Design and Construction of Dust Extractors in Effect to reduce Pneumoconiosis
by Uchechukwu Clinton Uchenna and Adiri Chidi
Published onSep 18, 2023
Design and Construction of Dust Extractors in Effect to reduce Pneumoconiosis
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Abstract
The construction of dust extractors, which play a vital role in homes, industries, offices, etc. to enhance the removal of harmful airborne particles for the protection of worker and individual health and the maintenance of equipment functionality, equally to improve the quality of air released and was designed to minimize the chance of having lungs diseases such as pneumoconiosis and others. This project was carried out in the workshop and the work was produced with a mild steel sheet metal due to its properties.
This is an electricity-powered system made up of assembly parts such as: rollers, dust container, base, support, filtration systems, suction mechanisms and the key focus is on developing efficient air handling systems that can effectively extract airborne dust particles generated during manufacturing, construction, or other industrial processes including homes and offices. The dimensions, materials and configuration of the extractor are critical considerations to maximize its dust capture capacity, and overall performance.
The functionality of a dust extractor involves the process of capturing and removing dust particles from the working environment. This is achieved through various stages, starting with the initial capture of dust near the source using suction or downdraft techniques. The extracted dust is then transported through a filtration system, where particulates are separated and collected, while cleaned air released into the surrounding environment or redirected for additional purification if necessary. The efficiency of the filtration system, suction power, and ease of maintenance greatly influence the extractor’s performance.
The presence and application dust extractors is widespread in industries such as coal milling, woodwork, metalworking, and construction, where the generation dust particles presents health hazards and impacts product quality. They are commonly used in workshops, factories, laboratories, and manufacturing plants to minimize dust-related health risks, (pneumoconiosis), improve air quality, and protect machinery from particulate damage.
This system in a working environment will proffer a solution to the occurring problem of excessive dust accumulating in the human system because after the construction and testing carried out in this project work, the researchers certified it standard and safe for public use.
Dust extractor is a system used to enhance the quality or air released from industrial and commercial processes by collecting dust and other impurities from or gas. Designed to handle high volume dust loads, a dust extractor system consist of a slower, dust filter, a filter-cleaning system and dust removal system.
Dust consists of particles in the atmosphere that comes from various sources such as soil dust lifted by weather (an Aeolian process), volcanos eruptions and pollution. Dust in homes, offices and other human environment contains small amount plant pollen, human and animal hairs, textile fibers, paper fibers, minerals from outdoor soil, human skin cells, burnt meteorite particles and many other materials which may be found in the local environment.
Dust in the atmosphere is produced by saltation and sand blasting of sand-size grains, and it is transported through the atmosphere. This airborne dust is considered an aerosol and once in the atmosphere, it can produce strong local radiative forcing. Saharan dust in particular can be transported and deposited as far as the Caribbean and Amazonia, may affect air temperatures, cause Ocean cooling and alter rainfall amounts.
Cosmic dust is widely present in space, where gas and dust clouds are primary precursors for planetary systems. The zodiacal light, as seen in a dark night sky is produced by sunlight reflected from particles of dust in orbit around the sun. The tails or cornets are produced by emissions of dust and ionized gas room the body of the comet. Dust also covers solid planetary bodies, and vast dust storms occur on Mars that cover almost the entire planet. Interstellar dust is found between the stars, and high concentrated produce diffuse nebulae and reflection nebulae. Dust is widely present in the galaxy. Ambient radiation beats dust and re-emits radiation unto the microwave beats band, which may distort the cosmic microwave background power spectrum.
Dust in this regime has a complicated emission spectrum, and includes both thermal dust emission and spinning dust emission.
Coal dust is responsible for the lung disease known. As pneumoconiosis, including black lung disease that occurs among coal dust resorted in environmental legislation regulating work place air quality in some jurisdictions. In addition, if enough coal dust is dispersed within the air in a given area, it can create an explosion hazard under certain circumstances.
1.1 BACKGROUND OF THE PROBLEM
This project works dwells on maintaining a clean and healthy environment and also reduce the health threat to children, older people and those with respiratory illness.
1.2 STATEMENT OF THE PROBLEM
Due to people reaction about dust, the researchers decided to see how movable this dust extractor will be and the depth of which the extractor can extract dust with ease.
1.3 PURPOSE OF THE STUDY
The purpose of this study is aimed at the following: Maintaining a clean and conducive environment.
∙ To reduce health threat on children, older people and those with respiratory illness because it is discovered that coal dust is responsible for lung disease known as pneumoconiosis.
∙ To construct a mobile extractor not stationary to extract dust with ease.
