about thermowell
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This post was last edited by Saiwai Jiangnan on 2010-12-13 at 18:17. Thermowells shall be tapered in high velocity streams in order to avoid resonance. What is a suitable way to translate this?
In high-speed fluids, to avoid resonance, the thermocouple sheath is generally made conical.
This post was last edited by tigerli358_Can on 2010-12-14 07:47. A direct translation of the original text is: The thermocouple should be inserted into fluid with high flow rates to avoid resonance. It’s not easy to understand. I saw the original poster’s words in an ammonia synthesis project in Thailand. In fact, according to the explanations provided in ASME PTC, thermocouples should be avoided in high-flow environments to prevent damage. According to the formula for calculating thermocouple vibration, Fs should be proportional to the flow velocity, since Ns is generally a constant. It is recommended to refer to ASME PTC and ANSI/API RP 551 and check the original text.
The second floor is correct. One question: this sleeve should include both a thermocouple and a thermal resistor ； Of course, unless otherwise indicated by context.
2# is absolutely right; I carefully examined the relevant sections of the original text as well as the relevant paragraphs in the ASME PTC 19.3 (2010) standard. First of all, measurements should be avoided in high-flow conditions; if use in such conditions is necessary, ASME recommends that the frequency inherent to thermocouple resonance, Fs (Hz), be calculated accurately. Additionally, the tapered contraction section of the thermocouple sheath must also be carefully calculated to suit high-flow applications. Here, the establishment of the taper involves adjusting the natural frequency Fs of the thermocouple sheath. Standard involved: ASME PTC standard; for specific references, see RP551, which contains detailed recommended methods. Thank you for the encouragement from the original poster.
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