Thanks!
Monotube Flash Boiler Design
- Thread starter Toymaker
- Start date
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K2, you were right about back pressure from steam production impacting the flow rate !! I just needed to get the boiler to over 80% power before the dial pressure guage on the feed pump moved enough to be noticed. Below left is the feed pump guage while the pump is pumping tap water through the boiler with the burner turned off, ie no steam production in the boiler. Below right shows the same guage with the boiler just over 80% power setting, making lots of steam. The right guage shows about 30 to 40 psi back pressure from steam production. That's certainly enough back pressure against the pump to allow me to measure a false, higher flow rate, once the boiler was turned off.
My friend, you need a new gauge. The pressure range you want to measure should fall with the two thirds to one third of the middle of the gauge.
Measuring your back pressure with that gauge is not giving you meaningful data...
Measuring your back pressure with that gauge is not giving you meaningful data...
Fair enough!Sometimes, you use what you got
Edit: What's the availability of stuff like gauges where you are? Can you walk into a hardware store and pick one up or do you need to order it? Genuinely asking.
Thailand has numerous hardware stores, much like the big-box stores found in the US (Home Depot) and carry mostly home-use items. Stores that carry hardware for builders like me, are typically mom-&-pop stores that carry a mixed bag of items,...one store may have what I want, but I need to go to the store, in person, to find out if they actually do have what I'm looking for. Sometimes I get lucky and the store has what I need, but mostly, I end up ordering my parts online.
I'm using the 0 to 1000 psi guage mounted on the feed pump because 1000 psi is the max pressure I intend to never exceed in the boiler, and 400 to 600 psi will be the likely working range. I never intended to use that guage to read pressures as low as 50 psi. The pressure sensors on the boiler input and output have both been plagued with so much noise that pressure readings bounce around +/- 25 psi, rendering them useless to read 30 or 40 psi.
