US 11,940,376 B2
System and method for detecting concentration of free SiO2 in coal dust
Huawei Jin, Huainan (CN); Fangzheng Yan, Huainan (CN); and Lei Fang, Huainan (CN)
Assigned to Anhui University of Science and Technology, Huainan (CN)
Filed by Anhui University of Science and Technology, Huainan (CN)
Filed on Dec. 28, 2022, as Appl. No. 18/147,236.
Application 18/147,236 is a continuation of application No. PCT/CN2022/087378, filed on Apr. 18, 2022.
Claims priority of application No. 202210322992.4 (CN), filed on Mar. 29, 2022.
Prior Publication US 2023/0314308 A1, Oct. 5, 2023
Int. Cl. G01N 21/17 (2006.01); G01N 1/20 (2006.01); G01N 1/22 (2006.01); G01N 1/24 (2006.01); G01N 33/00 (2006.01)
CPC G01N 21/1702 (2013.01) [G01N 1/24 (2013.01); G01N 33/0027 (2013.01); G01N 2021/1704 (2013.01); G01N 2201/06113 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A system for detecting a concentration of free SiO2 in coal dust, comprising a first sampling tube and a second sampling tube for sampling the coal dust, a three-way control valve communicated with the first sampling tube and the second sampling tube respectively, a photoacoustic spectrometry detection device communicated with the three-way control valve through a connecting pipeline, and a SiO2 reaction tube for reacting SiO2 in the coal dust; and the SiO2 reaction tube is disposed on the second sampling tube;
wherein the SiO2 reaction tube comprises a carbon tube and an air inlet heating tape from inside to outside, the carbon tube is heated through the air inlet heating tape, the SiO2 in the coal dust delivered by the second sampling tube reacts with the heated carbon tube, and reacted gas is delivered into the photoacoustic spectrometry detection device through the three-way control valve;
the photoacoustic spectrometry detection device comprises a photoacoustic cavity communicated with the connecting pipeline, a laser device, a signal modulator, a reflector, quartz windows disposed at two ends of the photoacoustic cavity, a rheomicrophone disposed at a middle of the photoacoustic cavity, a lock-in amplifier for collecting and amplifying a photoaccoustic signal generated by the rheomicrophone and a detection software; and the laser device outputs laser through the signal modulator, and after the reflector reflects the laser, the laser enters the photoacoustic cavity through the quartz windows;
the photoacoustic spectrometry detection device further comprises a sampling pump for extracting gas and a flowmeter disposed on the sampling pump;
the system further comprises a tail gas treatment device, which comprises a tail gas conversion tube communicated with an air outlet of the sampling pump and a NaOH liquid bottle communicated with the tail gas conversion tube, and the NaOH liquid bottle is provided with an air outlet tube for discharging the processed tail gas.