WNIP SEPT OCT 19.5 DIGITAL

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24 <strong>19.5</strong> Accurate measurements for process control and product quality of LNG Natural gas is sourced from various gas fields and offers a major leap towards a renewablebased energy future. Colourless, odourless and nontoxic, it is the cleanest-burning hydrocarbon on the market today, with global demand on the rise. It is used for both heat and power, and the automotive market has also embraced it to keep vehicles on the road. The majority of natural gas is transported in gaseous form via onshore or offshore gas pipelines. For stranded gas reserves where there is little or no local demand, or for long transport distances – more than 1000km offshore or less than 3000km onshore - it becomes more economical to liquefy the natural gas prior to transportation, especially as it ensures safe and easy storage to its various locations. In addition, due to the nearly 600-fold reduction in volume for liquid natural gas (LNG) versus natural gas, LNG is often the preferred method for local storage. Continuous uninterrupted operation – the gas pre-treatment, dehydration, and liquefaction process trains – is essential to ensure on-time LNG loading and shipment. In addition, processing feed gas to remove contaminants is critical to the operation of LNG plants. Raw natural gas from different geological formations contains varying amounts of acid gases (H2S and CO2). These contaminants must be removed from LNG feed gas to prevent CO2 from freezing at cryogenic processing temperatures and H2S from exceeding gas quality specifications. Once LNG has been liquefied and stored in tanks, it is ready for transport to other markets, usually via LNG carrier. These custody transfers from the storage tank to the ship, or from the ship at a receiving terminal, often involve millions of rands of product in a single shipment. As such, it is essential that both the deliverer and recipient of the LNG know exactly how much energy has been transacted, and an uncertainty of as little as one percent in energy transferred can cost the buyer or seller dearly. The compositional measurements of natural gas in gaseous and liquefied states, and of mixed refrigerants, help LNG plants operate efficiently and determine the energy value of LNG. According to the Group International des Importateurs de Gaz Naturel Liquéfié (GIIGNL), a key factor in determining proper energy transfer is the measurement of gross calorific value (GCV), which is calculated from LNG composition. For traditional GC-vaporiser systems, it is essential to eliminate partial and pre-vaporisation for all LNG flow rates of the LNG sample, which requires careful installation and proper maintenance to ensure good insulation and no hot spots in the sample vaporisation and transport paths. In addition, the GIIGNL states that LNG must be sampled during stable flow of LNG. Data collected during flow variations and interruptions is not used in the calculation of the energy transferred, and can result in a significant amount of LNG being transferred without known GCV. Laser spectroscopy analysers from SpectraSensors have the technology to perform critical measurements throughout the LNG value chain - from pretreatment and liquefaction through to custody transfer and regasification to support on-time shipments. Its tuneable diode laser absorption spectroscopy analysers (TDLAS) monitor H2O, H2S and CO2 concentrations in natural gas as the gas undergoes treatment to remove and control these contaminants prior to liquefaction. Furthermore, SpectraSensors Raman Optograf LNG analysers perform on-line composition measurements of feed gas, LNG as a cryogenic liquid, mixed refrigerant, and gas following LNG regasification. A unique feature of the Optograf LNG analyser is that it measures the composition of LNG in the cryogenic liquid state, resulting faster update times because it does not require any vaporisation, sample conditioning, or sample transport. The Optograf LNG analyser is essentially immune to LNG flow variations, and so can provide a more complete measurement of the GCV of the entire shipload. Maintenance is also significantly lower with the Optograf LNG analyser, since there is no moving parts and no insulation to degrade. LNG that has been delivered to an import terminal may be however too rich or too lean to meet local pipeline specifications of the downstream markets to which the gas will be delivered. There are several ways to modify the CV of the natural gas. The CV can be reduced by adding N2 or CO2, or by selectively removing C3/C4 components from the sample. The CV can be increased by mixing with liquefied petroleum gas (LPG) or natural gas liquids (NGL). And, in some cases, LNG with different CVs can be blended to achieve target quality. Measurement of the CV of the final mixture is essential to confirming that the product quality meets local regulations to avoid significant tariffs. The Wobbe Index (WI), which is calculated from the gas composition, is the most widely accepted measure of gas quality and interchangeability. The Optograf LNG analyser provides composition measurement of the LNG, WI, and simultaneously provides the concentration of nitrogen, which can be used to ensure that nitrogen levels do not exceed pipeline specifications. WI modification of natural gas at import terminals is often measured with a Process GC. Prior to analysis, the LNG sample must be vaporised. Poor repeatability in vaporisation leads to large variations in WI, adding uncertainty to the ballasting process. In addition, vaporisation and sample transport lag time, coupled with typical Process GC update times of four to five minutes, means that this approach provides only sporadic updates during ballasting, increasing the likelihood of overshooting the WI target, and incurring additional cost. Because the Optograf LNG analyser is able to measure the sample in the cryogenic liquid, response times are much faster and repeatability is much higher than with legacy GC/ vaporiser systems. As demand grows, LNG export facilities will need to handle natural gas feeds of varying quality from multiple sources, and so adjust refrigerant composition to ensure the lowest energy consumption during liquefaction. In addition, these plants will need to dynamically compensate for refrigerant losses with makeup refrigerant. The technology from SpectraSensors measures both natural gas and make-up refrigerant composition in both the gas and liquid phases, so plant operators can measure the quality of the feed gas and thus adjust their make-up refrigerant for optimum plant operating efficiency. carmine.canale@ za.endress.com
