| 摘要 |
FIELD: machine building. ^ SUBSTANCE: procedure for evaluation of dust content of working zone consists in forced sedimentation of aero-dispersed impurities on filter from certain volume of air. To determine weight of clean filter equipment is initially prepared and set. Further, the clean filter is weighted on a balance (analytical or electron). Successively, there is set an installation for forced sedimentation of dust aerosol in the working zone of a shop floor. Air is sampled with capture of dust particles on the filter. The filter with captured particles of dust is weighted. There is calculated concentration of dust aerosol in milligrams per cubic metre by formula: C=(m2 -m1)/V0, where m2 is weight of a dusted filter, mg; m1 is weight of a clean filter, mg; V0 is volume of air (m3), passed through the filter. Also, volume of air (m3) passed through the filter should be preliminary reduced to normal conditions (i.e. to volume, which it would occupy at temperature 0C and normal atmospheric pressure equal to 101325 Pa by formula: where 273 is absolute temperature, K; T is temperature of air (gas) C; Bact is actual barometer pressure at the moment of sampling, Pa; Bn is normal atmospheric pressure equal to 101325 Pa; v is flow rate of sampling, l/min; ä is time sampling, min; 1000 is coefficient of conversion of litres into cubic metres (1 m3=1000 l). There is evaluated dust content of the working zone by comparison of obtained concentration with an allowed value. ^ EFFECT: raised efficiency, operation speed and reliability of system response. ^ 2 tbl, 3 dwg |
