Differential pressure transmitter sampling point
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Use a differential pressure transmitter to measure the pressure values before and after the catalyst in the flue; can the two sampling points of the differential pressure transmitter be placed on opposite sides of the flue?
It’s best to put it on one side. Due to the influence of the wall roughness, there is a certain difference in the resistance losses on the two sides of the pipe wall; in other words, the flow pattern is different. Placing it on one side allows for a more accurate measurement of the differential pressure.
1. The pressure difference measured is the difference between the static pressures at two points. Based on the concept of static pressure, it has nothing to do with factors such as the roughness of the pipe walls. 2. Starting from the concept of static pressure, at points on a cross-section of the flow stream with the same elevation, the static pressure is equal. 3. Therefore, at the same level, whether the pressure probe is installed on the left, right, or elsewhere, the measured pressure difference should be the same.
But when measured on a 5500x9000 flue cross-section, is the cross-section too large?
The accuracy requirement isn’t very high anyway; it’s just to check whether the catalyst is clogged or not. I think there’s no major problem with installing it this way.
The position can be arbitrary, but being on the same side facilitates installation and saves material; most importantly, the pipes do not need to be too long, which reduces pipe losses and improves accuracy.
“A \"5500x9000 flue\" really can’t be considered to have a large cross-section. For example, when it comes to the principles of measuring air pressure at different altitudes, we talk about cross-sections and pressure isotherms; these are essentially spherical surfaces carved out of the Earth’s surface :lol In other words, when observing and thinking about something, the focus should be on the boundaries of the conceptual principles involved. .