of filter devices F is started and stopped respectively. It is, of course, permissible to provide solenoid valves one each for the first feed pipes 71 connected severally to the filter devices F and to enable the plurality of solenoid valves to be opened and shut independently.

As illustrated in Fig. 6, a control box 95 of the control device 112 obtains supply from an external electric power source via a cable 96 and drives a built-in control circuit in response. On the operating panel of the control box 95, a power feed display lamp 97 which is turned on when the external electric power is supplied, a feed display lamp 98 which is turned on or off as synchronized with the opening or shutting motion of the solenoid valve 111, a drought alarm lamp 99 which flickers when the lower-limit level is detected, first to fourth alarm display lamps 100 which serve the purpose of indicating the particular one of the plurality of (four, for example) filter devices F which has developed a defect, and a buzzer stop switch 101 which is used for stopping the operation of the alarm buzzer are laid out.

Fig. 7 is a block diagram illustrating the control system of the control device. A control circuit 102 obtains supply of external electric power from a power source 1011 via a power supply circuit 103 and receives a signal from the upper-limit level sensor 79 and the lower-limit level sensor 80. The control circuit 102 emits a control signal for controlling the opening and shutting motions of the solenoid valve 111, control signals for turning on or off or flickering the lamps 97 to 100, and a control signal for starting or stopping an alarm buzzer 105. A timer 106 and the buzzer stop switch 101 are connected to the control circuit 102.

The alarm buzzer 105 is intended to function as an alarm generating means. It emits a buzzer sound when the upper-limit level sensor 79 is turned on, namely when the level of the separating liquid inside the pan 46 reaches the upper-limit level or when the lower-limit level sensor 80 is turned on, namely when the level of the separating liquid inside the pan 116 reaches the lower-limit level. During normal operation, the separating liquid L supplied from the first supply system 38 is adjusted to a proper flow volume.

Unless the discharge system 40 develops a defective discharge, the level of separating liquid L inside the pan 46 will never rise to the upper-limit level. Further in the present embodiment, even when the first supply system 38 develops a defect of supply due to one cause or another, the float valve 77 is set operating to supply separating liquid L by way of replenishment from the second supply system 39.

Thus, the level of the separating liquid L inside the pan 46 will not descend to the lower-limit level unless both the first and second supply system 38 and 39 both suffers from a defect of supply. The sound emitted by the alarm buzzer 105, therefore, informs the operator of the occurrence of a discharge defect in the discharge system 40 or of the occurrence of a supply defect in both the first and second supply systems 38 and 39. Whether or not the drought alarm lamp 99 is flickering enables the operator to discriminate between a discharge defect or a supply defect.

The timer 106 mentioned above is intended to function as a time setting means. It is capable of setting the time for starting the supply of the separating liquid L by the first supply system 38 and the time for stopping the supply of the separating liquid L by the first supply system 38. When the timer 106 clicks the starting time, the solenoid valve 41 is opened in response to the signal from the control circuit 102. When the timer 106 clicks the stopping time, the solenoid valve 41 is shut.

Now, the operation of the present embodiment will be described below.

First, the operation of the filter device F for the seizure of dispersed particles contained in air will be described with reference to Fig. 2 and Fig. 3.

When the fan 35 disposed on the outlet side of the duct 36 is set operating while the water is stored in the pan 46 as illustrated in Fig. 2, the pressure of the air on the outlet 311 side falls below the pressure of the air on the inlet 33 side. As a result, the level of separating liquid on the outlet 311 side separated by the partition plate 55 ascends and the level of separating liquid L on the inlet 33 side separated by the partition plate 55 descends.

When the level of separating liquid on the inlet side 33 falls slightly below the lower edge 55b of the partition plate 55, the air aspirated through the inlet 33 passes under the lower edge 55b of the partition plate 55 and guides itself into the water. Since the lower edge 63a of the lower side retaining plate 63 retaining the separating member 61 is dipped in the water to a greater depth than the lower edge 55b of the partition plate 55 at this time, the air which has been guided into the water passes between the partition plate 55 and the lower side retaining plate 63 and floats in the form of bubbles to the surface of the water in the space S1 (hereinafter, the phenomenon just mentioned will be referred to as "bubbling"). While this bubbling is in process, most of the dispersed particles such as oil contained in the air, are separated from the air and seized in the water or allowed to float up to the surface of the water or mingled in the water.

