Ho phatloha ha Lerōle le Chesang le Mello ea Powder ea Metal ea Sehlopha sa D¶

Hoo e ka bang lintho life kapa life tse tiileng tsa lintho tse phelang kapa tšepe e ka chesoang ke oxidizable e ka tukang ka bongata, le lisebelisoa tse ngata tse bonahalang li sa che ka sebopeho se tiileng, joalo ka aluminium, titanium, magnesium, tšepe, cornstarch, tsoekere e phofshoana, phofo ea koro, sawdust ea patsi, mashala le lesela la polasetiki, li tla phatloha ka matla a senyang a lerōle le lengata la mafura le lerung le lenyenyane la leru. moea. Hobane leru la likaroloana tsa lerōle tse 50-micron le pepesetsa oksijene ea sepakapaka makhetlo a likete ho feta lehong le tiileng la lehong kapa tšepe, tlhase e le 'ngoe ea electrostatic, conveyor bearing, kapa tramp metal friction spark e ka hotetsa leqhubu la pholiso** le mathang ka setsing se bophahamong ba limithara tse 1 ho isa ho lekholo le leng le le leng* bar (100 ho 145 pounds per square inch / psi)**, ho feta makhetlo a leshome khatello e hlokahalang ho heletsa li-silo tsa konkreite tse matlafalitsoeng le meaho ea tšepe ea meaho.

Se etsang hore ho phatloha ha lerole liindastering ho be kotsi ka tsela e ikhethang ke tatellano ea mekhahlelo e 'meli ea ho phatloha ho ea ho ea bobeli. Ha mollo o monyane, o fumanehang sebakeng sa mollo oa mantlha kapa pop o hlaha ka har'a ntlo ea pokello ea lerōle, leoto la lifti ea libakete, kapa hammermill, leqhubu la khatello le sisinya marako a moaho a kaholimo, lithapo tsa likotopo le lisiling tse emisitsoeng. Haeba esita le 0.8 millimeters (1/32 ea inch) ea sawdust e sa sebetseng, lerōle la lijo-thollo, tsoekere, kapa lerōle la tšepe li lumeletsoe ho bokellana holim'a maballo ao, leqhubu le sisinyehang le ileng la oela lerung le leholo le hotetsang karoloana ea motsotsoana hamorao ka mor'a koluoa** e phatlohang lerōleng lohle** Ho feta moo, ha lirafshoa tse sebetsang li arotsoe hantle (tse kang magnesium swarf, aluminiamo e silang lerole, titanium turning, kapa 3D-printing metal powders) li tšoara mollo, ** ho fafatsa ka metsi, foam, kapa setima-mollo se tloaelehileng sa ABC holim'a tšepe e tukang se baka hore hang-hang hydrogen-gase le ho phatloha ha mouoane**. Ho tseba ho tsoa hang-hang ka mor'a "pop" leha e le efe e nyenyane pele ho phatloha ha bobeli, ke hobane'ng ha u sa lokela ho sebelisa moea o hatelitsoeng ho theola maballo a lerōle kapa ho roala qubu ea tšepe e tukang ka metsi, le mokhoa oa ho tima mollo oa tšepe oa Sehlopha sa D ka lehlabathe le omileng kapa sodium chloride flux ho pholosa bophelo.

