Explosion Proof Roots Blower for Chemical Industry

An explosion proof roots blower for chemical industry is designed for operation in potentially explosive atmospheres – where flammable gases, vapors, or dusts are present. ATEX certification (Europe) or Class I/II (North America) is mandatory. Explosion proof blowers incorporate spark-resistant rotors, explosion-proof motors, gas-tight seals, and temperature monitoring.

Based on commissioning experience across chemical plants, refineries, and processing facilities, explosion proof roots blowers are essential for safety in hazardous areas. Non-explosion proof blowers in these environments create explosion risk – and legal liability. Material selection is equally critical – 316L stainless steel for corrosive gases.

This guide covers explosion proof requirements, ATEX certification, material selection, and selection for chemical industry applications.

Table of Contents

• What Is an Explosion Proof Roots Blower for Chemical Industry?

• Hazardous Area Classifications

• ATEX Directive Overview

• Explosion Proof Requirements

• Material Selection – Chemical Service

• Main Components – Explosion Proof Upgrades

• Chemical Industry Applications

• Engineering Advantages

• Selection Guide

• Performance and Engineering Calculations

• Cost Factors and Pricing

• Procurement Considerations

• Frequently Asked Questions

• Final Thoughts

What Is an Explosion Proof Roots Blower for Chemical Industry?

An explosion proof roots blower for chemical industry is a positive displacement rotary lobe machine designed and certified for use in potentially explosive atmospheres with corrosive gases. It combines explosion protection with corrosion resistance – essential for chemical processing.

Explosion proof + corrosion resistant features:

• Explosion-proof motor (Ex d, Ex e, Ex n)

• Spark-resistant rotors (aluminum, bronze, stainless steel)

• 316L stainless steel rotors (corrosion resistance)

• Gas-tight seals (labyrinth with buffer gas)

• Temperature monitoring (T-class)

• ATEX certification (Europe) or Class I/II (North America)

• Grounding and static dissipation

Based on chemical plant installation records, explosion proof roots blowers are mandatory for VOC, hydrogen, solvent, and acid gas handling. Non-certified blowers in these applications are a serious safety hazard.

Hazardous Area Classifications

North America (Class/Division system):

Europe/International (Zone system – ATEX):

Gas groups (ATEX):

Temperature classes:

ATEX Directive Overview

ATEX Directive 2014/34/EU:

• Applies to equipment in potentially explosive atmospheres

• Covers electrical and non-electrical equipment

• Requires certification by notified body

• Mandatory for EU member states

Equipment categories:

For chemical industry:

• Category 2G is most common (Zone 1 gas)

• Category 3G for Zone 2 (less hazardous)

• Category 2D for Zone 21 dust

• Gas group IIB or IIC depending on gas

Explosion Proof Requirements

1. Explosion-proof motor.

• Ex d (flameproof): most common

• Ex e (increased safety): less common

• Ex n (non-sparking): for Zone 2

• Must be ATEX certified for gas group and T-class

2. Spark-resistant rotors.

• Aluminum: lightweight, spark-resistant

• Bronze: non-sparking, higher strength

• Stainless steel: corrosion + spark-resistant

• Cast iron is NOT acceptable for ATEX

3. Corrosion-resistant materials.

• 316L stainless steel for corrosive gases

• Special alloys for severe corrosion

• Epoxy coating for casing

4. Gas-tight seals.

• Labyrinth seals with buffer gas

• Double lip seals with purge

• Magnetic seals (zero leakage)

• Prevent gas leakage to atmosphere

5. Temperature monitoring.

• Thermocouple at discharge

• Automatic shutdown at set temperature

• T-class compliance

6. Grounding.

• All piping and equipment grounded

• Static electricity dissipation

• Grounding straps on flanges

7. ATEX marking.

• CE marking with notified body number

• ATEX classification (II 2G c T4, etc.)

• Equipment identification

Material Selection – Chemical Service

Corrosion-resistant materials:

Chemical gas compatibility:

Main Components – Explosion Proof Upgrades

Rotor (impeller). Most critical. Cast iron not acceptable – sparks + corrosion. Options: aluminum (spark-resistant), bronze (non-sparking), stainless steel (corrosion + spark-resistant). Expected lifespan: 25,000–40,000 hours.

Timing gears. Stainless steel or hardened gears with corrosion-resistant coating. Inspection: backlash annually (0.05–0.10 mm).

Bearings. C3 or C4 clearance. Stainless steel housings. Synthetic lubricant with corrosion inhibitors. Lifespan: 25,000–35,000 hours.

Casing. Stainless steel or epoxy-coated ductile iron. Conductive (grounding). Lifespan: 10–15 years with coating, 20+ with stainless.

Shaft seals. Gas-tight seals mandatory – labyrinth with buffer gas, double lip with purge, or magnetic. Failure: gas leakage creates explosion hazard.

