US 12,241,840 B2
Real-time silica discriminating respirable aerosol monitor with particle sizer and particle growth chamber upstream of reagent tank
James E. Boulter, Eau Claire, WI (US)
Filed by WiSys Technology Foundation, Inc., Madison, WI (US)
Filed on Apr. 9, 2019, as Appl. No. 16/379,263.
Claims priority of provisional application 62/654,713, filed on Apr. 9, 2018.
Prior Publication US 2019/0310202 A1, Oct. 10, 2019
Int. Cl. G01N 21/76 (2006.01); G01N 21/85 (2006.01); G01N 33/00 (2006.01)
CPC G01N 21/766 (2013.01) [G01N 21/85 (2013.01); G01N 33/0036 (2013.01); G01N 33/0062 (2013.01); G01N 33/0073 (2013.01); G01N 2021/8578 (2013.01); G01N 33/0068 (2024.05); G01N 2201/126 (2013.01)] 16 Claims
OG exemplary drawing
 
1. An airborne silica detection system comprising:
a particle sizer for receiving an airstream and preferentially removing particles greater than 4 μm average diameter from the airstream;
a reagent tank having an inlet and an outlet for receiving and discharging the airstream respectively, the reagent tank adapted to contain at least one liquid reagent at a reagent height below the outlet within the reagent tank and receiving the airstream downstream from the particle sizer through the inlet to a nozzle positioned below the outlet, to bubble the airstream through the at least one liquid reagent when so contained so that at least one liquid reagent may react with silica of the particles;
a photodetector positioned adjacent a sidewall of the reagent tank at a position lower than the outlet, the photodetector monitoring the reagent tank to detect a change in light caused by the reacting of the silica;
a particle growth chamber receiving the airstream from the particle sizer to increase the individual mass of the particles less than 4 μm in diameter prior to receipt by the reagent tank to increase capture of the particles in the at least one liquid reagent during the bubbling of the airstream through the at least one liquid reagent when so contained;
a flow sensor sensing an amount of air received by the reagent tank from the particle growth chamber; and
an electronic computer executing a stored program held in non-transitory computer readable medium to receive a signal from the photodetector and the flow sensor to provide an output upon silica concentrations in the airstream rising above a predetermined threshold;
an air pump for moving the airstream along a path through the particle sizer, the particle growth chamber, the flow sensor, and the reagent tank.
 
14. An airborne silica detection system comprising:
a particle sizer for receiving an airstream and preferentially removing particles greater than 4 μm average diameter from the airstream;
a reagent tank having an inlet and an outlet for receiving and discharging the airstream respectively, the reagent tank adapted to contain at least one liquid reagent at a reagent height below the outlet within the reagent tank and receiving the airstream downstream from the particle sizer through the inlet to a nozzle positioned below the outlet, to bubble the airstream through the at least one liquid reagent when so contained so that at least one liquid reagent may react with silica of the particles;
a photodetector positioned adjacent a sidewall of the reagent tank at a position lower than the outlet, the photodetector monitoring the reagent tank to detect a change in light caused by the reacting of the silica;
a particle growth chamber receiving the airstream from the particle sizer to increase the individual mass of the particles less than 4 μm in diameter prior to receipt by the reagent tank to increase capture of the particles in the at least one liquid reagent during the bubbling of the airstream through the at least one liquid reagent when so contained;
a flow sensor sensing an amount of air received by the reagent tank from the particle growth chamber;
an electronic computer executing a stored program held in non-transitory computer readable medium to receive a signal from the photodetector and the flow sensor to provide an output indicating silica concentrations in the airstream over a predetermined amount;
an air pump for moving the airstream along a path through the particle sizer, the reagent tank, the particle growth chamber, and the flow sensor; and
further including a cartridge providing at least two compartments holding reagents for use in the reagent tank and at least one compartment for receiving waste reagent from the reagent tank and wherein the airborne silica detection system provides pumps controlled by the electronic computer executing the stored program for moving the reagents and waste to and from the reagent tank respectively.