- Subject Name:Air Pollution Control and Management (3161308)
- Date:16-12-2022
- Paper solved by : Om Sonawane
Q.1
(a) Give your comments on Effect of Fuel on emission of pollutant.
The type of fuel used in a vehicle or power generation facility can have a significant impact on the emissions of pollutants. For example, burning fossil fuels such as coal, oil, and natural gas can release significant amounts of pollutants into the air, including carbon dioxide, sulfur dioxide, and nitrogen oxides. On the other hand, using cleaner fuels such as electric, hydrogen, and biofuels can greatly reduce or eliminate these emissions. Additionally, modern technologies like catalytic converters and emissions control systems can help to reduce the pollutants emitted from fossil fuels.
It's also worth mentioning that different fuels have different emissions levels, for example: Natural gas is considered cleaner than oil and coal, and electric vehicles produce no emissions at the tailpipe.
(b) Draw a neat sketch of Cyclone Separator.
A cyclone separator is a mechanical device that uses centrifugal force to separate particles from a fluid mixture. It typically consists of a cylindrical chamber that is tapered at the top, with a tangential inlet near the top and an outlet at the bottom. The inlet is connected to a pipe or duct that carries the fluid mixture, while the outlet is connected to a pipe or duct that carries the separated particles. The tapered shape of the chamber causes the fluid to spin as it enters, creating centrifugal force that separates the particles from the fluid.
The separated particles collect at the bottom of the chamber and are removed through the outlet, while the cleaned fluid exits through the top.
Additionally, some Cyclone separator has a conical bottom and a vertical axis, and some have also a cylindrical shape with a horizontal axis. It's also worth mentioning that the efficiency of the separator can be increased by adding an external device such as a pre-filter or an internal device like a vortex finder.
(C) Explain Working principle of Bag filter.
A bag filter, also known as a fabric filter or a baghouse, is a type of air pollution control device that uses bags made of porous materials to capture and retain particulate matter from an industrial process or exhaust stream. The working principle of a bag filter is based on the principle of filtration.
The industrial process or exhaust stream is directed into the bag filter through an inlet duct. As the air or gas flows through the bags, particulate matter such as dust, dirt, and other particles become trapped on the surface of the bags. The cleaned air or gas then exits through an outlet duct.
The bags are typically made of a variety of materials such as polypropylene, polyester, or glass fiber. The bags are suspended in a housing or chamber and are typically arranged in a parallel or a series configuration.
The particulate matter that is collected on the bags can be periodically removed by a process called "pulsing." During pulsing, a burst of compressed air or reverse air is introduced into the bags, which causes the particulate matter to fall off the bags and into a hopper or receptacle at the bottom of the chamber for disposal.
It's also worth mentioning that bag filters are available in different types such as:
Shaker Bag Filters: These filters use mechanical shaking devices to dislodge the particulate matter from the bags.
Reverse-air Bag Filters: These filters use a reverse flow of air to clean the bags.
Pulse-jet bag filters: These filters use a pulse of compressed air to clean the bags.
Bag filters are an effective and efficient means of controlling particulate emissions, and are widely used in various industries such as cement, power generation, and chemical processing.
Q.2
(a) Enlist Selection criteria of Air Pollution Control Equipments.
There are several selection criteria that are typically considered when choosing air pollution control equipment, including:
Type of pollutants: Different types of air pollution control equipment are designed to control specific pollutants, so it is important to identify the types of pollutants present in the industrial process or exhaust stream.
Concentration of pollutants: The concentration of pollutants in the industrial process or exhaust stream can affect the design and size of the air pollution control equipment.
Volume of airflow: The volume of airflow in the industrial process or exhaust stream can affect the design and size of the air pollution control equipment.
Temperature and humidity: The temperature and humidity of the industrial process or exhaust stream can affect the design and materials of the air pollution control equipment.
Space and Location: The availability of space and the location of the industrial process or exhaust stream can affect the design and size of the air pollution control equipment.
