INSTRUMENTATION,
INSTRUMENTATION, CONTROL, AUTOMATION The automated retractable sensor housing with rinse control system improves measurement value availability and sensor lifetime while simultaneously reducing manual servicing requirements where most problems emerge in industrial pH measurement. Errors in pH measurements obtained with glass sensors are usually caused by sensor contamination. In many processes, coverings form on the sensors which, after a few days, can only be removed by using highly concentrated cleaning agents, often strong acids. These chemical cleaning agents must act for longer periods of time to become fully effective. Consequently, manual maintenance on a pH measuring point is relatively timeconsuming. It is also rather dangerous for operators, because they have to handle aggressive cleaning agents. Hence, maintenance personnel usually do not consider this one of their favourite tasks. As a result, planned maintenance work is skipped or not performed adequately, which leads to unreliable measurement values. This creates a vicious circle. In practice, many plant operators have surrendered and are ignoring the problem, not knowing that there is a simple and cost-effective solution. The solution The vicious circle described above can easily be broken by using automated retractable sensor housings with a cleaning control system. The retractable sensor housing is at the heart of such a measurement system. If selected and configured properly for the respective process conditions, it will work maintenance-free for many years. Once you have eliminated the maintenance work on a manual measurement point, you don’t want to go right back and do maintenance on the sensor housing. The Extract range of sensor housings can be used for virtually any kind of application. Featuring a very robust PTFE process seal, extremely short stroke movements even when deeply submersed and maintenance-free drives, these sensor housings form the basis for reliable measuring points. The patent-protected rinsing chamber of the Extract product series provides for excellent cleaning of the glass sensor, ensuring the best possible care of the delicate sensors. The Exmatic 460 is precisely tailored to the fittings, making it the perfect rinse control system. The control system is connected to the fitting via a multi-hose. Installation is quick and easy thanks to size and colour-coded hose connections. The program sequence is pre-installed in the controls and only has to be adjusted and parameterised to the various application conditions. The operator is guided through the program step-bystep. Longer sensor lifetime Yet how can such a retractable sensor housing and rinse control system improve measurement value availability and sensor lifetime while simultaneously reducing manual servicing requirements? The automated, periodic and consistent rinsing of the sensor and the level of care achieved by it are key to this effect. The rinse control system is specifically designed for the cleaning procedure and adapted to the different process requirements. Thanks to the regular rinsing of the sensor with water and cleaning agents, it is almost impossible for coverings or dirt to accumulate on the sensor. In many applications, rinsing is performed every two hours. The minor deposits that form during the measurement interval are simply rinsed off. Long reaction times, as seen with chemical cleaning agents, become obsolete in most cases because the sensor is returned to the medium for the next measuring task in a clean state, similar to a laboratory measurement. Due to the fully automated nature of the system, cleaning is performed with such regularity as cannot be achieved by maintenance personnel. When a pH sensor is cared for in this way, its calibration intervals become significantly longer compared to manual measuring points. The same is true with regard to the lifetime of the sensors. Due to greatly reduced manual maintenance activities and the longer sensor lifetime, it is possible to recoup the investment within a few months in most applications. In order to remind operators of the existing pH measuring points, the control system transmits their respective operating condition, measurement or service, and any possible errors directly to a higher process control system. This way, operators always have a complete overview of their measuring points. Of course, the measured value is “frozen” during cleaning to prevent any influence on the current process control. Overall, this solution is a robust, easy-to-use and virtually maintenance-free system that can be used for very long periods of time. » www.cpp-net.com Online search: cpp0117exner Author Detlef Exner General Manager, Exner Process Equipment 26 cpp 1-2017
PRODUCTS Check valves for demanding applications Reverse flows in pipes of process plants and in natural gas applications can cause major damage and downtime and pose safety risks. Hoerbiger plate check valves offer effective protection against dangerous reverse gas flows and improve equipment safety by closing quickly during and before any flow reversal, made possible by a low-wear and low-mass design featuring a minimised number of components. The plate check valves can be mounted in any orientation and position, both upstream and downstream. This in turn reduces engineering complexity and increases flexibility in pipe planning. Hoerbiger check valves come in two housing configura - tions. Both meet international standards for face-to-face dimensions and can be adapted to specific customer requirements. The bell-type housing offers the lowest pressure drop and enhanced fire safety. The wafer-type housing is more compact, and consequently more cost-effective, making it ideal for most applications. » www.cpp-net.com Online search: cpp0117hoerbiger Windows tablet PCs for field workers The Pad-Ex 01 Z2 and Pad-Ex 01 D2 are lightweight 11.6“ Windows tablet PCs which are certified for use in Atex Zone 2 and Division 2 classified hazardous locations. With Pad-Ex 01, the desktop PC used by field workers and their managers becomes mobile. Pad-Ex 01 can be used as a field-portable desktop extension (or replacement) to the desktop PC, offering a desktop dock for fast connection to your office monitor, mouse and keyboard. Supporting an Intel i5/i7 processor powerful enough to adequately run the full Windows 10 operating system together with demanding Windows applications, Pad-Ex 01 is also designed to be light enough (at 1.2 kg) to easily carry around the plant. Pad-Ex 01 is based on an ultrarugged Windows tablet – useful if you have both hazardous and non-hazardous areas. Software developed for the Ex-protected Pad-Ex 01 runs unaltered on the rugged device, and vice versa, further reducing your deployment costs. » www.cpp-net.com Online search: cpp0117ecom cpp 1-2017 27
