WO2025042269A1

WO2025042269A1 - An air purifier apparatus

Info

Publication number: WO2025042269A1
Application number: PCT/MY2024/050049
Authority: WO
Inventors: Charng Yung LOH
Original assignee: Loh Charng Yung
Priority date: 2023-08-22
Filing date: 2024-06-27
Publication date: 2025-02-27

Abstract

The invention relates to an air purifier apparatus (1) comprising a housing (2) having an air intake opening (3) through which contaminated air is introduced, and an air discharge opening (4) through which purified air is discharged, a blower fan (5) for drawing a stream of contaminated air to be purified through the housing (2), a recirculation pipe (7) for recirculating solvent within the housing (2) such that the solvent contacts with the contaminated air thereby producing contaminated solvent, a contact unit (8) configured to bring the recirculated solvent into contact with the contaminated air during recirculation, a tank (9) disposed at a lower portion of the housing (2) for collecting the contaminated solvent and a solvent monitoring unit (10) adapted to monitor the quality of the contaminated solvent collected therein, wherein the solvent monitoring unit (10) comprises a pH sensor (11) to measure pH of the collected contaminated solvent, a solvent resistivity sensor (12) to measure electrical resistance of the collected contaminated solvent and an illumination indicator (13) coupled to the pH sensor (11) and the solvent resistivity sensor (12) for indicating pH and ionic material content of the collected contaminated solvent and replacement timing of the tank (9).

Description

AN AIR PURIFIER APPARATUS

FIELD OF INVENTION

The present invention relates to an air purifier apparatus capable of effectively removing contaminants in the air. This invention relates generally to air purifier appliances and more particularly to electrically operated air purifiers intended for domestic use.

BACKGROUND OF THE INVENTION

Generally, an air purifier is an apparatus that removes and eliminates contaminants by passing contaminated air containing fine dust particles, noxious gas, and microorganisms such as bacteria, mould and viruses, through a purification or cleansing medium and then discharges the substantially purified or cleansed air. Air purifiers have not only an air purification function but also other useful functions such as a function to eliminate small particles including odourant chemical molecules, ticks, pollens, pet furs and the like. Optionally, air purifiers may be equipped with a function of preventing airborne infectious diseases. The basic construction of air purifiers may include a suction port for sucking contaminated air, means for filtering out contaminants from the air, and a discharge port for discharging the cleansed or purified air.

Air purifiers are largely categorised into direct interception air purifiers utilizing conventional filters and solvent absorption air purifiers. Direct interception air purifiers utilize filters having a smaller pore size to entrap bigger particles from escaping whereas solvent absorption air purifiers use both the absorption and adsorption processes to entrap both the particles and gases into the solvent. As for filter purification-type, such air purifiers exhibit a high purification performance as various types of fine particles are removed while air flows through the filter. Thus, filter

filtration-type air purifiers are suitable for filtering out fine dust particles from air. However, this type of air purifier has an evidently common drawback which can only remove particles and not noxious gases in the air. In addition, the filter type air purifiers are known to unload particles due in certain condition (when particles are full) or when agitated. Furthermore, due to the pore size of the filters, restriction of the air flow will cause the purification process to deteriorate overtime. Given that the current measurement of Air Quality Index (AQI) is not the only factors of PM2.5, it is also measured by noxious gases like sulphur oxides (SOx), nitrogen oxides (NOx) and ozone in the air, direct interception purifiers utilizing filters are not able to purify noxious gas.

Solvent absorption air purifiers are particularly advantageous in that the working mechanism involves purifying air in a manner of bringing the suctioned air into contact with solvent usually but not limited to water so that the contaminants such as particles and noxious gases from air are absorbed into the solvent. Ideally, the contaminants from the suctioned air are adsorbed with solvent and collected in a storage tank which could be periodically discarded. Therefrom, the purified or cleansed air exits the air purifier without requiring filter replacement. As solvent recirculates through the air purifier for the purpose of absorbing particles and noxious gas. In addition depending on the selection of solvent used, toxic gas like hydrogen cyanide could also be removed from the contaminated air. For these reasons, solvent absorption air purifiers are generally more advantageous over direct interception air purifiers.

