Figure showing the proposes cement plant and material flow

The Relevance of systems engineering to handling bulk materials
Projects dealing with bulk material handling are in most circumstances inter-disciplinary, complex and large. System Engineering, as a tool for design and management is normally used for building and designing systems which are complete in order to avoid difficulties that such projects may face. This is because it translates the needs of the client from past experiences or business objectives into specific system specifications. For the whole project to succeed, it normally involves four principles.
One of first principles is top-down design which involves the splitting of a complex system into smaller subsystems through the use of its components. The reason of doing this is to be able to deliver through pipeline, two million tones of limestone to a cement plant that is located 78 kilometers away to manufacture cement. Even though the whole process may appear to be complicated, breaking it into subsystems makes it to be a little easier. Some of the subsystems include (a) Grinding or Crushing of limestone into desirable shapes and sizes for easy transportation. (b) Mixing water with the limestone and pumping the slurry through the pipeline. (c) The slurry is then ridded of water and dried to be used at the receiving terminal. These processes therefore make it easy for the subsystems to be designed.
The Bottom up integration approach is the second principle of system design in which complex and large systems are built through completing and establishment of low level components alongside moving of each level at a time. The approach is advantageous because it adequately addresses minute details of the project and therefore reducing the number of bugs that the project may have. For instance, pumps and pipelines selected should always be of high quality standards before being installed into the pumping sub-system. The combination of these systems together with the crushing systems makes it to be well integrated and therefore to easily achieve its intended objective.
The system Life Cycle is the third principle of system design and it comprises of systematic stages from the concept, designing, implementation, operation of the system, maintaining of the system and finally when the system is disposed. All the above mentioned stages will normally have their own life cycle. This therefore greatly demystifies how each small component of the system easily fits in it and therefore easily helping to split the complex ad large conceptual processes and procedures into easily manageable smaller chunks.
User perspective is the last relevance of system engineering and it involves the needs and wants of the user like for instance in transporting two million t/a of limestone to the processing cement plant. In order to satisfy the needs of the customers, system engineering is used so as to perform a complex project. The design of the system involves the services of all the users thus the maintainer, management, operator and maintainer. For successfully transportation of limestone to the cement plant, a variety of subsystems must work together. The table below indicates how the elements of each sub-system like manpower, equipments, machines control and monitor software are arranged. The proper functioning of each of these small pieces makes the whole system top easily achieve its objective.
Figure showing the proposes cement plant and material flow
Figure One


Functions of each item in Figure one
Stacks and Electrostatic Precipitators
The function of the Electrostatic precipitators is to eliminate the harmful gases which have a hazardous effect. These harmful gases go through metal collection plates that have high voltage which ensures that the gas is cleaned.
Distributor: Its function is to transport the slurry into agitated tanks which in turn distributes it to the major pipelines with the aid of the booster pumps.
Filtering: It is a procedure which separates particles from the liquid by use of the vacuum process.
Agitated Storage Tanks: the slurry is at this stage, separated into sludge and powder. While the powder is obtained from the tanks that have the main line pump, the sludge is obtained at the bottom. Agitated storage tanks are used at all the ends of the main pipelines along with the booster pumps.
Clarifier, Vacuum Filter and Drier: in circumstances where space is limited or scarce like in this in this case, the use of vacuum filters cannot be downplayed. The material is sent to the drier once it is filtered. The hot gases is used by the drier which sends it to the major cement plant after drying it for more relevant processes that are needed. Figures 8 and 9 clearly and respectively indicates the filter and the drier.
Primary Crusher: The major function of the primary crusher is to crush the big limestone rocks into small sizes in order for them to be easily stored in the conveying and storage. Because of gravity chute, the limestone is conveyed from the limestone deposit to the crusher and it is eventually crushed into small particles with smaller diameters.
Ball Mill: The work of the ball mill is to grind the limestone into smaller particles and then convert them into the size of the millimeter whole at the same time adding water to the cement in order to make it slurry. The size of the mill may be different based on the demand of cement and the production. The Discrete Element Method (DEM) is the major method for the grinding.
Pump Box: This is a device that is used in pumping a mixture of solid and liquid particles fast away and over long distances.
Storage Bin: The work of the storage bin is to store fine cement powder. The size of this storage bin may differ depending on the demand of cement at the processing plant and the type of production that is being used. The storage bin can be composed of steel walls which may comprise of the belt conveyor located at the bottom end in order to make a fast transfer of cement to the ball mill.
Cyclone Separator: This one divides the larger particles and fine particles. The large particles have to be further broken into smaller sizes and eventually sent to the ball mill while the smaller ones are sent to the pump box whereby they are finally distributed through the distribution box to the pipe.
Rotor Impactor Hammer: The limestone coming from the storage conveyor is moved to the crusher via the conveyor. The crusher then reduces the limestone’s size from 1 cu. M TO THE 25MM SIZE. The Limestone which is crushed is then sent to a stacker reclaimer through a belt conveyor. A suitable bag filter system is normally provided so as to control the emissions arising from the crusher.
4. The Functions of the Rheological and Flow Tests
Rheological tests
The flow or rheological property of slurry is vital in general since factors like for instance durability, strength, ease of placement and consolidation are based on the flow properties. Defects such s air voids, particles segregation and honey combs may normally merge as a result of improperly constituted slurry. The design of several test methods has therefore been triggered because of important performance attributes. The flow behavi...