Air flow through a high temperature chamber

[Kahuna1965]

I am in need of your genius assistance. I need to measure the air flow inside a chamber where the the temperature is 193C. There is a movable belt that I envision I could sit an instrument on and it is carried through the chamber with a dwell time of ~60 seconds. I don't want to assume that the flow is the same from end to end. The device should be able to log or transmit down the convey. I am able to accomplish this for temperature with a Datatrace probe. I am looking for something similar for airflow. Do you have any suggestions? Thank you for your consideration.

 

[Comcokid]

Not a 100% familiar with this, but it sounds like a measurement problem similar to the data logging needs of reflow ovens for circuit board soldering which can reach up to 260C. Check out the companies and products used in this industry. Usually these devices log temperature, but I would assume some airflow airflow measurement is needed as well.

 

[danw2]

Industrial thermal dispersion (Sierra, Kurz) has standard models rated to 200 Deg C, special models to over 400 Deg C.

I've found ambient temperature thermal dispersion instruments to be direction-sensitive, expecting a fixed up-stream/down-stream flow orientation. Maybe your flow in unidirectional, maybe not. Maybe there's a model that measures angular flow.

Let us know what you find.

 

[itsmoked]

How long is the tunnel?
Is it open at both ends during operation?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[IRstuff]

????? I don't want to assume that the flow is the same from end to end

Where are you assuming that the flow can go to? Unless there are holes in the chamber? Conservation of mass says that gazinta = gazouta; mass flow is conserved.

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[Compositepro]

A Pitot tube is the standard instrument for this type of survey. Since it is just a metal tube the temperature limit is close to the melting point of the metal. The pressure transducers stay outside the oven.

 

[VEBill]

Pitot tube - good idea. One could put the transducers in a little Styrofoam box to protect them for the 60s. Just in case running wires is easier than hoses.

Would one have to correct for (or calibrate for) the density, due to the high 193°C temperature?

 

[Kahuna1965]

Thanks for all the information. I am not familiar with all the suggestions and will have to study a bit to decide what to try and in what order. A question was asked about length. The chamber is 5.5 meters long. The air flow as I understand is top to bottom. The purpose here is to study if product is not running in one channel but in others, how is air flow affected. As well as temp for which I have two devices that takes care of that parameter. Again, I appreciate the input.

 

[IRstuff]

Seems to me that building a 5.5-m tree of sensors, say, one every 10 inches or so, might be more appropriate, since you really need to be seeing the transient as the carrier moves along the tunnel and how the air flows in sections without a carrier. This is not that different that how the first pictures of a moving horse were taken, which was with an array of still cameras.

TTFN
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