Several technologies related to wet air purifiers have been established. For example, Chinese Patent Publication No. CN104056511A discloses a water-filtration humidification-type air purifier consisting of a shell, a liner and a water tank, wherein the top of the shell is provided with an air outlet and the bottom of the shell is connected with the lower part of the liner, the top of the liner is provided with a centrifugal fan, a water distributor arranged below the centrifugal fan, a packing layer arranged below

the water distributor, an air inlet arranged below the packing layer, the water tank arranged at the bottom and internally provided with a water pump and a water outlet pipe of the water pump connected with the water distributor. Basically, water is pumped via a pipeline to the water distributor from the water tank and is then sprayed onto the packing layer to flow therethrough back into the water tank to complete recirculation of water. Suction of air is initiated by the centrifugal blower whereby the substantially contaminated air contacts with the recirculated water while the purified air exits through the centrifugal blower. The problem with this invention is that the conical shape of the shell will increase the air velocity which will likely spew out more liquid droplets that will re-contaminate the air. Where the purpose of the invention is to humidify the air instead of retaining the impurities of particles and gases in the air. In addition, the major setback of this device has no indication of when the solvent required to be replenish or when it is empty. Another similar technology is also revealed in Chinese Patent Publication No. CN106310846A whereby a water washing-based air purifier is characterized in that a fan is arranged on the upper part of a purification tower which is provided with a gas outlet, one side of the purification tower provided with a water inlet being located at the upper part of a filling layer. The filling layer is arranged below the purification tower, a water tank arranged at the bottom of the purification tower whereby an air inlet and a water pump are arranged in the water tank. A water outlet of the water pump is connected to the water inlet so that water is injected into the water tank and a housing that covers the fan, the purification tower and the filling layer. Another related technology is exemplified in United States of America Patent Publication No. US20180147523A1 which discloses a wet air purifier that eliminates contaminants while contaminated air passes therethrough by causing the contaminated wait to come into contact with water. Particularly, the wet air purifier suctions external air by rotating a rotary fan installed therein and disperses water droplets by causing water to collide with a rotary fan to increase a contact surface between air and water. The mixture of contaminated external air and water is made to pass through a long narrow passage and guided to a storage tank in which contaminants settle.

The major difference in view of CN106310846A and US20180147523A1 is that the application of these devices are used for industrial application and not for domestic use. In addition, the abovementioned technologies have a void between the packing and the liquid level of the tank, the flow of the water splashing will create noise nuisance which us not suitable for domestic application.

SUMMARY OF INVENTION

One aspect of the invention is to provide an air purifier apparatus capable of continuously removing contaminants from contaminated air drawn into the air purifier apparatus from the surrounding environment. In particular, the air purifier apparatus controls the annular velocity of the air in contact with the liquid in the random packing to maximize the mass transfer between the air and the liquid.

Another aspect of the invention is to provide an air purifier apparatus that can be based in both absorption process from chemical mass transfer between contaminated air with solvent thereby producing contaminated solvent containing the contaminants which can be discarded. Advantageously, air is effectively purified through absorption process and discharged into the surrounding environment from the air purifier apparatus.

Still, one aspect of the invention is to provide an air purifier apparatus having a solvent quality monitoring function and a notification function for notifying a user to discard the contaminated solvent and replenish thereof with fresh solvent. A level transmitter in the tank will also indicate the level of solvent in the event when the solvent level is low.

At least one of the preceding objects is met, in whole or in part, in which the embodiment of the present invention describes an air purifier apparatus comprising a housing having an air intake opening through which contaminated air is introduced, and

an air discharge opening through which purified air is discharged, a blower fan for drawing a stream of contaminated air to be purified through the housing, a recirculation pipe for recirculating solvent within the housing such that the solvent contacts with the contaminated air thereby producing contaminated solvent, a contact unit configured to bring the recirculated solvent into contact with the contaminated air during recirculation; a tank disposed at a lower portion of the housing for collecting the contaminated solvent and a solvent monitoring unit adapted to monitor the quality of the contaminated solvent collected therein, wherein the solvent monitoring unit comprises a pH sensor to measure pH of the collected contaminated solvent.

In a preferred embodiment of the present invention, it is disclosed that the recirculation pipe connects to the lower portion of the housing in fluid communication with the tank at one end thereof and the other end being connected at an upper portion of the housing.

In another preferred embodiment of the present invention, it is disclosed that the recirculation pipe extends to pass into the upper portion of the housing for recirculating the contaminated solvent from the tank to the contact unit.

Further embodiment of the present invention discloses that the recirculation pipe is provided with a pump for pumping the contaminated solvent.

Preferably, the contact unit is disposed between the other end of the recirculation pipe at the upper portion of the housing and the air intake opening.

