Why are two thermistor temperature sensors installed on the reaction vessel?
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At the site, I saw a reaction vessel (with an agitator) in a resin workshop, equipped with two thermistor temperature sensors at different heights on the side. I don’t understand; why install two? Can’t just use one? Is the temperature different between the top and bottom inside the reactor? Also, for temperature measurement in a reaction kettle, is it better to install the thermal resistor on the side or on the top? Do we still need to add a protective sleeve?
The temperatures at the top and bottom of the reactor can indeed differ; the top part isn’t necessarily filled completely, and it may be filled with certain gases. The temperature measured at the bottom represents the temperature of the reactants.
There are temperature gradients in both the radial and axial directions of the reactor, so two or more temperature measurement ports need to be installed to enable the detection of the temperature at various points.
If the reactor is large, or if the gas and liquid are in different phases, there will be different temperatures.
That is the measurement of the temperature inside and outside the reactor; the internal temperature refers to the temperature within the reactor itself, while the external temperature refers to the temperature of the reactor’s jacket. I*?apologize for the confusion??it’s difficult to explain properly??from Ω?to the other side, it’s hard to understand what’s going on there??from Ω?to those chaotic situations, it’s really confusing
I’ll try to answer this question. Controlling the temperature of a reactor is generally very important. The use of two thermistors for temperature measurement takes into account the following factors: 1. First and foremost, it is certain that these two temperature readings are consistent under normal operating conditions; although they vary slightly, the difference between them is minimal. 2. Process control (for example, the control loops fed into the DCS) usually adopts a two-out-of-one configuration, with the higher value being chosen more often ； 3. By using two thermistors, it is easy to objectively determine whether the measurement values are accurate. Because if there is only one, with no comparison, it is difficult to determine if the thermoresistor is inaccurate. 4. Easy for maintenance. If one is broken, just replace it. 5. A protective sleeve is necessary, and it is common to install it on the side, so that the sleeve can be relatively short. This mounting port is reserved during the design and manufacturing of the reactor.