Technical Field The present invention relates to an air drain apparatus, and more particularly to, an industrial air drain apparatus and method which perfectly filters and drains moisture or oil contained in the air to be used for the industrial purpose to thereby provide a better quality of air, enhance a quality of product, and extend a life of air-use equipment.

Background Art As air can be used for cleaning products, generating power, and injecting raw materials, an industrial development requires air pressure equipment in various forms. Accordingly, the technology using air is being abruptly developed, in order for users to use it conveniently and diversely. However, ordinary air containing impurities such as moisture, oil, and other foreign matters, may not only damage the air-use equipment but also lower a quality of product contacting the air directly. Thus, it is the largest problem of removing impurities contained in the air. In order to solve the above conventional problems, there has been provided an air drain apparatus using a simple air expansion for extracting moisture in the air along an air path through which air flows. This has a limitation of removing impurities contained in the air. Accordingly, a system which cools air to thus extract moisture in the air has been developed. However, this has also a number of problems that moisture contained in the air is frozen so as for the system not only to function playing its own role, but also to fail to filter oil contained in the air.

Disclosure of the Invention To solve the above problems, it is an object of the present invention to provide an air drain apparatus for spraying air to an impeller, to thereby turn the impeller to simultaneously crush a lump of moisture or oil contained in the air, and for spraying the crushed air to a condensing housing having an excellent heat conductivity through a nozzle to thus recollect moisture and oil contained in the air, in a primary step, and then for dehydrating the air secondarily in a dehydrating housing, to thereby perfectly filter and drain impurities from the air to obtain a good quality of air to be supplied to an air-use place, and to resultantly protect products as well as air use equipment in a secondary step. It is another object of the present invention to provide an air drain method of performing a primary step of spraying air to an impeller, to thereby turn the impeller to simultaneously crush a lump of moisture or oil contained in the air, and of spraying the crushed air to a condensing housing having an excellent heat conductivity through a nozzle to thus .recollect moisture and oil contained in the air, in an air drain apparatus, and a secondary step of dehydrating the air secondarily in a dehydrating housing, to thereby perfectly filter and drain impurities from the air to obtain a good quality of air to be supplied to an air-use place, and to resultantly protect products as well as air use equipment. To accomplish the above object of the present invention, according to the present invention, there is provided an air drain apparatus comprising: a circular cover having an air inlet hole and an air outlet hole which are formed in both sides thereof respectively, and a coupler having a bearing which is formed at the center of the lower end thereof; a cylindrical crushing housing which is coupled with the coupler in the cover, having at least one ejection hole corresponding to the air inlet hole, a number of scattering holes which discharges air to the lower end thereof, and a power generation crushing chamber having a bearing formed at the center of the bottom surface thereof; a cylindrical condensing housing which is coupled with and adjacent the scattering holes in the outside of the crushing housing and made of a good heat conductivity material; a cylindrical dehydrating housing which is coupled with the lower end of the condensing housing to thereby form a dehydration chamber and which includes a number of discharging holes and a bearing; a rotational shaft to the upper end of which the bearing of the cover is supported, to the central portion of which the bearing of the crushing housing is supported, and to the lower end of which the bearing of the dehydration housing is supported; an impeller which is formed on the rotational shaft in the position of the ejection holes through which air is ejected in the crushing housing; a cylindrical dehydration vessel formed on the rotational shaft and having a number of dehydration holes in the inside of the dehydration housing, in which the dehydration vessel is rotated by the power obtained by the impeller; and a cylindrical main housing which is coupled with the cover to surround the crushing housing, the condensing housing and the dehydration housing, and which includes an annular counterflow prevention piece formed in the inner wall of the lower side thereof, and a drainage formed at the center of the lower end thereof. Preferably, the scattering holes which scatter and discharge air in the crushing housing are formed in the form of a horn whose inner side is narrow and outer side is wide. Preferably, an annular counterflow prevention piece is further coupled with the cover to surround the crushing housing, the condensing housing and the dehydration housing and formed in the inner wall of the lower side of the main housing. There is also provided an air drain method for removing impurities such as moisture and oil from air, the air drain method comprising: a crushing/power generation step which crushes impurities in the air and generates power; a primary separation step which primarily separates impurities from the air using condensation due to scattering; a secondary separation step which secondarily separates impurities from the air using a centrifugal force; and a recollection step which recollects impurities such as moisture and oil contained in the finally discharged air.

