Assessment of retention capacity of filtering material by densitometry

The paper presents a research into the possibility of a comprehensive assessment of filtering textile materials retention capacity by the combination of gravimetric and optical characteristics. Images of sample surfaces with different degrees of contamination are given, as well as indicators of retention capacity and optical density for non-woven material, and dependency graphs of optical density on the degree of contamination. The study subject is the optical density of the contaminant layer retained by the textile material during filtration of a gas medium containing solid particles. The samples of non-woven fabric produced by the stitchbonding process type Malifleece (Lenom JSC) are obtained [1-3], the samples being contaminated with technical carbon P-110 (produced by Omsk Carbon Group JSC). The tests are carried out on a laboratory facility. As a part of the study the amount of carbon black is changed, which makes it possible to obtain samples with different amounts of the retained contaminant. The optical density is measured by a spectrophotometer Gretag Macbeth SpectroEye (Germany). It is established that the densitometry method for filtering textile materials can be used to deduce dependences of the optical density on the amount of contaminant retained in them. This allows investigating the mechanism of contaminant absorption until a solid layer (cake) is formed on the surface of the filter material. It is essential in defining the time to clean or replace the filter medium. When using an experimental flax-containing non-woven fabric, cake formation occurred at 9.5 g / m2, which corresponds to an optical density of 1.64. It is shown that it is possible to conduct live monitoring of the filter state by measuring and evaluating the surface optical density of its filter medium by densitometry, and this will significantly simplify the assessment of the current state of the filter and the forecast for its future use. The development of a device to measure the optical density remotely will allow assessing the state of the filter and the need to replace it in hard-to-reach places.