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Understanding Carbon Monoxide(CO):Pollution, Health Impacts,Safety Limits And Industrial Solutions.

Blog Banner explaining carbon monoxide (CO) pollution, health impacts, safety limits, and industrial solutions.

Understanding Carbon Monoxide(CO): Pollution, Health Impacts, Safety Limits And Industrial Solutions.

Pollution, especially industrial pollution, is increasing day by day, and the air quality is decreasing as a result. When we talk about air pollution, there are various pollutants like CO2, SO2, and VOC among them. CO, or carbon monoxide,(CO Pollution) is one of them. In this article, we will look into carbon monoxide, its impact on the industrial work environment, health impacts, safety limits, and the solutions required to limit exposure for industry.

What is carbon monoxide (CO)?- CO Pollution

Carbon monoxide (CO) is a poisonous, flammable gas that is colorless, odorless, and tasteless. It is slightly less dense than air and is soluble in water. 

How Carbon Monoxide is Generated:

Carbon monoxide (CO) generated by natural gas, wood, or gasoline is burned incompletely.

Carbon Monoxide (CO) Sources:

Natural Sources:

Natural sources of carbon monoxide include the following:

  • Volcanoes
  • Natural Gas
  • Forest Fires
  • Lighting

Man-made sources

Man-made or artificial sources of carbon monoxide (CO) are as follows:

  • Vehicle Emissions
  • Barbeques
  • Wood stoves
  • Gas and water heaters
  • Gas stoves
  • Fuel-fired heaters
  • Fireplaces
  • Gas dryers

Industrial Sources

  • Metal manufacturing
  • Electricity supply
  • Mining metal, ore, and coal
  • Food manufacturing
  • Extracting oil and gas from land or sea
  • Production of chemicals
  • Cement, lime, plaster 
  • Concrete manufacturing 
  •  Petroleum refining

Industrial Processes That Generate CO

  • Laser Cutting
  • Soldering 
  • Plasma Cutting
Infographic explaining carbon monoxide (CO) pollution, health impacts, safety limits, and industrial solutions.

Health Impacts of Carbon Monoxide(CO Pollution):

Carbon monoxide has Severe health impacts are on industrial workers and all people who are in constant contact with fossil fuel burning and processes that produce carbon monoxide, which are listed above. Some of the important health impacts are listed below:

Short-term:
 exposure from breathing carbon monoxide can cause:

  • Headache
  • Nausea and vomiting
  • Blurred vision
  • Confusion
  • Dizziness
  • Chest pain
  • Weakness
  • Difficulty breathing
  • Damage to the heart and brain
  • Unconsciousness

Breathing in high amounts of carbon monoxide is life-threatening.

Long-term:
Exposure to high carbon monoxide levels can cause:

  • Miscarriage
  • Damage to a developing fetus
  • Seizures
  • Coma
  • Heart failure

Safety Limits for Carbon Monoxide (CO Pollution):

The Occupational Safety and Health Administration (OSHA) states that the permissible exposure limit (PEL) for carbon monoxide (CO) is 50 parts per million (ppm). This means that the average concentration of CO in the air over an 8-hour period should not exceed 50 ppm. The 8-hour PEL for CO in maritime operations is also 50 ppm.

You can read various safety limits for CO here.

In India, the Central Pollution Control Board (CPCB) has also set some norms about carbon monoxide exposure. These are as follows:

For industries, the 8-hour PEL of CPCB for industrial, residential, rural, and other areas is 02 mg/m3, and for 1 hour, PEL is 04 mg/m3. The 8-hour PEL of the conditional and sensitivity areas declared by the central government . is 02 mg/m3, and the 1-hour PEL is 04 mg/m3.

Solutions for Carbon Monoxide (CO Pollution) Exposure in Industries:

To limit the exposure of carbon monoxide (CO) in industries and mitigate the risks for industrial workers.

