The Radar Solution to Dust

The dusty challenge Obtaining reliable level measurement has traditionally been a severe challenge because cement production is such a dusty process. During homogenization, for example, silos are continuously filled and emptied, and the component materials are constantly aerated to ensure good mixing. This creates a tremendous amount of dust that makes it difficult to obtain reliable readings with traditional non-contacting measurement devices. The concentrated dust blocks the signal, especially in this long-range application. Some plants have relied on manual measurements taken from the top of the silo using a rope. This is time consuming and provides only periodic readings. Tensile forces in these high silos can reach several tons, causing cables or moving parts inside the silo to break off and fall into the product. For this reason, contacting technologies such as TDR (cable radar) and yo-yo systems are problematic. Noncontacting ultrasonic systems have a hard time penetrating the extreme dust created by the powdery materials being mixed and aerated throughout the homogenizing process. The intense heat of cement production is also a limiting factor for many level instruments. High process temperatures, along with the severe dust, make level measurement in cement silos very difficult. Nonetheless, reliable level measurement is essential for good process control. The petroleum coke silo At one site, the company sought a level measurement solution for its petroleum coke silo. Petroleum coke, or pet coke, is a petroleum industry by-product that is often used as a fuel by the cement industry. It is a cost-effective alternative to oil, gas or coal, and generates a lot of heat. The plant uses petroleum coke to fire its kiln, and also transports pet coke to the company’s other nearby plants. The pet coke is conveyed from a trainunloading station and pneumatically fed The Radar Solution to Dust