Seeking advice on the layout scheme for flue gas pressure measurement
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This post was last edited by lotos1987 on 2019-3-9 at 13:30. In the scientific research project I am currently working on, there is a fluidized bed system for which it is necessary to measure the flue gas pressure. The working fluid temperature is 300°C+, with an uncertain pressure. Since no instrument suitable for high temperatures or with an appropriate isolation method can be selected, an instrument piping layout is required to ensure heat dissipation. However, since it is an indoor installation, insulation measures must be taken for the instrument pipelines at the height accessible to people. It seems contradictory like this. Preliminary analysis suggests that: 1. Due to the natural presence of gas inside the instrument tube, it possesses isolation capabilities. Therefore, when the fluidized bed is in operation, as long as the instrument tubes have a sufficient length, the flue gas cannot directly impact the instruments and cause damage to them. 2. Due to the uncertain water content in the working fluid, a condensation tank is required for cooling in order to collect the condensed water. 3. The installation of insulation on the pipe sections at subsequent heights does not affect operations. I’m asking the experts here: is this analysis correct?
This post was last edited by hfrs on 2019-3-9 at 14:09. If it is flue gas, a slight positive or negative pressure is sufficient; there is no need for insulation or a condensation tank. The pressure sensing tube should be longer than 2 meters, with a slope of over 10%, and the pressure transmitter should be installed at the higher point.
Actually, a pressure lead of a little over 1 meter is sufficient; 2 meters seems just right – too long or too short isn’t good.
Actually, a pressure lead of a little over 1 meter is sufficient; 2 meters seems just right – too long or too short isn’t good.
I think the original poster is absolutely right; if there is a platform available, it’s possible to consider using pressure lead pipes that run upward. Sometimes, however, the pipes are already at a great height, so it’s necessary to use pressure lead pipes that run downward – there’s no other choice. After all, the location of the instruments needs to be determined from the perspective of on-site maintenance and ease of operation. Therefore, I think that if it is directed downward, it is necessary to ensure that the instrument is not located at the end of the pressure lead, in order to prevent ash from mixing with water and settling, which could cause the instrument to become clogged. It is possible to consider installing a condensate tank and draining it regularly. Personally, I recommend that the pressure of this gauge be directed upward; if that’s not possible, a split-type design or the use of a secondary gauge at the lower part could be considered. However, the table above should also be placed in a location that is easy to maintain.