Capital and operational cost: The cost of the equipment, installation, and operation must be considered in the decision-making process.
Maintenance: The ease of maintenance, the frequency of maintenance and the spare parts availability must be taken into account.
Compliance with regulations: The air pollution control equipment must comply with relevant federal, state, and local regulations.
Energy consumption: Energy consumption of the equipment should be considered in order to reduce the operational cost.
Reliability & Durability: The equipment should be reliable and durable in order to minimize downtime and maintenance.
By considering these selection criteria, it is possible to select the most appropriate air pollution control equipment for a specific industrial process or exhaust stream.
(b) Enlist and Explain the Advantages of ESP.
Electrostatic Precipitator (ESP) is an air pollution control device that uses an electric field to remove particulate matter from an industrial process or exhaust stream. The main advantages of ESP are:
High Efficiency: ESPs are able to remove particulate matter with a high degree of efficiency, typically 99% or higher.
Low Pressure Drop: ESPs have a low pressure drop across the device, which means that the pressure drop is minimal and does not significantly affect the energy consumption of the system.
Low Maintenance: ESPs require minimal maintenance, and the maintenance that is required is usually limited to cleaning or replacing the collecting electrodes.
Long Service Life: ESPs have a long service life, and the components of the device can be replaced as needed to extend the service life of the device.
Compact size: ESPs can be designed to be compact, which allows them to be installed in tight spaces.
Low operating cost: The operating cost of ESPs is relatively low compared to other air pollution control devices.
Adaptability: ESPs can be adapted to a wide range of industrial processes and exhaust streams.
Low Environmental Impact: ESPs do not produce any secondary pollutants and have a low environmental impact.
Can Handle High Temperature: ESPs can handle high temperature and corrosive gases, making them suitable for different types of industrial processes.
Can Handle High Moisture Content: ESPs can handle high moisture content which is a common problem in many industrial processes.
Overall, ESPs are a cost-effective and efficient means of controlling particulate emissions, and are widely used in various industries such as power generation, cement, and chemical processing.
(c) Write a short note on scrubber along with sketch.
a scrubber is a type of air pollution control device that uses a liquid, such as water, to remove pollutants from an industrial process or exhaust stream. it works by spraying the liquid into the exhaust stream, where it comes into contact with the pollutants and causes them to adhere to the liquid droplets. the scrubbed air or gas then exits through an outlet duct, while the pollutants are collected in the liquid and can be removed for disposal.
The main components of a scrubber are:
- A spray nozzle: which sprays the liquid into the exhaust stream
- A contact chamber: where the exhaust stream and the liquid come into contact
- A Mist Eliminator: which separates the liquid droplets from the scrubbed gas
- A Collection Tank: where the pollutants are collected
A scrubber can be in different types such as:
Wet Scrubbers: These scrubbers use a liquid to remove pollutants.
Dry scrubbers: These scrubbers use a dry sorbent material, such as lime or soda ash, to remove pollutants.
Semi-dry scrubbers: These scrubbers use a combination of a liquid and a dry sorbent material to remove pollutants.
Unfortunately, I am not able to create a sketch as it goes beyond my capabilities as a language model. However, I can describe a scrubber in general terms: It looks like a tall cylindrical chamber with an inlet and an outlet. The inlet is connected to a pipe or duct that carries the exhaust stream, while the outlet is connected to a pipe or duct that carries the scrubbed air or gas. Inside the chamber, there are several components that are responsible for the treatment process, such as the spray nozzle, the contact chamber, the mist eliminator, and the collection tank.
Scrubbers are an effective and efficient means of controlling gaseous emissions, and are widely used in various industries such as power generation, cement, and chemical processing.
OR
(c) Briefly explain the working principle of gravity settling chamber along with sketch.
A gravity settling chamber, also known as a sedimentation basin or clarifier, is a device used to remove solids from liquid by allowing them to settle to the bottom due to gravity. The liquid flows into the chamber, and as it slows down, the heavier solid particles settle to the bottom, forming a sludge layer. The clarified liquid then flows out of the chamber through an overflow weir.
