Particle microtrap screen

A method of cleaning air, collecting particles, sampling biological specimens, comprising admitting air with suspended particles through an inlet, flowing the air through multiple jet orifices in a jet orifice screen, entraining particles in the air flowing through the jet orifices, impacting particles in multiple particle traps on a particle impact and trap assembly opposite the jet orifice screen, and flowing air from which particles for sampling have been removed between the particle impact and trap assembly and the jet orifice screen and through an outlet.

A particle microtrap screen process, comprising etching multiple, relatively small microjet orifices through a relatively thin plate and forming a multiple microjet screen with microjets arranged in a pattern, forming multiple, relatively large microtrap openings in the same pattern through plural, relatively thick microtrap plates, forming aligned large gas passages in an impact plate and in the plural thick microtrap plates between the microtrap openings, assembling the multiple microjet screen on a peripheral spacer and assembling the plural microtrap plates on the spacer with the openings and the passages aligned and assembling the impact plate on the microtrap plates with the passages aligned, flowing gas with particles suspended therein to the microjet screen, flowing the gas with the particles entrained therein through the multiple microjets, accelerating the gas and the entrained particles, impacting the particles on the impact plate and collecting the particles in the microparticle traps, slowing and flowing the gas from which the particles have been removed between the microtrap plates and the microjet screen, and flowing the gas through the passages and out through a gas outlet.

Particle microtrap screen apparatus, comprising a multiple microjet screen having multiple microjet orifices etched through a screen plate in a predetermined pattern, a spacer ring, microtrap plates relatively thicker than the microjet screen and having microtrap openings formed therethrough aligned with the microjet orifices in the predetermined pattern and having gas flow passages, an impact plate having aligned gas flow passages, for flowing gas with suspended particles from an inlet to the microjet screen and accelerating the gas and entraining the particles in the gas through the microjet orifices, and impacting the particles on the impact plate, trapping the particles in the microtraps and flowing gas from which particles have been removed through the passages to an outlet.

Particle microtrap screen apparatus, comprising a relatively thin jet screen having jet orifices etched therethrough, a spacer ring, plural relatively thick particle trap plates having particle trap openings etched therethrough, and an impact plate assembled with the plural particle trap plates having etched particle trap openings for forming multiple, relatively deep particle traps leading to an impact plate, the particle trap plates and the impact plate having enlarged openings for flowing gas therethrough to an outlet.