{"id":90389,"date":"2023-03-21T17:03:53","date_gmt":"2023-03-21T15:03:53","guid":{"rendered":"https:\/\/obera.fr\/nase-rada\/comment-utiliser-la-lie-la-lse-le-domaine-dexplosivite-dune-substance-explosive\/"},"modified":"2025-04-25T10:16:26","modified_gmt":"2025-04-25T08:16:26","slug":"comment-utiliser-la-lie-la-lse-le-domaine-dexplosivite-dune-substance-explosive","status":"publish","type":"post","link":"https:\/\/obera.fr\/cs\/nase-rady\/comment-utiliser-la-lie-la-lse-le-domaine-dexplosivite-dune-substance-explosive\/","title":{"rendered":"Jak pou\u017e\u00edv\u00e1te: LEL, UEL, rozsah v\u00fdbu\u0161nosti v\u00fdbu\u0161n\u00e9 l\u00e1tky?"},"content":{"rendered":"\n

Jak jsme vid\u011bli, LEL a UEL vymezuj\u00ed rozsah v\u00fdbu\u0161nosti<\/strong>, kter\u00fd je tvo\u0159en v\u0161emi v\u00fdbu\u0161n\u00fdmi koncentracemi v\u00fdbu\u0161n\u00e9 l\u00e1tky v atmosf\u00e9\u0159e. Pro posouzen\u00ed rizika zam\u011bstnavatel vyhodnot\u00ed koncentraci v\u00fdbu\u0161n\u00e9 l\u00e1tky podle pou\u017e\u00edvan\u00e9ho mno\u017estv\u00ed a porovn\u00e1 ji s mezn\u00edmi hodnotami v\u00fdbu\u0161nosti. Jako preventivn\u00ed opat\u0159en\u00ed si ponech\u00e1 bezpe\u010dnostn\u00ed rezervu a pot\u00e9 koncentraci z\u0159ed\u00ed alespo\u0148 na bezpe\u010dnostn\u00ed koncentraci pomoc\u00ed sac\u00edho\/filtra\u010dn\u00edho syst\u00e9mu<\/strong> ATEX. <\/p>\n\n

LEL se pou\u017e\u00edv\u00e1 k pom\u011bru rizika v\u00fdskytu ATEX k mno\u017estv\u00ed pou\u017eit\u00e9ho v\u00fdrobku.<\/h2>\n\n

Doln\u00ed mez v\u00fdbu\u0161nosti<\/strong> se porovn\u00e1v\u00e1 s koncentracemi v\u00fdbu\u0161n\u00fdch l\u00e1tek, kter\u00e9 by mohly tvo\u0159it ATEX. Tyto koncentrace z\u00e1vis\u00ed na rychlosti emis\u00ed v\u00fdbu\u0161n\u00fdch l\u00e1tek. Ta zase vypl\u00fdv\u00e1 z mno\u017estv\u00ed produkt\u016f p\u0159\u00edtomn\u00fdch ve zkouman\u00e9 provozn\u00ed situaci. Zadavatel tyto koncentrace<\/strong> odhadne pro r\u016fzn\u00e9 sc\u00e9n\u00e1\u0159e vzniku ATEX<\/strong>. <\/p>\n\n

\"dolní<\/figure>\n\n

Teoretick\u00fd p\u0159\u00edklad: sc\u00e9n\u00e1\u0159 ATEX zahrnuj\u00edc\u00ed \u00fanik plynu<\/a> z potrub\u00ed. Rychlost proud\u011bn\u00ed v potrub\u00ed z\u00e1vis\u00ed na rychlosti emis\u00ed ho\u0159lav\u00e9ho produktu do okoln\u00ed atmosf\u00e9ry. To vede k v\u00fdpo\u010dtu gradient\u016f koncentrace v pracovn\u00edm prostoru. Hodnoty koncentrace jsou um\u00edst\u011bny ve vztahu k rozsahu v\u00fdbu\u0161nosti<\/strong>. Z toho se odvod\u00ed stupe\u0148 rizika ATEX. Posuzuje se trvalost tohoto rizika v z\u00e1vislosti na poloze v pracovn\u00edm prostoru. Pot\u00e9 se ur\u010d\u00ed z\u00f3ny ATEX. Nakonec se pou\u017eij\u00ed preventivn\u00ed opat\u0159en\u00ed, jako je nap\u0159\u00edkladfiltrovan\u00e9 ods\u00e1v\u00e1n\u00ed ho\u0159lav\u00e9ho plynu<\/strong>. Rychlost ods\u00e1v\u00e1n\u00ed zohled\u0148uje mo\u017enou m\u00edru \u00faniku ho\u0159lav\u00e9ho plynu. <\/p>\n\n

