DZD 25/2 B Ex e PLANNING INSTRUCTIONS - MAICO
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
PLANNING INSTRUCTIONS DZD 25/2 B Ex e Selection help for fans for areas subject to explosion hazards. The following flowchart shows you the steps from the job definition to the selection of the fan. Each individual step is ex- plained briefly in this section. A detailed description is found in the following chapters. Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 1 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e for quick reference Step 1: Are there combustible materials in the room? Page... Combustible materials are in particular all substances, which can be classified as flammable or highly inflammable. These can be gases, liquids and dust particles from combustible solid materials. Examples: ■ Combustible gases: Liquid gas (butane, butene, propane, propene), natural gas, combustible gases (carbon monoxide, methane) or gas-forming, combustible chemicals (acetylene, ethylene oxide, vinyl chloride) ■ Combustible fluids: Solvents, fuels, crude oil, heating oil, lubrication oil or used oil, paint or non-water soluble chemicals ■ Dust particles from combustible solid materials Coal, wood, food and animal foodstuffs (sugar, flour, grain), man-made materials, metals or chemicals Step 2: Can there be a build up of an explosive atmosphere? Page ... Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 2 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e A potentially explosive atmosphere is a mixture of air or oxygen with combustible gases, vapours, mists or dust under atmos- pheric conditions. When ignited, the combustion occurs throughout the complete, non-burned mixture. Locations where such a potentially explosive atmosphere is present are known as areas subject to explosion hazards. Whether an explosion will occur or not when combustible materials are present, depends on the concentration and the "igni- tion qualities" of the air-mixture. Explosive atmospheres can build up when combustible materials are being stored, transported and processed. Examples: ■ Spraying and splashing from a stream of liquid ■ Vaporising and condensation of combustible liquids ■ Leakages in gas or fluid piping ■ Raising the dust of combustible solid materials Step 3: Underground usage? Page ... Special regulations are in force for underground usage. MAICO fans are not suitable for usage underground. Step 4: Is there an Explosion Protection Document available? Page ... Whenever there is risk that a potentially explosive atmosphere may build up, an Explosion Protection Document must be cre- ated. There must be an overview of the results of the danger assessment and the resulting technical and organisational pro- tection measures. This documentation must be created by the employer before work commences and it must contain the following information: ■ Determining and assessing the risks of explosion ■ Definitions of the implemented explosion protection measures ■ Definitions of the zone classification ■ Definitions of the design, operation and maintenance of the working and warning equipment used Ex specialists, trade supervisory boards, TÜV (German Technical Inspection Agency) or the employers' liability insurance as- sociation provide support during the creation of the Explosion Protection Document. Step 5: Take primary and secondary explosion protection measures Page ... Primary explosion protection measures prevent the creation and the spreading of a potentially explosive atmosphere. The fol- lowing are examples of measures that could be used for this purpose: Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 3 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e ■ Diluent ventilation ■ Extraction ■ The avoidance of combustible materials Secondary explosion protection measures prevent the ignition of an explosive atmosphere. Ignition protection measures in both electrical and non-electrical resources are used for this purpose. Step 6: Which zones can the areas with explosive atmospheres be classified into? Page ... Areas at risk of explosion are sub-divided into Zones depending on the frequency and duration of explosive atmospheres. MAICO fans can be used in Zones 1 and 2: ■ Zone 1: An area where an explosive atmosphere consisting of a mixture of air and combustible gasses, vapours or mists can occur during normal operation. ■ Zone 2: An area where an explosive atmosphere consisting of a mixture of air and combustible gases, vapours or mists normally doesn't occur or only occurs short-term during normal operation. Step 7: Can the increased safety motor ignition protection type "e" be used? Page ... If the build-up of an explosive atmosphere cannot be prevented, the ignition of this explosive atmosphere is to be avoided. Possible sources of ignition are: ■ Electrical equipment ■ Static electricity ■ Hot surfaces ■ Mechanically generated sparks ■ Flames and hot gases Electrical equipment can have different levels of ignition protection. MAICO fan motors for areas at risk of explosion have the increased safety motor ignition protection type "e". This means that safety measures have been introduced at the motor to prevent the occurrence of inadmissibly high temperatures or sparks. Step 8: Check present temperature class as well as air stream and ambient temperatures? Page ... The ignition temperature of a potentially explosive atmosphere is the lowest heated surface temperature at which ignition oc- curs. For this reason, the maximum surface temperature of a piece of equipment (in the case of fans, this is the motor), must always be lower than the ignition temperature of the explosive atmosphere in question. The temperature classes T1 to T6 define the maximum ignition temperature that a piece of equipment can be used at. MAICO fans are designed for use in different temperature classes, depending on the product type. Step 9: Fan layout Page ... There is a wide range of MAICO fans to choose from, based on the installation location and the point-of-use. There are fans for installation in ducting systems as well as roof- and wall-mounted fans. The available air stream volumes range from 300 m³/h up to 11,000 m/h. Step 10: Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 4 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS
DZD 25/2 B Ex e
Is the build up of a potentially explosive atmosphere prevented in an approved way?
Page ...
It is critical that you check whether there is still the threat of a build-up of a potentially explosive atmosphere, in spite of all the
primary and secondary explosion protection measures. If this is the case, tertiary explosion protection measures must be tak-
en. These should be aimed at reducing the effects of an explosion to a non-dangerous level.
■ Explosion-proof construction
■ Release of pressure
■ Suppression of explosion
Introduction
Legal requirements
The regulations relating to explosion protection in Germany and in other member states of the European Union have migrat-
ed from the previous EC Ex framework directives 76/117/EWG ff to new EC directives. With this step, explosion protection
has been completely harmonised within the European body of legislation and national regulations and guidelines have been
adjusted to meet the legal demands within the European Union.
The new legal system governing European explosion protection is based on two EC directives:
■ Directive 2014/34/EU: This defines the duties of the manufacturer in terms of the quality requirements for electrical and
non-electrical equipment as well as protection systems.
