US 11,925,893 B2
Device for separating sub-micron particles in the air
Xiaodong Li, Beijing (CN); and Jizhou Liu, Beijing (CN)
Assigned to BEIHANG UNIVERSITY, Beijing (CN)
Appl. No. 17/424,471
Filed by BEIHANG UNIVERSITY, Beijing (CN)
PCT Filed Aug. 4, 2020, PCT No. PCT/CN2020/106702
§ 371(c)(1), (2) Date Jul. 20, 2021,
PCT Pub. No. WO2022/027210, PCT Pub. Date Feb. 10, 2022.
Prior Publication US 2022/0305426 A1, Sep. 29, 2022
Int. Cl. B01D 49/00 (2006.01); A61M 1/36 (2006.01); B01D 21/28 (2006.01); B01J 19/10 (2006.01); C12N 13/00 (2006.01)
CPC B01D 49/006 (2013.01) [A61M 1/3678 (2014.02); B01D 21/283 (2013.01); B01J 19/10 (2013.01); B01L 2300/0861 (2013.01); B01L 2400/0439 (2013.01); C12N 13/00 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A device for separating sub-micron particles in the air, comprising: a first separation channel, a second separation channel and a collection device which are connected in sequence,
wherein each of the first separation channel and the second separation channel is of a rectangle structure with two open ends, and the height H1 of the first separation channel is greater than the height H2 of the second separation channel;
by taking the leftmost end of the inner surface of the lower wall of the first separation channel as the origin of coordinates, the height direction of the first separation channel as the positive direction of the y axis, and the length direction of the first separation channel as the positive direction of the x axis, a coordinate system is constructed;
the outer surface of the upper wall of the first separation channel is provided with a first vibration sound source, and the inner surfaces of the upper wall and the lower wall are provided with a first antimicrobial coating layer; the first vibration sound source is used to generate a first standing wave field in the y direction, the first standing wave field is used to aggregate particles with a first diameter dp1, and the first diameter dp1 is ranged from 350 nm to 1.2 μm;
the outer surface of the upper wall of the second separation channel is provided with a second vibration sound source, and the inner surfaces of the upper wall and the lower wall are provided with a second antimicrobial coating layer; the second vibration sound source is used to generate a second standing wave field in the y direction, the second standing wave field is used to aggregate particles with a second diameter dp2, and the second diameter dp2 is ranged from 80 nm to 500 nm;
the relationship between a standing wave frequency fa1 of the first standing wave field and the height H1 is set such that particles flowing into the first separation channel are aggregated on the Inner surface of the upper wall of the first separation channel, and the horizontal surface of the central axis in the y direction of the channel and the inner surface of the lower wall; and the first antimicrobial coating layer is used to adsorb particles aggregated on the inner surface of the upper wall and the inner surface of the lower wall of the first separation channel;
the relationship between a standing wave frequency fa2 of the second standing wave field and the height H2 is set such that particles flowing into the second separation channel are aggregated on the inner surface of the upper wall of the second separation channel, and the horizontal surface of the central axis in the y direction of the channel and the inner surface of the lower wall; and the second antimicrobial coating layer is used to adsorb particles aggregated on the inner surface of the upper wall and the inner surface of the lower wall of the second separation channel;
the relationship between the standing wave frequency of the first standing wave field and the standing wave frequency of the second standing wave field and the diameter of the corresponding aggregated particles is determined by the following formulas (1) to (4):
0.45≤2πfa1τ1≤5.35  (1)
τ1=ρmpdp12/(18μg)  (2)
0.06≤2πfa2τ2≤2.32  (3)
τ2ρmpdp22/(18μg)  (4)
where τ1 and τ2 represent relaxation time of the viscous force of the air in the first separation channel and the second separation channel respectively, ρmp represents the material density of the particles, and μg represents the dynamic viscosity of air; and
the collection device is used to collect particles aggregated on the central surface.