Mechanical ship-unloaders boldly brave the elements

摘要

Ten years ago, engineering studies found that pneumatic continuous ship-unloaders (CSUs) were usually preferred for unloading capacities up to 250 t/h. At 300 t/h, the number of installed pneumatic and mechanical machines was virtually the same, but above 300 t/h, mechanical solutions were the norm. As technology has advanced though, those thresholds have steadily crept upwards. Pneumatic CSUs have closed the gap in terms of power consumption compared with mechanical systems, through innovations such as the use of frequency inverters that fine tune the motors and other mechanical components. This allows both continuous and precise control of the suction pattern. Air overflow is also regulated, in order to limit the power absorbed by the main electrical motor. So, with the pneumatic option hard on their heels, mechanical CSU providers have to run just as fast, or even faster. Ship-unloading has also developed into an exact science. With the choice of systems now on the market, it is no longer a case of just trying an installed grain unload-er to see if it will unload other material as well.