Clothes dryer sensor design

[Bourdon]

I am designing a sensor apparatus to determine the temperature, pressure, mass flow rate, and absolute humidity of the exiting air of a residential electric clothes dryer.

The point of the machine is to determine the drying time of the fabrics being tumble dried. I would like to determine the mass flow rate of the air + water mixture exiting the dryer.

I am having trouble sourcing sensors for this project. I have considered using an automotive MAF sensor or a differential pressure sensor. The MAF solution would be ideal, but I cannot find the voltage/flow correlation for the MAF that I have.

Does anyone have any suggestions on how to determine the flow rate inside of a 4" circular duct?

 

[ivymike]

you could use a venturi with a delta-p sensor

you could use a heated wire and correlate the power required to maintain constant temperature to the airflow (potentially problematic due to lint fouling)

are you trying to simply come up with the correlation for the MAF you already have? If so, why not use a venturi downstream, or a commercially-available airflow meter (try google)?

 

[kchan711]

http://en.wikipedia.org/wiki/Mass_flow_sensor

http://en.wikipedia.org/wiki/Flow_measurement

The two previous links should give you a few ideas for measuring air flow accurately.

Are you trying to improve dryer mechanics/performance or are you trying to determine the drying time of a certain fabric/material? Or both?

Kyle Chandler

http://www.chiefengineering.net

 

[Bourdon]

I am trying to determine the effectiveness of my fabric treatment as a performance enhancer. I want to see if the additive quickens drying time. I have a computer-controlled system for determining water release rate, but it works at room temperature. I want to develop a testing machine for the dryer.