Air shower apparatus
An air shower for removing a particle from an object by blowing air to the object which includes at least one first outlet for discharging the air from the at least one first outlet toward at least a portion of the object so that a flow axis of the air flowing out of the at least one first outlet is swung frequently and alternately in a first swingable direction, and at least one second outlet for discharging the air from the at least one second outlet so that a flow axis of the air flowing out of the at least one second outlet is swung frequently and alternately in a second swingable direction which is different from the first swingable direction. The first swingable direction and the second swingable direction extend so as to be non-parallel to one another and to intersect one another.
This application is a continuation of U.S. application Ser. No. 11/075,794, filed Mar. 10, 2005, which is a continuation of U.S. application Ser. No. 10/382,834, filed Mar. 7, 2003, and is copending with U.S. application Ser. No. 10/873,185, filed Jun. 23, 2004, which is a continuation of U.S. application Ser. No. 10/382,834, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTIONThe present invention relates to an air shower apparatus for blowing an air toward an object.
JP-A-10-52654 discloses a pulsed air jet generator in which a passage or opening area of the air is alternately open-and-closed or increased-and-decreased by a mechanical shutter or flow restriction throttle to generate a pulsed air jet.
JP-A-06-193958 discloses an air blowing device with an air flow direction deflector in which deflector a member is movable in a direction perpendicular to an air flow direction to adjust directing a part of the air to be applied to a directing surface on which Coanda effect is obtained to emphasize a deflection of the air flow by the directing surface so that another part of the air is prevented from being deflected by the directing surface and the part of the air is deflected strongly by the directing surface.
JP-U-63-165437 and JP-U-62-76848 disclose air shower devices in each of which an air injection nozzle is swung to deflect the air flow.
BRIEF SUMMARY OF THE INVENTIONAn object of the present invention is to provide an air shower apparatus for blowing an air, in which apparatus a flow direction of the air is capable of being deflected frequently without a movable member contacting the air to be deflected or extending through the air to be deflected.
An air shower apparatus for blowing an air, comprises, an inlet duct for guiding the air so that the air flowing out from the inlet duct is directed along a first flow axis of the air, and a variable condition area adapted to communicate fluidly with the air flowing out from the inlet duct at at least one side in a direction perpendicular to the first flow axis, to generate a fluctuation at the variable condition area in at least one of a pressure to be applied to the air flowing out from the inlet duct at the variable condition area and a mass flow rate of a supplemental air to be applied from the variable condition area onto the air flowing out of the inlet duct in a fluctuating direction oblique to the first flow axis so that a second flow axis of the air passing the variable condition area is frequently deflected from the first flow axis by the fluctuation in at least one of the pressure and the mass flow rate in the fluctuating direction.
Since the second flow axis of the air passing the variable condition area is frequently deflected from the first flow axis by the fluctuation in at least one of the pressure and the mass flow rate in the fluctuating direction applied from the variable condition area at the at least one side in the direction, a flow direction of the air can be deflected frequently without a “movable” member contacting the air to be deflected or extending through the air to be deflected.
It is preferable for enlarging the deflection of the second flow axis by utilizing Coanda effect that the air shower apparatus further comprises an outlet duct arranged at a downstream side with respect to the variable condition area in an air flow direction from the inlet duct toward the variable condition area, the outlet duct includes an axial area along the first flow axis in which axial area a distance between an inner surface of the outlet duct and the first flow axis in the direction increases in the air flow direction, and the first flow axis passes through a minimum air flow opening area of the outlet duct along a transverse imaginary plane perpendicular to the first flow axis so that Coanda effect is generated along the inner surface of the outlet duct. It is preferable for maximizing the deflection of the second flow axis that the distance between the inner surface of the outlet duct and the first flow axis in another direction perpendicular to the direction is prevented from increasing in the air flow direction within the axial area so that the air passing the axial area is restrained from being expanded in the another direction.