Etsa sena hona joale¶

1. Tloha mohahong kaofela hang-hang haeba u utloa molumo oa "pop" o sa hlakang, kapa o benya ka har'a mokelikeli oa lerōle, leoto la lijo-thollo, silo, kapa kotopo. Lerata leo la pele ke ho phatloha ha lerōle le ka sehloohong; ka mor'a metsotsoana e seng mekae, ho thothomela ha eona ho ka sisinya lerōle le holim'a maballo 'me ha baka tlokotsi seqhomane sa bobeli sa mohaho. Kenya tsela e haufi ea ho tsoa e eang sebakeng se bulehileng sa kopano ea moea o fokang moea bonyane limithara tse 100 (maoto a 330) ntle le lisila le litšepe tsa lerōle tse kantle.
2. ** LE KA mohla u se ke ua fafatsa metsi, foam ea Sehlopha sa A, carbon dioxide (\(CO_2\)), kapa setima-mollo sa lik'hemik'hale tse ngata sa ABC holim'a qubu e tukang ea lerōle la tšepe kapa li-turnings (aluminium, magnesium, titanium, zirconium, sodium, kapa lithium).** Mocheso o ka holimo ho likhato tse 2,000 tsa Celsius (3,600), chesa molecule ea metsi a oksijene ka ho toba. (\(H_2O\)) le \(CO_2\), e lokolla ho phatloha khase ea haedrojene le ho qhomisa likotoana tsa tšepe tse qhibilihisitsoeng ho pholletsa le lebenkele.
3. Beha phofo e nyane ea tšepe ea Sehlopha sa D kapa chip fire ka ho e epela ka bonolo tlas'a phofo e omileng ea Sehlopha sa D (sodium chloride, phofo ea koporo, kapa graphite), lehlabathe le omeletseng, kapa liboro tse omeletseng tsa tšepe. Le ka mohla u se ke ua qhomisa jete ea setima-mollo e hatelletsoeng ka ho toba ka har'a qubu ea lerōle le tukang leru; kenya sesebediswa se omileng ka bonolo ka scoop e nang le matshwao a malelele kapa wand ya sesebediswa sa Sehlopha sa D sa lebelo le tlase.
4. *Le ka mohla u se ke ua bula sekheo sa tlhahlobo sa moqomo oa mapolanka a kubellang, silo ea lijo-thollo, kapa pokello ea lerōle la baghouse. Ha u bula seqhoqho ho kenya oksijene e ncha qubung ea lerōle le kunkelang ke oksijene, ebe ho tsosa leru le leketlileng holim'a mashala a benyang, 'me seo se etsa hore sefahleho sa hao se phatlohe hang-hang.
5. *Itheohele fatše 'me u sireletse tsela ea hao ea moea haeba e ka oela ka har'a mollo kapa leqhubu la lerōle. Ha leru la lerole le hotetsa ho u pota-pota, theoha hang-hang (mocheso le khatello e feteletseng li shebane le siling), tšoara moea oa hao kapa u phefumolohe ka lesela le metsi ho thibela lerōle le chesang haholo hore le se ke la chesa trachea ea hao, 'me u khase ka pele ka tlas'a mosi hang-hang hang ha lesira le le ka pele.
6. Letsa nomoro ea hau ea ts'ohanyetso ea lehae (911 United States le Canada, 112 ho pholletsa le European Union, 999 United Kingdom) hang-hang. Ela hloko litima-mollo tse fihlang ka ho khetheha haeba li-silo tsa lerōle tse tukang kapa metale e sebetsang ea Sehlopha sa D (magnesium, aluminium, kapa lerōle la titanium) li tuka hoo litima-mollo li sa sebeliseng litima-mollo kapa litšepe hlahloba dinomoro tsa tshohanyetso le chesa.

flowchart TD
    Start["Lerōle le tukang kapa Tšohanyetso ea phofo ea tšepe"] --> Incident{"Ke mofuta ofe oa lerōle kapa oa tšepe o etsahalang?"}
    Incident -->|"Muffled Pop, Shake, or Flash in Duct / Baghouse / Silo"| PrimaryBlast["TLHOKOMELISO EA TLHOKOMELISO EA HO PROMA LEROLE<br/>1. Otla setopong sa boemo ba tšohanyetso / alamo ea ho tsoa hang-hang <br/>2. Tloha mohahong ka mor'a metsotsoana PELE ho phatloha ha lerōle la bobeli <br/>3. Qoba ho se be le masoba a ka ntle a ho phatloha ha mekotla le marulelo a silo"]
    Incident -->|"Mollo o kubellang ka hare ho Pokello ea Lerōle, Silo, kapa Hoppers"| Smolder["1. Koala fene e bokellang lerole le li- dampers tsa conveyor hang-hang<br/>2. LE KA mohla u se ke oa bula likheo tsa ho kena kapa oa phunya liqubu tsa lerōle le kubellang (Kotsi ea ho phatloha ha Backdraft)<br/>3. Tloha 'me u emele karabelo e ikhethang ea khase / moroallo oa Lefapha la Mollo"]
    Incident -->|"Burning Metal Dust, Chips, or 3D-Printing Powder (Class D)"| MetalFire["1. NEVER use Water, Foam, CO2, or standard ABC fire extinguishers<br/>2. Shut off ventilation fans so burning metal dust is not lofted into air<br/>3. Gently smother small fires using a scoop of Class D powder (Met-L-X / Lith-X / Copper) or Bone-Dry Sand<br/>4. If fire spreads or involves bulk metal dust: Evacuate immediately"]
    PrimaryBlast --> Medical["Tšoara ho chesa ha flash ka metsi a pholileng a phallang (20 min) 'me u hlahlobe hore na ho na le kotsi ea ho hema"]
    Smolder --> Medical
    MetalFire --> Medical

The Combustible Dust Pentagon le sefi sa bobeli sa ho phatloha¶

Kamoo lintho tse tiileng tse tloaelehileng li fetohang liqhomane tse phahameng kateng¶

Batho ba bangata ba tloaelane le mokhoa oa khale oa Fire Triangle (Mafura, Oksijene, le Mohloli oa Mollo). Bakeng sa thepa e tiileng e ka hlahisang ** ho phatloha ha lerōle le tukang **, ho tlameha ho eketsoa maemo a mabeli a 'mele, ho theha Pentagon ea Mahlakore a Mahlano a Combustible Dust Explosion:

