How to perform gas flow detection

sfcsdc

How to perform gas flow detection [Copy link]

The purpose of detecting the gas flow is to detect the working status of the speed-regulated suction pump.

The rotation speed is adjusted to maintain a stable flow rate in different environments.

The pump used draws air through a plastic tube.

How can I detect the gas flow rate? Does anyone have any good solutions?

chunyang

Gas flow meters are readily available, so just buy the right one according to your needs. If making your own is unrealistic, there is no need to spend energy in this direction.

chunyang

For some flow controls, the controlled quantity is pressure. When the flow corresponds to pressure, it is simpler, cheaper and more responsive to control the flow based on pressure.

蓝雨夜

Air flow meter in car

sfcsdc

chunyang posted on 2020-9-3 16:08 Gas flow meters are readily available. Just buy the right one according to your needs. It is unrealistic to make your own, so there is no need to spend energy in this direction.

The pump I am using has speed feedback. Can the speed be used to represent the relative size of the flow rate?

If a gas pressure sensor is used, should the sensor be placed in the middle of the gas path? Will gases with different flow rates produce different pressures?

maychang

sfcsdc posted on 2020-9-3 17:05 The pump I use has speed feedback. Can the speed represent the relative size of the flow rate? If a gas pressure sensor is used, is it necessary to put the sensor...

There are many kinds of air pumps, including plunger pumps, turbine pumps, centrifugal pumps, diaphragm pumps...

For some types of air pumps, the flow rate is strictly related to the speed, but for some air pumps, the flow rate and speed are less correlated.

blade365

Gas flow is generally measured using pressure difference

liyancao001

There are many principles for measuring gas flow. The cheaper and more commonly used ones are differential pressure flowmeters, and there are also vortex flowmeters, etc. Of course, the rotational speed can also be used, but the rotational speed should be much worse in terms of anti-interference and error.

sfcsdc

liyancao001 Published on 2020-9-3 18:00 There are many principles for measuring gas flow. The cheaper and more commonly used ones are differential pressure flowmeters, and there are also vortex flowmeters, etc. Of course, the speed can also be used, but...

But I am not measuring the flow rate of the pipeline. I am just using a micro pump to pump air through a small plastic tube to detect the target gas concentration for the gas sensor. That is why the flow rate must be stable. By testing the flow rate, the speed is adjusted to achieve the required flow rate. Now I wonder if it can be detected by a thermistor, because the flowing air can take away the heat.

chunyang

sfcsdc posted on 2020-9-3 17:05 The pump I use has speed feedback. Can the speed represent the relative size of the flow rate? If a gas pressure sensor is used, is it necessary to put the sensor...

In most cases, the speed of the pump is not necessarily strictly related to the flow rate. Only when it is strictly related can the speed be used as the basis for the flow rate, but you have to confirm it first. It is better to first clarify your system structure and application goals.

chunyang

sfcsdc posted on 2020-9-3 18:43 But I am not measuring the flow rate of the pipeline. I am just using a micro pump to pump air through a small plastic tube to the gas sensor to detect the target gas concentration. That is why I have to ensure...

The thermal solution is not feasible, the resolution is too low, and the inertia is too large. If you want to get effective help, again, first describe your system structure and application requirements clearly.