More preferably, the contact unit is a packed bed having a plurality of passages through which the contaminated solvent flows downwardly and the purified air filtered from the packed bed passes upwardly.

Even more preferably, the packed bed is made from a metallic material of copper.

Even more preferably, the packed bed has a packing configuration selected from structured packing and random packing.

Even more preferably, the contact unit comprises a tray provided on the lower surface of the contact unit for directing the contaminated solvent into the tank.

It is preferred that the pH sensor and the solvent resistivity sensor are installed in the space in the tank.

Preferably, the blower fan is installed in contact with the housing on top thereof.

More preferably, the blower fan is connected to a motor for operating thereof.

One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiment described herein is not intended as limitations on the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawing the preferred embodiments from an inspection of which when considered in connection with the following description, the invention, its construction and operation and many of its advantages would be readily understood and appreciated.

FIG. 1 illustrates a perspective view of the air purifier apparatus, according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the invention shall be described according to the preferred embodiments of the present invention and by referring to the accompanying description and drawings. However, it is to be understood that limiting the description to the preferred embodiments of the invention is merely to facilitate discussion of the present invention and it is envisioned that those skilled in the art may devise various modifications without departing from the scope of the appended claim.

The invention will now be describer in greater detail with reference to the drawings.

Referring in particular to FIG. 1, there is shown an embodiment of the air purifier apparatus 1 constructed in accordance to the invention. In its preferred form, the air purifier apparatus 1 comprises mainly a housing 2 forming an outer appearance. The housing 2 has a space for flows of air for purification and discharge of contaminated solvent in the interior thereof. The housing 2 may be variously and conveniently configured according to the scale of the air purifier apparatus 1. For example, the housing 2 may be provided in a substantially cuboid shape. Alternatively, the housing 2 may also be provided in a substantially cylindrical shape if desired.

The housing 2 may be provided with an air intake opening 3 through which contaminated air is introduced thereinto and an air discharge opening 4 through which substantially purified air is discharged out from the housing 2. Referring to FIG. 1, the air intake opening 3 may be formed as a through-slit on side walls 19 of the housing 2 which defines an opening for passage of contaminated air to be drawn from the external surroundings into the housing 2 of the air purifier apparatus 1. Preferably, the housing 2 may be provided with a plurality of air intake openings 3 being arranged at regular intervals along either side walls thereon for substantially increasing the amount of

contaminated air to be introduced thereinto so as to substantially increase air purification capacity of the air purifier apparatus 1. Optionally, the air intake opening 3 may also be formed as a through-hole if desired. According to a preferred embodiment of the invention, an air discharge opening 4 is disposed at a top portion of the housing 2. Essentially, substantially purified air is discharged from the housing 2 through the air discharge opening 4. As such, the top portion of the housing 2 may be opened.

As illustrated in FIG. 1, a blower fan 5 may be fixedly installed under the top portion in communication with the housing 2 such that the blower fan 5 is arranged horizontally. That is, a plurality of blades 6 is arranged in the horizontal direction. Particularly, the blower fan 5 operates on the principle in which air around the blower fan 5 is introduced therethrough and is then discharged through an upper portion of the blower fan 5 when the blades 6 are rotated. According to a preferred embodiment of the invention, the blower fan 5 may be connected to a motor 18 for operating thereof being coupled to the bottom portion of the blower fan 5. When the motor 18 is operated, the blower fan 5 rotates in one direction such that external contaminated air is forcibly introduced into the housing 2 through the air intake opening 3.

Prior to discharge of the substantially purified air through the air discharge opening 4, operation of the air purifier apparatus 1 recites that contaminated air introduced into the housing 2 via the air intake opening 3 is mixed with solvent whereby contaminants in the contaminated air such as fine particles and noxious gas are absorbed into the solvent and the consequently purified air is discharged out from the housing 2. As depicted in FIG. 1, the air purifier apparatus 1 comprises a recirculation pipe 7 for recirculating solvent within the housing 2 such that the solvent contacts with the contaminated air thereby producing contaminated solvent. The contaminated solvent will flow through the solvent guide in particular to reduce the splashing and dripping sound of the solvent. A tank 9 is disposed at a lower portion of the housing 2 for collecting the contaminated solvent.

