Paint & Coatings Industry - March 2009 - (Page 51) their behavior changes with the flow rate. In addition to the high viscosity, DN 40 flowmeters also have to cope with high pigment contents. Moreover, BASF Coatings did not want to risk any further pressure loss by installing the flowmeter; otherwise, they would have to increase the performance of the pump. BASF Coatings thus opted for the OPTIMASS, a mass flowmeter that is virtually made for this application thanks to its straighttube design (Figure 3). OPTIMASS Straight-Tube Design KROHNE has always relied on the straight-tube design because it offers obvious advantages compared to mass flowmeters with curved or twin tubes. A range of media, such as viscous, non-Newtonian, shear-sensitive fluids and fluids containing solids, cause high-pressure losses in twin tube meters. Abrasive media can corrode flow splitters and bent tubes, whereas process liquids containing fibers, such as palm oil or cellulose, can accumulate FIGURE 2 | Mobile paddle mixers. Adaptive Sensor Technology With its third generation of straight-tube mass flowmeters, KROHNE has developed a revolutionary patented technology known as “Adaptive Sensor Technology” (AST), which has been successfully implemented time and again. KROHNE has taken a quantum leap in Coriolis technology with AST, which has rendered every OPTIMASS insensitive to system vibrations and external process conditions. In traditional straight-tube mass flowmeters, so-called absorber masses (vibration dampers) are often used to mechanically isolate the measuring system from the process. An absorber mass is a springsupported mass on the inner cylinder. Instead of an absorber mass (vibration damper) and the spring, however, KROHNE’s OPTIMASS uses an integral spring mass system incorporating the dynamic elements of the measuring system. As the absorber masses and the rigidity of the spring are constant in conventional straight-tube meters, but the density of the medium – and consequently the resonance frequency – changes, the vibration damper can only compensate in tight density limits. KROHNE’s patented AST design, on the other hand, comprises an inner cylinder, with the ends of the connection pipes serving as a spring for the absorber mass system. The main advantage of this is that the spring (i.e., the measuring tube ends) is self-compensating. As the fluid density changes, so too does the dynamic behavior of the measuring tube ends (or the spring), depending on the mass of the inner cylinder. This produces a fully balanced system optimized accordingly under all process conditions. As no vibration energy is transferred outwards, the zero-point stability and measuring accuracy are excellent. FIGURE 3 | KROHNE OPTIMASS in the pipeline. OPTIMASS 7000: Technical Specifications Measuring tube materials Titanium, stainless steel, Hastelloy DN 06 to DN 80 950 kg/h to 430,000 kg/h 150 °C and 100 bar (titanium), 100 °C and 40 bar (Hastelloy and stainless steel) RA < 0.8 μm (Ra30), optional RA < 0.5 μm (Ra20) Suitable for CIP/SIP up to 150 °C, self-draining and sterilizable Fully welded Tri-Clamp/Tri-Clover connections, fully welded aseptic flange as per DIN 11864-2 ATEX, FM, CSA, PED, 3A, EHEDG, custody transfer as per OIML R 117 (titanium appliances) FIGURE 4 | PLC terminal. Sizes Measuring range Process liquid temperature and pressure Roughness Cleaning Connections Approvals PA I N T & C O A T I N G S I N D U S T R Y 51
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