Technical Specifications

Model Type	Flow Rate (CFM)	Dew Point	Explosion Zone	Voltage	Dimensions (mm)	Cert.
EX-RFD-100 Refrigerated	100	-20°C	Zone 1/2	220V/1Ph/50Hz	900×600×1000	ATEX
EX-DSD-200 Desiccant	200	-40°C	Zone 1	380V/3Ph/50Hz	1100×700×1200	IECEx
EX-ADS-300 Adsorption	300	-70°C	Zone 2	380V/3Ph/60Hz	1200×800×1300	ATEX, CE

Explosion-Proof Dryer Types and Their Operating Principles

Refrigerated Explosion-Proof Dryers

Utilizes a closed-loop refrigerant cycle to cool compressed air and condense moisture to a dew point typically between +2°C and -20°C. Well-suited for general manufacturing, pneumatic conveying, and instrumentation supply lines in Zone 1/2 classified areas where ambient conditions are moderate.

Zone 1 / Zone 2 Dew Point: +2°C to -20°C

Desiccant Explosion-Proof Dryers

Employs twin-tower desiccant beds — typically silica gel or activated alumina — alternating between adsorption and regeneration cycles to deliver compressed air at dew points as low as -40°C. Designed for continuous duty in critical process applications within petrochemical plants and mining operations where moisture carry-over is intolerable.

Zone 1 Dew Point: -40°C

Adsorption Explosion-Proof Dryers

Achieves ultra-low dew points down to -70°C using molecular sieve or activated alumina media with heat-of-compression or purge-based regeneration. The preferred solution for instrument air in offshore platforms, subsea controls, and gas analysis systems where trace moisture causes measurement error or equipment failure.

Zone 2 Dew Point: -70°C

Key Features of Explosion-Proof Compressed Air Dryers

ATEX / IECEx Certified Enclosures

All electrical and control components are housed within certified explosion-proof enclosures rated for the applicable equipment group and temperature class, in full conformance with ATEX Directive 2014/34/EU and IECEx international standards.

Anti-Corrosion and Non-Sparking Construction

Pressure vessels and piping components are manufactured from stainless steel or specialized alloys with surface treatments to resist corrosive atmospheres. Internal parts are selected to eliminate ignition risks from mechanical friction or impact.

Automatic Condensate Drain Systems

Timer-controlled or level-sensing automatic drains remove accumulated condensate without operator access to the hazardous zone, reducing maintenance frequency and eliminating the need for manual drain valves in restricted areas.

Integrated Monitoring and Alarm Systems

Built-in temperature, pressure, and dew point sensors feed into a local display panel and optional remote signal outputs. Fault alarms and shutdown interlocks prevent operation under out-of-specification conditions, protecting downstream equipment and personnel.

Modular and Scalable Design

Compact footprint modules with standardized inlet/outlet connections allow installation in space-constrained machinery rooms or outdoor enclosures. Multiple units can be arranged in parallel to match system flow requirements without redesigning the air distribution layout.

Wide Voltage and Frequency Compatibility

Units are available in single-phase 220V/50Hz and three-phase 380V/50-60Hz supply configurations to match regional power infrastructure across international project sites, reducing the need for external transformer equipment.

Dryer Technology Comparison: Refrigerated vs. Desiccant vs. Adsorption

Parameter	Refrigerated	Desiccant	Adsorption
Typical Dew Point	+2°C to -20°C	-20°C to -40°C	-40°C to -70°C
Energy Consumption	Low to Medium	Medium (purge loss)	High (heat-of-comp. variant lower)
Maintenance Interval	Annual refrigerant check	3–5 yr desiccant replacement	3–5 yr molecular sieve replacement
Best Suited For	General pneumatic tools, conveyors	Process instrumentation, packaging	Gas analysis, offshore controls
Explosion Zone	Zone 1 / Zone 2	Zone 1	Zone 2
Continuous Duty Rating	Yes	Yes (alternating towers)	Yes (with regeneration cycle)

Hazardous Industry Applications

Oil and Gas Exploration and Refining

Instrument air and control valve supply in wellhead, separation, and refining units classified as Zone 1 hazardous areas.

Petrochemical Plants

Dry air supply for reactor pneumatics, valve actuators, and analyser shelters where moisture ingress causes process deviation or catalyst degradation.

