Problems with heat exchangers
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Hello, everyone! When using a spiral plate heat exchanger, the hot fluid is high-carbon organic hydrocarbons, while the coolant is water at -7 degrees Celsius. It was observed that in the discharged liquid, the upper part was hot while the lower part was cold; it is preliminarily assumed that this is due to a problem with the design of the heat exchanger itself. I wonder if anyone has encountered this issue – is there any way to improve it without altering the structure?
Use water at -7 degrees? Is the freezing inside the heat exchanger quite severe?
The heat exchange efficiency is poor. Check if there are any issues with the installation of the spiral plate heat exchanger?
In a spiral plate condenser, are the plates packed very closely together? Could something be blocking the lower part, causing local flow channels and short circuits that prevent the fluid in that area from being cooled? Try removing it, cleaning it, and testing anti-scaling effects? ?
I think there are only a few possible reasons: 1, blockage; 2, incomplete exhaust; 3, too many plates, which results in a decreasing flow velocity as we move further downstream, and the heat transfer coefficient drops to a certain level
It might be due to an incorrect flow state and low flow velocity, resulting in a stagnant condition and poor heat exchange efficiency. Or the heat exchanger is scaled, affecting the flow pattern.
I’ve really never encountered that before; with spiral plate heat exchangers, there shouldn’t be such a situation where one side is affected. Perhaps what you said isn’t accurate. When using cold water for cooling, the temperature of the hot material is likely not very high, so the possibility of scaling is low. It’s possible that there’s too much dirt during the preparation of the chilled water. I recommend cleaning it with dilute hydrochloric acid along with a retardant
I think it might be because the water temperature of -7 degrees is too low and the temperature of the heat source is insufficient, resulting in a stagnant condition and poor heat exchange efficiency
The most likely cause: incomplete exhaust.
Is it because the temperature of the cold material is too low, causing the high-carbon hydrocarbons in the organic substances to condense locally? Thus affecting the heat exchange efficiency!
Personally, I think it’s caused by incomplete exhaust.
Is there a problem with the installation, or is it blocked?
The temperature of the hot material itself is 50-60 degrees, which is considered quite high. However, this phenomenon occurred after just a few days of operation; several possible causes were analyzed and corresponding adjustments were made: 1. It was assumed that there was some water present in the hot material, and that this water was condensed into ice by the -7 degree water, thereby blocking the flow channels. During operation, the cooling water was deliberately turned off to prevent heat exchange; once the temperature difference between the outlet and inlet of the hot material became small, the cooling water valve was slowly opened. This phenomenon persisted after some time, so this possibility was ruled out ； 2. Exhaust from the hot material channel: During operation, exhaust is carried out through exhaust holes; however, due to the design of the spiral plates, these exhaust holes are not located at the highest point, which prevents complete removal of gases ； 3. It is suspected that it is a design issue with the heat exchanger itself; this seems to be the most likely explanation. The spacing between the flow channels might be too large, and the flow rate of the hot material is too low, resulting in low flow velocities within the heat exchanger.