When the air which has reached the space S1 is passing the separating member 61 made of a porous material 65, the oil which persists in a very small amount in the air is separated and removed by the porous material 65. At the same time, when the air is passing the air vents 60 of the porous material 65, the stream of air is rectified and the water hurled from the water surface is removed. Owing to the rectification of the stream of air, the possible occurrence of a hissing sound of wind is avoided. The air which has been thoroughly deprived of the dispersed particles such as oil as described above, is passed through the space S2, caused to flow down the duct 36 through the outlet 311, and blown out of the room via the outblowing mouth 37.

The oil, dust, etc. which have been seized in the water as a consequence of the bubbling are discharged from the pan 116 accompanied by the water which overflows the overflow pipe 70. In the meantime, freshly supplied water L is supplied into the pan 46 through the first supply system 38 and the second supply system 39.

Now, the operation of the supply-discharge device W will be described with reference to the flow charts illustrated in Fig. 8 and Fig. 9.

At Step S1, the power feed display lamp 97 is turned on when an external electric power is supplied to the control box 95. The timer 1(Y6 begins operating (S2) when the timer 106 is set at the current time and then the starting time and the stopping time are set. When the timer 106 clicks the starting time (S3), the solenoid valve 41 provided for the first supply system 38 is opened in response to the signal from the control circuit 102. As a result, the water is supplied in a prescribed flow volume from the first outlet 73 of the first feed pipe 71 into the pan 116 (S4). The feed display lamp 98 is turned on as synchronized with the opening motion of the solenoid valve 41 (S5). When the supply of separating liquid L and the rotation of the fan 35 are started together, the aspiration of air through the inlet 33 into the filter device F begins and the bubbling mentioned above is initiated. Further, part of the water in the pan 46 flows into the overflow pipe 70 of the discharge system 40, passes through the discharge pipe 82 and the grease trap 83, and gets discharged into the discharge channel 84 (S6). The dispersed particles such as oil contained in the air which has been aspirated into the filter device F are seized in the water in the process of bubbling and separated or removed additionally by the separating member 61. The air which has been deprived of the dispersed particles is passed through the outlet 311 of the filter device F, caused to flow down the duct 36, and blown out of the room through the outblowing mouth 37.

Meanwhile, the oil, dust, etc. which have been seized in the water are discharged from the pan 46 together with the overflowing water. When the filter device F is operating as described above, the processing for checking the safety of water being supplied and discharged is carried out (S7).

This processing will be given further treatment hereafter with reference to Fig. 9. The aforementioned steps S6, S7, and S8 are repeated until the stopping time. When the timer 106 clicks the stopping time (S8), the solenoid valve 41 is shut in response to the signal from the control circuit 102 and the supply of separating liquid L from the first supply system 38 is stopped (S9). At the same time, the feed display lamp 98 is turned off as synchronized with the shutting motion of the solenoid valve 111 (S10). Then, the operation returns to Step S3, at which the timer 106 is checked as to the question whether or not the starting time for the operation of the filter device F has been reached.

When the starting time is reached, the operation from Step 511 onward will be carried out as described above.

Now, the processing for checking the safety of the supply and discharge will be described with reference to Fig. 9. This processing is to be executed on the basis of the level of the separating liquid inside the pan 116.

Hence, the output signals from the upper-limit level sensor 79 and the lower-limit level sensor 80 are continuously injected into the control circuit 102.

For the purpose of ideally effecting the seizure of the dispersed particles such as oil by bubbling while the filter device F is in operation, it is necessary to maintain the water in the pan 116 in an overflowing state. For the sake of maintaining this overflowing state of the water, the first supply system 38 is adjusted so as to supply the water at a prescribed flow volume. The amount of the water to be supplied, however, is prone to variation, depending as on the variation of the pressure of the supply source. Thus, the float valve 77 provided for the second supply system 39 operates as follows in accordance with the level of the separating liquid within the plate member 116.