1. Combustible dust (Fuel in microscopic particle size): Generally defined by the National Fire Protection Association (NFPA) as finely divided solid particles 500 microns (0.5 millimeters) or smaller in diameter (capable of passing through a U.S. No. 40 standard sieve), with particles under 75 microns (as fine as talcum powder or flour) posing the most violent explosion hazard.
2. Oxygen (Oxidizer): Present in normal workplace air at 20.9 percent.
3. Ignition source (Heat / Spark): Electrostatic discharge inside ungrounded plastic vacuum hoses, friction sparks from a loose tramp bolt inside a grinder, an overheated ball bearing on a conveyor belt, hot welding slag, or self-heating spontaneous combustion in damp grain or wood pellets.
4. Ho hasana moeeng (Leru le leketlileng ka holim'a Minimum Explosible Concentration / MEC): qubu e bataletseng ea phofo kapa sawdust e lutseng fatše e khutsitse e ka chesa butle, empa e ke ke ea phatloha ho fihlela khathatso ea 'mele e e phahamisetsa moeeng ka bongata bo kaholimo ho **20 ho isa ho 60 grams ka cubic meter ho isa ho 2 cubic meter*0.0 Nakong eo, leru la lerōle le letenya hoo u ke keng ua bona lebone la lebone la 25-watt kapa mosebetsi-'moho le uena ea emeng 1.5 ho 2 metres (5 ho 6.5 feet) hole.
5. Tlhaloso (Sekoahelo): Ha leru le qhalakaneng la lerōle le hotetsa ka har'a sekepe se koetsoeng, kotopo, leoto la libakete, kapa kamore e nang le mabota a mane le marulelo, khase e chesang ka potlako e ke keng ea phonyoha, e bakang khatello ea ho haha ​​ka sekhahla ho fihlela sekepe kapa mohaho o phatloha ka matla.

(Tlhokomeliso ea bohlokoa: Leha o sa koaloe, Lintlha tsa 1 ho isa ho tse 4 feela, leru le tukang la lerōle le hlahisa flash fire ball e bolaeang e balang likhato tse 1,000 ho isa ho tse 2,000 tsa Celsius tse bakang ho chesoa ho hoholo le ho chesoa ha moea sebakeng se bulehileng sa workshop.)

Hobaneng ha "Ho phatloha ha Bobeli" ho senya lifeme kaofela¶

Litlaleho tsa liphuputso tse entsoeng ke U.S. Chemical Safety and Hazard Investigation Board (CSB) le UK Health and Safety Executive (HSE) li bontša hore basebetsi ha ba bolaoe ka seoelo ka ho chesetsoa ha pele ka har’a mochine. Ho e-na le hoo, likotsi li etsahala nakong ea Domino Secondary Explosion:

1. Lilemo tsa lerōle le sa bonahaleng le sa bonahaleng: Lerōle le phonyohang le tsoa lisakha, li-sander, lipalangoang tsa lijo-thollo, liloala tsa tsoekere, kapa li-mixer tsa phofo ebe le phaphamala ho ea holimo holim'a moea o futhumetseng o futhumetseng, le lula le khutsitse holim'a maballo a holimo a holimo, literei tsa likhoele, mabone a fluorescent moo ho sa boneng marotholi le lithaelese.
2. Molao oa paperclip oa 0.8-millimeter (1/32-inch): Ho ea ka NFPA 652 / NFPA 660, haeba lerōle le lokisitsoeng le koahetse feela **5% ea sebaka sa kamore ** (ho kenyeletsoa le bokaholimo ba maballo) ho ea botebong ba *0.8 millimeters (1/32 ea pampiri e lekaneng e se e ntse e le teng) ho tlatsa phaposi kaofela ho tloha mokatong ho isa siling ka leru le phatlohang la lerole ha le sisinyeha.
3. Leqhubu la acoustic shockwave: Ho phatloha ho honyane ho honyane ho etsahala ka har'a pokello ea lerōle e koetsoeng kapa buti ea lifti ea lijo-thollo, e utloang eka ke lerata le hole kapa phalete e oeleng. Leqhubu leo ​​la kgatello le thekesela haufi le kotopo ea tšepe ebe le sisinya foreimi ea mohaho.
4. The ceiling rains fuel: Millions of grams of dry, powdery dust rain down from the overhead rafters and false ceiling across the entire 100-meter-long factory floor, creating an instantaneous, building-wide dust fog. One-half second later, the trailing flame jet from the ruptured duct reaches the falling dust cloud and detonates the entire building in a secondary blast (sometimes followed by tertiary blasts through connected tunnels and silos).