■ Directive 1999/92/EC: This regulates the duties for the operator (employer) in terms of the minimum requirements for the
improvement of the protection of the health and security of employees, who could be placed in danger by explosive atmos-
pheres.
Duties of the manufacturer
:
Basically, safety in areas at danger from explosion can only be guaranteed through close cooperation between all concerned
parties (manufacturers, installers, operators, test personnel, regulatory bodies).
The manufacturer analyses and evaluates the ignition risks of his equipment and assigns them to the device groups and cat-
egories ass defined in Directive 2014/34/EU, Appendix 1.
■ Explosion protected fans from MAICO correspond to Device Group II, Category 2 G and when installed correctly, meet the
basic safety and health requirements.
■ The requirements for the application of the CE mark will be fulfilled within the scope of a conformity evaluation process.
■ The equipment will be tested by an independent, recognised testing authority, which will confirm the conformity to the rele-
vant regulations by the issuing of an EC-Type-Examination certificate.
■ Proof of a suitable QA system through an EC Certificate.
Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 5
right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e Duties of the installer and the operator The Directive 1999/92/EC regulates the duties of the operator and/or employer, when there is likely to be a build-up of explo- sive atmospheres. In particular, the following topics are handled, which are documented in the Explosion Protection Docu- ment (see Chapter 7). Prevention of and protection against explosions (Article 3) ■ Prevention of the build-up of explosive atmospheres ■ Avoidance of the ignition of explosive atmospheres ■ Mitigation of detrimental effects Assessment of explosion risks (Article 4) ■ What is the likelihood that explosive atmospheres will occur? ■ How long will the explosive atmosphere persist? ■ Are there ignition sources present? ■ Assessment of the installations, substances used, processes and their possible interactions. Implementing necessary measures for working in atmospheres at risk from explosion (Article 5) ■ The design of a danger-free working environment ■ Danger-free work through appropriate technical supervision Duty of coordination (Article 6) ■ Sub-contractors shall carry the responsibility for their own employees ■ The employer of a sub-contractor's employees shall coordinate the implementation of all the measures concerning work- ers’ safety and shall give exact definitions in the Explosion Protection Document referred to in Article 8. Places where explosive atmospheres may occur (Article 7) ■ The employer shall classify places where explosive atmospheres may occur into zones ■ The employer shall ensure that the minimum requirements for the improvement of the safety and health of employees, placed at risk by explosive atmospheres as laid down in Annex II are applied ■ Areas subject to explosion hazards must be marked Explosion Protection Document (Article 8) The employer must ensure that an Explosion Protection Document is created and kept up-to-date. The Explosion Protection Document must demonstrate: ■ that the explosion risks have been determined and assessed, ■ that adequate measures have been taken, ■ which areas have been classified into zones, ■ which areas the minimum regulations according to Directive 1999/92/EC, Appendix II apply to. Special requirements for work equipment and workplaces (Article 9). Fans and their accessories, which were installed prior to 1st July 2003 may continue to be used. Relevance of the EU Directives for MAICO Fans All devices sold by MAICO since 1st July 2003 are type-tested and conform to the current regulations. Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 6 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS
DZD 25/2 B Ex e
All devices sold by MAICO, which were installed before the 1st July 2003, may continue to be used after this date, without
any time constraints.
Explosive atmosphere
Preconditions for an explosion
An explosion can only occur if the following events occur simultaneously at one location:
■ Combustible substances which, together with air, may form a potentially explosive atmosphere
■ Air or oxygen
■ Ignition source
Combustible materials
The pre-requirement for the occurrence of an explosion is that combustible material is present in the working and/or produc-
tion process. This means that at least one combustible substance is used as a raw material or additive, is produced as a
residual, intermediary or final product or can be produced through a normally occurring breakdown situation.
Combustible gases Combustible fluids Dust particles from combustible solid
materials
Liquid gas (butane, butene, propane, Solvents Coal
propene) Fuel stuffs Wood
Natural gas Crude, heating, lubricating or used oil Food and animal foodstuffs, e.g sugar,
Combustible gases, e.g. carbon Paint flour or grain
monoxide or methane Soluble and non-water soluble chemi- Plastics
Gaseous combustible chemicals, e.g. cals Metals
acetylene, ethylenoxide, vinlychloride Chemicals
Example: Combustible materials can also occur unintentionally, e.g. when storing weak acids or leaching agents in metal
containers. This can result in the production of hydrogen and the build-up of gases.
Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 7
right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS
DZD 25/2 B Ex e
In general all materials that are capable of an exothermic oxidisation reaction should be considered as combustible. This in-
cludes in particular all materials that are classified as flammable or highly inflammable according to the Materials Directive RL
67/548/EEC.
There is a range of materials, which under normal conditions are very difficult to ignite. However when in very small parti-
cle sizes or when the ignition energy is hot enough, they become liable to exploded when mixed with air ( e.g. metal dust or
aerosols).
The ignition properties of an explosive atmosphere are material-dependant. Gases and vapours are sub-divided into 4 explo-
sion groups in order to differential the level of danger: I, IIA, IIB and IIC. The ignition properties and therefore the danger risks
increase through the groups from IIA to IIC.
Explosion groups Combustible materials
I Methane
IIA Acetone
Petrol
Heating oil
IIB City gas
Ethylene
IIC Hydrogen
Acetylene
Explosion group I only occurs in mining.
This assignment is particularly significant for electrical equipment with the protection type pressure-proof housing "d" and in-
herent safety "i". [EXAM]
Explosive atmosphere
A potentially explosive atmosphere is a mixture of air or oxygen with flammable gases, vapours, mists or dusts under atmos-
pheric conditions. In the event of ignition, combustion will spread to the entire non-combusted mixture.
An area at risk of explosion is one where an explosive atmosphere could occur.
Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 8
right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e An explosion can only occur when the concentration of combustible materials in the air is within a certain range. This so- called "explosion range" is very dependant on the type of combustible material. The explosion range is defined by a lower (LEL) and an upper (UEL) concentration limit. An explosion can occur when the concentration is in between this two limit val- ues. This can lead, for example, to the build-up of an explosive atmosphere in a partly filled petrol tank whereas a full one would not present any danger as the UEL would be exceeded. Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 9 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e Application example: ERM ... E Ex e for air extraction of storage rooms with explosive atmospheres MAICO fans can be used for air extraction to bring the concentration of combustible gases under the explosion limit. This prevents the build-up of an explosive atmosphere. In the example shown, an ERM ... E EX e fan extracts gasses that are heavier than air. This is why the fan is installed close to the ground. A potentially explosive atmosphere can occur above combustible materials through evaporation. The lowest temperature at which a spontaneously inflammable mixture of gas or vapour and air can occur above a liquid, under prescribed norm condi- tions is known as the flash point. A potentially explosive atmosphere can build up if the maximum possible room temperature is higher than the flash point of a combustible liquid. [EXAM] TF - Flash point 1 Combustible fluids 2 Potentially explosive atmosphere Build-up of a potentially explosive atmosphere In principle, a potentially explosive atmosphere can occur during the production, storage, processing and transportation of combustible materials. [EXAM] Gases: ■ Leakages in glass bottles or gas pipes Liquids: ■ Evaporation of combustible liquids at temperatures above the flash point ■ Spraying, splashing or breaking a stream of liquid. Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 10 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e ■ If the liquid is spread in drops, a potentially explosive atmosphere can build-up, even at ambient temperatures below the flash point. Application example: Wall fans for air extraction The build-up of an potentially explosive atmosphere from combustible liquids can be avoided by air extraction. In this case, DZQ...E Exe wall fans are used for extraction, at the point where the air/gas mixture build-up can occur. Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 11 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e ■ Leakages from pipes carrying liquids ■ If there are leakages in the enclosure of combustible liquids with high excess pressure, the liquid can spray out and form an explosive mist, depending on the size of the leak and the level of pressure. This can then turn into explosive vapours. Dusts: Fans Temperature class Useable? DZD 25/4 A-Ex T1 to T4 x DZD 30/6 A-Ex T1 to T4 x DZD 30/4 A-Ex T1 to T4 x DZD 30/2 A-Ex T1 to T3 DZD 35/6 A-Ex T1 to T4 x DZD 35/4 A-Ex T1 to T4 x DZD 35/2 A-Ex T1 to T3 DZD 40/6 A-Ex T1 to T4 x DZD 40/4 A-Ex T1 to T4 x DZD 50/6 A-Ex T1 to T4 x DZD 50/4 A-Ex T1 to T3 DZD 60/6 A-Ex T1 to T3 Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 12 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS
DZD 25/2 B Ex e
Maximum surface temperature of the Ignition temperature of the explosive Temperature class
equipment [°C] atmosphere [°C]
450 TIgn > 450 T1
300 300 < TIgn < 450 T2
200 200 < TIgn < 300 T3
135 135 < TIgn < 200 T4
100 100 < TIgn < 135 T5
85 85 < TIgn < 100 T6
■ Grinding or sifting
■ Conveying, filling or emptying
Application example: ERM 22 E Ex e airstreams
The ERM 22 E Ex e fan is approved for use with temperature classes T1 to T3. For this reason, it can be used to convey
an explosive atmosphere with an ignition temperature greater than 200 °C.
Therefore this fan can be used, for example, to convey petrol, diesel or heating oil vapours.
■ Drying
Temperature class I IIA IIB IIC
\explosion group
T1 Methane Acetone City gas Hydrogen
Ethane
Propane
T2 N-butane Ethylene Acetylene
N-butyl alcohol
Ethyl alcohol
T3 Heating oil
Diesel
Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 13
right to make technical modifications without giving prior noticePLANNING INSTRUCTIONS
DZD 25/2 B Ex e
Temperature class I IIA IIB IIC
\explosion group
Petrol
T4 Acetaldehyde
Ethyl ether
T5
T6 Carbon disulphide
■ Stirring up of dust
Temperature classes
The ignition temperature is the lowest temperature of a surface, e.g. of electric motors, at which an explosive atmosphere ig-
nites on that surface.
Potentially explosive substances can be classified into temperature classes by their ignition temperatures. The maximum sur-
face temperature of a piece of equipment (the motor in the case of fans) must always be below the ignition temperature of the
explosive atmosphere in which it is used.
TZ - Ignition temperature
Equipment that falls into a higher temperature class, e.g. T4, may also be used for applications in which a lower temperature
class is required e.g. T2 or T3.
Example: An electric motor with a surface temperature of 175°C may be used only in the potentially explosive atmosphere of
temperature classes T1, T2 and T3.
Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 14
right to make technical modifications without giving prior noticePLANNING INSTRUCTIONS DZD 25/2 B Ex e The following table assigns a range of flammable gases to a temperature class and explosion group. Key parameters of a potentially explosive atmosphere A potentially explosive atmosphere is characterised by: ■ The potentially explosive substance it contains ■ The concentration of that substance ■ The flash point and ignition temperature ■ The temperature class These parameters must be known in order to be able to assess the risk of explosion and the corresponding explosion protec- tion measures. Key parameters of electrical operating equipment and systems in the area subject to explosion hazards Device groups and device categories Electrical equipment for use in potentially explosive atmospheres is divided into 2 device groups: ■ Group I: Electrical operating equipment used underground where there is a risk of firedamp (not included in the MAICO product range). ■ Group II: Electrical equipment in all other areas subject to explosion hazards. These are then further sub-divided into three categories 1, 2 and 3, dependant on the level of danger. Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 15 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS
DZD 25/2 B Ex e
Equipment from Device group II are given a letter, which identifies the state of the atmosphere:
■ G - for areas in which explosive gas-, vapour- or mist-air mixtures are present. These are applications where MAICO fans
can be used.
■ D - for areas in which dust mixed with air can cause the build up of an explosive atmosphere. These are not applications
where MAICO fans can be used.
