Process Control
Power Applications
In all power plant types, there is a continuing need for upgrading of existing final control elements. In many cases installed damper, valve and actuator designs are not able to provide the reliable performance or precise control required for plant operation. Exlar’s new technology is now available for various power plant valve applications that offer significant cost savings related to extended life and improved control.
Turbine engineers have been utilizing the advantages of Exlar actuators for years with the replacement of hydraulic actuators for governor valve control with Exlar electric. Advantages include improved frequency control, faster start-up, less maintenance and the elimination of hydraulic oil and all of its nuances such as filters and pumps. Exlar offers linear forces from 0 to 100,000 lbs.
In addition to the replacement of the main governor actuator, Exlar is also used for pilot valve applications where the replacement of the main hydraulic is not feasible. With this application the effects of stiction, friction, and hydraulic reaction forces acting on the spool valve are greatly reduced, leading to increased sensitivity. With the reduced dead band, the high static and dynamic control accuracy can be better than 0.02 percent.
In other areas of the plant, Exlar actuators are the perfect choice for utilities who are seeking the best heat rate or efficiency. Replacement of high maintenance traditional electric or hydraulic actuators is one place to start.
A few examples include injection spray valve actuators, pressure control actuators, boiler bypass and soot blower actuators. Many of these valves need to operate close to the valves seat. It is very difficult to get fast response to small signals to obtain the precise control required when using conventional actuator technologies. With the high stiffness and precise closed loop feedback available with an Exlar actuator, control down to the smallest flow rate is possible even with high pressure differentials. Exlar also has valve seat technology to assure a tight shutoff for retrofitted valves as well as new installations.
As clean air regulations become more stringent, many plants rely upon low-NOx burners within their boilers. These burners rely upon accurate control of the combustion air to achieve the required NOx reduction. Controlling combustion air is achieved through precise control of multiple dampers. Many older units operate with damper drives that are not responsive to small input changes. Exlar has the capability of controlling dampers with extreme precision in a very robust package that reduces maintenance by 90% compared to other technologies.
In addition to secondary air dampers, Exlar is also an excellent choice for ID and FD dampers, Burner tilts, scrubber dampers, and burner turbulators.
Tritex Actuators for Process Control Brochure
Exlar in Action Industrial Turbine Pilot Valve
Exlar in Action Coal Diverter Gate
Exlar in Action Fish Diverter Doors