Class D combustible metal fires: Aluminum, magnesium, titanium, and 3D-printing powders¶

Why water and standard fire extinguishers cause metal fires to explode¶

In machine shops, aerospace manufacturing, automotive die-casting, foundries, and additive manufacturing (metal 3D printing / Direct Metal Laser Sintering), workers machine, grind, polish, or laser-sinter reactive metals including magnesium, aluminum, titanium, zirconium, hafnium, lithium, sodium, and potassium.

When finely divided metal dust, drill swarf, lathe turnings, or wet grinding sludge ignites, it burns at extreme temperatures between 2,000 and 3,300 degrees Celsius (3,600 and 6,000 degrees Fahrenheit) with a blinding white or ultraviolet glare:

1. Why Water (\(H_2O\)) triggers a hydrogen detonation: At 2,500 degrees Celsius, reactive metals have a far stronger chemical affinity for oxygen than hydrogen does. The instant a single stream of water hits burning magnesium, aluminum, or titanium powder, the molten metal rips the oxygen atoms directly out of the water molecules to form metal oxide, releasing massive quantities of free hydrogen gas (\(H_2\)) according to the violently exothermic reaction: $\(\text{Mg} + \text{H}_2\text{O} \rightarrow \text{MgO} + \text{H}_2\uparrow + \text{Heat}\)$ That liberated hydrogen gas mixes with shop air and detonates instantaneously, while the remaining water flashes to steam (expanding 1,700 times in volume), hurling white-hot globules of molten metal up to 30 meters (100 feet) in every direction.
2. Why Carbon Dioxide (\(CO_2\)), Halon, and ABC Dry Chemical extinguishers fail and explode:
3. Carbon Dioxide (\(CO_2\)): Burning magnesium, titanium, and aluminum burn right through pure carbon dioxide, stripping the oxygen atoms out of the \(CO_2\) gas and leaving black carbon soot behind while accelerating the fire.
4. Standard Multipurpose ABC Dry Chemical (Monoammonium Phosphate) and BC (Sodium Bicarbonate): At 2,500 degrees Celsius, ammonium phosphate decomposes violently and reacts with burning magnesium or aluminum, while the high-pressure nitrogen propellant jet from a standard extinguisher blasts the fine burning metal powder up into the air, turning a small workbench pile fire into a fatal Class D metal dust explosion.
5. Nitrogen (\(N_2\)) gas is NOT inert to all metals: While nitrogen gas smothers organic fires, burning titanium, magnesium, and zirconium react chemically directly with nitrogen at high temperatures to form metal nitrides, continuing to burn even in a 100 percent nitrogen atmosphere (only pure Argon or Helium gas is truly inert to burning titanium).

Sefi se patiloeng "Thermite" ka li-grinders tsa mabenkele tse tsoakiloeng le ba bokellang lerōle¶

E 'ngoe ea lisosa tse bolaeang khafetsa tsa mollo oa tšepe oa workshop e etsahala ha setsebi sa machini se sebelisa sander e tšoanang ea lebanta, grinder ea benche, kapa pokello ea lerōle le omeletseng ho sila aluminium le carbon steel (tšepe ea tšepe):

• Ho sila carbon steel ho hlahisa lerole le letle le tlositsweng ka ** iron oxide (\(\text{Fe}_2\text{O}_3\), rust)**.
• Aluminium e silang e hlahisa phofo e ntle aluminium (\(\text{Al}\)).
• Motsoako o haufi-ufi oa phofo ea iron oxide le phofo ea aluminium ke mokhoa o nepahetseng oa lik'hemik'hale bakeng sa ** Thermite **. Nakong e tlang ha mosebeletsi a ama sekotoana sa tšepe lebiling le silang ebe a romela tlhase e chesang ea lamunu ho theosa le kotopo ea lerōle e kopaneng ea aluminium le mafome, motsoako ona o hotetsa karabelo e etsang oxidizing ea mocheso ka 2,500 degrees Celsius (4,500 degrees Fahrenheit) e ke keng ea tima le mokatong o chesang esita le tlas'a metsi hobane e fana ka oksijene ea eona e tsoang ho oksijene ea tšepe.

Protocol ea mohato ka mohato bakeng sa ho tima mollo o monyane oa tšepe oa Sehlopha sa D¶

Only attempt to control a reactive metal fire if it is small, confined to a small pile of chips/turnings or a single machine tray, and has not lofted into an airborne dust cloud. If a dust collector, wet scrubber (whose water circulation failed), or bulk drum of metal powder is on fire, evacuate the building immediately.