The level of separating liquid L within the pan 46 is detected by the degree of rise and fall of the float 75 of the float valve 77 (S13). When the level of separating liquid L falls below the overflow level, the float 75 descends and the valve part 76 opens to induce the supply of water from the second inlet 78 of the second feed pipe 74 into the pan 46 (S27). Conversely, when the level of separating liquid L rises above the overflow level, the float 75 ascends and the valve part 76 shuts to stop the supply of water (S28). By the procedure described above, the water inside the pan 46 is maintained in an overflowing state.

When the smoothness of flow of the water in the discharge system 110 is impaired by one cause or another during the operation of the filter device F, the level of separating liquid L inside the pan 46 gradually ascends because the supply of separating liquid L at the prescribed flow volume from the first supply system 38 continues. When the level further ascends and reaches the upper-limit level, the upper-limit level sensor 79 is turned on (S11). When the control circuit 102 detects the occurrence of this defect in the discharge system 40 based on the ON signal from the upper-limit level sensor 79 (5111), the solenoid valve 41 is shut, the supply of water from the first supply system 38 is stopped (S15), and the feed display lamp 98 is turned off (S16). At the same time, the alarm buzzer 105 is set operating to issue a sound (S17) and the alarm display lamp 100 corresponding to the particular filter device F in trouble is caused to flicker (S18). When the operator depresses the buzzer stop switch 101, the alarm buzzer 105 ceases emitting the sound (S19). The operator, on finding the drought alarm lamp 99 in the OFF state, discerns a discharge defect in the discharge system 40 and, on finding the alarm display lamp 100 in a flickering state, discerns a defect in one of the four filter devices F. When the operation of the first supply system 38 is stopped, the level of separating liquid L inside the pan 116 gradually descends (S20). The operation then returns to the main flow and the filter device F continues its operation. When the level of separating liquid L inside the pan 116 falls below the overflow level as a consequence of the continuation of the operation just mentioned, the float valve 77 is actuated to start the supply of water from the second supply system 39 (S13, S27, and S28).

In the present embodiment, the supply of water in an amount necessary for normal operation of the filter device F can be attained even by exclusive use of the second supply system 39. Even when the discharge system 40 happens to develop a discharge defect, immediate adoption of some countermeasure or other is not necessary. inspection and cleaning to be given to the discharge system 40 after use of the kitchen is completed and the operation of the filter device F has stopped is sufficient to remedy the trouble.

When the supply-discharge device W is normally operating, the first supply system 38 supplies the water constantly and the second supply system 39 supplies the water by way of replenishment as occasion demands. Even when the supply of water by the first supply system 38 is stopped by some cause or other in spite of the open state of the solenoid valve 111, the float valve 77 is actuated to start the supply of water from the second supply system 39.

As a result, the level of the separating liquid L in the pan 46 is not lowered extremely below the overflow level but is maintained at the prescribed level. When the supply of water by the second supply system 39 is stopped owing to the occurrence of a defect of operation in the float valve 77 in addition to the defect of supply in the first supply system 38, the water in the pan 46 flows into the overflow pipe 70 as a consequence of the bubbling and the level of separating liquid in the pan 46 gradually descends.

When the level of the separating liquid begins to descend as a consequence of the occurrence of a supply defect while the filter device F is in operation and the level eventually reaches the lower-limit level, the lowerlimit level sensor 80 is turned on (S12). When the control circuit 102 detects a defect in the first and second supply systems 38 and 39 based on the ON signal from the lowerlimit level sensor 80 (S21), the alarm buzzer 105 is actuated to issue a sound (S22), the drought alarm lamp 99 is caused to flicker (S23), and the alarm display lamp 100 corresponding to the particular filter device F which has developed the defect is caused to flicker (S211). When the operator depresses the buzzer stop switch 101, the alarm buzzer 105 ceases emitting the sound (S25). The operator, on finding the drought alarm lamp 99 in a flickering state, discerns the occurrence of a supply defect in both the first supply system 38 and the second supply system 39 and, on finding the alarm display lamp 100 in a flickering state, discerns a defect in a particular one of the filter devices F. Even when both the first and second supply systems 38 and 39 develop a operation defect , the possibility that the aspirated air will reach the outlet 34 without passing through the water is nil because the lower-limit level is set at a position higher than the lower edge 55b of the partition plate 55. Since the depth to which the partition plate 55 is dipped in the water decreases and the efficiency of the seizure of oil by bubbling is impaired in this case, necessary remedial measures such as the inspection of the origin of supply must be carried out (S26).