  • Measurement through CO sensors: Industries should monitor and measure carbon monoxide (CO) by using carbon monoxide monitoring sensors, through which they can monitor, control, and measure carbon monoxide exposure.
  • Using extraction solutions: Industries must use extraction solutions to control CO exposure in the industrial environment. Solutions such as Filter on Soldering Fumes Extraction Solutions, Filter on Laser Fumes Extraction Solutions, and Filter on Plasma Cutting Fumes Extraction Solutions are for controlling soldering fumes, laser cutting fumes, and plasma cutting fumes exposure, which also results in CO exposure.
  • Using ventilation solutions: Industries must use ventilation solutions such as LEV (local exhaust ventilation) for a clean air environment in the workplace. 
  • No Vehicle Use for Walking Distance:  Everyone should follow the no vehicle use policy for walking distance, which can reduce CO in the environment. Making such little effort can create a big impact on the environment in the long run, which is the best initiative for our long-term goal, “Mission Zero Pollution.” 
Visit  blogs to learn more about the critical features of clean air system design and air pollution control systems created by Filter On India.

Filter On India has been working towards “Mission Zero Pollution” for the last 40+ years as a clean air solutions partner for industries. We specialize and have expertise in welding fumes, oil mist, coolant mist, dust collection, soldering, laser marking, laser cutting, plasma cutting, fumes in fastener manufacturing, ball point tip manufacturing, oil quenching, kitchen fumes, etc. Filter On has 70+ clean air solutions, so you can contact us for more information about our solutions. You can reach us through the web or visit us at our corporate office at Pune, or mail us at : marketing@filter-on.com

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Clearing the Air: Understanding NO₂ Pollution, Health Risks, Safety Standards, and Industrial Solutions

NO₂ Pollution: Health Risks, Safety Standards & Industrial Solutions
NO₂ Pollution: Health Risks, Safety Standards & Industrial Solutions

Clearing the Air: Understanding NO₂ Pollution, Health Risks, Safety Standards, and Industrial Solutions

Air pollution is an important and serious issue, as the world is facing critical consequences due to its impact on people's health. Government . agencies took serious action against those who caused pollution. Nitrogen oxide is one of the primary air components in the air and, if inhaled, is dangerous to health. In this article, we will discuss nitrogen oxide (NO₂ )'s role as a pollutant, health effects due to NO₂ Pollution, safety limits, and industrial solutions and precautions amid its exposure.

What is nitrogen dioxide (NO₂ ) & NO₂ Pollution

Nitrogen dioxide (NO₂ ) is a gaseous air component composed of nitrogen and oxygen. NO₂  is one of a group of related gasses called nitrogen oxides, or NOx. NO₂ is created when fossil fuels such as coal, oil, methane gas (natural gas), or diesel are burned at high temperatures.

Nitrogen Dioxide (NO₂) as a Pollutant:

Natural Sources of Nitrogen Dioxide (NO₂):

Nitrogen dioxide (NO₂) can be formed from both natural and human activity. Natural sources include:

  • lightning strikes
  • volcanoes
  • oceans
  • biological decay

Combustion creates oxides of nitrogen, a major portion of which is nitrogen dioxide. When vehicles emit oxides of nitrogen, 90 to 95 percent of the emissions are nitric oxide (NO).

However, nitric oxide quickly oxidizes in outdoor air when reacting with oxygen, ozone, and volatile organic compounds (VOCs) to form nitrogen dioxide. The oxidation process occurs indoors, but at a slower rate.

Man-Made Sources:

The main source of nitrogen dioxide resulting from human activities is the combustion of fossil fuels (coal, gas, and oil), especially fuel used in cars.

Industrial sources that are responsible for nitrogen oxide (NO₂) are as follows:

Welding:

Nitrous gasses are often responsible for acute poisoning when welding. They occur during gas welding and arc welding processes.

