. Mechanical engineer requires advice with chemistry problem !! Is it possible for fine concrete powder, any size, any concentration (generated by crushing during demolition) to ignite in dry air ? Any info welcome Apart from silica content, cement and concrete dust can be harmful by inhalation in other ways. On contact with moisture in your mouth, cement and concrete dust forms a corrosive and highly alkaline solution
Cement dust is/was used to suppress fires and coal dust explosions in coal mines. Like stated above I've never seen any measures taken around cement storage silos that would suggest an explosive potential. The one thing missing is there is no organic material available ., are inert materials in their pure form (i.e., these materials will neither burn nor support combustion and do not pose a risk of fire or dust explosion) Burning combustible metals produce an unusual amount of heat. Such a fire may cause water to come out of concrete (the water of hydration in the concrete) or even rocks. This water may cause increased burning, burst the materials and cause pieces of rock or concrete to be thrown about The most problematic component of dust and fines from concrete are silicates, which pose health risks if inhaled. Repeated or chronic exposure may result in silicosis, which is bad. The dust will also contain calcium hydroxide and will be quite alkali, so it has other components that will irritate skin, eyes and mucous membranes For example, granite, which is frequently used in kitchen countertops, may contain up to 70% silica. When materials such as concrete, stone, brick, or granite are cut or ground by workers, it can create extremely fine dust particles, which can make their way deep into the lungs if inhaled
When combustible dusts ignite, there are often two explosions known as primary and secondary explosions. The primary dust explosion is the first explosion. It occurs when there is a dust suspension in a confined space (such as a container, room, or piece of equipment) that is ignited and explodes. Figure When concrete is heated to extremely high temperatures, it can actually explode. Those explosions can have pretty significant consequences when a fire breaks out near a concrete structure, but the.. Scabbling or concrete cutting can also produce high levels of dust that may contain silica. Find out more about Howden's Centrifugal Fans used during cement production . Deadly Dust. Silica dust is very fine, much smaller than a tiny grain of sand found on a beach. This is what makes it so easy to inhale But, cement manufacturing and the raw materials used in the process pose a fire or explosion risk. A fire or explosion in a cement manufacturing plant damages the property and or causes injuries or fatalities to workers. It is, therefore, important for all stakeholders to understand how to avert these dangers
Build-up of explosive mixtures like finely dispersed coal dust in air, or carbon monoxide in air can result in an explosion hazard in Electrostatic Precipitators. As such, special care is required at these locations to prevent such a build-up. 4) Storage and Handling of Explosives. Most cement plants own limestone quarries that are located nearby A study2 of dust explosions over a ten-year period identified over a dozen different types of ignition sources. Trying to prevent the ignition source will reduce the frequency of explosions, but a responsive strategy will reduce the consequences of an explosion. For silo applications there are three responsive methods: explosion venting. The explosions claimed the lives of 14 workers and critically injured 36 others. The blaze ravaged storehouses, packaging buildings, and processing areas that had been operating for more than eighty years. The U.S. Chemical Safety Board deemed it the most devastating dust explosion in decades. Combustible Dust Explosion
Top 10 Tips for Dust Explosion Safety in the Cement Industry. Historically the majority of fire and explosions in the cement industry occurred in the coal-fired systems. Now the cement industry represents 5 percent of the world carbon emissions, . This is evident from the explosive mushrooming of the towers into vast clouds of concrete as they fell, and from the fact that virtually no large pieces of concrete were found at Ground Zero, only twisted pieces of steel. 1 Estimates put the size of the particles, which also included gypsum and hydrocarbons, in the ten- to 100-micron range. Amin N. Alameddin1 and Steven J. Luzik2 Coal Dust Explosions in the Cement Industry REFERENCE: Alameddin, A. N. and Luzik, S. J.,ﬁCoal Dust Explosions in the Cement Industry,ﬂ Industrial Dust Explosions, ASTM STP 958, Kenneth L. Cashdollar and Martin Hertzberg, Eds., American Society for Testing and Materials, Philadelphia, 1987, pp. 217-233
There were 9 grain dust explosions reported in the U.S. in 2019 according to Kingsly Ambrose, Associate Professor, Purdue University. This compares to 12 in 2018 and a ten-year average of 8.5 explosions. There were 1 fatality and 7 injuries. The explosions were in 3 feed mills, 1 ethanol plant, 2 grain mills and 4 grain elevators Dexpan non-explosive demolition agent has a number of potential benefits: - No noise, dust, explosions, ground vibrations or shock waves. - Easily breaks reinforced concrete and all types of stone and boulders into more manageable sizes and shapes making clean-up and removal easier and less expensive. - Safer than blasting with no explosives. The cause of the explosion was ignition of the flammable gas hydrogen evolved from foamed concrete. The liquid concrete had been aerated, or foamed, by mixing air into it by agitation in the presence of a foaming agent (surfactant). There is evidence that hydrogen was produced from the concrete as it was setting