P\u0159\u00edklad ze \u017eivota: v roce 2011 explodovala v Nogent sur Seine n\u00e1dr\u017e na pap\u00edr oobjemu 1 000m3<\/sup> napln\u011bn\u00e1 na 95 % a zabila jednu osobu. Z pap\u00edroviny v n\u00e1dr\u017ei se do ovzdu\u0161\u00ed uvol\u0148oval vod\u00edk. M\u00edra emis\u00ed na jednotku such\u00e9 hmotnosti \u010dinila 20 dm3<\/sup> za hodinu (su\u0161ina buni\u010diny 10 %). P\u0159i t\u00e9to rychlosti bylo LEL dosa\u017eeno po 1,6 hodin\u00e1ch. Vod\u00edk se sm\u00edsil satmosf\u00e9rou v n\u00e1dr\u017ei a vytvo\u0159il ATEX<\/strong>. Po tomto v\u00fdbuchu zam\u011bstnavatel vybavil n\u00e1dr\u017ee vertik\u00e1ln\u00ed ventilac\u00ed, aby se vod\u00edk v atmosf\u00e9\u0159e z\u0159edil ihned po jeho uvoln\u011bn\u00ed, a to otev\u0159en\u00edm horn\u00ed \u010d\u00e1sti n\u00e1dr\u017ee.<\/strong> <\/p>\n\n

Rozsah v\u00fdbu\u0161nosti, LEL a UEL poskytuj\u00ed informace o vzniku ATEX a rozsahu rizika v\u00fdbuchu spojen\u00e9ho s v\u00fdrobkem.<\/h2>\n\n

Hodnoty LEL a UEL ur\u010duj\u00edamplitudu rozsahu v\u00fdbu\u0161nosti<\/strong> a doln\u00ed a horn\u00ed rozsah v\u00fdbu\u0161nosti (rozsahy nev\u00fdbu\u0161n\u00fdch koncentrac\u00ed v\u00fdbu\u0161n\u00e9 l\u00e1tky). V d\u016fsledku toho poskytuj\u00ed informace jak o pravd\u011bpodobnosti vzn\u00edcen\u00ed a v\u00fdbuchu ATEX, tak o pravd\u011bpodobnosti vzniku ATEX. <\/p>\n\n

\u010c\u00edm \u0161ir\u0161\u00ed<\/strong> je tedy rozsah v\u00fdbu\u0161nin<\/strong>, t\u00edm u\u017e\u0161\u00ed je rozsah nev\u00fdbu\u0161n\u00fdch koncentrac\u00ed. Je tedy t\u00edm pravd\u011bpodobn\u011bj\u0161\u00ed, \u017ee emise v\u00fdbu\u0161n\u00e9 l\u00e1tky vyvol\u00e1 koncentraci v rozsahu v\u00fdbu\u0161nosti<\/strong>. <\/p>\n\n

S rostouc\u00edm rozsahem koncentrac\u00ed v\u00fdbu\u0161nin<\/strong> nav\u00edc roste i pravd\u011bpodobnost v\u00fdbuchu. (V\u0161imn\u011bte si, \u017ee pravd\u011bpodobnost rizika v\u00fdbuchu z\u00e1vis\u00ed na dal\u0161\u00edch faktorech souvisej\u00edc\u00edch s atmosf\u00e9rou a pr\u016fmyslov\u00fdm prost\u0159ed\u00edm). Pokud je doporu\u010den\u00fdm preventivn\u00edm opat\u0159en\u00edm <\/strong>filtra\u010dn\u00ed ods\u00e1v\u00e1n\u00ed, z\u00e1vis\u00ed pr\u016ftokods\u00e1v\u00e1n\u00ed ATEX <\/strong>\u010d\u00e1ste\u010dn\u011b na koncentraci v\u00fdbu\u0161n\u00e9 l\u00e1tky v t\u00e9to atmosf\u00e9\u0159e (V\u0161imn\u011bte si, \u017ee koncentrace v\u00fdbu\u0161n\u00e9 l\u00e1tky nen\u00ed jedin\u00fdm faktorem ur\u010duj\u00edc\u00edm pr\u016ftok ods\u00e1v\u00e1n\u00ed pot\u0159ebn\u00fd k zaji\u0161t\u011bn\u00ed bezpe\u010dnosti z\u00f3ny). <\/p>\n\n

