WO2004099678A2

WO2004099678A2 - Drying type air purifying device with moisturing mist eliminator

Info

Publication number: WO2004099678A2
Application number: PCT/KR2004/000697
Authority: WO
Inventors: In-Seob Lee; Im-Kyun Byun; Jong-Hwa Kim; Sang-Kwun Lee
Original assignee: Dai Sung Environment Engineering Co., Ltd.
Priority date: 2003-03-26
Filing date: 2004-03-26
Publication date: 2004-11-18
Also published as: WO2004099678A3

Abstract

Disclosed is a dry type air purifying device with wet type mist eliminators. The dry type air purifying device with wet type mist eliminators according to the invention includes a wet purification unit having wet type mist eliminators, and a dry type purification unit having ceramic filters, which comprise incalcinable coating agent layer and a calcium hydroxide layer. The dry type air purifying device with wet type mist eliminators according to the invention is an air purifying system capable of cleanly purifying the composite materials polluted in the air by first filtering polluted water or oil in the air including particle-like materials, reaction materials such as acid or alkaline gas reacted with chemicals, or harmful gas dissolved into water or oil, and secondly purifying micro-dust, dioxin, smoke, volatile organic chemicals (VOC), water insoluble gas, offensive odor, germs, etc.

Description

DRYING TYPE AIR PURIFYING DEVICE WITH MOISTURING MIST ELIMINATOR

Technical Field The invention relates to a dry type air purifying device with wet type mist eliminators for purifying simultaneously fine particulates, dioxin, smoke, volatile organic compounds (VOCs), water insoluble gas, offensive odor, germs, etc. in a dry type purification unit, and in particular, to an air purifying device applicable to industrial sites, which emit multi-pollutants harmful to a human body such as fine particulates containing dioxin, offensive odor, VOC, smoke, carbon dioxide, sulfur oxides, nitrogen oxides, hydrogen chloride, etc.

BACKGROUND ART

The conventional art in the industrial field has failed to apply wet type scrubbers to the front end of a bagfilter, which is a facility to control air pollutants, because if any wet type facilities exist in the front end, moisture penetrate to wet the bagfilter downstream, and drastically increase the pressure drop of the bagfilter. As a result, the bagfilter needs to be frequently exchanged, thereby deteriorating workability and rising maintenance costs. Hence, the wet type reactor before bagfilter is never used as means to eliminate gas and dust. Rather, spray drying scrubber having lower efficiency than the wet scrubber has mainly been used.

Disclosure of Invention

It is, therefore, an object of the invention to provide a dry type air purifying device with mist eliminators having a maximum air purifying efficiency and filters with almost permanent life by constructing air purification devices with ceramic bagfilters and a plurality of eliminators as well as with demisters in front thereof.

To achieve the above object, there is provided a dry type air purifying device with wet type mist eliminators, the device comprising: a duct installed in a work site for flowing of air; an exhaust fan provided in the duct for sucking air into the duct and exhausting the same; a wet type purification unit having a plurality of eliminators on a pipeline of the duct for filtering and purifying both liquid and solid particles in the air flown into the duct, and waste sorbents reacted with acid gases, or harmful gas dissolved into water or liquid solution; and a dry type purification unit including a plurality of filters composed of an ceramic coating layer and a calcium hydroxide layer provided on a pipeline of the duct spaced from the wet type purification unit for eliminating micro-dust other than the air first purified by the wet type purification unit, dioxin, smoke, NOC, water insoluble gas, offensive odor or germs, etc. and for easily detaching the filters.

The wet type purification unit first purifies particulate in the air flown into the duel, reaction products reacted with acid gases, or harmful gas dissoluble into water or liquid solution. The calcium hydroxide layer in the dry type purification unit secondly purifies micro-dust, dioxin, smoke, NOC, water insoluble gas, offensive odor or germs, etc Thus, the invention has advantageous effects of completely purifying polluted air and easy detachment of filters.

Brief Description of Drawings

Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a block diagram illustrating an air purifying device according to the invention;

Fig. 2A is a front view of the eliminators in the air purifying device according to the invention;

Fig. 2B is a top-plan view of the eliminators in the air purifying device according to the invention;

Fig. 2C is a side view of the eliminators in the air purifying device according to the invention; Fig. 2D is a partially enlarged view of the eliminators in the air purifying device according to the invention;

Figs. 3 to 12 are views of a wet type purification unit in the air purifying device according to diverse best modes for carrying out the invention.