It is preferable for minimizing a pressure loss in the air shower apparatus by utilizing a diffuser effect that the variable condition area has an enlarged air flow opening area along the transverse imaginary plane, the enlarged air flow opening area is larger than the minimum air flow opening area of the outlet duct, and the minimum air flow opening area of the outlet duct is larger than a minimum air flow opening area of the inlet duct along the transverse imaginary plane. It is preferable for minimizing the pressure loss and enlarging the deflection of the second flow axis that the whole of the minimum air flow opening area of the inlet duct is overlapped by the minimum air flow opening area of the outlet duct as seen along the first flow axis, and/or that the whole of the minimum air flow opening area of the outlet duct is overlapped by the enlarged air flow opening area as seen along the first flow axis.
It is preferable for generating the fluctuation in at least one of the pressure and the mass flow rate in the fluctuating direction by utilizing effectively Coanda effect and Venturi effect that in a cross-section of the inlet and outlet ducts in the apparatus along a longitudinal imaginary plane including the first flow axis and being parallel to the direction, an imaginary line extending parallel to the first flow axis from an inner surface of the inlet duct at the minimum air flow opening area of the inlet duct passes a radially inner side with respect to an inner surface of the outlet duct at the minimum air flow opening area of the outlet duct at the at least one side.
It is preferable for enlarging effectively the deflection of the second flow axis in the direction that a diameter of the minimum air flow opening area of the outlet duct in the direction is smaller than a diameter of the minimum air flow opening area of the outlet duct in another direction perpendicular to the direction.
It is preferable for enlarging effectively the deflection of the second flow axis that the outlet duct has a Venturi-type inner surface so is that that a Venturi effect is obtainable at an upstream side with respect to the minimum air flow opening area of the outlet duct in the air flow direction to generate the supplemental air flow from the variable condition area in the fluctuating direction to be applied to the air flowing into the outlet duct from the variable condition area. It is preferable for generating the fluctuation in the mass flow rate of the air in the fluctuating direction without the movable member contacting the air to be deflected and/or the supplemental air or extending through the air to be deflected and/or the supplemental air that the fluctuation in the mass flow rate of the air in the fluctuating direction is obtainable by the air flow in the fluctuating direction generated by the Venturi effect.
It is preferable for enlarging effectively the deflection of the second flow axis that the variable condition area is adapted to communicate fluidly with the air flowing out from the inlet duct at each of the sides opposite to each other in the direction in such a manner that an air pressure at one of the sides is relatively low when an air pressure at the other one of the sides is relatively high.
It is preferable for enlarging effectively the deflection of the second flow axis and generating the frequent fluctuation in the mass flow rate of the air in the fluctuating direction without the movable member contacting the air to be deflected and/or the supplemental air or extending through the air to be deflected and/or the supplemental air that the variable condition area is adapted to communicate fluidly with the air flowing out from the inlet duct at each of the sides opposite to each other in the direction, and the variable condition area has a bypass passage for fluidly connecting the sides to each other while bypassing the variable condition area so that the air is capable of flowing through the bypass passage to decrease a difference in pressure between the sides.
It is preferable for generating the frequent fluctuation in the mass flow rate of the air in the fluctuating direction without the movable member contacting the air to be deflected and/or the supplemental air or extending through the air to be deflected and/or the supplemental air that the air shower apparatus comprises an air supply passage fluidly communicating with the variable condition area to compensate a change in pressure of the air generated at the at least one side or to generate a change in pressure of the air generated at the at least one side.
If the frequent fluctuation in the mass flow rate of the air in the fluctuating direction is generated without the movable member contacting the air to be deflected and/or the supplemental air or extending through the air to be deflected and/or the supplemental air, the whole of the minimum air flow opening area of the inlet duct is seeable through the minimum air flow opening area of the outlet duct as seen in a direction opposite to the air flow direction and along the first flow axis, all the time when the fluctuation is generated, and/or the inlet duct and the variable condition area are stationary with respect to each other in position and attitude, and/or that the inlet duct, the variable condition area and the outlet duct are stationary with respect to each other in position and attitude.
It is preferable for generating the frequent fluctuation in the mass flow rate of the air in the fluctuating direction without the movable member contacting the air to be deflected and/or the supplemental air or extending through the air to be deflected and/or the supplemental air that the second flow axis is movable away from the inner surface of the outlet duct by the fluctuation in at least one of the pressure and the mass flow rate in the fluctuating direction against the Coanda effect.
