On the transportation systems for bulk materials and goods.
Dobre, George ; Mirica, Radu Florin ; Vladu, Mihai Robert 等
1. INTRODUCTION
The transportation systems are destined to travel the bulk
materials and goods between different operational places - a process
needed in different engineering or social-economic activities. The
interoperation transport (included in them) is considered to be between
processes from manufacture: for example, production and montage.
Their large area of types and solutions is difficult to be
classified. Really, the references (especially those with education aim)
are generally very old (Spivakovskii & Rudenko, 1949; Segal et al.,
1960; Segall, 1988) and give classifications of these systems at the
time of the books' writing. New references classifying only some
types of transportation systems for the bulk materials and goods, for
example: Alspaugh (2008), Boteanu (2006), Enciu (2008), Iordache (2007),
Radulescu & Vatau (2008). Alspaugh (2008) treats particularly the
belt conveyors used for the transportation of bulk materials; Radulescu
& Vatau (2008) analyze the moving systems as automated
transportation systems, especially the automated guided vehicles;
Boteanu (2006) and Iordache (2007) study electromechanical controlled
transportation systems, especially the conveyor types for bulk materials
and goods.
The present paper proposes own classification schemes of the
transportation systems for bulk materials and goods (individual
products) on the basis of the literature (selected in the list of
references) and on the own experience in the field. Definitions and
considerations (characterizations) on the classification schemes are
also achieved. Thus, the paper is an attempt of survey or overview of
the mentioned knowledge field needed in the academic education and
researches.
Future studies will suggest new classifications and corresponding
classifications for complex transportation systems as combinations by
many individuals included in the given classifications. Moreover, future
researches could be oriented to develop software and the necessary
databases referring to transportation systems appearing in the product
development.
2. CLASSIFICATIONS, CONSIDERATIONS
The general classification of the transportation systems used for
bulk materials and goods is represented in the fig. 1. It is visible
that the transportation systems can be classified after several
criteria: the relative fixation on frame or ground; the transport
direction; the working position; the driving manner; the action
continuity; the trajectory type. In the restricted space of the paper,
the given examples are limited.
About the relative fixations on frame or ground, the systems could
be fixed (conveyors, sub-classified into the fig. 2) or moving
(vehicles, sub-classified in the fig. 3).
[FIGURE 1 OMITTED]
[FIGURE 2 OMITTED]
[FIGURE 3 OMITTED]
Evidently, the moving transportation systems (fig. 3) offer new
service functions in comparison with the fixed system ones.
The conveyors with flexible elements (belt, chain etc.) offer the
motion between the components and by this a supplementary freedom
degrees needed in many applications, in the conditions of a simple
building and reliable function. The other type of conveyors (without
flexible elements) has a limited number of freedom degrees and could
operate in some cases in extreme conditions of environment (temperature,
pressure, corrosive materials etc.).
The vehicles (on wheels for travel) are in a large constructive
diversity synthesized in the fig 3 (without other discussion): simple
vehicles, vehicle with trailers (coupled or decoupled), forklifts (for
pallets or for heights) and automated guided vehicles.
The transportation systems travel the bulk materials and goods on
direction: horizontal (slat conveyor), vertical (bucket conveyor),
inclined (screw conveyor) or combined in function of necessity.
By the working position, the transportation systems can be placed
on ground (winch conveyors), on frame (chain conveyors, escalators),
hanged (overhead conveyor) or combined.
By the driving manner, the systems can be driven by handshift
(electrocar), electro-mechanical controller (roller or wheel or flexi
conveyers) or computer (automated guided vehicles).
By the action continuity, the systems can be with continuous action
(in the montage or assembling production line) or with discontinuous action (shipping conveyors, construction cranes).
By the transport trajectory type, the materialized ones have
concrete shape: mechanical (rail, cable, band, belt), optical (transport
reflective band), magnetic (magnetic guide) or inductive (guide using
inductive coils).
The virtual trajectory is carried out by computer. The system needs
also sensors to establish the current position (of the vehicle,
transported product) by measurement of: the motion (of wheels); the mass
inertia (of an accelerometer) for translation or rotation; the deviation
from a laser radius or from the intersection of two laser radius.
Another way to establish the position on the virtual trajectory is based
on the environment recognition; using signals from optical or acoustic
devices, the computer establishes the current environment relief, the
effective position and the travel direction of the product in this space
avoiding the collisions.
The discussed schemes are useful for the CAD approach of
technological processes using expert software.
3. CONCLUSIONS
The conclusions are given punctually below.
1. The classification and characterization of the transport systems
destined for bulk materials and goods represent a complicate problem to
solve in the actual state of these types of product in engineering area.
2. A general scheme of the transportation systems and two
sub-schemes about different criteria for main sub-components (conveyors
and vehicles) give a primary image on the existing such systems. These
schemes could be enlarged and improved in another attempt of this aim.
3. Future researches are necessary to build software and database
to design transportation systems in the product development.
4. ACKNOWLEDGEMENTS
The work has been funded by the Sectoral Operational Programme
Human Resources Development 2007-2013 of the Romanian Ministry of
Labour, Family and Social Protection through the Financial Agreement
POSDRU/88/1.5/S/60203.
5. REFERENCES
Alspaugh, M. (2008) Bulk material handling by conveyor belt 7,
Society for Minning, Metalurgy and Exploration, 2008, ISBN:
978-0-87335-260-4, Littleton-Colorado
Boteanu, N. (2006). Installations de levage et transport, Editura
Universitara Craiova, ISBN 973-742-310-0, Craiova
Enciu, G. (2008). Sisteme de alimentare, transport, transfer
(Translation in English: Systems for power, transportation, transfer),
Editura Didactica si Pedagogica RA, ISBN 978973-30-2344-9, Bucuresti
Iordache, G. (2007). Utilaje si instalatii de transport continuu
(Translation in English: Machinery and equipment for continued
transportation), Editura Matrixrom, ISBN 978973-755-271-6, Bucuresti
Radulescu, C. & Vatau, S. (2008). Roboti mobili. Vehicule
ghidate automat (Translation in English: Mobile robots. Automated guided
vehicles), Editura Politehnica Timisoara, ISBN 978-973-625-664-6,
Timisoara
Segal, H.; Linde, C. & Purcariu, I. (1960). Ma[section]ini de
ridicat si de transportat (Translation in English: Lifting and
transportation machines), Editura Tehnica, Bucuresti
Segall, H. (1988). Masini de ridicat si de transportat pentru
constructii (Translation in English: Lifting and transportation
machines: continuous transport installations), Editura Institutul de
Constructii, Bucuresti
Spivakovskii, A. O. & Rudenko, N. F. (1949).
Pod'emnotransportnye mashiny, Mashgiz, Moskva