Brief Description of the Drawings The above and other objects and advantages of the present invention will become more apparent by describing the preferred embodiment thereof in detail with reference to the accompanying drawings in which: FIG. 1 is a cross-sectional view schematically showing an air drain apparatus according to the present invention; FIG. 2 shows an example of using the air drain apparatus according to the present invention; and FIG. 3 is a cross-section view showing scattering holes which are essential parts of the present invention.

Best Mode for Carrying out the Invention Hereinbelow, an air drain apparatus and method according to the present invention will be described with reference to the accompanying drawings . Referring to FIG. 1, an air drain apparatus according to the present invention includes a circular cover 10, a cylindrical crushing housing 20, a cylindrical condensing housing 30, a cylindrical dehydrating housing 40, a rotational shaft 50, an impeller 52, a cylindrical dehydration vessel 54, and a cylindrical main housing 60. The circular cover 10 includes an air inlet hole 11 and an air outlet hole 12 which are formed in both sides thereof respectively, and a coupler 13 having a bearing 10a which is formed at the center of the lower end thereof. The cylindrical crushing housing 20 is coupled with the coupler 13 in the cover 10, and includes at least one ejection hole 21 corresponding to the air inlet hole 11, a number of scattering holes 22 which discharges air to the lower end thereof, and a power generation crushing chamber 20a having a bearing 23 formed at the center of the bottom surface thereof. The cylindrical condensing housing 30 is coupled with and adjacent the scattering holes 22 in the outside of the crushing housing 20 and is made of a good heat conductivity material. The cylindrical dehydrating housing 40 is coupled with the lower end of the condensing housing 30 to thereby form a dehydration chamber 40a and includes a number of discharging holes 41 and a bearing 42. The upper end of the rotational shaft 50 is supported to the bearing 10a of the cover 10, the central portion of the rotational shaft 50 is supported to the bearing 23 of the crushing housing 20, and the lower end of the rotational shaft 50 is supported to the bearing 42 of the dehydration housing 40. The impeller 52 is formed on the rotational shaft 50 in the position of the ejection holes 21 through which air is ejected in the crushing housing 20. The cylindrical dehydration vessel 54 is formed on the rotational shaft 50 and includes a number of dehydration holes 54a in the inside of the dehydration housing 40, in which the dehydration vessel 54 is rotated by the power obtained by the impeller 52. The cylindrical main housing 60 is coupled with the cover 10 to surround the crushing housing 20, the condensing housing 30 and the dehydration housing 40, and includes a drainage 61 formed at the center of the lower end thereof. Here, the scattering holes 22 which scatter and discharge out air in the crushing housing 20 are formed in the form of a horn whose inner side is narrow and outer side is wide. The dehydration hole 54a in the dehydration vessel 54 can be formed of a horn shape. The discharging holes 41 formed in the lower end of the dehydration housing 40 may be separated into a drain hole formed on the wall side thereof and an air path formed at the side of the bearing 42. The air drain apparatus according to a preferred embodiment of the present invention will be described below in more detail. As shown in FIG. 2, an air drain apparatus according to the present invention is connected with an air compressor C which generates an air pressure in order to use air in an industrial field, via an air line 70. An air inlet hole 11 in the air drain apparatus according to the present invention is connected with the air line 70 formed at the side of the compressor C which generates the air pressure, that is, an air line 70a, and an air outlet hole 12 thereof is connected with the air line 70 formed at the side of using the air actually, that is, an air line 70b. As described above, when the air drain apparatus is completely installed, air compressed in the compressor C is sent via the air line 70. Accordingly, the air containing impurities such as moisture and oil is put into the air drain apparatus via the air inlet hole 11, and collides with an impeller 52 installed in a crushing chamber 20a via an ejection hole 21 corresponding to the air inlet hole 11. When the air has collided with the impeller 