Fig. 13 is a side view of a quantitative pulverization supply means in the air purifying device according to the invention;

Fig. 14 is a top-plan view of Fig. 13; and

Fig. 15 is a cross-sectional view illustrating filters of a dry type purification unit in the air purifying device according to the invention. Best Modes for Carrying out the Invention

Best modes for carrying out the invention will now be described with reference to the accompanying drawings. In the following description, same drawing reference numerals are used for the same elements even in different drawings. The matters defined in the description are nothing but the ones provided to assist in a comprehensive understanding of the invention. Thus, it is apparent that the present invention can be carried out without those defined matters. Also, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Fig. 1 is a block diagram illustrating an air purifying device according to the invention, and Fig. 15 is a cross-sectional view illustrating a filter of a dry type purification unit in the air purifying device according to the invention.

Referring to Figs. 1 and 15, the air purifying device A according to the invention mainly comprises a duct 100 for flowing of air, a wet type purification unit having first and second eliminators 260, 270 and demisters 280, a dry type purification unit including a coating layer 340a and a plurality of filters 340 composed of ceramic calcium hydroxide layers, and an exhaust fan 130 installed on the duct 100.

The wet type purification unit 200 provided on the duct 100 is constructed to filter the particle-like materials in the air sucked and polluted in the duct 100, reaction materials such as acid gas reacted with chemicals, and harmful gas dissolved into moisture and water.

The wet type purification unit 200 comprises a first eliminator 260 and a second eliminator 270 layered on a pipeline of the duct 100. The first eliminator 260 and the second eliminator 270 comprise contact units 262, 272 and drain units 264, 274 perpendicularly bent from the respective ends of the contact units 262, 272.

Meanwhile, the eliminators 260, 270 installed as described above have upward or downward drains at each one end thereof so as to be repeatedly alternated.

Demisters 280 are provided at respective ends of the eliminators 260, 270 to filter moisture in the polluted air. The wet type purification unit 200 includes spray means B for spraying water or liquid solution (hereinafter, inclusively referred to as the "water") mixed with chemicals, which are reacted with gas, toward the polluted air flown into the wet type purification unit so that the sprayed moisture can adsorb the particle-like polluted materials such as dust mixed with the polluted air as well as the reaction materials such as acid gas reacted with chemicals. Once becoming voluminous, the absorbed materials are eliminated due to inertia, centrifugal force or collision gravity, etc.

The spray means B comprises an oil-water separation tub 220 having at least one or more tanks for storing water, a pump 230 connected to the oil-water separation tub 220 for exhausting water in the oil-water separation tub 220 and delivering the same, a supply tube 240 connected to the pump 230 for flowing of water, a plurality of spray nozzles 242 provided in the supply tube 240 for spraying water toward air flown into the eliminators 260, 270, and a recovery tube 250 for recovering water sprayed by the spray nozzles 242 to the oil-water separation tub 220. Here, the water sprayed as described above moves in the state of adsorbing the polluted materials in the air, and flows down to drain units 264, 274 when in contact with contact units 262, 272 of the eliminators, as shown in Fig. 2. Thus, the recovery tube 250 is preferably installed at lower portions of the eliminators 260, 270 and the demisters 280. Meanwhile, a first checking window 210 is installed on the duct 100 between the spray nozzles 242 and the eliminators 260, 270 so that a user can easily check the Cf spraying status of water sprayed from the spray nozzles 242 with his or her naked eyes. A second checking window 110 is installed on the duct 100 at rear sides of the demisters 280 so that the user can easily check flow of the first purified air and existence or non- existence of moisture.

Chemicals supply means D is provided in the oil-water separation tub 220 of the spray means B.

The chemicals supply means D comprises a pH rod 298 soaked at one side of the oil-water separation tub 220, a pH meter 296 connected to the pH rod 298 and controlled by a control unit 400, and a chemicals supply pump 292 for supplying chemicals within a chemicals tank 290 to the oil-water separation tub 220 through a chemicals supply tube 294 through operation of the pH meter 296.