A preferred embodiment of the invention discloses that the recirculation pipe 7 connects to the lower portion of the housing 2 in fluid communication with the tank 9 at one end 14 thereof and the other end 15 being connected at an upper portion of the housing 2. The recirculation pipe 7 also extends upwardly from the lower portion of the housing 2 to the upper portion of the housing 2. During operation, solvent from the tank 9 is recirculated upwardly via the recirculation pipe 7 so that the recirculated solvent reaches the upper portion of the housing 2. Preferably, the recirculation pipe 7 is provided with a pump 16 for facilitating pumping of the solvent from the tank 9. It is also preferable that the other end 15 of the recirculation pipe 7 is constructed in such a way that it extends to pass into the upper portion of the housing 2 for recirculating the contaminated solvent within the housing 2.

To increase the mass transfer of the recirculating solvent and the contaminated air within the housing 2 of the air purifier apparatus 1, a contact unit 8 may be removably installed in the interior of the housing 2. According to a preferred embodiment of the invention, the contact unit 8 is configured to bring the recirculated solvent into contact with the contaminated air during recirculation. As such, the contact unit 8 is preferably a packed bed having a plurality of passages through which the contaminated solvent supplied from the other end 14 of the recirculation pipe 7 flows downwardly and the purified air filtered from the packed bed passes upwardly. The packed bed of the contact unit 8 may be constructed from a variety of materials including, but not limited to, corrugated sheets of perforated embossed metal, plastic or wire gauze. Preferably, the packed bed is made from a metallic material of copper. Advantageously, the metallic material of copper imparts a natural antimicrobial and antiviral properties to the contact unit 8, thereby providing a substantial efficiency to the air purifier apparatus 1. The working mechanism follows that the contaminated solvent, which may consist germs and microbial particles, upon commingling of the recirculated solvent and the contaminated air at the contact unit 8 can be subjected to antimicrobial purification.

Essentially, construction of the packed bed of the contact unit 8 is not restricted by the aforementioned, as long as the resulting construction thereof provides substantially inclined passages for the contaminated solvent to flow downwardly and the purified air to pass upwardly therethrough. For example, the packed bed of the contact unit 8 produces a high surface area coupled with a low gas resistance, which ideally maximizes the mass transfer of the recirculating solvent due to extra inter-facial area for contact between contaminated air and the recirculating solvent while assisting in upward flow of purified air to be discharged from the housing 2 of the air purifier apparatus 1. Therefore, it is preferred that the packed bed of the contact unit 8 has a packing configuration selected from structured packing and random packing. Generally, a packed bed having a structured packing configuration uses a fixed and organized packing structure to channel liquid or fluid into a specific shape to provide a large surface area for the liquid or fluid to contact without causing resistance that impedes the liquid’s flow. On the other hand, a packed bed having a random packing configuration uses a random distribution of small packing materials to assist in separation processes. These small pieces of random packing is designed to form a large surface area where the liquid and fluid can interact while maximizing surface-to- volume ration and minimizing pressure drop. Without wishing to bind to the theory, the packed bed may be selected from either configuration aforementioned depending on the convenience and application of the air purifier apparatus 1.

As illustrated in FIG. 1, the contact unit 8 is preferably disposed between the other end 15 of the recirculation pipe 7 at the upper portion of the housing 2 and the air intake opening 3. Ideally, a solvent dispersing unit (NOT SHOWN) may be provided at the other end 15 of the recirculation pipe 7 to facilitate even dispersing of the solvent to the contact unit 8. For example, the solvent dispersing unit may be a spray nozzle for spraying solvent onto the contact unit 8. Such arrangement allows the solvent recirculated from the tank 9 via the recirculation pipe 7 to the other end 15 thereof can

be supplied to the contact unit 8 for the air purification operation to take place. As the contaminated solvent is subsequently produced upon mass exchange of contaminated air and recirculating solvent, the contaminated solvent flows downwardly through the inclined passages of the structured packing of the contact unit 8 by the force of gravity and solvent pressure. To prevent undesired splashing of the contaminated solvent upon collected in the tank 9, a solvent guide 16 may be provided on the lower surface of the contact unit 8 for directing the contaminated solvent into the tank 9. The tray 17 may have a plurality of tubular elements 20 that forms flow channels for guiding the contaminated solvent into the tank 9. As such, the tubular elements 20 may be configured to extend downwardly to substantially submerge in the collected contaminated solvent in the tank 9.