1. Shut off local ventilation fans and machine coolant pumps immediately: Stopping airflow prevents the burning powder from being sucked into overhead ducts where it can explode.
2. Sireletsa mahlo a hao mahlaseling a matla a ultraviolet (UV): Ho chesa magnesium le titanium li ntša khanya e foufatsang ea ultraviolet le actinic white light e ka bakang photokeratitis e matla ("welder's flash") ka metsotsoana; sheba ka tsela e sa tobang kapa apara likhalase tsa tšireletso tse nang le moriti / thebe ea sefahleho; bona leihlo la ntho e tsoang linaheng tse ling, cornea abrasion, le flash flash.
3. Khetha FEELA setima-mollo sa Sehlopha sa D se tiisitsoeng se tsamaisanang le tšepe e khethehileng:
4. Sodium Chloride-based Class D Dry Powder (mohlala, Met-L-X / Super-D): E na le letsoai le omeletseng la sodium chloride e kopantsoeng le metsoako ea thermoplastic. E loketse **magnesium, sodium, potassium, le aluminium ** chip fires; mocheso o qhibilihisa letsoai lekhapetleng le sa keneleng moea le sa kenyelletseng oksijene. (O SE KE oa sebelisa mollong oa lithium.)
5. Moemeli oa Copper Powder Class D (Navy 125S): E entsoe ka ho khetheha bakeng sa mollo oa lithium le lithium-alloy; li-alloys tsa koporo tse nang le lithium e qhibilihisitsoeng ho theha bokaholimo bo sa sebetseng bo tsamaisang mocheso.
6. Graphite Powder Class D Agent (G-Plus / Lith-X): E tlosa mocheso le ho tima lithium, magnesium, titanium, le zirconium mello ntle le ho sebetsa ka lik'hemik'hale.
7. Bone-Dry Foundry Sand kapa Dry Cast-Iron Borings (Emergency Shop Improvisation): Haeba setima-mollo se inehetseng sa Sehlopha sa D se sa fihlellehe, o ka koala qubu e nyane ea benche ea magnesium kapa aluminium e tukang u sebelisa ** lehlabathe la silika le omeletseng ka ho felletseng, lehlabathe le omeletseng la silika, tafole e omeletseng ea letsoai kapa letsoai le omileng nkho e thibelang mongobo. (Tlhokomeliso: Le ka mohla u se ke ua sebelisa lehlabathe le mongobo la ka ntle kapa lehlohlojane le metsi le tsoang jareteng; mongobo o ka har'a lehlabathe le mongobo o tla baka ho phatloha ha mouoane/hydrogen.)
8. Sebelisa moemeli ka bonolo u sebelisa scoop e ts'oaroang ka nako e telele kapa sekontiri sa lebelo le tlase:
9. Le ka mohla u se ke ua phatlola phofo ka har'a lerōle la tšepe le tukang. Ha u sebelisa setima-mollo se tšehla sa Sehlopha sa D se hatelitsoeng, ema morao ka limithara tse 1.5 ho isa ho tse 2.5 (maoto a 5 ho isa ho a 8), bula belofo ea sesebelisuoa sa nozzle ka bonolo e le hore lehloa le theohele holim'a mollo, 'me u hahe lesela le lekanang *. bonyane lisenthimithara tse 2 ho isa ho tse 2 ka botlalo. ho koahela tšepe e tukang.
10. Haeba u sebelisa bakete ea phofo ea Sehlopha sa D kapa lehlabathe le omeletseng masapong, sebelisa garafo e sephara e nang le mohano o molelele ho ala phofo ka bonolo ho pota-pota le ka holim'a lichipisi tse tukang ntle le ho sisinya kapa ho akhela tšepe.
11. Se ke oa khathatsa qubu e khorohileng ho fihlela e folile ka ho feletseng: Ka tlas'a letsoai le qhibilihisitsoeng kapa lehlabathe, tšepe e qhibilihisitsoeng e lula ka holim'a mocheso oa eona oa ho itima metsotso e 30 ho isa ho e 90. Haeba letheba le letšo le lekhubelu le chesa ka holim'a lekhapetla, ka bonolo kenya phofo e 'ngoe ea Sehlopha sa D sebakeng seo. Le ka mohla u se ke ua phunya kapa ua kharatsa qubu eo ho fihlela thermometer e sa amaneng le eona e bontša hore e pholile mocheso oa kamore.

Thuso ea pele bakeng sa likotsi tsa ho phatloha ha lerōle le ho chesoa ha tšepe ea tšepe¶

Batho ba phonyohileng mollong o tukang oa lerōle kapa ho phatloha ha bobeli ba na le likotsi tse ngata tsa mocheso, ho hema le barotrauma:

