Emission measurements at dryers

The scope depends on what is dried and how it is heated. At grain, biomass and wood dryers we typically address particulates, NOx and CO from combustion; for drying wood chips and wood fibres, TOC may also be relevant.

If a dryer has several stacks, for example separate extraction branches, the pollution level is generally determined at each of them unless the operating permit says otherwise. Where the burner is part of the dryer, we clarify the measuring point and whether the flue gas is measured separately or mixed with process air.

From the permit we verify the source, the stacks, the fuel and the measured substances. We measure at a standard production load; for batch operation we describe the whole production cycle beforehand so that the result reflects real operation.

We describe the state of the dryer during the measurement in the report, so we need data on the load, the output and the amount of processed material. One-off measurements are carried out by an authorised person; the date is announced in ISPOP at least 5 working days in advance and the protocol data are reported within 60 days.

We measure emissions from grain, biomass and wood dryers and linked combustion sources under representative operating conditions. The scope follows the operating permit, the fuel and the drying technology.

What we measure within our accreditation

Within our accreditation we measure solid particulate matter (TZL) isokinetically, NOx, CO, SO₂ and O₂ with analysers, TOC and VOC, HCl and inorganic chlorine compounds, heavy metals (As, Be, Cd, Cr, Co, Cu, Mn, Ni, Pb, Sb, Se, Sn, Te, Tl, V, Zn, Al, Fe, Si, Hg) and gas moisture, velocity and volume flow. The specific scope is determined by the permit for your operation.

We use the same procedure for other sources: boiler plants, paint shops, dryers, biogas plants, diesel generator sets, wood-processing plants, electroplating shops and other technologies. You will find the overview under Facilities and technologies.