Zone Aggregation state of the combustible Frequency with which a potentially ex-
material plosive atmosphere occurs
0 Gas, vapour, mist Constantly, for long periods or fre-
quently
1 Gas, vapour, mist Occasionally
2 Gas, vapour, mist Seldom and for short periods
20 Dust Constantly, for long periods or fre-
quently
21 Dust Occasionally
22 Dust Seldom and for short periods
Classification of zones
Areas subject to explosion hazards are classified into zones according to the frequency with which potentially explosive at-
mospheres occur. A differentiation is also made between gas/vapour and dust according to the aggregate status of the in-
flammable substance.
Usage example: MAICO fans in Zone 1 and Zone 2
In the graphic shown, representing production and storage areas, the operator has divided the area into zones 0, 1 and 2.
The concentration of combustible material in the air is reduced through constant cross-ventilation. This reduces the explo-
sion hazard.
MAICO wall fans EZQ ... E Ex e or DZQ ... E Ex e are installed for this purpose in zone 1 and zone 2.
Equipment for Zone 1 may also be used in Zone 2.
All MAICO fans approved for use in areas subject to explosion hazards may be used in Zones 1 and 2.
Key parameters of electrical operating equipment and systems in the area subject to
explosion hazards
Explosion protection
Explosion protection measures
There are three levels of explosion protection:
Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 16
right to make technical modifications without giving prior noticePLANNING INSTRUCTIONS DZD 25/2 B Ex e ■ Primary explosion protection: Avoidance of the build-up of explosive atmospheres ■ Secondary explosion protection: Avoidance of sources of ignition ■ Tertiary explosion protection: Prevention of the spread of an explosion and the reduction of the effects of an explosion. An integrated explosion protection concept should be used: The primary measures to be adopted should be aimed at the avoidance of explosive atmospheres. Only when the build-up of such atmospheres cannot be avoided in spite of protection measures should the attention turn to measures to avoid sources of ignition. If these cannot be completely ruled out, measures to prevent the spread of an explosion must be taken. Primary explosion protection There is a range of measures that can be taken to avoid the build-up of explosive atmospheres: ■ Ventilation (extraction, air-thinning) ■ Replace combustible materials with safe ones ■ Inertisation Ventilation as the central measure for primary explosion protection If it is not possible to exclude the use of combustible materials, the build-up of a potentially explosive atmospheres can often be avoided with suitable ventilation measures. Gases and dust are only explosive when the mixture with air falls within cer- tain concentration levels. Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 17 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e The use of suitable ventilation equipment can often result in bringing the concentration below the lower explosion level, which in turn is a reliable method of preventing the build-up of explosive atmospheres. In any case, the probability of them occurring or the scope of areas at risk of explosion (zones) is reduced. Applications for ventilation equipment in areas subject to explosion hazards Typical applications for ventilation equipment in areas subject to explosion hazards are: ■ Storage facilities ■ Process technical applications ■ Workshops ■ Petro-chemicals ■ Battery rooms ■ Laboratories Basically in such cases, a ventilation system is always necessary to convey the combustible gasses, vapours or mist from the explosive atmosphere out of the building. An addition ventilation system may be necessary, depending on the application. Otherwise the naturally generated fresh air supply through the ventilation grill or shutters is enough. Extraction Ventilation at the point of exit, e.g. rim extraction with open containers, to prevent the dispersion of explosive material into the room. 1 Ventilation duct, to be supplied by the customer 2 ELM ... Ex Fixing cuff 3 ERM ... E Ex e fan Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 18 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e SGM ... Ex Protective grille 1 Potentially explosive atmosphere Diluent ventilation By distributing the combustible material through the air, concentration levels can be reduced such that they are below the lower explosion level. The lower explosion level is the lowest concentration level value of a combustible material in a mixture of gases, vapours, mist or dust, below which it is no longer possible for flames to propagate themselves independently after an ignition source has been ignited. 1 MLA or MLZ external grille 2 Potentially explosive atmosphere EZQ ... E Ex e or DZQ ... E Ex e fan Technical implementation of ventilation systems in areas subject to explosion hazards Experience shows that you should try to achieve air exchange rates of at least 5 1/h in areas at risk of explosion. The corre- sponding values for specific individual cases are given through Employers' liability insurance association or other regulations. Further, you must ensure that the air limit values, e.g. maximum workplace concentration values, for all gases, vapours and mist that may occur are adhered to. For this reason, it is often advisable to install an active ventilation system for the affected rooms in addition to the air extrac- tion or exhaust air system. If required, lower levels of overpressure or negative pressure can be achieved through suitable control of air flows for the outside and outgoing air. There should always be negative pressure in rooms with areas subject to explosion hazards. Therefore, the mass flow in the supply air pipes should be slightly smaller than that in the exhaust ducts. Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 19 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e Depending on the application, there are many different options for the location of the supply and exhaust air fans, the ventila- tion ducting, the supply and exhaust air openings, etc. A range of technical measures have proved themselves for achieving effective ventilation: Cross-ventilation With cross-ventilation, the supply air flows through the whole room before being extracted again. Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 20 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e In this case, the supply air should be blown in near to and parallel to the ceiling. The induction effect then distributes the sup- ply air throughout the whole room. Exhaust air should be extracted at floor level as most combustible gases and vapours are heavier than air. The exception to this is hydrogen, which collects under the ceiling. Please refer in this case to the following usage example: "Cross-ventilation in battery rooms". 1 EZQ ... E Ex e or DZQ ... E Ex e wall-mounted fan 2 Air flow with cross-ventilation 3 Potentially explosive atmosphere 4 ERM ... E Ex e duct fan 1 Outgoing air 2 DZD ... E Ex e roof fan 3 Air flow with cross-ventilation 4 Potentially explosive atmosphere 5 ERM ... E Ex e duct fan 6 ERM ... E Ex e duct fan In the application shown above, the supply air is blown into the room parallel to the ceiling. This supply air is mixed well with the air already in the room as it makes its way across the room. Air extraction is then done direct at the workplace, in a dangerous material cabinet with a fan connected directly to it or gen- erally through extractor fans at floor level. Supply and exhaust air openings Supply should be introduced through cross-ventilation in order to create as little disturbance as possible. In order to keep pressure loss at the supply air opening as low as possible, the free cross section of the supply air opening should be at least 3 or 4 times that of the fan. This can be done with one opening of a suitable size or through several smaller ones. Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 21 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS
DZD 25/2 B Ex e
The MAICO MLA and MLZ external grilles, size 20 to 50, can be used.