[A simple sketch of a gravity settling chamber with an inlet pipe, an outlet pipe and a sludge layer at the bottom of the chamber, which has a rectangular or circular shape]
In the chamber, the solids settle to the bottom while the liquid flows out of an overflow weir. The settled solids are then removed from the bottom of the chamber, typically by a scraper or pump. The process of gravity settling is most effective when the difference in density between the solids and liquid is large and the flow rate is slow enough to allow the solids to settle.
Q.3
(a) Differentiate between four stroke and two stroke engine.
A four-stroke engine and a two-stroke engine are both internal combustion engines, but they have a different number of strokes (or movements of the piston) per combustion cycle.
A four-stroke engine, also known as a four-cycle engine, completes four distinct strokes - intake, compression, power, and exhaust - during one combustion cycle. This cycle takes place over two revolutions of the crankshaft.
A two-stroke engine, on the other hand, completes two strokes - intake and power (or compression and power) - during one combustion cycle. This cycle takes place over one revolution of the crankshaft.
The main difference between the two is that four stroke engines use one complete revolution of the crankshaft to complete the combustion cycle while two stroke engines complete the combustion cycle on half revolution of the crankshaft. This difference causes two stroke engines to have higher power to weight ratio and higher RPM capabilities but at the cost of a higher fuel consumption and more pollution. On the other hand, four stroke engines are more fuel efficient and produce less pollution, but they have lower power to weight ratio and lower RPM capabilities.
(b) Explain Alternative Fuels & their utilization.
Alternative fuels are any materials or substances that can be used as a fuel, other than conventional fossil fuels (such as coal, oil, and natural gas). Some examples of alternative fuels include:
Biomass: Biomass is a renewable energy source that comes from plant and animal matter. It can be burned to produce heat, electricity, and transportation fuels. Examples include wood, crops such as corn and soybeans, and waste materials such as agricultural and municipal waste.
Ethanol: Ethanol is an alcohol-based fuel made from the fermentation of sugars and starches from plants such as corn, sugarcane, and wheat. It can be blended with gasoline to create a fuel known as E10 (10% ethanol and 90% gasoline).
Biodiesel: Biodiesel is a renewable fuel made from vegetable oils and animal fats. It can be used in diesel engines as a replacement for, or a supplement to, petroleum-based diesel fuel.
Natural Gas: Natural gas is primarily composed of methane, and it is a cleaner-burning alternative to gasoline and diesel fuel. It can be used in vehicles that have been specially adapted to run on natural gas, or it can be converted into a liquid form (LNG) for use in transportation.
Hydrogen: Hydrogen is an energy carrier, not an energy source, meaning it can be produced from various sources such as natural gas, coal, water and biomass. It can be used as a fuel in fuel cell vehicles, which convert the chemical energy of hydrogen into electricity to power an electric motor, producing only water as a by-product.
These alternative fuels can be used to power vehicles, generate electricity, and heat buildings. Utilization of these alternative fuels can help reduce dependence on fossil fuels, decrease greenhouse gas emissions, and promote energy security. However, the adoption of alternative fuels depends on factors such as availability, cost, and infrastructure, which can vary widely depending on the region or country.
(c) Write a short note on A/F ratio.
The air-fuel ratio (AFR) is the ratio of the amount of air to the amount of fuel in a combustion process. It is typically expressed as a ratio, such as 14.7:1, meaning 14.7 parts air to 1 part fuel. The ideal air-fuel ratio for a combustion process depends on the type of fuel and engine being used.
In internal combustion engines, the AFR is critical for proper engine operation. If the AFR is too rich (too much fuel in relation to air), the engine will produce too much emissions, have poor fuel economy and can cause engine damage. On the other hand, if the AFR is too lean (too much air in relation to fuel), the engine will run hot, produce less power, and can cause engine damage as well.
Tuning the air-fuel ratio can help improve engine performance and efficiency, while also reducing emissions. This is done by adjusting the amount of fuel being delivered to the engine by the fuel injectors and/or carburetor, and adjusting the amount of air entering the engine through the throttle body.
In modern vehicles, the A/F ratio is closely monitored by the engine control module (ECM) which uses a sensor (lambda sensor) to measure the oxygen level in the exhaust pipe. Based on this measurement, the ECM adjusts the fuel delivery to maintain the desired A/F ratio.
OR Q.3
(a) Draw a neat sketch of stratified charge engine.
A stratified charge engine is a type of internal combustion engine in which the fuel and air are not thoroughly mixed before being ignited, but instead are injected in specific patterns to create a "stratified" mixture. This can result in improved fuel efficiency and reduced emissions.
The basic components of a stratified charge engine include:
Fuel injectors: These inject fuel into the combustion chamber in a specific pattern to create a "stratified" mixture.
Spark plugs: These ignite the fuel and air mixture in the combustion chamber.
Pistons and cylinders: These compress and expand the fuel and air mixture to drive the engine.
Exhaust system: This removes the waste products of combustion from the engine.
In a stratified charge engine, the fuel is injected directly into the combustion chamber in a pattern that creates a high-fuel, low-air mixture near the spark plug, and a low-fuel, high-air mixture in the rest of the combustion chamber. This allows for more efficient combustion and improved fuel efficiency.
It's a bit difficult to explain the exact functionality in a text, I recommend looking into some diagrams or videos for better understanding.
(b) Highlight the importance of rotary combustion engine.
Rotary combustion engines, also known as rotary engines or Wankel engines, are internal combustion engines that use a rotary design, as opposed to the more common reciprocating design found in traditional internal combustion engines.
Rotary Engines have a number of advantages over traditional engines.
One of the main advantages is their compact size and shape. Because the rotary design eliminates the need for a cylinder block, connecting rods, and other components found in traditional engines, rotary engines can be much smaller and more compact. This makes them ideal for use in applications where space is limited, such as in aircraft, motorcycles, and compact cars.
Another advantage is their high power-to-weight ratio. Rotary engines are relatively lightweight compared to traditional engines of similar power, which means they can provide more power per unit of weight. This makes them suitable for high-performance vehicles.
They also have a high power density. Rotary engines have a higher power density than traditional engines of similar size, meaning they can generate more power from a given displacement.
Rotary engines also have a lower noise level and vibration level than traditional engines, which makes them more suitable for use in applications where noise and vibration are a concern.
Additionally, rotary engines have a low emissions and high thermal efficiency. This makes them a good candidate for hybrid and electric vehicles, as well as for use in stationary power generation.
However, rotary engines also have some disadvantages, such as high fuel consumption, reduced durability and also more complex design.
Therefore, rotary combustion engines can be considered as a good alternative in many cases, with its unique advantages, and it's usage is determined by the specific application and design needs.
(c) How Engine Design Changes affect The auto exhaust emission?
Engine design changes can have a significant impact on auto exhaust emissions. The main ways in which engine design can affect emissions include:
Fuel injection: Improvements in fuel injection technology can help to more precisely control the amount of fuel that is injected into the engine, which can result in more efficient combustion and lower emissions.
Emissions control systems: Addition of devices such as catalytic converters, diesel particulate filters and selective catalytic reduction (SCR) can help to reduce emissions by removing pollutants before they are released into the atmosphere.
Engine management systems: Advances in engine management systems can help to optimize engine performance and reduce emissions by controlling the timing and duration of fuel injection, as well as the ignition timing.
Engine Downsizing: By reducing the engine size, and increasing the power output per unit of volume, the engine can run more efficiently and produce lower emissions.
Hybridization: Addition of electric motor in a vehicle can reduce the fuel consumption and emissions by allowing the vehicle to run on electric power alone, or by allowing the engine to run at a more efficient point.
Alternative Fuels: Use of alternative fuels such as ethanol, bio-diesel, and hydrogen can reduce emissions, especially of carbon dioxide.
Overall, engine design changes can help to improve fuel efficiency and reduce emissions. However, it is important to note that the emissions of a vehicle are also affected by other factors, such as the type of fuel used and the way in which the vehicle is driven.
Q.4
(a) Discuss desulphurization process of coal.
Desulphurization of coal is the process of removing sulfur from coal before it is burned. Sulfur is a naturally occurring element in coal, and when coal is burned, it releases sulfur dioxide (SO2) into the atmosphere, which can contribute to acid rain and other environmental problems.
There are several methods that can be used to desulfurize coal, including:
Physical cleaning: This method involves using physical processes to remove sulfur-containing minerals from the coal. Techniques such as crushing, washing, and gravity separation can be used to remove these minerals.
Chemical cleaning: This method involves using chemicals to remove sulfur from the coal. Techniques such as leaching, flotation, and oxidation can be used to remove sulfur from the coal.
Biological cleaning: This method involves using microorganisms to remove sulfur from the coal. Microorganisms can be used to convert sulfur compounds in the coal into less harmful compounds such as sulfuric acid or sulfates.
Gasification: This method involves converting the coal into a gas before burning it, which removes the sulfur and other impurities from the coal.
Flue Gas Desulphurization: This method involves removing sulfur dioxide from the flue gas after the coal has been burned. Techniques such as wet scrubbing and dry scrubbing can be used to remove sulfur dioxide from the flue gas.
Physical cleaning and chemical cleaning methods are commonly used in coal preparation plant to reduce sulfur content before burning, while flue gas desulphurization is widely used after burning the coal.
It's worth noting that desulfurization process will have a direct impact on the cost and efficiency of burning coal, and depending on the method chosen, it can have different levels of effectiveness and efficiency.
(b) Draw a neat sketch of Double alkali scrubbing.
Double alkali scrubbing is a method of removing sulfur dioxide (SO2) from flue gas, which is a byproduct of burning fossil fuels such as coal, oil, and natural gas.
The basic components of a double alkali scrubbing system include:
Spray nozzles: These are used to distribute the scrubbing solution into the scrubber.
Scrubbing solution: This is typically a mixture of lime or limestone slurry (Ca(OH)2) and soda ash (Na2CO3) which are used to remove sulfur dioxide from the flue gas.
Absorption tower: This is a device where the flue gas and scrubbing solution come into contact and the SO2 is removed from the flue gas
Pumps: These are used to circulate the scrubbing solution through the scrubber and absorption tower.
Settling tanks: These are used to separate the scrubbing solution from the flue gas and to allow the solid particles to settle out of the solution.
In double alkali scrubbing, the flue gas is first passed through a spray of lime or limestone slurry, which reacts with the SO2 to form calcium sulfite (CaSO3). The flue gas is then passed through a spray of soda ash, which reacts with the calcium sulfite to form calcium carbonate (CaCO3) and sulfur dioxide.
The now cleaned flue gas is released into the atmosphere, and the scrubbing solution containing calcium carbonate is sent to settling tanks for separation. The solid particles are then removed and the scrubbing solution is recycled.
This method is considered to be more effective in removing sulfur dioxide from flue gas than single alkali scrubbing, as the double alkali process increases the reaction rate and the overall removal efficiency.
(c) Discuss combustion control methods for NOx.
Combustion control methods refer to techniques used to control the combustion process in order to reduce the emissions of nitrogen oxides (NOx) from internal combustion engines and boilers. NOx is a group of highly reactive gases, primarily nitrogen oxide (NO) and nitrogen dioxide (NO2) and are major contributors to air pollution and smog.
Some common methods used to control NOx emissions include:
Low NOx burners: These are designed to reduce NOx emissions by controlling the combustion process to reduce the amount of nitrogen in the fuel that can be converted to NOx. This can be achieved by controlling the temperature and mixing of the fuel and air in the combustion chamber.
Selective catalytic reduction (SCR): This method uses a catalyst to convert NOx into nitrogen and water vapor. A reducing agent such as ammonia or urea is injected into the flue gas stream and reacts with the NOx over the catalyst, reducing the NOx emissions.
Selective non-catalytic reduction (SNCR): This method uses a reducing agent such as ammonia or urea to react with NOx in the combustion chamber or flue gas stream, reducing the NOx emissions.
Oxy-fuel combustion: This method uses oxygen instead of air in the combustion process, which results in a higher flame temperature and less nitrogen in the combustion products.
Advanced combustion systems: These are systems that combine different methods to control NOx emissions, such as low NOx burners, flue gas recirculation, and advanced combustion control strategies.
Fuel-lean combustion: This method uses more air than fuel in the combustion process, which reduces the amount of nitrogen in the combustion products, resulting in lower NOx emissions.
It's worth noting that the most effective combustion control methods for NOx emissions can vary depending on the specific type of combustion process and the fuel being used. In addition, many of the methods have trade-offs between NOx reduction, efficiency and cost. Therefore, it's important to evaluate the suitability of a particular method for a given application.
ORQ.4
(a) Enlist the sources of VOCs.
Volatile Organic Compounds (VOCs) are a group of chemicals that easily evaporate at room temperature and can have negative impacts on air quality and human health. There are many different sources of VOCs, some of which include:
Industrial processes: VOCs are emitted from a variety of industrial processes such as oil and gas production, chemical manufacturing, and wood processing.
Solvents: Many common solvents used in manufacturing, cleaning, and printing emit VOCs when they evaporate.
Transportation: VOCs are released from the tailpipes of cars, trucks, and buses, as well as from the evaporation of fuel from storage tanks and pipelines
Consumer products: Many consumer products emit VOCs, including paints, cleaning products, pesticides, personal care products, and adhesives.
Building materials: Many building materials, such as flooring, insulation, and adhesives, emit VOCs.
Agriculture: Livestock operations, pesticide application, and manure storage can emit VOCs.
Natural sources: Some VOCs come from natural sources such as plants, forest fires, and wetlands.
Biomass combustion: Burning of wood and other biomass materials can generate VOCs.
It's worth noting that VOCs are complex group of chemicals and the specific VOCs present and the amount emitted can vary depending on the source. Some VOCs such as benzene, formaldehyde and toluene are considered harmful and have a greater potential to impact human health and the environment.
(b) Write the control methods of VOCs.
There are several methods that can be used to control Volatile Organic Compounds (VOCs) emissions, some of which include:
Source reduction: This method involves reducing the amount of VOCs emitted by changing the process or equipment used. For example, switching to low-VOC paints, adhesives, or cleaning products, or using closed systems to contain emissions.
Capture and control: This method involves capturing the VOCs before they are released into the atmosphere and either destroying them or recycling them for further use. Techniques such as adsorption, condensation, and thermal oxidation can be used to capture and control VOCs emissions.
Substitution: This method involves using alternative materials or processes that do not emit VOCs or emit lower levels of VOCs.
Ventilation: This method involves using fans and other ventilation equipment to remove VOCs from the air and exhaust them to the outside.
Air pollution control equipment: This method involves using equipment such as carbon adsorbers, catalytic oxidizers, and thermal oxidizers to remove VOCs from the air before they are released into the atmosphere.
Emission offset: This method involves reducing emissions from one source to offset emissions from another source.
Emission trading: This method allows companies that emit VOCs to buy and sell emission allowances in order to meet emission reduction targets.
It's worth noting that the most effective control methods can vary depending on the specific VOCs present, the amount emitted, and the source of the emissions. In addition, many methods have trade-offs between VOCs reduction, efficiency and cost. Therefore, it's important to evaluate the suitability of a particular method for a given application.
(c) Write a short note on single alkali scrubbing.
Single alkali scrubbing is a method of removing sulfur dioxide (SO2) from flue gas, which is a byproduct of burning fossil fuels such as coal, oil, and natural gas. This method is used to reduce the emissions of SO2, which can contribute to acid rain and other environmental problems.
In single alkali scrubbing, the flue gas is passed through a spray of a solution of an alkali, typically lime (Ca(OH)2) or soda ash (Na2CO3) which reacts with the SO2 to form calcium sulfite (CaSO3) or sodium sulfite (Na2SO3) respectively. The flue gas is now cleaned and released into the atmosphere, and the scrubbing solution containing calcium sulfite or sodium sulfite is sent to settling tanks for separation. The solid particles are then removed and the scrubbing solution is recycled.
Single alkali scrubbing is considered to be less effective in removing sulfur dioxide from flue gas than double alkali scrubbing, as the reaction rate and the overall removal efficiency are lower. Additionally, the large amount of solid waste produced by this method is another drawback.
It's worth noting that single alkali scrubbing is not as widely used as double alkali scrubbing, but it is still used in some cases due to its low cost and simplicity of operation.
Q.5
(a) Draw neat sketch of cyclone in series and scrubber in series.
A cyclone in series is a method of removing particulate matter from industrial gases. It is a combination of multiple cyclones in a series, where each cyclone is designed to remove a specific size range of particulate matter. This method is used when the particulate matter size is varied and multiple size ranges need to be captured.
The basic components of a cyclone in series include:
Inlet: where the dirty gas enters the system
Cyclone separators: multiple cyclones connected in series, each with different dimensions and designs to capture different size range of particulate matter
Outlet: where the cleaned gas exits the system
A scrubber in series is a method of removing pollutants from industrial gases. It is a combination of multiple scrubbers in a series, where each scrubber is designed to remove a specific type of pollutant. This method is used when the pollutant types are varied and multiple types need to be captured.
The basic components of a scrubber in series include:
Inlet: where the dirty gas enters the system
Scrubbers: multiple scrubbers connected in series, each with different designs and absorbents to capture different types of pollutants.
Outlet: where the cleaned gas exits the system
Both methods are typically used in industrial processes to remove pollutants and particulate matter from the gases before they are released into the atmosphere. They can be used alone or in combination with other methods, such as bag filters or electrostatic precipitators, to achieve the desired level of pollution control.
(b) Enlist and explain industrial applications of ESP.
Electrostatic precipitator (ESP) is a device that uses electrostatic forces to remove particulate matter, such as dust and smoke, from industrial gases. ESPs are widely used in various industrial applications for the control of particulate matter emissions. Some of the common industrial applications of ESP include:
Power Generation: ESPs are used in power plants to remove particulate matter from the flue gases produced by burning coal, oil, or natural gas. This helps to reduce air pollution and protect the environment.
Cement Production: ESPs are used in cement plants to remove particulate matter from the gases produced by the burning of limestone and other materials. This helps to reduce emissions and improve the quality of the final product.
Steel production: ESPs are used in steel plants to remove particulate matter from the gases produced by the smelting of iron ore and other materials. This helps to reduce emissions and improve the quality of the final product.
Incineration: ESPs are used in waste incineration plants to remove particulate matter from the gases produced by the burning of waste materials. This helps to reduce emissions and improve the efficiency of the incineration process.
Chemical and petrochemical industry: ESPs are used in chemical and petrochemical plants to remove particulate matter from the gases produced by the manufacturing of chemicals and petrochemicals. This helps to reduce emissions and improve the efficiency of the process.
Pharmaceutical and food industry: ESPs are used in the pharmaceutical and food industry to remove particulate matter from the gases produced by the manufacturing of drugs, food and other related products. This helps to reduce emissions and improve the efficiency of the process.
Overall, ESPs are widely used in various industrial sectors to control particulate matter emissions, improve the quality of the final product, and increase the efficiency of the process.
(C) Draw Air pollution control scheme for foundry and also mentioned sources and types of air pollutants.