Other than welding, nitrogen dioxide (NO₂) can be found in the following processes:

  • Nitric acid manufacturing
  • Titanium pickling
  • Stainless steel pickling
  • Aluminum bright dip
  • Metal finishing
  • Precious metals refining
  • Chemical etching
  • Fertilizer production
  • Glass making
  • Industrial boilers
  • Aqueous chemical production 

Health Impacts of Nitrogen Dioxide(NO₂ Pollution):

Breathing air with a high concentration of NO₂ Pollution can irritate the airways in the human respiratory system. Such exposures over short periods can aggravate respiratory diseases, particularly asthma, leading to respiratory symptoms (such as coughing, wheezing, or difficulty breathing), hospital admissions, and visits to emergency rooms. Longer exposures to elevated concentrations of NO₂ Pollution may contribute to the development of asthma and potentially increase susceptibility to respiratory infections. People with asthma, as well as children and the elderly, are generally at greater risk for the health effects of NO₂ Pollution.

NO₂ , along with other NOx, reacts with other chemicals in the air to form both particulate matter and ozone. Both of these are also harmful when inhaled due to their effects on the respiratory system.

As per the 1998 National Research Council Committee on Toxicology study, which investigated incidents of accidental exposure to NO₂ Pollution, Workers in agriculture, mining explosions, space exploration, and military activities have been accidentally exposed to high concentrations of NO₂ Pollution, resulting in a wide range of severe medical ailments, including:

  • breathing difficulty
  • fever
  • bronchial pneumonia
  • acute bronchitis
  • death

In short, the health impact of nitrogen dioxide categories is:

Short-term:
Breathing nitrogen oxides can cause:

  • Irritation of the respiratory system, eyes, and skin
  • Aggravation of respiratory diseases, particularly asthma
  • Coughing and choking
  • Nausea
  • Headache
  • Abdominal pain
  • Difficulty breathing

Skin and eye contact with nitrogen oxide gases or liquid nitrogen dioxide can cause irritation and burns.

Long-term:
 Long-term exposure to nitrogen dioxide can cause:

Exposure to very high levels of nitrogen oxides may cause:

  • Death
  • Genetic mutations
  • Harm to a developing fetus
  • Decreased female fertility
  • Spasms
  • Swelling of the throat
  • Rapid pulse 
  • Dilated heart

Safety Limits for Nitrogen Dioxide (NO₂ Pollution):

In the industrial environment, nitrogen dioxide (NO₂) has exposure limits set by OSHA that are as follows:.

Safety guidelines by OSHA for NO₂ Pollution

The EPA limit for Nitrogen Dioxide(NO₂) exposure is as follows:

The official level of the annual NO₂ standard is 0.053 ppm, equal to 53 ppb, which is shown here for the purpose of clearer comparison to the 1-hour standard.

In India CPCB has set the norms for Nitrogen Dioxide(NO₂) exposure limits that are as follows:

NO₂ Pollution CPCB Standards
NO₂ Pollution Safety Precautions

How do I evaluate the exposure to nitrogen 

According to the New Jersey Department of Health and Senior Services fact sheet to evaluate exposure to nitrogen dioxide (NO2), here are some answers to the following questions:

  • How hazardous is the substance?
  • How much of the substance is released into the workplace?
  • Whether harmful skin or eye contact could occur?

Safety Precautions for Nitrogen Dioxide (NO₂) Exposure:

  1. Change the NO₂-exposed clothes immediately.
  2. Eye wash fountains are required at the workplace for emergency use.
  3. If skin exposure happens, then emergency shower facilities should be provided.
  4. In an emergency, if the exposure limit is 20 PPM or higher, then you must use strong self-breathing apparatus approved by NIOSH with a full face piece. 
Solutions for Nitrogen Dioxide (NO₂ Pollution) Exposure in Industries:

Nitrogen dioxide is harmful for industrial workers, especially welders, so industries need to take care and implement solutions to control exposure to nitrogen dioxide. The following solutions must be implemented:

Using extraction solutions:

Using extraction solutions like Filter on Welding Fumes Extraction Solutions will be very effective for reducing nitrogen dioxide (NO₂) exposure due to welding fumes. This reduces the concentration in the breathing zone of the welder effectively.