Motor. Ex d (flameproof) most common. ATEX certified for gas group and T-class.

Temperature monitoring. Thermocouple at discharge with shutdown at T-class limit.

Inlet filter. Stainless steel housing. Corrosion-resistant.

Discharge silencer. Stainless steel. Corrosion-resistant.

Chemical Industry Applications

VOC recovery. Recovering volatile organic compounds. Explosion-proof. 316L stainless. Gas-tight seals. ATEX Zone 1 or 2. Category 2G, IIB, T3/T4.

Solvent handling. Moving solvent vapors. Explosion-proof. 316L stainless. PTFE coating for non-stick. Temperature monitoring.

Hydrogen handling. Hydrogen gas – explosive. Class I, Division 1 or Zone 1. IIC gas group (hydrogen). Ex d motor. Gas-tight seals. Special materials for hydrogen embrittlement.

Acid gas handling. HCl, SO2, chlorine. Corrosive + hazardous. Special alloys (Hastelloy, titanium). Explosion-proof. Gas-tight seals. Temperature monitoring.

Tank blanketing. Nitrogen or inert gas for storage tanks. Explosion-proof. 316L stainless. Gas-tight seals.

Pneumatic conveying. Chemical powders, flakes, granules. Explosion-proof for combustible dust. ATEX Zone 21 or 22. Spark-resistant rotors. Dust-tight seals.

Process air. Air for chemical reactors, oxidation. Explosion-proof if flammable. Oil-free air – catalyst contamination. Stainless steel.

Flare gas. Moving gas to flare. Explosion-proof. Stainless steel. Temperature monitoring.

Engineering Advantages

Safety. Explosion proof blowers prevent ignition of explosive atmospheres. Non-explosion proof blowers are not safe for hazardous areas.

Compliance. ATEX certification is mandatory for EU hazardous areas. Non-certified equipment cannot be legally installed.

Corrosion resistance. Stainless steel and special alloys resist chemical attack – essential for chemical service.

Reliability. Explosion proof components are designed for rigorous service. Gas-tight seals and temperature monitoring ensure safe operation.

Debris tolerance. Roots blowers handle particulates and moisture better than other technologies.

Selection Guide

Step 1 – Define ATEX classification.
Zone (0, 1, 2 for gas; 20, 21, 22 for dust). Gas group (IIA, IIB, IIC). Temperature class (T1–T6). Category (1, 2, 3).

Step 2 – Define gas composition.
Corrosive components (HCl, H2S, etc.), temperature, moisture. Material selection depends on gas.

Step 3 – Select rotor material.
Aluminum: general ATEX. Bronze: higher strength. Stainless steel: corrosion + spark-resistant – standard for chemical.

Step 4 – Select motor type.
Ex d (flameproof): most common. Ex e (increased safety). Ex n (non-sparking): Zone 2.

Step 5 – Specify seals.
Labyrinth with buffer gas. Double lip with purge. Magnetic (zero leakage).

Step 6 – Specify temperature monitoring.
Thermocouple with shutdown at T-class limit.

Step 7 – Verify ATEX certification.
Notified body certificate. Current and valid. Matches equipment.

Common selection mistakes:

• Cast iron rotors – spark + corrosion hazard

• Non-ATEX motor – explosion hazard

• Wrong material for gas – corrosion failure

• No temperature monitoring – ignition risk

• Standard seals – gas leakage

• Wrong ATEX category for zone

Cost Factors and Pricing

Explosion proof + corrosion resistant cost (100 HP class, 2026):

Complete ATEX + corrosion resistant package:

• ATEX blower with 316L rotors: $25,000–45,000

• Ex d motor: included

• Stainless silencers: $1,500–2,500

• VFD (Ex d enclosure): $6,000–10,000

• Total FOB: $32,000–58,000

Procurement Considerations

When requesting quotes for explosion proof roots blower for chemical industry:

1. Specify ATEX classification. Zone, gas group, temperature class. Category.

2. Specify gas composition. Corrosive components, H2S, acids. Material selection depends on gas.

3. Require ATEX certificate from notified body. Current. Verify notified body number.

4. Specify spark-resistant + corrosion-resistant rotors. 316L stainless minimum.

5. Specify explosion-proof motor. Ex d, Ex e, or Ex n. Must match ATEX classification.

6. Specify gas-tight seals. Labyrinth with buffer gas.

7. Specify temperature monitoring. Thermocouple with shutdown.

8. Require material certificates. EN 10204 3.1 for stainless steel.

9. Specify grounding. All components grounded. Resistance < 1 ohm.

Red flags when sourcing:

• Cannot provide ATEX certificate from notified body

• Cast iron rotors

• Standard motor (not Ex d/e/n)

• No temperature monitoring

• Cannot provide material certificates

• Unfamiliar with chemical industry requirements

Frequently Asked Questions

1. What is an explosion proof roots blower for chemical industry?
A positive displacement rotary lobe machine certified for explosive atmospheres with corrosion-resistant materials. ATEX certification, spark-resistant rotors, 316L stainless steel, gas-tight seals, and temperature monitoring. Required for chemical plant hazardous areas.

2. What ATEX classification do I need?
Zone 1 (gas): Category 2G. Zone 2 (gas): Category 3G. Zone 21 (dust): Category 2D. Gas group: IIA (solvents), IIB (ethylene), or IIC (hydrogen). Temperature class: T1–T6 (below gas ignition temperature). Consult ATEX specialist.

3. What materials are required for chemical service?
316L stainless steel is standard for most chemical applications. For severe corrosion (HCl, chlorine), specify Hastelloy or titanium. PTFE coating for non-stick. Material selection depends on gas composition.

4. Is ATEX certification required for chemical plants?
Yes – for equipment in potentially explosive atmospheres. ATEX certification (Europe) or Class I/II (North America) is mandatory. Non-certified equipment cannot be legally installed. This is not optional – it is safety and legal compliance.

5. What motors are used for ATEX blowers?
Ex d (flameproof) is most common – motor enclosure can contain internal explosion. Ex e (increased safety) – less common. Ex n (non-sparking) – for Zone 2 only. Motor must be ATEX certified for the gas group and temperature class.

6. What seals are required?
Gas-tight seals are mandatory – gas leakage creates explosion hazard. Labyrinth seals with buffer gas (nitrogen or air). Double lip seals with purge. Magnetic seals (zero leakage). Gas detection recommended.

7. How much does an explosion proof chemical blower cost?
100–300% more than standard blowers. Example: 100 HP standard $8,500–11,000. ATEX + 316L stainless $25,000–45,000. Premium includes Ex d motor, 316L rotors, gas-tight seals, temperature monitoring, and ATEX certification.

8. What is the payback for ATEX?
ATEX is about safety and legal compliance – not payback. Non-ATEX equipment in hazardous areas creates explosion risk and legal liability. The cost of ATEX equipment is justified by safety and compliance.

9. What documentation is required?
ATEX certificate from notified body, Declaration of Conformity, material certificates (EN 10204 3.1), technical file, installation and maintenance instructions, and ATEX marking on equipment.

10. Can I convert a standard blower to ATEX?
Not easily. ATEX requires certified components and notified body certification. Converting requires replacing motor, rotors, seals, adding temperature monitoring, and ATEX certification. More cost-effective to purchase ATEX blower.

11. What is the notified body?
A notified body is an organization designated by an EU member state to assess conformity of ATEX equipment. The notified body issues the ATEX certificate. The notified body number appears on the certificate and CE marking.

12. Can ATEX blowers handle dust?
Yes – dust ATEX available for Zone 21, 22. Requires Category 2D or 3D, dust-tight seals, spark-resistant rotors, grounding, and dust-tight construction. For combustible dust (chemical powders).

13. What are the maintenance requirements?
Regular maintenance is critical – ATEX components must remain in certified condition. Replace seals preventively. Check temperature monitoring. Verify grounding. Inspect rotors for corrosion. Document all maintenance.

14. What is the lifespan of an ATEX chemical blower?
With 316L stainless: 25,000–40,000 hours (3–5 years) in corrosive service. Cast iron fails in 6–12 months. Special alloys last longer. Key factor: corrosion and maintenance.

15. When should I choose ATEX over standard?
Always for hazardous areas. If flammable gases, vapors, or dusts are present – ATEX is mandatory. Non-ATEX equipment is not safe and not legal. For clean, non-hazardous areas, standard blowers are acceptable.

Final Thoughts

After commissioning explosion proof roots blowers for chemical industry applications, here is my practical advice:

Selection logic. For any chemical industry hazardous area, specify ATEX certification with the correct category, gas group, and temperature class. 316L stainless rotors for corrosion resistance. Ex d motor. Gas-tight seals. Temperature monitoring. Zhanggu and other established manufacturers offer ATEX-certified chemical blowers.

ATEX is about safety – not cost. The premium for ATEX + corrosion resistant equipment (100–300% over standard) is justified by explosion prevention and legal compliance. Non-ATEX equipment in hazardous areas creates explosion risk and legal liability.

Material selection is survival. Chemical gases are corrosive. 316L stainless is standard. For severe corrosion, specify special alloys. Material certificates (EN 10204 3.1) required. Monitor gas composition – changes may require material upgrade.

Certification is non-negotiable. ATEX certification from a notified body is required. Request the ATEX certificate, Declaration of Conformity, and material certificates before shipment. Verify documentation.

The bottom line. Explosion proof roots blowers for the chemical industry are mandatory for hazardous areas. Safety and compliance are not optional. Specify correctly. Verify certification. Maintain properly. The blower will operate safely in explosive environments.