MAICO recommends the use of the automatic AS shutter, size 20 to 60, with external shutters.
Application example:
Cross-ventilation in battery rooms
Hydrogen is produced in battery rooms while the cells are being charged, which collects under the ceiling. At the same
time, sulphuric acid mist collects at floor level with lead batteries. Both of these must be extracted.
For this purpose, equip the exhaust air system with openings both at floor and ceiling level or extract the exhaust air di-
rectly with EZQ ... E Ex e or DZQ ... E Ex e wall fans.
Supply air is introduced through a separate ventilation system at the the other end of the battery room. If possible the sim-
plest solution in this case is the use of EZQ ... E Ex e or DZQ ... E Ex e wall fans to blow air from outside into the room.
The RS shutter may only be used if the corresponding MS 2 servomotor is installed outside the area subject to explosion
hazards.
Additionally, MAICO offers an extensive range of system components and accessories for ventilation systems for use in ar-
eas subject to explosion hazards.
1 MLA or MLZ external grille
2 ERM ... E Ex e duct fan
3 Supply air opening
4 Potentially explosive atmosphere
5 Exhaust air exit opening
6 DZD ... E Ex e roof fan
Exhaust air / Extraction equipment
The expelling of exhaust air from the building must meet different requirements, depending on the industry. For example, the
following rules are valid for the treatment of exhaust air in the paint industry:
■ The exhaust air opening must be at least 2 metres above the ridge of a gable roof or 5 metres above a flat roof.
■ The exhaust air opening must be at least 10 metres above the ground.
■ The exhaust air exit speed must be at least 7 m/s.
■ In the case of extraction equipment, there must be a suitable run-on time in order to ensure that there cannot be a build-up
of an explosive atmosphere, even after the actual work itself has been completed.
Folded, spiral ducting is suitable for use as the ventilation piping.
Plastic ducting should not be used because of the danger of electro-static discharge. Special plastic ducting that can conduct
electricity may however be used.
1 Potentially explosive atmosphere
Gaseous inert material Dustlike inert material
Nitrogen Stone dust
Carbon dioxide Calcium sulphate
Inert gases (Helium, Neon, Argon) Ammonia phosphate
Combustible exhaust fumes Sodium bicarbonate
Water vapour
1 Exhaust air exit opening
2 DZD ... E Ex e roof fan
3 ERM ... E Ex e duct fan
4 Outgoing air
Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 22
right to make technical modifications without giving prior noticePLANNING INSTRUCTIONS DZD 25/2 B Ex e Replacement of combustible material The build-up of potentially dangerous, explosive atmospheres can be prevented by the avoidance of or the reduction in the use of combustible materials. One example for this is the replacement of combustible solvents or cleaning agents by wa- ter-based solutions. Another option is to dampen the dust or to use highly viscous products, so that it is no longer possible to disturb the dust. [EXAM] Inertisation A potentially dangerous, explosive atmosphere can also be avoided by thinning the oxygen in the air inside the equipment or by thinning the fuel with chemical, non-reactive (inert) material. This protective measure is known as inertisation. [EXAM] As a rule, inertisation by the use of gases can only be used in closed equipment, where only a relatively limited gas volume exchange per unit is possible. If an inert gas escapes from the equipment through openings that are normally there or that are caused by an error, this can represent a danger to the operator by reducing the level of oxygen and increasing the risk of suffocation. If combustion gasses are used as inert gasses, an escape of gas in this case can lead to the operator being poisoned. Secondary explosion protection If it is not possible to prevent the build-up of an explosive atmosphere, measures must be implemented to avoid the igniting of the explosive atmosphere. This is achieved by measures that avoid the occurrence of ignition sources. The various types of ignition sources and their effects must be known, in order to define effective protective measures. Ignition sources The following ignition sources can occur in commercial and industrial operations: ■ Hot surfaces ■ e.g. radiators, cooker hobs, heating boiler, heated machine parts, ... ■ Flames and hot gases ■ e.g. Bunsen burners, candles, matches, open-flame heating ■ Mechanically generated sparks Application example: Ignition protection concept, with AC motor fans from MAICO The potential source of ignition with MAICO fans is their hot surfaces. This is caused by the dissipated energy from the motor. In normal operation, the surface temperature reaches a stable level after some time. In the case of malfunctions, e.g. a blocked impeller, this temperature can rise significantly in a very few seconds. Without appropriate protective measures, the ignition temperature of an explosive atmosphere could be exceeded and as a result, an explosion could be triggered. The protective measures are based on monitoring the temperature of the motor. For this purpose, there are PTC thermis- tors built into the motor winding, which are connected to a separate MVS 6 triggering device. When a particular maximum temperature is exceeded, the MVS 6 switches the fan off, giving you a reliable way of preventing an ignition temperature level being reached. Further protective measures have been implemented in the external, mechanical parts of the fan. These address in partic- ular friction with rotating parts, the build-up of static electricity and the unit's flammability. ■ Sparks caused by friction, grinding or striking, e.g. nailed shoes on cement, rusty iron on aluminium, hammer on metal. There are tools, e.g. sockets sets made of material that does not generate sparks. ■ Electrical equipment: Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 23 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS
DZD 25/2 B Ex e
■ Opening and closing electrical circuits, e.g. light switches, electrical motors, switching on a refrigerator, heating system
burners
Type of protection Function principle Main application
"e" Safety measures have been Terminal boxes, motors,
Increased safety introduced to prevent the lights
occurrence of inadmissibly
high temperatures or sparks
in the inner or outer parts.
