FAI Spring 2023 Process Safety News.ai

Process Safety News Spring 2023 - Vol. 30 - Issue 2

Upcoming Events:

In this Issue:

ASTM E27 Meeting on Hazard Potential of Chemicals May 17 - 18

The Potential Hazards of Hydrogen Elizabeth Meegan, Principal Engineer

pg 3

AIHcE EXP 2023 - Association of Industrial Hygiene, Booth 1219 May 22 - 24, Phoenix Convention Center, Phoenix, AZ

pg 7

Explosions in the Grain Industry - Why? Ashok G. Dastidar, PhD MBA, Vice President, Dust & Flammability Testing and Consulting Services

Heat of Combustion Testing Patrick Wojcik, Manager, Flammability Testing and Consulting Services

NFPA 652 - An Introduction to Dust Hazard Analysis June 14 - 15, Fauske & Associates, Burr Ridge, IL

pg 9

3rd Journal of Thermal Analysis and Calorimetry Conference and 9th V4 Thermoanalytical Conference June 20 - 23, Balatonfured, Hungary / Danubius Hotel Annabella

Evaluating the Flammability Hazards of Liquid Vapors The Fauske Flammability Team

pg 13

2023 Mary Kay O’Connor Safety & Risk Conference October 11-13, Hilton Hotel College Station, Texas

How to Choose the Right VSP2 Test Cell for your Experiment PDF available for download on pg 12

Free Vent Sizing Basic Course and Calorimeter Users Group Forum (more info on page October 17 - 19, Fauske & Associates, Burr Ridge, IL

pg 16

Water Hammer Solutions & Testing

www.fauske.com info@fauske.com +1 630 323 8750

FAUSKE & A S S O C I A T E S

LUNCH & LEARN

Lunch & learns provide our employees with a forum for personal and professional growth by encouraging interaction and collaboration between groups, providing training on new technology or methodologies, and emphasizing professional skills such as public speaking and technical writing.

Some examples of lunch & learn topics include:

Applications of combustible dust experiments

Experimentally identifying reactive hazards and assessing their consequences

Design considerations for active and passive ventilation systems

Experiences from supporting a plant outage

It was great connecting with so many new and familiar faces this Spring!

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Jim Burelbach, Chief Commercial Officer Sara Townsend, Manager, Thermal Hazards/Reaction Calorimetry Elizabeth Meegan, Principal Engineer

Ken Kurko, Sr. Vice President Zach Hachmeister, President

pictured left to right

Mark Yukich, Manager, OnSite Safety Services r, s

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The Potential Hazards of Hydrogen Elizabeth Meegan, Principal Engineer, Fauske & Associates

Why Hydrogen? Growing interest in hydrogen revolves around the recognition that clean hydrogen could play a crucial role in global decarbonization. Currently 40% of all carbon dioxide emissions come from power plants burning fossil fuels for energy. Other high pollution fields include transportation and industrial factories. Consumption of hydrogen for energy produces only water, and hydrogen carries a high energy density by mass, which makes it an interesting low carbon alternative. The demand for hydrogen has increased threefold since 1975 and is expected to continue this trajectory with the

Where Does Hydrogen Come From? Not all hydrogen is considered “clean” as its production can be carbon intensive, and so while hydrogen is a colorless gas, it is typically described by color to represent its source. Green hydrogen is of particular interest to combat global warming, because it is produced in a “climate-neutral manner.” Table 1 provides a comparison of the commonly discussed hydrogen production methods. demand for clean hydrogen anticipated to be a crucial component of Net Zero Emissions by 2050 Scenario (NZE) with a potential demand of 150 to 500 million metric tonnes of hydrogen a year. To try and meet this demand, there is a global push for financial investment in clean hydrogen at scale in both commercial and industrial applications.

Hydrogen is produced by electrolyzing (splitting) water molecules from surplus renewable energy sources (e.g. solar or wind). This process is carbon free, but currently only makes up 0.1% of overall hydrogen production because it’s very expensive. Hydrogen is produced by steam methane reforming (SMR, brings together steam and natural gas to generate hydrogen). This process does generate carbon dioxide as a product, but it utilizes a carbon capture and storage system to trap and store it. This process is often referred to as low-carbon hydrogen, because only 85-95% of the carbon is typically captured.

