Diverter dampers are used to divert the flow of gas from one outlet to another. While any two dampers can divert flow, diverter dampers are particularly suited to this purpose. Diverter dampers are useful and necessary for a variety of industrial processing applications.
Diverter Damper Basics
Diverter dampers are simple tools that can provide effective results. The diverter damper’s frame is a large piece of ducting with a branch in it, and it has to have reinforcement so its seal seats will retain flatness at temperatures nearing 900°F.
The tool’s blade is designed to provide stiffness for tight sealing and flutter resistance. The mounting of the blade is at the duct top and its aperture edge is furthest away from the hot gas to allow for upstream pressure that helps tightly seal the blade.
The diverter damper provides several types of seals. One is a rolled-up inconel fiber sheet—or a tadpole-type gasket—that is created by the closing blade. So that the gasket doesn’t compress beyond the desired shape, the blade strikes a metal bar stop before compression. The gasket surrounds the exit port and leaves clearance along the duct wall for the blade to swing without hindrance.
In a straight duct, the swinging blade damper can also act as a bypass damper for flue gas desulfurization work.
Advantages of Diverter Dampers
A diverter damper might be your preferred choice for diverting gas flow over two regular dampers. Here are a few of the benefits of diverter dampers:
- They can withstand high temperatures.
- There is a low pressure drop across the open damper.
- Erosive particles don’t impact its surface because the blade is located out of the gas stream.
- The blade can be insulated to temper the effects of condensation.
- Flow modulation can be easily adjusted.
- Their seal air requirements are lower than with louver types.
- They have good isolation.
Disadvantages of Diverter Dampers
While the advantages likely outweigh the disadvantages, diverter dampers also have some problems that you should consider. Here are a few of the cons:
- They require a large side of the frame and drive.
- Their movement is slow.
- They don’t have much experience in coal-fired boiler applications.
- They are often more costly than louver- or guillotine-type dampers on a per-unit basis.
- Their attitude sensitivity is higher than for the louver-type dampers.
- The blade flutters when moving across the flow or splitting the flow between outlets.
- Their linkages are exposed to flue gas.
Gas Flow Diverting Damper
A gas flow diverting damper is another choice if you’re looking for solutions for gas flow diversion in bypass systems. This type of damper is commonly used in gas/turbine-combined cycle plants.
Used for alternate isolation, a gas flow diverting damper is a three-way damper that can replace two guillotine or louver dampers. Because only one actuator system is required, the gas flow diverting damper is cost effective, simplifies flow controls, and prevents improper isolation. Like other types of diverter dampers, the gas flow diverting damper’s frame requires reinforcement for seal seats to retain flatness at high temperatures.
If you’re looking to introduce diverter dampers to your operation, contact Streamline Industries. For close to 20 years, we’ve been making custom damper valves made to fit many different applications. We can also replace or repair your existing dampers. Our experienced professionals are all skilled in helping you pinpoint your machinery problems and finding you workable solutions.