Presentation on theme: "SMOKE DENSITY MEASUREMENT Particles emitted give rise to a nuisance factor –Plume visibility and haze due to finer particles –Ground level deposits in."— Presentation transcript:
SMOKE DENSITY MEASUREMENT Particles emitted give rise to a nuisance factor –Plume visibility and haze due to finer particles –Ground level deposits in the case of larger particles Appearance of plume assessed according to Ringelmann scale of plume greyness –Used for spot check –Shades of grey from white to black –Ringelmann 0 (white) to Ringelmann 5 (Black) in steps of 20% obscuration –<40% or Ringelmann 2 is legal requirement
SMOKE METER Photo cell type Focused light beam through the duct or chimney on a photo cell Variation in signal of the photo cell a measure of variation in obscuration of light source due to smoke and dust Difference exists between what the meter shows and Ringelmann chart as Light path and chimney diameter not same
SMOKE METER –Deposits of particles on the camera lens and Receiver Aluminium tubes of length (4:1 dia for coarser and 16:1 for finer ) eliminates deposits –Zero drift due to ageing of components and dust –Misalignment of lamp and photocell with duct distortions more so with everclean windows To be installed platforms not attached to duct.
DUST MONITORS Knowledge of dust emission as weight per unit volume –Got from dust samples –Continuous monitoring Direct measurement on weight basis not given by instruments Calibration done through dust samples and indication as a function of particle size Particle size grading does not change (assumed)
CERL flue dust monitor Collects dust samples periodically and measures obscuration caused by this collection A glass plate collects the dust and after measurement, dust blown away with compressed air Favors larger particles, hence warns of emission likely to cause nuisance. Recorder consists of circular chart with radial lines drawn proportional to dust.
AEI Flue dust monitor Withdraws a continuous sample of dusty gas Given a swirl it results in electricity due to to friction Measurement of this static electricity is a measure of dust
SEROP dust monitor Records light scattered by dust An emitter beams light on to dust flow and scattered light collected by a photocell No alignment problem Scans larger volume Free from corrosion as components are outside.