小优视频app为爱而生

Hazardous Area Protection Guide

Date:2010年7月9日 14:57


 

Explosion Protection

There are many ways of protecting Plants from risk of explosion due to hazardous Gasses and Dusts.

 

小优视频app为爱而生 The Explosion Triangle shows we need three component parts to create an explosion:

小优视频app为爱而生 1 Oxidiser (Oxygen / Air)

小优视频app为爱而生 2 Fuel (Gas / Dust)

3 Energy (Ignition Source)

Remove any one and the area is safer.

Air
小优视频app为爱而生 This is naturally occuring all around us and would be very difficult to remove.

Gas / Dust
This has to be the right mixture before an explosion will occur. Too much air or too much gas / Dust and the mixture will not ignite.
小优视频app为爱而生 If the explosive atmosphere is caused by gases, vapours and mists the hazardous area is coded G. If the explosive atmosphere is caused by dusts the hazardous area is coded D.

Ignition Source
This can be in the form of a Naked Flame, A Hot Surface, Mechanically Generated Sparks, Electrically Generated Sparks, or Electrostatic Discharge etc..

ATEX

小优视频app为爱而生 What is ATEX?  

     

ATEX is the term used for the European Unions directive 94/9/EC that concerns equipment and protective systems intended for the use in potentially explosive atmospheres. The purpose of the directive is to facilitate trade within the EU buy aligning the laws of the member states regarding the safety requirements for hazardous area products.

 The Directive does not cover:

小优视频app为爱而生 1 Medical devices intended for use in a medical environment

小优视频app为爱而生 2 Equipment and protective systems where the explosion hazard results exclusively from the presence of explosive substances or unstable chemical substances

3 Equipment intended for use in domestic and non-commercial environments where potentially explosive atmospheres may only rarely be created, solely as a result of the accidental leakage of fuel gas.

小优视频app为爱而生 4 Personal protective equipment covered by Directive 89/686/EEC

5 Seagoing vessels and mobile offshore units together with equipment on board such vessels or units Means of transport, i.e. vehicles and their trailers intended solely for transporting passengers by air, road, rail or water networks, as well as means of transport in so far as such means are designed for transporting goods by air, by public road or rail networks or by water.

6 Vehicles intended for use in a potentially explosive atmosphere shall not be excluded.

Symbols
 Under the Old Directive, the "Epsilion x" (shown) symbol indicated conformity with CENELEC requirements. This symb
 Under the New Directive, the "Epsilion x" symbol will move into the marking string and be used to indicate explosion
 

小优视频app为爱而生 Explosion Groups

Explosion protected electrical equipment is classified in terms of the ignition temperature, the ignition capability and flame transmission capacity of the explosive atmosphere in which it is designed to operate.

小优视频app为爱而生 In the first instance equipment is divided into two groups depending on its location above or below ground.

Group I Electrical equipment for use below ground in areas susceptible to firedamp.
Group II Electrical equipment for all other areas.
小优视频app为爱而生 Group II equipment is further divided into three sub groups depending on the ignition and flame transmission characteristics of the explosive hazard.

These sub-groups are designated IIA, IIB and IIC.

Zones the probability of an explosive atmosphere occurring

Zone 0 defines an area in which an explosive atmosphere caused by a mixture of air and gases, vapours and mists is present continuously for long periods or very frequently (Category 1G under Atex)

Zone 1 defines areas in which an explosive atmosphere caused by a mixture air and gases, vapours and mists is expected to occur occasionally. (Category 2G under Atex)

小优视频app为爱而生 Zone 2 defines areas in which an explosive atmosphere caused by a mixture of air and gases, vapours and mists is unlikely and if it should occur it will be for a short time and then only rarely. (Category 3G under Atex)

小优视频app为爱而生 Zone 20 defines an area in which an explosive atmosphere caused by a cloud of combustible dust and air is present continuously for long periods or very frequently. (Category 1D under Atex)

Zone 21 defines areas in which an explosive atmosphere caused by a cloud of combustible dust and air is expected to occur occasionally. (Category 2D under Atex)

Zone 22defines areas in which an explosive atmosphere caused by a cloud of combustible dust and air is unlikely and if it should occur it will be for a short time and then only rarely. (Category 3D under Atex)

The main differences within ATEX are that Zones 0, 1 & 2 have now been replaced with Categories 1, 2 & 3, the inclusion of D

Zone

小优视频app为爱而生 Category

Presence of explosibles atmospheres

Group II equipment

zone 0

category 1 G

Continuous, frequent
小优视频app为爱而生 or for long periods

zone 20

category 1 D

zone 1

小优视频app为爱而生 category 2 G

Intermittent
小优视频app为爱而生 in normal operation (likely)

小优视频app为爱而生 zone 21

category 2 D

zone 2

category 3 G

Occasionalor for short periods
(never in normal operation)

zone 22

小优视频app为爱而生 category 3 D

Group I equipment

小优视频app为爱而生  

小优视频app为爱而生 category M 1

小优视频app为爱而生 Presence(methane, dust)

 

category M 2

小优视频app为爱而生 Risk of presence(methane, dust)

 

Types of Electrical Equipment Suitable for use in Potentially Explosive Atmospheres
小优视频app为爱而生 Different techniques are used to prevent electrical equipment from igniting explosive atmospheres. There are restrictions on where these different types of equipment can be used as follows:

 

European - Area of use Designation Standard
 

IEC - Area of use Designation Standard
 

小优视频app为爱而生 USA - Area of use Designation Standard

Flameproof Enclosure – An enclosure used to house electrical equipment, which when subjected to an internal explosion will not ignite a surrounding explosive atmosphere.
 