The basic arrangement of the air purifier apparatus 1 as exemplified in the abovementioned allows uninterrupted recirculation of solvent within the housing 2 and drawing of contaminated air thereinto so that air purification can be operated continuously. However, such conventional air purification mechanism would cause saturation and sedimentation of the contaminated solvent collected in the tank 9. Furthermore, in the case when a user of the air purifier apparatus 1 is unaware of the saturation and sedimentation of the contaminated solvent, the continuous recirculation of the contaminated solvent for supplying thereof to the contact unit 8 may cause clogging of the recirculation pipe 7 and the contact unit 8 due to eventual saturation of contaminated solvent and particulate contaminant build-up. Consequently, this may deteriorate air purification performance of the air purifier apparatus 1.

The invention provides a unique feature to eliminate such a nuisance. Particularly, the air purifier apparatus 1 comprises a solvent monitoring unit 10 adapted to monitor the quality of the contaminated solvent collected in the tank 9, as exemplified in FIG. 1. A preferred embodiment of the invention recites that the solvent monitoring unit 10 further comprises a pH sensor 11 to measure pH of the collected contaminated solvent,

a solvent resistivity sensor 12 to measure electrical resistance of the collected contaminated solvent and an illumination indicator 13 coupled to the pH sensor 11 and the solvent resistivity sensor 12. The pH sensor 11 may be any kind of pH-sensing device which is able to precisely measure the pH value to the collected contaminated solvent in the tank 9. The solvent resistivity sensor 12 may also be any kind of solvent resistivity measuring device which is able to precisely measure the electrical resistance of the collected contaminated solvent. Particularly, the solvent resistivity sensor 12 is configured to monitor the ionic purity of the collected contaminated solvent. Preferably, the pH sensor 11 and the solvent resistivity sensor 12 are installed in the space in the tank 9 so that the pH sensor 11 and the solvent resistivity sensor 12 are in direct contact with the collected contaminated solvent to be measured.

Particularly, the illumination indicator 13 functions to indicate pH and solvent resistivity of the collected contaminated solvent and replacement timing of the solvent in the tank. As such, the illumination indicator 13 may include a first illumination 21 indicating the pH value of the collected contaminated solvent. The illumination indicator 12 may also include a second illumination 21 indicating the solvent resistivity measurement of the collected contaminated solvent. It is preferred to include a third illumination 23 for indicating a replacement period of the solvent in the tank 9. According to a preferred embodiment, the illumination indicator 12 is installed externally on the lower portion of the housing 2.

The first illumination 21 is provided to notify the user of the quality of the collected contaminated solvent in the tank 9 in terms of pH value. For example, the first illumination light 21 may emit light of different colours corresponding to the pH value of the collected contaminated solvent. By way of example, the first illumination 21 may emit a red-coloured light when the pH of the collected contaminated solvent is low. Alternatively, the first illumination 21 may emit a blue-coloured light when the pH of the collected contaminated solvent is high. It is also preferred that the first illumination

21 emits a green-coloured light when the solvent in the tank 9 is substantially neutral, that is the solvent is freshly replenished in the tank 9.

Similarly, the second illumination 22 is provided to notify the user of the quality of the collected contaminated solvent in the tank 9 in terms of ionic material content. Particularly, this refers to the content of ionic concentration in the collected contaminated solvent. The exemplary working principle follows that solvent resistivity decreases as the ionic concentration in the collected contaminated solvent increases. Therefore, the second illumination 22 enables notification to the user to be aware of the purity level of the collected contaminated solvent. For example, the second illumination 22 may emit light of different colours corresponding to the solvent resistivity measurement of the collected contaminated solvent.

Essentially, respectively suitable coloured light-emitting diodes may be utilised as the first illumination 21 and second illumination 22. It is to be appreciated that the configuration of the first illumination 21 and the second illumination 22 is not restricted to the aforementioned and may be manipulated to fit into any desirable sequence and arrangement. In this manner, the light emitting state of the first illumination 21 and the second illumination 22 varies according to the quality of the collected contaminated solvent in the tank 9, so that the user may check and evaluate the operation state and performance of the air purifier apparatus 1. It is therefore advantageous that the user may also identify the degree of contamination of the room air through evaluation of the first illumination 21 and the second illumination 22 or whether the air purifier apparatus 1 is operating at a weaker performance or a stronger performance.