In the air cleaner 30 which is applied to a kitchen, the removal of oil from an oil-containing air can be attained with high efficiency because the air is passed through the water stored in the filter device F and the oil is consequently seized in the water by virtue of the bubbling as described above. The results of the experiment in the present embodiment indicate that the ratio of seizure or removal of the oil is about 99%, the ratio of seizure of the dust about 100%, and the ratio of seizure of odor about 80%. Since the ratio of seizure of oil in the filter device F is high as described above and further since the seized oil is discharged together with the overflowing water due to the function of the supply-discharge system W, the possibility tat the oil will stagnate and accumulate in the filter device F and adhere fast to the inner surface of the duct 36 and to the fan 35 and the outblowing mouth 37 is nil. The filter device F, thereof, is easily cleaned and the duct 36 and the fan 35 require no cleaning. Further, since the possibility that the oil will be scattered out of the room through the outblowing mouth 37 is nil, the outer wall of the building is not smeared by the oil and the wall surface requires neither cleaning nor repair. Moreover, since the oil neither accumulates in the filter device F nor adheres fast to the fan 35, the efficiency of removal of the oil and the efficiency of operation of the fan 35 are not degraded and the air cleaner 30 is allowed to operate stably for a long time.

Even when the flame used in the kitchen reaches the filter device F, it is intercepted by the separating liquid and precluded from flaring into the duct 35. The air cleaner, therefore, enjoys prominently enhanced fireproofness because the flame is intercepted by the separating liquid and the oil is prevented from accumulating or inducing fast deposition. Since the temperature of the air discharged from the filter device F is lowered as a consequence of the bubbling, it is not possible for the duct 36 and the fan 35 to be heated to a high temperature and they are not required to adopt a heatproof structure.

Further, since the supply-discharge device W stops the supply of water from the first supply system 38 and, at the same time, issues an alarm when the discharge system 40 has developed a discharge defect, separating liquid L does not overflow the pan 46 and the operator is able to discern easily the occurrence of a discharge defect. Since the supply-discharge device W issues an alarm when a supply defect occurs in the first and second supply systems 38 and 39, the operator is able to take an appropriate measure promptly against the supply defect and prevent the efficiency of separation from being degraded as a consequence of a fall of the level of the separating liquid.

Moreover, since the solenoid valve 41 provided for the first supply system 38 of the supply-discharge device W is controlled by the timer, the starting and stopping of the supply of separating liquid L can be effected automatically in due compliance with the schedule as to the use of the kitchen. Thus, the air cleaner 30 enjoys conspicuously improved convenience. The solenoid valve 41, when necessary, may be adapted so as to be turned on and off synchronously with the operation of the switch for the fan 35.

Further, since the filter device F permits a change in the selected position for attachment of the partition plate 55, the depth of dip m of the partition plate 55 in the water can be finely adjusted to the magnitude in faithful compliance with the performance of separation and the performance of ventilation which depend on the volume of air discharged by the fan 35. When the filter device F is provided with an inspection window 54 adapted to allow visual inspection of the level of the separating liquid L during the operation of the air cleaner as indicated by an imaginary line in Fig. 2, the adjustment of the position for attachment of the partition plate 55 can be easily carried out and, in the meantime, the change in the level of the separating liquid L can be kept under constant watch through the inspection window 54.

Though the embodiment described thus far represents a case of applying the air cleaner 30 to a kitchen, this invention is not limited to this particular application.