1.4 SIGNIFICANCE OF THE STUDY
This study shows that the construction work is of great importance to the society especially engineering sectors because without this work, there may be increase in death as a result of lung disease called pneumoconiosis cause by dust Pollution.
1.5 SCOPE OF THE STUDY
The researchers limited their area of study to the internet and the construction works to enable them have amble knowledge of the study. This was as result of time constraint and finance.
1.6 LIMITATION OF THE STUDY
Finance was a major limitation to this study but through some financial assistance from friends, we were able to achieve our goal.
CHAPTER TWO
REVIEW OF RELATED LITERATURE
The first pulse jet collector was developed by pulverizing machinery of Summit new Jersey in the early 1960's, to collect dust from their pulverizes. They had tried to use the blow ring design but it could not handle the dust (powder) loads as pulverizes became bigger. The typical load to the collector/extractor was between 50 and 300 grains per cubic foot. The collector design was based on the same blow ring velocity and the rages were based on available designs from hipping pulverizes shafts. Pulverizes selected were diaphragms valves that were fast and the lowest Cost valve available. This happened to be a ¾ inch valve. They decided to use several valves in a collector and pulse them with an electronic timer. It was found that the whole sizes and venture were air ejector design that had the same jet velocity that the blow ring collector was using. But the big breakthrough came with the realization that the dust was ejected from the bag during the first 4 or 5 milliseconds of the valve opening. It became apparent that the frequency of cleaning was a function of the load to the collector.
For instance, for loadings of 300grains, the collector would operate at a filtering velocity of between 7 and 9ft per minute. At material handling facilities such as quarry would operate at a filtering velocity of 14 to 16 feet per minute. The typical pressure drop in these collector designs were about 2 or 3.5 inches water gauge pressure. The typical compressed air usage on the high loads was 1 to 2 SCFM at 80 psig per 1000 CFM of filtered air. For loads under 10 grains per cubic foot, the air usage was 0.2 to 0.8 SCFM per 1000 CFM of filtered air. Determining the filter velocity (then referred to as ratio) became a rather complicated procedure. The ratio presumably was determined by dust load, fineness of the dust, temperature of process gas stream and other factors.
By 1969, there were over 10,000 collectors in operation. Almost all of them were installed on process equipment or in foundries. Pulverizing machinery changed their name to Mikropul and licensed Flexkleen to build and market collectors. The collectors for Mikropul had 41/2 inch diameter bags and the Flexkleen units had 5 inch bags. The Mikro units had six foot and an occasion a collector with 8Ft long bags (to compete with Flexkleen on some projects) and the flex units had nominally eight foot long bags, bag life as usually 4 to 7 years. In 1971, the patent was challenged and the pulverizing machinery patent was declared invalid. The market changed radically because air pollution control regulations became effective. Many new suppliers entered the market in order to compete Mikropul change their design. They went from 6 foot to 10 0ot bags. They increased their pulse pipe holes by the same ratio. The whole industry followed and copied the new design for whole size and venturi throat diameter. At the time Mikropul had 40,000 venturies in stock and kept the same venturi sizes. This increased the jet velocity of the cleaning jet by 66percent. 1 This was when the dust collector market was growing at a 29%annual rate. With the new design pressure drop increase to 4/2 – 61/2 inches W.C. Compressed air consumption increased by 50% for similar applications. Bags life was reduced by over 50%. In the mid 70's, it discovered that the compressed air cleaning pulse jet collectors were encountering high pressure drops when applied to grains and to a lesser extent on wood working applications. The reason was that the compressed air as it left the pulse pipes was subject to refrigeration cycle as the compressed air expanded. The first approach was to apply reverse air blowers to the cleaning system. The blowers were mounted on the roof of dampers. The reverse air jet actually was higher in temperature than the process gas stream because of heat regain from the clearing air as it passed through the fan. The downside of these collectors was that the fan on top of the roof of the collector was difficult to service and as collectors system expanded, the weight of the fan was significant.
This collector pioneered some arrangements that allowed them to operate with grain dust with densities under 10 pounds per cubic foot.
They introduced the high cyclonic inlet of cylindrical shaped collectors. They also featured a rotating reverse air manifold. There are thousands of these collectors some we serviced for over 20 years. Twenty-four years ago, one of our associates worked for a company called Scientific Dust Collectors and developed new pulse jet collector that basically changed the cleaning system design. The key to this system design was he changed the jet velocity to a fraction of the existing designs. This eliminated the penetration of dust from the row of cleaning bags to the adjoining now in a filtering mode. This allowed pulse jet collectors to operate at lower pressure drops (2-3 inches w.c), lower air, consumption (50-75% less), 3 to 4 times more bags life and filter ratios of over 12:1 on any application while decreasing dust penetration by up to 90%.
