Vapor Flow Control

Vapor Flow Control

Our unique and patented 'CEM' technology, which stands for Controlled Evaporation Mixing, is developed for accurate vapor flow control. Traditional bubbler systems are often not capable of handling sufficient quantities of liquid with a low vapor pressure, or perform in an imperfect way. Moreover, they cannot instantaneously provide vapor of a mixture of liquids with different vapor pressures. These issues are overcome with our vapor delivery solutions.

Bronkhorst's evaporation technology is fast, accurate, highly repeatable and efficient.

CEM-Technology: Controlled Evaporation Mixing

The CEM-System (Controlled Evaporation and Mixing) is an innovative Liquid Delivery System (LDS) that can be applied for atmospheric or vacuum processes. The vapor generation system consists of a (thermal or Coriolis) liquid flow controller, an MFC for carrier gas and a temperature controlled mixing and evaporation device. The system is suitable for mixing liquid flows of 1-1200 g/h resulting in saturated vapor flows of 50 mln/min up to 100 ln/min. This vaporizer system can replace bubblers. New opportunities created with the CEM-system: mixtures can be evaporated and even solids, dissolved in solvents can be vaporized successfully.


  • Accurately controlled gas/liquid mixture
  • Fast response
  • High reproduceability
  • Very stable vapor flow
  • Flexible selection of gas/liquid ratio
  • Lower working temperature than conventional systems
  • Optional control by PC/PLC (RS232/fieldbus)

Video Vapor Delivery Modules

In this video, we present our all-in-one solution for an accurately controlled vapor flow, providing fast response and high flexibility: The VDM-Series Vapor Delivery Modules.

Vapor Delivery Module

VDM-Series: Vapor Delivery Modules

Based on the CEM-technology as described above, we designed a new series of Vapor Delivery Modules. These compact sub-systems incorporate the components of the CEM-System and more! Besides gas and liquid flow controllers and the temperature controlled evaporator, the VDM-Series feature integrated power supply with display (1.8” TFT) and control functions. As an option, the unit offers local or remote trace heating temperature control. The compact, ‘plug and work’ module can generate (saturated) vapor flows within the range of 100 mln/min up to 10 ln/min. It can be applied for atmospheric or vacuum processes and is capable of evaporating mixtures and even solids, dissolved in solvents.

Additional features (compared to separate CEM system components)

  • No need for engineering or manufacturing
  • Pre-tested, safe and ready to use
  • Readout/Control panel, incl. 1,8” TFT display, alarm/signaling and counter functions.
  • Integrated fieldbus interface (option)

Vapor Control Applications

  • CVD (Chemical Vapor Deposition), e.g. for hardening, thin film coating or planarization processes
  • Testing/calibration of analyzers with reference gas vapor concentrations
  • Toxic gas effects on protective clothing
  • Analyzers with reference H2O vapor concentrations
  • Humidification of fuels
  • Anesthetics
  • Sorption experiments or processes in pharma or food applications

Application stories



CEM and VDM brochure: Solutions for Vapour Flow Control
Manual CEM Controlled Evaporator and Mixer
Manual Vapor Delivery Module

Select your model

Model Description Max. capacity (based on water) Max. capacity Max. temp.
W-101A 10 W, for µ-FLOW 2 g/h Liquid 4 ln/min Gas 200°C
W-102A 10 W, for LIQUI-FLOW™/ mini CORI-FLOW™ 30 g/h Liquid 4 ln/min Gas 200°C
W-202A 100 W, for LIQUI-FLOW™/ mini CORI-FLOW™ 120 g/h Liquid 10 ln/min Gas 200°C
W-303B 1000 W, for LIQUI-FLOW™/ mini CORI-FLOW™ 1200 g/h Liquid 100 ln/min Gas 200°C
SW-100 10 W, VDM-Series 30 g/h Liquid 4 ln/min Gas 200°C
SW-200 100 W, VDM-Series 120 g/h Liquid 10 ln/min Gas 200°C