Bulk material handling is an
engineering field that is centered on the design of equipment used for the handling of dry materials. Bulk materials are those dry materials which are powdery, granular or lumpy in nature, and are stored in heaps.
[http://practicalmaintenance.net/wp-content/uploads/Maintenance-of-Ash-Handling-Plants-and-Pneumatic-Conveying-Systems.pdf ] Examples of bulk materials are
minerals,
ores,
coal,
cereal
A cereal is any Poaceae, grass cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, Cereal germ, germ, and bran. Cereal Grain, grain crops are grown in greater quantit ...
s,
woodchips
Woodchips are small- to medium-sized pieces of wood formed by cutting or chipping larger pieces of wood such as trees, branches, logging residues, stumps, roots, and wood waste.
Woodchips may be used as a biomass solid fuel and are raw material ...
,
sand,
gravel
Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone.
Gravel is classifi ...
,
clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4).
Clays develop plasticity when wet, due to a molecular film of water surrounding the clay part ...
,
cement
A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel (aggregate) together. Cement m ...
,
ash,
salt,
chemicals,
grain
A grain is a small, hard, dry fruit (caryopsis) – with or without an attached hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and legum ...
,
sugar
Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double ...
,
flour
Flour is a powder made by grinding raw grains, roots, beans, nuts, or seeds. Flours are used to make many different foods. Cereal flour, particularly wheat flour, is the main ingredient of bread, which is a staple food for many culture ...
and
stone in loose bulk form. It can also relate to the handling of mixed
wastes. Bulk material handling is an essential part of all industries that process bulk ingredients, including: food, beverage, confectionery, pet food, animal feed, tobacco, chemical, agricultural, polymer, plastic, rubber, ceramic, electronics, metals, minerals, paint, paper, textiles and more.
Major characteristics of bulk materials, so far as their handling is concerned, are: lump size,
bulk weight (density),
moisture content
Water content or moisture content is the quantity of water contained in a material, such as soil (called soil moisture), rock, ceramics, crops, or wood. Water content is used in a wide range of scientific and technical areas, and is expressed as a ...
, flowability (particle mobility),
angle of repose
The angle of repose, or critical angle of repose, of a granular material is the steepest angle of descent or dip relative to the horizontal plane to which a material can be piled without slumping. At this angle, the material on the slope fac ...
,
abrasiveness and
corrosivity, among others.
Bulk material handling systems are typically composed of stationary machinery such as
conveyor belt
A conveyor belt is the carrying medium of a belt conveyor system (often shortened to belt conveyor). A belt conveyor system is one of many types of conveyor systems. A belt conveyor system consists of two or more pulleys (sometimes referred to ...
s,
screw conveyors, tubular drag conveyors,
moving floors, toploaders,
stacker
A stacker is a large machine used in bulk material handling. Its function is to pile bulk material such as limestone, ores and cereals on to a stockpile. A reclaimer can be used to recover the material.
Gold dredges in Alaska had a stacker ...
s,
reclaimers,
bucket elevators, truck dumpers,
railcar dumpers or wagon tipplers,
shiploaders,
hoppers and diverters and various mobile equipment such as
loaders, mobile hopper loaders / unloaders, various shuttles, combined with storage facilities such as
stockyards,
storage silos or
stockpile
A stockpile is a pile or storage location for bulk materials, forming part of the bulk material handling process.
Stockpiles are used in many different areas, such as in a port, refinery or manufacturing facility. The stockpile is normally cre ...
s. Advanced bulk material handling systems feature integrated bulk storage (silos), conveying (mechanical or pneumatic
), and discharge.
The purpose of a bulk material handling facility may be to transport material from one of several locations (i.e. a source) to an ultimate destination or to process material such as ore in concentrating and
smelting or handling materials for manufacturing such as logs, wood chips and sawdust at sawmills and paper mills. Other industries using bulk materials handling include flour mills and coal-fired utility boilers.
Providing storage and inventory control and possibly material blending is usually part of a bulk material handling system.
In ports handling large quantities of bulk materials
continuous ship unloaders are replacing
gantry cranes.
Other materials handling classifications (non-bulk)
Non-bulk materials handling classifications include
palletization and
containerization.
See also
*
Bulk cargo
*
Bulk carrier
*
Caking
*
Double dump valve
*
Rotary car dumper
*
Self-discharger
SS Carl D. Bradley unloading hopper in 1958
A self-discharger (or self-unloader) is a ship that is able to discharge its cargo using its own gear. The most common discharge method for bulk cargo is to use an excavator that is fitted on a traver ...
References
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