Too big to fail?

摘要

The cement industry relies upon silos for storage of materials throughout the process of the creation of cement. Many arrive on site at a production facility fully realizing that mechanical systems and equipment need maintenance, but never think twice about their storage structures. Unfortunately, this can lead to tragic consequences for facility personnel as attested to by past failures. Many factors affect the behavior of storage silos. From the type of silo (raw material, blending, clinker, finish cement, and beyond), reclaim system, feeding system, construction date, contractor, design engineer, modifications to the structure, and more, there are many factors that can affect the behavior of a silo. Fortunately, silos typically give notices and warnings prior to failure. Observation of cracking patterns, concrete chunks in reclaim, delaminating and spalling concrete, and others can be sure indicators that something unintended is happening with your silos. A silo inspection by an experienced engineer can make sense of what the silo is telling us. Not all cracks are created the same, and different cracking patterns mean different issues. Silos, especially those around cement production, have their own unique issues. From abrasion and impact loads, to asymmetric flow, over pressurization from pneumatic feed systems, rat holing and bridging, differential foundation settlement can lead to disastrous results that could be better managed with the creation and implementation of an inspection program. This paper will discuss: Some of these warning signs in detail,; Failure modes (from hopper to wall connection failures, wall damage, roof beam support issues and collapse) in silos,; Give owners tips on what to seek during their plant walk downs, and show how an inspection program can arm owners of silos, both at individual plants as well as a fleet of facilities with information for their future planning.