Search

WO-2026093612-A1 - SYSTEM FOR FILTERING AN AIRFLOW

WO2026093612A1WO 2026093612 A1WO2026093612 A1WO 2026093612A1WO-2026093612-A1

Abstract

The invention relates to a filtration system (1) for filtering an airflow (2) containing particles (3), the system comprising: - a support (10); - an active layer (11) arranged on the support (10), the active layer (11) being impermeable and not traversed by the airflow (2); and - means (12) for directing the airflow onto a surface (S) of the active layer (11); the active layer being formed from a material comprising a polymer and at least one plasticizer for the polymer, and comprising, on the surface of the active layer, a film of the plasticizer allowing the particles to be trapped.

Inventors

  • DUMAS, ANTOINE
  • DENEUVILLE, David

Assignees

  • TERA SENSOR

Dates

Publication Date
20260507
Application Date
20251104
Priority Date
20241104

Claims (15)

  1. [Claim 1] A filtration system (1) for an air stream (2) containing particles (3), comprising: - a support (10); - an active layer (11) disposed on the support (10), the active layer (11) being airtight (2) and not traversed by said airflow; and - means (12) for directing the airflow towards a surface (S) of the active layer (11); the active layer (11) being formed of a material comprising a polymer and at least one plasticizer of the polymer, and comprising on the surface (S) of the active layer (11) a film of said plasticizer.
  2. [Claim 2] System (1) according to claim 1, wherein the polymer is poly(vinyl chloride).
  3. [Claim 3] System (1) according to claim 2, wherein the active layer material comprises at least one secondary plasticizer of poly(vinyl chloride).
  4. [Claim 4] System (1) according to any one of claims 2 and 3, wherein the active layer material (11) comprises between 15% and 45% by mass of poly(vinyl chloride) and between 55% and 85% by mass of plasticizer. [Claims] System (1) according to any one of claims 1 to 4, further comprising an air filter (16) of class “ISO Coarse”, “ePM10” or “ePM2,
  5. 5.
  6. [Claim 6] System (1) according to claim 5, wherein the air filter (16) is located upstream of the active layer (11) in the direction of airflow.
  7. [Claim 7] System (1) according to claim 5, wherein the air filter (16) is located downstream of the active layer (11) in the direction of airflow.
  8. [Claims] System (1) according to any one of claims 5 to 7, wherein the air filter (16) is separated from the surface (S) of the active layer (11) by a distance (d) between 10 mm and 50 mm.
  9. [Claim 9] System (1) according to any one of claims 1 to 8, further comprising a device for circulating (13) the airflow (2).
  10. [Claim 10] System (1) according to claim 9, further comprising a housing (14) containing the active layer (11), the airflow circulation device (13) for the airflow (2) and the means (12) for directing the airflow.
  11. [Claim 11] System (1) according to claim 10, wherein the housing (14) comprises: - an upstream compartment (141) in which the airflow circulation device (13) is located (2); - a downstream compartment (142) in which the active layer (11) is disposed; the upstream and downstream compartments (141, 142) having a common partition in which an opening (121) is provided, the opening being located opposite the active layer (11).
  12. [Claim 12] System (1) according to any one of claims 9 to 11, wherein the airflow (2) circulation device (13) is configured so that the airflow reaches the active layer (11) with a velocity between 0.01 m.s' 1 and 1 m.s' 1 .
  13. [Claim 13] System (1) according to any one of claims 1 to 12, wherein the means (12) for directing the airflow (2) are configured so that the airflow reaches the active layer (11) with an angle of incidence between 0° and 20° in absolute value.
  14. [Claim 14] System (1) according to any one of claims 1 to 13, wherein the surface (S) of the active layer (11) has an area between 5 mm2 and 1 m2 .
  15. [Claim 15] A system (1) according to any one of claims 1 to 14, comprising, upstream of the active layer (11) in the direction of airflow, a device (15) for measuring the concentration of particles (3) in the airflow (2).

