Flare gas recovery systems handle gas conditions that must be evaluated before vacuum equipment is selected. Gas composition, suction pressure, capacity, temperature, working liquid and wetted materials all affect the equipment arrangement. Kenflo's CBF Liquid Ring Vacuum Pump is positioned for relatively high-vacuum and/or high-capacity applications, and Kenflo's application references include a flare gas recovery system using a tandem vacuum package. CBF is therefore considered together with the gas conditions and the complete recovery package.

Why Flare Gas Recovery Needs Careful Vacuum Equipment Selection

Flare gas recovery is a special-gas handling duty rather than a simple air vacuum application. Gas composition can include flammable, explosive, toxic or corrosive components, and it may vary with the process. The vacuum pump is therefore evaluated against the actual gas, pressure and capacity requirements.

Kenflo's liquid ring vacuum pump range is described for chemical, pharmaceutical and special gas transfer applications. The product information also identifies flammable, explosive and toxic gases for evaluation. CBF and its package arrangement are selected from the gas conditions and required vacuum duty.

How a Liquid Ring Vacuum Pump Fits the Recovery System

A liquid ring vacuum pump uses a working liquid to create the vacuum required for gas movement. Water is generally used as the working liquid in Kenflo's liquid ring vacuum pump information. In a flare gas recovery package, CBF is evaluated together with the gas path, working-liquid management and auxiliary equipment.

CBF application information refers to a flare gas recovery system with a tandem vacuum package. This shows how the pump can be integrated into a packaged recovery system; the package arrangement is selected from the required suction pressure, capacity, operating pattern and site conditions.

CBF Capacity for High Vacuum or High Capacity Duties

CBF is described as suitable for relatively high-vacuum and/or high-capacity conditions. Kenflo lists a suction pressure range of 160–1013 mbar(A) and a capacity range of 35–1600 m³/min. These values provide a starting point for evaluating the required flare gas recovery duty:

The listed CBF ranges are used with the gas load, pressure, temperature and site conditions to select the model and package arrangement.

Gas Conditions That Affect Pump Selection

The gas data should be prepared before the pump is selected. Important inputs include gas composition, suction pressure, required capacity, gas temperature, moisture or condensable content, corrosive characteristics, flammable or explosive properties and toxicity. The operating pattern and the consequence of an unplanned shutdown are also relevant to the package arrangement.

Working Liquid and Closed Circulation

Water is generally used as the working liquid for Kenflo liquid ring vacuum pumps. For a CBF flare gas recovery package, working-liquid temperature, cooling and consumption are part of the system review. Kenflo's product information supports closed circulation with a heat exchanger, which can be considered when the package needs to control water loss and working-liquid conditions.

The circulation arrangement is selected according to working-liquid quality, cooling, make-up, filtration, drainage and maintenance requirements. Closed circulation with a heat exchanger is one available approach when the package needs tighter control of working-liquid conditions.

Materials for Flare Gas Recovery Service

CBF lists carbon steel plus cast iron, SS304, SS304L, SS316L and duplex stainless steel for wetted end parts. The wider liquid ring vacuum pump range also identifies titanium alloy and Hastelloy among available material options. Material selection should follow the actual gas composition, working liquid, temperature and corrosion conditions.

The word flare does not identify one universal material arrangement. Gas components, water chemistry and temperature may lead to different requirements. The final material configuration should be confirmed from the process data and selected package.

Single Pump, Tandem Package or Complete Vacuum System

A flare gas recovery project may require a single liquid ring vacuum pump, a tandem vacuum package or a broader system with auxiliary equipment. CBF application information identifies a tandem vacuum package for a flare gas recovery system. Kenflo also provides liquid ring vacuum packages for chemical process systems, which can be reviewed when the project requires more than the pump unit itself.

The configuration should be based on suction pressure, gas capacity, operating continuity, working-liquid management and available site utilities. Pump count, standby philosophy and control logic should be confirmed in the project specification.

How to Evaluate a Flare Gas Recovery Vacuum Pump

A useful inquiry should contain the following information:

• Gas composition and hazardous characteristics

• Normal and upset suction pressure

• Required gas capacity

• Gas temperature and condensable content

• Corrosion, flammability or toxicity risks

• Working-liquid type and cooling conditions

• Wetted material requirements

• Open or closed circulation preference

• Single-pump, tandem-package or complete-system requirement

• Site conditions and continuous operating requirements

This information lets the manufacturer compare the real duty with the pump capacity, suction pressure range, materials and package arrangement.

Installation, Commissioning and Maintenance

Installation should account for the pump, piping, working-liquid circuit and auxiliary equipment as one system. Confirm the available maintenance space, safe isolation points, working-liquid supply and cooling path. Before start-up, check valve positions, rotation, liquid level and the expected suction conditions.

During commissioning, record suction pressure, gas capacity, working-liquid condition, temperature, vibration and motor current where applicable. These records provide a baseline for later maintenance.

FAQ

Can liquid ring vacuum pumps be used for flare gas recovery?

Yes. Kenflo's CBF application information identifies a flare gas recovery system using a tandem vacuum package. CBF is also described for relatively high-vacuum and/or high-capacity conditions and for special gas transfer duties. The required model and package are matched to the gas composition, suction pressure, capacity, temperature and materials.

What CBF capacity and suction pressure ranges are available?

CBF is listed with a suction pressure range of 160–1013 mbar(A) and a capacity range of 35–1600 m³/min. These values are CBF product information and must be checked against the actual flare gas recovery duty.

What working liquid is used in a liquid ring vacuum pump?

Water is generally used as the working liquid. The project should still confirm working-liquid quality, cooling, circulation, make-up and drainage requirements. Closed circulation with a heat exchanger can be considered when the system needs to manage working-liquid conditions.

Which materials are available for flare gas recovery vacuum pumps?

CBF lists carbon steel plus cast iron, SS304, SS304L, SS316L and duplex stainless steel for wetted end parts. The wider liquid ring vacuum pump range also lists titanium alloy and Hastelloy. The final material selection depends on gas composition, working liquid, temperature and corrosion conditions.

What information should be provided before selecting a flare gas recovery vacuum pump?

Provide the gas composition, suction pressure, required capacity, gas temperature, condensable content, hazardous or corrosive characteristics, working-liquid conditions, material requirements, site utilities and the preferred package arrangement. These data support a configuration review against the real duty.

Planning a Flare Gas Recovery Vacuum System

Before requesting a quotation, prepare the complete gas and vacuum data and define the required package boundary. Confirm the suction pressure, capacity, materials, working-liquid system and site conditions together. Then determine whether the project needs a single pump, a tandem vacuum package or a complete vacuum system. This gives engineering and procurement teams a consistent basis for technical evaluation.

Conclusion

Kenflo's CBF Liquid Ring Vacuum Pump is positioned for relatively high-vacuum and/or high-capacity duties, and Kenflo's application references include a flare gas recovery tandem vacuum package. CBF is listed with a suction pressure range of 160–1013 mbar(A) and a capacity range of 35–1600 m³/min. The pump and package are selected from the actual process conditions.