"At roughly $4 billion annually, the liquids level sensor market is mature, and we can generally provide suitable technology," said Joe Willson, vice president and general manager, Rosemount Level, Emerson Process Management, in a press conference Tuesday morning at Emerson Global Users Exchange 2014 in Orlando, Florida. "Solids applications are at least 20 years behind in terms of sophistication." You can use a liquid technology like radar to get a spot reading, but "your understanding of what's in the bin is a combination of a level and a set of assumptions," Willson said. "That may be OK for a tall cylinder with a cone of material at the top—the error may be irrelevant—but otherwise, it's inaccurate."
The new Rosemount 5708 Series of 3D Solids Scanners use three transducers, radiating acoustic waves and fuzzy logic algorithms to measure solids in silos, large open bins, bulk solid storage rooms, stockpiles and warehouses. There are models to deliver either level data only or both level and volume data using intuitive monitoring software. They map the uneven surface typically found in solids applications and can provide the minimum and maximum level, the total volume and a 3D visualization of the surface.
Unlike laser-based technologies that can take several hours to take measurements and require the process to be shut down, Rosemount 3D Solids Scanners provide continuous volume measurements that are representative of the material's surface. They can measure practically any kind of material, including difficult-to-measure fly ash and materials with a low dielectric that would challenge other technologies. The self-cleaning design requires little maintenance even when used in the dustiest environments.
The 5708 "brings to bulk solids the same resolution as liquid level measurement," Willson said. Along with better measurement, it's a significant improvement in safety when personnel don't have to climb vessels that are "tall, exposed and slippery when wet," he said. "There are numerous fatalities each year from techs falling off silos."
The instruments also can detect asymmetric buildup that can overload a silo structure. "Big silos collapse due to asymmetric loads," Willson said.
The Rosemount 5708 Series includes level scanners for silos up to 5 m (16 feet) diameter and 70 m (230 feet) height, and there is also a version for larger vessels and silos up to 12 m (39 feet) diameter and 70 m (230 feet) height. Emerson can also supply systems of multiple devices to cover large areas such as 30 m x 70 m (98 feet x 230 feet) warehouses.
The new Rosemount 3D Solids Scanners are part of Emerson's comprehensive range of level measurement devices for many applications across a range of industries. The new 3D solids scanners complement Emerson's existing Rosemount 5400 Series of non-contacting radar level transmitters and the Rosemount 5300 Series guided wave radar for solids measurement in smaller vessels.