Materials Science

Characterization of needle felts for cleanable dust filtration

Summary: A method of determination has been developed for comparative characterization of the particle penetration and dust storage capacity of surface-treated needle felts. This method is based on transmitted light and reflected light microscopy used in combination with specially developed image analysis software with which it is possible to determine the two-dimensional surface porosity and the pore depth distribution at the surface of the filter medium. Two straight calibration lines are obtained when the surface porosity measurements are combined with filter test results that conform to the VDI (Confederation of German Industry) guidelines, such as average clean gas dust concentration and mass of residual dust. These two straight calibration lines can be used to estimate the particle penetration and the dust storage capacity of different surface-treated needle felts.

1  Introduction
The fine dust fraction in dust emissions is particularly important from the point of view of air hygiene. Interest is focused on the low sinking velocities of sub-micron dust particles (resulting in a relatively long residence time in the earth’s atmosphere), their respirability and their ability to combine adsorptively with harmful substances like heavy metals. Because of their outstanding dust collecting characteristics, including in the fine dust range, cleanable dust filters are being used increasingly in virtually all sectors of exhaust gas dedusting as well as for the...

Related articles:

Issue 11/2013

New membrane product line PM-Tec®

Airborne fine dust is to a considerable extent detrimental to human health. Fine dust contamination is particularly high in conurbations and industrial zones. Primary fine dusts particularly occur...

more
Issue 01/2012

Dust emissions reduced

In 2010 the RHI AG placed an order with Intensiv-Filter ­Austria for dedusting of two rotary kilns. On October 11th, 2011, the ­process filter was put into operation and now filters 99 % of the...

more
Issue 09/2009

Change in dust collection technology

The development of PowerCore® fulfils the requirements for an easy and  service-friendly maintenance of dust collectors, which has been a demand of the industry for many years: With the incomparably...

more
Issue 05/2011

The optimal operating point of a filtering ­installation

Modern companies make tremendous efforts to identify any energy saving potentials. The possibilities lie not only in the construction optimisation but also in process streamlining. However, the gap...

more
Issue 03/2011

Filtering and electrical particle separation

The 3rd HDT Specialist Conference on Filter Plant Technology will take place in Essen from 19.-20.05.2011. The lecture topics will deal with the progress of development and the current state of...

more