Settings for the temperature gauge in the tower

I have to ask you: is the purpose of setting up the thermometer to measure the temperature of the liquid phase or that of the gas phase?

During the distillation process, there is no clear separation between the gas and liquid phases inside the tower; the temperatures of both phases are the same. If it is possible to measure the liquid phase, this is preferred as it provides greater sensitivity. If higher requirements are needed, measure the gas phase at the flange on the sensitive plate and the liquid phase at the lower flange.

For the stripping tower, there is a temperature difference of 1-2°C between the gas and liquid phases; what are your insights on this?

For the stripping tower, there is a temperature difference of 1-2°C between the gas and liquid phases; what are your insights on this?

Repost: Temperature measurement in a packing tower is carried out in accordance with the requirements of the process. First, it is necessary to determine which part of the temperature needs to be measured, such as which layer of packing plates Furthermore, it is also necessary to take into account the structure of your tower. If the tower is tall and the opening for the thermometer is located on the side, then the choice of where to place the thermometer opening already takes into account the location where temperature measurement is required. As for the insertion depth, since thermometers are generally used to measure the temperature at a specific point, the insertion depth should not be too great. In general, the temperature of the filler in the same layer does not remain constant during the reaction; in other words, the temperatures of different parts of the same layer of filler vary. Therefore, it is possible to consider measuring the temperature at points that are sensitive to temperature changes, in order to determine the appropriate length for the thermometer. Alternatively, as a general guideline, an insertion depth of around 300 units can be used; a shorter depth is also acceptable, but it is important to keep in mind the tower walls, as what is being measured is not the temperature of those walls. Personal opinion, for reference only. Please refer to SH3104-2000T Code for Design of Installation of Instrumentation in Petrochemical Industries, Clause 3.02, 7 Requirements for the Installation of Thermal Resistors and Thermocouples on Equipment: a Thermal resistors and thermocouples at different elevations should preferably be installed in the same orientation ； b ..... on the device body. c The length of the thermal resistors and thermocouples inserted into the device must not be less than 150 mm ； ...... In fact, it’s mainly important that the temperature points being measured are representative. ------- For structured packing towers, try to keep it under 150 mm to avoid damaging more of the packing structure. For bulk packing, keeping it at 200–300 is sufficient; there’s no need for it to be too long.