Green Hydrogen

Blue Hydrogen

Turquoise Hydrogen

Hydrogen is generated by methane pyrolysis, which is the thermal decomposition of methane into hydrogen and solid carbon, but this process seems primarily experimental currently.

Pink Hydrogen

Analogous to green hydrogen production, except the source of energy is from nuclear power.

Yellow Hydrogen

Primarily considered the production of hydrogen from electrolyzing water using solar energy.

Hydrogen production from biomass. Grey hydrogen is currently the most common form of hydrogen production where hydrogen is generated from natural gas through SMR, but without carbon capture system.

Grey/Black/Brown Hydrogen

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Hydrogen Properties & Potential Hazards Hydrogen has many properties that make it attractive as a source of energy, and many of which are inherently safe features, however there are potential hazards associated with any fuel source. Here are some of hydrogen’s properties, and how they might relate to potential hazards to consider depending on the application: ▪ Hydrogen is a colorless, odorless, and tasteless non-toxic gas typically in the form of a diatomic molecule (H 2 ). While rare, hydrogen is a potential asphyxiation hazard in confined spaces. In addition to the gaseous form, hydrogen flames are also nearly colorless, and the low radiant heat and low emissivity of the flame can make it difficult for early identification. ▪ Hydrogen is non-corrosive, however it can cause embrittlement leading to unexpected failures or leaks. Properly selected materials and system layout, periodic visual checks, adequate passive or active ventilation systems, and safety systems (e.g. leak or hydrogen detection sensors) are important aspects of a safe design. ▪ Hydrogen has excellent energy density, however its vapor density is incredibly low (around 1/15 th of air). This is excellent when considering the dissipation of a buoyant vapor cloud following a leak, however this can make it difficult to store large quantities of hydrogen. In the gaseous form, high pressure vessels can be employed. Alternatively, hydrogen can be compressed, and stored at cryogenic conditions. Both options should be considered for potential overpressure hazards, and unignited releases (e.g. loss of temperature control in cryogenic storage or fire exposure in gaseous storage, both of which can lead to rapid pressurization and a loss of containment).

▪ Hydrogen has a very large flammable range (typically considered 4% to 75% by volume in air) and a very high burning velocity when compared to other typical fuel types. This increases the likelihood and potential consequences of combustion (via fire or explosion). Despite hydrogens propensity to diffuse quickly in air, high-pressure leaks can lead to unconfined jet fires or explosions, and the low minimum ignition energy of hydrogen makes it difficult to eliminate all potential ignition sources. Confined vapor cloud explosions (i.e. deflagrations or deflagrations that transition to detonations) are also a hazard to consider with potentially severe consequences. Proper siting and barriers can help to protect against this hazard.

Expansion of Initially Choked Jet and Entrainment after Depressurization

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Hydrogen Safety Developing a safe process to harvest or utilize hydrogen is much like developing any other safe process involving chemical hazards:

1. Identify Potential Hazards (via HAZOP, FMEA, or other tools) 2. Evaluate the Hazard Risk Level in Terms of Likelihood and Severity 3. Identify Preventative, Mitigative, or Elimination Techniques 4. Document the Findings, Employ the Techniques, and Train Personnel

5. Ensure Safety Systems and Facility Meet Relevant Regulations, Codes, and Standards 6. Periodically Review System and Monitor for Changes, and Repeat Process if Change Occurs

References:

https://www.iea.org/reports/the-future-of-hydrogen https://www.iea.org/reports/hydrogen https://www.un.org/en/climatechange/net-zero-coalition https://www.energy.gov/articles/how-were-moving-net-zero-2050 https://netl.doe.gov/research/Coal/energy-systems/gasification/gasifipedia/hydrogen https://www.weforum.org/agenda/2021/07/clean-energy-green-hydrogen/ https://chfcc.org/hydrogen-fuel-cells/about-hydrogen/hydrogen-properties https://www.energy.gov/eere/fuelcells/safe-use-hydrogen https://www.nrdc.org/bio/christian-tae/hydrogen-safety-lets-clear-air https://www.nrel.gov/hydrogen/safety-codes-standards.html

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continued from page 5 continued from page 9 NFPA 652 An Introduction to Dust Hazards Analysis Presented by Fauske & Associates s ske & Associates

