Help needed regarding the temperature issue in electrodialysis

If the deviation is 1 or 2 degrees, it’s plausible even in the absence of a heat source, but a difference of 6 degrees is hard to explain without a heat source. Can it be said that the electrode plates of electrodialysis possess a significant heating function? Check the voltage between the electrode plates; there might be a short circuit or poor isolation.

Yes, big brother. I can’t figure it out; this is the first time I’ve encountered such a problem. Both the second and third stage temperatures are about seven to eight degrees higher. Is it caused by a leakage or short circuit? Can leakage cause the crude oil to heat up?

First, check the meter; next, see if there is any deviation in the flow of fluid into the tank at the primary level. If there are no significant changes in current and voltage, then there is generally no problem with the electrical system

I think it’s probably a problem with the thermocouple display； The electric field will not become a heating element ； Check the process or heat tracing issue again

This post was last edited by qugd on 2020-7-7 at 10:13. It should be caused by a leakage current or short circuit. The electrodes or plates used in electrodialysis should have high resistance, so as to ensure the generation of a stable high-voltage electric field for removing the conductive water and salts present in the oil. If there is a leakage current, the electrodes are damaged, or there is a conductive path between the plates, it means that a low-impedance load has been connected in series with the high-voltage isolation; this load is the electric heater, and as a result, heating occurs. Furthermore, the desalination efficiency of this desalination tank will be significantly reduced, as the voltage of the electric field decreases due to partial conduction. Let the equipment manufacturer carry out the repair; this requires professional technicians and specialized knowledge. But perhaps the manufacturers of electrodialysis tanks have some new technology that adds an additional electric heating function to these tanks; however, it is too expensive for refineries to use electric heating for electrodialysis.

A deviation of one or two degrees in the thermosensitive element is acceptable, but a deviation of six or seven degrees is impossible. Thermistors are, in principle, very stable and reliable devices, and they undergo strict calibration before being installed and put into use. If such large deviations occur, it is no longer a matter of technology or negligence; it is intentional interference with normal production operations.

This problem can be solved through calculation. Assuming the thermometer reads accurately, and the temperature of the crude oil rises by 6 degrees (when it should normally decrease), a heat balance calculation is performed on the incoming and outgoing materials to determine the required heat load. If it is caused by thermal effects resulting from short circuits or leakage in electrodesalination, the corresponding power consumption can be determined easily by calculation. If the deviation is large, it is likely that the deviation of the temperature sensing element is causing the current situation. Some way should be found to calibrate the table.

I’m truly so grateful to you, sir. I’ll go back and check