P
Hi,
My company builds machines that have hot air dryers. We use a supply blower to push air through an electric heater on its way to the dryer, and we use an exhaust blower to remove heated air from the dryer. The exhausted air contains solvent vapors from the product that we are drying.
One of my requirements on these machines is that I need a means by which I can confirm that the blowers are moving air. I have been doing this by using differential pressure switches. In most cases, I use Dwyer 1910-00 (range: 0.07-0.15 inches WC). I have run into cases where my customer's blower speeds were fairly low and did not create enough of a pressure drop to make the switch change states. In one of these cases, I used a Dwyer 1638-0 (range 0.05-0.25 inches WC).
I am now working on a machine on which my expected air flows might be even lower, and I'm afraid I might have trouble even with the lower range of the 1638-0.
I was wondering if anyone here could recommend a sensor that might give me more flexibility in terms of being able to set it to change states at lower air flows. Ideally, I would like something that could withstand temperatures up to at least 100 degrees C and that would not be adversely affected by solvent vapors. Any advice will be greatly appreciated.
Also, if anyone has had success confirming low air flows using pressure switches, I'd appreciate it you could let me know if there are any "tricks" for maximizing your sensitivity. I have always used air tube to connect the "high" port on my pressure switch to the duct just upstream of my blower, while leaving the "low" port open to atmosphere. If anyone can suggest a different arrangement that might work better, I'd really appreciate it.
Thanks in advance,
Paul
My company builds machines that have hot air dryers. We use a supply blower to push air through an electric heater on its way to the dryer, and we use an exhaust blower to remove heated air from the dryer. The exhausted air contains solvent vapors from the product that we are drying.
One of my requirements on these machines is that I need a means by which I can confirm that the blowers are moving air. I have been doing this by using differential pressure switches. In most cases, I use Dwyer 1910-00 (range: 0.07-0.15 inches WC). I have run into cases where my customer's blower speeds were fairly low and did not create enough of a pressure drop to make the switch change states. In one of these cases, I used a Dwyer 1638-0 (range 0.05-0.25 inches WC).
I am now working on a machine on which my expected air flows might be even lower, and I'm afraid I might have trouble even with the lower range of the 1638-0.
I was wondering if anyone here could recommend a sensor that might give me more flexibility in terms of being able to set it to change states at lower air flows. Ideally, I would like something that could withstand temperatures up to at least 100 degrees C and that would not be adversely affected by solvent vapors. Any advice will be greatly appreciated.
Also, if anyone has had success confirming low air flows using pressure switches, I'd appreciate it you could let me know if there are any "tricks" for maximizing your sensitivity. I have always used air tube to connect the "high" port on my pressure switch to the duct just upstream of my blower, while leaving the "low" port open to atmosphere. If anyone can suggest a different arrangement that might work better, I'd really appreciate it.
Thanks in advance,
Paul