VariFuel2/VariFuel2+ Air/Gas Mixers

MOTORTECH´s VariFuel2 is a high-tech variable Venturi type air/gas mixer that can constantly adjust to any fuel changes and allows the engine to operate at its most efficient point. Series 100, 140, 200, 250, 300 and 350 are available for engines with an air requirement up to 12,000 m3/h. Coupled to an air/fuel ratio controller, lean-burn or stoichiometric, it precisely regulates the mixture. The VariFuel2 is very popular for applications with constant changes in calorific value of fuel.

VariFuel2 air/gas mixers are equipped with a high precision stepper motor which is extremely precisely actuated by the VariStep3 stepper motor driver. Different flow bodies and variable gas inlet and mixture outlet configurations allow flexible adaptation of the gas mixer to the respective application.

Varifuel2 and VariFuel2+ air/gas mixers are suitable for a wide range of gas types:

  • Natural gas
  • Biogas
  • Landfill gas
  • Sewage gas
  • Wood gas
  • Wellhead gas
  • Mine gas

Basic Design

The main task of a gas mixer is to mix the fuel (gas) and air in such a way that optimum combustion takes place in the gas engine. High efficiency and low emissions, in accordance with current regulations, are the decisive parameters for optimization.

In the VariFuel2, air and gas are mixed according to the Venturi principle. The air is sucked through the air intake into the Venturi nozzle by the suction vacuum of the engine. Due to the Venturi principle, a vacuum is created at the narrowest point, which sucks the gas through the gas inlet. In this way, gas and air are mixed and released at the mixture outlet. Various mixer sizes and flow bodies (1) in the Venturi nozzle allow different volumetric flows to be achieved.

Regulation of the Air/Fuel Mixture

The fuel (gas) is guided into the nozzle via the adjustable openings (2) in a fuel ring (3). The openings of the fuel ring are adjusted by a drive belt (4) via a stepper motor. The stepper motor (5) can be controlled by the VariStep3 stepper motor driver, which can process the signals of a master control. In addition, the VariFuel2 air/gas mixers are equipped with a port for an air pressure gauge and a connection for the pulse line of a zero pressure regulator.

VariFuel+ air/gas mixers are specially designed for use with natural gas-powered gas engines and are based on the general operating principle of the VariFuel2 series. The geometry of the built-in fuel ring, adapted to the application, ensures improved engine starting behavior and control of the air/gas mixture in natural gas operation.

Downloads

  • Sales Flyer VariFuel2
    Sales Flyer VariFuel2  (2 MB)
  • Sales Flyer VariFuel2 Belt Tension Tool
    Sales Flyer VariFuel2 Belt Tension Tool  (503 KB)
  • Sales Flyer VariFuel2 Repair Kits
    Sales Flyer VariFuel2 Repair Kits  (698 KB)
  • Sales & Service Bulletin Isolation Amplifier for VariFuel2/EmCon5
    Sales & Service Bulletin Isolation Amplifier for VariFuel2/EmCon5  (511 KB)
  • Sales & Service Bulletin Stepper Motor Harness
    Sales & Service Bulletin Stepper Motor Harness  (312 KB)
  • Operating Manual VariFuel2
    Operating Manual VariFuel2  (2 MB)
  • Instruction Leaflet VariFuel2 Troubleshooting Guide
    Instruction Leaflet VariFuel2 Troubleshooting Guide  (96 KB)
  • VariFuel2 Dimensioning Data Sheet
    VariFuel2 Dimensioning Data Sheet  (596 KB)

Accessories