Location: 16W070 83rd Street, Burr Ridge, IL 60527 3 e 3rd Street, e, IL 60527

Date: June 14-15, 2023 Time: 8 AM - 4:30 PM CDT Price: Day 1 only - $500 Days 1 and 2 - $950 0 M 5 $950 023 M CDT 500

Day 1

This course will ensure all participants are aware of important issues associated with NFPA 652 and describe how this standard interacts with other relevant NFPA codes and guidelines. A special emphasis will be placed on explaining the requirements for a Dust Hazard Analysis (DHA) and an overview of the methodologies that can be employed to perform a DHA. The course will also include a logical approach to characterizing a powder's hazardous dust properties, as well as a description of various techniques used to control and/or avoid dust explosions in a safe and compliant manner.

Day 2 The Advanced DHA Workshop will focus on how to organize, lead, and implement the DHA study. This will include how to utilize appropriate test methods to determine potential dust hazards; as well as how to apply appropriate mitigation techniques to prevent or control combustible dust hazards. During the workshop, participants will have the opportunity to apply DHA methodologies to realistic combustible dust scenarios.

Scheduled Agenda

Outcomes

▪ Introduction ▪ Overview of NFPA 652

▪ Protection Options ▪ Daily Learning Assessment ▪ Questions and Answers ▪ Course Evaluation Instruction

▪ Fundamentals of Dust Explosions ▪ Introduction to DHA methodology ▪ Mock DHA on a Small Blending Operation ▪ Introduction to NFPA 660

www.fauske.com Info@fauske.com f k Register

Figure 5: 20221213-Battery Scoping Test 1 – Containment Pressure vs. Time (0 min to 70 min)

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Explosions in the Grain Industry - Why?

Ashok G. Dastidar, PhD MBA, Vice President, Dust & Flammability Testing and Consulting Services, Fauske & Associates One of the first recorded and studied dust explosions occurred in a bakery in Turin, Italy in 1785

Count Morozzo from the Academy of Science in Turin investigated the incident to conclude that the explosion was caused by the flour dust suspended in the air and not gases generated by mold or fungus eating the flour. Dust explosions are very common in industry. They occur in all industries from wood working, sawmills, pharmaceutical plants, chemical plants and more importantly for this discussion at agricultural facilities. In April of 1980 there was a large explosion at a grain terminal in Saint Joseph, MO. One person was killed and four were injured. An electric arc from a damaged level indicator initiated an explosion in one of the silos. The explosion traveled through the headhouse to the other silos and caused over two million dollars in damages. Later, in June of that same year an explosion occurred at a river grain terminal in Saint Paul, MN. Luckily there were no fatalities but 13 workers were injured. An electrician was working on live electrical circuitry while grain loading operations were taking place. The arc from the electrical work initiated an explosion that traveled along the tunnel to the headhouse and through the bucket elevator to the other tunnels resulting in $300,000 in damages. A month later in Fonda, IA an explosion occurred at a train-loading country grain terminal where electrical welding on a bucket elevator initiated an event. No one was killed or injured in that event.

1980 Grain Silo Explosion, Saint Joseph, MO Photo by Tim Hynds, Sioux City Journal

Nine months later in April 1981 a large explosion at an export grain silo plant in Corpus Christi, TX killed nine people and injured 30. Smoldering lumps of grain entered a bucket elevator and initiated a dust cloud explosion. The resulting explosion propagated to other elevators, and then onto the headhouse, tunnels, conveyers and silos, resulting in thirty million dollars of damage. It was after this last event that the Occupational Safety and Health Administration (OSHA) released the "grain handling standard" 29CFR1910.272 in 1987. This standard is the backbone of the government's safety program to protect grain elevators, feed mills, flour mills, rice mills, dust pelletizing plants, dry corn mills, soybean flaking operations, and the dry grinding operations of soy cake from violent dust explosions. Some of the key requirements of the standard are that employers develop an emergency plan to deal with dust explosions, train their employees and contractors to recognize dust explosion hazards and safely work in that environment, establish a hot work permit system to minimize potential ignition sources, keep fugitive dust at bay with a documented housekeeping program, and requirements for emergency escape. Additionally, it provides requirements for the safe use of driers, bucket elevators and air filtrations systems.