"d" Parts that could ignite an Switching devices, motors,
Pressure-proof housing explosive atmosphere are transformers, heaters
installed in a housing that
can withstand the pressure
of an explosion and pre-
vents transfer to the sur-
rounding explosive atmos-
phere.
"p" The build-up of an explo- Switching and control cab-
Pressurisation sive atmosphere within the inets, analysis equipment,
housing is prevented by large motors
an ignition protection gas,
which maintains an excess
pressure higher than that
of the surrounding atmos-
phere.
"i" The equipment contains in- Measurement and control
Intrinsic safety trinsically safe power cir- technology, communica-
cuits, which guarantee that tions technology, sensors
no sparks or thermal effects
can cause the ignition of ex-
plosive atmospheres.
"q" Parts which could become a Capacitors
Powder filling source of ignition are fixed
in their position and then
completely surrounded with
a filling agent, in order to
prevent the ignition of an
external explosive atmos-
phere.
Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 24
right to make technical modifications without giving prior noticePLANNING INSTRUCTIONS
DZD 25/2 B Ex e
Type of protection Function principle Main application
"o" Parts which could become a Starting resistances, trans-
Oil immersion source of ignition are com- formers
pletely surrounded with a
protective liquid, e.g. oil, in
order to prevent the ignition
of an external explosive at-
mosphere.
"m" Parts which could become a Sensors, switching devices
Encapsulation source of ignition are com-
pletely surrounded with a
casting compound, in order
to prevent the ignition of an
external explosive atmos-
phere.
■ Electrical circulating current, cathodic corrosion protection:
■ Stray and leakage current in electrically conductive equipment
■ Static electricity:
■ Discharge sparks when coming into contact with charged parts because of a potential difference, e, g. charging of plas-
tic materials and non-conductive liquids
■ Lightning
Electrical equipment protection types as measures in secondary explosion protection
Costly pressure-proof housing is not necessary with equipment where no ignition is expected during normal operation, e.g. all
MAICO fans designed for use in areas subject to explosion hazards.
MAICO fans for these applications are constructed with the increased safety protection type "e", which can achieve the same
level of security as pressure-proof housing.
Tertiary explosion protection
Tertiary explosion protection is measures that are taken to reduce the effect of an explosion to a non-dangerous level. This
means that the explosion actually occurs but its dangerous effects are restricted by the implementation of the corresponding
measures.
Such measures could be:
■ Explosion-proof construction
■ Release of pressure
■ Suppression of explosion
MAICO fan selection guide
MAICO fans, for use in areas subject to explosion hazards
The following details must be known, in order to select the suitable fan:
Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 25
right to make technical modifications without giving prior noticePLANNING INSTRUCTIONS
DZD 25/2 B Ex e
MAICO offers: Valid for:
Device group Device group II, Category 2 G All Ex-fan product groups.
i.e. suitable for explosive atmospheres
with gases, vapours and mists, other
than mining
Zone Approved for Zone 1 and Zone 2 All Ex-fan product groups.
Not approved for use in dusty areas
subject to explosion hazards (zones
21. 21. 22).
Type of protection Increased safety "e" All Ex-fan product groups.
Installation site Fans for installation in ceilings, walls Corresponding product group
or ducts
Point of work Roof fans: Corresponding product group
DZD ... E Ex e
800 m³/h up to 7100 m³/ h
Wall fans:
EZQ ... E Ex e, DZQ ... E Ex e
400 m³/h up to 10400 m³/ h
Duct fans:
DZR ... E Ex e
1100 m³/h up to 10500 m³/ h
Duct fans:
ERM ... E Ex e
300 m³/h up to 900 m³/ h
Temperature class Depending on product type T1 - T3 to Corresponding product type
T1 - T5
Additionally, the following factors play a role in the selection of the correct fan:
MAICO offers: Valid for:
Air medium Vapours that are neutral or that have a All Ex-fan product groups.
slight acidic or alkaline content
Maximum airstream temperature 50°C All Ex-fan product groups.
Rated voltage 400 V DZQ / DZR / DZD ... E Ex e
230 V ERM... E Ex e, EZQ ... E Ex e
Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 26
right to make technical modifications without giving prior noticePLANNING INSTRUCTIONS
DZD 25/2 B Ex e
MAICO offers: Valid for:
Speed controllable Yes DZQ / DZR / DZD ... E Ex e
No ERM... E Ex e, EZQ ... E Ex e
Application example
A fan is required for the following area subject to explosion hazards:
■ Zone 1
■ Ignition temperature 150°C - corresponds to temperature class T4
■ Installation location roof
All MAICO fans for use in areas at risk of explosion may be used in Zone 1.
All DZD-...Ex roof fans highlighted in the following table may be used in temperature class T4:
ERM... semi-centrifugal duct fans E Ex e
■ AC model
■ Not speed-controllable
■ Compact construction for space-saving installation
■ Can be fitted in any position
Product type Temperature class Rotating speed Air volume: Nominal size
-1 m³/ h mm
min
ERM 18 E Ex e T1 to T4 2780 310 180
ERM 22 E Ex e T1 to T3 2860 560 225
ERM 25 E Ex e T1 to T3 2860 870 250
Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 27
right to make technical modifications without giving prior noticePLANNING INSTRUCTIONS DZD 25/2 B Ex e A - ERM 18 E Ex e B - ERM 22 E Ex e C - ERM 25 E Ex e Extensive product information (tender text, technical data, prices, etc.) can be found under www.maico -ventilatoren.com. If you have technical questions, please use our Service Hotline: Phone: 0 18 05 / 69 41 10 Fax: 0 77 20 / 69 42 39 DZR ... axial duct fans E Ex e ■ Three-phase AC version ■ Speed-controllable with transformers ■ Duct sleeve made of galvanised sheet-steel, with flanges on both sides. ■ Switchable for ventilation and air extraction ■ Can be fitted in any position ■ Connect the built-in temperature sensor resistor to a tested resistor triggering device. ■ We reserve the right to make technical modifications. Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 28 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS
DZD 25/2 B Ex e
Product type Temperature class Rotating speed Air volume: Nominal size
-1 m³/ h mm
min
DZR 20/2 B E Ex e 2920 1150 200
DZR 25/4 B E Ex e 1470 1100 250
DZR 25/2 B E Ex e 2835 2200 250
DZR 30/6 B E Ex e 992 1250 300
DZR 30/4 B E Ex e 1445 1950 300
DZR 30/2 B E Ex e 2730 3800 300
DZR 35/6 B E Ex e 985 1850 350
DZR 35/4 B E Ex e 1390 2800 350
DZR 35/2 B E Ex e 2750 6000 350
DZR 40/6 B E Ex e 975 2800 400
DZR 40/4 B E Ex e 1420 4400 400
DZR 45/6 B E Ex e 960 4500 450
DZR 45/4 B E Ex e 1320 6500 450
DZR 50/6 B E Ex e 920 5800 500
DZR 50/4 B E Ex e 1360 9100 500
DZR 60/6 B E Ex e 890 10500 600
Extensive product information (tender text, technical data, prices, etc.) can be found under www.maico-ventilatoren.com .
If you have technical questions, please use our Service Hotline:
Phone: 0 18 05 / 69 41 10
Fax: 0 77 20 / 69 42 39
Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 29
right to make technical modifications without giving prior noticePLANNING INSTRUCTIONS DZD 25/2 B Ex e A - DZR 30/6 B Ex e B - DZR 25/4 B Ex e C - DZR 20/2 B Ex e D - DZR 25/2 B Ex e A - DZR 35/6 B Ex e B - DZR 30/4 B Ex e C - DZR 35/4 B Ex e D - DZR 30/2 B Ex e A - DZR 40/6 B Ex e B - DZR 45/6 B Ex e Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 30 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e C - DZR 40/4 B Ex e D - DZR 35/2 B Ex e A - DZR 50/6 B Ex e B - DZR 60/6 B Ex e C - DZR 45/4 B Ex e D - DZR 50/4 B Ex e EZQ/DZQ ... wall-mounted fans E Ex e ■ Single- and three-phase AC versions ■ AC model Not speed-controllable ■ Three-phase AC model. Speed-controllable with transformers ■ Connect the built-in temperature sensor resistor to a tested resistor triggering device. ■ EZQ and DZQ series models with square wall plates. ■ EZS and DZS series models with steel wall ring ■ DZQ and DZS series models: Switchable for ventilation and air extraction ■ We reserve the right to make technical modifications. Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 31 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS
DZD 25/2 B Ex e
Product type Temperature class Rotating speed Air volume: Nominal size
-1 m³/ h mm
min
EZQ 20/4 E E Ex e 1340 440 200
DZQ 20/4 B E Ex e 1485 500 200
DZQ 20/2 B E Ex e 2920 1150 200
DZQ 25/4 B E Ex e 1470 1050 250
DZQ 25/2 B E Ex e 2835 2200 300
DZQ 30/6 B E Ex e 992 1250 300
DZQ 30/4 B E Ex e 1445 1900 300
DZQ 30/2 B E Ex e 2730 3800 300
DZQ 35/6 B E Ex e 985 1850 350
DZQ 35/4 B E Ex e 1390 2800 350
DZQ 35/2 B E Ex e 2750 6000 350
DZQ 40/6 B E Ex e 975 2800 400
DZQ 40/4 B E Ex e 1420 4350 400
DZQ 45/6 B E Ex e 960 4300 450
DZQ 45/4 B E Ex e 1320 6400 450
DZQ 50/6 B E Ex e 920 5700 500
DZQ 50/4 B E Ex e 1360 8700 500
DZQ 60/6 B E Ex e 890 10400 600
Extensive product information (tender text, technical data, prices, etc.) can be found under www.maico -ventilatoren.com.
If you have technical questions, please use our Service Hotline:
Phone: 0 18 05 / 69 41 10
Fax: 0 77 20 / 69 42 39
Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 32
right to make technical modifications without giving prior noticePLANNING INSTRUCTIONS DZD 25/2 B Ex e A - DZQ 20/4 B Ex e B - DZQ 25/4 B Ex e C - DZQ 20/2 B Ex e D - DZQ 25/2 B Ex e A - DZQ 30/6 B Ex e B - DZQ 35/6 B Ex e C - DZQ 30/4 B Ex e D - DZQ 30/2 B Ex e A - DZQ 40/6 B Ex e B - DZQ 35/4 B Ex e Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 33 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e C - DZQ 40/4 B Ex e D - DZQ 35/2 B Ex e A - DZQ 45/6 B Ex e B - DZQ 50/6 B Ex e C - DZQ 45/4 B Ex e D - DZQ 50/4 B Ex e E - DZQ 60/6 B Ex e DZD ... roof fans E Ex e ■ Three-phase AC version ■ Speed-controllable with transformers ■ Horizontal air outlet direction ■ Switchable for ventilation and air extraction ■ Connect the built-in temperature sensor resistor to a tested resistor triggering device. ■ We reserve the right to make technical modifications. Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 34 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS
DZD 25/2 B Ex e
Product type Temperature class Rotating speed Air volume: Nominal size
-1 m³/ h mm
min
DZD 25/4 B E Ex e 1470 820 250
DZD 25/2 B E Ex e 2835 1700 250
DZD 30/6 B E Ex e 992 950 300
DZD 30/4 B E Ex e 1445 1500 300
DZD 30/2 B E Ex e 2730 2900 300
DZD 35/6 B E Ex e 985 1370 350
DZD 35/4 B E Ex e 1390 2150 350
DZD 35/2 B E Ex e 2750 4450 350
DZD 40/6 B E Ex e 975 2050 400
DZD 40/4 B E Ex e 1420 3200 400
DZD 50/6 B E Ex e 920 4000 500
DZD 50/4 B E Ex e 1360 6400 500
DZD 60/6 B E Ex e 890 7100 600
Extensive product information (tender text, technical data, prices, etc.) can be found under www.maico -ventilatoren.com.
