Stack emission sampling
Heavy metal Sampling System compliant to UNI EN – 14385 DLgs 152-2006
This method is dedicated to the sampling of discharged heavy metals in emissions coming from hazardous city waste incinerators. The elements analyzed are: Antimony, Arsenic, Cadmium, Chromium, Cobalt, Copper,Magnesium,Nickel, Lead, and Thallium. This method is applicable to each one of these specific elements in the concentration range of 0.005 mg/m3 to 0.5 mg/m3.
The system includes a heated probe with glassware set necessary for sampling heavy metals, without any metal part coming into contact with sampling gas. A special bubbler support is located outside the sensor, immediately after the heated container holding the filter holder. This process avoid forming condense in the sampling line with the loss of the speciment.
The norm foresees two different sampling methods, the first one consist of direct gas passage in both supports in the same suction flux, the second one with a derived flow.
The device may be placed directly to the heated probe complete with heated filter holder box (600/SIR1500BB) through a set of glass unions. Sample is absorbed through three sealed and refrigerated bubblers straight to the tank located in the back of the device; in addition to a fourth empty bubbler. The volume of a sample extracted will be considered compatibly at the instrumental detectability limits, in order to analytical chosen method. Three kind of filtering membranes may be used: dealing with low concentration sample, membrane must be high quality and free to any binder. Choose is between: fiber glass, quartz fiber or preferably glass fiber covered by PTFE (maximum recommended temperature 300°C)
Isokinetic direct sampling. Sampling device has to be designed to reduce gas time to the minimum between sonde nozzle and bubbling absorbers (less than 5s). Sonde temperature must be checked at least at 120°C and also 20°C over the acid dew gas point. The heating device must be designed to reduce to the minimum the non-heated area next to the filter holder union.
Derivate Sampling. Device does not concern isokintetic sampling mode in real time. The filter holder must have a heated tank (extractor sensor is the same as the isokintetic option) and linked directly to the bubblers attached at the output, three of them with sintered baffle containing a solution adsorption and an empty impinger without baffle. Due to lower gas concentrations and environmental limits, sampling time might be extended.