Narcotics and explosives particle removal system
View Patent ↗An explosive and narcotics detection system detects the presence of trace particles of those materials that are adhering to surfaces. The particles are removed from the surface, transported and collected in a particle collection medium, and then provided to detection instrument. Narcotics and explosive particles are often bound tenaciously to the surface, and simple techniques, such as blowing air, will either remove only the largest particles or none at all. Techniques for the removal of narcotics and explosives particles are described which utilize an aerosol mixture of aerosol particles in a gas stream to impact and more efficiently remove the target narcotics and explosives particles from the surface.
1. A method for dislodging and collecting target particles from a target surface, the method comprising:
providing an aerosol mixture including aerosol particles dispersed in a pressurized gas, wherein the aerosol particles include solid aerosol particles;
directing said aerosol mixture including solid aerosol particles at said target surface including said target particles, said solid aerosol particles of the aerosol mixture impacting said target particles causing removal of said target particles from said target surface via momentum transfer from the impact of the solid aerosol particles and causing said target particles to be included in a flow of said pressurized gas with said solid aerosol particles, wherein the solid aerosol particles are selected to dislodge the target particles via the momentum transfer from the impact while having a hardness that provides no significant damage to the target surface;
providing a suction flow into an orifice into which said flow of said target particles, said solid aerosol particles, and said pressurized gas are directed; and
collecting particles entrained in said suction flow, wherein the particles entrained in the suction flow are collected in a collecting medium that is disposed in a position that is at least one of: upstream of said orifice or within said orifice, and wherein said suction flow into the orifice is bounded circumferentially by a spinning vortex.
2. The method of claim 1 , the method further comprising:
delivering said pressurized gas in timed pulses; and
delivering said aerosol particles in accordance with said timed pulses.
3. The method of claim 2 , further comprising:
combining said pressurized gas with said aerosol particles to form said aerosol mixture.
4. The method of claim 1 , wherein said suction flow is created utilizing a vacuum suction flow into the orifice.
5. The method of claim 4 , wherein the collecting medium includes at least one of: a filter, a chemically coated adsorbing surface, a metal mesh, a three dimensional woven metal, a metal wire, a metal foil, a metal and electrical insulator laminate, and a resistive coating on a substrate.
6. The method of claim 5 , wherein the collecting medium is disposed upstream of said orifice.
7. The method of claim 5 , wherein the collecting medium is disposed within said orifice.
8. The method of claim 2 , wherein said pressurized gas is pressurized at about 80 pounds per square inch and delivered at a timed pulse between 0.03 seconds and 1 second.
9. The method of claim 1 , wherein the hardness of the solid aerosol particles is less than about 4 on Mohs hardness scale.
10. The method claim 1 , wherein the solid aerosol particles include at least one of: talc, fuller's earth, diatomaceous earth, gypsum, chalk, frozen carbon dioxide, frozen water, sodium bicarbonate and plastic microspheres.
11. The method of claim 1 , wherein the solid aerosol particles have a flashpoint significantly higher than ambient temperature.
12. The method of claim 1 , wherein the solid aerosol particles are non-toxic.
13. The method of claim 1 , wherein the pressurized gas includes at least one of: air, nitrogen, argon and carbon dioxide.
14. The method of claim 1 , wherein the solid aerosol particles are provided from a reservoir.
15. The method of claim 14 , wherein the reservoir includes a pressurized tank of liquefied gas, and wherein said pressurized liquefied gas is converted to the solid particles upon expansion into atmospheric pressure.
16. A method for dislodging and collecting target particles from a target surface, the method comprising:
providing an aerosol mixture including aerosol particles dispersed in a pressurized gas, wherein the aerosol particles include solid aerosol particles;
directing said aerosol mixture including solid aerosol particles at said target surface including said target particles, said solid aerosol particles of the aerosol mixture impacting said target particles causing removal of said target particles from said target surface via momentum transfer from the impact of the solid aerosol particles and causing said target particles to be included in a flow of said pressurized gas with said solid aerosol particles, wherein the solid aerosol particles are selected to dislodge the target particles via the momentum transfer from the impact while having a hardness that provides no significant damage to the target surface;
providing a suction flow into which said flow of said target particles, said solid aerosol particles, and said pressurized gas are directed; and
collecting particles entrained in said suction flow, wherein said suction flow is created utilizing a vacuum suction flow into an orifice, and wherein said vacuum suction flow into the orifice is bounded circumferentially by a spinning vortex.
17. The method of claim 16 , the method further comprising:
delivering said pressurized gas in timed pulses; and
delivering said aerosol particles in accordance with said timed pulses.
18. The method of claim 16 , wherein the solid aerosol particles include at least one of the following features:
(i) have a hardness than about 4 on Mohs hardness scale;
(ii) are non-toxic;
(iii) have a flashpoint higher than ambient temperature; or
(iv) include at least one of: talc, fuller's earth, diatomaceous earth, gypsum, chalk, frozen carbon dioxide, frozen water, sodium bicarbonate and plastic microspheres.
19. The method of claim 16 , wherein the pressurized gas includes at least one of: air, nitrogen, argon and carbon dioxide.
20. The method of claim 16 , wherein the solid aerosol particles are provided from a reservoir.
21. A method for dislodging and collecting target particles from a target surface, the method comprising:
providing an aerosol mixture including aerosol particles dispersed in a pressurized gas, wherein the aerosol particles include solid aerosol particles;
directing said aerosol mixture including solid aerosol particles at said target surface including said target particles, said solid aerosol particles of the aerosol mixture impacting said target particles causing removal of said target particles from said target surface via momentum transfer from the impact of the solid aerosol particles and causing said target particles to be included in a flow of said pressurized gas with said solid aerosol particles, wherein the solid aerosol particles are selected to dislodge the target particles via the momentum transfer from the impact while having a hardness that provides no significant damage to the target surface;
delivering said pressurized gas in timed pulses of between 0.03 seconds and 1 second;
delivering said aerosol particles in accordance with said timed pulses;
providing a suction flow into which said flow of said target particles, said solid aerosol particles, and said pressurized gas are directed; and
collecting particles entrained in said suction flow, wherein said suction flow into the orifice is bounded circumferentially by a spinning vortex.
22. The method of claim 21 , wherein said pressurized gas is pressurized at about 80 pounds per square inch.