Dust in the Middle East has been a historic phenomenon. Recently, because of climate change and the escalating process of desertification, the problem has worsened dramatically. As a multi-factor phenomenon, there is not yet a clear consensus on the sources or potential solutions to the problem.
In Iran, the dust is already affecting more than 5 million people directly, and has emerged as a serious government issue in recent years. In the province of Khuzestan, if has led to the severe reduction of air quality. The amount of pollutants in the air has surpassed more than 50 times the normal level several times in a year.
Recently, initiatives such as Project Dust have been established to directly study the Middle Eastern Dust.
The U.S Environmental Protection Agency (EPA) ma facilities that generate dust minimize or mitigate the production of dust in their operation. The most frequent dust control violations occur at new residential housing development in urban areas. United State Federal Law enquires that contractions sites obtain permit to conduct earth moving and include plans to control dust emissions. Control measures include such simple practices as spraying construction and demolition sites with water and preventing the tracking of dust unto adjacent roads. U.s federal laws require dust control on sources such as vacant lots, unpaved parking lots and unpaved roads. Dust in such places may be suppressed by mechanical methods including paving or laying down gravel or stabilizing the surface with water, vegetable oils or other dust suppressants or by using water misters to suppress dust that is already airborne.
CHAPTER THREE
RESEARCH METHODOLOGY
Dust extractor is a system used to enhance the quality of air from the source point on a continuous basis. It may be of single unit construction or a collection of devices used to separate particulate from the process air. They are often used as an air pollution control device to maintain or improve air quality. The method and proceeds of this research are as follows:
3.1 MATERIAL SELECTION
During the research of this project, the researchers went on market survey to know the material suitable for the construction work. They came to a conclusion of getting a mild steel metal sheet as a result of the properties it possesses.
3.2 PROPERTIES OF THE MATERIAL
∙ Malleability: The material possesses flexibility whereby it can be hit or pressed into different shapes without breaking or cracking.
∙ Durability: The material has a long lasting quality without breaking or getting weaker.
∙ Low cost: The mild steel metal sheet is at a cheap price and available at all times.
∙ Low tensile strength: The strength at which the material can be stretched is low compared to other metal sheets. ∙ Surface hardness: The material also possesses hardness on its surface to overcome wear during the cutting operation.
3.3 SEQUENCE OF OPERATION CARRIED OUT
In the course of the construction work, various workshop operations were carried out sequentially with the aid of adequate workshop tools which will be highlighted alongside with.
Operations carried out are:
3.3.1 MARKING OUT OPERATION
This is the first operation carried out with the aid of a try square, steel rule, scriber and measuring tape. This operation was carried out to ensure accurate measurement and limit waste of sheet metals.
3.3.2 CUTTING OPERATION
This operation is done after marking out on the sheet metal. The cutting is done according to marking out on the sheet metal. It involves the use of filing machine.
3.3.3 ROLLING OPERATION
Rolling operation was carried out with the aid of the rolling machine. This is the operation used to produce the chamber and vacuum container of the dust extractor.
3.3.4 WELDING OPERATION
This is the form of assembly that requires a welding machine to effectively join component parts together. The type of welding used for this operation is the arc welding with gauge 12 mild steel electrode. At this point, goggle glasses are worn for safety reasons.
3.3.5 DRILLING OPERATION
This operation involves the use of a drilling machine which comprises of bit and chuck to bore holes for bolts and nuts.
3.3.6 ASSEMBLY OPERATION
In this operation, assembling of various parts are done with the aid of bolts and nuts after drilling operation has been carried out.
3.3.7 FINISHING OPERATION
This is the final operation whereby all welded joint rough surfaces are filed and smoothened with the aid of filing machines and hand files. Also, anti-rust paints are used to coat the work.
3.4 ASSEMBLY DRAWING OF THE DUST EXTRACTOR
3.5 PARTS OF THE DUST EXTRACTOR
∙ Roller: The dust extractor comprises of four rollers which enables it move and flow freely. They are located directly beneath the base of the extractor.
∙ Base: This is a platform in which other parts rest upon for effective operation. This platform is formed as a result of welding operation.
∙ Supporter: It is a metal support that keeps the chambers in alignment with the vacuum to enable free flow of dust.
∙ Chamber: This is a cylindrical vacuum which has an impeller contained in it. The rotation of this impeller aids the extraction of the dust through the hose pipe.
∙ Electric motor: It is an electronic machine mounted using bolt and nut in the same level with the chamber. It converts electrical energy into mechanical energy thereby aiding the rotation of the impeller.