As depicted in FIG. 1, the third illumination 23 is provided to notify the user when it is necessary to discard the collected contaminated solvent in the tank 9 and to replenish fresh recirculating solvent therein. As such, the third illumination 23 may be configured to emit light of different colours or blinks in a different pattern so as to alert the user of

the time to discard the collected contaminated solvent in the tank 9 and when to replenish fresh recirculating solvent therein. In the aforementioned description, the replacement time of the solvent, the time to discard the collected contaminated solvent or replenish fresh recirculating solvent are displayed by illumination means, however the notification function may be performed in various ways such as visual display.

When solvent but not limited to water goes through a mass transfer between air containing noxious gases such as nitrogen oxides (NOx) and sulphur oxides (SOx), water becomes acidic wherein the pH value defers. If ozone is dissolved into the water in the packing area, the pH meter will indicate towards the alkaline range. Dissolution of toxic gas like hydrogen cyanide in the water will also cause the pH meter to point towards the alkaline range. When water which usually has a neutral pH value of 7 turns acidic or alkaline, it is an indication that the water would require replenishment. Solvent resistivity sensor to measure electrical resistance of the collected contaminated solvent. Pure water usually has 18.2 M'Q. Solvent but not limited to tap water typically has a resistivity range of 1000 ~ 5000 ' . When there is absorption of both acidic and alkaline gas, the effect will reduce the resistivity of the solvent or water. An indication with a logic controller to indicate resistivity, pH value and solvent level in the tank. The logic controller will indicate the required change of solvent or water from the pH or resistivity value.

The present disclosure includes as contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a degree of particularly, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangements of parts may be resorted to without departing from the scope of the invention.

Claims

1. An air purifier apparatus (1) comprising: a housing (2) having an air intake opening (3) through which contaminated air is introduced, and an air discharge opening (4) through which purified air is discharged; a blower fan (5) for drawing a stream of contaminated air to be purified through the housing (2); a recirculation pipe (7) for recirculating solvent within the housing (2) such that the solvent contacts with the contaminated air thereby producing contaminated solvent; a contact unit (8) configured to bring the recirculated solvent into contact with the contaminated air during recirculation; a tank (9) disposed at a lower portion of the housing (2) for collecting the contaminated solvent; and a solvent monitoring unit (10) adapted to monitor the quality of the contaminated solvent collected therein; wherein the solvent monitoring unit (10) comprises a pH sensor (11 ) to measure pH of the collected contaminated solvent, a solvent resistivity sensor (12) to measure electrical resistance of the collected contaminated solvent and an illumination indicator (13) coupled to the pH sensor (11) and the solvent resistivity sensor (12) for indicating pH and ionic material content of the collected contaminated solvent and replacement timing of the tank (9).

2. The apparatus according to Claim 1 , wherein the recirculation pipe (7) connects to the lower portion of the housing (2) in fluid communication with the tank (9) at one end (14) thereof and the other end (15) being connected at an upper portion of the housing (2).

3. The apparatus according to Claim 1 or 2, wherein the recirculation pipe (2) extends to pass into the upper portion of the housing (2) for recirculating the contaminated solvent from the tank (9) to the contact unit (8).

4. The apparatus according to any one of Claims 1 to 3, wherein the recirculation pipe (7) is provided with a pump (16) for pumping the contaminated solvent.

5. The apparatus according to any one of Claims 1 to 4, wherein the contact unit (8) is disposed between the other end (15) of the recirculation pipe (7) at the upper portion of the housing (2) and the air intake opening (3).

6. The apparatus according to any one of Claims 1 to 5, wherein the contact unit (8) is a packed bed having a plurality of passages through which the contaminated solvent flows downwardly and the purified air filtered from the packed bed passes upwardly.

7. The apparatus according to any one of Claims 1 to 6, wherein the packed bed is made from a metallic material of copper.

8. The apparatus according to any one of Claims 1 to 7, wherein the packed bed has a packing configuration selected from structured packing and random packing.

9. The apparatus according to any one of Claims 1 to 8, wherein the contact unit (8) comprises a solvent guide (17) provided on the lower surface of the contact unit (8) for directing the contaminated solvent into the tank (9).

10. The apparatus according to any one of Claims 1 to 9, wherein the pH sensor

(11) and the solvent resistivity sensor (12) are installed in the space in the tank

(9).

11. The apparatus according to any one of Claims 1 to 10, wherein the illumination indicator (13) is installed externally on the lower portion of the housing (2).

12. The apparatus according to any one of Claims 1 to 11, wherein the blower fan (5) is installed in contact with the housing (2) on top thereof.

13. The apparatus according to any one of Claims 1 to 12, wherein the blower fan (5) is connected to a motor (18) for operating thereof.