Rotary and Linear Drives for Damper Control on Combustion Air and Flue Gas Applications

Pneumatic vane damper drive, one of several
variants available.
Image courtesy Rotork

Combustion air and flue gas damper drives fill a critical role requiring safety, accuracy and reliability above all else. It is critical to deploy the best drive technology to maximize combustion efficiency, minimize emissions and reduce installation costs.

Damper Operator (Drives) Types :

Damper drives can be one of three types: pneumatic, electric, or electro-hydraulic, as described below.

• Pneumatic. These damper operators are used whenever controls rely primarily on compressed air (pneumatic) for moving operators.
• Electric. These damper operators are used whenever controls rely primarily electricity as the power source.
• Electro-hydraulic. These damper operators are the same as the electric type described above, but also have a hydraulic system to position the damper.

A very important part of damper design is determination of damper torque, and sizing and selection of the damper actuator for the maximum torque. Actuator torque should be selected to provide the maximum torque required to operate the damper as well as to provide margin and allow for degradation over the life of the damper. Actuators should be evaluated for damper blade movement in both directions, at the beginning of blade movement, and while stroking blades through the full cycle of movement.

The Goal for Selecting the Best Drive Technology:

Reduced emissions, lower fuel consumption and improved boiler draft control.

Ways to achieve this goal:

• High speed continuous modulation of ID/FD fan and inlet guide vanes 
• Improved modulation and control of secondary air dampers 
• Improved automation and burner management 
• Quick response to plant demand 
• Improved reliability in high temperature environments 
• Precise damper and burner positioning 
• Simple commissioning and diagnostics 
• Low running costs, virtually maintenance free 
• Pneumatic, analog and bus network communications 

For more information, share your requirements and challenges with combustion experts. The combination of your facilities and process experience and knowledge with their application expertise will yield an effective solution.