The air shower apparatus may further comprise a flow vibration generator (for example, a rotary fan, a fluidal switching device, a self-exciting fluidal oscillating circuit or the like) for changing a mass flow rate of the supplemental air to be supplied to the variable condition area so that the fluctuation in at least one of the pressure and the mass flow rate in the fluctuating direction is generated at the variable condition area.
Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
In an air shower apparatus of the invention as shown in
As shown in
When the air flowing out of the inlet duct 9 is adhered to or reaches securely one of the inner surfaces 12 and 13 by the Coanda effect after the air flowing out of the inlet duct 9 is drawn toward the one of the inner surfaces 12 and 13 of the outlet duct 6 by the Coanda effect, a vortex 7 is generated at the step shape 10 so that a supplemental air flow 8 flows from the chamber duct 11 into the air flowing into the outlet duct 6 to urge the air flowing out of the inlet duct 9 away from the one of the inner surfaces 12 and 13 toward another one of the inner surfaces 12 and 13. When the air flowing out of the inlet duct 9 is adhered to or reaches securely the another one of the inner surfaces 12 and 13 by the Coanda effect after the air flowing out of the inlet duct 9 is drawn toward the another one of the inner surfaces 12 and 13 of the outlet duct 6 by the supplemental air flow 8 and the Coanda effect, the vortex 7 is generated at the step shape 10 so that the supplemental air flow 8 flows from the chamber duct 11 into the air flowing into the outlet duct 6 to urge the air flowing out of the inlet duct 9 away from the another one of the inner surfaces 12 and 13 toward the one of the inner surfaces 12 and 13. These operations are repeated to frequently deflect alternately a second flow axis of the air flowing out of the outlet duct 6 from the first flow axis.
As understood from
As understood from
It is preferable for strongly removing the particle from the object that a velocity of the air discharged from the air flow directing devices 4 is not less than 18 m/s, and the frequency is as low as possible. It is preferable for widely removing the particle from the object that the area or length of an object to which the swung air flow is applied from the air flow directing devices 4 is as great as possible.
Since the minimum air flow opening area of the outlet duct 6 is greater than the minimum air flow opening area of the inlet duct 9 to bring about a diffuser effect, a pressure loss in the air flow directing devices 4 is decreased in comparison with the prior art air nozzle as shown in
As shown in
If the swing of the air flow by the air flow directing devices 4 is is obtained when a mass flow rate of the air decreasing in accordance with to an increase of pressure loss across the filter 3 caused by an increase of plugging of the filter 3 is not less a lower limit of mass flow rate corresponding to unacceptable increase of plugging of the filter 3 and the pressure of the air pressurized by the blower 2 is kept as constant as possible, and the swing of the air flow by the air flow directing devices 4 is not obtained when the mass flow rate of the air is less than the lower limit of mass flow rate and the pressure of the air pressurized by the blower 2 is kept as constant as possible, whether or not the unacceptable plugging of the filter 3 occurs can be judged from the swing of the air flow by the air flow directing devices 4.
As shown in
It should be further understood by those skilled in the art that although the foregoing description has been made on embodiments of the invention, the invention is not limited thereto and various changes and modifications may be made without departing from the spirit of the invention and the scope of the appended claims.
Claims
1. An air shower apparatus for blowing air from an air blower through a filter to an object such as a human body with a cloth or a product to blow off dust therefrom, comprising:
- a plurality of outlets arranged on a wall surface of the air shower and capable of swinging directions of the airs blown respectively from the outlets with Coanda effect,
- wherein each of the swung directions is capable of being arranged along at least one of a vertical direction, a horizontal direction and a combination of the vertical and horizontal directions, and
- each of the outlets has an air inlet duct, a chamber duct and an outlet duct whose opening area is greater than an opening area of the inlet duct to form a step shaped air flow passage between the inlet and outlet ducts.
Type: Application
Filed: May 10, 2006
Publication Date: Sep 14, 2006
Inventors: Takeshi Honda (Nakajo), Yoko Shimizu (Niigata), Hiroshi Matsuda (Arakawa), Hiroshi Mukai (Ishioka)
Application Number: 11/430,964
International Classification: F24F 7/00 (20060101);