Calculating Damper Torque for an actuator

[MechEng92]

I'm trying to calculate the maximum torque on a damper to select an actuator. The damper will be made in-house so there are no manufacturer damper torque ratings. Is there a method to calculating the maximum torque of the damper in operation without using a damper torque rating?

Also this is for a single blade damper with the pivot point at the end of the blade, most manufacturer websites only have information for multi-blade dampers.

Thanks in advance.

 

[DRWeig]

May not apply to you since I can't visualize your damper but here are rules of thumb per square foot of damper:

http://www.kele.com/templates/content.aspx?id=6442462341

Best to you,

Goober Dave

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[MechEng92]

The damper I am designing is similar to a lid of a box pivoting at one end. The damper will be designed to block air paths to direct the flow of air to one of two paths. So far all I have is the torque of the damper is equal to half the damper length multiplied by gravity and mass of the damper when the damper is at its lowest point. T = L/2 x g x M.

I'm not sure if this is right for my application however. And how to account for forces acting on the damper from air velocity.

 

[dynamo78]

I guess the best bet is: If you are fabricating that damper, then do it, assemble as it is then make a contraption to measure the torque yourself, when the pull is established, you can calculate the required motor/actuator power requirement and then look for an actuator that satisfies your requirement. that's not complicated I think.But that's just me an ordinary blogger.

 

[MechEng92]

I agree that does seem like an appropriate method, however I'm unsure if my company's testing facility has the time to dedicate someone to carry this out with much higher priority tasks at hand. I was hoping for a theoretical method :/

 

[dynamo78]

I thought you are designing and fabricating the damper? if you are, then you know the size and weight. from that you can visualize where the actuator will be, like is it shaft mounted,like the Belimo? or being pulled or pushed by a rod all you need is an engineering aptitude. But again I am just a handyman.

 

[MechEng92]

I have a rough idea of the size, calculated the weight, calculated the Torque as if it were a beam supported at one end (where the actuator will clamp on to the shaft) but I would assume I'd need to factor in forces on the damper blade from air velocity?

Unfortunately we don't have the time or resources to plan a test for this, it's very much in the stage of getting a complete prototype unit built as soon as possible so I'd like to size the actuator now based on theoretical calculations rather than test results.