樂清市依客思林芝經過幾天的整理,新的防爆小常識終于出爐了,請大家好好瀏覽,有啥問題可以隨時!,防止爆炸的產生必從三個必要條件來考慮,限制了其中的一個必要條件,就限制了爆炸的產生。在工業(yè)過程中,通常從下述三個方面著手對易燃易爆場合進行處理:(1) 預防或大限度地降低易燃物質泄漏的可能性;(2) 不用或盡量少用易產生電火花的電所元件;(3) 采取充氮氣之類的方法維持惰性狀態(tài)
一、危險場所區(qū)域劃分
危險場所區(qū)域的含義,是對該地區(qū)實際存在危險可能性的量度,由此規(guī)定其可適用的防爆型式。電工委員會/歐洲電工委員會劃分的防爆區(qū)域為:
0區(qū):連續(xù)地存在危險性大于1000小時/每年的區(qū)域;
1區(qū):斷續(xù)地存在危險性10~1000小時/每年的區(qū)域;
2區(qū):事故狀態(tài)下存在的危險性0.1~10小時/每年的區(qū)域;
中劃分的有效區(qū)域和以上相同。
二、防爆標志解析
①氣體組別
典 型 的
危險性
氣 體歐洲電工
標準化委員會
EN50014EC北 美
NEC500條款
CLASS1表氣中
GB-3836-1小點燃能量
(微 焦)
乙 炔ⅡCAⅡC20
氫 氣ⅡCAⅡC20
乙 烯ⅡBCⅡB60
丙 烷ⅡADⅡA180
注:中GB3836標準規(guī)定ⅡC小點燃能量為19微焦耳,ⅡA小點燃能量為200微焦
耳。
氣體分組和點燃溫度,在一定環(huán)境溫度和壓力下與可燃性氣體和空氣的混合濃度有關。
②溫度組別(T組)
這是與氣體點燃溫度有關的電氣設備(假定環(huán)境溫度為40℃時)的高表面溫度,點燃能量與點燃溫度無關。在標準BS5345*部分中列出了所有可燃性氣體和其組別。
高表面溫度(℃)溫度組別
IEC79-8GB3836-1
450℃T1T1
300℃T2T2
200℃T3T3
135℃T4T4
100℃T5T5
85℃T6T6
③防爆標志
以下以CENELEC氫氣防爆標志為例:E Ex ia ⅡC T4
E:按CENELEC標志認可Ex:防爆公用標志
ia:防爆型式(本質安全)Ⅱ:設備組別
C:氣體組別 T4:溫度組別
④名詞解釋
隔爆型電氣設備(d):是指把能點燃爆炸性混合物的部件封閉在一個外殼內,該外殼能承受內部爆炸性混合物的爆炸壓力并阻止和周圍的爆炸性混合物傳爆的電氣設備。
增安型電氣設備(e):正常運行條件下,不會產生點燃爆炸性混合物的火花或危險溫度,并在結構上采取措施,提高其安全程度, 以避免在正常和規(guī)定過載條件下出現(xiàn)點燃現(xiàn)象的電氣設備。
本質安全型電氣設備(i):在正常運行或在標準試驗條件下所產生的火花或熱效應均不能點燃爆炸性混合物的電氣設備。
無火花型電氣設備 (n): 在正常運行條件下不產生電弧或火花,也不產生能夠點燃周圍爆炸性混合物的高溫表面或灼熱點,且一般不會發(fā)生有點燃作用的故障的電氣設備。
防爆特殊型(s): 電氣設備或部件采用GB3836-83未包括的防爆型式時,由主管部門制訂暫行規(guī)定。送勞動人事部備案,并經的鑒定單位檢驗后,按特殊電氣設備"s"型處置。
三、防爆標準及選型
①各種防爆型式的對應標準
防爆型式在英允許
使用的場所中標準
GB3836防爆型式
符 號IEC標準
79-CENELEC標準
EN50
增安型1或23e7019
本質安全型0,1或24ia或ib11020(設備)
隔爆型d2d1018
特殊型s無s無無
②氣體爆炸危險場所用電氣設備防爆類型選型表
爆炸危險區(qū)域適用的防護型式
電氣設備類型符 號
0區(qū)1、本質安全型(ia)ia
2、其他特別為0區(qū)設計的電氣設備(特殊型)s
1、適用于0區(qū)的防護類型
2、隔爆型d
3、增安型e
1區(qū)4、本質安全型ib
5、充油型o
6、正壓型p
7、充砂型q
2區(qū)1、適用于0區(qū)或1區(qū)的防護類型
2、無火花型n
四、外殼防護等(IP)代碼
(BS EN60529;1992)
*位特征數(shù)字防止固定導體異物進入
0無防護
1固定異物直徑大于50mm
2固定異物直徑大于12mm
3固定異物直徑大于2.5mm
4固定異物直徑大于1.0mm
5防塵
6塵密
第二位特征數(shù)字防止進水造成有害影響
0無防護
1垂直滴水
2傾角75-90°滴水
3淋水
4濺水
5噴水
6猛烈噴水
7短時間侵水
8連續(xù)侵水
舉例:IP 65即要求具有塵密及對外殼噴水有防護功能
A zoning, dangerous places
Dangerous locations of meaning, a measure of the likelihood is a real danger to the region, the provisions of the applicable explosion-proof type. International electrotechnical commission/European electrotechnical commission of explosion-proof area as follows:
0 area: continuously hazardous region of greater than 1000 hours/year;
1 area: there is risk in an intermittent 10 ~ 1000 hours/year area;
2 area: the risk of accident situation is 0.1 ~ 10 hours/year area;
Dividing the effective area of China is the same as the above.