Underground Mining Sites

Rock drilling rigs, pneumatic hoisting equipment, and ventilation controls operating in coal or mineral extraction zones with methane or dust explosion risk.

Paint and Coating Facilities

Moisture-free atomizing air for spray guns and robotic applicators in booths where solvent vapors create explosive atmospheres throughout the production shift.

Chemical Storage and Warehousing

Purging and blanketing compressed air lines in tank farms and chemical warehouses handling reactive or moisture-sensitive bulk substances stored in explosion-rated buildings.

Offshore Platforms

Topside instrument air systems and subsea control module supply on fixed or floating production platforms, where both marine corrosion and hydro-carbon explosion hazards apply simultaneously.

Frequently Asked Questions

Q1: What distinguishes an explosion-proof dryer from a standard industrial air dryer?

A standard dryer is designed for safe, general-purpose environments and does not carry formal explosion protection certification. An explosion-proof dryer incorporates sealed electrical enclosures that contain any internal sparks or arcs, non-sparking internal components, pressure-rated fittings, and temperature-class-rated materials — all verified by a third-party certification body (ATEX or IECEx). This prevents the dryer itself from becoming a source of ignition in areas where flammable gases or vapors may be present.

Q2: How do I determine which dryer type (refrigerated, desiccant, or adsorption) is appropriate for my application?

Selection is primarily governed by the required pressure dew point (PDP) for your process. Refrigerated dryers are sufficient when PDP between +3°C and -20°C satisfies the application — typically general pneumatics and conveyors. Desiccant dryers are required when PDP reaches -40°C, common for instrumentation and packaging lines. Adsorption dryers producing PDP down to -70°C are reserved for gas analysis, subsea controls, or any process where trace moisture causes measurement error or component failure. Consult your system pressure, flow rate, and ambient temperature alongside the PDP requirement before specifying a unit.

Q3: What do Zone 1 and Zone 2 classifications mean, and which dryer applies to each?

Under the IEC 60079 classification system, Zone 1 is an area where flammable gas or vapor is likely to be present during normal operation, while Zone 2 refers to areas where it is only present in abnormal conditions or infrequently for short periods. Equipment certified for Zone 1 is also safe to install in Zone 2. Refrigerated dryers in this range are typically rated for both Zone 1 and Zone 2. Desiccant models are generally specified for Zone 1 only due to the higher ignition energy present in regeneration cycles. Adsorption dryers in the series are certified for Zone 2 unless specifically upgraded with Zone 1-rated controls.

Q4: What routine maintenance does an explosion-proof air dryer require?

Maintenance requirements vary by dryer type. Refrigerated units require annual inspection of refrigerant charge, condenser coil cleaning, and automatic drain valve testing. Desiccant and adsorption dryers require periodic replacement of the adsorption media (typically every 3 to 5 years depending on inlet air quality and operating hours), along with inspection of switching valves and regeneration heaters. All types should have inlet filters serviced at manufacturer-recommended intervals to protect media and heat exchangers from particulate contamination. Any work inside a classified hazardous zone must comply with site hot-work and permit-to-work procedures.

Q5: Can these dryers be installed outdoors or in marine environments?

Yes, subject to correct specification. Units intended for outdoor or offshore installation are typically supplied with IP55 or higher ingress protection enclosures, stainless steel external fasteners, and epoxy or marine-grade coatings to resist salt spray and UV exposure. For offshore platforms, additional documentation — including material traceability certificates, third-party inspection records, and compliance with platform-specific area classification drawings — is normally required before installation approval. Confirm the operating ambient temperature range with the supplier if the site experiences extremes below -10°C or above 45°C.

Q6: Is a single explosion-proof dryer sufficient for a large compressed air network?

Capacity depends on the total compressed air flow rate of the network. For high-demand facilities, multiple dryer units can be installed in parallel to match peak demand while providing redundancy during maintenance shutdowns. A lead-lag control arrangement — where one unit handles base load and others activate on demand — is common in petrochemical and offshore installations where continuous dry air availability is a process requirement, not merely a convenience. Correct sizing requires knowing the system's maximum flow rate, inlet air temperature, inlet pressure, and required PDP.