The oil-water separation tub 220 of the spray means B further comprises waste water disposal means E in addition to the chemicals supply means D. The waste water disposal means E comprises a sludge recovery pump 600 connected to the oil-water separation tub 220 via a sludge recovery tube 610 for exhausting sludge such as particle-like materials or reaction materials filtered by the wet type purification unit 200 from the oil-water separation tub 220, a concentration tub 620 for storing the sludge exhausted and flown from the oil-water separation tub 220 by the sludge recovery pump 600, a dehydrator pump 630 connected to the concentration tub 620 for exhausting the sludge stored in the concentration tub 620, and a dehydrator 640 for supplying the dehydrated water to the oil-water separation tub 220 through a water supply tube 650. Meanwhile, the particle-like materials filtered by the wet type purification unit

200 as described above and the reaction materials such as acid gas reacted with chemicals are precipitated at a lower portion of the oil-water separation tub 220 so that a high quality water within the oil -water separation tub 220 can be circulated. At the same time, the precipitated materials are flown into the waste water disposal means E so as to be dehydrated, dried and disposed.

A dry type purification unit 300 is provided at a rear side of the duct 100, which is spaced from the wet type purification unit 200.

The dry type purification unit 300 comprises a housing 310 connected to the duct 100. Inside of the housing is composed of a coating agent layer 340a first coated with a coating agent, which is incalcinated even in contact with water and has a specific gravity of 0.12ton/m². A plurality of ceramic filters 340, which has a calcium hydroxide layer 340b coated with calcium hydroxide and formed on the coating agent layer 340a, are installed on an exhausting path of the housing 310. Since the filters 340 are installed on an exhausting path of the housing 310, all the air flown into the air purifying device A is exhausted through the ceramic filters 340 having the calcium hydroxide layer 340b and the coating agent layer 340a.

An incalcinable coating agent and a baffle 330 are formed at a size equivalent to the filters 340 on a front side of the filters 340, i.e., at one end thereof facing the wet type purification unit 200, to prevent the coating agent and calcium hydroxide from directly flowing toward the filters 340 within the housing 310 and to allow the coating agent and the calcium hydroxide to evenly flow when coating the calcium hydroxide on the filters 340. Thus, the coating agent first flown into the housing 310 and the calcium hydroxide secondly flown into the housing 310 are evenly dispersed to a lower portion of the housing 310 by the baffle 330, and flown toward the filters 340 by the exhaust fan 130. The coating agent and the calcium hydroxide are evenly adsorbed and coated on each filter 340.

Assuming that a pressure of approximately 360mmAq is laid on the duct 100 by the exhaust fan 130, more than 2L/m² of the incalcinable coating agent is thrown onto the filters 340 so as to be first adsorbed and coated on the coating layer 340a under this pressure. Calcium hydroxide of more than IL/m² is secondly thrown onto the filters 340 so as to be coated on the coating layer 340a.

The incalcinated coating agent first coated on the filters 340 of the dry type purification unit as described above is neutral and has a low specific gravity of 0.12ton/m² and a porosity of 85-95%. The coating agent is not calcinated even after absorption of moisture. Such coating agent is composed of SiO , which is a drying/desiccating agent; A1 0₃, which is an adsorbing/dehydrating agent; K₂O, which is a catalyst reacted with water; Na₂O, which is a reducing/catalytic agent; CaO, which is a moisture collecting/drying agent, and Fe O , which is a moisture adsorbent.

The first coating agent of the above composition has a following mixture ratio as shown in Table 1 below: 75.5 t%~79.5wt% of SiO₂; 10.9wt%~12.9wt% of Al₂O₃; 5.4wt%~6.4wt% of K₂O; 3.1wt%~3.7wt% of Na₂O; 0.8wt%~1.0wt% of CaO; and 0.3wt%~0.5wt% of Fe₂O₃.

Table 1 "Com osition Mixture Ratio of the Coatin A enP

The coating agent and the calcium hydroxide are consecutively thrown into the housing 310 at lower portions of the filters 340 when adsorbing and coating the coating agent and the calcium hydroxide on the filters 340 with the driving exhaust fan 130. More than 2L/m² of the coating agent needs to be thrown into the housing 310 so that the coating agent can be coated on the filters with regular thickness. Thereafter, more than IL/m² of the calcium hydroxide needs to be thrown into the housing 310 for coating on the coating agent layer 340a and forming the calcium hydroxide layer 340b to be ceramic.