Canada concrete plant dust explosion injures three. 06 November 2018. A November 5 dust explosion at the Quality Concrete plant in Dartmouth, Nova Scotia, resulted in three minor injuries, according to CBC. The explosion blew the roof off a fly ash silo, propelling it hundreds of metres where it fell on a parked vehicle safety against coal dust explosions. Other ma1or preventive measures which can be adopted include rock dust barriers, concrete stoppihgs, and pressure relief vents in their various forms and modifications Dust: This is the source of all dust collector explosions, dust acts as a fuel and combustion to continue burning. The difference with a fire and an explosion, in our case, is that a fire burns static material whereas explosions come from the rapid ignition of multiple dust particles creating an intense hot expansion of fire and pressure It makes sense to consider all dust as potentially combustible dust. The great Banbury custard explosion of 1981 is still often joked about - but nobody was killed. Unfortunately, other incidents have taken hundreds of lives. Dust can never be taken for granted. In November 2018, there was a major explosion in a cement silo in Martinsburgh, WV 
Confined dust explosions have had the power to lift roofs from buildings or buckle solid concrete floors. In the case of the Imperial Sugar dust explosion, being confined pushed the explosion through tunnels and halls that led it to other confined dust clouds. This caused a chain reaction of combustions, destroying the building and claiming. combustible dust. • The consensus is that the code does not specifically require protection for < 8 cu. ft. • Yet unprotected < 8 cu. ft dust collector may leave the operator at risk . Code Prescribed Fixes Venting Flameless Venting Explosion Suppression Immersion Separator To understand the specific dangers of your dust, it is best to have it tested by professionals. They can analyze a sample of your dust and produce a full report describing it. Their report would include two key numbers: the Pmax and Kst values. These numbers measure the explosive power of your airborne dust. The Pmax value is the maximum. from a dust explosion can therefore propagate through piping, across galleries, and reach other pieces of equipment or enclosures, leading to extensive damage. While the ability of dust explosions to propagate has been widely recognized, some misconceptions lead to the false sense of security that explosion isolation is not required Explosion Proof Vacuum Cleaners. When it comes to cleaning up combustible dust, our line of certified combustible dust vacuums deliver the power and safety you need. Our complete line of explosion proof vacuum systems are ETL Certified to UL and CSA standards for Class I, Div 1, 2, Group D and Class II, Div 1, 2, Group F & G and ATEX Zone 22.
A carpenter was grinding the concrete in the wall and the room so full of dust. Then the TV channel box malfunctioned.. is it possible cement dusts can.. Combustible Dust | Hughes Environmental. Hughes Environmental has performed combustible dust cleaning in a wide array of facilities throughout the United States and has dealt with many types of combustible dust. Keeping your facility clean and free of dust hazards can help you keep your workplace safe, and help avoid regulatory fines Combustible dust explosions can be one of the most under-recognized hazards in industrial facilities. Without proper awareness and planning, the risk of an incident can threaten life safety, operational continuity and regulatory compliance (given that cement dust is very fine and one might expect a high proportion of the total dust to be respirable), and the other concerning the meaning of total dust. In the study of Noor et al. (2000), the ratio of total to respirable dust was reported as 8.5 mg.m-3 to 5.7 mg.m-3. In contrast, in the study of Fell et al., th
where combustible dust is liberated in normal operation so as to minimize the escape of dust. •The dust should be conveyed to dust collectors • Regular cleaning frequencies should be established for floors and horizontal surfaces, such as ducts, pipes, hoods, ledges, and beams, t ATF: Series of dust explosions Originated at base of concrete tower near receiving area Ignited natural gas line. 4/6/2018 8 Central Valley Ag elevator March 17, 2016 Explosion and fire Dump control house in flames • Hazard Statement: May form combustible dust concentration
