Rosemount differential pressure transmitter issues
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This post was last edited by Yanyan Ruogusong on 2018-7-9 at 14:01. This device has a heat exchanger, and a differential pressure transmitter is connected to the inlet and outlet of the tube side. According to the instructions, the purpose of measuring the pressure difference here is mainly to detect any blockages in the tube side of the heat exchanger. I would like to ask what it means when the value displayed on the transmitter is positive or negative To which ports of the heat exchanger are the positive and negative pressure sides of the transmitter connected, respectively?
Is it flue gas heat exchange? The high-pressure side is connected to the inlet, and the low-pressure side is connected to the outlet; the measured pressure difference represents the resistance of the heat exchanger. Connecting it this way usually results only in a positive value. If it’s a negative value, it’s likely that the inlet pressure tube is blocked :)
It’s not heat exchange with flue gas; it’s heat exchange with the process gas, specifically between sulfur dioxide and sulfur trioxide gases. The current differential pressure shows a negative value
If a negative value is displayed, it means the high and low voltage sides are reversed.
At first it showed a positive value, but later it turned negative
Remove both pressure tapping tubes to drain any debris; if that doesn’t work, use compressed air to blow through them to check for blockages. You can also take the opportunity to see whether the transmitter returns to zero when neither side is connected, in order to rule out issues with the transmitter itself.
The positive pressure chamber is connected to the inlet of the heat exchanger, while the negative pressure chamber is connected to the outlet of the heat exchanger. The pressure difference increases as the heat exchanger becomes more clogged, and when it reaches a certain level, the heat exchanger must be cleaned.
It measures the pressure difference between the inlet and outlet of the heat exchanger!
When my brother came in and took a look, the replies all showed — “This post is only visible to the author.” Ugh, what a stingy person; why do you want to keep all the mess for yourself? . . . :P You eat shit by yourself, in isolation; society cannot share, and the crops protest.
A positive reading on the differential pressure transmitter indicates that the pressure in the positive pressure chamber is higher than that in the negative pressure chamber; the opposite is true for negative pressure. Positive pressure inlet, negative pressure outlet; if there is a blockage in the tube side, the differential pressure increases.
The current differential pressure shows a negative value, and it’s not above the specified range. I’m not sure whether the instrument needs to be repaired