∙ Channel: It is a passage in which extracted dust flows through to the dust container. This channel is aligned using bolts and nuts.
∙ Dust container: The dust container is a cylindrical container in which extracted dust are stored and discarded. ∙ Hose (pipe): This is a rubber tube that has attached nozzle in which it is used to extract the dust. This is the point at which dust extraction starts.
∙ Switch: This is a small device that is used to turn the dust extractor ON and OFF. It is attached to the body of the dust extractor.
3.6 PRINCIPLE OF OPERATION
This system is made up of several parts such as; rollers, base support, switch, electric motor, .chamber, dust container, hose pipe. The assembling of these parts makes up the dust extractor and it is electrically powered.
When the system is plugged to an electric current, the switch is put ON which powers the electric motor that converts electrical energy to mechanical energy. The impeller that is connected to the motor through a shaft rotates at the supposed speed, 1400 rev/min and generates power of 0.75kw. The rotation of the impeller exerts pressure on the pipe which in return extracts dust where it is concentrated. The dust passes through the pipe, along the channel and finally deposits into the dust container. When the dust container is filled up with dust, the container is loosed at the foundation and the dust is being discarded and tightened back to the base. The dust in the container is not allowed to get filled above the channel opening to avoid blockage and this extractor can be mobile with the aid of the rollers.
3.7 SAFETY PRECAUTION
In the course of the construction work, there were certain safety measures that were taken. This measure includes:
∙ Safety boot: This is personal protective equipment produced with iron at the head. It is worn to prevent heavy objects from hitting the leg and also sharp objects from penetrating through.
∙ Cover all: This is worn to avoid dirt staining your inner cloth because the constructing involves dirty jobs. ∙ Hand gloves: There are gloves worn to protect the hand from mishaps as a result of share objects. Also, it is used to hold tools firmly avoid double handling.
∙ Goggle glasses: This is an eye goggle worn especially during welding, cutting and filling operation to avoid chips entering the eyes.
∙ Ear muff: This is equipment worn to prevent the ears from noise pollution.
∙ Helmet: It is worn on the head to prevent objects from hitting the head.
3.8 BILL OF QUANTITY
S/N
QTY
MATERIAL DESCRIPTION
UNIT
COST (N)
1
1
Electric motor
1 horse power
20,000
2
1
Impeller
1 horse power
7,000
3
1
Sheet of metal
1mm
10,000
4
1
Hose (pipe)
Ø30mm
2,000
5
1
Angle iron
11/2x 11/2 inch
3,000
6
4
Paint
Liters
2,000
7
22
Bolt and nut
M17 & M13
1,000
8
4
Rollers
-
1,000
9
1
Switch
-
500
10
1
Seal rubber
-
300
11
2
Clip
-
200
12
-
AutoCAD drawing
-
3,000
13
-
Transportation
-
3,000
₦53,000
CHAPTER FOUR
RESULT AND DISCUSSION
4.1 RESULT OF THE CONSTRUCTION
After the construction of the dust extractor, it underwent various testing procedures which certified that the project work is recommended for public use. The test conducted on the dust extractor are as follows:
First and foremost, we ran test on the rollers to see how effective they are. It was concluded that the rollers were moving uniformly and no wobbling and also, it was taken to different ground which yielded positive results.
Secondly, we put on the dust extractor to check the speed and power at which the electric motor is rotating and it was moving at the required speed and also producing supposed power needed.
Thirdly, the pipe was carefully examined to determine if there is any loss of pressure due to leakage but the pipe was producing the adequate amount of pressure required to extract the dust.
Fourthly, we powered the equipment and carefully observed the level of noise pollution but the system was sounding fine.
Next was the level of vibration at which the machine will produce during the extraction process and it was found that there was no much vibration detected.
Again, we checked the OFF and ON switch and it was operating at ease.
Furthermore, we checked the safety of the dust extractor and it was drawn to conclusion that the system is safe to operate with.
In conclusion, various test carried out on the dust extractor certified it fit and standard for use in various organizations.
4.2 DISCUSSION ON THE CONSTRUCTION WORK
The discussion of this construction work will be based on selecting a dust extractor, what constitute a good dust extractor, maintenance of the dust extractor and importance of dust extraction.
4.2.1 SELECTING A DUST EXTRACTOR
Dust extractors vary widely in design, operation, effectiveness, space requirements, construction and capital, operating and maintenance costs. Each type has advantages and disadvantages. However, the selection of a dust extractor should be based on the following general factors:
∙ Dust concentration and particle size: For minerals processing operations, the dust concentration can range from 0.1-5.0 grains (0.32g) of dust per cubic feet of air (0.23 to 11.44 grain per standard cubic meter) and the particle size can vary from 0.5 to 100um+.