\"oblast<\/figure>\n\n

Nap\u0159\u00edklad rozsah v\u00fdbu\u0161nosti vod\u00edku<\/strong> je 71 procentn\u00edch bod\u016f (4 % a\u017e 75 % objemov\u00fdch ve vzduchu), zat\u00edmco u propanu je to 7,8 procentn\u00edch bod\u016f (2,2 % a\u017e 10 % objemov\u00fdch ve vzduchu); to je p\u0159ibli\u017en\u011b desetkr\u00e1t m\u00e9n\u011b. Mo\u017enosti v\u00fdskytu v\u00fdbu\u0161n\u00fdch situac\u00ed jsou tedy u vod\u00edku v\u011bt\u0161\u00ed. <\/p>\n\n

A doba pot\u0159ebn\u00e1 ke z\u0159ed\u011bn\u00ed ATEX ods\u00e1v\u00e1n\u00edm<\/strong> za \u00fa\u010delem sn\u00ed\u017een\u00ed rizika ATEX bude t\u00edm del\u0161\u00ed, \u010d\u00edm bl\u00ed\u017ee je koncentrace v\u00fdbu\u0161n\u00e9 l\u00e1tky k horn\u00ed hranici <\/strong>rozsahu v\u00fdbu\u0161nosti.<\/p>\n\n

Krom\u011b toho plat\u00ed, \u017ee p\u0159i stejn\u00e9 amplitud\u011b rozsahu v\u00fdbu\u0161nosti<\/strong> plat\u00ed, \u017ee \u010d\u00edm ni\u017e\u0161\u00ed je LEL (nebo \u010d\u00edm vy\u0161\u0161\u00ed je UEL v p\u0159\u00edpad\u011b atmosf\u00e9ry s nedostatkem kysl\u00edku), t\u00edm men\u0161\u00ed je doln\u00ed (nebo horn\u00ed) rozsah v\u00fdbu\u0161nosti. V d\u016fsledku toho je p\u0159echod od nev\u00fdbu\u0161n\u00e9 koncentrace<\/strong> k v\u00fdbu\u0161n\u00e9 koncentraci rychlej\u0161\u00ed. \u010c\u00edm ni\u017e\u0161\u00ed je tedy LEL, t\u00edm v\u011bt\u0161\u00ed je riziko vzniku ATEX. <\/p>\n\n

\"oblast<\/figure>\n\n

Pokud je nap\u0159\u00edklad v\u00fdchoz\u00ed situac\u00ed atmosf\u00e9ra bez ho\u0159lav\u00fdch l\u00e1tek<\/strong>, pak propan (LEL = 2,2 %) p\u0159edstavuje vy\u0161\u0161\u00ed riziko vzniku ATEX ne\u017e vod\u00edk (LEL = 4,4 %). Riziko vzn\u00edcen\u00ed a v\u00fdbuchu je<\/strong> v\u0161ak ni\u017e\u0161\u00ed.<\/strong> <\/p>\n\n

Za v\u011bt\u0161iny provozn\u00edch podm\u00ednek je snaz\u0161\u00ed udr\u017eet koncentraci pod hodnotou LEL<\/strong>. K dosa\u017een\u00ed tohoto c\u00edle je obvykl\u00fdm preventivn\u00edm opat\u0159en\u00edm ods\u00e1v\u00e1n\u00ed\/filtrace ho\u0159lav\u00fdch l\u00e1tek. \u010c\u00edm ni\u017e\u0161\u00ed je hodnota LEL, t\u00edm vy\u0161\u0161\u00ed mus\u00ed b\u00fdt rychlost ods\u00e1v\u00e1n\u00ed<\/strong>, aby se bu\u010f opustilo p\u00e1smo v\u00fdbu\u0161nosti, nebo aby se sn\u00ed\u017eila koncentrace v\u00fdbu\u0161n\u00e9<\/strong> l\u00e1tky, dokud se z atmosf\u00e9ry nevylou\u010d\u00ed. <\/p>\n\n

N\u011bkter\u00e9 pr\u016fmyslov\u00e9 procesy vy\u017eaduj\u00ed, aby se v\u00fdbu\u0161n\u00fd produkt<\/strong> udr\u017eoval v koncentraci vy\u0161\u0161\u00ed ne\u017e LSE<\/strong>. Nap\u0159\u00edklad \u010distic\u00ed procesy zahrnuj\u00edc\u00ed pono\u0159en\u00ed do ho\u0159lav\u00e9ho rozpou\u0161t\u011bdla v uzav\u0159en\u00e9 atmosf\u00e9\u0159e. <\/p>\n\n

Rozsah v\u00fdbu\u0161nosti slou\u017e\u00ed k zaji\u0161t\u011bn\u00ed bezpe\u010dnostn\u00ed rezervy, aby se zabr\u00e1nilo vzniku ATEX.<\/h2>\n\n