It is apparent that in so doing, starch or other combustible dust stored in this vicinity was disturbed, whereby it became suspended in the atmosphere, forming an explosive mixture Dry concrete dust may cause mechanical irritation resulting in redness and lachrymation Skin Contact with plastic concrete will cause severe irritation and possible chemical burns, cement dermatitis and dry skin - Portland cement is alkaline in nature so plastic concrete and mortars are strongly alkaline (pH of 12 -13) A gender-reveal celebration at a concrete plant in rural New Hampshire involved someone detonating 80 pounds of Tannerite, an over-the-counter explosive, police said Contact (dust) with powerful oxidizing agents may cause fire and/or explosions (see section 10 of SDS). 3/01/2017 CRUSHED CONCRETE - Page 3 of 7 SDS #3239-04 The explosive nature of some types of dust poses an entirely different - though no less important - risk to workers. Combustible dust is the term for any fine material that can catch fire and explode when mixed with air. It includes a variety of substances, from sugar, flour, and grain to various types of metal
to eliminate the ignition sources. The fuel for a dust explosion is the grain dust in suspension in the air at or above the minimum explosive concentration (MEC). Most experts use 50 grams per cubic meter (g/m3) as the MEC for grain dust. If the dust concentration at a grain transfer point i A number of industrial processes produce combustible dust as a by-product. The most common being wood dust.Combustible dust has been defined as: a solid material composed of distinct particles or pieces, regardless of size, shape, or chemical composition, which presents a fire or deflagration hazard when suspended in air or some other oxidizing medium over a range of concentrations An explosion Monday afternoon at the Burnside Industrial Park in Dartmouth, N.S., shook nearby buildings and left parked vehicles caked in brown dust. Firefighters, police and ambulances were seen. Expect to vacuum volumes of concrete dust and days, weeks and even years later the cartridge filter will still be clean ~ Guaranteed. Plus the HEPA Cartridge Filter is Completely Washable! BONUS : Vacuums or Dust Extractors with Pulse, Vibration and/or Air Reversal Filter Cleaning Systems are strictly for dry debris
List of Historic Explosions (Dust, vapour and Gas) 1785 The earliest Dust Explosion recorded Giacomelli's Bakery Italy. A boy had his face and arms scorched shovelling flour under an open flame. It blew out the windows and their frames into the street Reasonable ventilation and dust removal technology plays a positive role in preventing dust explosion. It is important to select the appropriate parameters and methods at design time. 15-17m/s is the best wind speed in the air duct. Collect the dust directly at the dust generating point, after the dust collector purifies, row to the outdoor Papers presented at a symposium on industrial dust explosions. Seven papers wholly concern coal dust explosions and the majority of the other contributions are relevant to coal handling and storage. Two papers discuss coal pulverizer fires and explosions with a third covering coal dust explosions in the cement industry Concrete, concrete block, cement, and mortar Masonry, tiles, brick, and refractory brick Granite, sand, fill dirt, and top soil Asphalt-containing rock or stone Abrasive used for blasting Silica is the most common hazard on a work site. Any activity that creates dust can expose workers to airborne silica
The use of non-conforming rock dust reduces the protection from potential dust explosions. If rock dust absorbs moisture and forms a cake, it is unlikely to be scoured and entrained in the pressure front of an explosion, thus reducing the ability of the rock dust to inert the coal dust and prevent the explosion from propagating For the most thorough cleaning, use a three-tier approach: First, sweep up dust and debris, then vacuum all surfaces using a shop vacuum, then damp-mop or use a microfiber dust cloth to remove the finest dust from all surfaces, walls to the floor. Pay particular attention to any powder efflorescence on the concrete foundation walls and floor
Ongoing exposure to airborne silica dust can pose significant health hazards, and over time, it can even prove fatal. To increase concrete worker safety on construction sites, the OSHA is instituting more stringent concrete dust collection regulations. Proper containment of silica-containing concrete dust is one of the most important safety precautions that employers can tak Dust strategy. The NSW Dust Strategy 2020-2022 aims to prevent occupational diseases by providing NSW workers and businesses with a coordinated approach for the safe handling of hazardous dust including asbestos, silica, wood and other dusts. Injuries and fatalities due to exposure to asbestos, silica, wood and other dusts are preventable
Dust to Dust. On February 7, 2008, a series of violent explosions devastated a sugar refinery in Port Wentworth, Georgia (Figure 1). Workers inside had little time to escape as pressure waves heaved concrete floors, blasted brick walls, and collapsed stairwells. Combustible sugar dust, along with sugar tha American Vacuum has been selling HEPA filtered vacuums since the 1950s for silica dust and concrete and has gained extensive knowledge and expertise in this field. From small portable vacuums to large central vacuum systems , we can equip almost all of our vacuums with HEPA filtration Expansive Concrete Demolition Expanding grout is used in a myriad of applications, including building demolition, concrete removal, rock demolition and quarrying. While these demolition situations vary, they share common features that mandate no flying rock, a dust free work site, ease of use, no required licensing, vibration free silent.
