Mercury Stack Gas Monitor SM-3 EMISSIONS Continuous emissions monitor (CEM) for Mercury • Detects elemental, ionic and bound mercury • Proven reliable detection method: UV absorption (CVAAS) • Thermocatalytic principle - no use of reagents • Maintenance-free solid state catalyst • True continuous measurement (no measuring cycle) • Sensitivity: 0.1 µg/m³ • Corrosion protected rugged construction • Tested and certified by German TÜV www.envea.global Fields of application The SM-3 Mercury Stack Gas Monitor is used for continuous monitoring of mercury in stack gas. Bound forms of mercury like HgCl2, HgO, HgS and particulate mercury are detected as well as elemental mercury. • Municipal waste incinerators • Sewage sludge incinerators • Hazardous waste incinerators • Cement production • Coal fired power plants • Thermal soil resanitation plants • Wood combustors using recycled wood • Metal recycling furnaces Operating principle A sample gas stream is taken from the duct through a heated sampling system. The gas is drawn through a high-temperature particulate filter and subsequently enters the reduction unit where a thermocatalytic reduction of ionic and bound mercury is performed. This results in the formation of elemental mercury vapor. The gas is then dried in a maintenance-free peltier cooler and fed to the mercury detector where the mercury concentration is measured. The high surface temperature of the gas entry filter guarantees that mercury is thermally completely desorbed from particles and thus also detected. Design features All surfaces coming into contact with the sample gas are heated to temperatures >180°C to prevent any adsorptional loss of mercury . The sample line is made of perfluor alkoxy (PFA), a material which shows extremely weak interaction with mercury vapor. Sampling and reduction are performed at temperatures far above the dew point. Therefore no condensate is formed before all mercury is in elemental state. This minimizes signal noise and avoids nonspecific peaks. The SM-3 does not use any gold collector for mercury preconcentration thus giving a very fast response and providing results continuously and in realtime. Possible problems connected with “poisoning” of the gold surface are also avoided. The straightforward analysis avoiding wet-chemical sample treatment ensures high reliability and low maintenance. Easy to operate The SM-3 is operated via a waterproof membrane keypad. All inputs required are selected in a readily under-standable menu shown on the graphical display. Conditions which may lead to a malfunction are detected by sensors and indicated by a status message provided via relay contacts. Low maintenance and low costs of ownership Thanks to the thermocatalytic sample treatment method no reagents are required. Compared to first generation instruments employing wet chemical sample preparation methods, the SM-3 features clearly increased reliability and requires only minimum maintenance. This results in particularly low cost of ownership and maximum availability. UV-Photometer Quantitative determination of the mercury concentration is performed in a UV-photometer (ENVEA GmbH VM-3000 Vapor Monitor) with an electrodeless low-pressure mercury lamp. This lamp is controlled using the reference-beam-method which ensures a highly stable baseline. Automatic zero adjustment The zero line of the SM-3 is checked and adjusted automatically after a preset period of time. A magnetic valve stops the sample gas stream and switches over to zero air which has been cleaned in a sulfurized carbon filter. Automatic zero adjustment is performed every hour and requires 30 seconds. Automatic calibration check The SM-3 is able to perform an automatic span check at preset time intervals if a suitable calibration gas source (for example from a compressed gas cylinder) is connected to the analyzer. Automatic self-cleaning filter To prevent the instrument from being clogged by dust-particles, the SM-3 has a self-cleaning filter system which is operated by compressed air. The cleaning function is automatically activated every hour and is a matter of seconds. Sampling system The sample gas is extracted with a stainless steel probe and conducted through a heated tube to the analyzer. The entire sample line is made of perfluoralkoxy (PFA), a material guaranteeing a minimum memory effect. The dimensions of the sampling system mounting flange are customized (for example DN 65/PN 6 or ANSI 3“/ 150 lbs) The importance of continuous mercury emission monitoring Monitoring of mercury emissions from stack has become a global issue. More strict regulations by authorities as well as the public claim for a complete surveillance of incinerators have caused an increasing interest in continuous emission monitors (CEMs) for mercury. For the potential user of such systems it is important to find a reliable and economic solution. First generation CEMs for mercury were based on the automation of known laboratory methods. This resulted in high maintenance costs, unreliable operation, oversized and heavy construction and last but not least a high price. A new analytical solution: the SM-3 The operating principle of the SM-3 is based on a completely new technique. Cracking of mercury compounds and reduction of ionic mercury contained in stack gas is performed applying the thermocatalytic method. Wet chemical sample gas treatment using reagents and bubblers is avoided. Maintenance and servicing of the SM-3 are therefore extremely easy. urchasing costs and costs of ownership are comparatively low. As the SM-3 is a compact-sized and low-weight device, it may also be used for mobile applications. Installation is easy and quickly done. Technical Specifications Mercury Stack Monitor SM-3 Measuring principle: Thermocatalytic reduction, atomic absorption at 253.7 nm Measuring component: Total mercury [Hg(tot)] Measuring range: 0 ... 10 µg / m³; 0 ... 50 µg / m³; 0 - 100 µg / m³; 0 - 500 µg / m³ Detection limit: < 1 µg / m³ Response time T90: < 60 sec Measurement cycle time: none, continuous measurement without time gaps Operating temperature: 5 ... 40°C Power supply: 230 V / 50 Hz(+10% / -15%) Electrical power consumption: Analyzer : max. 1000 VA; Sample line: max. 150 VA/m Signal outputs: 4 ... 20 mA; RS 232; RS 485 Dimensions: 55 x 100 x 70 cm (W x H x D) Weight: approx. 50 kg ©2020 ENVEA GmbH, Mercury Stack Gas Monitor SM-3 Specifications subjet to change without notice ENVEA GmbH Analytical Technologies As a leading supplier of high precision analytical Liebigstraße 5 equipment, we strive at all times to offer top quality D-85757 Karlsfeld solutions. Our products are manufactured according mail.mi@envea.global to the ISO 9001 quality regulations. Tel.: +49(0)8131 - 50 57 20 Fax.: +49(0)8131 - 50 57 22 ENVEA (Headquarters) 111 Bd Robespierre / CS 80004 78304 Poissy CEDEX 4 - FRANCE Visit us at: +33(0)1 39 22 38 00 www.envea.global info@envea.global