Problem with heat exchanger leakage?
Thread Content
On November 10, the heat exchanger used for heat exchange between the rich absorbent oil in our catalytic unit and light diesel was taken out of service due to a leak. At that time, the vacuum caused by the top circulation pump led to significant fluctuations in the liquid level of the diesel stripping tower; it took about 50 minutes for the top circulation volume to return to normal. Afterward, the heat exchanger began to make noise; the temperature of the rich absorption oil returning to the tower rose from 96 degrees to 102.9 degrees. The adjustments made had little effect, and it was determined that the baffles in the heat exchanger had come loose and were leaking, allowing diesel to mix into the rich absorption oil. The flow of such oil was immediately stopped for repair. Question: Do you, fellow sea users, often experience leaks in your high-absorption oil heat exchangers during startup or when there are operational fluctuations? How to determine the processing?
It doesn’t leak often; it might be a material issue. It can be determined from temperature and liquid level.
It rarely misses. Equipment leaks should be analyzed from both process and equipment perspectives: 1. Equipment aspect: How long has this heat exchanger been in use, and has it reached its maintenance cycle? How high is the sulfur content in diesel, and what is the degree of corrosion? Is the equipment selection correct? Is the anti-corrosion method correct? 2. In terms of process: Are there fluctuations in operations? When activating the heat exchanger, should the cold flow be sent in first and then the hot flow? Is there enclosed heating? Wait
When putting it into use, the operating procedures must be strictly followed; for equipment selection, U-tube type tubes are to be used for the heat exchange tubes
This should rarely cause problems, have you reached the maintenance cycle? Is the sulfur content in diesel high? Why is it assumed that there is a leak in the heat exchanger? Is it based on the increase in the temperature of the rich absorption oil returning to the tower? I don’t think so. The reason is that when the top circulation pump loses its function, it inevitably leads to an increase in the gas phase load inside the tower, resulting in a rise in temperature. Is the tower experiencing a complete overflow, or just a partial one? Does an increase in the extraction temperature of diesel as well as an increase in its density lead to an improved heat exchange effect? Shouldn’t the temperature of the rich absorbent oil returning to the tower decrease instead? Moreover, even if the heat exchanger leaks, with a pressure of 1.0 Mpa in the reabsorption tower and around 0.15 Mpa in the fractionation tower, only the rich absorption oil can leak into the diesel, causing the temperature of the poor absorption oil to rise, resulting in poor absorption efficiency and affecting the quality of the dry gas. Is the noise from the heat exchanger caused by backpressure? !
Increasing the frequency conversion of the pump and the outlet pressure can reduce the impact of leaks