深海防爆
Let’s start by explaining the various explosion-proof ratings, 它們意味住乜嘢, 以及如何在實踐中選擇它們, 以防爆配電箱為例.
| 氣體組/溫度組 | T1航站樓 | T2航站樓 | T3航站樓 | T4 | T5系列 | T6型 |
|---|---|---|---|---|---|---|
| 國際投資協定 | 甲醛, 甲苯, 甲酯, 乙仞, 丙烷, 丙酮, 丙烯酸, 苯, 苯乙烯, 一氧化碳, 乙酸乙酯, 醋酸, 氯苯, 乙酸甲酯, 氯 | 甲醇, 乙醇, 乙苯, 丙醇, 丙烯, 丁醇, Butyl acetate乙酸丁酯, Amyl acetate （乙酸戊酯）, 環戊烷 | 戊烷, 戊醇, 己烷, 乙醇, 庚烷, 辛烷, 環己醇, 松節油, 石腦油, 石油 (包括汽油), 燃料油, 四氯化戊醇 | 乙醛, 三甲胺 | 亞硝酸乙酯 | |
| IIB公司 | 丙烯酯, 二甲醚 | 丁二烯, 環氧丙烷, 乙烯 | 二甲醚, 丙烯醛, 碳化氫 | |||
| IIC公司 | 氫, 水氣 | 乙仞 | 二硫化碳 | 硝酸乙酯 |
認證標誌:
Ex d IIB T4 Gb/Ex tD A21 IP65 T130°C係氣體和粉塵防爆嘅通用證書, where the part before the slash (/) indicates the gas explosion-proof level, and the part after the slash indicates dust explosion-proof.
前任: Explosion-proof marking, the standard format of IEC (International Electrotechnical Commission) 防爆等級.
d: 隔爆 類型, indicating the primary form of explosion protection is flameproof.
IIB公司: Represents Class B gas explosion protection.
T4: Indicates the 溫度 class.
國標: Indicates this product is suitable for Zone 1 防爆.
For the 粉塵爆炸 part in the latter half, it’s sufficient to achieve the highest dust protection grade 6 based on the gas explosion-proof standards.
TD嘅: Represents the type of enclosure protection (preventing dust ignition with enclosure).
A21: Indicates the applicable area, suitable for Zone 21, 區 22.
IP65防護等級: Represents the protection grade.
It’s crucial to choose the correct explosion-proof rating in actual environments.
第一, it’s important to understand two main categories, as described below:
Explosion-proof types:
I類: Electrical equipment for underground coal mines;
II類: Electrical equipment for all other 爆炸物 gas environments except coal mines and underground.
Class II can be divided into IIA, IIB公司, 同IIC, where equipment marked IIB can be used under conditions suitable for IIA devices; IIC can be used under conditions suitable for both IIA and IIB.
III類: Electrical equipment for explosive dust environments other than coal mines.
IIIA型: Combustible flyings; IIIB級: Non-conductive dust; IIIC公司: 導電粉塵.
Explosion-proof areas:
區 0: Where explosive gases are always or frequently present; continuously hazardous for more than 1000 hours/year;
區 1: Where 易燃嘅 gases might occur during normal operation; intermittently hazardous for 10 自 1000 hours/year;
區 2: Where flammable gases are not normally present and, if they occur, are likely to be infrequent and short-lived; hazardously present for 0.1 自 10 hours/year.
It is important to note that we deal with Class II and III, 區 1, 區 2; 區 21, 區 22.
通常, reaching IIB is sufficient for gases, but for 氫, 乙仞, 同二硫化碳, a higher level of IIC is required. For dust explosion protection, just achieve the corresponding gas 防爆等級 and the highest dust grade.
There’s also a combined type of 防爆配電箱 额定值: ExdeIIBT4Gb.