If you have technical questions, please use our Service Hotline:
Phone: 0 18 05 / 69 41 10
Fax: 0 77 20 / 69 42 39
A - DZD 30/6 B Ex e
B - DZD 25/4 B Ex e
Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 35
right to make technical modifications without giving prior noticePLANNING INSTRUCTIONS DZD 25/2 B Ex e C - DZD 30/4 B Ex e A - DZD 35/6 B Ex e B - DZD 35/4 B Ex e C - DZD 25/2 B Ex e D - DZD 30/2 B Ex e A - DZD 40/6 B Ex e B - DZD 40/4 B Ex e C - DZD 35/2 B Ex e A - DZD 50/6 B Ex e B - DZD 60/6 B Ex e Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 36 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e C - DZD 50/4 B Ex e The explosion protection document Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 37 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e Sample format for an explosion protection document Within the scope of his duties under Article 4 of the Directive 1999/92/EC, the employer undertakes that an Explosion protec- tion document will be created and kept up-to-date. The Explosion protection document must contain at least the following in- formation: ■ Determining and assessing the risks of explosion. ■ Definition of the measures, in order to achieve the aim of the Directive ■ Definitions of the zone classification ■ Definitions of the design, operation and maintenance of the workplaces and the working and warning equipment used The Explosion protection document must be created before starting the work. It will be updated when significant modifica- tions, expansions or redesigns are made to the workplaces, equipment or work processes. The employer can combine exist- ing danger assessments, documents or other equivalent reports with each other and integrate them into the Explosion pro- tection document. Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 38 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS DZD 25/2 B Ex e Implementation The Explosion protection document must give an overview of the results of the danger assessment and the resulting techni- cal and organisational protection measures for the equipment and its working environment. The following gives you a sample format for an Explosion protection document. It contains points, which are suitable for the representation of the requirements outlined above and can be used to assist you in the formulation of your Explosion protec- tion document. This doesn't however mean that all these points mist be included in an Explosion protection document. It is much more important that the Explosion protection document is adapted to meet your particular operational requirements. Description of the working areas The Explosion protection document includes a description of the working areas where there is a danger through the build-up of explosive atmospheres. The description includes the name of the company and the type of equipment. Employees responsible for the working areas Details of the company's responsible employees with room and telephone numbers. Short description of the constructional and geographical details The constructional and geographical details can be shown graphically, e.g. through floor layouts and space occupancy plans. Emergency and escape routes should also be included. It also makes sense to include details about ventilation equipment and dimensions of windows and doors. Description of the process steps and/or activities The corresponding process should be described in words, possibly in conjunction with a process flowchart. This description should include all the important details about explosion protection: ■ Description of the process steps ■ Description of start-up and shutdown procedures ■ Overview of the layout and operational data, e.g. temperature, pressure, throughput, rotations, equipment. ■ Details of room and equipment ventilation Material data In particular there should be a description of which material could cause the build-up of the explosive atmosphere and under what process-technical conditions this could occur. It makes sense to list those safety parameters that are relevant for explo- sion protection at this stage, e.g. those included in the safety data sheet. Danger assessment ■ Where can an explosive atmosphere occur? ■ Zone classification in words and pictures. This should include a differentiation between the inside of the equipment and its environment. ■ Differences between normal operation, start-up and shutdown and operational breakdowns ■ Procedures to be followed in the case of process or product modifications Technical explosion protection measures This chapter should include the explosion protection measures based on the danger assessment. The basic protection princi- ple should be referred to, e.g. "Avoidance of ignition sources". The responsible person should be named alongside each indi- vidual measure. Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 39 right to make technical modifications without giving prior notice
PLANNING INSTRUCTIONS
DZD 25/2 B Ex e
■ Preventive measures:
■ If the explosion protection concept is based on the preventative measure "Avoidance of explosive atmospheres or
Avoidance of ignition sources", a detailed description of the implementation of these measures is necessary.
■ Constructive measures:
■ If the equipment is to be protected by constructive explosion protection measures, the type, operation and location of
the protection measure should be described.
■ Process control engineering:
■ If process control measures are part of the explosion protection concept, the type, operation and location of the protec-
tion measure should be described.
Organisational measures
The responsible person should be named alongside each of the individual measures.
■ Which work instructions have been created for the workplace or an activity?
■ How is the qualification level of the operator(s) guaranteed?
■ What training is there?
■ How is it guaranteed that the operator(s) wear suitable safety clothing?
■ How are maintenance, test and supervisory work organised?
■ How are areas subject to explosion hazards identified?
Important terms
Extraction
Ventilation at the point of exit, e.g. rim extraction with open containers, to prevent the dispersion of explosive material into the
room.
Combustible materials
Combustible materials are in particular all substances, which can be classified as flammable or highly inflammable. These
can be gases, liquids and dust particles from combustible solid materials.
Detonation
Detonation is an explosion under ideal conditions. The resulting pressure wave spreads out in the supersonic range.
Explosion
An explosion is a chemical process with strong gas and heat development. Oxygen in the air is not necessary for an explo-
sion. It is already present in the ideal relationship in the ignition mixture. Pressure waves with high levels of overpressure are
generated by an explosion.
Potentially explosive atmosphere
A mixture of air or oxygen with combustible gases, vapours, mists or dusts under atmospheric conditions. In the event of igni-
tion, combustion will spread to the entire non-combusted mixture.
Area subject to explosion hazards
A location where a potentially explosive atmosphere may develop.
Version: 2020-08-12 - MAICO VENTILATOREN, www.maico-fans.com - We are not responsible for mistakes or printing errors and retain the Page 40
right to make technical modifications without giving prior noticeYou can also read