Zones 1 & 2
EExd
EN50018
 

Zones 1 & 2
Exd
IEC60079-1
 

Class 1 Divisions 1 & 2
UL1203

Intrinsic Safety – A technique whereby electrical energy is limited such that any sparks or heat generated by electrical equipment is sufficiently low as to not ignite an explosive atmosphere.
 

Zones 0, 1 & 2
EExi
EN50020
 

Zones 1 & 2
Exi
IEC60079-11
 

Class 1
Divisions 1 & 2
UL913

Increased Safety – This equipment is so designed as to eliminate sparks and hot surfaces capable of igniting an explosive atmosphere.
 

Zones 1 & 2
EExe
EN50019
 

Zones 1 & 2
Exe
IEC60079-7
 

Purged and Pressurised – Electrical equipment is housed in an enclosure which is initially purged to remove any explosive mixture, then pressurised to prevent ingress of the surrounding atmosphere prior to energisation.
 

Zones 1 & 2
EExp
EN50016
 

Zones 1 & 2
Exp
IEC60079-2
 

Class 1
Divisions 1 & 2
NFPA496

Encapsulation – A method of exclusion of the explosive atmosphere by fully encapsulating the electrical components in an approved material.
 

Zones 1 & 2
EExm
EN50028
 

Zones 1 & 2
Exm
IEC60079-18
 

Oil Immersion – The electrical components are immersed in oil, thus excluding the explosive atmosphere from any sparks or hot surfaces.
 

Zones 1 & 2
EExo
EN50015
 

Zones 1 & 2
Exo
IEC60079-6
 

Class 1
Division 2
UL698

Powder Filling – Equipment is surrounded with a fine powder, such as quartz, which does not allow the surrounding atmosphere to come into contact with any sparks or hot surfaces.
 

Zones 1 & 2
EExq
EN50017
 

Zones 1 & 2
Exq
IEC60079-5
 

Non-sparking – Sparking contacts are sealed against ingress of the surrounding atmosphere, hot surfaces are eliminated.
 

Zone 2
EExn
EN50021
 

Zone 2
Exn
IEC60079-15
 

Special Protection – Equipment is certified for use in a Potentially Explosive Atmosphere but does not conform to a type of protection listed above.
 

Zones 0, 1 & 2
*Exs
 

Zones 0, 1 & 2
Exs
 

Ignition temperature - temperature class  

小优视频app为爱而生 Many factors such as size, shape, type and surface quality have an influence on the ignition temperature. IEC, CENELEC and other standardisation committees have agreed on a method for gases and vapours defined in IEC 60079-4 „Method of test ignition temperature“. This method is defined in such a way, that a value very close to the lowest practically possible, is determined.

小优视频app为爱而生 By means of this method, gases and vapours are divided into temperature classes. According to these temperature classes, the surface temperatures in explosion-protected equipment and other technological objects is designed in such a way that ignition by the surface is not possible. In th

小优视频app为爱而生 Group I

Temperatures < 150°C or < 450°C
小优视频app为爱而生 according to coal dust accumulation on equipment

Group II

Temperature
classes

Ignition temperature
range of the mixture

Permissible surface temperature
小优视频app为爱而生 of the electrical equipment

T1

> 450 °C

小优视频app为爱而生 450 °C

T2

> 300 ... ≥450 °C

300 °C

T3

小优视频app为爱而生 > 200 ... ≥300 °C

200 °C

T4

小优视频app为爱而生 > 135 ... ≥200 °C

135 °C

T5

小优视频app为爱而生 > 100 ... ≥135 °C

100 °C

T6

> 85 ... ≥100 °C

小优视频app为爱而生 85 °C

小优视频app为爱而生 Self Ignition Temperature and Temparature Classes

Self Ignition Temperature °C

Temperature Class of the Equipment

T6

T5

T4

T3

T2

T1

(85°)

小优视频app为爱而生 (100°)

(135°)

(200°)

(300°)

(450°)

85° ≤ T ≤ 100 °c

 

 

 

 

 

 

100° ≤ T ≤ 135 °c

 

 

 

 

 

小优视频app为爱而生  

小优视频app为爱而生 135° ≤ T ≤ 200 °c

 

 

小优视频app为爱而生  

 