Using ventilation solutions:

Using ventilation solutions can reduce nitrogen dioxide (NO₂) exposure to some extent, so for the safety of welders, companies must take the necessary precautions for ventilation at the workplace. The ventilation facilities have to be arranged in such a way that the welders work in the supply air stream. Ventilation systems like local exhaust ventilation (LEV) are an effective solution in such scenarios. 

Using personal protective equipment:

If the room ventilation is not adequate in particularly confined spaces, then suitable breathing masks have to be worn. These should be independent from the atmosphere, such as, for example, fresh-air breathing apparatus. Welding helmets with a compressed air supply may also be necessary in confined spaces.

Other Solutions:

Companies should pay attention to certain procedural and workplace-specific factors to ensure that nitrous gasses are released in quantities that are as low as possible. These include, among others:

  • Always use smaller burner sizes and flame lengths.
  • Avoiding free-burning flames or
  • Always maintain a small distance between the burner and the workpiece.
  • Always use low-NOx burners in boilers.
  • Please set policies that reduce the use of diesel transportation.
  • Try to switch diesel fuel-burning vehicles to electric vehicles.
  • Encourage public transport, biking, and walking.
Visit  blogs to learn more about the critical features of clean air system design and air pollution control systems created by Filter On India.

Filter On India has been working towards “Mission Zero Pollution” for the last 40+ years as a clean air solutions partner for industries. We specialize and have expertise in welding fumes, oil mist, coolant mist, dust collection, soldering, laser marking, laser cutting, plasma cutting, fumes in fastener manufacturing, ball point tip manufacturing, oil quenching, kitchen fumes, etc. Filter On has 70+ clean air solutions, so you can contact us for more information about our solutions. You can reach us through the web or visit us at our corporate office at Pune, or mail us at : marketing@filter-on.com

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Fume Extraction Standards & Regulations: The Essential Guide to Safer Workspaces and Smarter Investments

Fume Extraction standards and regulations
Fume extraction standards and regulations

Fume Extraction Standards & Regulations: The Essential Guide to Safer Workspaces and Smarter Investments

Global market changes Day by day, manufacturers and companies need to comply with standards and regulations at every manufacturing process, such as welding, brazing, oil mist, dust collection, laser marking, laser cutting, etc. These processes need to comply with the safety standards and government regulations for each process as per the latest government norms specified.

Fume extraction standards and regulations

Safety Standards and Exposure Limits For Workers—Welding Applications:

As per the OSHA factsheet and India's PEL (Permissible Exposure Limits), the welding process is as follows:

OSHA standards for galvanized steel:

OSHA warns of welding hazards in galvanized steel and stainless steel. Galvanized steel, coated with zinc, can cause metal fume fever.

Want to know about health hazards related to welding fumes? Click here to read more.

OSHA standards for stainless steel:

Stainless steel coated with chromium is highly toxic and can cause cancer. Companies have a duty to guarantee that no worker is exposed to levels of chromium greater than 5 µg/m³.

Safety Standards and Exposure Limit for Workers: Oil Mist Applications:

The OSHA Occupational Safety and Health Administration sets permissible exposure limits for air contaminants in metalworking fluids, including oil and solvent mist. These limits are set at 5 milligrams per cubic meter for an 8-hour, time-weighted average (TWA).

The Indian government's Factory Act also follows these standards to control oil and coolant mist exposures in India. Vent lines at lubrication points are also required to collect stray mist.

Want to know about health hazards related to oil mist? Click here to read more.

Safety Standards and Exposure Limit for Workers: Dust Exposure :

As Per OSHA and Indian Factory Act:

Typically, the PEL for total dust is 15 mg/m3, while respirable particles have a lower PEL of 5 mg/m3.