1. Suthela motho ea hlasetsoeng moeeng o mocha o fokang moea 'me u time liaparo tsa mosebetsi tse kubellang ("Emisa, Lahlela, U Roll" kapa u kolobise ka metsi, KA NTLE HO KHAOTSOE ka lerōle la tšepe):
2. Haeba liaparo tsa mosebeletsi li tuka ke mollo oa lerōle la tlhaho (lehong, lijo-thollo, tsoekere, phofo, mashala, polasetiki), li tšele hang-hang ka metsi kapa shaoara ea tšireletso.
3. Mokhelo o ka sehloohong bakeng sa lerōle la tšepe le sebetsang liaparong: Haeba likoahelo tsa mosebeletsi li koahetsoe ka ho sa chesoa kapa ho chesa ** magnesium, aluminium, lithium, kapa sodium powder , u se ke ua kenya tlas'a metsi a seng makae; ba thuse ho hlobola likoahelo tsa ka ntle hang-hang (ho sebelisa sekere sa trauma ho kuta liaparo) ha ba ntse ba hlatsoa phofshoana e hlephileng PELE ho pholile letlalo le ka tlas'a mocheso le chesoa ke metsi a mangata ka metsotso e 20; bona ho chesoa ho matla le ho phatloha ha lik'hemik'hale.
4. Lekola hore na ho na le kotsi ea hang-hang ea ho hema moeeng: Ha mosebeletsi a hema nakong ea mollo oa lerōle, likaroloana tsa lerōle tse tukang li huleloa ka hare ho pharynx le trachea. Batla moriri oa nko, mosili o pota-potileng hanong kapa lelemeng, khohlela e hlabang, lehoatata, kapa ho hema ka lentsoe le phahameng (stridor). Tsela ea moea e chesitsoeng ke lerōle le chesang haholo e ka ruruha ka ho feletseng ka hare ho metsotso e 20 ho isa ho e 45; lula mokuli ea nang le tsebo, ea phefumolohang a otlolohile ka likhato tsa 45 (e leng ho liehisa edema ea moea) le ho lokisetsa lipalangoang tsa hang-hang bakeng sa ho kenella ha endotracheal intubation.
5. Letlalo le pholileng le chesoa ke metsi a pompo a pholileng ka metsotso e 20, ebe u thibela hypothermia: Hlatsoa matsoho a chesitsoeng, sefahleho le matsoho ka metsi a pholileng a phallang (15 ho isa ho 20 likhato tsa Celsius / 59 ho isa ho 68 degrees Fahrenheit, ha ho mohla leqhoa) ka metsotso e 20, tlosa mehele le lioache pele menoana e kokomoha, ebe u thatela filimi e kolokileng ka polasetiki e sa sisinyeheng, ebe u phuthela ka polasetiki e hloekisitsoeng. joaloka tourniquet) kapa liaparo tse sa tsitsang tse sa khomarelang ha li ntse li boloka mokokotlo oa mokuli o futhumetse ka likobo; bona chesa.
6. Sheba likotsi tsa ho phatloha ho hoholo le thuto e phahameng: Haeba ho phatloha ho ile ha qhoma mabota kapa ho lahlela mohlaseluoa khahlano le mochini, lekola hore na o na le litsebe tse phatlohileng, lets'oafo le phatlohileng (ho khohlela mali a mapinki a lerootho, ho haelloa ke moea ho matla), likotoana tse phunyeletsang, le lesapo la mokokotlo kapa hlooho; bona ho phatloha ha li-fireworks, ho chesoa ha sparkler, le likotsi tsa ho phatloha.

Tlhokomelo ea ntlo le lethathamo la thibelo ea kotsi ea setsi¶

Ho thibela ho phatloha ha lerōle la bobeli kapa mollo oa lebenkele la Sehlopha sa D ho itšetlehile ka boenjiniere bo thata le taeo ea tlhokomelo ea ntlo:

• Tiisa molao oa "Paperclip Rule" oa 0.8-millimeter (1/32-inch) libakeng tse ka holimo: Lekola bokaholimo ba maballo a holimo, likotopo, lisebelisoa tsa mabone le siling e kentsoeng beke le beke. Haeba lerōle le lokisitsoeng le pata 'mala oa pente e ka tlase kapa le feta 0.8 millimeters (1/32 inch) ho feta karolo ea 5 lekholong ea sebaka sa kamore, koala mehloli ea ho tima 'me u hloekise hang-hang.
• ** LE KA mohla u se ke ua sebelisa moea o hatelletsoeng ("theolela fatše") kapa ho fiela ka mokhoa o omileng ho hloekisa lerōle le tukang:** Ho butsoela mapolanka, phofo kapa lerōle la tšepe holim'a maballo kapa mechini e nang le 6-bar (90-psi) moea o hatelitsoeng ka molomo ho baka leru le phatlohileng le batlang ho phatlola mohaho. Sebedisa feela Sehlopha sa II, Ditshipa tse thibelang ho phatloha tsa Karolo ya 1 (likotikoti tsa tšepe tse sireletsehileng ka ho sa feleng, tse theiloeng fatše tse nang le liphaepe tse tsamaisang motlakase, eseng vac ea lebenkele la bolulo la polasetiki).
• Le ka mohla u se ke ua sebelisa peipi ea polasetiki ea PVC bakeng sa ho betla mapolanka kapa ho bokella lerōle la indasteri: Peiso ea sawdust e tsamaisoang moeeng ka peipi ea PVC e sa keneng e hlahisa mashome a likete a li-volts tsa motlakase o tsitsitseng; sebelisa li-ductwork tsa tšepe tse theohileng (kapa tlama le ho liha likarolo tsohle tsa pokello ea lerōle kamehla).
• Arola ka ho hlaka ho sila ha aluminium/magnesium ho tloha ho tšila ea tšepe/tšepe (Thibela Thermite): Nehelana ka lisila tse arohaneng, tse ngotsoeng ka ho hlaka le tse bokellang lerole la mofuta o metsi bakeng sa aluminium, magnesium, kapa titanium feela; Le ka mohla u se ke ua sila tšepe e entsoeng ka tšepe mochining o nang le lerole la aluminium, 'me u hloekise litšila tsa litšila letsatsi le letsatsi e le hore khase ea haedrojene e se ke ea bokellana ka har'a hood.
• Beha litima-mollo tsa Sehlopha sa D tse tšehla le libakete tsa lehlabathe le omeletseng sebakeng sa limithara tse 10 (maoto a 33) ho tloha liteishene tsohle tse sebetsang ka tšepe le tsa khatiso ea 3D: Koetlisa mokhanni e mong le e mong hore le ka mohla a se ke a hula setima-mollo sa ABC kapa sa CO2 se sefubelu mollong oa tšepe.

