Centrifugal Blowers for Oil, Gas and Refineries: Process Heater Combustion Air and Cooling

Oil, gas, and refinery sites are heavy users of process heater combustion air, cooling systems, and building ventilation, and they are also some of the most hazardous-area-sensitive sites in industry. Almost every classified process area needs equipment rated for its zone, and this is the industry where the boundary between what a standard blower can do and what a specialist ATEX supplier must provide matters most. This page sets out both sides clearly.

Where Blowers Fit

Duty	Typical pressure	Notes
Process heater and furnace combustion air	High	Fired heaters, reformers, boilers
Cooling systems (process gas coolers, SCR skids)	Medium to high	Often duty and standby pairs
Building and control room ventilation	Low to medium	Non-classified buildings
Pump house and compressor house ventilation	Low to medium	Heat removal, dilution of small releases
Battery room and utility ventilation	Low to medium	Classified if hydrogen is released
Process gas at classified locations	Any pressure	Needs a specialist ATEX supplier

Process Heater Combustion Air

Fired heaters and process furnaces need combustion air blowers sized from the fuel input, in the same way as any combustion duty.

Worked example. A process heater has a fuel input of 15 MW, about 12.9 million kcal/h. With 15% excess air, required air is about 17,505 Nm³/h, or roughly 18,790 m³/h at 20 °C, about 5.22 m³/s. If the burner and ductwork need 250 mm WC (2,452 Pa), air power is about 12.8 kW, and at 70% efficiency the blower needs about 18.3 kW at the shaft. This is a standard combustion-air duty, well within our range, provided the blower and its motor sit outside any classified zone. See combustion air.

Where This Industry’s Hazard Boundary Really Matters

Refineries and gas plants have more classified area than almost any other industry we serve. Most process units, tank farms, loading areas, and much of the pipe rack are zoned for flammable gas or vapour. NextAir Systems does not currently manufacture ATEX-certified or AMCA 99 spark-resistant blowers, so any blower and motor that would sit inside a classified zone, or that would handle flammable gas or vapour directly, needs a specialist supplier. A standard blower from us is only appropriate for a position confirmed as outside any classified zone, handling air or gas that is not explosive, such as an administration building, a non-classified control room, or a heater’s combustion air intake drawing from a non-classified area. Confirm the zone with your hazardous-area study before specifying, and tell us where the blower sits relative to it. See combustible dust and hazardous atmospheres.

Process Cooling Skids

Refineries and gas plants cool process gas ahead of catalysts, filters, and emissions-control equipment, often on duty and standby skids so a single blower failure does not interrupt the process. See cooling air.

Building and Non-Classified Ventilation

Administration buildings, non-classified control rooms, and workshops need ordinary ventilation and cooling, sized in the standard way and outside the hazardous-area constraints that apply elsewhere on site. See ventilation and exhaust.

Pump Houses and Compressor Houses

Many pump and compressor houses handle hydrocarbons and are classified, so their ventilation typically falls to specialist equipment. Where a pump or compressor house is confirmed non-classified, standard ventilation applies, sized to remove heat and dilute any small releases, sweeping from clean areas toward the dustiest or most exposed point.

Battery Rooms and Utility Areas

Battery rooms can release hydrogen and are often classified for that reason, needing specialist equipment as above. Utility buildings away from process units are typically non-classified and use standard ventilation and cooling.

Corrosive and Sour Service

Where a non-classified duty still involves corrosive or sour gas, such as some cooling and combustion-air applications near sour service units, material selection for the specific gas and concentration matters. See fume extraction and scrubber systems for the general approach to corrosive and wet gas handling.

Documentation and Vendor Approval

Refinery and gas-plant projects typically run under strict vendor-approval and documentation processes, even for equipment outside classified areas. Expect to provide material certificates, performance curves based on recognised test standards, and a clear statement of the zone the equipment is rated for, even when that statement is “non-classified only.” Agree the acceptance basis, including the pressure basis and gas density, before ordering, and keep the boundary between what we supply and what a specialist ATEX vendor supplies clearly documented in the project’s equipment list, so it is not lost between engineering, procurement, and site installation. See blower performance testing.

Where Our Range Fits

NextAir Systems manufactures centrifugal blowers up to 800 HP (about 597 kW) and up to 500 mm WC (about 4.9 kPa) static pressure, with backward-curved and forward-curved wheels. That covers process heater combustion air, process cooling skids, and building ventilation confirmed to be outside classified zones. Any blower for a classified hazardous area, or handling flammable gas or vapour directly, needs a specialist ATEX supplier, and we will say so plainly rather than force a selection.

What to Specify

1. Duty: combustion air, process cooling, or building ventilation.
2. Zone classification of the blower’s location, confirmed by the site’s hazardous-area study.
3. Airflow and resistance, at clean and worst-case conditions.
4. Gas conditions, including any corrosive or sour content.
5. Redundancy requirement for critical cooling duties.
6. Control approach and noise limits.

Confirm the Zone Before You Specify the Blower

Send your location, its zone classification, and your duty, and we’ll tell you plainly whether a standard blower suits it. Contact us for a free quote.

Frequently Asked Questions