King of the bin: Rotary paddle point level indicator
A point level indicator indicates a material's presence or absence in a vessel, typically at a high or low point. Some of the point level indicator's most common applications are maintaining a predetermined material level in a vessel, preventing vessel overflow, and indicating plugging in a conveyor or pneumatic conveying line. This article looks at one indicator type -- the rotary paddle point level indicator -- whose simple electromechanical design, low cost, and other advantages make it one of today's most popular point level indicators.
Detecting the level of dry bulk materials at specific points in bins, silos, and other vessels can be a challenge. Factors like your material's bulk density, dielectric constant (the material's ability to hold an electrical charge), particle size, moisture content, and flowability -- as well as changes in these characteristics -- often limit which point level indicators can perform well in your application. Process and environmental factors like the vessel's internal temperature and pressure and your application's ambient temperature can also affect your choice of point level indicator.