Description

AIR FLOW FILTRATION SYSTEM TECHNICAL FIELD OF THE INVENTION [0001] The technical field of the invention is that of air filtration. The invention relates more particularly to a system for filtering an airflow by trapping particles suspended in the air. TECHNOLOGICAL BACKGROUND OF THE INVENTION [0002] Air quality is an essential parameter for ensuring a good quality of life, particularly in cities and urban areas. Among the causes of air pollution, fine particulate matter (PM) is particularly dangerous for human health. These particles are produced largely by human activities related to industry and transportation. They are responsible for health problems such as impaired lung function and can lead to a reduction in life expectancy. [0003] PM fine particles are particles with an aerodynamic diameter of less than 10 pm. They are not retained by the upper respiratory tract (nose, mouth) and are therefore "breathable." PM fine particles are often classified according to their size. The designation PM10 is used for particles with an aerodynamic diameter of less than 10 pm; PM2.5 for particles with an aerodynamic diameter of less than 2.5 pm; and PM1 for particles with an aerodynamic diameter of less than 1 pm. The aerodynamic diameter of a particle is an equivalent quantity used to describe the aerodynamic behavior of particles in a gas flow such as an airflow. The aerodynamic diameter of a particle is defined as the diameter of a sphere with a unit density (1 g/ cm³ ) and having the same terminal settling velocity as said particle in a fluid at rest. In the remainder of this application, the term "diameter" will be used to refer to the aerodynamic diameter of a particle. [0004] Various filtration systems are put in place to improve air quality in buildings (homes, schools, hospitals, offices, shops, etc.), industrial environments, vehicle interiors, etc. These systems generally incorporate a filter (or a combination of several filters) which captures particles suspended in the air as the air circulates through the filter. [0005] The most common filters are mechanical filters and electrostatic filters. [0006] Mechanical filters are classified according to their efficiency: classes “ISO Coarse”, “ePM10”, “ePM2.5” and “ePM1” (according to ISO 16890) for coarse, medium and fine air filters; and classes “E” (E10, E11, E12), “H” (H13, H14) and “U” (U15, U16, U17) (according to EN 1822) for high-efficiency air filters. [0007] High-efficiency particulate air (HEPA) filters, classified as H13 or H14, are very common. They are used, for example, in hospitals and in cleanrooms in the microelectronics industry. They have an efficiency greater than 99.95% for particles larger than 0.3 µm in diameter. However, these filters have a significant pressure drop (on the order of several hundred Pa) and require a powerful air circulation system to guarantee a minimum airflow. They are therefore not suitable for low-energy air filtration systems, such as portable and self-contained (battery-powered) air purification systems. [0008] Electrostatic precipitators, also called "electrostatic precipitators," are complex and generally bulky devices that use an electrostatic force to extract particles (previously highly charged) from the airflow. They are used, for example, in industrial flue gas dust collection systems (thermal power plants, waste incinerators, cement plants, etc.) and in air handling units (AHUs) for commercial buildings. Electrostatic precipitators have a lower efficiency than HEPA filters and require the use of very high voltages to generate the strong electric field needed to attract the particles. SUMMARY OF THE INVENTION [0009] It is noted that there is a need to provide an airflow filtration system which offers a good compromise between efficiency and pressure loss and which is simple to manufacture and integrate. [0010] According to the invention, this need is met by providing a filtration system for an airflow containing particles, this system comprising: [0011] a support; an active layer disposed on the support, the active layer being airtight and not traversed by said airflow; and means for directing the airflow towards a surface of the active layer; the active layer being formed of a material comprising a polymer and at least one plasticizer of the polymer, and comprising on the surface of the active layer a film of said plasticizer. [0012] Since plasticizers are by nature slightly sticky or tacky, the plasticizer film is able to trap particles on the surface of the active layer. [0013] Indeed, the surface of the active layer is electrically charged by the effect of the plasticizer molecules, thus trapping particles contained in the airflow, which naturally possess partial charges. The bonds created by these partial charges are weak but nevertheless sufficient to trap the particles. Furthermore, since the active layer is airtight, it does not create resistance to the airflow. [0014] Furthermore, even if all or