PCME’s involvement with the Cement Industry has lead to the development of many novel and unique solutions for in-stack particulate monitoring. Working worldwide in conjunction with the industry’s major producers, PCME provides an unparalleled range of instrumentation suitable for aggressive conditions and to help not only to protect our environment by aiding legislative compliance, but also in reducing operator costs by reducing filter maintenance and process downtime.
PCME's range of technologies are matched to the differing process conditions found in cement plant
Bagfilters are widely in use as the preferred emission abatement for cement plant, with up to 20 or more separate bagfilters for larger plant, and a range of sizes and chamber configurations in use. Under normal circumstances, emissions are well below emissions limits of 30 or 50mg/m3, however there is a growing need for continuous monitoring to understand how the arrestment plant is working and provide information to help locate and replace leaking bags early on before failures can create contagious failures in other bags.
For example, European cement plant operators are faced with a changing regulatory regime, as cement kilns using waste as a fuel source (eg tyres, plastics and municipal waste) are classified as co-incineration and therefore fall under the European Waste Incineration Directive 2000/76/EC (WID), and particulate emissions monitoring systems must be upgraded to comply with standards EN 14181 and EN 13284-2. Because of the lower emission limits in force, cement kilns and a growing number of other processes are replacing electrostatic precipitators with high temperature bagfilters to abate emissions, which are exposed to elevated environmental stresses and therefore are more prone to failure. These large, multi-compartment bagfilters can be monitored on individual filter compartment outlets, providing data to plant operators which permits location of faulty and failing filter media before gross failure occurs. This in turn allows efficient operation and control of bagfilter arrestment plant, and considerably reduces maintenance costs and expensive process downtime.
The principle sources of particulate emissions in the cement industry are rotary kiln, raw mill, clinker cooler and cement mill plant, with additional sources such as coal mill and crusher plant also subject to emission abatement. Most modern cement plant uses either electrostatic precipitators or highly efficient fabric bagfilters for emissions arrestment, with bagfilters increasingly dominant.
Crushing and Milling
With coal milling (if used as kiln fuel), clinker milling, and raw material crushing and milling, particulate emissions are controlled and abated using fabric bagfilters. As the catch from the abatement plant after raw milling is returned to the process, they are considered as production plant as well as pollution control devices, and therefore gains in process efficiency can be made by monitoring abatement plant performance to maximise efficiency and minimise product loss.
Pyroprocessing, Calcination and Kilns
Emissions from cement kilns are potentially subject to strict emissions limits, particularly if waste is used as a fuel source. Unless the process includes preheating, emissions after cement kilns are inevitably humid which can create problems for particulate monitoring systems based on standard opacity technology. Combined with the fact that electrostatic precipitators are often in use after kilns, caution has to be applied when selecting a particulate monitoring system so that both accurate measurement and robust, reliable operation is assured.
ElectroDynamic™ sensors with patented insulated probe offer unrivalled performance in humid process applications. See DynamicOpacity™ Ratiometric Opacity technology for monitoring after electrostatic precipitators
Range of Technologies:
PCME recognise that differing environmental conditions and process applications require different technologies to ensure maximised system reliability, to provide the most accurate emissions measurement, and to provide operators with data that facilitates process and arrestment plant management for reduced costs and maximised efficiency. Selecting the best technology for each application can mean considerably reduced maintenance and servicing requirements.
For electrostatic precipitator abatement plant, PCME offer a range of DynamicOpacity™ Ratiometric Opacity instruments, which require significantly reduced maintenance compared to typical Opacity instruments. PCME’s DynamicOpacity™ technology also operates with heavy lens contamination of up to 90%, and the instrument is not damaged in the event of air purge failure. For PS-11 (US) and EN 14181 (Europe) compliance with cement kilns, the PCME QAL 181 using unique ProScatter™ Forward Scatter technology offers high sensitivity (minimum detection limit <0.05mg/m3) and rugged operation, with extensive quality assurance and audit features to meet and exceed regulatory requirements. Bagfilter arrestment plant can be monitored by a networked system of ElectroDynamic™ Probe Electrification instruments, certified to TUV and MCERTS performance standards with patented features for high performance under a wide range of process conditions.
Sufficient minimum detection level for highly abated emissions:
PCME’s ElectroDynamic™ Probe Electrification technology has a minimum detection level (0.1mg/m3) suitable for highly abated emissions, such as those found after bagfilters in cement plant, including QAL1 approved instruments with certification range 0-15mg/m3 for Emission Limit Values as low as 10mg/m3. ProScatter™ Forward Scatter instruments such as PCME QAL 181 are suitable for even lower concentrations of <0.05mg/m3, and are also certified to the most demanding European (MCERTS and TUV) and US EPA (PS-11) standards.
Network Integration:
Cement plant typically requires instrumentation across several emissions sources. PCME sensors can be networked into one central control unit, integrated with existing plant DCS/SCADA systems, and provide Ethernet connectivity for plant-wide LAN integration.
Quality Assurance:
Stricter compliance programs and more rigidly enforced emission limits within the cement industry means that operators require an increased level of quality assurance, and confidence in their emissions monitoring systems to operate correctly and also minimise emission limit excursion events. PCME offer systems approved to the latest MCERTS & TUV standards, with manual or automated zero and span / reference drift checks for ongoing quality assurance.
Humid Process Application:
PCME’s ElectroDynamic™ range includes a patented insulated sensing probe option for use in high humidity and condensing gas applications, for unrivalled performance in humid processes including those found in cement plant such as after cement kilns. The insulated probe has been demonstrated to operate with minimum maintenance for extended periods with ‘sticky’ particulate matter caking the sensing probe, due to the unique ElectroDynamic™ measurement technique.