Safety Standards and Exposure Limit for Workers: Laser Marking Applications:

  • The Occupational Safety and Health Administration (OSHA) has established safety limits for laser marking, categorized into different classes based on their power and potential hazards.
  • Class 1 is safe under all conditions, while Class 2 is safe for short viewing times but can cause eye damage if mishandled.
  • Class 3B is unsafe for direct viewing and can cause skin and eye injuries.
  • Class 4 is high-power lasers that can cause skin and eye injuries and fire hazards.
  • Laser beams should not be directed at employees, and systems should not be operated in rainy, snowy, or dusty weather conditions.
  • Other safety limits include limiting diffused reflected light to 2.5 watts per square centimeter, preventing employees from exposure to microwave power densities above 10 milliwatts per square centimeter, and having removable panels and doors with interlocks that automatically reduce or stop laser emissions when the enclosure is opened.

Safety Standards and Exposure Limit for Workers: Laser Cutting Applications:

  • The Occupational Safety and Health Administration (OSHA) has established safety limits for laser equipment, categorized by power and hazard level.
  • Class III B lasers are moderate power, while Class IV high power lasers pose hazards to view, ignite materials, and produce air pollutants.
  • It is not appropriate to point the laser beam toward workers, and it is not advisable to run systems in wet, snowy, or dusty environments.Laser equipment labeling should indicate its maximum output, and Class IIIB or Class IV lasers should be enclosed in a Class I enclosure or have a Laser Safety Officer present.
  • Ideally, the laser unit should be set up above employees' heads.

Visit  blogs to learn more about the critical features of clean air system design and air pollution control systems created by Filter On India.

Filter On India has been working towards “Mission Zero Pollution” for the last 40+ years as a clean air solutions partner for industries. We specialize and have expertise in welding fumes, oil mist, coolant mist, dust collection, soldering, laser marking, laser cutting, plasma cutting, fumes in fastener manufacturing, ball point tip manufacturing, oil quenching, kitchen fumes, etc. Filter On has 70+ clean air solutions, so you can contact us for more information about our solutions. You can reach us through the web or visit us at our corporate office at Pune and our virtual locations at Delhi, Bangalore, Ahmadabad, Hyderabad, or Chennai locations.

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Analyzing Total Ownership Costs: Selecting the Right Clean Air Project Option

Total ownership cost
Total ownership cost

Analyzing Total Ownership Costs: Selecting the Right Clean Air Project Option

In the previous couple of blogs, we discussed planning and designing clean air systems, including choosing the right filtration technology and fan selection. Total ownership cost is a crucial parameter to consider, including filter technology, air flow capacity, running costs, filter replacement costs, blower capacity, and ducting length.

What is the total ownership cost?

Total ownership coat, a management accounting concept, helps determine the direct and indirect costs of a product or service over the long term to arrive at the correct decision while making decisions.

What is the total ownership cost of a clean-air system?

Total ownership cost for a clean air system consists of some parameters such as air flow capacity, filter efficiency, compliance with EMS, size of equipment, considered duct length, static pressure, blower capacity, cell configuration, total initial investment cost, running cost for 1 year, AMC charges per year, standby filter cell, replacement cost of the filter, any optional accessories, etc.

In short:

Total Ownership Cost concept for 3-5 years (installation cost + running cost + maintenance cost + replacement cost = Total Ownership Cost)

Consider a simple case study to illustrate this concept. A fume extraction system with a 45,000 CMH airflow capacity—three options based on different filtration technologies—is worked out.

Total Ownership Cost Scenario for

  • Electrostatic Precipitator Technology (ESP)
  • Cartridge Technology
  • Wet Scrubber Technology

You can read about the above 3 technologies in our previous blog article <a href="https://filter-on.com/2024/04/05/selecting-the-right-filtration-technology/" style a:link, a:visited { background-color: #f44336; color: white; padding: 15px 25px; text-align: center; text-decoration: none; display: inline-block; } a:hover, a:active { background-color: red; } here.