Here, the coating of the filters 340 should take a first step of coating the incalcinable coating agent on the filters and a second step of coating the calcium hydroxide on the first-coated coating agent layer 340a.

The calcium hydroxide layer 340b is formed by mixing at least one or more materials of calcium hydroxide, active carbon, silica gel, dextrin, bentonite, alumina, diatomite, zeolite, ferrite, powder or ceramics. The coating agent and the calcium hydroxide thrown into the duct 100 as described above are supplied by quantitative pulverization supply means F, which is provided on the duct 100. Dust exhaust means is constructed at a lower portion of the housing 310 of the dry type purification unit 300.

Here, the quantitative pulverization supply means F may be substituted by a non-powered throw-in hopper, etc.

The dust exhaust means may be any means if capable of exhausting the air inside of the housing 310 to outside. It is more preferable, however, to constitute the dust exhaust means with a rotary valve 350 capable of opening or closing the tube path alone of the housing 310 without generating any particular ventilation force. Accordingly, the dust exhaust means comprising the housing 310, which has a gradually narrowing inner diameter at lower portions of the filters 340, and the rotary valve 350 provided on a bottom point of the housing 310 realizes easy exhaustion of the dust.

The quantitative pulverization supply means F is installed by fixing a bracket 570 at one side of the housing 310 of the dry type purification unit 300 and a frame 560 at the bracket 570.

A hollow screw housing 500 comprising a big diameter unit 500a, a taper unit 500a, and a small diameter unit 500c is installed on the frame 560.

A throw-in tube 510 for throwing the coating agent and the calcium hydroxide into the screw housing 500 and an exhaust tube 520 for exhausting the same are formed in the big diameter unit 500a and the small diameter unit 500c of the screw housing 500, respectively, so as to be connected to each other. It is preferable to form the exhaust tube 520 to be connected to the duct 100 at one end thereof, and to install a cover at an upper portion of the throw-in tube 510 so as to be opened or closed. A transfer screw 530 is installed to transverse the big diameter unit 500a and the small diameter unit 500c within the screw housing 500. A pulverization screw 534 is formed around an external periphery of the screw housing 500 to pulverize the coating agent and the calcium hydroxide.

A chain sprocket 536 is formed at one end of the transfer screw 530 with external protrusion of the screw housing 500. A motor 540 having a chain sprocket 542, which is connected to the chain sprocket 536 of the transfer screw 530 to convey power through a chain 550 in the middle thereof, is provided at one side of the frame 560. Detaching means C is provided in the dry type purification unit 300 to detach the coating agent, which has been polluted due to continuous process of purification, from the filters 340. If the calcium hydroxide absorbs polluted materials and moisture in the air, a calcium hydroxide film is formed to elevate pressure within an airflow path thereof by blocking the same before the pressure within the filters 340 is elevated. As a consequence, if a normal pressure of a differential pressure gauge 390, which will be described later, becomes higher than that at the time of coating, an alarm generation unit 380, which will be described later, is operated by the differential pressure gauge 390. Detaching process is then performed by the detaching means C for about an hour. Since the coating agent, which is incalcinated even after absorption of moisture, is coated on the filters 340, the process of detaching the coating agent and the calcium hydroxide is smoothly performed, thereby leaving unpolluted filters 340 only.

The detaching means C comprises a compressor 370 for storing compressed air, an air distribution pipe 360 for supplying compressed air, which has been discharged from the compressor 370, spray nozzles 362 for spraying the compressed air supplied to the air distribution pipe 360 toward the filters 340, and a control unit 400 for controlling the respective constitutional elements above.

The differential pressure gauge 390 for detecting differential pressure of the ceramic filters 340 caused by the exhaust fan 130 as well as the alarm generation unit 380 controlled by a control unit 400 in accordance with a pressure value detected from the differential pressure gauge 390 are provided at a rear side of the detaching means C, i.e., on the housing 310 between the dry type purification unit 300 and the exhaust fan 130. The alarm generation unit 380 generates alarming light and alarming sound by means of a lamp and a speaker.

