Tripper cars typically function as a shiftable transfer point for raw material, moving back and forth along a track to direct the discharge of mined material at specific locations, such as conveyor loading points, mills, bins or stockpiles, for example.
Krohne, a Duisburg, Germany-based provider of technology for measurement of flow, mass flow, level, pressure and temperature in process applications, reports that one of the world’s largest gold mines solved a bulk storage problem by using its Optiwave 6300 non-contact radar level meter to reliably measure ore levels in multiple bins, with product height typically exceeding 10 m (33 ft). In operation, the position of the tripper car is controlled by the bin levels and the demand for material in the bins. However, due to mounting and mechanical restrictions, the existing bin level radar meters were positioned to the side of the bins and consequently could not measure full product level when the top of the pile approached the height of the conveyor, resulting in the possibility for ore to build up to the level of the tripper, damaging the car and causing a potentially hazardous situation. After mounting an Optiwave 6300 radar level meter on the tripper car itself, the 6300’s radar proved capable of quickly locking onto and measuring the material height in each of the bins. The car-mounted radar, according to Krohne, provides redundancy for the bin-mounted radars and protects the tripper cars from damage caused by an overfilled bin.
Krohne also noted that the dust and dirt inherent in handling ore makes reliable bin level measurement from a moving tripper car even more challenging. In these conditions, the 6300’s radar level meter, said the company, provides a more stable and responsive measurement than pulse radar because it features a teardrop antenna design that prevents product build-up in dusty applications. In addition, the unit’s frequency-modulated, continuous-wave (FMCW) measuring principle provides continuous measurement at high bandwidth, resulting in enhanced reliability and accuracy in the presence of strong multiple reflections, like a dusty environment. An installation wizard specifically for solids, powders and granulates permits the instrument to measure uneven surfaces accurately with ranges up to 80 m (260 ft).