For example, we take into consideration the air flow capacity of 45000 CMH. Here is an illustrative calculation of the total ownership cost of the above 3 technologies, provided with the parameters.

Total Ownership Cost Structure
Parameters ESP Technology Cartridge Technology Wet type:Venturi Scrubber
Airflow Capacity 45000 CMH 45000 CMH 45000 CMH
Filtration Efficiency 95+/-2% for 0.5 micron and above particles It depends on media selection. Generally chosen cartridge: 99% for 1 micron or 0.5 micron for welding fumes 99% for 5 microns and 98% for 2 microns
Compliance with EMS Filtered air output is less than 5 ppm. Filtered air output is less than 5 ppm. Filtered air output is less than 5 ppm.
Size of Equipement Compact Larger than ESP system. The biggest of the three
Considered Duct Length Approx. 100 mtr. per system Approx. 100 mtr. per system Approx. 100 mtr. per system
Blower Capacity 50HP/37Kw 100HP/74.5Kw 150HP/112Kw
Total Initial (Basic) Investment Cost (Equipment, Ducting, and Installation) INR 60.16 lakh INR 76.31 lakh INR 104.81 lakh
Running Cost for 1 Year (considering 16 hours per day x 300 days and 10 Rs/unit) INR 17.76 lakh (per year) X 3 years = 53.28 lakh INR 35.76 lakh (per year) X 3 years = 107 lakh + compressed air charges INR 53.66 lakh (per year) X 3 years = 161 lakh + water charges
AMC Charges per Year (All Scope) Approx. Rs 6 lakh (for 12 visits per year) X 3 years = 18 lakh Approx. 1 lakh (for 4 visits per year) X 3 years = 3 lakh Approx. Rs 6 lakh (for 12 visits per year) X 3 years = 18 lakh
Replacement Cost Filter After 3 years, Rs 1.20 lakh for pre- and after filter replacement & After 5 years, Rs. 3 lakh for ESP filter refurbishment After 2 years, Rs 9.90 lakh N/A
Optional accessories like a VFD, PLC, motorized damper, spark trap, etc. INR 12.92 lakh INR 19.73 lakh INR 27.15 lakh
Total Ownership Cost for 3 Years 154.56 Lakh 215.94 Lakh 310.96 Lakh

Cost Breakdown Parameter-wise & Technology-wise:

Cost breakdown for total ownership cost is here as follows:

Total Ownership Cost Structure
Cost Parameters Cost Of ESP Technology Cost Of Cartridge Technology Cost Of Wet type:Venturi Scrubber
Installation Cost 60.16 lakh 76.31 lakh 104.81 lakh
Running Cost 53.28 lakh 107 lakh 161 lakh
Maintenance Cost-AMC 18 lakh 3 lakh 18 lakh
Replacement Cost 1.2 lakh 9.9 lakh 0
Optional Cost 12.92 lakh 19.73 lakh 27.15 lakh
Total Ownership Cost for 3 Years 154.56 Lakh 215.94 Lakh 310.96 Lakh

Total ownership cost - parameters wise breakup

Fig: Total ownership cost(Parameter wise breakup)

Total Ownership Cost Structure
Technology Total Ownership Cost
ESP Technology 154.56 lakh
Cartridge Technology 215.94 lakh
Wet/Venturi Scrubber Technology 310.96 lakh

Total ownership cost technology wise breakup

Fig: Total ownership cost(Technology wise breakup)

Understandings from the above example:

As per the above example of total ownership cost calculation about the 3 technologies, we can conclude that the ESP technology is totally beneficial in the long run as per the costing, as the total cost is very low; it’s only 154.56 lakh as compared to cartridge technologies 215.94 lakh and wet scrubbers 310.96 lakh for the period of 3 years.

