While engineers are devastated when they first learn of a failure of a structure that they have designed, modified, or participated in its construction, this is just the beginning of an often years-long litigation journey if, eventually, there are legal claims as a consequence of that failure. Failures of silos in industrial facilities bring another level of complexity due to the number of parties involved (e.g., contractors, subcontractors, equipment suppliers, raw material suppliers, owners, plant operators, and maintenance personnel), the level of complexity in these industrial systems, and the cost of the equipment damaged as well as downtime, and potentially, serious injuries or loss of life. There are many causes of silo failures including design, construction, usage, and maintenance. During the long process of designing and constructing a silo, many omissions or oversights can occur. Many of these are due to the lack of training in this specialized field and the paucity of reliable, useful information in the literature, including relevant codes available for engineers in charge of the design of silo structures. Engineers in charge of the design and construction of silos as well as similar industrial facilities used to store and/or process bulk solids will benefit from this paper as they will be able to better understand the legal implications beyond silo failures. Engineers involved in forensic engineering and insurance claims will be able to gather information on the engineering as well as the legal side of failures in industrial storage facilities for bulk solids.

With the advancement of renewable energy, the processing and handling of biomass feedstocks has drawn enormous research interest. The key to economically viable and operationally reliable biomass handling processes involves a complete understanding of the flow behavior of different feedstocks as functions of the inherent critical material properties environmental conditions, and critical processing parameters. This review introduces the basic principles and methods in bulk solids flow and highlights recent efforts to understand the flow behavior of biomass feedstocks. The effects of inherent properties, environmental parameters, and handling equipment on the flow behavior of biomass feedstocks are presented. Particle size, shape, moisture, consolidation stress, temperature, storage time at rest, chemical treatment, and the material and geometry of the handling equipment all substantially influence biomass flowability. The limitations of current studies and the potential methods to overcome them are presented. Finally, an outlook for future research effort is provided, with proposed opportunities for improving the characterization of biomass flow.

Abstract Handling powders and bulk solids is difficult and costly and may affect production, quality, and the overall bottom line. Therefore, measurement of the flow properties of powders and bulk solids has become a necessity for their successful handling, storage, and transfer. This article covers the common methods for measuring the flow properties of powders and bulk solids.

The field of bulk solids flow has been developed considerably since the development of the theory of bulk solids flow began in early 1950s, which allowed the design of equipment and testing methods. More recent advances in numerical modeling have had a significant impact on the design methodology of bulk solids handling equipment. In this article, bulk flow patterns, measurement, and their simulation, as well as equipment design and maintenance are described. Special considerations including sifting, and mixing and blending, are also discussed.

In order to structurally design a silo, an engineer must determine all loads that are likely to be applied to it. These include, among others, wind, seismic, external, and loads induced by the stored bulk solid. Numerous codes and standards specify means to calculate the latter (so-called solids-induced loads). Among them, the four most common in use in the world today are:•British Standard BS EN 1991-4:2006 “Eurocode 1 – Actions on structures – Part 4: Silos and Tanks”•American Concrete Institute ACI 313-97 “Standard practice for design and construction of concrete silos and stacking tubes for storing granular materials”•American Society of Agricultural Engineers ANSI/ASAE EP433 DEC1988 (R2011) “Loads exerted by free-flowing grain on bins”•Australian Standard AS 3774-1996 “Loads on bulk solids containers”

Numerous codes and standards specify means to calculate material-induced loads that are needed to design silos. The three most commonly used of such codes do not provide users with consistent information, and many common silo design conditions are not covered. A brief description of each code and its limitations is provided, and common design conditions not covered by any code are identified. (C) 2014 American Society of Civil Engineers.

This year marks the centennial of the birth of Andrew Jenike. At the age of 39 he made a momentous decision -- one that influenced and affected his life and indeed thousands of people around the world. His decision was to devote his life to the study of the design of bins and hoppers for storage and flow of bulk solids. Jenike was truly a visionary. He developed a theory to fulfil a practical need, and he approached his work with enthusiasm and focus not unlike famous inventors like Thomas Edison. Indeed he changed the way we design and build storage vessels for solids in a very revolutionary way. As Reg Davies once said, “As scientists and engineers, rarely do we accomplish something that changes the way people think and behave to such a degree that our name becomes synonymous with its application. That's Jenike”.

Design of reliable bulk solids handling equipment usually requires the results from shear tests. Thus, such results need to be reliable and consistent. A global procedure or standard helps designers to use data measured by various laboratories. After preliminary work in Europe, a well defined shear test procedure has now become an ASTM standard.

Although statistics are not available, hundreds of industrial and farm silos, bins and hoppers experience some degree of failure each year. Sometimes the failure is a complete and dramatic structural collapse. Other times the failure is not as dramatic or as obvious. For example, cracks may form in a concrete wall, or dents in a steel shell, either of which might appear harmless to the casual observer. Nevertheless, these are danger signals which indicate that corrective measures are probably required. The economic cost of a silo failure is never small. The owner faces the immediate costs of lost production and repairs, personnel in the vicinity are exposed to significant danger, and the designer and builder face possible litigation because of their liability exposure. The major causes of silo failures are because of shortcomings in one or more of four categories: design, construction, usage, and maintenance. Each of these is explored in this chapter, with examples and lessons learned.

AbstractWhen work on the development of the theory of bulk solids flow began in the early 1950s, bulk solids were thought to behave much like liquids, and thus were expected to flow easily from bins. Powder flow is not always reliable, however. The field of bulk solids flow has since been developed to allow design of equipment and testing methods.Typical flow problems include no‐flow (arching, ratholing), erratic flow, flooding, limited discharge rate, and segregation. Flow patterns experienced by bulk solids include funnel flow, which occurs when some of the material in a bin moves toward the outlet while the rest remains stationary; mass flow, where all of a material is in motion whenever any is withdrawn; and expanded flow, which uses the best aspects of funnel flow and mass flow.Equipment design, maintenance, and special considerations including sifting, particle velocity, and entrainment are discussed.

Segregation (separation) of particles in mixtures is a common problem in many industries. In the pharmaceutical industry such segregation is often of major concern when handling direct compression formulations prior to pressing tablets or capsules. The result can be unacceptable variations in tablet or capsule weights and/or assays. Similarly in the cosmetics industry, particle segregation can cause severe quality control problems.Particle segregation can occur by one of five primary mechanisms, three of which are common in the pharmaceutical and cosmetics industries. Which mechanism is predominant in a given application depends on the physical properties of the material being handled as well as the type of equipment being used.Each of the three common mechanisms will be described in detail. Then typical solutions will be presented for both retrofitting existing facilities as well as designing new plants. While it is not always possible to eliminate segregation, it can usually be minimized to the point that significant gains in product quality can be realized.