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This standard, according to OSHA's figures, has been effective. The average number of grain elevator explosions has decreased from 20 per year in the 7O's and 80's to 13 per year in the 90's and to less than 8 per year in the 21st century. However, that still amounts to 503 incidents between 1976 and 2011 with 677 injuries and 184 fatalities in that time. A relatively recent incident occurred at the Andersen Farms Inc. grain elevator explosion in South Sioux City, Nebraska, on Tuesday, May 29, 2018. The accident resulted in one fatality and one injury. Compounding this great tragedy is that the OSHA standard that would have kept the employees safe does not apply to family-farm owned facilities with less than 11 non-family employees. As a result they cannot enforce the 29CFR1910.272 at the facility or investigate the incident.

What potentially could have kept the employees safe and avoided the accident is enforcement of the Nebraska Fire Code, Title 153 and the Grain Elevator Fees and Guidelines, Title 161. Both these documents have adopted NFPA 61 "Standard for the Prevention of Fires and Dust Explosions in Agricultural and Food Processing Facilities" and reference it for safety inspections. Compliance with NFPA 61, a document that greatly influenced the OSHA standard, would have reduced the risk of a catastrophic explosion. NFPA 61 is one of the oldest NFPA standards dating back to 1923 and was initially developed to prevent dust explosions in grain terminals and flour mills. Gradually, over time, the standard was combined with other NFPA documents to become a universal fire and dust explosion prevention and protection standard for agricultural and food facilities. The document has a long history and is adopted by most state and local fire codes. Therefore, state/ local building inspectors and state fire marshals should be very familiar with the document and on how it should be enforced.

Additionally, many insurance carriers require agricultural facilities to comply with NFPA 61 for property loss and business interruption protection. These companies have engineers and inspectors who are trained in the NFPA 61 requirements and frequently audit facilities for compliance before offering them insurance coverage. They can spot deficient housekeeping, or bad hot work/electrical work practices or building/machinery construction without explosion/fire protection. Their enforcement of NFPA 61 as an authority having jurisdiction can greatly reduce the risk of an explosion or fire. With these three layers of protection; the OSHA Grain Handling Standard, State Fire Codes that adopt NFPA 61 and insurance companies that require NFPA 61 compliance for coverage to be offered, why do we still have explosions in the grain industry? Even if one of these three layers were to fail; for example, the OSHA standard not being enforceable on small family-farm facilities, the other two layers of protection should be able to catch any deficiencies and protect workers and the surrounding community.

Need help evaluating the safety of your facility? We can help. Contact us at dust@fauske.com to learn more.

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Heat of Combustion Testing Patrick Wojcik, Manager, Flammability Testing and Consulting Services, Fauske & Associates Introduction With the growing global demand for more efficient and sustainable energy sources, determination of the heat of combustion of substances is expected to continue to play a critical role in the development of new fuels and the optimization of existing fuels. The heat of combustion (also referred to as the calorific value, fuel value, or energy value) is the amount of energy released as heat when a material undergoes complete combustion in a pure oxygen environment at constant volume. In this article, we will explore the concept of heat of combustion testing and its significance in various industries.

What is Heat of Combustion Testing? Heat of combustion testing is carried out using an isoperibol oxygen bomb calorimeter, which consists of a high-pressure rated vessel (bomb) that is immersed in a water bath inside of a calorimeter (Figure 1). Prior to immersing the vessel into the water bath, a measured amount of solid or liquid sample that is being tested is transferred into a sample cup which in turn is placed inside of the bomb. Afterwards, the bomb is pressurized with a measured quantity of pure oxygen, and then the entire vessel is sealed and immersed in the water bath inside of the calorimeter.

Figure 1: Heat of Combustion Apparatus

After the temperature of the water bath stabilizes, a fuse wire is used to ignite the sample, causing it to combust in the oxygen. The heat generated by the combustion reaction inside the bomb is transferred to the water in the surrounding bath, and the resulting temperature rise is measured. This temperature rise is then used to calculate the heat of combustion of the sample. Why is Heat of Combustion Testing Important? Heat of combustion testing provides valuable information about the energy content of a substance which is critical for a wide range of applications, including fuel development, reaction analysis, and classification of aerosol products (see the following page for details). Heat of combustion testing can also be used to determine the number of calories per gram of food and it is also currently one of the chemical property requirements for the development of commercial and military turbine fuels (ASTM D240).

