Fully automated mixing valve for a targeted quality control with simultaneous control of the flow volume capacity. The application area of the ZDM mixing valve is where gases  with varying calorific values will be mixed to archieve a gas mixture at the valve outlet of constant quality for using it in a downstreaming combustion process.

Biogas & Landfill gas, Glass trough heating, Steelworks
Application areas
  • Combustion processes in furnaces and boilers
  • Feed-in into the natural gas distribution system, e.g. as biomethane
  • Thermal processes for exact temperature control
Nominal size: DN 50 to DN 400
Operating pressure: PN 6 – PN 25
Flow control range: 1 : 30
Mixing ratio: 50 : 50 to 20 : 80
Operating temperature: max. + 200°C

  • Immediate availability of the gas quality individuell selected
  • Highly constant quality of the gas mixture

  • Exact gas quality control

  • Flow control range 1:30

  • Short reaction times when changing the gas injection
  • Compact design
  • Precise flow and quality control for targeted setting of the calorific value or the Wobbe index
The positioner controls the corresponding valve position against the force of the closing spring. The vertical movement opens the defined flow cross sections determined by the control plug and allow the gases to flow into the valve (flow control).
The calorific value of the gas mixture is subsequently optimised further by another rotary motion of the control plug, determined by the quality control. This sets the proportion of the two gases.
The integrated static mixer ensures a homogeneous mixture of both gases for downstream processes.

Technical features
Valve body: Compact welded steel construction with two entry flanges and one discharge flange
Seat sealing system: Sealing of the stem by elastomere sealing rings without stuffing box
Actuator type:
  • Integrated pneumatic KÜHME piston control actuators for axial- and rotary movements.
  • Optionally: electrical drives for axial- and rotary movements
  • Optionally: combined integrated pneumatic KÜHME piston control actuator and electrical drive for axial and rotary movements
Process connection: Flange connection in acc. to DIN/EN or ANSI