The range of applications in which the air cleaner 30 finds utility can be widened by aptly selecting the kind of separating liquid L and the material of the separating member 61, depending on the purpose for which the air cleaner 30 is to be used. When the air cleaner 30 is to be used as a deodorizing device, for example, it is only required to accommodate therein the well-known deodorant.

The separating liquid L to be selected is preferably of such a type as to permit ideal solution therein of the minute dispersed particles of the odor which varies with the site of use of the air cleaner such as, for example, a livestock shed or a beauty parlor. The air cleaner 30 is also used effectively for primary treatment of a deodorizing system.

When the air cleaner 30 is used for the purpose of cleaning the air in a given room, for example, an aromatic agent selected as the separating liquid L may be utilized for the dual purpose of removing the dust contained in the room air and imparting a pleasant smell to the interior of the room.

When the air cleaner 30 is used in a food processing plant, for example, a disinfecting liquid may be used as the separating liquid for the sake of seizing microorganisms which are detrimental to the food under treatment. In an experiment performed on the use of disinfecting liquid as the separating liquid L for the seizure of microorganisms suspended in air, the ratio of seizure was found to be about 90Z.

The filter device F in the air cleaner 30 of this invention is not limited to the first embodiment described thus far but permits various modifications. Now, other embodiments of the filter device F will be described below.

Second Embodiment of Filter Device The filter device F of the second embodiment illustrated in Fig. 10 is utilized where the fan 35 is installed on a vertical wall 110. This filter device F has a structure which is one of two roughly equal halves of the filter device F of the first embodiment severed with a vertical plane. The setting flange 50 at the upper end of the lateral wall 47 is fixed on the ceiling 31 and the pan 46 on the vertical wall 110. The partition plate 55 is set in place so as to isolate the outlet 34 from the interior of the room. The lower edge 55b of this partition plate 55 is dipped in a prescribed length into the separating liquid L which is stored in the pan 116. This partition plate 55 is set movably relative to the lateral wall 117 so as to allow necessary adjustment of the length of dip m. The separating member 61 made of a porous material 65 is installed on the downstream side of the partition plate 55. The lower edge 63a of the lower side retaining plate 63 for fixing the separating member 61 Es dipped in the separating liquid L to a level lower than the lower edge 55b of the partition plate 55.

In the case of the filter device F constructed as described above similarly to that of the first embodiment, when the fan 35 is set operating, the level of the separating liquid L on the inlet 33 side descends to the lower edge 55b of the partition plate 55 and the air aspirated through the inlet 33 flows through the gap and floats to the surface of the water in the space S1. While this bubbling is in process, the greater part of the dispersed particles contained in the air are captured in the separating liquid L. The residual dispersed particles in the air which has reached the space S1 are subject to separation by collision while the air is passing through the air vents 60 of the porous member 65. Further, since the stream of air is rectified while the air is passing through the air vents 60, the otherwise possible occurrence of a hissing sound of wind is prevented and the scattering of water droplets from the surface of water in the space S1 or the space S2 possibly caused otherwise by the aspirating force of the fan 35 is avoided. As a result, the possibility of the fan 35 and its immediate neighborhood being corroded with moist air is nil. Since the filter device F of this nature permits miniaturization of its own by reason of construction, it can be ideally used such as in an ordinary home kitchen.

Third Embodiment of Filter Device In the filter device F of the third embodiment illustrated in- Fig. 11, the fan 35 is attached directly to the upper surface part of the filter device F. This filter device F has the same construction as the filter device F of the first embodiment cited above, except that the lateral wall 47, the partition plate 55, and the separating member 61 are laid out in the vertical direction for the sake of dimensional reduction. This filter device F can be installed as an indoor deodorizing device or air cleaner on the floor, on the table in a restaurant, or at another similarly desired place. It may be adapted to form a simplified air cleaner which serves the purpose of returning cleaned air to the room. Further, this filter device F can be moved to a desired place and installed there. Even when it incorporates a supply-discharge device therein, the movability of the filter device F described above can be retained utterly intact by adapting the supply pipes 71 and 711 and the discharge pipe 82 to be freely attached and detached such as by a connector.