Lipotso tse botsoang khafetsa¶

Ke hobane'ng ha ho le kotsi hakaale ho sebelisa hose ea moea e hatelitsoeng ho fehla lerōle la mapolanka kapa la lijo-thollo maballong le mechineng?¶

Lerōle le lutseng fatše holim'a sefate se ka holimo kapa tafoleng ea mochine ha le khone ho phatloha ho fihlela le hasane moeeng e le leru le fanyehiloeng. Ha mosebeletsi a sebelisa molomo oa moea o hatelitsoeng ka khatello e phahameng ho butsoela mapolanka, phofo, tsoekere kapa lerōle la tšepe holim'a maballo a ka holimo kapa ka lik'haboteng tsa motlakase, sefofane sa sefofane se phahamisa lik'hilograma tsa likaroloana tse nyenyane tse nyenyane ka ho toba lerung le teteaneng le fetang The Minimum Explosible Concentration (MEC). Haeba leru leo ​​le theohang le hokahana le tleloubu e le 'ngoe e chesang, tlhase ea sethunya sa motlakase, se futhumatsang sebaka, kapa mokelikeli o sa fetoheng o hlahisoang ke hose ea moea ka boeona, kamore eohle e tla hotetsoa hang-hang ka lebaka la ho phatloha ha mollo kapa lerōle. Ka linako tsohle hloekisa lerōle le chang u sebelisa li-vacuum tse thibelang ho phatloha, mekhoa ea ho hlatsoa metsi moo ho loketseng.

Ho tla joang hore ebe metsoako e tloaelehileng ea lijo e kang tsoekere e phofshoana, cornstarch kapa phofo ea koro e ka phatloha joalo ka dynamite?¶

Lik'habohaedreite life kapa life (tsoekere, starch, phofo, lijo-thollo, cocoa, phofo ea lebese) li na le matla a lik'hemik'hale a mangata, tsona lik'halori tseo 'mele oa hau o li chesa bakeng sa mafura. Ka har'a cube e tiileng ea tsoekere kapa qubu ea phofo, oksijene e nyane haholo e ka ama limolek'hule tsa ka hare, kahoo e chesa butle kapa chars. Leha ho le joalo, ha tsoekere kapa starch e siloa hore e be likaroloana tse nyenyane ho feta li-micron tse 50 ’me e leketla moeeng e le leru la lerole, karoloana e ’ngoe le e ’ngoe e nyenyane haholo e pota-potiloe ka ho feletseng ke limolek’hule tsa oksijene. Ha tlhase e hotetsa karoloana e le 'ngoe, mocheso o khanyang o hotetsa likaroloana tsohle tse pota-potileng ka nako e le' ngoe ka har'a ketane e tsamaeang ka limithara tse makholo ka motsotsoana, e futhumatsa moea o potolohileng ho feta likhato tse 1,500 tsa Celsius (2,700 degrees Fahrenheit) ka milliseconds le ho baka leqhubu le senyang le fihlang ho 8 bar (115 psi).