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What are Examples of Applications for Heat of Combustion Testing?

Various industries use heat of combustion testing for different objectives and applications. Some examples include: 1. Fuel Development & Optimization: Heat of combustion testing is used considerably in the development of new fuels and in optimization of existing fuels. Scientists and engineers can use this method to determine the energy value as well as quantify the amount of waste heat that is generated during combustion of different substances, such as metal fuels, biofuels, and renewable fuels. These data are then used to optimize fuel composition and production processes, as well as minimize emissions, to create fuels that are more cost-effective, efficient, and environmentally friendly. 2. Reaction Analysis: Determination of material energy content is essential for research and development of new chemistries, as it allows researchers to assess the heats of formation of raw materials prior to a synthesizing into the final product to understand the total energy consumption/generation of the reaction. Before scaling up a reaction, it is important to fully understand the reactivity and energetic potential of the materials involved. This way the reaction can be optimized to achieve high yields and avoid any unwanted reactions, some of which can be extremely violent. 3. Aerosol Classification: In conjunction with ignition distance and enclosed space ignition tests using methods outlined in the United Nations Chemical Classification Manual, the results of heat of combustion tests can be used to characterize an aerosol product as non-flammable, flammable, or extremely flammable (see Figure 2). The classification of aerosols is essential in determining proper packaging and shipping groups for transportation purposes to avoid any accidents.

Spray aerosol

NO

YES

In the ignition distance test, does ignition occur at a distance >75 cm?

Does it have a heat of combustion <20 kJ/g?

Extremely flammable

YES Y

NO

Flammable

In the ignition distance test, does ignition occur at a distance >75 cm?

YES

Extremely flammable

NO

In the ignition distance test, does ignition occur at a distance >15 cm?

YES

Flammable

NO

In the enclosed space

YES

ignition test, is the time equivalent < 300 s/m 3 deflagration density <300 g/m 3 ?

Flammable

NO

Not classified as flammable aerosol

Figure 2: UN Classification of Spray Aerosols

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Summary Heat of combustion testing is a vital method for evaluating the energy value of a material and is critical in a wide variety of applications. An accurate and precise analytical measurement of a material’s energy content is crucial in research, development, optimization, and safety.

References

ASTM D240. (2017). Standard Test Method for Heat of Combustion of Liquid Hydrocarbon Fuels by Bomb Calorimeter . Philadelphia, PA: American Society for Testing and Materials. United Nations. (2019). Recommendations of the Transport of Dangerous Goods: Manual of Tests and Criteria. New York: United Nations.

If you are interested in receiving a quote for heat of combustion testing or would like to learn more, please do not hesitate to contact us at flammability@fauske.com.

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Join Fauske & Associates (FAI) for our Fall 2023 Free Vent Sizing Basic Course and Calorimeter Users Group Forum

Fauske & Associates 16W070 83rd Street, Burr Ridge, IL 60527 Location:

Date:

Tuesday, October 17 - Thursday, October 19, 2023

Time:

8:30 AM - 4:30 PM on Tuesday and Wednesday 8:30 AM - Noon on Thursday

Contact U s to L earn M ore

Seminar Objectives

FAI’s Free Users Group Forum provides users with tips and techniques for obtaining high quality data and discussions on analyzing and applying the collected data for important safety parameters. Detailed classroom style presentations and meaningful, customized “hands-on” lab training will enable users to understand the full capabilities of their own equipment. Users will be given a crash course in vent sizing basics, and example vent sizing problems will be discussed. Network with other uses and leverage their experience with similar applications as found in your facility.

