Bulk solids transport

For there to be chemistry there must be movement of the reacting species. Some surface reactions occur between adsorbed species that diffuse over the surface. The number of degrees of freedom for moving reacting species is lower on surfaces than in three-dimensional space (in the fluid or the interior of a bulk solid). Transport is anisotropic and the diffusion rate on the surface is between that in the solid and in fluids. The dimension of the reaction space is a very significant factor in the chemistry and for diffusion rates in that space. 

Bulk solids transport comprises not only several fields of specialized technical expertise but also a major industry whose manufacturers have developed countless proprietary designs for various applications. This is a very brief overview, focusing on the project engineering and layout interface. 

The issues listed above are some of the important considerations when laying out a plant incorporating belt conveyors, or in deciding whether a belt conveyor or system of conveyors is the best solution for a given application of bulk solids transport. The following alternative devices are often worthy of consideration. 

A wide variety of containers of differing capacity and design are used for solids transport, i.e. fibreboard, metal, resin-lined metal, plastic drums plastic, paper or hessian sacks tote bins bulk tanker lorry-load. The material may then be stored in the containers as received, in hoppers or silos, or simply in piles depending upon its properties and value. 

Punwani, D. V., Modi, M. U., and Tarman, P. B., A Generalized Correlation for Estimating Choking Velocity in Vertical Solids Transport, Proc. International Powder and Bulk Solids Handling and Processing Conference, organized by the Powder Advisory Centre and the IIT Research Institute, Chicago (1976)... 

Yang, W. C., A Unified Theory on Dilute Phase Pneumatic Transport, J. Powder Bulk Solids Tech., 1 89 (1977)... 

The pneumatic transportation of bulk solids through pipelines has been in existence for over one hundred years. Some of the earlier applications included the vacuum unloading of grain from ships and the extraction of sawdust from timber mills. 

Cabrejos, F. J., and Klinzing, G. E., Minimum Conveying Velocity in Horizontal Pneumatic Transport and the Pickup and Saltation Mechanisms of Solid Particles, Bulk Solids Handling, 14(3) 541-550 (1994)... 

Wypych, P. W., Latest Developments in the Pneumatic Pipeline Transport of Bulk Solids, 5th Int. Conf. on Bulk Materials Storage, Handling and Transportation, Newcastle, IEAust, Proc, 1 47-56 (1995a)... 

Wypych, P. W., and Arnold, P. C., Pneumatic Transportation and Fluidization Performance of Power Station Fly Ash, Bulk Solids Handling, 6(1 ) 93—97 (1986a)... 

A.J. Stepanoff, Gravity Flow of Bulk Solids and Transport of Solids in Suspension, Wiley, New York, 1969. 

P. Marjanovic, Theoretical and practical silo design, Seminar on Storage and Transportation of Bulk Solids, Moreton-in-Marsh, UK, March 1996. 

Pneumatic conveying belongs to the well established processes for transporting a vast variety of bulk solids. Especially in the handling of granular polymers it is used extensively. Nevertheless, the problem of product degradation due to attrition is unresolved to date. This is partly due to the fact that research was focused on different topics like bend erosion or pipe wear [1,2]. But with the increas-... 

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