low pressure gas valve
low pressure gas valve
(OP)
hi, i need to find an electric or electronic gas valve for low pressure applications, i need to control by means of a computer, humidity, TEMPERATURE and other parameters
the gas comes from one of those gas cilynders.
regards
killabyte
the gas comes from one of those gas cilynders.
regards
killabyte





RE: low pressure gas valve
What gas?
What exact pressure range?
What exact electrical output?
RE: low pressure gas valve
RE: low pressure gas valve
electric output would fit transducer requirements, it will be in normal air.
it is to develop a huge greenhouse temperature (and others) controller.
on/off valve is not allowed cause i need to control the flow to the heater, so il need to deliver smoothly from 0% to 100%
best
killa
RE: low pressure gas valve
Dan
Owner
http://www.Hi-TecDesigns.com
RE: low pressure gas valve
the gas heater responds to money limitations in order to implement those systems in resource limited environments.
the gas valve is a must. im sure we dont know about it but somewhere it exists. if not we will have to develop such.
best
killa
RE: low pressure gas valve
Mike Halloran
Pembroke Pines, FL, USA
RE: low pressure gas valve
You need:
Test cycles.
Purge cycles.
Delays.
Ignition proving.
Ignition proving.
Flame out detection.
RE: low pressure gas valve
Ignitor proving.
Ignition proving
RE: low pressure gas valve
i think it would be somewhere a valve attached to a small motor to control that.
killa
RE: low pressure gas valve
I don't think that you can throttle a gas burner over a wide range as you are assuming.
Once you've priced propane, you may go back to electricity.
Mike Halloran
Pembroke Pines, FL, USA
RE: low pressure gas valve
I would add:
or blown all the glass out of the greenhouse and settled all claims and wrongful death suits...
RE: low pressure gas valve
Try this site for controllers. They have models that can connect directly to the internet and be monitored and or controlled from computers. Many offer Time Proportional outputs, (Similar to pulse width modulation). I didn't see them today, on a quick check, but these people did offer a dual controller complete with a combined temperature/humidity probe. It was capable of independent control of both Temp. and RH., and the internet option was available.
I would suggest going between pilot light and full flame on a time proportional basis. The heating time constants in a green house don't require close modulating control.
http
yours
RE: low pressure gas valve
Here's another link. Temperature control, Humidity Control, Time proportional Output, PID Control, Internet conectivity, Probe Included.
These people also supply solenoid valves.
http://
No, I don't work for them, but I have had good experiences with their products for years.
Please note the other posts as to not trying to modulate a small heater. If you're using a comercial heater, it will probably have a thermostat control. Replace the thermostat with the output of a time proportional controller. You may have good luck using a timer in series with the valve so that it ignores on times less than about 30 to 60 seconds.
MikeHalloran
If you substitute the term "Time Proportional Control" for PWM you will find this controller is described by your suggestion.
I believe that it can use a PID algorithm to calculate the Time Proportional Value.
yours