1.1 Introduction
Dust is a serious health hazard especially to the respiratory system. It can have a cumulative effect eventually resulting in permanent damage to the health.
Fine dust is the most dangerous and the most difficult to get rid off. The sharing and the large particles of dust are not much of a problem as most of it falls to the floor quickly and lungs have a built in mechanism which can eject relatively large particles.
The dust particles that causes damage are normally in the range of 0.2 to 5 micron in size (a micron is one thousand of a millimeter) and so small as t o be invisible to the naked eye. They can remain suspended in the air for hours. Even if one cannot see any dust, the atmosphere may still be harming ones lungs. One is likely to breath 8 to 10 cubic meters of air during and 8 hour working day most especially those working in the engineering workshops that has to do with metal drilling (drilling, shaping etc) drugs manufacturing industry, paint industry and food processing industry.
If the dust in the air average out of 5 mg per cubic meter during that period, then you will suck in 50gm (2 ounces0 of dust. Most of this w ill be dealt with by the body's own dust defence mechanism the nasal hair and mucus lined walls of the air ways leading to the lungs will swallow most of it. Only a very tiny percentage of the dust is permanently trapped in the lungs but it is this which causes the damage.
Dust from some wood can cause skin complaints such as dermatitis.
Dust Extractors: With a small dust extractor couple with the respirator to give a primary protection. You must not need a huge powerful machine it will help to keep the workshop clean and you can use it with it's flexible hose to cover up the sharing and remove dust which has settled on surfaces. Because you have a wood turning lathe you can quickly turn up a wooden adaptor to accept the hose form your domestic vacuum cleaner to give you a handy extension hose. If you have other wood working machines such as a table saw you can hookup the extractor to them when you need to use them.
Extracting Dust: The fan sucks the air into an oil drum shaped container and then through an internal filter. These machines usually also make use of the cyclone effect to reduce the load on the filter. This type of machine is cheaper, takes less space, has superior filtration and has a stronger suction for hovering. The motor however is very noisy and the airflow is much less than the external bag machine.
The small filter clog quickly reducing he air flow dramatically. The wood turner really need is a machine which moves a larger volume of air at a lower speed breeze which wafts the fine suspended dust away from the lathe into an efficient filter.
Those extractors setups for paint spraying welding which consist of a large three sided box built around the work area. Built into the rear of the box in an array of huge powerful fans which sucks all fine dust and fumes through suitably design filters at the rear and recalculate the air. They work well because they move a very large volume of air.
Another dust extractor BB100, this is a low cost fine dust extractor (performance rating 3) for the hobby workshop. It is equipped with a 1000 watt vacuum cleaner motor which generates 195 cubic metres per hour of air flow and provides enough suction to cater for even the smallest of power tool inlets. The two stage filtration system consist of a pleated paper filter, rather like a car filter, surrounding the in let to the vacuum motor and a sub micron paper bag filter which totally encloses the pleated filter.
Largest sized waste, such as planer chippings, falls straight to the bottom of the drum whilst the smaller dust particles are captured by the paper filters. The paper filters can be easily replaced as necessary whilst the pleated filter can be a vacuum cleaner periodically. Typical uses for this extractor are small band saws; bench mounted sanding machines and portable power tools such as routers, planners and sanders. It also serves as a very effective vacuum cleaner for keeping the workshop clean and tidy.
1.2 Aims and Objectives of Study
This project is aimed not only at providing a dust extraction machine in factories and workshops. In achieving this aim, the following objectives were set out as follows:
- To provide a life equipment in the workshop which can be used for exhibition by students.
- To provide a machine (dust extractor) which could be further modified and improved on, for the extraction of dust from the atmosphere, which can favourably compete with the best in the market.
1.3 Economics Importance Of A Dust Extractor
- For extraction of dust fro the air
- Locally made dust extractors can be sourced in the market
- Effective dust extraction can only be achieved if handled by an experienced person
- Durability if proper maintenance culture is adopted.
1.4 Uses Of A Dust Extractor
- Can be used in extracting dust from the workshops
- Can be produced and sold to factories thereby serving as a source of income to the producer.
- Reduces disease that could have been contacted from the air through dust.
1.5 Design Consideration
The design and selection of materials is governed by many factors, first, considering the physical characteristics of the extractor i.e the shape, size and weight.
- Design also to protect man against his negligence and for the safety of the motor.
- Design to work effectively in any place of application.
- The weather condition of any place of its application was also considered, therefore it can be used anywhere without being affected by the weather condition of the environment.
- Working Method: Metal cutting process consist in removing a layer of metal from blank to obtain a machine part of the required shape and dimensions and with a specified quality of surface finish.
A metal cutting tool is the part of a metal cutting machine tool that, in the cutting process, acts directly on the blank from which the finished part is to be made. The metal cutting process accompanied by deformation in compression, tension and shear by a great deal friction and heat generation, tension and shear by a great deal friction and heat generation governed by definite laws. In order to cut the material from blank, the cutting tool should be harder than the material to be cut, the tool should penetrate the blank and the tool should be strong enough to withstand the forces developed in cutting.
In this construction of these dust extraction machine, a lot of welding activities was done and more also, forging in general. Welding is defined as a group of processes in which metals are joined by bringing abutting surfaces to a molten state. It facilitates light weight construction.
1.6 Limitations of the Study
During the course of this study, many things militated against its completion, some of which are:
- Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
- Research material: availability of research material is a major setback to the scope of the study.
- Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
- Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, and literature or information.
1.7 Significance of the Study
This device is targeted at solving the problem of dust pollution occurring from small scale business ventures where dust is generated such as solid mineral processing factories, wood processing factories, grain milling and threshing and other such similar ventures or activities where dust is readily and openly released to the atmosphere or the environment. Indigenous extractor devices are not common; this research will be an indigenous design of a dust extractor machine.
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