For manufacturers and producers with solids in storage need accurate level measurements for inventory management. In a Power & Bulk Solids article, Meeting the Level Measurement Challenges at Lime Processing Plants, Emerson’s Kurt Gieselman describes some level measurement technologies to meet the challenges in solids storage.
…with products crushed, ground into powders and heated in a kiln to create hydrated lime. Due to the processes involved and nature of the products, conditions in the plant are harsh.
…have challenging operating conditions due to the weight of the material, dust, and low reflectivity of the surface.
He describes the challenges in a hydrated lime surge bin where a screw compressor is run:
…to carry the material out of the surge bin at a steady rate. To do this, an optimal level height was needed but getting a stable reading was challenging. Within the small surge bin, the material tended to compress in some areas and to create gaps and bridges in other areas. To prevent this, pneumatic vibrators are used to shake and re-distribute the material.
Capacitance probe measurements were erratic and were replaced with Rosemount 5303 guided wave radar (GWR) level measurements.
A critical advantage of the GWR is its ability to provide accurate measurements in small tanks with rapidly changing levels, which is essential for this application and enables a steady level to be maintained. The device is proving to be reliable and maintenance free. The improvement in measurement accuracy has allowed the process to become more stable.
Kurt describes challenges and successful solutions in other applications such as coal used in kiln heating where non-contacting radar [Rosemount 5408] replaced ultrasonic level sensors. Other applications and solutions Kurt highlights are hydrated storage lime silos measurements and load outs on hydrated lime product.
Read the article for more on these applications and comparisons of the different level measurement technologies used in these applications. Visit the Continuous Level Measurement section on Emerson.com for more on these technologies and the applications for which they are well suited.