Ke hobane'ng ha ho fafatsa metsi mollong o tukang oa magnesium kapa aluminium ho baka ho phatloha ho hoholo?¶

Litšepe tse sebetsang tse kang magnesium, aluminium, titanium, zirconium, le lithium li chesa ka mocheso o feteletseng pakeng tsa 2,000 le 3,300 degrees Celsius (3,600 le 6,000 degrees Fahrenheit). Lithempereichara tseo, metsi ($H_2O$) ha a pholise tšepe; ho e-na le hoo, tšepe e qhibilihisitsoeng e hlobola liathomo tsa oksijene ka ntle ho limolek'hule tsa metsi ho etsa metal oxide, hang-hang e ntša maru a khase e phatlohang ea hydrogen ($H_2$) ha e ntse e bentša metsi a setseng ka har'a mouoane o chesang haholo. Khase eo ea haedrojene e phatloha hang-hang moeeng o potolohileng, e phatloha litšepe tse qhibilihisitsoeng ho pholletsa le phaposi. Ka linako tsohle bitse litšepe tse tukang kapa phofo ka bonolo ka sesebelisoa se omileng sa Sehlopha sa D (joalo ka sodium chloride salt flux, copper powder, kapa graphite) kapa lehlabathe le omeletseng ka ho feletseng masapong.

"Paperclip rule" ke efe bakeng sa ho bokella lerōle le tukang ka har'a workshop kapa fekthering?¶

Ho ea ka Mokhatlo oa Sechaba oa Tšireletso ea Mollo (NFPA 652 le NFPA 660), u ka etsa tlhahlobo e potlakileng ea pono bakeng sa kotsi ea bobeli ea ho phatloha ha lerōle u sebelisa botenya ba pampiri e tloaelehileng ea tšepe, e ka bang 0.8 millimeters (1/32 ea inch). Haeba lerōle le tukang (joalo ka lerōle la lehong, lerōle la lijo-thollo, phofo, resin ea polasetiki kapa lerōle la mashala) le bokane ho isa botenya ba limilimithara tse 0.8 (1/32 inch) kapa ho feta ho feta karolo ea 5 lekholong feela ea sebaka sa mokatong oa kamore (ho bala sebaka se kaholimo sa marang-rang a marang-rang a marang-rang, likotopo tse lokisang lisebelisoa, lisebelisoa tse nang le mafura le lisebelisoa tse lekaneng. ho phatloha ho hoholo ha lerōle la bobeli haeba ho thothomela ho honyenyane ho sisinya lerōle moeeng.

• Tataiso ena e fana ka boitsebiso ba ho itokisetsa maemo a tšohanyetso le boitsebiso ba thuso ea pele bakeng sa ho phatloha ha lerōle le tukang le mello ea tšepe ea Sehlopha sa D 'me ha e nke sebaka sa boenjiniere ba ts'ireletso ea ts'ebetso ea indasteri kapa koetliso ea bo-ralitima-mollo. Nahana ka ho nka thuso ea pele le thupelo ea CPR ho tsoa ho Sefapano se Sefubelu, St John Ambulance, kapa mokhatlo oa sebaka sa tšireletso.

Litataiso tse amanang¶

• Ho chesa le ho chesa thuso ea pele
• Ho chesa ho matla le ho phalla ha lik'hemik'hale
• Ho phatloha ha li-fireworks, ho chesoa ha sparkler, le likotsi tsa ho phatloha
• Mechini ea temo ea PTO e ts'oarella le ho ts'oaroa ha moqomo oa lijo-thollo
• Mello ea betri ea lithium-ion
• Likotsi tsa mosebetsing le likotsi tsa indasteri

Mehloli e hlahlobiloe¶

• Mokhatlo oa Naha oa Tšireletso ea Mollo (NFPA, United States): Maemo a Metheo ea Lerōle le tukang (NFPA 652 / Consolidated Standard for Combustible Dusts NFPA 660), Tekanyetso ea Thibelo ea Mello le Ho phatloha ha Lerōle Mehahong ea Temo le Phetoho ea Lijo (NFPA 61), le Standard for Combustible Dusts (NFPA 48 Metal)
• US Chemical Safety and Hazard Investigation Board (CSB, United States): Tlaleho ea Patlisiso ea Kotsi ea Lerōle e tukang (Tlaleho ea No. 2006-H-1) le Litlaleho tsa Ketsahalo ea Imperial Sugar / Metal Dust Incident
• Tsamaiso ea Ts'ireletso le Bophelo bo Botle mosebetsing (OSHA, United States): Lenaneo la Naha la Khatello ea Lerōle le tukang (CPL 03-00-008) le Litlhokomelo tsa ho Thibela Mollo bakeng sa Mello ea Metal e tukang ea Sehlopha sa D.
• Phethahatso ea Bophelo bo Botle le Tšireletseho (HSE, United Kingdom): Tšoaro e Sireletsehileng ea Lerōle le tukang: Litlhokomelo Khahlanong le Liqhomane (HSG103)
• Institution of Chemical Engineers (IChemE) and Verein Deutscher Ingenieure (VDI 2263): Dust Explosion \(K_{st}\) Deflagration Index Classification and Secondary Explosion Prevention