The concept of disposing the partition plate 55 and the separating member 61 along the vertical direction can be applied effectively to the filter devices F of the first and second embodiments described above. It is also permissible to obtain simplified filter devices F by directly attaching the fan 35 to the filter devices F of the first and second embodiments.

Fourth Embodiment of Filter Device The fourth embodiment illustrated in Fig. 12 is a filter device F which reflects modifications such as in the construction of the separating member 61 and the construction of the pan 116. In this filter device F, an empty cavity part 111 which has the approximate shape of a quadrangular pyramid is formed on the bottom wall of the pan 46 containing the separating liquid L therein. This empty cavity part 111 serves the purpose of curbing the possible elevation of the temperature of the separating liquid L stored in the pan 46 and preventing the separating liquid L from e stream of air. The visible outlines of the empty cavity part 111 may be suitably varied in conformity with the shape of the fitting position of the filter device F and the volume of wind to be discharged by the fan 35, for example.

Further, in this filter device F, a drain pipe 113 fitted with a drain valve 112 is connected to the lowermost position inside the pan 116. This drain pipe 113 is connected to the discharge pipe 82. A level gauge 1111 is disposed at a position which allows visual observation of the level of the separating liquid L on the inlet 33 side.

Since the drain pipe 113 thus provided for the filter device F permits thorough discharge of the separating liquid L from within the pan 116, the work of replacing the separating liquid L with a new supply can be expedited. The level gauge 114 also facilitates the recognition of the length of dip of the partition plate 55.

The separating member 61 in the present embodiment is made of a separating plate 115 which has a plurality of air vents 60 formed therein. The upper end 175a of the separating plate 115 is fixed to the lateral wall 47 of the filter box 45 and the lower edge 115b thereof is dipped in the separating liquid L to a level lower than the lower edge 55b of the partition plate 55.

In the case of the filter device F constructed as described above similarly to that of the first embodiment, when the fan 35 is set operating, the level of the separating liquid L on the inlet 33 side descends to the lower edge 55b of the partition plate 55 and the air which has been aspirated through the inlet 33 passes under the lower edge 55b of the partition plate 55 and floats to the surface of the water in the space S1. While this bubbling is in process, the greater part of the dispersed particles are captured by the separating liquid L. The residual dispersed particles in the air which has reached the space S1 are separated from the air due to the collision of the air against the peripheral walls of the air vents 60 present in the separating plate 115. Further, since the stream of air is rectified while the air is passing through the air vents 60, the occurrence of a hissing sound of wind and the scattering of water droplets are prevented.

Incidentally, the concept of forming the empty cavity part 111 on the bottom wall of the pan 46 can be effectively applied to the first and second filter devices F described above. This concept can be effectively applied also to the filter device F of the third embodiment which is capable of being installed such as on the floor surface, on the condition that the bottom wall of the empty cavity part 111 is formed in a flat shape. The concept of connecting a drain pipe to the pan 46 and the concept of forming the separating member 61 with a separating plate 115 may be applied effectively to the filter devices F of the first, second, and third embodiments.

Fifth Embodiment of Filter Device The fifth embodiment illustrated in Fig. 13 is a filter device F which reflects a modification of the fourth embodiment with respect to the fitting position of the separating plate 115. In this filter device F, the separating plate 115 is set in place near the outlet 34 which is formed in the upper surface of the filter box 115.

In all the other respects, this filter device F is identical in construction with that of the fourth embodiment.

Likewise in the filter device F constructed as described above, when the fan 35 is set operating, the level of the separating liquid L on the inlet 33 side descends to the lower edge 55b of the partition plate 55 and the air which has been aspirated through the inlet 33 flows under the lower edge 55b of the partition plate 55 and floats to the surface of the water on the outlet 34 side. While this bubbling is in process, the greater part of the dispersed particles are captured in the separating liquid L. Then, the residual dispersed particles in the air are finally separated from the air while the air is passed through the separating plate 115 disposed near the outlet 311. Further, the separating plate 115 functions to rectify the stream of air and prevent the separating liquid L from being scattered. The separating plate 115 attached as described above lends itself to simplifying the construction of the filter device F, enhancing the operational efficiency of assemblage, and lowering the cost of production.