52, particles of the impurities such as moisture and oil contained in the air are crushed and simultaneously the air turns the impeller 52 to obtain a rotational force. The dehydration vessel 54 installed on the same rotational shaft 50 as that of the impeller 52 is rotated by the obtained rotational force. The air which has collided with the impeller 52 to generate power and to crush large particles of impurities are scattered to collide with the inner wall of the condensing housing 30 which is installed to surround the outer side of the scattering holes 22 whose each inner side is narrow and each outer side is wide and which are formed on the outer circumferential wall of the crushing chamber 20a. The scattered air whose pressure is abruptly lowered cools the inner wall of the condensing housing 30 and has the impurities such as moisture and oil contained in the air cohered on the inner wall of the condensing housing 30, to then flow down. Here, the water and oil cohered on the inner wall of the condensing housing 30 flow down along the inner wall of the condensing housing 30 separately from the air. The air from which the impurities such as moisture and oil are released out on the inner wall of the condensing housing 30 is inhaled again into the dehydration vessel 54 which rotates at high speed by the power obtained by the impeller 52. Referring to FIGs. 2 and 3, the air having inhaled into the dehydration vessel 54 is strongly released out via a number of dehydration holes 54a formed on the outer wall of the dehydration vessel 54 by the centrifugal force, and thus the remaining impurities such as moisture and oil are separated from the air again to then be cohered on the inner wall of the dehydration housing 40. Then, the fresh air obtained by removing the remaining moisture and oil from the air is discharged downwards in the main housing 60 via the discharging hole 41 in the lower side of the dehydration housing 40 and goes up between the main housing 60 and the dehydration housing 40, so as to be supplied to a place where fresh air is needed via the air line 70b. Here, the impurities containing the condensed water and oil in the condensing housing 30 flow down along the inner wall of the condensing housing 30 and added to the impurities such as the water and oil which have been condensed again on the inner wall of the dehydration housing 40, to then be collected on the bottom of the main housing 60. The impurities containing the water and oil which are collected on the bottom of the main housing 60 are discharged out via the drainage 61. The water which has flown downwards from the main housing 60 and flows out along the air which exits via a gap between the main housing 60 and the dehydration housing 40 is recollected by an annular counterflow prevention piece 62 which is annularly installed in the main housing 60 and flows down. The operation of the air drain apparatus according to the present invention will be described below according to an air flow. An air drain method for removing impurities such as moisture and oil from air, includes a crushing/power generation step which crushes impurities in the air and generates power, a primary separation step which primarily separates impurities from the air using condensation due to scattering, a secondary separation step which secondarily separates impurities from the air using a centrifugal force, and a recollection step which recollects impurities such as moisture and oil contained in the finally discharged air. Here, in the case that the specific description of the relevant known functions or structures are not necessary to make the gist of the invention clear in the specification, the detailed description thereof will be omitted. Terms to be described are selected to consider the functions of the invention, but they may be expressed in various forms according to producers ' intention or customs . Thus, the definition of the terms used should be based on the total description over the specification.

Industrial Applicability As described above, the air drain apparatus and method according to the present invention supplies air-use equipment which uses air for the industrial purpose with fresh air. Thus, the present invention protects all kinds of equipment which uses air to thereby extend a life of air-use equipment, and prevents impurities from being attached on the surface of a product which requires an air-use work, to thereby enhance a quality of product. Also, the present invention improves a working environment to thereby protect a worker's health.