A third checking window 320 is installed so as to be opened or closed in the housing 310, which is spaced from the filters 340 of the dry type purification unit 300, by means of hinge means to check the degree of pollution of the filters 340.

Operation of the air purifying device constructed as above will now be described with further detail.

Before operating the air purifying device A, the incalcinable coating agent having a specific gravity lighter than that of silica gel, active carbon, diatomite or calcium hydroxide, etc. is first coated on the filters 340 provided on the dry type purification unit 300. The calcium hydroxide is secondly coated on the coating agent layer 340a to form the calcium hydroxide layer 340b. The ceramic filters 340 are formed as a consequence.

The reason for first coating the coating agent on the filters 340 and secondly coating the calcium hydroxide on the coating agent layer 340a as described above is to filter smoke, micro-dust, offensive odor or germs, etc. with a calcium hydroxide film by allowing the calcium hydroxide to absorb moisture in the air. The first coating is to ease detachment of the coating agent and the calcium hydroxide in the detaching process by the detaching means C in addition to the filtering purpose.

When coating the coating agent on the filters 340 as described above, the exhaust fan 130 installed on the rear side of the duct 100 is first operated. Thereafter, more than 2L/m² of the neutral, incalcinated and powered coating agent, which has a mixed composition of SiO , Al₂O₃ K₂O, Na₂O, CaO and Fe₂O₃ with a low specific gravity of 0.12ton/m² and a porosity of 85-95%, is thrown into the duct 100 by means of the quantitative pulverization supply means F provided on the duct 100. Secondly, more than IL/m² of the calcium hydroxide is thrown into the duct 100 to coat the calcium hydroxide layer 340b on the coating agent layer 340a. The ceramic filters 340 are formed as a consequence. If the pressure is elevated up to 150mmAq as demanded by the user, the throwing process of the calcium hydroxide is terminated.

Supply of the coating agent and the calcium hydroxide as described is continuously performed by the quantitative pulverization supply means F.

To be specific, if power source is supplied to the motor 540 through operation of the quantitative pulverization means F, the motor 540 operates the chain sprocket 542 thereof. The chain sprocket 536 on the transfer screw 530, which is connected to the chain sprocket 542 via the chain 550, is subsequently operated. The transfer screw

530 is rotatably operated within the screw housing 500 as a consequence.

If the coating agent or the calcium hydroxide is thrown into the throw-in tube 510 of the screw housing 500, the coating agent or the calcium hydroxide is finely pulverized by the pulverizing screw 534 on the transfer screw 530. The pulverized coating agent or the calcium hydroxide is transferred by the transfer screw 530 toward the small diameter unit 500c via the big diameter unit 500a and the taper unit 500b. The pulverized coating agent or the calcium hydroxide is continuously supplied into the duct 100 through the exhaust tube 520.

In particular, even the calcium hydroxide easily calcinated by moisture can be efficiently pulverized and continuously supplied into the duct 100 through fine pulverization in the shape of powder. The coating agent and the calcium hydroxide supplied into the duct 100 as described are flown into the housing 310 of the dry type purification unit 300 through the duct 100. The coating agent and the calcium hydroxide flown into the housing 310 cannot be directly flown toward the filters 340 due to the baffle 330 provided at the front end portion of the housing 310. Therefore, the coating agent and the calcium hydroxide detour the baffle 330 and are spattered to the inner lower portion of the housing 310.

Thereafter, the coating agent and the calcium hydroxide spattered as described above flow to an upper portion of the housing 310 and into the filters 340 installed on the exhausting path of the housing 310. The coating agent and the calcium hydroxide are evenly coated to eliminate micro-dust, smoke, NOC, water insoluble gas, offensive odor or germs, etc.

Here, a pressure of 150mmAq is laid on the ceramic filters 340 by the exhaust fan 130. Coating thickness of the coating agent layer 340a and the calcium hydroxide may be variable depending on the pressure laid on the filters 340 that can be varied by a capacity of the exhaust fan 130.

Thereafter, the user throws water and chemicals into the chemical tank 290, and operates the pH meter 296 and the chemicals supply pump 292 in accordance with the pH concentration detected by the pH rod 298. The user then operates the pump 230 in the wet type purification unit 200 to spray the water in the oil-water separation tub 220 by means of the supply tube 240 and the spray nozzles 242. If any abnormal water spraying status is detected through the first checking window, the user takes necessary measures.