Dexpan demolition grout. Instructions, FAQ, pictures, videos and reviews. Dexpan is a simple, safe and cost effective alternative to explosives, hydraulic breakers, jack hammering for breaking concrete, rock or boulders. No noise, vibration, dust or blasting. No permits, special training or in Combustible dust explosions over the past decade in U.S. plants are blamed for well over 100 fatalities and hundreds more injuries. Sadly, experts believe these accidents could have been prevent-ed if the companies involved had followed best practices for fire and explosion protection such as th TailScrape is mounted precisely to the existing AirScrape system, so that it seals the transfer to the bend, averting dust generation and material spillage, also reducing the risk of explosion.b metal sheet is used in the rear area of the transfer, matching the contour of the belt trough and installed approximately 20 mm from the belt. The. Squibs are blasting caps (initiators) used in the explosive industry to set off high explosives. 1 In discussions of the collapses of the WTC skyscrapers, the term has been appropriated to describe the physical appearance of puffs or jets of dust emerging from buildings during a demolition, caused by the detonation of explosive charges. . Several such squibs can be seen in videos and. Dust Explosions Dust / Powders that WILL NOT Explode Silicates, Sulphates Nitrates,Carbonates,Phosphates Cement, Sand, limestone Any Stable Oxide 12 13. Dust Explosions Glass breaks at 50 kpa (7 psi.) Wood frame at 56-70 kpa (8-10 psi.) Reinforced concrete 70-85 kpa (10-12 psi.) FORCE FROM DUST EXPLOSIONS CAN EXCEED 700 kpa or 100 PSI 13 14
3. Airborne combustible sugar dust accumulated above the minimum explosible concentration inside the newly enclosed steel belt assembly under silos 1 and 2. 4. An overheated bearing in the steel belt conveyor most likely ignited a primary dust explosion. 5. The primary dust explosion inside the enclosed steel conveyor belt under silos 1 and The Jobe Materials cement plant in El Paso, TX was rocked by an explosion on Sunday morning that was felt across the western portion of the city, ABC News affiliate KVIA reported. Fire officials told the television news station that the container blew up at about 8 am, but the structure was not damaged during the blast Dust explosions Dust explosions occur when combustible dust is airborne in a room or inside equipment, oxygen is present and there is an ignition source. The confinement of the room or vessel causes pressure to build up as the dust burns, leading to an explosion. These factors are illustrated as a Dust Explosion Pentagon below: Dust. Dust Explosion Info Dust Explosion Info is an information centre for Engineers, Safety Professionals and anyone involved with the potential hazard of dust explosions. The website is an excellent starting point for those wanting to know more about explosions; the physical characteristics of a dust explosion, the necessary conditions for an explosion to occur, potential ignition sources, dust. The dust emitted from coal grinding contains a certain amount of coal powders. Coal-bearing dust is flammable and explosive, and piles of coal powder will spontaneously ignite under certain conditions. Therefore, the dust collection equipment of the coal-grinding system must have flame-proof and explosion-proof devices, such as an explosion.
Re: Breaking News: Explosion in Cement Plant. Hello Mr Nael, I am very sad to know this as I had operated this kiln in 2007.Thanks for your detailed report and this sharing attitude which will alert the most of the cement industry and kiln operators to take care about such observations during heatup in future When a combustible dust explosion occurs, it is often followed by one or more subsequent explosions. The first explosion stirs up dust that has settled on surrounding surfaces and forms a dust cloud. The dust cloud can fuel a second explosion, which typically starts almost immediately after the first August 8, 2017. Q&A: OSHA Regulations On Concrete Silica Dust. The U.S Department of Labor will start enforcing its new concrete silica dust ruling for construction on September 23, 2017 (moved from June 23, 2017). With those new OSHA regulations coming up, it's important to be up to date on all the new changes regarding the OSHA standards