Photo courtesy of Bühler.
Usually, bottom and inlet slide gates in the scales are operated by pneumatic cylinders. The use of compressed air means expensive infrastructure susceptible to leaks. In addition, using compressed air is energy intensive and is characterized by low efficiency. The new Tubex generation scales from Bühler work without compressed air. Electromagnetic valves are used instead of pneumatic cylinders.
“Conventional scales have the compressed air permanently available, even when the scale is closed,” said Andreas Kleiner, whose design team developed the concept over two years. “And that is the case for more than 95% of the operating time. So energy is used just to keep things stable. The drive of our new scale generation works in exactly the opposite way. As long as the valve is closed, the electromagnetic drive is off. When the valve needs to open, then it starts operating.”
That massively reduced the amount of energy used, Kleiner said. In addition, the energy that is created when the bottom gates are braked can be recovered with so-called supercapacitors, like the ones that are used in Formula 1.
“Our new scale, fitted with a 40-liter scale hopper, has reduced energy consumption by 95%,” Kleiner said.
Since the same drive is used for all sizes of the new scale generation from Bühler, the energy savings potential for a 300-liter scale comes to 99.4%. Converted into U.S. dollars, energy costs drop to $60 instead of $10,500 every year.
Tubex is a completely closed scale, which means it has no false-air opening. An accurate differential pressure sensor measures the internal pressure fluctuations. The sophisticated algorithms of the control system process the measurement values and compensate for the influence of the pressure fluctuations on the measurement accuracy. That increases process safety as well as sanitation, Bühler said. In addition, cleaning openings improve access, which shortens cleaning time.
The parts that come into contact with product are made of stainless steel. The combination of a closed system, stainless steel and clever design forms the basis for optimal sanitation.
The user-friendly controls also may be used with mobile end devices. The new control system evaluates the various measuring cells individually and has a big range of service functions available. The intelligent measuring technology constantly monitors all important operating and service parameters while the diagnostic system detects problems at an early stage. Thanks to a modern interface, it is best prepared for the needs of IoT.