Otherwise, the user starts to work in his plant of an industrial site. The air generated and polluted in the plant is flown into the duct 100 through operation of the exhaust fan 130.

When flown into the wet type purification unit, the polluted air flown into the duct 100, e.g., particle-like materials, moisture or harmful gas, are delivered by the pump 230 from the oil-water separation tub 220, and absorbed by water mixed with chemicals, which are sprayed through the supply tube 240 and the spray nozzles 242. The absorbed materials are then reacted with the chemicals mixed with the water.

The sprayed water, the particle-like polluted materials, moisture and the reaction materials flow downward when in contact with the contact units 262, 272 of the first and second eliminators 260, 270 while passing the same. The down-flown particle-like materials, moisture and reaction materials then flow into the recovery tube

250 via the drain units 264, 274 at one end of the contact units 262, 272.

Moisture in the air, which has passed through the first and second eliminators 260, 270, is filtered while passing the demisters 280. The filtered moisture is flown into the recovery tube 250. As described above, the moisture flown into the recovery tube 250 is flown into the oil-water separation tub 220 again so as to be circulated.

Meanwhile, the sludge such as the particle-like materials or reaction materials precipitated within the oil-water separation tub 220 by the wet type purification unit 200 is exhausted through the sludge recovery tube 610. The exhausted sludge is flown into the concentration tub 620 so as to be stored. The sludge stored in the concentration tub 620 is exhausted one again by the dehydration pump 630, and flown into the dehydrator 640 so as to be dehydrated.

Here, the dehydrated water is supplied to the oil-water separation tub 220 again via the water supply tube 650. The dehydrated sludge is dried and disposed. As described above, the particle-like polluted materials such as dust in the air, the reaction materials, moisture as well as soluble harmful gas are eliminated by the wet type purification unit 200. Once after the moisture is first eliminated in the above process, the micro-dust, smoke, dioxin, water insoluble gas, offensive odor or germs, etc. are flown into the dry type purification unit 300. Meanwhile, airflow and existence or non-existence of moisture in the air passed through the wet type purification unit 200 can be easily checked by the user through the second checking window 110.

The air first purified as described above and flown into the dry type purification unit 300 is flown into the housing 310 by the exhaust fan 130. To be specific, the air flown into the dry type purification unit 300 cannot be directly flown toward the filters

340 due to the baffle 330 but are evenly spattered to an inner lower portion of the housing 310 by detouring the baffle 330. Thereafter, the air then passes the filters 340 through the calcium hydroxide layer 340b comprising the calcium hydroxide at an upper portion of the housing 310 and the incalcinable coating agent layer 340a in order. At this stage, the rotary valve 350, which is dust exhaust means, is in closed state, thereby preventing leakage of the air.

The polluted materials in the air passing through the filters 340, e.g., residual moisture, micro-dust, smoke, vapor, NOC, water insoluble gas, offensive odor or germs, etc., are once again filtered and purified, by the ceramic filters 340 comprising the incalcinable coating agent layer 340a with even coating and the calcium hydroxide layer 340b composed of the calcium hydroxide. The purified and clean air is exhausted outside through the exhaust fan 130 via the duct 100.

Because of the continuous purifying process, the coating agent coated on the filters 340. If the air purifying device is continuously operated for 24 hours and if 5 days elapse, the pressure of the differential pressure gauge 390 normally becomes higher than that at the time of coating. An available measure in that case is to operate the alarm generation unit 380 to activate the exhaust fan and open the rotary valve 350 under the state of not leading in the polluted materials in the air. Then, the detaching means C can be operated to detach the coating agent, which has adsorbed alien materials, from the filters 340 for about an hour and eliminate the coating agent. Thereafter, the detaching means C may be ceased to operate, and an incalcinable new coating agent and new calcium hydroxide may be thrown into the housing 310 for recoating and continuous operation. If the air purifying device is not continuously operated for 24 hours, the detaching process may be performed by operating the alarm generation unit 380 with the differential pressure gauge 390. Then, operate the pump 230 as it is, while stop operating the exhaust fan. Once the wet type purification unit is ceased to operate as a consequence, the detaching process can be performed for 40 minutes. To be specific, the rotary valve 350 and the detaching means C are respectively opened and operated. The coating agent, which has adsorbed alien materials, is detached and eliminated from the filters 340. On the next day, an incalcinable new coating agent and new calcium hydroxide are thrown into the housing 310 in order to form a new coating agent layer 340a and a calcium hydroxide layer 340b. Depending on kinds and concentration of the polluted materials, diatomite, zeolite or active carbon may be used as the second coating agent.

