Extrusion International 6-2018

43 Extrusion International 6/2018 now. The production expansion in 2016/2017 was no excep- tion. The company was looking to buy systems for plants in Brazil, Colombia and Peru. And once again, they opted for the experts from Leonberg. “The customer’s central solu- tion requirements were reliability, safety and precision. We were able to offer a solution that met these requirements, both technically andeconomically,” explains Roland Schwab, Product Manager at LEWA GmbH. Tried-and-tested systems with customdesigns: The LEWA Ecoflowdiaphragmmetering pumps are the core of the new systems. Customers have the option to select from a variety of pump head types (diaphragm or packed plunger pump head), materials and surfaces, which means that their systems can be built to handle a wide range of fluids, including flammable, toxic, abrasive, viscous, envi- ronmentally harmful and sensitive fluids. The Ecoflow series can be used for flow rates up to 19m³/h per pump head (the model used by the customer operates between 0.5 and 10 l/h) and discharge pressures up to a maximum of 1,200 bar. Tank sizes also vary between 60 and 240 l/h. The hydrauli- cally actuated pump heads stand out in particular for their high operating reliability aswell as a long service life, which is made possible by features such as the patented diaphragm protection system (DPS). This ensures that the pumps remain hydraulically stable even in the event of accidents or operat- ing errors. As a result, the pumps are extremely reliable and have lowmaintenance and operating costs. The systems have also been adapted to the customer’s spe- cific requirements. This way, it is possible to make modifica- tions to the flow rates, connection voltage, system hierarchy and product supply without a hitch. At the same time, it was also necessary to construct the systems in accordance with the valid regulations of the country of installation – for exam- ple relating to implementing explosion protection. “Beyond that, the visual displays were each delivered in the language of the specific country,” Schwab adds. Another one of the purchaser’s requirements was that it be possible to use the systems universally for different silane liquid types. LEWA met this requirement by using high-quality materials. Stain- less steel was used for the pump housing and PTFE was used for the sandwich diaphragm. These materials show hardly any wear, even when pumping aggressive fluids. Measures for greater safety when handling silane: LEWA took a variety of steps to guarantee the level of safety required by the customer for the handling the silane be- ing used. These steps included designing the system in ac- cordance with Ex-Zone 2 and equipping it with continuous monitoring for certain parameters such as fill level, flow rate and pressure or diaphragm status. “Additionally, an inert atmosphere is created by nitrogen blanketing,” explains Schwab. The reliable “LEWA Smart Control” controller allows for in- tuitive operation using a color touch panel directly on the control cabinet. The controller is integrated into the high- er-level system control. Among other features, the touch panel delivers a general graphic overview of the individual processes and parameters as well as a summation of produc- tion related data. This data can then be used as a foundation for initial analyses in the event that maintenance should be required. Using an optional data connection, LEWA is able to connect to the system directly and provide support from their headquarters in Leonberg. This data connection even allowed LEWA to provide the customer with support during commissioning. Thereby, the process was able to be signifi- cantly shortened. Smart accuracy: “We also fulfilled the third essential requirement – the requirement for accuracy—using LEWA Smart Control,” Schwab explains. “The controller handles this by carrying out a continuous variance analysis and then instantly adjusting the flow rate as necessary.” For the alignment, a high preci- sion mass-flow meter is used as a measurement instrument for the actual value, and an external 4-20 mA guide signal is used for the target value. The customer also receives infor- mation on the status of the systemby comparing the current flow rate for a specific point of operation with the flow rate stored in the controller for that operating point. For even greater reliability, the systems also each feature a redundant metering pump. “To ensure optimal reproducibility, consistency and product purity of the plastics, it is necessary for the silane to be me- tered precisely and independently of external influences,” Schwab states. “The fact that the customer once again called upon us to implement this process at various plants shows that we have truly earned the trust of this customer thanks to our technical expertise.” LEWA GmbH Ulmer Str. 10, 71229 Leonberg, Germany www.lewa.de LEWA Smart Control guarantees metering accuracy. The controller handles this by carrying out a variance analysis and then instantly adjusting the flow rate as necessary (Source: LEWA GmbH)