A typical air pollution control scheme for a foundry may include the following components:
Source Capture: It includes the use of hoods, enclosures, and ductwork to capture pollutants at their source. This can be used to capture particulate matter, fumes, and gases emitted by the melting, pouring, and sand-casting operations.
Particulate Control: It includes the use of devices such as baghouses, electrostatic precipitators, or cyclones to remove particulate matter from the captured pollutants.
Gas Control: It includes the use of devices such as thermal oxidizers, catalytic oxidizers, or scrubbers to remove gases such as volatile organic compounds (VOCs), sulfur dioxide, and nitrogen oxides from the captured pollutants.
Recovery and Recycling: It includes the recovery and recycling of materials, such as metals, sand, and energy, from the pollutants, to minimize waste and reduce the environmental impact.
Some of the common sources of air pollutants in foundries include:
Melting: The release of particulate matter and gases from the melting of metals, such as iron and steel, in the furnaces.
Pouring: The release of particulate matter and gases from the pouring of molten metal into molds.
Sand-casting: The release of particulate matter and gases from the mixing and handling of sand used in the casting process.
Cooling and cleaning: The release of particulate matter and gases from the cooling and cleaning of castings.
OR Q.5
(a) Explain advantages of cyclone in series and scrubber in series.
Cyclone in series and scrubber in series are two different air pollution control methods that are used to remove pollutants from industrial gases. Each method has its own advantages.
Advantages of cyclone in series include:
High efficiency: Cyclone in series are able to remove a high percentage of particulate matter from industrial gases, typically over 90%.
Low maintenance: Cyclone in series do not have any moving parts, which means that they require very little maintenance and have a long service life.
Low cost: Cyclone in series are relatively inexpensive to install and operate compared to other air pollution control methods.
Versatility: Cyclone in series can be used to remove a wide range of particulate matter sizes, making them suitable for a variety of industrial applications.
Advantages of scrubber in series include:
High efficiency: Scrubbers in series can remove a high percentage of pollutants such as VOCs, sulfur dioxide and nitrogen oxides from industrial gases.
Customizable: Different types of scrubbers can be used depending on the type of pollutants present in the gas stream.
Low operating costs: Scrubbers in series can be designed to minimize energy consumption, making them more cost-effective to operate.
Flexibility: Scrubbers in series can be designed to operate effectively over a wide range of gas flow rates and temperatures.
It's worth noting that the choice of air pollution control method depends on the type and concentration of pollutants, flow rate and temperature of the gas stream, and the specific requirements of the industry.
(b) Enlist advantages and disadvantages of venturi scrubber.
A venturi scrubber is a type of air pollution control device that uses a venturi-shaped nozzle to create a high-pressure drop that causes pollutants in the gas stream to be entrained in a scrubbing liquid. The pollutants are then removed from the scrubbing liquid by a separation device such as a cyclone or a mist eliminator. Here are some of the advantages and disadvantages of venturi scrubbers:
Advantages:
High efficiency: Venturi scrubbers are able to remove a high percentage of pollutants such as particulate matter, sulfur dioxide, and acid gases from industrial gases.
Versatility: Venturi scrubbers can be used to remove a wide range of pollutants, including both particulate matter and gases.
Low maintenance: Venturi scrubbers have few moving parts and are relatively simple to operate and maintain.
Compact size: Venturi scrubbers are relatively small in size and can be easily integrated into existing systems.
Disadvantages:
High pressure drop: Venturi scrubbers require a high-pressure drop to operate effectively, which can result in high energy consumption.
Limited applicability: Venturi scrubbers are not suitable for the removal of certain pollutants such as volatile organic compounds (VOCs)
Liquid waste: Venturi scrubbers produce a liquid waste stream that contains the pollutants that have been removed from the gas stream, which may require additional treatment before disposal.
Corrosion: Certain pollutants may cause corrosion in the scrubber, which may limit the life of the equipment.
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