The detaching means C is operated as the user manipulates the control unit 400. Once the detaching means C is operated, the compressed air generated from the compressor 370 is supplied to the air distribution tube 360 along a predetermined pipeline.

The compressed air supplied as above is sprayed toward the filters 340 at a high pressure of 7Kgf/cm² through the plurality of spray nozzles 362 provided in the air distribution tube Thus, the coating agent adsorbed and coated on the filters 340 is detached therefrom so as to be exhausted outside through the rotary valve 350 opened at a lower portion of the housing 310.

As described above, the differential pressure gauge 390 can detect the state such that the differential pressure of the ceramic filters 340 between the dry type purification unit 300 and the exhaust fan 130 becomes higher than that at the time of coating due to blocking of the filters 340 when performing the coating or purifying process by the coating agent. Subsequently, the control unit 400 controls the alarm generation unit 380 to operate the alarming light or alarming sound. As a result, the user an easily check normal or abnormal operation of the air purifying device A. Meanwhile, Figs. 3 to 12 illustrate diverse constructions and structures of the wet type purification unit 200 comprising the spray means B, the first and second eliminators 260, 270 and the demisters 280. The wet type purification unit may be embodied in any shape.

Industrial Applicability

The air purifying device A according to the invention is capable of cleanly purifying and exhausting the polluted air by means of the wet type purification unit 200 and the dry type purification unit 300.

As described above, the air purifying device according to the invention first purifies polluted water or oil in the air including particle-like materials, reaction materials such as acid gas reacted with chemicals, or harmful gas dissolved into water or oil in a wet type purification unit, and secondly purifies micro-dust, dioxin, smoke, NOC, water insoluble gas, offensive odor, germs, etc. in a dry type purification unit. Therefore, the air purifying device according to the invention has advantageous effects of purifying and exhausting complicatedly polluted air as an air purifying system as well as of elongating the life span of the filters in the dry type purification unit on an almost permanent basis.

Further, the air purifying device according to the invention has another advantageous effect of purifying the polluted materials in the air generated due to high temperature even without expensive facilities, such as a heat exchanger, etc., if metallic filters available at high temperature are employed to the facilities for exhausting polluted materials in the air as described above with reference to the best modes for carrying out the invention.

While the invention has been described with reference to the best modes for carrying out the invention, it is not to be restricted by the best modes but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the best modes without departing from the scope and spirit of the invention.

Claims

What Is Claimed Is:

1. A dry type air purifying device with wet type mist eliminators, the device comprising: a duct installed in a work site for flowing of air; an exhaust fan provided in the duct for sucking air into the duct and exhausting the same; a wet type purification unit having a plurality of eliminators on a pipeline of the duct for first filtering and purifying polluted materials and harmful gas in the air flown into the duct; and a dry type purification unit having filters on the pipeline of the duct, which is spaced from the wet type purification unit for secondly purifying the air first purified by the wet type purification unit.

2. The dry type air purifying device of claim 1, further comprising a plurality of demisters provided at respective ends of the plurality of eliminators in the wet type purification unit.

3. The dry type air purifying device of claim 1 or 2, wherein the wet type purification unit comprises spray means for spraying water or oil in the polluted air to filter the polluted materials, the spray means including: an oil-water separation tub having at least one or more tanks for storing water or oil; a pump connected to the oil- water separation tub for exhausting water or oil within the oil-water separation tub and delivering the same; a supply tube connected to the pump for flowing of water or oil; a plurality of spray nozzles provided on the supply tube for spraying water or oil toward the air flown into the plurality of eliminators; and a recovery tube for recovering the water or oil sprayed by the spray nozzles to the oil-water separation tub.