25 Precise, hygienic and dynamic switching and control from electromotive diaphragm valves <strong>19.5</strong> The Type 3323 shut-off valve and the Type 3363 control valve are two new additions to a line of electromotive valves, which – especially for applications without a compressed air supply – set new standards with respect to performance, reliability and costeffectiveness. The valves with an electromotive actuator are ideal for applications that either do not require compressed air or for which compressed air is not available due to the difficulty of conveying it to the application. They feature high control accuracy and highly dynamic control, which allows them to reach the set point exactly and instantaneously with dynamic performance of 4 mm/s. The maximum closing time is below 4.5 s. Overshooting or undershooting, which can occur with pneumatic valves, is not possible. Integration of the piloting function in the compact drive eliminates the need for control cabinet installation, as well as field piping and the power supply for the compressed air. The electromotive drive principle allows adaptation of the driving force to the respective application, which increases the life of the diaphragms and maintenance intervals, thus reducing maintenance costs. Safety is the top priority The electromotive drives can be combined with diverse standard bodies and diaphragms of the family of pneumatically operated products. Electromotive valves are very cost-effective due to their low energy costs and savings throughout the entire system. A special advantage of the this solution is an innovative cogging torque controller, which fixes the position of the valve without additional energy consumption. If there is a power outage the safety position can be approached via the optional SAFEPOS energy storage pack. The safety position can also be adapted to the particular process. A mechanical position indicator with a 360° LED clearly indicates the position and status of the valve at all times. Hygienic, high-quality and durable The field bus capable Type 3323 / 3363 diaphragm valves consist entirely of high-quality components. The linear motion is executed by a brushless DC motor with a planetary gear via a low-friction, permanently lubricated ball screw. This also prevents negative effects from pressure surges, which occur in pneumatic drives. Precise control with segment disc valves Segment disc valves work on a very simple but effective principle. The central throttling elements – the segment discs that glide and seal against each other – are positioned in the valve body perpendicular to the flow direction. On a non-rotatable aligned segment disc whose geometry determines the flow rate and characteristic, a movable disc having the same number of segments is shifted by a tangentially engaging rod in such a way that the free cross-sectional area of the segments changes continuously. Regardless of the prevailing pressure difference, a spring assembly constantly presses the movable disc onto the fixed disc. As a result, the flow direction is variable and the valve can be installed in any position. This special design makes segment disc valves one of the few valves that combine control precision even in extreme operating conditions with a high seal tightness and very low exposure to wear. Segment disc valves and Segment disc orifices Perfect and variable control with high precision over a wide flow range is made possible by the segment disc valves from Schubert & Salzer. Due to the robust design and the reciprocal flow direction, segment disc valves are suitable The robust powder-coated aluminium body with protection type IP65/IP67 features an easy-toclean and closed design. The shutoff and control valves are resistant to weather, impacts and vibrations, which makes them ideal for use in harsh environments. Ideal for hygienic applications The new electromotive diaphragm valves are offered as a shut-off valve (Type 3323) and as a control valve (Type 3363), in diameters up to DN50. The FDA, USP and EHEDG compliant valves are especially suitable for cleanroom, filling, packaging and CIP/SIP applications in the pharmaceutical and health care sectors, for use in the dairy and cosmetics industries, as well as for industrial water treatment. When pressurised air is not available or not wanted, electromotive valves are ideal. For valves that are operated remotely from the central air supply, the operational costs can be reduced. The superior control characteristics are another benefit of electromotive actuators. dave.strydom@burkert.com for fluids as well as vapours, even if these are contaminated by particles. The wide range of applications includes areas such as building materials, chemical and power plants, pipelines, water supply and disposal, as well as shipbuilding. This ingeniously simple but effective valve design is available up to nominal size DN800. keith.hedges@macfluid.co.za Robust and rugged tablet Announcing the launch of a new rugged tablet, the Windows HR 802-RG. This “worker-proof” tablet, with CPU: Intel Bay-Tray Z3735F Quad-core turbo 1.8GHz, boasts two cameras as well as GPS and barcode scanner. The tablet comes standard with Windows 10, Wi-Fi and Bluetooth 4.0 capabilities as well as 2G ram and an additional 32G SSD. The 8 inch display, with Capacitive Multi-touch IPS screen at 1280*800 pixels, operates in temperatures from -10⁰C up to 50⁰C. Optional extras include finger-print scanner, external battery, handheld belt, docking station and support for 2D code. info@rjconnect.co.za
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Page 3 and 4: 3 On the Cover... 19.5 Laser distan
Page 5 and 6: 5 19.5 Temperature measurement evol
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Page 11 and 12: 11 New powerful switched-mode power
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Page 23: 23 New AC power supply with integra
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Page 31 and 32: 31 19.5 THE PLUG VALVE COMPANY ARMA

WNIP SEPT OCT 19.5 DIGITAL

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