Second, explosion-proof marks parsing
(1) gas group
Canon model
The risk
Gas electrician in Europe
Committee for standardization
EN50014EC North America
NEC500 terms
CLASS1 table in China
GB - 3836-1 minimum ignition energy
(micro)
B acetylene Ⅱ CA Ⅱ C20
Hydrogen gas Ⅱ CA Ⅱ C20
B ene Ⅱ BC Ⅱ B60
Propyl silane Ⅱ AD Ⅱ A180
Note: China GB3836 standard Ⅱ c-class 19 micro joule, minimum ignition energy Ⅱ class A minimum ignition energy of 200 micro focus
Ear.
Gas group and light temperature, in a certain environment temperature and pressure is associated with the mixed concentration of combustible gas and air.
(2) temperature group (T group)
This is related to gas ignited temperature electrical equipment (assuming the environment temperature of 40 ℃) of the surface of the highest temperature, the light energy has nothing to do with the set temperature. In the first part of the standard BS5345 lists all combustible gas and its category.
Temperature of the maximum surface temperature (℃) group
IEC79-8 gb3836-1
450 ℃ T1T1
300 ℃ T2T2
200 ℃ T3T3
135 ℃ T4T4
100 ℃ T5T5
85 ℃ T6T6
(3) explosion-proof marks
The following sign CENELEC hydrogen explosion, for example: E Ex ia Ⅱ C T4
E: approved by CENELEC logo Ex: explosion-proof public signs
Ia: explosion-proof type (intrinsically safe) Ⅱ: equipment category
C: T4 gas group: temperature classes
(4) noun explanation
Flameproof electrical equipment (d) : refers to can ignite an explosive mixture of the components are enclosed in a shell, the shell can withstand the internal pressure and prevent explosion of explosive mixture and detonating an explosive mixture around electrical equipment.
Increased safety electrical equipment (e) : under the condition of normal operation, won't produce sparks ignite an explosive mixture or dangerous temperature, and measures in the structure, to improve the safety degree, so as to avoid overload conditions prescribed by the normal and phenomenon of lighting electric equipment.
Intrinsically safe electrical equipment: (I) in normal operation or under standard test conditions spark or heat effect generated by the mixture can ignite an explosive electric equipment.
No spark type electrical equipment (n) : under the condition of normal operation does not produce electric arc or spark, also does not produce around can ignite an explosive mixture of the surface of the high temperature or hot point, and generally do not have lighting effect of failure of electrical equipment.
Explosion-proof special type (s) : electrical equipment or components the GB3836-83 not including explosion-proof type, provisional rules drawn up by the competent departments. To send labor personnel department for the record, and after identification unit designated by the test, according to the special electrical equipment "s" type.
Three, explosion-proof standards and selection
(1) all kinds of explosion-proof types of corresponding standards
Explosion-proof type allowed in the UK
Place of use Chinese standard
GB3836 explosion-proof type
Operator, IEC standard
79 - CENELEC standards
EN50
Increased safety type 1 or 23 e7019
Intrinsically safe 0, 1 or 24 ia or ib11020 (equipment)
Flameproof d2d1018
S no s no special type
(2) gas explosion for the dangerous sites with explosion-proof electrical equipment type selection table
Suitable protective type explosion danger area
Electrical equipment type descriptor
Area 0 1, intrinsically safe (ia) ia
2, other electrical equipment specially designed for zero area (special) s
1, applies to the protection type in 0
2, flameproof d
3, increase safety type e
4, intrinsically safe ib 1 area
5, oil-filled type o
6, type positive pressure p
7, sand mold filling q
2 area 1, applies to 0 area or zone 1 protection type
2, no spark, n
Four, enclosure protection class (IP) code
(BS EN60529; 1992)
The first characteristic digital fixed conductor to prevent foreign matter into the
0 no protection
1 fixed foreign body diameter greater than 50 mm
2 fixed foreign material is greater than 12 mm in diameter
3 fixed foreign material is greater than 2.5 mm in diameter
4 fixed foreign material is greater than 1.0 mm in diameter
5 dust
6 dust tight
The second characteristic Numbers to prevent harmful impacts into water
0 no protection
1 vertical drop of water
2 inclination of 75-90 ° dripping water
3 water spray
4, splashed water
Five water spray
6 heavy water spray
Contamination of water 7 a short time
Eight consecutive inundation
Example: IP 65 requiring have dust and water protection function of enclosure
意見與反饋