4. The dry type air purifying device of claim 3, wherein the oil-water separation tub in the wet type purification unit comprises chemicals supply means, which includes a pH rod soaked in the oil-water separation tub; a pH meter connected to the pH rod and controlled by a control unit; and a chemicals supply pump for supplying chemicals within a chemicals tank to the oil-water separation tub through operation of the pH meter.

5. The dry type air purifying device of claim 4, wherein the oil-water separation tub of wet type purification unit comprises waste water disposal means, including: a sludge recovery pump connected to the oil-water separation tub for exhausting sludge filtered by the wet type purification unit from the oil-water separation tub; a concentration tub for storing the sludge exhausted by the sludge recovery pump and flown thereto; a dehydration pump connected to the concentration tub for exhausting the sludge stored in the concentration tub; and a dehydrator for dehydrating the sludge flown by the dehydration pump, and re-supplying the dehydrated water to the oil-water separation tub.

6. The dry type air purifying device of claim 3, further comprising a plurality of checking windows provided on the duct between the spray nozzles 242 and the plurality of eliminators and at rear sides of the plurality of demisters, for checking the spraying status of water or oil and flow of the first purified air.

7. The dry type air purifying device of claim 1, wherein the plurality of filters in the dry type purification unit have a mixed composition of SiO₂, which is a drying/desiccating agent; A1₂0₃, which is an adsorbing/dehydrating agent; K₂O, which is a catalyst reacted with water; Na₂O, which is a reducing/catalytic agent; CaO, which is a moisture collecting/drying agent, and Fe₂O₃, which is a moisture adsorbent, and a coating gent, .which is neutral and has a low specific gravity of 0.12ton/m² with a porosity of 85-90%, is first coated to form a coating agent layer, and calcium hydroxide is secondly coated on the coating agent layer to form a calcium hydroxide layer.

8. The dry type air purifying device of claim 7, wherein the composition of the coating agent constituting the coating agent layer 340a has a mixture ratio of 75.5wt%~79.5wt% of SiO₂; 10.9wt%~12.9wt% of Al₂O₃; 5.4wt%~6.4wt% of K₂O; 3.1wt%~3.7wt% ofNa₂O; 0.8wt%~1.0wt% of CaO; and 0.3wt%~0.5wt% ofFe₂O₃.

9. The dry type air purifying device of claim 7 or 8, wherein the calcium hydroxide layer has a mixed composition of at least one or more materials from calcium hydroxide, active carbon, silica gel, dextrin, bentonite, alumina, diatomite, zeolite, ferrite, powder or ceramics.

10. The dry type air purifying device of claim 1 or 7, wherein the duct between the wet type purification unit and the dry type purification unit includes a quantitative pulverization supply means for pulverizing and supplying the coating agent and the calcium hydroxide coated on the plurality of filters, the quantitative pulverization supply means comprising: a screw housing installed at one side of the duct and having a big diameter unit, a taper unit and a small diameter unit for throwing the coating agent and the calcium hydroxide into the big diameter unit and supplying the pulverized coating agent and the calcium hydroxide to the duct through the small diameter; a transfer screw and a pulverizing screw for pulverizing and transferring the coating agent and the calcium hydroxide in the screw housing; and a motor for driving the transfer screw and the pulverizing screw.

11. The dry type air purifying device of claim 10, further comprising a baffle for preventing the air, the coating agent and the calcium hydroxide flown into the housing of the dry type purification unit from directly flowing toward the plurality of filters and for even spattering of the air, the coating agent and the calcium hydroxide.

12. The dry type air purifying device of claim 1 or 7, wherein the housing in the dry type purification unit comprises a rotary valve for exhausting dust.

13. The dry type air purifying device of claim 7, wherein the dry type purification unit includes detaching means for detaching the coating agent and the calcium hydroxide polluted due to the purifying process from the plurality of filters, the detaching means comprising: a compressor for storing compressed air; an air distribution tube for supplying the compressed air discharged from the compressor; a plurality of spray nozzles provided on the air distribution tube for spraying the compressed air toward the plurality of filters; and a control unit for controlling the respective constitutional elements of the detaching means.

14. The dry type air purifying device of claim 1, wherein the duct includes: a differential pressure gauge provided on the housing between the dry type purification unit and the exhaust fan for detecting differential pressure of the plurality of filters; and an alarm generation unit controlled by the control unit in accordance with a pressure value detected by the differential pressure gauge.