Key takeaways from the above example:

  1. From the above example, you can see that the total cost of ownership of ESP technology is low as compared to the other two technologies.
  2. The total cost of ownership consists of several parameters that are very important, including air flow, blower capacity, initial cost, filter cost, cost of ducting, etc.
  3. The most important parameter of the clean air system is air flow calculation, so air flow rate is the most comparable factor to check which proposal is capable of solving your industrial indoor pollution problem.

Visit blogs to learn more about the critical features of clean air system design and air pollution control systems created by Filter On India.

Filter On India has been working towards “Mission Zero Pollution” for the last 40+ years as a clean air solutions partner for industries. We specialize and have expertise in welding fumes, oil mist, coolant mist, dust collection, soldering, laser marking, laser cutting, plasma cutting, fumes in fastener manufacturing, ball point tip manufacturing, oil quenching, kitchen fumes, etc. Filter On has 70+ clean air solutions, so you can contact us for more information about our solutions. You can reach us through the web or visit us at our corporate office at Pune and our virtual locations at Delhi, Bangalore, Ahmadabad, Hyderabad, or Chennai locations.

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Comprehensive Guide to Duct Design: Types, Velocity, Power, and Pressure Drop with 7 Practical Design Guidelines

Duct Deign Guide
Duct Design Guide

Comprehensive Guide to Duct Design: Types, Velocity, Power, and Pressure Drop with 7 Practical Design Guidelines

Ducting is a main and important component of any clean air system design. Ducting involves various parameters, including ducting type, required velocity, power consumption, and pressure drop. We will discuss all the above parameters in today's blog post, “Duct Design: Guide for Ducting Design of a Clean Air System,"  as well as a few guidelines for standard duct design. 

Duct Design: Types of ducting:

Ducting has two types:

  • Round Ducting
  • Rectangular Ducting

Duct type, such as round or spiral duct, is a type of steel pipe made from various materials like stainless steel, aluminum, copper, and galvanized steel.

Round ducts are more common in fume extraction and dust collection systems, whereas rectangular ducts are more common in air conditioning systems and fresh air ventilation systems.

Round vs. Rectangular

Why round ducting is preferred over rectangular ducting in air pollution control systems:

The main reason is that the dust accumulation inside round ducts is very low as compared to rectangular ducts. In rectangular ducts, dust keeps getting accumulated at the corners. This is not a good situation in any way because it creates a safety or fire hazard in the case of some industrial pollutants like aluminum dust and where there is a possibility of sparks or hot particles entering the duct. Other factors are:

  • A round duct has a low pressure drop.
  • Round ducting is also more rigid than rectangular ducting.
  • The round duct has a lower duct vibration drum effect than the rectangular duct.
  • A round duct has a lower noise level as compared to a rectangular duct.
  • Round ducting has less friction for the air to move around, so it tends to move faster and more efficiently as compared to rectangular ducting.
  • Round ducts work best with medium- to high-pressure clean air systems.

Duct Design :Duct Velocity and Sizing

Duct Velocity:

The air duct velocity, also known as air flow velocity, is a measurement of the air that moves through your clean air system's air supply and return grilles. This can be measured by either feet per minute (FPM) or meters per second (m/s).

Certain optimum ranges are recommended as per application; e.g., for dust collector applications, a range of 20–22 m/s is common so as to avoid dust deposition inside the duct. This velocity ensures that most of the dust particles are swept effectively up to the dust collector. In the case of welding fumes, this value is lower (@15–17 m/s), as it would need much less velocity to convey fumes as compared to dust.

CFM, which is “cubic feet per minute,” = velocity, which is shown in “feet per minute,” multiplied by the area, which is shown in “square feet.”

Duct Sizing:

Duct sizing is the most important factor in the design of a duct.

How is the duct size calculated then?

The Darcy equation reveals that reducing duct diameter increases pressure loss at a constant volume flow rate, while larger volume flow rates require larger duct diameters.