It is permissible to apply to the present embodiment the separating member 61 which is made of the porous material 65 as illustrated in the first embodiment, for example.

Sixth Embodiment of Filter Device In the filter device F of the sixth embodiment illustrated in Fig. 14 and Fig. 15, the filter device F is wholly formed in a cylindrical shape and the empty cavity part 111 in a conical shape is formed on the bottom wall of the pan 116. To this pan 46, the filter box 45 which opens in the upper and lower ends thereof is attached through the medium of a connecting member 116. In the upper end part of the lateral wall 47 of the filter box 45, the fitting flange 50 and a plurality of bolt holes 51 are formed. In the filter box 45, the separating plate 115 having a cylindrical shape is integrally formed. In this separating plate 115, a plurality of air vents 60 are formed. In the interval between the separating plate 115 and the pan 46, the partition plate 55 of a cylindrical shape fitted with a top plate 117 is detachably set in place. The lower edge 55b of this partition plate 55 is positioned above the lower edge 115b of the separating plate 115 and, at the same time, dipped a prescribed length m into the separating liquid L stored in the pan 116. Incidentally, in Fig. 14 and Fig. 15, the illustration of the supply-discharge device W is omitted.

In the construction described above, the upper opening part of the filter box 115 constitutes itself the outlet 34 and the gap intervening between the pan 46 and the partition plate 55 forms the inlet 33. This inlet 33 is isolated from the outlet 34 by the partition plate 55 and it is formed throughout the entire periphery of the filter device F. This filter device F produces the same operation and effect as the first embodiment when the fan 35 is set operating.

Incidentally, it is permissible to apply to this embodiment the separating member 61 which is made of the porous material 65 as illustrated in the first embodiment.

Seventh Embodiment of Filter Device The filter device F of the seventh embodiment illustrated in Fig. 16 represents a case of modification having the position of the inlet 33 and that of the outlet 34 interchanged. Inside the filter box 115, the partition plate 55 is raised upright and the lower edge 55b thereof is dipped in a prescribed length into the separating liquid L stored in the pan 116. The inlet 33 and the outlet 311 are formed so as to be isolated from each other by the partition plate 55. This partition plate 55 is provided on the outside thereof, namely on the outlet 34 side thereof, with the separating plate 115 which is dipped to a level lower than the lower edge 55b of the partition plate 55.

In the case of the construction described above, when the fan 35 disposed in the outlet 311 is operated to discharge the air, the level of separating liquid on the inlet 33 side in the central part of the filter box 45 descends and the level on the outlet 311 side ascends to bring about the same operation and effect as those of the first embodiment.

The filter device F of this construction can be ideally used in a smoke-removing device which is installed such as on a table or a kitchen table. This embodiment may effectively adopt the separating member 61 which is made of porous material 65.

This invention need not be limited to the specific embodiments cited above but may permit various modifications. The purpose of use, the construction of the filter device F, the kind of the separating liquid L, etc.

may be suitably varied in accordance with the particular position to be selected for the use of the air filter. This rich versatility constitutes itself one of the characteristic features of this invention.

As described above, the air cleaner of this invention is capable of efficiently removing dispersed particles contained in air by aspirating the air containing the dispersed particles into the filter device and then causing the aspirated air to pass through the separating liquid stored in the filter device. By further selecting the type of separating liquid, the air cleaner is able to effect the removal of dispersed particles of any sort.

Thus, it excels in the ability to clean air and finds utility in a wide range of applications. It enjoys conspicuously improved fireproofness because the fire used such as in a kitchen is intercepted perfectly by the separating liquid. Further, since the air cleaner is provided with the supply-discharge device and consequently able to keep the level of water in the pan constantly at a prescribed level, it can stably carry out the seizure of dispersed particles in the separating liquid. The filter device is so constructed as to discharge the removed dispersed particles together with the separating liquid.

Thus, this filter device exhibits a distinct improvement in the cleanability, precludes the possibility of allowing copious accumulation of dispersed particles, and enjoys further increased safety.

