Design and fabrication of a motorized mobile sand filter and separator.
Abstract
Construction of buildings requires sand as an important ingredient Sand is used at different
stages in construction right from the foundation to the finishing work i.e. plaster. This sand is
needs to be screened properly for various stages in construction, i.e. size of sand for
construction work is slightly coarse whereas that used for plaster work is fine. Conventionally
screening is normally done manually using fixed screens or machines. This manual process
time consuming and laborious takes a lot of time and cost. It is also observed that the
conventional machine prove of no or little help as the sand needs to be manually transported
and material handling takes place twice to get different sizes of sand. These processes are
carried out manually. The main objective of this research was to design and fabricate a sand
filtering and separating machine.
Sieving of sand is carried out using rectangular mesh which is inclined at certain angle. The
sieve/filter box (containing sand) is set into a horizontal reciprocating motion through a
connecting rod attached to a crank. The crank converts circular motion into reciprocating
motion of the sand sieve box. The crank is driven by a power transmission mechanism ie Vbelt and pulley system with a motor providing the input power. The velocity of the sieve box
accelerates the sand particles in a horizontal motion. This movement distributes the particles
over the sieve while changing orientation. The particles interact with the sieve mesh thus
passing through the larger openings as they move to and fro.
The design factors, calculations and fabrication are consistent. The machine was tested in the
workshop in kabanyoro Makerere University and it was confirmed in good working
condition.The length of the belt calculated as 1168mm was considered the minimum. An
allowable excess of 8mm was added to avoid losses. The fabrication was carried out under
adequate precautionary measures, thus no accident occurred. The cost, as estimated, is
considerable affordable and the machine is economical, in terms of time and effort. The
efficiency, calculated, is 90% with a Sieving rate - Itonne-tonne/hr (5mm sieve); -800kgItonne/hr. (2.36mm sieve); -600-800kg/hr(2.00mm sieve) thus the machines durability is high,
based on the discussion of results. It was concluded that the prototype is able to efficiently
sieve sand and separate it from unwanted material. Further modifications are also are necessary
on this machine, towards reducing cost, weight, and increasing efficiency and output while at
the same time meeting the required standards.