∙ Degree of dust extraction required: The degree of dust extraction required depends on its potential as a health hazard or public nuisance, the plant location, the allowable emission rate, the nature of the dust, its salvage value, and so forth. The selection of an extractor should be based on the efficiency required and should consider the need for high
efficiency, high-cost equipment, high-efficiency, such as electrostatic precipitators; moderate-cost equipment, such as bag houses or wet scrubbers; or lower cost, primary units, such as dry centrifugal extractors.
∙ Characteristics of airstream: The characteristics of the airstream can have a significant impact on extractor selection. For example, cotton fabric filters cannot be used where air temperatures exceed 180F (82°C). Also, condensation of steam or water vapor can blind bags. Various chemicals can attack fabric or metal and cause corrosion in wet scrubbers.
∙ Characteristics of dust: Moderate to heavy concentrations of many dusts (such as dust from silica sand or metal ores) can be abrasive to dry centrifugal extractors. Hygroscopic material can blind bag extractors. Sticky material can adhere to extractor elements and plug passages. Some particle sizes and shapes may rule out certain types of fabric extractors. The combustible nature of many fine materials rules out the use of electrostatic precipitators.
∙ Method of disposal: Methods of dust removal and disposal vary with the material, plant process, volume, and type of extractor used. Extractors can unload continuity or in batches. Dry materials can create secondary dust problems during unloading and * disposal that do not occur with wet extractors. Disposal of wet slurry or sludge can be an additional material-handling problem; seer or water pollution problems can result if wastewater is not treated properly.
4.2.2 WHAT CONSTITUTE A GOOD DUST EXTRACTOR? What constitute a good dust extractor is a system that;
∙ Is low in maintenance
∙ Is designed with worker and property of safety in mind ∙ Provides total design flow at pick-up point sufficient to control dust
∙ Meets required dust emission standard
∙ Uses the least electrical energy practical to accomplish the above
∙ Has the flexibility to accommodate varying flows and pressures or future system requirements
4.2.3 MAINTENANCE OF THE DUST EXTRACTOR
∙ The system should be put off when not in operation to avoid malfunctioning.
∙ Always thoroughly clean the extractor after use to promote effective operation because particles of dust could cause poor operation.
∙ Once in a while, you re-paint the dust extractor to enable it last long.
∙ From time to time, you service the electric motor to avoid breakdown.
∙ Avoid leaving dust in the dust container. I.e. after extracting dust for the day, disposed the dust immediately.
4.2.4 IMPORTANCE OF DUST EXTRACTION
Professional workshops have known for decades that one of the most important pieces of machinery in the workshop is an adequate extractor. A clean dust free workplace is not only safer, but far less working the long run. There is less clean up and less airborne dust, which is very important when it comes to the finishing stage. Another important fact is that it is far better for your machinery to have this dust and shavings removed. Other than being forced back around the cutting area and affecting the quality of the work, fine dust particles can be sucked into electrical component, build up on moving parts or pile up in areas underneath your machinery (becoming a fire hazard in the process). Worst of all, these particles can find their way into your lungs. Dust extraction is NOT a replacement for PPE (Personal Protective Equipment) but if it reduces the dust in your immediate Work area, it means your PPE is going to work more efficiently too. The sad fact is that running machinery without dust extraction may affect your warranty if something does go wrong.
CHAPTER FIVE
CONCLUSION AND RECOMMENDATION
5.1 CONCLUSION
The construction of the dust extractor whose purpose is to enhance the quality of air released from industries and commercial processes should be of utmost importance because this research work will bring about economic development and ensure quality air in the working environment.
The design, functionality, and application of dust extractor are essential elements in maintaining a safe and healthy working environment in various industries.
Equally this research work will also go a long way as limiting the chances of having lungs disease called Pneumoconiosis' due to proven fact that excessive dust inhaled by humans do cause pneumoconiosis which increases death rate in the society.
Ongoing advancements in filtration technology, operation automation, and energy efficiency contribute to the continuous improvement of dust extractor systems, ensuring enhanced worker welfare, improved productivity, and sustainable operation.
Finally, this research work underwent due proceeds such as; material selection, operations carried out, safety measures, maintenance, test and results which certified the equipment safe and standard to operate with.
5.2 RECOMMENDATION
Having constructed and tested the dust extractor, the researchers have recommended this work to be available in every organization in other to eliminate dust to the barest minimum. Also the maintenance procedures should be carried out to keep the system in good working condition.
Researchers have also advised that persons using this system should have full knowledge on the working principles to avoid mishandling of equipment.
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