Further, since the supply-discharge device stops the.

supply of water from the first supply system and, at the same time, issues an alarm when the discharge system develops a discharge defect, the possibility that the separating liquid will overflow the pan is nil and the operator is able to discern easily the occurrence of the discharge defect in the discharge system. Since the supply discharge device issues an alarm when a supply defect arises in the first and second supply systems, the operator is able to promptly take an appropriate measure to overcome the supply defect and prevent the efficiency of separation from being degraded by a descent of the level of water. When the switch means provided for the first supply system of the supply-discharge device is adapted to be controlled by means of a timer, this adaptation produces the effect of conspicuously enhancing the convenience of the air cleaner.

Claims

1. An air cleaner comprising: a filter device for removing dispersed particles contained in air by means of a separating liquid, a supply-discharge device for supplying the separating liquid to the filter device and, at the same time, discharging the separating liquid which has captured the dispersed particles, and a fan for aspirating air, in which the filter device includes: a filter box which has an inlet for aspirating air containing dispersed particles and an outlet for discharging the air which has been cleaned; a pan disposed in the bottom part of the filter box and adapted to store the separating liquid; a partition plate adapted to isolate the inlet and the outlet from each other and to have its lower edge immersed to a prescribed depth into separating liquid stored in the pan; a separating member fitted with a plurality of air vents formed on the downstream side of the partition plate relative to the stream of air.

2. An air cleaner as claimed in Claim 1, in which the fan is installed in a duct connected to an opening in a ceiling and the filter device is attached to the ceiling in such a manner that the outlet will confront the opening.

3. An air cleaner as claimed in Claim 1, in which the fan is set in place in an opening formed in a vertical wall and the filter device is attached to the vertical wall in such a manner that the outlet will confront the opening.

4. An air cleaner as claimed in Claim 1, in which the filter device is a freely movable type having the fan attached to the outlet of the filter box.

5. An air cleaner as claimed in Claim 1, in which the filter device is of a table-top type having the inlet formed in the central part of the filter box, the outlet formed on the outer edge part of the filter box, and the fan attached to the outlet of the filter box.

6. An air cleaner as claimed in any preceding Claim, in which the separating member is made of a porous ceramic material.

7. An air cleaner as claimed in any preceding Claim, in which the pan has an empty cavity part formed in its bottom wall.

8. An air cleaner as claimed in any preceding Claim, in which the supply-discharge device is provided with a discharge system having an inflow part for admitting the separating liquid inside the pan disposed at a position higher than the lower edge of the partition plate, a first supply system for supplying the separation liquid to the pan, and a second supply system for supplying the separating liquid to the pan when the level of liquid in the pan is at the second level which is lower than the first level to be fixed by the height of the inflow part of the discharge system.

9. An air cleaner as claimed in Claim 8, in which the supply-discharge device is further provided with: switch means provided for the first supply system and adapted to permit free switching of the first supply system; upperlimit level sensing means for detecting the upper-limit level sensing means for detecting the upper-limit level higher than the first level; control means for imparting a shutting motion to the switch means to shut the first supply system when the upper-limit level sensing means has detected the upper-limit level; and an alarm device for issuing an alarm when the upper-limit level is detected.

10. An air cleaner as claimed in Claim 8 or Claim 9, in which the supply-discharge device is further provided with lower-limit level detecting means for detecting the lower-limit level higher than the height of the lower edge of the partition plate and lower than the second level, and an alarm device for issuing an alarm when the lower-limit level is detected.

11. An air cleaner as claimed in Claim 9, in which the supply-discharge device is further provided with time setting means for setting the starting time for opening the first supply system by imparting an opening motion to the switch means for setting and the stopping time for shutting the first supply system by imparting a shutting motion to the switch means, the control means being so adapted as to control the opening and shutting motions of the switch means thereby starting the supply of the separating liquid into the pan via the first supply system when the starting time is reached and stopping the supply of the separating liquid when the stopping time is reached.

12. An air cleaner constructed and arranged substantially as herein specifically described with reference to and as shown in Figures 1 to 9 optionally or any one of Figures 10 to 16.