▪ Overview of VSP2 and ARSST equipment ▪ Equipment demonstratons Seminar Topics

▪ FERST software basics

▪ Instrument trouble-shooting techniques ▪ Test design and advanced testing techniques ▪ Safety and sensibility in chemical testing

training & demonstration

▪ DIERS vent sizing methodology

▪ Daily “hand-on” lab sessions

▪ Data interpretation and

application for crucial safety parameters

Please contact us if you have any questions: thermalhazardsgroup@fauske.com Lunch will be provided Tuesday and Wednesday. Participants are responsible for their travel & accommodations. Lunch will be provided

Download our graphic with key information to consider when choosing a test cell for your experiment g y How to Choose the Right VSP2 Test Cell

Download PDF

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Evaluating the Flammability Hazards of Liquid Vapors The Flammability Team, Fauske & Associates With the increased number of reported fires and explosions, it is evident that there is an unacceptable absence of proper preventative measures and mitigative safeguards in place to reduce the number of fire-related incidents. Prior to scaling up a chemical process or working with a new chemical, it is critical to fully characterize the flammable properties of the chemical to get a strong understanding of the flammability potential and to set up the appropriate safeguards.

Before discussing flammable properties further, it is important to first understand the three general elements that are required for a fire or an explosion to occur: a fuel, an oxidizer, and an ignition source (Figure 1). Through removal of one of these elements, a fire/explosion will not occur (in most cases 1 ). Eliminating the ignition source is often not a practical method of prevention due to flammable vapors typically having very low minimum ignition energies (meaning they are very easy to ignite) as well as the likely existence of numerous different potential ignition sources (known and unknown). Therefore, moderating the fuel and oxidizer concentrations to avoid a flammable concentration of gases/vapors, otherwise known as the flammable region, is necessary for reducing the risk of a fire/explosion.

Figure 1: Fire Triangle

In the chemical industry, processing and handling of chemicals could result in the formation of a flammable or explosive atmosphere. For liquid chemicals, this may occur at temperatures other than at ambient conditions. Figure 2 shows the relationship between the flammable properties of a material and how they are related to temperature. As temperature increases, the vapor pressure of a material exponentially increases, and there becomes a point where the concentration of the vapor is sufficient to create a flammable atmosphere in air. This temperature is commonly known as the flash point (FP). In theory, the lower flammability limit (LFL) should intersect the vapor pressure curve at the

Figure 2: Temperature Effects on a Flammable Mixture (Crowl, 2003)

1 There are some unstable chemicals, like acetylene, which do not require an oxidizer to exothermally decompose.

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flash point temperature. As a result, this temperature is also referred to as the lower temperature limit of flammability (LTL). However, in reality, these two temperatures (FP and LTL), may not always be the same. Knowledge of the disparity between these two points will help better assess the flammability hazards of a specific chemical as well as help implement the proper safety precautions during handling.

Table 1: Flash Point and Lower Temperature Limit of Flammability Results

To understand the variation between the lower temperature limit of flammability and flash point, tests were performed to compare the results. The lower temperature limit of flammability tests were conducted using ASTM E1232 “Standard Test Method for Temperature Limit of Flammability of Chemicals” modified to be conducted in a 5.3-L stainless steel spherical vessel using a fuse wire ignition source for safety and environmental purposes. The criterion for a positive ignition was a 7% pressure rise above the starting pressure. The flash point tests were performed using ASTM D3278 “Standard Test Methods for Flash Point of Liquids by Small Scale Closed-Cup Apparatus”. These tests were performed on four different chemicals and the results are summarized in Table 1.

LTL (oC)

Flash Point (oC)

Chemical

Organosulfur Compound Lactam Ring Compound Pyridine Compound 1 Pyridine Compound 2

89.5

81

81.5

79

100

92

119

137

Vessel Size and Geometry – As the size of a vessel increases, the heat losses to the vessel wall become negligible. Through minimizing heat losses to the vessel wall, more heat is transferred to the combustion reaction, promoting flame propagation. This results in a widening of the flammable region and potentially allowing for combustion to occur at lower temperatures. Furthermore, a study performed by Takahashi, Urano, Takuhashi, and Kondo (2003) determined that flammability properties should be determined using either a spherical vessel or a cylindrical vessel with a diameter of at least 30 cm and a height of at least 60 cm to minimize the effect of flame quenching which may artificially result in a narrower flammable region. Ignition Source Location – A lower ignition source elevation in a vessel has been shown to widen the flammable region as compared to a central ignition source location (Van den Schoor, Norman & Verplaetsen, 2006). With a lower placed ignition source, a larger percentage of the combustible mixture participates in the upward moving combustion reaction with minimal heat losses to the wall, thereby, causing more heat being transferred to the combustion reaction resulting in a wider flammable region. The deviation between the values determined by these two tests is a result of differences in the test apparatus and methodology used in each of these experiments. It is important to understand that flammable properties are influenced by numerous factors. Below are a few factors that may provide an explanation for the differences between the two test results: 2. 1.