 

小优视频app为爱而生  

小优视频app为爱而生 200° ≤ T ≤ 3 00 °c

小优视频app为爱而生  

 

小优视频app为爱而生  

 

 

小优视频app为爱而生  

300° ≤ T≤ 450 °c

小优视频app为爱而生  

小优视频app为爱而生  

小优视频app为爱而生  

 

小优视频app为爱而生  

 

450° ≤

小优视频app为爱而生  

 

 

 

 

 

小优视频app为爱而生  

小优视频app为爱而生  

 

小优视频app为爱而生 =   EXPLOSION

Gases groups

小优视频app为爱而生 Groups

Gas

Ignition
temperatures

小优视频app为爱而生 Temperatures classes

T1

T2

T3

T4

T5

T6

I

小优视频app为爱而生 methane (firedamp)

 

 

 

 

 

 

 

II

A

acetone
acetic acide
ammonia
ethane
methylene chloride
methane (CH4)
carbon monoxyde
propane

540 °C
485 °C
630 °C
515 °C
556 °C
595 °C
605 °C
470 °C

小优视频app为爱而生  

小优视频app为爱而生  

 

 

小优视频app为爱而生  

 

n-butane
小优视频app为爱而生 n-butyl

365 °C
小优视频app为爱而生 370 °C

 

 

小优视频app为爱而生  

 

 

小优视频app为爱而生  

小优视频app为爱而生 n-hexane

小优视频app为爱而生 240 °C

 

 

小优视频app为爱而生  

 

小优视频app为爱而生  

小优视频app为爱而生  

acetaldehyde
ethyl ether

140 °C
小优视频app为爱而生 170 °C

 

 

 

 

 

小优视频app为爱而生  

ethyl nitrite

90 °C

小优视频app为爱而生  

 

 

小优视频app为爱而生  

小优视频app为爱而生  

 

B

ethylene
小优视频app为爱而生 ethyl oxyde

425 °C
小优视频app为爱而生 429 °C - 440 °C

 

小优视频app为爱而生  

 

 

小优视频app为爱而生  

小优视频app为爱而生  

小优视频app为爱而生 hydrogen sulfide

270 °C

 

 

 

 

 

小优视频app为爱而生  

C

小优视频app为爱而生 acetylene (C2H2)

305 °C

 

小优视频app为爱而生  

 

小优视频app为爱而生  

 

 

carbon disulphide (CS2)

102 °C

 

 

 

 

小优视频app为爱而生  

小优视频app为爱而生  

小优视频app为爱而生 hydrogen (H2)

小优视频app为爱而生 560 °C

 

 

 

小优视频app为爱而生  

 

小优视频app为爱而生 Ignition temperature for dusts

The dust ignition temperature depends on its consistency and nature.
小优视频app为爱而生 The ignition temperatures for various types of dust are available from reference tables: See examples

Dusts

Ignition temperature

Clouds

5 mm layer

Aluminium

560°C

小优视频app为爱而生 =450°C

Charcoal

小优视频app为爱而生 520°C

320°C

小优视频app为爱而生 Coal dust (lignite)

380°C

225°C

Cocoa

590°C

250°C

小优视频app为爱而生 Coffee (ground)

小优视频app为爱而生 580°C

小优视频app为爱而生 290°C

Corn

530°C

小优视频app为爱而生 460°C

Methyl cellulose

420°C

小优视频app为爱而生 320°C

Paper fiber

小优视频app为爱而生 570°C

小优视频app为爱而生 335°C

小优视频app为爱而生 Phenolic resin

530°C

小优视频app为爱而生 >450°C

小优视频app为爱而生 Polyethylene

440°C

小优视频app为爱而生 melts

PVC

小优视频app为爱而生 700°C

小优视频app为爱而生 >450°C

小优视频app为爱而生 Sugar

490°C

460°C

Soot

小优视频app为爱而生 810°C

小优视频app为爱而生 570°C

Toner

520°C

melts

Wheat

小优视频app为爱而生 510°C

小优视频app为爱而生 300°C

小优视频app为爱而生 Nota: temperature information is given as an example and cannot be used as a reference table.

Products lables

The ATEX standards call for the manufacturers of hazardous area electrical equipment to label their products with the following information.
 

1. Name of manufacturer

2. Product type code

4. Year of manufacture

小优视频app为爱而生 3. Address of manufacturer

5. Marking in accordance with directive 94/9/EC II 3 GD – group II location, category 3 equipment, for gas and dust hazards

小优视频app为爱而生 6. Marking in accordance with European standards EEx nR II T – built and tested to European standards, type of protection, explosion group, temperature class

7. CE marking together with notified body registration number

小优视频app为爱而生 8. Notified testing body and reference number

小优视频app为爱而生 9. Serial number

10. Technical data

11. Ingress protection

Marks of explosion protection for Europe 

TypeInfo:小优视频app为爱而生 Technical Resoureces

小优视频app为爱而生Keywords for the information: