Method and apparatus for purging unwanted substances from air

• US 10,478,517 B2
• Filed: 10/04/2013
• Issued: 11/19/2019
• Est. Priority Date: 09/19/2008
• Status: Active Grant

• Current Assignee: Fipak Research And Development Company
• Original Assignee: Fipak Research And Development Company
• Inventors: Hauville, Francois, Herry, Cedric
• Primary Examiner(s): Tai, Xiuyu
• Application Number:
  US14/046,641
• Publication Number:
  US 20140037522A1
• Time in Patent Office: 2,237 Days
• CPC Class Codes: A61L 9/22 Ionisation
• CPC Class Codes: B01D 2255/1021 Platinum
• CPC Class Codes: B01D 2255/106 Gold
• CPC Class Codes: B01D 2255/2073 Manganese
• CPC Class Codes: B01D 2255/20761 Copper
• CPC Class Codes: B01D 2259/818 Employing electrical discharges or the generation of a plasma
• CPC Class Codes: B01D 53/323 by electrostatic effects or by high-voltage electric fields
• CPC Class Codes: B01D 53/75 Multi-step processes
• CPC Class Codes: B01D 53/864 Removing carbon monoxide or hydrocarbons
• CPC Class Codes: B01D 53/8675 Ozone
• CPC Class Codes: B01D 53/90 Injecting reactants
• CPC Class Codes: B08B 15/023 Fume cabinets or cupboards, e.g. for laboratories

Abstract

Apparatus comprising:

• • a fumehood; and
  • an air treatment device for purging unwanted substances from the exhaust air of the fumehood, the air treatment device comprising:
    • a non-thermal plasma reactor stage for producing air byproducts comprising O., N., OH. and O₃ and introducing those air byproducts into the exhaust air of the fumehood so as to treat the exhaust air of the fumehood; and
    • a catalyst stage downstream of the non-thermal plasma reactor stage for further treating the air downstream of the non-thermal plasma reactor stage.

Claims

1. A method for purging unwanted substances from air, the method comprising:

providing apparatus comprising;

a fumehood comprising a protective enclosure for safely handling hazardous substances, and an exhaust vent for venting exhaust air from the protective enclosure of the fumehood; and

an air treatment device for purging unwanted substances from the exhaust air of the fumehood, the air treatment device comprising;

a non-thermal plasma reactor stage comprising an air inlet for receiving the air to be treated in the non-thermal plasma reactor stage, a plurality of separate non-thermal plasma reactor units for dividing the air to be treated into a plurality of chambers and simultaneously treating the air in each of the plurality of chambers, and an air outlet for exhausting the treated air from the non-thermal plasma reactor stage;

wherein each of the plurality of separate non-thermal plasma reactor units comprises a dielectric barrier discharge construction, wherein the dielectric barrier discharge construction comprises a first electrode and a second electrode, with the first electrode of one of the plurality of separate non-thermal plasma reactor units being separated by a dielectric plate from the second electrode of the same one of the plurality of separate non-thermal plasma reactor units, and further wherein the air within one of the non-thermal plasma reactor units is separated from the air within another of the non-thermal plasma reactor units;

wherein the plurality of separate non-thermal plasma reactor units are assembled together in parallel so as to form a collective cross-section equal in size to the air inlet of the non-thermal plasma reactor stage and equal in size to the air outlet of the non-thermal plasma reactor stage, and further wherein the air entering the air inlet is divided between the plurality of separate non-thermal plasma reactor units; and

a catalyst stage, wherein the catalyst stage is formed separately from the non-thermal plasma reactor stage and located downstream from the non-thermal plasma reactor stage; and

operating the fumehood, wherein operating the fumehood comprises;

passing the exhaust air of the fumehood through the non-thermal plasma reactor stage of the air treatment device, wherein the air is passed through the air inlet, divided between the plurality of separate non-thermal plasma reactor units and passed out the air outlet, with the divided air simultaneously passing through the plurality of separate non-thermal plasma reactor units so as to provide treated exhaust air; and

passing the treated exhaust air through the catalyst stage.

2. A method according to claim 1 wherein a potential difference applied across the first electrode and the second electrode comprises electric pulses at a frequency of 50 Hz to 2000 Hz.

3. A method according to claim 1 wherein the catalyst stage comprises MnO₂.

4. A method according to claim 3 wherein at least one of the plurality of non-thermal plasma reactor units comprises a coronal tube comprising a wire electrode and a cylinder electrode disposed around the wire electrode.

5. A method according to claim 4 wherein the wire electrode and the cylinder electrode are disposed coaxially.

6. A method according to claim 4 wherein the non-thermal plasma reactor unit is driven by electrical pulses, and further wherein the electrical pulses are regulated to minimize arcing.

7. A method according to claim 1 wherein at least one of the plurality of non-thermal plasma reactor units comprises a wire electrode, a cylinder electrode disposed around the wire electrode, and a cylinder dielectric disposed between the wire electrode and the cylinder electrode.

8. A method according to claim 7 wherein the wire electrode, the cylinder electrode and the cylinder dielectric are disposed coaxially.

9. A method according to claim 1 wherein the first electrode comprises a wire electrode and the second electrode comprises a plate electrode, and the dielectric plate is disposed between the wire electrode and the plate electrode.

10. A method according to claim 1 wherein at least one of the plurality of non-thermal plasma reactor units comprises a first plate electrode, a second plate electrode, and a plate dielectric disposed between the first plate electrode and the second plate electrode.

11. A method according to claim 3 wherein the catalyst stage further comprises CuO.

12. A method according to claim 3 wherein the catalyst stage comprises a plurality of different catalysts.

13. A method according to claim 3 further comprising a filter located upstream of the non-thermal plasma reactor stage.

14. A method according to claim 3 further comprising a filter located downstream of the catalyst stage.