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3.

These example results demonstrate that it is imperative to fully characterize the flammability hazards of chemicals. Determination of the flash point by itself may not always be sufficient in providing data that is used to implement proper safety measures to avoid flammable temperatures when assessing the hazards of flammable liquids. As shown from the LTL and FP tests, there can be potentially large deviations between the two values. Therefore, the use of a safety margin with the flash point value may not always be adequate. The safest approach would be to conduct an LTL test to assess the temperature at which there is sufficient vapor for flame propagation. Flame Propagation – Generally, the flammable region is wider for upward flame propagation compared to downward flame propagation due to flame buoyancy (EU-Project SAFEKINEX, 2006). Tests performed in the 5.3L vessel measure upward flame propagation as compared to the flash point tester which measures downward flame propagation. This wider range means that the LTL will generally occur at a lower temperature than the FP. Homogeneity of Mixture – Slight changes in the vapor concentration could result in a mixture becoming flammable or not flammable. In the LTL tests, the vapor mixture is stirred to provide a homogenous mixture of the fuel in air, unlike the flash point tests where the vapor space is not stirred and thus allows concentration gradients to form. Furthermore, the LTL tests provide more uniform heating of the vessel as well as a longer mixing time to allow the vapor and the liquid to reach equilibrium. All of these factors will impact the concentration of the fuel in the vapor space and may influence the flammability results. 4.

If you are interested in receiving a quote for flash point or lower temperature limit of flammability testing, or would like to learn more, please do not hesitate to contact us at flammability@fauske.com.

References

Crowl, D.A. (2003). Understanding Explosions. New York: American Institute of Chemical Engineers.

EU-Project SAFEKINEX (2003-2006). Report on the experimental factors influencing explosion indices determination. Programme “Energy, Environment and Sustainable Development”, Contract No: EVG1-CT-2002-00072. Takahashi, Urano, Tokuhashi, Kondo (2003). Effect of vessel size and shape on experimental flammability limits of gases, Journal of Hazardous Materials. Van den Schoor, F., Norman, F., & Verplaetsen, F. (2006). Influence of the ignition source location on the determination of the explosion pressure at elevated initial pressure. Journal of Loss Prevention in the Process Industries.

Flame propagation venting of a flammable event in a 5-L glass sphere

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When fluid flow is suddenly subjected to a stop or change in direction, a pressure surge commonly referred to as a water hammer event will occur. The momentum of the fluid abruptly stopping creates a pressure wave that travels through the media within the pipe system. This same principle is also applicable when the flowing medium is steam rather than water. In the case of steam, the pressure surge is known as a steam hammer event. Both water and steam Water Hammer Solutions and Testing

hammer events have the potential to cause catastrophic damage. This phenomenon can also occur in non-aqueous systems.

A structured approach to addressing water hammer issues provides an efficient, cost effective, and safe solution to address your water hammer issues. Our expert team of engineers has extensive experience addressing and resolving various types of water hammer issues utilizing the following:

• Analysis using key industry recognized transient analysis software • Experimental testing simulating water hammer events • Equipment qualification to meet industry standards

To learn more, please contact us!

info@fauske.com

Process Safety News Spring 2023 - Vol. 30 - Issue 2

FAI Contributors

Ashok Ghose Dastidar, PhD MBA, Vice President, Dust & Flammability Testing and Consulting Services

Elizabeth Meegan, MS, Principal Engineer

Patrick Wojcik, Manager, Flammability Testing and Consulting Services

Editorial Staff

James P. Burelbach, PhD, Chief Commercial Officer Carol Raines, Graphic Illustrator

Statement of Purpose: "Process Safety News" is offered as a way to share our decades of experience in chemical and nuclear process safety and to present advances in our related products and services. We aim to facilitate better understanding of current process safety issues, standards, and practices, including hazard identification, lab testing, accident prevention and mitigation.

Learn More

Contact Us

FAUSKE & A S S O C I A T E S

www.fauske.com info@fauske.com +1 630 323 8750