1.0 Introduction
Filtration is the removal of solid particles from a fluid by passing the fluid through a filtering medium or septum, on which the solids are deposited, example of such filtering medium is known as sand filter.
The fluid may be a liquid or gas; the valuable stream from the filter may be fluid, the solid on both. Sometimes it is neither as when waste solid, must be separated from waste prior to disposal, in chemical laboratory.
In chemical laboratory, filtration is often carried out in a form of buchnor funnel and liquid is sucked through a thin layer of particles using a source of vacuum or even sampler cases, the suspension is pored into a conical funnel filtered unit a filter perper.
Generally, a thick layer of particles or solid particles as to be formed and in order to achieve a high rate of passage of fluid through the solids, high pressure will be required and it will be necessary to provide a far greater area.
Fluid flows through a filter medium by virtue of pressure differences across the medium. The volume of the suspension to be handled will very from the extremely large quantities involved in water purification and are handling in the miming industry to relative small quantity in the fine chemical industry where the variety of solids would be considered.
For large scale filtration, cloth or canvas is frequently used as the medium, and the liquid is forced by pressure through the bed of the solid that collects impurities in the liquid. A common method of large scale and domestic filtration is the purification of water by collecting some suspended penticle on a bed composed of coarse gravel covers with fine layers of sand. The water sinks down through gravel and is run off by gravity. The equipment used is the sand filter.
However, filters are divided into three major groups such as cake fitters, clarifying filters, and gross flow filters; there are different types of filters such as pressure filters, rotary filters, cake filters, string discharge filters, centrifugal filters, granular filters and send filter.
1.1 Scope of Study
The constructional project involves the project of slow sand filter for portable water filtration. Only two different sand layers of varying sizes were used as filter medium due to size required and cost implications.
Among other materials of construction, mild steel sheet were used due to its low resistance to corrosion, compare to stainless steel sheet, but among other considerations, availability cost were the major constraints. Therefore it has high quality properties like hardness, resistance to corrosion, resistance to chemicals, and resistance to heat.
1.2 Aims and Objectives
The aim of constructing sand filter equipment for portable water filtration is to learn a craft work. Construction of sand filter enable students to be conversant with the use of industrial equipment such as fabrication machine, flooding machine, bending machine and drilling machine etc.
The construction of sand slitter gives a basic knowledge, which will equip student in designing of other industrial equipment. Therefore, sand filter is an equipment designed for the separation of solid material from liquid or gas. Sand filter are constructed for water purification and removal of suspended matter particles from a liquid in the industries, laboratories and domestic home etc.
Also, the equipment determine the amount of that would passes through a particular amount of sand and the amount of water that was displaced in the particle.
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