Duct Sizing Methods:

There are three important duct-sizing methods:

  • Equal friction method
  • Velocity Method
  • Friction Method
  • Static Regain

Duct Velocity and Pressure Drop

Duct velocity and pressure drop are important factors in a clean-air system. These factors influence airflow, duct velocity, and total pressures. Accurate calculations help ensure optimal airflow, comfort, and efficient system design. Excessively higher velocities than the recommended range would produce a very high pressure drop. Also, too little velocity will increase the size of the duct and, thus, the ducting cost.

Velocity and power consumption

Higher velocity leads to a higher pressure drop, and thus, you would need more power to overcome that pressure drop. This will increase the running cost of the system.

Duct Sizing: Increasing and Reducing Diameters

Increasing and decreasing diameters in duct sizing are based on the Darcy equation. The Darcy equation reveals that reducing duct diameter increases pressure loss at a constant volume flow rate, while larger volume flow rates require larger duct diameters.

Elbows, sharp bends, reducers, etc.

Elbows:

Elbow Design Guidelines

Fig: Principles Of Duct Design-Elbows(ACGIH Industrial Ventilation-23 Edition)

Radius elbows are recommended for rectangular ducts, while mitered elbows with turning vanes are suitable for medium- and high-velocity VAV systems. Short-radius elbows with splitters are recommended for medium- and high-velocity systems. Mitered elbows with turning vanes are used if necessary, but not for low-velocity systems.

Sharp Bends:

Avoid sharp bends or turns to make the air flow clear, because sharp bends or turns restrict the air flow speed in ducting.

The ductwork system utilizes various types of bends, including long radius bends with a gradual centerline radius, short radius bends with a sharper radius, and U-shaped bends like return bends. Mitered bends, offset bends, and bumper bends are used to change flow direction, redirect flow, and absorb shock or vibration.

Reducers:

Sharp-step-type reducers are to be avoided. Smooth tapering reducers should be considered. Also, ensure that the size of the duct is expanded prior to connecting branches and not after the connecting branch.

Dampers for balancing

Dampers are essential in CV (constant volume) systems, including self-balancing methods. The use of dampers ensures that we get the required air flow as per design at each branch.

7 Practical Guidelines for Duct Design:

Duct Enlargements1

Fig: Principles Of Duct Design-Duct Enlargements(ACGIH Industrial Ventilation-23 Edition)

Duct Enlargements2

Fig: Principles Of Duct Design-Duct Enlargements(ACGIH Industrial Ventilation-23 Edition)

  1. The general rule of thumb is that the less duct work you have, the cheaper it’s going to be. The fewer bends and elbows required are ideal.
  2. The blower needs to be less static, meaning a more cost-friendly exhaust blower, requiring less HP and energy consumption.
  3. Straight runs are best because they reduce wear issues and resistance in your duct system.
  4. Long-radius bends, curves, and turns are essential in creating airflow, reducing static pressure resistance and enhancing airflow by ensuring soft and delicate designs. .
  5. The static pressure generated during duct runs can significantly impact the velocity of the air, requiring careful consideration and management.
  6. The nature of open or larger-diameter pipe sizes can allow for more movement and less static pressure.
  7. Consult an expert like Filter On India for typical duct-carrying velocities based on dust density.

Visit blogs to learn more about the critical features of clean air system design and air pollution control systems created by Filter On India.

Filter On India has been working towards “Mission Zero Pollution” for the last 40+ years as a clean air solutions partner for industries. We specialize and have expertise in welding fumes, oil mist, coolant mist, dust collection, soldering, laser marking, laser cutting, plasma cutting, fumes in fastener manufacturing, ball point tip manufacturing, oil quenching, kitchen fumes, etc. Filter On has 70+ clean air solutions, so you can contact us for more information about our solutions. You can reach us through the web or visit us at our corporate office at Pune and our virtual locations at Delhi, Bangalore, Ahmadabad, Hyderabad, or Chennai locations.

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