Aby se zabr\u00e1nilo vzniku ATEX<\/strong>, mus\u00ed b\u00fdt koncentrace plynu nebo par udr\u017eov\u00e1na mimo oblast v\u00fdbu\u0161nosti. V z\u00e1vislosti na okoln\u00edch podm\u00ednk\u00e1ch bude v\u00fdbu\u0161n\u00e1 atmosf\u00e9ra z hlediska ho\u0159lav\u00fdch produkt\u016f<\/strong> v\u00edce \u010di m\u00e9n\u011b homogenn\u00ed<\/strong>. Nap\u0159\u00edklad v d\u016fsledku turbulence by ur\u010dit\u00e9 z\u00f3ny pova\u017eovan\u00e9 za z\u00f3nu mimo ATEX mohly z\u00edskat v\u00fdbu\u0161nou koncentraci. <\/p>\n\n

Aby se p\u0159ede\u0161lo riziku ATEX, zam\u011bstnavatel proto p\u0159ijme bezpe\u010dnostn\u00ed rezervu s ohledem na mezn\u00ed hodnoty v\u00fdbu\u0161nosti<\/strong>. V t\u00e9to souvislosti p\u0159edpisy ATEX doporu\u010duj\u00ed stanovit koncentraci minim\u00e1ln\u011b o 10 % ni\u017e\u0161\u00ed, ne\u017e je hodnota LEL na pracovi\u0161ti, kde by mohlo doj\u00edt ke vzniku ATEX. A pod 25 % v ostatn\u00edch prostor\u00e1ch. [i]<\/a><\/p>\n\n

\n\n

[i]<\/a> Ob\u011b\u017en\u00edk ze dne 9.5.1985 t\u00fdkaj\u00edc\u00ed se technick\u00e9ho koment\u00e1\u0159e k vyhl\u00e1\u0161k\u00e1m\u010d. <\/sup>84-1093 a 84-1094 ze dne 7.12.1984 o v\u011btr\u00e1n\u00ed a hygien\u011b pracovi\u0161\u0165.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

Jak jsme vid\u011bli, LEL a UEL vymezuj\u00ed rozsah v\u00fdbu\u0161nosti, kter\u00fd je tvo\u0159en v\u0161emi v\u00fdbu\u0161n\u00fdmi koncentracemi v\u00fdbu\u0161n\u00e9 l\u00e1tky v atmosf\u00e9\u0159e. Pro posouzen\u00ed rizika zam\u011bstnavatel vyhodnot\u00ed koncentraci v\u00fdbu\u0161n\u00e9 l\u00e1tky podle pou\u017e\u00edvan\u00e9ho mno\u017estv\u00ed a porovn\u00e1 ji s mezn\u00edmi hodnotami v\u00fdbu\u0161nosti. <\/p>\n","protected":false},"author":4,"featured_media":90166,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_seopress_robots_primary_cat":"none","_seopress_titles_title":"Jak pou\u017e\u00edvat : LEL, UEL, rozsah v\u00fdbu\u0161nosti l\u00e1tky","_seopress_titles_desc":"Zjist\u011bte v\u00edce o pou\u017eit\u00ed doln\u00ed meze v\u00fdbu\u0161nosti, horn\u00ed meze v\u00fdbu\u0161nosti a rozsahu v\u00fdbu\u0161nosti v\u00fdbu\u0161n\u00e9 l\u00e1tky.","_seopress_robots_index":"","footnotes":""},"categories":[310],"tags":[113],"class_list":["post-90389","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-nase-rady","tag-entete-male","generate-columns","tablet-grid-50","mobile-grid-100","grid-parent","grid-50","no-featured-image-padding","resize-featured-image"],"acf":[],"_links":{"self":[{"href":"https:\/\/obera.fr\/cs\/wp-json\/wp\/v2\/posts\/90389","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/obera.fr\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/obera.fr\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/obera.fr\/cs\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/obera.fr\/cs\/wp-json\/wp\/v2\/comments?post=90389"}],"version-history":[{"count":1,"href":"https:\/\/obera.fr\/cs\/wp-json\/wp\/v2\/posts\/90389\/revisions"}],"predecessor-version":[{"id":90392,"href":"https:\/\/obera.fr\/cs\/wp-json\/wp\/v2\/posts\/90389\/revisions\/90392"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/obera.fr\/cs\/wp-json\/wp\/v2\/media\/90166"}],"wp:attachment":[{"href":"https:\/\/obera.fr\/cs\/wp-json\/wp\/v2\/media?parent=90389"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/obera.fr\/cs\/wp-json\/wp\/v2\/categories?post=90389"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/obera.fr\/cs\/wp-json\/wp\/v2\/tags?post=90389"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}